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GEOCHEMISTRY ARTICLES – February 2020?Analytical ChemistryAnyakudo, F., Adams, E., Van Schepdael, A., 2020. Thin-layer chromatography–flame ionization detection. Chromatographia 83, 149-157.Hong, T., Culp, J.T., Kim, K.-J., Devkota, J., Sun, C., Ohodnicki, P.R., 2020. State-of-the-art of methane sensing materials: A review and perspectives. TrAC Trends in Analytical Chemistry 125, 115820.Proriol, D., Chahen, L., 2020. Toward new descriptors of basic nitrogen compounds in middle distillates by 2D NMR. Energy & Fuels 34, 1347-1354.Wang, Y., Han, Y., Hu, W., Fu, D., Wang, G., 2020. Analytical strategies for chemical characterization of bio-oil. Journal of Separation Science 43, 360-371.Gas Chromatography/GC×GC/GC-MSAl-Rabiah, H., Al-Ostad, L., Al-Shamary, T., Al-Hendi, A., Al-Henayyan, H., Khazemi, R., 2020. Sulfur speciation of Kuwaiti crude oils fractions using two-dimensional gas chromatography. Arabian Journal of Chemistry 13, 3615-3623.Aloisi, I., Schena, T., Giocastro, B., Zoccali, M., Tranchida, P.Q., Caram?o, E.B., Mondello, L., 2020. Towards the determination of an equivalent standard column set?between cryogenic and flow-modulated comprehensive two-dimensional gas chromatography. Analytica Chimica Acta 1105, 231-236.Dauphin, C.-E., Durand, A., Lubonis, K., Wortham, H., Dron, J., 2020. Quantification of monosaccharide anhydrides by gas chromatography/mass spectrometry in lichen samples. Journal of Chromatography A 1612, 460675.Fang, J., Zhao, H., Zhang, Y., Lu, M., Cai, Z., 2020. Atmospheric pressure chemical ionization in gas chromatography-mass spectrometry for the analysis of persistent organic pollutants. Trends in Environmental Analytical Chemistry 25, e00076.Fialkov, A.B., Lehotay, S.J., Amirav, A., 2020. Less than one minute low-pressure gas chromatography - mass spectrometry. Journal of Chromatography A 1612, 460691.Gruber, B., David, F., Sandra, P., 2020. Capillary gas chromatography-mass spectrometry: Current trends and perspectives. TrAC Trends in Analytical Chemistry 124, 115475.Hong, L., Li, Y., He, M., Zhao, C., Li, M., 2020. An algorithm to calibrate ionic isotopes using data mining strategy in hyphenated chromatographic datasets from herbal samples. Journal of Chromatography A 1613, 460668.Ikonen, K.E., Wehde, K.E., Khalida, H., Kentt?maa, H.I., 2020. Bias, limit of detection, and limit of quantitation for the ASTM D2425 method updated in 2019. Journal of Chromatography A 1614, 460705.Jaramillo, R., Dorman, F.L., 2020. Retention time prediction of hydrocarbons in cryogenically modulated comprehensive two-dimensional gas chromatography: A method development and translation application. Journal of Chromatography A 1612, 460696.Javadi, T., Farajmand, B., Yaftian, M.R., Zamani, A., 2020. Homogenizer assisted dispersive liquid-phase microextraction for the extraction-enrichment of phenols from aqueous samples and determination by gas chromatography. Journal of Chromatography A 1614, 460733.Lelevic, A., Souchon, V., Moreaud, M., Lorentz, C., Geantet, C., 2020. Gas chromatography vacuum ultraviolet spectroscopy: A review. Journal of Separation Science 43, 150-173.Mondello, L., Donato, P., 2020. Selected papers from the 42th International Symposium on Capillary Chromatography and 15th GC?×?GC symposium (RIVA 2018). Journal of Chromatography A 1613, 460626.Randazzo, G.M., Bileck, A., Danani, A., Vogt, B., Groessl, M., 2020. Steroid identification via deep learning retention time predictions and two-dimensional gas chromatography-high resolution mass spectrometry. Journal of Chromatography A 1612, 460661.Rosso, M.C., Mazzucotelli, M., Bicchi, C., Charron, M., Manini, F., Menta, R., Fontana, M., Reichenbach, S.E., Cordero, C., 2020. Adding extra-dimensions to hazelnuts primary metabolome fingerprinting by comprehensive two-dimensional gas chromatography combined with time-of-flight mass spectrometry featuring tandem ionization: Insights on the aroma potential. Journal of Chromatography A 1614, 460739.Sch?neich, S., Gough, D.V., Trinklein, T.J., Synovec, R.E., 2020. Dynamic pressure gradient modulation for comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry detection. Journal of Chromatography A 1609, 460982.Tian, Y., Zhan, Z.-W., Zou, Y.-R., Liao, Z., Peng, P.a., 2020. Separation of crocetane and phytane and measurement of their compound-specific carbon isotopic compositions. Journal of Chromatography A 1612, 460621.Tranchida, P.Q., Mondello, L. (eds.), 2020. Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, 514 pp. (See below for individual chapters)Trinklein, T.J., Gough, D.V., Warren, C.G., Ochoa, G.S., Synovec, R.E., 2020. Dynamic pressure gradient modulation for comprehensive two-dimensional gas chromatography. Journal of Chromatography A, 460488.Vyviurska, O., ?pánik, I., 2020. Novel sample preparation approaches in gas chromatographic analysis: Promising ideas. Journal of Separation Science 43, 174-188.Wang, F.C.-Y., 2020. GC × VUV study of diesel: A two-dimensional separation approach. Energy & Fuels 34, 1432-1437.Extraction/Sample preparationAngeles, L.F., Aga, D.S., 2020. Catching the elusive persistent and mobile organic compounds: Novel sample preparation and advanced analytical techniques. Trends in Environmental Analytical Chemistry 25, e00078.Azizi, A., Bottaro, C.S., 2020. A critical review of molecularly imprinted polymers for the analysis of organic pollutants in environmental water samples. Journal of Chromatography A 1614, 460603.Burato, J.S.d.S., Medina, D.A.V., de Toffoli, A.L., Soares Maciel, E.V., Lan?as, F.M., 2020. Recent advances and trends in miniaturized sample preparation techniques. Journal of Separation Science 43, 202-225.Feng, J., Loussala, H.M., Han, S., Ji, X., Li, C., Sun, M., 2020. Recent advances of ionic liquids in sample preparation. TrAC Trends in Analytical Chemistry 125, 115833.Javadi, T., Farajmand, B., Yaftian, M.R., Zamani, A., 2020. Homogenizer assisted dispersive liquid-phase microextraction for the extraction-enrichment of phenols from aqueous samples and determination by gas chromatography. Journal of Chromatography A 1614, 460733.Li, M., Xiong, Y., Qing, G., 2020. Smart bio-separation materials. TrAC Trends in Analytical Chemistry 124, 115585.Murtada, K., 2020. Trends in nanomaterial-based solid-phase microextraction with a focus on environmental applications - A review. Trends in Environmental Analytical Chemistry 25, e00077.Nouri, N., Khorram, P., Duman, O., Sibel, T., Hassan, S., 2020. Overview of nanosorbents used in solid phase extraction techniques for the monitoring of emerging organic contaminants in water and wastewater samples. Trends in Environmental Analytical Chemistry 25, e00081.Santos, H., Martins, R.O., Soares, D.A., Chaves, A.R., 2020. Molecularly imprinted polymers for miniaturized sample preparation techniques: strategies for chromatographic and mass spectrometry methods. Analytical Methods 12, 894-911.Vyviurska, O., ?pánik, I., 2020. Novel sample preparation approaches in gas chromatographic analysis: Promising ideas. Journal of Separation Science 43, 174-188.Wells, S.S., Kennedy, R.T., 2020. High-throughput liquid–liquid extractions with nanoliter volumes. Analytical Chemistry 92, 3189-3197.Xia, L., Li, Y., Liu, Y., Li, G., Xiao, X., 2020. Recent advances in sample preparation techniques in China. Journal of Separation Science 43, 189-201.Zhang, J.-H., Xie, S.-M., Zi, M., Yuan, L.-M., 2020. Recent advances of application of porous molecular cages for enantioselective recognition and separation. Journal of Separation Science 43, 134-149.Zhu, R., Tolu, J., Deng, L., Fiskal, A., Winkel, L.H.E., Lever, M.A., 2020. Improving the extraction efficiency of sedimentary carbohydrates by sequential hydrolysis. Organic Geochemistry 141, 103963.Imaging: AFMAbarghani, A., Ostadhassan, M., Hackley, P.C., Pomerantz, A.E., Nejati, S., 2020. A chemo-mechanical snapshot of in-situ conversion of kerogen to petroleum. Geochimica et Cosmochimica Acta 273, 37-50.Jia, Z., Niu, Z., Yang, Z., Li, X., Wang, J., He, X., Sui, H., He, L., 2020. Interfacial behaviors of ionic liquid cations and asphaltenes at oil–water interface: Dynamic diffusion and interfacially competitive adsorption. Energy & Fuels 34, 1259-1267.Memon, K.R., Mahesar, A.A., Ali, M., Tunio, A.H., Mohanty, U.S., Akhondzadeh, H., Awan, F.U.R., Iglauer, S., Keshavarz, A., 2020. Influence of cryogenic liquid nitrogen on petro-physical characteristics of Mancos Shale: An experimental investigation. Energy & Fuels 34, 2160-2168.Imaging: SEM, TEM, HIMDavudov, D., Moghanloo, R.G., Zhang, Y., 2020. Interplay between pore connectivity and permeability in shale sample. International Journal of Coal Geology 220, 103427.He, J., He, S., Liu, Z., Zhai, G., Wang, Y., Han, Y., Wan, K., Wei, S., 2020. Pore structure and adsorption capacity of shale in the Lower Cambrian Shuijingtuo Formation in the southern flank of Huangling anticline, western Hubei. Acta Petrolei Sinica 41, 27-42.Huang, Y., Dong, L., Hursthouse, A., Yu, Y., Huang, J., 2019. Characterization of pore microstructure and methane adsorption of organic-rich black shales in northwestern Hunan, South China. Energy Exploration & Exploitation 38, 473-493.Jones, R.M., D’Angelo, T., Orcutt, B.N., 2020. Using cathodic poised potential experiments to investigate extracellular electron transport in the crustal deep biosphere of North Pond, Mid-Atlantic Ridge. Frontiers in Environmental Science 8, 11. doi: 10.3389/fenvs.2020.00011.Khan, M.S.I., Oh, S.-W., Kim, Y.-J., 2020. Power of scanning electron microscopy and energy dispersive X-ray analysis in rapid microbial detection and identification at the single cell level. Scientific Reports 10, 2368.Lan, Z., Zhang, S., Tucker, M., Li, Z., Zhao, Z., 2020. Evidence for microbes in early Neoproterozoic stromatolites. Sedimentary Geology 398, 105589.Li, C., Reimers, C.E., Alleau, Y., 2020. Inducing the attachment of cable bacteria on oxidizing electrodes. Biogeosciences 17, 597-607.Li, T., Huang, Z., Feng, Y., Chen, X., Ma, Q., Liu, B., Guo, X., 2020. Reservoir characteristics and evaluation of fluid mobility in organic-rich mixed siliciclastic-carbonate sediments: A case study of the lacustrine Qiketai Formation in Shengbei Sag, Turpan-Hami Basin, Northwest China. Journal of Petroleum Science and Engineering 185, 106667.Liu, Z., Yan, D., Niu, X., 2020. Insights into pore structure and fractal characteristics of the Lower Cambrian Niutitang Formation shale on the Yangtze Platform, South China. Journal of Earth Science 31, 169-180.Liu, Z., Zhang, Z., Wang, Z., Jin, B., Li, D., Tao, J., Tang, R., De Yoreo, J.J., 2020. Shape-preserving amorphous-to-crystalline transformation of CaCO3 revealed by in situ TEM. Proceedings of the National Academy of Sciences 117, 3397-3404.Lv, X., Zhang, T., Luo, Y., Zhang, Y., Wang, Y., Zhang, G., 2020. Study on carbon nanotubes and activated carbon hybrids by pyrolysis of coal. Journal of Analytical and Applied Pyrolysis 146, 104717.Memon, K.R., Mahesar, A.A., Ali, M., Tunio, A.H., Mohanty, U.S., Akhondzadeh, H., Awan, F.U.R., Iglauer, S., Keshavarz, A., 2020. Influence of cryogenic liquid nitrogen on petro-physical characteristics of Mancos Shale: An experimental investigation. Energy & Fuels 34, 2160-2168.Milad, B., Slatt, R., Fuge, Z., 2020. Lithology, stratigraphy, chemostratigraphy, and depositional environment of the Mississippian Sycamore rock in the SCOOP and STACK area, Oklahoma, USA: Field, lab, and machine learning studies on outcrops and subsurface wells. Marine and Petroleum Geology 115, 104278.Muhling, J.R., Rasmussen, B., 2020. Widespread deposition of greenalite to form Banded Iron Formations before the Great Oxidation Event. Precambrian Research 339, 105619.Müller, Y.K., Wernicke, T., Pittroff, M., Witzig, C.S., Storck, F.R., Klinger, J., Zumbülte, N., 2020. Microplastic analysis—are we measuring the same? Results on the first global comparative study for microplastic analysis in a water sample. Analytical and Bioanalytical Chemistry 412, 555-560.Pearce, J.K., La Croix, A.D., Underschultz, J.R., Golding, S.D., 2020. Long term reactivity of CO2 in a low salinity reservoir-seal complex. Applied Geochemistry 114, 104529.Pearson, A.R., Hartland, A., Frisia, S., Fox, B.R.S., 2020. Formation of calcite in the presence of dissolved organic matter: Partitioning, fabrics and fluorescence. Chemical Geology 539, 119492.Pu, S., Gong, C., Robertson, A.W., 2020. Liquid cell transmission electron microscopy and its applications. Royal Society Open Science 7, 191204.Romero, I.C., Urban, M.A., Punyasena, S.W., 2020. Airyscan superresolution microscopy: A high-throughput alternative to electron microscopy for the visualization and analysis of fossil pollen. Review of Palaeobotany and Palynology 276, 104192.Salgaonkar, B.B., Rodrigues, R., 2019. A study on the halophilic archaeal diversity from the food grade iodised crystal salt from a saltern of India. Microbiology 88, 709-719.Shabbir, S., Faheem, M., Ali, N., Kerr, P.G., Wang, L.-F., Kuppusamy, S., Li, Y., 2020. Periphytic biofilm: An innovative approach for biodegradation of microplastics. Science of The Total Environment 717, 137064.Shang, F., Zhu, Y., Gao, H., Wang, Y., Liu, R., 2020. Relationship between tectonism and composition and pore characteristics of shale reservoirs. Geofluids 2020, 9426586.Tarduno, J.A., Cottrell, R.D., Bono, R.K., Oda, H., Davis, W.J., Fayek, M., Erve, O.v.t., Nimmo, F., Huang, W., Thern, E.R., Fearn, S., Mitra, G., Smirnov, A.V., Blackman, E.G., 2020. Paleomagnetism indicates that primary magnetite in zircon records a strong Hadean geodynamo. Proceedings of the National Academy of Sciences 117, 2309-2318.Wang, Y., Liu, L., Hu, Q., Hao, L., Wang, X., Sheng, Y., 2020. Nanoscale pore network evolution of Xiamaling marine shale during organic matter maturation by hydrous pyrolysis. Energy & Fuels 34, 1548-1563.Wei, S., He, S., Pan, Z., Zhai, G., Dong, T., Guo, X., Yang, R., Han, Y., Yang, W., 2020. Characteristics and evolution of pyrobitumen-hosted pores of the overmature Lower Cambrian Shuijingtuo Shale in the south of Huangling anticline, Yichang area, China: Evidence from FE-SEM petrography. Marine and Petroleum Geology 116, 104303.Yuan, W., Zhou, H., Yang, Z., Hein, J.R., Yang, Q., 2020. Magnetite magnetofossils record biogeochemical remanent magnetization in hydrogenetic ferromanganese crusts. Geology 48, 298-302.Zhang, W., Huang, Z., Guo, X., Pan, Y., Liu, B., 2020. A study on pore systems of Silurian highly mature marine shale in Southern Sichuan Basin, China. Journal of Natural Gas Science and Engineering 76, 103094.Zhang, X., Shi, W., Hu, Q., Zhai, G., Wang, R., Xu, X., Meng, F., Liu, Y., Bai, L., 2020. Developmental characteristics and controlling factors of natural fractures in the lower Paleozoic marine shales of the upper Yangtze Platform, southern China. Journal of Natural Gas Science and Engineering 76, 103191.Zheng, H., Yang, H., Zhang, W., Yang, R., Su, B., Zhao, X., Zhou, Y., Dai, X., 2020. Insight of silk relics of mineralized preservation in Maoling Mausoleum using two enzyme-linked immunological methods. Journal of Archaeological Science 115, 105089.Imaging: Xray CTDong, H., Sun, J., Arif, M., Golsanami, N., Yan, W., Zhang, Y., 2020. A novel hybrid method for gas hydrate filling modes identification via digital rock. Marine and Petroleum Geology 115, 104255.Galkin, S.V., Kolychev, I.Y., Savitskii, Y.V., 2019. Potentialities of investigation of reservoir hydrophobization by compilation of X-ray core tomography and lateral logging. Russian Geology and Geophysics 60, doi: 10.15372/RGG2019094.Nikitin, V.V., Dugarov, G.A., Duchkov, A.A., Fokin, M.I., Drobchik, A.N., Shevchenko, P.D., De Carlo, F., Mokso, R., 2020. Dynamic in-situ imaging of methane hydrate formation and self-preservation in porous media. Marine and Petroleum Geology 115, 104234.Pearce, J.K., La Croix, A.D., Underschultz, J.R., Golding, S.D., 2020. Long term reactivity of CO2 in a low salinity reservoir-seal complex. Applied Geochemistry 114, 104529.Rothschild, B.M., Tanke, D., Rühli, F., Pokhojaev, A., May, H., 2020. Suggested case of Langerhans Cell Histiocytosis in a Cretaceous dinosaur. Scientific Reports 10, 2203.Xu, Z., Lin, M., Jiang, W., Cao, G., Yi, Z., 2020. Identifying the comprehensive pore structure characteristics of a rock from 3D images. Journal of Petroleum Science and Engineering 187, 106764.Liquid Chromatography/LC-MS/SFCAcquaviva, A., Siano, G., Quintas, P., Filgueira, M.R., Castells, C.B., 2020. Chiral × achiral multidimensional liquid chromatography. Application to the enantioseparation of dintitrophenyl amino acids in honey samples and their fingerprint classification. Journal of Chromatography A 1614, 460729.Ali, A.a.-k.F., Danielson, N.D., 2020. Liquid chromatography of short chain carboxylic acids using a glutamic acid surfactant coated C18 stationary phase. Talanta 213, 120807.Becker, C., Deeb, A.A., Teutenberg, T., Jochmann, M.A., Schmidt, T.C., 2020. Determination of liquid chromatography/flame ionization detection response factors for N-heterocycles, carboxylic acids, halogenated compounds, and others. Analytical and Bioanalytical Chemistry 412, 171-179.Chen, Y., Montero, L., Luo, J., Li, J., Schmitz, O.J., 2020. Application of the new at-column dilution (ACD) modulator for the two-dimensional RP×HILIC analysis of Buddleja davidii. Analytical and Bioanalytical Chemistry 412, 1483-1495.Covas, T.R., de Freitas, C.S., Tose, L.V., Valencia-Dávila, J.A., Rocha, Y.d.S., Rangel, M.D., da Silva, R.C., Vaz, B.G., 2020. Fractionation of polar compounds from crude oils by hetero-medium pressure liquid chromatography (H-MPLC) and molecular characterization by ultrahigh-resolution mass spectrometry. Fuel 267, 117289.D'Orazio, G., 2020. Chiral analysis by nano-liquid chromatography. TrAC Trends in Analytical Chemistry 125, 115832.Gallego, R., Arena, K., Dugo, P., Mondello, L., Ibá?ez, E., Herrero, M., 2020. Application of compressed fluid–based extraction and purification procedures to obtain astaxanthin-enriched extracts from Haematococcus pluvialis and characterization by comprehensive two-dimensional liquid chromatography coupled to mass spectrometry. Analytical and Bioanalytical Chemistry 412, 589-599.García-Cicourel, A.R., van de Velde, B., Roskam, G., Janssen, H.-G., 2020. Supercritical fluid chromatography as a rapid single-step method for the determination of mineral oil saturated and aromatic hydrocarbons in purified mineral oils for food and cosmetics applications. Journal of Chromatography A 1614, 460713.Gathungu, R.M., Kautz, R., Kristal, B.S., Bird, S.S., Vouros, P., 2020. The integration of LC-MS and NMR for the analysis of low molecular weight trace analytes in complex matrices. Mass Spectrometry Reviews 39, 35-54.Hong, L., Li, Y., He, M., Zhao, C., Li, M., 2020. An algorithm to calibrate ionic isotopes using data mining strategy in hyphenated chromatographic datasets from herbal samples. Journal of Chromatography A 1613, 460668.Jiang, D., Ke, Y., Cai, J., Zhang, H., Fu, Q., Jin, Y., Liang, X., 2020. Evaluation of a series of phenyl-type stationary phases in supercritical fluid chromatography with the linear solvation energy relationship model and its application to the separation of phenolic compounds. Journal of Chromatography A 1614, 460700.Lefebvre, T., Talbi, A., Atwi-Ghaddar, S., Destandau, E., Lesellier, E., 2020. Development of an analytical method for chlorophyll pigments separation by reversed-phase supercritical fluid chromatography. Journal of Chromatography A 1612, 460643.Lesellier, E., 2020. Usual, unusual and unbelievable retention behavior in achiral supercritical fluid chromatography: Review and discussion. Journal of Chromatography A 1614, 460582.Sander, L.C., Rimmer, C.A., Wilson, W.B., 2020. Characterization of triacontyl (C-30) liquid chromatographic columns. Journal of Chromatography A 1614, 460732.Sokolowska, I., Mo, J., Rahimi Pirkolachahi, F., McVean, C., Meijer, L.A.T., Switzar, L., Balog, C., Lewis, M.J., Hu, P., 2020. Implementation of a high-resolution liquid chromatography–mass spectrometry method in quality control laboratories for release and stability testing of a commercial antibody product. Analytical Chemistry 92, 2369-2373.Sorensen, M.J., Anderson, B.G., Kennedy, R.T., 2020. Liquid chromatography above 20,000 PSI. TrAC Trends in Analytical Chemistry 124, 115810.Zhou, W., Liu, Y., Wang, J., Guo, Z., Shen, A., Liu, Y., Liang, X., 2020. Application of two-dimensional liquid chromatography in the separation of traditional Chinese medicine. Journal of Separation Science 43, 87-104.Mass Spectroscopy/ICR-FTMS/OrbitrapActer, T., Solihat, N.N., Kim, S., Uddin, N., Mustafa, A.I., Shamsuddin, S.M., Kim, S., 2020. Application of silver-assisted laser desorption ionization ultrahigh-resolution mass spectrometry for the speciation of sulfur compounds. Analytical and Bioanalytical Chemistry 412, 243-255.Bowman, A.P., Blakney, G.T., Hendrickson, C.L., Ellis, S.R., Heeren, R.M.A., Smith, D.F., 2020. Ultra-high mass resolving power, mass accuracy, and dynamic range MALDI mass spectrometry imaging by 21-T FT-ICR MS. Analytical Chemistry 92, 3133-3142.Butturini, A., Herzsprung, P., Lechtenfeld, O.J., Venturi, S., Amalfitano, S., Vazquez, E., Pacini, N., Harper, D.M., Tassi, F., Fazi, S., 2020. Dissolved organic matter in a tropical saline-alkaline lake of the East African Rift Valley. Water Research 173, 115532.Covas, T.R., de Freitas, C.S., Tose, L.V., Valencia-Dávila, J.A., Rocha, Y.d.S., Rangel, M.D., da Silva, R.C., Vaz, B.G., 2020. Fractionation of polar compounds from crude oils by hetero-medium pressure liquid chromatography (H-MPLC) and molecular characterization by ultrahigh-resolution mass spectrometry. Fuel 267, 117289.Duncan, K.D., Richards, L.C., Monaghan, J., Simair, M.C., Ajaero, C., Peru, K.M., Friesen, V., McMartin, D.W., Headley, J.V., Gill, C.G., Krogh, E.T., 2020. Direct analysis of naphthenic acids in constructed wetland samples by condensed phase membrane introduction mass spectrometry. Science of The Total Environment 176, 137063.Guillemant, J., Berlioz-Barbier, A., Albrieux, F., de Oliveira, L.P., Lacoue-Nègre, M., Joly, J.-F., Duponchel, L., 2020. Low-level fusion of Fourier transform ion cyclotron resonance mass spectrometry data sets for the characterization of nitrogen and sulfur compounds in vacuum gas oils. Analytical Chemistry 92, 2815-2823.Han, H., Hu, S., Li, A., Zhang, Y., Xiong, Z., Ma, S., He, L., Li, H., Wang, Y., Su, S., Xiang, J., 2020. Evolution of nitrogen/oxygen substituted aromatics from sludge to light and heavy volatiles. Journal of Cleaner Production 257, 120327.Kondyli, A., Schrader, W., 2020. Evaluation of the combination of different atmospheric pressure ionization sources for the analysis of extremely complex mixtures. Rapid Communications in Mass Spectrometry 34, e8676.Liu, Y., Ye, Q., Huang, W.-L., Feng, L., Wang, Y.-H., Xie, Z., Yong, S.-S., Zhang, S., Jiang, B., Zheng, Y., Wang, J.-J., 2019. Spectroscopic and molecular-level characteristics of dissolved organic matter in the Pearl River Estuary, South China. Science of The Total Environment 710, 136307.McDonough, L.K., Rutlidge, H., O'Carroll, D.M., Andersen, M.S., Meredith, K., Behnke, M.I., Spencer, R.G.M., McKenna, A.M., Marjo, C.E., Oudone, P., Baker, A., 2020. Characterisation of shallow groundwater dissolved organic matter in aeolian, alluvial and fractured rock aquifers. Geochimica et Cosmochimica Acta 273, 163-176.Merder, J., Freund, J.A., Feudel, U., Niggemann, J., Singer, G., Dittmar, T., 2020. Improved mass accuracy and isotope confirmation through alignment of ultrahigh-resolution mass spectra of complex natural mixtures. Analytical Chemistry 92, 2558-2565.Neubauer, C., Crémière, A., Wang, X.T., Thiagarajan, N., Sessions, A.L., Adkins, J.F., Dalleska, N.F., Turchyn, A.V., Clegg, J.A., Moradian, A., Sweredoski, M.J., Garbis, S.D., Eiler, J.M., 2020. Stable isotope analysis of intact oxyanions using electrospray quadrupole-Orbitrap mass spectrometry. Analytical Chemistry 92, 3077-3085.Niles, S.F., Chacón-Pati?o, M.L., Smith, D.F., Rodgers, R.P., Marshall, A.G., 2020. Comprehensive compositional and structural comparison of coal and petroleum asphaltenes based on extrography fractionation coupled with Fourier transform ion cyclotron resonance MS and MS/MS analysis. Energy & Fuels 34, 1492-1505.Poltash, M.L., McCabe, J.W., Shirzadeh, M., Laganowsky, A., Russell, D.H., 2020. Native IM-Orbitrap MS: Resolving what was hidden. TrAC Trends in Analytical Chemistry 124, 115533.Schmitt-Kopplin, P., Kanawati, B., 2019. Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, p. 778. (See below for individual chapters)Smith, D.F., Blakney, G.T., Beu, S.C., Anderson, L.C., Weisbrod, C.R., Hendrickson, C.L., 2020. Ultrahigh resolution ion isolation by stored waveform inverse Fourier transform 21 T Fourier transform ion cyclotron resonance mass spectrometry. Analytical Chemistry 92, 3213-3219.Wang, H., Lu, L., Chen, H., McKenna, A.M., Lu, J., Jin, S., Zuo, Y., Rosario-Ortiz, F.L., Ren, Z.J., 2020. Molecular transformation of crude oil contaminated soil after bioelectrochemical degradation revealed by FT-ICR mass spectrometry. Environmental Science & Technology 54, 2500-2509.Wang, Y., Luo, C., Yang, M., Jianwei, R., Wang, W., Li, Y., Gao, G., Ren, L., Zou, X., 2020. Target quantification and semi-target screening of halogenated carboxylic acids in drinking water using ultra-high performance liquid chromatography-quadrupole Orbitrap high-resolution mass spectrometry. Journal of Chromatography A 1614, 460710.Yan, G., Xu, Y., Liu, Y., He, W., Chang, X., Tang, P., 2020. The evolution of acids and neutral nitrogen-containing compounds during pyrolysis experiments on immature mudstone. Marine and Petroleum Geology 115, 104292.Zhang, X.-Y., Wang, R.-Y., Ma, F.-Y., Wei, X.-Y., Fan, X., 2020. Structural characteristics of soluble organic matter in four low-rank coals. Fuel 267, 117230.Mass Spectroscopy/OtherFan, J., Lian, P., Li, M., Liu, X., Zhou, X., Ouyang, Z., 2020. Ion mobility separation using a dual-LIT miniature mass spectrometer. Analytical Chemistry 92, 2573-2579.Hinners, P., Thomas, M., Lee, Y.J., 2020. Determining fingerprint age with mass spectrometry imaging via ozonolysis of triacylglycerols. Analytical Chemistry 92, 3125-3132.Krenkel, H., Hartmane, E., Piras, C., Brown, J., Morris, M., Cramer, R., 2020. Advancing liquid atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry toward ultrahigh-throughput analysis. Analytical Chemistry 92, 2931-2936.Kuo, T.-H., Dutkiewicz, E.P., Pei, J., Hsu, C.-C., 2020. Ambient ionization mass spectrometry today and tomorrow: Embracing challenges and opportunities. Analytical Chemistry 92, 2353-2363.Li, C., Attanayake, K., Valentine, S.J., Li, P., 2020. Facile improvement of negative ion mode electrospray ionization using capillary vibrating sharp-edge spray ionization. Analytical Chemistry 92, 2492-2502.Lian, L., Yan, S., Zhou, H., Song, W., 2020. Overview of the phototransformation of wastewater effluent by high-resolution mass spectrometry. Environmental Science & Technology 54, 1816-1826.Maciel, E.V.S., de Toffoli, A.L., Sobieski, E., Nazário, C.E.D., Lan?as, F.M., 2020. Miniaturized liquid chromatography focusing on analytical columns and mass spectrometry: A review. Analytica Chimica Acta 1103, 11-31.Nisar, M.S., Zhao, X., 2020. High resolution mass spectrometry for single cell analysis. International Journal of Mass Spectrometry 450, 116302.Spraker, J.E., Luu, G.T., Sanchez, L.M., 2020. Imaging mass spectrometry for natural products discovery: a review of ionization methods. Natural Product Reports 37, 150-162.Metabolomics/LipidomicsGathungu, R.M., Kautz, R., Kristal, B.S., Bird, S.S., Vouros, P., 2020. The integration of LC-MS and NMR for the analysis of low molecular weight trace analytes in complex matrices. Mass Spectrometry Reviews 39, 35-54.Gruber, B., David, F., Sandra, P., 2020. Capillary gas chromatography-mass spectrometry: Current trends and perspectives. TrAC Trends in Analytical Chemistry 124, 115475.Hu, C., Wang, M., Duan, Q., Han, X., 2020. Sensitive analysis of fatty acid esters of hydroxy fatty acids in biological lipid extracts by shotgun lipidomics after one-step derivatization. Analytica Chimica Acta 1105, 105-111.Junot, C., Fenaille, F., 2019. Chapter 11 - Metabolomics using Fourier transform mass spectrometry, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 325-356.Kanawati, B., Wanczek, K.P., Schmitt-Kopplin, P., 2019. Chapter 6 - Data processing and automation in Fourier transform mass spectrometry, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 133-185.Kreutzer, L., Aichler, M., Walch, A.K., 2019. Chapter 9 - In situ metabolomics in cancer tissue by high-resolution mass spectrometry imaging, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 253-279.Moritz, F., Hemmler, D., Kanawati, B., Schnitzler, J.-P., Schmitt-Kopplin, P., 2019. Chapter 12 - Mass differences in metabolome analyses of untargeted direct infusion ultra-high resolution MS data, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 357-405.Pezzatti, J., Boccard, J., Codesido, S., Gagnebin, Y., Joshi, A., Picard, D., González-Ruiz, V., Rudaz, S., 2020. Implementation of liquid chromatography–high resolution mass spectrometry methods for untargeted metabolomic analyses of biological samples: A tutorial. Analytica Chimica Acta 1105, 28-44.Rosso, M.C., Mazzucotelli, M., Bicchi, C., Charron, M., Manini, F., Menta, R., Fontana, M., Reichenbach, S.E., Cordero, C., 2020. Adding extra-dimensions to hazelnuts primary metabolome fingerprinting by comprehensive two-dimensional gas chromatography combined with time-of-flight mass spectrometry featuring tandem ionization: Insights on the aroma potential. Journal of Chromatography A 1614, 460739.Rychlik, M., Kanawati, B., Roullier-Gall, C., Hemmler, D., Liu, Y., Alexandre, H., Gougeon, R.D., Gmelch, L., Gotthardt, M., Schmitt-Kopplin, P., 2019. Chapter 21 - Foodomics assessed by Fourier transform mass spectrometry, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 651-677.Tranchida, P.Q., Mondello, L., 2020. Chapter 1.2 - Conventional GC-MS applications, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 75-108.Wilson, S.R., Berg, H.E., Roberg-Larsen, H., Lundanes, E., 2020. Chapter 3.3 - Hyphenations of one-dimensional capillary liquid chromatography with mass spectrometry: State-of-the-art applications, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 319-367.Wright, R.J., Bosch, R., Gibson, M.I., Christie-Oleza, J.A., 2020. Plasticizer degradation by marine bacterial isolates: A proteogenomic and metabolomic characterization. Environmental Science & Technology 54, 2244-2256.PuppyomicsAulet, L.S., Chiu, V.C., Prichard, A., Spivak, M., Lourenco, S.F., Berns, G.S., 2019. Canine sense of quantity: evidence for numerical ratio-dependent activation in parietotemporal cortex. Biology Letters 15, 20190666.Kis, A., Tóth, K., Kanizsár, O., Topál, J., 2020. The effect of oxytocin on yawning by dogs (Canis familiaris) exposed to human yawns. Applied Animal Behaviour Science 223, 104916.Maglieri, V., Prato-Previde, E., Tommasi, E., Palagi, E., 2019. Wolf-like or dog-like? A comparison of gazing behaviour across three dog breeds tested in their familiar environments. Royal Society Open Science 6, 190946.Puurunen, J., Hakanen, E., Salonen, M.K., Mikkola, S., Sulkama, S., Araujo, C., Lohi, H., 2020. Inadequate socialisation, inactivity, and urban living environment are associated with social fearfulness in pet dogs. Scientific Reports 10, 3527.Root-Gutteridge, H., Ratcliffe, V.F., Korzeniowska, A.T., Reby, D., 2019. Dogs perceive and spontaneously normalize formant-related speaker and vowel differences in human speech sounds. Biology Letters 15, 20190555.Tranchida, P.Q., Mondello, L., 2020. Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, p. 514.Mour?o, M.P.B., Kolk, A.H.J., Janssen, H.-G., 2020. Chapter 1.1 - General principles and history, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 3-74.Tranchida, P.Q., Mondello, L., 2020. Chapter 1.2 - Conventional GC-MS applications, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 75-108.Tranchida, P.Q., Zoccali, M., Mondello, L., 2020. Chapter 1.3 - High-speed GC-MS: Basic theory, practical aspects, and applications, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 109-132.David, F., 2020. Chapter 2.1 - Classical two-dimensional GC combined with mass spectrometry, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 135-182.Tranchida, P.Q., Mondello, L., 2020. Chapter 2.2 - Comprehensive 2D Gas Chromatography, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 183-226.Purcaro, G., 2020. Chapter 2.3 - Classical and comprehensive 2D LC-GC, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 227-275.de Koster, C.G., Schoenmakers, P.J., 2020. Chapter 3.1 - History of liquid chromatography—mass spectrometry couplings, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 279-295.Donato, P., Arena, P., Mondello, L., 2020. Chapter 3.2 - Theoretical and practical aspects of LC-MS analysis, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 297-317.Wilson, S.R., Berg, H.E., Roberg-Larsen, H., Lundanes, E., 2020. Chapter 3.3 - Hyphenations of one-dimensional capillary liquid chromatography with mass spectrometry: State-of-the-art applications, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 319-367.Cacciola, F., Mangraviti, D., Mondello, L., Dugo, P., 2020. Chapter 3.4 - Hyphenations of 2D capillary-based LC with mass spectrometry, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 369-412.Fanali, C., D'Orazio, G., Fanali, S., 2020. Chapter 4 - Capillary electrophoresis-mass spectrometry: History, general principles, theoretical aspects, and state-of-the-art applications, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 413-447.Reaser, B.C., Watson, N.E., Prebihalo, S.E., Pinkerton, D.K., Skogerboe, K.J., Synovec, R.E., 2020. Chapter 5 - Management and interpretation of capillary chromatography-mass spectrometry data, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 449-480.Schmitt-Kopplin, P., Kanawati, B., 2019. Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, p. 778.Wanczek, K.P., Kanawati, B., 2019. Chapter 1 - Historical developments in Fourier transform ion cyclotron resonance mass spectrometry, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 3-33.Makarov, A., Grinfeld, D., Ayzikov, K., 2019. Chapter 2 - Fundamentals of Orbitrap analyzer, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 37-61.Easterling, M.L., Agar, J.N., 2019. Chapter 3 - Fundamentals, strengths, and future directions for Fourier transform ion cyclotron resonance mass spectrometry, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 63-88.Nikolaev, E.N., Kostyukevich, Y.I., Vladimirov, G., 2019. Chapter 4 - Fundamentals and simulations in FT-ICR-MS, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 89-111.Tsybin, Y.O., Nagornov, K.O., Kozhinov, A.N., 2019. Chapter 5 - Advanced fundamentals in Fourier transform mass spectrometry, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 113-132.Kanawati, B., Wanczek, K.P., Schmitt-Kopplin, P., 2019. Chapter 6 - Data processing and automation in Fourier transform mass spectrometry, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 133-185.Floris, F., O'Connor, P.B., 2019. Chapter 7 - Fundamentals of two dimensional Fourier transform mass spectrometry, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 187-232.Fernandez-Lima, F., 2019. Chapter 8 - Trapped ion mobility spectrometry coupled to FT-ICR MS: Fundamentals and applications, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 233-251.Kreutzer, L., Aichler, M., Walch, A.K., 2019. Chapter 9 - In situ metabolomics in cancer tissue by high-resolution mass spectrometry imaging, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 253-279.Aubriet, F., Carré, V., 2019. Chapter 10 - Fourier transform ion cyclotron resonance mass spectrometry and laser: A versatile tool, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 281-322.Junot, C., Fenaille, F., 2019. Chapter 11 - Metabolomics using Fourier transform mass spectrometry, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 325-356.Moritz, F., Hemmler, D., Kanawati, B., Schnitzler, J.-P., Schmitt-Kopplin, P., 2019. Chapter 12 - Mass differences in metabolome analyses of untargeted direct infusion ultra-high resolution MS data, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 357-405.Gonsior, M., 2019. Chapter 13 - FT-ICR MS and Orbitrap mass spectrometry approaches in environmental chemistry, in: Kanawati, B., Schmitt-Kopplin, P. 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Chapter 17 - Proteomics and proteoforms: Bottom-up or top-down, how to use high-resolution mass spectrometry to reach the Grail, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 529-567.Wanczek, K.P., Kanawati, B., 2019. Chapter 18 - Gas phase ion-molecule reactions of inorganic compounds in FT-ICR-MS, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 569-591.Dillinger, S., Niedner-Schatteburg, G., 2019. Chapter 19 - Cryo trapping by FT-MS for kinetics and spectroscopy, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 593-621.Duan, J., Amster, I.J., 2019. Chapter 20 - Application of FTMS to the analysis of glycosaminoglycans, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. 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Recent divergence in the contributions of tropical and boreal forests to the terrestrial carbon sink. Nature Ecology & Evolution 4, 202-209.Turetsky, M.R., Abbott, B.W., Jones, M.C., Anthony, K.W., Olefeldt, D., Schuur, E.A.G., Grosse, G., Kuhry, P., Hugelius, G., Koven, C., Lawrence, D.M., Gibson, C., Sannel, A.B.K., McGuire, A.D., 2020. Carbon release through abrupt permafrost thaw. Nature Geoscience 13, 138-143.Wang, H., An, Z., Lu, H., Zhao, Z., Liu, W., 2020. Calibrating bacterial tetraether distributions towards in situ soil temperature and application to a loess-paleosol sequence. Quaternary Science Reviews 231, 106172.Zhang, D., Yang, Y., Ran, M., 2020. Variations of surface soil δ13Corg in the different climatic regions of China and paleoclimatic implication. Quaternary International 536, 92-102.Remote Sensing-Hydrocarbon SeepageBaldermann, A., Abbasov, O.R., Bayramova, A., Abdullayev, E., Dietzel, M., 2020. New insights into fluid-rock interaction mechanisms at mud volcanoes: Implications for fluid origin and mud provenance at Bahar and Zenbil (Azerbaijan). Chemical Geology 537, 119479.Chen, J., Zhu, W., Tian, Y.Q., Yu, Q., 2020. Monitoring dissolved organic carbon by combining Landsat-8 and Sentinel-2 satellites: Case study in Saginaw River estuary, Lake Huron. Science of The Total Environment 718, 137374.Dembicki, H., 2020. Reducing the risk of finding a working petroleum system using SAR imaging, sea surface slick sampling, and geophysical seafloor characterization: An example from the eastern Black Sea basin, offshore Georgia. Marine and Petroleum Geology 115, 104276.Feenstra, E.J., Birgel, D., Heindel, K., Wehrmann, L.M., Jaramillo-Vogel, D., Grobéty, B., Frank, N., Hancock, L.G., Van Rooij, D., Peckmann, J., Foubert, A., 2020. Constraining the formation of authigenic carbonates in a seepage-affected cold-water coral mound by lipid biomarkers. Geobiology 18, 185-206.Ferré, B., Jansson, P.G., Moser, M., Serov, P., Portnov, A., Graves, C.A., Panieri, G., Gründger, F., Berndt, C., Lehmann, M.F., Niemann, H., 2020. Reduced methane seepage from Arctic sediments during cold bottom-water conditions. Nature Geoscience 13, 144-148.Ge, L., Chen, W., Zhu, B., Fan, M., Yang, T., Jiang, S., 2020. Sr and Nd isotopes of cold seep carbonates from the northern South China sea as proxies for fluid sources. Marine and Petroleum Geology 115, 104284.Gorshkov, A., Pavlova, O., Khlystov, O., Zemskaya, T., 2020. Fractioning of petroleum hydrocarbons from seeped oil as a factor of purity preservation of water in Lake Baikal (Russia). Journal of Great Lakes Research 46, 115-122.Kalmychkov, G.V., Egorov, A.V., Hachikubo, A., Khlystov, O.M., 2019. Hydrocarbon gases of the Gorevoi Utes underwater oil-gas seep (Lake Baikal, Russia). Russian Geology and Geophysics 60, doi: 10.15372/RGG2019110.Kret, K., Tsuji, T., Chhun, C., Takano, O., 2020. 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Discovery and mapping of the Triton seep site, Redondo Knoll: Fluid flow and microbial colonization within an oxygen minimum zone. Frontiers in Marine Science 7, 108. doi: 110.3389/fmars.2020.00108.Zhao, L., Wang, D., Chen, S., Li, L., Zhang, T., 2020. Remote detection of hydrocarbon microseepage in a loess covered area. Journal of Earth Science 31, 207-214.AbstractsAbarghani, A., Ostadhassan, M., Hackley, P.C., Pomerantz, A.E., Nejati, S., 2020. A chemo-mechanical snapshot of in-situ conversion of kerogen to petroleum. Geochimica et Cosmochimica Acta 273, 37-50. matter (OM) from various biogenic origins converts to solid bitumen in-situ when it undergoes thermal maturation. It is well documented that during this process, the ratios of both hydrogen and oxygen to carbon will decrease, resulting in an increase in OM aromaticity and molecular chemo-mechanical homogeneity. Although there have been extensive efforts to reveal molecular alteration occurring to OM during conversion, in-situ and continuous observation of such alterations on naturally occurring samples is missing. Therefore, evaluation of previous results cannot be made independent from natural sample variability. In this study, we identified OM particles (Tasmanites) that are evolving in-situ into solid bitumen in the Bakken Formation. This in-situ bituminization allows examination of a continuous transformation in OM molecular structure at micron-scale using AFM based IR spectroscopy applied at the transition/interface zone. Moreover, contact mode in the AFM was employed to reveal and relate changes in mechanical properties at a similar scale of measurement. Understanding these chemical and mechanical alterations is important to understand shale reservoir properties and better explain hydrocarbon generation, expulsion, and migration processes at the microscale.Abd-Allah, A.M.A., El-Naby, A.A., Abdel Aal, M.H., 2020. Tectonic and basin evolution of South Eastern Mediterranean for hydrocarbon potentiality in North Sinai, Egypt. Journal of Petroleum Science and Engineering 190, 107080. Eastern Mediterranean margin has expressed two Jurassic-Recent tectonic cycles that related to the opening and closure of the Neotethys Ocean. Structural and sedimentological complications related to these cycles and the basin evolution are selected to be the main targets of the present study in North Sinai. 2D seismic, boreholes, and outcrop data are used to achieve these targets. The development of the margin began by the formation of the NE and E-W oriented normal faults during the Jurassic-Early Cretaceous rifting. Two Albian uplifting phases occurred by the end of this rifting and followed by the Cenomanian-Oligocene positive inversion that was interrupted by a tectonic loading subsidence phase allowed the deposition of the pelagic Campanian-Maastrichtian chalk on the shallow Upper Cretaceous carbonate. Shortening related to this inversion inverted completely the normal-slip on some rift-related faults into reverse faults and related folds or partially inverted by decreasing of the normal slip on the others. Inversion was ended by the post-Oligocene extensional-subsidence event that is related to north-sinking of the northern part of the African margin under the European plate. The three-tectonic regimes in association with the sediments supplies, sea level changes, total basin subsidence, basin extension, uplifting, and erosion resulted in complex sedimentary packages that are interrupted by many unconformities and exhibited dramatic lateral facies and thickness changes. Considerable depositional environments were transited northward, from the reefal and subtidal to shelf and then to the deep marine, where the facies formation was controlled by mix effects of the sediment supplies, north-tilting continental margin, tectonic activities, sediment load and subsidence. Offshore part of Sinai preserves good conditions favorable for hydrocarbon accumulation and requires more intensive exploration.Abdelwahhab, M.A., Raef, A., 2020. Integrated reservoir and basin modeling in understanding the petroleum system and evaluating prospects: The Cenomanian reservoir, Bahariya Formation, at Falak Field, Shushan Basin, Western Desert, Egypt. Journal of Petroleum Science and Engineering 189, 107023. inferences on understanding the reservoir heterogeneity and processes of the respective petroleum system are essential to reduce risks throughout the petroleum exploration and development phases. In this paper we present integrated static reservoir modeling and basin modeling to better characterise the reservoir rock; hydrocarbon-bearing sandstones of the Cenomanian Bahariya Formation. This reservoir is an element of the petroleum system; whose times of hydrocarbon generation-migration-accumulation, and entrapment, are also to be addressed; in Falak Field, Meleiha Area, Shushan Basin, Western Desert, Egypt. We utilized dataset including seismic profiles and well logs of four wells. Stratigraphic and structural modeling was performed to delineate the reservoir framework, then facies and petrophysical modeling, using stochastic simulation algorithms, was performed to delineate the reservoir architecture. 1D basin modeling was performed to retrieve the geohistory and maturation models of the area. Combining both reservoir and basin models was aimed, in this study, at identifying new petroleum prospects and estimating the volume of hydrocarbons within the reservoir intervals of the study area. According to the constructed reservoir and basin models, we identified three new petroleum prospect areas; to the NE, NW, and southern parts of Falak Field; that lead to reliable consistent inferences reasonably have sound impact on the oilfield development phases of the area.Abid, M., Geng, J., 2020. Effective attributes quantification to bridge gap between elastic properties and reservoir parameters in self-resource rocks. Scientific Reports 10, 2534. successful production of unconventional resources such as shale gas is highly dependent on its two reservoir properties, organic matter and rock brittleness. High resolution spatially characterization of these two unconventional reservoir properties needs surface reflection seismic data. However, to delineate these two parameters on seismic scale is a challenging task because poor correlation is observed between these parameters and elastic properties of the rock. To encounter this adversity in current study we proposed effective attributes method in which organic shale reservoir properties are divided into their hard and soft elastic response. From the analysis of worldwide laboratory dataset, we find that hard and soft components have shown us much better linear correlation with P- and S- wave impedance. The proposed effective attributes, helped us to reduce the gap between unconventional reservoir properties and seismic characteristics. These attributes are the main controlling factor for rock elastic properties and exhibit information about hydrocarbon generation capacity and rock brittleness. A well data example from Sembar shale has also shown successful results for proposed effective attributes methodology. These attributes application on inverted P-wave impedance seismic data of employed organic shale reservoir have shown productive results to quantify its unconventional prospect on seismic scale. The approach used in this study can be confidently employed to assess unconventional reservoir potential in other parts of the world.Acquaviva, A., Siano, G., Quintas, P., Filgueira, M.R., Castells, C.B., 2020. Chiral × achiral multidimensional liquid chromatography. Application to the enantioseparation of dintitrophenyl amino acids in honey samples and their fingerprint classification. Journal of Chromatography A 1614, 460729. HPLC enantiomer separations are performed with columns packed with a chiral stationary phase (CSP) operated with an achiral mobile phase. The intrinsically limited chemical selectivity of most CSPs to the simultaneous resolution of several pairs of enantiomers means that complex mixtures of diverse pairs of enantiomers cannot be resolved in a single run due to peak overlapping. Moreover, some drawbacks remain when the analyte is present in very complex samples containing other achiral compounds which can co-elute with the enantiomer peaks. Multidimensional chromatography becomes an option to increase peak capacity and resolve these samples.The aim of this work was to study an online fully comprehensive 2D-LC mode utilizing a combination of a chiral column in the first dimension and an achiral column in the second dimension. The 2D-LC system was built with an active flow splitter pump in order to easily adjust the volume of sample transferred into the second dimension and to independently optimize the flow rate in the first dimension.The present LCxLC method was optimized for the separation of amino acids present in honey samples, taking into account key parameters that influence the bidimensional peak capacity (orthogonality, sampling frequency, etc.). The amino acids have been preconcentrated on a cation-exchange column followed by derivatization. Several amino acids present in different honey samples have been identified and the data generated has been analyzed by principal component analysis.Acter, T., Solihat, N.N., Kim, S., Uddin, N., Mustafa, A.I., Shamsuddin, S.M., Kim, S., 2020. Application of silver-assisted laser desorption ionization ultrahigh-resolution mass spectrometry for the speciation of sulfur compounds. Analytical and Bioanalytical Chemistry 412, 243-255. herein report the optimization and application of silver cationization (Ag+) in combination with laser desorption ionization (LDI) ultrahigh-resolution mass spectrometry (UHR-MS) to determine the structures of the sulfur-containing compounds present in heavy crude oil. A number of sulfur-containing model compounds were used to optimize the positive-ion mode LDI-MS conditions in the presence of a silver-complexing agent. Under the optimized LDI conditions, sulfur-rich heavy oil fractions were treated with the silver salt, where Ag+ coordinated with the sulfur atoms to speciate the sulfur species. The obtained results suggested that benzothiophenic, naphtheno-non-aromatic sulfides, and non-aromatic thiols were the major components present in the analyzed oil sample.Adam, N., Kriete, C., Garbe-Sch?nberg, D., Gonnella, G., Krause, S., Schippers, A., Kurtz, S., Schwarz-Schampera, U., Han, Y., Indenbirken, D., Perner, M., 2020. Microbial community compositions and geochemistry of sediments with increasing distance to the hydrothermal vent outlet in the Kairei Field. Geomicrobiology Journal 37, 242-254. metabolisms in sediments play a pivotal role in marine element cycling. In hydrothermal sediments chemosynthetic microorganisms likely prevail, while in non-hydrothermally impacted sediment regimes microorganisms associated with organic matter decomposition are primarily recognized. To test how these microorganisms are distributed along the hitherto neglected transition zone influenced to different degrees by hydrothermal input we sampled four sediment sites: these were (i) near an active vent, (ii) the outer rim, and (iii) the inactive area of the Kairei hydrothermal field as well as (iv) sediments roughly 200?km south-east of the Kairei field. Chemistry and microbial community compositions were different at all sampling sites. Against expectations, the sediments near the active vent did not host typical chemosynthetic microorganisms and chemistry did not indicate current, extensive hydrothermal venting. Data from the outer rim area of the active Kairei field suggested microbially mediated saponite production and diffuse hydrothermal flow from below accompanied by increased metal concentrations. A steep redox gradient in the inactive Kairei field points towards significant redox driven processes resulting in dissolution of hydrothermal precipitates and intense metal mobilization. Local microorganisms were primarily Chloroflexi, Bacillales, Thermoplasmata, and Thaumarchaeota.Ado, M.R., 2020. A detailed approach to up-scaling of the Toe-to-Heel Air Injection (THAI) In-Situ Combustion enhanced heavy oil recovery process. Journal of Petroleum Science and Engineering 187, 106740. Air Injection (THAI) is a variant of conventional In-Situ Combustion (ISC) that uses a horizontal production well to recover mobilised partially upgraded heavy oil/bitumen/tar sand. For the promise of THAI to be fully realised, realistic and validated field scale simulations are required to design process operations. Firstly, a brief review of the available laboratory to field up-scaling techniques was presented. Then sequential volume up-scaling was used to obtain larger length scales predictions. It was found that, as with conventional ISC, the kinetics parameters had to be altered to obtain a realistic representation of the physico-chemical processes occurring at larger length scales. Consequently, a new approach, which is grounded in theory, to up-scaling laboratory-scale simulations, already validated against experiment, has been proposed and tested. It is shown for the first time that for the fraction of fuel formed and consumed at laboratory scale to be the same as that at field scale, the Damkh?ler number must be the same. From this relationship, it has been shown mathematically that the frequency factor of the reactions must be down-scaled from laboratory values to field values in order for the fuel deposition and consumption at the laboratory scale to be the same as at field scale. This is clearly another key finding in this study that has not been shown before. Therefore, an initial estimate must be made and iterative runs used to determine the value of the down-scaling factor. The new model led to improvements in the key prediction of the distribution of fuel (coke) deposition over previous field-scale works.Agrawal, V., Sharma, S., 2020. Are we modeling the properties of unconventional shales correctly? Fuel 267, 117316. advancements have led to impressive growth in hydrocarbon (HC) production from unconventional shale reservoirs. However, major limiting factors in shale gas development are i) low recovery of gas in place (<20%), (ii) a rapid decline in well productivity, iii) release of contaminants, despite the use of advanced hydraulic fracturing fluids and multiple fracturing stages. This is mainly due to a lack of understanding of the nanoscale physicochemical properties of shales, especially that of kerogen, the macromolecule that is not only the source of the majority of the HC’s in shales but also holds most of the HC’s in adsorbed state. Over the last few years, a large number of studies have been published on simulating the physicochemical properties of shale utilizing molecular models of kerogen. However, the molecular models of kerogen input into these simulations are based on the kerogen “type” derived from a very limited number of shale samples. In this paper, we examine the variations that can exist in kerogen structure within a particular kerogen “type” across different shale basins and single shale basin at similar thermal maturity levels. We propose that using kerogen “type” based structural models for molecular simulations could lead to inaccurate estimation of HC reserves, HC recovery, HC production, frackability, and quantity and quality of produced water. This study highlights the need for developing a better classification of kerogen based on its “molecular structure” instead of “type” for a more accurate prediction of physicochemical properties of shales.Al-Fattah, S.M., 2020. Non-OPEC conventional oil: Production decline, supply outlook and key implications. Journal of Petroleum Science and Engineering 189, 107049. prediction of oil production is a vital task for developing oil field strategies, upstream investment opportunities, future production plans, and the global oil market supply. This paper addresses the following strategic question: How much new oil production capacity is required to bridge the expected supply gap due to the production decline of existing non-OPEC oil-producing fields? The paper analyzes the decline in non-OPEC conventional oil production, develops an outlook for the supply gap, estimates the required additional capacity, discusses the factors impacting the production decline, and presents key policy implications. Results of analysis show that non-OPEC conventional production declines annually at 3.5% excluding ramping-up fields and 2.5% including nondeclining fields by 2017. The supply gap due to this decline will be 4.4 million barrels per day (MMBD) in 2023 under current production and economic conditions, where an additional production capacity of 8.1?MMBD by 2030 is required to maintain 2017 production levels. A 1% shift in the current decline rates may result in either adding or removing approximately 3.4 MMBPD from the global oil market in 2030. Possible sources for bridging the expected global supply gap are, namely, the use of OPEC+?oil supply led by Saudi Arabia and Russia, the temporary use of OPEC spare capacity, the use of nonconventional oil, and the reserves growth and replacement. The findings of this study provide a guide for policymakers in the oil markets, upstream operators, national and international oil companies, and oilfield service providers seeking to develop effective upstream development strategies, engage in proper planning, and identify oil investment opportunities.Al-Rabiah, H., Al-Ostad, L., Al-Shamary, T., Al-Hendi, A., Al-Henayyan, H., Khazemi, R., 2020. Sulfur speciation of Kuwaiti crude oils fractions using two-dimensional gas chromatography. Arabian Journal of Chemistry 13, 3615-3623. main objective of this study is to develop a methodology for sulfur compounds speciation using two-dimensional gas chromatography coupled with a flame ionization detector and sulfur chemiluminescence detectors. The methodology enhances the ability to detect and quantify the refractory sulfur in petroleum distillates, and it was utilized to screen the molecular differences between distillates of two Kuwaiti heavy crude oils from different reservoirs but with similar physical properties. Despite the similarity in the physical properties, the detailed comparative analysis indicated significant differences in molecular composition, which suggests substantial differences in crude oil processability based on the reactivity of the detected compounds. The distillates that have been considered in this study include heavy naphtha, kerosene, and gas oil. The compositional differences between the distillates were observed using the two-dimensional gas chromatography system with an in-house developed method. This method groups the sulfur compounds into thiols, benzothiophenes (BTs), and dibenzothiophene (DBTs), and it can handle any atmospheric distillate up 365°C. Furthermore, the method includes the possibility of identifying and quantifying a total number of 44 sulfur species, which covers the previously mentioned sulfur groups.Al-Shayeb, B., Sachdeva, R., Chen, L.-X., Ward, F., Munk, P., Devoto, A., Castelle, C.J., Olm, M.R., Bouma-Gregson, K., Amano, Y., He, C., Méheust, R., Brooks, B., Thomas, A., Lavy, A., Matheus-Carnevali, P., Sun, C., Goltsman, D.S.A., Borton, M.A., Sharrar, A., Jaffe, A.L., Nelson, T.C., Kantor, R., Keren, R., Lane, K.R., Farag, I.F., Lei, S., Finstad, K., Amundson, R., Anantharaman, K., Zhou, J., Probst, A.J., Power, M.E., Tringe, S.G., Li, W.-J., Wrighton, K., Harrison, S., Morowitz, M., Relman, D.A., Doudna, J.A., Lehours, A.-C., Warren, L., Cate, J.H.D., Santini, J.M., Banfield, J.F., 2020. Clades of huge phages from across Earth’s ecosystems. Nature 578, 425-431. typically have small genomes and depend on their bacterial hosts for replication. Here we sequenced DNA from diverse ecosystems and found hundreds of phage genomes with lengths of more than 200 kilobases (kb), including a genome of 735 kb, which is—to our knowledge—the largest phage genome to be described to date. Thirty-five genomes were manually curated to completion (circular and no gaps). Expanded genetic repertoires include diverse and previously undescribed CRISPR–Cas systems, transfer RNAs (tRNAs), tRNA synthetases, tRNA-modification enzymes, translation-initiation and elongation factors, and ribosomal proteins. The CRISPR–Cas systems of phages have the capacity to silence host transcription factors and translational genes, potentially as part of a larger interaction network that intercepts translation to redirect biosynthesis to phage-encoded functions. In addition, some phages may repurpose bacterial CRISPR–Cas systems to eliminate competing phages. We phylogenetically define the major clades of huge phages from human and other animal microbiomes, as well as from oceans, lakes, sediments, soils and the built environment. We conclude that the large gene inventories of huge phages reflect a conserved biological strategy, and that the phages are distributed across a broad bacterial host range and across Earth’s ecosystems.Alade, O.S., Hamdy, M., Mahmoud, M., Al Shehri, D.A., Mokheimer, E., Patil, S., Al-Nakhli, A., 2020. A preliminary assessment of thermochemical fluid for heavy oil recovery. Journal of Petroleum Science and Engineering 186, 106702. production of heavy oil has heavily relied upon steam injection method due to its effectiveness to reduce the viscosity and improved mobility. However, due to uncertainty of oil price, high energy cost, water requirement, heat loss, and environmental issues, attention is being given to new thermal EOR technologies such as insitu steam generation using thermochemical fluid (TCF) injection. This technology essentially involves downhole generation of heat and pressure from exothermic chemical reaction. In this investigation, thermochemical reactants were injected, at different temperatures (100, 50, and 30?°C) and constant rate of 0.5 ml/mln, into Berea sandstone core samples saturated with heavy oil (18 %wt./wt. asphaltene content and 11° API) and brine. It was observed that the pressure generated at the inlet of the core due to 100, 50, and 30?°C injection temperatures of the thermochemical fluids rose to 1600, 1200, and 280 psi, respectively; while the recovery factor was 83%, 66% and 54% OOIP, respectively. In comparison, from the injection of steam generated at 250?°C, the pressure at the inlet of the core was 212 psi and the recovery factor was 71% OOIP. These results therefore confirm increase in interest in the application of the TCF injection technology in heavy oil production.Alhosani, A., Daraboina, N., 2020. Unified model to predict asphaltene deposition in production pipelines. Energy & Fuels 34, 1720-1727. are heavy-molecular-weight condensed aromatic fractions present in crude oil along with saturates, resins, and aromatics. Asphaltene particles start precipitating when the phase stability is affected by the change in pressure, temperature, or composition. The asphaltene particles may affect fluid properties as well as the production rate due to contraction of the flow lines simultaneously. It is important to develop a robust model to accurately predict the deposition behavior at a wide range of operating conditions. Therefore, by considering possible precipitation, aggregation, and deposition mechanisms, a unified model has been developed in this study. Experimental data in the literature are used to verify the model performance, and results showed a good agreement with the data. Furthermore, this model is used to analyze the effects of flow rate, pipe size, and particle size on the deposition rate and the thickness profile. Moreover, the diameter of the pipe was scaled up to analyze the effect of deposition on fieldlike conditions. Based on the results, the thickness of deposit increased sharply in the first few days, signifying the importance of the early detection of asphaltenes. Despite its simplicity, the model proved its capability to predict asphaltene deposition at different operating conditions.Ali, A.a.-k.F., Danielson, N.D., 2020. Liquid chromatography of short chain carboxylic acids using a glutamic acid surfactant coated C18 stationary phase. Talanta 213, 120807. C18 column was modified with the anionic amino acid surfactant lauroyl-l-glutamate (LLG) to facilitate the separation of ten short-chain aliphatic carboxylic acids (oxalic, tartaric, malic, malonic, lactic, acetic, maleic, citric, fumaric, and succinic). The developed method was proven to be fast, versatile, and environmentally friendly. After the coating of the column using 1% LLG solution and optimizing chromatographic conditions such as pH and temperature, near baseline resolution of the ten carboxylic acids within 4 min with excellent peak shape at pH = 1.8 using 100% H2O acidified with sulfuric acid was possible. Although the design of this stationary phase, with the hydrophilic group at the end of the alkyl chain, seems to be in contrast to such columns designed for a totally aqueous mobile phase that have a polar (often amide) group embedded near the silica surface, no evidence of phase collapse was noted. Linear relationships of ln retention factor (k) versus 1/Temperature (T) (van't Hoff plots) were generated for all the acids indicating a single retention mechanism was likely. As the pH of the mobile phase decreased, the analyte retention factors increased due to the increase of the fraction of the analyte with neutral charge (alpha zero). The surfactant amide linkage, being electron donating, increased the pKa of the more acidic carboxyl group of glutamic acid so both carboxyl groups were protonated (neutral) at pH 1.8. The exact nature of the retention mechanism is uncertain but there certainly seems to be a pronounced hydrophobic component due to the large difference in retention of fumaric acid and methyl fumarate at pH 1.8. In addition, eleven beverage samples were analyzed for their aliphatic carboxylic acid contents. The results showed that malic, fumaric, and citric acids were the most common carboxylic acids in natural beverages with concentrations as high as 6432 ppm of malic acid in organic apple juice, 64 ppm of fumaric acid in organic concord juice, and 6543 ppm citric acid in strawberry lemonade juice.Alnarabiji, M.S., Husein, M.M., 2020. Application of bare nanoparticle-based nanofluids in enhanced oil recovery. Fuel 267, 117262. offer many advantages over surfactant and polymer solutions during enhanced oil recovery (EOR). This review discusses the current state and future prospects of nanofluids consisting of bare nanoparticles (NPs) in aqueous media and their application in EOR. The following topics are addressed: advantages and challenges of bare and functionalized nanofluid injection, observations on NP mobility within reservoirs as well as mechanisms pertaining to nanofluid EOR. The role of the NP chemical nature, size, size distribution, surface charge, isoelectric point and concentration is thoroughly reviewed. The impact of factors such as high temperature, pH, salinity and the nature of reservoir rock surface are highlighted in order to provide a better understanding and ability to predict EOR rate of nanofluid injection. Potential synergy among the different NP characteristics is gaged through experimental results from multiple research clusters. The proposed mechanisms; namely reduction of interfacial tension, increment in viscosity, in situ formation of Pickering emulsion and/or alteration of the disjoining pressure and wettability are critically discussed. Future work in this field should address the following gaps; (1) precise determination of the isoelectric point of the NPs under reservoir conditions; (2) workable measurement to faithfully capture particle size distribution; (3) a mean to correlate aging time of the NPs in the base fluid under reservoir environment; and (4) exploring the fine balance between surface charge needed to stabilize the particles while maintain their effectiveness as interfacial tension modifiers.Aloisi, I., Schena, T., Giocastro, B., Zoccali, M., Tranchida, P.Q., Caram?o, E.B., Mondello, L., 2020. Towards the determination of an equivalent standard column set?between cryogenic and flow-modulated comprehensive two-dimensional gas chromatography. Analytica Chimica Acta 1105, 231-236. preliminary research is focused on the task of defining an equivalent standard column set between cryogenic and flow-modulation comprehensive two-dimensional gas chromatography (GC × GC) combined with mass spectrometry (MS). Cryogenic modulation (CM) was carried out by using a loop-type device, while the flow modulator used was a seven-port wafer chip, equipped with an external accumulation loop.Initially, a common low-polarity + mid-polarity CM GC × GC column set was selected (30 m × 0.25 mm ID × 0.25 μm df + 1.5 m × 0.25 mm ID × 0.25 μm df), a method was developed, and a GC × GC-MS fingerprint was attained (on a sample of bio-oil derived from coconut fibers). After, a column set with the same stationary phases was selected for the flow modulation GC × GC-MS method (20 m × 0.18 mm ID × 0.18 μm df + 5 m × 0.32 mm ID × 0.25 μm df), with the capability to provide a-similar-as-possible separation. A side-by-side measurement of several chromatography parameters (efficiency, peak capacity, resolution, peak widths, retention factors, elution temperatures) was made.?lvarez-Ruiz, R., Picó, Y., 2020. Analysis of emerging and related pollutants in aquatic biota. Trends in Environmental Analytical Chemistry 25, e00082. bodies cover approximately 70 % of the earth?s surface, making them ecosystems with a high environmental value and the habitat for numerous species of flora and fauna. Emerging pollutants (EPs) are ubiquitous anthropogenic compounds of environmental concern that can be found at different concentration levels in matrices such as sediment, water and aquatic biota. In addition, EPs can be bioaccumulated and biomagnified, inducing adverse effects on biota, and posing a risk to humans when contaminated biota is consumed. Unlike abiotic matrices, the occurrence of EPs in aquatic biota has not been widely studied. This is probably because their complexity, due to the presence of lipids, proteins and other organic compounds, makes the extraction and analysis of EPs difficult. This review gathers the most relevant analytical methods published between 2014 and 2019, comparing them and evaluating their strengths and weaknesses. It is intended to provide a better understanding of the development of new and improved methods, and to be a reference for researchers who are looking for the best methodology for their studies.Amaral-Zettler, L.A., Zettler, E.R., Mincer, T.J., 2020. Ecology of the plastisphere. Nature Reviews Microbiology 18, 139-151. plastisphere, which comprises the microbial community on plastic debris, rivals that of the built environment in spanning multiple biomes on Earth. Although human-derived debris has been entering the ocean for thousands of years, microplastics now numerically dominate marine debris and are primarily colonized by microbial and other microscopic life. The realization that this novel substrate in the marine environment can facilitate microbial dispersal and affect all aquatic ecosystems has intensified interest in the microbial ecology and evolution of this biotope. Whether a ‘core’ plastisphere community exists that is specific to plastic is currently a topic of intense investigation. This Review provides an overview of the microbial ecology of the plastisphere in the context of its diversity and function, as well as suggesting areas for further research.Angeles, L.F., Aga, D.S., 2020. Catching the elusive persistent and mobile organic compounds: Novel sample preparation and advanced analytical techniques. Trends in Environmental Analytical Chemistry 25, e00078. and Mobile Organic Compounds (PMOCs) are emerging pollutants in the environment that have only been rarely detected in previous years due to the lack of analytical techniques available for their analysis. These compounds, being very polar, are able to spread through the surface waters, and reach groundwaters and drinking water sources. The challenges in the analysis of these compounds in water include their poor extraction efficiencies from environmental matrices and weak retention in conventional chromatographic columns. As a result, the toxicity and environmental fate of PMOCs are largely unknown. This review will examine recent developments in sorbent and chromatographic column technologies, and other sample preparation strategies that will enable analysis of PMOCs and advance our knowledge on their fate and transport in the environment. In addition, analysis of these compounds in water via liquid chromatography with tandem mass spectrometry (LC–MS/MS) are discussed in this review.Anyakudo, F., Adams, E., Van Schepdael, A., 2020. Thin-layer chromatography–flame ionization detection. Chromatographia 83, 149-157. layer chromatography–flame ionization detection (TLC–FID) is a versatile analytical technique that can be used for fast analysis of organic compounds. It has been implemented in past decades for the analysis of lipids and petrochemical products, but rarely in other fields. Despite the improvement in the latest Iatroscan model and the introduction of an automatic programmable sample spotter, this system is still struggling to gain acceptance in universities and major research laboratories. The reason behind this might be a lack of awareness on the potential application of this system to other fields of analytical chemistry. This review presents TLC–FID as a mature and reliable, state of the art technique that combines the separation power of TLC with FID as a universal detector, which can be applied to the analysis of a wide variety of organic compounds. Basic operational procedures and previous literature, including its potential for ultrafast analysis of commercial samples, are discussed in order to create awareness on the potentials of this piece of equipment to other fields.Archer, C., Vance, D., Milne, A., Lohan, M.C., 2020. The oceanic biogeochemistry of nickel and its isotopes: New data from the South Atlantic and the Southern Ocean biogeochemical divide. Earth and Planetary Science Letters 535, 116118. (Ni) is important for a number of enzymes in oceanic phytoplankton. It has received less attention than some other bioactive metals because it is not reduced to extremely low dissolved concentrations in the photic zone. However, there are strong indications in previous studies that this residual pool is not bio-available. Oceanic Ni isotope data are still scarce, but have great potential for understanding this issue, as well as for understanding the Ni mass balance of the oceans now and in the past. Here, we present new concentration and isotope data for the UK GEOTRACES section at 40°S in the Atlantic (GA10). Nickel concentration data show typical nutrient-like profiles, slightly modified by variable pre-formed concentrations in sub-surface water masses, e.g. North Atlantic Deep Water. Nickel isotopes, in common with findings in previous studies, are homogeneous beneath 500 m, at about +1.3‰ in δ60Ni, in samples with Ni concentrations above 3-3.5 nM. The surface South Atlantic, however, has concentrations below 3 nM, and shows significantly higher δ60Ni, up to +1.74‰, that are closely anti-correlated with Ni concentrations.The data for the deep South Atlantic dissolved pool, with a δ60Ni = 1.31 ± 0.12‰ (average and 2SD) confirm the homogeneity of the global deep ocean, which previous data demonstrate extends all the way to the surface in the upwelling zone of the Southern Ocean south of the Polar Front. This Ni isotope composition is significantly heavier than known inputs to the oceanic dissolved pool. This mass balance requires an isotopically light sink that may be represented by sedimentary Mn-oxide associated Ni. The magnitude of the isotope fractionation implied by the upper ocean data is not consistent with plausible potential abiotic removal processes. Rather, these data are best explained by biological uptake. However, consideration of the detailed relationships between Ni concentrations and isotope compositions requires that a substantial portion of the oceanic dissolved Ni pool is not bio-available. The data are consistent either with a small preference for the light isotope during uptake (about 0.1‰) or two distinct pools of dissolved Ni, one bio-available and one strongly bound in organic complexes, with limited isotopic exchange between them. Patterns of co-variation in Ni concentrations and isotopes with the major nutrients point to strong contrasts across the Polar Front of the Southern Ocean, contrasts that exhibit both similarities and differences with those for the major nutrients and other trace metal micronutrients. South of the Polar Front, Ni is taken up in modest amounts by diatoms, without isotope fractionation. North of the Polar Front the data are most consistent with cyanobacteria as the dominant control on Ni uptake, leading to significant coupled abundance and isotope variation.Arjomand, E., Easton, C.D., Myers, M., Tian, W., Saeedi, A., Wood, C.D., 2020. Changing sandstone rock wettability with supercritical CO2-based silylation. Energy & Fuels 34, 2015-2027. of subsurface reservoir rocks is a key parameter that influences multiphase flow characteristics of the fluid–rock system, including relative permeability, capillary pressure, saturation distribution, and displacement efficiency. To investigate such effects, various techniques have been implemented to change wettability, including nanoparticle injection, chemical treatment, surfactant injection, brine salinity adjustment, etc. However, most studies have focused on the use of model surfaces (e.g., mineral surfaces) and not actual rock samples, which are far more representative of real-world application. The ability to modify the wettability of the pore space in the reservoir has implications in a range of areas, such as reducing/preventing water/condensate banking around hydrocarbon production wells, CO2 geo-sequestration, enhanced hydrocarbon recovery, and separation of CO2 using porous media. In light of the above findings, in this research, we primarily explored supercritical fluid-based silane surface modification of quarried sandstones (i.e., Gray Berea, Upper Gray Berea, Bentheimer, and Bandera Brown). Using high-throughput treatment methods, these samples were treated with five different silanes and then characterized using X-ray photoelectron spectroscopy and contact angle measurements. Conventional techniques for depositing silanes onto a surface from organic solvent (i.e., toluene) were also conducted for comparison. In all of the cases studied, our experimental results show that, when supercritical CO2 (scCO2) is used as a carrier for the silanes, improved surface coverage and wettability alteration were achieved in comparison to when the conventional solvent (e.g., toluene) is used. As a result, the wettability of sandstone surfaces as measured under high-pressure conditions was altered significantly from strongly water-wet (θ ≈ 11 ± 5°) to strongly non-water-wet (θ ≈ 145 ± 6°). Furthermore, we showed that scCO2 at even relatively modest reservoir conditions (10 MPa at 60 °C) could be used rather than toluene for application in real-world scenarios; this reduces environmental and safety concerns significantly.Arvest?l, E.H.M., Willman, S., 2020. Organic-walled microfossils in the Ediacaran of Estonia: Biodiversity on the East European Platform. Precambrian Research 341, 105626. organic-walled microfossils are not only a source for studying evolution but also increasingly associated with stratigraphic correlation, based on key fossils and assemblage composition. For this reason, two drill cores from north-eastern Estonia have been studied for their content and stratigraphic distribution of organic-walled microfossils (OWM), analysing samples from the Precambrian Gdov, Kotlin, and Voronka formations. The recovered assemblages are generally well-preserved and diverse consisting of abundant sphaeromorphs, such as Leiosphaeridia spp. and Pterospermopsimorpha spp., filamentous cyanobacteria, e.g. Cephalonyx geminatus and Palaeolyngbya catenata, and different types of cellular/colonial aggregates. In contrast, acanthomorphic acritarchs are rare with only a few unidentified examples present. The presence of taxa such as Pomoria rhomboidalis and Primoflagella speciosa in combination with the absence of large acanthomorphs suggests a late Ediacaran age of the studied samples. All in all, 38 species within 22 different genera are described herein, as are 9 taxa of unknown taxonomic affiliation. Another 11 taxa are briefly mentioned and depicted in order to provide for a better overview of the diversity of the assemblage. The stratigraphic distribution of the recognized taxa and assemblages can provide a powerful tool for correlation on the East European Platform as well as between Baltica and other palaeogeographic regions during the Ediacaran.Asemani, M., Rabbani, A.R., 2020. Detailed FTIR spectroscopy characterization of crude oil extracted asphaltenes: Curve resolve of overlapping bands. Journal of Petroleum Science and Engineering 185, 106618. recent years, characterization of asphaltenes as an appropriate way to deal with their related problems in the oil industry has been received considerable attention. The Fourier-transform infrared (FTIR) analysis, since its appearance in the 1880s, become one of the most applicable techniques to gain the valuable information about characteristics and functional groups of different samples especially petroleum related materials (e.g. asphaltenes). Despite these advantages, this technique suffers from a severe drawback especially in analyzing complex compounds such as asphaltenes. This problem is defined as overlapping related to the functional groups with the near occurrence bands which can hinder thorough qualitative and quantitative analyzing. A considerable number of studies were dedicated to FTIR analysis of asphaltenes, but the curve resolving of petroleum asphaltenes spectra has not yet been extensively studied. In this paper, four asphaltenes extracted from crude oils were analyzed by FTIR and then these spectra were completely resolved. The results, for the first time, provide a deep insight into the functional groups present in asphaltenes and their attaching substitutions. The comprehensive investigation of bands shifting and the relationship of their band area with elemental results reveal that carboxylic acids are linked to both saturate (band at about 1743?cm?1) and aromatic compounds (band at about 1698?cm?1); however, esters and alcohols (e.g., secondary and tertiary alcohols) are attached to saturated compounds in the studied asphaltenes (band at 1743?cm?1 for saturated esters and bands at 1347, 1160 and 1110?cm?1 for saturated alcohols). Ketones occur as diaryl and mixed (1616 and 1685?cm?1 bands), but ethers appear as alkyl/aryl (1018?cm?1). The sulfoxide (1033?cm?1), secondary amides (bands at 3239, 1649, 1575 and 1310?cm?1), polyaromatic (with different substitutions at region below 900?cm?1), phenols (3430 and 1229?cm?1) and aliphatic compounds (such as methyl, methylene, and methine in the 1460 and 1375?cm?1 bands and in the 3850-3000?cm?1 region) are also present in the studied asphaltenes.Atmani, L., Valdenaire, P.-L., Pellenq, R.J.M., Bichara, C., Van Damme, H., van Duin, A.C.T., Ulm, F.J., Leyssale, J.-M., 2020. Simulating the geological fate of terrestrial organic matter: Lignin vs cellulose. Energy & Fuels 34, 1537-1547. shale gas has become a major source of energy, a more sustainable recovery requires a better understanding of the gas/kerogen matrix interactions. Here, we use replica exchange molecular dynamics to investigate the geological conversion of two important classes of gas-forming constituents of the terrestrial organic matter: lignin and cellulose. In agreement with results from pyrolysis experiments, we show that lignin produces twice as much kerogen and 5 times more methane than cellulose. In addition, while ex-cellulose kerogen is relatively stiff and almost nonporous, ex-lignin kerogen, despite having a very similar composition and bonding, is an order of magnitude more compliant due to the presence of large micropores. The obtained results can potentially improve the nanoscale brick of bottom-up models of shale gas recovery.Atwah, I., Puckette, J., Becker, M., Moldowan, J.M., 2020. Source-rock reservoirs geochemistry of Devonian–Mississippian mudrocks in central Oklahoma. American Association of Petroleum Geologists Bulletin 104, 657-680. Woodford Shale and the overlying Mississippian limestone constitute one of the prolific unconventional hydrocarbon targets in central and northern Oklahoma. With the advantage of horizontal drilling technology, Devonian and Mississippian mudrocks have become important topics for research to understand the petroleum system fundamentals, including sources of hydrocarbons for these unconventional reservoirs. In this study, organic geochemistry and petrography of Mississippian mudrocks and the Woodford Shale were examined. The key study core is from Lincoln County, Oklahoma, representing the Mississippian mudstone and Woodford Shale. Three additional cores in Payne County and one core from Logan County were studied. Core samples were assessed for hydrocarbon generation potential using Rock-Eval pyrolysis together with biomarker analysis using gas chromatography–mass spectrometry. Organic and thin-section petrography was performed to identify maceral composition and develop a sedimentary facies classification.Mudrocks within the Mississippian section exhibited adequate organic richness for petroleum generation, thereby augmenting the established generation potential of the Woodford Shale. Several unique Mississippian biomarkers were identified, including diterpenoids and extended tricyclic terpanes. Macerals of the Mississippian rocks exhibit dominance of lamalginite and bituminite, whereas Woodford macerals are high in telalginite. Based on the organic matter composition and sedimentology, six facies were identified within the Mississippian mudrocks. Furthermore, based on organic richness and key biomarker ratios, the Mississippian succession is divided into three units. Organic and sedimentological signatures suggest a shoaling-upward succession from the Woodford Shale to the Mississippian carbonate.Aubriet, F., Carré, V., 2019. Chapter 10 - Fourier transform ion cyclotron resonance mass spectrometry and laser: A versatile tool, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 281-322. the numerous ion sources coupled to Fourier transform ion cyclotron resonance mass spectrometers, the laser-based ion sources have a key role. Pulsed lasers have the unique ability to generate neutrals and/or ions from a condensed or gaseous sample in a non-invasive way and to be focused on a very thin area. Depending on both the laser beam and the sample features, various processes could happen during laser–matter interaction that directly impact the detected ions. In this chapter, the factors driving this interaction will be firstly described especially to understand that leading to: the laser desorption (LD), desorption/ionization with (MALDI) or without (LDI) matrix assistance and the laser ablation (LA). The resulting technical advances of laser ion sources, including those, which operate under atmospheric pressure are explained in detail in this chapter for achieving robust FT-ICR-MS measurements. The advent of high performance imaging mass spectrometry using laser ion sources also push up some new developments which will be summarized. A great number of applications demonstrate the versatility of the combination of laser and FT-ICR-MS and some of them will be illustrated in a last section.Aulet, L.S., Chiu, V.C., Prichard, A., Spivak, M., Lourenco, S.F., Berns, G.S., 2019. Canine sense of quantity: evidence for numerical ratio-dependent activation in parietotemporal cortex. Biology Letters 15, 20190666. approximate number system (ANS), which supports the rapid estimation of quantity, emerges early in human development and is widespread across species. Neural evidence from both human and non-human primates suggests the parietal cortex as a primary locus of numerical estimation, but it is unclear whether the numerical competencies observed across non-primate species are subserved by similar neural mechanisms. Moreover, because studies with non-human animals typically involve extensive training, little is known about the spontaneous numerical capacities of non-human animals. To address these questions, we examined the neural underpinnings of number perception using awake canine functional magnetic resonance imaging. Dogs passively viewed dot arrays that varied in ratio and, critically, received no task-relevant training or exposure prior to testing. We found evidence of ratio-dependent activation, which is a key feature of the ANS, in canine parietotemporal cortex in the majority of dogs tested. This finding is suggestive of a neural mechanism for quantity perception that has been conserved across mammalian evolution.Azizi, A., Bottaro, C.S., 2020. A critical review of molecularly imprinted polymers for the analysis of organic pollutants in environmental water samples. Journal of Chromatography A 1614, 460603. imprinted polymers (MIPs) with tailor-made recognition sites are used in water analysis for selective sample pretreatment before quantitation. The exceptional performance of MIPs with reduced interferences and matrix effects during sample preparation has resulted in selective and precise analytical methods by enhancing chromatographic separation and detection. MIPs are fabricated using a varying range of synthetic procedures and used as the adsorptive phase in solid phase extraction (SPE), dispersive solid phase extraction (DSPE), solid phase microextraction (SPME), stir bar sorptive extraction (SBSE), and membrane-based extraction techniques. In this paper, a comprehensive review of MIP technologies reported in the literature for water analysis is provided. MIPs are critically evaluated using key performance criteria, such as adsorption capacity, imprinting factor, chromatographic retention factor, and cross-selectivity. The recent advances of MIP technologies including the preparation protocols, applications and developments are discussed. Additionally, the performance of MIPs which can be improved by optimizing the composition of the polymeric network is reviewed regarding the characteristics of rebinding medium. The limitations of MIPs for water analysis, especially restricted selectivity for water soluble analytes, material wettability, and MIP inhomogeneity are discussed by providing the possible solutions. Finally, some novel applications and prospects for online, rapid and direct analysis of environmental samples using MIPs are included.Babak, O., Gallop, J., 2019. Uncovering potential of seismic for reservoir characterization in Canadian oil sands. Bulletin of Canadian Petroleum Geology 67, 283-291. of high cost, seismic data have routinely been collected for oil sands development. While these data can be extremely valuable for the whole array of applications, including reservoir characterization, they are still, for the most part, largely underutilized. The main reason for the limited use of seismic in oil sands is the subtle sandstone-shale elastic differences and the lack of practical methods and techniques that make efficient use of the seismic information and mimic geophysical interpretation. In this paper, we present two novel approaches to deal with this challenge. The first approach works with 3D post-stack inverted seismic acoustic impedance data to derive facies trend models based on the local analysis of impedance geobodies. Too much impedance overlap between different facies that is observed globally and prevents efficient facies differentiation is resolved by extracting and analyzing objects from the 3D seismic volume that have local impedance contrasts. The second approach presents an optimization of empirical differential compaction calculations for the use in probabilistic 2D mapping of continuous/SAGD-able pay and its quality characteristics. Both approaches are shown to be straightforward and easy to implement into any software of choice. They are proven to lead to significant improvements in oil sands reservoir characterization based on a study of the Christina Lake and Kirby East leases of Cenovus Energy Inc.Bai, C., Cai, J., Zhou, L., Jiang, X., Hu, Y., Dai, J., Shao, K., Tang, X., Yang, X., Gao, G., 2020. Geographic patterns of bacterioplankton among lakes of the middle and lower reaches of the Yangtze River Basin, China. Applied and Environmental Microbiology 86, e02423-19.: The revolution of molecular techniques has revealed that the composition of natural bacterial communities normally includes a few abundant taxa and many rare taxa. Unraveling the mechanisms underlying the spatial assembly process of both abundant and rare bacterial taxa has become a central goal in microbial ecology. Here, we used high-throughput sequencing to explore geographic patterns and the relative importance of ecological processes in the assembly of abundant and rare bacterial subcommunities from 25 lakes across the middle and lower reaches of Yangtze River basin (MLYB), located in Southeast China, where most of the lakes are interconnected by river networks. We found similar biogeographic patterns of abundant and rare subcommunities which could significantly distinguish the community compositions of the two lake groups that were far from each other but which could not distinguish the community compositions of the nearby lakes. Both abundant and rare bacteria followed a strong distance-decay relationship. These findings suggest that the interconnectivity between lakes homogenizes the bacterial communities in local areas, and the abundant and rare taxa therein may be affected by the same ecological process. In addition, based on the measured environmental variables, the deterministic processes explain a small fraction of variation within both abundant and rare subcommunities, while both neutral and null models revealed a high stochasticity ratio for the spatial distribution patterns of both abundant and rare taxa. These findings indicate that the stochastic processes exhibited a greater influence on both abundant and rare bacterial subcommunity assemblies among interconnected lakes.Importance: The middle and lower Yangtze Plain is a typical floodplain in which many lakes connect with each other, especially in the wet season. More importantly, with the frequent change of regional water level in the wet season, there is a mutual hydrodynamic exchange among these lakes. The microbial biogeography among these interconnected lakes is still poorly understood. This study aims to unravel the mechanisms underlying the assembly process of abundant and rare bacteria among the interconnected lakes in the middle and lower Yangtze Plain. Our findings will provide a deeper understanding of the biogeographic patterns of rare and abundant bacterial taxa and their determined processes among interconnected aquatic habitats.Bai, Y., Subdiaga, E., Haderlein, S.B., Knicker, H., Kappler, A., 2020. High-pH and anoxic conditions during soil organic matter extraction increases its electron-exchange capacity and ability to stimulate microbial Fe(III) reduction by electron shuttling. Biogeosciences 17, 683-698. organic matter (SOM) is redox-active, can be microbially reduced, and transfers electrons in an abiotic reaction to Fe(III) minerals, thus serving as an electron shuttle. The standard procedure to isolate organic matter (OM) from soil involves the use of alkaline and acidic solutions and the separation of humic acids (HAs) and fulvic acids (FAs). This process potentially leads to unwanted changes in SOM chemical and redox properties. To determine the effects of extraction conditions on the redox and electron-shuttling properties of SOM extracts, we prepared HA, FA, and water-extractable organic matter (OM) extracts, applying either a combination of 0.1?M?NaOH and 6?M?HCl or ultrapure water (pH 7), from soil samples collected from the subsoil (0–15?cm, A horizon, pH 6.5–6.8) in Sch?nbuch forest, Baden-Württemberg, Germany. Both chemical extractions (NaOH∕HCl) and water extractions were done in separate experiments under either oxic or anoxic conditions. Furthermore, we applied the NaOH∕HCl treatment to a subsample of the water-extractable OM to separate HA and FA from the water-extractable OM. When comparing the amount of carbon extracted from soil by different extraction methods, we found that FA and HA chemically extracted from the soil can make up to 34?%–40?% of the soil organic carbon pool while the water-extractable OM only represents 0.41?%–2.74?% of the total soil organic carbon. The higher extraction efficiency of the chemical extraction is probably due to the deprotonation of carboxyl and phenol functional groups under high pH. Anoxic extraction conditions also led to more extracted carbon. For water-extractable OM, 7 times more C was extracted under anoxic conditions compared to oxic conditions. This difference was probably due to the occurrence of microbial reduction and dissolution of Fe(III) minerals in the soil during the anoxic water extraction and thus the concomitant release of Fe(III) mineral-bound organic matter. To compare the redox activity of different SOM extracts, the electron-exchange capacity (EEC) of all extracted HA, FA, and water-extractable OM was analyzed and our results showed that, under anoxic extraction conditions, the HA chemically isolated from the water-extractable OM had 2 times higher EEC values compare to the water-extractable OM itself, suggesting the potential formation of redox-active aromatic functional groups during the extraction with NaOH under anoxic conditions by condensation reactions between amino acids, aldehydes, and hydroxyl- and catechol-containing molecules. We also performed a microbial Fe(III) reduction experiment with all extracts and found that higher EEC of extracts in turn resulted in a higher stimulation of microbial Fe(III) mineral reduction by electron shuttling, i.e., faster initial Fe(III) reduction rates, and in most cases also in higher reduction extents. Our findings suggest that OM extracted with water at neutral pH should be used to better reflect environmental SOM redox processes in lab experiments and that potential artefacts of the chemical extraction method and anoxic extraction condition need to be considered when evaluating and comparing abiotic and microbial SOM redox processes.Baldermann, A., Abbasov, O.R., Bayramova, A., Abdullayev, E., Dietzel, M., 2020. New insights into fluid-rock interaction mechanisms at mud volcanoes: Implications for fluid origin and mud provenance at Bahar and Zenbil (Azerbaijan). Chemical Geology 537, 119479. the fluid-rock interactions occurring in terrestrial mud volcanoes is a premise for elucidating the (bio)geochemical processes involved in the release of aqueous fluids, mud and gases to the Earth's surface and atmosphere. For the first time, fluid and mud ejecta from the mud volcanoes at Bahar and Zenbil, located in eastern Azerbaijan and in the shallow coastal water of the South Caspian, were collected and analyzed for their mineralogical, textural and chemical composition. The expelled aqueous fluids have a Na-Cl-(HCO3) composition and are generated by the mixing of evaporitic Caspian seawater and ancient, low- to high-salinity, sedimentary pore water at temperatures of 32 ± 3 °C and 42 ± 5 °C for the mud volcanoes at Bahar and Zenbil, consistent with mud chambers to be situated in the Pliocene sediments at 2–3 km depth. These aqueous fluids are strongly enriched in major solutes, like Na, Cl, HCO3, B, Br, NH4 and DOC, as well as in some trace elements (As, Ba, Cu, Fe, Li, Sr and Zn), with concentrations up to 220 times that of the current Caspian seawater. This chemical concentration is caused mainly by a combination of (i) strong surface evaporation, ion exchange and adsorption-desorption involving smectite clays, redox-driven reactions and carbonate mineral precipitation at relatively shallow depths (not deeper than 4 km) as well as (ii) thermal breakdown of organic matter and methane production in deeply buried (4 to 7 km depth) organic-rich strata. Biogenic processes are only of minor importance. The mud is sourced from all horizons the mud volcanoes are cross-cutting, partly altered by diagenetic processes. Alteration is comprised of illitization of smectite during burial diagenesis (120 to 150 °C), replacements of feldspar by kaolinite and smectite, weathering of sulfide minerals, Fe-(oxy)hydroxide formation, as well as oxidation of methane and organic matter in the near sub-surface environments at low temperature (<40 °C). Our results indicate that fluid-mud mixtures expelled from mud volcanoes of the South Caspian basin can influence the chemistry of local surface and ground water as well as of (sub-)surface sediments.Bardají, D.K.R., Moretto, J.A.S., Furlan, J.P.R., Stehling, E.G., 2020. A mini-review: current advances in polyethylene biodegradation. World Journal of Microbiology and Biotechnology 36, 32. (PE) has been described as the most abundant plastic worldwide since it is used for the manufacture of disposable recipients, such as bottles and bags. Consequently, large quantities of PE have been accumulating in the environment causing serious ecological problems. Although there are numerous plastic disposal methods, each one has its own inherent limitations, but biodegradation seems to be the least harmful method to deal with this type of contaminant. This mini-review summarizes current advances in PE contamination, focusing on the recent findings related to the biodegradation of PE in different environmental conditions, presenting the microorganisms, genes, and enzymes involved, as well as the mechanisms of PE biodegradation. It also attempts to address the main and current biodegradation methods used to minimize the impacts of this polymer on the environment.Barron, M.G., Bejarano, A.C., Conmy, R.N., Sundaravadivelu, D., Meyer, P., 2020. Toxicity of oil spill response agents and crude oils to five aquatic test species. Marine Pollution Bulletin 153, 110954. majority of aquatic toxicity data for petroleum products has been limited to a few intensively studied crude oils and Corexit chemical dispersants, and acute toxicity testing in two standard estuarine test species: mysids (Americamysis bahia) and inland silversides (Menidia beryllina). This study compared the toxicity of two chemical dispersants commonly stock piled for spill response (Corexit EC9500A?, Finasol?OSR 52), three less studied agents (Accell Clean?DWD dispersant; CytoSol? surface washing agent; Gelco200? solidifier), and three crude oils differing in hydrocarbon composition (Dorado, Endicott, Alaska North Slope). Consistent with listings on the U.S. National Contingency Plan Product Schedule, general rank order toxicity was greatest for dispersants and lowest for the solidifier. The results indicate that freshwater species can have similar sensitivity as the conventionally tested mysids and silversides, and that the sea urchin (Arbacia punctulata) appears to be a reasonable addition to increase taxa diversity in standardized oil agent testing.Barton, L., Bingham, B., Sankaranarayanan, K., Monroe, C., Thomas, A., Kemp, B.M., 2020. The earliest farmers of northwest China exploited grain-fed pheasants not chickens. Scientific Reports 10, 2556. chickens (Gallus gallus domesticus) are globally ubiquitous today, the timing, location, and manner of their domestication is contentious. Until recently, archaeologists placed the origin of the domestic chicken in northern China, perhaps as early as 8,000 years ago. Such evidence however complicates our understanding of how the chicken was domesticated because its wild progenitor – the red jungle fowl (Gallus gallus) – lives in tropical ecosystems and does not exist in northern China today or in the recent past. Increasingly, multiple lines of evidence suggest that many of the archaeological bird remains underlying this northern origins hypothesis have been misidentified. Here we analyze the mitochondrial DNA of some of the earliest purported chickens from the Dadiwan site in northern China and conclude that they are pheasants (Phasianus colchicus). Curiously, stable isotope values from the same birds reveal that their diet was heavy in agricultural products (namely millet), meaning that they lived adjacent to or among some of the earliest farming communities in East Asia. We suggest that the exploitation of these baited birds was an important adaptation for early farmers in China’s arid north, and that management practices like these likely played a role in the domestication of animals – including the chicken – in similar contexts throughout the region.Basu, A., Wanner, C., Johnson, T.M., Lundstrom, C.C., Sanford, R.A., Sonnenthal, E.L., Boyanov, M.I., Kemner, K.M., 2020. Microbial U isotope fractionation depends on the U(VI) reduction rate. Environmental Science & Technology 54, 2295-2303. isotope fractionation may serve as an accurate proxy for U(VI) reduction in both modern and ancient environments, if the systematic controls on the magnitude of fractionation (ε) are known. We model the effect of U(VI) reduction kinetics on U isotopic fractionation during U(VI) reduction by a novel Shewanella isolate, Shewanella sp. (NR), in batch incubations. The measured ε values range from 0.96 ± 0.16 to 0.36 ± 0.07‰ and are strongly dependent on the U(VI) reduction rate. The ε decreases with increasing reduction rate constants normalized by cell density and initial U(VI). Reactive transport simulations suggest that the rate dependence of ε is due to a two-step process, where diffusive transport of U(VI) from the bulk solution across a boundary layer is followed by enzymatic reduction. Our results imply that the spatial decoupling of bulk U(VI) solution and enzymatic reduction should be taken into account for interpreting U isotope data from the environment.Bates, H.C., King, A.J., Donaldson Hanna, K.L., Bowles, N.E., Russell, S.S., 2020. Linking mineralogy and spectroscopy of highly aqueously altered CM and CI carbonaceous chondrites in preparation for primitive asteroid sample return. Meteoritics & Planetary Science 55, 77-101. highly hydrated, petrologic type 1 CM and CI carbonaceous chondrites likely derived from primitive, water‐rich asteroids, two of which are the targets for JAXA's Hayabusa2 and NASA's OSIRIS‐REx missions. We have collected visible and near‐infrared (VNIR) and mid infrared (MIR) reflectance spectra from well‐characterized CM1/2, CM1, and CI1 chondrites and identified trends related to their mineralogy and degree of secondary processing. The spectral slope between 0.65 and 1.05 μm decreases with increasing total phyllosilicate abundance and increasing magnetite abundance, both of which are associated with more extensive aqueous alteration. Furthermore, features at ~3 μm shift from centers near 2.80 μm in the intermediately altered CM1/2 chondrites to near 2.73 μm in the highly altered CM1 chondrites. The Christiansen features (CF) and the transparency features shift to shorter wavelengths as the phyllosilicate composition of the meteorites becomes more Mg‐rich, which occurs as aqueous alteration proceeds. Spectra also show a feature near 6 μm, which is related to the presence of phyllosilicates, but is not a reliable parameter for estimating the degree of aqueous alteration. The observed trends can be used to estimate the surface mineralogy and the degree of aqueous alteration in remote observations of asteroids. For example, (1) Ceres has a sharp feature near 2.72 μm, which is similar in both position and shape to the same feature in the spectra of the highly altered CM1 MIL 05137, suggesting abundant Mg‐rich phyllosilicates on the surface. Notably, both OSIRIS‐REx and Hayabusa2 have onboard instruments which cover the VNIR and MIR wavelength ranges, so the results presented here will help in corroborating initial results from Bennu and Ryugu.Bauersachs, T., Gugger, M., Schwark, L., 2020. Heterocyte glycolipid diketones: A novel type of biomarker in the N2-fixing heterocytous cyanobacterium Microchaete sp. Organic Geochemistry 141, 103976. heterocyte (heterocyst) glycolipid (HG) content of heterocytous (heterocystous) cyanobacteria can principally be separated into two different types. In the first type, the aglycone moiety attached to the sugar headgroup exclusively contains hydroxyl functionalities resulting in the formation of HG diols and HG triols. In the second type, one of the hydroxyl groups is replaced by a ketone functionality giving rise to HG keto-ols and HG keto-diols. In the N2-fixing heterocytous cyanobacterium Microchaete sp. PCC 7126 both types of HGs were dominant and consisted primarily of two structural isomers each of the HG28 diol and HG28 keto-ol. In addition to these well-characterized HGs, Microchaete sp. PCC 7126 also contained a yet undescribed type of HG that based on comparison of retention times, molecular weight and mass spectrometry consisted of a hexose headgroup attached to an aglycone moiety with 28 carbon atoms at which two instead of one ketone functionalities were attached. Hence, the novel HG structure was identified as HG28 diketone. This study thus provides further evidence for the large structural diversity of HGs, which allows chemotaxonomic profiling of heterocytous cyanobacteria and in turn studying the community Baumgartner, R.J., Caruso, S., Fiorentini, M.L., Van Kranendonk, M.J., Martin, L., Jeon, H., Pagès, A., Wacey, D., 2020. Sulfidization of 3.48?billion-year-old stromatolites of the Dresser Formation, Pilbara Craton: Constraints from in-situ sulfur isotope analysis of pyrite. Chemical Geology 538, 119488. study reports in–situ sulfur isotope analyses (32S, 33S, 34S and 36S) of pyrite in strongly sulfidized stromatolites from the ~3.48 billion–year–old Dresser Formation, Pilbara Craton, Australia. These data shed light on sulfur reservoirs and sulfide precipitation processes and provide clues for the contribution of sulfur–cycling microbes to sulfidization.Sulfur isotope signatures derived from mass dependent fractionation (MDF; monitored by δ34S) and mass independent fractionation (MIF; here Δ33S and Δ36S) of pyrite in stromatolites, and of microscopic pyrite within associated barite, allow for the identification of distinctive sulfur sources: i) magmatic–hydrothermal sulfide (H2S) with δ34S and Δ33S ~ 0%; ii) magmatic–hydrothermal sulfate (SO42?) with a MDF signature (MDF–SO42?; δ34S ~ 10‰ and Δ33S ~ 0‰; iii) photochemically–derived sulfate with a MIF signature (MIF–SO4; δ34S ~ ?6‰ and Δ33S ~ ?3.0‰); iv) photochemically–derived elemental sulfur (S0) with δ34S ? 0 and Δ33S ? 0‰.The sulfur isotope data suggest that sulfidization was largely driven by reduction of intermixed MDF–SO42? and MIF–SO42? (bulk signature of δ34S ~ 5‰ and Δ33S ~ ?1.4‰), and dilution of produced H2S (δ34S ~ ?12‰ and Δ33S ~ ?1.4‰) by native H2S in magmatic–hydrothermal fluids. The δ34S shifts (up to ~17‰) generated by sulfate reduction are consistent with both thermochemical reactions and influence of sulfate–cycling microbes, the latter which may have facilitated rapid pyrite precipitation and preservation of microbial remains that are entombed within the petrogenetically earliest pyrite generation of stromatolites.Collectively, our data are consistent with ancient stromatolite growth in proximity to shallow marine hydrothermal vents, where hydrothermal fluids contributed to sulfidization that may have been further influenced by sulfur–cycling microbes.Baur, F.U.M., Katz, B.J., Gaus, G., 2020. Gas sorption in source rocks – A short discussion. International Journal of Coal Geology 219, 103372. now the gas sorption capacity threshold from Pepper and Corvi (1995) of 20 mgGas/gTOC based on coal measurements was used widely to estimate gas expulsion from source rocks in a conventional setting and to provide estimates of sorbed gas quantities retained for unconventional resources. However, more recent gas sorption experiments on oil-prone source rocks show that an average of 35 mgGas/gTOC is more appropriate to use for non-terrigenous influenced source rocks and this value does not include sorption on minerals.The overall range of sorption capacity is very wide for non-terrigenous source rocks and ranges between 15 and 65 mgGas/gTOC (± 25 mgGas/gTOC). Hence, in the absence of Langmuir sorption measurements, the rock intrinsic uncertainty is much larger than the Langmuir pressure and temperature effects. Only when the uncertainty of rock sorption capacity is reduced to ±10 mgGas/gTOC pressure and temperature effects on source rock sorption capacity should be considered in the form of Langmuir calculations.Becker, C., Deeb, A.A., Teutenberg, T., Jochmann, M.A., Schmidt, T.C., 2020. Determination of liquid chromatography/flame ionization detection response factors for N-heterocycles, carboxylic acids, halogenated compounds, and others. Analytical and Bioanalytical Chemistry 412, 171-179. gas chromatography-flame ionization detection (GC/FID) studies are dealing with response behavior of analytes such as alcohols and alkanes. Studies in the field of liquid chromatography (LC)/FID mainly focused on volatile analytes. In contrast, studies on LC/FID by conveyor type interface covered high molecular weight non-volatile biopolymers, whereby no response factors were calculated. With this study, we fill the gap and present response factors of volatile and non-volatile analytes by LC/FID in terms of flow injection (FIA) measurements of the single compounds without an analytical separation by an LC column. In the present study, 56 different compounds such as carboxylic acids, N-heterocycles, halogenated acids, pharmaceuticals, and other compounds were investigated. In some cases, the obtained response factor data confirmed aspects known from GC/FID studies. But this study also disproves several assumptions done in previous response studies as well as the prediction models based upon the experimental data and literature. Especially the response factors and effective carbon number (ECN) values of structural isomers such as pyrazine, pyridazine, and pyrimidine are assumed to be equal in current response prediction models. Contradictory to these assumptions, the experimental response factors and ECN values of, e.g., the structural isomers pyrazine (RFExp = 0.59; ECNExp = 3.66), pyridazine (RFExp = 0.66; ECNExp = 4.1), and pyrimidine (RFExp = 0.63; ECNExp = 3.93) reveal different experimental response factors and ECN than proposed by response factor prediction models (RFExp = 0.64; ECNExp = 4).Bellanova, P., Frenken, M., Reicherter, K., Jaffe, B., Szczuciński, W., Schwarzbauer, J., 2020. Anthropogenic pollutants and biomarkers for the identification of 2011 Tohoku-oki tsunami deposits (Japan). Marine Geology 422, 106117. geochemistry is commonly used in environmental studies. In tsunami research, however, its applications are in their infancy and it is still rarely used. We present results for two types of organic geochemical markers, biomarkers and anthropogenic markers, present in deposits left by 2011 Tohoku-oki tsunami on the Sendai Plain, Japan. As the tsunami inundated the coastal lowland up to 4.85 km inland, sediments from various sources were eroded, transported and deposited. This led to the distribution of biomarkers from different sources across the Sendai Plain creating a unique geochemical signature in the tsunami deposits. The tsunami also caused destruction along the Sendai coastline, leading to the release of large quantities of environmental pollutants (e.g., fossil fuels, tarmac, pesticides, plastics, etc.) that were distributed across the inundated area. These anthropogenic markers, represented by three main compound groups (polycyclic aromatic hydrocarbons, pesticides, and halogenated compounds), were preserved in tsunami deposits (at least until 2013, prior to land clearing). Their concentrations differed significantly from the pre- and post-tsunami background contamination levels. Organic proxy concentrations can differ for sand and mud deposits due to various factors (e.g., preservation, dilution, microbial alteration). However, it can be concluded that anthropogenic markers and biomarkers have the potential to be a valuable proxy for future studies of recent tsunami deposits because of their high source specificity and relatively good preservation potential providing information about sediment sources and transport pathways (e.g., marine source, evidence of backwash).Belz, L., Schüller, I., Wehrmann, A., K?ster, J., Wilkes, H., 2020. The leaf wax biomarker record of a Namibian salt pan reveals enhanced summer rainfall during the Last Glacial-Interglacial Transition. Palaeogeography, Palaeoclimatology, Palaeoecology 543, 109561. continental geoarchives are rarely available in arid southern Africa. Therefore, palaeoclimate data in this area are still patchy and late Quaternary climate development is only poorly understood. In the western Kalahari, salt pans (playas, ephemeral lakes) are common and can feature quasi-continuous sedimentation. This study presents the first climate-related biomarker record using sediments from the Omongwa Pan, a Kalahari salt pan located in eastern Namibia. Our approach to reconstruct vegetation and hydrology focuses on biogeochemical bulk parameters and plant wax-derived lipid biomarkers (n-alkanes, n-alkanols, and fatty acids) and their compound-specific carbon and hydrogen isotopic compositions. The presented record reaches back to 27 ka. During the glacial, rather low δ2H values of n-alkanes and low sediment input exclude a strong influence of winter rainfall. n-Alkane and n-alkanol distributions and δ13C values of n-hentriacontane (n-C31) indicate a shift to a vegetation with a higher proportion of C4 plants at the end of the Last Glacial Maximum until the end of Heinrich Stadial I (ca. 18–14.8 ka), which we interpret to indicate an abrupt excursion to a short wetter period likely to be caused by a temporary southward shift of the Intertropical Convergence Zone. Shifts in δ2H values of n-C31 and plant wax parameters give evidence for changes to drier conditions during early Holocene. Comparison of this dataset with representative continental records from the region points to a major influence of summer rainfall at Omongwa Pan during the regarded time span and demonstrates the potential of southern African salt pans as archives for biomarker-based climate proxies.Bemani, A., Baghban, A., Mohammadi, A.H., Andersen, P.?., 2020. Estimation of adsorption capacity of CO2, CH4, and their binary mixtures in Quidam shale using LSSVM: Application in CO2 enhanced shale gas recovery and CO2 storage. Journal of Natural Gas Science and Engineering 76, 103204. dioxide enhanced shale gas recovery depends strongly on adsorption properties of carbon dioxide and methane. In this work, Least Squares Support Vector Machine (LSSVM) optimized by Particle Swarm Optimization, has been proposed to learn and then predict adsorption capacity of methane and carbon dioxide from pure and binary gas mixtures in Jurassic shale samples from the Qaidam Basin in China based on input parameters pressure, temperature, gas composition and TOC. A literature dataset of 348 points was applied to train and validate the model. The predicted values were compared with the experimental data by statistical and graphical approaches. The coefficients of determination of carbon dioxide adsorption were calculated to 0.9990 and 0.9982 for training and validation datasets, respectively. For CH4 the numbers are 0.9980 and 0.9966. The model was extrapolating reasonable trends beyond measurement ranges. More extensive datasets are needed to properly parameterize the role of shale properties.Benoit, S.L., Maier, R.J., Sawers, R.G., Greening, C., 2020. Molecular hydrogen metabolism: A widespread trait of pathogenic bacteria and protists. Microbiology and Molecular Biology Reviews 84, e00092-19. microorganisms use various mechanisms to conserve energy in host tissues and environmental reservoirs. One widespread but often overlooked means of energy conservation is through the consumption or production of molecular hydrogen (H2). Here, we comprehensively review the distribution, biochemistry, and physiology of H2 metabolism in pathogens. Over 200 pathogens and pathobionts carry genes for hydrogenases, the enzymes responsible for H2 oxidation and/or production. Furthermore, at least 46 of these species have been experimentally shown to consume or produce H2. Several major human pathogens use the large amounts of H2 produced by colonic microbiota as an energy source for aerobic or anaerobic respiration. This process has been shown to be critical for growth and virulence of the gastrointestinal bacteria Salmonella enterica serovar Typhimurium, Campylobacter jejuni, Campylobacter concisus, and Helicobacter pylori (including carcinogenic strains). H2 oxidation is generally a facultative trait controlled by central regulators in response to energy and oxidant availability. Other bacterial and protist pathogens produce H2 as a diffusible end product of fermentation processes. These include facultative anaerobes such as Escherichia coli, S. Typhimurium, and Giardia intestinalis, which persist by fermentation when limited for respiratory electron acceptors, as well as obligate anaerobes, such as Clostridium perfringens, Clostridioides difficile, and Trichomonas vaginalis, that produce large amounts of H2 during growth. Overall, there is a rich literature on hydrogenases in growth, survival, and virulence in some pathogens. However, we lack a detailed understanding of H2 metabolism in most pathogens, especially obligately anaerobic bacteria, as well as a holistic understanding of gastrointestinal H2 transactions overall. Based on these findings, we also evaluate H2 metabolism as a possible target for drug development or other therapies.Berenshtein, I., Paris, C.B., Perlin, N., Alloy, M.M., Joye, S.B., Murawski, S., 2020. Invisible oil beyond the Deepwater Horizon satellite footprint. Science Advances 6, eaaw8863. oil spills are catastrophic events that immensely affect the environment and society, yet determining their spatial extent is a highly complex task. During the Deepwater Horizon (DWH) blowout, ~149,000 km2 of the Gulf of Mexico (GoM) was covered by oil slicks and vast areas of the Gulf were closed for fishing. Yet, the satellite footprint does not necessarily capture the entire oil spill extent. Here, we use in situ observations and oil spill transport modeling to examine the full extent of the DWH spill, focusing on toxic-to-biota (i.e., marine organisms) oil concentration ranges. We demonstrate that large areas of the GoM were exposed to invisible and toxic oil that extended beyond the boundaries of the satellite footprint and the fishery closures. With a global increase in petroleum production–related activities, a careful assessment of oil spills’ full extent is necessary to maximize environmental and public safety.Bian, B., Bajracharya, S., Xu, J., Pant, D., Saikaly, P.E., 2020. Microbial electrosynthesis from CO2: Challenges, opportunities and perspectives in the context of circular bioeconomy. Bioresource Technology 302, 122863. CO2 into organic products through microbial electrosynthesis (MES) is attractive from the perspective of circular bioeconomy. However, several challenges need to be addressed before scaling-up MES systems. In this review, recent advances in electrode materials, microbe-catalyzed CO2 reduction and MES energy consumption are discussed in detail. Anode materials are briefly reviewed first, with several strategies proposed to reduce the energy input for electron generation and enhance MES bioeconomy. This was followed by discussions on MES cathode materials and configurations for enhanced chemolithoautotroph growth and CO2 reduction. Various chemolithoautotrophs, effective for CO2 reduction and diverse bioproduct formation, on MES cathode were also discussed. Finally, research efforts on developing cost-effective process for bioproduct extraction from MES are presented. Future perspectives to improve product formation and reduce energy cost are discussed to realize the application of the MES as a chemical production platform in the context of building a circular economy.Bickle, M.J., Stevenson, E.I., Haese, R.R., 2020. Sr-isotopic ratios trace mixing and dispersion in CO2 push-pull injection experiments at the CO2CRC Otway Research Facility, Australia. Chemical Geology 538, 119489. of 87Sr/86Sr ratios and modelling of formation water, injection water and produced water compositions from the CO2CRC Otway Research Facility in Victoria, Australia are used to test tracer behaviour and response in push-pull experiments. Such experiments are an essential pre-requisite to understanding the controls imposed by reservoir heterogeneities on CO2 dissolution rates which may be an important stabilising mechanism for geological carbon storage. The experiments (Otway stage 2B extension in 2014) comprised two sequential tests in which ~100 t of CO2-saturated water was injected with combinations of Sr and Br or Li and Fluorescein tracers, each injection being followed by two staged extractions of ~10 t and a final extraction of ~50 t all spaced at ~10 day intervals. Analysis of the 87Sr/86Sr ratios of the produced fluids from the first injection, spiked with SrCl2 and NaBr, is consistent with Sr behaving conservatively. This contrasts with previous interpretations in which Br was argued to have behaved conservatively while Sr, which dilutes ~three times as fast as Br, was thought to be lost to a mineral phase. Such Sr-loss cannot explain the evolution of 87Sr/86Sr ratios. The analysis of 87Sr/86Sr ratios in the waters produced after the second injection episode, spiked with LiCl and Fluorescein tracers, allows calculation of the fractions of the formation waters and the injection waters from both tests 1 and 2. The Sr, Li and SO4 tracers (the later formed by oxidation of formation sulphide) all indicate similar rates of dilution that is consistent with conservative behaviour. The results of the two injection episodes with spaced extractions are compared with two subsequent push-pull injections in which the produced waters, spiked with methanol, were extracted continuously. These continuous extraction experiments exhibited significantly less dilution over the same range of produced to injected water volumes (up to only ~0.6) than the earlier experiments with spaced extractions. This implies that some process related to the pauses in extraction enhances mixing of injected and formation waters. Achieving the objective of using push-pull experiments to assess reservoir heterogeneities and CO2 dissolution rates will require better assessment of the various tracers to establish which behave conservatively followed a proper understanding of the causes of the variations in mixing as fluids are extracted from the formations.Bochet, O., Bethencourt, L., Dufresne, A., Farasin, J., Pédrot, M., Labasque, T., Chatton, E., Lavenant, N., Petton, C., Abbott, B.W., Aquilina, L., Le Borgne, T., 2020. Iron-oxidizer hotspots formed by intermittent oxic–anoxic fluid mixing in fractured rocks. Nature Geoscience 13, 149-155. environments host most of the fresh water on Earth as well as diverse microorganisms that may constitute a significant part of the biosphere. However, the dynamics and spatial distribution of subsurface microorganisms and their response to hydrological processes are poorly understood. Here we used chemical and metagenomic analyses of groundwater in a fractured rock aquifer in western France to determine the role of fractures in the formation of deep microbial hotspots in the subsurface. The majority of fractures, sampled in a 130-m-deep borehole, were anoxic, but a fracture carrying oxic groundwater was detected at 54-m depth, associated with a fivefold increase in the abundance of iron-oxidizing bacteria. We developed a mechanistic model of fluid flow and mixing in fractures and found that such microbial hotspots are sustained by the mixing of fluids with contrasting redox chemistries at intersections of fractures. The model predicts that metre-scale changes in near-surface water table levels cause intermittent oxygen delivery through deep fractures, which can extend the depth of the habitable zone for iron-oxidizing bacteria hundreds of metres into the subsurface. Given that fractures are ubiquitous at multiple scales in the subsurface, such deep microbial hotspots may substantially influence microbial communities and their effect on Earth’s biogeochemical cycles.Bodmer, P., Wilkinson, J., Lorke, A., 2020. Sediment properties drive spatial variability of potential methane production and oxidation in small streams. Journal of Geophysical Research: Biogeosciences 125, e2019JG005213.: Emissions of the potent greenhouse gas methane (CH4) from streams and rivers are a significant component of global freshwater methane emissions. The distribution of CH4 production and oxidation within stream sections and in vertical sediment profiles is not well understood, and the environmental controls on CH4 production and emission in such systems create a significant challenge for assessing larger‐scale dynamics. Here we investigate factors driving the spatial variability of sediment potential methane production (PMP) and potential methane oxidation (PMO) in a temperate stream network in Germany. PMP was highly variable, ranging from 5 × 10?4 to 28.58 μg CH4 gDW?1 d?1 and PMO ranged from 0.43 μg CH4 gDW?1 d?1 to 14.41 μg CH4 gDW?1 d?1. Important drivers of spatial variability of PMP and PMO in the sediments of the stream main‐stem were related to fine sediment fraction and organic carbon content. At smaller spatial scale, that is, in a sub‐catchment stream section, the drivers were more complex and included sediment nitrogen and organic carbon content, as well as porewater dissolved organic carbon, dissolved organic matter quality, and metal concentrations. As with reservoirs and impounded rivers, fine sediment deposition and organic carbon content were found to be key controls on the spatial variability of CH4 production and oxidation. These findings enhance our understanding of CH4 dynamics, improve the potential for identifying CH4 production hotspots in small streams, and provide a potential means for upscaling emission rates in larger‐scale assessments.Plain Language Summary: Globally, streams and rivers emit a significant amount of the highly potent greenhouse gas methane. The methane emitted from streams is mainly produced in sediments. The distribution of production and consumption in stream sections and sediment profiles is not well understood, which creates a significant challenge for estimating, for example, regional methane emissions from streams and rivers. We investigated possible factors controlling the variability from site to site and different depths of methane production and consumption in sediments of a stream network in south‐west Germany. Sediment properties, the amount of fine sediment and organic carbon content, were key drivers of this variability in the main stream. In a smaller side arm of the main stream, the drivers were more complex, including nitrogen and organic carbon content of the sediment, but also porewater dissolved organic carbon, dissolved organic matter quality, and metals. As for reservoirs and dammed rivers, the accumulation of fine sediments and organic carbon content was found to be key controls of sediment methane production and consumption. These findings enhance our understanding of methane dynamics, improve the potential for identifying methane production hotspots in small streams, and provide a potential means for upscaling emission rates in larger‐scale assessments.Bodor, A., Bounedjoum, N., Vincze, G.E., Erdeiné Kis, ?., Laczi, K., Bende, G., Szilágyi, ?., Kovács, T., Perei, K., Rákhely, G., 2020. Challenges of unculturable bacteria: environmental perspectives. Reviews in Environmental Science and Bio/Technology 19, 1-22. biotechnology offers several promising techniques for the rehabilitation of polluted environments. The modern industrialized world presents novel challenges to the environmental sciences, requiring a constant development and deepening of knowledge to enable the characterization of novel pollutants and a better understanding of the bioremediation strategies as well as their limiting factors. The success of bioremediation depends heavily on the survival and activities of indigenous microbial communities and their interaction with introduced microorganisms. The majority of natural microbiomes remain uncultivated; therefore, further investigations focusing on their intrinsic functions in ecosystems are needed. In this review, we aimed to provide (a) a comprehensive overview of the presence of viable but nonculturable bacteria and yet-to-be-cultivated cells in nature and their diverse awakening strategies in response to, among other factors, signalling extracellular metabolites (autoinducers, resuscitation promoting factors, and siderophores); (b) an outline of the trends in isolating unculturable bacteria; and (c) the potential applications of these hidden players in rehabilitation processes.Bonaglia, S., Broman, E., Brindefalk, B., Hedlund, E., Hjorth, T., Rolff, C., Nascimento, F.J.A., Udekwu, K., Gunnarsson, J.S., 2020. Activated carbon stimulates microbial diversity and PAH biodegradation under anaerobic conditions in oil-polluted sediments. Chemosphere 248, 126023. by microorganisms is a useful tool that helps alleviating hydrocarbon pollution in nature. Microbes are more efficient in degradation under aerobic than anaerobic conditions, but the majority of sediment by volume is generally anoxic. Incubation experiments were conducted to study the biodegradation potential of naphthalene—a common polycyclic aromatic hydrocarbon (PAH)—and the diversity of microbial communities in presence/absence of activated carbon (AC) under aerobic/anaerobic conditions. Radio-respirometry experiments with endogenous microorganisms indicated that degradation of naphthalene was strongly stimulated (96%) by the AC addition under anaerobic conditions. In aerobic conditions, however, AC had no effects on naphthalene biodegradation. Bioaugmentation tests with cultured microbial populations grown on naphthalene showed that AC further stimulated (92%) naphthalene degradation in anoxia. Analysis of the 16S rRNA gene sequences implied that sediment amendment with AC increased microbial community diversity and changed community structure. Moreover, the relative abundance of Geobacter, Thiobacillus, Sulfuricurvum, and methanogenic archaea increased sharply after amendment with AC under anaerobic conditions. These results may be explained by the fact that AC particles promoted direct interspecies electron transfer (DIET) between microorganisms involved in PAH degradation pathways. We suggest that important ecosystem functions mediated by microbes—such as hydrocarbon degradation—can be induced and that AC enrichment strategies can be exploited for facilitating bioremediation of anoxic oil-contaminated sediments and soils.Bonaiuti, S., Blodau, C., Knorr, K.-H., 2020. Evaluating biogeochemical indicators of methanogenic conditions and thermodynamic constraints in peat. Applied Geochemistry 114, 104471. of organic matter in deep peat deposits has already been experimentally demostrated to slow down or even inhibit anaerobic decomposition due to lack of diffusive transport and end-product accumulation. However, so far little is known about potential biogeochemical or thermodynamic indicators for the observed inhibition of further decomposition. For example, theoretical energy yields for methanogenesis, hydrogen partial pressures, stable isotope fractionation factors between CO2 and CH4, and electrochemical properties of dissolved organic matter have been proposed as thermodyamic indicators for such inhibition. To test the applicability and explanatory power of these indicators to identify conditions inhibiting organic matter decomposition, we incubated homogenized ombrotrophic peat for 300 days at 20 °C under diffusive flux conditions as control, and compared the observed effects to a treatment with vertical advective transport by water circulation and to a treatment in which both the unsaturated and water-saturated zone of the peat profile were kept anoxic. Results of energy yields of acetoclastic and hydrogenotrophic methanogenesis were compared to hydrogen partial pressures, to 13C isotope fractionation factors and to redox properties of dissolved organic matter as obtained from mediated electrochemical oxidation and reduction. While CO2 and CH4 production slowed substantially in the deep peat profile, a concomitant decrease of Gibs free energy yields available to hydrogenotrophic and acetoclastic methanogensis and hydrogen and acetate concentrations over time supported a thermodynamic constraint on methanogenesis. Although, energy yields for the hydrogenotrophic pathway were close to or below the theoretical energy minimum levels already after 15 days. Transiently elevated H2 concentrations, not related to actual methanogenesis rates were observed for about 150–225 days. Thereafter, hydrogen concentrations diminished to levels below thresholds to thermodynamically support ongoing methanogenesis. Thus even on incubation timescales of 150–225 days, steady-state hydrogen concentrations as would be expected from thermodynamic considerations did not adjust on the bulk scale of observation. Gibbs free energy estimates for methanogenesis based on hydrogen partial pressures were consequently biased and did not reach the minimum required threshold despite ovious net CH4 production. Ratios between electron accepting (EAC) and donating (EDC) capacity of dissolved organic matter, however, turned out to provide suitable indicators of predominant redox conditions along gradients, stabilizing at low values upon onset of methanogenesis. Thus, our study demonstrated that the thermodynamically driven slow down of decomposition in deep peat deposits, preventing the peat to decompose further, cannot be easily identified based on a single indicator. However, constant and high concentrations of decomposition end-products, indicating zero net turnover and low energy yields, and constantly low EAC/EDC ratios, indicating no further availability of terminal electron acceptors, seem to be characteristic of the onset of conditions inhibiting further significant decomposition of peat.Bone, S.E., Cliff, J., Weaver, K., Takacs, C.J., Roycroft, S., Fendorf, S., Bargar, J.R., 2020. Complexation by organic matter controls uranium mobility in anoxic sediments. Environmental Science & Technology 54, 1493-1502. contamination threatens the availability of safe and clean drinking water globally. This toxic element occurs both naturally and as a result of mining and ore-processing in alluvial sediments, where it accumulates as tetravalent U [U(IV)], a form once considered largely immobile. Changing hydrologic and geochemical conditions cause U to be released into groundwater. Knowledge of the chemical form(s) of U(IV) is essential to understand the release mechanism, yet the relevant U(IV) species are poorly characterized. There is growing belief that natural organic matter (OM) binds U(IV) and mediates its fate in the subsurface. In this work, we combined nanoscale imaging (nano secondary ion mass spectrometry and scanning transmission X-ray microscopy) with a density-based fractionation approach to physically and microscopically isolate organic and mineral matter from alluvial sediments contaminated with uranium. We identified two populations of U (dominantly +IV) in anoxic sediments. Uranium was retained on OM and adsorbed to particulate organic carbon, comprising both microbial and plant material. Surprisingly, U was also adsorbed to clay minerals and OM-coated clay minerals. The dominance of OM-associated U provides a framework to understand U mobility in the shallow subsurface, and, in particular, emphasizes roles for desorption and colloid formation in its mobilization.Bosco-Santos, A., Gilhooly, W.P., Fouskas, F., Fabricio-Silva, W., Oliveira, E.P., 2020. Euxinia in the Neoarchean: The starting point for early oxygenation in a Brazilian Craton. Precambrian Research 341, 105655. evidence for local redox transitions is observed 300 Ma years prior to the Great Oxygenation Event (GOE ca. 2400 Ma) and suggests evolving environmental conditions through a continuous sequence where euxinia (anoxic and sulfidic) preceded the expansion of more oxidizing conditions. Based on multiproxy data such as iron speciation (FePy/FeHR > 0.7) and Mo enrichments (varying from 3 to 64), we present one of the oldest records of euxinia from the Archean Pitangui greenstone belt (~2700 Ma), Minas Gerais, Brazil. The sulfur isotopic composition of sedimentary sulfides indicates early inputs of sulfate from oxidative weathering and an attenuation of sulfur mass independent fractionation that combined with other geochemical signatures (FeHR/FeT, Ce anomalies and rare earth element fractionation) is consistent with the expansion of oxygen availability, and suggests localized oxic conditions before the GOE.Bourtsoukidis, E., Pozzer, A., Sattler, T., Matthaios, V.N., Ernle, L., Edtbauer, A., Fischer, H., K?nemann, T., Osipov, S., Paris, J.D., Pfannerstill, E.Y., St?nner, C., Tadic, I., Walter, D., Wang, N., Lelieveld, J., Williams, J., 2020. The Red Sea Deep Water is a potent source of atmospheric ethane and propane. Nature Communications 11, 447. hydrocarbons (NMHCs) such as ethane and propane are significant atmospheric pollutants and precursors of tropospheric ozone, while the Middle East is a global emission hotspot due to? extensive oil and gas production. Here we compare in?situ hydrocarbon measurements, performed around the Arabian Peninsula, with global model simulations that include current emission inventories (EDGAR)?and state-of-the-art atmospheric circulation and chemistry mechanisms (EMAC model). While measurements of high mixing ratios over the Arabian Gulf are adequately simulated, strong underprediction by the model was found over the northern Red Sea. By examining the individual sources in the model and by utilizing air mass back-trajectory investigations and Positive Matrix Factorization (PMF) analysis, we deduce that Red Sea Deep Water (RSDW) is an unexpected, potent source of atmospheric NMHCs. This overlooked underwater source is comparable with total anthropogenic emissions from entire Middle Eastern countries, and significantly impacts the regional atmospheric chemistry.Bowman, A.P., Blakney, G.T., Hendrickson, C.L., Ellis, S.R., Heeren, R.M.A., Smith, D.F., 2020. Ultra-high mass resolving power, mass accuracy, and dynamic range MALDI mass spectrometry imaging by 21-T FT-ICR MS. Analytical Chemistry 92, 3133-3142. characterization of complex biological surfaces by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) requires instrumentation that is capable of high mass resolving power, mass accuracy, and dynamic range. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) offers the highest mass spectral performance for MALDI MSI experiments, and often reveals molecular features that are unresolved on lower performance instrumentation. Higher magnetic field strength improves all performance characteristics of FT-ICR; mass resolving power improves linearly, while mass accuracy and dynamic range improve quadratically with magnetic field strength. Here, MALDI MSI at 21T is demonstrated for the first time: mass resolving power in excess of 1?600?000 (at m/z 400), root-mean-square mass measurement accuracy below 100 ppb, and dynamic range per pixel over 500:1 were obtained from the direct analysis of biological tissue sections. Molecular features with m/z differences as small as 1.79 mDa were resolved and identified with high mass accuracy. These features allow for the separation and identification of lipids to the underlying structures of tissues. The unique molecular detail, accuracy, sensitivity, and dynamic range combined in a 21T MALDI FT-ICR MSI experiment enable researchers to visualize molecular structures in complex tissues that have remained hidden until now. The instrument described allows for future innovative, such as high-end studies to unravel the complexity of biological, geological, and engineered organic material surfaces with an unsurpassed detail.Boyer, G.M., Schubotz, F., Summons, R.E., Woods, J., Shock, E.L., 2020. Carbon oxidation state in microbial polar lipids suggests adaptation to hot spring temperature and redox gradients. Frontiers in Microbiology 11, 229. doi: 10.3389/fmicb.2020.00229. influence of oxidation-reduction (redox) potential on the expression of biomolecules is a topic of ongoing exploration in geobiology. In this study, we investigate the novel possibility that structures and compositions of lipids produced by microbial communities are sensitive to environmental redox conditions. We extracted lipids from microbial biomass collected along the thermal and redox gradients of four alkaline hot springs in Yellowstone National Park (YNP) and investigated patterns in the average oxidation state of carbon (ZC), a metric calculated from the chemical formulae of lipid structures. Carbon in intact polar lipids (IPLs) and their alkyl chains becomes more oxidized (higher ZC) with increasing distance from each of the four hot spring sources. This coincides with decreased water temperature and increased concentrations of oxidized inorganic solutes, such as dissolved oxygen, sulfate, and nitrate. Carbon in IPLs is most reduced (lowest ZC) in the hot, reduced conditions upstream, with abundance-weighted ZC values between ?1.68 and ?1.56. These values increase gradually downstream to around ?1.36 to ?1.33 in microbial communities living between 29.0 and 38.1°C. This near-linear increase in ZC can be attributed to a shift from ether-linked to ester-linked alkyl chains, a decrease in average aliphatic carbons per chain (nC), an increase in average degree of unsaturation per chain (nUnsat), and increased cyclization in tetraether lipids. The ZC of lipid headgroups and backbones did not change significantly downstream. Expression of lipids with relatively reduced carbon under reduced conditions and oxidized lipids under oxidized conditions may indicate microbial adaptation across environmental gradients in temperature and electron donor/acceptor supply.Brachmann, C.G., Hernandez-Ramirez, G., Hik, D.S., 2020. CH4 uptake along a successional gradient in temperate alpine soils. Biogeochemistry 147, 109-123. effects of climate change appear to be amplified in mountains compared with lowland areas, with rapid changes in plant community composition, soil properties, and increased substrate for biological development following retreat of glaciers. Associated soil gaseous fluxes in alpine ecosystems contribute to the global balance of greenhouse gases, but methane and carbon dioxide soil fluxes and their controls are not well known. We used a dynamic closed-chamber method to measure methane and carbon dioxide fluxes along a successional gradient during the peak growing season in the North Selkirk Mountains, British Columbia, Canada. Soil physico-chemical properties, vegetation cover, and topographic variables were quantified to determine mechanisms influencing these fluxes. Mean methane uptake ranged from ??155 ?g CH4-C m??2 h?1 in well vegetated sites to zero in recently deglaciated terrain. Soil total carbon (TC) and water content were the primary drivers of methane uptake. Sites with TC greater than 4% and moisture below 0.22 water fraction by volume (w.f.v) corresponded to the strongest methane sinks. Increased vegetation cover and relatively drier soil conditions, anticipated with future climate change, suggest that methane uptake may increase in these alpine ecosystems.Brantson, E.T., Ju, B., Opoku Appau, P., Akwensi, P.H., Peprah, G.A., Liu, N., Aphu, E.S., Annan Boah, E., Aidoo Borsah, A., 2020. Development of hybrid low salinity water polymer flooding numerical reservoir simulator and smart proxy model for chemical enhanced oil recovery (CEOR). Journal of Petroleum Science and Engineering 187, 106751. MATLAB based finite volume CEOR simulator was developed for modeling the recovery of oil by low salinity water polymer flooding (LSWPF) in a proposed geostatistical method of generating porous media. Firstly, this paper coupled ion exchange, wettability and fluid flow transport models to the proposed heterogeneous porous media to investigate LSWPF oil recovery performance. Secondly, for the first time, a new hybrid smart proxy model of particle swarm optimization artificial neural network (PSO-ANN) recovery factor (RF) correlation was derived for LSWPF oil recovery performance using the extracted weights and biases. The proposed porous media as well as stochastic multi-fractal random field and circulant embedding method (CEM) permeability field realizations did not exhibit artificial banding unlike turning bands method (TBM) realizations when compared. A fast convergence pre-conditioner solution technique of algebraic multigrid (AMG) linear solver combined with an acceleration method of biconjugate gradients stabilized method (BI-CGSTAB) was used to solve the fully implicit system of coupled linearized equations. The simulator was validated with PHREEQC geochemical package and a secondary LSWPF coreflood test with outstanding history match. Numerical 2D examples study in this paper revealed the synergetic effects of LSWPF and high salinity water polymer flooding (HSWPF) with higher oil RFs of 39% and 31%, respectively than the standalone LSWF of 23% and normal waterflood of 11% for 50 days of production. The optimal architecture of the PSO-ANN RF model is 7 inputs, 3 hidden neurons and 1 output. Also, the PSO-ANN RF model predictions were compared to the LSWPF numerical simulation results with the former remarkably having reduced computational time in seconds with training and blind testing errors <1% average absolute percentage error (AAPE) for various permeability field realizations investigated. Finally, the PSO-ANN RF model will serve as a fast-alternative reservoir management and planning tool to supplement the high-fidelity LSWPF CEOR simulator developed to minimize computational overheads, risks and uncertainties in oil recovery performance modeling.Bretherton, L., Hillhouse, J., Kamalanathan, M., Finkel, Z.V., Irwin, A.J., Quigg, A., 2020. Trait-dependent variability of the response of marine phytoplankton to oil and dispersant exposure. Marine Pollution Bulletin 153, 110906. Deepwater Horizon oil spill released millions of barrels of crude oil into the Gulf of Mexico, and saw widespread use of the chemical dispersant Corexit. We assessed the role of traits, such as cell size, cell wall, motility, and mixotrophy on the growth and photosynthetic response of 15 phytoplankton taxa to oil and Corexit. We collected growth and photosynthetic data on five algal cultures. These responses could be separated into resistant (Tetraselmis astigmatica, Ochromonas sp., Heterocapsa pygmaea) and sensitive (Micromonas pusilla, Prorocentrum minimum). We combined this data with 10 species previously studied and found that cell size is most important in determining the biomass response to oil, whereas motility/mixotrophy is more important in the dispersed oil. Our analysis accounted for a third of the variance observed, so further work is needed to identify other factors that contribute to oil resistance.Brewer, A., Harrold, Z., Chang, E., Gorman-Lewis, D., Teng, F.-Z., 2020. Magnesium isotope fractionation during microbially enhanced forsterite dissolution. Geobiology 18, 225-236. subtilis endospore‐mediated forsterite dissolution experiments were performed to assess the effects of cell surface reactivity on Mg isotope fractionation during chemical weathering. Endospores present a unique opportunity to study the isolated impact of cell surface reactivity because they exhibit extremely low metabolic activity. In abiotic control assays, 24Mg was preferentially released into solution during forsterite dissolution, producing an isotopically light liquid phase (δ26Mg = ?0.39 ± 0.06 to ?0.26 ± 0.09‰) relative to the initial mineral composition (δ26Mg = ?0.24 ± 0.03‰). The presence of endospores did not have an apparent effect on Mg isotope fractionation associated with the release of Mg from the solid into the aqueous phase. However, the endospore surfaces preferentially adsorbed 24Mg from the dissolution products, which resulted in relatively heavy aqueous Mg isotope compositions. These aqueous Mg isotope compositions increased proportional to the fraction of dissolved Mg that was adsorbed, with the highest measured δ26Mg (?0.08 ± 0.07‰) corresponding to the highest degree of adsorption (~76%). The Mg isotope composition of the adsorbed fraction was correspondingly light, at an average δ26Mg of ?0.49‰. Secondary mineral precipitation and Mg adsorption onto secondary minerals had a minimal effect on Mg isotopes at these experimental conditions. Results demonstrate the isolated effects of cell surface reactivity on Mg isotope fractionation separate from other common biological processes, such as metabolism and organic acid production. With further study, Mg isotopes could be used to elucidate the role of the biosphere on Mg cycling in the environment.Brewer, T.E., Aronson, E.L., Arogyaswamy, K., Billings, S.A., Botthoff, J.K., Campbell, A.N., Dove, N.C., Fairbanks, D., Gallery, R.E., Hart, S.C., Kaye, J., King, G., Logan, G., Lohse, K.A., Maltz, M.R., Mayorga, E., O’Neill, C., Owens, S.M., Packman, A., Pett-Ridge, J., Plante, A.F., Richter, D.D., Silver, W.L., Yang, W.H., Fierer, N., 2019. Ecological and genomic attributes of novel bacterial taxa that thrive in subsurface soil horizons. mBio 10, e01318-19.: While most bacterial and archaeal taxa living in surface soils remain undescribed, this problem is exacerbated in deeper soils, owing to the unique oligotrophic conditions found in the subsurface. Additionally, previous studies of soil microbiomes have focused almost exclusively on surface soils, even though the microbes living in deeper soils also play critical roles in a wide range of biogeochemical processes. We examined soils collected from 20 distinct profiles across the United States to characterize the bacterial and archaeal communities that live in subsurface soils and to determine whether there are consistent changes in soil microbial communities with depth across a wide range of soil and environmental conditions. We found that bacterial and archaeal diversity generally decreased with depth, as did the degree of similarity of microbial communities to those found in surface horizons. We observed five phyla that consistently increased in relative abundance with depth across our soil profiles: Chloroflexi, Nitrospirae, Euryarchaeota, and candidate phyla GAL15 and Dormibacteraeota (formerly AD3). Leveraging the unusually high abundance of Dormibacteraeota at depth, we assembled genomes representative of this candidate phylum and identified traits that are likely to be beneficial in low-nutrient environments, including the synthesis and storage of carbohydrates, the potential to use carbon monoxide (CO) as a supplemental energy source, and the ability to form spores. Together these attributes likely allow members of the candidate phylum Dormibacteraeota to flourish in deeper soils and provide insight into the survival and growth strategies employed by the microbes that thrive in oligotrophic soil environments.Importance: Soil profiles are rarely homogeneous. Resource availability and microbial abundances typically decrease with soil depth, but microbes found in deeper horizons are still important components of terrestrial ecosystems. By studying 20 soil profiles across the United States, we documented consistent changes in soil bacterial and archaeal communities with depth. Deeper soils harbored communities distinct from those of the more commonly studied surface horizons. Most notably, we found that the candidate phylum Dormibacteraeota (formerly AD3) was often dominant in subsurface soils, and we used genomes from uncultivated members of this group to identify why these taxa are able to thrive in such resource-limited environments. Simply digging deeper into soil can reveal a surprising number of novel microbes with unique adaptations to oligotrophic subsurface conditions.Briggs, N., Dall’Olmo, G., Claustre, H., 2020. Major role of particle fragmentation in regulating biological sequestration of CO2 by the oceans. Science 367, 791-793.: A critical driver of the ocean carbon cycle is the downward flux of sinking organic particles, which acts to lower the atmospheric carbon dioxide concentration. This downward flux is reduced by more than 70% in the mesopelagic zone (100 to 1000 meters of depth), but this loss cannot be fully accounted for by current measurements. For decades, it has been hypothesized that the missing loss could be explained by the fragmentation of large aggregates into small particles, although data to test this hypothesis have been lacking. In this work, using robotic observations, we quantified total mesopelagic fragmentation during 34 high-flux events across multiple ocean regions and found that fragmentation accounted for 49 ± 22% of the observed flux loss. Therefore, fragmentation may be the primary process controlling the sequestration of sinking organic carbon.Editor's summary: Breaking up is easy to do. Sinking particles transport carbon to the seafloor, where they are buried in sediments and either provide food for benthic organisms or sequester the carbon they contain. However, only ～30% of the maximum flux reaches depths of a kilometer. This loss cannot be fully accounted for by current measurements. Briggs et al. used data collected by robotic Biogeochemical-Argo floats to quantify total mesopelagic fragmentation and found that this process accounts for roughly half of the observed flux loss (see the Perspective by Nayak and Twardowski). Fragmentation is thus perhaps the most important process controlling the remineralization of sinking organic carbon.Brunswick, P., Shang, D., Frank, R.A., van Aggelen, G., Kim, M., Hewitt, L.M., 2020. Diagnostic ratio analysis: A new concept for the tracking of oil sands process-affected water naphthenic acids and other water-soluble organics in surface waters. Environmental Science & Technology 54, 2228-2243. diagnostic ratio forensics tool, similar to that recognized internationally for oil spill source identification, is proposed for use in conjunction with existing LC/QToF quantitative methodology for bitumen-derived water-soluble organics (WSOs). The concept recognizes that bitumen WSOs bear a chemical skeletal relationship to stearane and hopane oil biomarkers. The method uses response ratios for 50 selected WSOs compared between samples by their relative percent difference and adopted acceptance criteria. Oil sands process-affected water (OSPW) samples from different locations within a single tailings pond were shown to match, while those from different industrial sites did not. Acid extractable organic samples collected over 3 weeks from the same location within a single tailings pond matched with each other; as did temporal OSPW samples a year apart. Blind quality assurance samples of OSPW diluted in surface waters were positively identified to their corresponding OSPW source. No interferences were observed from surface waters, and there was no match between bitumen-influenced groundwater and OSPW samples, as expected for different sources. Proof of concept for OSPW source identification using diagnostic ratios was demonstrated, with anticipated application in the tracking of OSPW plumes in surface receiving waters, together with the potential for confirmation of source.Burato, J.S.d.S., Medina, D.A.V., de Toffoli, A.L., Maciel, E.V.S., Lan?as, F.M., 2020. Recent advances and trends in miniaturized sample preparation techniques. Journal of Separation Science 43, 202-225. in the area of sample preparation are significant and have been growing significantly in recent years. This initial step of the analysis is essential and must be carried out properly, consisting of a complicated procedure with multiple stages. Consequently, it corresponds to a potential source of errors and will determine, at the end of the process, either a satisfactory result or a fail. One of the advances in this field includes the miniaturization of extraction techniques based on the conventional sample preparation procedures such as liquid-liquid extraction and solid-phase extraction. These modern techniques have gained prominence in the face of traditional methods since they minimize the consumption of organic solvents and the sample volume. As another feature, it is possible to reuse the sorbents, and its coupling to chromatographic systems might be automated. The review will emphasize the main techniques based on liquid-phase microextraction, as well as those based upon the use of sorbents. The first group includes currently popular techniques such as single drop microextraction, hollow fiber liquid-phase microextraction, and dispersive liquid-liquid microextraction. In the second group, solid-phase microextraction techniques such as in-tube solid-phase microextraction, stir bar sorptive extraction, dispersive solid-phase extraction, dispersive micro solid-phase microextraction, and microextraction by packed sorbent are highlighted. These approaches, in common, aim the determination of analytes at low concentrations in complex matrices. This article describes some characteristics, recent advances, and trends on miniaturized sample preparation techniques, as well as their current applications in food, environmental, and bioanalysis fields.Burazer, N., ?ajnovi?, A., Vasi?, N., Ka?anin-Grubin, M., ?ivoti?, D., Mendon?a Filho, J.G., Vuli?, P., Jovan?i?evi?, B., 2020. Influence of paleoenvironmental conditions on distribution and relative abundance of saturated and aromatic hydrocarbons in sediments from the NW part of the Toplica basin, Serbia. Marine and Petroleum Geology 115, 104252. investigation of the relationship between paleoenvironmental conditions and distribution and relative abundance of specific saturated and aromatic hydrocarbons was the main objective of this study, thus marking the parameters, which were most sensitive to environmental changes. Insights on the type, generative potential, and maturity of organic matter (OM), as well as paleoclimate conditions, along with the reconstruction of depositional settings of the northwest part of the Toplica basin (Serbia), were provided. Organic petrographic, palynofacies, organic geochemical, mineralogical, and XRF analyses were carried out to investigate 40 sediment samples of the Prebreza and ?u?ale sedimentary units.Investigated samples were deposited in the saline and anoxic environment, under semi-arid to semi-humid/humid climate conditions, along with the constant inflow of volcanoclastic material. The predominance of δ-methyltrimethyltridecil chroman (δ-MTTC) within euxinic portions of the stratified water column was associated with an increase in salinity, which was noticed for sediments of the Prebreza unit. Sediments from this stratigraphic unit showed a higher contribution of algae precursor, whereas sediments of the ?u?ale unit suggested higher participation of microbiologically reworked OM.Most of the samples contained oil-prone kerogen type II. Maturity of the OM for sediments of the Prebreza unit ranged from immature to early-mature, while for samples of the ?u?ale unit varied from early-mature to mature stages. Distribution of hopane biomarkers typical for crude oil indicated that depth of 1 km was a boundary for the genesis of thermodynamic, more stable compounds.A significant portion of semifusinite was correlated with the paleofire event, which affected the distribution of n-alkanes. The high production of hydrocarbons was related to volcanic activity.Parameters, which proved to be highly susceptible at the stratigraphic boundary between the Prebreza and ?u?ale units, were C-value, S/H, α-MTTC, δ-MTTC, β-/γ-MTTC, and (1,3- + 1,6-)/(1,4 + 1,5-DMC), respectively.Bushnev, D.A., Burdel’naya, N.S., Valyaeva, O.V., 2020. С21 n?alkylbenzene and 1?n?alklylnaphthalene in oils: Isotope effect during cyclization/aromatization? Geochemistry International 58, 61-65. isotope composition was analyzed in С21 n?alkylbenzene and n?alklylnaphthalene from five Upper Devonian oils of the Timan–Pechora Basin. In spite of the variations in carbon isotope composition, the difference in δ13C between n?alkylbenzene and n?alklylnaphthalene is relatively constant and accounts for, on average, 2.7‰. It is generally accepted that these compounds were derived from a common source. Thus, the revealed carbon isotope fractionation is related to the cyclization and aromatization of aliphatic chain.Büsing, J., Buchner, D., Behrens, S., Haderlein, S.B., 2019. Deciphering the variability of stable isotope (C, Cl) fractionation of tetrachloroethene biotransformation by Desulfitobacterium strains carrying different reductive dehalogenases enzymes. Environmental Science & Technology 54, 1593-1602. isotope effects have been used successfully to prove and characterize organic contaminant transformation on various scales including field and laboratory studies. For tetrachloroethene (PCE) biotransformation, however, causes for the substantial variability of reported isotope enrichment factors (ε) are still not deciphered (εC = ?0.4 to ?19.0‰). Factors such as different reaction mechanisms and masking of isotope fractionation by either limited intracellular mass transfer or rate-limitations within the enzymatic multistep reaction are under discussion. This study evaluated the contribution of these factors to the magnitude of carbon and chlorine isotope fractionation of Desulfitobacterium strains harboring three different PCE-transforming enzymes (PCE-RdhA). Despite variable single element isotope fractionation (εC = ?5.0 to ?19.7‰; εCl= ?1.9 to ?6.3‰), similar slopes of dual element isotope plots (ΛC/Cl values of 2.4 ± 0.1 to 3.6 ± 0.1) suggest a common reaction mechanism for different PCE-RdhAs. Cell envelope properties of the Desulfitobacterium strains allowed to exclude masking effects due to PCE mass transfer limitation. Our results thus revealed that different rate-limiting steps (e.g., substrate channel diffusion) in the enzymatic multistep reactions of individual PCE-RdhAs rather than different reaction mechanisms determine the extent of PCE isotope fractionation in the Desulfitobacterium genus.Butturini, A., Herzsprung, P., Lechtenfeld, O.J., Venturi, S., Amalfitano, S., Vazquez, E., Pacini, N., Harper, D.M., Tassi, F., Fazi, S., 2020. Dissolved organic matter in a tropical saline-alkaline lake of the East African Rift Valley. Water Research 173, 115532. lakes of the East African Rift are known to have an extremely high primary production supporting a potent carbon cycle. To date, a full description of carbon pools in these lakes is still missing. More specifically, there is not detailed information on the quality of dissolved organic matter (DOM), the main carbon energy source for heterotrophs prokaryotes. We report the first exhaustive description of DOM molecular properties in the water column of a meromictic saline-alkaline lake of the East African Rift. DOM availability, fate and origin were studied either quantitatively, in terms of dissolved organic carbon (DOC) and nitrogen (DON) or qualitatively, in terms of optical properties (absorbance) and molecular characterization of solid-phase extracted DOM (SPE-DOM) through negative electrospray ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS). DOM availability was high (DOC ～ 8.1?mM in surface waters) and meromixis imprinted a severe quantitative and qualitative change on DOM pool. At the surface, DOM was rich in aliphatic and moderately in aromatic molecules and thus mirroring autochthonous microbial production together to photodegradation. At the bottom changes were extreme: DOC increased up to 5 times (up to 50?mM) and, molecular signature drifted to saturated, reduced and non-aromatic DOM suggesting intense microbial activity within organic sediments. At the chemocline, DOC was retained indicating that this interface is a highly reactive layer in terms of DOM processing. These findings underline that saline-alkaline lakes of the East African Rift are carbon processing hot spots and their investigation may broaden our understanding of carbon cycling in inland waters at large.Cacciola, F., Mangraviti, D., Mondello, L., Dugo, P., 2020. Chapter 3.4 - Hyphenations of 2D capillary-based LC with mass spectrometry, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 369-412. liquid chromatography is a technique of great analytical impact for handling very complex real-world samples. Principally based on the use of two orthogonal stationary phases, the separation power of a two-dimensional liquid chromatography system is greatly enhanced when compared to a conventional one-dimensional separation. In this chapter, general principles and theoretical/practical aspects of both heart-cutting and comprehensive two-dimensional liquid chromatography coupled to mass spectrometry methods are described. Significant applications in the field of downscaled miniaturized systems, viz. capillary liquid chromatography, are also reported and are mainly focused on the development of innovative strategies in proteomics studies.Cao, J., Rao, Z., Shi, F., Jia, G., 2020. Decoupling of water and air temperature in winter causes warm season bias of lacustrine brGDGTs temperature estimates. Biogeosciences Discussions 2020, 1-48. has been frequently found that lacustrine brGDGTs-derived temperatures are warm season biased relative to measured annual mean air temperature (AT) in the mid to high latitudes, the mechanism of which, however, is not very clear. Here, we investigated the brGDGTs from catchment soils, and suspended particulate matter (SPM) and surface sediments in the Gonghai Lake in north China to explore this question. Our results showed that the brGDGTs distribution in sediments resembled that in the SPM but differed from the surrounding soils, suggesting a substantial aquatic origin of the brGDGTs in the lake. Therefore, established lake-specific calibrations were applied to estimate local mean annual AT. As usual, the estimates were significantly higher than the measured mean annual AT. However, they were similar to, and thus actually reflected, the mean annual lake water temperature (LWT). Interestingly, the mean annual LWT is close to the measured mean warm season AT, hence suggesting that the apparent warm season bias of lacustrine brGDGTs-derived temperatures could be caused by the discrepancy between AT and LWT. In our study region, ice forms at the lake surface during winter, leading to isolation of the underlying lake water from air and hence higher LWT than AT, while LWT follows AT during warm seasons when ice disappears. Therefore, we believe what lacustrine brGDGTs actually reflected is the mean annual LWT, which is higher than the mean annual AT in our study location. Since the decoupling between LWT and AT in winter due to ice formation is a universal physical phenomenon in the mid to high latitudes, we propose this phenomenon could be also the reason for the widely observed warm season bias of brGDGTs-derived temperatures in other lakes, especially the shallow lakes.Carmeille, M., Bourillot, R., Pellenard, P., Dupias, V., Schnyder, J., Riquier, L., Mathieu, O., Brunet, M.-F., Enay, R., Grossi, V., Gaborieau, C., Razin, P., Visscher, P.T., 2020. Formation of microbial organic carbonates during the Late Jurassic from the Northern Tethys (Amu Darya Basin, Uzbekistan): Implications for Jurassic anoxic events. Global and Planetary Change 186, 103127. Late Jurassic was a period of major global carbon cycle perturbations with episodes of anoxia leading to regional accumulation of organic matter in sediments worldwide. The Tubiegatan section (SW Gissar Mountains, Uzbekistan) located in the Northern Tethys, shows atypical organic-rich limestone and marl deposits (up to 6% of total organic carbon) marked by pronounced negative excursions of δ13Ccarb (amplitude of ca. 12‰) and δ13Corg (amplitude of ca. 4‰) recorded during the Middle Oxfordian (Transversarium Zone). A transdisciplinary approach including sedimentology, palynofacies characterization, mineralogy, organic and inorganic geochemistry was carried out to elucidate the origin of these organic-rich deposits. Highest TOC are measured in nodular limestones, and lowest δ13Ccarb values in thinly laminated facies consisting in alternances of infra-millimeter-thick organic and carbonate laminae. In the latter, the presence of organic-carbonate peloids and of possible remnants of exopolymeric substances associated with clay indicate that these structures are probably mineralized laminated benthic microbial mats (i.e., stromatolites). Rock-Eval pyrolysis coupled to palynofacies analyses point to a dominant altered marine organic matter of probable algal/microbial origin, with subordinate continental phytoclasts inputs in the upper part of the organic-rich interval. Trace elements (U/Th, V/Cr and Mo/Al ratios) indicate two anoxic episodes coinciding with the highest TOC, punctuated by dysoxic periods. Such O2-depleted conditions have allowed the preservation and probably the development of anaerobic microbial communities in the microbial mats. In these latter, sulfate reduction probably had a significant contribution to the production of carbonates, which would explain the precipitation of pyrite and the relatively low δ13Ccarb values. The progressive decrease then disappearance of kaolinite from the base of the organic-rich interval, is interpreted as a progressive aridification of the Amu Darya Basin during the Transversarium Zone, culminating with the progradation of a large-scale gypsum sabkha overlying the organic deposits. Overall, the organic-rich deposits could record the onset of the disconnection of the Amu Darya Basin from the open sea to the south, induced by compression and subsequent uplifts in the Afghan and Central Iranian blocks. The elevated evaporation, coupled with the presence of hydrological barriers (such as coral reefs) could have led to the formation of local to regional anoxic conditions in the Amu Darya Basin. Similar microbial organic accumulations are recently known throughout the Tethys (e.g., Arabian Plate, Western Europe) and from other oceans (e.g., Central Atlantic, Pacific) during the Late Jurassic, suggesting common controlling factors. The increase of organic matter storage worldwide coupled with potential methane release could have in turn induced major perturbations of the carbon cycle during the Oxfordian-Kimmeridgian interval. The relatively shallow anoxia model proposed in this study contrasts with the well-known organic carbon-rich pelagic models proposed for the Jurassic anoxia (e.g., Toarcian, Kimmeridgian) and Cretaceous OAEs.Carroll, A.R., Copp, B.R., Davis, R.A., Keyzers, R.A., Prinsep, M.R., 2020. Marine natural products. Natural Product Reports 37, 175-223. review covers the literature published between January and December in 2018 for marine natural products (MNPs), with 717 citations (706 for the period January to December 2018) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1554 in 469 papers for 2018), together with the relevant biological activities, source organisms and country of origin. Reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included. The proportion of MNPs assigned absolute configuration over the last decade is also surveyed.Castillo-Rogez, J.C., Neveu, M., Scully, J.E.C., House, C.H., Quick, L.C., Bouquet, A., Miller, K., Bland, M., De Sanctis, M.C., Ermakov, A., Hendrix, A.R., Prettyman, T.H., Raymond, C.A., Russell, C.T., Sherwood, B.E., Young, E., 2020. Ceres: Astrobiological target and possible ocean world. Astrobiology 20, 269–291., the most water-rich body in the inner solar system after Earth, has recently been recognized to have astrobiological importance. Chemical and physical measurements obtained by the Dawn mission enabled the quantification of key parameters, which helped to constrain the habitability of the inner solar system's only dwarf planet. The surface chemistry and internal structure of Ceres testify to a protracted history of reactions between liquid water, rock, and likely organic compounds. We review the clues on chemical composition, temperature, and prospects for long-term occurrence of liquid and chemical gradients. Comparisons with giant planet satellites indicate similarities both from a chemical evolution standpoint and in the physical mechanisms driving Ceres' internal evolution. Castillo M, A., Páez, A., Rueda-Chacón, H., Agudelo, J.L., Molina V, D., 2019. Prediction of the insolubility number and the solubility blending number of Colombian heavy crude oils by 1H nuclear magnetic resonance and partial least squares. Energy & Fuels 34, 1592-1600. indexes have been proposed in the literature to measure the stability and compatibility of crude oil blends, including the insolubility number (IN), which measures the degree of asphaltene insolubility, and the solubility blending number (SBN), which measures the ability of the oil to dissolve asphaltenes. In this work, various chemometric models were developed to predict the IN and SBN values of Colombian heavy crude oils (°API from 6 to 27), in which the integral areas of the resonance signals, from 12 regions of 1H nuclear magnetic resonance (1H NMR) spectra, were correlated with their IN and SBN. Correlations between the 1H NMR spectra and the said properties were found via partial least squares (PLS) regression so as to create the predictive models. Coefficients of determination (R2) above 0.92 and cross-validated (CV) predictive correlation coefficients (qcv2) above 0.86 were attained with the developed PLS prediction models for IN and SBN. The use of these NMR-based predictive methods entails a faster estimation of the stability and compatibility of crude oil blends and a more eco-friendly and cheaper methodology compared to conventional methods. From the 1H NMR data, it is observed that crude oils with a low tendency to precipitate asphaltenes (high SBN) are those with a high aromatic content and a low content of paraffins.Celia-Silva, L.G., Vilela, P.B., Morgado, P., Lucas, E.F., Martins, L.F.G., Filipe, E.J.M., 2020. Preaggregation of asphaltenes in the presence of natural polymers by molecular dynamics simulation. Energy & Fuels 34, 1581-1591. nut shell liquid (CNSL), its extract, cardanol, and polycardanol, are known to influence the dispersion behavior of asphaltenes in model solvent mixtures. CNSL and cardanol act as dispersants, while polycardanol can act as both dispersant or flocculant depending on its molecular architecture, concentration, and asphaltene source. In this work, the preaggregation of asphaltenes in model solvents (toluene, n-heptane, and their mixtures) has been studied by atomistic molecular dynamics simulation. The influence of cardanol, addition polycardanol, and condensation polycardanol as additives has been addressed. The simulation results remarkably reproduce the experimental trends, thus contributing to a better understanding of the molecular processes underlying the stabilization or precipitation of asphaltenes by cardanols and their polymers.Chai, F., Li, L., Xue, S., Liu, J., 2020. Auxiliary voltage enhanced microbial methane oxidation co-driven by nitrite and sulfate reduction. Chemosphere 250, 126259. this study, single-chamber bioelectrochemical reactors (EMNS) were used to investigate the methane oxidation driven by sulfate and nitrite reduction with the auxiliary voltage. Results showed that the methane oxidation was simultaneously driven by sulfate and nitrite reduction, with more methane being converted using the auxiliary voltage. When the voltage was 1.6 V, the maximum removal rate was achieved at 8.05 mg L?1 d?1. Carbon dioxide and methanol were the main products of methane oxidation. Simultaneously, nitrogen, nitrous oxide, sulfur ions, and hydrogen sulfide were detected as products of sulfate and nitrite reduction. Microbial populations were analyzed by qPCR and high-throughput sequencing. The detected methanotrophs included Methylocaldum sp., Methylocystis sp., Methylobacter sp. and M. oxyfera. The highest abundance of M. oxyfera was (3.97 ± 0.32) × 106 copies L?1 in the EMNS-1.6. The dominant nitrite-reducing bacteria were Ignavibacterium sp., Hyphomicrobium sp., Alicycliphilus sp., and Anammox bacteria. Desulfovibrio sp., Desulfosporosinus sp. and Thiobacillus sp. were related to the sulfur cycle. Ignavibacterium sp., Thiobacillus sp. and Desulfovibrio sp. may transfer electrons with electrodes using humic acids as the electronic shuttle. The possible pathways included (1) Methane was mainly oxidized to carbon dioxide and dissolved organic matters by methanotrophs utilizing the oxygen produced by the disproportionation in the cells of M. oxyfera. (2) Nitrite was reduced to nitrogen by heterotrophic denitrifying bacteria with dissolved organic compounds. (3) Desulfovibrio sp. and Desulfosporosinus sp. reduced sulfate to sulfur ions. Thiobacillus sp. oxidized sulfur ions to sulfur or sulfate using nitrite as the electron acceptor.Chakraborty, N., Karpyn, Z., Liu, S., Yoon, H., Dewers, T., 2020. Experimental evidence of gas densification and enhanced storage in nanoporous shales. Journal of Natural Gas Science and Engineering 76, 103120. is a growing body of evidence that gas situated within the pores of nanoporous materials may not have the same equation of state (pressure, volume, and temperature, PVT) properties as macroscopic free gas. However, there is limited experimental measurement of in-situ fluid properties for gases taken up by nanoporous shales. In this work, we use a gas injection porosimetry approach to measure the gas storage capacity of four different North American shales (Bakken, Marcellus, Haynesville, and Mancos) and in-situ gas density for a few different hydrocarbon and noble gases. We find the porosity measured with helium to be reasonable between 5% and 16.4%. However, when using other gases such as methane, argon, and ethylene, the equivalent porosity estimations are extremely high, with the highest measured value being 309% for ethylene gas in a Marcellus shale sample. Such extreme results raise questions on the validity of the underlying assumptions of the porosimetry equations, in particular, the description of gas density within shale nanopores with macroscopic density. The experimentally measured density of in-situ gas is found to be up to 28 times higher than the theoretically estimated one at the equilibrium PVT conditions. This in-situ densification of gas is independently verified using X-ray CT imaging on one of the samples – the Marcellus. The underlying mechanism for gas densification could be explained by adsorption, in which case the proportion of adsorbed gas is estimated to be between 12% and 96% for the various gas-sample pairs. Surface area measurements show that a monolayer of adsorbed gas can only account for 27%–42% of the adsorbed gas. This calls into question the commonly assumed Langmuir monolayer model of adsorption, and indicates that gas densification within shale nanopores can be attributed to a multilayer adsorption mechanism and/or other unidentified mechanisms that require further study.Chang, B., Defliese, W.F., Li, C., Huang, J., Tripati, A., Algeo, T.J., 2020. Effects of different constants and standards on the reproducibility of carbonate clumped isotope (Δ47) measurements: Insights from a long-term dataset. Rapid Communications in Mass Spectrometry 34, e8678.: Carbonate clumped isotope (Δ47) thermometry examines the temperature‐dependent excess abundance of the 13C–18O bond in the carbonate lattice. Inconsistent temperature calibrations and standard values have been reported among laboratories, which has led to the use of equilibrated gases and carbonate standards for standardization. Furthermore, different acid fractionation factors and isotopic parameter sets have been proposed for improving inter‐laboratory data comparability. However, few long‐term datasets have been generated to explore the effects of these factors on the long‐term reproducibility of Δ47 data within a laboratory. Methods: Four standards (ISTB‐1, NBS‐19, GBWO4416, and GB04417) were analyzed as unknowns by isotope ratio mass spectrometry from 2015 to 2019. The values of Δ47 were calibrated using the ETH standards. We investigated the Assonov, Brand, and Gonfiantini isotope parameter sets for carbon and oxygen isotopes, as well as two correction schemes of equilibrated gas and carbonate standardization, using the same sample measurements to determine which procedures enhanced reproducibility. ISTB‐1 (calcite) and ZK312‐346W (dolomite) were measured to determine the 90°C acid fractionation factor. Results: The corrected 90°C acid fractionation factors are 0.076?±?0.008‰ for ISTB‐1 and 0.077?±?0.009‰ for ZK312‐346W. The choice of isotope parameter set had no significant influence on final Δ47 values in this study. However, using the Assonov parameters to calculate Δ47 values improved the reproducibility of the results. The use of carbonate standards improved reproducibility through time compared with the use of equilibrated gases for standardization. Conclusions: At 90°C, the acid fractionation factors of calcite and dolomite are statistically indistinguishable. We find an insignificant effect from changing the isotope parameter set, suggesting that the choice of isotope parameter set among laboratories is not a major factor affecting inter‐laboratory reproducibility. We find that using carbonate standards improved the reproducibility of results, suggesting that the use of carbonate standards may help to achieve inter‐laboratory comparability of results in future studies.Charbonnier, G., Adatte, T., F?llmi, K.B., Suan, G., 2020. Effect of intense weathering and postdepositional degradation of organic matter on Hg/TOC proxy in organic-rich sediments and its implicationsfor deep-time investigations. Geochemistry, Geophysics, Geosystems 21, e2019GC008707. (Hg) enrichments in sediments are increasingly used as tracer for distal volcanism in deep-time investigations. The impact of changes in organic-matter deposition and preservation on sedimentary Hg sequestration is, however, poorly understood. In this study, we evaluate the potential role of intense weathering and postdepositional organic-matter degradation on the Hg/TOC proxy in sediments. For this, we investigate weathering profiles in organic-rich sediments from lowermost Toarcian sediments (T-OAE; Lafarge cement quarry, France) and organic-rich deposits from the uppermost Cenomanian-lowermost Turonian Bonarelli level (OAE2; Furlo and Monte Velo, Italy; Manilva and El Chorro, Spain). The comparison of Hg data along weathering profiles in lowermost Toarcian sediments indicates that recent intense oxidation of the originally organic-rich deposits has removed up to 89% of the Hg signal. The organic-rich sediments of the Furlo and Manilva sections are characterized by lower Hg/total organic carbon (TOC) ratios, which suggest important Hg scavenging by organic matter (OM) deposition. At the opposite, in equivalent successions, three significant positive Hg/TOC excursions persist at El Chorro and Monte Velo. These samples exhibit low Hydrogen Index (HI) values, which plot in the field of type-III OM. This resulted from postdepositional degradation of marine OM type II to type III, which largely modified the amount and the quality of OM. Consequently, the recorded Hg/TOC ratios do not reflect original Hg drawdown but postdepositional oxidation, suggesting that extreme care is needed in the evaluation of the history of OM preservation when using Hg as a proxy for volcanic activity.Chemodurova, A.A., Kaparullina, E.N., Machulin, A.V., Spr?er, C., Lang, E., Doronina, N.V., 2020. Ancylobacter lacus sp. nov. and Ancylobacter plantiphilus sp. nov., novel aerobic facultative methylotrophic bacteria. Microbiology 89, 35-43. aerobic facultatively methylotrophic bacteria were isolated from the water of a freshwater lake (strain F30LT), soil sample of rhizosphere of white clover Trifolium repens L. (strain 1TCT), and rhizosphere of carrot Daucus carota L. (strain Dau2). The isolates were gram-negative, non-spore-forming, nonmotile, pleomorphic/rod-shaped cells, propagating by binary fission; they were facultative methylotrophs, using a broad range of polycarbon compounds, apart from methanol. Optimum growth occurred at 25?29 °C and pH 7.0?7.5, 0.5 vol % СН3OH, and 0.05 wt % NaCl. The strains employ the ribulose bisphosphate pathway for C1 assimilation. The predominant phospholipids were phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol. In the whole-cell fatty acid pattern of strains, C18:1 ω7c, C19: 0 ω8c cyclo, C16:0 and С18:0 acids were predominant. The major ubiquinone was Q-10. According to the 16S rRNA gene sequencing, strain F30LT exhibited high similarity to Ancylobacter dichloromethanicus DM16T (97.8%), while strains 1ТСT and Dau2 were closely related to A. oerskovii DSM 18746T (98.6%). The 16S rRNA gene sequence similarity between strains 1TCT and Dau2 was 99.4%. DNA–DNA hybridization of the strain F30LT with A. dichloromethanicus DM16T revealed only 22% homology; homology for strain 1ТСT and A. oerskovii DSM 18746T was 27%, while DNA?DNA homology between strains 1TCT and Dau2 was 77%. Based on the data obtained, strain F30LT was identified as a new species within the genus Ancylobacter, Ancylobacter lacus sp. nov. (VKM В-3280Т = DSM 106439T). Strains 1ТСТ and Dau2 (=ВКМ В-3227 = CCUG71988) represent a novel species of the same genus, for which the name Ancylobacterplantiphilus sp. nov. is proposed, with the type strain 1ТСТ (=VKM В-3219Т = DSM 106438T).Chen, J., Zhu, W., Tian, Y.Q., Yu, Q., 2020. Monitoring dissolved organic carbon by combining Landsat-8 and Sentinel-2 satellites: Case study in Saginaw River estuary, Lake Huron. Science of The Total Environment 718, 137374. organic carbon (DOC) in aquatic environments is an important cycled pool of organic matter on the Earth. Satellite remote sensing provides a useful tool to determine spatiotemporal distribution of water quality parameters. Previous DOC remote sensing studies in inland water suffered from either low spatial resolution or low temporal frequency. In this study, we evaluated the potential of jointly using Landsat-8 and Sentinel-2 with high spatial resolution to estimate DOC concentrations in Saginaw River plume regions of Lake Huron. Firstly, CDOM (colored dissolved organic matter) was estimated from images using the known models and then DOC can be derived in terms of the good correlations between DOC and CDOM. The results show that Landsat-8 and Sentinel-2 had acceptable accuracy and good consistency in DOC estimation so that jointly using them can improve the observation frequency. In different seasons from 2013 to 2018, DOC was typically higher in spring and autumn but lower in summer. Monthly spatiotemporal variations of DOC in 2018 were also observed. The image-derived DOC spatiotemporal variations show that DOC was covaried with Saginaw River discharge (r = 0.82) and also weakly and negatively correlated with water temperature (r = ?0.6). This study demonstrated that using Landsat-8 and Sentinel-2 together can offer the potential applications for monitoring DOC and water quality dynamic in complex inland water.Chen, X., Hao, F., Zou, H., Guo, L., 2020. Oil-source correlation and contributions of effective source rocks to accumulation in Renqiu buried hill reservoirs in the Raoyang sag Acta Petrolei Sinica 41, 59-67. further study the source of crude oil and the contributions of source rocks to accumulation in Renqiu buried hill reservoirs in the Raoyang sag, this paper detailedly analyzes the crude oil from the buried hill based on the analysis data of gas chromatography-mass spectrometry of saturated hydrocarbons and the biomarker characteristics of crude oil and source rocks, determines the relationship between crude oil and source rocks, explains the reason for source-mixed accumulation through analysis of the geological conditions, and finally determines the source-mixed ratio of the mixed oil. The C29 sterane 20S/(20S+20R) reflects that the crude oil in Renqiu buried hill reservoirs is dominated by mature crude oil. The biomarker parameters such as Pr/Ph, G/H, S/H, and C19/C23 indicate that there are three types of crude oil in Renqiu buried hill reservoirs, namely Type A, B and C. The biomarker parameters of the three types of crude oil change regularly, presenting a regular spatial distribution. Type A is only originated from the source rock of the middle-lower submember of the third Member of Shahejie Formation in the Maxi subsag, and it is mainly distributed in the Ordovician reservoirs north by east of the Renqiu buried hill. Types B and C are sourced from the lower submember of the first Member of Shahejie Formation in the Renxi subsag and the middle-lower submember of the third Member of Shahejie Formation in the Maxi subsag. Type B from source rocks in the middle-lower submember of the third Member of Shahejie Formation accounts for 60%-70%, followed by the crude oil from the source rocks of the lower submember of the first Member of Shahejie Formation; the latter is mainly distributed in the Proterozoic Wumishan Formation and Cambrian Fujunshan Formation,in the north by west of the Renqiu buried hill. Type C is mainly from source rocks of the lower submember of the first Member of Shahejie Formation. The crude oil from the middle-lower submember of the third Member of Shahejie Formation accounts for 30%-40%, and is dominantly distributed in the Proterozoic Wumishan Formation in the southern Renqiu buried hill. On the whole, the contribution of source rocks of the lower submember in the first Member of Shahejie Formation to the Renqiu buried hill reservoir is low in the north and high in the south, while high in the north and low in the south for source rocks of the middle-lower submember in the third Member of Shahejie Formation.Chen, Y., Ma, D., Xia, Y., Guo, C., Yang, F., Shao, K., 2019. Characteristics of the mud shale reservoirs in coal-bearing strata and resources evaluation in the eastern margin of the Ordos Basin, China. Energy Exploration & Exploitation 38, 372-405. the co-exploration and co-production of unconventional gas have become a new trend of the unconventional gas exploration and development in the eastern margin of the Ordos Basin, this study focuses on the distribution, pore characteristics, geochemical properties, and mineral composition of the mud shale in the coal-bearing strata. The results show that the mud shale in the coal-bearing strata is distributed relatively stably with an average cumulative thickness of 77.60?m and a buried depth of 200–2400?m, increasing from east to west. The total organic carbon content of mud shale is relatively high, ranging from 0.14% to 39.9%, and the thermal maturity ranges from 0.23% to 2.49%, affected by both buried depth and magmatic intrusion. The organic matter type of the mud shale is dominated by type III, favorable for gas generation. The mineral composition of mud shale is mainly clay minerals and quartz, with low brittle minerals content (averaging 30.34%) and high kaolinite content (averaging 59.23%). Pores and micro-fissures are relatively developed in the mud shale, dominated by intergranular pores, organic pores, and the micro-fissures developed between brittle mineral crystals, within crystals and between clay mineral particles, with a porosity of 1.05%–1.59% and a permeability of 0.001–0.142 (×10?3?m2). The specific surface area of pores in mud shale is 12.31–28.99 m2/g, and the total pore volume is 0.0146–0.0483?cm3/g. Mesopores and micropores (mainly slit shaped pores) provide the main pore volume of mud shale, and micropores contribute most of the specific surface area. The controlling factors on pore development include the total organic carbon, thermal maturity, and inorganic minerals composition. The total amount of shale gas resources is 2.49?×?1012 m3, and the Linxian-Xingxian area and Shilou-Daning area are the potential favorable zones for shale gas exploration and development.Chen, Y., Montero, L., Luo, J., Li, J., Schmitz, O.J., 2020. Application of the new at-column dilution (ACD) modulator for the two-dimensional RP×HILIC analysis of Buddleja davidii. Analytical and Bioanalytical Chemistry 412, 1483-1495. focus of this study was the analysis of the complex chemical composition from different parts of Buddleja davidii, whose species are commonly known as ornamental plants and herbal medicines in many countries. As an herbal medicine, it has been utilized for stroke treatments, headache, wound healing, neurological disorder, etc. However, the understanding of its chemical matrices is still insufficient. Therefore, an online two-dimensional reversed phase liquid chromatography x hydrophilic interaction liquid chromatography (RPLCxHILIC) system coupled with mass spectrometry was applied for further detailed investigation of the chemical constituents in Buddleja dividii. In this two-dimensional liquid chromatography (2D-LC) method, a new at-column dilution (ACD) modulator was introduced in the 2D-LC system to solve the incompatibility problem of the mobile phase between two dimensions, which resulted in a 2D-LC analysis with high orthogonality. For the root extract, as one of the analyzed samples, the optimization of the 1D and 2D gradients was carried out carefully. With this new modulator, much better peak separation and better peak shape were achieved compared to two-dimensional liquid chromatography system using a traditional standard (TS) modulator. With a similar approach, the other four parts of Buddleja davidii were well separated. Comparing the different analyzed parts, flowers and leaves showed the most complex profiles. MS and MS/MS data were obtained successfully, which demonstrated the potential of the proposed RPLCxHILIC-MS system in the constituents’ analysis of herbal medicine. However, due to the lack of reported reference information, 24 compounds could be tentatively identified.Chiu, C.-Y., Jones, J.R., Rusak, J.A., Lin, H.-C., Nakayama, K., Kratz, T.K., Liu, W.-C., Tang, S.-L., Tsai, J.-W., 2020. Terrestrial loads of dissolved organic matter drive inter-annual carbon flux in subtropical lakes during times of drought. Science of The Total Environment 717, 137052. ecosystems are important agents of local and global carbon cycling, but their contribution varies along gradients of dissolved organic matter (DOM) and productivity. We investigated how contrasting summer and autumn precipitation can shape annual and inter-annual variation in ecosystem carbon (C) flux (gross primary production (GPP), ecosystem respiration (ER), and CO2 efflux) in two subtropical lakes differing substantially in trophic state and water color. Instrumented buoys recorded time series of free-water DO, terrestrial DOM (tDOM), chlorophyll a, water temperature profiles, and meteorological measurements over five years (2009–2011 and 2014–2015). Reduced precipitation caused immediate and prolonged effects on C flux in both lakes. During the drought year (2014) GPP and ER declined by 60 to 80% and both lakes were either CO2 sinks or neutral. In the subsequent wet year (2015), GPP and ER increased by 40 to 110%, and both lakes shifted to strong net CO2 emitters. Higher ecosystem R resulted from larger GPP while higher tDOM contributed to a dramatic increase in dissolved inorganic carbon, which intensified CO2 emission in both lakes. C flux was more responsive in the clear mesotrophic lake, declining by approximately 40% in the cumulative GPP and ER, and increasing by >400% in CO2 efflux whereas changes in the oligotrophic colored lake were more modest (approximately 30% and 300% for metabolic declines and efflux increases, respectively). Temporal variation and magnitude of C flux were governed by tDOM-mediated changes in epilimnetic nutrient levels and hypolimnetic light availability. This study demonstrated terrestrial loads of DOM strongly influence the inter-annual response and sensitivity of ecosystem C flux to variation in inter-annual precipitation. Our findings have important implications for predicting the trend, magnitude, duration, and sensitivity of the response of C flux in subtropical lakes/reservoirs to future changes in precipitation patterns under altered climatic conditions.Choi, J., Kim, S.-H., 2020. Whole-proteome tree of life suggests a deep burst of organism diversity. Proceedings of the National Academy of Sciences 117, 3678-3686.: Tree of life (ToL) is a metaphorical tree that captures a simplified narrative of the evolutionary course and kinship among all living organisms of today. We have reconstructed a whole-proteome ToL for over 4,000 different extant species for which complete or near-complete genome sequences are available in public databases. The ToL suggests that 1) all extant organisms of this study can be grouped into 2 “Supergroups,” 6 “Major Groups,” or 35+ “Groups”; 2) the order of emergence of the “founders” of all the groups may be assigned on an evolutionary progression scale; and 3) all of the founders of the groups have emerged in a “deep burst” near the root of the ToL—an explosive birth of life’s diversity.Abstract: An organism tree of life (organism ToL) is a conceptual and metaphorical tree to capture a simplified narrative of the evolutionary course and kinship among the extant organisms. Such a tree cannot be experimentally validated but may be reconstructed based on characteristics associated with the organisms. Since the whole-genome sequence of an organism is, at present, the most comprehensive descriptor of the organism, a whole-genome sequence-based ToL can be an empirically derivable surrogate for the organism ToL. However, experimentally determining the whole-genome sequences of many diverse organisms was practically impossible until recently. We have constructed three types of ToLs for diversely sampled organisms using the sequences of whole genome, of whole transcriptome, and of whole proteome. Of the three, whole-proteome sequence-based ToL (whole-proteome ToL), constructed by applying information theory-based feature frequency profile method, an “alignment-free” method, gave the most topologically stable ToL. Here, we describe the main features of a whole-proteome ToL for 4,023 species with known complete or almost complete genome sequences on grouping and kinship among the groups at deep evolutionary levels. The ToL reveals 1) all extant organisms of this study can be grouped into 2 “Supergroups,” 6 “Major Groups,” or 35+ “Groups”; 2) the order of emergence of the “founders” of all of the groups may be assigned on an evolutionary progression scale; 3) all of the founders of the groups have emerged in a “deep burst” at the very beginning period near the root of the ToL—an explosive birth of life’s diversity.Chu, C., Liu, B., Lian, Z., Zheng, H., Chen, C., Yue, Z., Li, L., Sun, Z., 2020. Solirhodobacter olei gen. nov., sp. nov., a nonphotosynthetic bacterium isolated from oil-contaminated soil. International Journal of Systematic and Evolutionary Microbiology 70, 582-588. nonphotosynthetic, Gram-stain-negative, rod-shaped and motile strain, designated Pet-1T, was isolated from oil-contaminated soil collected from Daqing oil field in China. Optimal growth occurred at 37 °C, pH 5.5 and in 1 % (w/v) NaCl. Q-10 was the sole respiratory quinone. The most abundant fatty acid was C18 : 1?7c/C18 : 1?6c (67.4 %). The major polar lipids were phosphatidylglycerol, aminolipid, phosphatidylethanolaine, phosphatidycholine, two unidentified lipids and two unidentified phospholipids. The genomic DNA G+C content was 69.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that Pet-1T shared the highest similarity (95.1 %) to Rhodobacter vinaykumarii DSM 18714T, followed by Sinorhodobacter populi sk2b1T (95.0 %) and Haematobacter massiliensis CCUG 47968T (95.0 %). In the phylogenetic tree, strain Pet-1T formed a separate branch from the closely related genera Rhodobacter, Pararhodobacter, Defluviimonas and Rhodovulum within the family Rhodobacteraceae. Based on the data from the current polyphasic study, it is proposed that the isolate is a novel species of a novel genus within the family Rhodobacteraceae, with the name Solirhodobacter olei gen. nov., sp. nov. The type strain of the type species is Pet-1T (=KCTC 72074T =CCTCC AB 2018368T).Clark, M.G., Humphreys, E.R., Carey, S.K., 2020. Low methane emissions from a boreal wetland constructed on oil sand mine tailings. Biogeosciences 17, 667-682. 58?ha mixed upland and lowland boreal plains watershed called the Sandhill Fen Watershed was constructed between 2008 and 2012. In the years following wetting in 2013, methane emissions were measured using manual chambers. The presence of vegetation with aerenchymous tissues and saturated soils were important factors influencing the spatial variability of methane emissions across the constructed watershed. Nevertheless, median methane emissions were equal to or less than 0.51?mg?CH4?m?2?h?1 even from the saturated organic soils in the lowlands. Although overall methane emissions remained low, observations of methane ebullition increased over the 3 study years. Ebullition events occurred in 10?% of measurements in 2013, increasing to 21?% and 27?% of measurements in 2014 and 2015, respectively, at the plots with saturated soils. Increasing metal ion availability and decreasing sulfur availability was measured using buried ion exchange resins at both seasonal and annual timescales potentially as a result of microbial reduction of these ions. Using principle component analysis, methane fluxes had a significant positive correlation to the leading principle component which was associated with increasing ammonium, iron, and manganese and decreasing sulfur availability (r=0.31, p<0.001). These results suggest that an abundance of alternative inorganic electron acceptors may be limiting methanogenesis at this time.Clarkson, C., Harris, C., Li, B., Neudorf, C.M., Roberts, R.G., Lane, C., Norman, K., Pal, J., Jones, S., Shipton, C., Koshy, J., Gupta, M.C., Mishra, D.P., Dubey, A.K., Boivin, N., Petraglia, M., 2020. Human occupation of northern India spans the Toba super-eruption ~74,000 years ago. Nature Communications 11, 961. is located at a critical geographic crossroads for understanding the dispersal of Homo sapiens out of Africa and into Asia and Oceania. Here we report evidence for long-term human occupation, spanning the last ~80 thousand years, at the site of Dhaba in the Middle Son River Valley of Central India. An unchanging stone tool industry is found at Dhaba spanning the Toba eruption of ~74?ka (i.e., the Youngest Toba Tuff, YTT) bracketed between ages of 79.6?±?3.2 and 65.2?±?3.1?ka, with the introduction of microlithic technology ~48?ka. The lithic industry from Dhaba strongly resembles stone tool assemblages from the African Middle Stone Age (MSA) and Arabia, and the earliest artefacts from Australia, suggesting that it is likely the product of Homo sapiens as they dispersed eastward out of Africa.Clarkson, C.R., Yuan, B., Zhang, Z., Tabasinejad, F., Behmanesh, H., Hamdi, H., Anderson, D., Thompson, J., Lougheed, D., 2020. Evaluation of the impact of multi-phase flow on reservoir signatures in the Wolfcamp shale. Journal of Natural Gas Science and Engineering 76, 103187. dominant transient flow regime for multi-fractured horizontal wells (MFHWs) producing from low-permeability and shale (unconventional) reservoirs has historically been interpreted to be transient linear flow (TLF) with analysis performed in the framework of classical diffusion (CD). Recently, observed deviations away from this classical behavior for Permian Basin Wolfcamp shale (oil) wells have been attributed to reservoir heterogeneity and anomalous diffusion (AD). However, some wells in the basin also produce below bubble point pressure and exhibit characteristics of multi-phase flow. The objective of the current study is therefore to investigate if multi-phase flow may also be contributing to observed deviations from classic TLF behavior.The conventional log-log diagnostics used to identify flow regimes do not account for reservoir complexities such as multi-phase flow and reservoir heterogeneity. Failure to correct for these effects when they are occurring may result in misdiagnosis of flow regimes. A new workflow is therefore introduced herein to improve flow regime identification when reservoir complexities are exhibited, with a specific focus on multi-phase flow. The workflow involves the correction of log-log diagnostics for multi-phase flow through the use of modified pseudo-variables (pseudo-pressure and pseudo-time) once characteristics of multi-phase flow are identified (e.g. rapid increase of gas-oil ratio after bubble point pressure is reached). Although reservoir heterogeneity and AD are accepted causes of deviations from TLF, the impact of multi-phase flow has not been investigated in detail. Therefore, corrections to pseudo-variables for multi-phase flow, a known reservoir complexity exhibited by Wolfcamp shale wells, are presented. Pressure-dependent permeability is also accounted for in pseudo-variable calculations, although its impact is demonstrated to be relatively minor in this study.Application of the new workflow to a simulated case and a Wolfcamp shale field case demonstrates the following: 1) multi-phase flow, and in particular the appearance of a mobile gas phase after two-phase oil and water production, results in deviations from classical TLF behavior when data is analyzed using conventional (uncorrected) diagnostics; 2) application of the modified diagnostics to a simulated case that includes multi-phase flow results in the “true” flow regime signature of TLF being observed; 3) application of the modified diagnostics to a field case exhibiting evidence of multi-phase flow reduces the deviation from TLF.This study suggests that multi-phase flow may be impairing our ability to identify flow regimes using conventional flow regime identification methods.Clayer, F., Gélinas, Y., Tessier, A., Gobeil, C., 2020. Mineralization of organic matter in boreal lake sediments: Rates, pathways and nature of the fermenting substrates. Biogeosciences Discussions 2020, 1-33. complexity of organic matter (OM) degradation mechanisms represents a significant challenge for developing biogeochemical models to quantify the role of aquatic sediments in the climate system. The common representation of OM by carbohydrates formulated as CH2O in models comes with the assumption that its degradation by fermentation produces equimolar amounts of methane (CH4) and dissolved inorganic carbon (DIC). To test the validity of this assumption, we modeled using reaction-transport equations vertical profiles of the concentration and isotopic composition (δ13C) of CH4 and DIC in the top 25?cm of the sediment column from two lake basins, one whose hypolimnion is perennially oxygenated and one with seasonal anoxia. Our results reveal that methanogenesis only occurs via hydrogenotrophy in both basins. Furthermore, we calculate, from CH4 and DIC production rates associated with methanogenesis, that the fermenting OM has an average carbon oxidation state (COS) below ?0.9. Modeling solute porewater profiles reported in the literature for four other seasonally anoxic lake basins also yields negative COS values. Collectively, the mean (±SD) COS value of ?1.4?±?0.3 for all the seasonally anoxic sites is much lower than the value of zero expected from carbohydrates fermentation. We conclude that carbohydrates do not adequately represent the fermenting OM and that the COS should be included in the formulation of OM fermentation in models applied to lake sediments. This study highlights the need to better characterize the labile OM undergoing mineralization to interpret present-day greenhouse gases cycling and predict its alteration under environmental changes.Cliffe, L., Nixon, S.L., Daly, R.A., Eden, B., Taylor, K.G., Boothman, C., Wilkins, M.J., Wrighton, K.C., Lloyd, J.R., 2020. Identification of persistent sulfidogenic bacteria in shale gas produced waters. Frontiers in Microbiology 11, 286. doi: 10.3389/fmicb.2020.00286. waters from hydraulically fractured shale formations give insight into the microbial ecology and biogeochemical conditions down-well. This study explores the potential for sulfide production by persistent microorganisms recovered from produced water samples collected from the Marcellus shale formation. Hydrogen sulfide is highly toxic and corrosive, and can lead to the formation of “sour gas” which is costly to refine. Furthermore, microbial colonization of hydraulically fractured shale could result in formation plugging and a reduction in well productivity. It is vital to assess the potential for sulfide production in persistent microbial taxa, especially when considering the trend of reusing produced waters as input fluids, potentially enriching for problematic microorganisms. Using most probable number (MPN) counts and 16S rRNA gene sequencing, multiple viable strains of bacteria were identified from stored produced waters, mostly belonging to the Genus Halanaerobium, that were capable of growth via fermentation, and produced sulfide when supplied with thiosulfate. No sulfate-reducing bacteria (SRB) were detected through culturing, despite the detection of relatively low numbers of sulfate-reducing lineages by high-throughput 16S rRNA gene sequencing. These results demonstrate that sulfidogenic produced water populations remain viable for years post production and, if left unchecked, have the potential to lead to natural gas souring during shale gas extraction.Cockitt, J., Lamb, A., Metcalfe, R., 2020. An ideal solution? Optimising pretreatment methods for artificially mummified ancient Egyptian tissues. Rapid Communications in Mass Spectrometry 34, e8686.: Although the analysis of skeletal remains dominates the study of ancient dietary stable isotopes, mummified bodies also allow short‐term diet to be studied through the analysis of soft tissues. The application of resins, waxes and oils during mummification can affect the results obtained. This study assesses a range of methods for removing such substances from mummified tissue.Methods: An experimental mummification model following ancient Egyptian methods was created using a modern pig leg. Sub‐samples of skin, muscle and bone were removed and coated with a range of substances used in Egyptian mummification. Four methods were used to clean these samples before the measurement of the carbon and nitrogen stable isotope ratios of their gelatinised collagen content using a ThermoFinnigan Flash Elemental analyser coupled to a DeltaPlus XL isotope ratio mass spectrometer via a ConFlo III interface.Results: The results showed that embalming materials can significantly affect dietary stable isotope ratios, and that these substances are most effectively removed using a mixture of polar and non‐polar solvents. Results indicate that bone samples demineralised with HCl and skin samples produce more accurate results than bone samples demineralised with EDTA or muscle samples.Conclusions: The choice of tissue and the preparation methods used can have a significant effect on the accuracy of stable isotope data obtained from mummified tissue, particularly when embalming materials are also present. A mixture of solvents appears to be a more effective cleaning agent than a single solvent. Demineralisation with HCl is preferable for well‐preserved bone, as used in this study, but whether this is the case for more fragile, less well‐preserved bone requires further study. Skin samples produce more consistent data than muscle, but visually distinguishing between these tissues is not simple on ancient mummies.Connolly, R.M., Connolly, F.N., Hayes, M.A., 2020. Oil spill from the Era: Mangroves taking eons to recover. Marine Pollution Bulletin 153, 110965. are highly susceptible to oil exposure. Depending on the severity, oil exposure can result in initial defoliation and eventual recovery through to mass mortality and complete loss of habitat. Some aspects of the impact of oil on mangroves and their recovery are well studied, but the focus has been on short-term responses, and the understanding of the longer-term trajectory of mangrove recovery from oiling is very limited. Here, we combine field results from sampling in the two years following a significant oiling event, with analysis of canopy cover in aerial images from before the event to 26 years afterwards. Approximately 100 ha of a monospecific stand of Avicenna marina mangroves were oiled as a result of a spill from the Era tanker in Spencer Gulf in southern Australia in September 1992. While lightly oiled trees made a full recovery, trees in heavily oiled areas experienced mass defoliation and ultimately mortality within several months of the oiling event. An analysis of aerial images indicated that there was no recovery in heavily oiled areas for 10 years following the oiling event. Between 10 and 25 years, seedling establishment and growth saw canopy cover increase to 35% of pre-oiling cover within heavily oiled areas. Predictive modelling estimates that complete recovery of mangroves to pre-oiling cover will take 55 years (median prediction in 2047). Our findings indicate that although mangroves can recover following a heavy oiling event, the rate of recovery can be slow, with full recovery in the order of half a century, much longer than has previously been anticipated.Conrad, R., Klose, M., Enrich-Prast, A., 2020. Acetate turnover and methanogenic pathways in Amazonian lake sediments. Biogeosciences 17, 1063-1069. sediments in Amazonia are a significant source of CH4, a potential greenhouse gas. Previous studies of sediments using 13C analysis found that the contribution of hydrogenotrophic versus acetoclastic methanogenesis to CH4 production was relatively high. Here, we determined the methanogenic pathway in the same sediments (n=6) by applying 14Cbicarbonate or 2-14Cacetate and confirmed the high relative contribution (50?%–80?%) of hydrogenotrophic methanogenesis. The respiratory index (RI) of 2-14Cacetate, which is 14CO2 relative to 14CH4+14CO2, divided the sediments into two categories, i.e., those with an RI?<?0.2 consistent with the operation of acetoclastic methanogenesis and those with an RI?>?0.4 showing that a large percentage of the acetate-methyl was oxidized to CO2 rather than reduced to CH4. Hence, part of the acetate was probably converted to CO2 plus H2 via syntrophic oxidation, thus enhancing hydrogenotrophic methanogenesis. This happened despite the presence of potentially acetoclastic Methanosaetaceae in all the sediments. Alternatively, acetate may have been oxidized with a constituent of the sediment organic matter (humic acid) serving as oxidant. Indeed, apparent acetate turnover rates were larger than CH4 production rates except in those sediments with a R<0.2. Our study demonstrates that CH4 production in Amazonian lake sediments was not simply caused by a combination of hydrogenotrophic and acetoclastic methanogenesis but probably involved additional acetate turnover.Coogan, L.A., Gillis, K.M., 2020. The average Phanerozoic CO2 degassing flux estimated from the O-isotopic composition of seawater. Earth and Planetary Science Letters 536, 116151. degassing rate of CO2 from the solid Earth, and matching burial rate, is critical to understanding the long-term carbon and oxygen cycles and the maintenance of a habitable climate. However, estimates of modern CO2 degassing rates vary by more than a factor of four and uncertainties are even larger further back in Earth history. Both the crustal C-inventory and C-isotope mass balance suggests that over long timescales ～70-90% of the CO2 degassed from the solid Earth is drawn-down through silicate weathering reactions (subaerial and submarine). These reactions involve dissolution of silicate minerals, that typically formed at relatively high temperatures, and formation of silicate and carbonate minerals in low temperature aqueous environments. These new low temperature minerals have much higher δ18O than their precursors; thus the rate of degassing of CO2 is tied to the rate of removal of materials with high δ18O from the hydrosphere into weathering products. Maintaining a near-constant O-isotopic composition of the ocean over the Phanerozoic means that this weathering sink of isotopically heavy O must have equaled the source of isotopically heavy O to the ocean. This isotopically heavy oxygen largely comes from high-temperature hydrothermal vent fluids at mid-ocean ridges. New O-isotope data for the previously under-sampled lower oceanic crust from fast-spreading ridges, along with a compilation of published O-isotopic compositions of other sections of oceanic crust altered at high-temperatures, allows the magnitude of this high δ18O flux to be quantified. Modelling the coupled O-isotope and CO2 mass balance constrains suggests that the average Phanerozoic solid Earth CO2 degassing rate was ～3.4 Tmol yr?1 (10th to 90th percentile of 1.8-5.3 Tmol yr?1). This is substantially lower than has been suggested by some recent studies, and is at or below the lower end of the range of previous estimates, with wide ranging implications for our understanding of the long term C cycle.Cook, G.T., Dunbar, E., Tripney, B.G., Fabel, D., 2020. Using carbon isotopes to fight the rise in fraudulent whisky. Radiocarbon 62, 51-62 major threat to the Scotch whisky industry is the sale of counterfeit single malt whiskies with purported distillation years in the 19th and early- to mid-20th centuries. However, these are often much more recent spirits, distilled in the latter part of the 20th or first part of the 21st centuries. These sales impinge upon the reputation of auction houses, retailers, brand owners and distillers. The atmospheric testing of nuclear weapons in the 1950s and early 1960s has enabled a precise calibration curve to be created, however, there are several reasons why this may not be appropriate for establishing the year of whisky distillation. We have created a 14C calibration curve derived from known-age, single malt whiskies for the period 1950–2015 that enables whisky distilled during the period from 1955 onwards to have the distillation year determined to within 1–3 years for certain periods. However, because of the shape of the curve, two possible age ranges are often possible. The correct range can often be determined from a further plot of δ13C values against distillation year, which shows a trend of decreasing values through time. Several examples are given of the determination of both genuine and fake products.Coonrod, C.L., Ben Yin, Y., Hanna, T., Atkinson, A.J., Alvarez, P.J.J., Tekavec, T.N., Reynolds, M.A., Wong, M.S., 2020. Fit-for-purpose treatment goals for produced waters in shale oil and gas fields. Water Research 173, 115467. fracturing (HF), or “fracking,” is the driving force behind the “shale gas revolution,” completely transforming the United States energy industry over the last two decades. HF requires that 4–6 million gallons per well (15,000–23,000?m3/well) of water be pumped underground to stimulate the release of entrapped hydrocarbons from unconventional (i.e., shale or carbonate) formations. Estimated U.S. produced water volumes exceed 150 billion gallons/year across the industry from unconventional wells alone and are projected to grow for at least another two decades. Concerns over the environmental impact from accidental or incidental release of produced water from HF wells (“U-PW”), along with evolving regulatory and economic drivers, has spurred great interest in technological innovation to enhance U-PW recycling and reuse. In this review, we analyze U-PW quantity and composition based on the latest U.S. Geographical Survey data, identify key contamination metrics useful in tracking water quality improvement in the context of HF operations, and suggest “fit-for-purpose treatment” to enhance cost-effective regulatory compliance, water recovery/reuse, and resource valorization. Drawing on industrial practice and technoeconomic constraints, we further assess the challenges associated with U-PW treatment for onshore U.S. operations. Presented are opportunities for targeted end-uses of treated U-PW. We highlight emerging technologies that may enhance cost-effective U-PW management as HF activities grow and evolve in the coming decades.Corrente, N.J., Dobrzanski, C.D., Gor, G.Y., 2020. Compressibility of supercritical methane in nanopores: A molecular simulation study. Energy & Fuels 34, 1506-1513. coalbeds are a promising source of natural gas and can act as a receptacle for CO2 sequestration. This is because they are composed of extensive nanoporous systems, which allow for significant amounts of methane or CO2 to be trapped in the adsorbed state. The amount of the fluid confined in the coal seams can be determined from seismic wave propagation using the Gassmann equation. However, to accurately apply the Gassmann theory to coalbed methane, the effects of confinement on methane in these nanoporous systems must be taken into account. In this work, we investigate these effects of confinement on supercritical methane in model carbon nanopores. Using Monte Carlo and molecular dynamics simulations, we calculated the isothermal elastic modulus of confined methane. We showed that the effects of confinement on the elastic modulus of supercritical methane are similar to the effects on subcritical fluids: (1) the elastic modulus of the confined fluid is higher than in bulk; (2) for a given pore size, the modulus monotonically increases with pressure; and (3) at a given pressure, the modulus monotonically increases with the reciprocal pore size. However, these effects appeared much more pronounced than for subcritical fluids, showing up to seven-fold increases of the modulus in 2 nm pores. Such a significant increase should be taken into account when predicting wave propagation in methane-saturated porous media.Costa, T.G., Meurer, L., Micke, G.A., Gon?alves, S., Szpoganicz, B., Mangrich, A.S., 2020. Potentiometric titration of microhydrolysis products of oils: A new low-cost methodology and investment for the analysis of oil binders present in works of art. Talanta 212, 120736. analysis of oil paints present in historical paintings is commonly carried out for research, authenticity and forensic purposes. This paper proposes potentiometric titration and calculation of the fatty acids concentrations with the aid of the Best7 program as an alternative technique to characterize the oil binders used in works of art. The method involves determining the ratio between the levels of palmitic (P) and stearic (S) acids present in the microhydrolysis products of commercial oil binders and paints. The microhydrolysis products were characterized, using FTIR spectroscopy, by displacement of the carbonyl band and the pKa values for the C16 and C18 in the system studied were determined. The P/S ratios found for the microhydrolysis products of linseed, palm and nut oils were 1.65, 5.91 and 2.42, respectively. For the commercial paints analyzed, values ranging from 1.34 to 1.98 were obtained, characterizing the presence of linseed oil. The values were confirmed by GC-MS and are in agreement with those reported in the literature for the oils investigated in this study.Covas, T.R., de Freitas, C.S., Tose, L.V., Valencia-Dávila, J.A., Rocha, Y.d.S., Rangel, M.D., da Silva, R.C., Vaz, B.G., 2020. Fractionation of polar compounds from crude oils by hetero-medium pressure liquid chromatography (H-MPLC) and molecular characterization by ultrahigh-resolution mass spectrometry. Fuel 267, 117289. compounds from three Brazilian crude oils were isolated and separated into seven fractions according to the polarity (low polarity-LP, low medium polarity-LMP, high medium polarity-HMP, high polarity-HP, basic-BAS, acidic-AC) by using hetero-medium pressure liquid chromatography (H-MPLC). Chemical characterization of all fractions was performed by mass spectrometry using an electrospray ionization source. In positive ion mode, the N1 compound class was detected with high relative abundance in all samples. Interestingly, the unsaturation degree of this heteroatom class decreased from fractions LP, LMP, HMP to the HP, BAS and AC fractions. On the other hand, the type of compound classes found in negative ion mode was more diverse, revealing that nitrogen species (N1) corresponding to carbazoles, were eluted in the less polar fraction (LP). Conversely, NxOy (x = 1, y = 1–4) heteroatom classes were found with a higher relative abundance in LMP, HMP, HP and BAS fractions. Overall, the H-MPLC reduced the complexity of the polar fraction contained in whole crude oils and allowed to extend the chemical characterization since the number of molecular formulas assigned in all fractions exceeds significantly to those detected in the whole crude oils. This separation methodology is an interesting alternative to other techniques such as gas chromatography (GC, GCxGC), liquid/liquid extraction, extrography, solid phase extraction and SARA (saturates, aromatics and resins) separation. MPLC not only isolate polar compounds but also fractionate them by the degree of polarity without previous de-asphalting steps. This separation approach, along with the molecular characterization of polar compounds by ESI-Orbitrap MS is also a tempting option to perform geochemical assessment of crude oils and source rocks.Cribb, A.T., Kenchington, C.G., Koester, B., Gibson, B.M., Boag, T.H., Racicot, R.A., Mocke, H., Laflamme, M., Darroch, S.A.F., 2019. Increase in metazoan ecosystem engineering prior to the Ediacaran–Cambrian boundary in the Nama Group, Namibia. Royal Society Open Science 6, 190548. disappearance of the soft-bodied Ediacara biota at the Ediacaran–Cambrian boundary potentially represents the earliest mass extinction of complex life, although the precise driver(s) of this extinction remain unresolved. The ‘biotic replacement’ model proposes that an evolutionary radiation of metazoan ecosystem engineers in the latest Ediacaran profoundly altered marine palaeoenvironments, resulting in the extinction of Ediacara biota and setting the stage for the subsequent Cambrian Explosion. However, metazoan ecosystem engineering across the Ediacaran–Cambrian transition has yet to be quantified. Here, we test this key tenet of the biotic replacement model by characterizing the intensity of metazoan bioturbation and ecosystem engineering in trace fossil assemblages throughout the latest Ediacaran Nama Group in southern Namibia. The results illustrate a dramatic increase in both bioturbation and ecosystem engineering intensity in the latest Ediacaran, prior to the Cambrian boundary. Moreover, our analyses demonstrate that the highest-impact ecosystem engineering behaviours were present well before the onset of the Cambrian. These data provide the first support for a fundamental prediction of the biotic replacement model, and evidence for a direct link between the early evolution of ecosystem engineering and the extinction of the Ediacara biota.Cron, B.R., Sheik, C.S., Kafantaris, F.-C.A., Druschel, G.K., Seewald, J.S., German, C.R., Dick, G.J., Breier, J.A., Toner, B.M., 2020. Dynamic biogeochemistry of the particulate sulfur pool in a buoyant deep-sea hydrothermal plume. ACS Earth and Space Chemistry 4, 168-182. deep-ocean hydrothermal vent systems, oxidation–reduction (redox) reactions involving sulfur are known to fuel primary production via chemosynthesis. The particulate sulfur pool within buoyant hydrothermal plumes available to microorganisms as metabolic substrates remains undescribed. In this study, buoyant hydrothermal plume particles were collected from the Von Damm Vent Field, Mid-Cayman Rise, Caribbean. A novel in situ filtration system and remotely operated vehicle were used to collect samples along vertical profiles above two sites close to the summit of Mount Dent. Particulate sulfur speciation was measured using sulfur 1s X-ray absorption near edge structure (XANES) spectroscopy. The activity of sulfur-cycling genes in the buoyant plume was measured using metatranscriptomic sequencing. Our results indicate that both solid-state sulfur chemistry and microbial activity within the Von Damm buoyant plume are dynamic and diverse over short temporal and spatial scales. The particulate sulfur species and sulfur-cycling microbial communities generated in the buoyant plume are inputs to the neutrally buoyant plume and thus have potential for distant transport in the deep ocean. The buoyant plume particulate sulfur species include metal sulfides, thiol and organic monosulfide, thiophene, sulfone, sulfonate, ester sulfate, and sulfate. The microbial community carries a suite of active sulfur-cycling proteins (dsrAB, the sox enzyme complex, sqr, psr, dprAB, and SAT). Should these materials be exported to the neutrally buoyant plume, they will have implications for deep-ocean biogeochemistry through sustained biomass production based on sulfur oxidation and reduction.Cullen, C.M., Aneja, K.K., Beyhan, S., Cho, C.E., Woloszynek, S., Convertino, M., McCoy, S.J., Zhang, Y., Anderson, M.Z., Alvarez-Ponce, D., Smirnova, E., Karstens, L., Dorrestein, P.C., Li, H., Sen Gupta, A., Cheung, K., Powers, J.G., Zhao, Z., Rosen, G.L., 2020. Emerging priorities for microbiome research. Frontiers in Microbiology 11, 136. doi: 10.3389/fmicb.2020.00136. research has increased dramatically in recent years, driven by advances in technology and significant reductions in the cost of analysis. Such research has unlocked a wealth of data, which has yielded tremendous insight into the nature of the microbial communities, including their interactions and effects, both within a host and in an external environment as part of an ecological community. Understanding the role of microbiota, including their dynamic interactions with their hosts and other microbes, can enable the engineering of new diagnostic techniques and interventional strategies that can be used in a diverse spectrum of fields, spanning from ecology and agriculture to medicine and from forensics to exobiology. From June 19–23 in 2017, the NIH and NSF jointly held an Innovation Lab on Quantitative Approaches to Biomedical Data Science Challenges in our Understanding of the Microbiome. This review is inspired by some of the topics that arose as priority areas from this unique, interactive workshop. The goal of this review is to summarize the Innovation Lab’s findings by introducing the reader to emerging challenges, exciting potential, and current directions in microbiome research. The review is broken into five key topic areas: (1) interactions between microbes and the human body, (2) evolution and ecology of microbes, including the role played by the environment and microbe-microbe interactions, (3) analytical and mathematical methods currently used in microbiome research, (4) leveraging knowledge of microbial composition and interactions to develop engineering solutions, and (5) interventional approaches and engineered microbiota that may be enabled by selectively altering microbial composition. As such, this review seeks to arm the reader with a broad understanding of the priorities and challenges in microbiome research today and provide inspiration for future investigation and multi-disciplinary collaboration.Curry, A., 2020. Europe's lost frontier. Science 367, 499-503. by dedicated amateurs and new methods, scientists reconstruct a now-submerged ancient landscape—and the people who lived there.On a clear, windy autumn afternoon last October, Willy van Wingerden spent a few free hours before work walking by the sea not far from the Dutch town of Monster. Here, in 2013, the cheerful nurse found her first woolly mammoth tooth. She has since plucked more than 500 ancient artifacts from the broad, windswept beach known as the Zandmotor, or “sand engine.” She has found Neanderthal tools made of river cobbles, bone fishhooks, and human remains thousands of years old. Once, she plucked a tar-covered Neanderthal tool from the water's edge, earning a co-author credit in the Proceedings of the National Academy of Sciences (PNAS) a few months ago.“Sun, wind, rain, snow—I'm here 5 or 6 days a week,” she says. “I find something every day, almost.”Van Wingerden's favorite beachcombing spot is no ordinary stretch of sand. Nearly half a kilometer wide, the beach is made of material dredged from the sea bottom 13 kilometers offshore and dumped on the existing beach in 2012. It's a €70 million experimental coastal protection measure, its sands designed to spread over time to shield the Dutch coast from sea-level rise. And the endeavor has made 21 million cubic meters of Stone Age soil accessible to archaeologists.That soil preserves traces of a lost world. During the last ice age, sea levels were 70 meters lower, and what is now the North Sea between Great Britain and the Netherlands was a rich lowland, home to modern humans, Neanderthals, and even earlier hominins. It all disappeared when glaciers melted and sea level rose about 8500 years ago.That vast continental shelf has been a blank spot on the map of prehistoric Europe because archaeologists can't mount traditional excavations underwater. Now, thanks to the Zandmotor and construction work on a harbor extension in nearby Rotterdam, van Wingerden and a dedicated cadre of amateur beachcombers are amassing an impressive collection of artifacts from that vanished landscape. Scientists on both sides of the North Sea are applying precise new methods to date the artifacts and sequence any genetic traces, as well as mapping the sea floor and analyzing sediment cores. The effort is bringing to light the landscape and prehistory of a lost homeland of ancient Europeans.The finds show that the region was an inviting place in the few thousand years before it vanished, with forests and river valleys rich in game. “It's not a blank area, it's not a land bridge, it's probably one of the best areas for hunter-gatherers in Europe,” says Vincent Gaffney, an archaeologist at the University of Bradford.The dark, cold waters that now hide the region add to its allure because they preserve organic material for DNA analysis and radiocarbon dating better than on land. And the techniques now being tested to explore the area could aid research on submerged landscapes elsewhere, such as Beringia, the vanished land between Asia and North America inhabited by the first Americans. “It really is a pioneer field and will make a huge difference to our understanding of prehistory,” retired University of York archaeologist Geoff Bailey says.Clad in a bright yellow windbreaker and blue rubber boots, van Wingerden kept her eyes on the sand as she crunched across razor clamshells and bits of driftwood. To the south, the cranes of Rotterdam harbor—Europe's largest port—were just visible on the horizon. To the north, oversize kites bobbed in the sky, pulling kitesurfers along far below. “Sometimes things are on dry sand; sometimes they're near the water,” van Wingerden said of her finds. “There's really no logic to it.”Fifty thousand years ago, the landscape looked different. Doggerland—which University of Exeter archaeologist Bryony Coles named in the 1990s after the Dogger Banks, a productive North Sea fishing spot—extended from Amsterdam up to Scotland and southern Norway. The region once encompassed at least 180,000 square kilometers of dry land, four times the size of the Netherlands today (see map, p. 501). But until the Zandmotor was built in 2011, archaeologists had glimpsed only the outlines of Doggerland. Fishermen had dragged up isolated bones, tusks, and stone tools.In calmer seas, archaeologists might have dived to the sea floor for follow-up searches. But the rough, cold, murky waters of the North Sea, crisscrossed with busy shipping lanes, ruled that out.“The technology [to explore the sea floor] wasn't available, nobody knew what might have survived sea-level rise, and it all seemed hopelessly expensive and useless,” Bailey says. Archaeologists were also reluctant to be seen chasing after “lost continents,” he adds, lest they be associated with fringe theories such as Atlantis.That's changing fast, thanks in part to beachcombers like van Wingerden. In his office at the National Museum of Antiquities, archaeologist Luc Amkreutz opens his email and scrolls through messages, some just hours old. “This morning a fisherman sent in photos of an elk antler with a shaft hole,” he says, opening an attachment. “It just goes on and on.”Using email and a WhatsApp group with the straightforward name “Stone Age Finds,” Amkreutz and Marcel Niekus, an independent archaeologist, keep in constant contact with amateurs scouring beaches all along the Dutch coast. The archaeologists help identify prehistoric artifacts from photos and get access to dozens of specimens in exchange. “We're easy to approach, and people can bring us finds,” Amkreutz says.Other researchers are reaping similar bonanzas. In late 2018, Leiden University Medical Center archaeogeneticist Eveline Altena was part of a research group that invited van Wingerden and other amateurs to an open house, asking them to bring human bones for identification. The response was overwhelming: In a single day, beachcombers brought more than 50 human skeletal fragments, many suitable for dating and DNA analysis. “Now, we're getting new fragments on a weekly basis,” she says. “I can't keep up anymore.”In 2015, van Wingerden found a flint flake with a gob of tar stuck to one end to form a simple handle. Niekus and Amkreutz recognized it as a Neanderthal hand tool at least 50,000 years old. Chemical analysis helped show how Neanderthals used complex methods to process birch bark into tar, as a team including Niekus, Amkreutz, and van Wingerden reported in PNAS.Archaeologists can't know exactly where on the sea floor an artifact found on the beach originated, so the context they prize is missing. But because coastal reclamation efforts such as the Zandmotor dredge from specific locations, archaeologists know the artifacts' sources to within a few kilometers. “There are complete cemeteries being sucked up and sprayed on beaches,” Amkreutz says. “Even though these finds aren't in their original find spot, they can say something about a huge area.”Those findings suggest several phases of occupation. Tools and other relics 800,000 years old or more harken back to when this part of Europe was likely occupied by Homo antecessor, an early human thought by many researchers to be an evolutionary dead end. One set of footprints, found in a layer of compressed sand on a beach in the United Kingdom and dated by its geological context, recorded children and adults apparently migrating across a mudflat.Long cold spells then covered parts of the region in ice. About 100,000 years ago, small, hardy bands of Neanderthals arrived on the trail of megafauna such as mammoths and woolly rhinoceros. Hundreds of tools and a lone skull fragment offer evidence of a population living on the fringes of habitable Europe, resourceful enough to eke out a living in small groups under what Amkreutz calls “extreme” conditions on the edge of glaciers.Neanderthals died out about 45,000 years ago—about when anatomically modern humans entered Europe. A few flint tools, found among stones dredged from the sea floor to create artificial sea walls for the Rotterdam harbor, suggest H. sapiens may have been active in Doggerland even as early as 40,000 years ago, when it was still an icy steppe. (More conclusive tools have turned up in the United Kingdom and Belgium, on each side of Doggerland.) About 20,000 years ago, a severe cold spell made the entire region too cold to be habitable.But the end of the last ice age, about 15,000 years ago, brought a brief idyll: Pollen samples, DNA evidence, and fossilized wood fragments recovered from the sea floor suggest a fertile landscape of forests and rivers, with plentiful birds, fish, and mammals. Human remains and finely worked stone, bone, and antler tools suggest modern humans made the most of the area, occupying it even as rising waves transformed large parts into a coastal wetland.The seafloor bones are filling in the picture of Europe's genetic past. Studies of ancient and modern DNA indicate that certain groups of hunter-gatherers entered northern Europe from the south and east perhaps about 14,000 years ago, after much of the ice had melted; modern European populations still carry their genetic legacy.The trove of human bones that amateurs turned over to Altena for sampling promises to add to the picture. Of the bones amassed in June 2019, 90 were well-preserved enough for radiocarbon dating and DNA analysis. Altena and researchers from the Max Planck Institute for the Science of Human History (SHH) in Jena, Germany, identified teeth and bones between 8000 and 10,000 years old, when modern human hunter-gatherers occupied Doggerland. They have started to extract DNA, and so far have recovered it from more than five individuals. “In some ways the context is limited, but we can still do so much more than anyone ever expected,” Altena says.Drawn from the outer limits of hunter-gatherer expansion in the fringes of Europe at that time, those samples “are fascinating,” says Cosimo Posth, an SHH geneticist. He notes that the DNA could illuminate how these early populations mixed with others in Europe.Most doggerland finds have been accidental. A long-term goal is to learn enough about the past landscape so researchers can go to sea and look for sites instead of waiting for evidence to wash ashore. “Until you have reliable maps, you can't do much,” Gaffney says. “We're dealing with a completely unexplored country we can't visit.”More than 10 years ago, Gaffney set out to do the next-best thing, persuading oil, gas, and wind power companies to pass on data gathered in seismic surveys done to plan offshore oil and gas wells. Initial maps were coarse, but over the past several years, Gaffney and colleagues used €2.5 million in funding from the European Research Council to deploy side-scan sonar and other undersea imaging technologies to make their own maps, in what they call the Europe's Lost Frontiers project. Maps in hand, the researchers looked for ancient areas suited to human habitation.More than a decade of work paid off last year when Gaffney and Belgian researchers headed to the Brown Banks, about 50 kilometers off the U.K. coast. Mapping had suggested that between 7000 and 13,000 years ago, the spot was an elevated area 30 kilometers long, overlooking a river.Researchers aboard the Belgian research vessel Belgica took core samples, scooped up sediment, and made “grabs” with a metal claw. Among the finds were traces of a fossilized forest 32 meters beneath the waves, including tree roots, terrestrial snail shells, and peat—plus a small flint flake and part of a broken flint hammerstone shaped by hunter-gatherers. “We went to the place where we thought [human artifacts] would be and recovered them,” Gaffney says. “That's a first.”Putting those maps together with the sheer number of samples emerging from the North Sea, researchers are beginning to answer a question particularly relevant to humanity's future: What do people do when sea levels rise?About 8500 years ago, a massive freshwater lake in North America called Lake Agassiz, formed by melting glaciers, drained suddenly into the sea. What had been gradual sea-level rise accelerated, and seas rose a few meters within decades. Doggerland transformed from a temperate, forested plain into an estuarial wetland dotted by drier highlands. Core samples collected along river valleys by the Lost Frontiers team traced the flooding, amounting to a “transect through time,” Gaffney says.To explore the impact on people, Amkreutz analyzed dozens of human bones dragged up by fishing boats as well as finds plucked off the Zandmotor and other Dutch beaches. He traced the bones to 18 offshore sites around the prehistoric Rhine River estuary and dated them with radiocarbon to a precision of about 100 years; all were about 8500 years old.He and Niekus then used chemical signatures from collagen preserved in dozens of the bones to analyze what people in Mesolithic Doggerland were eating before and during that transition. As the landscape changed, the diet of its residents did, too, shifting from land animals to freshwater fish. “It shows their flexibility in the face of climate change,” Amkreutz says. “They didn't leave as sea levels rose; they changed their diet.”Eventually, that, too, came to an end. On the basis of sediments and computer models, researchers think a tsunami originating off modern-day Norway around 6150 B.C.E. devastated Doggerland with waves at least 10 meters high. Soon the landscape vanished as global sea levels continued to rise.At his lab at the University of Warwick, Robin Allaby is tracing the changes by searching 60 of the core samples collected by Gaffney and his team for what's called environmental DNA, shed into water and soil by ancient species. The team scoops up and analyzes all the DNA in a sample, using next-generation sequencing methods that capture millions of DNA fragments, and compares it with libraries of known genomes. “The surprising thing is just how much DNA is still down there,” Allaby says. The results chronicle changes in Doggerland's ecosystems as seas rose.In the older, earlier layers, “We can see quite a broad range of DNA that's clearly terrestrial,” he says. Allaby has picked out terrestrial species, including bears, boars, birds, spiders, and mosquitoes. He has identified plant species, too, including hazel and linden trees and meadow grasses. “It's obviously a lowland, very fertile and probably more attractive than the British uplands and adjacent Europe,” he says.Higher up, in the younger core samples, the DNA tells a tale of inexorable transformation. “We can see the rise of an estuarine environment and a slow switch to marine taxa,” Allaby says, as bears and boars give way to sea grasses and fish.Researchers say the techniques being pioneered or perfected in the North Sea could be applied to far-flung hot spots of human migration, including Beringia and the waters that surround the archipelagos of Oceania. “There are big questions about human dispersal and development which can only be answered by looking at submerged landscapes,” Bailey says. “These same landscapes were probably good places to provide stepping stones into new territory.”At the end of van Wingerden's afternoon walk, all she had to show for 2 hours of searching were a few pieces of animal bone and a wide smile. But the next day, her luck turned. Tucked in among a pile of seashells, she found a carefully worked tool with characteristic Neanderthal handiwork, dating back at least 45,000 years: one more piece of a lost landscape, rediscovered.D'Orazio, G., 2020. Chiral analysis by nano-liquid chromatography. TrAC Trends in Analytical Chemistry 125, 115832. concept of stereoisomerism in the biological activity of compounds in living systems emerged in 1948 with the work of Louis Pasteur, who first observed the optical activity of tartaric acid. Enantiomers can produce undesired effects on biological system, due to their different optical activity, even though they possess the same physico-chemical properties in an achiral environment. For this reason, they are a topic that has arisen interest in different areas including pharmaceutical, biomedical, agrochemical and food fields etc. Nowadays, the development of arduous stereospecific synthesis for the production of a single enantiomer gives way to a greater challenge turning attention to the racemic mixture separation by employing analytical methods. This review intends to offer a recent “state of the art” about separation of chiral compounds by nano and capillary liquid chromatography (LC). This overview is organized in two parts. The first one describes general considerations on nano-LC, including some theoretical features and a description of the experimental settings. In addition, enantiomers separation, chiral selectors and chiral stationary phase are also described in the first part or the manuscript. The second part includes the main applications in recent years, applications that confirm the great potential of nano-LC in the field of enantiomeric separation.d’Ippolito, G., Landi, S., Esercizio, N., Lanzilli, M., Vastano, M., Dipasquale, L., Pradhan, N., Fontana, A., 2020. CO2-induced transcriptional reorganization: Molecular basis of capnophillic lactic fermentation in Thermotoga neapolitana. Frontiers in Microbiology 11, 171. doi: 10.3389/fmicb.2020.00171. lactic fermentation (CLF) is a novel anaplerotic pathway able to convert sugars to lactic acid (LA) and hydrogen using CO2 as carbon enhancer in the hyperthermophilic bacterium Thermotoga neapolitana. In order to give further insights into CLF metabolic networks, we investigated the transcriptional modification induced by CO2 using a RNA-seq approach. Transcriptomic analysis revealed 1601 differentially expressed genes (DEGs) in an enriched CO2 atmosphere over a total of 1938 genes of the T. neapolitana genome. Transcription of PFOR and LDH genes belonging to the CLF pathway was up-regulated by CO2 together with 6-phosphogluconolactonase (6PGL) and 6-phosphogluconate dehydratase (EDD) of the Entner–Doudoroff (ED) pathway. The transcriptomic study also revealed up-regulation of genes coding for the flavin-based enzymes NADH-dependent reduced ferredoxin:NADP oxidoreductase (NFN) and NAD-ferredoxin oxidoreductase (RNF) that control supply of reduced ferredoxin and NADH and allow energy conservation-based sodium translocation through the cell membrane. These results support the hypothesis that CO2 induces rearrangement of the central carbon metabolism together with activation of mechanisms that increase availability of the reducing equivalents that are necessary to sustain CLF. In this view, this study reports a first rationale of the molecular basis of CLF in T. neapolitana and provides a list of target genes for the biotechnological implementation of this process.Dang, H., Peng, N., Ma, X., Wan, S., Jian, Z., 2020. Possible linkage between the long-eccentricity marine carbon cycle and the deep-Pacific circulation: Western equatorial Pacific benthic foraminifera evidences of the last 4?Ma. Marine Micropaleontology 155, 101797. ~400-kyr period of marine carbon isotope records, in concert with the long eccentricity cycle, is a meaningful signature of the global carbon cycle, and this period was prolonged to ~500 kyr in the last ~1.6?Ma. The cause of the elongation of the long-eccentricity carbon cycle at ~1.6?Ma has not been fully understood, partly due to the conundrum of its relationship to changes in the circulation of deep-water masses. In this study, we present the benthic foraminifera δ13C and δ18O and the relative abundances of selected benthic foraminifera, from the upper ~80?m of Site U1489 of IODP Expedition 363. First, we established an age model for our samples, covering the last 4?Ma, based on the correlation of benthic foraminifera δ18O to the LR04 global stack as well as ship-board magneto-stratigraphy. Then we compared the δ18O and δ13C between Cibicidoides and Uvigerina to reconfirm the inter-genus isotopic adjustments. The coarse fraction, benthic foraminifera δ13C and the abundances of selected benthic species/genera show detectable 400–500 kyr cycles, with minimal coarse fraction and maximal δ13C around eccentricity minima. The variations in the relative abundances of selected benthic foraminifera, especially Favocassidulina favus, and the comparisons among deep-Pacific δ13C records, reveal a shift to a more sluggish mode of Pacific deep-water circulation occurring coincidently at ~1.6?Ma. Therefore, it may be implied that the lengthening of the long-term δ13C cycle at ~1.6?Ma is linked to a deep Pacific circulation change that prolonged the cycling of carbon in the ocean.Darriba, D., Posada, D., Kozlov, A.M., Stamatakis, A., Morel, B., Flouri, T., 2019. ModelTest-NG: A new and scalable tool for the selection of DNA and protein evolutionary models. Molecular Biology and Evolution 37, 291-294. is a reimplementation from scratch of jModelTest and ProtTest, two popular tools for selecting the best-fit nucleotide and amino acid substitution models, respectively. ModelTest-NG is one to two orders of magnitude faster than jModelTest and ProtTest but equally accurate and introduces several new features, such as ascertainment bias correction, mixture, and free-rate models, or the automatic processing of single partitions. ModelTest-NG is available under a GNU GPL3 license at , last accessed September 2, 2019.Dauphin, C.-E., Durand, A., Lubonis, K., Wortham, H., Dron, J., 2020. Quantification of monosaccharide anhydrides by gas chromatography/mass spectrometry in lichen samples. Journal of Chromatography A 1612, 460675. are effective atmospheric bioindicators, and the bioaccumulation of pollutants is frequently measured in their tissues to assess contamination levels. Even though monosaccharide anhydrides are not directly considered as contaminants, Levoglucosan is a common tracer of biomass burning in atmospheric samples and measuring their accumulation in lichens could help to evaluate the main atmospheric pollution sources on a spatially resolved scale depending on the size of the sampling grid. In this work, a realiable analytical method to determine monosaccharide anhydrides in liches was developed. It is based on ASE extraction, solid phase extraction to clean the sample, and silylation derivatization before GC/MS analysis. The reliability and detection limits of the method were suited to the analysis of lichen samples, and additional quality tests achieved the validation of the method with lichen test matrix. Finally field samples were quantified and the results obtained were consistent with atmospheric levels.David, F., 2020. Chapter 2.1 - Classical two-dimensional GC combined with mass spectrometry, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 135-182. this chapter, the basic principles of heart-cut two-dimensional capillary gas chromatography (2D-GC, GC-GC) and its hyphenation to mass spectrometry are described. An overview is given of the instrumental evolution from the original Deans switch system to state-of-the-art capillary flow technology-based systems. The potential and advantages of heart-cut 2D-GC-MS are illustrated with several examples of the author's laboratory, including fragrance analysis, food aroma analysis, petrochemical and environmental analysis, and determination of genotoxic impurities in pharmaceuticals. It is clear that GC-GC can be considered as complementary to comprehensive 2D GC and both techniques offer interesting possibilities for tackling challenging analytical problems by capillary GC.Davies, N.S., Shillito, A.P., Slater, B.J., Liu, A.G., McMahon, W.J., 2020. Evolutionary synchrony of Earth’s biosphere and sedimentary-stratigraphic record. Earth-Science Reviews 201, 102979. landscapes and seascapes of Earth’s surface provide the theatre for life, but to what extent did the actors build the stage? The role of life in the long-term shaping of the planetary surface needs to be understood to ascertain whether Earth is singular among known rocky planets, and to frame predictions of future changes to the biosphere. Modern geomorphic observations and modelling have made strides in this respect, but an under-utilized lens through which to interrogate these questions resides in the most complete tangible record of our planetary history: the sedimentary-stratigraphic record (SSR). The characteristics of the SSR have been frequently explained with reference to changes in boundary conditions such as relative sea level, climate, and tectonics. Yet despite the fact that the long-term accrual of the SSR was contemporaneous with the evolution of almost all domains of life on Earth, causal explanations related to biological activity have often been overlooked, particularly within siliciclastic strata. This paper explores evidence for the ways in which organisms have influenced the SSR throughout Earth history and emphasizes that further investigation can help lead towards a mechanistic understanding of how the planetary surface has co-evolved with life. The practicality of discerning life signatures in the SSR is discussed by: 1) distinguishing biologically-dependent versus biologically-influenced sedimentary signatures; 2) emphasizing the importance of determining relative time-length scales of processes and demonstrating how different focal lengths of observation (individual geological outcrops and the complete SSR) can reveal different insights; and 3) promoting an awareness of issues of equifinality and underdetermination that may hinder the recognition of life signatures. Multiple instances of life signatures and their historic range within the SSR are reviewed, with examples covering siliciclastic, biogenic and chemogenic strata, and trigger organisms from across the spectrum of Earth’s extant and ancient life. With this novel perspective, the SSR is recognised as a dynamic archive that expands and complements the fossil and geochemical records that it hosts, rather than simply being a passive repository for them. The SSR is shown to be both the record and the result of long-term evolutionary synchrony between life and planetary surface processes.Davoodi, S.M., Miri, S., Taheran, M., Brar, S.K., Galvez-Cloutier, R., Martel, R., 2020. Bioremediation of unconventional oil contaminated ecosystems under natural and assisted conditions: A review. Environmental Science & Technology 54, 2054-2067. is a general understanding that unconventional oil is petroleum-extracted and processed into petroleum products using unconventional means. The recent growth in the United States shale oil production and the lack of refineries in Canada built for heavy crude processes have resulted in a significant increase in U.S imports of unconventional oil since 2018. This has increased the risk of incidents and catastrophic emergencies during the transportation of unconventional oils using transmission pipelines and train rails. A great deal of effort has been made to address the remediation of contaminated soil/sediment following the traditional oil spills. However, spill response and cleanup techniques (e.g., oil recuperation, soil–sediment–water treatments) showed slow and inefficient performance when it came to unconventional oil, bringing larger associated environmental impacts in need of investigation. To the best of our knowledge, there is no coherent review available on the biodegradability of unconventional oil, including Dilbit and Bakken oil. Hence, in view of the insufficient information and contrasting results obtained on the remediation of petroleum, this review is an attempt to fill the gap by presenting the collective understanding and critical analysis of the literature on bioremediation of products from the oil sand and shale (e.g., Dilbit and Bakken oil). This can help evaluate the different aspects of hydrocarbon biodegradation and identify the knowledge gaps in the literature.Davudov, D., Moghanloo, R.G., Zhang, Y., 2020. Interplay between pore connectivity and permeability in shale sample. International Journal of Coal Geology 220, 103427. formations demonstrate distinct characteristics, such as a wide spectrum of pore size from micro-scale to nano-scale, limited pore connectivity and ultra-low permeability. Despite extensive research work over recent years to characterize flow properties of shale samples, the interplay between pore connectivity and permeability still remains to be understood. In this study, numerical methods were used in tandem with experimental data to characterize and evaluate pore connectivity of shale samples.To evaluate permeability and pore connectivity in the shale matrix, three-dimensional (3D) pore structure constructed by stacking scanning electron microscopy (SEM) images of an Eagle Ford sample is used. First, static petrophysical properties of the shale sample such as total and the connected porosity, pore size distribution and geometric tortuosity are calculated and evaluated. Next, pore connectivity is assessed using Euler-Poincare Characteristics (EPC) method. Finally, fluid flow through the sample is simulated using Lattice Boltzmann Method (LBM) to predict single-phase permeability of the whole system.Results indicate that total porosity of the studied Eagle Ford shale sample is around 12.5% and slightly decreases as the thickness of the digital sample increases. On the other hand, the connected porosity of the sample decreases resulting in a 50% reduction when the sample thickness increases from 1 μm to 6 μm. Moreover, the calculated permeability is 17.6 md and 1.17 μd for the sample thickness of 1 μm and 6 μm, respectively; i.e. 15,000 times reduction is observed when the digital sample thickness increases. Consistent with the permeability results, the pore connectivity determined through EPC method is strongly (and inversely) correlated with the sample thickness and 80% reduction of the pore connectivity is realized when the sample thickness is increased from 1 μm to 6 μm.The results from this study will provide new insights into how pore structure characteristics scale up and help improve the better estimation of permeability in shale formations. In addition, the outcome of this work has some important implications to fluid flow research studies in shale formations.de Koster, C.G., Schoenmakers, P.J., 2020. Chapter 3.1 - History of liquid chromatography—mass spectrometry couplings, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 279-295. liquid chromatography (LC) with mass spectrometry (MS) has produced an extremely powerful range of analytical tools for the qualitative and quantitative analysis of complex samples. LC-MS combines separation power with high sensitivity and it provides detailed information on compound identity. Many obstacles had to be overcome before LC-MS instruments became widely applicable and highly successful. The greatest breakthrough has come from atmospheric-pressure ionization techniques, in which the ionization preceded the vacuum stage. Robust and reliable systems have emerged and the range of analytes that are amenable to LC-MS has been greatly expanded. A broad spectrum of LC setups can be used, ranging from conventional (mL/min) to nanoflow (< 1?mL/min) systems, together with the full range of MS analysers. LC-MS/MS and LC-MSn techniques are commonly employed, both for qualitative and quantitative purposes.Dean, J.F., 2020. Old methane and modern climate change. Science 367, 846-848. is stored over thousands of years in many natural reservoirs in land and ocean ecosystems. This is vital for regulating global climate. These old carbon stores are vulnerable to climate change, which can cause this carbon to be released in the form of greenhouse gases such as methane. If these gases reach the atmosphere, they can drive further warming, which has implications for all life on Earth (see the figure) (1). But such positive feedback loops are a major uncertainty when predicting future climate change (2). On page 907 of this issue, Dyonisius et al. (3) describe their search for signals of old methane released to the atmosphere during the last deglaciation about 18,000 to 8000 years ago. This was when Earth last showed warming similar to what is predicted for our immediate future. They found that methane emissions from old carbon sources during this time were small, suggesting that substantial emissions of old methane may not be triggered in response to current and near-future climate change.Methane is about 86 times mores powerful as a greenhouse gas than carbon dioxide over a 20-year time period—the time scale in which global action is needed to reduce carbon emissions from human activities and limit catastrophic climate change. The two main sources of potential methane release to the atmosphere from destabilization of old carbon stores are methane hydrates and permafrost regions of the Arctic, taiga forests, and Tibetan Plateau (4). During the last deglaciation period, Earth shed much of its vast glacial ice sheets as the global climate warmed by around 4°C. If old methane was an important driver of that period of warming, it will likely be important in modern climate change.Dyonisius et al. extracted methane from ice cores collected in Antarctica for radiocarbon (carbon-14) dating in the same way an archaeologist radiocarbon dates cultural artifacts. Contemporary methane will have a radiocarbon age close to the year of its release. By contrast, old methane will be so old that it will have no radiocarbon in it at all, a state known as “radiocarbon dead.” Ice core records trap bubbles of air during formation, and these bubbles represent an archive of atmospheric composition that spans up to a million years. However, large amounts of ice on the order of 1000 kg are needed for a single radiocarbon date of this methane. The study of Dyonisius et al. presents an impressive 11 such dates spanning 15,000 to 8000 years ago.Dyonisius et al. found no evidence for substantial releases of methane from old carbon sources. The methane they found was overwhelmingly contemporary relative to the time period that each sample represented, indicating that the vast majority of methane in the atmosphere during the period under study was derived from the decomposition of recently formed organic carbon, such as plants and soil, and not from the destabilization of old carbon stores. Given the substantial size of these old carbon reservoirs and their theorized sensitivity to climate change, why don't we see evidence for their release as methane?Methane hydrates contain between 500 and 4000 giga–metric tons of old carbon, roughly one to five times the amount of carbon currently in the atmosphere (including carbon dioxide). This old carbon is mostly biologically produced methane that has been trapped in a crystalline water (icelike) structure as the result of low temperatures and high pressures. Methane hydrates are found deep in the ocean and also trapped under permafrost and glacial ice sheets. Regions of permanently frozen ground, or permafrost, contain around 1300 giga–metric tons of carbon in frozen soils, almost a quarter of which is at least as old as the last glacial maximum (5). Both methane hydrates and permafrost are carbon reservoirs that are vulnerable to climate warming because their storage capabilities are temperature controlled. Methane hydrates are also vulnerable to pressure changes owing to sea level fluctuations and disappearing permafrost and ice sheets.However, old methane release occurs much slower than the pace of modern climate change. This is because methane is a rich source of energy within ecosystem food webs, particularly for microorganisms that consume this methane and release carbon dioxide. Thus, old methane is often rapidly consumed by microorganisms living in sediments, soils, and water, which convert it to carbon dioxide before it can be released to the atmosphere (6, 7). Some methane will escape this process and, along with the carbon dioxide produced from these microorganisms, will still have the potential to influence global climate (8).How important will old methane be to modern climate change? Old methane release may have been important in the geological past because of the long time scales involved (9). Hundreds or even thousands of years of warming may be required to generate sustained methane release from old carbon stores that can then outpace methane consumption (4, 8). Old methane release therefore does not occur fast enough nor at magnitudes that will be important in the immediate future when compared with methane release from contemporary sources such as wetlands and human activity, which release a third and half of all methane currently in the atmosphere, respectively (2, 10, 11). And despite the potency of methane as a greenhouse gas, it is still second in importance to carbon dioxide, which is a much more abundant climate pollutant from human industrial activity and a product of natural ecosystem carbon cycling.Slowing modern climate change is important to decrease the chance of old methane adding substantially to an already overloaded atmospheric carbon pool (11). Reduction of methane as a product of human activity, such as agriculture and the fossil-fuel industry, remains an important component of climate change mitigation efforts (2, 12). Although methane hydrates and permafrost carbon are unlikely to be major sources of methane to the atmosphere in the immediate future, unrestrained climate change over the coming century could lead to their destabilization. This could drive sustained emissions of old methane to the atmosphere over the following centuries, causing further warming.How much methane would be released, at what rates, and for how long are important unanswered questions. In the geological past before the time span of ice cores, the full importance of methane to global climate fluctuations is a mystery. To better explore this geological time span, the development of a useful proxy for past atmospheric methane concentrations, parallel to what is used as a proxy for carbon dioxide (13), remains an elusive goal (14). It will also be important to search for evidence of old methane release as an indicator of destabilization of current old carbon reservoirs and to serve as a baseline for the future. Methane hydrates and permafrost regions are large potential sources of old methane to the atmosphere in the long term but are less important for our immediate future than contemporary sources.References and Notes1. C. D. Elder et al, Nat. Clim. Chang. 8, 166 (2018).2. E. G. Nisbet et al, Global Biogeochem. Cycles 33, 318 (2019).3. M. N. Dyonisius et al, Science 367, 907 (2020)4. J. F. Dean et al., Rev. Geophys. 56, 207 (2018)5. J. Strauss et al., Earth Sci. Rev. 172, 75 (2017)6. J. W. Pohlman et al, Proc. Natl. Acad. Sci. U.S.A. 114, 5355 (2017).7. M. D. A. Cooper et al, Nat. Clim. Chang. 7, 507 (2017).8. B. Ferré et al, Nat. Geosci. 13, 144 (2020)9. J. Frieling et al, Proc. Natl. Acad. Sci. U.S.A. 113, 12059 (2016).10. M. Saunois et al, Earth Syst. Sci. Data 8, 697 (2016)11. S. E. Mikaloff Fletcher, H. Schaefer, Science 364, 932 (2019)12. R. B. Jackson, E. I. Solomon, J. G. Canadell, M. Cargnello, C. B. Field, Nat. Sustain. 2, 436 (2019)13. C. R. Witkowski, J. W. H. Weijers, B. Blais, S. Schouten, J. S. Sinninghe Damsté, Sci. Adv. 4, eaat4556 (2018)14. G. N. Inglis, B. D. A. Naafs, Y. Zheng, J. Schellekens, R. D. Pancost, Geochim. Cosmochim. Acta 260, 244 (2019)Deelaman, W., Pongpiachan, S., Tipmanee, D., Choochuay, C., Iadtem, N., Suttinun, O., Wang, Q., Xing, L., Li, G., Han, Y., Hashmi, M.Z., Cao, J., 2020. Source identification of polycyclic aromatic hydrocarbons in terrestrial soils in Chile. Journal of South American Earth Sciences 99, 102514. this study, a combination of the diagnostic binary ratios of PAHs and multivariate descriptive statistics was applied to identify the sources of PAHs in Chilean terrestrial soils. A total of 15 PAHs from the terrestrial soil of 28 locations in three cities of Chile were chemically characterized using gas chromatography mass spectrometry (GC-MS). The total concentrations of twelve likely carcinogenic PAHs were defined as the sum of Phe, An, Fluo, Pyr, B[a]A, Chry, B[b]F, B[k]F, B[a]P, Ind, D[a, h]A and B[g, h, i]P and ranged from 0.0215 to 4.37 μg g?1 with an arithmetic mean of 0.618 ± 0.911 μg g?1. The levels of these PAHs were classified as moderate to high compared to World Soils (WS). All sampling stations were dominated by high molecular weight PAHs, four-ring (39.1%) and five-ring (29.6%) PAHs were the most abundant groups in the terrestrial soils of Chile. The PAH diagnostic ratios suggested that PAHs are primarily of pyrogenic origin. Further multivariate descriptive statistics (i.e., hierarchical cluster analysis (HCA) and principal components analysis (PCA)) identified pyrogenic combustion as the main emission source of PAH contamination in Chilean terrestrial soils.Defliese, W.F., Tripati, A., 2020. Analytical effects on clumped isotope thermometry: Comparison of a common sample set analyzed using multiple instruments, types of standards, and standardization windows. Rapid Communications in Mass Spectrometry 34, e8666.: Carbonate clumped isotope geothermometry is being increasingly used in multiple disciplines in the geosciences. However, potential interlaboratory issues are arising from different standardization procedures that may contribute to the multiple Δ47‐temperature calibrations reported in the literature. We investigate this issue by comparing a common temperature calibration sample set across three different mass spectrometers, using multiple standardization methods. Methods: The same temperature calibration sample set was analyzed on three different mass spectrometers. Several standardization methods were utilized, including the use of carbonate versus gas standards, and different types of background correction were applied to the raw data.Results: All standardization types applied resulted in statistically indistinguishable Δ47‐temperature slopes, with the exception of standardization calculations that did not correct for background effects. Some instruments and standardizations showed different intercepts relative to each other. The use of carbonate standards improved comparability between different instruments relative to gas standards. Conclusions: Our results show that background effects are the largest factor potentially affecting Δ47 results, and there may be an improvement in interlaboratory precision using carbonate standards. Critically, all techniques used for standardizing Δ47 results converge on a common slope as long as background effects are properly corrected. The use of carbonate standards is recommended as a component of standardization procedures. Del Cortona, A., Jackson, C.J., Bucchini, F., Van Bel, M., D’hondt, S., ?kaloud, P., Delwiche, C.F., Knoll, A.H., Raven, J.A., Verbruggen, H., Vandepoele, K., De Clerck, O., Leliaert, F., 2020. Neoproterozoic origin and multiple transitions to macroscopic growth in green seaweeds. Proceedings of the National Academy of Sciences 117, 2551-2559.: Green seaweeds are important primary producers along coastlines worldwide. Their diversification played a key role in the evolution of animals. To understand their origin and diversification, we resolve key relationships among extant green algae using a phylotranscriptomic approach. A time-calibrated tree, inferred from available fossil data, reconstructs important evolutionary events, such as transitions to benthic environments and the evolution of macroscopic growth in the late Tonian/Cryogenian periods, followed by a marked Ordovician diversification of macroscopic forms. This ancient proliferation of green seaweeds likely modified shallow marine ecosystems, which set off an evolutionary arms race between ever larger seaweeds and grazers.Abstract: The Neoproterozoic Era records the transition from a largely bacterial to a predominantly eukaryotic phototrophic world, creating the foundation for the complex benthic ecosystems that have sustained Metazoa from the Ediacaran Period onward. This study focuses on the evolutionary origins of green seaweeds, which play an important ecological role in the benthos of modern sunlit oceans and likely played a crucial part in the evolution of early animals by structuring benthic habitats and providing novel niches. By applying a phylogenomic approach, we resolve deep relationships of the core Chlorophyta (Ulvophyceae or green seaweeds, and freshwater or terrestrial Chlorophyceae and Trebouxiophyceae) and unveil a rapid radiation of Chlorophyceae and the principal lineages of the Ulvophyceae late in the Neoproterozoic Era. Our time-calibrated tree points to an origin and early diversification of green seaweeds in the late Tonian and Cryogenian periods, an interval marked by two global glaciations with strong consequent changes in the amount of available marine benthic habitat. We hypothesize that unicellular and simple multicellular ancestors of green seaweeds survived these extreme climate events in isolated refugia, and diversified in benthic environments that became increasingly available as ice retreated. An increased supply of nutrients and biotic interactions, such as grazing pressure, likely triggered the independent evolution of macroscopic growth via different strategies, including true multicellularity, and multiple types of giant-celled forms.Dembicki, H., 2020. Reducing the risk of finding a working petroleum system using SAR imaging, sea surface slick sampling, and geophysical seafloor characterization: An example from the eastern Black Sea basin, offshore Georgia. Marine and Petroleum Geology 115, 104276. new plays emerge in deepwater settings, sea surface slicks are often overlooked as a source of geochemical information to help define potential petroleum systems. To demonstrate how sea surface hydrocarbon slicks can be used, a case study is presented from the eastern Black Sea in the Rioni Basin, offshore Republic of Georgia. There source rocks of Oligo-Miocene age (Maikop) are suspected of charging upper Miocene deepwater channel-levee sands in fold and thrust system traps. To reduce exploration risk, direct evidence of hydrocarbon generation and migration was sought using sea surface slicks observed there.To provide confirmation of charge, a collection of diverse data was used. First, synthetic aperture radar satellite images were utilized to verify the presence of large recurring sea surface slicks over prospective structures. These slicks were then sampled for later analysis during the acquisition of 3-D seismic data. To verify that the slicks were related to the subsurface expulsion, seafloor bathymetric and amplitude data were extracted from the 3-D seismic volume and used to identify potential seafloor features consistent with hydrocarbon seepage. Some of these seafloor features were found to be coincident with the apparent sea surface origins of the slicks. Seismic imaging was also used to demonstrate potential migration pathways which may link suspected deep subsurface traps and the seafloor. And finally, geochemical analysis showed that the compositional characteristics of the slicks’ hydrocarbons were similar to known Maikop sourced oils in the region.This combination of data provided a high level of confidence that the seismically imaged traps in offshore Republic of Georgia are charged, suggesting a working petroleum system was present. What it cannot tell us is how much petroleum may be in these structures. That question can only be answered by the drill bit.Demongeot, J., Seligmann, H., 2020. Pentamers with non-redundant frames: Bias for natural circular code codons. Journal of Molecular Evolution 88, 194-201. natural circular code consists of 20 codons (X0) overrepresented in the coding frame of protein-coding genes as compared to remaining noncoding frames, and X1 and X2 (N1N2N3?→?N3N1N2 and N1N2N3?→?N2N3N1 permutations of X0, overrepresented in?+?1 and ? 1 frames of protein-coding genes, not self-complementary). X0, X1 and X2 detect ribosomal,?+?1 and ? 1 frames. X0 spontaneously emerges in the 25 theoretical minimal RNA rings, 22-nucleotide-long circular RNAs designed to code once for each of the genetic code’s coding signals (a start, a stop and each of the 20 amino acids) by three overlapping frames. RNA rings presumed ancient are biased for X1, and bias for X0 increases in presumed recent RNA rings, indicating an evolutionary X1-to-X0 switch. Here, analyses explore biases for X0, X1 and X2 in non-redundant nucleotide tetra- and pentamers, for different genetic codes. Biases for X0 occur in non-redundant nucleotide pentamers and seem stronger in nuclear than mitochondrial genetic codes; tendencies are opposite for X1. Strand-asymmetric replication presumably causes mitogenomes to escape Chargaff’s rule which expects ratios A/T = G/C = 1 in single-stranded sequences. Hence, presumably X1 emerged in ancient genetic codes used in single-stranded protogenomes/coding RNAs; the self-complementary X0 presumably evolved secondarily with double-stranded genomes and strand-symmetric replication. Results indicate that selection for non-redundant overlap coding in short nucleotide sequences produced the natural circular code.Deng, Z., Jiang, Y., Chen, K., Li, J., Zheng, C., Gao, F., Liu, X., 2020. One biosurfactant-producing bacteria Achromobacter sp. A-8 and its potential use in microbial enhanced oil recovery and bioremediation. Frontiers in Microbiology 11, 247. doi: 10.3389/fmicb.2020.00247. plays an important role in bioremediation of crude oil contamination and microbial enhanced oil recovery (MEOR). In the present study, a salt-tolerant, biosurfactant-producing bacterium, designated A-8, was isolated from wastewater contaminated with petroleum collected from the Changqing reservoir in China. A phylogenetic analysis based on the 16S rRNA sequence suggests that strain A-8 belongs to the genus Achromobacter. The optimal growth conditions for strain A-8 in mineral salt (MS) medium were 30°C, pH 7, and 10 g/L NaCl, while the optimal conditions for biosurfactant production in a fermentation medium were 40–45°C, pH 7, and more than 70 g/L NaCl. Better biosurfactant production was obtained from strain A-8 when edible oil and liquid paraffin were used as carbon sources and when (NH4)2SO4 was used as an inorganic nitrogen source compared with other tested carbon and nitrogen sources. The biodegradation of petroleum in MS medium in different optimized conditions reached 56.23–73.87% for 20 days. The biodegradation of petroleum, together with the production of organic acid and biosurfactant, decreased the viscosity of petroleum by about 45%. The decrease in petroleum viscosity and the biodegradation of petroleum suggest the potential use of strain A-8 for MEOR and bioremediation of petroleum-contaminated environments.Dezfuli, M.G., Jafari, A., Gharibshahi, R., 2020. Optimum volume fraction of nanoparticles for enhancing oil recovery by nanosilica/supercritical CO2 flooding in porous medium. Journal of Petroleum Science and Engineering 185, 106599. gas injection is a practical process in enhanced oil recovery (EOR) methods, but the important defects of this injection type are recognized as the creation of finger and quick breakthrough of the injected fluid in terms of the gas low viscosity and also inappropriate mobility ratio. Along with the nanotechnology advancement, special attention has been paid to the nanoparticles usage. It is possible that nanoparticles addition could enhance the gas viscosity and the injected gas density, and the result is increasing the oil recovery factor from reservoirs. Therefore, the purpose of this study was to investigate the nanoparticles presence in injected supercritical gas effect on the oil recovery. Therefore, here mathematical equations were modeled that were relevant to nanosilica/supercritical CO2 injection into a long fully oil saturated core, and they were solved using MATLAB software. Results indicated that for the light oil by nanoparticles addition up to 3.5?vol %, oil recovery would increase with a constant slope, but for the amounts higher than 3.5?vol % of the nanoparticles, oil recovery increment slope tends to zero, and after 4?vol % of the nanoparticle oil recovery factor indicates reduction. The maximum ultimate light oil recovery factor achieved by supercritical CO2 injection in the 4?vol % presence is 30.47%. Although, for heavy oil by nanoparticles addition in the range of 0–5?vol %, oil recovery will be gradually increased. Consequently, the maximum ultimate heavy oil recovery factor obtained by supercritical CO2 injection is 27.82% in 5?vol % presence.Di Valentino, E., Melchiorri, A., Silk, J., 2020. Planck evidence for a closed Universe and a possible crisis for cosmology. Nature Astronomy 4, 196-203. recent Planck Legacy 2018 release has confirmed the presence of an enhanced lensing amplitude in cosmic microwave background power spectra compared with that predicted in the standard Λ cold dark matter model, where Λ is the cosmological constant. A closed Universe can provide a physical explanation for this effect, with the Planck cosmic microwave background spectra now preferring a positive curvature at more than the 99% confidence level. Here, we further investigate the evidence for a closed Universe from Planck, showing that positive curvature naturally explains the anomalous lensing amplitude, and demonstrating that it also removes a well-known tension in the Planck dataset concerning the values of cosmological parameters derived at different angular scales. We show that since the Planck power spectra prefer a closed Universe, discordances higher than generally estimated arise for most of the local cosmological observables, including baryon acoustic oscillations. The assumption of a flat Universe could therefore mask a cosmological crisis where disparate observed properties of the Universe appear to be mutually inconsistent. Future measurements are needed to clarify whether the observed discordances are due to undetected systematics, or to new physics or simply are a statistical fluctuation.Dillinger, S., Niedner-Schatteburg, G., 2019. Chapter 19 - Cryo trapping by FT-MS for kinetics and spectroscopy, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 593-621. we describe the reasoning for cryo FT-MS technologies in terms of pressure broadening and activation by black body radiation, and the development and achievements of such technologies in chemistry and nuclear physics, shortly referring to other cryo ion technologies. We present an illustrative example on isotope effects in black body induced radiative dissociation (BIRD), and some recent experiments on the elucidation of transition metal (TM) cluster surface morphologies and of TM complexes by cryo FT-MS. Such studies record infrared spectra by multiple photon dissociation (IR-MPD), and adsorption kinetics by reaction delay scans. Some most recent studies invoke a combination of cryo FT-MS with another cryo ion trap thus enabling tandem cryo trapping experiments. One of these studies revealed the interaction of molecular co-adsorbates on TM clusters. We conclude by and outlook onto future directions of cryo FT-MS.Dillon, M.L., Hawes, I., Jungblut, A.D., Mackey, T.J., Eisen, J.A., Doran, P.T., Sumner, D.Y., 2020. Energetic and environmental constraints on the community structure of benthic microbial mats in Lake Fryxell, Antarctica. FEMS Microbiology Ecology 96, fiz207. communities are regulated by the flow of energy through environments. Energy flow is typically limited by access to photosynthetically active radiation (PAR) and oxygen concentration (O2). The microbial mats growing on the bottom of Lake Fryxell, Antarctica, have well-defined environmental gradients in PAR and (O2). We analyzed the metagenomes of layers from these microbial mats to test the extent to which access to oxygen and light controls community structure. We found variation in the diversity and relative abundances of Archaea, Bacteria and Eukaryotes across three (O2) and PAR conditions: high (O2) and maximum PAR, variable (O2) with lower maximum PAR, and low (O2) and maximum PAR. We found distinct communities structured by the optimization of energy use on a millimeter-scale across these conditions. In mat layers where (O2) was saturated, PAR structured the community. In contrast, (O2) positively correlated with diversity and affected the distribution of dominant populations across the three habitats, suggesting that meter-scale diversity is structured by energy availability. Microbial communities changed across covarying gradients of PAR and (O2). The comprehensive metagenomic analysis suggests that the benthic microbial communities in Lake Fryxell are structured by energy flow across both meter- and millimeter-scales.Dim, C.I.P., Onuoha, K.M., Ozumba, B.M., 2020. Hydrocarbon leads and prospects opportunities across a cluster of fields in parts of Onshore Niger Delta Basin. Journal of African Earth Sciences 164, 103804. increase in oil and gas production over the years from already discovered fields at relatively shallower intervals, and corresponding decrease in the discovery of new fields has led to observable decline in the available hydrocarbon reserves within the Niger Delta Basin of Nigeria. Therefore, there is need to grow or add to the existing reserves through “searching wider and drilling deeper” across the onshore sector of the Niger Delta Basin, which is the focus of this work. Although, there has been several hydrocarbon prospectivity studies in the Onshore Niger Delta Basin, most of these studies were conducted on individual fields, except where adjacent fields belonged to the same operator. This has provided limited information on stratigraphic intervals, structural features and reservoir zones continuity across several fields. This study is aimed at interpreting recently acquired within the Coastal Swamp Depobelt of the Niger Delta, long-cable regional 3D seismic data over nine producing fields, and data from twenty-five wells, using sequence stratigraphic, structural and reservoir exploration tools, thus providing a regional scale interpretation and information that will unravel new prospective zones across these fields primarily based on amplitude supported structural plays. Results from stratigraphic studies, show the occurrence of regional extensive chrono/sequence stratigraphic surfaces such as maximum flooding surfaces (7.4–12.8?Ma) and sequence boundaries (8.5–13.1?Ma) that depict sediment packages deposited during the Middle-Miocene through Upper Miocene age. Well log sequence stratigraphic and reservoir correlation studies reveal that depositional sequences, bounded by these surfaces, comprise reservoir and non-reservoir packages within their systems tracts. Reservoir architectural studies show sands of lowstand, transgressive, and highstand systems tracts that make up the reservoir units, are relatively thick, laterally continuous and quite extensive across the area. Interpreted seismic sections unravelled the influence of structure on stratigraphy as sediment packages show variable thicknesses across faults. This was linked to syndepositional deformation associated with sediment deposition within the basin. Mapped reservoir tops at intermediate and deeper intervals reveal the dominance of fault-dependent closures. In addition, root mean square amplitude extraction done on these maps, unravelled eight structurally controlled regional hydrocarbon prospects and eight leads with booming amplitude responses that are conformable to structures. Overall, this study has shown that there exist hydrocarbon prospective zones that cut across several fields at deeper depths that are yet to be drilled, which could contribute to the Niger Delta Basin's existing reserve base.Dixon, R.A., Barros, J., 2019. Lignin biosynthesis: old roads revisited and new roads explored. Open Biology 9, 190215. is a major component of secondarily thickened plant cell walls and is considered to be the second most abundant biopolymer on the planet. At one point believed to be the product of a highly controlled polymerization procedure involving just three potential monomeric components (monolignols), it is becoming increasingly clear that the composition of lignin is quite flexible. Furthermore, the biosynthetic pathways to the major monolignols also appear to exhibit flexibility, particularly as regards the early reactions leading to the formation of caffeic acid from coumaric acid. The operation of parallel pathways to caffeic acid occurring at the level of shikimate esters or free acids may help provide robustness to the pathway under different physiological conditions. Several features of the pathway also appear to link monolignol biosynthesis to both generation and detoxification of hydrogen peroxide, one of the oxidants responsible for creating monolignol radicals for polymerization in the apoplast. Monolignol transport to the apoplast is not well understood. It may involve passive diffusion, although this may be targeted to sites of lignin initiation/polymerization by ordered complexes of both biosynthetic enzymes on the cytosolic side of the plasma membrane and structural anchoring of proteins for monolignol oxidation and polymerization on the apoplastic side. We present several hypothetical models to illustrate these ideas and stimulate further research. These are based primarily on studies in model systems, which may or may not reflect the major lignification process in forest trees.Dolomatov, M.Y., Shutkova, S.A., Bakhtizin, R.Z., Dolomatova, M.M., Latypov, K.F., Gilmanshina, K.A., Badretdinov, B.R., 2020. Structure of asphaltene molecules and nanoclusters based on them. Petroleum Chemistry 60, 16-21. chemical, electronic, and supramolecular structures of asphaltenes, isolated from the atmospheric–vacuum distillation residue of Western Siberian crude oil, have been experimentally and theoretically studied. The chemical structure of asphaltenes has been studied by IR, UV, and visible spectroscopy. Using UV–visible absorption spectra, the electronic structure of asphaltene molecules has been determined and the highest occupied and lowest unoccupied molecular orbitals have been assessed from the effective ionization potential and effective electron affinity. The average structure of asphaltene molecules has been obtained according to chemical analysis and spectroscopy data. Quantum-chemical DFT calculations have shown that the ionization potentials and electron affinity are consistent with optical spectroscopy and electrical conductivity measurement data. The molecular mechanics calculations of nanoclusters containing up to ten molecular units of asphaltene have also shown compliance with experimental results.Dombrosky, J., 2019. A ~1000-year 13C Suess correction model for the study of past ecosystems. The Holocene 30, 474-478. about how an ecosystem has changed through time often rely on longitudinal records of species characteristics or niche parameters, and stable isotope analysis is a common tool employed to study changes in an organism’s niche. One of the most frequently used stable isotope measures is δ13C, a ratio of 13C to 12C. However, applying δ13C to historical samples comes with some methodological hurdles. One such hurdle is correcting for the 13C Suess effect or the change in atmospheric δ13C due to increased anthropogenic CO2 emissions. The change in the amount of carbon isotopes in the atmosphere through time can confound the study of historical shifts in species characteristics. No standard way of correcting for the 13C Suess effect has been suggested despite this problem. Here, I propose a standard 13C Suess correction model for the past ~1000 years using three prehistoric/historic records of atmospheric δ13C.Donato, P., Arena, P., Mondello, L., 2020. Chapter 3.2 - Theoretical and practical aspects of LC-MS analysis, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 297-317. the early gloomy prospects for the development of a suitable interface and operation, instrumental couplings of liquid chromatography (LC) to mass spectrometry (MS) have experienced an enormous growth in the last two decades; the number of applications of this powerful hyphenated technique have exponentially increased, consistently. Arguably, the advances made in miniaturized LC systems and column technology have strongly prompted such an evolution; as a matter of fact, capillary LC-MS (and tandem MS) nowadays accounts for the vast majority of applications performed, e.g., through “omics” technologies. Today any mass spectrometer potentially can be hyphenated to an LC separation system by properly interfacing the chromatographic and spectrometric components; this was a major technical challenge earlier. Understanding the working principles and technical properties of different MS instruments gives an insight into the technical possibilities and limitations to be acknowledged when coupling MS with LC. In the sections that follow, the readers will be given theoretical and practical guidance on the analytical capabilities of most common types of MS analyzers, which constrain the utility of an instrument for handling the specific analytical task at hand.Dong, H., Sun, J., Arif, M., Golsanami, N., Yan, W., Zhang, Y., 2020. A novel hybrid method for gas hydrate filling modes identification via digital rock. Marine and Petroleum Geology 115, 104255. hydrates are one of the most abundant clean energy resources and can effectively solve the energy crisis with a lower carbon footprint. Gas hydrates typically exhibit complex microscopic filling modes, including adhesive mode, cemented mode and scattered mode. Furthermore, the scientific understanding of such filling modes and the associated petrophysical parameters is essential for successful exploitation and development of hydrate formations. However, a precise identification of such filling modes remains a big challenge. Thus, here we proposed a novel hybrid gas hydrate filling mode identification method via digital rock technique. The hybrid method uses a combination of multiple methodologies. Firstly, the dry core samples were scanned by the high-resolution micro-scale 3D X-ray computed tomography (μCT) and the digital rock models were built. Then the resistivity was simulated as a function of gas hydrate saturation with three idealized gas hydrate-filling modes. The differences between the resistivity of three idealized gas hydrate-filling modes were analyzed, and based on the correlations obtained, the idealized gas hydrate saturation calculation models were formulated. We then considered well log data from a real hydrate reservoir in order to evaluate the application of proposed hydrate saturation model and identify the filling mode. Essentially, the gas hydrate saturation results from digital rock models and field well logging data are compared, and the filling modes in the research reservoir were successfully identified.Doud, D.F.R., Bowers, R.M., Schulz, F., De Raad, M., Deng, K., Tarver, A., Glasgow, E., Vander Meulen, K., Fox, B., Deutsch, S., Yoshikuni, Y., Northen, T., Hedlund, B.P., Singer, S.W., Ivanova, N., Woyke, T., 2020. Function-driven single-cell genomics uncovers cellulose-degrading bacteria from the rare biosphere. The ISME Journal 14, 659-675. a functional role to a microorganism has historically relied on cultivation of isolates or detection of environmental genome-based biomarkers using a posteriori knowledge of function. However, the emerging field of function-driven single-cell genomics aims to expand this paradigm by identifying and capturing individual microbes based on their in situ functions or traits. To identify and characterize yet uncultivated microbial taxa involved in cellulose degradation, we developed and benchmarked a function-driven single-cell screen, which we applied to a microbial community inhabiting the Great Boiling Spring (GBS) Geothermal Field, northwest Nevada. Our approach involved recruiting microbes to fluorescently labeled cellulose particles, and then isolating single microbe-bound particles via fluorescence-activated cell sorting. The microbial community profiles prior to sorting were determined via bulk sample 16S rRNA gene amplicon sequencing. The flow-sorted cellulose-bound microbes were subjected to whole genome amplification and shotgun sequencing, followed by phylogenetic placement. Next, putative cellulase genes were identified, expressed and tested for activity against derivatives of cellulose and xylose. Alongside typical cellulose degraders, including members of the Actinobacteria, Bacteroidetes, and Chloroflexi, we found divergent cellulases encoded in the genome of a recently described candidate phylum from the rare biosphere, Goldbacteria, and validated their cellulase activity. As this genome represents a species-level organism with novel and phylogenetically distinct cellulolytic activity, we propose the name Candidatus ‘Cellulosimonas argentiregionis’. We expect that this function-driven single-cell approach can be extended to a broad range of substrates, linking microbial taxonomy directly to in situ function.Dragone, G., Kerssemakers, A.A.J., Driessen, J.L.S.P., Yamakawa, C.K., Brumano, L.P., Mussatto, S.I., 2020. Innovation and strategic orientations for the development of advanced biorefineries. Bioresource Technology 302, 122847. biorefineries, which aim at valorizing biomass (from agriculture, forestry, aquaculture, among others) into a wide spectrum of products and bioenergy, are seen today as key to implement a sustainable biobased economy. Although different concepts of biorefinery are currently under development, further research and improvement are still required to obtain environmentally friendly and economically feasible commercial scale biorefineries. Valorization of all biomass components and integration of different disciplines are some of the strategies that have been considered to improve the economic and environmental performance. This paper summarizes and discusses the most recent innovations and strategic orientations for the development of advanced biorefineries. Focus is given on the valorization of non-carbohydrate components of biomass (protein, acetic acid and lignin), on-site and tailor-made production of enzymes, big data analytics, and interdisciplinary efforts. The idea is to provide new insights and directions to support the development and large-scale implementation of biorefineries.Du, F., Huang, J., Chai, Z., Killough, J., 2020. Effect of vertical heterogeneity and nano-confinement on the recovery performance of oil-rich shale reservoir. Fuel 267, 117199. to the effect of compaction, stress-dependent properties such as permeability, porosity, and pore size vary in the vertical direction of shale reservoir. The heterogeneity of physical properties influences the fluid flow in shale formation. Meanwhile, the confinement effects, including large oil-gas capillary pressure and critical property shifts, as a function of pore-throat radius could greatly alter phase behaviors in nano-pores. Thus, vertical heterogeneity affects the interpretation of production performance of an oil-rich shale reservoir. In this study, a compositional simulation model incorporated with confinement effects is applied to simulate primary depletion in an intensively fractured oil-rich shale formation. Stress-dependent properties are assigned to different depth of the pay zone. Two nano-confinement effects on phase behavior and recovery performance are examined, respectively. Simulation results show that nano-confinement effects affect the well productivity through altering the fluid properties and phase behaviors. Inclusion of capillary pressure effect increases oil production but suppresses gas production. Considering critical property shift enhances both oil and gas recoveries. In very tight shale formation, confinement effects are more comparable to gravity drainage on improving oil recovery. As pore size is reduced with depth, confinement effects become more apparent on increasing oil recovery. However, it still cannot exceed the benefits from drilling the well at high permeable formation. Drilling the horizontal well in relatively high-permeability layer that has high permeable adjacent layers could achieve the largest oil and gas recoveries.Duan, J., Amster, I.J., 2019. Chapter 20 - Application of FTMS to the analysis of glycosaminoglycans, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 623-649. (GAGs) are linear chain glycans consisting of repeating uronic sugar and amino sugar copolymers and play major roles in fundamental biological processes. Despite being ubiquitous in cells, the structure of GAGs remains relatively elusive and is challenging to characterize with mass spectrometry. This chapter discusses how Fourier transform mass spectrometry (FTMS) plays a vital role in developing methods for high throughput structural elucidation of GAGs. High mass accuracy measurements of the mass spectrum allow for composition assignment of the intact glycan; tandem mass spectrometry with various ion activation techniques have been used to determine the location of structural microheterogeneities with high specificity. Software analysis packages for GAGs have also been developed recently, allowing for the option of high-throughput analysis without the need for any user supervision. New and promising developments in FTMS have significantly improved structural characterization possibilities in the field of glycomics.Dugerdil, L., Joannin, S., Peyron, O., Jouffroy-Bapicot, I., Vannière, B., Boldgiv, B., Ménot, G., 2020. Climate reconstructions based on GDGTs and pollen surface datasets from Mongolia and Siberia: Calibrations and applicability to extremely dry and cold environments. Biogeosciences Discussions 2020, 1-35. understanding of climate and vegetation changes throughout the Holocene is hampered by biases in the proxy representativeness in sedimentary archives. Such potential biases are identified by comparing proxies to modern environments. Consequently, it becomes important to conduct multi-proxy studies and robust calibrations. The taiga-steppes of the Mongolian plateau, ranging from the extremely cold-dry Baikal basin to the Gobi desert, are characterized by low annual precipitation and continental annual air temperature as well as livestock grazing. The characterization of the climate system of this area is crucial for the understanding of Holocene Monsoon Oscillations. This study focuses on the calibration of proxy-climate relationships for pollen and glycerol dialkyl glycerol tetraethers (GDGTs) by comparing large published Eurasian calibrations with a set of 53 new surface samples (moss, soil and surface sediments). We show that: (1) preserved pollen assemblages are clearly imprinted on the extremities of the ecosystem range but mitigated and unclear on the ecotones; (2) for both proxies, inferred relationships depend on the geographical range covered by the calibration database as well as on the sample nature; (3) local calibrations, even those derived to the low range of climate parameters encompassed in the study area, better reconstruct climatic parameters than the global ones by reducing the limits for saturation impact, and (4) a bias in climatic reconstructions is induced by the over-parameterization of the models by addition of artificial correlation. We encourage the application of this surface calibration method to consolidate our understanding of the Holocene climate and environment variations.Duncan, K.D., Richards, L.C., Monaghan, J., Simair, M.C., Ajaero, C., Peru, K.M., Friesen, V., McMartin, D.W., Headley, J.V., Gill, C.G., Krogh, E.T., 2020. Direct analysis of naphthenic acids in constructed wetland samples by condensed phase membrane introduction mass spectrometry. Science of The Total Environment 176, 137063. application of direct mass spectrometry techniques to the analysis of complex samples has a number of advantages including reduced sample handling, higher sample throughput, in situ process monitoring, and the potential for adaptation to on-site analysis. We report the application of a semi-permeable capillary hollow fibre membrane probe (immersed directly into an aqueous sample) coupled to a triple quadrupole mass spectrometer by a continuously flowing methanol acceptor phase for the rapid analysis of naphthenic acids with unit mass resolution. The intensity of the naphthenic acid-associated peaks in the mass spectrum are normalized to an internal standard in the acceptor phase for quantitation and the relative abundance of the peaks in the mass spectrum are employed to monitor compositional changes in the naphthenic acid mixture using principle component analysis. We demonstrate the direct analysis of classical naphthenic acids (CnH2n+zO2) in a synthetic oil sands process water as they are attenuated through constructed wetlands containing sedge (Carex aquatilis), cattail (Typha latifolia), or bulrush (Schoenoplectus acutus). Quantitative results for on-line membrane sampling compare favourably to those obtained by solid-phase extraction high-resolution mass spectrometry. Additionally, chemometric analysis of the mass spectra indicates a clear discrimination between naphthenic acid-influenced and natural background waters. Furthermore, the compositional changes within complex naphthenic acid mixtures track closely with the degree of attenuation. Overall, the technique is successful in following changes in both the concentration and composition of naphthenic acids from synthetic oil sands process-affected waters, with the potential for high throughput screening and environmental forensics.Duran, J.A., Schoeggl, F.F., Yarranton, H.W., Fávero, C.V.B., Fogler, H.S., 2020. Effect of air on the kinetics of asphaltene precipitation from diluted crude oils. Energy & Fuels 34, 1408-1421. kinetics of asphaltene precipitation was investigated for five crude oils diluted with n-heptane at 21 °C in air and nitrogen atmospheres. The onset of precipitation, defined as the precipitant (n-heptane) content at which detectable asphaltene particles first appear, was measured in air at different contact times using optical microscopy and a gravimetric method. Asphaltene yields (mass asphaltene/mass oil) were measured in air over time gravimetrically. The data were compared with yields and “yield onsets” previously measured for the same mixtures in a nitrogen atmosphere.1 In a nitrogen atmosphere, the yields increased and the onsets decreased over approximately 50 h but then reached plateau values, indicating that an equilibrium condition existed. In an air atmosphere, the yields and onsets were the same as in nitrogen for the first 50 h, but then the yields gradually increased for the duration of the experiments. The onsets shifted to lower values over time, and there was no equilibrium onset condition. Hence, precipitation data collected in air below 50 h can be used for kinetic modeling as is; however, data collected in air over longer times overstates asphaltene yields under anaerobic conditions and requires correction. It is hypothesized that the oxygen in the air catalyzes or participates in reactions that alter the asphaltenes and other crude oil components over time so that they become less soluble. The oxidation rate appears to correlate approximately with the asphaltene content of the oil. The population balance first developed by Maqbool et al., Modeling the Aggregation of Asphaltene Nanoaggregates in Crude Oil-Precipitant Systems. Energy Fuels, 25 (4), 2011, 1585-1596, and later modified by Duran et al., Kinetics of Asphaltene Precipitation/Aggregation from Diluted Crude Oil. Fuel, 255,2019, 115859, was further adapted to account for the increase in yield over time due to oxygen by introducing a term for the generation of unstable asphaltene primary particles. The proposed model matched the precipitation yield data from this study and from the literature with an average absolute deviation of less than 2 wt %.Dyonisius, M.N., Petrenko, V.V., Smith, A.M., Hua, Q., Yang, B., Schmitt, J., Beck, J., Seth, B., Bock, M., Hmiel, B., Vimont, I., Menking, J.A., Shackleton, S.A., Baggenstos, D., Bauska, T.K., Rhodes, R.H., Sperlich, P., Beaudette, R., Harth, C., Kalk, M., Brook, E.J., Fischer, H., Severinghaus, J.P., Weiss, R.F., 2020. Old carbon reservoirs were not important in the deglacial methane budget. Science 367, 907.: Permafrost and methane hydrates are large, climate-sensitive old carbon reservoirs that have the potential to emit large quantities of methane, a potent greenhouse gas, as the Earth continues to warm. We present ice core isotopic measurements of methane (Δ14C, δ13C, and δD) from the last deglaciation, which is a partial analog for modern warming. Our results show that methane emissions from old carbon reservoirs in response to deglacial warming were small (<19 teragrams of methane per year, 95% confidence interval) and argue against similar methane emissions in response to future warming. Our results also indicate that methane emissions from biomass burning in the pre-Industrial Holocene were 22 to 56 teragrams of methane per year (95% confidence interval), which is comparable to today.Editor's summary: Small burden from old sources. Methane is a potent greenhouse gas with large natural sources, reservoirs, and sinks. Dyonisius et al. found that methane emissions from old, cold-region carbon reservoirs like permafrost and methane hydrates were minor during the last deglaciation (see the Perspective by Dean). They analyzed the carbon isotopic composition of atmospheric methane trapped in bubbles in Antarctic ice and found that methane emissions from those old carbon sources during the warming interval were small. They argue that this finding suggests that methane emissions in response to future warming likely will not be as large as some have suggested.Easterling, M.L., Agar, J.N., 2019. Chapter 3 - Fundamentals, strengths, and future directions for Fourier transform ion cyclotron resonance mass spectrometry, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 63-88. for a range of uses from chemical purification to analytical instrumentation have exploited the constant relationship between a confining magnetic field and its captured charged particle. The path to mass spectrometry from particle physics was clearly evolutionary containing key and bit players along the development pathway. Modern Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometers retain notable characteristics of many stepwise advancements dating back to the simple copper cyclotron of Lawrence. Common themes among these milestones were flexibility and performance that seemingly transcended the sum of parts of a simple device that relied on a simple physical relationship. Recent advances to this simplistic concept have enabled dramatic increases in analytical figures-of-merit beyond what could be imagined even a decade ago. The emerging instrumentation has a core competence for separation of complex mixtures to include isotopologue masses of individual isotopic peaks in those very mixtures. With this routine capability comes new ideas for analysis of biomolecules and effectively supplements the advantage of selectivity for complex mixtures with specificity of their composition or heteroatom content.Edie, R., Robertson, A.M., Soltis, J., Field, R.A., Snare, D., Burkhart, M.D., Murphy, S.M., 2019. Off-site flux estimates of volatile organic compounds from oil and gas production facilities using fast-response instrumentation. Environmental Science & Technology 54, 1385-1394. estimates of volatile organic compounds (VOCs) from oil and gas (O&G) production facilities are fundamental in understanding hazardous air pollutant concentrations and ozone formation. Previous off-site emission estimates derive fluxes by ratioing VOCs measured in canisters to methane fluxes measured in the field. This study uses the Environmental Protection Agency’s Other Test Method 33A (OTM 33A) and a fast-response proton transfer reaction mass spectrometer to make direct measurements of VOC emissions from O&G facilities in the Upper Green River Basin, Wyoming. We report the first off-site direct flux estimates of benzene, toluene, ethylbenzene, and xylenes from upstream O&G production facilities and find that these estimates can vary significantly from flux estimates derived using both the canister ratio technique and from the emission inventory. The 32 OTM 33A flux estimates had arithmetic mean (and 95% CI) as follows: benzene 17.83 (0.22, 98.05) g/h, toluene 34.43 (1.01, 126.76) g/h, C8 aromatics 37.38 (1.06, 225.34) g/h, and methane 2.3 (1.7, 3.1) kg/h. A total of 20% of facilities measured accounted for ～67% of total BTEX emissions. While this heavy tail is less dramatic than previous observations of methane in other basins, it is more prominent than that predicted by the emission inventory.Einsiedl, F., Wunderlich, A., Sebilo, M., Coskun, ?.K., Orsi, W.D., Mayer, B., 2020. Biogeochemical evidence of anaerobic methane oxidation and anaerobic ammonium oxidation in a stratified lake using stable isotopes. Biogeosciences Discussions 2020, 1-21. pollution of freshwaters and methane emissions into the atmosphere are crucial factors in deteriorating the quality of drinking water and in contributing to global climate change. The nitrate dependent anaerobic methane oxidation and the anaerobic oxidation of ammonium (anammox) have the potential to reduce nitrogen loading of aquatic ecosystems and to reduce methane emissions to the atmosphere.Here, we report vertical concentration profiles and corresponding stable isotope compositions of CH4, NO3?, NO2? and NH4+ in the water column of a stratified lake, which suggest linkages between anaerobic oxidation of methane (AOM), denitrification, and anammox. In a water depth from 12 to 20?m, a methane-nitrate transition zone (NMTZ) was observed, where δ13C values of methane and δ15N and δ18O of dissolved nitrate markedly increased in concert with decreasing concentrations of methane and nitrate. These data patterns, together with a simple 1D diffusion model show that the non-linear methane concentration profile cannot be explained by diffusion or micro-aerobic methane oxidation, and that microbial oxidation of methane coupled with denitrification under anaerobic conditions is the most likely explanation for these data trends.In the methane zone at the bottom of the NMTZ (20?m to 22?m) δ15N of ammonium increased by 4?‰, while ammonium concentrations decreased. In addition, a strong 15N enrichment of dissolved nitrate was observed at a water depth of 20?m, suggesting that anammox is occuring together with denitrification coupled to AOM. The conversion of nitrite to N2 and nitrate during anammox is namely associated with an inverse N isotope fractionation and may explain the observed increasing offset (Δδ15N) of 26?‰ between δ15N values of dissolved nitrate and nitrite at a water depth of 20?m compared to the Δδ15Nnitrate-nitrite of 11?‰ obtained in the NMTZ between a water depth of 16?m and 18?m.The geochemcical zones were found to contain significantly different microbial communities that consist of bacteria known to be involved in denitrification with AOM (Crenothrix and NC10), and anammox (Candidatus Anammoximicrobium), confirming the presence of microbial groups potentially responsible for the proposed linkages between AOM, denitrification, and anammox. This study gives insights into the yet overlooked AOM-denitrification-anammox process in stratified lakes that can regulate methane emisssions from and nitrogen concentrations in lakes.El Diasty, W.S., El Beialy, S.Y., Khairy, A., El Attar, R.M., Edwards, K.J., 2020. Palaeoenvironmental and source rock potential of the Turonian–Miocene sequence in the West Esh El Mellaha (SW margin of the Suez rift, Egypt): Insights from palynofacies, palynology and organic geochemistry. Review of Palaeobotany and Palynology 276, 104190. detailed palynological, palynofacies and geochemical study has been undertaken on cuttings samples selected from wells drilled in the Gulf of Suez, Egypt. Inter alia, the samples yielded marine palynomorphs, non-marine palynomorphs, amorphous organic matter (AOM) and phytoclasts. Deposits of the Matulla Formation are dated as Coniacian–Santonian based on the angiosperm pollen and dinoflagellate cyst content. Angiosperm pollen Areolipollis vespiformis in the Rudeis Formation is taken as a biostratigraphic marker for the early Miocene.Two palynofacies associations were identified. Association-A from the Matulla and upper Rudeis formations consists mainly of Type-III gas-prone kerogen. Association-B contains Type-II and Type-II/III kerogens with mixed oil and gas, and is typical of Duwi, Esna, Thebes and lower Rudeis samples. Samples were deposited under various dysoxic–anoxic and suboxic–anoxic conditions.The peridiniacean assemblage from the Upper Cretaceous Matulla Formation intimates deposition in a tropical to subtropical setting within the Tethyan Realm of the Malloy Suite. Salixipollenites, fern spores, and dinoflagellate cysts suggest successive phases of humidity versus aridity during the early Miocene.Geochemical data show that samples from the Duwi Formation are Type-II and Type-II/III kerogens. Based on low HI values and low abundance of AOM, palynofacies association-A samples indicate Type-III gas-prone kerogen, whereas association-B samples have the greatest values of HI and AOM, indicating oil-prone Type-II to Type-II/III kerogens.Fan, J., Lian, P., Li, M., Liu, X., Zhou, X., Ouyang, Z., 2020. Ion mobility separation using a dual-LIT miniature mass spectrometer. Analytical Chemistry 92, 2573-2579. mobility (IM) has been increasingly used in combination with mass spectrometry (MS) for chemical and biological analysis. While implementation of IM with MS usually requires complex instrumentation with delicate controls, in this study we explored the potential of performing IM separation using dual-linear ion traps (LITs) in a miniature mass spectrometer, which was originally developed for performing comprehensive MS/MS scan functions with a simple instrumentation configuration. The IM separation was achieved by ion transfer between the LITs with dynamic gas flow. Its performance was characterized for analysis of a broad range of chemical and biological compounds including small organic compounds such as trisaccharides, raffinose, cellotriose, and melezitose, as well as protein conformers. The demonstrated technique serves as another example of developing powerful hybrid instrument functions with simple configurations and miniaturized sizes.Fan, X., Mao, X., Geng, T., Wang, H., 2020. Geochemical characteristics and shale oil potential analysis of Bilongco Jurassic shale in the southern Qiangtang Basin China. Petroleum Science and Technology 38, 225-231. Jurassic shale in the Bilongco area has always been considered to have good resource potential. In order to better evaluate the hydrocarbon generation potential of shale. In this paper, organic geochemical data are used to analyze shale samples in this area. The results show that the shale has a high organic matter content, the average TOC is 5.12%; Mainly type II1 and type I kerogen; Organic matter had a high thermal evolution(The average Tmax is 435?°C); The organic matrix is a mixed input of terrestrial plants and marine organisms. The shale was matured but had not been a large-scale oil and gas migration. The hydrocarbon generation potential is high, especially the oil shale with TOC >8% have great potential for shale oil.Fanali, C., D'Orazio, G., Fanali, S., 2020. Chapter 4 - Capillary electrophoresis-mass spectrometry: History, general principles, theoretical aspects, and state-of-the-art applications, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 413-447. chapter presents the main features of capillary electrophoresis hyphenated with mass spectrometry (CE-MS), its advantages over CE techniques employing conventional detectors such as the ultraviolet and diode array detectors. Special attention is paid to the latest developments related to instrumentation and methodology especially in coupling CE with MS. Interfaces currently used, e.g., sheath-liquid, sheathless, and liquid-junction, are also illustrated. In order to document the usefulness of CE-MS, some selected applications in the field of proteomics, pharmaceutical, environmental, food, and forensic analysis are presented and discussed.Fang, J., Zhao, H., Zhang, Y., Lu, M., Cai, Z., 2020. Atmospheric pressure chemical ionization in gas chromatography-mass spectrometry for the analysis of persistent organic pollutants. Trends in Environmental Analytical Chemistry 25, e00076. pressure chemical ionization (APCI) was primarily applied as the ion source for liquid chromatography-mass spectrometry (LC–MS). While APCI started to be used in gas chromatography-mass spectrometry (GC–MS) in 1970s, GC-APCI-MS was not widely used until recently. As a soft ionization technique, APCI provides highly diagnostic molecular ions, which is favored for the wide-scope screening. With the capability of tandem mass spectrometry (MS/MS), GC-APCI-MS methods with high sensitivity and selectivity have been developed and applied in the analysis of persistent organic pollutants (POPs) in environment and biological samples at trace levels. The present review introduces the history of the APCI source, with emphasis on mechanisms of ionization processes under the positive and negative ionization modes. Comparison between GC-APCI-MS and GC–MS with traditional electron ionization (EI) and chemical ionization (CI) are provided and discussed for selectivity, sensitivity and stability for the analyses of POPs. Previous studies found that the GC-APCI-MS methods provided limits of detection (LODs) around 10–100 times lower than other methods. An overview of GC-APCI-MS applications is given with the discussions on the advantages and drawbacks of various analytical methods applied for the analyses of POPs.Feenstra, E.J., Birgel, D., Heindel, K., Wehrmann, L.M., Jaramillo-Vogel, D., Grobéty, B., Frank, N., Hancock, L.G., Van Rooij, D., Peckmann, J., Foubert, A., 2020. Constraining the formation of authigenic carbonates in a seepage-affected cold-water coral mound by lipid biomarkers. Geobiology 18, 185-206.‐water coral (CWC) mounds are build‐ups comprised of coral‐dominated intervals alternating with a mixed carbonate‐siliciclastic matrix. At some locations, CWC mounds are influenced by methane seepage, but the impact of methane on CWC mounds is poorly understood. To constrain the potential impact of methane on CWC mound growth, lipid biomarker investigations were combined with mineralogical and petrographic analyses to investigate the anaerobic oxidation of methane (AOM) and authigenic carbonate formation in sediment from a seep‐affected CWC mound in the Gulf of Cadiz. The occurrence of AOM was confirmed by characteristic lipids found within a semi‐lithified zone (SLZ) consisting of authigenic aragonite, high‐magnesium calcite and calcium‐excess dolomite. The formation of high‐Mg calcite is attributed to AOM, acting as a lithifying agent. Aragonite is only a minor phase. Ca‐excess dolomite in the SLZ and upper parts may be formed by organoclastic sulphate reduction, favouring precipitation by increased alkalinity. The AOM biomarkers in the SLZ include isoprenoid‐based archaeal membrane lipids, such as abundant glycerol dibiphytanyl glycerol tetraethers (GDGTs) dominated by GDGT‐2. The δ13C values of GDGT‐2, measured as ether‐cleaved monocyclic biphytanes, are as low as ?100‰ versus V‐PDB. Further, bacterial dialkyl glycerol diethers with two anteiso‐C15 alkyl chains and δ13C values of ?81‰ are interpreted as biomarkers of sulphate‐reducing bacteria. The lipid biomarker signatures and mineralogical patterns suggest that anaerobic methane‐oxidizing archaea of the ANME‐1 group thrived in the subsurface at times of slow and diffusive methane seepage. Petrographic analyses revealed that the SLZ was exhumed at some point (e.g. signs of bioerosion of the semi‐lithified sediment), providing a hard substrate for CWC larval settlement. In addition, this work reveals that AOM‐induced semi‐lithification likely played a role in mound stabilization. Lipid biomarker analysis proves to be a powerful tool to disentangle early diagenetic processes induced by microbial metabolisms.Feng, D., Hodges, B.R., 2020. The oil spill transport across the shelf-estuary interface. Marine Pollution Bulletin 153, 110958. spills caused by ship collisions and offshore oil wells are an ongoing risk for estuaries in the northern Gulf of Mexico. The fate and transport of the oil spill across the interface between a bar-built estuary and the adjacent coast are influenced by multi-scale forcing mechanisms and their corresponding interactions. Of primary interest are the alongshore currents on the shelf encountering strong tidal flows at the estuary entrance. A new cross-scale model was developed for Galveston Bay to reproduce the multi-scale flows. The model was employed in regionally-distributed numerical Lagrangian experiments to investigate the oil spill transport across the shelf-estuary interface. The influence of the multi-scale flows on the oil spill transport was characterized in terms of Lagrangian connectivity and Lagrangian flushing. The new Galveston Bay model was also used to evaluate the Texas City “Y” spill and resulted in a reasonable agreement with the NOAA observations. This research enhances our understanding of the oil transport across the threshold between two contiguous water systems and highlights the importance of resolving the multi-scale flows for the purpose of oil spill predictions.Feng, J., Loussala, H.M., Han, S., Ji, X., Li, C., Sun, M., 2020. Recent advances of ionic liquids in sample preparation. TrAC Trends in Analytical Chemistry 125, 115833. paper reviews the recent advances of ionic liquids (ILs) in sample preparation from more than 100 works mainly in last five years, including liquid-liquid microextraction, solid-phase extraction, solid-phase microextraction, stir bar or stir cake sorptive extraction. ILs, polymer of ILs and their composites with molecular imprinted polymer, carbon nanotubes, graphene oxide and magnetic materials have been explored as promising sorbents for inorganic or organic pollutants, majorly relying on the affinity of ILs with the target. The improved sensitivity and selectivity towards different types of analytes were displayed, attributed from various mechanism of ILs-based extraction materials including π-π, ion-exchange, hydrogen bond, dipole-dipole, electrostatic, hydrophobic and hydrophilic interactions. The prospects of ILs for sample preparation were also presented, which can offer an outlook for the further applications of ILs.Fernandez-Lima, F., 2019. Chapter 8 - Trapped ion mobility spectrometry coupled to FT-ICR MS: Fundamentals and applications, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 233-251. the introduction of Trapped Ion Mobility Spectrometry in 2011, a major transformation is happening on the way gas-phase; post-ionization mobility separations can be performed and coupled to existing mass spectrometry workflows. The possibility to decouple the mobility analysis from the experimental time scale, allows for better coupling of mobility and mass analysis; in particular, when current mass analyzers require seconds to achieve ultrahigh mass resolution and high mass accuracy. In this chapter, we will cover the history of trapped IMS and FT-ICR MS, the principles of a TIMS analyzer, modes of operation, mobility calibration of a TIMS-FT-ICR MS datasets, and the comparison of TIMS-TOF MS and FT-ICR MS during the analysis of complex mixtures.Ferré, B., Jansson, P.G., Moser, M., Serov, P., Portnov, A., Graves, C.A., Panieri, G., Gründger, F., Berndt, C., Lehmann, M.F., Niemann, H., 2020. Reduced methane seepage from Arctic sediments during cold bottom-water conditions. Nature Geoscience 13, 144-148. amounts of methane are trapped within gas hydrate in subseabed sediments in the Arctic Ocean, and bottom-water warming may induce the release of methane from the seafloor. Yet the effect of seasonal temperature variations on methane seepage activity remains unknown as surveys in Arctic seas are conducted mainly in summer. Here we compare the activity of cold seeps along the gas hydrate stability limit offshore Svalbard during cold (May 2016) and warm (August 2012) seasons. Hydro-acoustic surveys revealed a substantially decreased seepage activity during cold bottom-water conditions, corresponding to a 43% reduction of total cold seeps and methane release rates compared with warmer conditions. We demonstrate that cold seeps apparently hibernate during cold seasons, when more methane gas becomes trapped in the subseabed sediments. Such a greenhouse gas capacitor increases the potential for methane release during summer months. Seasonal bottom-water temperature variations are common on the Arctic continental shelves. We infer that methane-seep hibernation is a widespread phenomenon that is underappreciated in global methane budgets, leading to overestimates in current calculations.Fialkov, A.B., Lehotay, S.J., Amirav, A., 2020. Less than one minute low-pressure gas chromatography - mass spectrometry. Journal of Chromatography A 1612, 460691. gas chromatography - mass spectrometry (GC-MS) takes 20–40?min per sample, which is undesirably slow in any application if speed can be increased while still meeting analytical needs. In this study, we achieved reasonably good separations with full analysis cycle times of less than 1?min by combining for the first time low-pressure (LP) GC-MS with low thermal mass (LTM) resistive-heating for rapid temperature ramping and cooling of the capillary column. The analytical column is threaded into the LTM thin-walled metal tubing in an instrumental device known as “LTM Fast GC” that is mounted at the top of the gas chromatograph in a detector port. The column inlet and outlet are connected to the GC injector and MS transfer line as usual. For LPGC-MS, a 40?cm, 0.1?mm. i.d. uncoated flow restrictor capillary connected at the injector is coupled with a 2.6?m, 0.25?mm i.d., 0.25??m film thickness analytical column leading to the MS. Thus, the inlet operates at normal GC pressures, but the analytical column is under vacuum, which increases the optimal helium carrier gas flow velocity thereby increasing speed of full range separations while maintaining acceptable quality of chromatography. This column configuration in LTM-LPGC-MS trades a 64-fold gain in speed of analysis vs. standard GC-MS for a 4-fold loss in chromatographic peak capacity, thereby converting analysis time from minutes into seconds in common applications. For example, jet fuel containing fatty acid methyl esters (akin to biofuel) was separated in 25?s with <1?min full analysis cycle time. An EPA Method 8270 mixture of 76 analytes was also analyzed in <1?min full cycle time by LTM-LPGC-MS. Other examples include very fast analysis of heroin in a street drug powder and elucidation of a new organic synthetic compound. In this report, we describe and discuss the several advantageous and practical features of LTM-LPGC-MS, as well as its trade-offs.Figueirêdo, M.B., Deuss, P.J., Venderbosch, R.H., Heeres, H.J., 2020. Catalytic hydrotreatment of pyrolytic lignins from different sources to biobased chemicals: Identification of feed-product relations. Biomass and Bioenergy 134, 105484. pyrolysis liquid biorefinery concept involves separation of pyrolysis liquids in various fractions followed by conversion of the fractions to value-added products. Pyrolytic lignins (PLs), the water-insoluble fractions of pyrolysis liquids, are heterogeneous, cross linked oligomers composed of substituted phenolics whose structure and physicochemical properties vary significantly depending on the biomass source. The catalytic hydrotreatment of six PLs from different biomass sources (pine, prunings, verge grass, miscanthus and sunflower seed peel) was investigated to determine the effect of different feedstocks on the final product composition and particularly the amount of alkylphenolics and aromatics, the latter being important building blocks for the chemical industry. Hydrotreatment was performed with Pd/C, 100?bar of hydrogen pressure and temperatures in the range of 350–435?°C, resulting in depolymerized product mixtures with monomer yields up to 39.1?wt% (based on PL intake). The molecular composition of the hydrotreated oils was shown to be a strong function of the PL feed and reaction conditions. Statistical analyses provided the identification of specific structural drivers on the formation of aromatics and phenolics, and a simple model able to accurately predict the yields of such monomers after catalytic hydrotreatment was obtained (R2?=?0.9944) and cross-validated (R2?=?0.9326). These feed-product relations will support future selections of PL feeds to obtain the highest amounts of valuable biobased chemicals.Filho, J.F.A., Lacerda, V., Rom?o, W., 2019. Chapter 15 - Fourier transform mass spectrometry applied to Forensic Chemistry, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 469-508. basis of Forensic Chemistry is the chemical characterization of an evidence or illegal substance for the purpose to determine or demonstrate the occurrence of a crime or an illegal practice. The broad of samples which are analyzed in Forensic Chemistry can be innumerous, e.g., hair, blood, urine, saliva, drugs, food, beverages, fraudulent documents, false banknotes, gunshot residue, explosives, fire residue, pharmaceuticals, and agrochemicals, among others. The combination of high resolution mass spectrometry (HRMS) based on Fourier transform mass analyzers with ambient ionization sources allows to reach reliable results with the specificity, which is mostly required in a wide diversity, reaching high complexity of forensic samples. In this chapter, the main studies using HRMS will be presented and discussed based on Fourier transform spectrometers applied in Forensic Chemistry (illicit abuse drugs, i.e., cocaine, marijuana; hallucinogens; and new psychoactive substances; food chemistry; agrochemicals; documentoscopy; and gunshot residues analysis).Floris, F., O'Connor, P.B., 2019. Chapter 7 - Fundamentals of two dimensional Fourier transform mass spectrometry, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 187-232. dimensional mass spectrometry (2D-MS) is a data-independent tandem mass spectrometry technique able to obtain information about the fragmentation patterns of all the analytes in a mixture in a single experiment, by correlating the in-cell generated fragments with their precursor ions. The amount of information generated by a single 2D-MS run is the equivalent of multiple tandem mass spectrometry studies on the entire sample, but without the necessity to isolate every single ion in the mixture before fragmentation, hence without any loss in sensitivity, and with the possibility to fragment ions otherwise impossible to isolate with standard 1D MS. From its conception in the 1980s, 2D-MS suffered an arrested development due to the required computational capacities of the technique, but it made its comeback in 2010, with implementation in the new-generation FT-ICR mass spectrometers. Subsequent developments in computer capabilities, FT-ICR technology, and the algorithms applied to the processing of 2D-MS data allowed two dimensional Fourier transform ion cyclotron resonance mass spectrometry (2D FT-ICR MS) to become a useful analytical technique. Since then, 2D-MS found its applications in the analysis of small molecules, top-down and bottom-up proteomics, and polymer analysis. The technique has also been exported to other mass analyzers, such as LITs, in a simulation study with SIMION. In this review, the history of 2D FT-ICR MS is revisited under the light of the recent improvements, the acquisition of 2D-MS data using contemporary FT-ICR mass spectrometers and processing software is explained, and the most recent applications of the technique are reported.Foster, W.J., Garvie, C.L., Weiss, A.M., Muscente, A.D., Aberhan, M., Counts, J.W., Martindale, R.C., 2020. Resilience of marine invertebrate communities during the early Cenozoic hyperthermals. Scientific Reports 10, 2176. hyperthermal events of the Cenozoic, including the Paleocene-Eocene Thermal Maximum, provide an opportunity to investigate the potential effects of climate warming on marine ecosystems. Here, we examine the shallow benthic marine communities preserved in the late Cretaceous to Eocene strata on the Gulf Coastal Plain (United States). In stark contrast to the ecological shifts following the end-Cretaceous mass extinction, our data show that the early Cenozoic hyperthermals did not have a long-term impact on the generic diversity nor composition of the Gulf Coastal Plain molluscan communities. We propose that these communities were resilient to climate change because molluscs are better adapted to high temperatures than other taxa, as demonstrated by their physiology and evolutionary history. In terms of resilience, these communities differ from other shallow-water carbonate ecosystems, such as reef communities, which record significant changes during the early Cenozoic hyperthermals. These data highlight the strikingly different responses of community types, i.e., the almost imperceptible response of molluscs versus the marked turnover of foraminifera and reef faunas. The impact on molluscan communities may have been low because detrimental conditions did not devastate the entire Gulf Coastal Plain, allowing molluscs to rapidly recolonise vacated areas once harsh environmental conditions ameliorated.Fosu, B.R., Ghosh, P., Viladkar, S.G., 2020. Clumped isotope geochemistry of carbonatites in the north-western Deccan igneous province: Aspects of evolution, post-depositional alteration and mineralisation. Geochimica et Cosmochimica Acta 274, 118-135. crystallise along a wide range of solidus temperatures and are commonly affected by post-magmatic textural re-equilibration and diagenesis. Further insights into the formation and modification of carbonatites are provided using carbon, oxygen and clumped isotope (Δ47) data of rocks from spatially associated Amba Dongar and Siriwasan alkaline complexes in the north-western Deccan igneous province, India. We derive apparent equilibrium blocking temperatures to help constrain the thermal evolution of the different rock types found within the alkaline complexes in a petrographic context. The apparent temperatures for the carbonatites are significantly low but are consistent with reports on other global carbonatites and model predictions. Rapidly cooled Oldoinyo Lengai natrocarbonatite yielded similar low temperatures, even in the absence of bulk isotopic alteration. The isotopic proxies and petrographic observations favour both isotopic exchange reactions and diagenesis in altering Δ47 values in calciocarbonatites. Diagenetic reactions are however strongly favoured, as secondary calcites in nephelinites and ferrocarbonatites record much lower temperatures than in the calciocarbonatites, highlighting the effect of fluids and diagenetic reactions in 13C-18O bond ordering in carbonatites. Variations in the C-O isotope data reveal the coupling of fractional crystallisation and post-magmatic fluid-rock interactions on bulk rock composition. After emplacement, the resetting of clumped isotope signatures in carbonatites is facilitated by post-magmatic processes in both open and closed systems.Frank, T.M., Fine, C.D., Burdett, E.A., Cook, A.B., Sutton, T.T., 2020. The vertical and horizontal distribution of deep-sea crustaceans in the order Euphausiacea in the vicinity of the Deepwater Horizon oil spill. Frontiers in Marine Science 7, 99. doi: 10.3389/fmars.2020.00099. vertical and horizontal distributions of Euphausiacea in the northern Gulf of Mexico (GOM), including the location of the Deepwater Horizon oil spill, were analyzed from 340 trawl samples collected between April and June 2011. This study is the first comprehensive survey of euphausiid distributions from depths deeper than 1000 m in the GOM and includes stratified sampling from five discrete depth ranges (0–200 m, 200–600 m, 600–1000 m, 1000–1200 m, and 1200–1500 m), and expands the depth ranges of 30 species. In addition, this study demonstrates significantly higher abundance and biomass of the euphausiid assemblage from slope vs. offshore stations, while the offshore assemblage was significantly more diverse. There is also some evidence for seasonality in reproduction amongst the seven species that had gravid females. Lastly, these data represent the first quantification of the euphausiid assemblage in the region heavily impacted by the Deepwater Horizon event, and as there are no pre-spill data, may serve as an impacted baseline against which to monitor changes in the euphausiid assemblage in the years following exposure to Deepwater Horizon oil and dispersants in the water column.French, K.L., Birdwell, J.E., Vanden Berg, M.D., 2020. Biomarker similarities between the saline lacustrine Eocene Green River and the Paleoproterozoic Barney Creek Formations. Geochimica et Cosmochimica Acta 274, 228-245. Paleoproterozoic Barney Creek Formation, which is currently interpreted as a restricted, deep marine paleoenvironment, plays a disproportionate role in our understanding of Proterozoic ocean chemistry and the rise of complex life. The Barney Creek Formation hosts several unusual biomarker features, specifically its methylhopane and carotenoid signatures. Herein, we demonstrate that the saline lacustrine Eocene Green River Formation shares a similar distribution of methylhopanes and carotenoids, which is characteristic of saline lacustrine organic matter more generally. These distinct methylhopane and carotenoid patterns are not observed together in marine organic matter of any geologic age. These results imply a saline lacustrine depositional environment for the Barney Creek Formation, which agrees with earlier but now abandoned depositional models of this formation. As a result, models of Proterozoic ocean chemistry and emergence of complex life that rely on a marine Barney Creek Formation should be reexamined. Alternatively, if Paleoproterozoic marine biomarker signatures resemble those of younger saline lacustrine systems, then this must be recognized to accurately interpret geologic biomarker and paleoenvironmental records.Froidl, F., Zieger, L., Mahlstedt, N., Littke, R., 2020. Comparison of single- and multi-ramp bulk kinetics for a natural maturity series of Westphalian coals: Implications for modelling petroleum generation. International Journal of Coal Geology 219, 103378. present a comprehensive new pyrolysis data set for a maturity series (0.55–2.86% vitrinite reflectance) of Pennsylvanian coals (Westphalian, Ruhr Basin). The broad similarity of the organofacies was established by elemental and petrographic data. Comparison of maximum temperatures reached by the coals was based on commonly applied algorithms (Easy%Ro, Easy%RoDL, Basin%Ro). These temperatures were finally compared to predicted temperatures of petroleum generation from the same coals in order to test the reliability of kinetic data for numerical petroleum generation reconstruction from coal. Kinetic parameters were determined based on data from open-system pyrolysis performed on two instruments (Rock-Eval? and Source Rock Analyzer?) and basin modelling was performed using PetroMod? software and a simple, rapid burial and heating history (about 20 °C/million years), which is similar to the rapid heating which caused natural maturation of these coals.With increasing maturity, pyrolysis curves shift towards higher temperatures, no matter which heating rate is used. However, pyrolysis curves of higher maturity samples are not embedded within the more extended and larger pyrolysis curves of low maturity coals. HI values and H/C ratios do not significantly decrease over the maturity range from 0.55 to 0.8–0.9% vitrinite reflectance. These observations indicate significant restructuring of organic matter in coals and only limited petroleum generation and expulsion within this maturity range.The kinetic parameters were derived from single (5 °C/min) and multiple (0.7, 2, 5, 15 °C/min) heating rate pyrolysis tests. After temperature correction, kinetic parameters obtained by the two instruments differ only slightly.Kinetics based on multiple heating rates using a variable frequency factor and variable activation energies provide the best mathematical fit to the laboratory data but geologically inconsistent predictions for natural petroleum generation, i.e. no increase in predicted generation temperatures with increasing sample maturity. In contrast, kinetics based on a constant, physically meaningful frequency factor and a calculated range of activation energies provide more consistent results for the maturity sequence. Interestingly, single-ramp kinetics (5 °C/min) show similar results, i.e. increasing calculated temperatures for petroleum generation with increasing maturity.For the lowest maturity sample, petroleum generation temperatures (10–75% conversion) are higher than calculated maximum rock temperatures, while this is not the case for all higher maturity samples, for which much of the predicted petroleum generation occurs at “too low” temperatures, i.e. temperatures clearly lower than calculated maximum rock temperatures. Maximum temperatures predicted by the Easy%RoDL approach are about 10 °C closer to the lower limit of petroleum generation than those calculated by Basin%Ro. Thus, kinetic data can act as a useful tool for calculating petroleum generation in petroleum system modelling providing clues towards the thermal stability of kerogen. However, such data are far from describing petroleum generation in nature exactly and quantitatively, especially for coals.Fu, S., Liao, Z., Chen, A., Chen, H., 2019. Reservoir characteristics and multi-stage hydrocarbon accumulation of the Upper Triassic Yanchang Formation in the southwestern Ordos Basin, NW China. Energy Exploration & Exploitation 38, 348-371. Chang-8 and Chang-6 members of the Upper Triassic Yanchang Formation (lower part) are regarded as the main oil producing members of the Ordos Basin. Recently, new hydrocarbon discoveries have been made in the upper part of the Yanchang Formation (e.g., Chang-3) in the southwestern Ordos Basin, implying that this interval also has a good potential for hydrocarbon exploration. However, studies on the origin of the high-quality reservoir, hydrocarbon migration, and accumulation patterns remain insufficient. In this study, integrated petrological, mineralogical, and fluid inclusion tests are employed to evaluate reservoir characteristics, and reconstruct the history of hydrocarbon migration and accumulation during oil and gas reservoir formation. The results reveal that the Yanchang Formation is characterized by low porosity (8???14%), medium permeability (0.5???5 mD), and strong heterogeneity; the reservoir properties are controlled by secondary porosity. Two types of dissolution are recognized in the present study. Secondary pore formation in the lower part of the formation is related to organic acid activity, while dissolution in the upper part is mainly influenced by atmospheric fresh water associated with the unconformity surface. The Yanchang Formation underwent hydrocarbon charging in three phases: the early Early Cretaceous, late Early Cretaceous, and middle Late Cretaceous. A model for hydrocarbon migration and accumulation in the Yanchang reservoirs was established based on the basin evolution. We suggest that hydrocarbon accumulation occurred at the early stage, and that hydrocarbons migrated into the upper part of the Yanchang Formation by way of tectonic fractures and overpressure caused by continuous and episodic hydrocarbon expulsion during secondary migration, forming potential oil reservoirs during the later stage.Fujiya, W., Aoki, Y., Ushikubo, T., Hashizume, K., Yamaguchi, A., 2020. Carbon isotopic evolution of aqueous fluids in CM chondrites: Clues from in-situ isotope analyses within calcite grains in Yamato-791198. Geochimica et Cosmochimica Acta 274, 246-260. report the variability in carbon and oxygen isotopic compositions, chemical compositions, and cathodoluminescence intensities within calcite grains in the Yamato-791198 CM chondrite measured by secondary ion mass spectrometry. To understand the change in carbon isotopic compositions during calcite formation, the carbon isotope-analyses were performed on a series of crystal growth bands of each calcite grain. The crystal growth of calcite grains was inferred from comprehensive analyses of oxygen isotopes, chemical compositions, and cathodoluminescence characteristics.The observed δ18O variations within individual grains are as large as 13‰. The oxygen-isotope data plot on a single straight line with a slope of 0.61?±?0.06 (2σ) in an oxygen three-isotope diagram. This slope steeper than that of the terrestrial fractionation line indicates that the oxygen isotopic compositions of aqueous fluids evolved from higher δ18O and Δ17O to lower δ18O and Δ17O compositions due to the oxygen-isotope exchange between water and anhydrous silicates in the parent body. Thus, calcite crystals grew from higher Δ17O to lower Δ17O areas. The crystal growth inferred from oxygen isotopic compositions is corroborated by the morphology and cathodoluminescence characteristics of the calcite grains. The minor element concentrations of the calcite grains did not increase/decrease monotonically during calcite formation.The δ13C variations within individual grains are no more than 4‰ except for one grain. The intra-grain δ13C variations observed here are much smaller than inter-grain δ13C variations of ～80‰ previously reported. These observations indicate that the carbon isotopic compositions of dissolved carbon species did not change during calcite formation and that they were locally heterogeneous which reflects variable proportions of carbon reservoirs with different isotopic compositions.Gadkari, P.S., McGuinness, L.R., M?nnist?, M.K., Kerkhof, L.J., H?ggblom, M.M., 2019. Arctic tundra soil bacterial communities active at subzero temperatures detected by stable isotope probing. FEMS Microbiology Ecology 96, fiz192. soils store vast amounts of carbon and are subject to intense climate change. While the effects of thaw on the composition and activities of Arctic tundra microorganisms has been examined extensively, little is known about the consequences of temperature fluctuations within the subzero range in seasonally frozen or permafrost soils. This study identified tundra soil bacteria active at subzero temperatures using stable isotope probing (SIP). Soils from Kilpisj?rvi, Finland, were amended with 13C-cellobiose and incubated at 0, ?4 and ?16°C for up to 40 weeks. 16S rRNA gene sequence analysis of 13C-labelled DNA revealed distinct subzero-active bacterial taxa. The SIP experiments demonstrated that diverse bacteria, including members of Candidatus Saccharibacteria, Melioribacteraceae, Verrucomicrobiaceae, Burkholderiaceae, Acetobacteraceae, Armatimonadaceae and Planctomycetaceae, were capable of synthesising 13C-DNA at subzero temperatures. Differences in subzero temperature optima were observed, for example, with members of Oxalobacteraceae and Rhizobiaceae found to be more active at 0°C than at ?4°C or ?16°C, whereas Melioribacteriaceae were active at all subzero temperatures tested. Phylogeny of 13C-labelled 16S rRNA genes from the Melioribacteriaceae, Verrucomicrobiaceae and Candidatus Saccharibacteria suggested that these taxa formed subzero-active clusters closely related to members from other cryo-environments. This study demonstrates that subzero temperatures impact active bacterial community composition and activity, which may influence biogeochemical cycles.Galkin, S.V., Kolychev, I.Y., Savitskii, Y.V., 2019. Potentialities of investigation of reservoir hydrophobization by compilation of X-ray core tomography and lateral logging. Russian Geology and Geophysics 60, doi: 10.15372/RGG2019094. potentialitises of studying rock wettability by X-ray core tomography are considered using Visean terrigenous reservoirs of the Solikamsk depression as an example. The studies included comparison of the tomograms of core samples in a dry state and saturated with a sodium iodide solution, which acts as a radiopaque analog of formation water. Differences in impregnation of the core samples, characterizing their wettability, have been established. According to the tomography data, in the hydrophilic samples the solution filled all pores, except for a small portion of the largest ones. In the hydrophobic samples, there was no impregnation of both small and large pores in the central zone. Based on the tomograms, the rocks were divided into groups by the type of wettability: absolutely hydrophobic, with strong signs of hydrophobicity, with signs of hydrophobicity, and hydrophilic. Comparison of the results of tomography with the standard approach showed that the Tulbovich method commonly used for the study area does not fully reflect the rock wettability. Comparison of the results of core tomography and study of thin sections with the results of electrometric logging shows their good agreement. The rocks with absolute hydrophobicity established by tomography have an anomalously high electric resistivity, >1000 Ohm·m, and the rocks with signs of hydrophobicity, >120 Ohm·m. For the hydrophilic intervals, the electric resistivity values are significantly lower, from 17 to 100 Ohm·m. Thin sections of the core samples were studied. Their microscopic analysis has shown a higher content of organic matter in the hydrophobic rocks as compared with the hydrophilic ones. Few exceptions might be due to the study of only local thin sections of the samples. Thus, rock wettability can be monitored by electrical methods, especially lateral logging. The results of the assessment of rock wettability by core study and well logging can be compiled for the exploration of Visean pools of the Solikamsk depression. Geological models constructed with regard to the recognized zones of hydrophilic and hydrophobic reservoirs can be effectively used to optimize the exploration of pools, especially reservoir flooding.Gallego, R., Arena, K., Dugo, P., Mondello, L., Ibá?ez, E., Herrero, M., 2020. Application of compressed fluid–based extraction and purification procedures to obtain astaxanthin-enriched extracts from Haematococcus pluvialis and characterization by comprehensive two-dimensional liquid chromatography coupled to mass spectrometry. Analytical and Bioanalytical Chemistry 412, 589-599. green microalga Haematococcus pluvialis has been widely studied due to its capacity to accumulate great amounts of astaxanthin, a high-value carotenoid with biological activities. In the present work, two green compressed fluid–based processes, pressurized liquid extraction (PLE) and supercritical antisolvent fractionation (SAF), are integrated to obtain an astaxanthin-enriched extract from this microalga. PLE was carried out using pressurized ethanol as solvent, for 20 min, at 10 MPa, and 50 °C as extraction temperature. Subsequently, the obtained extract was processed by SAF to further purify the carotenoid fraction. The SAF process was optimized using a 3-level factorial experimental design and considering three experimental variables: (i) CO2 pressure (10–30 MPa), (ii) percentage of water in the PLE extract (20–50%), and (iii) PLE extract/supercritical-CO2 flow rate ratio (0.0125–0.05). Total carotenoid content was evaluated in both extracts and raffinates. Best results were obtained at 30 MPa, 0.05 feed/SC-CO2 mass flow rate, and 20% (v/v) of water in the feed solution, achieving values of 120.3 mg g?1 carotenoids in extract (in the SAF extract fraction), which were significantly higher than those obtained in the original PLE extract. In parallel, a new fast two-dimensional comprehensive liquid chromatography (LC×LC) method was optimized to get the full carotenoid profile of these extracts in less than 25 min. This is the first time that the use of a C30 column is reported in an on-line LC×LC system.Galletti, Y., Becagli, S., di Sarra, A., Gonnelli, M., Pulido-Villena, E., Sferlazzo, D.M., Traversi, R., Vestri, S., Santinelli, C., 2020. Atmospheric deposition of organic matter at a remote site in the Central Mediterranean Sea: implications for marine ecosystem. Biogeosciences Discussions 2020, 1-26. fluxes of dissolved organic matter (DOM) were studied for the first time at the Island of Lampedusa, a remote site in the Central Mediterranean Sea (Med Sea), close to the Sahara desert, between 19 March 2015 and 1 April 2017. The main goals of this work are: to quantify total atmospheric deposition of DOM in this area and to evaluate the impact of dust deposition on DOM dynamics in the surface waters of the Mediterranean Sea. Our data show high variability in DOM deposition rates without a clear seasonality and allow to estimate a dissolved organic carbon (DOC) input from the atmosphere of 120.7?mmol?DOC?m?2?yr?1. Over the entire time-series, the average dissolved organic phosphorous (DOP) and dissolved organic nitrogen (DON) contributions to the total dissolved pools were 40?% and 26?%, respectively. The data on atmospheric elemental ratios also show that each deposition event is characterized by a specific elemental ratio, suggesting a high variability in DOM composition and the presence of multiple sources. This study indicates that the organic substances transported by Saharan dust at Lampedusa site mainly have natural origin, especially from sea spray and that Saharan dust can be an important carrier of organic substances, even if the load of DOC associated with dust is highly variable. Our estimates suggest that atmospheric input has an impact to the Med Sea larger than to the global ocean and that DOC fluxes from the atmosphere to the Med Sea can be up to 6-fold larger than river input. Longer time series, combined with a modelling effort, are therefore mandatory in order to investigate the response of DOM dynamics in the Med Sea to the change in aerosol deposition pattern due to the effect of climate change.Galushkin, Y.I., Leichenkov, G.L., Dubinin, E.P., 2020. Estimation and comparison of hydrocarbon generation in the eastern and western Mawson Sea (Antarctica) using vitrinite reflectance data. Geochemistry International 58, 91-99. paper reports the results of numerical estimation of the degree of organic matter maturity and hydrocarbon generation in the rocks of the Bremer 1–6 formations during the burial of the sedimentary basin of the Mawson Sea on the passive margin of East Antarctica. Numerical simulation of basins was conduced for 15 areas along two profiles, 5903 and 5909, in the eastern and western parts of the Mawson Sea. The calculations revealed correlations between the yield of various hydrocarbon fractions and vitrinite reflectance in the supposed source rocks of the basin. Using these correlations, the generation characteristics of the rocks of the Bremer formations in the eastern and western Mawson Sea were compared. It was shown that the rocks of the Bremer 1–4 formations are mainly gas-prone in the eastern part of the basin, but could generate heavy and light oil in the western part of the basin. On the other hand, it was suggested on the basis of modeling that the rocks of the least buried Bremer formations (Bremer 5 and 6) produce mainly heavy oil in the western part of the Mawson Sea and light oil in its eastern part.Gao, J., Zou, C., Li, W., Ni, Y., Yuan, Y., 2020. Transition metal catalysis in natural gas generation: Evidence from nonhydrous pyrolysis experiment. Marine and Petroleum Geology 115, 104280. metal catalysis has been advocated as a critical mechanism for natural gas generation. But its presence and significance in geological settings have long been debated due to conflicting results of laboratory experiments and the lack of reliable field indicator. In this study, a low rank coal sample from the Shahezi Formation of the Songliao Basin was subjected to nonhydrous pyrolysis with and without transition metal. The chemical and isotopic compositions of gaseous products in experiments were analyzed to investigate the mechanism and potential indicator of transition metal catalysis in sedimentary basins. The chemical and carbon isotopic compositions of hydrocarbon gases generated in pyrolysis experiments revealed that transition metal could catalyze both decomposition of organic matters and methane synthesis such as Fischer-Tropsch Type reactions during maturation of source rocks under experimental conditions resembling geological settings. Catalytic methane has uniform δD values unrelated to source rock maturity, which is helpful in identification of catalytic natural gases in sedimentary basins. Transition metal catalysis is probably not a common mechanism for natural gas generation in sedimentary basins due to the positive correlation between δDCH4 of natural gases and maturities of source rocks observed in most natural cases. However, transition metal catalysis could well interpret the restricted range of δDCH4 and carbon isotopic reversal phenomenon of natural gases in the Yingcheng Formation of the Xujiaweizi fault-depression whose origin has long been debated. So we inferred that the transition metal catalysis may have occurred in deep strata of the Xujiaweizi fault-depression and played a significant role in natural gas generation. Our study revealed that restricted range of δDCH4 of natural gases with different maturities may serve as an effective indicator of transition metal catalysis in sedimentary basins. It provides a new perspective to investigate the significance and universality of transition metal catalysis in different geological settings.Gao, R., Luo, Y., Deng, H., 2019. Experimental study on repair of fractured rock mass by microbial induction technology. Royal Society Open Science 6, 191318. surrounding rock mass is often required to have good strength and impermeability in underground engineering. Some grouting methods, such as the chemical grouting method and the cement grouting pressure pump method, are often applied to reform underground environment and improve the engineering performance of rock mass. However, the application of some traditional grouting materials would destroy the original environment in which the project is located. This paper focuses on the repairing effect of Bacillus pasteurii composites in fractured rocks. The repairing effect of microbial materials on fractured sandstone is analysed through nuclear magnetic resonance (NMR) and unconfined compression-shearing equipment. The result shows that the longer the repairing time is, the better the effect will be. After 42 days of repairing, the porosity of fractured sandstone decreases by 36.41%, the impermeability increases by 94.62%, and the compressive strength increases by 30.52%. Through the study of reaction mechanisms, this technology has the advantages of mild reaction conditions, no pollution and good environmental compatibility. The application of this technology to the maintenance of geotechnical engineering can provide new ideas for the research and development of new environmental grouting materials and underground space reconstruction technology.Gao, Y., Wen, Z., Li, W., 2020. Effects of lacustrine organic-rich fine-grained sedimentary rocks on the accumulation of tight oil. Petroleum Science and Technology 38, 368-376. order to establish the distribution pattern of fine-grained sedimentary rocks and clarify the coupling relationship between lacustrine organic-rich fine-grained sedimentary rocks and tight oil reservoir, the Chang7 Member of Triassic Yanchang Formation in Longdong area was taken as an example to be studied by core description and log interpretation, gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Lacustrine organic-rich fine-grained sedimentary rocks were divided into shale and mudstone according to their lithology and texture. The results show that the shale is mainly developed in Chang73 Sub-member, while the mudstone is developed in each sub-member of Chang7 Member. The organic-rich fine-grained sedimentary rocks in Bazhu-Maling-Qingcheng-Huachi area are the thickest in Longdong area. During the Chang73 sedimentary period, the shale was widely distributed in the center of the lake. In the Chang72 sedimentary period, the mudstone and turbidite were interstratified and superimposed. During the Chang71 sedimentary period, the mudstone was only distributed as thin layers between the thick turbidite. The Chang7 tight oil is widely distributed in the turbidite sand bodies, and it is mainly sourced from the Chang73 shale. The distribution of tight oil is controlled by the development of organic-rich fine-grained sedimentary rocks.García-Alix, A., Toney, J.L., Jiménez-Moreno, G., Pérez-Martínez, C., Jiménez, L., Rodrigo-Gámiz, M., Anderson, R.S., Camuera, J., Jiménez-Espejo, F.J., Pe?a-Angulo, D., Ramos-Román, M.J., 2020. Algal lipids reveal unprecedented warming rates in alpine areas of SW Europe during the industrial period. Climate of the Past 16, 245-263. ecosystems of the southern Iberian Peninsula are among the most vulnerable and the first to respond to modern climate change in southwestern Europe. While major environmental shifts have occurred over the last ～1500 years in these alpine ecosystems, only changes in the recent centuries have led to abrupt environmental responses, but factors imposing the strongest stress have been unclear until now. To understand these environmental responses, this study, for the first time, has calibrated an algal lipid-derived temperature proxy (based on long-chain alkyl diols) to instrumental historical data extending alpine temperature reconstructions to 1500 years before present. These novel results highlight the enhanced effect of greenhouse gases on alpine temperatures during the last ～200 years and the long-term modulating role of solar forcing. This study also shows that the warming rate during the 20th century (～0.18?°C per decade) was double that of the last stages of the Little Ice Age (～0.09?°C per decade), even exceeding temperature trends of the high-altitude Alps during the 20th century. As a consequence, temperature exceeded the preindustrial record in the 1950s, and it has been one of the major forcing processes of the recent enhanced change in these alpine ecosystems from southern Iberia since then. Nevertheless, other factors reducing the snow and ice albedo (e.g., atmospheric deposition) may have influenced local glacier loss, since almost steady climate conditions predominated from the middle 19th century to the first decades of the 20th century.García-Cicourel, A.R., van de Velde, B., Roskam, G., Janssen, H.-G., 2020. Supercritical fluid chromatography as a rapid single-step method for the determination of mineral oil saturated and aromatic hydrocarbons in purified mineral oils for food and cosmetics applications. Journal of Chromatography A 1614, 460713. oil hydrocarbons are used in the consumer goods sector for the elaboration of a wide range of foods and cosmetics. Traditional methods for determining their levels and composition are time consuming and laborious, besides requiring complex instrumentation. Here a simple and fast method was developed that uses columns packed with silver-modified silica in supercritical fluid chromatography with flame ionization and UV detection (SFC-FID/UV) for the determination of mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH) in purified mineral oil samples. The method requires no sample preparation apart from dilution. Direct quantification of MOSH and MOAH was possible for samples with MOSH/MOAH ratios around one. For other samples deconvolution of the MOSH and MOAH humps in the FID chromatogram using the UV signal was needed since baseline separation of the two fractions could not be obtained. Validation of the method performance showed an excellent linearity (R2 > 0.9995) in the range of concentrations tested (2.5–100 mgmL?1) and a better repeatability than the standard methods (<5%). MOAH detection limits were better than 0.36% MOAH, which makes the method sufficiently sensitive for analysis of all but the highest purity mineral oils. The proposed SFC-FID/UV method was suitable for the analysis of mineral oils with viscosities and molecular weights below approximately 56 mm2s?1 and 450 gmol?1. The quantitative results of the new method were not statistically significantly different from those obtained with the standard SPE-GC-FID method where the new method has the advantages of a better repeatability, simpler operation and a significantly shortened analysis time. This new method could potentially also be used for the analysis of mineral oil contaminations in consumer products such as foods. However, in this case additional sample clean-up and preconcentration steps are needed for reducing matrix interferences from e.g. triglycerides and olefins and for improving the detection limits.Gardiner, N.J., Kirkland, C.L., Hollis, J.A., Cawood, P.A., Nebel, O., Szilas, K., Yakymchuk, C., 2020. North Atlantic Craton architecture revealed by kimberlite-hosted crustal zircons. Earth and Planetary Science Letters 534, 116091. cratons are composites of terranes formed at different times, juxtaposed during craton assembly. Cratons are underpinned by a deep lithospheric root, and models for the development of this cratonic lithosphere include both vertical and horizontal accretion. How different Archean terranes at the surface are reflected vertically within the lithosphere, which might inform on modes of formation, is poorly constrained. Kimberlites, which originate from significant depths within the upper mantle, sample cratonic interiors. The North Atlantic Craton, West Greenland, comprises Eoarchean and Mesoarchean gneiss terranes – the latter including the Akia Terrane – assembled during the late Archean. We report U–Pb and Hf isotopic, and trace element, data measured in zircon xenocrysts from a Neoproterozoic (557 Ma) kimberlite which intruded the Mesoarchean Akia Terrane. The zircon trace element profiles suggest they crystallized from evolved magmas, and their Eo- to Neoarchean U–Pb ages match the surrounding gneiss terranes, and highlight that magmatism was episodic. Zircon Hf isotope values lie within two crustal evolution trends: a Mesoarchean trend and an Eoarchean trend. The Eoarchean trend is anchored on 3.8 Ga orthogneiss, and includes 3.6–3.5 Ga, 2.7 and 2.5–2.4 Ga aged zircons. The Mesoarchean Akia Terrane may have been built upon mafic crust, in which case all zircons whose Hf isotopes lie within the Eoarchean trend were derived from the surrounding Eoarchean gneiss terranes, emplaced under the Akia Terrane after ca. 2.97 or 2.7 Ga, perhaps during late Archean terrane assembly. Kimberlite-hosted peridotite rhenium depletion model ages suggest a late Archean stabilization for the lithospheric mantle. The zircon data support a model of lithospheric growth via tectonic stacking for the North Atlantic Craton.Garrido-Benavent, I., Pérez-Ortega, S., Durán, J., Ascaso, C., Pointing, S.B., Rodríguez-Cielos, R., Navarro, F., de los Ríos, A., 2020. Differential colonization and succession of microbial communities in rock and soil substrates on a maritime Antarctic glacier forefield. Frontiers in Microbiology 11, 126. doi: 10.3389/fmicb.2020.00126. forefields provide a unique chronosequence to assess microbial or plant colonization and ecological succession on previously uncolonized substrates. Patterns of microbial succession in soils of alpine and subpolar glacier forefields are well documented but those affecting high polar systems, including moraine rocks, remain largely unexplored. In this study, we examine succession patterns in pioneering bacterial, fungal and algal communities developing on moraine rocks and soil at the Hurd Glacier forefield (Livingston Island, Antarctica). Over time, changes were produced in the microbial community structure of rocks and soils (ice-free for different lengths of time), which differed between both substrates across the entire chronosequence, especially for bacteria and fungi. In addition, fungal and bacterial communities showed more compositional consistency in soils than rocks, suggesting community assembly in each niche could be controlled by processes operating at different temporal and spatial scales. Microscopy revealed a patchy distribution of epilithic and endolithic lithobionts, and increasing endolithic colonization and microbial community complexity along the chronosequence. We conclude that, within relatively short time intervals, primary succession processes at polar latitudes involve significant and distinct changes in edaphic and lithic microbial communities associated with soil development and cryptogamic colonization.Gathungu, R.M., Kautz, R., Kristal, B.S., Bird, S.S., Vouros, P., 2020. The integration of LC-MS and NMR for the analysis of low molecular weight trace analytes in complex matrices. Mass Spectrometry Reviews 39, 35-54. review discusses the integration of liquid chromatography (LC), mass spectrometry (MS), and nuclear magnetic resonance (NMR) in the comprehensive analysis of small molecules from complex matrices. We first discuss the steps taken toward making the three technologies compatible, so as to create an efficient analytical platform. The development of online LC-MS-NMR, highlighted by successful applications in the profiling of highly concentrated analytes (LODs 10??g) is discussed next. This is followed by a detailed overview of the alternative approaches that have been developed to overcome the challenges associated with online LC-MS-NMR that primarily stem from the inherently low sensitivity of NMR. These alternative approaches include the use of stop-flow LC-MS-NMR, loop collection of LC peaks, LC-MS-SPE-NMR, and offline NMR. The potential and limitations of all these approaches is discussed in the context of applications in various fields, including metabolomics and natural product discovery.Gaus, G., Kalmykov, A., Krooss, B.M., Fink, R., 2020. Experimental investigation of the dependence of accessible porosity and methane sorption capacity of carbonaceous shales on particle size. Geofluids 2020, 2382153. and grinding of carbonaceous shale samples is likely to enhance the accessibility of pores and embedded organic matter as compared to the intact rock. This may lead to an overestimation of the total (volume and sorptive) gas storage capacity. In order to investigate the importance of these effects we have measured unconfined apparent grain densities (helium pycnometry) and methane sorption capacities (high-pressure methane excess sorption) of four carbonaceous shales (Cambro-Ordovician Alum Shale, Jurassic Kimmeridge Clay, Jurassic/Cretaceous Bazhenov Shale, and Late Cretaceous Eagle Ford Shale) as a function of particle size. Measurements were first conducted on 38?mm diameter core plugs, which then were crushed and milled to successively smaller particle sizes (<10?mm, <2?mm, <64?μm, and <1?μm). Apparent grain densities of the smallest particle fractions of the Alum, Bazhenov and Kimmeridge samples were consistently higher by 0.5 to 1% than apparent grain densities of the original sample plugs. Methane excess sorption capacity increased significantly for particle sizes <64 μm for the Alum and <1?μm for the Bazhenov and Kimmeridge samples while no significant changes upon grinding were observed for the Eagle Ford Shale. For the Bazhenov Shale, the apparent grain density increased slightly from 2.446?g/cm3 to 2.450?g/cm3 upon particle size reduction from <64?μm to <1?μm while the maximum sorption capacity (“Langmuir volume”) increased substantially from 0.11?mmol/g to 0.19?mmol/g. Similarly, for the Kimmeridge Clay and Alum Shale, a slight increase of the apparent grain density from 1.546?g/cm3 to 1.552?g/cm3 and from 2.362?g/cm3 to 2.385?g/cm3, respectively, was accompanied by increases in sorption capacity from 0.37?mmol/g to 0.45?mmol/g and from 0.14?mmol/g to 0.185?mmol/g, respectively. The increase in sorption capacity indicates an opening of a considerable amount of micropores with large internal surface area upon physical disruption of the rock fabric and/or removal of included fluids. It may also be due to increased swelling abilities of clay minerals and organic matter upon destruction of the stabilizing rock fabric with decreasing particle size. Grain density and sorption isotherms measured on small particle sizes are likely to overestimate the gas storage capacities and the amounts of producible gas-in-place since under field conditions (largely undisrupted rock fabric), significant portions of this storage capacity are essentially inaccessible. Poor interconnectivity of the pore system and slow, diffusion-controlled transport will massively retard gas production. Based on these findings, particle sizes >64 μm should be used for porosity and sorption measurements because they are more likely to retain the properties of the rock fabric in terms of accessible pore volume and sorptive storage capacity.Gauthiez-Putallaz, L., Nutman, A., Bennett, V., Rubatto, D., 2020. Origins of high δ18O in 3.7–3.6?Ga crust: A zircon and garnet record in Isua clastic metasedimentary rocks. Chemical Geology 537, 119474. δ18O is used as a marker for the presence of continents and surficial alteration in the Eoarchean and Hadean. This study establishes a timeline for δ18O enrichment in Eoarchean metasedimentary rocks of the Isua supracrustal belt in Greenland. The source-rocks for the protolith of these metasedimentary rocks are mafic to intermediate magmatic rocks of ≥3709 ± 4 Ma, based on the age of zircons found in volcanogenic layers. The δ18O of +5.4 ± 0.4‰ of the zircon crystals indicate that the sources had a primary mantle-derived signature. However, garnet in two metasediments yields higher δ18O values of +8.7 to +9.7‰, in equilibrium with a whole-rock of +11 to +12‰ at 500–600 °C. This requires that the mafic protolith was weathered at surficial conditions, in agreement with previous conclusions based on major element geochemistry. The garnet grains with high δ18O record four growth zones, assigned to I) arc-building thermal metamorphism, II–III) terrane assembly at medium to high-pressure conditions, estimated to occur at 3660–3690 Ma and IV) late-Archaean overprint likely at ca. 2690 Ma. This shows that material with originally mantle-like δ18O was altered at low temperature (near-surface) to generate elevated oxygen isotope signatures and then recycled to middle-crustal conditions within 10–50 million years of crystallization in the Eoarchean. We propose that melting of such rocks could produce the zircon crystals with high δ18O that are found in the detrital and magmatic record in the Archean.Ge, L., Chen, W., Zhu, B., Fan, M., Yang, T., Jiang, S., 2020. Sr and Nd isotopes of cold seep carbonates from the northern South China sea as proxies for fluid sources. Marine and Petroleum Geology 115, 104284. this study, Sr isotopes combined with Nd isotopes of modern cold seep carbonates were studied to provide reliable proxies for sources and pathways of seep fluids. We presented Sr and Nd isotopes together with stable carbon and oxygen isotope data of cold seep carbonates recovered from the northern continental slope of the South China Sea (SCS). Based on the evidence for negligible detrital contamination and diagenetic alteration, carbonate samples are considered dependable archives which record Sr and Nd isotope signals of the original pore waters from which carbonates have precipitated. Excellent correlation between 87Sr/86Sr ratios and 1/Sr observed in carbonate samples indicates two end-members with distinct Sr isotopic signatures, including modern seawater as a major source and a lesser contribution from methane-rich seep fluid driven from a deep source. Besides these two end-members, release of Nd from organic matter and Fe–Mn oxyhydroxide is an additional contribution to pore water Nd. Furthermore, Sr and Nd isotopic compositions suggest water-rock interactions between upward seep fluid and detrital component in sediments, which resulted in the isotopic shift towards pronounced 143Nd depleted and slightly 87Sr enriched in the fluid phase. This study provides insight into the knowledge for tracing seepage fluid circulation by Sr–Nd isotope system at modern seep systems.Ghaani, M.R., Allen, C.C.R., Young, J.M., Nandi, P.K., Dandare, S.U., Skvortsov, T., English, N.J., 2020. Microbial stabilization and kinetic enhancement of marine methane hydrates. Geomicrobiology Journal 37, 279-286. clathrate hydrates, a water host lattice encages small guest molecules in cavities. Methane hydrates are the most widespread in-situ clathrate in the permafrost and continental-shelf ocean regions, constituting a significant energy resource, and prompting recent marine-hydrate gas-production trials. Despite exciting engineering advances and a few marine-mimicking laboratory studies of methane-hydrate kinetics and stabilization, from microbial perspectives, little is known about a potential microbial origin of marine hydrates, nor their possible formation kinetics or potential stabilization by microbial sources. Here, for the first time, we show that an exported, extra-cytoplasmic porin ? produced by a marine methylotrophic bacterium culture ? provides the basis for kinetic enhancement and stabilization of methane hydrates under conditions simulating the seabed environment. We then identify the key protein at play, and we therefore suggest microbe-based stabilization of marine hydrates is evidently a property likely to be found in many marine bacteria. Our research opens the possibility of managing marine-hydrate deposits using microbiological strategies for environmental and societal benefit.Ghosh, A.K., Bandopadhyay, A.K., 2020. Formation of thermogenic gases with coalification: FTIR and DFT examination of vitrinite rich coals. International Journal of Coal Geology 219, 103379. evolution of thermogenic gases during coalification has not yet been theoretically attempted. Examinations on Indian Permian vitrinites of various ranks ranging from Cwt% 76 to 92 were performed. Fourier Transform Infra-red spectroscopy (FTIR) provided insight into the structural changes where the aliphatic CH increases with increase in percentage of carbon up to ~85% and then decreases. In contrast, the aromatic CH, the ratio of aromatic CH to aliphatic CH and aromaticity (fa) increase monotonically with the advancement of rank. A relationship between fa and atomic H/C ratio as fa = 1.12–0.45H/C was established to predict fa from elemental analysis. The structural data from FTIR served as an input to construct six representative hypothetical models of coal of varying Cwt% (76, 80, 83, 86, 87 and 89). Density Functional Theory (DFT) has been applied to these coal models and the formation of principal thermogenic gases, viz. CO2 for the low-(76%C)and CH4 for the high-rank (87%C), with simultaneous increase in the rank was demonstrated considering the smaller structural units extracted from the relevant coal models. The suggested reaction pathways are supported by the negative values of changes in free energies of the reactions computed from the Gaussian thermo-chemistry. The studies could, therefore, show that gas evolution as a natural (spontaneous) process with feasibility of rank advancement.Gibbons, A., 2020. Strange bedfellows for human ancestors. Science 367, 838-839. story of human evolution is full of ancient trysts. Genes from fossils have shown that the ancestors of many living people mated with Neanderthals and with Denisovans, a mysterious group of extinct humans who lived in Asia. Now, a flurry of papers suggests the ancestors of all three groups mixed at least twice with even older “ghost” lineages of unknown extinct hominins. One candidate partner: Homo erectus, an early human who left Africa by 1.8 million years ago, spread around the world, and could have mated with later waves of human ancestors.The new genomic studies rely on complex models of inheritance and population mixing, and they have many uncertainties, not least the precise identities of our ancestors' strange bedfellows and when and where the encounters took place. But, taken together, they build a strong case that even before modern humans left Africa, it was not uncommon for different human ancestors to meet and mate. “It's now clear that interbreeding between different groups of humans goes all the way back,” says computational biologist Murray Cox of Massey University of New Zealand, Turitea, who was not involved in the new studies.The gold standard for detecting interbreeding with archaic humans is to sequence ancient DNA from fossils of the archaic group, then look for traces of it in modern genomes. Researchers have done just that with Neanderthal and Denisovan genomes up to 200,000 years old from Eurasia. But no one has been able to extract full genomes from more ancient human ancestors. So population geneticists have developed statistical tools to find unusually ancient DNA in genomes of living people. After almost a decade of tantalizing but unproven sightings, several teams now seem to be converging on at least two distinct episodes of very ancient interbreeding.In Science Advances this week, Alan Rogers, a population geneticist at the University of Utah, Salt Lake City, and his team identified variations at matching sites in the genomes of different human populations, including Europeans, Asians, Neanderthals, and Denisovans. The team tested eight scenarios of how genes are distributed before and after mixing with another group, to see which scenario best simulated the observed patterns. They conclude that the ancestors of Neanderthals and Denisovans—whom they call Neandersovans—interbred with a “super-archaic” population that separated from other humans about 2 million years ago. Likely candidates include early members of our genus, such as H. erectus or one of its contemporaries. The mixing likely happened outside of Africa, because that's where both Neanderthals and Denisovans emerged, and it could have taken place at least 600,000 years ago.“I think the super-archaics were in the first wave of hominids who left Africa,” Rogers says. “They stayed in Eurasia, largely isolated from Africans, until 700,000 years ago when Neandersovans left Africa and interbred with them.”Occurring much earlier than encounters of modern humans with Neanderthals and Denisovans, the episode was “the earliest known interbreeding between ancient human populations and an expansion out of Africa,” Rogers says. Other studies have hinted at such ancient mixing, Cox says, but Rogers's analysis is “particularly convincing.”Others, though, say Rogers's bold claim needs testing. One challenge is reconciling it with new results from other researchers that show modern human ancestors mixed with super-archaic groups more recently, in Africa. Just last week, for example, population geneticist Sriram Sankararaman and his student Arun Durvasula at the University of California (UC), Los Angeles, identified signs of a separate, more recent episode of mixing. The researchers analyzed the genomes of 405 people from four subpopulations in West Africa that were included in the 1000 Genomes Project, a catalog of genomes from around the world. They found numerous gene variants not seen in Neanderthals or Denisovans and concluded that the best explanation was that the variants came from an archaic, extinct human.This ghost species may have been late H. erectus, H. heidelbergensis, or a close relative. One or more late-surviving members of this ancient group met and mated with the ancestors of living Africans sometime in the past 124,000 years, the modern genomes suggest.Another paper last month reported Neanderthal DNA in living Africans, likely from migrations back to Africa by early Europeans who bore Neanderthal DNA (Science, 31 January, p. 497). Sankararaman thinks some of the archaic DNA he detects in Africans may be from Neanderthals, but most is from the older ghost species. “I think the true picture is a combination of both an archaic population unrelated to Neanderthals as well as Neanderthal-related ancestry,” he says.In December 2019, yet another study found hints of an extinct ghost population in living Africans, although it was silent on the identity of the ghosts and when they bred with our ancestors. Population geneticist Jeff Wall at UC San Francisco and colleagues analyzed 1667 genomes from diverse populations in the GenomeAsia 100K consortium. They reported the strongest ghost signal in the Khoisan people and in Central African hunter-gatherers formerly known as pygmies.But Wall and others warn their methods cannot rule out that the “ghosts” could be one or several groups of modern humans in Africa that were separated from other moderns for so long that their genes looked “archaic” when the groups finally came together again and mixed. “Our understanding of African population history in particular, is so far behind,” says Joshua Akey of Princeton University.Even if they differ on particulars, the studies emphasize that long after new lineages of humans emerge, they still can mix with others quite different from themselves. Other species, such as cave bears and mammoths, show the same pattern of divergence and later mixing, says population geneticist Pontus Skoglund of the Francis Crick Institute in London. “We are losing the idea that separation between populations is simple with instant isolation.” Such mating between long isolated groups may quickly introduce valuable new genes (Science, 18 November 2016, p. 818). For example, some of the archaic alleles Sankararaman spotted in Africans were in genes that suppress tumors and regulate hormones.Today, H. sapiens doesn't have the possibility of quickly grabbing a load of diversity by mating with another group: For perhaps the first time in our history, we're the only humans on the planet. It's another reason to miss our extinct cousins, says population geneticist Carina Schlebusch of Uppsala University. “To have such a large densely spread species with … so little genetic diversity … is a dangerous situation,” she says.Gilevska, T., Sullivan Ojeda, A., Renpenning, J., Kümmel, S., Gehre, M., Nijenhuis, I., Sherwood Lollar, B., 2020. Requirements for chromium reactors for use in the determination of H isotopes in compound-specific stable isotope analysis of chlorinated compounds. Analytical Chemistry 92, 2383-2387. is a strong need for careful quality control in hydrogen compound-specific stable isotope analysis (CSIA) of halogenated compounds. This arises in part due to the lack of universal design of the chromium (Cr) reactors. In this study, factors that optimize the critical performance parameter, linearity, for the Cr reduction method for hydrogen isotope analysis were identified and evaluated. These include the effects of short and long vertically mounted reactors and temperature profiles on trapping of Cl to ensure accurate and precise hydrogen isotope measurements. This paper demonstrates the critical parameters that need consideration to optimize any Cr reactor applications to ensure the accuracy of δ2H analysis for organic compounds and to enhance intercomparability for both international standards and reference materials run by continuous flow versus an elemental analyzer.Goedert, J., Amiot, R., Berthet, D., Fourel, F., Simon, L., Lécuyer, C., 2020. Combined oxygen and sulphur isotope analysis—a new tool to unravel vertebrate (paleo)-ecology. The Science of Nature 107, 10. the living environment of extinct vertebrates is often challenging due to the lack of proxies. We propose a new proxy to the living environment based on the combined oxygen and sulphur stable isotope analysis of vertebrate hydroxyapatite. We tested this isotopic proxy to 64 biogenic apatite (bones) samples that represent a wide spectrum of the extant vertebrate phylogenetic diversity including crocodiles, snakes, turtles, mammals, birds, lizards, fish and amphibians. We show that the combination of these two isotopic systems allows the living environment of all these vertebrates to be unambiguously distinguished between freshwater (aquatic vs semi-aquatic), seawater (aquatic vs semi-aquatic) and terrestrial. The main goal of this study is to provide a present-day isotopic reference frame and to discuss methodological issues that will serve to interpret future oxygen and sulphur isotope results obtained either from fossil or modern skeletal material. This new isotopic approach of combined oxygen and sulphur isotope analysis will be particularly useful to document major aquatic-terrestrial transitions in the fossil record but also to better constrain the living environment of some present-day species.Golonka, J., 2020. Late Devonian paleogeography in the framework of global plate tectonics. Global and Planetary Change 186, 103129. paper presents Late Devonian (Frasnian–Famennian) global and regional paleogeographic maps displaying present day coastlines, tectonic elements' boundaries, subductions, rifts, spreading centers, transform faults, paleogeographic configuration and volcanism 370 million years ago. The regional maps illustrate the paleoenvironment and paleolithofacies distribution.The Late Devonian was a time of the onset and development of a major collisional event, the Variscan orogeny. The trench-pulling (or slab-pull) effect of the north dipping subduction, which developed along the Laurussia margin, caused the creation of the back-arc Rheno-Hercynian basin, as well as the transfer of tectonic elements. These tectonic elements included Saxothuringian, Southern Proto-Carpathian and Balkan terranes. The Antler and Ellesmerian orogenies constituted major collisional events in North America.The spreading of the Paleotethys Ocean constituted the main extensional event. This spreading is associated with the movement of tectonic elements towards Laurussia, Siberia and Northern Kazakhstan. In addition, a branch of the Paleotethys Ocean was opened between South China and Gondwana, during the Late Devonian times. The spreading was displayed along the proto-Andean margin of western Gondwana and is thought to have opened the newly proposed Chilean Ocean. The development of major rift systems took place throughout Laurussia and Siberia. Late Devonian rifting was associated with volcanic activity, especially prominent in the Viluy rift in Siberia. The deposition, during the Late Devonian time, is characterized by the existence of large carbonate platforms with reefs on large continents and synorogenic flysch in collisional areas. The sea-level dropped towards the Devonian- Carboniferous boundary. The climate was undergoing change from greenhouse to icehouse.The following plate tectonic events could have influenced the extinction of biotas at the Frasnian-Famennian boundary: 1) The very extensive basaltic volcanism in Laurussia and Siberian and along the arcs.2) The closure of the Rheic Ocean and the development of the Variscan orogeny.3) Intensive spreading in the Paleotethys and the development of numerous subductions and volcanic arcs.These events resembled a transition from a rift to a drift phase, during the Permian–Mesozoic break-up of Pangaea. This break-up was associated with other biota extinctions.Gong, G.-q., Zhao, Y.-f., Zhang, Y.-j., Deng, B., Liu, W.-x., Wang, M., Yuan, X., Xu, L.-w., 2020. Establishment of a molecular structure model for classified products of coal-based fulvic acid. Fuel 267, 117210. acid (FA) is used widely in materials, medicine, and agriculture because of its unique chemical properties. FA has good chemical activity due to its molecular structure which contains many functional moieties such as hydroxyl and carboxyl groups. Moreover, FA is biologically compatible enabling its use in medicine is agriculture. The chemical activity and physical properties of FA polymers differ based on its molecular weight. In order to reveal the specific structural characteristics of FA, column chromatography was used to fractionate FA into three different molecular weight products. Elementary analysis, infrared spectroscopy, and 13C nuclear magnetic resonance were used to study the composition and content of the classified FA products. The three different molecular weights of FA all contained carboxyl groups and phenolic hydroxyl groups. Our findings show that the carboxyl group was mostly distributed at the end of the aliphatic chain, while a small portion was connected to the benzene ring. The higher molecular weight FA contained more carboxyl groups, and some oxygen elements were present in the form of carbonyl and ether bonds. The chemical formulas of the three molecular weights were C17H19NO10, C33H27NO23, and C48H37NO36, which were calculated by molecular mechanics and dynamics. The molecular structure of FA was optimised by quantum chemical calculation methods. Finally, the average molecular structure model of FA with different molecular weights was established.Gong, H., Qin, X., Shang, S., Zhu, C., Xu, L., San, Q., Li, Y., Dong, M., 2020. Enhanced shale oil recovery by the huff and puff method using CO2 and cosolvent mixed fluids. Energy & Fuels 34, 1438-1446. oil, as one of the unconventional resources, has become increasingly important to supplement conventional oil and gas. Although CO2 has great potential to enhance shale oil recovery by the huff and puff method, the experimental results show that the enhanced values of shale oil recovery are unstable and have great fluctuations for different cores. In order to increase the stability of CO2 huff and puff and further enhance oil recovery, cosolvents such as ethanol, isopropanol, ethyl acetate, and acetone were chosen to construct CO2/cosolvent mixed fluids and the experiments of huff and puff by the mixed fluids were carried out. The results show that CO2/cosolvents can enhance the shale oil recoveries of the matrix and fracture. CO2/ethanol has the highest oil recovery among the mixed fluids. In particular, for cycles 2 and 3 in the huff and puff process, CO2/ethanol has a much larger oil recovery than CO2. Moreover, the effects of ethanol concentration in the mixed fluids on the enhanced shale oil recovery were investigated. The enhanced oil recoveries by CO2/ethanol mixed fluids increase with the increase of ethanol concentration. Furthermore, the mechanisms to enhance shale oil recovery by CO2/cosolvent fluids were discussed by measurements of the pressure decay process and interfacial tension. The presence of ethanol can not only accelerate the transfer of CO2 to the oil phase in the porous media during the huff process, to make more CO2 transfer into the oil phase, but also decrease the interfacial tension between oil and CO2 as well as the minimum miscibility pressure, to make oil and CO2 mixed fluids have a longer time to flow out in one phase than CO2 in the puff process. Therefore, the CO2/cosolvent mixed fluids, especially CO2/ethanol, can be used to further enhance shale oil recovery during the huff and puff process.Gonsior, M., 2019. Chapter 13 - FT-ICR MS and Orbitrap mass spectrometry approaches in environmental chemistry, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 407-423. chapter will address non-target ultrahigh resolution mass spectrometric approaches currently implemented in aquatic and sediment environmental chemistry with a focus on drinking water, wastewater and emerging pollutant screening in aquatic/sediment systems. How to discover new and previously unknown DBPs will be described in drinking water. Non-target screening for unknown contaminants in wastewater is also an emerging field and examples are given describing approaches used in hydraulic fracturing (fracking) fluids and secondary treated effluent. Non-targeted screening for known and unknown contaminants in surface, groundwater and also sediments is discussed and approaches are summarized.Gorshkov, A., Pavlova, O., Khlystov, O., Zemskaya, T., 2020. Fractioning of petroleum hydrocarbons from seeped oil as a factor of purity preservation of water in Lake Baikal (Russia). Journal of Great Lakes Research 46, 115-122. aromatic hydrocarbons (PAHs) and n-alkanes were found in five different types of oil-containing samples emanating from deep oil seeps in Lake Baikal, the deepest and oldest lake in the world containing 20% of the world’s surface freshwater. The n-alkanes were the dominant component of the seeped oil on the water surface. PAHs were minor compounds of the oil, but this group is included in a priority series of organic contaminants that are subject to environmental regulation. The set of studied samples from the seep included: (i) freshly-emitted oil on the lake surface, (ii) oil at the lake bottom, (iii) samples of asphalt towers at the lake bottom, (iv) oil from voids within the sediment core and (v) samples of water from different depths. High variability in the concentrations of n-alkanes and PAHs suggested the presence of oil fractionation at the sediment-water interface. A light fraction of oil enriched by n-alkanes migrates to the surface of the lake’s water column, where n-alkanes are biodegraded by the Baikal microbial community while heavy oil fractions remain at the lake bottom and form asphalt towers in which PAHs with maximum toxicity accumulate. In the lake’s photic water layer, PAHs from light oil can be accumulated by phytoplankton. In the lake’s water column, benzo[a]pyrene was not detected over their detection limit (0.1 ng/L). The Toxic Equivalent (TEQ) value of PAHs identified in the Baikal water ranged from 0.001 to 0.012 ng/L.Gou, Q., Xu, S., Hao, F., Zhang, B., Shu, Z., Yang, F., Wang, Y., Li, Q., 2020. Quantitative calculated shale gas contents with different lithofacies: A case study of Fuling gas shale, Sichuan Basin, China. Journal of Natural Gas Science and Engineering 76, 103222. accurately evaluate pore structure and gas content characteristics of shale reservoir, a series of tests, including XRD, TOC, porosity, FE-SEM, N2 and CO2 adsorption, and high-pressure methane sorption, were conducted on the Wufeng-Longmaxi shale in the Fuling area. The principal objective of this work is to reveal the development mechanisms of shale pores, and quantitatively calculated both free gas and absorbed gas contents in different lithofacies. A total of three main lithofacies, i.e., clay-rich siliceous shale lithofacies (S-3), argillaceous/siliceous mixed shale lithofacies (M-2) and silica-rich argillaceous shale lithofacies (CM-1) were identified in the study area. The highest values of TOC, helium porosity, pore volume, and specific surface area are recognized in the S-3 shales, with a mean of 3.94%, 5.12%, 22.13 × 10?3 cm3/g, and 35.23 m2/g, respectively. The pore volume and specific surface area of S-3 shales are primarily contributed by OM pores, with an average proportion of 66.99% and 66.38%. However, the pore volume and specific surface area of clay-related pores, a significant component of CM-1 shales, occupied an average of 64.30% and 52.72%, respectively. Owing to the change of lithofacies from S-3 to M-2 and CM-1 shales, the pore volume is reduced by 28.74% and 22.37%, while the specific surface area is reduced by 30.28% and 32.89%, respectively. The total shale gas contents of S-3 shales are calculated to be 5.54–7.72 m3/t, with an average of 6.64 m3/t, and that of M-2 shales and CM-1 shales are ranging from 4.28 m3/t to 5.03 m3/t and 2.43 m3/t to 4.33 m3/t, with a mean of 4.61 m3/t and 3.51 m3/t, respectively. However, due to the difference of pore types, the CM-1 shales are characterized by the highest proportion of free gas (average 59.08%), whereas that of M-2 shales and S-3 shales are recognized with 54.96% and 50.93%, respectively.Griffith, E.M., Fantle, M.S., 2020. Introduction to calcium isotope geochemistry: Past lessons and future directions. Chemical Geology 537, 119470. (Ca) isotopes have been utilized as geochemical tools since the 1970s, increasing in popularity and scope since the mid- to late 1990s. Research conducted over the past thirty years has revealed a range of applications for Ca isotopes that are highlighted in this introduction and Special Issue, as well as a series of interesting and fundamental problems that have yet to be resolved. For such a chemically-simple system, in comparison to redox-active elements for instance, the level of complexity is both surprising and intellectually attractive. While the advent of multiple collector inductively coupled plasma mass spectrometers made metals such as Fe, Mg, and Zn considerably more accessible analytically, the precision and ease of Ca isotopic analysis did not radically improve in a comparable manner. For a variety of reasons, one of which may be perceived analytical difficulty, the application of Ca isotopes to geological questions remains in the shadows, to some extent, in the Geosciences. In this introduction, we identify (i) areas that we think are most fertile for the application of Ca isotopes as tools and (ii) outstanding questions and future directions that can move the field towards increased utility and broader acceptance by the Geosciences community.Gross, J.H., 2020. Book Review: Basem Kanawati and Philippe Schmitt-Kopplin (Eds.): Fundamentals and applications of Fourier transform mass spectrometry. Analytical and Bioanalytical Chemistry 412, 257-258.’s topicFundamentals and applications of Fourier transform mass spectrometry, edited by Basem Kanawati and Philippe Schmitt-Kopplin, presents a comprehensive and up-to-date monograph on Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS) and Orbitrap-MS. FT-ICR-MS, introduced by Melvin Comisarow and Alan Marshall in 1974, presented the first—and for decades, the only—technique in mass spectrometry employing FT. It was not until the advent of the Orbitrap mass analyzer, the concept of which was presented by Alexander Makarov in 2000, that a second technique recording a transient signal made its way into MS. Since then, Fourier transform-mass spectrometry (FT-MS) can be regarded as a cumulative term for MS techniques employing FT to translate a time domain transient signal into frequency domain data. FT-MS instruments provide both high to ultra-high resolving power and sub-ppm level mass accuracy, and thus, serve for the most demanding analytical applications in MS.Contents This monograph is structured into three sections comprising a total of 22 chapters. The chapters have been prepared by an international team of 50 authors including the editors themselves; quite a number of them can be regarded the top researchers in their particular field. Section A, “Historical chapters,” essentially contains just a single chapter on “Historical developments in Fourier transform ion cyclotron resonance mass spectrometry”. Section B, “Fundamental/technology chapters”, presents nine chapters dealing with a range of topics on theory, instrumentation, operation, and data processing with both FT-ICR and Orbitrap mass analyzers. This section explaining the fundamentals of FT-MS represents the core of the book. Finally, Section C, “Applications chapters”, provides twelve chapters on topics selected across the vast field of FT-based mass spectrometry to illustrate the technique and to showcase the power of FT-parison with the existing literature The probably best known—and in fact only relevant—predecessor of this book is FT-ICR/MS: Analytical applications of Fourier transform ion cyclotronresonance mass spectrometry edited by Bruce Asamoto back in 1991. Apart from this book that, at its time, provided a well-balanced introduction and state-of-the-art overview, there are only books containing single chapters on FT-ICR-MS or Orbitrap-MS. These books are either MS textbooks or devoted to dedicated analytical applications where FT-MS plays a role. Other book titles popping up during searches deal with highly specialized topics and apparently present theses published as books. Thus, the present monograph is the first of its kind for almost four decades.Critical assessment Basically, this monograph is well-structured and the assignment of the chapters into Sections A to C provides orientation for the reader. Generally, the authors have taken great care to provide well-prepared and informative chapters each contributing to the whole package offered by this book. All chapters, notably varying in length from just 18 to an extensive 56 pages, close with a comprehensive list of references including the titles of the articles. Chap. 2, a concise and structured description of the fundamentals of the Orbitrap and its operation, Chap. 3 on fundamentals of and trends in FT-ICR technology, and Chap. 7 on the rather recent and promising technique of 2D-MS present highlights of Section B. The second to last chapter of Section B, “In situ metabolomics in cancer tissue by high-resolution mass spectrometry imaging”, should rather belong in Section C dealing with applications. Also Chap. 2 on Orbitraps might have been better located later in Section B.Section C delivers a wide coverage ranging from complex mixture analysis and various forms of “omics”, over biomedical and forensic applications to gas phase ion chemistry and ion spectroscopy.The coverage of this monograph is restricted to FT-ICR-MS and Orbitrap-MS, and thus misses to provide a glimpse beyond that scope. Emerging FT-MS devices such as the electrostatic linear ion trap by Scott McLuckey would have deserved a chapter of their own in Section B.Given the fact that illustrations tremendously aid in understanding complex science and relationships, the number of just 134 figures and 8 schemes in a 786-page volume is below average; chapters 1, 6, and 18 even do not contain a single figure. In this regard, chapters 7 and 19 to 22 positively stand out by providing up to 16 figures each. It should be noted that a majority of figures, many of them in color, are well-prepared while just a few are either not sharp or scaled too tiny to read.Measuring accurate mass for formula determination is one of the pillars of FT-MS and this depends on using the correct mass scale. It is thus disappointing to note that in Chaps. 12 and 17 the outdated atomic mass unit (amu, until 1961, based on oxygen) is erroneously used instead of the correct unified atomic mass (u, based on 12C, i.e., 1 amu ≠ 1 u).Finally, the print version of such an expensive 786-page monograph that can be expected to serve as the reference book for the next decade or so would have deserved a hardcover rather than a softcover.Apart from these minor flaws, the book delivers. It presents a well-rounded overview of FT-MS to the reader and provides a wealth of information and references to the literature for those needing to dig even deeper into the subject.Readership recommendations: This monograph can be recommended for researchers and practitioners in the field of mass spectrometry. While the more tutorial chapters of Section B teach the knowledge of how the various FT-MS techniques work, Section C presents the reader a great selection of what can be achieved when applying these techniques. Readers with entry-level knowledge of MS, e.g., undergraduate students or career changers, should refer to more introductory-level books prior to reading this one.Summary: Fundamentals and applications of Fourier transform mass spectrometry provides an up-to-date resource on probably any aspect of FT-ICR-MS and Orbitrap-MS from fundamentals to applications of these powerful techniques. As is often the case with multi-authored books, there is notable variation in length, depth of treatment, and writing style between the chapters. Overall, this book deserves a place on the bookshelves not only of academic libraries but even more so in MS laboratories using FT-based instrumentation. This review rates it at four of five stars.Gruber, B., David, F., Sandra, P., 2020. Capillary gas chromatography-mass spectrometry: Current trends and perspectives. TrAC Trends in Analytical Chemistry 124, 115475. the advent of gas chromatography - mass spectrometry (GC-MS), the evolution in high-performance GC-MS has boosted the quality and quantity of information. Continuing technical advances and topics of current focus are pushing GC-MS in areas such as metabolomics, biochemistry, medical analysis, and pharmacology, traditionally dominated by other separation techniques. Still, selection and optimization of sample preparation, analysis and data evaluation need to be carefully assessed to address the purpose of the analytical question, both in targeted and non-targeted approaches. In particular, studies on increasingly complex samples require sophisticated techniques. In this review, recent and significant advances in GC-MS are discussed, which includes a brief overview of challenges and limitations as well as solutions. Trends towards softer ionization techniques, high-resolution MS and multidimensionality further extend the analyte range in GC-MS. Especially, the implementation of standardized and streamlined workflows will enable the exploitation of the full potential of GC-MS in future.Grundy, W.M., Bird, M.K., Britt, D.T., Cook, J.C., Cruikshank, D.P., Howett, C.J.A., Krijt, S., Linscott, I.R., Olkin, C.B., Parker, A.H., Protopapa, S., Ruaud, M., Umurhan, O.M., Young, L.A., Dalle Ore, C.M., Kavelaars, J.J., Keane, J.T., Pendleton, Y.J., Porter, S.B., Scipioni, F., Spencer, J.R., Stern, S.A., Verbiscer, A.J., Weaver, H.A., Binzel, R.P., Buie, M.W., Buratti, B.J., Cheng, A., Earle, A.M., Elliott, H.A., Gabasova, L., Gladstone, G.R., Hill, M.E., Horanyi, M., Jennings, D.E., Lunsford, A.W., McComas, D.J., McKinnon, W.B., McNutt, R.L., Moore, J.M., Parker, J.W., Quirico, E., Reuter, D.C., Schenk, P.M., Schmitt, B., Showalter, M.R., Singer, K.N., Weigle, G.E., Zangari, A.M., 2020. Color, composition, and thermal environment of Kuiper Belt object (486958) Arrokoth. Science 367, eaay3705.: The outer Solar System object (486958) Arrokoth (provisional designation 2014 MU69) has been largely undisturbed since its formation. We studied its surface composition using data collected by the New Horizons spacecraft. Methanol ice is present along with organic material, which may have formed through irradiation of simple molecules. Water ice was not detected. This composition indicates hydrogenation of carbon monoxide–rich ice and/or energetic processing of methane condensed on water ice grains in the cold, outer edge of the early Solar System. There are only small regional variations in color and spectra across the surface, which suggests that Arrokoth formed from a homogeneous or well-mixed reservoir of solids. Microwave thermal emission from the winter night side is consistent with a mean brightness temperature of 29 ± 5 kelvin.Structured AbstractIntroduction: The New Horizons spacecraft flew past (486958) Arrokoth (provisional designation 2014 MU69) on 1 January 2019. Arrokoth is a member of the subclass of trans-neptunian or Kuiper Belt objects (KBOs), known as the cold classical KBOs (CCKBOs). Most KBOs formed in a disk of planetesimals that extended to about 30 AU from the Sun. Neptune eventually disrupted that disk by migrating outward through it, with the migration halted by the sparseness of the disk beyond 30 AU. That event eliminated most members of the planetesimal disk, but a minority were emplaced into dynamically excited orbits in the present-day Kuiper belt. CCKBOs differ from those objects in having formed well beyond the 30-AU edge of the main planetesimal disk. They remain approximately where they formed, on low-inclination, near-circular orbits between 42 and 47 AU from the Sun, relicts of the early Solar System. Their distributions of colors, albedos, sizes, and binarity differ from those of the more excited KBOs.Rationale: Initial results from the exploration of Arrokoth were published previously. More data have since been received from the spacecraft, allowing a more detailed analysis. We analyze a high–spatial resolution color imaging observation, near-infrared spectral imaging, and microwave radiometry of Arrokoth. The infrared spectral data have been processed to compensate for the changing range and scale during the observation. Our multiple scattering radiative transfer models provide compositional constraints from the infrared spectral imagery. Microwave thermal radiometry at 4.2-cm wavelength is combined with heat transport models that account for the bilobate shape of Arrokoth and for self-radiation.Results: At visual wavelengths, Arrokoth’s reflectance rises toward longer wavelengths. This red coloration is typical of the broader CCKBO population that has been studied using telescopic observations. Color differences across the surface of Arrokoth correspond to geological features. These color differences are subtle, with deviations of just a few percent around the prevailing red coloration. Some of the color variations are associated with albedo markings, such as the bright neck between the two lobes, bright splotches associated with a large pit or crater on the smaller lobe, and poorly resolved small bright spots. Methanol ice (CH3OH) and complex organic tholins dominate the near-infrared reflectance spectrum, with H2O ice contributing little or no detectable absorption. At the 4.2-cm microwave wavelength of New Horizons’ radio system, Arrokoth’s winter night side glows with an average brightness temperature of 29 ± 5 K. This emission probably emerges from below the cold winter surface, at depths where warmth from the previous summer lingers. Our models show that self-radiation more than compensates for self-shadowing in the neck region between the two lobes, resulting in warmer temperatures in that region, by up to a few kelvin.Conclusion: The nearly uniform coloration across Arrokoth is consistent with expectations for an object that accreted too quickly for the composition of the available nebular solids to have changed during the course of its accretion. Radiolysis and photolysis from long exposure to space radiation would be expected to result in a dark, space-weathered surface veneer that is distinct from the more pristine interior, but there is little evidence for such a coating, perhaps because radiolytically processed material is eroded away faster than it accumulates. The abundance of CH3OH ice and apparent scarcity of H2O ice appear to be signatures of a distinct environment in the cold, dust-shaded midplane of the outer nebula during formation of the Solar System. In this region, temperatures would have been low enough that volatile CO and CH4 could freeze onto dust grains, enabling production of CH3OH and perhaps also destruction of H2O. When the nebular dust dissipated some time after Arrokoth’s formation, exposure to sunlight would have raised its temperature, rapidly driving off condensed CO and CH4. The temperature has remained too cold to crystallize amorphous H2O. Volatile species may remain trapped in amorphous H2O ice within Arrokoth’s interior, but the infrared spectrum shows little evidence for such ice at the surface. Although the neck region gets slightly warmer than the rest of Arrokoth’s surface, this effect is small relative to the winter-summer temperature contrast and is thus unlikely to account for the distinctly higher albedo and slightly less red material that is seen there. A more plausible explanation for the neck’s albedo and color contrasts involves texture changes induced by the merger of the two lobes or subsequent downslope movement of material there.Editor's summary: Examining Arrokoth. The New Horizons spacecraft flew past the Kuiper Belt object (486958) Arrokoth (also known as 2014 MU69) in January 2019. Because of the great distance to the outer Solar System and limited bandwidth, it will take until late 2020 to downlink all the spacecraft's observations back to Earth. Three papers in this issue analyze recently downlinked data, including the highest-resolution images taken during the encounter (see the Perspective by Jewitt). Spencer et al. examined Arrokoth's geology and geophysics using stereo imaging, dated the surface using impact craters, and produced a geomorphological map. Grundy et al. investigated the composition of the surface using color imaging and spectroscopic data and assessed Arrokoth's thermal emission using microwave radiometry. McKinnon et al. used simulations to determine how Arrokoth formed: Two gravitationally bound objects gently spiraled together during the formation of the Solar System. Together, these papers determine the age, composition, and formation process of the most pristine object yet visited by a spacecraft.Gu, N., Song, Q., Yang, X., Yu, X., Li, X., Li, G., 2020. Fluorescence characteristics and biodegradability of dissolved organic matter (DOM) leached from non-point sources in southeastern China. Environmental Pollution 258, 113807. the increasingly intensive measures for surface water restoration in China, point source discharge has been strictly regulated; however, for non-point sources, which constitute a large part of surface water pollutants, effective control has been difficult to reach. A comprehensive understanding of the characteristics of non-point source pollutants is essential for surface water improvement programs of cities such as Ningbo, on the southeast coast of China. Ningbo has made tremendous efforts in the past few years to control point source pollutants, but available data and management strategies on the non-point source pollutants are still limited. To this end, leachates of representative non-point source samples from the territory of Ningbo, including cropland and wetland soil, urban channel sediment, and poultry manure, were examined and compared focusing on the fluorescence characteristics and biodegradability of the dissolved organic matter (DOM). Results indicated that biodegradable dissolved organic carbon (BDOC) accounting for the total DOC was 46.7 ± 0.7% for cropland, wetland (56.3 ± 6.8%), non-sewage channel (60.1 ± 0.4%), sewage channel (74.5 ± 1.1%), and poultry manure (62.7 ± 4.5%). The leachates of the studied samples showed significant differences in both the amount and composition of DOM. However, a fluorescence component representing tryptophan-like substances identified by the excitation-emission matrix (EEM) combined with parallel factor (PARAFAC) analysis effectively predicted the BDOC variations among the studied samples. Moreover, under the studied nutrient concentrations, which were equivalent to Grade III water quality in China, nutrient limitation of microbial degradation was not observed. Threats to water quality, especially excessive consumption of dissolved oxygen, could be posed by the non-point source leachates due to their high bioavailability, large distribution, and weak nutrient restraint. Further investigations, including a quantitative evaluation of the non-point source pollution contribution, and pollutant blocking techniques are required.Guglielmini, J., Woo, A.C., Krupovic, M., Forterre, P., Gaia, M., 2020. Reply to Ku and Sun: Ancestors of modern giant and large eukaryotic dsDNA viruses infected proto-eukaryotes. Proceedings of the National Academy of Sciences 117, 2749-2750. Guglielmini et al. (1), we analyze the evolutionary relationships between Nucleo-Cytoplasmic Large DNA Viruses (NCLDVs) and the cellular domains based on the two largest universal markers, that is, the two largest RNA polymerase subunits (RNAP). We conclude that NCLDVs diversified before the emergence of the last eukaryotic common ancestor (LECA). Our results now draw criticism from Ku and Sun (2).They notably describe as a flaw the three-domain (3d) topology displayed by our RNAP trees, exposing an unjustified prejudice in favor of the two-domain (2d) topology. Indeed, the debate between the 2d and 3d scenarios is still open, as exemplified by the still unsolved phylogenomic challenges and the recent robust multigene phylogenies … Reply to comment: Ku, C., Sun, T.-W., 2020. Did giant and large dsDNA viruses originate before their eukaryotic hosts? Proceedings of the National Academy of Sciences, 117(6), 2747-2748Original article Comment on: Julien Guglielmini, Anthony C. Woo, Mart Krupovic, Patrick Forterre, and organ Gaia. Diversification of giant and large eukaryotic dsDNA viruses predated the origin of modern eukaryotes, PNAS September 24, 2019 116 (39) 19585-19592Guillemant, J., Berlioz-Barbier, A., Albrieux, F., de Oliveira, L.P., Lacoue-Nègre, M., Joly, J.-F., Duponchel, L., 2020. Low-level fusion of Fourier transform ion cyclotron resonance mass spectrometry data sets for the characterization of nitrogen and sulfur compounds in vacuum gas oils. Analytical Chemistry 92, 2815-2823. total of 18 vacuum gas oils have been analyzed by Fourier transform ion cyclotron resonance mass spectrometry considering six replicates in three different ionization modes (electrospray ionization (ESI)(+), ESI(?), and atmospheric pressure photoionization (APPI)(+)) to characterize the nitrogen and sulfur compounds contained in these samples. Classical data analysis has been first performed on generated data sets using double bond equivalents (DBE) versus number of carbon atoms (#C) plots in order to observe similarities and differences within the nitrogen and sulfur-containing molecular classes from samples produced by different industrial processes. In a second step, three-way arrays have been generated for each ionization mode considering three dimensions: DBE related to aromaticity, number of carbon atoms related to alkylation, and sample. These three-way arrays have then be concatenated using low-level data fusion strategy to obtain a new tensor with three new modes: aromaticity, alkylation, and sample. The PARAFAC method has then been applied for the first time to this three-way data structure. A two components decomposition has allowed us to highlight unique samples with unexpected reactivity behaviors throughout hydrotreatment. The obtained loadings led to the identification of the variables responsible for this specific character. This original strategy has provided a fast visualization tool able to highlight simultaneously the impact of the three ionization modes in order to explain the differences between the samples and compare them.Gunning, J., Ennis-King, J., LaForce, T., Jenkins, C., Paterson, L., 2020. Bayesian well-test 2D tomography inversion for CO2 plume detection. International Journal of Greenhouse Gas Control 94, 102804. inversion of cross-well time-lapse pressure tests is investigated as a monitoring technique for locating CO2 plumes in the subsurface. Fast inversion methods are possible which treat the gas plume as either a constant-pressure or reduced diffusivity region. However, neither constant-pressure nor diffusivity-barrier approaches are adequate for modelling the full behaviour of the plume dynamics, especially the late time pressurisation of small plumes. The saturation dependence of the flow is dominated by the compressibility contrast, which justifies the use of an approximate mixed-phase flow equation with saturation dependence confined to the compressibility terms. This fast proxy flow model enables the construction of efficient inversion methods using either low dimensional object–based representations of the plume, or voxelised models exploiting gradients from nonlinear adjoint theory. It allows the inclusion both of cross-well and single-well responses.The inversion algorithms are then tested on a simplified three-dimensional full-physics simulation model of CO2 injection, and give a 2D image for the most probable plume location. By using subsets of the full well data, it is shown that the inversion algorithms can detect and locate the plume with only three monitoring wells, but even two monitoring wells have utility given prior information. More certain delineation of the plume geometry occurs as the number of wells increases, and it is most clearly inferred when the testing well geometry fully surrounds the plume.Guo, B., Eley, Y., Hilton, J., Zou, M., Wang, Q., 2020. Carbon-isotope, petrological and floral record in coals: Implication for Bajocian (Middle Jurassic) climate change. International Journal of Coal Geology 220, 103417. of our existing knowledge of Middle Jurassic paleoclimate is based on well-dated marine isotopic records that show fluctuations between warm (greenhouse effected) and cool climates. In contrast, much less is known from contemporaneous terrestrial deposits that are often difficult to correlate stratigraphically with marine successions, and are typically considered as showing regional rather than global signals. In this paper we show that the carbon-isotopic, petrological and floral record through 20 m thick coals in the Northern Qaidam Basin (NW, China) represents a relatively comprehensive northern hemisphere Bajocian (Middle Jurassic) record for terrestrial climatic change. δ13Ccoal values for 88 samples from the Yuqia area in Northern Qaidam Basin range from–25.3‰ to –22.5‰, indicating that C3 plants were the main coal-forming vegetation in the region during the Middle Jurassic. This isotopic variation follows fluctuations in the composition of ferns and gymnosperms, where higher ratios correspond to more negative δ13C values. The similar carbon isotope values of gymnosperms and coal from the Yuqia area indicate that the coal comprises a high proportion of organic material derived from gymnosperm taxa, which is consistent with the very high abundance of diterpenoids in coal and especially pimarane and abietane that are produced primarily by gymnosperms. Results from the coal matrix provide an opportunity to record paleoclimate changes, showing several striking and regular coal-forming cycles with distinct long- and short-term variations. Trends of δ13Ccoal values changes coupled with the evolution of coal-forming plants may record a gradual increase in paleo-CO2 (pCO2) concentration, water-table level changes and the decrease in abundance of Classopollis conifer pollen through Bajocian. This result is in accordance with the published marine carbonate records for this time, with correlation enabled through matching carbon isotope curves from the terrestrial succession at Yuqia and marine records. The similarity of the terrestrial and marine geochemical and floral record is an indication that the observed paleoclimate signal is a global phenomenon. Furthermore, the high-frequency fluctuation of δ13Ccoal values, along with the coal petrologic variations may record short-term changes of environmental factors (e.g. temperature or humidity/precipitation), especially during intervals when palaeobotanical composition has not fluctuated intensely.Guo, X., Li, Y., Borjigen, T., Wang, Q., Yuan, T., Shen, B., Ma, Z., Wei, F., 2020. Hydrocarbon generation and storage mechanisms of deep-water shelf shales of Ordovician Wufeng Formation–Silurian Longmaxi Formation in Sichuan Basin, China. Petroleum Exploration and Development 47, 204-213. the hydrocarbon generation and storage mechanisms of high quality shales of Upper Ordovician Wufeng Formation- Lower Silurian Longmaxi Formation remain unclear, based on geological conditions and experimental modelling of shale gas formation, the shale gas generation and accumulation mechanisms as well as their coupling relationships of deep-water shelf shales in Wufeng–Longmaxi Formation of Sichuan Basin were analyzed from petrology, mineralogy, and geochemistry. The high quality shales of Wufeng–Longmaxi Formation in Sichuan Basin are characterized by high thermal evolution, high hydrocarbon generation intensity, good material base, and good roof and floor conditions; the high quality deep-water shelf shale not only has high biogenic silicon content and organic carbon content, but also high porosity coupling. It is concluded that: (1) The shales had good preservation conditions and high retainment of crude oil in the early times, and the shale gas was mainly from cracking of crude oil. (2) The biogenic silicon (opal A) turned into crystal quartz in early times of burial diagenesis, lots of micro-size intergranular pores were produced in the same time; moreover, the biogenic silicon frame had high resistance to compaction, thus it provided the conditions not only for oil charge in the early stage, but also for formation and preservation of nanometer cellular-like pores, and was the key factor enabling the preservation of organic pores. (3) The high quality shale of Wufeng–Longmaxi Formation had high brittleness, strong homogeneity, siliceous intergranular micro-pores and nanometer organic pores, which were conducive to the formation of complicated fissure network connecting the siliceous intergranular nano-pores, and thus high and stable production of shale gas.Gutierrez-Villagomez, J.M., Vázquez-Martínez, J., Ramírez-Chávez, E., Molina-Torres, J., Trudeau, V.L., 2020. Profiling low molecular weight organic compounds from naphthenic acids, acid extractable organic mixtures, and oil sands process-affected water by SPME-GC-EIMS. Journal of Hazardous Materials 390, 122186. acids (NAs) are complex mixtures of carboxylic acids from petroleum that have industrial applications and that may be released to the environment after oil spills. There is significant research on the chemical composition and toxicity of water-soluble NAs derived from oil sands mining in Alberta, Canada. Yet, little is known about low molecular weight organic compounds (LMWOC) from these sources. Headspace solid-phase microextraction coupled to gas chromatography-electron impact mass spectrometry was used for LMWOC profiling of commercial NA blends, and an acid-extractable organics (AEOs) mixture from a tailings pond. From Sigma 1, Sigma 2, Merichem NAs and the AEO extract, 54, 56, 40 and 4 compounds were identified, respectively. These include aliphatic and cyclic hydrocarbons, carboxylic acids, alkylbenzenes, phenols, naphthalene and alkyl-naphthalene, and decalin compounds. A sample of oil sands process-affected water (OSPW) and aqueous solutions of the NA blends were evaluated for matrix effects on LMWOC profiles. Principal component and clustering analyses revealed that LMWOC profiles of commercial extracts were closely related but distinct from the AEO and OSPW samples. Some of the identified LMWOC are reported to be genotoxic or carcinogenic, and therefore the NA mixtures and AEOs should be considered hazardous materials and further evaluated.Ha, J.H., Jeen, S.-W., Hwang, H.-T., Lee, K.-K., 2020. Changes in geochemical and carbon isotopic compositions during reactions of CO2-saturated groundwater with aquifer materials. International Journal of Greenhouse Gas Control 95, 102961. study evaluated impacts of CO2 leakage on a shallow groundwater system through laboratory column experiments, which simulated field push-and-pull and natural-gradient tests. The sediment and groundwater were collected from the Environmental Impact evaluation Test (EIT) facility in the Korea CO2 Storage Environmental Management (K-COSEM) test site, and temporal and spatial changes in aqueous chemistry at different stages were monitored. The results showed that as CO2-saturated groundwater was passing through the columns, the concentrations of cations, electrical conductivity (EC), and alkalinity increased, indicating dissolution of primary silicate minerals and perhaps trace amounts of undetected carbonate minerals. There was a significant difference in carbon-13 isotope ratios between the background and CO2-saturated groundwater, and isotopic composition change (with an enrichment factor of 1‰) occurred as CO2-saturated groundwater reacted with the aquifer materials. This study suggests that detailed temporal and spatial geochemical changes are helpful providing insights into the underlying geochemical mechanisms. Also, the isotopic fractionation modeling applied in this study is useful for detecting a small degree of carbon fractionation during the reactions of leaked CO2 and aquifer materials.Hackley, P.C., Dennen, K.O., Garza, D., Lohr, C.D., Valentine, B.J., Hatcherian, J.J., Enomoto, C.B., Dulong, F.T., 2020. Oil-source rock correlation studies in the unconventional Upper Cretaceous Tuscaloosa marine shale (TMS) petroleum system, Mississippi and Louisiana, USA. Journal of Petroleum Science and Engineering 190, 107015. U.S. Geological Survey assessed undiscovered unconventional hydrocarbon resources reservoired in the Upper Cretaceous Tuscaloosa marine shale (TMS) of southern Mississippi and adjacent Louisiana in 2018. As part of the assessment, oil-source rock correlations were examined in the TMS play area where operators produce light (38–45° API), sweet oil from horizontal, hydraulically-fractured wells in an overpressured ‘high-resistivity’ (>5 Ω-m) zone at the base of the TMS. Geochemical data from 39 oil samples and 17 source rock solvent extracts collected from the TMS play area indicate close correspondence for Tuscaloosa Group oils [from lower Tuscaloosa, middle Tuscaloosa (the TMS) and upper Tuscaloosa reservoirs] in thermal maturity (computed from MPI), SARA proportions, n-alkane distributions, isoprenoid and DBT/P ratios, monoaromatic steroids, and δ13C isotopic compositions (from whole oils, saturate and aromatic fractions). Other parameters (normal steranes, extended homohopanes, C31R/C30 hopane, norhopane/hopane and tricyclic terpane ratios, gammacerane/hopane) show most oil samples have similar values, suggesting all Tuscaloosa Group oils are from a common mixed marine-terrigenous source rock. Tighter distributions for triaromatic steroid (TAS) and δ13C isotopic composition for conventional oils in lower and upper Tuscaloosa reservoirs may indicate charge occurred in a single or shorter pulse relative to TMS oils which show broader TAS and δ13C properties, possibly from their generation over an extended period of burial maturation. Dissimilarity in geochemical properties between lower Tuscaloosa source rock solvent extracts and Tuscaloosa Group oils indicates lower Tuscaloosa source rocks did not contribute significantly to conventional and unconventional Tuscaloosa Group hydrocarbon accumulations. Whereas, TMS solvent extracts are similar to Tuscaloosa Group oils, suggesting an oil-source rock correlation. Excluding the possibility for long-distance lateral migration from a similar source downdip (which is unnecessary given thermal maturity considerations), the observations indicate 1. the TMS is a self-sourced reservoir, 2. the TMS is the source of oils accumulated in nearby conventional Tuscaloosa Group reservoirs, and 3. thin organic-rich shales in the lower Tuscaloosa did not contribute substantially to any oil accumulations in the Tuscaloosa Group.Haghighat, N., Hashemi, H., Tavakoli, V., Nestell, G.P., 2020. Permian–Triassic extinction pattern revealed by foraminifers and geochemical records in the central Persian Gulf, southern Iran. Palaeogeography, Palaeoclimatology, Palaeoecology 543, 109588.–Triassic boundary (PTB) foraminifers are studied from the upper part of the Dalan Formation and the base of the Kangan Formation in four wells (A, B, E, F) on and near the Qatar Arc, Persian Gulf, Iran. Isotope studies including δ13C and δ18O values from wells B and E and 87Sr/86Sr ratios in wells (B, E, and F) have also been carried out to possibly provide a high-resolution extinction pattern of foraminifers in the PTB interval. The latter has been thoroughly investigated in Iran, Turkey, South China, Vietnam, Slovenia, Carnic Alps and Bükk Mountains, Kashmir, Greenland, and Serbia. The distribution of the last appearance of foraminiferal genera from the PTB interval in all of the wells is very similar featuring a stepwise extinction from 3 to 2 m before the boundary and compares to that observed in some of the sections from elsewhere, i.e., South China, Vietnam, Slovenia, and Serbia. The δ13C value in wells B and E shows a negative shift at the base of a thrombolite unit immediately after the considered PTB, and another negative shift at about 11 m below it in well E. The thrombolite unit is assumed as earliest Triassic, but questionable with no supportive conodonts. The δ18O isotope values in wells B and E demonstrate the same negative upward trend due to dysoxic or anoxic conditions in the end-Permian oceans. The uniform reduction without any sharp incline in the δ18O profile suggests concurrent global warming. The highest 87Sr/86Sr ratio fluctuations in wells B, E, and F coincide with the appearance of thrombolites. Changes in the profiles of carbon, oxygen, and strontium isotopes close to the PTB in wells B, E, and F seem to correspond to lithofacies variations from limestone to dolostone and a reduction in foraminiferal diversity. These changes substantiate a clear perturbation in the marine environmental and global geochemistry elements through the PTB interval. The δ13C, δ18O and 87Sr/86Sr values obtained from the studied wells are comparable to those in other PTB stratigraphic sections in the Paleo-Tethyan region.Hakimi, M.H., Abdullah, W.H., Al Faifi, H.J., Mustapha, K.A., Kahal, A.Y., Lashin, A.A., 2020. Source rock evaluation and hydrocarbon generation potential of Mid-Late Cretaceous sediments from Mintaq-01 well in the Wadi Hajar of Southern Sabatayn Basin, Yemen. Petroleum Science and Technology 38, 216-224. cutting shale and coal samples from the Mid-Late Cretaceous Mukalla and Harshiyat formations in the Mintaq-01 well, Wadi Hajar of Southern Sabatayn Basin were investigated using organic geochemical methods. The geochemical results indicate that the analyzed shale and coal samples are fair to excellent source rocks, with TOC values between 0.50 and 53.13%. The analyzed samples also have Rock-Eval HI between 99 and 676?mg HC/g TOC, indicating types I/II and II/III kerogen and thus are oil and gas-prone source rocks. However, these Mid-Late Cretaceous sediments of the Wadi Hajar are still in an immature to very early mature stage, and they have not yet generated oil or gas.Hale, R.C., Seeley, M.E., La Guardia, M.J., Mai, L., Zeng, E.Y., 2020. A global perspective on microplastics. Journal of Geophysical Research: Oceans 125, e2018JC014719. Society has become increasingly reliant on plastics since commercial production began in about 1950. Their versatility, stability, light weight, and low production costs have fueled global demand. Most plastics are initially used and discarded on land. Nonetheless, the amount of microplastics in some oceanic compartments is predicted to double by 2030. To solve this global problem, we must understand plastic composition, physical forms, uses, transport, and fragmentation into microplastics (and nanoplastics). Plastic debris/microplastics arise from land disposal, wastewater treatment, tire wear, paint failure, textile washing, and at-sea losses. Riverine and atmospheric transport, storm water, and disasters facilitate releases. In surface waters plastics/microplastics weather, biofoul, aggregate, and sink, are ingested by organisms and redistributed by currents. Ocean sediments are likely the ultimate destination. Plastics release additives, concentrate environmental contaminants, and serve as substrates for biofilms, including exotic and pathogenic species. Microplastic abundance increases as fragment size decreases, as does the proportion of organisms capable of ingesting them. Particles <20 ?m may penetrate cell membranes, exacerbating risks. Exposure can compromise feeding, metabolic processes, reproduction, and behavior. But more investigation is required to draw definitive conclusions. Human ingestion of contaminated seafood and water is a concern. Microplastics indoors present yet uncharacterized risks, magnified by the time we spend inside (>90%) and the abundance of polymeric products therein. Scientific challenges include improving microplastic sampling and characterization approaches, understanding long-term behavior, additive bioavailability, and organismal and ecosystem health risks. Solutions include improving globally based pollution prevention, developing degradable polymers and additives, and reducing consumption/expanding plastic reuse.Han, H., Hu, S., Li, A., Zhang, Y., Xiong, Z., Ma, S., He, L., Li, H., Wang, Y., Su, S., Xiang, J., 2020. Evolution of nitrogen/oxygen substituted aromatics from sludge to light and heavy volatiles. Journal of Cleaner Production 257, 120327. treatments of sludge lead to the emission of carcinogenic aromatics, which has already attracted the attention of researchers for years. However, until now the evolution of substituted polycyclic aromatic hydrocarbons (PAHs), especially those with high molecular weight, during thermal treatments of sludge was not paid enough attention even though some of them are more toxic than their parent PAHs. To comprehend the generation of substituted PAHs, in particular that of heavy substituted PAHs, volatiles released from the pyrolysis of three sludge at three temperatures were comprehensively analyzed. The results show oxygen-substituted PAHs (O-PAHs) and nitrogen-substituted PAHs (N-PAHs) are the most abundant light substituted PAHs at 450?°C, while PAHs containing both nitrogen and oxygen atoms (NO-PAHs) and O-PAHs are the dominant substituted aromatics in heavy components. With the temperature increased, condensation degree and content of substituted PAHs in light and heavy components both increase due to condensation effect. Deamination and deoxygenation of NO-PAHs also enhance content of O-PAHs and N-PAHs, respectively. At 850?°C, nearly all heavy components derive from the condensation of light molecules instead of the direct decomposition of sludge. Aromatics, especially N-PAHs, are the dominant compounds in both light and heavy components. Calcium compounds in sludge can greatly affect the formation of substituted PAHs at high temperatures.Han, J., Han, S., Kang, D.H., Kim, Y., Lee, J., Lee, Y., 2020. Application of digital rock physics using X-ray CT for study on alteration of macropore properties by CO2 EOR in a carbonate oil reservoir. Journal of Petroleum Science and Engineering 189, 107009. study the fluid flow in reservoirs considering chemical and physical reactions, alterations in pore structure and rock properties should be examined. This study aims to investigate the changes in the main flow path (macropores) and rock properties caused by CO2 injection in carbonate rock. Results from pre- and post-CO2 injection have been obtained by core flooding, mercury injection capillary pressure (MICP), X-ray CT, digital rock physics (DRP) techniques, and subsequent analysis. This study proposes combining the methods of X-ray CT imaging with MICP to improve both the realization of and understanding of alterations in pore structure.Following CO2 injection, the capabilities of flow and storage in carbonate rock are significantly altered by chemical and physical reactions among CO2, fluid, and minerals. In realization of a pore network for main flow paths as elucidated using X-ray CT and MICP, those reaction effects develop abundant non-connected pores due to disintegration of rock grains by dissolution and precipitation of mineral particles in contact with the fluid stream. Furthermore, Lattice Boltzmann (LB) simulation results show increased irreducible oil saturation and entry capillary pressure, indicating reduced displacement efficiency of oil by CO2 in main flow paths, particularly around the injection well where rock is usually exposed to CO2 for a long time. Therefore, alteration of pore networks by CO2 injection can lead to poor injectivity and may require a very delicate injection scheme when follow-up injection method applies.This study can be applied to forecast fluid flow in pore structures altered by CO2 injection for CCS and EOR projects. Further study is needed to investigate the effects of small pore size and complex flow phenomena such as multi-phase flow and fluid-fluid interactions.Han, S., Bai, S., Tang, Z., Rui, Y., Gong, D., Zhang, J., 2020. Nitrogen-rich gas shale logging evaluation and differential gas-bearing characterization of lower Cambrian formation in northern Guizhou, south China. Marine and Petroleum Geology 115, 104270. are significant differences in the gas content between the two sets of lower Paleozoic shale in south China. The nitrogen content of the lower Silurian shale gas that has been commercially developed is very low, whereas that of the lower Cambrian shale (LCS) is relatively high. Shale has complex gas-bearing mechanistic characteristics. The genesis of nitrogen is complex and sources are diverse. A gas containing high nitrogen and low hydrocarbons increases the risk and difficulty of developing a shale gas resource. Based on the key geological parameters of the LCS in the northern Guizhou area (NGA), this study investigates the characteristics of nitrogen in the highly mature shale and discusses the logging evaluation method for nitrogen-bearing shale gas reservoirs in this complex tectonic area. Changes in the gas-bearing characteristics of the LCS in the study area are complex. The shale gas composition was found to vary widely due to differential enrichment; the methane content was between 1.2% and 82.4%, and the nitrogen content was between 0.03% and 97.4%. The nitrogen-rich shale formations exhibited a high compensation density (2.46–2.58 g/cm3), high compensation neutron (10.2–17.9%), and low acoustic time difference (192–230 μs/m). There were two different types of resistivity responses in nitrogen-bearing shale gas reservoirs, which had distribution characteristics of 21–56 Ω m and 100–1000 Ω m. With these response characteristics, the logging evaluation of nitrogen-bearing shale gas reservoirs was interpreted by selecting differential gas-sensitive parameters, and different gas-bearing types were divided into dry, nitrogen, mixed, and methane gas layers. Furthermore, the identification and computational evaluation of the gas composition (methane/nitrogen) and content were carried out quantitatively. Differential gas-bearing property was characterized and that is beneficial to the exploration practice in the study area.Han, X., Tomaszewski, E.J., Sorwat, J., Pan, Y., Kappler, A., Byrne, J.M., 2020. Oxidation of green rust by anoxygenic phototrophic Fe(II)-oxidising bacteria. Geochemical Perspectives Letters 12, 52-57. rust (GR) may have been a primary mineral phase during the deposition of Fe(III) (oxyhydr)oxides in Precambrian iron formations (IFs). However, the transformation pathways of GR into secondary mineral phases in IFs remain unclear. One potentially relevant mechanism on early Earth is anoxygenic phototrophic microbial oxidation of either dissolved Fe(II) or Fe(II)-bearing minerals that leads to the formation of Fe(III) (oxyhydr)oxides. It is currently unknown whether phototrophic Fe(II)-oxidisers can access lattice Fe(II) in GR. Here, we studied microbial Fe(II) oxidation of carbonate green rust by two anoxygenic phototrophic Fe(II)-oxidising bacteria, Rhodobacter ferrooxidans SW2 and Rhodopseudomonas palustris TIE-1. We found that these two species could oxidise GR to a short range ordered Fe(III) oxyhydroxide, likely ferrihydrite, with faster GR oxidation rates by SW2 than by TIE-1. These results suggest that anoxygenic phototropic Fe(II) oxidation of GR can contribute to the formation of Fe(III) (oxyhydr)oxides and thus, this process could have been an important mechanism for Precambrian IFs deposition in ancient oceans.Hancy, A.D., Antcliffe, J.B., 2020. Anoxia can increase the rate of decay for cnidarian tissue: Using Actinia equina to understand the early fossil record. Geobiology 18, 167-184. experimental decay methodology is developed for a cnidarian model organism to serve as a comparison to the many previous such studies on bilaterians. This allows an examination of inherent bias against the fossilisation of cnidarian tissue and their diagnostic characters, under what conditions these occur, and in what way. The decay sequence of Actinia equina was examined under a series of controlled conditions. These experiments show that cnidarian decay begins with an initial rupturing of the epidermis, followed by rapid loss of recognisable internal morphological characters. This suggests that bacteria work quicker on the epidermis than autolysis does on the internal anatomy. The data also show that diploblastic tissue is not universally decayed more slowly under anoxic or reducing conditions than under oxic conditions. Indeed, some cnidarian characters decay more rapidly under anoxic conditions than they do under oxic conditions. This suggests the decay pathways acting may be different to those affecting soft bilaterian tissue such as soft epidermis and internal organs. What is most important in the decay of soft polyp anatomy is the microbial community, which can be dominated by oxic or anoxic bacteria. Different Lagerst?tte, even of the same type, will inevitably have subtle difference in their bacterial communities, which among other factors, could be a control on soft polyp preservation leading to either an absence of compelling soft anthozoans (Burgess Shale) or an astonishing abundance (Qingjiang biota).Hand, E., 2020. Underground oil fires liberate carbon-free fuel. Science 367, 617. month, on the frozen plains of Saskatchewan in Canada, workers began to inject steam and air into the Superb field, a layer of sand 700 meters down that holds 200 million barrels of thick, viscous oil. Their goal was not to pump out the oil, but to set it on fire—spurring underground chemical reactions that churn out hydrogen gas, along with carbon dioxide (CO2). Eventually the company conducting the $3 million field test plans to plug its wells with membranes that would allow only the clean-burning hydrogen to reach the surface. The CO2, and all of its power to warm the climate, would remain sequestered deep in the earth.“We want to launch the idea that you can get energy from petroleum resources and it can be zero carbon emissions,” says Ian Gates, a chemical engineer at the University of Calgary and co-founder of the startup, called Proton Technologies.Markets are growing for hydrogen as a fuel for power, heat, and transport, because burning it only releases water. But most hydrogen is made from natural gas, through a process that spews carbon into the air, or by electrolyzing water, which is pricey. Proton Technologies says it can cut costs by relying on oil reservoirs shunned by drillers because they are water-logged or because their oil is too thick. “Someone's abandoned liability becomes our hydrogen field,” says CEO Grant Strem, who bought the Superb field out of bankruptcy.Geoffrey Maitland, a chemical engineer at Imperial College London, says he is a “great fan” of the concept, which treats the oil reservoir as a hot, naturally pressurized reactor. “This chemistry is well-proven at the surface,” he says. “The challenge is controlling these processes several kilometers underground.”Industry has experimented for decades with underground burning, also known as fire flooding. Fed by air or oxygen pumped into the ground, the fire releases gases that can push oil toward wells, and its heat can soften tarlike bitumens and other heavy oils, making them easier to pump. In the early 1980s, fire-flooding tests on an oil field called Marguerite Lake, in Canada's vast oil sands, produced substantial amounts of hydrogen as a byproduct. No one cared very much at the time, but the finding sowed “the seed of the idea,” Gates says. “What if we only produce hydrogen out of the reservoir?”In a 2011 paper in the journal Fuel, he and his colleagues sketched out how it could work. The first step would be to use steam to heat a reservoir to 250°C or so and add air or oxygen to touch off combustion. The heat “cracks” the oil's long hydrocarbon chains into smaller pieces and produces small amounts of hydrogen. But if the fire reaches temperatures above 500°C, injected steam or water vapor from the hot reservoir itself will react with the hydrocarbons to make syngas: a mixture of carbon monoxide and hydrogen. Adding more water to the syngas sets off a final reaction that produces CO2 and more hydrogen.The main obstacle will be raising temperatures above 500°C with in situ combustion, which is “complicated and not easy to control,” says Berna Hascakir, a heavy oil reservoir engineer at Texas A&M University, College Station. Gates says the reactions can still proceed below 500°C, just less efficiently. “Ideally, we'd like to get hotter,” he says. “But those temperatures are fine to produce meaningful amounts of hydrogen.”Another challenge is separating the produced hydrogen from the CO2 and other impurities in the mix, such as toxic hydrogen sulfide. Strem says the company will use thin membranes made of palladium alloys, which will decompose hydrogen gas into individual hydrogen atoms. Those atoms will diffuse through the metal lattice, then combine to form hydrogen gas again on the other side. But palladium membranes can be fragile and finicky, even when used at the surface, notes Jennifer Wilcox, a chemical engineer at Worcester Polytechnic Institute. “When doing everything underground, it's difficult to have control.”For now, Proton Technologies will use their membranes at the surface and vent the separated CO2. But if the company can raise roughly $50 million for the next field test, Strem would like to test the membranes deep in the wells. He also wants to buy an air separation unit and inject pure oxygen into a reservoir, which would make it a hotter and more efficient reactor. He hopes to produce commercial amounts of hydrogen in the coming months and says the company could eventually produce the gas for between 10 and 50 cents per kilogram—significantly cheaper than current sources.The vast majority of the world's produced hydrogen is used to refine petroleum products and make ammonia fertilizer. But the market for hydrogen as a green fuel is growing, says Ken Dragoon, executive director of the Renewable Hydrogen Association. In pilot projects, utilities are injecting small amounts of hydrogen into natural gas pipelines for home heating and appliances. In transportation, he says, fleets of trains, buses, and forklifts are turning to hydrogen fuel cells, which offer a longer range and much faster refueling than the other green alternative, electric batteries.Dragoon, an advocate for renewable hydrogen made with electrolyzers, would be happy to see a competitor like Proton Technologies. “We need everything we can,” he says. “If it's safe, and it produces a climate neutral fuel, more power to them.”Hao, Y., Pang, Z., Tian, J., Wang, Y., Li, Z., Li, L., Xing, L., 2020. Origin and evolution of hydrogen-rich gas discharges from a hot spring in the eastern coastal area of China. Chemical Geology 538, 119477. the typical low-temperature (<150 °C) continental geothermal systems usually characterized by high N2, CH4 and CO2 concentrations but a trace H2 concentration, the sandstone-dominated Jimo hot spring on China's eastern coast exhibits: (1) abnormally high H2 concentrations (2.4–12.5 vol%) and H2/CH4 (up to 46.5); (2) depleted δD-H2 (?822 to ?709‰), comparable to the Kansas hot springs near the Mid-Continent rift system with the most depleted δD-H2 (?836 to ?740‰) recorded in nature; and (3) dramatic gas concentration and isotope ratio variations within an area of 0.2 km2. Gas chemistry and H-C-He-Ne isotope ratios are studied with reference to published H2 isotope data from various systems. The origin of the gas is most likely attributed to: (a) allochthonous abiotic H2 generated by the reduction of water and oxidation of FeII-rich pyroxene and olivine (serpentinization) in the basalt located 2 km away under near-surface conditions and migration to the deep sandstone reservoir; (b) primary thermogenic CH4 produced in the sandstone; (c) mixing with a considerable amount of microbial H2 from shallow fresh and marine sediments; and (d) biotic CH4 with typical abiotic signatures resulting from isotope exchanges with fluids high in H2/CH4 and CO2/CH4 ratios. Allochthonous abiotic H2 in a sandstone-dominated continental geothermal system and massive microbial fermentation-based H2 production in shallow fresh and residual marine sediments with insignificant but differential consumption activity are highlighted. The published hydrogen isotope ratios for H2 produced under various natural geological environmental and experimental conditions have been collected systematically to provide a fundamental framework and an initial tool for restricting the dominant origin of H2.Hao, Y., Shardanova, T.A., Chongxing, H., 2019. Features of the structure of carbon-rich rocks (based on the example of the Lower Silurian sediments of the Sichuan depression of the Yangtze Platform). Moscow University Geology Bulletin 74, 510-515. petrophysical, geochemical, and lithological features of the structure of graptolite shales from the lower part of the Longmaxi Formation of the Lower Silurian age of the Sichuan Province of the People’s Republic of China are considered. The basic patterns of the formation of carbon-rich sediments in the intrashelf depressions are revealed.Haq, B., Liu, J., Liu, K., Al Shehri, D., 2020. The role of biodegradable surfactant in microbial enhanced oil recovery. Journal of Petroleum Science and Engineering 189, 106688. aerobic microorganisms can produce bio-surfactants which are capable of effectively reducing interfacial tensions between oil, water and rock. However, there are few publications on the production of bio-surfactants from anaerobic organisms. The combined effect of bio-surfactant, green surfactant and alcohol in the MEOR process, are not well understood yet and require further investigation. This experimental study was conducted to examine the effectiveness of combination of two microbial by-products, bio-surfactant and bio-alcohol, in recovering residual oil within the pores of rock. It also considered whether bio-surfactant capability could be improved by blending it with non-ionic green surfactant. Two formulations of surfactant and co-surfactant mixtures were selected for core-flood experiments based on phase behaviour study and IFT reduction to examine their potential for enhanced oil recovery. In the first formulation, JF-2 bio-surfactant was mixed with butanol; it was found that this formulation did not produce a significant quantity of incremental oil after water flooding. Lastly, a bio-surfactant (anionic) was blended with non-ionic green surfactant alkyl polyglucoside and butanol; this produced about 25% tertiary oil and 64% OIIP.Harning, D.J., Curtin, L., Geirsdóttir, ?., D'Andrea, W.J., Miller, G.H., Sepúlveda, J., 2020. Lipid biomarkers quantify Holocene summer temperature and ice cap sensitivity in icelandic lakes. Geophysical Research Letters 47, e2019GL085728.: Although recent research has made significant advances in characterizing Iceland's Holocene environmental history, the region still lacks reliable and continuous records of corresponding paleotemperature. Here we merge bacterial and algal lipid biomarkers (branched glycerol dialkyl glycerol tetraethers and long‐chain alkenones, respectively) to quantify Holocene temperature change from a small lake in northwest Iceland. Our local proxy record shows that early Holocene and late Holocene temperatures ranged from 3.2 to ?1.1 oC relative today, which are in close agreement with independent estimates from regional ice cap models. At 2.4 ka, we observe abrupt cooling across bacteria‐, algae‐, and glacier‐derived proxy records, which may have been initiated by extratropical volcanism and/or ocean/atmospheric climate variability of the North Atlantic region. Using early Holocene warmth and ice cap demise as an analog for modern climate change, Intergovernmental Panel on Climate Change temperature projections suggest that the local ice cap, Drangaj?kull, could vanish by ~2050 CE.Plain Language Summary: Numerical climate and glacier models are necessary tools to forecast the changing climate of the coming century. However, in order to improve the accuracy and precision of the models, it is critical to test their ability to reconstruct past climate observed through proxy records. Here, we present an Icelandic lake temperature proxy record for the last 10,000 years that covers a period in Earth's history when temperatures were comparable to those expected in our near future. This proxy temperature reconstruction is used to assess the controls on Iceland's climate, the performance of existing Icelandic glacial models and, alongside regional climate simulations, forecast the future demise of a local ice cap. We find that Iceland's past temperatures are strongly controlled by regional atmospheric and oceanic variability, and that as modern temperatures continue to rise, a local ice cap in northwest Iceland may vanish by 2050 CE. This forecast holds critical value for Icelandic policy making and energy security, as hydroelectric dams on glacier‐fed rivers currently provide ~73% of Iceland's electricity.Harper, D.T., H?nisch, B., Zeebe, R.E., Shaffer, G., Haynes, L.L., Thomas, E., Zachos, J.C., 2020. The magnitude of surface ocean acidification and carbon release during Eocene Thermal Maximum 2 (ETM-2) and the Paleocene-Eocene Thermal Maximum (PETM). Paleoceanography and Paleoclimatology 35, e2019PA003699. Thermal Maximum 2 (ETM‐2; 54.1 Ma) was the second largest Eocene hyperthermal. Like the Paleocene‐Eocene Thermal Maximum (PETM), ETM‐2 was characterized by massive carbon emissions and several degrees of global warming and thus can serve as a case study for assessing the impacts of rapid CO2 emissions on ocean carbonate chemistry, biota, and climate. Marine carbonate records of ETM‐2 are better preserved than those of the PETM due to more subdued carbonate dissolution. As yet, however, the magnitude of this carbon cycle perturbation has not been well constrained. Here, we present the first records of surface ocean acidification for ETM‐2, based on stable boron isotope records in mixed‐layer planktic foraminifera from two midlatitude ODP sites (1210 in the North Pacific and 1265 in the SE Atlantic), which indicate conservative minimum global sea surface acidification of ?0.20 +0.12/?0.13 pH units. Using these estimates of pH and temperature as constraints on carbon cycle model simulations, we conclude that the total mass of C, released over a period of 15 to 25 kyr during ETM‐2, likely ranged from 2,600 to 3,800 Gt C, which is greater than previously estimated on the basis of other observations (i.e., stable carbon isotopes and carbonate compensation depth) alone.Hartmann, J.F., Günthel, M., Klintzsch, T., Kirillin, G., Grossart, H.-P., Keppler, F., Isenbeck-Schr?ter, M., 2020. High spatiotemporal dynamics of methane production and emission in oxic surface water. Environmental Science & Technology 54, 1451-1463. discovery of methane (CH4) accumulation in oxic marine and limnic waters has redefined the role of aquatic environments in the regional CH4 cycle. Although CH4 accumulation in oxic surface waters became apparent in recent years, the sources are still subject to controversial discussions. We present high-resolution in situ measurements of CH4 concentration and its stable isotope composition in a stratified mesotrophic lake. We show that CH4 accumulation in surface waters originates from a highly dynamic interplay between (oxic) CH4 production and emission to the atmosphere. Laboratory incubations of different phytoplankton types and application of stable isotope techniques provide a first unambiguous evidence that major phytoplankton classes in Lake Stechlin per se produce CH4 under oxic conditions. Combined field and lab results show that the photoautotroph community is an important driver for CH4 production and its highly dynamic accumulation in oxic surface waters.Harvey, V.L., LeFebvre, M.J., deFrance, S.D., Toftgaard, C., Drosou, K., Kitchener, A.C., Buckley, M., 2019. Preserved collagen reveals species identity in archaeological marine turtle bones from Caribbean and Florida sites. Royal Society Open Science 6, 191137. in molecular science are continually improving our knowledge of marine turtle biology and evolution. However, there are still considerable gaps in our understanding, such as past marine turtle distributions, which can benefit from advanced zooarchaeological analyses. Here, we apply collagen fingerprinting to 130 archaeological marine turtle bone samples up to approximately 2500 years old from the Caribbean and Florida's Gulf Coast for faunal identification, finding the vast majority of samples (88%) to contain preserved collagen despite deposition in the tropics. All samples can be identified to species-level with the exception of the Kemp's ridley (Lepidochelys kempii) and olive ridley (L. olivacea) turtles, which can be separated to genus level, having diverged from one another only approximately 5 Ma. Additionally, we identify a single homologous peptide that allows the separation of archaeological green turtle samples, Chelonia spp., into two distinct groups, which potentially signifies a difference in genetic stock. The majority of the archaeological samples are identified as green turtle (Chelonia spp.; 63%), with hawksbill (Eretmochelys imbricata; 17%) and ridley turtles (Lepidochelys spp.; 3%) making up smaller proportions of the assemblage. There were no molecular identifications of the loggerhead turtle (Caretta caretta) in the assemblage despite 9% of the samples being morphologically identified as such, highlighting the difficulties in relying on morphological identifications alone in archaeological remains. Finally, we present the first marine turtle molecular phylogeny using collagen (I) amino acid sequences and find our analyses match recent phylogenies based on nuclear and mitochondrial DNA. Our results highlight the advantage of using collagen fingerprinting to supplement morphological analyses of turtle bones and support the usefulness of this technique for assessing their past distributions across the Caribbean and Florida's Gulf Coast, especially in these tropical environments where DNA preservation may be poor.Hazeena, S.H., Sindhu, R., Pandey, A., Binod, P., 2020. Lignocellulosic bio-refinery approach for microbial 2,3-butanediol production. Bioresource Technology 302, 122873. approach using agricultural and industrial waste material as feedstock is becoming a preferred area of interest in biotechnology in the current decades. The reasons for this trend are mainly because of the declining petroleum resources, greenhouse gas emission risks and fluctuating market price of crude oil. Most chemicals synthesized petro chemically, can be produced using microbial biocatalysts. 2,3-Butanediol (BDO) is such an important platform bulk chemical with numerous industrial applications including as a fuel additive. Although microbial production of BDO is well studied, strategies that could successfully upgrade the current lab-scale researches to an industrial level have to be developed. This review presents an overview of the recent trends and developments in the microbial production of BDO from different lignocellulose biomass.He, J., He, S., Liu, Z., Zhai, G., Wang, Y., Han, Y., Wan, K., Wei, S., 2020. Pore structure and adsorption capacity of shale in the Lower Cambrian Shuijingtuo Formation in the southern flank of Huangling anticline, western Hubei Acta Petrolei Sinica 41, 27-42. at the marine organic-rich shale in the Lower Cambrian Shuijingtuo Formation in the Well Zidi2 in the southern flank of the Huangling anticline in western Hubei, this study selects shale samples from the first and second members of Shuijingtuo Formation. Using the multi-scale testing techniques such as CO2 and N2 physical absorption, high-pressure mercury injection, and argon ion polishing-field emission scanning electron microscope (FE-SEM) the observation methods for pore structure and the statistical analysis methods of organic pores in combination with methane isothermal adsorption experiments and other basic testing methods, this paper describes the geochemistry, mineral composition and lithofacies characteristics of shale, investigates the pore type, pore shape, pore size distribution and specific surface area of shale and other pore structure parameters, analyzes the methane adsorption capacity of shale, and explores the factors affecting the pore development and pore structure of shale. The research results show that Ro of the organic-rich black shale in the first and second members of Shuijingtuo Formation in the Well Zidi2 is about 2.5%, and the shale lithofacies are mainly siliceous shale, migmatitic shale, and clayey shale; organic pores of shale have various shapes, irregular boundaries, and small pore sizes, most of which have a pore diameter of less than 50 nm. Inorganic pores/seams are abundant, with various types of geneses and variable shapes micropores in shale (pore size of 0.3-2.0 nm) develops well, and organic mesopores occupy a large proportion in mesopores with the pore size of 2-5 nm; inorganic pores are dominant in mesopores with a pore size> 5nm and macropores. Shale has a large specific surface area and strong methane adsorption capacity; the pore structure and adsorption capacity of siliceous shale are even better. The organic carbon content, carbonate mineral and clay mineral content of shale, shale lithofacies and other factors have important effects on the pore development and pore structure of shale.He, J., Xu, Z., Zhang, J., Luo, X., Wu, J., Lu, Q., 2020. Geochemical characteristics and origins of the crude oil of Carboniferous formation in Dajing area, Junggar basin, China. Petroleum Science and Technology 38, 210-215. area is one of the key exploration areas in Junggar basin. In this paper, based on scientific exploration and exploitation, the geochemical characteristics of the carboniferous crude oil and potential source rocks were analyzed using gas chromatograph-mass method. The correlation of biomarkers showed that the parent materials of the carboniferous crude oil formed in freshwater-mildly brackish water environment and were sourced from low grade aquatic organisms and terrigenous higher plants. Oil-source correlation results showed that the carboniferous crude oil in Dajing area was derived from the source rocks of Songkaersu.He, T., Lu, S., Li, W., Sun, D., Pan, W., Zhang, B., Tan, Z., Ying, J., 2020. Paleoweathering, hydrothermal activity and organic matter enrichment during the formation of earliest Cambrian black strata in the northwest Tarim Basin, China. Journal of Petroleum Science and Engineering 189, 106987. earliest Cambrian black strata are widely deposited in many continents, and attracted increasing attention from scholars worldwide. Based on detailed investigations of strata from the Shiairike section in the Aksu area, northwest Tarim Basin, China, the effects of paleoweathering and hydrothermal activity on the organic matter enrichment of this black series was revealed. Combined organic and inorganic geochemistry evidence indicated that relatively strong weathering carried abundant nutrient elements and terrigenous detritus into the sea, which promoted a period of paleoproductivity and enhanced the sinking of dissolved organic matter. Moreover, the hydrothermal activity triggered the enrichment of abundant reducing gases (e.g. H2S) and minerals, whereby gases created euxinic benthic conditions that were favorable for the preservation of sedimentary organic matter, while minerals simultaneously diluted primary productivity. As a result, the low section of the black strata was characterized by dominant siliceous rocks with enrichments of P, Ba, Zn and Cu; whereas the upper section contained abundant organic matters that had the potential to generate and expel a remarkable volume of hydrocarbons. These results provide a theoretical basis for the international exploration of paleo-hydrothermal minerals within the early Cambrian black strata as well as that of the deep Cambrian oil and gas, particularly in the Tarim Basin, northwest China.He, T., Lu, S., Li, W., Wang, W., Sun, D., Pan, W., Zhang, B., 2020. Geochemical characteristics and effectiveness of thick, black shales in southwestern depression, Tarim Basin. Journal of Petroleum Science and Engineering 185, 106607. interval of black shales deposited from Precambrian to lower Cambrian from the southwestern depression of the Tarim basin (SDTB) was systematically evaluated in terms of hydrocarbon potential, organic matter, depositional environment and oil-source relationship. The shales have good TOC contents (up to 3.15%) but low S1+S2 values (<0.03?mg/g), indicating the source rocks are currently at high thermal maturities. The relationship between pristane/n-C17 and phytane/n-C18 indicates the kerogen was oil prone and dominant by algal input. Furthermore, the depositional environment had relatively moderate salinity and stratified water environment indicated by G/C30H ratios (0.15–0.24). The high algal input may have enhanced TOC preservation under reducing conditions reflected by high dibenzothiophene content and low pristane/phytane ratios (mean 0.79). Thus, these source rocks may have generated a significant amount of oil during their geological history. Additionally, in view of the molecular geochemistry indicators, the extracts of black shales hold marked differences with the Cambrian-Ordovician end-member oils, but are quite similar to oils in the northeastern portion of the SDTB. It means that the lightly explored SDTB may contain significant hydrocarbon resources, and coeval source rocks in the ultra-deep portion of the basin may have contributed to the prolific petroleum resources in the Tarim Basin.He, Y., Fu, X., Li, T., Wang, X., Chang, Y., Tang, L., Liu, Y., 2020. Geochemical characteristics and sources of the crude oil of Yan’an formation Yan 9 in Zhao’an area, Ordos Basin, China. Petroleum Science and Technology 38, 240-246. certain scale of Yan 9 reservoir was found in Zhao’an area, but the oil source is not clear. The geochemical characteristics of Yan 9 crude oil and potential source rocks were analyzed by using gas chromatograph-mass method. Analysis results showed that the parent materials of Yan 9 crude oil were sourced from lower aquatic organism and higher terrigenous plants and formed in freshwater- brackish water lacustrine facies. Oil-source correlation results showed that Yan 9 crude oil was derived from the source rocks of Chang 7.Helle, I., M?kinen, J., Nevalainen, M., Afenyo, M., Vanhatalo, J., 2020. Impacts of oil spills on Arctic marine ecosystems: A quantitative and probabilistic risk assessment perspective. Environmental Science & Technology 54, 2112-2121. spills resulting from maritime accidents pose a poorly understood risk to the Arctic environment. We propose a novel probabilistic method to quantitatively assess these risks. Our method accounts for spatiotemporally varying population distributions, the spreading of oil, and seasonally varying species-specific exposure potential and sensitivity to oil. It quantifies risk with explicit uncertainty estimates, enables one to compare risks over large geographic areas, and produces information on a meaningful scale for decision-making. We demonstrate the method by assessing the short-term risks oil spills pose to polar bears, ringed seals, and walrus in the Kara Sea, the western part of the Northern Sea Route. The risks differ considerably between species, spatial locations, and seasons. Our results support current aspirations to ban heavy fuel oil in the Arctic but show that we should not underestimate the risks of lighter oils either, as these oils can pollute larger areas than heavier ones. Our results also highlight the importance of spatially explicit season-specific oil spill risk assessment in the Arctic and that environmental variability and the lack of data are a major source of uncertainty related to the oil spill impacts.Henne, A., Craw, D., Gagen, E.J., Southam, G., 2020. Contribution of bacterially-induced oxidation of Fe-silicates in iron-rich ore to laterite formation, Salobo IOCG mine, Brazil. Chemical Geology 539, 119499. diverse array of microorganisms, found within the uppermost lithosphere, can mediate the dissolution and precipitation of minerals and therefore contribute to the formation of laterites. The Salobo iron-oxide copper gold (IOCG) mine in Brazil is an ideal environment to examine the specific interaction between iron-oxidising bacteria and ferrous iron-bearing minerals during formation of a ~60 m thick laterite weathering profile. We identified bacteria using DNA extracted from samples in active weathering zones. Many of the identified species are capable of oxidising the ferrous iron and/or reduced sulphur that occurred in minerals associated with the unweathered rocks of the deposit. Fe-bearing phyllosilicates have been variably altered to clays along cleavage planes by bacterial iron oxidation. Accelerated weathering of fresh rocks in laboratory-scale leaching column experiments was conducted using an endemic Acidithiobacillus ferrooxidans ssp. previously cultured from the Salobo mine. There were strong similarities between field samples from the Salobo laterite zone, and experimental leachate chemistry, associated precipitates, and fossilised bacteria remnants, particularly with respect to ferric (oxyhydr)oxide formation. Groundwaters in the Salobo laterite zone have circumneutral pH, whereas some iron-oxidising bacteria thrive in, and locally create, more acidic conditions (~pH 3). The leaching experiments showed that bacterially-facilitated silicate weathering, and bornite (Cu5FeS4) oxidation, can consume acid generated by bacterial oxidation reactions, creating an effective equilibrium with ferric (oxyhydr)oxide precipitation. However, the current acid neutralisation capacity of the ferricrete horizon at the top of the laterite zone was minimal. While bacterial activity promoted mineral oxidation and decomposition within the thick laterite at the Salobo mine, related iron mobility is restricted to the micrometre scale by essentially instantaneous precipitation of ferric (oxyhydr)oxide that eventually transforms via inorganic dehydration to goethite and hematite. Similar processes to those described in this study have likely occurred during the formation of many other iron-rich laterites.Hepp, J., Sch?fer, I.K., Lanny, V., Franke, J., Bliedtner, M., Rozanski, K., Glaser, B., Zech, M., Eglinton, T.I., Zech, R., 2020. Evaluation of bacterial glycerol dialkyl glycerol tetraether and 2H–18O biomarker proxies along a central European topsoil transect. Biogeosciences 17, 741-756. fossils, like bacterial branched glycerol dialkyl glycerol tetraethers (brGDGTs), and the stable isotopic composition of biomarkers, such as δ2H of leaf wax-derived n-alkanes (δ2Hn-alkane) or δ18O of hemicellulose-derived sugars (δ18Osugar), are increasingly used for the reconstruction of past climate and environmental conditions. Plant-derived δ2Hn-alkane and δ18Osugar values record the isotopic composition of plant source water (δ2Hsource-water and δ18Osource-water), which usually reflects mean annual precipitation (δ2Hprecipiation and δ18Oprecipiation), modulated by evapotranspirative leaf water enrichment and biosynthetic fractionation (εbio). Accuracy and precision of respective proxies should be ideally evaluated at a regional scale. For this study, we analysed topsoils below coniferous and deciduous forests as well as grassland soils along a central European transect in order to investigate the variability and robustness of various proxies and to identify effects related to vegetation. Soil pH values derived from brGDGTs correlate reasonably well with measured soil pH values but are systematically overestimated (ΔpH?=?0.6±0.6). The branched vs. isoprenoid tetraether index (BIT) can give some indication whether the pH reconstruction is reliable. Temperatures derived from brGDGTs overestimate mean annual air temperatures slightly (ΔTMA=0.5?°C?±?2.4). Apparent isotopic fractionation (εn-alkane/precipitation and εsugar∕precipitation) is lower for grassland sites than for forest sites due to signal damping; i.e. grass biomarkers do not record the full evapotranspirative leaf water enrichment. Coupling δ2Hn-alkane with δ18Osugar allows us to reconstruct the stable isotopic composition of the source water more accurately than without the coupled approach (Δδ2H?=?～?21 ?‰?±?22?‰ and Δδ18O?=?～?2.9 ?‰?±?2.8?‰). Similarly, relative humidity during daytime and the vegetation period (RHMDV) can be reconstructed using the coupled isotope approach (ΔRH MDV =～?17±12 ). Especially for coniferous sites, reconstructed RHMDV values as well as source water isotope composition underestimate the measured values. This can likely be explained by understorey grass vegetation at the coniferous sites contributing significantly to the n-alkane pool but only marginally to the sugar pool in the topsoils. Vegetation-dependent variable signal damping and εbio (regarding 2H between n-alkanes and leaf water) along our European transect are difficult to quantify but likely contribute to the observed underestimation in the source water isotope composition and RH reconstructions. Microclimate variability could cause the rather large uncertainties. Vegetation-related effects do, by contrast, not affect the brGDGT-derived reconstructions. Overall, GDGTs and the coupled δ2Hn-alkane–δ18Osugar approach have great potential for more quantitative paleoclimate reconstructions.Hertzog, J., Carré, V., Aubriet, F., 2019. Chapter 22 - Contribution of Fourier transform mass spectrometry to bio-oil study, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 679-733. obtained from the thermochemical conversion of the lignocellulosic biomass are potential sources of renewable materials (bio-fuels, chemicals, …). However, their high chemical complexity and the high amount of oxygenated compounds limit their ready-to-use capacity. Upgrading treatments, such as deoxygenation and/or cracking, have to be applied. In order to assess the most suited and the most efficient upgrading process, it is necessary to obtain an extensive composition description of the bio-oils at all processing stages. In this respect, the non-targeted approach, using Fourier transform high-resolution mass spectrometry combined with different ionization sources, has demonstrated its great abilities to characterize thousands of bio-oil components over a large range of mass and polarity. In this chapter, an exhaustive review of the studies performed in this field will be presented. To define the main challenges related to the bio-oil characterization, some relevant information will be briefly given in regards to the biomass composition and the used processes that ensure its conversion into bio-oils. Additionally, information achieved by “classical” analytical methods will be presented. This will allow demonstrating the contribution of high-resolution Fourier transform mass spectrometry (FTMS) analyses to characterization of bio-oils.Hewitt, L.M., Roy, J.W., Rowland, S.J., Bickerton, G., De Silva, A.O., Headley, J.V., Milestone, C.B., Scarlett, A.G., Brown, S., Spencer, C., West, C.E., Peru, K.M., Grapentine, L., Ahad, J.M.E., Pakdel, H., Frank, R.A., 2020. Advances in distinguishing groundwater influenced by oil sands process-affected water (OSPW) from natural bitumen-influenced groundwaters. Environmental Science & Technology 54, 1522-1532. objective of this study was to advance analytical methods for detecting oil sands process-affected water (OSPW) seepage from mining containments and discriminating any such seepage from the natural bitumen background in groundwaters influenced by the Alberta McMurray formation. Improved sampling methods and quantitative analyses of two groups of mono-aromatic acids (Family A and B) were employed to analyze OSPW and bitumen-affected natural background groundwaters for source discrimination. Both groups of mono-aromatic acids showed significant enrichment in OSPW, while ratios of O2:O4 containing heteroatomic ion classes of acid extractable organics (AEOs) did not exhibit diagnostic differences. Evaluating the mono-aromatic acids to track a known plume of OSPW-affected groundwater confirmed their diagnostic abilities at this site. A secondary objective was to assess anthropogenically derived artificial sweeteners and per- and polyfluoroalkyl substances (PFAS) as potential tracers for OSPW. Despite the discovery of acesulfame and PFAS in most OSPW samples, trace levels in groundwaters influenced by general anthropogenic activities preclude them as individual robust tracers. However, their inclusion with the other metrics employed in this study served to augment the tiered, weight of evidence methodology developed. This methodology was then used to confirm earlier findings of OSPW migrations into groundwater reaching the Athabasca River system adjacent to the reclaimed pond at Tar Island Dyke.Heydari-Farsani, E., Neilson, J.E., Alsop, G.I., Hamidi, H., 2020. Tectonic controls on residual oil saturation below the present-day fluid contact level in reservoirs of the Persian Gulf. Journal of Asian Earth Sciences 190, 104133. presence of residual oil below the present-day free water level (FWL) and oil water contact (OWC) is common in many oil fields in the Middle East, particularly those in the Persian Gulf. This residual oil is seen in both clastic and carbonate reservoirs prior to the start of production. The characterisation and modelling of these fields is difficult in practice. Also, these residual oils below the FWL and OWC could become classified as reserves if ways to produce them could be found. However, the first step is to better understand their origin. Therefore, the goal of this study was to investigate the role of geological events on the presence of the residual oil zone (ROZ) below the FWL and OWC.It has been suggested that the presence of residual oil below the present day FWL and OWC is related to the geotectonic history of the region. From the middle Miocene, reverse faulting and overfolding propagated over the Zagros, leading to the amplification of folds and the migration of the Zagros orogeny towards its foreland basin (Persian Gulf). In response to this additional massive loading on the continental margin, the forebulge amplitude was increased, its location migrated towards the uplifted Zagros Mountains, and consequently the Persian Gulf became narrower. This exerted a north to north-east downward tilting of the entire basin, including all the structures and reservoirs previously filled by hydrocarbons. This basin tilting changed the equilibrium of the structures and their fluid contents, and resulted in the hydrocarbons and water attempting to find a new equilibrium. Under these conditions, the early migrated and accumulated oil was flushed out by water (imbibition), and a ROZ was left below the present day FWL and OWCs. The angle of regional basin tilt has been calculated to be 0.836° based on seismic sections.Hinners, P., Thomas, M., Lee, Y.J., 2020. Determining fingerprint age with mass spectrometry imaging via ozonolysis of triacylglycerols. Analytical Chemistry 92, 3125-3132. the common use of fingerprints as a trusted means of identification, no method currently exists to reliably establish the time since deposition of latent fingerprints. A reproducible method of establishing latent fingerprint age would allow forensic personnel to determine if a latent fingerprint was relevant to a crime. This work investigates the ambient aging of triacylglycerols (TGs) and other lipids in latent fingerprint residue utilizing matrix-assisted laser desorption/ionization - mass spectrometry imaging (MALDI-MSI). Unsaturated TGs were found to undergo ambient ozonolysis resulting in a decrease over time. At the same time, two series of compounds related to the degradation of unsaturated TGs due to ambi-ent ozonolysis emerged with time and were detectable within a single day of aging. Tracking the degradation of unsaturated TGs over time proved to be relatively reproducible in multiple individuals and is suggested as a means of establishing latent fingerprint age.Hiraoka, S., Hirai, M., Matsui, Y., Makabe, A., Minegishi, H., Tsuda, M., Juliarni, Rastelli, E., Danovaro, R., Corinaldesi, C., Kitahashi, T., Tasumi, E., Nishizawa, M., Takai, K., Nomaki, H., Nunoura, T., 2020. Microbial community and geochemical analyses of trans-trench sediments for understanding the roles of hadal environments. The ISME Journal 14, 740-756. trench bottom (>6000?m below sea level) sediments harbor higher microbial cell abundance compared with adjacent abyssal plain sediments. This is supported by the accumulation of sedimentary organic matter (OM), facilitated by trench topography. However, the distribution of benthic microbes in different trench systems has not been well explored yet. Here, we carried out small subunit ribosomal RNA gene tag sequencing for 92 sediment subsamples of seven abyssal and seven hadal sediment cores collected from three trench regions in the northwest Pacific Ocean: the Japan, Izu-Ogasawara, and Mariana Trenches. Tag-sequencing analyses showed specific distribution patterns of several phyla associated with oxygen and nitrate. The community structure was distinct between abyssal and hadal sediments, following geographic locations and factors represented by sediment depth. Co-occurrence network revealed six potential prokaryotic consortia that covaried across regions. Our results further support that the OM cycle is driven by hadal currents and/or rapid burial shapes microbial community structures at trench bottom sites, in addition to vertical deposition from the surface ocean. Our trans-trench analysis highlights intra- and inter-trench distributions of microbial assemblages and geochemistry in surface seafloor sediments, providing novel insights into ultradeep-sea microbial ecology, one of the last frontiers on our planet.Hmiel, B., Petrenko, V.V., Dyonisius, M.N., Buizert, C., Smith, A.M., Place, P.F., Harth, C., Beaudette, R., Hua, Q., Yang, B., Vimont, I., Michel, S.E., Severinghaus, J.P., Etheridge, D., Bromley, T., Schmitt, J., Fa?n, X., Weiss, R.F., Dlugokencky, E., 2020. Preindustrial 14CH4 indicates greater anthropogenic fossil CH4 emissions. Nature 578, 409-412. methane (CH4) is a potent greenhouse gas, and its mole fraction has more than doubled since the preindustrial era. Fossil fuel extraction and use are among the largest anthropogenic sources of CH4 emissions, but the precise magnitude of these contributions is a subject of debate. Carbon-14 in CH4 (14CH4) can be used to distinguish between fossil (14C-free) CH4 emissions and contemporaneous biogenic sources; however, poorly constrained direct 14CH4 emissions from nuclear reactors have complicated this approach since the middle of the 20th century. Moreover, the partitioning of total fossil CH4 emissions (presently 172 to 195 teragrams CH4 per year) between anthropogenic and natural geological sources (such as seeps and mud volcanoes) is under debate; emission inventories suggest that the latter account for about 40 to 60 teragrams CH4 per year. Geological emissions were less than 15.4 teragrams CH4 per year at the end of the Pleistocene, about 11,600 years ago8, but that period is an imperfect analogue for present-day emissions owing to the large terrestrial ice sheet cover, lower sea level and extensive permafrost. Here we use preindustrial-era ice core 14CH4 measurements to show that natural geological CH4 emissions to the atmosphere were about 1.6 teragrams CH4 per year, with a maximum of 5.4 teragrams CH4 per year (95 per cent confidence limit)—an order of magnitude lower than the currently used estimates. This result indicates that anthropogenic fossil CH4 emissions are underestimated by about 38 to 58 teragrams CH4 per year, or about 25 to 40 per cent of recent estimates. Our record highlights the human impact on the atmosphere and climate, provides a firm target for inventories of the global CH4 budget, and will help to inform strategies for targeted emission reductions.Hofer, U., 2020. Asgard archaeon rises from the mud. Nature Reviews Microbiology 18, 122-123. study reports the cultivation of a member of the Asgard archaea, which are the closest living relatives of the cells that gave rise to eukaryotes.Hong, L., Li, Y., He, M., Zhao, C., Li, M., 2020. An algorithm to calibrate ionic isotopes using data mining strategy in hyphenated chromatographic datasets from herbal samples. Journal of Chromatography A 1613, 460668. bottleneck of analytical instrument itself and non-ideal instrumental performance will produce a certain degree of drifts between the measured isotopes and the true values. An AAID-IC algorithm was thereby proposed to keep the isotopic distributions more accurate in hyphenated instruments, e.g. Gas Chromatography (GC)/ Liquid Chromatography (LC) - Mass Spectrometry (MS). During this data mining process, chemical information will be fully used from dozens of data points in retention time (rt) dimension: the target isotopes were firstly re-constructed in mass charge ratio (m/z) dimension; their re-calculation values were then averaged from an interesting rt zone; the calibration functions were followed established based on a well-defined series of calibration ions. It is worth mentioning that natural metabolites in complex samples can be identified as reference materials to amend the target isotopes. Next, the corrected mass axes (m/z values)/isotope abundances were transformed into an ionic isotopic curve using Gaussian box. Taking herbal sample as an example, AAID-IC can better reduce the systematic and random errors of the m/z ions in one run environment, whether it's profile or bar graph from any type of MS and any ionization method employed. Finally, the calibrated values can be utilized to deduce the elemental compositions of molecular (fragment) ions in GC/LC–MS determination.Hong, T., Culp, J.T., Kim, K.-J., Devkota, J., Sun, C., Ohodnicki, P.R., 2020. State-of-the-art of methane sensing materials: A review and perspectives. TrAC Trends in Analytical Chemistry 125, 115820. (CH4) is primarily used as a fuel for heating and electricity generation throughout the world. Despite its advantages such as high calorific value and low toxicity after combustion, CH4 is considered a greenhouse gas with a global warming potential greater than CO2 per molecule. CH4 is also explosive for concentrations above the lower explosive limit. Therefore, the development of high performing, low cost and ubiquitously deployable CH4 sensing materials could be beneficial from both environmental and safety perspectives. This article reviews sensing platforms and sensing mechanisms of current CH4 sensing materials, as well as summarizing their strengths and weaknesses. Metal Oxide, Carbon Materials, Conducting Polymers, Supramolecular Materials and Metal-Organic Frameworks based on Chemi-resistive, Optical and Electroacoustic platforms are discussed. Their operating conditions, sensing performances and limit of detection are carefully reviewed. Additionally, current challenges, including water vapor cross-sensitivity and selectivity, along with future perspectives are discussed.Horel, A., Schiewer, S., 2020. Microbial degradation of different hydrocarbon fuels with mycoremediation of volatiles. Microorganisms 8, 163. Naturally occurring microorganisms in soil matrices play a significant role in overall hydrocarbon contaminant removal. Bacterial and fungal degradation processes are major contributors to aerobic remediation of surface contaminants. This study investigated degradation of conventional diesel, heating diesel fuel, synthetic diesel (Syntroleum), fish biodiesel and a 20% biodiesel/diesel blend by naturally present microbial communities in laboratory microcosms under favorable environmental conditions. Visible fungal remediation was observed with Syntroleum and fish biodiesel contaminated samples, which also showed the highest total hydrocarbon mineralization (>48%) during the first 28 days of the experiment. Heating diesel and conventional diesel fuels showed the lowest total hydrocarbon mineralization with 18–23% under favorable conditions. In concurrent experiments with growth of fungi suspended on a grid in the air space above a specific fuel with little or no soil, fungi were able to survive and grow solely on volatile hydrocarbon compounds as a carbon source. These setups involved negligible bacterial degradation for all five investigated fuel types. Fungal species able to grow on specific hydrocarbon substrates were identified as belonging to the genera of Giberella, Mortierella, Fusarium, Trichoderma, and Penicillium. Hosseini, E., Tahmasebi, R., 2020. Experimental investigation of the performance of biosurfactant to wettability alteration and interfacial tension (IFT) reduction in microbial enhanced oil recovery (MEOR). Petroleum Science and Technology 38, 147-158. this Study, the biosurfactant production potential of Enterobacter Cloacae and Enterobacter Hormaechei microorganisms that were isolated from one of the oil reservoir formation water located in the southwest of Iran was explored. The produced biosurfactant caused substantial surface tension reduction of the growth medium and interfacial tension reduction between oil and brine to 31 and 3.2?mN/m from the original value of 72 and 29?mN/m respectively. In addition, the impact of other parameters such as temperature and salinity were investigated by performing appropriate experiments. The results show that the wettability alteration toward neutrally wet conditions could be the dominant mechanism on the improvement of oil recovery and the adsorption of bacteria cells and forming biofilm was the main contributor to this wettability alteration.Houfani, A.A., Anders, N., Spiess, A.C., Baldrian, P., Benallaoua, S., 2020. Insights from enzymatic degradation of cellulose and hemicellulose to fermentable sugars– a review. Biomass and Bioenergy 134, 105481., the most abundant and renewable resource on Earth is an important raw material, which can be converted into high value products. However, to this end, it needs to be pretreated physically, chemically, or biologically. Its complex structure and recalcitrance against physical, chemical, or biological degradation render its breakdown an important target of study. The understanding of the enzymatic processes of lignocellulose breakdown and the changes in its chemistry are thus essential. Here, we review the current analytical challenges in the analysis of lignocellulose composition, lignocelluloytic pretreatment, analysis of enzymatic hydrolysis catalyzed by cellulases or hemicellulases and their biotechnological plex techniques including biochemical, genomic, and metagenomics methods such as high performance anion exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD), Respiration Activity Monitoring System (RAMOS), and next-generation sequencing are described. HPAEC-PAD is a promising, rapid, and reliable analytical technique for sugar quantification following lignocellulose breakdown. RAMOS is an effective technique for monitoring the growth of microorganisms during the different phases of enzyme production, enzymatic hydrolysis, and fermentation. The emergence of high throughput, next-generation sequencing techniques has enriched the databases of genes encoding glycoside hydrolase classes commonly involved in lignocellulose decomposition, and this knowledge can be readily used to analyse the involved processes. Still, novel analytical methods are highly welcome to understand the complete process of lignocelluloytic breakdown. In order to decrease environmental pollution and to save energy, lignocellulose conversion needs to be promoted in order to effectively compete with fossil resources on a global scale in future.Hu, C., Wang, M., Duan, Q., Han, X., 2020. Sensitive analysis of fatty acid esters of hydroxy fatty acids in biological lipid extracts by shotgun lipidomics after one-step derivatization. Analytica Chimica Acta 1105, 105-111. fatty acid esters of hydroxy fatty acids (FAHFAs) are an important family of endogenous lipids, possessing antidiabetic and anti-inflammatory functions. Therefore, analysis of FAHFAs in biological samples obtained under healthy and disease states can uncover underlying mechanisms of various relevant disorders (e.g., diabetes and autoimmune diseases). Up to now, due to their extremely low abundance, the determination of the changed levels of these species is still a huge challenge, even though great efforts have been made by utilizing liquid chromatography-tandem mass spectrometry with or without derivatization. Herein, we described a novel method for analysis of FAHFAs present in lipid extracts of biological examples after solid-phase extraction and chemical derivatization with one authentic FAHFA specie as an internal standard based on the principles of multi-dimensional mass spectrometry-based shotgun lipidomics. The approach possessed marked sensitivity, high specificity, and broad linear dynamic range of over 3 orders without obvious matrix effects. Moreover, after chemical derivatization, the molecular masses of FAHFAs shift from an overlapped region with ceramide species to a new region without overlaps, removing these contaminating signals from ceramides, and thereby reducing the false results of FAHFAs. Finally, this novel method was successfully applied for determining FAHFAs levels in varieties of representative biological samples, including plasma from lean and overweight/obese individuals of normoglycemia, and tissue samples (such as liver and white adipose tissue from diabetic (db/db) mice). We revealed significant alterations of FAHFAs in samples under patho(physio)logical conditions compared to their respective controls. Taken together, the developed method could greatly contribute to studying altered FAHFA levels under a variety of biological/biomedical conditions, and facilitate the understanding of these lipid species in the patho(physio)logical process.Hu, D., Liu, B., Wang, L., Reeves, P.R., 2019. Living trees: High-quality reproducible and reusable construction of bacterial phylogenetic trees. Molecular Biology and Evolution 37, 563-575. ideal bacterial phylogenetic tree accurately retraces evolutionary history and accurately incorporates mutational, recombination and other events on the appropriate branches. Current strain-level bacterial phylogenetic analysis based on large numbers of genomes lacks reliability and resolution, and is hard to be replicated, confirmed and reused, because of the highly divergent nature of microbial genomes. We present SNPs and Recombination Events Tree (SaRTree), a pipeline using six “living trees” modules that addresses problems arising from the high numbers and variable quality of bacterial genome sequences. It provides for reuse of the tree and offers a major step toward global standardization of phylogenetic analysis by generating deposit files including all steps involved in phylogenetic inference. The tree itself is a “living tree” that can be extended by addition of more sequences, or the deposit can be used to vary the programs or parameters used, to assess the effect of such changes. This approach will allow phylogeny papers to meet the traditional responsibility of providing data and analysis that can be repeated and critically evaluated by others. We used the Acinetobacter baumannii global clone I to illustrate use of SaRTree to optimize tree resolution. An Escherichia coli tree was built from 351 sequences selected from 11,162 genome sequences, with the others added back onto well-defined branches, to show how this facility can greatly improve the outcomes from genome sequencing. SaRTree is designed for prokaryote strain-level analysis but could be adapted for other usage.Hu, R., Li, F., Yu, H., Yang, J., 2020. Weathering of basalts by Aspergillus sp. FS-4 strain: Glass compositions are prone to weathering. Geomicrobiology Journal 37, 101-109. underlying microbe-induced dissolution of basalt and its effect on glass composition remain unclear. Two powdered basalts, with a glass composition of 27?vol% (Basalt-T) and 18?vol% (Basalt-F), respectively, were inoculated with Aspergillus sp. FS-4 in Czapek medium. Changes in pH, siderophores and main dissolved elements were examined. Basalt-F led to a greater decrease in pH and higher production of siderophores than Basalt-T mainly due to the fungi activity. Element dissolution was 2 to 3 fold higher in Basalt-T than in Basalt-F, and the dissolution was non-stoichiometric for both basalts. FS-4 appears important for basalt weathering. Composition of geologic material had a considerable impact on weathering. Materials with a higher glass percentage are prone to weathering. Further quantitative evaluation is required.Hu, X., Qiao, Y., Chen, L.-Q., Du, J.-F., Fu, Y.-Y., Wu, S., Huang, L., 2020. Enhancement of solubilization and biodegradation of petroleum by biosurfactant from Rhodococcus erythropolis HX-2. Geomicrobiology Journal 37, 159-169. demand to repair areas contaminated with hydrocarbon products has led to the development of new technologies for the treatment of contaminants in an unconventional method, that is, no physical or chemical methods are used. Biosurfactants are amphiphilic biomolecules produced by microorganisms that can be used in environments contaminated by petroleum products due to their unexceptionable tensile properties. Petroleum degrading strain Rhodococcus erythropolis HX-2 was found to be an effective producer of biosurfactants. The resulting biosurfactant (named NK) exhibits high physicochemical properties in terms of surface activity. It is capable of reducing surface tension from 54.99 to 28.89?mN/m and critical micelle concentration (CMC) is 100?mg/L. NK was found to be a substitute for chemically synthesized surfactants because of its higher solubilization efficiency for petroleum and polycyclic aromatic hydrocarbons, superior to SDS, Tween 80, Triton X-100 and Rhamnolipid (a wide used biosurfactant). In addition, it exhibits favorable emulsion stability over a wide range of pH (3–10), temperature (20–100?°C) and salinity ranges (5–20?g/L). It was found that the addition of biosurfactant can improve the efficiency of petroleum degradation, therefore it has potential applications in bioremediation. Huang, H., Yin, M., Han, D., 2020. Novel parameters derived from alkylchrysenes to differentiate severe biodegradation influence on molecular compositions in crude oils. Fuel 268, 117366. extracted bitumens from oil sands in the Athabasca region, West Canada and Liaohe Basin, NE China and oils from the Bongor Basin, SW Chad have been geochemically characterized to investigate biodegradation influence on molecular compositions. All samples in each case history were derived from the same source rock systems and have a similar maturity level. The variations in molecular compositions are merely caused by variable levels of biodegradation. GC–MS analysis results based on overall saturated and aromatic hydrocarbon distributions illustrated that biodegradation influences on Athabasca oil sands were less severe than these in Liaohe oil sands and Bongor oils but biodegradation level assignment is inconclusive and confusion. Novel biodegradation parameters based on methylchrysene (MCh) isomer distributions and relative abundance between alkylchrysenes and alkylphenanthrenes were proposed to differentiate biodegradation influence at heavy to severe biodegradation levels. The 3-MCh is proved to be the most stable methylchrysene isomer and the ratio of 3-MCh/∑MCh can serve as a novel biodegradation parameter. Meanwhile, alkylchrysenes show much higher ability to resist biodegradation than alkylphenanthrenes and the ratio of C0-1Ch/C2P was proposed as another novel biodegradation parameter. While the nature of organic source input may exert some impacts on the initial values of these novel parameters, continuous increases in these two parameters with intensified biodegradation levels may provide a supplemental tool for biodegradation influence assessment especially when biodegradation approaches to severe levels.Huang, L., Khoshnood, A., Firoozabadi, A., 2020. Swelling of Kimmeridge kerogen by normal-alkanes, naphthenes and aromatics. Fuel 267, 117155. recognition of kerogen swelling in liquid solvents, swelling trends in different classes of petroleum liquids remain unexplored. Modeling results based on the extended polymer theory have not been beyond curve-fitting of swelling measurements. This work centers on measurement of swelling of Kimmeridge kerogen in three classes of petroleum liquids: normal-alkanes, naphthenes and aromatics. The measured data show that swelling decreases as the molecular size increases for the three classes of solvents. Compared with naphthenes, normal-alkanes with flexible linear chains, and aromatics having π–π interaction with kerogen induce higher swelling. In the Kimmeridge kerogen, the swelling in both normal-alkanes and naphthenes monotonously decreases with the solvent solubility parameter and molar volume starting with hydrocarbon molecules with 5 carbon atoms. Compared with solvent solubility parameter, the effect of solvent molar volume dominates the swelling of Kimmeridge kerogen. The extended Flory-Rehner and regular solution theory framework does not describe the swelling behavior of Kimmeridge kerogen in petroleum liquids despite widespread applications of the framework. Results from the model show an increase in swelling in normal alkanes with molecular size which is opposite to our measurements.Huang, X.-F., Dai, J., Zhu, Q., Yu, K., Du, K., 2020. Abundant biogenic oxygenated organic aerosol in atmospheric coarse particles: Plausible sources and atmospheric implications. Environmental Science & Technology 54, 1425-1430. organic aerosol (SOA) is a key component in atmospheric aerosols, strongly influencing air quality and climate. Most previous studies focused on SOA formation in the fine aerosol mode, and little is known about SOA formation across a broader size range, especially for the coarse aerosol mode. In this study, we coupled radiocarbon analysis and the offline aerosol mass spectrometric method to characterize water-soluble organic matter in size-segregated samples between 0.056 and 18 μm collected in urban Shenzhen, China. For the first time, detailed size distributions of different types of oxygenated organic aerosols (OOAs) are obtained. Fossil fuel OOA was mostly distributed in fine particles, and biogenic OOA occurred mostly in coarse particles. Organic composition and correlation analyses suggested that the major source of the coarse-mode OOA was more plausible to be heterogeneous reactions of biogenic volatile organic compounds (VOCs) on soil dust rather than primary biological materials. If so, this mechanism would complement the missing sinks of biogenic VOCs, significantly influence the regional and global organic aerosol budgets, and thus should be considered in air quality and climate models. This study highlights the urgent need for laboratory simulations of heterogeneous reactions of various VOCs on soil dust.Huang, Y., Dong, L., Hursthouse, A., Yu, Y., Huang, J., 2019. Characterization of pore microstructure and methane adsorption of organic-rich black shales in northwestern Hunan, South China. Energy Exploration & Exploitation 38, 473-493. gas adsorption of shale is one of the most important factors influencing shale gas accumulation and production. Different from other shale gas fields, the shale in Northwestern Hunan province with strong structural deformation has especially high portion of adsorbed gas. The adsorption abilities of shale reservoir play a significant role in the success of exploration and production of shale gas in Northwestern Hunan. Therefore, based on many experiments including field emission scanning electron microscopy, N2/CO2 adsorption, excess CH4 adsorption with constant temperature and others, this paper found that: (1) the shale pores were identified with mineral matrix pores, organic-matter pores and fracture pores, and the pores can be further classified according to their shape features and forming mechanism; (2) after analyses of the distribution of the pore size, mesoporous is the largest contributor and widely distributed, and micropores provide more contribution on surface area but limited contribution to pore volume. Meanwhile, depth has little effect on the properties of shale reservoirs; (3) based on the fractal geometry theory, surface roughness is positively correlated to microstructure irregularity, which means the effects between the gas adsorption by Van der Waals force and by multilayer or capillary condensation in single pore system are consistent during the N2 adsorption process. (4) The abilities of gas storage are apparently sensitive to the surface roughness of shale pores and nonsensitive to microstructure irregularity. Total organic carbon has strong positive correlation with the surface roughness, specific surface area, total pore volume, and Langmuir volume, which means TOC can improve the adsorption of shale reservoir in many ways. Pyrite can offer much contribution to the ability of gas adsorption.Huang, Y., Qing, X., Wang, W., Han, G., Wang, J., 2020. Mini-review on current studies of airborne microplastics: Analytical methods, occurrence, sources, fate and potential risk to human beings. TrAC Trends in Analytical Chemistry 125, 115821. (MPs) are emerging pollutants and have potential adverse effects to organisms. Airborne MPs are of great concern, because they are an important contributor to MPs in other environmental compartments such as water and soils and may pose potential risk to human health via inhalation or dust ingestion. Analytical methods, abundance, pollution characteristics, potential sources and risk to human beings of airborne MPs in suspended particulates, atmospheric fallout and deposited dusts were summarized in the present review. Research gaps and suggestions for future works on airborne MPs were also given. Digestion of samples was suggested to avoid the interference of organic materials to airborne MPs. New techniques such as hyperspectral imaging technique, pyrolysis and thermal desorption gas chromatography mass spectrometry were expected to be used for the analysis of airborne MPs. Furthermore, more studies were required to fully understand the pollution status and potential risk of airborne MPs.Hudgins, M.N., Uhen, M.D., Hinnov, L.A., 2020. The evolution of respiratory systems in Theropoda and Paracrocodylomorpha, the end-Triassic extinction, and the role of Late Triassic atmospheric O2 and CO2. Palaeogeography, Palaeoclimatology, Palaeoecology 545, 109638. the Late Triassic Period (235–201.3 Ma), Paracrocodylomorpha and Theropoda switched predatory roles, with the former filling the subsidiary predator niche and the latter filling the top predator niche at the end-Triassic extinction. Reasons for the transition in predator guilds remain unknown, but atmospheric conditions during this time, which involved high CO2 and low O2 concentration levels, may be associated with the event. Evidence of bird-like pneumatic post-crania, present in both groups as foramina and fossae, correlates with an avian-like respiratory system. This may have allowed organisms to cope with declining atmospheric O2 environments of the Late Triassic. This study estimated pO2 throughout the late Triassic using organic carbon isotope measurements from Newark-Hartford basin paleosols and examined the morphological change in skeletal remains of Theropoda, focusing on pneumatic bones, compared with Paracrocodylomorpha during the Late Triassic and across the Triassic-Jurassic boundary. With data compiled from the Paleobiology Database and published anatomical literature, the change of pneumaticity in taxa is quantified by a Pneumatic Index (PI), in which the number of pneumatized units is divided by the total number of bones examined. Patterns of pneumaticity are individually scored for the presence or absence of pneumatic bones. Morphological data are compared to corresponding femur length, estimated atmospheric O2 and CO2 level reconstructions, and an ancestral state reconstruction depicting how PI values change throughout various clades. Our results suggest that PI values in Theropoda and Paracrocodylomorpha correspond with the vacillating pO2 and pCO2 throughout the Late Triassic and into the Jurassic. High PI values are prevalent in advanced theropod taxa, while Paracrocodylomorpha PI values vary by clade with a generally negative trend throughout the Triassic. Ancestral state reconstruction analysis highlights the increasing PI values within Theropoda and clade dependent trends in Paracrocodylomorpha. This study is instrumental in reconstructing how Theropoda became evolutionarily successful and perhaps how and why the avian-like respiratory system originated.Hutchings, J.A., Bianchi, T.S., Najjar, R.G., Herrmann, M., Kemp, W.M., Hinson, A.L., Feagin, R.A., 2020. Carbon deposition and burial in estuarine sediments of the contiguous United States. Global Biogeochemical Cycles 34, e2019GB006376. represent the primary linkage between the terrestrial and marine carbon cycles, and estuarine processing of riverine and coastal carbon plays a disproportionately large role in the global carbon cycle relative to the small areal extent of the estuarine environments. However, knowledge of the rate of organic carbon deposition and burial in estuarine sediments is lacking at regional scales. Data on surficial total organic carbon, linear sedimentation, and bulk density of estuarine sediments were compiled and categorized via a cluster analysis in order to estimate carbon deposition within the contiguous United States (CONUS). The cluster analysis broadly grouped estuaries by geography, but exceptions to geographic clustering highlighted differences within regions. A transfer function from deposition to burial based on linear sedimentation rate was used to estimate burial efficiency, and thus the rate of carbon burial within each cluster. We estimate organic carbon deposition rates within CONUS estuarine sediments to be 161 [121–217, 95% confidence] g C/m2/yr with a burial efficiency estimated at 38 [34–42, 95% confidence] %, which yields a long‐term burial rate of 64 [44–97, 95% confidence] g C/m2/yr. Spatially integrated organic deposition and burial rates are 11.3 [8.5–15.2, 95% confidence] and 4.5 [3.1–6.8, 95% confidence] Tg C/yr, respectively. Our findings allow a more thorough understanding of coastal carbon cycling, which is critical for both management purposes as well as for the assessment of the role of estuaries in past and future climate change.Ibrar, M., Zhang, H., 2020. Construction of a hydrocarbon-degrading consortium and characterization of two new lipopeptides biosurfactants. Science of The Total Environment 714, 136400. solubility and bioavailability of hydrophobic compounds are the major problems in the bioremediation process, which could be overcome by the bacteria capable of biosurfactant production and concurrent hydrocarbon degradation. In this work, we constructed an artificial bacterial consortium containing Lysinibacillus, Paenibacillus, Gordonia and Cupriavidus spp. from glyceryl tributyrate enriched bacteria collected from the non-contaminated site. The consortium was capable of using common raw materials (olive oil, paraffin oil, and glycerol) and polyaromatic hydrocarbons pollutants (naphthalene and anthracene) as the sole carbon source with simultaneous biosurfactant production. Two new lipopeptide isoforms, containing heptapeptide and lipid moieties, were structurally elucidated by LC-MS/MS, FTIR, NMR and molecular networking analysis. Our findings indicate that hydrocarbons degradation and biosurfactant production is an intrinsic property of non-contaminated soil community. Interestingly, we observed the hyper chemotactic activity of Lysinibacillus strains towards glyceryl tributyrate, which has not been reported before. The study may deepen our understanding of microbial strains and consortium with the potential to be used for bioremediation of hydrocarbons contaminated environments.Igwe, I., Gholinezhad, J., Hassan Sayed, M.G., Ogbuagu, F., 2020. Technical implications of neglecting compositional grading effects in petroleum reservoir simulation models. Energy & Fuels 34, 1467-1481. compositional reservoir simulation practices assume that the compositions of various fluid components are the same at all locations within the reservoir system. This constant composition assumption is incorrect and unrealistic as it grossly ignores the occurrences of some less obvious physical processes in the reservoir. Gravitational force, temperature gradient, and thermal diffusion, among other factors, contribute to distribution and gradation of hydrocarbon fluid compositions in the reservoir. Therefore, incorporating compositional grading models that adequately account for the individual and combined effects of gravity force, temperature gradient, and thermal diffusion is crucial when initializing reservoir simulation models. This research seeks to elucidate the technical implications of compositional grading on improved reserve estimation and reservoir performance prediction. The mathematical framework for the compositional grading modeling is based on one-dimensional zero-mass-flow stationary state assumption. The Computer Modeling Group’s equation of state multiphase equilibrium property simulator, WinProp, was used for the fluid modeling, while the Computer Modeling Group’s compositional reservoir simulator, GEM, was used for the reservoir modeling and simulation. In the absence of historical production data, Computer Modeling Group’s CMOST was used to perform uncertainty assessment for the validation of the initialized reservoir models. The research results show that initialized reservoir models that neglected or inadequately accounted for compositional grading effects overestimated oil in-place and underestimated gas in-place. The constant composition (without compositional grading) initialized reservoir model overestimates ultimate cumulative oil production by 14.271 MMbbl more than the isothermal compositional grading model and 24.088 MMbbl more than Kempers’ thermal diffusion compositional grading initialized reservoir model. It underestimated ultimate cumulative gas production by 30.133 Bft3 less than the isothermal compositional grading and 50.408 Bft3 less than Kempers’ thermal diffusion compositional grading initialized reservoir model. These figures suggest that neglecting compositional grading or an inadequate account of compositional grading effects in reservoir simulation initialization has detrimental technical consequences.Ikonen, K.E., Wehde, K.E., Khalida, H., Kentt?maa, H.I., 2020. Bias, limit of detection, and limit of quantitation for the ASTM D2425 method updated in 2019. Journal of Chromatography A 1614, 460705. update for ASTM D2425, “Standard Test Method for Hydrocarbon Types in Middle Distillates by Mass Spectrometry,” was recently released to expand its scope by adding modern mass spectrometric instrumentation and a new sample type, synthesized hydrocarbons. While the method update is a proper step towards modernization, it still lacks validation parameters. The description of the updated standard method contains precision estimations but no consideration for a possible bias, meaning that the method accuracy was not evaluated. The 2019 update does not either provide the lowest concentration of an analyte that can be detected and quantitatively determined, ‘limit of detection’ (LOD) and ‘limit of quantification’ (LOQ). In the present study, the LOD, LOQ, and bias were evaluated as an intra-laboratory study. The LOD and LOQ determination was based on the adjusted standard deviation of the least abundant hydrocarbon type in a sample, and were 0.004 and 0.01?w/w% in renewable jet fuel (RJF) and 0.01 and 0.02?w/w% in gas oil (GO), respectively. The bias was determined by measuring relative hydrocarbon recovery percentages for spiked samples. The renewable jet fuel was spiked with cycloparaffins and alkylbenzenes and the recovery percentages were 140% and 63%, respectively. The gas oil was spiked with paraffins and alkylbenzenes and the recovery percentages were 117% and 90%, respectively. Both sample sets were positively biased for paraffin content (recovery percentage over 100%) and negatively biased for alkylbenzene content (recovery percentage less than 100%). Based on above results, this method may not work well for RJF samples.Isaji, Y., Ogawa, N.O., Boreham, C.J., Kashiyama, Y., Ohkouchi, N., 2020. Evaluation of δ13C and δ15N uncertainties associated with the compound-specific isotope analysis of geoporphyrins. Analytical Chemistry 92, 3152-3160. isotope analyses of geoporphyrins, which are derivatives of chloropigments possessed by phototrophs, provide essential records of the biogeochemical cycle of past aquatic environments. Here, we evaluated uncertainties in carbon and nitrogen isotopic compositions (δ13C and δ15N) associated with high-performance liquid chromatography (HPLC) purification and isotopic measurements of geoporphyrins. Evaluation of total blank carbon and nitrogen for the HPLC and our sensitivity-improved elemental analyzer/isotope ratio mass spectrometer (nano-EA/IRMS) analysis confirmed that blank carbon can be corrected and that blank nitrogen is negligible compared to the mass of geoporphyrins required for the isotopic measurement. While geoporphyrins exhibited substantial in-peak carbon and nitrogen isotopic fractionations, no systematic changes in δ13C and δ15N values were observed during reversed- and normal-phase HPLC isolation of Ni- and VO-porphyrin standards, with the changes in δ13C and δ15N values being within ±0.6‰ and ±1.2‰ (2σ), respectively. These values are comparable to the instrumental precision of the nano-EA/IRMS system (±1.3‰ for 0.70 μgC and ±1.1‰ for 0.08 μgN, 2σ), confirming that no substantial artifact in the δ13C and δ15N values would be expected during the reversed- and normal-phase HPLC purification. The sensitivity and precision of our method enable us to determine δ13C and δ15N values of both major and minor geoporphyrins found in ancient sediments, which would provide detailed information on the photosynthetic primary producers and the carbon and nitrogen cycles in the past.Isson, T.T., Planavsky, N.J., Coogan, L.A., Stewart, E.M., Ague, J.J., Bolton, E.W., Zhang, S., McKenzie, N.R., Kump, L.R., 2020. Evolution of the global carbon cycle and climate regulation on Earth. Global Biogeochemical Cycles 34, e2018GB006061. existence of stabilizing feedbacks within Earth's climate system is generally thought to be necessary for the persistence of liquid water and life. Over the course of Earth's history, Earth's atmospheric composition appears to have adjusted to the gradual increase in solar luminosity, resulting in persistently habitable surface temperatures. With limited exceptions, the Earth system has been observed to recover rapidly from pulsed climatic perturbations. Carbon dioxide (CO2) regulation via negative feedbacks within the coupled global carbon‐silica cycles are classically viewed as the main processes giving rise to climate stability on Earth. Here we review the long‐term global carbon cycle budget, and how the processes modulating Earth's climate system have evolved over time. Specifically, we focus on the relative roles that shifts in carbon sources and sinks have played in driving long‐term changes in atmospheric pCO2. We make the case that marine processes are an important component of the canonical silicate weathering feedback, and have played a much more important role in pCO2 regulation than traditionally imagined. Notably, geochemical evidence indicate that the weathering of marine sediments and off‐axis basalt alteration act as major carbon sinks. However, this sink was potentially dampened during Earth's early history when oceans had higher levels of dissolved silicon (Si), iron (Fe), and magnesium (Mg), and instead likely fostered more extensive carbon recycling within the ocean‐atmosphere system via reverse weathering—that in turn acted to elevate ocean‐atmosphere CO2 levels.Iudicone, D., 2020. Some may like it hot. Nature Geoscience 13, 98-99. biomass of some of the smallest ocean organisms may be stable or even increase in a warming world, suggests a data analysis based on machine-learning techniques.Every time we swim in the ocean, we perturb the life of millions of nearly invisible organisms. These organisms comprise bacteria, fungi, microscopic algae and other unicellular critters, as well as tiny crustaceans, jellyfish and larvae. This vibrant and varied ensemble of organisms, called plankton, supports most of the life in the ocean. Plankton are thus key to the provision of seafood for many other species, from walruses to humans. Moreover, plankton regulate the climate by modulating the atmospheric carbon content and, via photosynthesis, provide nearly half of the oxygen we breathe. Ocean warming as a result of climate change is expected to reduce the productivity of these vast communities, mostly by altering the supply of nutrients to the surface layer of the ocean that supports these life forms1. Writing in Nature Geoscience, Flombaum and colleagues2 propose that not all plankton will necessarily suffer in warming oceans: the abundance of some tiny algae and photosynthesizing bacteria, including the Earth’s prevailing primary producers, could remain unchanged or even increase in biomasses, according to niche model analyses applied to a global abundance dataset.That a closer examination of these natural phenomena may lead to unforeseen outcomes is not surprising. Phytoplankton, in particular, display a large variety of biological traits, and many of them interact or cooperate in various forms of symbioses. While transported by currents, plankton are subjected to continuous changes in their proximal, patchy environment because of turbulence or active swimming. They will always surprise us. For example, mixotrophs that combine photosynthesis and feeding on particles or dissolved substances — the oceanic equivalents of carnivorous plants (which are rare in the terrestrial realm) — may constitute the majority of phytoplankton in the oceans3.Understanding the functioning of plankton ecosystems is a challenge. This difficulty is exacerbated by the minuscule size of plankton, which limits our ability to scrutinize their broad diversity. Notably, only in the 1980s did the use of flow cytometry, a technique invented to count blood cells, allow the classification of picophytoplankton, the ensemble of photosynthetic organisms smaller than three microns. The general use of this technique, later on supported by genomic and genetic methods, led to the recognition that two cyanobacteria, Synechococcus and Prochlorococcus (Fig. 1), and several pico-eukaryotes4, are the most abundant photosynthetic organisms on Earth5.Flombaum and colleagues wondered what the influence of ocean warming on these picophytoplankton abundances might be. They used a machine-learning algorithm from an artificial intelligence (AI) computational framework to predict the global picophytoeukaryotic biomass and combined it with previous estimates for the cyanobacterial component. Specifically, they trained the AI algorithm to relate picophytoplankton biomass to environmental parameters, such as light and temperature, on a subset of data. They then derived the global distributions of these picophytoplankton, using global estimates for the same parameters. A similar approach has been used to estimate the biomasses of all the organisms on the planet, and surprisingly suggested, for example, that most of the planet’s biomass is found in plants on land whereas the oceans are dominated by animals6. Then they ran the trained algorithm with the future environmental conditions predicted by a climate model and derived the expected distributions with that change.Flombaum and colleagues’ assessment of present-day picophytoplankton biomass amounts to 0.55 gigatonnes of carbon (GtC), which is comparable to the biomass of all terrestrial animals6. Cyanobacteria prefer warmer waters, where they are the dominant carbon fixers. By contrast, the model predicts that in colder and more nutrient-rich waters, the tiny picophytoeukaryotes dominate within the picophytoplankton size class. As for the projections for the future, the bacteria were found to slightly increase under a high-emissions scenario for the rest of the century whereas the picophytoeukaryotes showed a globally neutral, more complicated pattern, with biomass reduction mainly in the mid-latitude regions, those predicted to attain more tropical characteristics in the future.These results contradict projections that predict lower phytoplankton biomass with ocean warming1,7. Importantly, Flombaum and colleagues thus wondered about possible mechanisms that may support the trained model predictions. They realized that higher temperatures might decrease cell nutrient requirements and favour recycling and longer nutrient retention in the ocean surface, which would allow for a biomass increase. Indeed, in the oceans, biomass consumers outnumber producers five to one6 (on land the ratio is one consumer per 22.5 producers6) and the recycling of nutrients is an important process. Prochlorococcus particularly live under close control of grazers and viruses, and most of the cells produced during the day are ingested at night by small flagellates and filter-feeders8,9, that ultimately release their nutrients in the water column.This daily wax and wane mimics what mid-latitude grasslands and forests experience over two seasons. Therefore, the dynamical equilibrium that controls biomass turnover results from many factors, including mixotrophy10. How a shift toward warmer, nutrient-depleted water will affect those factors is very difficult to predict. This point advocates for in-depth analyses of the trained machine-learning algorithms and corresponding models.More generally, a smaller amount of available nutrients and a poleward extension of the nutrient-poor regions, with patchy blooms for larger species due to more intense and frequent storms, is expected to promote a shift toward an even more critical relative dominance of the smallest organisms. This shift, in turn, could promote a higher abundance of filter-feeders, which are part of the diet of many fish, partly mitigating the overall impact of ocean warming on the marine food web. Overall, a shift in the composition and abundance of primary producers could have significant effects on the higher trophic levels (trophic amplification11), with implications for fisheries, for instance. Notably, Flombaum and colleagues’ analysis generally confirms lower biomass in the mid-latitudes of the Northern Hemisphere and in the coastal areas where productivity is highest.Flombaum and colleagues note that there are significant uncertainties in the ecological predictions at species or group level, which may require rethinking the way we do projections on the status of marine ecosystems. The mathematical equations that represent the central physical, chemical and biological processes in numerical models suffer from substantial simplifications. Specifically, estimates of the future phytoplankton composition based solely on the reduction of available nutrients is like guessing the population growth of a country only considering the efficiency in the use of food, while ignoring changes in births and deaths, immigration and emigration rates. Predictions based on a few environmental factors such as light and nutrients and AI tools may possibly work to spatially extrapolate the data12 but we lack the observations to definitely assess the uncertainties associated with the method, especially given that the current climate–ecosystem relationship may change13.Flombaum and colleagues emphasize the need for new approaches to ecological predictions. Innovative conventional and AI-based numerical models of the pelagic ecosystems should be implemented14. However, the remaining critical hurdle is the lack of biological and ecological knowledge of plankton in the moving seascape. In this context, AI techniques could be used to consider the full complexity and inherent uncertainties15 in order to gain a better understanding and thus prediction of the global ocean ecosystems.References1. Bopp, L. et al. Biogeosciences 10, 6225–6245 (2013).2. Flombaum, P., Wang, W.-L., Primeau, F. & Martiny, A. C. Nat. Geosci. (2020).3. Stoecker, D. K., Juel Hansen, P., Caron, D. A. & Mitra, A. Annu. Rev. Mar. Sci. 9, 311–335 (2017).4. Worden, A. Z. & Not, F. in Microbial Ecology of the Oceans 2nd edn (ed. Kirchman, D. L.) 159–205 (John Wiley & Sons, 2008).5. Biller, S., Berube, P., Lindell, D. & Chisolm, S. W. Nat. Rev. Microbiol. 13, 13–27 (2015).6. Bar-On, Y. M., Phillips, R. & Milo, R. Proc. Natl Acad. Sci. USA 115, 6506–6511 (2018).7. Agusti, S., Lubián, L. M., Moreno-Ostos, E., Estrada, M. & Duarte, C. M. Front. Mar. Sci. 5, 506 (2019).8. Ribalet, F. et al. Proc. Natl Acad. Sci. USA 112, 8008–8012 (2015).9. Zubkov, M. V. & Tarran, G. A. Nature 455, 224–226 (2008).10. Yelton, A. P. et al. ISME J. 10, 2946–2957 (2016).11. Lotze, H. K. et al. Proc. Natl Acad. Sci. USA 116, 12907–12912 (2019).12. Brun, P., Ki?rboe, T., Licandro, P. & Payne, M. R. Glob. Change Biol. 22, 3170–3181 (2016).13. Litzow, M. A. et al. Proc. R. Soc. B 285, 20181855 (2018).14. Coles, V. J. et al. Science 358, 1149–1154 (2017).15. Delahaye, B., Eveillard, D. & Bouskill, N. mSystems 2, e00169–17 (2017).Ivanovsky, R.N., Lebedeva, N.V., Keppen, O.I., Chudnovskaya, A.V., 2020. Release of photosynthetically fixed carbon as dissolved organic matter by anoxygenic phototrophic bacteria. Microbiology 89, 28-34. organic matter (DOM) release by anoxygenic phototrophic bacteria belonging to diverse taxonomic groups is a ubiquitous process, resulting in 5–20% of the CO2 fixed by photosynthesis leaving the cell. The green photosynthetic bacterium Chlorobaculum limnaeum releases ~10% of the carbon assimilated during autotrophic СО2 fixation. Extracellular DOM release by Cba. limnaeum is a normal function of living cells, since it does not occur in the dark and is inhibited by fluoroacetate, an inhibitor of СО2 fixation via the reducing TCA acids cycle, which is used for CO2 assimilation in this bacterium. In the presence of acetate or pyruvate in the medium, DOM release increases to 30 and 60%, respectively. Nitrogen limitation stimulates DOM release by Cba. limnaeum up to 60% of assimilated СО2. Under these conditions, addition of acetate results in DOM release increasing up to 100%. Therefore, the extracellular release of DOC by anoxygenic phototrophic bacteria can be considered as an important source of substrates for the growth of heterotrophic bacteria in oxygen-free aquatic ecosystems.Jaramillo, R., Dorman, F.L., 2020. Retention time prediction of hydrocarbons in cryogenically modulated comprehensive two-dimensional gas chromatography: A method development and translation application. Journal of Chromatography A 1612, 460696. modeling of GC?×?GC separations provides a tool for rapid method evaluation and optimization. Separations of 95 hydrocarbons on two cryogenically modulated GC?×?GC systems (atmospheric outlet and vacuum outlet) are modeled, displaying average second dimension retention time modeling absolute errors of 0.17?s and 0.12?s respectively, and generating modeled chromatograms which sufficiently represent experimental data. A web-based GC?×?GC modeling routine is presented which allows users to model separations, currently focused on hydrocarbons, with full control over all system parameters. The method translation capabilities of the application are further demonstrated by replicating Piotrowski et al.’s GC?×?GC-HRT temporal distribution plots of hydraulic fracturing flowback fluid hydrocarbons [28].Javadi, T., Farajmand, B., Yaftian, M.R., Zamani, A., 2020. Homogenizer assisted dispersive liquid-phase microextraction for the extraction-enrichment of phenols from aqueous samples and determination by gas chromatography. Journal of Chromatography A 1614, 460733. this research, dispersive liquid-phase microextraction has been used for the extraction of some phenols including phenol, 3-methylphenol, 4-nitrophenol, 2-chlorophenol, tert-buthylphenol from aqueous samples, and then the analysis was done by the gas chromatography-flame ionization detector technique. For the first time, a laboratory homogenizer has been applied for dispersing of extracting organic solvent. To improve the chromatographic behavior, acetic anhydride was used as a derivatization reagent of the analytes. The effective parameters on the extraction and derivation process such as extraction solvent type and volume, amount and time of derivatization, sample pH and ionic strength, homogenization time and speed were investigated and optimized. The analytical performances of the method, such as linear dynamic range, repeatability, and detection limit were evaluated under the optimum condition. Under the optimal experimental conditions, the calibration plots were linear the range of 1–500?μg L?1 with the detection limits between 0.1–0.9?μg L?1, and the repeatability in the range of 2.6 to 10.0%. These values vary depend on the compounds. The proposed method was evaluated for the determination of the studied phenolic compounds in different real samples such as river water, tap water and industrial wastewater. The relative recoveries were between 90 and 111%.Jellinek, A.M., Lenardic, A., Pierrehumbert, R.T., 2020. Ice, fire, or fizzle: The climate footprint of Earth's supercontinental cycles. Geochemistry, Geophysics, Geosystems 21, e2019GC008464. assembly and breakup can influence the rate and global extent to which insulated and relatively warm subcontinental mantle is mixed globally, potentially introducing lateral oceanic‐continental mantle temperature variations that regulate volcanic and weathering controls on Earth's long‐term carbon cycle for a few hundred million years. We propose that the relatively warm and unchanging climate of the Nuna supercontinental epoch (1.8–1.3 Ga) is characteristic of thorough mantle thermal mixing. By contrast, the extreme cooling‐warming climate variability of the Neoproterozoic Rodinia episode (1–0.63 Ga) and the more modest but similar climate change during the Mesozoic Pangea cycle (0.3–0.05 Ga) are characteristic features of the effects of subcontinental mantle thermal isolation with differing longevity. A tectonically modulated carbon cycle model coupled to a one‐dimensional energy balance climate model predicts the qualitative form of Mesozoic climate evolution expressed in tropical sea‐surface temperature and ice sheet proxy data. Applied to the Neoproterozoic, this supercontinental control can drive Earth into, as well as out of, a continuous or intermittently panglacial climate, consistent with aspects of proxy data for the Cryogenian‐Ediacaran period. The timing and magnitude of this cooling‐warming climate variability depends, however, on the detailed character of mantle thermal mixing, which is incompletely constrained. We show also that the predominant modes of chemical weathering and a tectonically paced abiotic methane production at mid‐ocean ridges can modulate the intensity of this climate change. For the Nuna epoch, the model predicts a relatively warm and ice‐free climate related to mantle dynamics potentially consistent with the intense anorogenic magmatism of this period.Ji, H., Han, J., Xue, J., Hatten, J.A., Wang, M., Guo, Y., Li, P., 2020. Soil organic carbon pool and chemical composition under different types of land use in wetland: Implication for carbon sequestration in wetlands. Science of The Total Environment 716, 136996. study was conducted to understand how different wetland vegetation-land use types influenced the storage and stability of soil organic carbon (SOC) in surface soils. We determined the concentration and chemical composition of SOC in both density (including light fraction organic carbon (LFOC) and heavy fraction organic carbon (HFOC)) and particle size fractions (including <2 μm, 2–63 μm, 63–200 μm and 200–2000 μm) in four wetland land use types covered with different vegetation: lake-sedge, reed, willow and poplar wetlands. Results showed that the concentrations and stock of SOC and LFOC in willow and poplar wetlands were significantly higher than those in lake-sedge and reed. However, a higher proportion of alkyl-C and a lower proportion of O-alkyl-C were observed in lake-sedge and reed wetlands than in willow and poplar, suggesting that accumulated C in willow and poplar wetlands was less stable than that in lake-sedge and reed. For all particle-size fractions except the silt (2–63 μm), the SOC concentrations were highest in willow and lowest in reed wetland surface soils, while their alkyl-C/O-alkyl-C (A/O-A) and hydrophobic-C/hydrophilic-C ratios progressively decreased from lake-sedge and reed wetland surface soils to poplar and willow surface soils. Moreover, the ratios of A/O-A and hydrophobic-C/hydrophilic-C in surface soils generally decreased with increasing concentrations of SOC in particle-size fractions, with these stability indexes being lowest in the largest particle-size fraction. These results indicate that the wetland vegetation-land use types that could incorporate more C into finer particle-size fractions had a greater potential for sequestering more stable C in such wetland ecosystems. Different wetland vegetation-land use types resulted in significant changes in the concentration and chemical structure of SOC, which could affect soil C sequestration and dynamics, C cycling in wetland ecosystems. Although both willow and poplar forests could increase SOC stock, the stability of SOC in willow wetland was higher. Therefore, on balance (stock and stability) the land use of wetland for willow forest could be a more promising way for enhancing soil C sequestration in wetlands.Ji, W., Hao, F., Song, Y., Tian, J., Meng, M., Huang, H., 2020. Organic geochemical and mineralogical characterization of the lower Silurian Longmaxi shale in the southeastern Chongqing area of China: Implications for organic matter accumulation. International Journal of Coal Geology 220, 103412. in organic matter, the lower Silurian Longmaxi shale in the Upper Yangtze Platform, South China, has been demonstrated to play important roles in the petroleum system as both a good source rock and a shale gas reservoir. In order to better understand the heterogeneous organic matter accumulation of such shales in the southeastern Chongqing area, the vertical variations of total organic carbon (TOC) contents, mineral concentrations and biomarker distributions were systematically analyzed in this study. The Longmaxi Formation consists of fine-grained siliciclastic rocks deposited in a restricted marine shelf environment, and it can be further subdivided into two members. The lower member is enriched in TOC, whereas a diminished TOC content is documented in the upper member. Laterally, the TOC content gradually drops southeast-ward in the study area. The mineralogical compositions, dominated by quartz and clay, and, to a lesser extent, feldspar and carbonate, show good correlations with TOC contents vertically, especially in the lower member. Saturated and aromatic hydrocarbon biomarkers indicate a dominant organic matter origin from lower hydrobionts (algae and bacteria) in a reducing marine environment. Negative correlation relationships between TOC contents and terrigenous clastic minerals indicate the predominant role of dilution of terrigenous clastic materials in controlling the organic matter accumulation. The sea level drop combined with the continuously active Xuefeng Uplift contributed to more terrigenous clastic inputs into the study area, which resulted in a significant reduction of TOC content in the upper Longmaxi member.Jia, L., Cao, C., Cheng, Z., Wang, J., Huang, J., Yang, J., Pan, Y., Xu, M., Wang, Y., 2020. Ex situ catalytic pyrolysis of algal biomass in a double microfixed-bed reactor: Catalyst deactivation and its coking behavior. Energy & Fuels 34, 1918-1928. catalytic fast pyrolysis (CFP) of algal biomass was conducted in a newly developed double microfixed-bed reactor. Real-time measurements of catalytic vapors as a function of the cumulative biomass-to-catalyst ratio (BCR) could be achieved by means of a single photoionization mass spectrometer. The coked zeolites were characterized by various methods. During the catalytic conversion of algal biomass, products would tend to be classified into three different types based on their conversion (or formation) efficiency in CFP at the given BCR. More importantly, it was inferred that the “step-1”, which had been defined in the CFP of lignocellulosic biomass and would cause the catalyst coking, was lacking in the upgrading processes of algae-based pyrolysis vapors, probably due to the catalytic effect of minerals in algal biomass. This indicates the fact that algal biomass (especially for Sargasso) could be potentially an ideal feedstock to obtain valuable products via CFP. Furthermore, the mass per injection was proven to be an important factor to influence the accessibility of HZSM-5 catalyst due to the “traffic jam” when the primary volatiles enter the zeolite pores.Jia, Z., Niu, Z., Yang, Z., Li, X., Wang, J., He, X., Sui, H., He, L., 2020. Interfacial behaviors of ionic liquid cations and asphaltenes at oil–water interface: Dynamic diffusion and interfacially competitive adsorption. Energy & Fuels 34, 1259-1267. ionic liquids (ILs) are reported to perform well in enhancing the oil–solid separation (in pure state or in solution) and oil–water separation (in solution) processes through interfacial alteration. Herein, the interfacial behaviors of IL ([C8mim][Br], [C10mim][Br], and [C12mim][Br]) cations and asphaltenes (from Indonesian asphalt) at the oil–water interface have been investigated through dynamic and equilibrium characterizations. The dynamic interfacial tensions (DIFTs) of toluene–water systems with and without the addition of ILs and asphaltenes are measured. It is found that both IL cations and asphaltenes could diffuse from bulk solution to the oil–water interface quickly, resulting in a competitive adsorption and accumulation at the interface. The IL cations show faster diffusion ability and stronger interfacial adsorbability compared with the asphaltenes. The π-A isotherms and atomic force microscopy (AFM) surface probing of the spreading protocol and the diffusion protocol show that the IL cations could protect the formation of a continuous cross-network, destroying the interfacial asphaltene film. There is also evidence that the efficiency of the interfacial alteration by IL cations is highly dependent on IL cation type. The above results are further understood by the COSMOthermX simulation. These findings suggest that the IL cations show stronger dynamic diffusion and interfacial adsorption properties compared with asphaltenes.Jiang, D., Ke, Y., Cai, J., Zhang, H., Fu, Q., Jin, Y., Liang, X., 2020. Evaluation of a series of phenyl-type stationary phases in supercritical fluid chromatography with the linear solvation energy relationship model and its application to the separation of phenolic compounds. Journal of Chromatography A 1614, 460700. recent years, supercritical fluid chromatography (SFC) has become a powerful tool in modern analytical chemistry, and the diversity of stationary phases in SFC promotes phenyl-type phases to confront with a significant resurgence of interest. In this paper, a series of phenyl-type stationary phases with different substituted benzenes involving N-propylbenzamide (PB), 4-fluoro-N-propylbenzamide (PB-F), and 4-ethyl-N-propylbenzamide (PB-ET) were synthesized. Retention mechanism of these phases in SFC was investigated using a linear solvation energy relationship (LSER) model. The phenyl-type stationary phases with all positive parameters can provide all types of interaction, typically involving hydrogen bonding, dipole-dipole and dispersive interactions. The different benzene's substituents of the stationary phases mainly affected their hydrogen bonding and dipole-dipole interactions, which could be reflected by the angle between the solvation vectors to some extent. The k-k plot showed that the selectivity difference of phenyl-type stationary phases was closely related to the type of solute. Thus, based on twenty-five natural phenolic compounds, two systems with high orthogonality (63.49%) were constructed using three columns, namely phenyl column (PHE) × PB-F and PB × PB-F. Finally, after investigating the influence of chromatographic conditions, ten flavonoids could be separated by using PB, PB-F and PHE columns in SFC.Johnson, S.S., Millan, M., Graham, H., Benison, K.C., Williams, A.J., McAdam, A., Knudson, C.A., Andrejkovi?ová, S., Achilles, C., 2020. Lipid biomarkers in ephemeral acid salt lake mudflat/sandflat sediments: Implications for Mars. Astrobiology 20, 167–178. strata on Mars often contain a mix of sulfates, iron oxides, chlorides, and phyllosilicates, a mineral assemblage that is unique on Earth to acid brine environments. To help characterize the astrobiological potential of depositional environments with similar minerals present, samples from four naturally occurring acidic salt lakes and adjacent mudflats/sandflats in the vicinity of Norseman, Western Australia, were collected and analyzed. Lipid biomarkers were extracted and quantified, revealing biomarkers from vascular plants alongside trace microbial lipids. The resilience of lipids from dead organic material in these acid saline sediments through the pervasive stages of early diagenesis lends support to the idea that sulfates, in tandem with phyllosilicates and iron oxides, could be a viable target for biomarkers on Mars. To fully understand the astrobiological potential of these depositional environments, additional investigations of organic preservation in ancient acidic saline sedimentary environments are needed. Jones, R.M., D’Angelo, T., Orcutt, B.N., 2020. Using cathodic poised potential experiments to investigate extracellular electron transport in the crustal deep biosphere of North Pond, Mid-Atlantic Ridge. Frontiers in Environmental Science 8, 11. doi: 10.3389/fenvs.2020.00011. crustal sub-seafloor covers a large portion of the Earth’s surface but is poorly understood as a habitat for life. It is unclear what metabolisms support the microscopic cells that have been observed, and how they survive under resource limitation. As the deep crustal subsurface represents a significant portion of the Earth’s surface, microbially mediated reactions may therefore be significant contributors to biogeochemical cycling. In the present study, we used electrochemical techniques to investigate the possibility that crustal subsurface microbial groups can use the solid rock matrix (basalts, etc.) as a source of electrons for redox reactions via extracellular electron transfer (EET). Subsurface crustal fluids and mineral colonization experiments from the cool and oxic basaltic crustal subsurface at the North Pond site on the western flank of the Mid-Atlantic Ridge were used as inocula in cathodic poised potential experiments. Electrodes in oxic microbial fuel cells (MFCs) were poised at ?200 mV versus a standard hydrogen electrode to mimic the delivery of electrons in an energy range equivalent to iron oxidation. In this way, microbes that use reduced iron in solid minerals for energy were selected for from the general community onto the electrode surface for interrogation of EET activity, and potential identification by scanning electron microscopy (SEM) and DNA sequencing. The results document that there are cathodic EET-capable microbial groups in the low biomass crustal subsurface at this site. The patterns of current generation in the experiments indicate that these microbial groups are active but likely not growing under the low-resource condition of the experiments, consistent with other studies of activity versus growth in the deep biosphere. Lack of growth stymied attempts to determine the phylogeny of EET-capable microbial groups from this habitat, but the results indicate that these microbial groups are a small part of the overall crustal deep biosphere community. This first demonstration of using electromicrobiology techniques to investigate microbial metabolic potential in the crustal deep biosphere reveals the challenges and opportunities for studying EET in the crustal deep biosphere.Junot, C., Fenaille, F., 2019. Chapter 11 - Metabolomics using Fourier transform mass spectrometry, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 325-356. metabolome is the set of small molecular mass compounds found in biological media, and metabolomics, which refers to as the analysis of metabolome in a given biological condition, deals with the large scale detection and quantification of metabolites in biological media. The metabolome is characterized by a large number of molecules exhibiting a high diversity of chemical structures and abundances, requiring complementary analytical platforms for extensive coverage. Among them, atmospheric pressure ionization Fourier transform mass spectrometry (FT/MS) instruments are now very popular because they provide accurate mass measurements with ppm and even sub-ppm errors, high and ultra-high resolving power, and also the possibility to perform MSn experiments for annotation and identification of metabolites. This chapter deals with the improvements provided by the different kinds of FT/MS instruments for metabolomics, together with their ability to cover the various analytical needs for metabolomics, from global metabolite profiling to structural characterization of compounds. The specificities of FT/MS in terms of data pre-processing and the input of accurate mass measurements for biological interpretation are also addressed.Kahn, J.S., Minevich, B., Gang, O., 2020. Three-dimensional DNA-programmable nanoparticle superlattices. Current Opinion in Biotechnology 63, 142-150. recent decades, there have been considerable efforts made in the design and synthesis of materials comprised of functional nanoscale particles. However, there is an increasing need to establish platform approaches for creating large-scale three-dimensional (3D) organizations from these particles, with the ability to control and prescribe ordered structures. The use of DNA, as a means of programming interactions between nanocomponents, provides powerful and tailorable means for the rational self-assembly of nanomaterials. The assembly pathway and assembled phases are highly dependent on both particle shape and interparticle interactions, governed by particle DNA coronas, binding modes, or linking mediators capable of complex topologies. This review highlights and discusses recent significant advancements in the field, as well as offers outlook towards future paths in the assembly of the DNA programmable three-dimensional nanoparticle superlattices.Kallistova, A.Y., Savvichev, A.S., Rusanov, I.I., Pimenov, N.V., 2019. Thermokarst lakes, ecosystems with intense microbial processes of the methane cycle. Microbiology 88, 649-661. lakes are formed as a result of thawing of ice-rich permafrost, causing development of land depressions which in flat areas are filled with water in the case of positive water balance. Activation of the thermokarst process is one of the possible indicators of permafrost degradation under the conditions of global warming. Thermokarst lakes occur in the areas of continuous, discontinuous, and sporadic permafrost, i.e., in Siberia, Alaska, Canada, and northern Scandinavia. Specific microbial communities adapted to long-term exposure to low temperatures develop in such lakes. They vary in the rates of aerobic and anaerobic metabolism depending on the mineral composition of bottom sediments, availability of organic matter, limnological and hydrological features of the lakes. High rates of methane emission are characteristic of a number of thermokarst lakes. Recent studies of thermokarst lakes revealed active methane formation via various methanogenic pathways, as well as aerobic and anaerobic methane oxidation by diverse methanogenic and methanotrophic bacteria and archaea. The question of what mechanisms and microorganisms are involved in anaerobic methane oxidation, which may be responsible for up to 80% of methane consumption in thermokarst lakes, remains, however, open. The microorganisms actively functioning beneath the ice during the long winter season, while highly important for northern aquatic ecosystems, also remain insufficiently studied. Almost no serious microbiological research on thermokarst lakes has been carried out in Russia, although permafrost occupies up to 65% of its territory, thermokarst process is common, and thermokarst lakes are numerous.Kalmychkov, G.V., Egorov, A.V., Hachikubo, A., Khlystov, O.M., 2019. Hydrocarbon gases of the Gorevoi Utes underwater oil-gas seep (Lake Baikal, Russia). Russian Geology and Geophysics 60, doi: 10.15372/RGG2019110. investigated the molecular and stable isotope compositions of hydrocarbon gases of the Gorevoi Utes oil-gas seep (Lake Baikal) characterized by a simultaneous discharge of oil and gas from the lake floor. It has been found that these hydrocarbon gases are mostly thermogenic methane (δ13С-С1 = -53.9 to -38.8‰; δ13С-С2 = -23.4 to -33.3‰). At the same time, the gases have a minor amount of С2+, seldom reaching 10%. The С1/С2+ value varies from 9 to 2700, with the average value being 807, which is atypical of petroleum hydrocarbons. We suggest that degassing of oil leaking to the lake floor affects the molecular composition of such gases. Some secondary processes, primarily molecular fractionation of gas during its migration into the subsurface sediments and anaerobic biodegradation of methane homologues, contribute to the decrease in С2+ content.Kalyuzhnaya, M.G., Kumaresan, D., Heimann, K., Caetano, N.S., Visvanathan, C., Karthikeyan, O.P., 2020. Editorial: Methane: A bioresource for fuel and biomolecules. Frontiers in Environmental Science 8, 9. doi: 10.3389/fenvs.2020.00009. (CH4), a highly reduced C1 compound, is one of the long-lived atmospheric gases with high global warming potential i.e., 28–36 times that of CO2 over 100 years. The atmospheric levels of CH4 reached ~1863 part per billions (ppb) in 2014, and annual increase of atmospheric CH4 level thereafter measured as ~10 ppb. The CH4 is projected to drive the rise in global temperature of ~4–6°C by 2050, and thus it is currently considered as the main target for global climate stabilization and mitigation (COP-21, 2015). Capturing anthropogenic CH4 to produce value products is highly feasible, but the great challenge is that to tap, concentrate, purify, store, transport, and utilize the CH4 from different point emission sources is presently not economically viable.In this special issue, a conceptual model of “Methane-Biorefinery Hub” is proposed as a sustainable development to mitigate the CH4 emissions from the most significant anthropogenic sources. The idea of “Methane-Biorefinery Hub” is deeply rooted in natural CH4 production and consumption processes (Figure 1). While in general, with a few exceptions, the natural CH4 cycle is balanced, the anthropogenic disturbances have typically led to increase the CH4 emissions. Thus, better understanding of mechanisms that control CH4 cycle in nature can be used to engineer better systems in human-built environments. For example, Holmes et al.. established that the bacteria (donors) and archaea (acceptors) communicate through nano-wires or electron transfer molecules i.e., the electrons transfer through e-pili (i.e., direct interspecies electron transfer), while protons diffusion (direct interspecies hydrogen transfer) is regulated by the partial pressure of the bioreactor system. Mimicking natural processes in laboratory/pilot-scale bioreactors that are designed to optimize specific operational conditions to regulate such communication may lead to successful implementation of technology to effectively utilize the waste materials e.g., municipal solid waste, food waste, industrial organics and wastewaters, or low-grade coals with/without the aid of external carbon/electron sources to produce CH4 as bio-energy, as shown by Yang et al. As pointed out by Wojcieszak et al., well-balanced microbial consortium are crucial for efficient biogas production, and inoculum sampled from typical methanogenic environments can be gradually adapted to industrial installations to allow effective biogas production. Addition of microbial supplements, metals/nutrients, organic sources (Zaldívar Carrillo et al.), electron conductive materials or electrodes, and altering the head-space gas composition (and partial pressure) are proposed as options for facilitating electron transfer and microbial interactions, while it may also change the equilibrium between dissolved vs. gas phase CH4 concentrations within the system.Another unique approach for recovering dissolved CH4 using degassing membrane contactors was proposed by Velasco et al.. While still at the stage of infancy, this unique technology highlights limitless opportunities for innovative approaches in CH4 capturing. If not recovered effectively, the dissolved CH4 and manipulating conditions may be expected to fuel the anaerobic methane oxidizers (ANME), and also sulfate reducing bacteria (SRB), to thrive and compete with methanogens for electrons/protons that may lead to low CH4 yield. The ANME possess a reverse methanogenesis process, i.e., utilizing CH4 (and CO2) as carbon sources to produce acetate or other products. On the other hand SRB compete with methanogens for similar substrates or electron donors. So, there may not be a competition between SRB and ANME for substrate, but it required investigation. On the other hand, the industrial applications of ANME are challenging, and still limited by the number of unresolved biochemical questions. However, an example of how a solid understanding of enzyme kinetics and energy transfer between the microbial communities can be used to manipulate the operating conditions to either facilitate or eliminate methane production was presented by Grisewood et al.. Alternatively, establishment of co-cultures of methanogens and ANME to produce value chemicals from anaerobic digestion processes was proposed and validated using a newly developed mathematical model by Nazem-Bokaee and Maranas, which, however, still relies on the electron coupling theory. Once fully understood, the ANME-based approach could be a viable option for reducing CH4 emissions from natural settings, while aerobic oxidation is recommended for industrial-scale organic digestion facilities.The aerobic CH4 oxidization process is easily coupled with digesters, while the process can yield a number of value products such as polymers, organic acids, single cell protein (SCP), compatible solutes, short/long chain fatty acids, omega fatty acids, vitamins, methanol, formate, etc. Methanotrophs are classified into Group I and Group II based on their physiology. Group I methanotroph e.g., Methylococcus capsulatus (Bath) is reported to produce SCP, while Group-II methanotrophs (e.g., Methylosinus trichosporium OB3b) are capable of accumulating biopolymers/SFA/LFA from CH4. An example of coupled production is highlighted by the work of Henard et al.. Metabolic modeling can further impower application of natural CH4 consuming bacteria, as exemplified by Lieven et al.. While it is widely acknowledged that the natural capacities of microbial systems (as axenic or mixed cultures) in CH4-consumption and accumulation of value products are governed by a number of factors e.g., carbon, nutrients, and metals, we are only now applying the knowledge for improving their industrial potential. Further, an example of how nitrogen starvation activates polyhydroxyalkanoate accumulation and alters the fatty acid compositions in biomass is provided by Tays et al.. The metal-switch impacts on the key enzyme activities, kinetics, the internal electron pool, and the carbon flux e.g., are described in the work by Akberdin et al..Nevertheless, the industrial applications and innovations remain to be challenged by long-standing fundamental questions regarding CH4 biocatalysts; including: (a) source of electron donors for CH4 activation as well as electron acceptors for process intensification; (b) regulation of contaminations or development of efficient strategies for controlling natural communities or synthetic co-cultures; (c) improved genetic traceability of methanotrophs in a mixed consortium and (d) coupling of CH4-conversion potential with efficient nitrogen fixation and denitrification. We would like to acknowledge significant progress in developing systems biology toolbox for manipulating methanotrophic bacteria, as well as new advances in overcoming technological bottlenecks related to CH4 mass-transfer limitation. Yet, some challenges still remain. New developments highlight additional need for further research, specifically in areas of O2-capturing, cell immobilization, CH4 and CO2 conversion by coculture of methanotrophs and algae/methylotrophs, coupling CH4 conversion and electrocatalysis. Algae and methanotrophs exchange nutrients during co-culturing are beneficial, while methylotrophs helps to alleviate any methanol toxicity.The papers published in this special issue confirm that CH4 emission/production is related to the microbiomes of the system, which are easy to be manipulated through biological/chemical augmentation methods. By coupling CH4 production with either ANME or methanotrophs, emissions could be significantly reduced and high-value products could be recovered through an integrated “Methane-Biorefinery” approach. Interestingly, in the work by Burton et al. it was concluded that the aerobic methanotrophs, methylotrophs and methanogenic archaea found to have common lineage i.e., use tetrahydromethanopterin (H4MPT) and/or tetrahydrofolate (H4F) as coenzymes in one-carbon (C1) transfer pathways that have been overlooked in the past and the relationships need to be well-studied for harnessing the benefits under “Microbiome” theory.Kanawati, B., Wanczek, K.P., Schmitt-Kopplin, P., 2019. Chapter 6 - Data processing and automation in Fourier transform mass spectrometry, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 133-185. resolution mass spectrometers produce large amount of MS and MS/MS spectra, whose interpretations may not be easy even for experts in this field. Noise among other interfering problems (such as chemical background, side lobes, side bands, multiple harmonics) gather in those spectra and make them complex. Moreover, all physical characteristics (resolution, peak shape, signal to noise ratio and signal intensity) of mass spectra originate and are actually derived from their corresponding frequency spectra, which are generally obtained by applying Fourier transform to time domain detected transients. In this chapter, several data processing techniques will be discussed for obtaining magnitude and absorption modes frequency spectra and a review of most important mass calibration equations will be discussed in great detail. De-noising, peak alignment, sum formula calculations and batch processing of FTMS spectra will also be discussed in this chapter. Moreover, automation of FT-ICR mass spectrometers is reviewed here and the author illustrates in this chapter a hand-on technical experience for achieving a successful full automation of the 12T FT-ICR mass spectrometer in Helmholtz Zentrum München metabolomics research laboratory, which could greatly enhance the productivity, by efficiently running in unattended mode on 24h basis. We selected over 135 related references in signal processing and automation in an attempt to provide a comprehensive guidance to mass spectrometry scientists.Kashinath, A., Szulczewski, M., Dogru, A.H., 2020. Modeling the effect of maturity on the elastic moduli of kerogen using atomistic simulations. Energy & Fuels 34, 1378-1385. mechanical properties of kerogen, the organic constituent of shale source rocks, change as it becomes progressively buried under sediment over geologic time. While these changes are due to both mechanical and chemical mechanisms, the individual impact of these mechanisms is poorly understood. In this work, we use atomistic models to isolate how the elastic properties of kerogen change with maturity. Our results show that increases in kerogen density upon burial are accommodated by proportional increases in the stacking of polyaromatic islands present in its structure. The increased stacking leads to the formation of π–π stacking bonds, which correlates to the increases in the elastic moduli. These results are useful for several reasons. First, they provide an estimate of Poisson’s ratio for kerogen over a range of densities and maturities. Second, the results demonstrate how atomistic modeling can be applied to gain new insight into the relationship between kerogen structure and its mechanical properties. Third, the agreement between the elastic moduli measured via simulation and experiment shows that atomistic methods can be utilized to accurately characterize kerogen, which is important for building accurate rock models for hydraulic fracturing simulation.Kashirtsev, V.A., Parfenova, T.M., Moiseev, S.A., Chernykh, A.V., Novikov, D.A., Burshtein, L.M., Dolzhenko, K.V., Rogov, V.I., Mel’nik, D.S., Zueva, I.N., Chalaya, O.N., 2019. The Sukhana sedimentary basin, Siberian Platform: Source rock characterization and direct evidence of oil and gas presence. Russian Geology and Geophysics 60, doi: 10.15372/RGG2019119. the known large natural bitumen accumulations and oil seeps in several kimberlite pipes along the periphery of the Sukhana sedimentary basin, interpreted as direct evidence of petroleum potential, the basin still remains one of the least studied (by geological and geophysical methods) regions of the Siberian Platform. The platform cover of the basin is composed by Riphean, Vendian, and Cambrian clastic (terrigenous) and carbonate deposits reaching 5.5-6 km in thickness in the central part of the basin. The hydrogeological specifics of the basin is largely governed by its location within the northern geocryological zone (Olenek cryoartesian basin) and is expressed as a continuous distribution of permafrost aggraded into the permafrost zone of unique thickness. Direct indicators of ore and gas presence are the East Anabar, Central Olenek, and Siligir-Markha fields of natural bitumen and oil shows in kimberlite pipes of the Daldyn-Alakit region (Udachnaya pipe). The bituminous-carbonate sediments of the Khatyspyt Formation (Vendian, Ediacaran) and the highly carbonaceous carbonate-siliceous-shaly sediments of the Kuonamka Formation (lower-middle Cambrian) are the Sukhana source rock complexes. The geochemically substantiated genetic relationship between the natural bitumen deposits of the East Anabar field and the organic matter of the Vendian Khatyspyt Formation makes it possible to estimate the area of the spread of the latter far to the west, beyond the axial part of the basin. Gammacerane, inherited from the organic matter of the Khatyspyt Formation and ranking as well-preserved and most characteristic biomarker of these bitumens, provides a compelling evidence of their consanguinity. The bitumen and oil of kimberlite pipes in the south of the basin, in the area of reefs of the Siligir-Markha bar, are similar in all geochemical criteria to oils of the Nepa-Botuobiya anteclise. In particular, in primary geochemical characteristics (12- and 13-monomethylalkanes, unique secosteranes, identical carbon isotope composition, etc.) the oils of the Udachnaya pipe are identical to the Irelyakh oils (oil field in the Mirnyi arch). No accumulations of oil or natural bitumen genetically related to the highly carbonaceous Kuonamka Formation have been found within the basin. At the same time, ?intraformational? shows of viscous oil, solid bitumen, and allochthonous bitumen (bitumen extracted with chloroform) were documented directly in the sections of the formation, which makes the sedimentary basin a very attractive target for ?shale oil? exploration. As for the regional assessment of the petroleum potential of the entire basin, its axial part (Sukhana depression) complicated by local uplifts is of the greatest interest. Both the Khatyspyt and Kuonamka Formations are widespread there, with the thermal maturity of their organic matter corresponding to the oil window. In addition, the regional reservoirs at the Vendian-Cambrian boundary have good petrophysical properties on both the western and the eastern flanks of the basin.Kayukova, G.P., Mikhailova, A.N., Kosachev, I.P., Emelyanov, D.A., Varfolomeev, M.A., Uspensky, B.V., Vakhin, A.V., 2020. The oil-bearing strata of Permian deposits of the Ashal’cha oil field depending on the content, composition, and thermal effects of organic matter oxidation in the rocks. Geofluids 2020, 6304547. features of the oil-bearing capacity of the productive strata of Permian deposits in the interval of 117.5-188.6?m along the section of individual wells of the Ashal’cha field of heavy superviscous oil (Tatarstan) were revealed depending on the content, composition, and thermal effects of organic matter (OM) oxidation in the rocks. It is shown that the rocks are very heterogeneous in their mineral composition and in the content of both free hydrocarbons by extraction with organic solvents and insoluble OM closely associated with the rock. The total content of OM in rocks varies from 1.72 to 9.12%. The features of group and hydrocarbon composition of extracts from rocks are revealed depending on their mineral composition and the content of organic matter in them. According to the molecular mass distribution of alkanes of normal and isoprenoid structure, extracts from rocks are differentiated according to three chemical types of oil: type A1, in which n-alkanes of composition C14 and above are present, and types A2 and B2, in which n-alkanes are destroyed to varying degrees by processes microbial destruction, which indicates a different intensity of biochemical processes in productive strata of Permian sediments. These processes lead to a decrease in the amount of OM in the rocks and an increase in the content of resins and asphaltenes in the oil extracted from them, as well as an increase in the viscosity of the oil. Using the method of differential scanning calorimetry of high pressure, it was found that the studied rock samples differ from each other in quantitative characteristics of exothermic effects in both low-temperature (LTO) 200-350°С and high-temperature (HTO) 350-600°С zones of OM oxidation. The total thermal effect of destruction processes of OM depends on the content of OM in the rocks and its composition. The research results show that when heavy oil is extracted using thermal technologies, the Permian productive strata with both low and high OM contents will be involved in the development, and the general thermal effect of the oxidation of which will contribute to increased oil recovery.Kazanenkov, V.A., Kurchikov, A.R., Plavnik, A.G., Shaporina, M.N., 2019. Geothermal conditions and petroleum potential of the Tyumen And Malyshevka formations of the West Siberian Basin. Russian Geology and Geophysics 60, doi: 10.15372/RGG2019013. paper considers present-day rock temperature distribution in the top of the Tyumen and Malyshevka Formations throughout the West Siberian sedimentary basin. A temperature variations map based on earlier and newly obtained data has been compiled for regional hydrocarbon reservoir Yu2. A forecast of the temperature variations in the Malyshevka Formation top has been made for the Arctic regions that have not been well studied with deep drilling. Analysis of hydrocarbon pools distribution within the Bathonian reservoir is presented.Kellner, C.M., Compton-Gore, K., Mayer, A.J., Sayre, M., Jennings, J., ?lvarez, W.Y., 2020. Comparing ritual foods and everyday diet from the Middle Horizon site of Tenahaha, Cotahuasi, Peru using stable isotope and macrobotanical analyses. Journal of Archaeological Science 115, 105095. populations actively chose what foods were used in different social and political contexts. Ritual meals may have included special foods or different preparation in contrast with quotidian meals. In this study, we compare plant remains with isotope values from human remains to understand food practices at the site of Tenahaha in the Cotahuasi Valley of highland Peru (CE 850–1050). Built in a time of rapid social change, Tenahaha was a local mortuary center where people stayed for a few days to bury their dead and celebrate ancestors. Most food and drink appear to have been prepared and consumed communally, in contrast to the more private dining practices typical in villages of the era. C3 foods such as quinoa, tubers, and molle were ubiquitous at the site, suggesting a diet heavy in C3 foods. In comparison, stable isotope analysis of individuals buried at Tenahaha shows a diet dominated by C4 plants (maize) and animal products that may have been foddered on maize. A more maize-centric diet was common by the Middle Horizon in the central Andean sierra, replacing diets dominated by C3 foods. Although taphonomic and sampling concerns must be taken into account, the emphasis on C3 foods seen macrobotanically at Tenahaha may reflect a desire to consume more traditional foods while honoring the dead.Keppler, F., Barnes, J.D., Horst, A., Bahlmann, E., Luo, J., Nadalig, T., Greule, M., Hartmann, S.C., Vuilleumier, S., 2019. Chlorine isotope fractionation of the major chloromethane degradation processes in the environment. Environmental Science & Technology 54, 1634-1645. (CH3Cl) is an important source of chlorine in the stratosphere, but detailed knowledge of the magnitude of its sources and sinks is missing. Here, we measured the stable chlorine isotope fractionation (εCl) associated with the major abiotic and biotic CH3Cl sinks in the environment, namely, CH3Cl degradation by hydroxyl (·OH) and chlorine (·Cl) radicals in the troposphere and by reference bacteria Methylorubrum extorquens CM4 and Leisingera methylohalidivorans MB2 from terrestrial and marine environments, respectively. No chlorine isotope fractionation was detected for reaction of CH3Cl with ·OH and ·Cl radicals, whereas a large chlorine isotope fractionation (εCl) of ?10.9 ± 0.7‰ (n = 3) and ?9.4 ± 0.9 (n = 3) was found for CH3Cl degradation by M. extorquens CM4 and L. methylohalidivorans MB2, respectively. The large difference in chlorine isotope fractionation observed between tropospheric and bacterial degradation of CH3Cl provides an effective isotopic tool to characterize and distinguish between major abiotic and biotic processes contributing to the CH3Cl sink in the environment. Our findings demonstrate the potential of emerging triple-element isotopic approaches including chlorine to carbon and hydrogen analysis for the assessment of global cycling of organochlorines.Khan, M.S.I., Oh, S.-W., Kim, Y.-J., 2020. Power of scanning electron microscopy and energy dispersive X-ray analysis in rapid microbial detection and identification at the single cell level. Scientific Reports 10, 2368. demand for rapid, consistent and easy-to-use techniques for detecting and identifying pathogens in various areas, such as clinical diagnosis, the pharmaceutical industry, environmental science and food inspection, is very important. In this study, the reference strains of six food-borne pathogens, namely, Escherichia coli 0157: H7 ATCC 43890, Cronobacter sakazakii ATCC 29004, Salmonella Typhimurium ATCC 43971, Staphylococcus aureus KCCM 40050, Bacillus subtilis ATCC 14579, and Listeria monocytogenes ATCC 19115, were chosen for scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis. In our study, the time-consuming sample preparation step for the microbial analysis under SEM was avoided, which makes this detection process notably rapid. Samples were loaded onto a 0.01-?m-thick silver (Ag) foil surface to avoid any charging effect. Two different excitation voltages, 10?kV and 5?kV, were used to determine the elemental information. Information obtained from SEM-EDX can distinguish individual single cells and detect viable and nonviable microorganisms. This work demonstrates that the combination of morphological and elemental information obtained from SEM-EDX analysis with the help of principal component analysis (PCA) enables the rapid identification of single microbial cells without following time-consuming microbiological cultivation methods.Kim, H., Kwon, S.Y., Lee, K., Lim, D., Han, S., Kim, T.-W., Joo, Y.J., Lim, J., Kang, M.-H., Nam, S.-I., 2020. Input of terrestrial organic matter linked to deglaciation increased mercury transport to the Svalbard fjords. Scientific Reports 10, 3446. has accelerated the transport of minerals as well as modern and ancient organic matter from land to fjord sediments in Spitsbergen, Svalbard, in the European Arctic Ocean. Consequently, such sediments may contain significant levels of total mercury (THg) bound to terrestrial organic matter. The present study compared THg contents in surface sediments from three fjord settings in Spitsbergen: Hornsund in the southern Spitsbergen, which has high annual volume of loss glacier and receives sediment from multiple tidewater glaciers, Dicksonfjorden in the central Spitsbergen, which receives sediment from glacifluvial rivers, and Wijdefjorden in the northern Spitsbergen, which receive sediments from a mixture of tidewater glaciers and glacifluvial rivers. Our results showed that the THg (52?±?15?ng?g?1) bound to organic matter (OM) was the highest in the Hornsund surface sediments, where the glacier loss (0.44 km3 yr?1) and organic carbon accumulation rates (9.3 ~ 49.4?g?m?2 yr?1) were elevated compared to other fjords. Furthermore, the δ13C (–27 ~ –24‰) and δ34S values (–10 ~ 15‰) of OM indicated that most of OM were originated from terrestrial sources. Thus, the temperature-driven glacial melting could release more OM originating from the meltwater or terrestrial materials, which are available for THg binding in the European Arctic fjord ecosystems.Kim, J., Franco, E., 2020. RNA nanotechnology in synthetic biology. Current Opinion in Biotechnology 63, 135-141. review recent advances in the design and expression of synthetic RNA sequences inside cells, to regulate gene expression and to achieve spatial localization of components. We focus on approaches that exploit the programmability of the secondary and tertiary structure of RNA to build scalable and modular devices that fold spontaneously and have the capacity to respond to environmental inputs.Kipp, M.A., Stüeken, E.E., Gehringer, M.M., Sterelny, K., Scott, J.K., Forster, P.I., Str?mberg, C.A.E., Buick, R., 2020. Exploring cycad foliage as an archive of the isotopic composition of atmospheric nitrogen. Geobiology 18, 152-166. nitrogen (N2) constitutes the majority of Earth's modern atmosphere, contributing ~0.79 bar of partial pressure (pN2). However, fluctuations in pN2 may have occurred on 107–109 year timescales in Earth's past, perhaps altering the isotopic composition of atmospheric nitrogen. Here, we explore an archive that may record the isotopic composition of atmospheric N2 in deep time: the foliage of cycads. Cycads are ancient gymnosperms that host symbiotic N2‐fixing cyanobacteria in modified root structures known as coralloid roots. All extant species of cycads are known to host symbionts, suggesting that this N2‐fixing capacity is perhaps ancestral, reaching back to the early history of cycads in the late Paleozoic. Therefore, if the process of microbial N2 fixation records the δ15N value of atmospheric N2 in cycad foliage, the fossil record of cycads may provide an archive of atmospheric δ15N values. To explore this potential proxy, we conducted a survey of wild cycads growing in a range of modern environments to determine whether cycad foliage reliably records the isotopic composition of atmospheric N2. We find that neither biological nor environmental factors significantly influence the δ15N values of cycad foliage, suggesting that they provide a reasonably robust record of the δ15N of atmospheric N2. Application of this proxy to the record of carbonaceous cycad fossils may not only help to constrain changes in atmospheric nitrogen isotope ratios since the late Paleozoic, but also could shed light on the antiquity of the N2‐fixing symbiosis between cycads and cyanobacteria.Kirkels, F.M.S.A., Ponton, C., Galy, V., West, A.J., Feakins, S.J., Peterse, F., 2020. From Andes to Amazon: Assessing branched tetraether lipids as tracers for soil organic carbon in the Madre de Dios River system. Journal of Geophysical Research: Biogeosciences 125, e2019JG005270.: We investigate the implications of upstream processes and hydrological seasonality on the transfer of soil organic carbon (OC) from the Andes mountains to the Amazon lowlands by the Madre de Dios River (Peru), using branched glycerol dialkyl glycerol tetraether (brGDGT) lipids. The brGDGT signal in Andean soils (0.5 to 3.5 km elevation) reflects air temperature, with a lapse rate of ?6.0 °C/km elevation (r2 = 0.89, p < 0.001) and ?5.6 °C/km elevation (r2 = 0.89, p < 0.001) for organic and mineral horizons, respectively. The same compounds are present in river suspended particulate matter (SPM) with a lapse rate of ?4.1 °C/km elevation (r2 = 0.82, p < 0.001) during the wet season, where the offset in intercept between the temperature lapse rates for soils and SPM indicates upstream sourcing of brGDGTs. The lapse rate for SPM appears insensitive to an increasing relative contribution of 6‐methyl isomer brGDGTs produced within the river. River depth profiles show that brGDGTs are well mixed in the river and are not affected by hydrodynamic sorting. The brGDGTs accumulate relative to OC downstream, likely due to the transition of particulate OC to the dissolved phase and input of weathered soils toward the lowlands. The temperature‐altitude correlation of brGDGTs in Madre de Dios SPM contrasts with the Lower Amazon River, where the initial soil signature is altered by changes in seasonal in‐river production and variable provenance of brGDGTs. Our study indicates that brGDGTs in the Madre de Dios River system are initially soil derived and highlights their use to study OC sourcing in mountainous river systems.Plain Language Summary: Rivers transport large amounts of carbon from soils to the ocean. However, following the route of carbon from mountains to river to sea is challenging in part due to the reactive nature of organic molecules in the environment. In this paper, we investigated the Madre de Dios (Peru), an upstream branch of the Amazon River, and identified carbon sources using temperature‐sensitive compounds. The expected correlation between altitude and temperature is found for soil and river material. The origin of river material is predominantly upstream soils and constant with river depth. Upon reaching the lowlands, input from weathered soils and lowland tributaries changed the compound distributions in the river main stem. Lowland soil input and/or in‐river microbial production become an increasingly important source and overprint the mountain‐sourced signal. Thus, the temperature‐sensitive compounds appear to be useful to study carbon sources in mountain watersheds. Furthermore, comparing our data (headwaters) with the downstream Amazon River shows that lowland soils and/or in river production seem to dominate the signal finally exported to the ocean.Kis, A., Tóth, K., Kanizsár, O., Topál, J., 2020. The effect of oxytocin on yawning by dogs (Canis familiaris) exposed to human yawns. Applied Animal Behaviour Science 223, 104916. studies have found that human yawning is contagious to dogs, but the results are still controversial. It is also debated whether contagious yawning is a sign of empathy, and the physiological mechanisms behind this phenomenon are also unknown. Our goal was to further investigate if human yawning is contagious to dogs, and how it is affected by intranasally administered oxytocin. We also tested if contagious yawning was related to dogs? empathetic skills measured via an owner-completed questionnaire. Dogs (N?=?33) were presented with human yawns (yawning condition – YC) or mouth openings (gaping condition – GC) on two test occasions after intranasal administration of 12 IU oxytocin or placebo. Contagious yawning (defined as a significant increase in the number of yawns in YC as compared to GC) was not found in either of the treatment groups and the number of yawns was not related to the owner-reported emotion contagion of the dogs. However, oxytocin pre-treatment significantly decreased the number of yawns in dogs (in general, but more particularly during the phase when human yawns and gaping were presented). Furthermore, there was a positive relation between signs of stress and anxiety (mouth licking) and the number of yawns (in general, but more particularly during the post phase when human yawns and gaping were not any more presented). We conclude that dogs’ yawning observed in this situation may largely be due to situational stress. Thus the difference between the oxytocin and the placebo group is possibly caused by the decreased social stress and not by oxytocin’s hypothesised effect on empathy.Kitzinger, K., Marchant, H.K., Bristow, L.A., Herbold, C.W., Padilla, C.C., Kidane, A.T., Littmann, S., Daims, H., Pjevac, P., Stewart, F.J., Wagner, M., Kuypers, M.M.M., 2020. Single cell analyses reveal contrasting life strategies of the two main nitrifiers in the ocean. Nature Communications 11, 767., the oxidation of ammonia via nitrite to nitrate, is a key process in marine nitrogen (N) cycling. Although oceanic ammonia and nitrite oxidation are balanced, ammonia-oxidizing archaea (AOA) vastly outnumber the main nitrite oxidizers, the bacterial Nitrospinae. The ecophysiological reasons for this discrepancy in abundance are unclear. Here, we compare substrate utilization and growth of Nitrospinae to AOA in the Gulf of Mexico. Based on our results, more than half of the Nitrospinae cellular N-demand is met by the organic-N compounds urea and cyanate, while AOA mainly assimilate ammonium. Nitrospinae have, under in situ conditions, around four-times higher biomass yield and five-times higher growth rates than AOA, despite their ten-fold lower abundance. Our combined results indicate that differences in mortality between Nitrospinae and AOA, rather than thermodynamics, biomass yield and cell size, determine the abundances of these main marine nitrifiers. Furthermore, there is no need to invoke yet undiscovered, abundant nitrite oxidizers to explain nitrification rates in the ocean.Klenner, F., Postberg, F., Hillier, J., Khawaja, N., Reviol, R., Stolz, F., Cable, M.L., Abel, B., N?lle, L., 2020. Analog experiments for the identification of trace biosignatures in ice grains from extraterrestrial ocean worlds. Astrobiology 20, 179–189. identification of biosignatures, such as amino acids, fatty acids, and peptides, on extraterrestrial ocean worlds is a key prerequisite for space missions that search for life or its emergence on these worlds. One promising approach is the use of high-performance in situ impact ionization mass spectrometers to sample water ice grains emerging from ocean-bearing moons such as Europa or Enceladus. A predecessor of such detectors, the Cosmic Dust Analyzer on board the Cassini spacecraft, has proven to be very successful in analyzing inorganic and organic ocean constituents and with that characterizing the habitability of Enceladus ocean. However, biosignatures have not been definitively identified in extraterrestrial ocean environments so far. Here, we investigate with an analog experiment the spectral appearance of amino acids, fatty acids, and peptides in water ice grains, together with their detection limits, as applicable to spaceborne mass spectrometers. We employ a laboratory-based laser induced liquid beam ion desorption technique, proven to simulate accurately the impact ionization mass spectra of water ice grains over a wide range of impact speeds. The investigated organics produce characteristic mass spectra, with molecular peaks as well as clearly identifiable, distinctive fragments. We find the detection limits of these key biosignatures to be at the μM or nM level, depending on the molecular species and instrument polarity, and infer that impact ionization mass spectrometers are most sensitive to the molecular peaks of these biosignatures at encounter velocities of 4–6?km/s. Klimenko, A., Molinier, V., Bourrel, M., 2020. Mechanisms underlying the adhesion of crude oil to mineral surfaces: Relevance of oil-brine interactions. Journal of Petroleum Science and Engineering 190, 107036. wettability state of mineral surface relative to water and oil is a key factor for crude oil recovery from reservoirs. It appears particularly relevant to EOR by low salinity brine, where change towards water wettability is often presented as a crucial factor. The purpose of this paper is to demonstrate the importance of the adsorption onto the mineral surface of species extracted from crude oils by the aqueous phase. The transfer of endogenous oil species during oil-water contact is evidenced by Total Organic Carbon, pH, interfacial tension and surface tension measurements for three different crude oils. The impact of the presence of these species on the wettability state of solid surfaces (silica and carbonate) is studied by using n-octane as a probe liquid. Contact angle measurements, Washburn capillary rise and flotation tests were carried out to evidence the hydrophobation of the surface. Interfacial tension is systematically taken into account to interpret contact angle and capillary rise results by calculating the adhesion tension, a quantity of thermodynamic significance. The effect of changes of water composition (salinity, pH) on oil adhesion is carefully investigated, and the efficiency of low salinity brine to decrease the adhesion of oil to the substrate, i.e. to remove the organic species adsorbed onto the surface, is evaluated. The importance of running wettability measurements with synthetic brine previously equilibrated with the crude oil is demonstrated.Klump, J.V., Edgington, D.N., Granina, L., Remsen, C.C., 2020. Estimates of the remineralization and burial of organic carbon in Lake Baikal sediments. Journal of Great Lakes Research 46, 102-114. cores collected from several stations throughout Lake Baikal in water depths from 100 m off the Selenga River delta to the deepest basin of the lake (~1640 m), have been analyzed for sedimentary organic carbon, nitrogen, and the remineralized components in pore water. The organic carbon content of surface sediments generally varied from 2.3 to 3.2% by weight, and profiles typically showed an exponential decrease in both organic carbon and nitrogen in the upper 20–30 cm of the sediment column. Steady state models of organic matter diagenesis yield first order decomposition rate constants which range from 0.0009 to 0.022 y?1. The calculated residence times for the metabolizable fraction of the organic matter in these sediments increases roughly with increasing water depth and is on the order of 50–300 years. Pore water concentration profiles were determined for dissolved inorganic carbon, dissolved organic carbon (DOC), methane, and dissolved ammonium. At depth (25–30 cm) methane concentrations ranged from 50 to 800 μmol Lpw?1 and DOC from 400 to 900 μmol Lpw?1. Estimation of carbon recycling rates based upon diffusion along pore water concentration gradients at the sediment-water interface, indicate that combined DOC and methane fluxes generally contribute <15% of the overall turnover of sedimentary organic carbon. Comparisons to Laurentian Great Lakes environments show trends in sediment deposition, organic matter remineralization, and the time scales of carbon recycling across nearly two orders of magnitude with the fraction of organic content buried generally decreasing with decreasing sedimentation rates.Kocsis, L., Usman, A., Jourdan, A.-L., Hassan, S.H., Jumat, N., Daud, D., Briguglio, A., Slik, F., Rinyu, L., Futó, I., 2020. The Bruneian record of “Borneo Amber”: A regional review of fossil tree resins in the Indo-Australian Archipelago. Earth-Science Reviews 201, 103005. this study we intend to provide an overview on fossilized tree resins (amber) commonly found in Southeast Asia, more particularly in the Indo-Australian Archipelago (IAA). These remains are often referred in literature as “Indonesian amber”, “Borneo amber” or simply as “dammar”. They are very common in the region and the Brunei Sultanate is no exception as most of its Neogene sedimentary successions contain amber-rich layers. Although amber is a common fossil in the country and in northern Borneo, to our knowledge it has not been studied in great detail so far. Here we present an account on the “Borneo Ambers” from Brunei, regarding their stratigraphic origin, basic physical properties, their interaction with the biosphere and their botanical origin using Fourier-transform infrared spectroscopy (FTIR). Additionally, a number of ambers and modern tree resins were analysed for their carbon isotope composition and a few were tested with gas chromatography. We discuss the results in a regional and global context, in comparison with available data from the IAA.The ambers come from four different lithostratigraphic units with an age range of 12 to 3 million years (middle Miocene to Pliocene). Recently reworked ambers from the coast, ambers from younger alluvial deposits, and several modern tree resins from Dipterocarpaceae and Araucariaceae (Agathis borneensis) were also included in the study. The >60 FTIR analyses of modern and fossil specimens suggest that all the Brunei ambers were produced by trees of Dipterocarpaceae. There is no indication of Agathis in the fossil record, in agreement with their lower abundance in the forests of Borneo. Modern and fossil dipterocarp resins were found to be different based on the following criteria: (1) Different reactions to solubility, hot needle and UV tests with faster reaction time and less fluorescence for the modern ones; (2) Clear distinction based on certain FTIR absorbance band ratios, mostly by those that represent carboxylic acids and esters (e.g., ~1700 and 1243?cm-1); (3) Modern resin yielded on an average 3‰ lower δ13C values, (4) Gas chromatography data reflect maturation differences among the samples. Although there is some overlap in the chemical results between the two groups, generally all these differences reflect different maturation stages of the resinous material and point towards loss of low δ13C components from the organic structure of the resin. The minor timewise decreasing trend in average δ13C from the late middle Miocene to late Miocene can be explained by (1) gradual changes in local environmental conditions, and/or (2) increased amount of less mature specimens among the younger samples. In contrast, the highest obtained δ13C values were found in the youngest Pliocene ambers. Instead of maturation bias this can be linked to environmental factors such as cooler-drier climate with increased seasonality, probably reflecting the onset of the northern hemisphere glaciation.Kolobova, K.A., Roberts, R.G., Chabai, V.P., Jacobs, Z., Krajcarz, M.T., Shalagina, A.V., Krivoshapkin, A.I., Li, B., Uthmeier, T., Markin, S.V., Morley, M.W., O’Gorman, K., Rudaya, N.A., Talamo, S., Viola, B., Derevianko, A.P., 2020. Archaeological evidence for two separate dispersals of Neanderthals into southern Siberia. Proceedings of the National Academy of Sciences 117, 2879-2885.: Neanderthals once inhabited Europe and western Asia, spreading as far east as the Altai Mountains in southern Siberia, but the geographical origin and time of arrival of the Altai populations remain unresolved. Excavations at Chagyrskaya Cave in the Altai foothills have yielded 90,000 stone artifacts, numerous bone tools, 74 Neanderthal fossils, and animal and plant remains recovered from 59,000- to 49,000-year-old deposits. The Chagyrskaya Neanderthals made distinctive stone tools that closely resemble Micoquian artifacts from eastern Europe, whereas other Altai sites occupied by earlier Neanderthal populations lack such artifacts. This suggests at least two dispersals of Neanderthals into southern Siberia, with the likely ancestral homeland of the Chagyrskaya toolmakers located 3,000 to 4,000 kilometers to the west, in eastern Europe.Abstract: Neanderthals were once widespread across Europe and western Asia. They also penetrated into the Altai Mountains of southern Siberia, but the geographical origin of these populations and the timing of their dispersal have remained elusive. Here we describe an archaeological assemblage from Chagyrskaya Cave, situated in the Altai foothills, where around 90,000 Middle Paleolithic artifacts and 74 Neanderthal remains have been recovered from deposits dating to between 59 and 49 thousand years ago (age range at 95.4% probability). Environmental reconstructions suggest that the Chagyrskaya hominins were adapted to the dry steppe and hunted bison. Their distinctive toolkit closely resembles Micoquian assemblages from central and eastern Europe, including the northern Caucasus, more than 3,000 kilometers to the west of Chagyrskaya Cave. At other Altai sites, evidence of earlier Neanderthal populations lacking associated Micoquian-like artifacts implies two or more Neanderthal incursions into this region. We identify eastern Europe as the most probable ancestral source region for the Chagyrskaya toolmakers, supported by DNA results linking the Neanderthal remains with populations in northern Croatia and the northern Caucasus, and providing a rare example of a long-distance, intercontinental population movement associated with a distinctive Paleolithic toolkit.Kondyli, A., Schrader, W., 2020. Evaluation of the combination of different atmospheric pressure ionization sources for the analysis of extremely complex mixtures. Rapid Communications in Mass Spectrometry 34, e8676.: Characterization of complex samples remains a challenging task due to the high number of compounds present. Matrix effects, ion discrimination and suppression are limiting factors which force the use of different methods for the same sample to gain a broad understanding of complex mixtures.Methods: Various ionization techniques such as electrospray ionization (ESI), atmospheric pressure photoionization (APPI) and atmospheric pressure chemical ionization (APCI) have been used in various problems for complex mixture analysis. Especially demanding is the analysis of energy‐related hydrocarbon mixtures, such as crude oil. Here, the different ionization sources alone and in combination with each other have been used on an ultrahigh resolution Orbitrap mass spectrometer to study a light crude oil.Results: Despite the great variety of the available ionization sources, there is no single technique which can fully characterize the crude oil. Each ionization technique shows a selectivity towards specific types of compounds. While ESI is the method of choice for the detection of polar compounds, APPI and APCI favor the detection of nonpolar and low‐to‐medium polar compounds, respectively. The combination of ESI/APPI favors hydrocarbons and oxygen‐containing species.Conclusions: Combining different ionization methods can be used as an alternative in order to gain more information about compounds present in a complex mixture although a combination of different ion sources could enhance suppression effects.Korovnikov, I.V., Marusin, V.V., Tokarev, D.A., Obut, O.T., 2019. Trace fossils from the Vendian-Cambrian transitional strata of the Igarka Uplift (northwestern Siberian Platform). Paleontological Journal 53, 566-574. Vendian–Cambrian transitional strata of the Igarka Uplift (northwestern Siberian Platform), originally erected as the Sukharikha Formation, are one of the key objects revealing evolution of marine ecosystems in the late Vendian. Herein we describe dwelling burrows Skolithos and Arenicolites from dolostones in the middle Sukharikha Formation (Nemakit-Daldynian Regional Stage). High density and local distribution of these burrows in the Sukharikha Formation demonstrate that the terminal Vendian shallow-marine sediments became occupied by vertical-burrowing benthic organisms, mirrored in the geological record as an archetypical Phanerozoic ichnoassemblage (Skolithos ichnofacies).Kovalev, S.V., Lebedev, A.T., 2019. Chapter 14 - Identification of biologically active peptides by means of Fourier transform mass spectrometry, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 425-468. the most various advantageous properties peptides are ubiquitous participants in nearly all biological processes. Elucidation of their structure is important in terms of physiology, for synthesis of their analogs, and for biomarkers discovery. New “omics” techniques and especially peptidomics, based on mass spectrometry (MS), have been applied to peptide structure elucidation. Fourier transform mass spectrometry (FTMS) offers advantages of high resolution and mass accuracy that are especially helpful in peptide mass fingerprinting and mass mapping. Tandem FTMS (a combination of FTMS with various ion activation and dissociation techniques) provides reliable information about the amino acid sequence. This chapter reviews application of FTMS for characterization and sequencing of bioactive peptides. Aspects of MS imaging, mass mapping, basics of different tandem MS methods, their advantages and drawbacks are discussed. Major peptidomics objects include amphibian skin secretion, venoms of vertebrates and invertebrates, neuropeptides of crustaceans and endogenous peptides in human biological fluids.Krenkel, H., Hartmane, E., Piras, C., Brown, J., Morris, M., Cramer, R., 2020. Advancing liquid atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry toward ultrahigh-throughput analysis. Analytical Chemistry 92, 2931-2936. high-throughput screening using mass spectrometry has the potential to provide rapid large-scale sample analysis at a speed of more than one sample per second. Such speed is important for compound library, assay and future clinical screening of millions of samples within a reasonable time frame. Herein, we present a liquid atmospheric pressure matrix-assisted laser desorption/ionization (AP-MALDI) setup for high-throughput large-scale sample analysis (>5 samples per second) for three substance classes (peptides, antibiotics, and lipids). Liquid support matrices (LSM) were used for the analysis of standard substances as well as complex biological fluids (milk). Throughput and analytical robustness were mainly dependent on the complexity of the sample composition and the current limitations of the commercial hardware. However, the ultimate limits of liquid AP-MALDI in sample throughput can be conservatively estimated to be beyond 10–20 samples per second. This level of analytical speed is highly competitive compared with other label-free MS methods, including electrospray ionization and solid state MALDI, as well as MS methods using multiplexing by labeling, which in principle can also be used in combination with liquid AP-MALDI MS.Kret, K., Tsuji, T., Chhun, C., Takano, O., 2020. Distributions of gas hydrate and free gas accumulations associated with upward fluid flow in the Sanriku-Oki forearc basin, northeast Japan. Marine and Petroleum Geology 116, 104305. applied automated velocity analysis to a 3D seismic data volume to obtain a high-resolution seismic velocity model that we used to investigate the influence of fluid behavior on the subsurface distribution of gas in the Sanriku-Oki forearc basin, northeast Japan. We identified free gas accumulations as zones of low P-wave velocity separated from overlying high-velocity gas hydrates by the clear seismic boundary of the bottom-simulating reflection (BSR) between them. We then used conductive modeling to map upward heat flow in our study area from the depth of the BSR derived from the velocity model. The estimated heat flow demonstrates that upward fluid flux has considerable influences on the distributions of both gas hydrate and free gas. The areas of high heat flow (representing high fluid flux) correspond to underlying permeable geological features such as gas chimneys, faults, and the edges of porous slumps, suggesting that these features provide fluid migration pathways from Eocene to Oligocene source rocks to free gas and hydrate accumulations in overlying sedimentary rocks. The techniques we have employed can contribute to the high-resolution mapping of gas hydrate and free gas accumulations in similar deep-water reservoirs off the eastern continental margin of Japan and at tectonically similar plate subduction margins in other regions.Kreutzer, L., Aichler, M., Walch, A.K., 2019. Chapter 9 - In situ metabolomics in cancer tissue by high-resolution mass spectrometry imaging, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 253-279. chapter introduces the in situ investigation on metabolomics in cancer tissues by high-resolution mass spectrometry imaging. Metabolomics is a rapidly increasing field, since the detection of biochemical processes can improve the diagnostic, therapeutic treatment prediction, and prognosis in diseases such as cancer. By analyzing metabolic alterations in cancer tissues, insights into the pathway regulations and the resulting clinical outcome can be obtained and associated. In recent years, especially high-resolution matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) was an emerging technique in the analysis of metabolite molecular data and their spatial distribution in tissues. The main intentions in the combination of metabolomics with MALDI MSI are the discovery of molecular biomarkers and metabolic pathways altered in tumors, as well as therapy response prediction and method development. Therefore, increasing numbers of studies were published recently, investigating the optimization of the MSI methods, overcoming the current difficulties and studying the role of clinical translation.Ku, C., Sun, T.-W., 2020. Did giant and large dsDNA viruses originate before their eukaryotic hosts? Proceedings of the National Academy of Sciences 117, 2747-2748. et al. (1) present phylogenetic trees of cellular organisms and Nucleo-Cytoplasmic Large DNA Viruses (NCLDVs) based on two subunits of DNA-dependent RNA polymerase (RNAP) and conclude that NCLDVs originated before their eukaryotic hosts and contributed RNAP to eukaryotes. While the study might provide insights into NCLDV phylogeny, the main conclusion is highly disputable. In addition to the small number of genes analyzed, we are particularly concerned about the accuracy of the trees, how much they represent the evolution of cellular life and viruses, and the overuse of lateral gene transfers (LGTs) to explain tree topologies.Based on only two genes encoding subunits of the same enzyme, Guglielmini … Comment on: Julien Guglielmini, Anthony C. Woo, Mart Krupovic, Patrick Forterre, and organ Gaia. Diversification of giant and large eukaryotic dsDNA viruses predated the origin of modern eukaryotes, PNAS September 24, 2019 116 (39) 19585-19592Reply to comment: Guglielmini, J., Woo, A.C., Krupovic, M., Forterre, P., Gaia, M., 2020. Reply to Ku and Sun: Ancestors of modern giant and large eukaryotic dsDNA viruses infected proto-eukaryotes. Proceedings of the National Academy of Sciences 117 (6), 2749-2750.Kuang, W., Saraji, S., Piri, M., 2020. Pore-scale sweep eciency enhancement by silica-based nanouids in oil-wet sandstone. Energy & Fuels 34, 1297-1308. has been shown that nanofluids can significantly impact the forces at both fluid-fluid and fluid-solid interfaces. Nanofluids have also been reported in laboratory studies to enhance oil recovery. However, mechanisms of oil recovery by nanofluids in natural porous media are not well understood. More specically, there is an absence of direct and quantitative evidence of oil mobilization by nanofluids at the pore level. In this study, we probe the mechanisms through which nanofluids enhance pore-scale sweep efficiency during oil displacements. We decouple the effects of nanofluids on interfacial tension and wettability by using a combination of silica nanoparticles and a non-ionic surfactant. We performed a set of miniature core-flooding experiments integrated with high-resolution imaging technique at elevated pressure and temperature conditions to examine the effects of nanofluids on oil recovery in Berea sandstone samples aged dynamically with crude oil. The pore-scale displacement mechanisms were investigated by directly measuring in-situ contact angles in visualized images of the pore space, mapping distribution of remaining oil globules, and examining the dynamic interfacial tension data. The SiOx nanofluid had better performance in recovering oil from an oil-wet sandstone sample compared with blank brine. Based on in-situ contact angle measurements, wettability reversal was identified as the principle mechanism responsible for the observed behavior. The complex SiOx nanofluid, which incorporated a non-ionic surfactant to lower IFT, generated the highest oil recovery because of a synergistic effect between wettability reversal and IFT reduction mechanisms.Kumar, P., Chevrier, V.F., 2020. Solubility of nitrogen in methane, ethane, and mixtures of methane and ethane at Titan-like conditions: A molecular dynamics study. ACS Earth and Space Chemistry 4, 241-248. have studied the temperature dependence of the solubility of nitrogen in methane, ethane, and mixtures of methane and ethane using vapor–liquid equilibrium simulations of binary and ternary mixtures of nitrogen, methane, and ethane for a range of temperatures between 90 and 110 K at a pressure of 1.5 atm, thermodynamic conditions that may exist on the Saturn’s giant moon, Titan. We find that (i) the solubility of nitrogen in both methane and ethane decreases with increasing temperature; (ii) the solubility of nitrogen in methane is much larger compared to that in ethane at low temperatures, and (iii) solubility of nitrogen in a ternary mixture of methane, ethane, and nitrogen increases upon increasing the mole fraction of methane. Our results are in quantitative agreement with the recent experimental measurement of the solubility of nitrogen in methane, ethane, and a mixture of methane and ethane. Furthermore, we find a strong temperature-dependent surface adsorption of nitrogen at the nitrogen–hydrocarbon interface, previously unknown. We have also investigated surface tension of the gas–liquid interface and find that it decreases upon decreasing the temperature below 100 K for both nitrogen–methane and nitrogen–ethane binary systems. Moreover, we find that the interfacial layer of adsorbed nitrogen and ethane shows a preferential orientational ordering at the interface.Kunzmann, M., Crombez, V., Catuneanu, O., Blaikie, T.N., Barth, G., Collins, A.S., 2020. Sequence stratigraphy of the ca. 1730 Ma Wollogorang Formation, McArthur Basin, Australia. Marine and Petroleum Geology 116, 104297. ca. 1730 Ma Wollogorang Formation is a mixed carbonate-siliciclastic unit in the southern McArthur Basin of northern Australia. It is an exploration target for base metals and may be a petroleum source unit and unconventional reservoir. Facies analysis indicates that the Wollogorang Formation records deposition in supratidal to offshore environments. Lateral consistency in facies, thickness, and stratigraphic architecture suggests deposition on an east-west trending (present coordinates) epeiric platform. According to recent tectonic models for northern Australia, this epeiric platform likely deepened to the present-day east. The Wollogorang Formation comprises one?second-order and five nested third-order sequences. Despite the unavailability of biostratigraphy and biofacies, and the general poor time control in Precambrian basins, we are able correlate third-order (i.e., our lowest rank) sequences over tens to hundreds of kilometers using high-resolution facies and petrophysical logs. As the distinction between stratigraphic sequences (related to shoreline shifts) and sedimentological bedsets (not related to shoreline shifts) becomes more difficult with decreasing hierarchical level, sedimentological, stratigraphic, paleontological, and mineralogical (including diagenetic) criteria were recently proposed to distinguish these cycles. Our study suggests that sedimentological and stratigraphic criteria are the most useful in Precambrian sequence stratigraphy. In contrast, paleontological criteria are irrelevant in Precambrian successions. Mineralogical (including diagenetic) criteria have not been tested in this study. In addition to further study these criteria, we suggest testing geochemical criteria, such as the enrichment of redox-sensitive trace elements and minor carbonate carbon isotope variation, to distinguish stratigraphic sequences from sedimentological bedsets.Kuo, T.-H., Dutkiewicz, E.P., Pei, J., Hsu, C.-C., 2020. Ambient ionization mass spectrometry today and tomorrow: Embracing challenges and opportunities. Analytical Chemistry 92, 2353-2363. ionization mass spectrometry (AIMS) has grown into a group of emerging analytical techniques that allow rapid, real-time, high-throughput, in situ, and in vivo analysis in many scientific fields including biomedicine, pharmaceuticals, and forensic sciences. While dozens of AIMS techniques have been introduced over the past two decades, their broad commercial and industrial use is still restricted by multiple challenges. In this Perspective, we discuss the most relevant technical challenges facing AIMS, i.e., reproducibility, quantitative ability, molecular coverage, sensitivity, and data complexity, and scientists’ recent attempts to overcome these hurdles. Furthermore, we present future directions of AIMS from our perspective, including the necessity that efforts should be made to unravel blind biomolecules in routine analysis, the construction of a data depository for AIMS users, the full automation of pipelines for prospect integration in a robotic laboratory, the movement toward on-site tests, and the expansion of outreach to motivate government officials in policymaking. We anticipate that, with progress in these critical but immature areas, AIMS technology will keep evolving to become a more robust and user-friendly set of technologies and, consequently, be translated into everyday life practice.Kutzbach, J.E., Guan, J., He, F., Cohen, A.S., Orland, I.J., Chen, G., 2020. African climate response to orbital and glacial forcing in 140,000-y simulation with implications for early modern human environments. Proceedings of the National Academy of Sciences 117, 2255-2264.: A computer model calculates the changing climate/vegetation from 140,000 y ago to the present for Africa, Arabia, and the Mediterranean Basin. The results illustrate how and when changes in Earth’s orbit, greenhouse gases, and ice sheets change the climate. The model makes this long calculation using the full set of dynamic/thermodynamic equations with sufficient spatial resolution to calculate monsoon and storm track rainfall over this region. The results explain when and where the climate was wetter or drier and how the vegetation changed. The simulated environmental changes agree with observed paleoenvironmental data in most areas. The results will help assess whether and how climate, hydrology, and vegetation changes may have influenced human dispersal out of Africa.Abstract: A climate/vegetation model simulates episodic wetter and drier periods at the 21,000-y precession period in eastern North Africa, the Arabian Peninsula, and the Levant over the past 140,000 y. Large orbitally forced wet/dry extremes occur during interglacial time, ～130 to 80 ka, and conditions between these two extremes prevail during glacial time, ～70 to 15 ka. Orbital precession causes high seasonality in Northern Hemisphere (NH) insolation at ～125, 105, and 83 ka, with stronger and northward extended summer monsoon rains in North Africa and the Arabian Peninsula and increased winter rains in the Mediterranean Basin. The combined effects of these two seasonally distinct rainfall regimes increase vegetation and narrow the width of the Saharan–Arabian desert and semidesert zones. During the opposite phase of the precession cycle (～115, 95, and 73 ka), NH seasonality is low, and decreased summer insolation and increased winter insolation cause monsoon and storm track rains to decrease and the width of the desert zone to increase. During glacial time (～70 to 15 ka), forcing from large ice sheets and lowered greenhouse gas concentrations combine to increase winter Mediterranean storm track precipitation; the southward retreat of the northern limit of summer monsoon rains is relatively small, thereby limiting the expansion of deserts. The lowered greenhouse gas concentrations cause the near-equatorial zone to cool and reduce convection, causing drier climate with reduced forest cover. At most locations and times, the simulations agree with environmental observations. These changing regional patterns of climate/vegetation could have influenced the dispersal of early humans through expansions and contractions of well-watered corridors.Kwon, H.J., Hwang, J.-Y., Shin, H.-J., Jeong, M.-G., Chung, K.Y., Sun, Y.-K., Jung, H.-G., 2020. Nano/microstructured silicon–carbon hybrid composite particles fabricated with corn starch biowaste as anode materials for Li-ion batteries. Nano Letters 20, 625-635. has a great potential as an alternative to graphite which is currently used commercially as an anode material in lithium-ion batteries (LIBs) because of its exceptional capacity and reasonable working potential. Herein, a low-cost and scalable approach is proposed for the production of high-performance silicon–carbon (Si–C) hybrid composite anodes for high-energy LIBs. The Si–C composite material is synthesized using a scalable microemulsion method by selecting silicon nanoparticles, using low-cost corn starch as a biomass precursor and finally conducting heat treatment under C3H6 gas. This produces a unique nano/microstructured Si–C hybrid composite comprised of silicon nanoparticles embedded in micron-sized amorphous carbon balls derived from corn starch that is capsuled by thin graphitic carbon layer. Such a dual carbon matrix tightly surrounds the silicon nanoparticles that provides high electronic conductivity and significantly decreases the absolute stress/strain of the material during multiple lithiation-delithiation processes. The Si–C hybrid composite anode demonstrates a high capacity of 1800 mAh g–1, outstanding cycling stability with capacity retention of 80% over 500 cycles, and fast charge–discharge capability of 12 min. Moreover, the Si–C composite anode exhibits good acceptability in practical LIBs assembled with commercial Li[Ni0.6Co0.2Mn0.2]O2 and Li[Ni0.80Co0.15Al0.05]O2 cathodes.La Nasa, J., Nardella, F., Andrei, L., Giani, M., Degano, I., Colombini, M.P., Ribechini, E., 2020. Profiling of high molecular weight esters by flow injection analysis-high resolution mass spectrometry for the characterization of raw and archaeological beeswax and resinous substances. Talanta 212, 120800. work presents a method to characterize high molecular esters in beeswax and resinous substances based on the use of microwave-assisted extraction and flow injection analysis-high resolution mass spectrometry that combines the high efficiency of the extraction procedure with the advantages of high resolution mass spectrometry. This approach allows us to identify archaeological beeswax and plant resinous substances by the characterization of the survived intact high molecular weight components. By this way, several raw materials (beeswax, pine resin and pitch, and resin extracted from Euphorbia tirucalli) were studied and used as reference substances. The procedure was then tested on an adhesive dated 44–42 ka BP recovered from Border Cave (KwaZulu-Natal, Africa), allowing us to detect the high molecular weight species even after almost 50,000 years, and then used to chemically investigate unknown archaeological adhesives from Antinoopolis (Egypt), dated to the 4th-5th century AD. The results allowed us to extend our knowledge on the long-term behavior of beeswax and resinous substances.Lan, Z., Zhang, S., Tucker, M., Li, Z., Zhao, Z., 2020. Evidence for microbes in early Neoproterozoic stromatolites. Sedimentary Geology 398, 105589. biogenesis of stromatolites has long been discussed since many lack convincing evidence of their biological origin. This has particularly been the case with older Precambrian examples where widespread diagenetic and metamorphic processes have commonly destroyed microbial relics; in some cases however, evidence has been preserved through very early mineralisation. Precambrian stromatolites are relatively abundant but it is extremely rare that they contain calcified or dolomitized cyanobacteria and biofilms. This study provides evidence from early Neoproterozoic columnar stromatolites in the Jiuliqiao Formation from the southeastern margin of the North China Platform for fossilized extracellular polymeric substances (EPS) and cyanobacteria, along with nanospheres which may represent permineralised viruses or viral-like particles. A similar chemical composition and colour along with their embedded and cross-cutting relationships with the matrix suggest they are syn-depositional products, and not modern artefacts or the result of sample preparation. The interweaving of cyanobacterial filaments with detrital grains such as quartz and intraclasts indicates trapping, baffling and binding processes. The presence of virus-like particles and mineralized EPS with anhedral, fine-grained calcite suggests they may have provided initial nucleation sites for subsequent carbonate precipitation. This study demonstrates the use of a high-definition scanning electron microscope to detect fossilized (calcified) filamentous and spheroidal bacteriomorphs within ancient stromatolites in order to confirm their biogenesis.Lau, M.P., del Giorgio, P., 2020. Reactivity, fate and functional roles of dissolved organic matter in anoxic inland waters. Biology Letters 16, 20190694. transit of organic matter (OM) through the aquatic compartment of its global cycle has been intensively studied, traditionally with a focus on the processing and degradation of its dissolved fraction (dissolved organic matter, DOM). Because this is so intimately related to oxidation, the notion tenaciously persists that where oxygen is absent, DOM turnover is markedly slowed. In this Opinion Piece, we outline how diverse processes shape, transform and degrade DOM also in anoxic aquatic environments, and we focus here on inland waters as a particular case study. A suite of biogeochemical DOM functions that have received comparatively little attention may only be expressed in anoxic conditions and may result in enhanced biogeochemical roles of these deoxygenated habitats on a network scale.Lee, E., Yi, S., Lim, J., Kim, Y., Jo, K.-n., Kim, G.Y., 2020. Multi-proxy records of Holocene hydroclimatic and environmental changes on the southern coast of South Korea. Palaeogeography, Palaeoclimatology, Palaeoecology 545, 109642. well-dated sediment core from the Goheung area of the southern coast of the Korean Peninsula was used to reconstruct the history of environmental and vegetation changes in response to variability in the East Asian summer monsoon (EASM) and the sea-level change during the Holocene. A multi-proxy analysis (palynomorphs, mean grain size, TOC, TS, C/N ratio, and δ13CTOC data) indicated that the study area underwent a change in environment from a fluvio-coastal (a fluvial to intertidal zone) to a subtidal zone due to a sea-level rise at ca. 7500 cal yr BP. Since ca. 6000 cal yr BP, it has gradually returned to a brackish-dominant environment (intertidal zone) due to coastal regression, with a decrease in relative sea-level. Palynological data show that the climate of the southern coast of the Korean Peninsula underwent a gradual cooling trend after ca. 5900 cal yr BP, due to weakening EASM intensity in response to decreasing insolation in the Northern Hemisphere. Therefore, the long-term vegetation dynamics in this study area were controlled primarily by solar insolation–driven temperature changes during the Holocene. They were also associated with sea surface temperature (SST) changes in the western tropical Pacific (WTP). The vegetation dynamics (sharp reduction of broad-leaved trees and freshwater discharge indicators) in our study area indicate cold and dry climatic conditions since ca. 4500 cal BP, which may have been caused by the decreasing SST in the WTP. In addition, the strong link between the Holocene vegetation dynamics in the East Asian coastal area (especially, Quercus-Lepidobalanus and Pinus-Diploxylon) and SST variation in the WTP may suggest that the centennial-timescale recurring variations in EASM activity have been controlled by low-latitude ocean forcing induced by El Ni?o Southern Oscillation activity.Lefebvre, T., Talbi, A., Atwi-Ghaddar, S., Destandau, E., Lesellier, E., 2020. Development of an analytical method for chlorophyll pigments separation by reversed-phase supercritical fluid chromatography. Journal of Chromatography A 1612, 460643. pigments give the green colour to plants, which is a quality attribute of food and vegetables. However, the chemical structure of native chlorophyll can change during varied processes (drying, freezing, extraction) applied to plants, which produce degradation compounds that could have a brown and unwanted colour.Systematic experiments have been conducted in supercritical fluid chromatography with a C18 stationary phase to understand and model the chromatographic behaviour of the compounds with respect to the nature of the modifier (MeOH, ACN, and MeOH/ACN 50/50) and its percentage, from 10% to 100%. Specific retention changes were observed, which provide numerous analytical conditions to achieve compound separation. The chromatographic profile of the extract containing native chlorophyll a, b and numerous phytylated chlorophyll derivatives (pheophytin a, a’, b, b’; hydroxypheophytin a, a’, b, b’; pyropheophytin and lactone derivatives) is strongly impacted by the nature of the modifier and, because of the complexity of the extract, the optimal conditions obtained are unusual for supercritical fluid chromatography. An original method development using an optimization criterion was discussed for the analyses of samples, leading to a fast analytical method with a very low backpressure and a flow rate gradient, but a simplest and rapid method is also suggested for samples displaying fewer derivatives.Lei, Z., Xu, H., Jiang, T., Li, Z., Li, J., Li, W., Xiong, Y., Li, S., Zhao, J., 2019. Multiphase hydrocarbons from carboniferous reservoir rocks and their origin in the Donghetang area, western Tabei uplift, Tarim Basin, NW China. Russian Geology and Geophysics 60, doi: 10.15372/RGG2019014. Carboniferous Donghe sandstone reservoir is the most important target in the Tabei Uplift of the Tarim Basin, which contains a range of hydrocarbon types, including bitumen, heavy oil, condensate oil, light oil, crude oil, and hydrocarbon gas, and has high contents of CO2 and N2. The origin of multiple phase hydrocarbons from Carboniferous reservoir rocks in the Donghetang area, Western Tabei Uplift, is documented in this paper based on integral analysis of the geochemistry, pyrolysis, and carbon isotopes of the bulk composition and light composition hydrocarbons. Oil-source correlations determined that the paleoreservoir hydrocarbons that formed from the Permian to the Triassic derived from the Lower Ordovician (O1) source rocks and that those of the present-day reservoir that formed in the Neogene derived from Middle-Upper Ordovician (O2-3) source rocks. During the uplift episode lasting from the Permian to the Triassic, the hydrocarbons in the entire paleoreservoir underwent water washing, biodegradation, and bacterial sulfate reduction (BSR), resulting in residual bitumen, heavy oil, H2S, and pyrites in the paleoreservoir. The high CO2 and N2 contents originated from volcanic degassing due to volcanic activity from the Permian to the Early Triassic. The present-day reservoirs underwent gas washing and evaporative fractionation due to natural gas charging that originated from oil cracking and kerogen degradation in the deeper reservoirs; this resulted in fractionation and formed condensate oil and light oil with a high wax content in the residual crude oil. Based on this research, it was concluded that the diverse hydrocarbon phases in the Donghetang area were primarily attributed to water washing, biodegradation, BSR, volcanic degassing, gas washing, and evaporative fractionation.Lelevic, A., Souchon, V., Moreaud, M., Lorentz, C., Geantet, C., 2020. Gas chromatography vacuum ultraviolet spectroscopy: A review. Journal of Separation Science 43, 150-173. technological progress and increased complexity of interrogated matrices imposes a demand for fast, powerful, and resolutive analysis techniques. Gas chromatography has been for a long time a ‘go‐to’ technique for the analysis of mixtures of volatile and semi‐volatile compounds. Coupling of the several dimensions of gas chromatography separation has allowed to access a realm of improved separations in the terms of increased separation power and detection sensitivity. Especially comprehensive separations offer an insight into detailed sample composition for complex samples. Combining these advanced separation techniques with an informative detection system such as vacuum ultraviolet spectroscopy is therefore of great interest. Almost all molecules absorb the vacuum ultraviolet radiation and have distinct spectral features with compound classes exhibiting spectral signature similarities. Spectral information can be ‘filtered’ to extract the response in the most informative spectral ranges. Developed algorithms allow spectral mixture estimation of coeluting species. Vacuum ultraviolet detector follows Beer–Lambert law, with the possibility of calibrationless quantitation. The purpose of this article is to provide an overview of the features and specificities of gas chromatography–vacuum ultraviolet spectroscopy coupling which has gained interest since the recent introduction of a commercial vacuum ultraviolet detector. Potentials and limitations, relevant theoretical considerations, recent advances and applications are explored.León-Palmero, E., Contreras-Ruiz, A., Sierra, A., Morales-Baquero, R., Reche, I., 2020. Dissolved CH4 coupled to photosynthetic picoeukaryotes in oxic waters and cumulative chlorophyll-a in anoxia. Biogeosciences Discussions 2020, 1-32. emissions from reservoirs are responsible for the majority of the atmospheric climatic forcing of these aquatic ecosystems, comparable to emissions from paddies or biomass burning. Primarily, CH4 is produced during the anaerobic mineralization of organic carbon in the anoxic sediments by methanogenic archaea. However, the origin of the recurrent and ubiquitous CH4 supersaturation in oxic waters (i.e., methane paradox) is still controversial. Here, we determined the dissolved CH4 concentration in the water column of twelve reservoirs during the summer stratification and the winter mixing. We obtained that the dissolved CH4 concentration varied up to four orders of magnitude (0.02–213.64?μM), and all depths were consistently supersaturated (710–7082234?%) in both periods. Phytoplanktonic sources of carbon appear to determine the concentration of CH4 in the reservoirs. In the anoxic waters, the depth-cumulative chlorophyll-a concentration, a proxy for the total phytoplanktonic biomass exported to sediments, determined the CH4 concentration. In the oxic waters, the photosynthetic picoeukaryotes abundance significantly determined the dissolved CH4 concentration both during the stratification and the mixing. The mean depth of the reservoirs, as a surrogate of the CH4 transport from sediment to the oxic waters, also contributed in shallow systems. Our findings suggest that photosynthetic picoeukaryotes can have a significant role in determining the CH4 concentration in oxic waters and, in comparison to cyanobacteria, have been poorly explored as CH4 sources.Leoncio, L., de Almeida, M., Silva, M., Oliveira, O.M.C., Moreira, ?.T.A., Lima, D.F., 2020. Evaluation of accelerated biodegradation of oil-SPM aggregates (OSAs). Marine Pollution Bulletin 152, 110893. studies of the formation of oil-Suspended Particulate Matter (SPM) aggregates (OSAs) have advanced significantly in the scientific community, however there is a need to accelerate oil biodegradation that was dispersed by the formation of OSAs. The present research presents a pioneering character regarding the addition of nutrients as biostimulus for autochthonous hydrocarboclastic bacteria in the biodegradation of Total Petroleum Hydrocarbons (TPH) dispersed by the formation of OSAs. Water aliquots were taken over 60?days from eight bioreactors to perform ionic species analysis, pH, salinity and temperature monitoring, liquid/liquid extraction, serial dilution methodology and filter membrane. TPH quantification was performed on the gas chromatograph with a flame ionisation detector (GC-FID). The addition of nutrients contributed positively to the rate and extent of biodegradation of TPH in association with field-collected SPM. The best result found was with the lowest nutrient concentration (Bio 1) with an average of 98.65% of TPH reduction.Leonova, G.A., Kopoteva, T.A., Melenevskii, V.N., Maltsev, A.E., Klimin, M.A., Bobrov, V.A., 2019. Methodological approach to the identification of the sources and genesis of buried organic matter in Holocene sections of lake sapropels (southern West Siberia and eastern Baikal area). Russian Geology and Geophysics 60, doi: 10.15372/RGG2019116. present results of study of the chemical composition of organic matter (C, H, N, and S) from Holocene sections of lake sapropels with undisturbed stratification penetrated by vibratory drilling of the bottom sediments, down to the underlying rocks, of lakes Bol’shie Toroki (1.8 m), Minzelinskoe (5 m), Ochki (4.5 m), Dukhovoe (7 m), and Kotokel’ (6 m). We consider methodological approaches to the identification of the sources and genesis of buried organic matter in marine and lacustrine sediments by a number of organo-geochemical indicators: data of a biological analysis (biostratification based on layer-by-layer determination of organic relics in bottom sediment sections); hydrocarbon biomarkers (molecular composition of normal aliphatic hydrocarbons (n-alkanes), nitrogen compounds of a protein complex, etc.); and C/N ratio reflecting a difference in the biochemical compositions of bioproducers. The results of biological analysis (biostratification) show that planktonogenic sapropel (phyto- and zooplankton, the autochthonous source of organic matter) in Lake Ochki formed for 10,760 years, and sphagnum and hypnum moss were supplied from the bogged shores (allochthonous source of organic matter). In Lake Minzelinskoe, peaty sapropel formed at the stage of a flooded lowland bog (5905 years ago); since 3980 years ago and till the present, macrophytogenic sapropel has formed. Pyrolytic study (RE pyrolysis and Pyr-GC-MS analysis) of bioproducers and sapropel from Lake Ochki has shown that phytoplankton and zooplankton were the main autochthonous source of OM in the lake, which is confirmed by the identified macromolecules of nitrogen compounds of different compositions. The presence of hopanes indicates the contribution of microorganisms to the formation of OM in the sediments. The organic matter of sapropel has a terrigenous component, which is confirmed by the presence of high-molecular odd-numbered n-alkanes, ketones, and methyl esters of fatty acid. The C/N ratios in the stratified sections of macrophytogenic sapropels of Lakes Bol’shie Toroki and Minzelinskoe fall in the range of values specific to higher aquatic and terrestrial vegetation (C/N = 15-18), whereas the C/N ratios in planktonogenic sapropel of Lake Dukhovoe are typical of marine and lake plankton (C/N = 5.7-8.6).Lesellier, E., 2020. Usual, unusual and unbelievable retention behavior in achiral supercritical fluid chromatography: Review and discussion. Journal of Chromatography A 1614, 460582. rules are well known in liquid chromatography. For the mobile phase composition, retention decreases when adding organic solvent to water for reversed-phase or increasing water proportion for hydrophilic interaction liquid chromatography, and a decrease in temperature usually increases retention. For supercritical fluids, the fluid density, which is related to temperature and column back-pressure, is significant for neat CO2 and with low percentages of organic modifiers, i.e. with compressible mobile phases. The increase in the modifier percentage reduces the fluid compressibility, leading to retention behaviors close to those observed with liquid mobile phases, for instance for temperature changes. Moreover, adsorption of carbon dioxide or modifiers modify the solutes/stationary phase interactions, further complicating the understanding of the observed retention changes, either with low amount of modifier, or with specific modifiers.Besides, the polar and nonpolar stationary phases (SPs) do not always behave identically, depending on physico-chemical properties. Silica, amino or ethyl-pyridine polar phases display mostly identical behavior for classical differences of compounds of different polarity, but can provide different retention order for more subtle differences, such as the position of polar groups. Moreover, the nature of the silica, inorganic or hybrid, or the additional charges onto the silica surface can also lead to different results.Even if the C18-bonded phases are not as popular as polar SPs, the non-polar SPs provide very high separation performances for suited compounds, i.e. for non-polar compounds, which are perfectly solubilized by supercritical fluids. Recently, unusual retention behaviors were observed with some specific C18-bonded phases, which display polar interactions in addition to dispersion interactions.Whatever the SPs used, supercritical fluids appear to favor specific effects that are not observed with liquid mobile phases that are more uniform in terms of physico-chemical properties.The objective of this paper is to describe different separation behaviors observed in SFC, to improve the general understanding of the specificities of the association of supercritical fluids and varied SPs.Lewan, M.D., 2020. Comment on “Ideas and perspectives: is shale gas a major driver of recent increase in global atmospheric methane?” by Robert W. Howarth (2019). Biogeosciences Discussions 2020, 1-10. ideas and perspectives presented by Howarth (2019) on shale gas being a major cause of recent increases in global atmospheric methane is based on his devised notion that methane δ13C of shale gas is lighter than that of conventional gas based on a meager and unrepresentative data set. A plethora of publicly available data show that the δ13C1 values of shale gas are typically heavier than those of conventional gas. This contradiction renders his ideas, perspectives, and calculations on methane emissions from shale gas invalid.Lewis, W.H., Lind, A.E., Sendra, K.M., Onsbring, H., Williams, T.A., Esteban, G.F., Hirt, R.P., Ettema, T.J.G., Embley, T.M., 2019. Convergent evolution of hydrogenosomes from mitochondria by gene transfer and loss. Molecular Biology and Evolution 37, 524-539. are H2-producing mitochondrial homologs found in some anaerobic microbial eukaryotes that provide a rare intracellular niche for H2-utilizing endosymbiotic archaea. Among ciliates, anaerobic and aerobic lineages are interspersed, demonstrating that the switch to an anaerobic lifestyle with hydrogenosomes has occurred repeatedly and independently. To investigate the molecular details of this transition, we generated genomic and transcriptomic data sets from anaerobic ciliates representing three distinct lineages. Our data demonstrate that hydrogenosomes have evolved from ancestral mitochondria in each case and reveal different degrees of independent mitochondrial genome and proteome reductive evolution, including the first example of complete mitochondrial genome loss in ciliates. Intriguingly, the FeFe-hydrogenase used for generating H2 has a unique domain structure among eukaryotes and appears to have been present, potentially through a single lateral gene transfer from an unknown donor, in the common aerobic ancestor of all three lineages. The early acquisition and retention of FeFe-hydrogenase helps to explain the facility whereby mitochondrial function can be so radically modified within this diverse and ecologically important group of microbial eukaryotes.Li, C., Attanayake, K., Valentine, S.J., Li, P., 2020. Facile improvement of negative ion mode electrospray ionization using capillary vibrating sharp-edge spray ionization. Analytical Chemistry 92, 2492-2502. ionization (ESI) is often affected by corona discharge when spraying 100% aqueous solutions as the voltage that induces discharge can be well below the onset voltage of ESI. As a result, it is especially challenging to perform native mass spectrometry in negative ion mode where 100% aqueous solution is preferred. Here we report a simple instrumentation method to improve the performance of ESI in negative ion mode based on capillary vibrating sharp-edge spray ionization. By attaching a fused silica capillary emitter to a vibrating glass slide, improved signal quality is achieved for various analytes in aqueous solutions over applying ESI alone. Compared to commercial ESI sources using nebulization gas to reduce discharge, 10–100-fold enhancement in signal intensity and 3–10-fold improvement in S/N are achieved for various kinds of molecules including DNA, peptides, proteins, and oligosaccharides. Finally, the new method demonstrates utility for native mass spectrometry analysis of proteins and G-quadruplex DNA. The present method is expected to have great potential to be adopted by the scientific community because of its improved analytical performance, simplicity, and low cost.Li, C., Reimers, C.E., Alleau, Y., 2020. Inducing the attachment of cable bacteria on oxidizing electrodes. Biogeosciences 17, 597-607. bacteria (CB) are multicellular, filamentous bacteria within the family of Desulfobulbaceae that transfer electrons longitudinally from cell to cell to couple sulfide oxidation and oxygen reduction in surficial aquatic sediments. In the present study, electrochemical reactors that contain natural sediments are introduced as a tool for investigating the growth of CB on electrodes poised at an oxidizing potential. Our experiments utilized sediments from Yaquina Bay, Oregon, USA, and we include new phylogenetic analyses of separated filaments to confirm that CB from this marine location cluster with the genus “Candidatus Electrothrix”. These CB may belong to a distinctive lineage, however, because their filaments contain smaller cells and a lower number of longitudinal ridges compared to cables described from other locales. The results of a 135?d bioelectrochemical reactor experiment confirmed that these CB can migrate out of reducing sediments and grow on oxidatively poised electrodes suspended in anaerobic seawater. CB filaments and several other morphologies of Desulfobulbaceae cells were observed by scanning electron microscopy and fluorescence in situ hybridization on electrode surfaces, albeit in low densities and often obscured by mineral precipitation. These findings provide new information to suggest what kinds of conditions will induce CB to perform electron donation to an electrode surface, further informing future experiments to culture CB outside of a sediment matrix.Li, H., Bao, M., Li, Y., Zhao, L., King, T., Xie, Y., 2020. Effects of suspended particulate matter, surface oil layer thickness and surfactants on the formation and transport of oil-sediment aggregates (OSA). International Biodeterioration & Biodegradation 149, 104925. study illustrated the significant effects of oil surface layer thickness, the presence of suspended particulate matter (i.e. sediment resuspension) and surfactants (chemical oil dispersants and a bio-surfactant) on the formation and transport of oil-sediment aggregates (OSA). Oil spill thickness on surface waters influenced the weathering rates of residual oil. Thin oil slicks on the water surface were more readily dispersed by physical processes. This study provided evidence for the dispersion of thin oil slicks by the bursting of air bubbles. The OSA formation within the water column by interaction of oil with suspended particulate materials promoted the sedimentation of oil. The addition of a chemical dispersant (i.e., GM-2) and biosurfactant (i.e., rhamnolipid) to a surface oil slick increased the dissolved and aggregated oil concentrations in the aqueous phase and subsequent oil biodegradation rates. These findings provide a deeper understanding on the processes influencing vertical distribution and environmental persistence of a crude oil spilled on the ocean surface both in the presence and absence of surfactant additions.Li, H., Lai, R., Jin, Y., Fang, X., Cui, K., Sun, S., Gong, Y., Li, H., Zhang, Z., Zhang, G., Zhang, Z., 2020. Directional culture of petroleum hydrocarbon degrading bacteria for enhancing crude oil recovery. Journal of Hazardous Materials 390, 122160. oxygen-constrained system of crude oil reservoir environment was constructed to stimulate the growth of indigenous microbes, such as petroleum hydrocarbon-degrading bacteria. Addition of nitrogen and phosphorus sources was investigated for the growth of petroleum hydrocarbon-degrading bacteria. The results show that nitrates and phosphates stimulated the growth of the bacteria and promoted the biodegradation of crude oil as the sole carbon source in this process. The minimum surface tension was 29.63 mN/m when the amounts of the nitrogen (NaNO3: (NH4)2SO4?=?2:1) and phosphorus (KH2PO4: NaH2PO4?=?5:2) sources added were 0.8?wt% and 1.4?wt%, respectively. Furthermore, the dominant petroleum hydrocarbon-degrading bacteria were shifted from Arcobacter in production water to Pseudomonas after the first subculture and then to Bacillus after the sixth subculture. The heteroatom groups in the crude oil were biodegraded simultaneously with normal alkanes and alkyl cyclohexanes. Addition of the nutrients resulted in microbial growth, microbial community shift, and enhanced microbial degradation.Li, H., Zhao, J., Liu, A., Zhang, L., Wei, N., Wu, K., Zhou, S., Pei, J., Zhang, W., Yang, L., Ji, H., 2020. Experiment and evaluation on the in-situ rapid preparation of marine non-diagenetic natural gas hydrate. Natural Gas Industry B 7, 93-100. China, marine natural gas hydrate (NGH) resources are mainly distributed in the deepwater areas of 300–3000?m deep in the coastal continental shelf, and they are characterized by weak cementation and non-diagenesis. In order to test and study this type of NGH, it is necessary to prepare samples quickly in situ in large quantities. At present, the commonly used preparation technologies (e.g. stirring method, spraying method and bubbling method) are defective with slow generation and low gas storage density. In view of this, the 1062?L rapid non-diagenetic NGH preparation kettle was designed and developed independently. Then, based on the physical properties of non-diagenetic NGH in the South China Sea, NGH preparation tests were carried out on stirring method, spraying method, bubbling method and “three-in-one” method (the combination of stirring method, spraying method and bubbling method). Temperature, pressure, resistivity and reaction time in the process of test were tested, and NGH generation situations and preparation efficiency of different preparation processes were analyzed and compared. And the following research results were obtained. First, in the process of NGH preparation by stirring method, spraying method and bubbling method, respectively, the generated NGH increases slowly and spreads the whole liquid level gradually. Second, inducing period is obvious in the preparation process by the stirring method, but not obvious by the spraying method, the bubbling method and the “three-in-one” method. Third, in the process of NGH preparation by stirring method, spraying method, bubbling method and “three-in-one” method, the resistivity increases as the reaction goes, and its change trend is basically accordant with the NGH preparation rate. Fourth, the preparation cycle of NGH by “three-in-one” method is greatly shorter than that by single preparation method. The preparation time by stirring method, spraying method and bubbling method is about 5.14 times, 3.59 times and 3.16 times that of “three-in-one” method respectively. In conclusion, the 1062?L rapid NGH preparation kettle developed in this paper can prepare marine non-diagenetic NGH samples quickly in situ. And compared with single preparation method, “three-in-one” method is much higher in NGH preparation efficiency.Li, J., Jiang, C., Wang, M., Lu, S., Chen, Z., Chen, G., Li, J., Li, Z., Lu, S., 2020. Adsorbed and free hydrocarbons in unconventional shale reservoir: A new insight from NMR T1-T2 maps. Marine and Petroleum Geology 116, 104311. free and adsorbed hydrocarbon is crucial for the resources assessment and mobility evaluation of shale oil plays. The complex feature of hydrogen-bearing components in shale reservoirs requires new analytical methods to study the occurrences of different states of hydrocarbons. In this study, forty core samples from five shale oil research wells in the Jiyang Depression of China were analyzed using various analytical tools including nuclear magnetic resonance (NMR) T1-T2 mapping, Leco total organic carbon (TOC) analysis, routine and special programmed Rock-Eval pyrolysis, solvent extraction and fractionation, as well as mercury injection capillary pressure (MICP) experiments. Additional experiments were conducted on a powdered shale for NMR T1-T2 maps under four states: as-received, after being dried at 110 °C, after special programmed pyrolysis to 350 °C, and after solvent extraction. The results showed that residual water signals in the NMR T1-T2 map disappeared after being dried at 110 °C. Free oil signals decreased dramatically when the sample was thermally treated to 350 °C, while adsorbed oil signals decreased sharply after solvent extraction. A good accordance was observed between the organic hydrogen T2 spectra and three modes of Rock-Eval pyrograms, representing free hydrocarbons, adsorbed hydrocarbons, and hydrocarbons from kerogen/bitumen decomposition. A positive correlation was also found between the intensity of NMR T1-T2 map signals and the free and adsorbed hydrocarbon contents from geochemical analysis. T2 cut-off values of adsorbed hydrocarbons and free hydrocarbons were determined to be 0.2 ms and 1 ms, respectively. Core samples with a high oil saturation index, porosity, and relative content of hydrocarbons display a low T1/T2 ratio indicative of a high shale oil mobility. As a complementary method to the Rock-Eval analysis, NMR T1-T2 mapping is a non-destructive technique for the characterization of adsorbed and free hydrocarbons at the core scale with limited sample preparation. The results of this study are helpful for NMR characterization of shale reservoirs.Li, L., Su, Y., Lv, Y., Tu, J., 2020. Asphaltene deposition and permeability impairment in shale reservoirs during CO2 huff-n-puff EOR process. Petroleum Science and Technology 38, 384-390. study focuses on asphaltene deposition and permeability impairment in shale oil reservoirs during CO2 huff-n-puff process. Four different huff-n-puff cycles, two oil samples and five different injection pressures were applied in this study. The results showed that the asphaltene deposed the most in the first cycle. The permeability reduced by 30.2%, 50.25%, and 58.31% after the first, third, and seventh injection cycle, respectively. After seven cycles, the cumulative oil recovery without asphaltene deposition was about 21.5% higher than that with asphaltene deposition. The permeability impairment degree first increased and then decreased with the increase of injection pressure.Li, M., Hou, F., Wu, T., Jiang, X., Li, F., Liu, H., Xian, M., Zhang, H., 2020. Recent advances of metabolic engineering strategies in natural isoprenoid production using cell factories. Natural Product Reports 37, 80-99.: up to 2019. As abundant natural products, isoprenoids have many useful industrial applications in the manufacturing of drugs, fragrances, food additives, colorants, rubber and advanced biofuels. The microbial production of isoprenoids has received much attention in recent years. Metabolic engineering approaches and synthetic biology have been utilized to reconstruct and optimize the metabolic pathways for isoprenoid production in cell factories. In this review, the recent advances in isoprenoid production using microbes are summarized, with a focus on MEP and MVA pathway engineering, downstream isoprenoid pathway engineering and microbial host engineering, which mainly includes central carbon pathway engineering. Finally, future perspectives for the improvement of isoprenoid production are discussed.Li, M., Xiong, Y., Qing, G., 2020. Smart bio-separation materials. TrAC Trends in Analytical Chemistry 124, 115585. advances of life science and biotechnology industry have raised the higher requirement for bio-separation. Current chromatographic and related separation techniques have been refined to such a degree that they present efficient separation capacity towards complex samples in proteomics, pharmaceuticals and food industry. Nevertheless, new breakthroughs, like higher selectivity, more controllable separation mode, lower cost, and milder operation conditions, are still highly desirable in more complicated application scenarios. Smart materials that could reversibly change their structures and properties responding to external stimuli as novel separation media provide an ideal solution to upgrade current separation techniques. In this review, recent advances on smart materials in bio-separation applications are intensively discussed, with an emphasize on the superiority of smart materials in improving the separation performance by a controlled mode. And current challenges encountered and conceivable solutions are also presented to benefit prospective development in design and applications of smart bio-separation materials.Li, Q., Huang, Y., Wen, D., Fu, R., Feng, L., 2020. Application of alkyl polyglycosides for enhanced bioremediation of petroleum hydrocarbon-contaminated soil using Sphingomonas changbaiensis and Pseudomonas stutzeri. Science of The Total Environment 719, 137456. is considered a cost-effective and environmentally sound method for degradation of petroleum hydrocarbons in contaminated soils. This study investigated the effects of biosurfactant alkyl polyglycosides (APG) on enhanced biodegradation of petroleum hydrocarbon-contaminated soils using Sphingomonas changbaiensis and Pseudomonas stutzeri and explored the mechanism responsible for the enhanced petroleum hydrocarbon degradation. To accomplish this, the following treatments were evaluated: (1) bioaugmentation with Sphingomonas changbaiensis; (2) bioaugmentation with Pseudomonas stutzeri; (3) a combination of Sphingomonas changbaiensis and APG; and (4) a combination of Pseudomonas stutzeri and APG. The results showed that the degradation rates of total petroleum hydrocarbons (TPH) in contaminated soil samples bioaugmented with S. changbaiensis and P. stutzeri for 30 days were 39.2 ± 1.9% and 47.2 ± 1.2%, respectively. The addition of biosurfactant APG enhanced the bioremediation processes and improved the biodegradation rates. The biodegradation rate at 1.5 g/kg APG in soil samples bioaugmented with S. changbaiensis was 52.1 ± 2.0%, while the rate at 1.5 g/kg APG in soil samples bioaugmented with P. stutzeri was 59.0 ± 1.8%. The half-life decreased from 39.7 d to 24.5 d and from 29.6 to 20.1 d when the dosage of APG was 1.5 g/kg in contaminated soil samples bioaugmented with S. changbaiensis and P. stutzeri, respectively. Mechanism studies showed that the addition of APG can increase the TPH solubility, promote the sorption of TPH onto microbial cells and subsequent trans-membrane transport by APG-induced structural changes, stimulate microbial activities and participate in the co-metabolism. Therefore, the combination of bioaugmentation and APG is an effective method for remediation of petroleum hydrocarbon-contaminated soil.Li, S., Chen, S., Jin, J., Li, T., Chen, Y., Ma, S., 2020. The Jurassic oil-source correlation of Dishuiquan oilfield in Junggar Basin, northwest China. Petroleum Science and Technology 38, 354-360. are many hydrocarbon generation sags around Dishuiquan Oilfield, such as Dishuiquan Sag, Dongdaohaizi Sag, Wucaiwan Sag, etc. But there is no result which hydrocarbon generation sag the Jurassic oil of Dishuiquan Oilfield is sourced from. Through comparisons on carbon isotopes, sterane distributions and maturities of source rocks and crude oil, the result shows that the geochemical characteristics of Jurassic crude oil in Dishuiquan Oilfield are highly consistent with those of Permian source rocks in Dongdaohaizi Sag and have obvious differences with other sags, which indicates the crude oil comes from the Permian source rocks in Dongdaohaizi Sag.Li, T., Huang, Z., Feng, Y., Chen, X., Ma, Q., Liu, B., Guo, X., 2020. Reservoir characteristics and evaluation of fluid mobility in organic-rich mixed siliciclastic-carbonate sediments: A case study of the lacustrine Qiketai Formation in Shengbei Sag, Turpan-Hami Basin, Northwest China. Journal of Petroleum Science and Engineering 185, 106667. matter-rich mixed siliciclastic-carbonate sediments is a special type of tight oil reservoir in the Turpan-Hami basin, which is characterized by complex fluid type, mineral composition and pore structure. By using casting thin sections, scanning electron microscopy (SEM) and whole rock X diffraction (XRD), pore types and petrological characterization of reservoirs are analyzed. Combined with the result of the physical property, nuclear magnetic resonance (NMR) experiments, the effects of the porosity, permeability, and pore size distribution on the movable fluid distribution in the tight reservoir were evaluated. The results showed that there are four types of mixed siliciclastic-carbonate sediments reservoir, which have high TOC. The reservoirs are characterized by low porosity range from 2% to 10% and extra low permeability mainly less than 0.1?×?10?3?μm2. Nanometer scale intergranular pores and micro-fractures were the main reservoir pore types, we further divided the pore sizes distribution into two categories based on their water-saturated NMR T2 spectra: Type I (bimodal pattern) and Type II (left unimodal, micropores with a diameter less than 100?nm). The fluid components in the reservoir including water in nano-pores, movable light oil, non-movable heavy oil and bound water were analyzed using advanced NMR T1-T2 maps. The mobile light oil content in the silt-bearing argillaceous arenaceous limestone and silt-bearing lime micritic dolomite is higher than that of other lithological reservoirs. The movable light oil content exhibited a strong correlation with permeability, and the proportion of large pores, indicating that the large pores, which are mainly supplied by the intergranular pores in dolomite, substantially contributed to mobility of the hydrocarbon fluid. The non-movable heavy oil fluid component is impacted the small pores ratio and solid organic matter, while water the in nano-pores is greatly affected by clay minerals.Li, X., Cai, J., Liu, H., Zhu, X., Li, Z., Liu, J., 2020. Characterization of shale pore structure by successive pretreatments and its significance. Fuel 269, 117412. matter (OM) or hydrocarbons occur in shales in different forms, and occurrence forms closely relate to pores and surfaces. Therefore, establishing the complex relationships among hydrocarbons or OM, pores and surfaces is highly necessary and requires stepwise removal of OM or hydrocarbon with different occurrence forms to obtain the pore structure progressively but with minimal effects on the mineral compositions and rock framework. In this paper, 11 organic rich shales and 3 organic lean shales from Dongying Sag were successively treated with Dichloromethane (CH2Cl2) and Sodium Hypochlorite (NaOCl), and raw, extracted and oxidized shales were analyzed by XRD, Rock-Eval VI pyrolysis, N2 adsorption and mercury intrusion porosimetry. Results show that there were minimal changes of mineral compositions, OM or hydrocarbon characteristics and pore structure of organic lean shales during pretreatments, indicating that pretreatments have minimal destruction on minerals. However, OM or hydrocarbon characteristics and pore structure of organic rich shales changed progressively, while there are minimal changes of mineral compositions, indicating that pretreatments can separate OM or hydrocarbon occur with different forms but also maintain the original mineral compositions and “recover” the original pore structure of organic rich shales. This research: (1) Demonstrates the necessity of pretreatment before pore structure detection, and recovers the original pore structure of shales abundant in OM. (2) Illustrate the complex relationships among OM or hydrocarbons, pores and surfaces. Analysis of these complex relationships will benefit shale oil potential evaluation.Li, Y., Liu, X., Gao, S., Duan, X., Hu, Z., Chen, X., Shen, R., Guo, H., An, W., 2020. A generalized model for gas flow prediction in shale matrix with deduced coupling coefficients and its macroscopic form based on real shale pore size distribution experiments. Journal of Petroleum Science and Engineering 187, 106712. an unconventional natural gas resource, shale gas is attracting increasing attention worldwide because of its potential to strengthen global energy security and reduce carbon emissions. The shale gas flow in nanopores is one of the main concerns affecting its development process. However, due to the strong nonlinearity and complexity of gas flow at the nanoscale, there is no satisfactory consensus on a physically sound flow mechanism scheme and its corresponding coupling method. Furthermore, although the integration method using specific functions has been proposed to facilitate the consideration of various pore sizes in shale matrix, the real shale experiments are rarely involved to realize this integration method with definitely determined parameters. In this study, the concept of “wall-associated diffusion” is firstly utilized to clarify the relationship among several flow mechanisms, and thereby a comprehensive flow mechanism scheme differing from common research is proposed, which physically considers both the division of mechanical mechanisms in nanopores and partition of flow space. Besides, the deficiencies in the mathematical models of viscous flow and several diffusion processes for flow description are illustrated. Using the molecular collision frequency expressions, a new coupling coefficient-based flow model in nanopores is derived to eliminate the aforementioned deficiencies by strengthening the correspondence between the flow models and Knudsen number (Kn), which is applicable in the full flow regime scope and avoids segment processing. Furthermore, based on the pore size distribution experiments of the real shale samples from a gas field, the fitting parameters needed for the macroscopic form of the above coupled model are obtained, so as to establish an integration method-based unified model for gas flow prediction in shale matrix. Results show that the prediction accuracy of the new model for the two tested shale samples is at least 2.2 times higher than several typical models and is also 1.9 and 7.5 times more accurate than the model without coupling coefficients, respectively. And the application of the proposed model to the flow experiment on another shale sample at higher pressure levels is in accordance with these observations. Interestingly, as temperature increases, the flow rate decreases with minor amplitudes. Under the conditions studied, the pressure change can cause over 10 times variation of the flow rate, revealing measures should be taken to maintain relatively high reservoir pressures to guarantee appreciable gas production from matrix if the other factors remain unchanged. In addition, the difference between the average flow shape in the whole rock and the gas motion in the pore of mean radius is revealed. Sounder in theoretical bases and better in application effects, the proposed model is expected to be of practical significance for guiding shale gas reservoir development.Li, Y., Luo, H., Li, H., Liu, X., Tan, Y., Chen, S., Cai, J., 2020. A brief review of dynamic capillarity effect and its characteristics in low permeability and tight reservoirs. Journal of Petroleum Science and Engineering 189, 106959. pressure plays a fundamental role for the characterization and development of oil and gas reservoirs. Traditionally, the capillary pressure measured in equilibrium state is adopted for the investigation of the multiphase flow in porous media. However, the actual multiphase flow in the underground reservoirs is dynamic (transient) at most time, which is affected by the dynamic capillarity effect. This review offers an overview of studies on the mechanisms, experiments and models of the dynamic capillarity effect, with particular emphasis on the dynamic capillarity effect in low permeability and tight reservoirs. The review initially discussed the controlling parameters of the dynamic capillarity effect, including fluid viscosity, heterogeneity, domain scale, wettability et al., among which conclusions on the influence of the properties of porous media and wettability are consistent. The second part of the review outlined the development of the porous media permeability and the experimental conditions for the dynamic capillarity effect experiments. In the third section, the dynamic capillarity effect models were concluded, namely the continuum models used in production prediction and the pore scale models mainly used to explore the physics of multiphase flow. In addition, an overview of the influence of the dynamic capillarity effect on low permeability and tight reservoirs was provided, and methods (e.g. adding surfactants) to optimize the behavior of dynamic capillarity effect were discussed. Finally, the criteria to consider the dynamic capillarity effect in a porous medium are proposed. This study can help for a better understanding of multiphase flow in porous media.Li, Y., Qin, S., Wang, Y., Holland, G., Zhou, Z., 2020. Tracing interaction between hydrocarbon and groundwater systems with isotope signatures preserved in the Anyue gas field, central Sichuan Basin, China. Geochimica et Cosmochimica Acta 274, 261-285. gas field is a large gas field located in the central Sichuan Basin, China. Although many studies have been carried out previously, the formation mechanism of this field is unclear and currently under debate. To better understand the accumulation history, the role that groundwater plays in transporting hydrocarbons within sedimentary basins and water-gas interactions, stable and noble gas isotopes were measured in thirteen free gas samples from the Anyue gas field. In addition, nine formation water samples and five reservoir bitumen samples were analyzed for stable carbon isotopes. δ13C(CH4) values in the gas samples range from ?35.0 to ?32.6‰, showing evidence of thermogenic origin. δ13C values among three different types of samples (free gases, water-dissolved gases and reservoir bitumen) show a pattern that cannot be explained by oil cracking followed by free gas accumulation. It suggests the occurrence of gas-groundwater interaction in the Anyue field. Free gas samples can be divided into 2 distinct groups by their geographical locations and stratigraphical source formations. 3He/4He ratios (R/Ra) in group 1 and group 2 samples range from 0.0118 to 0.0132 and 0.0115 to 0.0256, respectively, indicating He is mainly derived from the crust. 20Ne/22Ne and 21Ne/22Ne ratios suggest a mixing between the air and crust sources. 40Ar/36Ar ratios ranging from 1658 to 2109 and 2168 to 5973 in group 1 and group 2 samples, respectively, are significantly higher than the air value of 298.6. In comparison, heavier noble gas (Kr and Xe) isotopic compositions are predominantly air-like. The relative enrichment of 4He and 21Ne* in group 1 samples can be possibly explained by preferential release of light noble gases in a low temperature environment. Samples in group 2 show a good fit to the solubility-controlled Rayleigh fractionation model, suggesting the presence of an open system degassing of gases from the groundwater. The excess heavy noble gases in natural gas samples can be attributed to the addition of sedimentary components from the source rocks during geological evolution. 4He groundwater ages considering in-situ production and external flux indicate the addition of young groundwater into the Anyue gas field. Low gas-groundwater ratios and high CH4/36Ar ratios suggest that only a small portion of the gases in the current Longwangmiao reservoir of Anyue gas field has been in contact with the relatively young groundwater. Based on the noble gas and stable carbon isotope results in all samples, we propose a two-stage gas and groundwater interaction process during the gas preservation and accumulation history in the Anyue gas field in China.Li, Z., Ripepi, N., Chen, C., 2020. Using pressure pulse decay experiments and a novel multi-physics shale transport model to study the role of Klinkenberg effect and effective stress on the apparent permeability of shales. Journal of Petroleum Science and Engineering 189, 107010. confining pressure imposed on a shale formation has a significant impact on the apparent permeability of the rock. Gas flow in low-permeability shales differs significantly from liquid flow because of the Klinkenberg effect, which results from gas molecule slip at the wall surfaces inside the nanopores. This effect causes the increase of apparent permeability (i.e., the measured permeability). In this study, cores extracted from four U.S. shale formations were tested using a pulse decay permeameter (PDP) under varying combinations of confining and pore pressures. The Klinkenberg coefficient was calculated to interpret the change in the measured apparent permeability as a function of pore pressure and effective stress. Next, based on the various combinations of confining and pore pressures, the actual values of the Biot coefficient were calculated by data fitting. Moreover, the samples were cored in the directions parallel to and perpendicular to the shale bedding planes to unravel the role of bedding plane direction on the apparent permeability. Furthermore, a novel, multi-physics shale transport (MPST) model was developed to account for the coupled multi-physics processes of geomechanics, fluid dynamics, and Klinkenberg effect for gas transport in shales. In the MPST model, pore pressure and effective stress are the two independent input variables, and the measured apparent permeability is the model output. The MPST model was then used to fit the PDP experimental data, and the successful data fitting confirmed that the MPST model captures the critical multi-physics processes that regulate the apparent permeability.Lian, L., Yan, S., Zhou, H., Song, W., 2020. Overview of the phototransformation of wastewater effluent by high-resolution mass spectrometry. Environmental Science & Technology 54, 1816-1826. transformation driven by sunlight is one of the most important natural processes for organic contaminant attenuation. In the current study, statistical analysis-assisted high-resolution mass spectrometry was employed to investigate the phototransformation of nontarget features in wastewater effluents under various radical quenching/enhancing conditions. A total of 9694 nontarget features were extracted from the effluents, including photoresistant features, photolabile features and transformation products. 65% of the wastewater effluent features were photoresistant, and the photolabile features could be classified into five groups: direct photolysis group (group I), HO?-originated species-dominated group (group II), 3OM*-dominated group (group III), photochemically produced reactive intermediates (PPRIs) combination-dominated group (group IV), and non-first-order degradation group (group V). The direct photolyzed features were observed to degrade significantly faster than the indirect photolyzed features. Moreover, group II dominated by HO?-originated species contributed 34% to the photolabile features. The reaction types that occurred in the phototransformation process were analyzed by linkage analysis. The results suggested that oxygen addition and dealkyl group reactions were the most common reaction types identified in the phototransformation process. Overall, high-resolution mass spectrometry coupled with statistical analysis was applied here to understand the photochemical behavior of the unknown features in wastewater effluents.Liang, J., Wang, H., Blum, M.J., Ji, X., 2020. Modeling of hydrocarbon migration and accumulation on the Chengzikou uplift, Bohai Bay Basin, China: Implications for petroleum exploration on slope belts in rift basins. Journal of Petroleum Science and Engineering 189, 106963. Chengzikou Uplift (CZKU) is a second-order structure surrounded by several hydrocarbon generative kitchens in the Bohai Bay Basin. However, six recently drilled wells on the CZKU failed to prove hydrocarbon occurrences, which causes confusion for the understanding of hydrocarbon migration and accumulation on the CZKU. Mainly based on the seismic database, this paper attempted to determine the hydrocarbon migration pathways and enrichment mechanisms on the CZKU. The results show that the lateral and vertical hydrocarbon migration seems to take place through a stepped pathway system consisting of permeable layers within unconformities, permeable carrier beds, and faults. Through a simple 3D modeling considering topography changes only, the hydrocarbons tend to migrate from the northern sags to the southern slope and uplift with parallel mainstreams and accumulate with convergent mainstreams. The potential hydrocarbon traps mainly include stratigraphic, structural, and structural-lithologic traps, most of which have been confirmed by previous explorations. Subsequently, two preliminary interpretations for the dry well on the CZKU are made: the first is hydrocarbons mainly accumulated in the Paleogene stratigraphic (onlapping) traps within the sag and slope area, conducting no further migration to the uplift; the other is hydrocarbons may migrate to the slope and uplift but were trapped in structural-lithologic traps associated with faults beyond the area of the dry wells. Moreover, favorable hydrocarbon accumulation targets are predicted to reduce exploration risk.Liang, X., Xu, Z., Zhang, Z., Wang, W., Zhang, J., Lu, H., Zhang, L., Zou, C., Wang, G., Mei, J., Rui, Y., 2020. Breakthrough of shallow shale gas exploration in Taiyang anticline area and its significance for resource development in Zhaotong, Yunnan Province, China. Petroleum Exploration and Development 47, 12-29. on exploration and development results and evaluation of marine shale gas in South China in the past ten years, in view of the features of “high maturity, strong tectonic reformation and high shear stress” of the shale in Zhaotong exploration zone in the Yunnan and Guizhou Plateau, as well as the key issues of long time diffusion and leakage of shallow shale gas, and the preservation conditions, the factors controlling shallow shale gas sweet spot and key zone selection evaluation technology of shale gas are investigated. From 2017 to 2018, the first significant exploration breakthrough was made in the Taiyang anticline at a buried depth of 700 to 2 000 m, discovering large-scale proved geological reserves of shallow shale gas. By examining the accumulation conditions and sweet spot control factors of the shallow shale gas in this area, it is found that the accumulation and productivity potential of shale gas in the mountainous area with complex structure outside basin are controlled by five factors: (1) The gas-rich area has weak tectonic reformation and good preservation conditions on the whole, taking on typical anticline trap occurrence mode. (2) The gas-rich area is in over-pressure state and high in shale gas content. (3) The gas-rich area has high quality shale and thus superior source rock condition. (4) The gas-rich area has high quality reservoirs dominated by class I. (5) The shale gas reservoir in the gas-rich area has high content of brittle minerals and small difference between maximum and minimum horizontal stresses which are conducive to hydraulic fracturing. The innovative practice and core technologies formed during the exploration and production capacity construction of shallow shale gas in the Zhaotong demonstration zone have great reference significance for shallow shale gas exploration and development in other areas.Liao, J., Lu, H., Feng, Q., Zhou, Y., Shi, Q., Peng, P.a., Sheng, G., 2020. Identification of a novel undecamethylhenicosane and three oxygenated precursors in a Maoming Basin shale, China. Organic Geochemistry 141, 103974. to our recent identification of a C33 botryococcane, a C33 botryococcan-24-one and two C31 botryococcanes (2,3,6,7,10,12,15,16,19,20-decamethylhenicosanes: C31 DMHs) with a methyl group β-positioned to the sole quaternary carbon in the skeleton in a sediment sample from the Maoming Basin, we report the NMR-based structural identification of a new C32 botryococcane (2,3,6,7,10,10,12,15,16,19,20-undecamethylhenicosane: C32 UMH), and MS-based structural identification of a C32 botryococcanal (C32 UMH-al) and two C31 epimeric botryococcanols (C31 DMH-ols) in the same sediment sample after trimethylsilylation. These three oxygenated botryococcanoids are speculated to possess the same β-positioned methyl group (to the sole quaternary carbon).We propose that the C32 UMH-al and two epimeric C31 DMH-ols are degradation products of the C=C double bond in the ethenyl group connected to the sole quaternary carbon in their biological precursor C33 botryococcene with a unique β-positioned methyl group (to the quaternary carbon), and are geochemical precursors for the C32 UMH and previously identified C31 DMHs, respectively. Since it is known that abiotic degradation (photo-mediated or autoxidation) preferentially acts on the internal double bond while sedimentary bacteria preferentially degrade the terminal double bond, our finding of a degraded terminal C24-25 double bond and an intact internal double bond (at C11-12) is indicative of bacterially mediated degradation. A detailed bacterially mediated degradation pathway is proposed to explain the formation of C31–C33 botryococcanes and their oxygenated derivatives.Liao, W., Hu, J., Zhou, H., Peng, P.a., 2020. Climatic and human impact on the environment: Insight from the tetraether lipid temperature reconstruction in the Beibu Gulf, China. Quaternary International 536, 75-84. proxies have been widely used to reconstruct temperature and terrestrial input variation at the interface between land and sea. However, the impact of human activities on these proxies has been little constrained, which might cause the misinterpretation of the sediment profile. In order to study the climatic and human impact on the environment, proxies in coastal regions, glycerol dialkyl glycerol tetraethers (GDGTs) in a sediment core spanning 115 years was analyzed from Beibu Gulf, China. The results indicate that isoprenoid GDGTs in the Beibu Gulf were mainly derived from Thaumarchaeota and the branched GDGTs originated mainly from terrestrial soil bacteria. The TEX86 index was applied to reconstruct the temporal SST variation. The results show that variation of TEX86-derived SST is controlled mainly by East Asian Monsoon system and partly by ENSO events. The methylation index of branched tetraethers or the cyclization index of branched tetraethers (MBT/CBT) derived mean annual air temperature (MAAT) agreed with MAAT record at the Qinzhou Station before 1982 AD. However, the population growth and economic development after 1982 AD caused the reduction of terrestrial organic matter input and increase of nutrient, leading to the thriving of Thaumarchaeota and increasing of in situ branched GDGTs proportion, which created the scatter of the MBT/CBT-reconstructed MAAT after 1982 AD. Therefore, human influence on GDGT proxies can be constrained in this way to avoid misinterpretation of paleoclimate and paleoenvironment records.Lieberman, N.R., Izquierdo, M., Mu?oz-Quirós, C., Cohen, H., Chenery, S.R., 2020. Geochemical signature of superhigh organic sulphur Ra?a coals and the mobility of toxic trace elements from combustion products and polluted soils near the Plomin coal-fired power station in Croatia. Applied Geochemistry 114, 104472. the northern Adriatic coast of Croatia, combustion of super-high organic sulphur rich Ra?a coal was common between 1970 and 2000. These Late Paleocene coals are enriched in a number of trace elements. This work aims to provide a detailed study on the distinctive geochemical patterns of the Ra?a coal and investigate the environmental effects of the coal and combustion by-products on the area. Several analytical techniques were used to study the mode of occurrence, distribution, levels and solubility of major and trace elements in the Ra?a coal, fly ash, slag and soils in an area within 10?km from the power station. Due to the sulphur-rich calcareous depositional environment of the Ra?a coal, the combustion by-products are enriched in S and Ca. Fly ash and slag are enriched in potentially harmful trace elements i.e. Se, Mo, Hg, V and U. Similar enrichment pattern was found for soils suggesting that resuspension and deposition of airborne coal and fly ash particles, transport of gaseous species in the flue gas by dominant winds and/or leaching from ash deposits may have affected the wider environment. Whilst a large number of trace elements were found to be poorly soluble across samples, the leachable concentrations of Se, Cr and Mo in fly ash and slag are noteworthy. Their organic association in coal enhances volatilisation during combustion and then further condensation on ash particles as readily soluble oxyanionic species. Other oxyanionic metalloids such as As or V were insoluble in fly ash and slag, due to precipitation of solubility-limiting Ca-bearing species.Lin, C.Y., Turchyn, A.V., Krylov, A., Antler, G., 2020. The microbially driven formation of siderite in salt marsh sediments. Geobiology 18, 207-224. employ complementary field and laboratory-based incubation techniques to explore the geochemical environment where siderite concretions are actively forming and growing, including solid-phase analysis of the sediment, concretion, and associated pore fluid chemistry. These recently formed siderite concretions allow us to explore the geochemical processes that lead to the formation of this less common carbonate mineral. We conclude that there are two phases of siderite concretion growth within the sediment, as there are distinct changes in the carbon isotopic composition and mineralogy across the concretions. Incubated sediment samples allow us to explore the stability of siderite over a range of geochemical conditions. Our incubation results suggest that the formation of siderite can be very rapid (about two weeks or within 400?hr) when there is a substantial source of iron, either from microbial iron reduction or from steel material; however, a source of dissolved iron is not enough to induce siderite precipitation. We suggest that sufficient alkalinity is the limiting factor for siderite precipitation during microbial iron reduction while the lack of dissolved iron is the limiting factor for siderite formation if microbial sulfate reduction is the dominant microbial metabolism. We show that siderite can form via heated transformation (at temperature 100°C for 48?hr) of calcite and monohydrocalcite seeds in the presence of dissolved iron. Our transformation experiments suggest that the formation of siderite is promoted when carbonate seeds are present.Lin, H., Guo, L., 2020. Variations in colloidal DOM composition with molecular weight within individual water samples as characterized by flow field-flow fractionation and EEM-PARAFAC analysis. Environmental Science & Technology 54, 1657-1667. excitation emission matrices (EEM) and parallel factor (PARAFAC) analysis have been widely used in the characterization of dissolved organic matter (DOM) in the aquatic continuum. However, large sample sets are typically needed for establishing a meaningful EEM-PARAFAC model. Applications of the EEM-PARAFAC technique to individual samples require new approaches. Here, flow field-flow fractionation (FlFFF) combined with offline EEM measurements and PARAFAC analysis was used to elucidate the dynamic changes in DOM composition/optical properties with molecular weight within individual samples. FlFFF-derived size spectra of ultrafiltration-isolated colloidal DOM show that peak-C related fluorophores (Ex/Em= 350/450 nm) are present mostly in the 1–3 kDa size range, while peak-T associated fluorophores (Ex/Em = 275/340 nm) have a bimodal distribution with peaks in both the 1–3 kDa and the >100 kDa size fractions. The integrated EEM spectra from FlFFF size-fractionated subsamples closely resembled the bulk EEM spectra, attesting to the convincing comparability between bulk and FlFFF size-fractionated EEMs. The PARAFAC-derived DOM components are distinctive among individual samples with the predominant components being humic-like in river water, but protein-like in a highly eutrophic lagoon sample. This compelling new approach combining FlFFF and EEM-PARAFAC can be used to decipher the dynamic changes in size spectra and composition of individual DOM samples from sources to sinks or across the redox/hydrological/trophic interfaces.Lin, Y.-S., Lee, J., Lin, L.-H., Fu, K.-H., Chen, C.-T.A., Wang, Y.-H., Lee, I.H., 2020. Biogeochemistry and dynamics of particulate organic matter in a shallow-water hydrothermal field (Kueishantao Islet, NE Taiwan). Marine Geology 422, 106121. particulate organic matter (POM) of shallow-water hydrothermal fields has been studied in the context of food web reconstruction, but the processes governing its biogeochemistry and dynamics are poorly explored. Here, we investigate the POM in the Kueishantao hydrothermal field using chemical and hydrodynamic approaches. The depletion of total suspended matter, lower C/N ratios, and higher carbon isotopic values of particulate organic carbon (δ13CPOC) in the vertical plumes relative to values derived from Si-based models were attributed to the hydraulic sorting of the vented particles, which tend to have more N and 13C in the fine fraction. The particulate organic carbon (POC), unlike the total suspended matter, was enriched in the vertical plumes and explained by physicochemical processes rather than biological addition. The POC-enriched plume-top water was found to be a better endmember than the vent fluids to explain particle mixing in the lateral plume. Physical mixing played a steering role in shaping the particle chemistry of the lateral plumes, but markedly 13C-enriched POC was still observable in several near-vent, low-to-intermediate-Si plume waters, implying locally enhanced primary production of at least 0.1–0.4 mg C/m3/h. The presence of eddies, confirmed by flow field measurements, should have contributed to the detection of biogeochemical anomalies via extending the retention time of plume water to 1–2 h. The dominating mixing process resulted in decoupling between the δ13CPOC signatures and carbonate chemistry in this shallow-water hydrothermal plume.Linse, K., Copley, J.T., Connelly, D.P., Larter, R.D., Pearce, D.A., Polunin, N.V.C., Rogers, A.D., Chen, C., Clarke, A., Glover, A.G., Graham, A.G.C., Huvenne, V.A.I., Marsh, L., Reid, W.D.K., Roterman, C.N., Sweeting, C.J., Zwirglmaier, K., Tyler, P.A., 2019. Fauna of the Kemp Caldera and its upper bathyal hydrothermal vents (South Sandwich Arc, Antarctica). Royal Society Open Science 6, 191501. assemblages at hydrothermal vents associated with island-arc volcanism are less well known than those at vents on mid-ocean ridges and back-arc spreading centres. This study characterizes chemosynthetic biotopes at active hydrothermal vents discovered at the Kemp Caldera in the South Sandwich Arc. The caldera hosts sulfur and anhydrite vent chimneys in 1375–1487 m depth, which emit sulfide-rich fluids with temperatures up to 212°C, and the microbial community of water samples in the buoyant plume rising from the vents was dominated by sulfur-oxidizing Gammaproteobacteria. A total of 12 macro- and megafaunal taxa depending on hydrothermal activity were collected in these biotopes, of which seven species were known from the East Scotia Ridge (ESR) vents and three species from vents outside the Southern Ocean. Faunal assemblages were dominated by large vesicomyid clams, actinostolid anemones, Sericosura sea spiders and lepetodrilid and cocculinid limpets, but several taxa abundant at nearby ESR hydrothermal vents were rare such as the stalked barnacle Neolepas scotiaensis. Multivariate analysis of fauna at Kemp Caldera and vents in neighbouring areas indicated that the Kemp Caldera is most similar to vent fields in the previously established Southern Ocean vent biogeographic province, showing that the species composition at island-arc hydrothermal vents can be distinct from nearby seafloor-spreading systems. δ13C and δ15N isotope values of megafaunal species analysed from the Kemp Caldera were similar to those of the same or related species at other vent fields, but none of the fauna sampled at Kemp Caldera had δ13C values, indicating nutritional dependence on Epsilonproteobacteria, unlike fauna at other island-arc hydrothermal vents.Liou, P., Cui, X., Guo, J., Zhai, M., 2020. Possible link between the oldest supracrustal unit and the oldest rock unit of China. Precambrian Research 342, 105672. Group (or Caozhuang supracrustal sequence) in Eastern Hebei, North China Craton (NCC) may represent the oldest supracrustal unit of China. Abundant Eoarchean and Paleoarchean detrital zircons (up to 3.88 Ga) in paragneisses of Caozhuang Group provide valuable memories of the earliest crustal evolution of China. There still remains confusion about the deposition time of the Caozhuang group, the origin and the igneous host rocks of their detrital zircons, and the earliest crustal evolution of NCC. In this study, the combined U–Pb and Lu–Hf datasets provide evidence that ~3.3–3.4 Ga is a probable estimate for the maximum deposition age of the Caozhuang Group. In addition, the increasingly subchondritic Hf isotopic compositions between 3.9 and 3.4 Ga reflected by the broadly linear Hf isotope evolution defined by Caozhuang detrital zircons may support the protracted intra-crustal reworking of a long-lived mafic source in composition with 176Lu/177Hf of 0.027. The Lu-Hf composition of the mafic source is similar to the average value of ocean floor basalts (176Lu/177Hf = 0.028) and Eoarchean-Paleoarchean Caozhuang mafic rocks (176Lu/177Hf = 0.026) in the same area. Based on the similarities between Caozhuang detrital zircons and TTG-hosted zircons of Anshan complex, as well as the significant differences with other Archean ancient complexes, the Anshan complex, where the oldest rock unit of China is preserved, may be the suitable host rocks for Caozhuang detrital zircons.Liu, B., Teng, J., Mastalerz, M., Schieber, J., 2020. Assessing the thermal maturity of black shales using vitrinite reflectance: Insights from Devonian black shales in the eastern United States. International Journal of Coal Geology 220, 103426. maturity of source rocks indicated by vitrinite reflectance (Ro) is an important and reliable parameter to determine the petroleum potential of sedimentary basins. Originally, Ro was used to characterize the degree of coalification of coals and thus works well for coal seams, but it has limitations when used to determine the thermal maturity of black shale successions. A suite of six coal-shale pairs from the Upper Devonian black shale formations in the eastern United States (New Albany Shale, Ohio Shale, Dunkirk Shale, and Rhinestreet Shale) was selected to study the applicability of Ro in assessing the thermal maturity of black shale successions. The results show that vitrinite in the studied coal samples is dominated by collotelinite, whereas vitrinite in black shales occurs as small dispersed particles (~5 μm) in the mineral matrix. When comparing the size and morphology of dispersed vitrinite particles in shales and collotelinite fragments in coals, vitrinite in shales and adjacent coals should have the same origin. The measured mean random Ro of vitrinite in coals ranges from 0.51–0.68%, and is 0.04–0.11% (average 0.07%) lower than that of dispersed vitrinite particles in enclosing shales. This observation contrasts with previously reported Ro suppression in liptinite-rich black shales. A high standard deviation of Ro measurements indicates a highly heterogeneous nature of vitrinite in black shales.Three mechanisms can be envisioned to contribute to the higher Ro of dispersed vitrinite particles in black shales relative to enclosed coals. First, small vitrinite particles may become more oxidized because small particles are more frequently suspended during transport to the site of deposition and reworking of bottom sediments after deposition than large pieces of driftwood that will turn into enclosed coal lenses during burial diagenesis. Second, misidentification of zooclast (e.g., chitinozoan) fragments as vitrinite due to loss of diagnostic morphology. Third, various macerals in the vitrinite group (e.g., corpogelinite and collotelinite) may have had different original reflectance values. Based on the petrographic characteristics of vitrinite and vitrinite-like particles, caution should be applied when using the Ro values of dispersed vitrinite and vitrinite-like particles in black shales as indicators of thermal maturity.Liu, C., Li, Y., Liu, L., Hu, G., Chen, Q., Wu, N., Meng, Q., 2020. An integrated experimental system for gas hydrate drilling and production and a preliminary experiment of the depressurization method. Natural Gas Industry B 7, 56-63. current natural gas hydrate extraction experimental research has always been carried out in a small-scale simulation test device, and the resulted boundary effect is so obvious due to the small size of samples in the reaction kettle that the experimental results will be difficult to apply in the field. In this paper, an integrated experimental system for drilling and exploitation of gas hydrate is developed innovatively based on the idea of depressurization method and the technological process. This experimental system consists of high-pressure vesselmodule, drilling & extraction module, liquid supply module, gas supply module, confining pressure loading module, back-pressure control module, three-phase separation module, temperature control module, data acquisition module and an operational platform. The hydrate-bearing samples similar to marine hydrate formations were prepared inthe experimental system with the actual geological surroundings simulated. The electrical resistance tomography was used to real-time monitor the dynamic distribution of gas hydrate in sediments inside the high-pressure vessel (521 L). This experimental system can also simulate the process of wellbore drilling in hydrate reservoirs and depressurization extraction, and realize the real-time monitoring of parameters in the whole production process such as gas production, water production, sand production, temperature, pressure, etc. We carried out a preliminary experiment on the CO2 hydrate extraction via depressurization by using this experimental system. Fundamental procedures for data acquisition and analysis were established and verified. The variations of temperature and pressure fields and gas/water output behaviors in the reservoirs were both achieved. The results show that (1) the gas and water production rate fluctuate greatly even at a constant backpressure; (2) the reservoir temperature distribution is uneven during hydrate decomposition, and the maximum temperature is decreased by 5 °C, suggesting that the hydrate decomposition is heterogeneous and stochastic. The abundant and credible experimental results based on this system are expected to provide important data support for marine gas hydrate production tests.Liu, F., Wang, M., 2020. Review of low salinity waterflooding mechanisms: Wettability alteration and its impact on oil recovery. Fuel 267, 117112. salinity waterflooding (LSW) has attracted attention of numerous researchers as a promising technique for enhanced oil recovery, yet its application is still limited because of incomplete mechanisms and unreliable predictions. This paper summarizes relevant mechanisms for predicting responses of LSW. Since the wettability alteration is generally regarded as the most important one among possible LSW mechanisms, two aspects of predicting LSW responses are reviewed: prediction of wettability alteration and effects of wettability alteration on oil recovery. For the first aspect, the importance of more quantitative prediction of wettability alteration is addressed because experimental results have suggested that the optimal wettability may not be water-wet as imagined. From the relation between wettability and interaction forces in the oil-brine-rock systems, mechanisms of wettability alteration are reviewed along with quantitative calculation. The extended Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, which has been often used to calculate the contact angles, is not available to obtain an accurate contact angle anymore. For the second aspect, an overview of the optimal wettability for oil recovery is given with relevant pore-scale fluid mechanisms. Though experiments found the maximum oil recovery from weakly water-wet or neutral wet rocks, the results were not elaborate enough to reveal the relation between the contact angle and the oil recovery. The pore-scale simulation is a powerful tool to investigate such relations but so far it still needs further developments on scaling and validations with experimental data.Liu, H., Su, T., He, W., Wang, Q., Lin, C., 2019. The universally conserved residues are not universally required for stable protein expression or functions of cryptochromes. Molecular Biology and Evolution 37, 327-340. conserved residues (UCRs) are invariable amino acids evolutionarily conserved among members of a protein family across diverse kingdoms of life. UCRs are considered important for stability and/or function of protein families, but it has not been experimentally examined systematically. Cryptochromes are photoreceptors in plants or light-independent components of the circadian clocks in mammals. We experimentally analyzed 51 UCRs of Arabidopsis cryptochrome 2 (CRY2) that are universally conserved in eukaryotic cryptochromes from Arabidopsis to human. Surprisingly, we found that UCRs required for stable protein expression of CRY2 in plants are not similarly required for stable protein expression of human hCRY1 in human cells. Moreover, 74% of the stably expressed CRY2 proteins mutated in UCRs retained wild-type-like activities for at least one photoresponses analyzed. Our finding suggests that the evolutionary mechanisms underlying conservation of UCRs or that distinguish UCRs from non-UCRs determining the same functions of individual cryptochromes remain to be investigated.Liu, J., Xie, H., Wang, Q., Chen, S., Hu, Z., 2020. The influence of pore structure on shale gas recovery with CO2 sequestration: Insight into molecular mechanisms. Energy & Fuels 34, 1240-1250. the focus of shale gas recovery has shifted to CO2 sequestration with enhanced gas recovery (CS-EGR) for overcoming the low recovery efficiency, the adsorption and recovery mechanism of methane (CH4) and carbon dioxide (CO2) considering the effect of pore structures remains to be revealed. In this work, we focus on the influence of pore structures on adsorption behaviors of CH4 and CO2 at different geological depths and recovery process in different pore structures with various injection gas pressure. The results demonstrate that the excess adsorption capacity of CH4 and CO2 is in the order of cylinder-shaped > bottle neck > wedge-shaped > slit-shaped. Both the adsorption capacity of CH4 and CO2 increase initially with geological depth until reaching maximum, and then decrease with the depth going deeper. As for competitive adsorption of CH4 and CO2, the pore structures have no much influence on the selectivity. But, the pore structures have significant impact on shale gas recovery, the difficulty of CH4 molecules being displaced in various pore structures is ordered as cylinder-shaped > bottle neck > slit-shaped > wedge-shaped pores, which is consistent with the system resistance. The displacement efficiency of CH4 in cylinder-shaped pores is about 59% much less than other pore structures. The injection pressure has a negative effect on the speed of shale gas recovery and displacement efficiency of CH4 for the reason that more molecules aggregate into clusters near the pore throat and the flow blocking effect become more obvious when the injection pressure increases. Based on this actuality, we proposed a probably reliable method for CS-EGR, lower injection pressure is initially set to improve recovery efficiency and higher pressure is finally used to increase CO2 sequestration amount.Liu, N., Qiu, N., Li, Z., Cai, C., Shan, X., Gao, T., Wang, Y., 2019. Significance and evolution characteristics of the isobutane/n-butane ratio of natural gas. Energy Exploration & Exploitation 38, 494-518. previous studies, two conflicting conclusions existed, which were: (a) the isobutane/n-butane ratio of natural gas increases with the increasing maturity (Ro) of source rocks and (b) decreases with the increasing Ro. In this paper, the correlations between the isobutane/n-butane ratios, dryness of natural gases, and the Ro values of source rocks of 77 gas samples from Cretaceous and Tertiary in Kuqa Depression, Tarim Basin, Triassic Xujiahe Formation in central Sichuan Basin, Carboniferous–Permian in Sulige and Yulin gas field, Ordos Basin, China, and 80 shale gas samples from Mississippian Barnett Shale in the Fort Worth Basin, the United States are analyzed to reveal the evolution of the isobutane/n-butane ratios, then mathematical models of the isobutane/n-butane ratios and Ro are attempted to be established. Results show that the isobutane/n-butane ratio initially increases and then decreases with increasing Ro, both coal-derived gas and oil-type gas. Diverse types of kerogens may be responsible for the different corresponding Ro values when the isobutane/n-butane ratios of gases reach their maximum values. The initial increase in the isobutane/n-butane ratios with increasing Ro is the reason that isobutane is mainly generated at a higher rate by carbonium ion reaction of α-olefins with protons during kerogen primary cracking at lower maturity, whereas free radical reactions to form n-butane relatively quickly during oil cracking at higher maturity and isobutane cracked at a higher rate during the wet gas cracking stage may result in the terminal decreases in the isobutane/n-butane ratios. Besides, mathematical models of the isobutane/n-butane ratios of different types of natural gas and maturity are established. Therefore, the maturity of gas source rock can be obtained quickly based on the models using the isobutane/n-butane ratio combined with other component information (such as dryness, wetness, etc.), which is of great significance to the characterization of natural gas maturity and gas source rock correlation.Liu, P., Shi, L., Liu, P., Li, L., Hua, D., 2020. Experimental study of high-temperature CO2 foam flooding after hot-water injection in developing heavy oil reservoirs. Journal of Petroleum Science and Engineering 185, 106597. water flooding is one of the main strategies employed in the recovery of heavy oil. However, the low viscosity of the injected hot water readily generates the formation of water channels in oil bearing formations with high permeability, resulting in relatively low oil recovery. This study addresses this issue by experimentally investigating the application of a CO2 foam injection process as a secondary strategy after hot water injection. Six surfactants were evaluated for foam generation at temperatures in the range of 57–200?°C in a series of screening tests, including static foam tests, thermal stability testing, and resistance factor evaluation. The optimum surfactant was accordingly selected for application in the CO2 foam injection process. The addition of 0.04?wt% anionic polyacrylamide (HPAM) as a stabilizer in the selected surfactant produced a more stable foam appropriate for use at a temperature of 80?°C or less. Oil displacement experiments were conducted using both a high permeability sand pack and a low permeability sand pack simultaneously to investigate water channel creation during hot water injection and the channel blockage resulting from the injected foam along with the corresponding oil recovery enhancement. The experimental results indicate that hot water in the hot water injection process flows readily through the high permeability sand pack and reduces the oil viscosity, which results in an increased degree of water channeling of the high-permeability sand pack. The high-temperature CO2 foam generated under optimum conditions using the selected surfactant effectively blocks the water channeling created during the preceding hot water injection process and significantly increases the oil displacement efficiencies of both the low- and high-permeability sand packs. The results of this study demonstrate that the secondary injection of CO2 foam following hot water injection represents a promising heavy oil recovery strategy for developing heavy oil reservoirs.Liu, X., Gao, H., Ward, J.E., Liu, X., Yin, B., Fu, T., Chen, J., Lovley, D.R., Yao, J., 2020. Power generation from ambient humidity using protein nanowires. Nature 578, 550-554. energy from the environment offers the promise of clean power for self-sustained systems. Known technologies—such as solar cells, thermoelectric devices and mechanical generators—have specific environmental requirements that restrict where they can be deployed and limit their potential for continuous energy production. The ubiquity of atmospheric moisture offers an alternative. However, existing moisture-based energy-harvesting technologies can produce only intermittent, brief (shorter than 50 seconds) bursts of power in the ambient environment, owing to the lack of a sustained conversion mechanism. Here we show that thin-film devices made from nanometre-scale protein wires harvested from the microbe Geobacter sulfurreducens can generate continuous electric power in the ambient environment. The devices produce a sustained voltage of around 0.5 volts across a 7-micrometre-thick film, with a current density of around 17 microamperes per square centimetre. We find the driving force behind this energy generation to be a self-maintained moisture gradient that forms within the film when the film is exposed to the humidity that is naturally present in air. Connecting several devices linearly scales up the voltage and current to power electronics. Our results demonstrate the feasibility of a continuous energy-harvesting strategy that is less restricted by location or environmental conditions than other sustainable approaches.Liu, X., Hilfert, L., Barth, J.A.C., van Geldem, R., Friese, K., 2020. Isotope alteration caused by changes in biochemical composition of sedimentary organic matter. Biogeochemistry 147, 277-292. carbon (C) and nitrogen (N) isotope ratios of sedimentary organic matter (OM) can reflect the biogeochemical history of aquatic ecosystems. However, diagenetic processes in sediments may alter isotope records of OM via microbial activity and preferential degradation of isotopically distinct organic components. This study investigated the isotope alteration caused by preferential degradation in surface sediments sampled from a eutrophic reservoir in Germany. Sediments were treated sequentially with hot water extraction, hydrochloric acid hydrolysis, hydrogen peroxide oxidation and di-sodium peroxodisulfate oxidation to chemically simulate preferential degradation pathways of sedimentary OM. Residue and extracts from each extraction step were analyzed using elemental analyzer-isotope ratio mass spectrometry and solid-state 13C nuclear magnetic resonance spectroscopy. Our results show that stable C and N isotope ratios reacted differently to changes in the biochemical composition of sedimentary OM. Preferential degradation of proteins and carbohydrates resulted in a 1.2‰ depletion of 13C, while the isotope composition of 15N remained nearly the same. Sedimentary δ15N values were notably altered when lignins and lipids were oxidized from residual sediments. Throughout the sequential fractionation procedure, δ13C was linearly correlated with the C:N of residual sediments. This finding demonstrates that changes in biochemical composition caused by preferential degradation altered δ13C values of sedimentary OM, while this trend was not observed for δ15N values. Our study identifies the influence of preferential degradation on stable C isotope ratios and provide additional insight into the isotope alteration caused by post-depositional processes.Liu, X., Wu, H., Gan, M., Qiu, G., 2020. Pyrite-based Cr(VI) reduction driven by chemoautotrophic acidophilic bacteria. Frontiers in Microbiology 10, 3082. doi: 10.3389/fmicb.2019.03082.(VI) is considered as a priority pollutant, and its remediation has attracted increasing attention in the environmental area. In this study, the driving of pyrite-based Cr(VI) reduction by Acidithiobacillus ferrooxidans was systematically investigated. The results showed that pyrite-based Cr(VI) reduction was a highly proton-dependent process and that pH influenced the biological activity. The passivation effect became more significant with an increase in pH, and there was a decrease in Cr(VI) reduction efficiency. However, Cr(VI) reduction efficiency was enhanced by inoculation with A. ferrooxidans. The highest reduction efficiency was achieved in the biological system with a pH range of 1–1.5. Pyrite dissolution and reactive site regeneration were promoted by A. ferrooxidans, which resulted in the enhanced effect in Cr(VI) reduction. The low linear relevancy between pH and Cr(VI) dosage in the biological system indicated a complex interaction between bacteria and pyrite. Secondary iron mineral formation in an unfavorable pH environment inhibited pyrite dissolution, but the passivation effect was relieved under the activity of A. ferrooxidans due to S/Fe oxidization. The balance between Cr(VI) reduction and biological activity was critical for sustainable Cr(VI) reduction. Pyrite-based Cr(VI) remediation driven by chemoautotrophic acidophilic bacteria is shown to be an economical and efficient method of Cr(VI) reduction.Liu, Y., Ye, J., Cao, Q., Yang, B., Liu, Z., 2020. Hydrocarbon generation, migration, and accumulation in the Eocene Niubao Formation in the Lunpola Basin, Tibet, China: Insights from basin modeling and fluid inclusion analysis. Journal of Earth Science 31, 195-206. Eocene Niubao Formation is the primary research target of oil exploration in the Lunpola Basin. Crude oil was extracted from Well Z1 on the northern margin of the basin in 1993. In this study, an integrated evaluation of the source rock, geothermal, and maturity histories and the fluid inclusion and fluid potential distributions was performed to aid in predicting areas of hydrocarbon accumulation. Due to the abundance of organic matter, the kerogen types, maturity, and oil-sources correlate with the geochemical data. The middle submember of the second member of the Niubao Formation (E2n2-2) is the most favorable source rock based on the amount of oil produced from the E2n2-3 and E2n3-1 reservoirs. One- and two-dimensional basin modeling, using BasinMod software, shows that the E2n2-2 source rock started to generate hydrocarbon at 35-30 Ma, reached a maturity of R0=0.7% at 25-20 Ma, and at present, it has reached the peak oil generation stage with a thermal maturity of R0=0.8% to less than R0=1.0%. By using fluid inclusion petrography, fluorescence spectroscopy, and microthermometry, two major periods of oil charging have been revealed at 26.1-17.5 and 32.4-24.6 Ma. The oil accumulation modeling results, conducted by using the Trinity software, show a good fit of the oil shows in the wells and predict that the structural highs and lithologic transitions within the Jiangriaco and Paco sags are potential oil traps.Liu, Y., Ye, Q., Huang, W.-L., Feng, L., Wang, Y.-H., Xie, Z., Yong, S.-S., Zhang, S., Jiang, B., Zheng, Y., Wang, J.-J., 2019. Spectroscopic and molecular-level characteristics of dissolved organic matter in the Pearl River Estuary, South China. Science of The Total Environment 710, 136307. populations are expanding globally, resulting in great anthropogenic impacts on the organic matter in estuaries and regional carbon cycles. However, the molecular-level characteristics of dissolved organic matter (DOM) within highly disturbed estuaries are still not well understood. Here, water samples collected during two seasons (wet and dry) from the subtropical Pearl River Estuary of China were analyzed using absorption and fluorescence spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to determine the spatiotemporal variations in the DOM characteristics. In the seaward direction, the abundances of chromophoric and fluorescent DOM decreased by greater percentages than the bulk dissolved organic carbon concentration. The spectroscopy and FT-ICR MS analyses collectively indicated seaward declines in the aromaticity of DOM and terrestrial DOM contributions from natural terrestrial markers and anthropogenic synthetic surfactants. In particular, the S content in DOM was much higher here than in previously reported estuaries, suggesting a strong anthropogenic impact on the estuarine DOM. Greater terrestrial and anthropogenic signatures in DOM were observed in the wet season than in the dry season. Importantly, this study implies that the terrestrial and anthropogenic contributions to DOM were strongly driven by season in the anthropogenically disturbed subtropical estuary.Liu, Z., Sun, Y., Guo, W., Li, Q., 2020. Sealing effects of marginal gas injection on oil shale in situ pyrolysis exploitation. Journal of Petroleum Science and Engineering 189, 106968. inrush and outward diffusion of pyrolysis products are two disadvantageous factors for oil shale in situ pyrolysis, leading to the loss of heat injected and groundwater pollution. Therefore, forming a closed in situ pyrolysis system is extremely important. The sealing effects of marginal gas injection were studied by numerical simulation. A two-dimensional model was established according to the engineering geology conditions of the National Pilot Project for Oil Shale in situ Exploitation of China (NPOSE), in which methane was regarded as the representative of pyrolysis products. The migration state of methane in dissolved and gas phases during in situ pyrolysis was revealed. The results showed that proper marginal gas injection pressure can effectively inhibit the outward diffusion of methane. Meanwhile, a marginal gas injection pressure of 0.60 or 0.61 MPa can effectively reduce water yield to ~0.5 m3/h. Consequently, a closed in situ pyrolysis system can be effectively formed by marginal gas injection, and the mass exchange inside and outside the pyrolysis zone is insulated, ensuring a clean and efficient pyrolysis process.Liu, Z., Yan, D., Niu, X., 2020. Insights into pore structure and fractal characteristics of the Lower Cambrian Niutitang Formation shale on the Yangtze Platform, South China. Journal of Earth Science 31, 169-180. from the Lower Cambrian Niutitang Formation of Yangtze Platform have been widely investigated due to its shale gas potential. To better illustrate the pore structure and fractal characteristics of shale, a series of experiments were conducted on outcrop samples from the Lower Cambrian Niutitang Formation on Yangtze Platform, including X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and low-temperature nitrogen adsorption. Frenkel-Halsey-Hill (FHH) model was adopted to calculate the fractal dimensions. Furthermore, the relationships between fractal dimensions and pore structure parameters and mineral composition are discussed. FE-SEM observation results show that interparticle pores are most developed in shale, followed by intraparticle pores. This study identified the fractal dimensions D1 (ranging from 2.558 0 to 2.710 2) and D2 (ranging from 2.541 5 to 2.765 2). The pore structure of the Niutitang Formation shale is primarily controlled by quartz and clay content. Fractal dimensions are able to characterize the pore structure complexity of Niutitang Formation shale because D1 and D2 correlate well with average pore diameter and quartz content.Liu, Z., Zhang, Z., Wang, Z., Jin, B., Li, D., Tao, J., Tang, R., De Yoreo, J.J., 2020. Shape-preserving amorphous-to-crystalline transformation of CaCO3 revealed by in situ TEM. Proceedings of the National Academy of Sciences 117, 3397-3404.: Understanding of the shape-preserving crystallization from transient amorphous precursors to crystalline products in biomineralization makes it possible to produce topologically complex morphologies that defy crystallographic controls. Here we use in situ liquid-phase TEM, FTIR, and molecular dynamics simulations to investigate transformation of amorphous CaCO3 to crystalline phases in the presence of multiple additives. In situ observations reveal that Mg2+, which brings excess water into the bulk, is unique in initiating crystallization within the amorphous phase, leading to a shape-preserving transformation that is accompanied by dehydration. Simulation results find that the water accelerates ionic rearrangement within the solid phase, enabling the shape-preserving transformation. This in-depth understanding provides an alternative strategy for manufacturing crystals with arbitrary morphologies by design.Abstract: Organisms use inorganic ions and macromolecules to regulate crystallization from amorphous precursors, endowing natural biominerals with complex morphologies and enhanced properties. The mechanisms by which modifiers enable these shape-preserving transformations are poorly understood. We used in situ liquid-phase transmission electron microscopy to follow the evolution from amorphous calcium carbonate to calcite in the presence of additives. A combination of contrast analysis and infrared spectroscopy shows that Mg ions, which are widely present in seawater and biological fluids, alter the transformation pathway in a concentration-dependent manner. The ions bring excess (structural) water into the amorphous bulk so that a direct transformation is triggered by dehydration in the absence of morphological changes. Molecular dynamics simulations suggest Mg-incorporated water induces structural fluctuations, allowing transformation without the need to nucleate a separate crystal. Thus, the obtained calcite retains the original morphology of the amorphous state, biomimetically achieving the morphological control of crystals seen in biominerals.Loktionova, O.A., Burshtein, L.M., Kalinina, L.M., Kontorovich, V.A., Safronov, P.I., 2019. Historical and geological modeling of the processes of hydrocarbon generation in the Hettangian-Aalenian deposits of the Ust’-Tym megadepression. Russian Geology and Geophysics 60, doi: 10.15372/RGG2019080. of the geologic structure of the Hettangian-Aalenian deposits of the Ust’-Tym megadepression was carried out. The history of the formation of traps in the Hettangian-Aalenian complex has been reconstructed on the basis of a comprehensive interpretation of seismic materials and deep-drilling data. The oil and gas potential has been estimated. The time of the subsidence of the Togur Formation into the oil window has been determined, and the history of the generation of liquid hydrocarbons (HC) by the organic matter (OM) of the Togur Formation has been reconstructed. The Lower Jurassic and Aalenian deposits overlap the rocks of the pre-Jurassic basement with disagreement and are distributed almost over the entire study area. The complete section of the Hettangian-Aalenian deposits is in the most submerged parts of the territory. The section includes the Urman, Togur, and Salat/Peshkov Formations and the lower Tyumen Subformation. Three oil and gas subcomplexes - Hettangian-Early Toarcian (U16-17), Toarcian-Aalenian (U15), and Aalenian (U11-14) - are distinguished within the Hettangian-Aalenian sediments. Closed positive structures that can serve as hydrocarbon traps have been identified in each of the subcomplexes. Positive structures developed in the Jurassic, Berriasian-Early Aptian, and Aptian-Albian-Turonian time were inherited and finally formed at the post-Turonian stage only. The authors carried out a quantitative assessment of the total oil resources of the D0 category for all promising objects, taking into account the success rate. The heterogeneous organic matter of the Togur formation is the main source of hydrocarbons in the Hettangian-Aalenian complex. The Togur Formation began to enter the oil window (OW) about 115-110 Ma and fully entered it about 5 Ma. The escape of rocks from the zone of the oil window began about 48 Ma and still continues. The history of the generation of liquid hydrocarbons by the organic matter of the Togur Formation has been reconstructed for types II and III of kerogen. For type II, the generation began about 94 Ma, at the beginning of the Late Cretaceous (Cenomanian), and for type III, it began in Turonian time (89.8 Ma). The most significant volumes of liquid HC were generated in the last 5 Myr. Potential hydrocarbon traps existed throughout the generation process, which allowed accumulation of the generated hydrocarbons in the Hettangian-Aalenian complex. Comparison of the estimated oil resources of the D0 category in the traps of the Hettangian-Aalenian complex with the volumes of generated hydrocarbons leads to the conclusion that the traps might have been filled. The results obtained in the course of the study suggest that the Hettangian-Aalenian complex is oil- and gas-promising and the Togur Formation is the main source of hydrocarbons.Lunina, O.N., Zhiltsova, A.A., Emeliantsev, P.S., Savvichev, A.S., Patsaeva, S.V., 2019. Quantitative determination of bacteriochlorophylls d and e in extracts from natural water samples with simultaneous presence of green- and brown-colored green sulfur bacteria. Microbiology 88, 777-780. the present work, separation and quantitative assessment of bacteriochlorophylls d and e of green sulfur bacteria (GSB) in lake water was attempted. The method developed reveals the ratio of green- and brown-colored GSB in natural water by measurement of absorption spectra of the pigments in the extracts from environmental samples.Luo, C., Miao, L., 2020. A Horodyskia-Nenoxites-dominated fossil assemblage from the Ediacaran-Cambrian transition (Liuchapo Formation, Hunan Province): Its paleontological implications and stratigraphic potential. Palaeogeography, Palaeoclimatology, Palaeoecology 545, 109635. of the scarcity of fossil data, life evolution in deep-water settings through the Ediacaran-Cambrian transitional interval is still poorly understood. This study describes a Horodyskia-Nenoxites-dominated fossil assemblage from the chert of the Liuchapo Formation in Liujiata Village, western Hunan Province, which was deposited in a slope to basinal setting at the terminal Ediacaran and earliest Cambrian. In this assemblage, Horodyskia covers the longest range, possibly from the upper part of the Lower Ediacaran to the base of the Cambrian. Other members, including three types of Nenoxites, ?Helanoichnus, ?Shaanxilithes, and two affinity-undetermined forms, appear in the upper part of the Liuchapo Formation. The whole assemblage exhibits an upward increasing complexity and fossil abundance, which reaches its acme at a few meters below the Cambrian Xiaoyanxi Formation. Regardless of the lithology of the host rock, these fossils are exclusively preserved with clay minerals and devoid of any detectable concentration of carbon. Such a preservation mode is dominant among the known records of these fossils worldwide and possibly related to an unknown biological commonality of these organisms. Microscope observations support a body-fossil origin of Nenoxites and contradict the trace-fossil interpretation. Meanwhile, some large Horodyskia show features implying a close relation to testate amoebae. However, despite some resemblances, the differences between these fossils and any suggested relatives are considerable. Taking all the information together, we tentatively interpret this fossil assemblage as a diverse and complex deep-water community of protist-grade organisms. The worldwide occurrence of some members in this assemblage endows them with a biostratigraphic potential. Nevertheless, to establish such a tool, more quality data of fossil occurrences and referential radiometric ages, and a better understanding of the interplay between these organisms and sedimentary environments are required.Luo, L., Xiao, Z., Zhou, X., Yang, L., Luo, S., Zhao, C., Luan, T., 2020. Quantum chemical calculation to elucidate the biodegradation pathway of methylphenanthrene by green microalgae. Water Research 173, 115598. polycyclic aromatic hydrocarbons (APAHs) are the main components of polycyclic aromatic hydrocarbons (PAHs) in petroleum-contaminated waters. In our study, three kinds of green microalgae (Pseudokirchneriella subcapitata, Chlorella vulgaris and Scenedesmus obliquus) were shown to degrade six kinds of methylphenanthrenes (1-methylphenanthren, 2-methylphenanthrenem, 3-nmmethylphenanthrene, 4-methylphenanthren, 9-methylphenanthrene and 3,6-dimethylphenanthrene) with different degrading abilities. Among the six methylphenanthrenes, 99.8% of 1-methylphenanthrene (1-MP) was removed and 75.6% of 3,6-dimethylphenanthrene (3,6-DMP) was removed by P. subcapitata after 7 days of incubation. The metabolites of 1-MP and 3,6-DMP were identified by gas chromatograph-mass spectrometer (GC-MS). Six metabolites of 1-MP and one metabolite of 3,6-DMP were found, they were all monohydroxylated methylphenanthrenes. The –OH group was added to either methyl-group or benzene ring through the monooxygenase system, and the methyl-group attack was the main pathway. This research increases our knowledge of the degrading ability of APAHs by green microalgae and offers information for the bioremediation of APAHs. Quantum chemical calculation was conducted to elucidate the biodegradation metabolites of methylphenanthrene by green microalgae, which is a helpful tool in the bioremediation of environmental pollution.Lv, X., Zhang, T., Luo, Y., Zhang, Y., Wang, Y., Zhang, G., 2020. Study on carbon nanotubes and activated carbon hybrids by pyrolysis of coal. Journal of Analytical and Applied Pyrolysis 146, 104717. nanotubes (CNTs) and activated carbon (AC) hybrids were obtained by co-pyrolysis of potassium hydroxide and bituminous coal. Scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Raman spectroscopy, X-ray Diffraction (XRD), and nitrogen adsorption measurements were used to investigate the characteristics of the samples and the effects of the final pyrolysis temperature and time on the structure of the carbon materials. The results indicated that the optimal range for the pyrolysis temperature and time for CNT growth were 900–950?°C and 45–90?min, respectively. The diameters of the as-prepared CNTs were in the range of 50–250?nm and their lengths were ～15 μm. During the pyrolysis process, potassium hydroxide not only acted as the catalytic precursor to catalyze the CNT growth but also reacted with carbon to produce abundant micropores. Furthermore, the content of CNTs in the product after demineralization was significantly reduced. It was further confirmed by Inductively Coupled Plasma (ICP) analysis that the content of Fe, Co, and Ni decreased after demineralization, indicating that minerals in coal play an important role in the growth of coal-based CNTs.Ma, L., Yu, Q., 2020. Dynamic behaviors of methane adsorption on partially saturated shales. Journal of Petroleum Science and Engineering 190, 107071. dynamic behavior of methane adsorption onto shales plays an important role in many resource and environmental problems. Previous studies have mainly analyzed gas diffusion, but the studies have also shown that the adsorption process consists of multiple forms of gas movement. In fact, water always exists in shale, but the process of methane adsorption onto partially saturated shales has received little attention. To study the movement behavior of methane in the adsorption process and determine how water influences the dynamic behaviors of methane adsorption, a dynamic adsorption model (DAM) was proposed. In this study, dynamic adsorption experiments involving three shale samples with four water saturation levels were conducted. Based on the experiments, 48 adsorption process curves were obtained. The dynamic adsorption process was divided into three stages based on the curves. The first stage occurred when the adsorption amount reached 50% of the equilibrium adsorption amount, and the corresponding time range was t < t50; the second occurred when the adsorption amount increased from 50% to 80%, and the corresponding time range was t50 < t < t80; and the third occurred when the adsorption amount increased from 80% to 100%, and the corresponding time range was t80 < t < t100. These stages were defined as the gas flow control stage, transition stage and interface interaction stage, respectively. The basis for this determination was that the adsorption rate was mainly controlled by the gas flow, gas flow and interface interaction, and interface interactions during these stages, respectively. The experimental data were fitted with the unipore diffusion model (UNM) based on Fick's second law and the modified unipore diffusion model (MM). The results showed that the UNM was better fit to the gas flow control stage but cannot describe the entire adsorption process. The MM was well fit to the dry shale methane adsorption process, although the wet shale fitting effect was inferior to that of the DAM. Analysis of the effect of water on the adsorption rate in each stage revealed that the inhibition of water acted against the methane gas flow more strongly than against the interface interaction. The effective pore volume (the fraction of pores not occupied by water molecules that could be reached by methane molecules) had a strong positive correlation with the adsorption rate in the early stage of the adsorption process, whereas the correlation was weak in the later stage. Under low water saturation conditions, the reduction of the adsorption rate due to the increase in the unit water saturation was larger, whereas this effect was smaller under high water saturation conditions. Gas flow was greatly affected by water in the clay matrix, whereas the interface interaction was less affected. The pattern was diametrically opposite in the organic matrix.Ma, W., Hou, L., Luo, X., Liu, J., Tao, S., Guan, P., Cai, Y., 2020. Generation and expulsion process of the Chang 7 oil shale in the Ordos Basin based on temperature-based semi-open pyrolysis: Implications for in-situ conversion process. Journal of Petroleum Science and Engineering 190, 107035. is a substantial amount of oil shale resources in the seventh member of the Triassic Yanchang Formation (abbreviated as Chang 7) in the Ordos Basin, and its geological and geochemical characteristics are highly suitable for in-situ conversion process (ICP). A comprehensive characterization of its hydrocarbon generation, expulsion and retention features will help determine the optimum conditions for future field tests. However, typical thermal simulation experiments based on either open-system or closed-system are not applicable to provide data to construct the models. Therefore, in this study, eight parallel thermal simulation experiments, which were based on the newly designed temperature-based semi-open pyrolysis experiments were performed on the Chang 7 oil shale. The yields (including cumulative yields and net incremental yields) and compositional characteristics of the expelled oil, expelled gas, and retained oil were analyzed. Results show that the hydrocarbon expulsion has a coupling relationship with hydrocarbon generation that can be divided into four stages: (1) Slow hydrocarbon generation stage (300–320 °C, 0.53–0.55 %Ro). Minimal amounts of oil and gas are generated in this stage. The hydrocarbon expulsion efficiency increases rapidly. (2) Quick oil-generation stage (320–380 °C, 0.55–1.09 %Ro). The fast cracking of kerogen and thermal bitumen generates a large amount of oil. The hydrocarbon expulsion efficiency remains relatively stable. (3) The secondary oil cracking and quick gas-generation stage (380–420 °C, 1.09–1.66 %Ro). The oil yield begins to decrease after reaching its maximum and a large amount of hydrocarbon gas is generated. The oil generation capability of kerogen is basically exhausted. The hydrocarbon expulsion efficiency and gas/oil ratio increase rapidly at this stage. (4) The heavy hydrocarbon gas cracking stage (after 420 °C, 1.66 %Ro). The oil yield continues to decline, accompanied by the onset decline in the gas yield (except methane). At this time, the hydrocarbon expulsion efficiency continues to increase but at a rather low speed. Under the experimental conditions in this study, 1.24–1.66% Ro is considered a favorable thermal maturity interval, in which maximum oil production with relatively light components can be obtained and the hydrocarbon gas is abundant.Ma, X., Wan, H., Zhou, J., Luo, D., Huang, T., Yang, H., Huang, C., 2020. Sediment record of polycyclic aromatic hydrocarbons in Dianchi lake, southwest China: Influence of energy structure changes and economic development. Chemosphere 248, 126015. polycyclic aromatic hydrocarbons (PAHs) in a sediment core from Dianchi Lake, southwest China, were analysed. The influence of changes in China’s energy structure for 2–6 ringed PAHs was investigated to assess sources and the impact of socioeconomic development on temporal changes in concentrations. The concentration of the ΣPAH16 ranged from 746 to 2293 ng g?1. Prior to the 1960s relatively low concentrations of the ΣPAH16 and a larger proportion of 2–3-ring PAHs indicated that biomass combustion was the main source of PAHs. A rapid increase in the concentrations of 2–3 ring PAHs between 1975 and 2004 was attributed to population growth and coal consumption. A declining trend since 2004 was interpreted as being due to local changes in household energy usage. Increased concentrations of 4-ring PAH between 1975–2005 and 5–6-ring PAHs between the 1980s to 2004 showed correlations with increased coal consumption and the number of motor vehicles, respectively. These were caused by rapid urbanization and industrialization in the Dianchi watershed following the implementation of the Reform and Open Policy in 1978. A subsequent decline in the concentrations of 4-ring and 5–6-ring PAHs may have been due to decreased coal consumption and improvements in emission standards, respectively. Source apportionment by a PMF model revealed that coal combustion (29.2%), vehicle emissions (24.2%), petrogenic sources (21.8%), and biomass combustion (24.9%) were the sources of PAHs in the lake sediment core, and that coal combustion was the most important regional source of PAHs pollution.Maaten, B., J?rvik, O., Pihl, O., Konist, A., Siirde, A., 2020. Oil shale pyrolysis products and the fate of sulfur. Oil Shale 37, 51–69. shale (OS) is a solid hydrogen rich fossil fuel whose organic part can, under appropriate conditions, be turned into liquid fuel. The obtained shale oil is a mixture of a large number of organic compounds. However, the exact composition and yield of shale oil depend not only on the composition of oil shale, but also on the type of the reactor where oil was produced, as well as on process parameters like heating rate, pyrolysis temperature, pyrolysis time, and the size of oil shale particles fed to the reactor. In this paper, we present the results of the full chemical analysis of Estonian Ojamaa oil shale – characteristics of oil shale and shale oil and distribution of sulfur. The results of ultimate, proximate, major components and pyrolysis mass balance analyses are also presented and the characteristics of crude shale oil and oil fractions are provided. Special emphasis is put on the analysis of sulfur and its distribution between the pyrolysis products. Additionally, thermogravimetric analysis (TGA) results are provided.Maciel, E.V.S., de Toffoli, A.L., Sobieski, E., Nazário, C.E.D., Lan?as, F.M., 2020. Miniaturized liquid chromatography focusing on analytical columns and mass spectrometry: A review. Analytica Chimica Acta 1103, 11-31. technological advances achieved over the last decades boosted the development of suitable benchtop platforms to work at miniaturized liquid chromatography scale (capillary and nano-LC). Under the right conditions, miniaturized LC can offer higher analysis efficiency resulting in superior chromatographic resolution and overall sensitivity than conventional LC. Among the main advantages are the reduced reagents and sample requirement, the decreasing on analytical column dimensions, and consequently flow rates and the easer coupling to mass spectrometry. This review describes fundamental aspects and advances over miniaturized LC technology with a focus on the last decade. Therefore, relevant characteristics of the most common analytical column, covering both filled (packed and monolithic) and open tubular (PLOT and WCOT) columns, are herein discussed. Alternatively, other modern approaches based on microchip separations or 2D configurations aiming for the sample preparation on the first dimension, are also introduced. Likewise, some positive and negative aspects of these systems over HPLC are underscored. Besides, considering the necessity to developed components to work at capillary or nanoscale, without significant dead-volumes, the most critical features of specially designed instrumentation for benchtop instruments are briefly discussed highlighting connectors, pumping, injections, oven and detection systems. Also, a more detailed section is presented focused on mass spectrometry efforts towards its miniaturization and how this trend can be useful working together with miniaturized LC. Finally, applications of capillary and nano-LC involving bioanalytical, environmental, and food methods are discussed to support the miniaturized LC as a powerful and emergent separation technique for the years ahead.Maglieri, V., Prato-Previde, E., Tommasi, E., Palagi, E., 2019. Wolf-like or dog-like? A comparison of gazing behaviour across three dog breeds tested in their familiar environments. Royal Society Open Science 6, 190946. gazing, a keystone in dog–human communication, has been suggested to derive from both domestication and breed selection. The influence of genetic similarity to wolves and selective pressures on human-directed gazing is still under debate. Here, we used the ‘unsolvable task’ to compare Czechoslovakian Wolfdogs (CWDs, a close-to-wolf breed), German Shepherd Dogs (GSDs) and Labrador Retrievers (LRs). In the ‘solvable task’, all dogs learned to obtain the reward; however, differently from GSDs and LRs, CWDs rarely gazed at humans. In the ‘unsolvable task’, CWDs gazed significantly less towards humans compared to LRs but not to GSDs. Although all dogs were similarly motivated to explore the apparatus, CWDs and GSDs spent a larger amount of time in manipulating it compared to LRs. A clear difference emerged in gazing at the experimenter versus owner. CWDs gazed preferentially towards the experimenter (the unfamiliar subject manipulating the food), GSDs towards their owners and LRs gazed at humans independently from their level of familiarity. In conclusion, it emerges that the artificial selection operated on CWDs produced a breed more similar to ancient breeds (more wolf-like due to a less-intense artificial selection) and not very human-oriented. The next step is to clarify GSDs' behaviour and better understand the genetic role of this breed in shaping CWDs’ heterospecific behaviour.Magris, R.A., Giarrizzo, T., 2020. Mysterious oil spill in the Atlantic Ocean threatens marine biodiversity and local people in Brazil. Marine Pollution Bulletin 153, 110961. study provides the first preliminary assessment of the potential impact from the recent oil spill in the Southern Atlantic Ocean. Using information on the occurrence of oil patches along the Brazilian coast, we quantified potential exposure of marine coastal habitats (estuaries, mangroves, beaches, seagrass meadows, tidal flats, and coral reefs) to oil-related disturbances. We also evaluated which threatened species in the coastal zone may have been impacted and the magnitude of the impacts on socioeconomic activities (i.e. artisanal fisheries and local tourism). Estuaries, mangroves, and seagrass meadows had the highest footprint among the habitats assessed. A total of 27 threatened coastal species occur within the area impacted by the oil residue. Approximately 870,000 people, employed in both artisanal fisheries and local tourism, appear to have been affected by the oil spill. We pinpointed priority areas for monitoring of contamination and accumulation in marine biota.Makarov, A., Grinfeld, D., Ayzikov, K., 2019. Chapter 2 - Fundamentals of Orbitrap analyzer, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 37-61. chapter discusses fundamentals of the Orbitrap? mass spectrometry—the use of a purely electrostatic ion trap with harmonic properties to store ions and analyze their mass-to-charge distributions. The first section demonstrates principles of ion confinement in the quadro-logarithmic electrostatic field, where the ions perform hundreds of thousands of oscillations without losing their common phase. The discussion covers practical aspects of ion injection into the trap and the image current detection. The subsequent section introduces the reader to the Orbitrap aberration theory, gives a classification of electric field perturbations, and outlines the compensation methods. The next section concerns signal processing methods of the detected transients and covers both the traditional Fourier transform approaches and super-FT resolving methods. The chapter concludes with the overview of historical milestones of the Orbitrap technology and selected applications.Makarov, M.M., Muyakshin, S.I., Kucher, K.M., Aslamov, I.A., Granin, N.G., 2020. A study of the gas seep Istok in the Selenga shoal using active acoustic, passive acoustic and optical methods. Journal of Great Lakes Research 46, 95-101. to locate and monitor bubble gas seeps in Lake Baikal have been conducted mainly using the active echolocation methods since the 2000s. This paper compares the active acoustic method with a newly developed optical and passive acoustic methods using the example of the shallow-water gas seep Istok in the Selenga shoal. The optical method is based on processing of underwater video records of ascending bubbles while the passive acoustic uses spectral analysis of gas jet noise recorded using a hydrophone. Optical and passive acoustic methods enables estimation of the bubble size distribution function, which is necessary for the calculation of the bubble gas flux. The latter can be evaluated from active echolocation or optical data. By applying these methods, their possibilities and limitations are revealed as well as benefits of their combined use and ways to improve their accuracy in future.Makled, W.A., Abd El Moneim, A.E.A., Mostafa, T.F., El Sawy, M.Z., Mousa, D.A., Ragab, M.O., 2020. Petroleum play of the Lower Cretaceous Alam El Bueib Formation in the El Noor-1X well in the north Western Desert (Egypt): A sequence stratigraphic framework. Marine and Petroleum Geology 116, 104287. North Umbaraka concession in Umbaraka Basin in the northern the Western Desert of Egypt has been the subject of continuous exploration efforts in the recent years. Despite many oil discoveries gave evidence of a working petroleum system, however, there is little economic production. The petroleum plays of the Alam El Bueib Formation are in the central focus of the exploration in this region because of their high economic reservoir potentiality in other areas of the Western Desert. In the present study, three powerful tools are used to delineate the sequence stratigraphic frame that considers the occurrences of the petroleum play chances of Alam EL Bueib Formation in El Noor-1 well. These tools are palynofacies, electric log and organic geochemistry. The palynofacies analysis revealed three biotopes that cover deposition in wave dominated to fluvial-wave dominated deltas with energetic, oxic and active reworking conditions. These environmental settings are only suitable for deposition of organic-lean hydrocarbon source. However, there are abundant organic materials that fluoresce under the UV-V-blue incident light especially in Proximal Delta Front/Prodelta Slope biotope (A) and these materials can generate oil as indicated also by pyrolysis gas chromatography. In addition, analysis of electric logs is used to assess reservoir capacities and effective porosities in the studied rocks. Eight sequences are identified based on these trends including E4, E3, E2, E1, D1, C1, C2 and B1. Four petroleum plays are determined in the studied succession within the frame of the stratigraphic sequences E, D, C and B. There are six reservoirs identified in the sandy bodies of the lowstand systems tracts and the carbonates of the transgressive and highstand systems tracts. The critical moment of hydrocarbon generation occurred during the Campanian (76?Ma). The entire succession of the Alam El Bueib Formation is in the oil window and the source rocks in this formation initiated petroleum expulsion during the Eocene time (32 Myr).Mand, T.D., Metcalf, W.W., 2019. Energy conservation and hydrogenase function in methanogenic archaea, in particular the genus Methanosarcina. Microbiology and Molecular Biology Reviews 83, e00020-19. biological production of methane is vital to the global carbon cycle and accounts for ca. 74% of total methane emissions. The organisms that facilitate this process, methanogenic archaea, belong to a large and phylogenetically diverse group that thrives in a wide range of anaerobic environments. Two main subgroups exist within methanogenic archaea: those with and those without cytochromes. Although a variety of metabolisms exist within this group, the reduction of growth substrates to methane using electrons from molecular hydrogen is, in a phylogenetic sense, the most widespread methanogenic pathway. Methanogens without cytochromes typically generate methane by the reduction of CO2 with electrons derived from H2, formate, or secondary alcohols, generating a transmembrane ion gradient for ATP production via an Na+-translocating methyltransferase (Mtr). These organisms also conserve energy with a novel flavin-based electron bifurcation mechanism, wherein the endergonic reduction of ferredoxin is facilitated by the exergonic reduction of a disulfide terminal electron acceptor coupled to either H2 or formate oxidation. Methanogens that utilize cytochromes have a broader substrate range, and can convert acetate and methylated compounds to methane, in addition to the ability to reduce CO2. Cytochrome-containing methanogens are able to supplement the ion motive force generated by Mtr with an H+-translocating electron transport system. In both groups, enzymes known as hydrogenases, which reversibly interconvert protons and electrons to molecular hydrogen, play a central role in the methanogenic process. This review discusses recent insight into methanogen metabolism and energy conservation mechanisms with a particular focus on the genus Methanosarcina.Manda, S., Punekar, J., 2020. Experimental validation of the planktic foraminifera fragmentation index as proxy for the end-Cretaceous Ocean Acidification. Marine Micropaleontology 155, 101821. final ~50 ky of the Maastrichtian leading up to the Cretaceous-Paleogene (K-Pg) boundary mass extinction at Bidart (France) and Gamsbach (Austria) record poor carbonate preservation indicative of ocean acidification preceding the mass extinction. Further evidence includes enhanced planktic foraminifera test fragmentation, anomalously low bulk-rock magnetic susceptibility (acidification) and peak mercury content (toxicity) related to peak Deccan volcanism in India. Here we present new experimental data that validates the Fragmentation Index of planktic foraminifera as a reliable proxy for the end-Cretaceous acidification.Pristine Cretaceous planktic foraminiferal shells (from DSDP 525A, palaeodepth ~1000 m) were exposed to buffers of pH 8.0, 7.5, 7.0 and 6.5 for 15 days each, and their preservation state was quantified as a function of time. The critical variables affecting test taphonomy are morphology, pH and time of exposure. Thin-walled fragile biserial species constitute an average ~60% of typical Late Maastrichtian assemblages (e.g Heterohelix globulosa and H. planata) and are most susceptible to dissolution, followed by simple coiled forms such as Rugoglobigerina sp. (~19% of the assemblage) and Hedbergella sp. (~6% of the assemblage). The globotruncanids (Globotruncana, Globotruncanita, ~12%) are least susceptible to chemical and physical damage. Lower pH conditions render tests more vulnerable to physical fragmentation. Caution is needed to assess taphonomic inflation of morphologically robust yet environmentally sensitive Cretaceous species (e.g. globotruncanids), that may result in an underestimation of the degree/nature of the faunal crisis and tempo of extinctions in the pre-extinction acidification interval.Mansour, A., Ger?lová, E., S?korová, I., V?r??, D., 2020. Hydrocarbon potential and depositional paleoenvironment of a Middle Jurassic succession in the Falak-21 well, Shushan Basin, Egypt: Integrated palynological, geochemical and organic petrographic approach. International Journal of Coal Geology 219, 103374. topmost Lower and Middle Jurassic formations of organic-rich clastics with minor carbonate deposits were recognized as very significant source/reservoir rocks in the North Western Desert of Egypt. Although several studies are devoted to their source rock characteristics and petroleum potential, the depositional paleoenvironment and paleoredox conditions are still poorly understood. In the current study, these sediments were assessed in terms of their organic matter richness, hydrocarbon generative potential and thermal maturity, total sulfur (TS) contents and organic petrographic characteristics. Depositional paleoenvironment was investigated using dinoflagellate cysts (dinocysts) and the composition of particulate organic matter along with organic petrographic characteristics. Redox conditions were assessed based on TS- total organic carbon (TOC) relationship and type of kerogen that was derived mainly from palynofacies analysis.TOC contents show fair to excellent generative potential of hydrocarbons mainly of kerogen type III (gas-prone). The thermal maturity, based on Tmax and Rr, indicates mature stage of oil window.Palynological analysis yielded poor to rich intervals of moderately-preserved, biostratigraphically useful dinocysts in the upper part of the Khatatba Formation. An assemblage of 81 species belonging to 54 genera of moderately diverse dinocysts, spores and pollen grains was identified. Freshwater algae, acritarchs and microforaminiferal test linings are sporadically documented within the studied interval. Based on the first downhole appearance (FDA) of the recovered marker dinocyts, the upper part of the Khatatba Formation was palynologically dated as late Bathonian-Callovian.The depositional environment was interpreted and three environments were deduced. The lower interval representing the topmost Ras Qattara and Yakout Red Shale Member was deposited in a fluvial-lacustrine environment, where oxic conditions prevailed as deduced from the color of reddish-brown sandstone and red shale. The middle interval spans Unit IIB, Kabrit and Unit III, which accumulated in a deltaic to shallow marine environment under dysoxic-suboxic settings. The upper interval covers Unit I and Unit IIA that have been deposited in a fluvio-deltaic to shallow marine with high paleoproductivity under suboxic conditions. One sample in the upper interval in Unit IIA reflected anoxic setting.Mansour, A., Wagreich, M., Gentzis, T., Ocubalidet, S., Tahoun, S.S., Elewa, A.M.T., 2020. Depositional and organic carbon-controlled regimes during the Coniacian-Santonian event: First results from the southern Tethys (Egypt). Marine and Petroleum Geology 115, 104285. and palynological proxies were determined for 31 samples representing the upper Coniacian-lowermost Campanian Abu Roash A Member, collected from the BED2-3 well. This was done to assess the prevailing paleoredox conditions, productivity levels, and water-column settings to: (1) understand controls and mechanisms related to accumulation of organic carbon within the sedimentary record; (2) assess principal environmental processes that triggered the preservation of organic matter-poor, calcareous shale and limestone facies of the Abo Roash A Member; and (3) to interpret the paleoceanographic settings and confirm the occurrence of either Oceanic Anoxic Event 3 (OAE3) or Cretaceous Oceanic Red Beds (CORBs) within the Abu Gharadig Basin in the southern part of the Tethyan Ocean, Egypt. Sedimentation rates were reconstructed based on the biostratigraphic-age constraints of marine dinoflagellate cysts (dinocysts). Trace elements-based ratios and relationships were used in order to study the role of clastic terrestrial input. Three groups of dinocysts and freshwater Pediastrum algae were used to study the water-column conditions.Results showed that the Abu Roash A Member was deposited under oxic to intermittently dysoxic conditions in a distal inner to middle neritic environment, with varying sedimentation rates from 32 to 119 mm kyr?1. Productivity appeared to be a significant factor for determining magnitudes of the organic carbon accumulation; however, low productivity was prevalent during deposition. Carbonate content was high, which resulted in dilution of organic matter during varied rates of sediment input. Such results indicate that the paleoceanographic conditions in the southern Tethys witnessed the absence of prevalent oceanic anoxia (i.e., the Coniacian-Santonian OAE 3) and deposition of the CORBs as in several parts of the Tethys, the Pacific, and the Indian oceans.Marchant, J., 2020. Is this Nefertiti’s tomb? Radar clues reignite debate over hidden chambers. Nature 578, 487-488. new survey hints at a previously unknown space beyond Tutankhamun’s burial chamber. A radar survey around the tomb of Tutankhamun in Egypt’s Valley of the Kings has revealed possible evidence of further hidden chambers behind its walls.The findings — in an unpublished report, details of which have been seen by Nature — resurrect a controversial theory that the young king’s burial place hides the existence of a larger tomb, which could contain the mysterious Egyptian queen Nefertiti.Researchers led by archaeologist Mamdouh Eldamaty, a former Egyptian minister of antiquities, used ground-penetrating radar (GPR) to scan the area immediately around Tutankhamun’s tomb. They report that they have identified a previously unknown corridor-like space a few metres from the burial chamber (see ‘Chamber of secrets’). Their finding was presented to Egypt’s Supreme Council of Antiquities (SCA) earlier this month.The data are “tremendously exciting”, says Ray Johnson, an Egyptologist at the University of Chicago’s Oriental Institute in Luxor, Egypt, who wasn’t involved in the research. “Clearly there is something on the other side of the north wall of the burial chamber.”The possibility of extra chambers beyond Tutankhamun’s tomb has previously been investigated by several teams, often working with private companies. But they produced conflicting results, and many researchers have dismissed the idea. For example, Francesco Porcelli, a physicist at the Polytechnic University of Turin in Italy who led a GPR survey inside the tomb in 2017, insists that his data rule out the existence of hidden rooms connected with the tomb. Egypt’s lost queen. Eldamaty’s team was investigating a theory that Tutankhamun’s tomb, which was discovered in 1922 and is unusually small for a royal burial, contains extensive hidden chambers and perhaps even Nefertiti’s missing resting place. Some Egyptologists believe that immediately before Tutankhamun’s reign in the fourteenth century bc, Nefertiti, whose daughter was married to Tutankhamun, briefly ruled as pharaoh. Her tomb in the Valley of the Kings has never been found.The team detected a long space in the bedrock a few metres to the east, at the same depth as Tutankhamun’s burial chamber and running parallel to the tomb’s entrance corridor. The space appears to be around 2 metres high and at least 10 metres long.It is not yet certain whether the space is physically linked to Tutankhamun’s tomb, known as KV62, or if it is part of another nearby tomb. The researchers argue that its orientation, perpendicular to KV62’s main axis, suggests that there is a connection, because unconnected tombs tend to be aligned at different angles.But not everyone is convinced. Zahi Hawass, another former antiquities minister, says that using geophysical techniques to search for tombs in Egypt has previously raised false hopes and he argues that such work should not be pursued. GPR “never made any discovery at any site in Egypt”, he claims. Hawass is himself searching for new tombs, including that of Nefertiti, but using more conventional techniques. He told Nature that in 2019, he excavated the area north of KV62 looking for tomb entrances, but found nothing.Contested histories. The radar survey is the latest in a succession of investigations that have tried to confirm whether additional chambers exist — provoking much disagreement and conflicting results.The new data are intriguing, says Nicholas Reeves, a British Egyptologist who has spent many years working in the Valley of the Kings. But the newly discovered feature is not where he was expecting — he had assumed that possible hidden chambers would continue north of Tutankhamun’s tomb rather than turn to the right, as the data suggest. However, Reeves, who first suggested the idea that there is an extension to KV62, still thinks Nefertiti will be found somewhere inside.In a 2015 paper, he reported finding straight lines and cracks in the painted walls of Tutankhamun’s burial chamber, which he suggested could indicate the presence of hidden doorways. In particular, he claimed that the far north wall of Tutankhamun’s burial chamber isn’t solid bedrock as previously understood, but is a false wall of a type commonly used by ancient Egyptian tomb builders to hide chambers beyond. From clues in the wall paintings themselves, Reeves concluded that there was a hidden occupant and that it was Nefertiti.Following this report, Eldamaty, as antiquities minister, oversaw two GPR surveys of the tomb walls. One, conducted by a team from Japan, seemed to confirm the existence of hidden rooms. But a second team, sent by the US media company National Geographic, failed to replicate these results.Eldamaty was replaced as antiquities minister in 2016. The following year, his successor invited two more teams to scan the area around KV62, in the hope of settling the debate. But the disagreements continued. One team, led by Porcelli, working inside the tomb, claimed to rule out the existence of hidden chambers beyond the walls of KV621. A second team — a geophysical survey company called Terravision Exploration, based in West Molesey, UK — was asked by the SCA to cut short its survey.Yet Terravision’s preliminary results — also from inside the tomb — suggested there was more to discover. So Eldamaty, who is now based at Ain Shams University in Cairo, says he was determined that the team should complete its investigation by scanning outside the tomb. “I never give up easily,” he says. The SCA approved a new application and in June 2019, Eldamaty, Terravision and a team of engineers from Ain Shams University returned to finish their work.However, interference from nearby air-conditioning units meant that the team was unable to collect definitive data for the crucial area directly north of Tutankhamun’s burial chamber.Eldamaty plans to submit a proposal to return and study the feature in more detail. It will be difficult to scan closer to the burial chamber without removing the air-conditioning units, says Terravision chief executive Charlie Williams. But he is confident that, by using a different antenna and taking readings closer together, he can pin down the shape and location of the void to within a few centimetres, and see where it leads.“It has to be intact”. Other Egyptologists have responded to the finding with enthusiasm. Johnson doesn’t rule out the possibility of finding Nefertiti in the hidden space. But if the chamber turns out to belong to a different undiscovered tomb, he suggests it could hold Tutankhamun’s wife Ankhesenamun, whose tomb has not been found.Aidan Dodson, an Egyptologist at the University of Bristol, UK, is sceptical of Reeves’s ideas about Nefertiti but backs the second-tomb theory, and suggests it might hold the remains of princesses from Tutankhamun’s time. Whoever is inside, he says the find could be “amazingly significant” because this part of the valley has been sealed by a layer of ancient flood debris that also kept KV62 safe from looters for millennia. “It has to be intact.”Reeves has high hopes, too. “If Nefertiti was buried as a pharaoh, it could be the biggest archaeological discovery ever,” he says. If the evidence continues to mount, he suggests, an international conference of experts should be convened to consider the next steps. Any physical investigation shouldn’t be rushed, he says, because digging through the bedrock would be extremely difficult, and drilling through the north wall of the burial chamber would damage its priceless artwork.Marcus, J.H., Posth, C., Ringbauer, H., Lai, L., Skeates, R., Sidore, C., Beckett, J., Furtw?ngler, A., Olivieri, A., Chiang, C.W.K., Al-Asadi, H., Dey, K., Joseph, T.A., Liu, C.-C., Der Sarkissian, C., Radzevi?iūt?, R., Michel, M., Gradoli, M.G., Marongiu, P., Rubino, S., Mazzarello, V., Rovina, D., La Fragola, A., Serra, R.M., Bandiera, P., Bianucci, R., Pompianu, E., Murgia, C., Guirguis, M., Orquin, R.P., Tuross, N., van Dommelen, P., Haak, W., Reich, D., Schlessinger, D., Cucca, F., Krause, J., Novembre, J., 2020. Genetic history from the Middle Neolithic to present on the Mediterranean island of Sardinia. Nature Communications 11, 939. island of Sardinia has been of particular interest to geneticists for decades. The current model for Sardinia’s genetic history describes the island as harboring a founder population that was established largely from the Neolithic peoples of southern Europe and remained isolated from later Bronze Age expansions on the mainland. To evaluate this model, we generate genome-wide ancient DNA data for 70 individuals from 21 Sardinian archaeological sites spanning the Middle Neolithic through the Medieval period. The earliest individuals show a strong affinity to western Mediterranean Neolithic populations, followed by an extended period of genetic continuity on the island through the Nuragic period (second millennium BCE). Beginning with individuals from Phoenician/Punic sites (first millennium BCE), we observe spatially-varying signals of admixture with sources principally from the eastern and northern Mediterranean. Overall, our analysis sheds light on the genetic history of Sardinia, revealing how relationships to mainland populations shifted over time.Martin, K.P., MacKenzie, S.M., Barnes, J.W., Ytreberg, F.M., 2020. Protein stability in Titan's subsurface water ocean. Astrobiology 20, 190–198. of Titan predict that there is a subsurface ocean of water and ammonia under a layer of ice. Such an ocean would be important in the search for extraterrestrial life since it provides a potentially habitable environment. To evaluate how Earth-based proteins would behave in Titan's subsurface ocean environment, we used molecular dynamics simulations to calculate the properties of proteins with the most common secondary structure types (alpha helix and beta sheet) in both Earth and Titan-like conditions. The Titan environment was simulated by using a temperature of 300 K, a pressure of 1000 bar, and a eutectic mixture of water and ammonia. We analyzed protein compactness, flexibility, and backbone dihedral distributions to identify differences between the two environments. Secondary structures in the Titan environment were found to be less long-lasting, less flexible, and had small differences in backbone dihedral preferences (e.g., in one instance a pi helix formed). These environment-driven differences could lead to changes in how these proteins interact with other biomolecules and therefore changes in how evolution would potentially shape proteins to function in subsurface ocean environments. Martyn, R., Craig, O.E., Sarah T.D. Ellingham, Meez Islam, 2020. A re-evaluation of manner of death at Roman Herculaneum following the AD 79 eruption of Vesuvius. Antiquity 94, 76-91. by the eruption of Mount Vesuvius in AD 79, Herculaneum is one of the world's most famous Roman settlements. Exactly how the victims died during the eruption, however, remains unclear. The authors address this issue by examining changes in bone apatite structure and collagen preservation, combined with collagen extraction. Results suggest that the prolonged presence of soft tissue, as well as the stone chambers in which inhabitants had sought shelter, acted as thermal buffers that minimised the heat-induced degradation of skeletal tissues. The results have implications for the interpretation of large residential sites and for contexts where heating and burning is associated with buildings,Mazhar, S.H., Herzberg, M., Ben Fekih, I., Zhang, C., Bello, S.K., Li, Y.P., Su, J., Xu, J., Feng, R., Zhou, S., Rensing, C., 2020. Comparative insights into the complete genome sequence of highly metal resistant Cupriavidus metallidurans strain BS1 isolated from a gold–copper mine. Frontiers in Microbiology 11, 47. doi: 10.3389/fmicb.2020.00047. highly heavy metal resistant strain Cupriavidus metallidurans BS1 was isolated from the Zijin gold–copper mine in China. This was of particular interest since the extensively studied, closely related strain, C. metallidurans CH34 was shown to not be only highly heavy metal resistant but also able to reduce metal complexes and biomineralizing them into metallic nanoparticles including gold nanoparticles. After isolation, C. metallidurans BS1 was characterized and complete genome sequenced using PacBio and compared to CH34. Many heavy metal resistance determinants were identified and shown to have wide-ranging similarities to those of CH34. However, both BS1 and CH34 displayed extensive genome plasticity, probably responsible for significant differences between those strains. BS1 was shown to contain three prophages, not present in CH34, that appear intact and might be responsible for shifting major heavy metal resistance determinants from plasmid to chromid (CHR2) in C. metallidurans BS1. Surprisingly, the single plasmid – pBS1 (364.4 kbp) of BS1 contains only a single heavy metal resistance determinant, the czc determinant representing RND-type efflux system conferring resistance to cobalt, zinc and cadmium, shown here to be highly similar to that determinant located on pMOL30 in C. metallidurans CH34. However, in BS1 another homologous czc determinant was identified on the chromid, most similar to the czc determinant from pMOL30 in CH34. Other heavy metal resistance determinants such as cnr and chr determinants, located on megaplasmid pMOL28 in CH34, were shown to be adjacent to the czc determinant on chromid (CHR2) in BS1. Additionally, other heavy metal resistance determinants such as pbr, cop, sil, and ars were located on the chromid (CHR2) and not on pBS1 in BS1. A diverse range of genomic rearrangements occurred in this strain, isolated from a habitat of constant exposure to high concentrations of copper, gold and other heavy metals. In contrast, the megaplasmid in BS1 contains mostly genes encoding unknown functions, thus might be more of an evolutionary playground where useful genes could be acquired by horizontal gene transfer and possibly reshuffled to help C. metallidurans BS1 withstand the intense pressure of extreme concentrations of heavy metals in its environment.McClain, C.R., Nunnally, C., Benfield, M.C., 2019. Persistent and substantial impacts of the Deepwater Horizon oil spill on deep-sea megafauna. Royal Society Open Science 6, 191164. Deepwater Horizon spill is one of the largest environmental disasters with extensive impacts on the economic and ecological health of the Gulf of Mexico. Surface oil and coastal impacts received considerable attention, but the far larger oil spill in the deep ocean and its effects received considerably less examination. Based on 2017 ROV surveys within 500 m of the wellhead, we provide evidence of continued impacts on diversity, abundance and health of deep-sea megafauna. At locations proximal to the wellhead, megafaunal communities are more homogeneous than in unimpacted areas, lacking many taxonomic groups, and driven by high densities of arthropods. Degraded hydrocarbons at the site may be attracting arthropods. The scope of impacts may extend beyond the impacted sites with the potential for impacts to pelagic food webs and commercially important species. Overall, deep-sea ecosystem health, 7 years post spill, is recovering slowly and lingering effects may be extreme.McDonough, L.K., Rutlidge, H., O'Carroll, D.M., Andersen, M.S., Meredith, K., Behnke, M.I., Spencer, R.G.M., McKenna, A.M., Marjo, C.E., Oudone, P., Baker, A., 2020. Characterisation of shallow groundwater dissolved organic matter in aeolian, alluvial and fractured rock aquifers. Geochimica et Cosmochimica Acta 273, 163-176. organic matter is processed within aquifers through transformations such as the adsorption of dissolved organic matter (DOM) to minerals and biodegradation. The molecular character of DOM varies according to its source and this can impact its bioavailability and reactivity. Whilst the character of DOM in riverine and oceanic environments is increasingly well understood, the sources, character and ultimately the fate of groundwater DOM remains unclear. Here we examine groundwater DOM from contrasting hydrogeological settings in New South Wales, Australia. For the first time, we identify the distinct molecular composition of three groundwater DOM end-members including a modern terrestrial input, an aged sedimentary peat source, and an aged stable by-product pool. We also identify and characterise the processing pathway of DOM in semi-arid, low sedimentary organic carbon (OC) environments. Based on size exclusion chromatography, ultrahigh-resolution Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS), isotopic analyses (13C, 14C and 3H) and principle component analysis (PCA), we show that in higher rainfall temperate coastal peatland environments, large amounts of aged sedimentary organic carbon can leach into groundwater resulting in higher molecular weight (500?g?mol?1?<?molecular weight?>?1000?g?mol?1) and highly aromatic groundwater DOM with high O/C ratios and low H/C ratios. We show that in semi-arid environments with low rainfall rates and high groundwater residence times, groundwater dissolved organic carbon (DOC) is processed into increasingly low molecular weight (<350?g?mol?1), low aromaticity DOM with low O/C ratios and high H/C ratios by subsurface processing mechanisms such as biodegradation and adsorption. We provide the first comprehensive study of groundwater DOM characterisation based on multiple analytical techniques, and highlight the impact of source inputs and processing on groundwater DOM composition at a molecular level.McKay, C.P., 2020. What is life—and when do we search for it on other worlds. Astrobiology 20, 163–166. has been considerable attention on how to detect life on other worlds by searching for biomolecules. However, there has been much less clarity as to when it becomes warranted to focus a mission on the search for life on another world. At a minimum, a life-detection mission should follow convincing evidence of (1) Liquid water of suitable salinity, past or present; (2) Carbon in the water; (3) Biologically available N in the water; (4) Biologically useful energy in the water; (5) Organic material that can possibly be of biological origin and a plausible strategy for sampling this material. Based on these prerequisites, the most promising targets for a life search are currently the plume of Enceladus and the subsurface of Mars—in equatorial lake bed sediments and in polar ice-cemented ground. Neither the surface of Europa nor the clouds of Venus meet the criteria listed here but may with further exploration. McLaughlin, M.C., Blotevogel, J., Watson, R.A., Schell, B., Blewett, T.A., Folkerts, E.J., Goss, G.G., Truong, L., Tanguay, R.L., Argueso, J.L., Borch, T., 2020. Mutagenicity assessment downstream of oil and gas produced water discharges intended for agricultural beneficial reuse. Science of The Total Environment 715, 136944. water is the largest waste stream associated with oil and gas operations. This complex fluid contains petroleum hydrocarbons, heavy metals, salts, naturally occurring radioactive materials and any remaining chemical additives. In the United States, west of the 98th meridian, the federal National Pollutant Discharge Elimination System (NPDES) exemption allows release of produced water for agricultural beneficial reuse. The goal of this study was to quantify mutagenicity of a produced water NPDES release and discharge stream. We used four mutation assays in budding yeast cells that provide rate estimates for copy number variation (CNV) duplications and deletions, as well as forward and reversion point mutations. Higher mutation rates were observed at the discharge and decreased with distance downstream, which correlated with the concentrations of known carcinogens detected in the stream (e.g., benzene, radium), described in a companion study. Mutation rate increases were most prominent for CNV duplications and were higher than mutations observed in mixtures of known toxic compounds. Additionally, the samples were evaluated for acute toxicity in Daphnia magna and developmental toxicity in zebrafish. Acute toxicity was minimal, and no developmental toxicity was observed. This study illustrates that chemical analysis alone (McLaughlin et al., 2020) is insufficient for characterizing the risk of produced water NPDES releases and that a thorough evaluation of chronic toxicity is necessary to fully assess produced water for beneficial reuse.Megaw, J., Kelly, S.A., Thompson, T.P., Skvortsov, T., Gilmore, B.F., 2019. Profiling the microbial community of a Triassic halite deposit in Northern Ireland: an environment with significant potential for biodiscovery. FEMS Microbiology Letters 366, fnz242. salt mine, a Triassic halite deposit located in County Antrim, Northern Ireland, is the only permanent hypersaline environment on the island of Ireland. In this study, the microbiome of this unstudied environment was profiled for the first time using conventional and enhanced culturing techniques, and culture independent metagenomic approaches. Using both conventional isolation plates and iChip devices, 89 halophilic archaeal isolates from six known genera, and 55 halophilic or halotolerant bacterial isolates from 18 genera were obtained, based on 16S rRNA gene sequencing. The archaeal isolates were similar to those previously isolated from other ancient halite deposits, and as expected, numerous genera were identified in the metagenome which were not represented among the culturable isolates. Preliminary screening of a selection of isolates from this environment identified antimicrobial activities against a panel of clinically important bacterial pathogens from 15 of the bacterial isolates and one of the archaea. This, alongside previous studies reporting the discovery of novel biocatalysts from the Kilroot mine microbiome, suggests that this environment may be a new, untapped source of of chemical diversity with high biodiscovery potential.Melnikov, S., Kwok, H.-S., Manakongtreecheep, K., van den Elzen, A., Thoreen, C.C., S?ll, D., 2019. Archaeal ribosomal proteins possess nuclear localization signal-type motifs: Implications for the origin of the cell nucleus. Molecular Biology and Evolution 37, 124-133. cells are divided into the nucleus and the cytosol, and, to enter the nucleus, proteins typically possess short signal sequences, known as nuclear localization signals (NLSs). Although NLSs have long been considered as features unique to eukaryotic proteins, we show here that similar or identical protein segments are present in ribosomal proteins from the Archaea. Specifically, the ribosomal proteins uL3, uL15, uL18, and uS12 possess NLS-type motifs that are conserved across all major branches of the Archaea, including the most ancient groups Microarchaeota and Diapherotrites, pointing to the ancient origin of NLS-type motifs in the Archaea. Furthermore, by using fluorescence microscopy, we show that the archaeal NLS-type motifs can functionally substitute eukaryotic NLSs and direct the transport of ribosomal proteins into the nuclei of human cells. Collectively, these findings illustrate that the origin of NLSs preceded the origin of the cell nucleus, suggesting that the initial function of NLSs was not related to intracellular trafficking, but possibly was to improve recognition of nucleic acids by cellular proteins. Overall, our study reveals rare evolutionary intermediates among archaeal cells that can help elucidate the sequence of events that led to the origin of the eukaryotic cell.Memon, K.R., Mahesar, A.A., Ali, M., Tunio, A.H., Mohanty, U.S., Akhondzadeh, H., Awan, F.U.R., Iglauer, S., Keshavarz, A., 2020. Influence of cryogenic liquid nitrogen on petro-physical characteristics of Mancos Shale: An experimental investigation. Energy & Fuels 34, 2160-2168. Mancos Shale core sample investigated in the present research has been extracted from the late Cretceous (upper cretaceous) geologic formation of USA. Shale gas is usually obtained by horizontal drilling which induces fractures to increase the flow ability of hydrocarbons. Therefore, it is important to understand the mechanical properties, heterogeneity and their complexities associated with elastic properties of shale. An experimental study was conducted to examine the morphological characteristics of the Mancos Shale core sample both pre and post treatment with cryogenic liquid nitrogen (LN2) for various immersion times namely 30, 60 and 90 minutes respectively. Atomic Force Microscopy (AFM) technique is used to understand the surface roughness, irregularities in core samples and for more accuracy. Scanning Electron Microscopy (SEM) results were employed to visualise the formation of cracks caused by cryogenic liquid nitrogen. Results from SEM showed an increase in fracture size from 2 to 25 ?m with increase in ageing time up-to 90 minutes under the atmosphere of cryogenic LN2. Nano- indentation measurements revealed that the Nano- indentation moduli of the Mancos samples subjected to applied forces of 50 mN and 200 mN underwent a decrease from 24.6 to 16.8 GPa and 15.6 GPa respectively with increase in cryogenic liquid nitrogen treatment to 90 minutes. The permeability of the shale samples after LN2 treatment showed a significant increase whereas, increasing net confining stress (NCS) from 1000 to 7000 psi for all untreated and treated rock samples exhibited a decrease in permeability, which is attributed to increased compaction between the pore spaces. Moreover, the porosity of the Mancos shale rose from 3.78 to 6.92% for pre-treated and treated rock samples.Menéndez-Serra, M., Ontiveros, V.J., Triadó-Margarit, X., Alonso, D., Casamayor, E.O., 2020. Dynamics and ecological distributions of the Archaea microbiome from inland saline lakes (Monegros Desert, Spain). FEMS Microbiology Ecology 96, fiaa019. characterized the rich Archaea microbiome of shallow inland lakes (Monegros Desert, NE Spain) by 16S rRNA gene tag sequencing covering a wide salinity range (0.1%–40% w/v) along 3 years. Up to 990 operational taxonomic units (OTUs; >97% identity) were detected allocated in 14 major archaeal phyla and heterogeneously distributed along the salt gradient. Dynamics and idiosyncratic ecological distributions were uncovered for the different phyla. A high genetic richness was observed for Woesearchaeota and Pacearchaeota (>370 OTUs each), followed by Halobacteria (105), Nanohaloarchaeota (62) and Thermoplasmata (19). Overall, the distribution of genetic richness was strongly correlated with environmental niche amplitude, but not with occurrence. We unveiled high occurrence for a very rich Woesearchaeota assemblage, and an unexpected positive correlation of Pacearchaeota abundance with salinity at >15% dissolved salt content. The estimated dynamic behaviour (temporal ‘turnover’ rates of presence/absence data) unveiled Thaumarchaeota and Halobacteria as the most dynamic groups, and Aenigmarchaeota and Thermoplasmata as the most stable. The DPANN Pacearchaeota, Woesearchaeota, and Nanohaloarchaeota showed intermediate rates, suggesting higher resilience to environmental perturbations. A rich and dynamic Archaea microbiome was unveiled, including unseen ecological traits for relevant members of the still largely unknown DPANN group, supporting a strong ecological differentiation between Pacearchaeota and Woesearchaeota.Merder, J., Freund, J.A., Feudel, U., Niggemann, J., Singer, G., Dittmar, T., 2020. Improved mass accuracy and isotope confirmation through alignment of ultrahigh-resolution mass spectra of complex natural mixtures. Analytical Chemistry 92, 2558-2565. ion cyclotron resonance mass spectrometry (FT-ICR-MS) is one of the state-of-the-art methods to analyze complex natural organic mixtures. The precision of detected masses is crucial for molecular formula attribution. Random errors can be reduced by averaging multiple measurements of the same mass, but because of limited availability of ultrahigh-resolution mass spectrometers, most studies cannot afford analyzing each sample multiple times. Here we show that random errors can be eliminated also by averaging mass spectral data from independent environmental samples. By averaging the spectra of 30 samples of our 15 Tesla instrument we reach a mass precision comparable to a single spectrum of a 21 Tesla instrument. We also show that it is possible to accurately and reproducibly determine isotope ratios with FT-ICR-MS. Intensity ratios of isotopologues were improved to a degree that measured deviations were within the range of natural isotope fractionation effects. In analogy to δ13C in environmental studies, we propose Δ13C as an analytical measure for isotope ratio deviances instead of widely employed C deviances. In conclusion, here we present a simple tool, extensible to Orbitrap-based mass spectrometers, for post-detection data processing that significantly improves mass accuracy and the precision of intensity ratios of isotopologues at no extra cost.Merkel, A.Y., Tarnovetskii, I.Y., Podosokorskaya, O.A., Toshchakov, S.V., 2019. Analysis of 16S rRNA primer systems for profiling of thermophilic microbial communities. Microbiology 88, 671-680. microorganisms are of special interest for phylogenetics and research in prokaryotic evolution, since many of them belong to deep branches of the tree of life. For this reason a number of broadly used universal primer systems for the 16S rRNA gene eliminate certain groups of thermophilic prokaryotes from their detection spectra. In the present work, the known 16S rRNA gene primer systems were analyzed in order to determine their ability to reveal members of deep phylogenetic lineages containing thermophilic microorganisms. It was shown that application of most of the published primer systems could result in elimination of certain groups of thermophilic prokaryotes. In silico analysis of existing primer systems was used to select the primer system for the V3?V4 region of the 16S rRNA gene, which minimized elimination of thermophilic prokaryotic groups. Comparison of the proposed system with the previously published ones was carried out using high-throughput sequencing. Statistical analysis of the sequencing results based on the Shannon and Chao1 indexes revealed high efficiency of the proposed system for analysis of microbial communities of Kamchatka hot springs.Miao, X., Chen, M., Li, Y., Zhan, H., Zhao, K., Yue, W., 2020. Simultaneous determination of organic distribution and content in oil shale by terahertz imaging. Energy & Fuels 34, 1664-1668. in oil shale play a significant role in the generation and production of oil gas. Visualizing the content and distribution of organics in the reservoir is the key objective of unconventional resource research. In this study, we demonstrate the application of terahertz (THz) imaging to measure the dielectric properties of oil shale from Huadian and Beipiao with different oil yields. The heterogeneous distributions of organics on the oil shale surface were evaluated by THz amplitude imaging, with the existence of kerogen-rich and kerogen-poor areas identified by different colors. Meanwhile, the average refractive indices of the samples were plotted with the oil yield, revealing a negative correlation between them. Our results prove that THz spectroscopy can provide not only a promising technique to visualize the organic distribution in oil shale but also a convenient means for the quantitative analysis of the organic content in oil shale.Milad, B., Slatt, R., Fuge, Z., 2020. Lithology, stratigraphy, chemostratigraphy, and depositional environment of the Mississippian Sycamore rock in the SCOOP and STACK area, Oklahoma, USA: Field, lab, and machine learning studies on outcrops and subsurface wells. Marine and Petroleum Geology 115, 104278. paper presents an interpreted depositional environment, developed 2nd order sequence stratigraphy framework, and detailed lithofacies identification from two Mississippian Sycamore outcrops (I-35 Sycamore and Speake Ranch) and subsurface wells in the SCOOP (South Central Oklahoma Oil Province). Then these rocks calibrate the rock properties with wireline log responses to identify the best landing zones.Qualitative and quantitative techniques of field, laboratory, and machine learning studies were conducted. For the field studies, we measured the complete 450 ft of the outcrop stratigraphic section, another separate 50 ft outcrop, examined the underlying Woodford Shale and overlying Caney Shale boundary contacts, documented sedimentary structures, constructed an outcrop gamma-ray profile, and developed a sequence stratigraphic framework. Laboratory studies included petrographic analyses, detailed X-ray Fluorescence (XRF), Scanning Electron Microscopy (SEM), and X-ray Diffraction (XRD). For machine learning studies, a principal component analysis (PCA), elbow method, and self-organizing map (SOM) were used to analyze the electrofacies and chemofacies from the outcrop and a subsurface uncored well.The outcrop hand-held gamma ray profile was obtained and correlated with subsurface wells. Five major outcrop lithofacies and chemofacies, within six stratigraphic units of alternating siltstone and shale strata, were identified from the wireline logs. A Maximum Flooding Surface (MFS), and two major 2nd order Sequence Boundaries (SB) were recognized at the outcrop and a nearby subsurface well. Bouma sequences and repetitive cycles of sedimentary structures indicated sediment gravity flow deposition on a marine slope setting.This study provides geologic insights to better understanding the depositional environment and the lithology of the Sycamore rocks. The bioturbated siliceous shale and/or the sandy siltstone can be potential target zones due to their reservoir quality, lithology, bed continuity, and brittleness. This information can be of direct benefit to the exploration and development programs of many companies in the SCOOP area, particularly in the Anadarko and Ardmore basins in Oklahoma.Miller, J.B., McKinnon, L.M., Whiting, M.F., Ridge, P.G., 2020. Codon use and aversion is largely phylogenetically conserved across the tree of life. Molecular Phylogenetics and Evolution 144, 106697. parsimony, we analyzed codon usages across 12,337 species and 25,727 orthologous genes to rank specific genes and codons according to their phylogenetic signal. We examined each codon within each ortholog to determine the codon usage for each species. In total, 890,814 codons were parsimony informative. Next, we compared species that used a codon with species that did not use the codon. We assessed each codon's congruence with species relationships provided in the Open Tree of Life (OTL) and determined the statistical probability of observing these results by random chance. We determined that 25,771 codons had no parallelisms or reversals when mapped to the OTL. Codon usages from orthologous genes spanning many species were 1109× more likely to be congruent with species relationships in the OTL than would be expected by random chance. Using the OTL as a reference, we show that codon usage is phylogenetically conserved within orthologous genes in archaea, bacteria, plants, mammals, and other vertebrates. We also show how to use our provided framework to test different tree hypotheses by confirming the placement of turtles as sister taxa to archosaurs.Milordov, D.V., Abilova, G.R., Yakubova, S.G., Tazeeva, E.G., Manaure, D.A., 2020. Comparative analysis of composition and solubility of asphaltes from heavy oils of different oil fields. Petroleum Science and Technology 38, 405-410. and solubility of asphaltenes from various oil fields have been compared. The structural group abundance in the asphaltenes have been determined according to Fourier transform infrared spectra, while the contents of sulfur, vanadium, nickel, vanadyl complexes, and free stable radicals has been evaluated using various methods. The solubility of asphaltenes in the n-heptane-toluene system has been evaluated by spectrophotometric kinetic analysis. It has been determined that the relative content of condensed aromatic structures and carbonyl groups, as well as sulfur-containing structures and vanadyl complexes affect to various extents the solubility of asphaltenes. Effect of the composition of asphaltenes on their solubility is different in the case of conventional and heavy oils.Min, K., Cuiffi, J.D., Mathers, R.T., 2020. Ranking environmental degradation trends of plastic marine debris based on physical properties and molecular structure. Nature Communications 11, 727. plastic marine debris continues to accumulate in the oceans, many important questions surround this global dilemma. In particular, how many descriptors would be necessary to model the degradation behavior of ocean plastics or understand if degradation is possible? Here, we report a data-driven approach to elucidate degradation trends of plastic debris by linking abiotic and biotic degradation behavior in seawater with physical properties and molecular structures. The results reveal a hierarchy of predictors to quantify surface erosion as well as combinations of features, like glass transition temperature and hydrophobicity, to classify ocean plastics into fast, medium, and slow degradation categories. Furthermore, to account for weathering and environmental factors, two equations model the influence of seawater temperature and mechanical forces.Mkemai, R.M., Gong, B., 2020. Geological performance evaluation of CO2 sequestration in depleted oil reservoirs: A simulation study on the effect of water saturation and vertical to horizontal permeability ratio. Journal of Natural Gas Science and Engineering 76, 103196. consumption of fossil fuel as a primary source of energy has led to the net increase of anthropogenic carbon dioxide (CO2) emission into the atmosphere. The magnitude of its contribution to global warming and climate change is unprecedented. Carbon capture and storage (CCS) in geological formations technology has merged as the key approach towards potential CO2 sequestration, and depleting oil and gas reservoirs appear to be promising candidates. Various researchers studied the concepts and processes about reservoirs' performance upon CO2 injection and storage with little attention on variations of reservoir water saturation and permeability ratio (vertical versus horizontal permeability). In this study, with the use of 3-dimensional (3D) numerical simulations the safe and long term evaluation of reservoir performance on CO2 storage in terms of storage capacity, trapping mechanism, injection rate, and operational pressures were performed at Liaohe basin, China. Results revealed that CO2 stored in a supercritical form was dominant of all and that at the end of 100 years more than 70% of injected CO2 existed as free gas in supercritical form, the tendency which decreased to less than 65% after 1000 years of its storage. Conversely, the storage of CO2 in trapped and dissolved forms was increased by 6% and 3% respectively. The results from this work provide valuable insights on CO2 phase relative storage potentiality for enhanced and safe CO2 storage in a depleted oil reservoir. It also provides an improved long term CO2 storage sequestration strategy which incorporated hysteresis metrics. The study recommends an optimum CO2 storage scheme with controlled pressure buildup in a depleted oil reservoir.Modugno, C., Peltier, C., Simonin, H., Dujourdy, L., Capitani, F., Sandt, C., Perrier-Cornet, J.-M., 2020. Understanding the effects of high pressure on bacterial spores using synchrotron infrared spectroscopy. Frontiers in Microbiology 10, 3122. doi: 10.3389/fmicb.2019.03122. spores are extremely resistant life-forms that play an important role in food spoilage and foodborne disease. The return of spores to a vegetative cell state is a three-step process, these being activation, germination, and emergence. High-pressure (HP) processing is known to induce germination in part of the spore population and even to inactivate a high number of Bacillus spores when combined with other mild treatments such as the addition of nisin. The aim of the present work was to investigate the mechanisms involved in the sensitization of spores to nisin following HP treatment at ambient temperature or with moderate heating leading to a heterogeneous spore response. Bacillus subtilis spores were subjected to HP treatment at 500 MPa at 20 and 50°C. The physiological state of different subpopulations was characterized. Then Fourier transform infrared (FTIR) microspectroscopy coupled to a synchrotron infrared source was used to explore the heterogeneity of the biochemical signatures of the spores after the same HP treatments. Our results confirm that HP at 50°C induces the germination of a large proportion of the spore population. HP treatment at 20°C generated a subpopulation of ungerminated spores reversibly sensitized to the presence of nisin in their growth medium. Regarding infrared spectra of individual spores, spores treated by HP at 50°C and germinated spores had similar spectral signatures involving the same structural properties. However, after HP was performed at 20°C, two groups of spores were distinguished; one of these groups was clearly identified as germinated spores. The second group displayed a unique spectral signature, with shifts in the spectral bands corresponding to changes in membrane fluidity. Besides, spores spectra in the amide region could be divided into several groups close to spectral properties of dormant, germinated, or inactivated spores. The part of the spectra corresponding to α-helix and β-sheet-structures contribute mainly to the spectral variation between spores treated by HP at 20°C and other populations. These changes in the lipid and amide regions could be the signature of reversible changes linked to spore activation.Molari, M., Janssen, F., Vonnahme, T., Wenzh?fer, F., Boetius, A., 2020. Microbial communities associated with sediments and polymetallic nodules of the Peru Basin. Biogeosciences Discussions 2020, 1-30. mining of deep-sea polymetallic nodules will need to remove nodules in large areas of the seafloor. The regrowth of the nodules by metal precipitation is estimated to take millions of years. Thus for future mining impact studies, it is crucial to understand the role of nodules in shaping microbial diversity and function in deep-sea environments. Here we investigated microbial community composition based on 16S rRNA gene sequences retrieved from sediments and nodules of the Peru Basin (>?4100?m water depth). The nodule field of the Peru Basin showed a typical deep-sea microbiome, with dominance of the classes Gammaproteobacteria, Alphaproteobacteria, Deltaproteobacteria, and Acidimicrobiia. Nodules and sediments host distinct bacterial and archaeal communities, with nodules showing lower diversity and a higher proportion of sequences related to potential metal-cycling bacteria (i.e. Magnetospiraceae, Hyphomicrobiaceae), bacterial and archaeal nitrifiers (i.e. AqS1, unclassified Nitrosomonadaceae, Nitrosopumilus, Nitrospina, Nitrospira), and bacterial sequences found in ocean crust, nodules, hydrothermal deposits and sessile fauna. Sediment and nodule communities overall shared a low proportion of Operational Taxonomic Units (OTU; 21?% for Bacteria and 19?% for Archaea). Our results show that nodules represent a specific ecological niche (i.e. hard substrate, high metal concentrations and sessile fauna), with a potentially relevant role in organic carbon degradation. Differences in nodule community composition (e.g. Mn-cycling bacteria, nitrifiers) between the Clarion-Clipperton Fracture Zone (CCZ) and the Peru Basin suggest that changes in environmental setting (i.e. sedimentation rates) play also a significant role in structuring the nodule microbiome.M?ller, J.N., L?der, M.G.J., Laforsch, C., 2020. Finding microplastics in soils: A review of analytical methods. Environmental Science & Technology 54, 2078-2090. on microplastics in soils is still uncommon, and the existing publications are often incomparable due to the use of different sampling, processing, and analytical methods. Given the complex nature of soils, a suitable and efficient method for standardized microplastic analysis in the soil matrix has yet to be found. This paper proposes a critical review on the different published methods for sampling, extraction, purification, and identification/quantification of microplastics in complex environmental matrices, with the main focus on their applicability for soil samples. While large microplastic particles can be manually sorted out and verified with chemical analysis, sample preparation for smaller microplastic analysis is usually more difficult. Of the analytical approaches proposed in the literature, some are established, whereas others are a proof of principle and have not yet been applied to environmental samples. For the sake of development, all approaches are discussed and assessed for their potential applicability for soil samples. So far, none of the published methods seems ideally suitable for the analysis of smaller microplastics in soil samples, but slight modifications and combinations of methods may prove promising and need to be explored.Mondello, L., Donato, P., 2020. Selected papers from the 42th International Symposium on Capillary Chromatography and 15th GC?×?GC symposium (RIVA 2018). Journal of Chromatography A 1613, 460626. its first edition in 1975 (Hindelang, Germany), the “International Symposium on Capillary Chromatography” (ISCC) is the premier meeting for pressure and electrodriven microcolumn separations and related techniques, and a stimulating forum for worldwide scientists. The 42th ISCC meeting was organized jointly with the “15th GCGC Symposium” (GC?×?GC) in Riva del Garda, Italy, on May 13–18 2018, to allow researchers to attend both meetings. The program included plenary lectures, keynote lectures by young scientists, prominently featured poster presentations, discussion sessions to stimulate intense scientific exchange, an instrument exhibition displaying the latest instrumental innovations, and a highly attractive social program offering opportunities to meet with colleagues and world-renown scientists.The Sunday was entirely dedicated to tailored courses, offering a wealth of value added information for the interested audience. In detail, the popular GC?×?GC workshop@Riva returned, featuring an updated coverage of basic principles, latest trends, optimization strategies, and key applications. Moreover, the LC?×?LC course was offered for the first time in Riva, with the aim to expand the coverage of knowledge on multidimensional chromatographic techniques. The courses were presented by leading experts of the comprehensive methodologies, and offered opportunity to ask questions through a Q&A session, share experiences, learn of new solutions, and provide tips and advice to improve the practitioners’ conduct of these powerful analysis approaches. Both classes attracted considerable interest, with a total of 142 participants who enjoyed a buffet cocktail (offered by Shimadzu) at the end of the day.The 15th GC?×?GC Symposium started on Monday 14th, with a warm opening address by the committee, followed by lectures and keynote lectures in seven sessions. The “GC?×?GC Lifetime Achievement Award 2018” (sponsored by Leco) was presented to Jean-Fran?ois F. Focant (University of Liège, Belgium) who gave a lecture entitled “GC?×?GC-(HR)TOFMS: From Expectations to Practical Applications”. The program included one poster session and a welcome reception (offered by DANI Instruments).Conferees met again on Tuesday to attend more lectures in three sessions, and a second poster session was held. The “John Phillips Award 2018” (sponsored by Leco) was presented to Flavio A. Franchina (Thayer School of Engineering – Dartmouth College, Hanover, US), who gave a lecture on “The Rewarding Challenge of GC?×?GC–MS Method Development for Valuable Lifescience Applications”. The closing ceremony included presentation of the following awards: the “Genzo Shimadzu Best Oral Award” to Vinicius B. Pereira (Federal University of Rio De Janeiro, Brazil), Marta Cialiè Rosso (University of Turin, Italy); the “Genzo Shimadzu Best Poster Award” to Matthew H. Kremer (Oregon State University, Corvallis, US); the “Richard Sacks Best Poster Award” to: Roman Jaramillo (Department of Chemistry - Penn State, State College, US), Federico Stilo (University of Turin, Italy), Vanessa O. Nunes (Federal University of Rio de Janeiro, Brazil); the “Chromatographia-Springer Best Poster Award” to Mathijs Baert (Ghent University, Belgium).The 42nd ISCC Symposium started in parallel on Tuesday 15th morning with the opening address of the chairman Luigi Mondello (University of Messina, Italy). Right after, the Award lecture “Practical Implications of Chromatographic Theory” was given by Leonid Blumberg (Advachrom, Wilmington, DE, US), awarded with the “M.J.E. Golay Award 2018” (sponsored by PerkinElmer). Later on, the “Giorgio Nota Award 2018” (sponsored by Waters) was presented to Hernan J. Cortes (Hernan Cortes Consulting LLC, Midland, US), lecturing on “Microcolumn Liquid Chromatography. Then and Now”. The first day of the ISCC conference included 3 lecture sessions, three vendor seminars and one user meeting. At the end of the day, all attendees enjoyed from the capturing notes of an instrumental orchestra (offered by PerkinElmer), followed by a cocktail buffet (offered by GERSTEL).The ISCC conference continued for the next three days with plenary lectures by leading scientists covering the latest achievements in the field of capillary chromatography, as well as keynote lectures by young scientists. The program included 9 lecture sessions, 4 keynote lecture sessions, 4 poster sessions, 13 vendor seminars and a “Short Course: Scientific writing and publishing”. The “Giovanni Dugo Medal” (sponsored by the Interdivisional Group of separation science of the Italian Chemical Society) was presented to Carlo Bicchi (University of Turin, Italy), lecturing on “Ionic Liquids as GC Stationary Phases in the Flavour and Fragrance Field”.The social program never took a rest, with the “Prosecco cocktail” to celebrate the launch of the journal “Separation Science Plus” (offered by Wiley-WCH), the traditional “Wine and cheese” cocktail (offered by Agilent), and the “Disco night” (offered by Thermo Scientific).The closing ceremony of the 42nd ISCC Symposium included presentation of the “Leslie S. Ettre Award” (sponsored by PerkinElmer) to Andrea Walzl (University of Technology Graz, Austria), presenting on “Characterization of Functional Barrier Properties for Food Contact Materials”. After, the following awards were presented: the “Genzo Shimadzu Best Oral Award” to Jeremi Nowak (College of Chemistry, Berkeley, US), Giorgia La Barbera (University of Rome La Sapienza, Italy); the “Genzo Shimadzu Best Poster Award” to Adissu A. Asfaw (Pharmaceutical analysis, Leuven, Belgium), Jan Leppert (University of Bonn, Germany), Milada Vávrová (Brno University of Technology, Czech Republic), Adrian Gutierrez-Serpa (Universidad de La Laguna, Spain); the “Chromatographia-Springer Best Poster Award” to Elena A. Bessonova (Saint-Petersburg St. Univ., Saint-Petersburg, Russia); the “Analytical Methods Best Poster Award” to Christian Lipok (University of Duisburg-Essen, Germany). Moreover, the “Journal of Chromatography A: Young Scientist Award” was presented to Margita Utczás (Chromaleont S.r.L., Messina, Italy and University of Physical Education, Budapest, Hungary), Bob W. Pirok (University of Amsterdam, the Netherlands), Jonathan J. Grandy (University of Waterloo, Canada), Nicola Marchetti (University of Ferrara, Italy).The closing addresses concluded with invitations to the 43rd ISCC – 16th GC?×?GC Symposium (May 12–17, 2019 Fort Worth, Texas, USA), and to the 44th ISCC – 17th GC?×?GC Symposium (May 24–29, 2020 Riva del Garda, Italy), followed by an open-air farewell cocktail outside the congress centre (offered by Waters).Here are some numbers from the final balance: 369 participants at the 15th GC?×?GC Symposium (of which 65 students), 709 participants to both symposia from 43 different countries (of which 97 ISCC students), 98 participants at the GC?×?GC course and 44 participants at the LC?×?LC course. A total of 20 scholarships were granted by the following Institutions/Companies: CASSS (Martina Hakova, Charles University, Czech Republic; Nirved Upadhyay, University of Tasmania, Australia); Chromaleont S.r.L. (Guilherme Alexandrino, University of Copenhagen, Denmark; Ahmet Dursun, Mustafa Kemal University, Turkey; Ocsana Izosimova, Russian Academy of Science, Russia; Jitka Klikarova, University of Pardubice, Czeck Republic; Yassine Oulad El Majdoub, Moulay Ismail University, Morocco; Ioannis Sampsonidis, University of Glasgow, UK; Vasic Vesna, University of Belgrade, Serbia); Divisione di Chimica Analitica - Società Chimica Italiana (Martina Catani, University of Ferrara, Italy; Placido Franco, University of Bologna, Italy); Interdivisional Group of Separation Science of the Italian Chemical Society (Giorgia La Barbera, University of Rome La Sapienza, Italy; Eduardo Sommella, University of Salerno, Italy); ISCC & GC?×?GC, Fort Worth, Texas, USA – May 2019 (Marco Beccaria, Dartmouth College, USA; Haleigh Boswell, University of Waterloo, Canada; Oleg Karaduta, University of Arkansas, USA; Kyra Murrel, The Pennsylvania State University, USA; Joao Raul de Souza, Institute of Chemistry – UNICAMP, Brazil); Separations ESCI by MDPI AG (Maria Antoniadou, Vienna University of Technology, Austria; Delphine Zanella, University of Lieges, Belgium).The scientific program included 166 lectures (59 lectures at the GC?×?GC symposium, 107 lectures at the ISCC symposium, and 6 award lectures), and 352 posters. In addition, 32 exhibitors were presenting the latest developments in commercial instrumentations and organized 17 technical seminars/user meetings, and 11 publishing houses.The event was supported by seventeen organizations: Association Francophone des Sciences Séparatives, Central European Group for Separation Sciences, Chinese American Chromatography Association, Chromatography and Electrophoresis Group of the Czech Chemical Society, European Society for Separation Science, Italian Chemical Society, Division of Mass Spectrometry of the Italian Chemical Society, Interdivisional Group of Food Chemistry of the Italian Chemical Society, Interdivisional Group of Separation Science of the Italian Chemical Society, Hungarian Society for Separation Sciences, Norwegian Chromatographic Group of the Norwegian Chemical Society, Separation Science Group Royal Society of Chemistry, Separation Science Section of the Societatea de Chimie din Romania, Slovenian Chemical Society, Sociedad Espagnola dem Cromatografia y Tecnicas Afines, The Japanese Society for Chromatographic Sciences, Ukranian Chromatographic Society.This virtual special issue collects 26 manuscripts presented at the 42nd ISCC Symposium and 15th GC?×?GC Symposium, and published in individual printed issues. They are focused on the latest developments in the field of liquid and gas chromatography, especially hyphenated with mass spectrometry, as well as improved sampling techniques and extraction methodologies. New insights are given into the separation mechanisms in monodimensional and multidimensional applications, using novel stationary phases, and notable achievements are presented from the detection standpoint. This virtual issue also offers the readers access to the program book, abstracts, list of award dinners, and photographs from the symposium. I hope the readers will be interested to this new format and enjoy its features.Moore, E.K., Hao, J., Spielman, S.J., Yee, N., 2020. The evolving redox chemistry and bioavailability of vanadium in deep time. Geobiology 18, 127-138. incorporation of metal cofactors into protein active sites and/or active regions expanded the network of microbial metabolism during the Archean eon. The bioavailability of crucial metal cofactors is largely influenced by earth surface redox state, which impacted the timing of metabolic evolution. Vanadium (V) is a unique element in geo?bio-coevolution due to its complex redox chemistry and specific biological functions. Thus, the extent of microbial V utilization potentially represents an important link between the geo- and biospheres in deep time. In this study, we used geochemical modeling and network analysis to investigate the availability and chemical speciation of V in the environment, and the emergence and changing chemistry of V-containing minerals throughout earth history. The redox state of V shifted from a more reduced V(III) state in Archean aqueous geochemistry and mineralogy to more oxidized V(IV) and V(V) states in the Proterozoic and Phanerozoic. The weathering of vanadium sulfides, vanadium alkali metal minerals, and vanadium alkaline earth metal minerals were potential sources of V to the environment and microbial utilization. Community detection analysis of the expanding V mineral network indicates tectonic and redox influence on the distribution of V mineral-forming elements. In reducing environments, energetic drivers existed for V to potentially be involved in early nitrogen fixation, while in oxidizing environments vanadate (VO4-3) could have acted as a metabolic electron acceptor and phosphate mimicking enzyme inhibitor. The coevolving chemical speciation and biological functions of V due to earth's changing surface redox conditions demonstrate the crucial links between the geosphere and biosphere in the evolution of metabolic electron transfer pathways and biogeochemical cycles from the Archean to Phanerozoic.Morandi, G., Wiseman, S., Sun, C., Martin, J.W., Giesy, J.P., 2020. Effects of chemical fractions from an oil sands end-pit lake on reproduction of fathead minnows. Chemosphere 249, 126073. sands process-affected water (OSPW) is a byproduct of bitumen extraction in the surface-mining oil sands industry in Alberta, Canada. Organic compounds in OSPW can be acutely or chronically toxic to aquatic organisms, so part of a long-term strategy for remediation of OSPW is ageing of water in artificial lakes, termed end-pit lakes. BaseMine Lake (BML) is the first oil sands end-pit lake, commissioned in 2012. At the time of its establishment, an effects-directed analysis of BML-OSPW showed that naphthenic acids and polar organic chemical species containing sulfur or nitrogen contributed to its acute lethality. However, the chronic toxicity of these same chemical fractions has not yet been investigated. In this work, the short-term fathead minnow reproductive bioassay was used to assess endocrine-system effects of two fractions of BML-OSPW collected in 2015. One of the fractions (F1) contained predominantly naphthenic acids, while the other (F2) contained non-acidic polar organic chemical species. Exposure of minnows to F1 or F2 at concentrations equivalent to 25% (v/v) of the 2015 BML-OSPW sample (5–15% of the 2012 BML-OSPW sample) did not alter reproductive performance, fertilization success, or concentrations of sex steroids in exposed female or male minnows. Additionally, there were no significant differences in fertility, hatching success or incidence of morphological indices of embryos collected on day 7 or 14 from exposed breeding trios. However, exposure of male fathead minnow to 25% (v/v) intact 2015 BML-OSPW resulted in a significantly greater hepatosomatic index. Exposure of fathead minnow to refined fractions of dissolved organic chemicals in 2015 BML-OSPW, or a 25% (v/v) of the intact mixture did not affect fertility or fecundity as measured by use of the 21-day reproductive bioassay. These data will be useful in setting future threshold criteria for OSPW reclamation and treatment.Morée, A.L., Schwinger, J., Ninneman, U.S., Jeltsch-Th?mmes, A., Bethke, I., Heinze, C., 2020. Evaluating the biological pump efficiency of the Last Glacial Maximum Ocean using δ13C. Climate of the Past Discussions 2020, 1-28. both physical and biological marine changes are required to explain the 100?ppm lower atmospheric pCO2 of the Last Glacial Maximum (LGM, ~?21?ka) as compared to pre-industrial (PI) times, their exact contributions are debated. Proxies of past marine carbon cycling (such as δ13C) document these changes, and thus provide constraints for quantifying the drivers of long-term carbon cycle variability. This modelling study explores the relative roles of physical and biological changes in the ocean needed to simulate an LGM ocean in satisfactory agreement with proxy data, and here especially δ13C. We prepared a PI and LGM ocean model state (NorESM-OC) with full biogeochemistry (including the carbon isotopes δ13C and radiocarbon) and dynamic sea ice. The modelled LGM-PI differences are evaluated against a wide range of physical and biogeochemical proxy data, and show agreement for key aspects of the physical ocean state within the data uncertainties. However, the lack of a simulated increase of regenerated nutrients for the LGM indicates that additional biogeochemical changes are required to simulate an LGM ocean in agreement with proxy data. In order to examine these changes, we explore the theoretical effects of different global mean biological pump efficiencies on the simulated marine biogeochemical tracer distributions. We estimate that (besides changes in ocean circulation) an approximate doubling of the global mean biological pump efficiency from 38?% (PI) to 75?% (LGM) reduces model-proxy biases the most. The remaining absolute model-proxy error in δ13C (which is 0.07?‰ larger than the 0.19?‰ data uncertainty) indicates that additional changes in ocean dynamics are needed to simulate an LGM ocean in agreement with proxy data, such as increased aging or volume of Southern Source Waters. Besides that, our theoretical approach of increasing the biological pump efficiency may be too simplified to capture the vertical redistribution of regenerated nutrients – also suggested by a too weak chemocline. Our results underline that only those coupled climate models that contain the processes and/or components that realistically change both ocean circulation and biogeochemistry will be able to simulate an LGM ocean in satisfactory agreement with proxy data – and hence be reliable for use in climate projections. Therefore, future research should aim to identify the exact physical and biogeochemical processes that could have doubled the global mean biological pump efficiency (i.e., the interior regenerated signature) between the PI and LGM, with a likely central role for Southern Source Waters.Moritz, F., Hemmler, D., Kanawati, B., Schnitzler, J.-P., Schmitt-Kopplin, P., 2019. Chapter 12 - Mass differences in metabolome analyses of untargeted direct infusion ultra-high resolution MS data, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 357-405. resolution mass spectrometers (UHR MS) including Fourier Transform ion cyclotron resonance (FT-ICR MS) and Orbitrap mass analyzers produce data of ever more increasing mass accuracy, resolution and information content. In its comparably long history of analyses on complex mixtures such as petroleum or natural organic matter, UHR-MS scientists have developed methods for mining and analysis of homologous hydrocarbon series, repetitive elemental compositional units that are characteristic for the chemistry of diverse complex organic matrices. The science of metabolomics considered the use of UHR-MS for the analysis of complete sets of metabolites since its infancy. However, the peculiarities of this type of UHR analytical instrumentation and the data it produces did not yet become a widely accepted source of biologically relevant information. This book chapter aims to assist the readers in their assessment of the great value that UHR-MS analyzers can produce for their own research. This book chapter's first section accordingly provides a short introduction into the history of metabolomics and attempts to gauge where UHR-MS is to be positioned amidst the various sub-classifications of metabolomic research. The second section then proceeds with introducing mass differences as the major means of mass spectrometric quality assessment, just to extend their use for the visual and computational localization of homologous molecular series and molecular formula assignment. After a review of major mass-difference based technologies in m/z signal identification, “Mass difference networks in the visualization and secondary analysis of UHR-MS data” section continues to line out the methods that are central for a systems biological analysis of metabolomic data. The chapter finishes by embedding mass differences into the context of the introduced methods and an example on their use for mining the chemical meaning of unknown metabolic features.Mour?o, M.P.B., Kolk, A.H.J., Janssen, H.-G., 2020. Chapter 1.1 - General principles and history, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 3-74. information on the composition of mixtures is crucial in many areas of modern life. Chromatographic techniques are one of the key techniques applied to answer questions on what is in a mixture and how much of each constituent is present. Gas chromatography (GC) is a very powerful separation method that can separate highly complex mixtures into its constituents, but unambiguous identification is difficult to obtain without the coupling to a sensitive mass spectrometer (MS). For optimum performance of hyphenated GC-MS, the requirements and performance characteristics of both techniques need to be considered and properly balanced. In this chapter the various parameters that are relevant for the coupling of GC and MS will be defined. In the hands of a well-trained analyst the technique is today more powerful than it has ever been.Muhling, J.R., Rasmussen, B., 2020. Widespread deposition of greenalite to form Banded Iron Formations before the Great Oxidation Event. Precambrian Research 339, 105619. Iron Formations (BIFs) are Precambrian sedimentary rocks interpreted to have been precipitated from anoxic seawater prior to the first permanent rise in atmospheric oxygen in the Great Oxidation Event at ca. 2.45–2.32?Ga. BIFs hold the key to understanding the chemistry of the oceans and atmosphere, and how these interacted with microbial life, prior to and during the evolution of oxygenic photosynthesis. To unlock this information, it is essential to know how BIFs formed, that is, what minerals were precipitated, by what mechanisms and in which environments. BIFs are found in almost all depositional settings at times when input of clastic detritus was lacking, for example, submarine proximal volcanic environments, basin floor, slope, deep marine shelf and shallow shelf settings. High-resolution electron microscopy of finely laminated BIFs and ferruginous cherts that range in age from 3.45 to ca. 2.4?Ga and that preserve depositional features indicates that the original sediment was a very fine mud composed of nanoparticles of the iron-silicate greenalite. In places, the greenalite mud experienced very early silicification on the sea floor enabling preservation of the mineral and its depositional textures. Very fine grained siderite and hematite in laminated BIFs post-date dehydration of the early silica cement and are not primary minerals. Greenalite nanoparticles are found in BIFs from all depositional settings indicating a common origin, likely precipitation resulting from mixing of plume water from hydrothermal vents with ambient seawater. The nanoparticles were carried throughout the oceans and were deposited on the seafloor and on continental margins to form the primary sediments of BIFs.Müller, Y.K., Wernicke, T., Pittroff, M., Witzig, C.S., Storck, F.R., Klinger, J., Zumbülte, N., 2020. Microplastic analysis—are we measuring the same? Results on the first global comparative study for microplastic analysis in a water sample. Analytical and Bioanalytical Chemistry 412, 555-560. paper presents the results of the first international comparative study of commonly applied analytical methods for microplastic analysis. Although it was shown that the comparability between previously published studies is highly limited, there are ambitious efforts regarding the standardization of microplastic analysis. This comparative study serves as a first step to assess the suitability of frequently used methods in microplastic research. Furthermore, it highlights obstacles when conducting a comparative study for microplastics. Results from 17 laboratories from eight different countries are compared. Samples comprised of five different types of microplastic reference particles with diameters ranging from 8 ?m to 140?μm suspended in ultrapure water. Microscopy, Fourier-transform infrared microspectroscopy (μ-FTIR), Raman microspectroscopy (μ-Raman), thermo-extraction-and-desorption- or pyrolysis- combined with gas chromatography coupled to mass spectrometry (Σ-GC/MS), scanning electron microscopy and particle counter were compared regarding results on total particle number, polymer type, number of particles and/or particle mass for each polymer type. In the scope of this comparative study, for the identification of polymer type μ-Raman and Σ-GC/MS performed best. The quantification of polymer mass for identified polymer types was questionable for Σ-GC/MS, whereas other methods failed to determine the correct polymer mass. Quantification of particle number per identified polymer type was evaluated successful for μ-FTIR and the quantification of total particle numbers was best for microscopy and to a lesser extent for μ-FTIR. Remarkable was the large variance of results between the methods but also within the methods. The latter is likely due to individual interpretations of methods and preparation protocols, in particular in regard to the handling of blank values. Results strongly emphasize the need for standardization and validation of analytical methods in microplastic research both on a global scale as well as in the context of individual laboratories.Mumford, A.C., Maloney, K.O., Akob, D.M., Nettemann, S., Proctor, A., Ditty, J., Ulsamer, L., Lookenbill, J., Cozzarelli, I.M., 2020. Shale gas development has limited effects on stream biology and geochemistry in a gradient-based, multiparameter study in Pennsylvania. Proceedings of the National Academy of Sciences 117, 3670-3677.: This investigation provides a comprehensive evaluation of the geochemical and biological effects of shale gas development on 25 small watersheds over the course of 2 y. Sampling headwater streams seasonally over two consecutive years yielded no statistically significant relationships between the intensity, presence, or absence of shale gas development and any signal in a comprehensive set of chemical constituents (including those recognized as oil and gas geochemical tracers) or any changes in microbial or benthic macroinvertebrate community composition. This work provides a framework for investigations of anthropogenic effects stemming from natural resource development, and highlights the importance of conducting studies which control for regional and temporal variability.Abstract: The number of horizontally drilled shale oil and gas wells in the United States has increased from nearly 28,000 in 2007 to nearly 127,000 in 2017, and research has suggested the potential for the development of shale resources to affect nearby stream ecosystems. However, the ability to generalize current studies is limited by the small geographic scope as well as limited breadth and integration of measured chemical and biological indicators parameters. This study tested the hypothesis that a quantifiable, significant relationship exists between the density of oil and gas (OG) development, increasing stream water concentrations of known geochemical tracers of OG extraction, and the composition of benthic macroinvertebrate and microbial communities. Twenty-five headwater streams that drain lands across a gradient of shale gas development intensity were sampled. Our strategy included comprehensive measurements across multiple seasons of sampling to account for temporal variability of geochemical parameters, including known shale OG geochemical tracers, and microbial and benthic macroinvertebrate communities. No significant relationships were found between the intensity of OG development, shale OG geochemical tracers, or benthic macroinvertebrate or microbial community composition, whereas significant seasonal differences in stream chemistry were observed. These results highlight the importance of considering spatial and temporal variability in stream chemistry and biota and not only the presence of anthropogenic activities in a watershed. This comprehensive, integrated study of geochemical and biological variability of headwater streams in watersheds undergoing OG development provides a robust framework for examining the effects of energy development at a regional scale.Murray, K.J., Shea, D., Boehm, P.D., 2020. Development of a computational method to quantify the partitioning of polycyclic aromatic hydrocarbons in seawater into dissolved and droplet forms. Marine Pollution Bulletin 153, 110955. ecological risk and potential injury from polycyclic aromatic hydrocarbons (PAHs) from spilled crude oil in water is dependent on whether they are dissolved or associated with droplets/particles. Using oil collected from the Deepwater Horizon incident, laboratory experiments were conducted to develop a computational method to determine the physical state of PAHs in sampled seawater and compare these to results from methods designed to physically separate dissolved and droplet oil used during the spill. The analytical results were used to develop a method to calculate droplet/particulate concentrations from unfractionated water samples based on oil composition and allocation of minimally soluble oil components to the droplet fraction. The computational method is less labor-intensive and costly than field fractionation and can be used to optimize the use of previously collected data. The results also showed that physical separation can result in insoluble high-molecular-weight PAHs being present in the filtrate (i.e., the “dissolved” fraction), potentially leading to an overestimate of dissolved components.Murtada, K., 2020. Trends in nanomaterial-based solid-phase microextraction with a focus on environmental applications - A review. Trends in Environmental Analytical Chemistry 25, e00077. solid-phase microextraction (SPME) in environmental field represents a crucial step for the adequate extraction of several analytes. Several materials have been traditionally developed for SPME of several analytes from environmental samples, even though their several restrictions such as post-treatment required, elevate costs and limited efficiency. Recently, nanomaterials (NMs) have emerged as a promising substitute for SPME in environmental applications of traditional techniques, due to their small size and their high specific surface-area which enhances their high reactivity. In this present review different NMs which have recently been utilized as SPME sorbent for environmental applications are classified into eleven main groups, namely nanoparticles, nanofibers, nanoflakes, nanocomposites, nanorods, nanotubes, nanohorns, nanosheets, nanocubes, nanospheres and polymer-based NMs. Application of these NMs in SPME modes and configurations for environmental analysis has been reviewed. The study discusses not only the advantages but also the major limitations of using such NMs.Nadis, S., 2020. Tough microbe's DNA could be a lasting archive. Science 367, 840. Davis is looking for the ultimate time capsule. He wants to preserve a record of humanity that could survive for eons, to be read by successors to Homo sapiens on Earth or by sapient extraterrestrials. He has now found the right medium, he thinks: the DNA of an odd microbe that lives in deposits of rock salt. He believes this archive—protected by salt and renewed by the microbe—could possibly survive for hundreds of millions of years.It's a visionary idea, owing as much to art as science. Davis, an artist affiliated with a Harvard University biology lab, bridges both worlds. His project took a step forward last week with a study posted on bioRxiv, a preprint repository. In the study, Davis and his colleagues show they can encode information in the DNA of Halobacterium salinarum (Hsal)—a hard-to-kill, salt-tolerant microbe that has, on average, 25 backup copies of each of its chromosomes.Other researchers have explored the storage potential of DNA, which packs the equivalent of about 300 megabytes of data into the nucleus of a human cell. But Davis is combining that capacity with the resilience of an extraordinarily hardy organism. “If you want to keep data for a long, long time, the best way to do that may be to hold it inside cells and utilize the cellular machinery for DNA self-repair,” he says. “They can conveniently and economically reproduce themselves with little or no intervention.”Jeff Nivala, a biological engineer at the University of Washington, Seattle, who studies halophiles and DNA storage, agrees. “For archival storage over millions of years, this might be a great application,” he says. “If all other life is destroyed on Earth, and this is the only thing left, maybe that information could propagate on its own.”Davis has no formal training in biology, save for a single course at a Mississippi junior college in the 1960s. But he has a record of turning biology into performance art that sometimes leads back to science. In 1987, for an artistic venture called Microvenus, he encoded a depiction of the female form into the DNA of living Escherichia coli bacteria—a feat that is widely cited as the first experimental demonstration of DNA data storage.Now, Davis is working with a tougher microbe than E. coli. Hsal can withstand desiccation, thermal extremes, prolonged vacuum, and intense radiation. Davis has even exposed it to ethylene oxide, a poisonous gas used to sterilize laboratory equipment, with no discernible effects. Hsal does have a kryptonite: Immersion in freshwater bursts its cells. But when entombed in briny pockets within salt crystals, Davis muses, Hsal could be “the thing that couldn't die.”For commercial DNA storage, in vitro techniques—encapsulating synthetic DNA in glass or stainless steel—are more advanced than in vivo approaches, says Emily Leproust, an organic chemist and CEO of Twist Bioscience. But living things could preserve DNA far longer, says Davis, who has revived hibernating Hsal cells from salt deposits hundreds of millions of years old. His collaborator, Harvard geneticist George Church, considers it “totally plausible” that the cells found deep within stable crystals survived all this time in a dormant state. The cells stop growing, and their DNA remains unchanged except for gradual degradation, he says. “But they can also replicate quickly when they need to,” he adds, repairing damage and generating lots of copies for researchers to work with. “So Hsal appears to be a good choice.”Jocelyne DiRuggiero, a Johns Hopkins University biologist and Hsal expert, regards the plan as “a cool idea.” Besides enduring environmental stresses, she says, Hsal is good at removing reactive oxygen species that harm DNA. With minimal nutrients, an Hsal colony could hibernate in salt for hundreds of thousands of years or more, she says. The microbes would not grow or reproduce, she says, and would only use energy to make repairs and counteract threats, such as DNA damage from cosmic rays.The first step in the new work was to encode data in Hsal's DNA. Davis chose the coordinates for a 3D picture of a needle and egg—objects in a Russian folktale about a wizard who hid his soul in the tip of a needle concealed inside an egg. After Davis synthesized the DNA, Alexandre Bisson, a biologist at Brandeis University, attached it to a site in the Hsal genome that wouldn't affect the microbe or produce anything in the cell. Bisson encouraged the modified halobacteria to replicate and sequenced their DNA to ensure the new code was unaltered.To learn more about the microbes' potential as time capsules, Bisson is studying how they behave in salt crystals, which “is largely a mystery.” Over the course of 10 years or more, he plans to compare Hsal strains encased in salt with “parent” or control strains kept in a freezer to see whether any mutations occur in the presumably more active salt strains. That data will help fill a void, though extrapolating it to millions of years “would be a stretch,” he says. Bisson also plans to use fluorescent proteins to find out whether the organisms stay trapped within the briny pockets that sustain them or if they move around.Davis hasn't lost sight of the project's primary motivation. “What kind of legacy should humans leave behind as a species?” he asks. Davis doesn't claim to know; he plans to gather input from scientists, historians, artists, poets, and philosophers. But he wants to safeguard more than just information. “I want to preserve the meaning,” he says.Naidko, V.I., Makarov, V.A., Koz’min, D.G., Shimanskii, A.F., Fertikov, A.I., 2019. Geologic and geochemical features of Cretaceous Ge-bearing lignites in the Yenisei middle reaches. Russian Geology and Geophysics 60, doi: 10.15372/RGG2019004. geological and geochemical studies were performed for lignite from the Yenisei middle reaches, represented by carbonized fragments of trees with high germanium contents. Geochemical characteristics of terrigenous sediments with Ge-bearing lignite are determined. The chemical and mineral compositions, textures, and structures of carbonized wood fragments were studied. Scanning of individual cross sections of lignite fragments has revealed a regular distribution of germanium and impurity elements. Consistent patterns of the formation of Ge-containing lignites have been established, as well as the processes of their posthydrothermal transformation, which led to the impoverishment of the primary contents of the valuable component and to the input of a number of impurity elements. The latter formed rims over the lignite fragments and microveinlets with sulfide mineralization. The hypothesis has been put forward that germanium mineralization formed in lignites of the Kas basin, in particular, the Serchanskoe deposit. Nayak, A.R., Twardowski, M.S., 2020. “Breaking” news for the ocean's carbon budget. Science 367, 738-739. play a critical role in Earth's carbon cycle. Quantifying essential processes in carbon cycling and extending these to future predictions remain great scientific challenges. Nearly 30% of anthropogenic carbon is absorbed from the atmosphere into the ocean, where sempiternal, ubiquitous populations of microscopic particles transport carbon into the isolated deep sea (1). This complex pathway is driven by various biophysical and chemical interactions, including phytoplankton productivity, zooplankton grazing, oceanic mixing and turbulence, advection, and the sinking of particles and aggregates (2) (see the figure). On page 791 of this issue, Briggs et al. (3) quantitatively describe the key role of particle fragmentation in carbon storage by the ocean, potentially accounting for half of the particle flux that fails to sink into the deep ocean.Of 10 to 12 billion metric tons of carbon absorbed at the ocean's surface, estimates suggest that only about 10 to 30% makes its way to 1000-m depth, a point of transition between the mesopelagic and abyssal regions (4, 5). What happens to the remaining carbon in the mesopelagic has puzzled the scientific community for decades. Traditionally, sediment traps, both moored and drifting, collect sinking particles at a certain depth over a period of days to months. However, limited spatial and temporal coverage, hydrodynamic effects that alter collection efficiency, and pooling of collected particles within traps hamper broad-ranging interpretation of results. Moreover, elucidating sinking rates of individual particles of different sizes and densities has been a difficult problem. Advances in optical instrumentation and autonomous robotic platforms show promise for characterizing particle concentrations, size distributions, bulk densities, and sinking rates over large regions of Earth's oceans (6), making carbon flux estimates a potentially more tractable problem. Briggs et al. leveraged a network of 25 Biogeochemical-Argo floats distributed over two different oceanic regions and equipped with optical scattering and chlorophyll fluorescence sensors to explore this problem.Since the emergence of practical beam transmissometers in the 1970s for measuring light attenuation through water, a wide range of optical sensors have been developed and commercialized. Approaches for measuring particle optical properties include spectral and angular scattering, silhouette and reflection imaging, holographic imaging, diffractometry, flow cytometry, and fluorescence (6, 7). Some of these sensors have been integrated on autonomous ocean platforms in the last 20 years. Coincident with these emerging technologies have been efforts to develop algorithms to interpret data in terms of particle biogeochemical properties. The study by Briggs et al. is in many ways a culmination of these efforts.The composition of sinking particles differs vastly in shape and size: Single-celled and colonial phytoplankton, zooplankton, marine snow, fecal pellets, organic detritus, and large aggregates can vary in size from 0.2 ?m to several centimeters (1). Particle sinking rates are higher for larger and denser particles (8). Quantification of sinking rates plays an important role in understanding carbon flux budgets. Typically, large phytoplankton blooms form in the Atlantic and Southern Oceans during spring and summer. When nutrients are depleted, blooms die out, forming rapidly sinking large aggregates (9). Briggs et al. isolated such “pulses” of large sinking particle fluxes for analysis and found that small and large particle-size classes increase concomitantly. Particle aggregation is a common occurrence in the water column, driven by various processes, including Brownian motion, shear coagulation, gravitational settling, and differential sedimentation (10). Assuming the absence of fragmentation, smaller particles would aggregate to form larger particles, leading to a decrease in their concentrations. Hence, increased small-particle concentrations support the claim that large-particle fragmentation is indeed occurring. This helps to explain carbon flux loss in the mesopelagic.The Briggs et al. study opens several new avenues of research. For example, the authors treated all particles in the 100- to 2000-?m range as “large.” This coarse binning can lead to incomplete characterization of particle aggregation and/or fragmentation processes within that size range. In situ imaging instrumentation is now advanced enough to be used in particle flux characterization studies (11) and can help investigate these processes in the future. Other emerging techniques, such as remote imaging with range-gated, scanning light detection and ranging (LIDAR) and holographic imaging to refine particle-size distributions and sinking rates, are also promising (12). Intriguingly, Briggs et al. found varying particle fragmentation rates between the Atlantic and Southern oceans. Characterizing fragmentation mechanisms might provide some clarity, as limited field studies have shown that several factors, including microbial action, oceanic turbulence, and zooplankton grazing, can be substantial contributors (13, 14). Elucidating these complex small-scale interactions holds the key to addressing bigger problems.Better understanding the intricate mechanisms involved in oceanic carbon export will improve global climate studies. Ongoing research initiatives implementing in situ optical particle-size measurements to quantify global carbon export include the U.S.-led EXport Processes in the Ocean from RemoTe Sensing (EXPORTS), and Europe-led programs such as Robots Explore plankton-driven Fluxes in the marine twIlight zoNE (REFINE), Gauging ocean Organic Carbon fluxes using Autonomous Robotic Technologies (GOCART), and CarbOcean. However, a major gap remains in providing the observational data required by models to accurately estimate global export. Of the 3858 Argo floats currently deployed throughout Earth's oceans, less than 5% are equipped with sensors that can resolve biogeochemical properties of particles. Briggs et al. demonstrate the value to be gained with an increased focus and investment in leading-edge optical technologies for ocean exploration.References and Notes1. J. T. Turner, Prog. Oceanogr. 130, 205 (2015).2. H. W. Ducklow, D. K. Steinberg, K. O. Buessler, Oceanography (Wash. D.C.) 14, 50 (2001).3. N. Briggs et al., Science 367, 791 (2020).4. K. O. Buesseler, P. W. Boyd, Limnol. Oceanogr. 54, 1210 (2009).5. G. A. Jackson et al., Deep Sea Res. Part I Oceanogr. Res. Pap. 99, 75 (2015).6. S. L. C. Giering et al., Front. Mar. Sci. 10.3389/fmars.2019.00834 (2020).7. M. S. Twardowski et al., in Remote Sensing of Coastal Aquatic Waters (Springer, 2007), pp. 69–100.8. T. L. Richardson, G. A. Jackson, Science 315, 838 (2007).9. V. Smetacek, Nature 406, 574 (2000).10. A. G. Burd, G. A. Jackson, Annu. Rev. Mar. Sci. 1, 65 (2009).11. A. B. Bochdansky et al., Front. Mar. Sci. 6, 778 (2019).12. A. R. Nayak et al, Limnol. Oceanogr. 63, 122 (2018).13. E. L. Cavan et al., Biogeosciences 14, 177 (2017).14. G. J. Herndl, T. Reinthaler, Nat. Geosci. 6, 718 (2013)Negahban, S., Kazemi, M., Kalantari, M., Dindoruk, B., Elshahawi, H., 2020. “Digital Fluid Physics”: Prediction of phase equilibria for several mixtures of CO2 with petroleum fluid systems. Journal of Petroleum Science and Engineering 187, 106752. oil recovery (EOR) techniques (miscible/near miscible hydrocarbon/non-hydrocarbon gas injection, chemical flooding such as surfactant/polymer and smart water, and combinations of the three) aim at increasing oil recovery factor over what could be achieved from natural depletion and pressure maintenance methods such as waterflooding. As we embark on more complex EOR processes (e.g.), complex phase equilibria, complicated rock/fluid interaction, and sophisticated transport through porous media will create several key technical challenges that must be addressed.Currently, all of the existing compositional reservoir simulators, such as ECLIPSE, CMG, NEXUS, etc., use semi-empirical cubic equation of state (EoS) to represent the phase equilibria (mainly for the hydrocarbon calculation of equilibrium phase compositions) and phase properties (densities, viscosities, volume fractions, saturations, etc.). These data in combination with rock/fluid interaction data (relative permeability and capillarity pressure) will describe transport through porous media under the assumption of instantaneous equilibrium. Many empirical binary interaction parameters are needed for cubic EoS. In addition, mixing parameters along with the proper mixing rules are also required for multi-component mixtures. Current cubic EOS models have limited extrapolation capabilities beyond measured data. They also fall short in predicting derivative properties (even within the range measurements), transport properties, critical behavior, and the surfactants and polar components' phase behavior.This work presents the application of “Digital Fluid Physics” to determine the phase behavior of petroleum mixtures. Three different petroleum systems are investigated. Molecular simulation shows promising results in comparison with experimental measurements and therefore can reduce the cost and time required for tuning equations of state.Neubauer, C., Crémière, A., Wang, X.T., Thiagarajan, N., Sessions, A.L., Adkins, J.F., Dalleska, N.F., Turchyn, A.V., Clegg, J.A., Moradian, A., Sweredoski, M.J., Garbis, S.D., Eiler, J.M., 2020. Stable isotope analysis of intact oxyanions using electrospray quadrupole-Orbitrap mass spectrometry. Analytical Chemistry 92, 3077-3085. stable isotopes of sulfate, nitrate, and phosphate are frequently used to study geobiological processes of the atmosphere, ocean, as well as land. Conventionally, the isotopes of these and other oxyanions are measured by isotope-ratio sector mass spectrometers after conversion into gases. Such methods are prone to various limitations on sensitivity, sample throughput, or precision. In addition, there is no general tool that can analyze several oxyanions or all the chemical elements they contain. Here, we describe a new approach that can potentially overcome some of these limitations based on electrospray hyphenated with Quadrupole Orbitrap mass spectrometry. This technique yields an average accuracy of 1–2‰ for sulfate δ34S and δ18O and nitrate δ15N and δ18O, based on in-house and international standards. Less abundant variants such as δ17O, δ33S, and δ36S, and the 34S–18O “clumped” sulfate can be quantified simultaneously. The observed precision of isotope ratios is limited by the number of ions counted. The counting of rare ions can be accelerated by removing abundant ions with the quadrupole mass filter. Electrospray mass spectrometry (ESMS) exhibits high-throughput and sufficient sensitivity. For example, less than 1 nmol sulfate is required to determine 18O/34S ratios with 0.2‰ precision within minutes. A purification step is recommended for environmental samples as our proposed technique is susceptible to matrix effects. Building upon these initial provisions, new features of the isotopic anatomy of mineral ions can now be explored with ESMS instruments that are increasingly available to bioanalytical laboratories.Nguyen Tu, T.T., Vidal, A., Quénéa, K., Mendez-Millan, M., Derenne, S., 2020. Influence of earthworms on apolar lipid features in soils after 1?year of incubation. Biogeochemistry 147, 243-258. and compound specific isotope compositions of apolar lipids were characterized in soil mesocosms incubated for 1 year with or without 13C-labelled plant residues and earthworms, in order to investigate, at the molecular scale, the effect of earthworms on the fate of organic matter (OM) in soils. Molecular and isotope composition of long chain alkanes in casts confirmed that earthworms preferentially ingest soil fractions rich in plant debris. Apolar lipid specific isotope composition allowed calculation of the proportion of carbon derived from the labelled residues (Clab). Casts displayed higher Clab values than surrounding soil while soil without earthworm exhibited intermediate Clab. The odd-over-even predominance (OEP) of alkanes suggested they are probably less degraded in casts than in the surrounding soil. Taken together, OEP and Clab values suggested that besides high incorporation of plant residues, earthworms may also favor the preservation of plant apolar lipids in their casts. Additionally, chain length and isotope pattern of alkanes further suggested root lipids were probably less degraded than shoot lipids. High 13C-incorporation level for the bacterial biomarker hopene provided evidence for intense recycling of plant OM and suggested further contribution of bacterial necromass to soil OM.Nikitin, V.V., Dugarov, G.A., Duchkov, A.A., Fokin, M.I., Drobchik, A.N., Shevchenko, P.D., De Carlo, F., Mokso, R., 2020. Dynamic in-situ imaging of methane hydrate formation and self-preservation in porous media. Marine and Petroleum Geology 115, 104234. present the results of dynamic in-situ 3D X-ray imaging of methane hydrates microstructure during methane hydrate formation and dissociation in sand samples. Short scanning times and high resolution provided by synchrotron X-rays allowed for better understanding of water movement and different types of gas-hydrate formation. Complementing previous observations, we conclude that the process of gas-hydrate formation is accompanied by the water movements caused by cryogenic water suction that happens in sequences of short fast movements with longer equilibrium states in between (when the water is immobile). Based on the 3D microstructure we identified two distinct types of gas-hydrate formation: (i) into the gas pockets and (ii) inside water volumes. For both mechanisms we do not see problems in gas or water supply to support the gas-hydrate formation. The rate of dissociation in the self-preservation mode (pressure drop at negative temperatures) appears to be different for these two types of gas hydrates. This means that the history of the gas-hydrate formation may influence its behaviour at the dissociation stage (e.g. gas-hydrate production).Nikolaev, E.N., Kostyukevich, Y.I., Vladimirov, G., 2019. Chapter 4 - Fundamentals and simulations in FT-ICR-MS, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 89-111. transforms ion cyclotron resonance (FT-ICR) mass spectrometry method introduced by Alan Marshall and Melvin Comisarow in 1974 is based on the measurement of the frequency of ion rotation in the magnetic field—cyclotron frequency. Ion mass to charge (m/q) ratio is inversely proportional to the cyclotron frequency and it is possible to determine the m/q ratio if we know this frequency and the magnetic field strength B. Since introduction of FT-ICR until now this technique demonstrates the highest mass resolution and mass measurement accuracy. The main part of the FT-ICR spectrometer is a measuring cell which is a Penning trap1. In this cell ions get trapped by electric field in the direction along magnetic field vector and by magnetic field in perpendicular direction. By applying RF electric field containing resonant frequency in the plane of ion cyclotron motion we are exciting ion's synchronous cyclotron motion. Rotating ions induce image charges in detection electrodes resulting in the current in electrical circuit of a signal amplifier. In the process of analysis of complex mixtures such as oil and humic acids more than 106 ions can be trapped in the ion trap and their cyclotron frequencies can be measured simultaneously. The ion–ion interactions considerably influence the ion motion resulting in shifting measured frequencies and m/q values. Further improvement of the main FT-ICR characteristics such as mass resolution, mass accuracy and dynamic range could be promoted by deeper understanding of ion motion dynamics in ion traps taking into account ion–ion interactions.Nikolaev, Y.A., Demkina, E.V., Perminova, I.V., Loiko, N.G., Borzenkov, I.A., Ivanona, A.E., Konstantinov, A.I., El’-Registan, G.I., 2019. Role of humic compounds in viability prolongation of the cells of hydrocarbon-oxidizing bacteria. Microbiology 88, 764-768. of humic compounds (9 preparations) to the cultures of hydrocarbon-oxidizing bacteria was shown to result in up to 15-fold increase in the number of viable cells in the cultures stored in the growth media with access to air at 20?25°C. The most oxidized humates exhibited the highest activity in induction of persister formation, which subsequently matured to dormant forms, while unoxidized humates with antioxidant activity supported viability persistence.Nikolaev, Y.A., Loiko, N.G., Demkina, E.V., Atroshchik, E.A., Konstantinov, A.I., Perminova, I.V., El’-Registan, G.I., 2020. Functional activity of humic substances in survival prolongation of populations of hydrocarbon-oxidizing bacteria Acinetobacter junii. Microbiology 89, 74-85. new approach is described to increasing the numbers of viable cells in long-term stored populations (cultures) of the hydrocarbon-oxidizing bacterium Acinetobacter junii, which involves application of humic substances (HSs). HSs are produced due to condensation and oxidation of phenolic compounds, including alkylresorcinols, factors of intercellular microbial communication with stress-potentiating and antioxidant activity. HS addition to the stationary-phase bacterial culture was shown to result in 10- to 15-fold increase in cell viability for bacterial preparations stored for 1 to 4 months under provocative conditions (free air supply, growth medium, and temperatures of 20–25°C). Analysis of death curves for experimental and control A. junii cultures revealed two phases, with the initial stage of rapid death (0.167 log CFU/mL day), usual for autolysis of the regular stationary cells, and the stage of slower death (log 0.015 CFU/mL day), typical of persister cells. This was previously shown to be the feature determining this type of phenotypic heterogeneity in the populations of opportunistic bacteria. The concentration dependence of HSs effect on persisters formation was determined. While treatment of A. junii stationary cultures with hydrogen peroxide (0.03–0.3%) as a stress factor also resulted in enhanced persisters formation (fourfold), unlike the HS-treated variants they survived for not more than 1.5 to 2 months. Plating of the control and experimental variants (with HSs or H2O2) after long-term storage (2–4 months) revealed their phase variation spectrum to change due to replacement of the dominant colony morphology phenotype by the minor ones (40% and more), which is one of the features of the dormant cystlike bacterial forms. The ratios of the variants in the control and experiments (with HSs) were different. Comparison of the chemical composition of HS preparations indicated that the most oxidized hydrophilic HSs affected formation of persister cells, while less oxidized humates with higher antioxidant activity were responsible for the viability prolongation. Thus, the effect of HSs on bacterial populations includes induction of persister cell formation (their increased number), prolongation of the colony-forming capacity in the cells surviving under provocative storage conditions, and alteration of the phase variant spectrum of the stored populations. Formation of stress-induced persister cells developing into mature dormant forms supporting survival of the population (species) was established for saprotrophic bacteria (in the case of A. junii). In practical terms, HS-induced formation of persister cells may be recommended for development of diverse bacterial preparations.Niles, S.F., Chacón-Pati?o, M.L., Smith, D.F., Rodgers, R.P., Marshall, A.G., 2020. Comprehensive compositional and structural comparison of coal and petroleum asphaltenes based on extrography fractionation coupled with Fourier transform ion cyclotron resonance MS and MS/MS analysis. Energy & Fuels 34, 1492-1505. recently developed extrography separation method fractionates petroleum asphaltenes based on their ionization efficiency, which correlates with polarity, aggregation tendency, and asphaltene structure (single-core or island versus multicore or archipelago). Archipelago asphaltenes were recently demonstrated to coexist with island structures in a variety of petroleum samples; however, archipelago compounds ionize much less efficiently than island compounds, making the former difficult to observe by mass spectrometry without prior separation. Highly processed coal-derived asphaltenes have been studied previously to reveal only small, single-core structure asphaltenes; however, the structure(s) of asphaltenes from unaltered coal extracts has not been extensively studied. Thus, this work focuses on the application of the extrography separation to an unaltered Illinois coal No. 6 asphaltene extract to reveal the coexistence of island and archipelago structural motifs by positive-ion (+) atmospheric pressure photoionization (APPI) Fourier transform ion cyclotron resonance mass spectrometry. Asphaltenes from a Wyoming crude oil sample are also characterized for comparison with coal asphaltenes. The results reveal that Wyoming crude oil asphaltenes contain mainly island species, whereas coal asphaltenes contain archipelago and island compounds with high oxygen content. The structural analysis is enabled by a new “multinotch” stored-waveform inverse Fourier transform isolation, which selectively isolates high-aromaticity precursor ions at each of several nominal mass ranges prior to fragmentation by infrared multiphoton dissociation, and enables unambiguous determination of island versus archipelago species in samples that contain compounds with high and low aromaticity. The more polarizable fractions from each asphaltene sample reveal low-aromaticity polyfunctional oxygenated species, with a solubility behavior consistent with asphaltenes but a compositional range typical of maltenes. These atypical asphaltene species, which ionize poorly, are hypothesized to participate in multiple hydrogen bonding interactions and thus exhibit strong adsorption on polar stationary phases such as SiO2. Furthermore, these polarizable polyfunctional species ionize preferentially as protonated cations by (+) APPI, accounting for their capability to hydrogen-bond in solution. Collectively, the results demonstrate the existence of archipelago structures in both coal and petroleum asphaltenes, along with polyoxygenated species with low aromaticity that behave like asphaltenes in terms of solubility, because they can establish stronger intermolecular forces such as hydrogen bonding.Ninomiya, T., Shimoyama, S., Miyata, Y., Yamanaka, T., Shimazu, T., Taniguchi, S., Aoki, T., Nishida, T., Takahashi, T., 2020. Origin and water depth of a newly identified seep carbonate and paleoecology of Bathymodiolus in the Miocene Taishu Group, southwestern Japan. Palaeogeography, Palaeoclimatology, Palaeoecology 546, 109655. Fukuzaki Limestone is a small limestone lens embedded in siliciclastic Taishu Group rocks on Tsushima Island in the southwestern Japan Sea. A fossil assemblage in this limestone consisting of the bivalve mollusc Bathymodiolus sp. (Bathymodiolinae) was previously inferred, on the basis of the limestone's isolated lenticular occurrence and the chemosynthetic nature of modern Bathymodiolinae, to rely on chemosynthetic production, but conclusive evidence was not provided. Carbon, nitrogen, oxygen, and sulfur isotope ratios in the limestone and its host rock mudstone were measured to clarify the paleoecology of the fossil assemblage and the formation environment of the limestone. The low δ13C (?39.8‰ to ?31.7‰) and δ18O (?13.8‰ to ?11.9‰) values of carbonate of the limestone lens strongly suggest that the limestone is composed of authigenic carbonate rock precipitated from bicarbonate derived from anaerobic oxidation of biogenic or thermogenic methane. The fossil assemblage in the limestone lens is consistent with a chemosynthesis-based animal assemblage harboring thioautotrophic (sulfur-oxidizing) symbionts, and the low δ13C and δ34S values of total organic carbon and sulfide sulfur, respectively, in the limestone lens and mud layers suggest that they reflect chemosynthetic production using hydrogen sulfide derived from anaerobic methane oxidation by microbes. Furthermore, the stratigraphic position of the lens in the upper part of the Lower Unit of the Taishu Group indicates that it was precipitated at a water depth >800?m (deeper than the lower middle bathyal zone). These findings indicate that a deep-sea basin locally supplied with methane had already formed in the southwestern Japan Sea by rapid subsidence during the opening stage of the Japan Sea (16–17?Ma).Nisar, M.S., Zhao, X., 2020. High resolution mass spectrometry for single cell analysis. International Journal of Mass Spectrometry 450, 116302. spectrometry is an important analytical tool that has found pervasive use in numerous fields. This review tries to look at the recent advances in high resolution mass spectrometry for single cell analysis. This manuscript is specifically focused at the developments, progresses and bottle necks in the resolution of the instruments developed for of mass spectrometry. These advances have been able to foment further challenges which require further research. This paper attempts to highlight these challenges and alludes to possible solutions for these challenges.Nitz, H., Duarte, M., Jauregui, R., Pieper, D.H., Müller, J.A., K?stner, M., 2020. Identification of benzene-degrading Proteobacteria in a constructed wetland by employing in situ microcosms and RNA-stable isotope probing. Applied Microbiology and Biotechnology 104, 1809-1820. wetlands (CWs) are effective ecological remediation technologies for various contaminated water bodies. Here, we queried for benzene-degrading microbes in a horizontal subsurface flow CW with reducing conditions in the pore water and fed with benzene-contaminated groundwater. For identification of relevant microbes, we employed in situ microcosms (BACTRAPs, which are made from granulated activated carbon) coupled with 13C-stable isotope probing and Illumina sequencing of 16S rRNA amplicons. A significant incorporation of 13C was detected in RNA isolated from BACTRAPs loaded with 13C-benzene and exposed in the CW for 28 days. A shorter incubation time did not result in detectable 13C incorporation. After 28 days, members from four genera, namely Dechloromonas, Hydrogenophaga, and Zoogloea from the Betaproteobacteria and Arcobacter from the Epsilonproteobacteria were significantly labeled with 13C and were abundant in the bacterial community on the BACTRAPs. Sequences affiliated to Geobacter were also numerous on the BACTRAPs but apparently those microbes did not metabolize benzene as no 13C label incorporation was detected. Instead, they may have metabolized plant-derived organic compounds while using the BACTRAPs as electron sink. In representative wetland samples, sequences affiliated with Dechloromonas, Zoogloea, and Hydrogenophaga were present at relative proportions of up to a few percent. Sequences affiliated with Arcobacter were present at <?0.01% in wetland samples. In conclusion, we identified microbes of likely significance for benzene degradation in a CW used for remediation of contaminated water.Norris, P.R., Falagán, C., Moya-Beltrán, A., Castro, M., Quatrini, R., Johnson, D.B., 2020. Acidithiobacillus ferrianus sp. nov.: an ancestral extremely acidophilic and facultatively anaerobic chemolithoautotroph. Extremophiles 24, 329-337. MG, isolated from an acidic pond sediment on the island of Milos (Greece), is proposed as a novel species of ferrous iron- and sulfur-oxidizing Acidithiobacillus. Currently, four of the eight validated species of this genus oxidize ferrous iron, and strain MG shares many key characteristics with these four, including the capacities for catalyzing the oxidative dissolution of pyrite and for anaerobic growth via ferric iron respiration. Strain MG also grows aerobically on hydrogen and anaerobically on hydrogen coupled to ferric iron reduction. While the 16S rRNA genes of the iron-oxidizing Acidi-thiobacillus species (and strain MG) are located in a distinct phylogenetic clade and are closely related (98–99% 16S rRNA gene identity), genomic relatedness indexes (ANI/dDDH) revealed strong genomic divergence between strain MG and all sequenced type strains of the taxon, and placed MG as the first cultured representative of an ancestral phylotype of iron oxidizing acidithiobacilli. Strain MG is proposed as a novel species, Acidithiobacillus ferrianus sp. nov. The type strain is MGT (=?DSM 107098T?=?JCM 33084T). Similar strains have been found as isolates or indicated by cloned 16S rRNA genes from several mineral sulfide mine sites.Nouri, N., Khorram, P., Duman, O., Sibel, T., Hassan, S., 2020. Overview of nanosorbents used in solid phase extraction techniques for the monitoring of emerging organic contaminants in water and wastewater samples. Trends in Environmental Analytical Chemistry 25, e00081. this article, we have critically overviewed some interesting articles published in 2015–2019 about the use of the nanosorbents for the extraction of emerging organic contaminants (EOCs) from various environmental samples. Properties, advantages, disadvantages, and the applicability of different categories of nanosorbents used for the extraction of EOCs are evaluated and discussed. The potential applications of these nanomaterials as adsorptive phase in solid-phase extraction (SPE) based techniques are reviewed.Novotnik, B., Nandy, A., Venkatesan, S.V., Radovi?, J.R., Fuente, J.D.l., Nejadi, S., Silva, R.C., Kouris, A., Thangadurai, V., Bryant, S., Karan, K., Shor, R., Strous, M., Larter, S.R., 2020. Can fossil fuel energy be recovered and used without any CO2 emissions to the atmosphere? Reviews in Environmental Science and Bio/Technology 19, 217-240. world’s energy system is still dominated by fossil fuels. While there is a rapid reduction in the cost of renewable energy and the environmental costs of continued carbon dioxide emissions from fossil fuel recovery and use are well understood, current economic, infrastructure and political constraints sustain the fossil fuel enterprise as a dominant component of the energy system. Though routes to decarbonizing fossil fuel use, such as carbon capture and storage, have been proposed and have been demonstrated at commercial scale, current CCS CO2 storage quantities are very small and no large-scale practical route to providing fossil fuel energy, without the CO2 emissions attendant with fuel production and use has been proposed. Here we look at some of the boundary conditions and possible routes to production of emissions free energy from fossil fuels, and specifically petroleum reservoirs. Focusing on the production of electrical power we look at possible applications of microbially mediated hydrocarbon oxidation, coupled to a range of energy harvesting strategies, to the provision of electrical power at surface at a range of scales suitable for grid power provision, powering upstream oilfield facilities or for powering in situ sensing and exploration systems. We also ask the question, even if practical, would direct production of electrical power from oil and gas fields be a politically and economically sensible strategy as part of the energy transition away from traditional fossil fuel use.Nye, J.J., Shock, E.L., Hartnett, H.E., 2020. A novel PARAFAC model for continental hot springs reveals unique dissolved organic carbon compositions. Organic Geochemistry 141, 103964. organic carbon in hot springs reflects a range of sources and biogeochemical processes. We evaluated ~200 continental hot spring samples, with a range in pH and temperature, collected from the Tengchong hydrothermal region, Yunnan Province, China and Yellowstone National Park, Wyoming, USA. Dissolved organic carbon concentrations ranged from 16.7 ?M to 2.97 mM. Acidic springs displayed the highest values and widest range in carbon concentration. Alkaline springs had a narrower range and lower average concentrations. Carbon composition was evaluated using ultraviolet absorption and 3D-fluorescence spectroscopy. Total fluorescence was correlated (p < 0.05) with dissolved organic carbon (DOC) concentration. Fluorescence excitation-emission matrices were deconvolved using parallel factor analysis. We validated a five-component model that represented >97% of the total fluorescence. Our model includes three humic-like components, one protein-like component, and one novel component exclusively observed in highly acidic springs. The closest spectral match to the novel component is an acid-soluble lignin produced during high-temperature, acid digestion of wood pulp. Humic-like components were dominant in mid-pH springs (4 < pH < 7) indicating these springs had greater terrestrial carbon input. Acidic springs also exhibited evidence for terrestrial carbon input. Alkaline springs, in contrast, consistently had low dissolved organic carbon content and low fluorescence intensity suggesting that these springs had little terrestrial input. This absence of terrestrial carbon implies a predominantly hydrothermal fluid source. A comparison of the traditional fluorescence indices with our five model components suggest that these indices may have limited utility in continental hot springs with multiple organic matter sources and alteration processes.Oppo, D., De Siena, L., Kemp, D.B., 2020. A record of seafloor methane seepage across the last 150 million years. Scientific Reports 10, 2562. methane seepage is a significant source of carbon in the marine environment. The processes and temporal patterns of seafloor methane seepage over multi-million-year time scales are still poorly understood. The microbial oxidation of methane can store carbon in sediments through precipitation of carbonate minerals, thus providing a record of past methane emission. In this study, we compiled data on methane-derived carbonates to build a proxy time series of methane emission over the last 150?My and statistically compared it with the main hypothesised geological controllers of methane emission. We quantitatively demonstrate that variations in sea level and organic carbon burial are the dominant controls on methane leakage since the Early Cretaceous. Sea level controls methane seepage variations by imposing smooth trends on timescales in the order of tens of My. Organic carbon burial is affected by the same cyclicities, and instantaneously controls methane release because of the geologically rapid generation of biogenic methane. Both the identified fundamental (26–27?My) and higher (12?My) cyclicities relate to global phenomena. Temporal correlation analysis supports the evidence that modern expansion of hypoxic areas and its effect on organic carbon burial may lead to higher seawater methane concentrations over the coming centuries.Ortmann, A.C., Cobanli, S.E., Wohlgeschaffen, G., MacDonald, J., Gladwell, A., Davis, A., Robinson, B., Mason, J., King, T.L., 2020. Measuring the fate of different diluted bitumen products in coastal surface waters. Marine Pollution Bulletin 153, 111003. bitumens are produced by adding lower viscosity diluent to highly viscous bitumen to enable it to flow through pipelines and thus may behave differently than conventional oils when spilled into coastal seawater. Simulated surface spills using three different diluted bitumen products were carried out in May, July and November and water column hydrocarbons were monitored over a 14?day period. Volatile and total petroleum hydrocarbons varied in the water column depending on season and type of diluent. In summer, products diluted with synthetic crude or a mixture of condensate and crude released droplets into the water column. Diluted bitumen did not sink to the bottom of the enclosures with surface slicks showing a range of weathering after 14 d. With most of the diluted bitumen product remaining on the surface for 14 d, a rapid conventional clean up response may be effective in low energy, coastal waters.Ozaki, N., Kindaichi, T., Ohashi, A., 2020. PAHs emission source analysis for air and water environments by isomer ratios — Comparison by modified Cohen's d. Science of The Total Environment 715, 136831. emission sources of PAHs in air and water environments were discussed by a comparison between the data sets of emission sources and environmental fields using five isomer ratios. The similarity of a pair of the datasets of different sources or environment fields for each isomer ratio was evaluated by a newly developed modified effect size d, and the mean of those for the five isomer ratios was applied as an index of similarity. From the analysis, diesel emission and/or biomass burning residues were considered to be major emission sources for almost all the datasets of environments. The pollution loading and path to the PAHs loading of coastal sediments in Hiroshima bay area were examined and it was inferred emission sources was consistently assigned by these newly developed indicators of isomer ratios. Diesel and/or biomass burning were considered to be major sources for the west side area of the bay and the biomass burning was considered to be for the east side area. Further, it was evaluated the west side area, which confronts the Hiroshima city downtown area more directly, was more similar to diesel, and the east side area, which is a bit remoted to the urban central was more similar to the biomass burning. This newly developed method would be a promising alternative application of isomer ratio analysis.Pang, B., Chen, J., Pang, X., Liu, T., Yang, H., Li, H., Wang, Y., Hu, T., 2019. Possible new method to discriminate effective source rocks in petroliferous basins: A case study in the Tazhong area, Tarim Basin. Energy Exploration & Exploitation 38, 417-433. with organic matter content (total organic carbon) TOC?≤?0.5% which can act as effective source rocks are critical and challenging in the field of petroleum geology. A new method is proposed through a case study to identify and evaluate the effective source rocks, which is applied to study the changing characteristic of hydrocarbon-generation potential index with depth. The burial depth corresponding to the beginning of hydrocarbon-generation potential index reduction represents the hydrocarbon expulsion threshold in source rocks. Then, new identification standards are established for discrimination of effective source rocks of Middle–Upper Ordovician in Tarim Basin. The critical value of TOC for effective source rocks change with their burial depth: the TOC?>?0.5% with source rock depth?>?4000?m, TOC?>?0.4% with depth >4500?m, TOC?>?0.3% with depth?>?5000?m, TOC?>?0.2% with depth >5500?m. Based on the new criteria, effective source rocks in the Middle–Upper Ordovician are identified and their total potential hydrocarbon resources is evaluated, reaches 0.68?×?109?t in the Tazhong area, which is 65.4% higher than that of previous studies and consistent with the exploration result. Thus, this new method is of significance to resource evaluation and can be applied in the carbonate source rocks and mudstone source rocks with high degree of exploration.Panwar, D.S., Suman, S., Singh, A.K., Saxena, V.K., Chaurasia, R.C., 2020. Assessment of hydrocarbon generation potential of bituminous coal from Raniganj Basin, India. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects 42, 824-834. present work deals with a study based on the geochemical techniques such as Rock-Eval pyrolysis, total organic carbon content (TOC), and detailed petrographic study to assess hydrocarbon generation potential of coal. A graph between TOC against hydrogen index (HI) has been plotted to detect the type of generating hydrocarbon, which lies in fair oil source. The signi?cant amount of TOC and HI supports the formation of hydrocarbon. The vitrinite reflectance value and Tmax (431°C–446°C) also confirm that samples are matured enough to generate liquid and gaseous hydrocarbon in coal. The coal samples also contain sufficient quantity of vitrinite and liptinite macerals varying from 70.28% to 75.41 wt%, which confirm the production of liquid hydrocarbon. The cross-plot between H/C and O/C atomic ratio indicates that samples were predominant in the bituminous rank and having kerogen Type III makes it suitable for hydrocarbon generation. Similar results were found in Rock-Eval pyrolysis analysis (Types II-III and Type III kerogen). Seyler’s diagram reveals that most of the samples are per-hydrous in nature.Park, S., Abate, I.I., Liu, J., Wang, C., Dahl, J.E.P., Carlson, R.M.K., Yang, L., Prakapenka, V.B., Greenberg, E., Devereaux, T.P., Jia, C., Ewing, R.C., Mao, W.L., Lin, Y., 2020. Facile diamond synthesis from lower diamondoids. Science Advances 6, eaay9405. nanomaterials have exceptional properties that make them attractive for a variety of technological applications. Here, we report on the use of diamondoids (diamond-like, saturated hydrocarbons) as promising precursors for laser-induced high-pressure, high-temperature diamond synthesis. The lowest pressure and temperature (P-T) conditions that yielded diamond were 12 GPa (at ~2000 K) and 900 K (at ~20 GPa), respectively. This represents a substantially reduced transformation barrier compared with diamond synthesis from conventional (hydro)carbon allotropes, owing to the similarities in the structure and full sp3 hybridization of diamondoids and bulk diamond. At 20 GPa, diamondoid-to-diamond conversion occurs rapidly within <19 μs. Molecular dynamics simulations indicate that once dehydrogenated, the remaining diamondoid carbon cages reconstruct themselves into diamond-like structures at high P-T. This study is the first successful mapping of the P-T conditions and onset timing of the diamondoid-to-diamond conversion and elucidates the physical and chemical factors that facilitate diamond synthesis.Pascoal, F., Magalh?es, C., Costa, R., 2020. The link between the ecology of the prokaryotic rare biosphere and its biotechnological potential. Frontiers in Microbiology 11, 231. doi: 10.3389/fmicb.2020.00231. research on the prokaryotic low abundance taxa, the prokaryotic rare biosphere, is growing, leading to a greater understanding of the mechanisms underlying organismal rarity and its relevance in ecology. From this emerging knowledge it is possible to envision innovative approaches in biotechnology applicable to several sectors. Bioremediation and bioprospecting are two of the most promising areas where such approaches could find feasible implementation, involving possible new solutions to the decontamination of polluted sites and to the discovery of novel gene variants and pathways based on the attributes of rare microbial communities. Bioremediation can be improved through the realization that diverse rare species can grow abundant and degrade different pollutants or possibly transfer useful genes. Further, most of the prokaryotic diversity found in virtually all environments belongs in the rare biosphere and remains uncultivatable, suggesting great bioprospecting potential within this vast and understudied genetic pool. This Mini Review argues that knowledge of the ecophysiology of rare prokaryotes can aid the development of future, efficient biotechnology-based processes, products and services. However, this promise may only be fulfilled through improvements in (and optimal blending of) advanced microbial culturing and physiology, metagenomics, genome annotation and editing, and synthetic biology, to name a few areas of relevance. In the future, it will be important to understand how activity profiles relate with abundance, as some rare taxa can remain rare and increase activity, whereas other taxa can grow abundant. The metabolic mechanisms behind those patterns can be useful in designing biotechnological processes.Patania, I., Goldberg, P., Cohen, D.J., Yuan, J., Wu, X., Bar-Yosef, O., 2020. Micromorphological and FTIR analysis of the Upper Paleolithic early pottery site of Yuchanyan cave, Hunan, South China. Geoarchaeology 35, 143-163. site of Yuchanyan cave (Hunan Province, China) contains evidence for some of the earliest‐known (ca. 18,000?cal BP) pottery in the world alongside a typical South China Upper Paleolithic cobble tool (chopper) industry. Here we present the results of a micromorphological study of the deposits with particular attention to site formation processes and recognizable human activities. Our study reveals that the majority of the sediments are anthropogenic and produced by repeated combustion episodes involving the complete expenditure of the fuel and then the refuse being raked out and redistributed across the cave. In relation to the pottery production, clay was also used to line fireplaces. Our results, combined with our Fourier‐transform infrared analysis of the clays and bones, and supported by the zooarchaeological data, suggest that fire and pottery were used here to boil bones and render grease. This behavior must be considered in respect to its associated chopper industry, and the presence of early pottery may be related, suggesting differences in behavioral modernity for hunter‐gatherers in Upper Paleolithic South China. This study demonstrates the advantages of analyzing sediments as a record of past human actions and the value of using micromorphology for the study of Late Pleistocene sites in China.Patterson, E.A., Purdie, S., Taylor, R.J., Waldon, C., 2019. An integrated digital framework for the design, build and operation of fusion power plants. Royal Society Open Science 6, 181847. development of a commercial fusion power plant presents a unique set of challenges associated with the complexity of the systems, the integration of novel technologies, the likely diversity and distribution of the organizations involved, and the scale of resources required. These challenges are reviewed and compared to those for other complex engineering systems. A framework for creating a digital environment that integrates research, test, design and operational data is discussed and is based on combining the integrated nuclear digital environment (INDE), proposed recently for nuclear fission power plants, with the hierarchical pyramid of test and simulation used in the aerospace industry. The framework offers the opportunity to plan modelling strategies that allow large design domains to be explored prior to optimizing a detailed design for construction; and in this context, the relationship between measurements and predictions are explored. The use of the framework to guide the socio-technical activity associated with a distributed and collaborative design process is discussed together with its potential benefits and the technology gaps that need to be addressed in order to realize them. These benefits include shorter development times, reduced costs and improvements in credibility, operability, reliability and safety.Paulo, C., Mckenzie, J.A., Raoof, B., Bollmann, J., Fulthorpe, R., Strohmenger, C.J., Dittrich, M., 2020. Organomineralization of proto-dolomite by a phototrophic microbial mat extracellular polymeric substances: Control of crystal size and its implication for carbonate depositional systems. American Journal of Science 320, 72-95. have postulated that a specific microbial metabolism or the presence of microbes or/and their extracellular polymeric substances (EPS) can lead to the formation of dolomite. Although now there is the consensus that dolomite can be formed in the presence of microorganisms, the exact nature of the involvement of microbes in the dolomite nucleation remains a matter of debate. The focus is now in understanding how microbial mats determine the mineralogy of dolomite. Here we report the effect of the EPS extracted from phototrophic microbial mat isolated from a sabkha in Qatar dominated by cyanobacteria (Lyngbya aestuarii) in the formation of dolomite precursors at 25 °C and 40 °C. Both the temperature and the presence of EPS impact the size and morphology of minerals, promoting spherulitic and dumbbell growth in sulfate free solutions. The formation of proto-dolomite was enhanced by the abundance of carboxylated molecules in EPS which controlled the polymorphism of carbonates. Our study emphasizes the dual importance of organic matter and temperature in dolomite formation and their impact on mineral morphology and chemical composition in sabkhas.Pavlova, O.N., Bukin, S.V., Kostyreva, E.A., Moskvin, V.I., Manakov, A.Y., Morozov, I.V., Galachyants, Y.P., Khabuev, A.V., Zemskaya, T.I., 2019. Experimental transformation of organic matter by the microbial community from the bottom sediments of Akademichesky Ridge (Lake Baikal). Russian Geology and Geophysics 60, doi: 10.15372/RGG2019099 discuss the results of a model experiment on cultivation of the microbial community from the area of the Khoboy mud volcano (Akademichesky Ridge) conducted under conditions typical of the hydrocarbon generation zone (80 °C, 5 MPa). The cultivation under conditions of biomass enrichment with the Baikal diatom Synedra acus changed the composition of organic matter. The transformation degree of organic matter in the sediment after the experiment was 16%, whereas the concentration of phenanthrenes relative to methyl-substituted homologues, including retene, decreased, and the concentration of dibenzothiophenes relative to normal alkanes increased. We have identified tri- and monoaromatic steroids, including 17-dismethyl, 23-methyl monoaromatic steroids C27. An increase in the concentration of tri- and monoaromatic steroids in the sediments after the experiment might indicate that the biomass of the Baikal diatom S. acus was destructed, which led to an increase in the steroid concentration. In the control (sterile) sediment, we detected no changes in the composition of organic matter. Representatives of various taxa capable of surviving in anaerobic thermophilic conditions have been identified in the microbial community by molecular genetic methods. Their presence in the surface sediments might be due to the inflow of deep-seated mineralized fluids and breccia from deep-seated sedimentary rocks.Pearce, J.K., La Croix, A.D., Underschultz, J.R., Golding, S.D., 2020. Long term reactivity of CO2 in a low salinity reservoir-seal complex. Applied Geochemistry 114, 104529. understanding of the long-term reactivity of different rock types to injected CO2 is needed for sequestration site assessment. Relative to saline aquifer studies, the long term reactivity of CO2 in low salinity aquifers has received little attention. Currently in Australia, the Surat Basin is being appraised for its large-scale CO2 storage potential within low salinity aquifers. Sixteen core samples from the Precipice Sandstone and Evergreen Formation – the notional target reservoir and seal complex – were characterized for mineral content; helium, mercury-injection and micro CT porosities; air permeability; and, imaged with SEM-EDS. Samples consisted of quartz rich reservoir sandstones, feldspar and clay rich or calcite cemented sandstones (secondary reservoir), mudstones (sealing complex), and oolitic ironstones (sealing complex) derived from braided river, fluvial-deltaic, and restricted marine shoal depositional environments, respectively. The reservoir sandstone samples characterized here had measured total porosity that ranged from 11 to 23% with pore throats mainly between 90 and 100 μm, and core air permeability from 558 to 3397 mD. In the Precipice Sandstone reservoir sample μCT plugs, 98% of the pore space was connected with calculated vertical permeability 145–4611 mD and horizontal 4291–8200 mD. Feldspar and clay rich sandstone and mudstone samples from the overlying Evergreen Formation had porosity that ranged between 0.2 and 22.9%, with a wide range of pore throat sizes from ~0.005 to 30 μm, and permeability from 0.2 to 28.1 mD, respectively. Ironstone and mudstone samples from the Westgrove Ironstone Member (Evergreen Formation) had porosity from 0.7 to 9.7% and a low permeability of 0.04 mD.Kinetic geochemical CO2 reactivity models made predictions over two time-scales: 30 or 1000 years. Selected models also accounted for the potential presence of 10 ppm SO2 gas. The Precipice Sandstone quartz-rich reservoir sandstones had consistently small amounts of reactive minerals and mineral trapping or scaling of the reservoir was not predicted over 30 years, with the pH approximately 4.5 after 30 years. Samples from the Evergreen Formation included feldspar and clay rich sandstones and mudstones, several contained variable amounts of carbonate cement. Their response to CO2 was more influenced by mineral content than rock type. Plagioclase feldspars and Fe-rich chlorite were the main silicate minerals that reacted to produce siderite and ankerite mineral trapping up to 2.57 kg/m3 CO2. In the very unlikely event that CO2 rich fluids migrated upwards as far as the Westgrove Ironstone Member, chlorite is predicted to alter to siderite. This study indicates that the Precipice Sandstone reservoir in the study region has a low likelihood of mineral scaling which is favorable to avoid CO2 injectivity issues. Mineral trapping as ankerite and siderite could be expected to trap CO2 in the chlorite and plagioclase rich Evergreen Formation seal lithologies. Further work is suggested on validating long term predictions with observation data from natural analogue studies.Pearson, A.R., Hartland, A., Frisia, S., Fox, B.R.S., 2020. Formation of calcite in the presence of dissolved organic matter: Partitioning, fabrics and fluorescence. Chemical Geology 539, 119492. organic matter (DOM) is omnipresent in natural waters and is commonly incorporated into carbonates. Records of DOM from speleothems (secondary carbonates found in caves) have often been interpreted to reflect groundwater DOM concentrations. However, the fidelity of these records is largely untested. An understanding of the relationship between dripwater and speleothem DOM is thus required to allow speleothems to be reliably used as archives of DOM concentration.We precipitated calcite (CaCO3) crystals from weak solutions of (NH4)2CO3, CaCl2 and NH4Cl. These solutions also contained peat DOM (from 0 to 15 mgC/L). Fluorescence 3D excitation-emission matrix (3D EEM) analysis showed a strong, positive correlation between [DOM] in the parent-solution, and [DOM] in the calcite. Calcite precipitation was reduced at high DOM concentrations, potentially indicating inhibition of crystallisation. Partition coefficient values showed that DOMaq was subtly preferentially incorporated into calcite.Scanning electron microscope images indicated that the crystal structures were heavily influenced by DOM adsorption with finer, smooth-faced, rhombohedral crystals forming in growth solutions with low aqueous [DOM] (0–5 mgC/L), and prismatic, ‘impure’ crystals produced at high aqueous [DOM] (10 and 15 mgC/L).Overall, our results indicate that authigenic carbonates are likely to faithfully record variations in aqueous [DOM] within the natural range of DOM concentrations in representative freshwater systems (caves, soil water), and that crystal habits are altered by aqueous [DOM] within their growth solutions.We also applied our findings to three flowstones collected from three New Zealand caves which vary in climatic, vegetation and hydrological regimes. We conclude that differences in initial aqueous [DOM] do indeed control incorporation of DOM into calcite, and thus 3D EEM fluorescence can be used to reconstruct original aqueous [DOM] from authigenic carbonates.Peng, P., Goris, T., Lu, Y., Nijsse, B., Burrichter, A., Schleheck, D., Koehorst, J.J., Liu, J., Sipkema, D., Sinninghe Damste, J.S., Stams, A.J.M., H?ggblom, M.M., Smidt, H., Atashgahi, S., 2020. Organohalide-respiring Desulfoluna species isolated from marine environments. The ISME Journal 14, 815-827. genus Desulfoluna comprises two anaerobic sulfate-reducing strains, D. spongiiphila AA1T and D. butyratoxydans MSL71T, of which only the former was shown to perform organohalide respiration (OHR). Here we isolated a third strain, designated D. spongiiphila strain DBB, from marine intertidal sediment using 1,4-dibromobenzene and sulfate as the electron acceptors and lactate as the electron donor. Each strain harbors three reductive dehalogenase gene clusters (rdhABC) and corrinoid biosynthesis genes in their genomes, and dehalogenated brominated but not chlorinated organohalogens. The Desulfoluna strains maintained OHR in the presence of 20?mM sulfate or 20?mM sulfide, which often negatively affect other organohalide-respiring bacteria. Strain DBB sustained OHR with 2% oxygen in the gas phase, in line with its genetic potential for reactive oxygen species detoxification. Reverse transcription-quantitative PCR revealed differential induction of rdhA genes in strain DBB in response to 1,4-dibromobenzene or 2,6-dibromophenol. Proteomic analysis confirmed expression of rdhA1 with 1,4-dibromobenzene, and revealed a partially shared electron transport chain from lactate to 1,4-dibromobenzene and sulfate, which may explain accelerated OHR during concurrent sulfate reduction. Versatility in using electron donors, de novo corrinoid biosynthesis, resistance to sulfate, sulfide and oxygen, and concurrent sulfate reduction and OHR may confer an advantage to marine Desulfoluna strains.Peral, M., Blamart, D., Bassinot, F., Da?ron, M., Dewilde, F., Rebaubier, H., Nomade, S., Girone, A., Marino, M., Maiorano, P., Ciaranfi, N., 2020. Changes in temperature and oxygen isotopic composition of Mediterranean water during the Mid-Pleistocene transition in the Montalbano Jonico section (southern Italy) using the clumped-isotope thermometer. Palaeogeography, Palaeoclimatology, Palaeoecology 544, 109603. advantage of the recent clumped-isotope methodological developments, the present study focuses on the reconstruction of temperatures and seawater δ18O in the central Mediterranean Sea across the Mid-Pleistocene section from Montalbano Jonico (south of Italy). Our results suggest that Mg/Ca paleothermometer can be biased over several intervals, making clumped-isotope a promising choice to reconstruct past changes in seawater temperature and isotopic composition in the Mediterranean Sea. Our results provide the first clumped-isotope temperature and δ18OSW reconstruction across several glacial and interglacial Marine Isotope Stages from MIS 36 to MIS 19 in the central Mediterranean Sea.During the climatic optimums of MIS 31 and MIS 19, considered as close analogues to the current interglacial in terms of insolation forcing, reconstructed average sub-surface temperatures from benthic foraminifer analyses (13.8?±?1.5?°C and 14.8?±?1.3?°C, respectively) and isotopic composition of seawater (between 1.6?±?0.4‰ and 2.0?±?0.3‰) are similar to the ones measured today below the thermocline in the Gulf of Taranto. Our results show that bottom water conditions remained similar in all the studied glacial periods, with cold temperatures around ~ 8?°C in average. The lack of a clear cooling across the Mid-Pleistocene either suggest that glacial oceanographic conditions in the Mediterranean Sea remained relatively stable between the 41?ka-world and the 100?ka-world or that the tectonic uplift that took place during this transition balanced out the MPT cooling trend through the shallowing of the deposition site.Pereira, I., de Aguiar, D.V.A., Vasconselos, G., Vaz, B.G., 2019. Chapter 16 - Fourier transform mass spectrometry applied to petroleomics, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 509-528. Fourier transform mass spectrometry (FTMS) revolutionized MS analysis by providing the possibility of determining the elemental compositions of thousands of chemical components simultaneously from accurate mass measurements. Fourier transform ion cyclotron (FT-ICR) and Orbitrap are remarkable mass analyzers which are part of the FTMS group. Combining FT-ICR and Orbitrap with a plenty of ionization methods, such as electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI), atmospheric pressure photoionization (APPI), and other ionization sources, enables a myriad of polar and non-polar compounds present in ultra-complex mixtures to be routinely identified and assigned with unmatched mass resolution and accuracy. Crude oil is an ultra-complex mixture and has been classified as the most complex organic mixture in the world regarding a number of chemical constituents in a single sample. The field of science that studies crude oil at the molecular level is called petroleomics, and its progress has been intimately tied to advances in MS ionization sources and instrumentation. Here, we describe the state of the art of several ionization methods that are used with FTMS for crude oil analysis as well as the latest applications of FT-ICR and Orbitrap analyzers in petroleomics.Pérez-García, A., 2020. Surviving the Cretaceous-Paleogene mass extinction event: A terrestrial stem turtle in the Cenozoic of Laurasia. Scientific Reports 10, 1489. of terrestrial stem turtles are not uncommon at Mesozoic continental sites in Laurasia, especially during the Upper Cretaceous. Thus, the record of several lineages is known in uppermost Cretaceous ecosystems in North America (Helochelydridae), Europe (Helochelydridae and Kallokibotion) and Asia (Sichuanchelyidae). No terrestrial stem turtle had been described in Laurasia after the Cretaceous-Paleogene mass extinction event. Thus, the only representatives described in the Cenozoic record worldwide corresponded to forms from southern Gondwana, where some of them survived until the Holocene. A bizarre terrestrial stem turtle from the upper Thanetian (upper Paleocene) of Europe is described here: Laurasichersis relicta gen. et sp. nov. Despite its discovery in France, in Mont de Berru (Marne), this Laurasian taxon is not recognized as a member of a European clade that survived the Cretaceous-Paleogene extinction event. It belongs to Sichuanchelyidae, a hitherto exclusively Asian Mesozoic group, known from the Middle Jurassic. Finds at the Belgian site of Hainin (Hainaut) show that this dispersion from Asia and the occupation of some niches previously dominated by European Mesozoic terrestrial stem forms had already taken place a few million years after the mass extinction event, at the end of the lower Paleocene.Pérez, V., Cortés, J., Marchant, F., Dorador, C., Molina, V., Cornejo-D’Ottone, M., Hernández, K., Jeffrey, W., Barahona, S., Hengst, M.B., 2020. Aquatic thermal reservoirs of microbial life in a remote and extreme high Andean hydrothermal system. Microorganisms 8, 208. Hydrothermal systems are ideal to understand how microbial communities cope with challenging conditions. Lirima, our study site, is a polyextreme, high-altitude, hydrothermal ecosystem located in the Chilean Andean highlands. Herein, we analyze the benthic communities of three nearby springs in a gradient of temperature (42–72 °C represented by stations P42, P53, and P72) and pH, and we characterize their microbial diversity by using bacteria 16S rRNA (V4) gene metabarcoding and 16S rRNA gene clone libraries (bacteria and archaea). Bacterial clone libraries of P42 and P53 springs showed that the community composition was mainly represented by phototrophic bacteria (Chlorobia, 3%, Cyanobacteria 3%, at P42; Chlorobia 5%, and Chloroflexi 5% at P53), Firmicutes (32% at P42 and 43% at P53) and Gammaproteobacteria (13% at P42 and 29% at P53). Furthermore, bacterial communities that were analyzed by 16S rRNA gene metabarcoding were characterized by an overall predominance of Chloroflexi in springs with lower temperatures (33% at P42), followed by Firmicutes in hotter springs (50% at P72). The archaeal diversity of P42 and P53 were represented by taxa belonging to Crenarchaeota, Diapherotrites, Nanoarchaeota, Hadesarchaeota, Thaumarchaeota, and Euryarchaeota. The microbial diversity of the Lirima hydrothermal system is represented by groups from deep branches of the tree of life, suggesting this ecosystem as a reservoir of primitive life and a key system to study the processes that shaped the evolution of the biosphere. Pezzatti, J., Boccard, J., Codesido, S., Gagnebin, Y., Joshi, A., Picard, D., González-Ruiz, V., Rudaz, S., 2020. Implementation of liquid chromatography–high resolution mass spectrometry methods for untargeted metabolomic analyses of biological samples: A tutorial. Analytica Chimica Acta 1105, 28-44. metabolomics is now widely recognized as a useful tool for exploring metabolic changes taking place in biological systems under different conditions. By its nature, this is a highly interdisciplinary field of research, and mastering all of the steps comprised in the pipeline can be a challenging task, especially for those researchers new to the topic. In this tutorial, we aim to provide an overview of the most widely adopted methods of performing LC-HRMS-based untargeted metabolomics of biological samples. A detailed protocol is provided in the Supplementary Information for rapidly implementing a basic screening workflow in a laboratory setting. This tutorial covers experimental design, sample preparation and analysis, signal processing and data treatment, and, finally, data analysis and its biological interpretation. Each section is accompanied by up-to-date literature to guide readers through the preparation and optimization of such a workflow, as well as practical information for avoiding or fixing some of the most frequently encountered pitfalls.Phan, T.T., Hakala, J.A., Sharma, S., 2020. Application of isotopic and geochemical signals in unconventional oil and gas reservoir produced waters toward characterizing in situ geochemical fluid-shale reactions. Science of The Total Environment 714, 136867. hydrocarbon production and waste management from unconventional oil and gas extraction requires an understanding of the fluid-rock chemical interactions. These reactions can affect flow pathways within fractured shale and produced water chemistry. Knowledge of these chemical reactions also provides valuable information for planning wastewater treatment strategies. This study focused on characterizing reservoir reactions through analysis of produced water chemistry from the Marcellus Shale Energy and Environmental Laboratory field site in Morgantown, WV, USA. Analysis of fracturing fluids, time-series produced waters (PW) over 16 months of operation of two hydraulically fractured gas wells, and shale rocks from the same well for metal concentrations and multiple isotope signatures (δ2H and δ18O of water, δ7Li, δ11B, 87Sr/86Sr) showed that the chemical and isotopic composition of early (<10 days) PW samples record water-rock interactions during the fracturing period. Acidic dissolution of carbonate minerals was evidenced by the increase in TOC, B/Na, Sr/Na, Ca/Na, and the decrease in 87Sr/86Sr in PW returning in the first few days toward the 87Sr/86Sr signature of carbonate cement. The enrichment of 6Li in these early (e.g., day 1) PW samples is most likely a result of desorption of Li from clays and organic matter due to the injection of fracturing fluid. Redox-active trace elements appear to be controlled by oxidation-reduction reactions and potentially reactions involving wellbore steel. Overall, PW chemistry is primarily controlled by mixing between early PW with local in-situ formation water however certain geochemical reactions (e.g., carbonate cement dissolution and desorption of 6Li from clays and organic matter) can be inferred from PW composition monitored immediately over the first ten days of water return.Pinto, ?.S.M., Dorn, M., Feltes, B.C., 2020. The tale of a versatile enzyme: Alpha-amylase evolution, structure, and potential biotechnological applications for the bioremediation of n-alkanes. Chemosphere 250, 126202. the primary source of a wide range of industrial products, the study of petroleum-derived compounds is of pivotal importance. However, the process of oil extraction and refinement is among the most environmentally hazardous practices, impacting almost all levels of the ecological chain. So far, the most appropriate strategy to overcome such an issue is through bioremediation, which revolves around the employment of different microorganisms to degrade hazardous compounds, generating less environmental impact and lower monetary costs. In this sense, a myriad of organisms and enzymes are considered possible candidates for the bioremediation process. Amidst the potential candidates is α-amylase, an evolutionary conserved starch-degrading enzyme. Notably, α-amylase was not only seen to degrade n-alkanes, a subclass of alkanes considered the most abundant petroleum-derived compounds but also low-density polyethylene, a dangerous pollutant produced from petroleum. Thus, due to its high conservation in both eukaryotic and prokaryotic lineages, in addition to the capability to degrade different types of hazardous compounds, the study of α-amylase becomes a rising interest. Nevertheless, there are no studies that review all biotechnological applications of α-amylase for bioremediation. In this work, we critically review the potential biotechnological applications of α-amylase, focusing on the biodegradation of petroleum-derived compounds. Evolutionary aspects are discussed, as well for all structural information and all features that could impact on the employment of this protein in the biotechnological industry, such as pH, temperature, and medium conditions. New perspectives and critical assessments are conducted regarding the application of α-amylase in the bioremediation of n-alkanes.Plyatsuk, L., Chernysh, Y., Ablieieva, I., Bataltsev, Y., Vaskin, R., Roy, I., Yakhnenko, E., Roubík, H., 2020. Modelling and development of technological processes for low rank coal bio-utilization on the example of brown coal. Fuel 267, 117298. paper described research into the biochemical processes of brown coal treatment. During the experimental research, chromatography was used for assesment of the composition of biogas, and its volume was measured by displacing a liquid column by gas. Taxonomic classification was carried out using electronic bioinformatic databases. The modified biochemical model was formed from a complex biological treatment of low-rank coals with an added cycle of aerobic conversion and the process of converting a sulphur compound under anaerobic conditions, as well as a number of ecological-trophic groups of microorganisms. Archaebacteria were determined under carbonate respiration processing during methanogenesis. Such methanogenic archaea include the genera Methanobacterium, Methanococcus and Methanosarcina. Biogas yield stabilized at 0.28 Nml/g of brown coal, which characterizes the steady-state growth phase of methanogenic association in the bioreactor space on days 13–15. Maximum biogas combustion heat was achieved by its purification from hydrogen sulphide and carbon dioxide gas to biomethane. The technological features for bioprocessing low-rank coal were formed for potential implementation in brown coal bio-utilization.Poltash, M.L., McCabe, J.W., Shirzadeh, M., Laganowsky, A., Russell, D.H., 2020. Native IM-Orbitrap MS: Resolving what was hidden. TrAC Trends in Analytical Chemistry 124, 115533. ion mobility-mass spectrometry (IM-MS) is an emerging biophysical approach to probe the intricate details of protein structure and function. The instrument design enables measurements of accurate first-principle determinations of rotationally-averaged ion-neutral collision cross sections coupled with high-mass, high-resolution mass measurement capabilities of Orbitrap MS. The inherent duty-cycle mismatch between drift tube IM and Orbitrap MS is alleviated by operating the drift tube in a frequency modulated mode while continuously acquiring mass spectra with the Orbitrap MS. Fourier transform of the resulting time-domain signal, i.e., ion abundances as a function of the modulation frequency, yields a frequency domain spectrum that is then converted (s?1 to s) to IM drift time. This multiplexed approach allows for a duty-cycle of 25% compared to <1% for traditional “pulse-and-wait” IM-ToF-MS. Improvements in mobility and mass resolution of the IM-Orbitrap allows for accurate analysis of intact protein complexes and the possibility of capturing protein dynamics.Polvani, L.M., Previdi, M., England, M.R., Chiodo, G., Smith, K.L., 2020. Substantial twentieth-century Arctic warming caused by ozone-depleting substances. Nature Climate Change 10, 130–133. rapid warming of the Arctic, perhaps the most striking evidence of climate change, is believed to have arisen from increases in atmospheric concentrations of GHGs since the Industrial Revolution. While the dominant role of carbon dioxide is undisputed, another important set of anthropogenic GHGs was also being emitted over the second half of the twentieth century: ozone-depleting substances (ODS). These compounds, in addition to causing the ozone hole over Antarctica, have long been recognized as powerful GHGs. However, their contribution to Arctic warming has not been quantified. We do so here by analysing ensembles of climate model integrations specifically designed for this purpose, spanning the period 1955–2005 when atmospheric concentrations of ODS increased rapidly. We show that, when ODS are kept fixed, forced Arctic surface warming and forced sea-ice loss are only half as large as when ODS are allowed to increase. We also demonstrate that the large impact of ODS on the Arctic occurs primarily via direct radiative warming, not via ozone depletion. Our findings reveal a substantial contribution of ODS to recent Arctic warming, and highlight the importance of the Montreal Protocol as a major climate change-mitigation treaty.Pomeroy, E., Bennett, P., Hunt, C.O., Reynolds, T., Farr, L., Frouin, M., Holman, J., Lane, R., French, C., Barker, G., 2020. New Neanderthal remains associated with the ‘flower burial’ at Shanidar Cave. Antiquity 94, 11-25. Cave in Iraqi Kurdistan became an iconic Palaeolithic site following Ralph Solecki's mid twentieth-century discovery of Neanderthal remains. Solecki argued that some of these individuals had died in rockfalls and—controversially—that others were interred with formal burial rites, including one with flowers. Recent excavations have revealed the articulated upper body of an adult Neanderthal located close to the ‘flower burial’ location—the first articulated Neanderthal discovered in over 25 years. Stratigraphic evidence suggests that the individual was intentionally buried. This new find offers the rare opportunity to investigate Neanderthal mortuary practices utilising modern Ponsaing, L., Mathiesen, A., Petersen, H.I., Bojesen-Koefoed, J.A., Schovsbo, N.H., Nytoft, H.P., Stemmerik, L., 2020. Organofacies composition of Upper Jurassic – lowermost Cretaceous source rocks, Danish Central Graben, and insight into the correlation to oils in the Valdemar Field. Marine and Petroleum Geology 114, 104239. organic-rich marine shales of the Upper Jurassic - lowermost Cretaceous Farsund Formation are the main hydrocarbon source rocks for the Cretaceous chalk reservoir of the Valdemar Field (Danish North Sea). Geochemical analyses of oil extracts from core samples across the greater Valdemar Field show substantial heterogeneity of the reservoir oils, suggesting contribution from kitchen areas with source rocks of variable organofacies and thermal maturity. In order to better understand the source rock facies that charged the field, a refined organofacies characterization of the Upper Jurassic - lowermost Cretaceous marine shale source rock succession (Farsund Formation) in the Danish Central Graben was established. This organofacies characterization is based on integration of petrographic and geochemical data and demonstrates large variations in both the regional and local distribution of the organofacies at the sequence level in the shales within the Danish Central Graben. In addition, the organofacies characterization shows that the respective sequences in the succession may be represented by several organofacies at the same time. Part of the explanation to the heterogeneity in the oil types accumulated within the Valdemar Field may lie in the presence of different organofacies within the uppermost sequences (Vol-3 to Ryaz-1) in the three kitchen areas. Each organofacies presumable generates different types of oils and the variation in the relative proportions of the different organofacies likely determines the composition of the generated oils. One dimensional (1-D) maturity modelling at three pseudo-well locations, each representing a potential Farsund Formation kitchen, shows that all kitchens are in the main oil window and that mainly oil was expelled from the Volg-3 to Ryaz-1 sequences. Modelling indicates that (i) average values of TOC, HI, thickness and the kinetic model are the main controls on generation and expulsion of hydrocarbons; and (ii) by increasing these parameters, expulsion could also occur from the lower part of the succession.Potapov, S., Belykh, O., Krasnopeev, A., Galachyants, A., Podlesnaya, G., Khanaev, I., Tikhonova, I., 2020. Diversity and biogeography of bacteriophages in biofilms of Lake Baikal based on g23 sequences. Journal of Great Lakes Research 46, 4-11., we report on the sequences of the g23 communities of phages from biofilms and the surface microlayer in the most ancient lake of the world. The data are interpreted in terms of biogeography of the g23 communities. We show that bacteriophages from biotopes of biofilms of stones and sponges from the littoral zone and of the water from the pelagic zone of Lake Baikal form a common Baikal cluster. Viruses of the surface microlayer in the shallow Maloye More Strait of Lake Baikal group into one cluster with the sequences from polar lakes forming a sisterly clade with the Baikal cluster.Poulet, F., Gross, C., Horgan, B., Loizeau, D., Bishop, J.L., Carter, J., Orgel, C., 2020. Mawrth Vallis, Mars: A fascinating place for future in situ exploration. Astrobiology 20, 199–234. the successful landing of the Mars Science Laboratory rover, both NASA and ESA initiated a selection process for potential landing sites for the Mars2020 and ExoMars missions, respectively. Two ellipses located in the Mawrth Vallis region were proposed and evaluated during a series of meetings (three for Mars2020 mission and five for ExoMars). We describe here the regional context of the two proposed ellipses as well as the framework of the objectives of these two missions. Key science targets of the ellipses and their astrobiological interests are reported. This work confirms that the proposed ellipses contain multiple past martian wet environments of a subaerial, subsurface, and/or subaqueous character, in which to probe the past climate of Mars; build a broad picture of possible past habitable environments; evaluate their exobiological potentials; and search for biosignatures in well-preserved rocks. A mission scenario covering several key investigations during the nominal mission of each rover is also presented, as well as descriptions of how the site fulfills the science requirements and expectations of in situ martian exploration. These serve as a basis for potential future exploration of the Mawrth Vallis region with new missions and describe opportunities for human exploration of Mars in terms of resources and science discoveries. Price, M., 2020. Africans, too, carry Neanderthal genetic legacy. Science 367, 497. 10 years, geneticists have told the story of how Neanderthals—or at least their DNA sequences—live on in today's Europeans, Asians, and their descendants. Not so in Africans, the story goes, because modern humans and our extinct cousins interbred only outside of Africa. A new study overturns that notion, revealing an unexpectedly large amount of Neanderthal ancestry in modern populations across Africa. It suggests much of that DNA came from Europeans migrating back into Africa over the past 20,000 years.“That gene flow with Neanderthals exists in all modern humans, inside and outside of Africa, is a novel and elegant finding,” says anthropologist Michael Petraglia of the Max Planck Institute for the Science of Human History. The work, reported in this week's issue of Cell, could also help clear up a mysterious disparity: why East Asians appear to have more Neanderthal ancestry than Europeans.As members of Homo sapiens spread from Africa into Eurasia some 70,000 years ago, they met and mingled with Neanderthals. Researchers knew that later back-migrations of Europeans had introduced a bit of Neanderthal DNA into African populations, but previous work suggested it was a just a smidgen. In contrast, modern Europeans and East Asians apparently inherited about 2% of their DNA from Neanderthals.Previous efforts simply assumed that Africans largely lacked Neanderthal DNA. To get more reliable numbers, Princeton University evolutionary biologist Joshua Akey compared the genome of a Neanderthal from Russia's Altai region in Siberia, sequenced in 2013, to 2504 modern genomes uploaded to the 1000 Genomes Project, a catalog of genomes from around the world that includes five African subpopulations. The researchers then calculated the probability that each stretch of DNA was inherited from a Neanderthal ancestor.The researchers found that African individuals on average had significantly more Neanderthal DNA than previously thought—about 17 megabases (Mb) worth, or 0.3% of their genome. They also found signs that a handful of Neanderthal genes may have been selected for after they entered Africans' genomes, including genes that boost immune function and protect against ultraviolet radiation.The results jibe with as-yet-unpublished work by Sarah Tishkoff, an evolutionary geneticist at the University of Pennsylvania. She told Science she has also found higher-than-expected levels of apparent Neanderthal DNA in Africans.The best fit model for where Africans got all this Neanderthal DNA suggests about half of it came when Europeans—who had Neanderthal DNA from previous matings—migrated back to Africa in the past 20,000 years. The model suggests the rest of the DNA shared by Africans and the Altai Neanderthal might not be Neanderthal at all: Instead, it may be DNA from early modern humans that was simply retained in both Africans and Eurasians—and was picked up by Neanderthals, perhaps when moderns made a failed migration from Africa to the Middle East more than 100,000 years ago.Akey's study might help explain another “head scratcher,” says computer biologist Kelley Harris of the University of Washington, Seattle. Studies had suggested East Asians have 20% more Neanderthal DNA than Europeans, she notes. “Europe is where Neanderthal remains are found, so why wouldn't Europeans have more Neanderthal ancestry than any other group?”By suggesting that Europeans introduced Neanderthal sequences into Africa, the new study points to an explanation: Researchers previously assumed that Neanderthal sequences shared by Europeans and Africans were modern and subtracted them out. After correcting for that bias, the new study found similar amounts of Neanderthal DNA in Europeans and Asians—51 and 55 Mb, respectively. It's a “convincing and elegant” explanation, Harris says.Proriol, D., Chahen, L., 2020. Toward new descriptors of basic nitrogen compounds in middle distillates by 2D NMR. Energy & Fuels 34, 1347-1354. nitrogen compounds (N-compounds), present in middle distillates, can inhibit acidic catalysts used in hydrotreatment processes. A better knowledge of these compounds, especially the environment of the nitrogen atom, may be interesting to improve these processes. Herein, we propose a new promising methodology to couple the extraction of the basic N-compounds by flash chromatography with 2D NMR analysis. The NMR sequence heteronuclear single-quantum correlation (HSQC) allows us to visualize specific C–H correlations and, with the help of the prediction software Advanced Chemistry Development/Laboratory (PS-ACDL), eleven areas of interest have been identified. The representativeness of these areas has been validated with data from literature and with a gas oil (GO) sample analysis. These areas are specific to C–H couples in pyridine, quinoline, isoquinoline, and acridine derivatives and give a detailed fingerprint of basic N-compounds in the GO cut. Moreover, certain areas allow us to describe the close environment of the nitrogen atom and allow, for example, to differentiate isoquinoline from quinoline derivatives.Pu, S., Gong, C., Robertson, A.W., 2020. Liquid cell transmission electron microscopy and its applications. Royal Society Open Science 7, 191204. electron microscopy (TEM) has long been an essential tool for understanding the structure of materials. Over the past couple of decades, this venerable technique has undergone a number of revolutions, such as the development of aberration correction for atomic level imaging, the realization of cryogenic TEM for imaging biological specimens, and new instrumentation permitting the observation of dynamic systems in situ. Research in the latter has rapidly accelerated in recent years, based on a silicon-chip architecture that permits a versatile array of experiments to be performed under the high vacuum of the TEM. Of particular interest is using these silicon chips to enclose fluids safely inside the TEM, allowing us to observe liquid dynamics at the nanoscale. In situ imaging of liquid phase reactions under TEM can greatly enhance our understanding of fundamental processes in fields from electrochemistry to cell biology. Here, we review how in situ TEM experiments of liquids can be performed, with a particular focus on microchip-encapsulated liquid cell TEM. We will cover the basics of the technique, and its strengths and weaknesses with respect to related in situ TEM methods for characterizing liquid systems. We will show how this technique has provided unique insights into nanomaterial synthesis and manipulation, battery science and biological cells. A discussion on the main challenges of the technique, and potential means to mitigate and overcome them, will also be presented.Purcaro, G., 2020. Chapter 2.3 - Classical and comprehensive 2D LC-GC, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 227-275. chromatography hyphenated with gas chromatography (LC-GC) was first presented in 1979 by Major et?al. [1]. Despite the fact that such a coupling leads to a series of undoubted advantages, it is non-trivial since the two separation techniques operate in two different physical states. Several interfaces to optimize the transfer of a large amount of liquid solvent into a gas chromatograph have been proposed over the years. The most interesting and applied interfaces are herein discussed in detail, elucidating the theory behind them. A brief overview of comprehensive 2D approaches (LC×GC) is also discussed. Furthermore, an overview of the application fields where LC-GC has been largely applied is reported, with a particular attention to the coupling with mass spectrometry, even though such a detector has not been as widely used as with other GC-based techniques.Puurunen, J., Hakanen, E., Salonen, M.K., Mikkola, S., Sulkama, S., Araujo, C., Lohi, H., 2020. Inadequate socialisation, inactivity, and urban living environment are associated with social fearfulness in pet dogs. Scientific Reports 10, 3527. behaviours are severe welfare issues for one of the world’s most popular pets, the domestic dog. One of the most prevalent behavioural problem that causes distress to dogs is social fearfulness, meaning fear of conspecifics or unfamiliar people. To identify demographic and environmental factors associated with fear of dogs and strangers, logistic regression was utilised with a large dataset of 6,000 pet dogs collected through an owner-filled behavioural survey. Social fearfulness was associated with several factors, including urban environment, poor socialisation during puppyhood, infrequent participation in training and other activities, small body size, female sex, and neutering. In addition, we identified several breed differences, suggesting a genetic contribution to social fearfulness. These findings highlight the role of inadequate socialisation, inactivity, and urban living environmental in fear-related behavioural problems in dogs. Improvements in the management and breeding practices of dogs could, therefore, enhance the welfare of man’s best friend.Qin, L., Li, S., Zhai, C., Lin, H., Zhao, P., Shi, Y., Bai, Y., 2020. Changes in the pore structure of lignite after repeated cycles of liquid nitrogen freezing as determined by nitrogen adsorption and mercury intrusion. Fuel 267, 117214. a non-aqueous medium for increasing permeability in coal seams, liquid nitrogen fracturing has been widely studied. The changes of the pores in coal fractured by liquid nitrogen have important effects on coalbed methane (CBM) migration. It is difficult to thoroughly characterize the pore structure in coal using a single method. Therefore, this study carried out a detailed study of the pores in coal samples fractured by liquid nitrogen using both nitrogen adsorption and mercury intrusion. The results show that combining these methods can accurately determine pore sizes and specific surface areas in the samples tested. The maximum liquid nitrogen adsorption capacity and the injected mercury volume in the samples were positively correlated with the freezing times and freeze–thaw cycles. This indicated that the number of pores in the coal gradually increased. Cumulative total pore and seepage pore volumes in the samples showed a positive exponential correlation with freezing time. The volume increases also correlated with the number of freeze–thaw cycles and this increase followed a quadratic function. The cumulative specific surface areas also varied with freezing time but the areas first rose and then fell as the freeze–thaw cycles increased. Liquid nitrogen freezing time significantly affects the micropores and specific surface area. However, freezing time has only a minor effect on the larger seepage pores and the total pore volume. Liquid nitrogen freeze–thaw cycles help the formation of connections between micropores and larger pores and thus promote the development of fracture networks. This provides favorable conditions for CBM production.Qiu, W., Lu, J., Zou, H., Li, Y., Hu, Z., 2020. The origin and source of Jurassic oil in Xihu anticline of Junggar Basin. Petroleum Science and Technology 38, 377-383. anticline is an oil-bearing structure in Sikeshu sag located in the southern margin of Junggar Basin. Great exploration prospect can be seen for the oil and gas show up to 100?m in Qigu Formation of Jurassic. Well Xihu 1 is the first drilling layer for its deep buried depth of Jurassic layers in Xihu anticline. The whole-hydrocarbon geochemical method is used to analyze the composition and carbon isotope of natural gas, as well as the physical properties and geochemical characters of crude oil to clarify the oil origin of this area based on the analyses of source rock characters. From the results, it can be seen that main source rocks are from Jurassic and Paleogene. Crude oil in the research area has relatively heavy carbon isotopes and relatively high Pr/Ph. Regular sterane is distributed in the shape of reverse L and the ratio of gammacerane/C31 hopane value is 0.1, suggesting its origin from source rocks at mature stage.Radchenko, K.A., Korobova, N.I., Bolshakova, M.A., Stoupakova, A.V., Zavyalova, A.P., Chupakhina, V.V., 2019. The lithological and geochemical characteristics of natural outcrops of Domanik sediments in the areas of the Cis-Ural regional trough of the Volga–Ural oil-and-gas basin. Moscow University Geology Bulletin 74, 458-463. problem of replenishing oil reserves requires a search for new alternative objects for prospecting, exploration, and production of hydrocarbons. The rocks of the Domanik sediments, which are rich in organic matter and occur widely over the Volga–Ural oil-and-gas basin, are among the objects. The Domanik highly carbonaceous formation is a thin-layered carbonate–siliceous structure with an increased content of organic matter, which is capable of both generating hydrocarbons in the proper oil-and-gas parental masses and concentrating oil and gas within individual layers and zones that function as the reservoirs (Stupakova et al., 2017). Studies of the material composition of the rocks are among the ways to obtain data on the nature of hydrocarbon accumulations in domanik sediments along with the potential of the recovery of hydrocarbons. Lithological and geochemical characteristics are essential constituents of the studies of the rocks.Radnaeva, L.D., Bazarsadueva, S.V., Taraskin, V.V., Tulokhonov, A.K., 2020. First data on lipids and microorganisms of deepwater endemic sponge Baikalospongia intermedia and sediments from hydrothermal discharge area of the Frolikha Bay (North Baikal, Siberia). Journal of Great Lakes Research 46, 67-74. this report, we study lipid components (fatty acids with various degrees of unsaturation, aldehydes and sterols) of deep-water sponges Baikalospongia intermedia and sediments sampled using deep-water manned submersibles “Mir” at a hydrothermal vent of Frolikha Bay at depths of 400–450?m. It was found that unsaturated fatty acids predominate in the FA-composition of the sponges: very long chain demospongic acid 26:3, as well as monounsaturated 24:1 and isomers of acids 16:1 and 18:1. Among the saturated fatty acids in addition to the stearic 18:0, palmitic 16:0 and heptadecanoic 17:0 acids, significant amounts of acids of microbial origin (iso-palmitic i16:0, isostearic i18:0, oxy-stearic 10?h18) were detected. Using the method of mass spectrometry of microbial markers, we conclude, that the main microbial components of sponges B. intermedia and sediments from Frolikha Bay are methanotrophic microorganisms.Randazzo, G.M., Bileck, A., Danani, A., Vogt, B., Groessl, M., 2020. Steroid identification via deep learning retention time predictions and two-dimensional gas chromatography-high resolution mass spectrometry. Journal of Chromatography A 1612, 460661. steroid identification represents a great analytical challenge even when using sophisticated technology such as two-dimensional gas chromatography coupled to high resolution mass spectrometry (GC?×?GC-HRMS) due to the chemical similarity of the analytes. Moreover, when analytical standards, mass spectral and retention index databases are not available, compound annotation is cumbersome. Hence, there is a need for the development of retention time prediction models in order to explore new annotation approaches. In this work, we evaluated the use of several in silico methods for retention time prediction in multidimensional gas chromatography. We use three classical machine learning (CML) algorithms (Partial Least Squares (PLS), Support Vector Regression (SVR) and Random Forest Regression (RFR)) and two deep learning approaches (dense neural network (DNN) and three-dimensional convolutional neural network (CNN)). Whereas molecular descriptors were utilized for the CLM and DNN algorithms, three-dimensional molecular representation based on the electrostatic potential (ESP) was studied as input data as is for the CNN. All the developed models showed similar performances with Q2 values over 0.9. However, among all CNN showed the best performance, resulting in average retention time prediction errors of 2% and 6% for the first and second separation dimension, respectively. Additionally, only the three-dimensional ESP representation coupled with CNN was able to extract the stereochemical information crucial for the separation of diastereomers. The combination of retention time prediction and high-resolution mass spectral data applied to clinical samples enabled the untargeted annotation of 12 steroid metabolites in the urine of new-borns.Rani, M., Weadge, J.T., Jabaji, S., 2020. Isolation and characterization of biosurfactant-producing bacteria from oil well batteries with antimicrobial activities against food-borne and plant pathogens. Frontiers in Microbiology 11, 64. doi: 10.3389/fmicb.2020.00064. biosurfactants, produced by fungi, yeast, and bacteria, are surface-active compounds with emulsifying properties that have a number of known activities, including the solubilization of microbial biofilms. In an on-going survey to uncover new or enhanced antimicrobial metabolite-producing microbes from harsh environments, such as oil-rich niches, 123 bacterial strains were isolated from three oil batteries in the region of Chauvin, Alberta, and characterized by 16S rRNA gene sequencing. Based on their nucleotide sequences, the strains are associated with 3 phyla (Actinobacteria, Proteobacteria and Firmicutes), as well as 17 other discrete genera that shared high homology with known sequences, with the majority of these strains identified to the species level. The most prevalent strains associated with the three oil wells belonged to the Bacillus genus. Thirty-four of the 123 strains were identified as biosurfactant-producers, among which Bacillus methylotrophicus strain OB9 exhibited the highest biosurfactant activity based on multiple screening methods and a comparative analysis with the commercially available biosurfactant, Tween 20. B. methylotrophicus OB9 was selected for further antimicrobial analysis and addition of live cultures of B. methylotrophicus OB9 (or partially purified biosurfactant fractions thereof) were highly effective on biofilm disruption in agar diffusion assays against several Gram-negative food-borne bacteria and plant pathogens. Upon co-culturing with B. methylotrophicus OB9, the number of either Salmonella enterica subsp. enterica Newport SL1 or Xanthomonas campestris B07.007 cells significantly decreased after 6 h and were not retrieved from co-cultures following 12 h exposure. These results also translated to studies on plants, where bacterized tomato seedlings with OB9 significantly protected the tomato leaves from Salmonella enterica Newport SL1 contamination, as evidenced by a 40% reduction of log10 CFU of Salmonella/mg leaf tissue compared to non-bacterized tomato leaves. When B. methylotrophicus 0B9 was used for bacterized lettuce, the growth of X. campestris B07.007, the causal agent of bacterial leaf spot of lettuce, was completely inhibited. While limited, these studies are noteworthy as they demonstrate the inhibition spectrum of B. methylotrophicus 0B9 against both human and plant pathogens; thereby making this bacterium attractive for agricultural and food safety applications in a climate where microbial-biofilm persistence is an increasing problem.Rao, Z., Shi, F., Li, Y., Huang, C., Zhang, X., Yang, W., Liu, L., Zhang, X., Wu, Y., 2020. Long-term winter/summer warming trends during the Holocene revealed by α-cellulose δ18O/δ13C records from an alpine peat core from central Asia. Quaternary Science Reviews 232, 106217. on previously reported monitoring results from the alpine Sahara sand peatland (SSP) in the southern Altai Mountains, and modern observational δ18Op data from the Altai area, the new SSP peat α-cellulose δ18O (δ18Ocell) record spanning the last ～11,000 years is determined to be an indicator of winter temperature. The record shows a long-term winter warming trend during the Holocene. Therefore, possibly for the first time, the SSP δ18Ocell record, combined with the reported SSP α-cellulose δ13C (δ13Ccell) record from the same peat core and supported by an independent modern-process study, provides records of Holocene winter and summer temperature. These signals demonstrate robust long-term winter/summer warming trends during the Holocene that are supported by independent records from nearby sites. Comparison of the SSP Holocene temperature records with those of winter/summer insolation and GHG (atmospheric greenhouse gas) forcing demonstrates a close link between temperature and insolation (a natural factor) prior to ～5 cal kyr BP (1 kyr = 1000 years; BP = before present, where “present” is defined as AD 1950). However, there may be a close link between increased GHG forcing (a possible anthropogenic factor) and increased temperature after ～5 cal kyr BP. We emphasize that, given the scarcity of high-quality, well-dated Holocene temperature records, the possible link between GHG forcing and temperature since the mid-Holocene needs to be further investigated. Thus we conclude that an increased number of reliable Holocene temperature records from other regions are urgently needed in order to determine the spatial extent (regional or global) of the Holocene warming trend.Ratnikova, N.M., Slobodkin, A.I., Merkel, A.Y., Kopitsyn, D.S., Kevbrin, V.V., Bonch-Osmolovskaya, E.A., Slobodkina, G.B., 2020. Sulfurimonas crateris sp. nov., a facultative anaerobic sulfur-oxidizing chemolithoautotrophic bacterium isolated from a terrestrial mud volcano. International Journal of Systematic and Evolutionary Microbiology 70, 487-492. novel mesophilic facultative anaerobic bacterium, strain SN118T, was isolated from a terrestrial mud volcano in Taman Peninsula, Russia. The cells were Gram-negative, motile, short, straight or curved rods with a single polar flagellum. Growth was observed at 5–40?°C (optimum, 30?°C) and pH 5.5–9.5 (optimum, pH 8.0). Growth of strain SN118T was observed in NaCl concentrations ranging from 0.5 to 8.0?% (w/v) with an optimum at 2.0–3.0?% (w/v). The isolate grew chemolithoautotrophically with sulfide, elemental sulfur or thiosulfate as electron donor, oxygen, nitrate or nitrite as an electron acceptor and CO2/HCO3- as a carbon source. Molecular hydrogen or organic substances did not support growth. Nitrate was reduced to N2. The dominant fatty acids were C16?:?1ω7c, C16?:?0 and C18 ?:? 1ω7c. The total size of the genome of the novel isolate was 2?209?279?bp and the genomic DNA G+C content was 38.8?mol%. Results of phylogenetic analysis based on 16S rRNA gene sequences indicated that the novel isolate belonged to the genus Sulfurimonas and was most closely related to Sulfurimonas denitrificans DSM 1251T (96.74?%). Based on its physiological properties and results from phylogenetic analyses, including average nucleotide identity and in silico DNA–DNA hybridization values, the isolate is considered to represent a novel species of the genus Sulfurimonas , for which the name Sulfurimonas crateris sp. nov. is proposed. The type strain is SN118T (=DSM 109248T=VKM B-3378T).Reaser, B.C., Watson, N.E., Prebihalo, S.E., Pinkerton, D.K., Skogerboe, K.J., Synovec, R.E., 2020. Chapter 5 - Management and interpretation of capillary chromatography-mass spectrometry data, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 449-480. challenges of data management and interpretation for purveyors of capillary chromatography instrumentation with mass spectrometric detection are reviewed. Techniques to succeed are detailed within the context of standard analytical targeted, nontargeted, and hybrid targeted/nontargeted work flows. The processes are divided into the common elements of preprocessing, comparative analysis, deconvolution (i.e., mathematical resolution), result analysis, and statistical presentation. Time-honored techniques are discussed throughout with a focus on the added complications created by the data size and density in modern experiments where the samples are analyzed by chromatographic instruments with mass spectrometric detection. Multidimensional and multivariate options are included throughout and the focus constantly returns to harvesting useful information from the windfall of data created by these technologies.Reinhard, C.T., Planavsky, N.J., Ward, B.A., Love, G.D., Le Hir, G., Ridgwell, A., 2020. The impact of marine nutrient abundance on early eukaryotic ecosystems. Geobiology 18, 139-151. rise of eukaryotes to ecological prominence represents one of the most dramatic shifts in the history of Earth's biosphere. However, there is an enigmatic temporal lag between the emergence of eukaryotic organisms in the fossil record and their much later ecological expansion. In parallel, there is evidence for a secular increase in the availability of the key macronutrient phosphorus (P) in Earth's oceans. Here, we use an Earth system model equipped with a size-structured marine ecosystem to explore relationships between plankton size, trophic complexity, and the availability of marine nutrients. We find a strong dependence of planktonic ecosystem structure on ocean nutrient abundance, with a larger ocean nutrient inventory leading to greater overall biomass, broader size spectra, and increasing abundance of large Zooplankton. If existing estimates of Proterozoic marine nutrient levels are correct, our results suggest that increases in the ecological impact of eukaryotic algae and trophic complexity in eukaryotic ecosystems were directly linked to restructuring of the global P cycle associated with the protracted rise of surface oxygen levels. Our results thus suggest an indirect but potentially important mechanism by which ocean oxygenation may have acted to shape marine ecological function during late Proterozoic time.Reis, P.C.J., Thottathil, S.D., Ruiz-González, C., Prairie, Y.T., 2020. Niche separation within aerobic methanotrophic bacteria across lakes and its link to methane oxidation rates. Environmental Microbiology 22, 738-751. methane (CH4) emissions are largely controlled by aerobic methane‐oxidizing bacteria (MOB) which mostly belong to the classes Alpha‐ and Gammaproteobacteria (Alpha‐ and Gamma‐MOB). Despite the known metabolic and ecological differences between the two MOB groups, their main environmental drivers and their relative contribution to CH4 oxidation rates across lakes remain unknown. Here, we quantified the two MOB groups through CARD‐FISH along the water column of six temperate lakes and during incubations in which we measured ambient CH4 oxidation rates. We found a clear niche separation of Alpha‐ and Gamma‐MOB across lake water columns, which is mostly driven by oxygen concentration. Gamma‐MOB appears to dominate methanotrophy throughout the water column, but Alpha‐MOB may also be an important player particularly in well‐oxygenated bottom waters. The inclusion of Gamma‐MOB cell abundance improved environmental models of CH4 oxidation rate, explaining part of the variation that could not be explained by environmental factors alone. Altogether, our results show that MOB composition is linked to CH4 oxidation rates in lakes and that information on the MOB community can help predict CH4 oxidation rates and thus emissions from lakes.Remírez, M.N., Algeo, T.J., 2020. Paleosalinity determination in ancient epicontinental seas: A case study of the T-OAE in the Cleveland Basin (UK). Earth-Science Reviews 201, 103072. Early Jurassic Toarcian oceanic anoxic event (T-OAE) was marked by deposition of organic-rich sediments and a pronounced negative carbon-isotope excursion across the Northwest European Sea (NWES), representing a signal that was stronger regionally than globally. Various models for the T-OAE have been proposed, some focusing on general atmospheric-oceanic controls to reflect its global character and others emphasizing local or regional factors to account for its strong expression in the NWES. In this study, we evaluate watermass dynamics of the Early Jurassic Cleveland Basin (UK) during the T-OAE using a combination of paleosalinity proxies (B/Ga, Sr/Ba, and S/TOC). These proxies suggest that brackish conditions existed prior to onset of the T-OAE, with a shift to nearly freshwater conditions during the T-OAE, reflecting a large increase in terrestrial runoff due to a stronger hydrological cycle, possibly combined with shallowing of the marginal sill of the Cleveland Basin through sea-level fall. Following the T-OAE, basinal salinity conditions first returned to brackish and then gradually shifted to fully marine. This hydrographic history accounts for low Mo concentrations in T-OAE sediments of the Cleveland Basin, demonstrating control by watermass restriction and local (rather than global) aqueous Mo drawdown. These findings demonstrate the importance of local hydrographic controls on the sedimentary expression of the T-OAE. The more general significance of this study is that it highlights the need for application of paired salinity and redox proxies in order to correctly interpret paleoenvironmental variations in marginal-marine basins.Ren, C., Yuan, H., Song, J., Duan, L., Li, X., Li, N., Zhou, B., 2020. The use of amino sugars for assessing seasonal dynamics of particulate organic matter in the Yangtze River estuary. Marine Chemistry 220, 103763. particulate amino sugars (PAS), organic carbon (POC) and nitrogen (PN), the chlorophyll a (Chl-a), and the heterotrophic bacterial cell count (HBC) in the Yangtze River Estuary (YRE) were determined to study the biological source, bioavailability and bacterial contribution of particulate organic matter (POM) under the influence of algal bloom during the spring and autumn of 2017. The contents of PAS were 2.6–69.6 nmol/(mg dw) and made up 5.29 ± 2.55% of POC and 5.39 ± 2.77% of PN. The strong positive correlations between Chl-a and POC, PN and PAS and their similar distributions indicated that phytoplankton was a major source of POM and PAS in the YRE. When algal blooms occurred, the high ratios of glucosamine to galactosamine (GlcN/GalN) (~10.9) and the high carbon and nitrogen normalized yields of PAS (%PAS-POC and %PAS-PN, respectively) clearly indicated the planktonic (especially zooplankton) source of POM, although the high muramic acid (Mur) contents implying high contents of fresh bacterial organic matter (OM) were also found. Additionally, the high proportion of fresh plankton- and bacterial-derived OM indicated that the POM was more labile when algal bloom occurred. In contrast, when the primary production was low, the lower %PAS-POC and GlcN/GalN ratios (< 3) in the POM demonstrated the decreased contribution of planktonic OM and the relatively elevated contribution of bacterial OM. In addition, the higher %PAS-PN and the lower DO concentrations in seawater indicated that the POM experienced some degree of degradation but was still at an early stage in the nearshore site in autumn. In spring, the Changjiang diluted water (CDW) carried considerable plankton-derived POM into the estuary and influenced the distribution of POM. In autumn, the terrestrial OM might become more bacterial-derived and had less influence on the bulk POM of the estuary. The bacterial OM estimated by the Mur accounted for an average of 10.8 ± 3.7% and 40.5 ± 19.1% of the POC in spring and autumn, respectively, which was approximately two times higher than the results based on the heterotrophic bacterial cell count (HBC), indicating that most of the bacterial OM in the POM was detritus. In summary, the content, source and bioavailability of POM were significantly affected by algal bloom and the CDW, and the amino sugars represent a reliable tool to indicate the source and bioavailability of POM.Riedel, M., Rohr, K.M.M., C?té, M.M., Schmidt, U., Richardson, T., 2019. Gas hydrate occurrences along the Haida Gwaii margin—Constraints on the geothermal regime and implications for fluid flow. Geosphere 16, 1-12. data along the Haida Gwaii margin collected from 1967 to 2013 were used to identify gas hydrate–related bottom-simulating reflectors (BSRs). The BSRs occur along the Queen Charlotte Terrace only, within more strongly folded and tectonically deformed sedimentary ridges. The BSRs are absent within well-bedded and sediment-filled minibasins. The BSR is modeled as the base of the phase boundary of the methane hydrate (structure I) stability zone and is used to estimate geothermal gradients. The P-wave velocity structure required to convert observed depths of the BSR in two-way time to meters below seafloor was constrained from ocean-bottom seismometers. The BSR-derived gradients are lower than data from heat-probe deployments in the region, as well as predicted values from previous modeling of the large-scale tectonic thermal regime. Lower values of the BSR-derived thermal gradients may be due to topographic effects across the ridges where BSRs were observed. The previously identified landward decrease in thermal gradients across the terrace was also identified to a lesser extent from the BSRs, in accordance with the effects of oblique convergence of the Pacific plate with the North American plate. Geothermal gradients decreased from south to north by a factor of two, which is likely an effect of plate cooling due to an increase in age of the underlying plate (ca. 8 Ma off southern Haida Gwaii to ca. 12 Ma at Dixon Entrance) as well as the fact that sediments triple in thickness over the same distance. This may be due to downward flexure of the underlying crust during transpression and/or a high flux of sediments through Dixon Entrance.Rita, P., N?tscher, P., Duarte, L.V., Weis, R., De Baets, K., 2019. Mechanisms and drivers of belemnite body-size dynamics across the Pliensbachian–Toarcian crisis. Royal Society Open Science 6, 190494. reduction is considered an important response to current climate warming and has been observed during past biotic crises, including the Pliensbachian–Toarcian crisis, a second-order mass extinction. However, in fossil cephalopod studies, the mechanisms and their potential link with climate are rarely investigated and palaeobiological scales of organization are not usually differentiated. Here, we hypothesize that belemnites reduce their adult size across the Pliensbachian–Toarcian boundary warming event. Belemnite body-size dynamics across the Pliensbachian–Toarcian boundary in the Peniche section (Lusitanian Basin, Portugal) were analysed based on the newly collected field data. We disentangle the mechanisms and the environmental drivers of the size fluctuations observed from the individual to the assemblage scale. Despite the lack of a major taxonomic turnover, a 40% decrease in rostrum volume is observed across the Pliensbachian–Toarcian boundary, before the Toarcian Oceanic Anoxic Event where belemnites go locally extinct. The pattern is mainly driven by a reduction in adult size of the two dominant species, Pseudohastites longiformis and Passaloteuthis bisulcata. Belemnite-size distribution is best correlated with fluctuations in a palaeotemperature proxy (stable oxygen isotopes); however, potential indirect effects of volcanism and carbon cycle perturbations may also play a role. This highlights the complex interplay between environmental stressors (warming, deoxygenation, nutrient input) and biotic variables (productivity, competition, migration) associated with these hyperthermal events in driving belemnite body-size.Roberts, E.A., Seyfullah, L.J., Loveridge, R.F., Garside, P., Martill, D.M., 2020. Cretaceous gnetalean yields first preserved plant gum. Scientific Reports 10, 3401. liquid plant exudates (e.g. resin) can be found preserved in the fossil record. However, due to their high solubility, gums have been assumed to dissolve before fossilisation. The visual appearance of gums (water-soluble polysaccharides) is so similar to other plant exudates, particularly resin, that chemical testing is essential to differentiate them. Remarkably, Welwitschiophyllum leaves from Early Cretaceous, Brazil provide the first chemical confirmation of a preserved gum. This is despite the leaves being exposed to water twice during formation and subsequent weathering of the Crato Formation. The Welwitschiophyllum plant shares the presence of gum ducts inside leaves with its presumed extant relative the gnetalean Welwitschia. This fossil gum presents a chemical signature remarkably similar to the gum in extant Welwitschia and is distinct from those of fossil resins. We show for the first time that a water-soluble plant exudate has been preserved in the fossil record, potentially allowing us to recognise further biomolecules thought to be lost during the fossilisation process.Rochman, F.F., Kwon, M., Khadka, R., Tamas, I., Lopez-Jauregui, A.A., Sheremet, A., Smirnova, A.V., Malmstrom, R.R., Yoon, S., Woyke, T., Dunfield, P.F., Verbeke, T.J., 2020. Novel copper-containing membrane monooxygenases (CuMMOs) encoded by alkane-utilizing Betaproteobacteria. The ISME Journal 14, 714-726. membrane monooxygenases (CuMMOs) are encoded by xmoCAB(D) gene clusters and catalyze the oxidation of methane, ammonia, or some short-chain alkanes and alkenes. In a metagenome constructed from an oilsands tailings pond we detected an xmoCABD gene cluster with <59% derived protein sequence identity to genes from known bacteria. Stable isotope probing experiments combined with a specific xmoA qPCR assay demonstrated that the bacteria possessing these genes were incapable of methane assimilation, but did grow on ethane and propane. Single-cell amplified genomes (SAGs) from propane-enriched samples were screened with the specific PCR assay to identify bacteria possessing the target gene cluster. Multiple SAGs of Betaproteobacteria belonging to the genera Rhodoferax and Polaromonas possessed homologues of the metagenomic xmoCABD gene cluster. Unexpectedly, each of these two genera also possessed other xmoCABD paralogs, representing two additional lineages in phylogenetic analyses. Metabolic reconstructions from SAGs predicted that neither bacterium encoded enzymes with the potential to support catabolic methane or ammonia oxidation, but that both were capable of higher n-alkane degradation. The involvement of the encoded CuMMOs in alkane oxidation was further suggested by reverse transcription PCR analyses, which detected elevated transcription of the xmoA genes upon enrichment of water samples with propane as the sole energy source. Enrichments, isotope incorporation studies, genome reconstructions, and gene expression studies therefore all agreed that the unknown xmoCABD operons did not encode methane or ammonia monooxygenases, but rather n-alkane monooxygenases. This study broadens the known diversity of CuMMOs and identifies these enzymes in non-nitrifying Betaproteobacteria.Rogers, A.R., Harris, N.S., Achenbach, A.A., 2020. Neanderthal-Denisovan ancestors interbred with a distantly related hominin. Science Advances 6, eaay5483. research has shown that modern Eurasians interbred with their Neanderthal and Denisovan predecessors. We show here that hundreds of thousands of years earlier, the ancestors of Neanderthals and Denisovans interbred with their own Eurasian predecessors—members of a “superarchaic” population that separated from other humans about 2 million years ago. The superarchaic population was large, with an effective size between 20 and 50 thousand individuals. We confirm previous findings that (i) Denisovans also interbred with superarchaics, (ii) Neanderthals and Denisovans separated early in the middle Pleistocene, (iii) their ancestors endured a bottleneck of population size, and (iv) the Neanderthal population was large at first but then declined in size. We provide qualified support for the view that (v) Neanderthals interbred with the ancestors of modern humans.Rolando, L., Vila, J., Baquero, R.P., Castilla-Alcantara, J.C., Barra Caracciolo, A., Ortega-Calvo, J.-J., 2020. Impact of bacterial motility on biosorption and cometabolism of pyrene in a porous medium. Science of The Total Environment 717, 137210. risks of pollution by polycyclic aromatic hydrocarbons (PAHs) may increase in bioremediated soils as a result of the formation of toxic byproducts and the mobilization of pollutants associated to suspended colloids. In this study, we used the motile and chemotactic bacterium Pseudomonas putida G7 as an experimental model for examining the potential role of bacterial motility in the cometabolism and biosorption of pyrene in a porous medium. For this purpose, we conducted batch and column transport experiments with 14C-labelled pyrene loaded on silicone O-rings, which acted as a passive dosing system. In the batch experiments, we observed concentrations of the 14C-pyrene equivalents well above the equilibrium concentration observed in abiotic controls. This mobilization was attributed to biosorption and cometabolism processes occurring in parallel. HPLC quantification revealed pyrene concentrations well below the 14C-based quantifications by liquid scintillation, indicating pyrene transformation into water-soluble polar metabolites. The results from transport experiments in sand columns revealed that cometabolic-active, motile cells were capable of accessing a distant source of sorbed pyrene. Using the same experimental system, we also determined that salicylate-mobilized cells, inhibited for pyrene cometabolism, but mobilized due to their tactic behavior, were able to sorb the compound and mobilize it by biosorption. Our results indicate that motile bacteria active in bioremediation may contribute, through cometabolism and biosorption, to the risk associated to pollutant mobilization in soils. This research could be the starting point for the development of more efficient, low-risk bioremediation strategies of poorly bioavailable contaminants in soils.Romero, I.C., Urban, M.A., Punyasena, S.W., 2020. Airyscan superresolution microscopy: A high-throughput alternative to electron microscopy for the visualization and analysis of fossil pollen. Review of Palaeobotany and Palynology 276, 104192. confocal superresolution microscopy is a new optical technique that can detect morphological features smaller than the diffraction limit of light. It captures both the external and internal ornamentation of modern and fossil pollen. Airyscan combines the ease of use of optical microscopy methods, such as confocal and brightfield microscopy (BM), with the high-resolution imaging of electron microscopy (EM). Modern and fossil pollen grains were imaged using Airyscan, BM, and EM to assess the viability of Airyscan as an alternative for EM. Our results demonstrate that: (1) Airyscan can capture diagnostic features of extant and fossil pollen similar to EM; (2) one-to-one comparisons of Airyscan images with other optical methods are possible (e.g., BM and conventional confocal); (3) Airyscan captures three-dimensional data, allowing reconstruction of pollen grains in different views; and (4) the time and effort required for Airyscan imaging is significantly less than that for EM. This paper demonstrates that Airyscan superresolution microscopy is a high-throughput alternative for morphological analyses of pollen specimens.Root-Gutteridge, H., Ratcliffe, V.F., Korzeniowska, A.T., Reby, D., 2019. Dogs perceive and spontaneously normalize formant-related speaker and vowel differences in human speech sounds. Biology Letters 15, 20190555. animals have been shown to recognize basic phonemic information from human speech sounds and to recognize familiar speakers from their voices. However, whether animals can spontaneously identify words across unfamiliar speakers (speaker normalization) or spontaneously discriminate between unfamiliar speakers across words remains to be investigated. Here, we assessed these abilities in domestic dogs using the habituation–dishabituation paradigm. We found that while dogs habituated to the presentation of a series of different short words from the same unfamiliar speaker, they significantly dishabituated to the presentation of a novel word from a new speaker of the same gender. This suggests that dogs spontaneously categorized the initial speaker across different words. Conversely, dogs who habituated to the same short word produced by different speakers of the same gender significantly dishabituated to a novel word, suggesting that they had spontaneously categorized the word across different speakers. Our results indicate that the ability to spontaneously recognize both the same phonemes across different speakers, and cues to identity across speech utterances from unfamiliar speakers, is present in domestic dogs and thus not a uniquely human trait.Roslee, A.F.A., Zakaria, N.N., Convey, P., Zulkharnain, A., Lee, G.L.Y., Gomez-Fuentes, C., Ahmad, S.A., 2020. Statistical optimisation of growth conditions and diesel degradation by the Antarctic bacterium, Rhodococcus sp. strain AQ5?07. Extremophiles 24, 277-291. pollution is a major concern in Antarctica due to the persistent nature of its hydrocarbon components coupled with the region’s extreme environmental conditions, which means that bioremediation approaches are largely inapplicable at present. The current study assessed the ability of the psychrotolerant phenol-degrader, Rhodococcus sp. strain AQ5-07, to assimilate diesel fuel as the sole carbon source. Factors expected to influence the efficiency of diesel degradation, including the initial hydrocarbon concentration, nitrogen source concentration and type, temperature, pH and salinity were studied. Strain AQ5-07 displayed optimal cell growth and biodegradation activity at 1% v/v initial diesel concentration, 1 g/L NH4Cl concentration, pH 7 and 1% NaCl during one-factor-at-a-time (OFAT) analyses. Strain AQ5-07 was psychrotolerant based on its optimum growth temperature being near 20 °C. In conventionally optimised media, strain AQ5-07 showed total petroleum hydrocarbons (TPH) mineralisation of 75.83%. However, the optimised condition for TPH mineralisation predicted through statistical response surface methodology (RSM) enhanced the reduction to 90.39% within a 2 days incubation. Our preliminary data support strain AQ5-07 being a potential candidate for real-field soil bioremediation by specifically adopting sludge-phase bioreactor system in chronically cold environments such as Antarctica. The study also confirmed the utility of RSM in medium optimisation.Rosso, M.C., Mazzucotelli, M., Bicchi, C., Charron, M., Manini, F., Menta, R., Fontana, M., Reichenbach, S.E., Cordero, C., 2020. Adding extra-dimensions to hazelnuts primary metabolome fingerprinting by comprehensive two-dimensional gas chromatography combined with time-of-flight mass spectrometry featuring tandem ionization: Insights on the aroma potential. Journal of Chromatography A 1614, 460739. information potential of comprehensive two-dimensional gas chromatography combined with time of flight mass spectrometry (GC × GC-TOFMS) featuring tandem hard (70 eV) and soft (12 eV) electron ionization is here applied to accurately delineate high-quality hazelnuts (Corylus avellana L.) primary metabolome fingerprints. The information provided by tandem signals for untargeted and targeted 2D-peaks is examined and exploited with pattern recognition based on template matching algorithms. EI-MS fragmentation pattern similarity, base-peak m/z values at the two examined energies (i.e., 12 and 70 eV) and response relative sensitivity are adopted to evaluate the complementary nature of signals.As challenging bench test, the hazelnut primary metabolome has a large chemical dimensionality that includes various chemical classes such as mono- and disaccharides, amino acids, low-molecular weight acids, and amines, further complicated by oximation/silylation to obtain volatile derivatives.Tandem ionization provides notable benefits including larger relative ratio of structural informing ions due to limited fragmentation at low energies (12 eV), meaningful spectral dissimilarity between 12 and 70 eV (direct match factor values range 222-783) and, for several analytes, enhanced relative sensitivity at lower energies. The complementary information provided by tandem ionization is exploited by untargeted/targeted (UT) fingerprinting on samples from different cultivars and geographical origins. The responses of 138 UT-peak-regions are explored to delineate informative patterns by univariate and multivariate statistics, providing insights on correlations between known precursors and (key)-aroma compounds and potent odorants. Strong positive correlations between non-volatile precursors and odorants are highlighted with some interesting linear trends for: 3-methylbutanal with isoleucine (R2 0.9284); 2,3-butanedione/2,3-pentanedione with monosaccharides (fructose/glucose derivatives) (R2 0.8543 and 0.8860); 2,5-dimethylpyrazine with alanine (R2 0.8822); and pyrroles (1H-pyrrole, 3-methyl-1H-pyrrole, and 1H-pyrrole-2-carboxaldehyde) with ornithine and alanine derivatives (R2 0.8604). The analytical work-flow provides a solid foundation for a new strategy for hazelnuts quality assessment because aroma potential could be derived from precursors’ chemical fingerprints.Rothschild, B.M., Tanke, D., Rühli, F., Pokhojaev, A., May, H., 2020. Suggested case of Langerhans Cell Histiocytosis in a Cretaceous dinosaur. Scientific Reports 10, 2203. to diseases is common to humans and dinosaurs. Since much of the biological history of every living creature is shaped by its diseases, recognizing them in fossilized bone can furnish us with important information on dinosaurs’ physiology and anatomy, as well as on their daily activities and surrounding environment. In the present study, we examined the vertebrae of two humans from skeletal collections with Langerhans Cell Histiocytosis (LCH), a benign osteolytic tumor-like disorder involving mainly the skeleton; they were diagnosed in life, along with two hadrosaur vertebrae with an apparent lesion. Macroscopic and microscopic analyses of the hadrosaur vertebrae were compared to human LCH and to other pathologies observed via an extensive pathological survey of a human skeletal collection, as well as a three-dimensional reconstruction of the lesion and its associated blood vessels from a ?CT scan. The hadrosaur pathology findings were indistinguishable from those of humans with LCH, supporting that diagnosis. This report suggests that hadrosaurids had suffered from larger variety of pathologies than previously reported. Furthermore, it seems that LCH may be independent of phylogeny.Rotich, E.K., Handler, M.R., Naeher, S., Selby, D., Hollis, C.J., Sykes, R., 2020. Re-Os geochronology and isotope systematics, and organic and sulfur geochemistry of the middle–late Paleocene Waipawa Formation, New Zealand: Insights into early Paleogene seawater Os isotope composition. Chemical Geology 536, 119473. the middle–late Paleocene, a marine, organic-rich sedimentary unit (Waipawa Formation [Fm]) in which the organic matter was derived mainly from terrestrial plants was deposited in many of New Zealand's sedimentary basins. The unique organofacies of this formation has not been identified in any other time interval within the geological history of the Southwest Pacific, indicating that unusual climatic and oceanographic conditions likely prevailed during this time. It has, therefore, attracted wide scientific interest due to its significance for regional and global reconstruction of the early Paleogene transitional climate as well as potential for oil and gas production. Scarcity of age-diagnostic fossils, presence of unconformities and lack of volcanic interbeds have, however, hindered precise dating and correlations of all the known occurrences of the formation. Here, rhenium?osmium (Re-Os) geochronology has yielded the first radiometric age for the formation (57.5 ± 3.5 Ma), which is consistent with available biostratigraphic age determinations (59.4–58.7 Ma). Further, a comparison of Re-Os, bulk pyrolysis, sulfur and palynofacies data for the Waipawa Fm with those of more typical marine sediments such as the underlying Whangai Fm supports the interpretation that the chelating precursors or fundamental binding sites responsible for uptake of Re and Os are present in all types of organic matter, and that these elements have a greater affinity for organic chelating sites than for sulfides. The results also indicate that sedimentation rate may not play a dominant role in enhanced uptake of Re and Os by organic-rich sedimentary rocks.The initial 187Os/188Os values for the Waipawa (~0.28) and Whangai (~0.36) formations are broadly similar to those reported for coeval pelagic sediments from the central Pacific Ocean, further constraining the low-resolution marine 187Os/188Os record of the Paleocene. We present a compilation of 187Os/188Os values from organic-rich sedimentary rocks spanning the period between 70 and 50 Ma which shows that seawater Os gradually became less radiogenic from the latest Cretaceous, reaching a minimum value in the earliest late Paleocene (~59 Ma) during the deposition of Waipawa Fm, and then increased through the later Paleocene and into the early Eocene. The composite Os isotope record broadly correlates with global temperature (δ18O and TEX86) and carbon isotope (δ13C) records from the middle Paleocene to early Eocene, which is inferred to reflect climate-modulated changes in continental weathering patterns.Ruebsam, W., Reolid, M., Marok, A., Schwark, L., 2020. Drivers of benthic extinction during the early Toarcian (Early Jurassic) at the northern Gondwana paleomargin: Implications for paleoceanographic conditions. Earth-Science Reviews 203, 103117. the early Toarcian multiple environmental perturbations led to the genesis of the Toarcian Oceanic Anoxic Event (T-OAE), expressed by the widespread occurrence of black shales that were formed under oxygen-deficient conditions. Factors promoting organic matter preservation also drove benthic extinction due to low aqueous O2 levels and habitats poisoned by H2S. However, the development of benthic barren intervals in oxygenated shelf areas, lacking black shales, indicates that even in these areas benthic communities experienced a crisis. To understand environmental changes and to determine factors driving benthic extinction we applied paleontological and geochemical techniques to the organic matter-lean Ratnek El Kahla section (Saharan Atlas, Algeria). During the Early Jurassic the study site was located at the northern Gondwana paleomargin, belonging to the southern West Tethys Shelf. The benthic barren interval coincides with the climax of the T-OAE that correlates with a major carbon cycle perturbation, expressed by a negative carbon isotope excursion. Compared to background values, sediments of the benthic barren interval are enriched in organic matter and redox-sensitive metals. In combination with the enhanced preservation of intact bacterial lipids and increased rates of organic matter sulfurization, data attest to a decline in pore water O2 and increased H2S concentration. It is thus reasonable to propose that, similar to northern shelf areas, benthic communities suffered from prolonged oxygen-deficient conditions. Absence of benthic activity and less intensive sediment reworking in combination with enhanced organic matter sulfurization favored organic matter preservation. Productivity proxies and δ15N data indicate moderate primary productivity rates. Lowered aqueous O2 levels did not result from excessive aerobic organic matter breakdown. Seafloor anoxia was rather promoted by rising seawater temperatures and sluggish ocean circulation during a transition from icehouse into a greenhouse climate. These conditions may have been a pre-requirement for genesis of the T-OAE.Rychlik, M., Kanawati, B., Roullier-Gall, C., Hemmler, D., Liu, Y., Alexandre, H., Gougeon, R.D., Gmelch, L., Gotthardt, M., Schmitt-Kopplin, P., 2019. Chapter 21 - Foodomics assessed by Fourier transform mass spectrometry, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 651-677. its ultrahigh resolution power and excellent mass accuracy, Fourier transform ion cyclotron resonance mass spectrometry is the perfct tool to analyze the “foodome” as the set of all polar small molecular compounds present in an investigated food sample. We present here selected applications of this technique in unraveling the metabolome in complex foods (thermally affected, fermentation products, distillates) such exemplified with Maillard reaction products or with wines and spirits. Technical considerations for high resolution mass analyzers are provided from a practical point of view. Moreover, aspects of food safety and nutritional quality are covered by presenting applications to the mycobolome of Alternaria fungi and vitamins of the folate group, respectively.Saleh, T.A., 2020. Characterization, determination and elimination technologies for sulfur from petroleum: Toward cleaner fuel and a safe environment. Trends in Environmental Analytical Chemistry 25, e00080. compounds are the most abundant compounds in crude oil. Sulfur in liquid fuel oil leads to the emission of sulfur oxides and sulfate particulate matter which not only endangers health and community property but also reduces the life of the catalysts and engines due to corrosion. Various methods, with a high level of precision and sensitivity, have been developed to analyze sulfur-containing compounds. On the other side, the removal and characterization of sulfur-containing compounds in crude oils and petroleum products is of great importance, not only for the downstream refining process, control/optimization, and environmental compliance, but also for upstream geochemical studies for exploration and production. This review summarizes the analytical strategies and some of the most important and promising technologies for the removal of sulfur from oil.Salgaonkar, B.B., Rodrigues, R., 2019. A study on the halophilic archaeal diversity from the food grade iodised crystal salt from a saltern of India. Microbiology 88, 709-719. study aimed to evaluate culturable halophilic archaeal diversity of iodised crystal salt, obtained from the solar salterns of Vedaranyam, Tamil Nadu, India. Bright yellow-orange-red pigmented colonies were obtained, by surface spreading of the saturated salt crystal suspension, on complex media such as NTYE (NaCl Tryptone Yeast Extract) and EHM (Extremely Halophilic Medium), followed by incubating the plates for 30–45 days. The viable halophilic pigmented/non-pigmented microbial counts were determined as colony forming units (CFU/g), which were ~1.1 × 104/5.5 × 103 and ~1.0 × 104/4.0 × 103 on NTYE and EHM, respectively. Six morphologically distinct isolates were purified and identified. Morphological characteristics of the isolates revealed the cells to be cocci and involuted/cup shape, whereas chemotaxonomic characteristics revealed the presence of bacterioruberin pigment. Small subunit ribosomal RNA (16S rRNA) gene analysis revealed that, majority of the isolates belonged to genus Halococcus, except one belonged to genus Halorubrum. To the best of our knowledge, this is the first study reporting, prevalence of Halococcus in iodised crystal salt, of Vedaranyam, Tamil Nadu, India.Samad, S.K., Mishra, D.K., Mathews, R.P., Ghosh, S., Mendhe, V.A., Varma, A.K., 2020. Geochemical attributes for source rock and palaeoclimatic reconstruction of the Auranga Basin, India. Journal of Petroleum Science and Engineering 185, 106665. present study aims to investigate the source and palaeoenvironmental conditions prevailed during the deposition of the Lower Permian shales of the Auranga Basin located at western flank of the Damodar valley, India. Both organic and inorganic geochemistry have been applied as tools to accomplish the objectives of this investigation. The n-alkane distribution within the samples reveals the dominance of the intermediate chain length n-alkanes over the short chain as well as long chain length homologues, possibly implying the organic matter derivation from the ferns, sphagnum moss, gymnosperms and/or aquatic plants. The intermediate chain n-alkane concentration along with its relations with the preference indices of odd to even carbons and proxy ratio as well as with average chain length may suggest the submergent aquatic plant communities as principle contributors of organic materials to the peatland. The presence of short chain length alkanes with pentacyclic triterpenoids may indicate the microbial organic matter input. The complete absence of <n-C16 alkanes and baseline humps in the pentacyclic triterpenoid chromatograms may indicate the influence of biodegradation of the organic matter in the shale samples. The pristane to phytane ratio (0.08–4.66) and the relation between pristane/n-C17 and phytane/n-C18 may imply transitional redox condition within the mire. The pristane/n-C17 ratio (0.08–1.24) may indicate the alternations of open water and swampy environments. The chemical weathering indices calculated from major elemental oxides may infer moderate to strong weathering due to reasonable period of precipitation during a wet spell. The selective trace element ratios and the palaeoclimatic factor (0.60–1.73) may, additionally, suggest high atmospheric humidity and consequent heavy precipitations that flourished the aquatic plants, which would have dominantly supplied the organic detritus in the peatland. In complementary, the hopanoid ratios, especially, the 22S/(22S + 22R) homohopane ratio may mark that the organic matter within the Auranga shales is in immature to early maturity phase for oil generation. Moreover, the combined mean random vitrinite reflectance and the thermal maturity parameter obtained from the Rock Eval data may indicate oil potential of these shales.Sambuelli, L., Comina, C., Catanzariti, G., Barsuglia, F., Morelli, G., Porcelli, F., 2019. The third KV62 radar scan: Searching for hidden chambers adjacent to Tutankhamun's tomb. Journal of Cultural Heritage 39, 288-296. existence of hidden chambers and corridors adjacent to Tutankhamun's tomb (code name KV62) has been long debated. In 2015 it was suggested that these chambers may host the as yet undiscovered burial of Nefertiti. In order to test this hypothesis, two Ground Penetrating Radar (GPR) surveys, conducted in 2015 and 2016 from inside KV62, were carried out, but gave contradictory results. To solve these uncertainties and obtain a more confident and conclusive response, a third GPR survey was conducted by our team in February 2018. The results of this third radar scan are reported in this article. Three GPR systems with multiple frequency bands (from 150?MHz to 3000?MHz) and very dense spatial sampling were adopted. After careful data processing, no evidence of marked discontinuities due to the passage from natural rock to artificial blocking walls were found in the radargrams. It is therefore concluded that there are no hidden chambers immediately adjacent to the Tomb of Tutankhamun.Sander, L.C., Rimmer, C.A., Wilson, W.B., 2020. Characterization of triacontyl (C-30) liquid chromatographic columns. Journal of Chromatography A 1614, 460732. in the characteristics of seventeen commercial C-30 liquid chromatographic columns were studied for the separation of carotenoid isomers. A mixture consisting of nine xanthophyll and hydrocarbon carotenoids were separated under conditions carefully chosen to reveal changes in selectivity. The influence of the mobile phase composition, column temperature, and mobile phase flow rate were evaluated. Shape selectivity was characterized with Standard Reference Material (SRM) 869b Column Selectivity Test Mixture, for correlation with carotenoid retention behavior. Regular changes were observed across a broad spectrum of shape selectivity characteristics as indicated by SRM 869b. Better separations of carotenoid isomers were achieved with C-30 columns than were possible with C-18 columns, even after optimization of separation conditions.Santos, H., Martins, R.O., Soares, D.A., Chaves, A.R., 2020. Molecularly imprinted polymers for miniaturized sample preparation techniques: strategies for chromatographic and mass spectrometry methods. Analytical Methods 12, 894-911. methods, especially miniaturized sample preparation methods, have seen technological progress with the use of molecularly imprinted polymers (MIPs). MIPs are polymers with specific sites for analyte recognition. They are combined with sample preparation at small scales for analyses with greater specificities and sensitivity. This review aims to provide an overview of current MIP research into increasing selectivity and sensitivity by chromatography and mass spectrometry techniques, with priority given to the small scale for applications in clinical and environmental analyses.Sasselov, D.D., Grotzinger, J.P., Sutherland, J.D., 2020. The origin of life as a planetary phenomenon. Science Advances 6, eaax3419. advocate an integrative approach between laboratory experiments in prebiotic chemistry and geologic, geochemical, and astrophysical observations to help assemble a robust chemical pathway to life that can be reproduced in the laboratory. The cyanosulfidic chemistry scenario described here was developed by such an integrative iterative process. We discuss how it maps onto evolving planetary surface environments on early Earth and Mars and the value of comparative planetary evolution. The results indicate that Mars can offer direct evidence for geochemical conditions similar to prebiotic Earth, whose early record has been erased. The Jezero crater is now the chosen landing site for NASA’s Mars 2020 rover, making this an extraordinary opportunity for a breakthrough in understanding life’s origins.Savelyeva, O.L., 2019. Geochemical events at the Cenomanian-Turonian boundary: Relation of anoxia with volcanism, climate, and ocean circulation. Russian Geology and Geophysics 60, doi: 10.15372/RGG2019068. paper presents a detailed review of chemostratigraphic data on the Bonarelli oceanic anoxic event (OAE2) at the Cenomanian-Turonian boundary from different regions worldwide, with a focus on the respective redox conditions in the basins, metal anomalies, and δ13C excursions. Marine sediments with OAE2 signatures in Eastern Kamchatka are compared with their counterparts from submarine volcanic rises in the northwestern Pacific. The available isotopic ages of lavas from some large igneous provinces are correlated with the age of OAE2. The Bonarelli event was triggered and governed by several interrelated factors: volcanism, climate, and ocean circulation. The supply of nutrients into oceans as a result of enhanced magmatism, hydrothermal activity, and weathering on continents played an important role in maintaining anoxia. The spatial patterns of black-shale deposition were controlled by ocean circulation. Geochemical and biochemical processes associated with high productivity ultimately led to its reduction and to the recovery of oxic conditions in oceans.Sayed, A.M., Hassan, M.H.A., Alhadrami, H.A., Hassan, H.M., Goodfellow, M., Rateb, M.E., 2020. Extreme environments: microbiology leading to specialized metabolites. Journal of Applied Microbiology 128, 630-657. prevalence of multidrug‐resistant microbial pathogens due to the continued misuse and overuse of antibiotics in agriculture and medicine is raising the prospect of a return to the preantibiotic days of medicine at the time of diminishing numbers of drug leads. The good news is that an increased understanding of the nature and extent of microbial diversity in natural habitats coupled with the application of new technologies in microbiology and chemistry is opening up new strategies in the search for new specialized products with therapeutic properties. This review explores the premise that harsh environmental conditions in extreme biomes, notably in deserts, permafrost soils and deep‐sea sediments select for micro‐organisms, especially actinobacteria, cyanobacteria and fungi, with the potential to synthesize new druggable molecules. There is evidence over the past decade that micro‐organisms adapted to life in extreme habitats are a rich source of new specialized metabolites. Extreme habitats by their very nature tend to be fragile hence there is a need to conserve those known to be hot‐spots of novel gifted micro‐organisms needed to drive drug discovery campaigns and innovative biotechnology. This review also provides an overview of microbial‐derived molecules and their biological activities focusing on the period from 2010 until 2018, over this time 186 novel structures were isolated from 129 representatives of microbial taxa recovered from extreme habitats.Scanlon, B.R., Reedy, R.C., Xu, P., Engle, M., Nicot, J.P., Yoxtheimer, D., Yang, Q., Ikonnikova, S., 2020. Can we beneficially reuse produced water from oil and gas extraction in the U.S.? Science of The Total Environment 717, 137085. is increasing interest in beneficial uses of large volumes of wastewater co-produced with oil and gas extraction (produced water, PW) because of water scarcity, potential subsurface disposal limitations, and regional linkages to induced seismicity. Here we quantified PW volumes relative to water demand in different sectors and PW quality relative to treatment and reuse options for the major U.S. shale oil and gas plays. PW volumes from these plays totaled ~600 billion liters (BL, 160 billion gallons, Bgal) in 2017. One year of PW is equal to ~60% of one day of freshwater use in the U.S. For these plays, the total irrigation demand exceeded PW volumes by ~5× whereas municipal demand exceeded PW by ~2×. If PW is reused for hydraulic fracturing (HF) within the energy sector, there would be no excess PW in about half of the plays because HF water demand exceeds PW volumes in those plays. PW quality can be highly saline with median total dissolved solids up to 255 g/L in the Bakken play, ~7× seawater. Intensive water treatment required for PW from most unconventional plays would further reduce PW volumes by at least 2×. Desalination would also result in large volumes of salt concentrates, equivalent to ~3000 Olympic swimming pools in the Permian Delaware Basin in 2017. While water demands outside the energy sector could accommodate PW volumes, much lower PW volumes relative to water demand in most regions would not substantially alleviate water scarcity. However, large projected PW volumes relative to HF water demand over the life of the play in the Permian Delaware Basin may provide a substantial new water source for beneficial use in the future. Large knowledge gaps in PW quality, lack of appropriate regulations, and economic factors currently preclude beneficial uses outside the energy sector in most regions.Scheuerl, T., Hopkins, M., Nowell, R.W., Rivett, D.W., Barraclough, T.G., Bell, T., 2020. Bacterial adaptation is constrained in complex communities. Nature Communications 11, 754. major unresolved question is how bacteria living in complex communities respond to environmental changes. In communities, biotic interactions may either facilitate or constrain evolution depending on whether the interactions expand or contract the range of ecological opportunities. A fundamental challenge is to understand how the surrounding biotic community modifies evolutionary trajectories as species adapt to novel environmental conditions. Here we show that community context can dramatically alter evolutionary dynamics using a novel approach that ‘cages’ individual focal strains within complex communities. We find that evolution of focal bacterial strains depends on properties both of the focal strain and of the surrounding community. In particular, there is a stronger evolutionary response in low-diversity communities, and when the focal species have a larger genome and are initially poorly adapted. We see how community context affects resource usage and detect genetic changes involved in carbon metabolism and inter-specific interaction. The findings demonstrate that adaptation to new environmental conditions should be investigated in the context of interspecific interactions.Schmitt-Kopplin, P., Kanawati, B., 2019. Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, p. 778.: Fundamentals and Applications of Fourier Transform Mass Spectrometry is the first book to delve into the underlying principles on the topic and their linkage to industrial applications. Drs. Schmitt-Kopplin and Kanawati have brought together a team of leading experts in their respective fields to present this technique from many different perspectives, describing, at length, the pros and cons of FT-ICR and Orbitrap. Numerous examples help researchers decide which instruments to use for their particular scientific problem and which data analysis methods should be applied to get the most out of their data.Key Features: Covers FT-ICR-MS and Orbitrap’s fundamentals, enhancing researcher knowledgeIncludes details on ion sources, data processing, chemical analysis and imagingProvides examples across the wide spectrum of applications, including omics, environmental, chemical, pharmaceutical and food analysisReadership: Postgraduate students of analytical chemistry, scientists in the broad world of mass spectrometry, Industry co-workers in quality control and pharmaceutical chemistry as well as in environmental and petroleum chemical analysis. Biologists including microbiology staff working in the field of RNA/DNA and proteomics. Physicists and scientists working on the cutting edge of analytical and physical chemistry. Industry Sectors: Health care and life sciences, Quality Control & Analytical chemical trace analysis, Manufacturers of all mass spectrometers, Academics, Chemical analysts in petroleum companiesTable of ContentsHistorical Chapters: 1. Historical Developments in FTICRMSFundamental/Technology Chapters2. Fundamentals of Orbitrap 3. Latest developments in FT-ICR-MS4. Fundamentals and simulations in FT-ICR-MS5. Advanced Fundamentals6. Data processing & Automation in ICR-FT-MS 7. Fundamentals of 2D-FTMS8. Ion Mobility and FTMS9. Imaging FTMS10. Laser Desorption Ionisation FT-ICR-MSApplications Chapters11. LC-MS Metabolomics in Orbitrap12. Visualizing metabolic hypotheses on FT-ICR-MS13. Environmental Chemistry/Organohalogens and FTMS14. Bioactive Peptides15. Forensic studies FTMS/Orbitrap16. Petroleomics Orbitrap/FTMS17. Proteomics/PTM Orbi/ICR18. Gas Phase Ion-Molecule Reactions / Inorganics19. Clusters Chemistry and Cold ICR-FTMS20. Application of FTMS to the Analysis of Glycosaminoglycans21. Foodomics in FTMS Schroeter, N., Lauterbach, S., Stebich, M., Kalanke, J., Mingram, J., Yildiz, C., Schouten, S., Gleixner, G., 2020. Biomolecular evidence of early human occupation of a high-altitude site in western Central Asia during the Holocene. Frontiers in Earth Science 8, 20. doi: 10.3389/feart.2020.00020. of early human occupation of high-altitude sites in Central Asia and possible migration routes during the Holocene are limited due to restricted archeological sample material. Consequently, there is a growing interest in alternative approaches to investigate past anthropogenic activity in this area. In this study, fecal biomarkers preserved in lake sediments from Lake Chatyr Kol (Tian Shan, Kyrgyzstan) were analyzed to reconstruct the local presence of humans and pastoral animals in this low-human-impact area in the past. Spanning the last ～11,700 years, this high-altitude site (～3,500 m above sea level) provides a continuous record of human occupancy in Western Central Asia. An early increase of human presence in the area during the mid-Holocene is marked by a sharp peak of the human fecal sterol coprostanol and its epimer epicoprostanol in the sediments. An associated increase in 5β-stigmastanol, a fecal biomarker deriving from herbivores indicates a human occupancy that most probably largely depended upon livestock. However, sterol profiles show that grazing animals had already occupied the catchment area of Lake Chatyr Kol before and also after a significant presence of humans. The biomarker evidence in this study demonstrates an early presence of humans in a high-altitude site in Central Asia at ～5,900–4,000 a BP. Dry environmental conditions during this period likely made high altitude regions more accessible. Moreover, our results help to understand human migration in Western Central Asia during the early and mid-Holocene as part of a prehistoric Silk Road territory.Schultz, J., Rosado, A.S., 2020. Extreme environments: a source of biosurfactants for biotechnological applications. Extremophiles 24, 189-206. surfactant industry moves billions of dollars a year and consists of chemically synthesized molecules usually derived from petroleum. Surfactant is a versatile molecule that is widely used in different industrial areas, with an emphasis on the petroleum, biomedical and detergent industries. Recently, interest in environmentally friendly surfactants that are resistant to extreme conditions has increased because of consumers' appeal for sustainable products and industrial processes that often require these characteristics. With this context, the need arises to search for surfactants produced by microorganisms coming from extreme environments and to mine their unique biotechnological potential. The production of biosurfactants is still incipient and presents challenges regarding economic viability due to the high costs of cultivation, production, recovery and purification. Advances can be made by exploring the extreme biosphere and bioinformatics tools. This review focuses on biosurfactants produced by microorganisms from different extreme environments, presenting a complete overview of what information is available in the literature, including the advances, challenges and future perspectives, as well as showing the possible applications of extreme biosurfactants.Schulz, F., Roux, S., Paez-Espino, D., Jungbluth, S., Walsh, D.A., Denef, V.J., McMahon, K.D., Konstantinidis, K.T., Eloe-Fadrosh, E.A., Kyrpides, N.C., Woyke, T., 2020. Giant virus diversity and host interactions through global metagenomics. Nature 578, 432-436. current knowledge about nucleocytoplasmic large DNA viruses (NCLDVs) is largely derived from viral isolates that are co-cultivated with protists and algae. Here we reconstructed 2,074 NCLDV genomes from sampling sites across the globe by building on the rapidly increasing amount of publicly available metagenome data. This led to an 11-fold increase in phylogenetic diversity and a parallel 10-fold expansion in functional diversity. Analysis of 58,023 major capsid proteins from large and giant viruses using metagenomic data revealed the global distribution patterns and cosmopolitan nature of these viruses. The discovered viral genomes encoded a wide range of proteins with putative roles in photosynthesis and diverse substrate transport processes, indicating that host reprogramming is probably a common strategy in the NCLDVs. Furthermore, inferences of horizontal gene transfer connected viral lineages to diverse eukaryotic hosts. We anticipate that the global diversity of NCLDVs that we describe here will establish giant viruses—which are associated with most major eukaryotic lineages—as important players in ecosystems across Earth’s biomes.Schwangler, M., Harris, N.B., Waldron, J.W.F., 2020. Source rock characterization and oil-to-source rock correlation of a Cambrian -Ordovician fold-and-thrust belt petroleum system, western Newfoundland. Marine and Petroleum Geology 115, 104283. this study, we use biomarker and isotope data to address the complexities of petroleum system analysis in fold-thrust systems, specifically related to hydrocarbon generation and migration, such as variable thermal maturities of source rocks, complex migration pathways, and mixing. Source rocks, extracts, and oil samples are taken from Paleozoic rocks along the Appalachian structural front in western Newfoundland. Oil seeps along this fold-and-thrust belt have motivated episodic exploration efforts over the last 150 years. However, economic development has been unsuccessful to date, in part because of the complex nature of oil-to-source relationships.Pyrolysis analyses identify promising source intervals in Lower Ordovician (Floian) formations, with an excellent source potential containing type I/II organic matter (TOC up to 9.35%, HI up to 840). A second good source interval, identified within the late Cambrian (Furongian) continental slope and rise sediments, contains type II/III organic matter (TOC up to 2.34%, HI = 380). Source rock samples from outcrops are marginally mature to mature with Tmax values between 436 and 447. Geochemical analyses of source rock extract imply a clastic shale-dominated source rock with a minor contribution from carbonate source rocks. Chemometric analyses yield 3 extract groups. Groups 1 and 2 contain lower Ordovician samples with organic matter derived from oxidized micro-plankton with varying amounts of Gleocapsomorpha prisca. Extract group 3 originates from Cambrian samples and shows evidence of a bacterial-derived organic matter.Similar genetic relationships among 10 oil samples from natural oil seeps and abandoned well sites are indicated by high-resolution biomarker analyses. Seven oil samples originated from Ordovician source rocks that produced high API oils with low bisnorhopane/hopane, tricyclic/hopane ratios, and high sterane concentrations, supporting interpretation of a source containing algal-derived organic matter. Three oils originated from Cambrian shales. These high API oils show high bisnorhopane/hopane and tricyclic/hopane ratios, low sterane concentrations, and low carbon isotope values, all indicative of organic matter derived from bacteria, generated over a wide range of maturities (0.98–1.26 %Ro). Thermal maturity-sensitive biomarkers and naphthalene ratios show that source rocks generated oils with a wide range of maturities related to their dipping character in the imbricated thrust stack. The Cambrian source generated oils that locally experienced secondary cracking during Acadian inversion, whereas the Ordovician source generated oil with low maturities after the Acadian inversion. Oil operaters exploring fold-and-thrust belt petroleum systems may expect extreme changes of oil properties (for example, API gravity) in spacially restricted areas.Sch?neich, S., Gough, D.V., Trinklein, T.J., Synovec, R.E., 2020. Dynamic pressure gradient modulation for comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry detection. Journal of Chromatography A 1609, 460982. pressure gradient modulation (DPGM) is investigated for comprehensive two-dimensional gas chromatography (GC×GC) with time-of-flight mass spectrometry (TOFMS) detection. With DPGM, a commercial pneumatic “pulse” valve is opened to introduce a suitably high auxiliary gas pressure at a T-junction connecting the first dimension (1D) and second dimension (2D) columns during the modulation period (PM), temporarily stopping the 1D flow. The valve is then closed for the duration of a pulse width (pw) to “re-inject” temporally focused 1D eluate onto the 2D column for separation. This flow modulation technique is observed to be compatible with TOFMS detection using a 2D flow rate of 4 ml/min for the separation of a 90-component test mixture. A 25 min separation window using a PM?=?1 s and pw?=?200 ms for full modulation (and 100% duty cycle) provided an average 1Wb?=?4.5 s and 2Wb?=?130 ms for a 2D peak capacity of nc,2D?=?2700 (100 peaks per min). The detector response enhancement factor (DREF) serves as a metric for the enhanced sensitivity of the modulated relative to the unmodulated 1D peaks, with DREFs ranging between 10 and 20 and about a 5-fold improvement in signal-to-noise ratio (S/N). The bilinear “quality” of the GC×GC data is studied using the chemometric method parallel factor analysis (PARAFAC). Since PARAFAC requires sufficiently trilinear data, the reproducibility of the 2D peak shape for a given analyte is confirmed using lack-of-fit (LOF) and percent variation (R2) metrics. The limit-of-detection (LOD) for the representative analyte hexadecane is determined using PARAFAC, providing an LOD of 0.7 ppb (± 0.03 ppb) for three replicates. Seven heavily overlapped analytes are also fully resolved by PARAFAC down to the part-per-million (ppm) concentration level, producing reproducible spectra with a majority of spectral match values (MV) over 800 (RSD ≤ 7.1%). This study provides promising results for DPGM as a flow modulation technique compatible with GC×GC-TOFMS, providing high sensitivity data suitable for chemometric analysis.Scott, A.C., Zubot, W., Davis, C.W., Brogly, J., 2020. Bioaccumulation potential of naphthenic acids and other ionizable dissolved organics in oil sands process water (OSPW) – a review. Science of The Total Environment 710, 134558. recovery via mining in Alberta’s Athabasca region generates large quantities of oil sands process water (OSPW). Aquatic toxicity of OSPW has been well-studied and the class of organic compounds referred to as naphthenic acids (NAs) are consistently implicated as the primary driver. Proposed lease closure options include treated produced waters in reclaimed landscapes such as pit lakes and wetlands. Consequently, it is crucial to understand the bioaccumulation potential of NAs and other OSPW dissolved organics in these environments. Early studies were focussed only on NAs due to analytical limitations, however, later studies investigated additional classes of dissolved organics in OSPW. Reported bioconcentration factors (BCFs) for NAs in fish and amphibians range from 0.24 to 53 L/kg wet-weight. Most quantitative assessments of NAs bioaccumulation potential evaluated commercial NAs mixtures as a surrogate for OSPW and used using single-ion monitoring for measuring NAs concentrations. The resulting BCF values are based on the NA isomers that conform to the formula, C13H22O2. More recently, an advanced analytical technique capable of determining the profile of different isomer classes in OSPW showed that NAs and other OSPW ionizable dissolved organics (OSPW-IDO) have low partitioning to simulated biological storage lipids, suggesting low bioaccumulation potential. Using the same analytical technique to assess in vivo fish exposures, a subsequent study reported a range of BCFs for OSPW NAs between 0.7 to 53 L/kg wet-weight and heteroatomic isomer classes containing S or N heteroatoms had BCFs between 0.6 to 28 L/kg wet-weight. Reported BCFs for all isomer classes of the OSPW-IDO fraction were less than the Canadian standard for bioaccumulative designation (i.e., BCF ≥5000).Semenova, E.M., Grouzdev, D.S., Tourova, T.P., Nazina, T.N., 2019. Physiology and genomic characteristics of Geotoga petraea, a bacterium isolated from a low-temperature petroleum reservoir (Russia). Microbiology 88, 662-670. of the order Thermotogales often occur in high-temperature oilfields. They possess a toga, a characteristic external sheath. Members of the genus Geotoga have been as yet isolated only from oilfields and are represented by three strains with unsequenced genomes. The information on the intraspecific phenotypic diversity is scarce. An enrichment growing anaerobically on oil was obtained from formation water of the Vostochno-Anzirskoe oilfield (Russia). High-throughput sequencing of the V3–V4 region of the 16S rRNA genes revealed the enrichment to contain members of the genera Tangfeifania (51% of the total number of sequences), Halanaerobium (36%), Arcobacter (10%), and Geotoga (3%). Strain HO-Geo1 isolated from this enrichment belonged to the known species Geotoga petraea (99.2% similarity of the 16S rRNA gene sequences). The cells were motile rods surrounded by sheaths. They grew anaerobically, fermented carbohydrates and proteins producing acetate, H2, and СО2, and reduced thiosulfate and elemental sulfur to sulfide. In pure culture the strain did not grow on oil. Growth occurred within broad ranges of temperature (24–55°C, optimum at 47–50°C) and salinity (0.2–140 g/L, optimum at 20–40 g/L), which was in agreement with conditions of the low-temperature oilfield with highly mineralized formation water. The genome of strain HO-Geo1 (~2.15 Mb) contained 2057 genes, most of which were involved in protein, amino acid, and carbohydrate metabolism. High salt-tolerance of strain HO-Geo1 depended on the genes of adaptation to hyperosmotic stress. H2 formation was determined by the presence of the genes encoding all four subunits of NADP-dependent dehydrogenase. In oilfields, members of the genus Geotoga probably utilize microbial biomass and the products of oil biodegradation formed by other microorganisms. They may be involved in corrosion of metal oilfield equipment.?en, ?., Kozlu, H., 2020. Impact of maturity on producible shale oil volumes in the Silurian (Llandovery) hot shales of the northern Arabian plate, southeastern Turkey. American Association of Petroleum Geologists Bulletin 104, 507-524. Silurian (Llandovery) hot shales in southeastern Turkey have excellent source rock potential, with an average total organic carbon (TOC) of 5.9 wt. % and generation potential values of 14.9 mg HC/g TOC. The hot shales contain type II organic matter and demonstrate oil and secondary gas generation potential. Hydrogen indices range from 36 to 510 mg HC/g TOC, depending on maturity. The hot shales in the Gulf Kevan 1 and Turkish Petroleum (TP) Do&gbreve;an 1 wells are immature–early mature with a vitrinite reflectance equivalent (Requ) of 0.58%–0.76%. The hot shales in the TP So&gbreve;uktepe 1 and TP K. Migo 2 wells are mature and in the oil window at 0.78%–0.92% Requ. The hot shales are interpreted to be in the wet gas–condensate maturity window with 1.08%–1.30% Requ in the TP G. Hazro 2 and TP-Arco Abdülaziz 1 wells. Corrected (evaporation loss restored using oil API gravity values) oil saturation index values (OSIc) within the Gulf Kevan 1, TP Do&gbreve;an 1, and TP-Arco Abdülaziz 1 wells are less than 100 mg HC/g TOC, which indicates that unconventional commercial oil production is not probable. The OSIc values of the mature hot shales at the TP So&gbreve;uktepe 1, TP K. Migo 2, and TP G. Hazro 2 wells all exceed 100 mg HC/g TOC, indicating potentially producible oil and wet gas condensate. Thus, producible oil and wet gas condensate in the hot shale play appear present in areas that have been assessed as having between 0.8% and 1.1% Requ.Sepp Neves, A.A., Pinardi, N., Navarra, A., Trotta, F., 2020. A general methodology for beached oil spill hazard mapping. Frontiers in Marine Science 7, 65. doi: 10.3389/fmars.2020.00065. current lack of a standardized approach to compute the coastal oil spill hazard due to maritime traffic accidental releases has hindered an accurate estimate of its global impact, which is paramount to manage and intercompare the associated risks. We propose here a hazard estimation approach that is based on ensemble simulations and the extraction of the relevant distributions. We demonstrate that both open ocean and beached oil concentration distributions fit a Weibull curve, a two-parameter fat-tail probability distribution function. The simulation experiments are carried out in three different areas of the northern Atlantic. An indicator that quantify the coastal oil spill hazard is proposed and applied to the study areas.Service, R.F., 2020. Electricity turns garbage into high-quality graphene. Science 367, 496. wonder material could soon become a bulk commodity. Researchers at Rice University report in Nature this week that they can zap virtually any source of solid carbon, from food scraps to car tires, and turn it into graphene—sheets of carbon atoms prized for use in high-strength plastic and flexible electronics. Current techniques yield tiny amounts of picture-perfect graphene or up to tons of less-prized graphene chunks; the new method already produces grams per day of near-pristine graphene in the lab, and researchers are now scaling it up to kilograms per day.“This work is pioneering from a scientific and practical standpoint,” says Ray Baughman, a chemist at the University of Texas, Dallas, as it promises graphene cheap enough to strengthen asphalt or paint. “I wish I had thought of it.” Already the Rice team has founded a company, Universal Matter, to commercialize the waste-to-graphene process.With atom-thin sheets of carbon atoms arranged like chicken wire, graphene is stronger than steel, conducts electricity and heat better than copper, and can serve as an impermeable barrier. But since its 2004 discovery, high-quality graphene—in single sheets or a few stacked layers—has remained expensive to make and purify on an industrial scale. That's not a problem for making diminutive devices such as transistors and light-emitting diodes. But current techniques, which make graphene by depositing it from a vapor, are too costly for high-volume applications. And higher throughput approaches, such as peeling graphene from chunks of graphite, produce flecks composed of up to 50 graphene layers that are not ideal for most applications.In 2014, James Tour, a chemist at Rice, and his colleagues found they could make a more pure form of graphene—each piece just a few layers thick—by zapping a form of amorphous carbon called carbon black with a laser. Brief pulses heated the carbon to more than 3000 kelvins, snapping the bonds between carbon atoms. As the carbon cooled, it coalesced into graphene. But the approach used a lot of energy to make tiny quantities.Then, Luong Xuan Duy, one of Tour's graduate students, read that other researchers had created metal nanoparticles by zapping a material with electricity, creating the same brief blast of heat as the laser. So Duy put a dash of carbon black in a glass vial and zapped it with 400 volts for up to 200 milliseconds. Initially he got junk. But after tweaks, he saw a yellowish white flash, indicating the temperature in the vial was about 3000 kelvins. Chemical tests revealed he had produced graphene.It was a type of graphene ideal for bulk uses: “turbostatic” graphene, with its layers at all angles atop one another. “That's a good thing,” Duy says. In water or other solvents, turbostatic graphene remains suspended instead of clumping, allowing each fleck to interact with the composite it's added to.“This will make it a very good material for applications,” says Monica Craciun, a materials physicist at the University of Exeter. In 2018, she and her colleagues reported that adding graphene to concrete more than doubled its compressive strength. Tour's team saw much the same result. When it added just 0.05% by weight of flash-produced graphene to concrete, the compressive strength rose 25%; graphene added to polydimethylsiloxane, a common plastic, boosted its strength by 250%. Other research suggests it can improve the durability of asphalt and paint.These applications would require high-quality graphene by the ton. Fortunately, the starting point for flash graphene could hardly be cheaper or more abundant: Virtually any organic matter, including coffee grounds, food scraps, old tires, and plastic bottles, can be vaporized to make the material. “We're turning garbage into graphene,” Duy says.Service, R.F., 2020. In ‘living materials,’ microbes are makers. Science 367, 841. bricks in Wil Srubar's lab at the University of Colorado, Boulder, aren't just alive, they're reproducing. They are churned out by bacteria that convert sand, nutrients, and other feedstocks into a form of biocement, much the way corals synthesize reefs. Split one brick, and in a matter of hours you will have two.Engineered living materials (ELM) are designed to blur boundaries. They use cells, mostly microbes, to build inert structural substances such as hardened cement or woodlike replacements for everything from construction materials to furniture. Some, like Srubar's bricks, even incorporate living cells into the final mix. The result is materials with striking new capabilities, as the innovations on view last week at the Living Materials 2020 conference in Saarbrüken, Germany, showed: airport runways that build themselves and living bandages that grow within the body. “Cells are amazing fabrication plants,” says Neel Joshi, an ELM expert at Northeastern University. “We're trying to use them to construct things we want.”Humanity has long harvested chemicals from microbes, such as alcohol and medicines. But ELM researchers are enlisting microbes to build things. Take bricks, normally made from clay, sand, lime, and water, which are mixed, molded, and fired to more than 1000°C. That takes lots of energy and generates hundreds of millions of tons of carbon emissions annually. A Raleigh, North Carolina, company called bioMASON was among the first to explore using bacteria instead of heat, relying on the microbes to convert nutrients into calcium carbonate, which hardens sand into a sturdy construction material at room temperature.Now, several groups are taking the idea further. “Could you grow a temporary runway somewhere by seeding bacteria in sand and gelatin?” asks Sarah Glaven, a microbiologist and ELM expert at the U.S. Naval Research Laboratory. In June 2019, researchers at Wright-Patterson Air Force Base in Ohio did just that to create a 232-square-meter runway prototype. The hope, says Blake Bextine, who runs an ELM program for the U.S. Defense Advanced Research Projects Agency, is that rather than ferrying tons of materials to set up expeditionary air fields, military engineers could simply use local sand, gravel, and water, and apply a few drums of cementmaking bacteria to create new runways in days.The bricks and runway cement don't retain living cells in the final structure. But Srubar's team is taking that next step. In their self-reproducing bricks, researchers mix a nutrient-based gel with sand and inoculate it with bacteria that form calcium carbonate. They then control the temperature and humidity to keep the bacteria viable. The researchers could split their original brick in half, add extra sand, hydro-gel, and nutrients, and watch as bacteria grew two full-size bricks in 6 hours. After three generations, they wound up with eight bricks, they reported in the 15 January issue of Matter. (Once the bacteria are done growing new bricks, the team can turn off the temperature and humidity controls.) Srubar calls it “exponential material manufacturing.”ELM makers are also harnessing microbes to make biomaterials for use in the human body. Microbes naturally exude proteins that bind to one another to form a physical scaffold. More bacteria can adhere to it, forming communal microbial mats known as biofilms, found on surfaces from teeth to ship hulls. Joshi's team is developing biofilms that could protect the gut lining, which erodes in people with inflammatory bowel disease, creating painful ulcers. In the 6 December 2019 issue of Nature Communications, they report that an engineered Escherichia coli in the guts of mice produced proteins that formed a protective matrix, which shielded the tissue from chemicals that normally induce ulcers. If the approach works in people, physicians could inoculate patients with an engineered form of a microbe that normally makes its home in the gut.In another medical use, bacteria could turn conventional materials into drug factories. In the 2 December 2019 issue of Nature Chemical Biology, for example, Christopher Voigt of the Massachusetts Institute of Technology and his colleagues describe seeding a plastic with bacterial spores that continuously generate bacteria. The microbes synthesize an antibacterial compound effective against Staphylococcus aureus, a dangerous infectious bacterium.A team of researchers led by Chao Zhong of ShanghaiTech University engineered biofilms for a different purpose: detoxifying the environment. They started with the bacterium Bacillus subtilis, which secretes a matrix-forming protein called TasA. Other researchers had shown that TasA was easy to genetically engineer to bind to other proteins. The team tweaked TasA to get it to bind an enzyme that degrades a toxic industrial compound called mono (2-hydroxyethyl terephthalic acid), or MHET. The researchers then showed that biofilms created by the engineered bacterium could break down MHET—and that biofilms made by a mix of two engineered strains of B. subtilis could carry out a two-step degradation of an organophosphate pesticide called paraoxon. The results, which the team reported in the January 2019 issue of Nature Chemical Biology, raise the prospect of living walls that purify the air.Regulatory issues could slow progress, however. Many of the bacteria that ELM researchers have harnessed occur in nature and should not trigger regulatory scrutiny. But genetically engineered organisms will—and the prospect of engineered microbes embedded in, say, living walls might unsettle regulators. Still, Voigt predicts, “I think in 10 years, we're going to find living cells in a whole range of living products.”Seuylemezian, A., Ott, L., Wolf, S., Fragante, J., Yip, O., Pukall, R., Schumann, P., Vaishampayan, P., 2020. Bacillus glennii sp. nov. and Bacillus saganii sp. nov., isolated from the vehicle assembly building at Kennedy Space Center where the Viking spacecraft were assembled. International Journal of Systematic and Evolutionary Microbiology 70, 71-76. Gram-stain-positive, motile, endospore-forming, aerobic strains, designated V44-8T and V47-23aT, were isolated from environmental air sampling at the vehicle assembly building at Cape Canaveral, Florida, where the Viking spacecraft were assembled. Growth was observed at pH 7–9 (optimum, pH 9) for strain V44-8T, and pH 5–10 (pH 9) for strain V47-23aT. Both strains displayed growth in 0–5?%?NaCl with an optimum at 1?% for strain V44-8T; 0?% for strain V47-23aT. Strains V44-8T and V47-23aT grew optimally at 32 °C, (15–32 °C) and 25 °C (20–45 °C), respectively. The cell wall of both strains contained meso-diaminopimelic acid as the diagnostic diamino acid. Both strains contained phosphatidylglycerol, phosphatidylethanolamine and diphosphatidylglycerol. The predominant cellular fatty acids were anteiso-C15?:?0, iso-C14?:?0 and iso-C15?:?0. Strain V47.23aT shared its highest 16S rRNA sequence similarity with Bacillus cavernae DSM-105484T at 96.9%, and V44.8T with Bacillus zeae DSM-103964T at 96.6?%. Based on their phenotypic characteristics and phylogenetic position inferred from 16S rRNA gene sequence analyses, the isolates were identified as being a members of the genus Bacillus that forms a separate clade when compared to close relatives. Average nucleotide identity and average amino acid identity values between strains V44-8T and DSM-103964T were 72.1% and 67.5?%; V47-23aT and DSM-105484T were 62.4% and 69.1%, respectively. Based on the phenotypic, genomic and biochemical data, strains V44-8T and V47-23aT represent two novel species in the genus Bacillus for which the names Bacillus glennii sp. nov. [type strain, V44-8T (=ATCC BAA-2860T =DSM 105192T)], and Bacillus saganii sp. nov. [V47-23aT (=ATCC BAA-2861T=DSM 105190T)] are proposed.Shabbir, S., Faheem, M., Ali, N., Kerr, P.G., Wang, L.-F., Kuppusamy, S., Li, Y., 2020. Periphytic biofilm: An innovative approach for biodegradation of microplastics. Science of The Total Environment 717, 137064. (MPs) have been gaining the attention of environmental researchers since the 1960s anecdotal reports of plastic entanglement and ingestion by marine creatures. Due to their increasing accretion in aquatic environments, as well as resistance towards degradation, marine litter research has focused on microplastics more recently. In the present study, a relatively new method of biodegradation was implemented for the biodegradation of three structurally different MPs i.e. polypropylene (PP), polyethylene (PE) and polyethylene terephthalate (PET). Periphytic biofilm was used for this purpose in various backgrounds of carbon sources (glucose, peptone, and glucose and peptone). Biodegradation of MPs was estimated in terms of weight loss. It was observed that the addition of glucose enhanced the biodegradation of MPs by periphyton biofilm for all MPs (from 9.52%–18.02%, 5.95%–14.02% and 13.24–19.72% for PP, PE and PET respectively) after 60 days compared to natural biofilm alone. To the contrary, peptone, and glucose and peptone together, were inhibitory. Biodegradation was further confirmed by morphological changes observed using SEM, FTIR spectra and GPC lent further support to the results whereby new peaks appeared along with reduction in old peaks and decrease in peak intensities. MiSeq sequencing shows that Deinococcus-thermus > Proteobacteria > Cyanobacteria are the dominant phyla in natural biofilms, and their relative abundances increase after the addition of glucose. However, the abundances shifted to Deinococcus-thermus > Cyanobacteria > Firmicutes > Bacteroidetes, when the biofilms were treated with either peptone alone, or with glucose and peptone together. Therefore, the change in biodegradation capability might also be due to the change in the microbial community structures after addition of the C-sources. These experiments provide an innovative approach towards effective biodegradation of MPs using a relatively new environment-friendly method.Shaik, I.K., Song, J., Biswal, S.L., Hirasaki, G.J., Bikkina, P.K., Aichele, C.P., 2020. Effect of brine type and ionic strength on the wettability alteration of naphthenic-acid-adsorbed calcite surfaces. Journal of Petroleum Science and Engineering 185, 106567. waterflooding is a technique, used in oil reservoirs, where the salinity and/or ionic composition of the injection water is tuned to improve oil recovery. It has been observed by many researchers that low-salinity waterflooding can enhance oil recovery by altering the wettability of carbonate rock surfaces from oil-wet to water-wet. Though wettability alteration is generally agreed to be the main mechanism for the improved oil recovery, the contributing parameters and necessary conditions for wettability alteration are not clearly understood. Hence, it is essential to decouple the effects of salinity, ionic composition, and oil composition on wettability alteration of the solid surface. In this work, we systematically investigated smart-water induced wettability alteration of naphthenic-acid-adsorbed oil-wet calcite surfaces. Well-characterized model systems were used to understand the effects of individual monovalent and divalent ions (Na+, Cl?, Mg2+ and SO42?), and salinity on the calcite surface wettability. Contact angle measurements were performed on smooth Iceland Spar calcite surfaces that were aged at 120?°C in 5M NaCl brine, acid number 1.5 model oil, and single-electrolyte-based brine solutions of different salinity and ionic composition. The extent of wettability alteration was assessed based on ACA values, which are more relevant during waterflooding, using a goniometer customized for obtaining multiple advancing and receding contact angles along the surface by the tilting plate method. The results indicate that, for 0.164?M ionic strength (equivalent to 4-times diluted seawater concentration) brine solutions, the wettability of calcite surfaces was changed from oil-wet state to water-wet state irrespective of the salt type. The lowest advancing contact angle (ACA) values (20°–30° range) were obtained for 0.164?M ionic strength NaCl and Na2SO4 solutions, indicating the presence of SO42? ions or reduction in NaCl concentration act in favor of wettability alteration towards water-wet. At this ionic strength, the relative merit of divalent SO42? ions over monovalent Cl? ions was not observed. Upon comparison of ACA values for 0.164?M ionic strength Na2SO4 and MgSO4 (SO42? ion is common) solutions, we concluded that the extent of wettability alteration is lower in the presence of Mg2+ ions. A similar conclusion was made by comparing ACA values for 0.164?M ionic strength NaCl and MgCl2 solutions (Cl? ion is common). The calcite surfaces aged in 0.656?M (equivalent to seawater concentration) NaCl solution demonstrated intermediate-wet state indicating the extent of wettability alteration towards water-wet state increases with a decrease in salinity.Shakerian, M., Afrough, A., Vashaee, S., Marica, F., Zhao, Y., Zhao, J., Song, Y., Balcom, B.J., 2020. Direct measurement of pore gas pressure and water/gas phase transitions during methane hydrate dissociation. Marine and Petroleum Geology 116, 104296. hydrate deposits worldwide are vast potential sources of natural gas. Although field tests, and many laboratory studies, of hydrate dissociation have been performed, long term gas recovery from hydrate deposits still requires a comprehensive knowledge of the pore gas pressure and related phenomena. Pore gas pressure can significantly affect the safety and efficiency of gas production from hydrate deposits. Capillary-trapped residual gas saturation, known to cause elevated pore gas pressure during methane hydrate dissociation, was measured by magnetic resonance. Elevated pore gas pressure was estimated to be 8500 psi. Different molecular species and fluid environments produced during the methane hydrate dissociation process were discriminated. The results show that the majority of gas is initially confined as capillary-trapped gas upon dissociation. The evolution of water and gas saturations was measured as a function of time. Water migration, bed failure, and crack growth, related to elevated pore gas pressure, were observed both spatially and temporally resolved. Hydrate dissociation proceeded from the sand pack exterior to the interior, in a shrinking core manner, due to heat transfer effects. It was observed that hydrate dissociation resulted in pronounced water migration toward the low-pressure surface.This study was undertaken with advanced magnetic resonance imaging (MRI) and magnetic resonance (MR) methods employing a MR/MRI-compatible metallic core holder. A hydrate-bearing sand pack, with 96% initial hydrate saturation, underwent dissociation by depressurization at 290 psi and 4 °C.Shan, C., Zhao, W., Wang, F., Zhang, K., Feng, Z., Guo, L., Ma, X., Liao, T., 2020. Nanoscale pore structure heterogeneity and its quantitative characterization in Chang7 lacustrine shale of the southeastern Ordos Basin, China. Journal of Petroleum Science and Engineering 187, 106754. gain a better understanding of nanoscale pore structure characteristics in Chang7 lacustrine shale, Ordos Basin, China, 33 shale samples from 15 wells are examined and analyzed by total organic carbon (TOC), X-ray diffraction (XRD), mercury porosimetry, helium pycnometry, low-pressure N2 adsorption experiments and fractal method. The results show that Chang7 lacustrine shale pores diameter is mainly from 1.5 to 5 nm, and mesopores give the largest contribution to the total pore specific surface area (SBET) and volume (VBJH), and micropores have the second contribution to SBET but little contribution to VBJH, macropores have very little contribution to SBET but make a good contribution to VBJH. According to the occurrence and origin of shale pores, micro-pores can be divided into mineral intragranular pore, minera intercrystalline pore and organic pore. Two fractal dimensions (D1 and D2) are obtained from N2 adsorption isotherms analysis using FHH method. Relationships between fractal dimensions and shale compositions, pore structure parameters are investigated, which show that both D1 and D2 have good positive relationships with SBET and VBJH, but obvious negative correlations with the average pore diameter. That is, the smaller the pore diameter, the more complex the pore structure is, resulting in the larger pore surface and volume. D1 and D2 are both positively correlated with total clay, illite, mixed-layer of illite-smectite, whereas no obvious relationships with chlorite, indicating that the layer and flocculent structure increase the complexity of nanoscale pore structure. TOC content has positive correlation with D1 but no obvious relationship with D2, indicating that the pores in organic matter are mostly micropores. Fractal dimensions are negatively correlated with total brittle mineral, quartz and feldspar content, that is because the surface of brittle minerals is smoother and more homogenous than that of clay minerals.Shang, F., Zhu, Y., Gao, H., Wang, Y., Liu, R., 2020. Relationship between tectonism and composition and pore characteristics of shale reservoirs. Geofluids 2020, 9426586. is one of the major controlling factors of shale gas accumulation and enrichment in China. To explore the relationship between tectonism and composition and pore characteristics of shale reservoirs, this research carried out mineralogy tests, organic geochemistry tests, field emission scanning electron microscopy (FE-SEM) experiments, and low-pressure gas adsorption (LPGA, N2 and CO2) experiments on the shale samples of various deformation intensities from Southwestern China. Based on the FE-SEM image analyses, it can be found that there are large differences in pore characteristics in shale samples with different deformation intensities. The samples with strong deformation have more organic pores, mainly related to the clay-organic aggregates and rigid grains. Tectonism can cause organic matter (OM) and clay minerals to be mixed or OM to fill in the clay layers, resulting in the retention of some organic pores. It is the presence of pressure shadows around the rigid grains that can resist tectonic extrusion and protect some organic pores. LPGA experiment results also show that micropore-specific surface areas and pore volumes of the samples with strong deformation are larger than those with weak deformation. The shale samples with strong deformation also have more microchannels and microfractures. Tectonism can also cause some micropores to become macropores; for example, tectonism can cause the rigid grains to slide and rotate, enlarging the dissolution pores at the edges of rigid grains. Shale samples with strong deformation have a smaller mesopore volume; but due to the presence of organic-clay aggregates, a larger mesopore-specific surface area embarks on these samples. According to fractal dimension calculations, it is found that in strong deformed shale, more multiple dimensions of the pore system tend to represent rougher pore surfaces and more irregular shapes. Besides, rougher pore surfaces are eager to provide more adsorption sites and enhance the adsorption capacity of the deformed shale. This study investigates the relationship between tectonism and composition and pore characteristics of shale reservoirs and may promote understanding of the accumulation of shale gas in highly deformed areas.Shawar, L., Said-Ahmad, W., Ellis, G.S., Amrani, A., 2020. Sulfur isotope composition of individual compounds in immature organic-rich rocks and possible geochemical implications. Geochimica et Cosmochimica Acta 274, 20-44. applied compound-specific sulfur isotope analysis (CSSIA) to organic matter (OM) extracted from ancient and immature organic-rich rocks from the Cretaceous Ghareb (Shefela Basin locality, Israel) and Miocene Monterey (Naples Beach locality, California, USA) Formations. Large variations in the δ34S values of different organosulfur compounds (OSCs), that reach up to 28‰ and 36‰, were observed in the Ghareb and Monterey samples, respectively. Additionally, some common OSCs in both locations showed consistent 34S trends relative to each other. The consistent enrichment in 34S of C35 hopane thiophene relative to iC20 thiophene in the studied sections probably resulted from differences in the timing of OM sulfurization. Reactive organic precursors quickly consume the most 34S-depleted reduced S, while less reactive species incorporate the heavier residual S at a later time. Despite the differences in the depositional environments, ages, and the initial δ34S values of the reduced S (represented by the δ34S of pyrite) between the Ghareb and the Monterey Formations, the sulfurization order of common organic compounds seems to be similar. All of the δ34S values of OSCs are 34S enriched relative to that of the coexisting pyrite with the exception of the C25 highly branched isoprenoid (HBI) thiophene in several samples from the Monterey Formation. The existence of 34S-depleted sulfurized HBI may point to OM sulfurization that occurred at or near the sediment-water interface during the deposition of the Monterey. Moreover, the δ34S of steroid sulfides shows an inverse trend with the pristane/phytane ratio, which may indicate that the sulfurization mechanism of these OSCs are affected by redox conditions. Further investigation of CSSI values in immature rocks from other basins may help constrain the OM sulfurization process, timescale, and depositional conditions and their possible use as paleoenvironmental proxies.Shemin, G.G., Vernikovsky, V.A., Smirnov, M.Y., Vakhromeev, A.G., Filimonova, V., Moiseev, S.A., Migurskii, A.V., 2019. Tectonic, lithofacies, and geochemical formation conditions and quantitative estimation of the petroleum potential of the giant Erema-Chona oil and gas pool (Siberian Platform). Russian Geology and Geophysics 60, doi: 10.15372/RGG2019120. present results of research into the tectonic, lithofacies, and geochemical formation conditions of the Erema-Chona oil and gas pool. We characterize present-day structures and their formation history, consider the composition, structure, formation conditions, postdepositional alterations, and porosity-permeability properties of the Osa, Ust’-Kut, Preobrazhenka, Erbogachen, and Upper Chona Horizons, assess the quality of the overlying seals, and describe the technique and results of quantitative estimation of the petroleum potential of seals. Modern technologies for the development of oil reserves are also presented, along with geological and economic assessment of hydrocarbon resources of the study object.Shen, Y., Thiel, V., Suarez-Gonzalez, P., Rampen, S.W., Reitner, J., 2020. Sterol preservation in hypersaline microbial mats. Biogeosciences 17, 649-666. mats are self-sustaining benthic ecosystems composed of highly diverse microbial communities. It has been proposed that microbial mats were widespread in Proterozoic marine environments, prior to the emergence of bioturbating organisms at the Precambrian–Cambrian transition. One characteristic feature of Precambrian biomarker records is that steranes are typically absent or occur in very low concentrations. This has been explained by low eukaryotic source inputs, or degradation of primary produced sterols in benthic microbial mats (“mat-seal effect”). To better understand the preservational pathways of sterols in microbial mats, we analyzed freely extractable and carbonate-bound lipid fractions as well as decalcified extraction residues in different layers of a recent calcifying mat (～1500 years) from the hypersaline Lake 2 on the island of Kiritimati, central Pacific. A variety of C27–C29 sterols and distinctive C31 4α-methylsterols (4α-methylgorgosterol and 4α-methylgorgostanol, biomarkers for dinoflagellates) were detected in freely extractable and carbonate-bound lipid pools. These sterols most likely originated from organisms living in the water column and the upper mat layers. This autochthonous biomass experienced progressive microbial transformation and degradation in the microbial mat, as reflected by a significant drop in total sterol concentrations, up to 98?%, in the deeper layers, and a concomitant decrease in total organic carbon. Carbonate-bound sterols were generally low in abundance compared to the freely extractable portion, suggesting that incorporation into the mineral matrix does not play a major role in the preservation of eukaryotic sterols in this mat. Likewise, pyrolysis of extraction residues suggested that sequestration of steroid carbon skeletons into insoluble organic matter was low compared to hopanoids. Taken together, our findings argue for a major mat-seal effect affecting the distribution and preservation of steroids in the mat studied. This result markedly differs from recent findings made for another microbial mat growing in the nearby hypersaline Lake 22 on the same island, where sterols showed no systematic decrease with depth. The observed discrepancies in the taphonomic pathways of sterols in microbial mats from Kiritimati may be linked to multiple biotic and abiotic factors including salinity and periods of subaerial exposure, implying that caution has to be exercised in the interpretation of sterol distributions in modern and ancient microbial mat settings.Sheng, Q., Wang, G., Jin, N., Husein, M.M., Gao, J., 2020. Hydroconversion of asphaltene in a hydrogen donor solvent: Stability analysis of the asphaltene-solvent colloidal system. Fuel 267, 117086. aggregation and precipitation out of the reaction mixture limits the extent of its hydroconversion. In this work, the colloidal stability of asphaltenes undergoing hydroconversion in tetralin solvent was monitored with time. The separability number was measured and the Gibbs energy of mixing together with the onset of asphaltene precipitation were calculated. The results show that the hydrogen transfer from tetralin to asphaltene radicals effectively quench the radicals. The colloidal stability of the system, nevertheless, decreased with reaction time and vanished for reaction times >3?h. In line with this observation, the onset of asphaltene precipitation decreased and, while the Gibbs energy of mixing was negative, it increased with time. The colloidal stability of the reaction system was chiefly influenced by the increased aromaticity of the asphaltene, which in turn decreased its solubility parameter. Within the stable colloidal domain, approximately 44% of the asphaltenes were converted with <1?wt% coke generation. This work is the first attempt in the literature to analytically and mathematically characterize the colloidal stability of asphaltenes undergoing reactions in a hydrogen donor solvent.Shi, Y., Xu, L., Xing, L., Wang, J., 2020. Geochemical characteristics of crude oil in the continental saline lake basin: a case study of the Upper Part of the Lower Ganchaigou Formation in Yingxi, Qaidam Basin, China. Petroleum Science and Technology 38, 232-239. crude oil in the Upper Part of the Lower Ganchaigou Formation in the Yingxi area of the Qaidam Basin, China, was formed in a strongly reducing and high-salinity sedimentary environment with algae as the main parental material. The crude oil in this area possesses the typical geochemical characteristics of saline lacustrine crude oil. The crude oil is mainly derived from source rocks of its own horizon, indicating that the reservoirs in the study area have self-generation and self-storage reservoir features.Shore, J.A., Holland, B.R., Sumner, J.G., Nieselt, K., Wills, P.R., 2020. The ancient operational code is embedded in the amino acid substitution matrix and aaRS phylogenies. Journal of Molecular Evolution 88, 136-150. underlying structure of the canonical amino acid substitution matrix (aaSM) is examined by considering stepwise improvements in the differential recognition of amino acids according to their chemical properties during the branching history of the two aminoacyl-tRNA synthetase (aaRS) superfamilies. The evolutionary expansion of the genetic code is described by a simple parameterization of the aaSM, in which (i) the number of distinguishable amino acid types, (ii) the matrix dimension and (iii) the number of parameters, each increases by one for each bifurcation in an aaRS phylogeny. Parameterized matrices corresponding to trees in which the size of an amino acid sidechain is the only discernible property behind its categorization as a substrate, exclusively for a Class I or II aaRS, provide a significantly better fit to empirically determined aaSM than trees with random bifurcation patterns. A second split between polar and nonpolar amino acids in each Class effects a vastly greater further improvement. The earliest Class-separated epochs in the phylogenies of the aaRS reflect these enzymes’ capability to distinguish tRNAs through the recognition of acceptor stem identity elements via the minor (Class I) and major (Class II) helical grooves, which is how the ancient operational code functioned. The advent of tRNA recognition using the anticodon loop supports the evolution of the optimal map of amino acid chemistry found in the later genetic code, an essentially digital categorization, in which polarity is the major functional property, compensating for the unrefined, haphazard differentiation of amino acids achieved by the operational code.Siddique, T., Semple, K., Li, C., Foght, J.M., 2020. Methanogenic biodegradation of iso-alkanes and cycloalkanes during long-term incubation with oil sands tailings. Environmental Pollution 258, 113768. indigenous to oil sands tailings ponds methanogenically biodegrade certain hydrocarbons, including n-alkanes and monoaromatics, whereas other hydrocarbons such as iso- and cycloalkanes are more recalcitrant. We tested the susceptibility of iso- and cycloalkanes to methanogenic biodegradation by incubating them with mature fine tailings (MFT) collected from two depths (6 and 31 m below surface) of a tailings pond, representing different lengths of exposure to hydrocarbons. A mixture of five iso-alkanes and three cycloalkanes was incubated with MFT for 1700 d. Iso-alkanes were completely biodegraded in the order 3-methylhexane > 4-methylheptane > 2-methyloctane > 2-methylheptane, whereas 3-ethylhexane and ethylcyclopentane were only partially depleted and methylcyclohexane and ethylcyclohexane were not degraded during incubation. Pyrosequencing of 16S rRNA genes showed enrichment of Peptococcaceae (Desulfotomaculum) and Smithella in amended cultures with acetoclastic (Methanosaeta) and hydrogenotrophic methanogens (Methanoregula and Methanoculleus). Bioaugmentation of MFT by inoculation with MFT-derived enrichment cultures reduced the lag phase before onset of iso-alkane and cycloalkane degradation. However, the same enrichment culture incubated without MFT exhibited slower biodegradation kinetics and less CH4 production, implying that the MFT solid phase (clay minerals) enhanced methanogenesis. These results help explain and predict continued emissions of CH4 from oil sands tailings repositories in situ.Sierra-Garcia, I.N., Belgini, D.R.B., Torres-Ballesteros, A., Paez-Espino, D., Capilla, R., Santos Neto, E.V., Gray, N., de Oliveira, V.M., 2020. In depth metagenomic analysis in contrasting oil wells reveals syntrophic bacterial and archaeal associations for oil biodegradation in petroleum reservoirs. Science of The Total Environment 715, 136646. biodegradation of hydrocarbons in petroleum reservoirs has major consequences in the petroleum value and quality. The identification of microorganisms capable of in-situ degradation of hydrocarbons under the reservoir conditions is crucial to understand microbial roles in hydrocarbon transformation and the impact of oil exploration and production on energy resources. The aim of this study was to profile the metagenome of microbial communities in crude oils and associated formation water from two high temperature and relatively saline oil-production wells, where one has been subjected to water flooding (BA-2) and the other one is considered pristine (BA-1). The microbiome was studied in the fluids using shotgun metagenome sequencing. Distinct microbial compositions were revealed when comparing pristine and water flooded oil wells in contrast to the similar community structures observed between the aqueous and oil fluids from the same well (BA-2). The equal proportion of archaea and bacteria together with the greater anaerobic hydrocarbon degradation potential in the BA-1 pristine but degraded reservoir contrasted with the predominance of bacteria over archaea, aerobic pathways and lower frequency of anaerobic degradation genes in the BA-2 water flooded undegraded well. Our results suggest that Syntrophus, Syntrophomonas, candidatus Atribacteria and Synergistia, in association with mainly acetoclastic methanogenic archaea of the genus Methanothrix, were collectively responsible for the oil biodegradation observed in the pristine petroleum well BA-1. Conversely, the microbial composition of the water flooded oil well BA-2 was mainly dominated by the fast-growing and putatively aerobic opportunists Marinobacter and Marinobacterium. This presumable allochthonous community introduced a greater metabolic versatility, although oil biodegradation has not been detected hitherto perhaps due to in-reservoir unfavorable physicochemical conditions. These findings provide a better understanding of the petroleum reservoir microbiomes and their potential roles in biogeochemical processes occurring in environments with different geological and oil recovery histories.Skoumal, R.J., Barbour, A.J., Brudzinski, M.R., Langenkamp, T., Kaven, J.O., 2020. Induced seismicity in the Delaware Basin, Texas. Journal of Geophysical Research: Solid Earth 125, e2019JB018558. seismicity rate in the Delaware Basin, located in western Texas and southeastern New Mexico, has increased by orders of magnitude within the past ~5 years. While no seismicity was reported in the southern Delaware Basin during 1980–2014, 37 earthquakes with M > 3 occurred in this area during 2015–2018. We generated an improved catalog of ~37,000 earthquakes in this region during 2009–2018 by applying multistation template matching at both regional and local stations using all earthquakes in the Advanced National Seismic System (ANSS) and TexNet catalogs. We found that the vast majority of the seismicity is most likely associated with wastewater disposal, while at least ~5% of the seismicity was induced directly by hydraulic fracturing. We inferred far‐field effects of wastewater disposal inducing earthquakes over distances >25 km. The spatial limits of seismicity correlate with geologic structures that include the Central Platform and Grisham Fault, suggesting hydrologic compartmentalization by low‐permeability boundaries. Given that the seismicity rate increased throughout the duration of the study, if industry operations continue unaltered, it is likely that both the seismicity rate and number of M > 3 earthquakes may continue to increase in the future.Skvortsov, M.B., Nemova, V.D., Dakhnova, M.V., Kopilevich, E.A., Surova, N.D., Kirsanov, A.M., Mozhegova, S.V., 2019. New methodological approaches to assessment of oil resources in the Bazhenov Formation sediments. Russian Geology and Geophysics 60, doi: 10.15372/RGG2019014. there is no verified methodology to calculate oil reserves in the Bazhenov Formation, which makes it impossible to identify any references for the initial oil reserves. Therefore, the analog approach that is usually applied for quantitative assessment of petroleum potential becomes inapplicable. The paper considers different approaches to assessment of the petroleum potential of the Bazhenov Formation in West Siberia. Since oil distribution in the formation is determined by the initial content and catagenetic maturity of organic matter in the rock and controls the formation of an effective reservoir, it becomes apparent that estimating the oil resources and reserves requires geochemical studies. The proposed methodological approaches consider separation of net oil pays using the Rock-Eval data, well log data, and results of oil-promising objects survey and the principles of differentiated assessment of oil resources and territory ranking by the compositions of saturating hydrocarbons.Slavchov, R.I., Salamanca, M., Russo, D., Salama, I., Mosbach, S., Clarke, S.M., Kraft, M., Lapkin, A.A., Filip, S.V., 2020. The role of NO2 and NO in the mechanism of hydrocarbon degradation leading to carbonaceous deposits in engines. Fuel 267, 117218. hypothetical mechanism of degradation of the fuel droplet leaking out from the injector nozzle in a direct injection combustion engine has been proposed recently. This involves as a key step a radical chain oxidation initiated by NO2 and branched by nitric oxide, NO, both produced by the combustion. The degradation causes the formation of injector nozzle carbonaceous deposits. The present work gives an experimental validation of some of the assumptions behind this model. An autoclave is used to oxidize isooctane under conditions relevant to the cylinder wall near the nozzle (~150 °C, 10 bar, 5% O2, 100 ppm of NO2 by mole and 500 ppm NO in the gas phase), and the degradation products are monitored via gas chromatography-mass spectrometry (GC–MS). The results show no observable fuel degradation in the absence of NOx. NO appears to be able to initiate a radical chain by producing NO2. Nitric oxide also alters the radical chain by transforming the alkyl peroxy radicals (ROO?) to more reactive alkoxy radicals (RO?), resulting in a range of different products. In addition, NO tends to terminate the radical chain by neutralizing a fraction of the alkyl peroxy radicals, producing alkyl nitrates as termination products. The existence of a radical chain is supported by demonstrating the antioxidative action of a radical scavenger. The chemical reaction mechanism is investigated, based on the detected products, and the key species involved in the degradation process are identified.Sluijs, A., Frieling, J., Inglis, G.N., Nierop, K.G.J., Peterse, F., Sangiorgi, F., Schouten, S., 2020. Late Paleocene-Early Eocene Arctic Ocean sea surface temperatures; reassessing biomarker paleothermometry at Lomonosov Ridge. Climate of the Past Discussions 2020, 1-52. Integrated Ocean Drilling Program Arctic Coring Expedition on Lomonosov Ridge, Arctic Ocean (IODP Expedition 302 in 2004) delivered the first Arctic Ocean sea surface temperature (SST) and land air temperature (LAT) records spanning the Paleocene-Eocene Thermal Maximum (PETM; ~56?Ma) to Eocene Thermal Maximum 2 (ETM2; ~54?Ma). The distribution of glycerol dialkyl glycerol tetraether (GDGT) lipids indicated elevated SST (ca. 23 to 27?°C) and LATs (ca. 17 to 25?°C). However, recent analytical developments have led to: (i) improved temperature calibrations and (ii) the discovery of new temperature-sensitive glycerol monoalkyl glycerol tetraethers (GMGTs). Here, we have analyzed GDGT and GMGT distributions in the same sediment samples using new analytical procedures, interpret the results following the currently available proxy constraints and assess the fidelity of new temperature estimates in our study site.The influence of several confounding factors on TEX86 SST estimates, such as variations in export depth and input from exogenous sources, are typically negligible. However, contributions of isoGDGTs from land, which we characterize in detail, complicate TEX86 paleothermometry in the late Paleocene and part of the interval between the PETM and ETM2. The isoGDGT distribution further supports temperature as the likely variable controlling TEX86 values and we conclude that background early Eocene SSTs generally exceeding 20 °C, with peak warmth during the PETM (~26?°C) and ETM2 (~27?°C). We also report high abundances of branched glycerol monoalkyl glycerol tetraethers throughout (branched GMGTs), most likely dominantly marine in origin, and show that their distribution is sensitive to environmental parameters. Further analytical, provenance and environmental work is required to test if and to what extent temperature may be an important factor.Published temperature constraints from branched GDGTs and terrestrial vegetation also support remarkable warmth in the study section and elsewhere in the Arctic basin, with vegetation proxies indicating coldest month mean temperatures of 6–13?°C. If TEX86-derived SSTs truly represent mean annual SSTs, the seasonal range of Arctic SST was in the order of 20?°C, higher than any open marine locality in the modern ocean. If SST estimates are skewed towards the summer season, seasonal ranges were comparable to those simulated in future ice-free Arctic Ocean scenarios. This uncertainty remains a fundamental issue, and one that limits our assessment of the performance of fully-coupled climate models under greenhouse conditions.Smith, D.F., Blakney, G.T., Beu, S.C., Anderson, L.C., Weisbrod, C.R., Hendrickson, C.L., 2020. Ultrahigh resolution ion isolation by stored waveform inverse Fourier transform 21 T Fourier transform ion cyclotron resonance mass spectrometry. Analytical Chemistry 92, 3213-3219. waveform inverse Fourier transform (SWIFT) is a versatile method to generate complex isolation/ejection waveforms for precursor isolation prior to tandem mass spectrometry experiments. Here, we report ultrahigh resolving power ion isolation by SWIFT on a 21 T Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. Individual histone proteoforms are isolated (0.6 m/z isolation window) with near 100% efficiency using a 52 ms SWIFT isolation, followed by in-cell fragmentation by ultraviolet photodissociation (UVPD). Ion isolation resolving power of 175?000 (m/Δm) is demonstrated by isolation of individual peaks at a spacing of 0.0034 Da at m/z 597 from a complex mixture of Canadian bitumen. An individual m/z ion, which corresponds to a single elemental composition, from a complex mixture is isolated and fragmented by infrared multiphoton dissociation (IRMPD). Theoretical and experimental considerations that limit achievable ion isolation resolving power are discussed.Snyder, G.T., Matsumoto, R., Suzuki, Y., Kouduka, M., Kakizaki, Y., Zhang, N., Tomaru, H., Sano, Y., Takahata, N., Tanaka, K., Bowden, S.A., Imajo, T., 2020. Evidence in the Japan Sea of microdolomite mineralization within gas hydrate microbiomes. Scientific Reports 10, 1876. the past 15 years, massive gas hydrate deposits have been studied extensively in Joetsu Basin, Japan Sea, where they are associated primarily with active gas chimney structures. Our research documents the discovery of spheroidal microdolomite aggregates found in association with other impurities inside of these massive gas hydrates. The microdolomites are often conjoined and show dark internal cores occasionally hosting saline fluid inclusions. Bacteroidetes sp. are concentrated on the inner rims of microdolomite grains, where they degrade complex petroleum-macromolecules present as an impurity within yellow methane hydrate. These oils show increasing biodegradation with depth which is consistent with the microbial activity of Bacteroidetes. Further investigation of these microdolomites and their contents can potentially yield insight into the dynamics and microbial ecology of other hydrate localities. If microdolomites are indeed found to be ubiquitous in both present and fossil hydrate settings, the materials preserved within may provide valuable insights into an unusual microhabitat which could have once fostered ancient life.Sokolowska, I., Mo, J., Rahimi Pirkolachahi, F., McVean, C., Meijer, L.A.T., Switzar, L., Balog, C., Lewis, M.J., Hu, P., 2020. Implementation of a high-resolution liquid chromatography–mass spectrometry method in quality control laboratories for release and stability testing of a commercial antibody product. Analytical Chemistry 92, 2369-2373. chromatography–mass spectrometry (LC–MS) has been widely used throughout biotherapeutic development. However, its implementation in GMP-compliant commercial quality control (QC) laboratories remains a challenge. In this publication, we describe the covalidation and implementation of an automated, high-throughput, and GMP compliant subunit LC–MS method for monitoring antibody oxidation for commercial product release and stability testing. To our knowledge, this is the first report describing the implementation of a high-resolution LC–MS method in commercial QC laboratories for product release and stability testing in the biopharmaceutical industry. This work paves the road for implementing additional LC–MS methods to modernize testing in commercial QC with more targeted control of product quality.Sola, M.C.R., Santos, A.G., Martinez, S.T., Nascimento, M.M., da Rocha, G.O., de Andrade, J.B., 2020. Occurrence of 3-nitrobenzanthrone and other powerful mutagenic polycyclic aromatic compounds in living organisms: polychaetes. Scientific Reports 10, 3465. this work we report the occurrence of powerful mutagenic 3-nitrobenzanthrone (3-NBA), in addition to 18 polycyclic aromatic hydrocarbons (PAHs), 6 oxygenated PAHs and 27 nitrated PAHs in polychaete worms. Benzanthrone (BA), another important mutagenic polycyclic aromatic compound (PAC) also was detected in the samples. Polychaete annelids have great ecological relevance, being widely distributed in different environmental conditions, from intertidal zones up to seven thousand feet deep areas. They are abundantly found in both contaminated and uncontaminated areas and, therefore, used as indicators of the pollution status of a given area. As we know, so far, most of these PACs has not been previously reported in living organisms before. The 3-NBA concentrations determined in this study were within 0.11–5.18??g?g?1. Other relevant PACs such as PAHs, quinones and nitro-PAHs were found in maximum concentrations at 0.013??g?g?1 (coronene) to 11.1??g?g?1 (benzo[k]fluoranthene), 0.823??g?g?1 (9,10-phenenthrenequinone) to 12.1??g?g?1 (1,4-benzoquinone) and 0.434 (1-nitronaphthalene) ?g g?1 to 19.2??g?g?1 (6-nitrobenzo[a]pyrene), respectively. Principal component analysis (PCA), ternary correlations and diagnostic ratios were employed in order to propose probable sources for PACs. Although statistical analysis preliminarily has indicated both pyrogenic and petrogenic contributions, petrogenic sources were predominant reflecting the impacts of petroleum exploration and intensive traffic of boats in the study area.Sorensen, M.J., Anderson, B.G., Kennedy, R.T., 2020. Liquid chromatography above 20,000 PSI. TrAC Trends in Analytical Chemistry 124, 115810. improvements in HPLC have led to faster and more efficient separations than previously possible. One important aspect of these improvements has been the increase in instrument operating pressure and the advent of ultrahigh pressure LC (UHPLC). Commercial instrumentation is now capable of up to ~20 kpsi, allowing fast and efficient separations with 5–15?cm columns packed with sub-2 μm particles. Home-built instruments have demonstrated the benefits of even further increases in instrument pressure. The focus of this review is on recent advancements and applications in liquid chromatography above 20 kpsi. We outline the theory and advantages of higher pressure and discuss instrument hardware and design capable of withstanding 20 kpsi or greater. We also overview column packing procedures and stationary phase considerations for HPLC above 20 kpsi, and lastly highlight a few recent applications of ultrahigh pressure instruments for the analysis of complex mixtures.Sousa-Silva, C., Seager, S., Ranjan, S., Petkowski, J.J., Zhan, Z., Hu, R., Bains, W., 2020. Phosphine as a biosignature gas in exoplanet atmospheres. Astrobiology 20, 235–268. long-term goal of exoplanet studies is the identification and detection of biosignature gases. Beyond the most discussed biosignature gas O2, only a handful of gases have been considered in detail. In this study, we evaluate phosphine (PH3). On Earth, PH3 is associated with anaerobic ecosystems, and as such, it is a potential biosignature gas in anoxic exoplanets. We simulate the atmospheres of habitable terrestrial planets with CO2- and H2-dominated atmospheres and find that PH3 can accumulate to detectable concentrations on planets with surface production fluxes of 1010 to 1014 cm?2 s?1 (corresponding to surface concentrations of 10s of ppb to 100s of ppm), depending on atmospheric composition and ultraviolet (UV) irradiation. While high, the surface flux values are comparable to the global terrestrial production rate of methane or CH4 (1011 cm?2 s?1) and below the maximum local terrestrial PH3 production rate (1014 cm?2 s?1). As with other gases, PH3 can more readily accumulate on low-UV planets, for example, planets orbiting quiet M dwarfs or with a photochemically generated UV shield. PH3 has three strong spectral features such that in any atmosphere scenario one of the three will be unique compared with other dominant spectroscopic molecules. Phosphine's weakness as a biosignature gas is its high reactivity, requiring high outgassing rates for detectability. We calculate that tens of hours of JWST (James Webb Space Telescope) time are required for a potential detection of PH3. Yet, because PH3 is spectrally active in the same wavelength regions as other atmospherically important molecules (such as H2O and CH4), searches for PH3 can be carried out at no additional observational cost to searches for other molecular species relevant to characterizing exoplanet habitability. Phosphine is a promising biosignature gas, as it has no known abiotic false positives on terrestrial planets from any source that could generate the high fluxes required for detection. Spacapan, J.B., D?Odorico, A., Palma, O., Galland, O., Senger, K., Ruiz, R., Manceda, R., Leanza, H.A., 2020. Low resistivity zones at contacts of igneous intrusions emplaced in organic-rich formations and their implications on fluid flow and petroleum systems: A case study in the northern Neuquén Basin, Argentina. Basin Research 32, 3-24. sills and laccoliths emplaced in sedimentary basins may significantly impact petroleum systems, both positively and negatively. Igneous intrusions provide heat to maturate regionally immature organic-rich host rocks, act as fractured reservoirs hosting commercial accumulations of hydrocarbons, and form structures affecting fluid flow and trapping at different scales. Nevertheless, the petrophysical implications of igneous intrusions on their host rock are poorly known. In this study, we analyse 200 wells in the Río Grande Valley oil field, Neuquén basin, Argentina, where the main reservoirs are in fractured igneous sills. This dataset represents a globally unique possibility to characterize the igneous?host rock interaction using both wireline logs and core material. We identify a systematic Contact Low Resistivity Zone (CLRsZ) at both the upper and lower contacts of the sills emplaced in the organic-rich Vaca Muerta and Agrio Formations. We characterize the nature of these CLRsZ and their petrophysical properties by integrating resistivity and gamma ray well logs, petrographic analyses, petrophysical tests and geochemical analyses. The low resistivity signal of the CLRsZ is dominantly carried by massive-sulphide deposits, mainly pyrite, observed both in the host rock and the chilled margin of the sills. Well log images and porosity-permeability analysis on core plugs show that both the sills and their associated CLRsZ can act as carrier for fluid flow and reservoir for hydrocarbons storage. The thickness of the upper and lower CLRsZ correlates linearly with the thickness of the sill, and the volume of both the upper and lower CLRsZ represents ca. 40% with respect to the volume of their associated sill. The thickness of the CLRsZ represents ca. 13% of the thickness of contact aureole induced by the sills. In the CLRsZ, a great proportion of kerogen was transformed to hydrocarbon, so that CLRsZ were restricted to the innermost contact aureole of the sills. Our results show that the CLRsZ can have major implications on fluid flow and should be considered in reservoir models in volcanic basins hosting sills emplaced in organic-rich formations.Spraker, J.E., Luu, G.T., Sanchez, L.M., 2020. Imaging mass spectrometry for natural products discovery: a review of ionization methods. Natural Product Reports 37, 150-162.: 2009–2019. Over the last decade, methods in imaging mass spectrometry (IMS) have progressively improved and diversified toward a variety of applications in natural products research. Because IMS allows for the spatial mapping of the production and distribution of biologically active molecules in situ, it facilitates phenotype and organelle driven discovery efforts. As practitioners of IMS for natural products discovery, we find one of the most important aspects of these experiments is the sample preparation and compatibility with different ionization sources that are available to a given researcher. As such, we have focused this mini review to cover types of ionization sources that have been used in natural products discovery applications and provided concrete examples of use for natural products discovery while discussing the advantages and limitations of each method. We aim for this article to serve as a resource to guide the broader natural product community interested in IMS toward the application/method that would best serve their natural product discovery needs given the sample and analyte(s) of interest. This mini review has been limited to applications using natural products and thus is not exhaustive of all possible ionization methods which have only been applied to image other types of samples such as mammalian tissues. Additionally, we briefly review how IMS has been coupled with other imaging platforms, such as microscopy, to enhance information outputs as well as offer our future perspectives on the incorporation of IMS in natural products discovery.Spranger, T., van Pinxteren, D., Herrmann, H., 2020. Atmospheric “HULIS” in different environments: Polarities, molecular sizes, and sources suggest more than 50% are not “humic-like”. ACS Earth and Space Chemistry 4, 272-282. study the complex compound mixture in atmospheric aerosol particles often referred to as “humic-like substances” (HULIS), a recently developed 2D fractionation method combining size-exclusion chromatography and reversed-phase liquid chromatography was applied to a set of 55 aerosol particle samples from five different sampling locations. The resulting heat maps, showing the 2D molecular weight versus polarity space, revealed a distinct seasonal and regional variability in the composition of solid-phase extracted water-soluble organic carbon (WSOC). Different sources were assigned to specific areas of the heat maps based on correlations with atmospheric markers. Biomass burning and secondary organic aerosol formation were found to be the most important sources, both assigned to the largest areas of the heat maps with up to 77 and 69% contribution to the total solid-phase extracted WSOC mass of individual sample clusters, respectively. Coal combustion (14–24%), traffic and industry (4–9%), and soil-derived fulvic acids (5–10%), all assigned to smaller areas of the heat maps, were identified as additional sources. Comparison with the 2D heat map of Suwannee River fulvic acids (SRFAs), a commonly used HULIS surrogate, revealed that only 37–55% of the solid-phase-extracted WSOC occupied similar areas in the molecular weight versus polarity space as SRFA. It is, therefore, suggested that only this fraction might qualify as real atmospheric “HULIS”, while for the broad compound mixture obtained after solid-phase extraction (SPE), denominations like SPE-WSOC or WSOCSPE seem more appropriate.Stamps, B.W., Bojanowski, C.L., Drake, C.A., Nunn, H.S., Lloyd, P.F., Floyd, J.G., Emmerich, K.A., Neal, A.R., Crookes-Goodson, W.J., Stevenson, B.S., 2020. In situ linkage of fungal and bacterial proliferation to microbiologically influenced corrosion in B20 biodiesel storage tanks. Frontiers in Microbiology 11, 167. doi: 10.3389/fmicb.2020.00167. fuels hold great promise for the future yet their susceptibility to biodegradation and subsequent corrosion represents a challenge that needs to be directly assessed. Biodiesel is a renewable fuel that is widely used as a substitute or extender for petroleum diesel and is composed of a mixture of fatty acid methyl esters derived from plant or animal fats. Biodiesel can be blended up to 20% v/v with ultra-low sulfur diesel (i.e., B20) and used interchangeably with diesel engines and infrastructure. The addition of biodiesel, however, has been linked to increased susceptibility to biodegradation. Microorganisms proliferating via degradation of biodiesel blends have been linked to microbiologically influenced corrosion in the laboratory, but not measured directly in storage tanks (i.e., in situ). To measure in situ microbial proliferation, fuel degradation and microbially influenced corrosion, we conducted a yearlong study of B20 storage tanks in operation at two locations, identified the microorganisms associated with fuel fouling, and measured in situ corrosion. The bacterial populations were more diverse than the fungal populations, and largely unique to each location. The bacterial populations included members of the Acetobacteraceae, Clostridiaceae, and Proteobacteria. The abundant Eukaryotes at both locations consisted of the same taxa, including a filamentous fungus within the family Trichocomaceae, not yet widely recognized as a contaminant of petroleum fuels, and the Saccharomycetaceae family of yeasts. Increases in the absolute and relative abundances of the Trichocomaceae were correlated with significant, visible fouling and pitting corrosion. This study identified the relationship between fouling of B20 with increased rates of corrosion and the microorganisms responsible, largely at the bottom of the sampled storage tanks. To our knowledge this is the first in situ study of this scale incorporating community and corrosion measurements in an active biodiesel storage environment.Stams, A.J.M., Sousa, D.Z., 2020. Biogenesis of Hydrocarbons, Handbook of Hydrocarbon and Lipid Microbiology. Springer, Cham, p. 449. book covers the microbiological, environmental and biotechnological aspects of alkane production. Alkanes are important energy-rich compounds on earth. Microbial synthesis of methane and other alkanes is an essential part of the geochemical cycling of carbon and offers perspectives for our biobased economy. This book discusses different aspects of current knowledge of microbial alkane production. Chapters with state of the art information are written by renowned scientists in the field.The chapters are organised into four themed parts:1. Biochemistry of Biogenesis - Hydrocarbons2. Taxonomy, Ecophysiology and Genomics of Biogenesis - Hydrocarbons3. Biogenic Communities: Members, Functional Roles4. Global Consequences of Methane ProductionThe chapters are organised into four themed parts:Introduction to Microbial Hydrocarbon Production: Bioenergetics, Bernhard Schink, Michael J. McInerney, Tori Hoehler, Robert P. Gunsalus, Pages 1-17 Diversity and Taxonomy of Methanogens, Zhe Lyu, Yuchen Liu, Pages 19-77 Hydrogenotrophic Methanogenesis, Tristan Wagner, Tomohiro Watanabe, Seigo Shima, Pages 79-107 Ecophysiology of Acetoclastic Methanogens, Alfons J. M. Stams, Bas Teusink, Diana Z. Sousa, Pages 109-121 Methanogenesis from Carbon Monoxide, Christian Sch?ne, Michael Rother, Pages 123-151 Environmental Constraints That Limit Methanogenesis, Tori Hoehler, Nathaniel A. Losey, Robert P. Gunsalus, Michael J. McInerney, Pages 153-178 Methanogens: Syntrophic Metabolism, Jessica R. Sieber, Michael J. McInerney, Nicolai Müller, Bernhard Schink, Robert P. Gunsalus, Caroline M. Plugge, Pages 179-209 Methanogenesis in Soils, Wetlands, and Peat, O. R. Kotsyurbenko, M. V. Glagolev, A. Y. Merkel, A. F. Sabrekov, I. E. Terentieva, Pages 211-228 Methanogenesis in the Digestive Tracts of Insects and Other Arthropods, Andreas Brune, Pages 229-260 Methanogenesis at High Latitudes, Xiuzhu Dong, Jianqing Tian, Lei Qi, Lingyan Li, Pages 261-281 Methanogens and Methanogenesis in Hypersaline Environments, Terry J. McGenity, Dimitry Y. Sorokin, Pages 283-309 Metagenomics of Methanogenic Communities in Rice Paddy: The Importance of Methanocella, Yahai Lu, Pages 311-336 Metagenomics of Methanogenic Communities in Anaerobic Digesters, Sabine Kleinsteuber, Pages 337-359 Anaerobic Digestion as Key Technology in the Bio-based Economy, Nayaret Acosta, Jo De Vrieze, Pages 361-378 Oxic Methane Cycling: New Evidence for Methane Formation in Oxic Lake Water, Mina Bi?i?-Ionescu, Danny Ionescu, Marco Günthel, Kam W. Tang, Hans-Peter Grossart, Pages 379-400 Contribution of Methane Formation and Methane Oxidation to Methane Emission from Freshwater Systems, Carsten J. Schubert, Bernhard Wehrli, Pages 401-430 Diversity and Taxonomy of Aliphatic Hydrocarbon Producers, Serina L. Robinson, Lawrence P. Wackett, Pages 431-450 Alkane Biosynthesis in Bacteria, Steven Brown, Josh Loh, Stephen J. Aves, Thomas P. Howard, Pages 451-470 Oil and Hydrocarbon-Producing Bacteria, Ana Rita Castro, Ana Júlia Cavaleiro, Maria Alcina Pereira, Pages 471-487 Stankevica, K., Vincevica-Gaile, Z., Klavins, M., Kalnina, L., Stivrins, N., Grudzinska, I., Kaup, E., 2020. Accumulation of metals and changes in composition of freshwater lake organic sediments during the Holocene. Chemical Geology 539, 119502. distribution of metals in the strata of sediments deposited in the freshwater environment formed during the Holocene in the territory of Latvia has been studied rather insufficiently. Considering the large volume of accumulated organic matter in sediments, studies on the content of metallic elements in sediments can help to determine the peculiarities of the metal accumulation process in limnic systems and the biogeochemical cycling of metals. Lake Pilvelis, which is located in the eastern part of Latvia (the northern part of Europe), was selected as the main study site. Lake Pilvelis is a small lake of a glacial origin, and >90% of its depression is filled with organic-rich sediments. The development stages of Lake Pilvelis since circa 10,000?cal BP are described in detail via reconstruction of the Holocene palaeoenvironmental conditions using multi-proxy sedimentary records. The elemental composition and content of metallic elements in sapropel are analysed with the main objectives of characterising the accumulation rate of metals in the full profile of sapropel and determining the anthropogenic impact depending on the evolution of the lake and the genesis of sediment organic matter. The correlation among the components characterising sediments such as sapropel and metallic elements revealed that the elemental distribution could be divided into three main groups according to the content of the elements associated with organic compounds (e.g., for Zn and Mn) and mineral compounds (for Ni, Co, Cr, K, Fe, Mg, and Cu). Ni and Co are partly associated with mineral compounds and partly associated with carbonates. A principal component analysis revealed the main factors indicating the origin of metallic elements and the accumulation tendencies of metals in sediment layers: the input of the mineral matter, the characteristics of organic matter, and human impact. The content of metallic elements in sapropel from Lake Pilvelis is mainly affected by the composition of mineral matter, not by the size of the particles.Stein, W.E., Berry, C.M., Morris, J.L., Hernick, L.V., Mannolini, F., Ver Straeten, C., Landing, E., Marshall, J.E.A., Wellman, C.H., Beerling, D.J., Leake, J.R., 2020. Mid-Devonian Archaeopteris roots signal revolutionary change in earliest fossil forests. Current Biology 30, 421-431. origin of trees and forests in the Mid Devonian (393–383 Ma) was a turning point in Earth history, marking permanent changes to terrestrial ecology, geochemical cycles, atmospheric CO2 levels, and climate. However, how all these factors interrelate remains largely unknown. From a fossil soil (palaeosol) in the Catskill region near Cairo NY, USA, we report evidence of the oldest forest (mid Givetian) yet identified worldwide. Similar to the famous site at Gilboa, NY, we find treefern-like Eospermatopteris (Cladoxylopsida). However, the environment at Cairo appears to have been periodically drier. Along with a single enigmatic root system potentially belonging to a very early rhizomorphic lycopsid, we see spectacularly extensive root systems here assigned to the lignophyte group containing the genus Archaeopteris. This group appears pivotal to the subsequent evolutionary history of forests due to possession of multiple advanced features and likely relationship to subsequently dominant seed plants. Here we show that Archaeopteris had a highly advanced root system essentially comparable to modern seed plants. This suggests a unique ecological role for the group involving greatly expanded energy and resource utilization, with consequent influence on global processes much greater than expected from tree size or rooting depth alone.Stigall, A.L., Freeman, R.L., Edwards, C.T., Rasmussen, C.M.?., 2020. A multidisciplinary perspective on the Great Ordovician Biodiversification Event and the development of the early Paleozoic world. Palaeogeography, Palaeoclimatology, Palaeoecology 543, 109521. abstract. Introduction to special section on the Great Ordovician Biodiversification EventThe papers in this special issue contribute new data from diverse faunas and various paleocontinents that support the interpretation of the GOBE as a narrow window of increased marine biodiversification that occurred primarily during the Darriwilian (Stigall et al., 2019—this issue). The GOBE was the result of a host of closely linked, biotic and abiotic shifts in marine ecosystems that were set in motion during the late Cambrian and Early Ordovician, finally converging to trigger a sudden increase in marine biodiversity during the Middle Ordovician. Although the GOBE was of brief duration, the fundamental changes in marine ecosystems that resulted were long-lasting, persisting after the end-Ordovician mass extinction, and continuing until the end-Permian mass extinction. Diversification continued at a lower rate during the Late Ordovician due to increased endemism and interbasinal dispersal. However, this pattern was interrupted by the Late Ordovician mass extinction, and biodiversity accumulation probably did not exceed early Katian levels until the Devonian.Stixrude, L., Scipioni, R., Desjarlais, M.P., 2020. A silicate dynamo in the early Earth. Nature Communications 11, 935. Earth’s magnetic field has operated for at least 3.4 billion years, yet how the ancient field was produced is still unknown. The core in the early Earth was surrounded by a molten silicate layer, a basal magma ocean that may have survived for more than one billion years. Here we use density functional theory-based molecular dynamics simulations to predict the electrical conductivity of silicate liquid at the conditions of the basal magma ocean: 100–140?GPa, and 4000–6000?K. We find that the electrical conductivity exceeds 10,000?S/m, more than 100 times that measured in silicate liquids at low pressure and temperature. The magnetic Reynolds number computed from our results exceeds the threshold for dynamo activity and the magnetic field strength is similar to that observed in the Archean paleomagnetic record. We therefore conclude that the Archean field was produced by the basal magma ocean.Stokke, R., Reeves, E.P., Dahle, H., Fed?y, A.-E., Viflot, T., Lie Onstad, S., Vulcano, F., Pedersen, R.B., Eijsink, V.G.H., Steen, I.H., 2020. Tailoring hydrothermal vent biodiversity toward improved biodiscovery using a novel in situ enrichment strategy. Frontiers in Microbiology 11, 249. doi: 10.3389/fmicb.2020.00249. hydrothermal vents are amongst the most extreme environments on Earth and represent interesting targets for marine bioprospecting and biodiscovery. The microbial communities in hydrothermal vents are often dominated by chemolithoautotrophs utilizing simple chemical compounds, though the full extent of their heterotrophic abilities is still being explored. In the bioprocessing industry, where degradation of complex organic materials often is a major challenge, new microbial solutions are heavily needed. To meet these needs, we have developed novel in situ incubators and tested if deployment of recalcitrant materials from fish farming and wood-pulping industries introduced changes in the microbial community structure in hot marine hydrothermal sediments. The incubation chambers were deployed in sediments at the Bruse vent site located within the Jan Mayen vent field for 1 year, after which the microbial populations in the chambers were profiled by 16S rRNA Ion Torrent amplicon sequencing. A total of 921 operational taxonomic units (OTUs) were assigned into 74 different phyla where differences in community structure were observed depending on the incubated material, chamber depth below the sea floor and/or temperature. A high fraction of putative heterotrophic microbial lineages related to cultivated members within the Thermotogales were observed. However, considerable fractions of previously uncultivated and novel Thermotogales and Bacteroidetes were also identified. Moreover, several novel lineages (e.g., members within the DPANN superphylum, unidentified archaeal lineages, unclassified Thermoplasmatales and Candidatus division BRC-1 bacterium) of as-yet uncultivated thermophilic archaea and bacteria were identified. Overall, our data illustrate that amendment of hydrothermal vent communities by in situ incubation of biomass induces shifts in community structure toward increased fractions of heterotrophic microorganisms. The technologies utilized here could aid in subsequent metagenomics-based enzyme discovery for diverse industries.Stokolos, O.A., Ivanova, L.V., Sorokin, A.S., Koshelev, V.N., 2020. Comparative study of the composition and structure of naphthenic acids of crude oil from the Naftalan and Anastasievsko-Troitskoe fields. Petroleum Chemistry 60, 22-29. comparative analysis has been made of the physicochemical properties and structural-group composition of acids isolated from crude oils of the Anastasievsko-Troitskoe (Krasnodar krai, Russia) and Naftalan (Azerbaijan) oil fields. For each crude, the following three fractions of acids have been obtained by vacuum fractionation and analyzed: 240–350, 350–390, and >390; their elemental composition has been determined; and formulas for average acid molecules in each of the fractions have been derived. It has been shown that the acids of the 240–350°С fraction are monocyclic monocarboxylic acids with the five-membered naphthene ring. The fractions with the higher boiling points contain bicyclic naphthenic acids and, possibly, hydroxy acids. The acid fractions obtained from the Anastasievsko-Troitskoe oil are distinguished by the presence of aromatic structures and a significant amount of unsaponifiable components, especially in the 240–350°С fraction, which is of the greatest practical interest.Stoll, H., 2020. 30 years of the iron hypothesis of ice ages. Nature 578, 370-371. 1990, an oceanographer who had never worked on climate science proposed that ice-age cooling has been amplified by increased concentrations of iron in the sea — and instigated an explosion of research.Thirty years ago this month, John Martin proposed a solution to one of the biggest mysteries of Earth’s climate system: how was nearly one-third of the carbon dioxide in the atmosphere (about 200 gigatonnes of carbon) drawn into the ocean as the planet entered the most recent ice age, then stored for tens of thousands of years, and released again as the ice sheets melted? These large natural cycles in atmospheric CO2 levels (Fig. 1a) were revealed in 1987 by an analysis of ancient air bubbles trapped in the first long ice cores taken from the Antarctic ice sheet1. Martin recognized that iron was a key ingredient that could have transformed the surface ocean during glacial times. His landmark iron hypothesis2, published in Paleoceanography, described a feedback mechanism linking climatic changes to iron supply, ocean fertility and carbon storage in the deep ocean.Two hundred gigatonnes is a lot of carbon to periodically withdraw from and release to the atmosphere. In the 1980s, a handful of models (see ref. 3, for example) had shown that an increase in biomass production in polar ocean regions was the most effective process for removing so much atmospheric carbon. Photosynthetic organisms in the surface ocean convert CO2 from the atmosphere into biomass, much of which is subsequently broken down into CO2 again by other organisms and returned to the atmosphere. But part of the biomass sinks into the deep ocean, which therefore effectively serves as a large storage reservoir of dissolved CO2. This mechanism of CO2 removal is called the biological pump.However, biomass production requires not only CO2, but also other nutrients to build lipids, proteins and enzymes. Researchers were struggling to ascertain how the ocean’s abundance of key nutrients, such as nitrates or phosphates, might have increased during glacial times to fuel a stronger biological pump.Martin argued that iron is another nutrient that limits the biological pump. He suggested that the modern marine ecosystem of the Southern Ocean around Antarctica is starved of iron, and therefore relatively low in biomass, despite having abundant nitrates and phosphates. But during glacial times, strong winds over cold, sparsely vegetated continents could have transported large amounts of iron-bearing dust into this ocean (Fig. 1b). Martin reasoned that this dust could have fertilized marine ecosystems and strengthened the biological pump, so that more carbon was transferred into the deep ocean, lowering atmospheric CO2 levels.Around the time of publication, evidence for high dust delivery during glacial periods had just emerged from studies of deep Antarctic ice cores4. But there were no reliable measurements of dissolved iron in the Southern Ocean that could confirm that its surface waters are iron-starved in modern times, or data supporting the proposal that delivery of iron-rich dust would make a difference to ocean productivity. It was clear, however, that large patches of the world’s ocean had much lower quantities of biomass than would be expected on the basis of the concentrations of key nutrients such as nitrates and phosphates. But many researchers argued that this was due to natural overgrazing of algae by herbivores5.The idea that modern algal growth is limited by iron availability had, in fact, been proposed6 in the 1930s, but had been incorrectly discounted by oceanographers — who had measured plenty of iron in seawater samples collected from the waters around their iron ships7. Martin was one of the first oceanographers to implement painstaking procedures to avoid the contamination of samples and to determine that iron concentrations in the north Pacific Ocean were extremely low7, certainly low enough to curtail biomass production.Despite the initial scepticism that greeted the iron hypothesis, 12 separate experiments8 were carried out between 1993 and 2005 in which around 300–3,000 kilograms of dissolved iron were injected into small patches of the Southern Ocean, the equatorial Pacific Ocean and the north Pacific. The biomass of algae increased wherever iron was added, as biological production surged.Unfortunately, Martin died mere months before the first of these experiments, and did not witness the ocean-scale confirmation of his hypothesis, nor the internationally coordinated campaign to measure iron geochemistry throughout the world’s oceans9 — which confirmed iron limitation and revealed the intricate strategies used by marine ecosystems to acquire and recycle iron10.Earth scientists also tried to test the iron hypothesis computationally using simple ocean models. They used the changes in the dust-accumulation rate recorded in ice cores as input to simulate changes in iron delivery to the Southern Ocean, and data from the experimental iron fertilizations to calculate how this iron could affect algal growth and the biological pump. Such models could reproduce the timing and magnitude of about half of the observed decrease in atmospheric CO2 levels during glacial periods11. Iron fertilization is therefore clearly an important process that causes atmospheric changes, but might not be the only one.Finding data to prove that biological production had been higher during glacials was a harder task — after all, the ecosystem during the most recent glacial period (about 20,000 years ago) is long dead. One possible solution was to extract cores from sediments piled on the sea floor, to see whether the mineral skeletons of algae accumulated faster during glacial times than in the modern era. However, the results were often ambiguous12, for several reasons: many algae don’t produce a preservable skeleton; numerous factors determine what proportion of biological remains is preserved on the sea floor; and the location of biological production changes through time as ocean fronts and sea-ice positions migrate.Fortunately, Martin2 and others13 had anticipated an alternative, global-scale test of the biological pump during glacial times. If more biomass reached the deep ocean during glacials, then deep-sea microorganisms would use up more oxygen as they consumed it, decreasing the concentration of oxygen in deep waters. Evidence of deep-ocean oxygen depletion would therefore be indicative of a strong biological pump.Martin recognized that the presence of certain microfossils in glacial-age sediments meant that the deep ocean had not become completely devoid of oxygen during glacials. But although this evidence crudely constrained estimates of the degree to which iron fertilization might have enhanced productivity during glacials, it could not be used to determine whether levels of deep-ocean oxygen were lower than during modern times. Since then, analysis of more-sensitive geochemical records indicates that the oxygen concentration in bottom waters did decrease during glacial times14. This provides the strongest confirmation yet of the large-scale accumulation of carbon in the deep ocean during glacial periods owing to a stronger biological pump.Slower rates of mixing between the deep and shallow oceans could also have enhanced the biological pump during glacials. The latest generation of climate models in which the ocean and atmosphere are coupled can test the contribution of the multiple processes that could have resulted in a reduction in bottom-water oxygen levels. Such models indicate that mixing rates can account for only half of the observed deep-ocean storage of CO2 during the glacial period, and that iron fertilization of the Southern Ocean is the major cause of the extra CO2 storage observed15.Martin concluded his paper by saying that iron availability “appears to have been a player” in strengthening the biological pump during glacial cycles, but that the size of its role remained to be determined. Thirty years later, the evidence convincingly shows that iron fertilization of the Southern Ocean was indeed a leading actor in this global-climaReferencesReferences1. Barnola, J. M., Raynaud, D., Korotkevich, Y. S. & Lorius, C. Nature 329, 408–414 (1987).2. Martin, J. H. Paleoceanography 5, 1–13 (1990).3. Sarmiento, J. L., Toggweiler, J. R. & Najjar, R. Phil. Trans. R. Soc. Lond. A 325, 3–21 (1988).4. De Angelis, M., Barkov, N. I. & Petrov, V. N. Nature 325, 318–321 (1987).5. Cullen, J. J. Limnol. Oceanogr. 36, 1578–1599 (1991).6. Hart, T. J. Discov. Rep. VIII, 1–268 (1934).7. Gordon, R. M., Martin, J. H. & Knauer, G. A. Nature 299, 611–612 (1982).8. Boyd, P. W. et al. Science 315, 612–617 (2007).9. Anderson, R. F. & Henderson, G. M. Oceanography 18, 76–79 (2005).10. Tagliabue, A. et al. Nature 543, 51–59 (2017).11. Watson, A. J., Bakker, D. C. E., Ridgwell, A. J., Boyd, P. W. & Law, C. S. Nature 407, 730–733 (2000).12. Kohfeld, K. E., Le Quéré, C., Harrison, S. P. & Anderson, R. F. Science 308, 74–78 (2005).13. Boyle, E. A. Nature 331, 55–56 (1988).14. Jaccard, S. L., Galbraith, E. D., Martínez-García, A. & Anderson, R. F. Nature 530, 207–210 (2016).15. Yamamoto, A., Abe-Ouchi, A., Ohgaito, R., Ito, A. & Oka, A. Clim. Past 15, 981–996 (2019).16. Bereiter, B. et al. Geophys. Res. Lett. 42, 542–549 (2015).17. Wolff, E. W. et al. Nature 440, 491–496 (2006).Storm, M.S., Hesselbo, S.P., Jenkyns, H.C., Ruhl, M., Ullmann, C.V., Xu, W., Leng, M.J., Riding, J.B., Gorbanenko, O., 2020. Orbital pacing and secular evolution of the Early Jurassic carbon cycle. Proceedings of the National Academy of Sciences 117, 3974-3982.: Cyclic variations in Earth’s orbit drive periodic changes in the ocean–atmosphere system at a time scale of tens to hundreds of thousands of years. The Mochras δ13CTOC record illustrates the continued impact of long-eccentricity (405-ky) orbital forcing on the carbon cycle over at least ～18 My of Early Jurassic time and emphasizes orbital forcing as a driving mechanism behind medium-amplitude δ13C fluctuations superimposed on larger-scale trends that are driven by other variables such as tectonically determined paleogeography and eruption of large igneous provinces. The dataset provides a framework for distinguishing between internal Earth processes and solar-system dynamics as the driving mechanism for Early Jurassic δ13C fluctuations and provides an astronomical time scale for the Sinemurian Stage.Abstract: Global perturbations to the Early Jurassic environment (～201 to ～174 Ma), notably during the Triassic–Jurassic transition and Toarcian Oceanic Anoxic Event, are well studied and largely associated with volcanogenic greenhouse gas emissions released by large igneous provinces. The long-term secular evolution, timing, and pacing of changes in the Early Jurassic carbon cycle that provide context for these events are thus far poorly understood due to a lack of continuous high-resolution δ13C data. Here we present a δ13CTOC record for the uppermost Rhaetian (Triassic) to Pliensbachian (Lower Jurassic), derived from a calcareous mudstone succession of the exceptionally expanded Llanbedr (Mochras Farm) borehole, Cardigan Bay Basin, Wales, United Kingdom. Combined with existing δ13CTOC data from the Toarcian, the compilation covers the entire Lower Jurassic. The dataset reproduces large-amplitude δ13CTOC excursions (>3‰) recognized elsewhere, at the Sinemurian–Pliensbachian transition and in the lower Toarcian serpentinum zone, as well as several previously identified medium-amplitude (～0.5 to 2‰) shifts in the Hettangian to Pliensbachian interval. In addition, multiple hitherto undiscovered isotope shifts of comparable amplitude and stratigraphic extent are recorded, demonstrating that those similar features described earlier from stratigraphically more limited sections are nonunique in a long-term context. These shifts are identified as long-eccentricity (～405-ky) orbital cycles. Orbital tuning of the δ13CTOC record provides the basis for an astrochronological duration estimate for the Pliensbachian and Sinemurian, giving implications for the duration of the Hettangian Stage. Overall the chemostratigraphy illustrates particular sensitivity of the marine carbon cycle to long-eccentricity orbital forcing.Struck, J., Bliedtner, M., Strobel, P., Schumacher, J., Bazarradnaa, E., Zech, R., 2020. Leaf wax n-alkane patterns and compound-specific δ13C of plants and topsoils from semi-arid and arid Mongolia. Biogeosciences 17, 567-580. wax n-alkane patterns and their compound-specific δ13C signatures are valuable proxies for paleoenvironmental reconstructions. So far, their potential has not been investigated in semi-arid to arid Mongolia. We have therefore analysed the leaf wax n-alkanes and their compound-specific δ13C signature of five plant species (Poaceae, Cyperaceae, Artemisia spp., Caragana spp. and Larix sp.) and topsoils (0–5?cm) along two transects in central and southern Mongolia.Grasses show a distinct dominance of the n-C31 homologue, whereas the shrubs Caragana spp. and Artemisia spp. are dominated by n-C29. Larix sp. is characterised by the mid-chain n-alkanes n-C23 and n-C25. From plant to topsoil, n-alkane patterns show the potential to differentiate between grass-covered sites from those covered by Caragana spp. n-Alkane concentrations and odd-over-even predominance (OEP) of the topsoils are distinctly influenced by mean annual temperature, mean annual precipitation and aridity, likely reflecting the degree of n-alkane degradation and biomass production. In contrast, the average chain length (ACL) and the n-alkane ratio (n-C31∕n-C29+n-C31) are not affected by climatic parameters and, thus, are not biased by climate. The compound-specific δ13C signatures are strongly correlated to climate, showing a significant enrichment with increasing aridity, indicating the effect of water use efficiency. Our calibration results suggest that long-chain n-alkanes and their compound-specific δ13C signatures have great potential to reconstruct paleoenvironmental and paleoclimatic conditions when used in sediment archives from Mongolia.Su, L., Zhang, D., Zheng, L., Liu, X., Yang, X., Zheng, J., Liu, P., 2020. Experimental study of the influences of pressure on generation and expulsion of hydrocarbons: A case study from mudstone source rocks and its geological application in the Tarim Basin. Journal of Petroleum Science and Engineering 189, 107021., pressure, temperature, depth of organic matter/kerogen burial and organic and inorganic matter interactions can influence the hydrocarbon generation process. However, different understandings were proposed to interpret the role of pressure in hydrocarbon generation. Meanwhile, previous investigations of the influence of pressure on hydrocarbons generation are mainly focused on fluid pressure (FP), only a few work was involved in the effect of lithostatic stress (LS) due to the limitation of experimental techniques. In this study, simulation experiments were conducted to investigate the influence of pressure, including lithostatic stress (LS) and fluid pressure (FP) on yield and process of hydrocarbon generation by a modified simulation instrument. Two systematic comparative pyrolysis experiments, including pressured experiments with LP range from 27.6 to 179.4 MPa and FP range from 12.0 to 109.2 MPa, and non-pressured experiments with LP for 6.0 MPa and FP range from 2.0 to 5.0 MPa were conducted in hydrous experimental condition. The results show that the peak yields of the expelled oil and the liquid hydrocarbons in pressured experiments and non-pressured experiments are 42.48 mg/g·TOC, 52.00 mg/g·TOC, 70.14 mg/g·TOC, and 72.15 mg/g·TOC, respectively. And Ro, ratio of the expelled oil to eluted oil, the accumulated yield of the expelled oil and liquid hydrocarbons, are lower in pressured experiments than that of non-pressured experiments. However, the accumulated yields of eluted oil and residual oil are higher in pressured experiments than that of non-pressured experiments. Additionally, the expulsion efficiencies of the oil range from 20% to 25%, which are lower in pressured experiments than that of non-pressured experiments near the oil generation-window. In addition, the yields of hydrocarbon gas in pressured experiments are greater compared to the yields in non-pressured experiments at the high maturity stage. Based on the experimental results, hydrocarbon generation process can be divided into three stages. Generally, LS and FP could retard the process of mudstone maturation as well as the generation and expulsion of the liquid hydrocarbons. Hence, the residual liquid hydrocarbons in high-pressure condition can act as another source of natural gas generation in the high maturity stage. The results could help us to properly evaluate hydrocarbon generation potentials of sources rocks at petroleum-producing sedimentary basins in China and elsewhere.Sullivan, G.L., Gallardo, J.D., Jones, E.W., Hollliman, P.J., Watson, T.M., Sarp, S., 2020. Detection of trace sub-micron (nano) plastics in water samples using pyrolysis-gas chromatography time of flight mass spectrometry (PY-GCToF). Chemosphere 249, 126179. identification and quantification of micro and nanoplastics (MPs and NPs respectively) requires the development of standardised analytical methods. Thermal analysis methods are generally not considered a method of choice for MPs analysis, especially in aqueous samples due to limited sample size introduction to the instrument, decreasing the detection levels. In this article, pyrolysis - Gas chromatography time of flight mass spectrometry (Py-GCToF) is used as a method of choice for detection of MPs and NPs due to its unprecedented detection capabilities, in combination with PTFE membranes as sample support, allow for smaller particle sizes (>0.1?μm) in water samples to be identified. The utilisation of these widely used membranes and the identification of several and specific (marker) ions for the three plastics in study (polypropylene (PP), polystyrene (PS) and polyvinyl chloride (PVC)), allows for the extraction of individual plastics from complex signals at trace levels. The method was validated against a number of standards, containing known quantities of MPs. Detection levels were then determined for PVC and PS and were found to be below <50 μg/L, with repeatable data showing good precision (%RSD <20%). Further verification of this new method was achieved by the analysis of a complex sample, sourced from a river. The results were positive for the presence of PS with a semi-quantifiable result of 241.8?μg/L. Therefore PY-GCToF seems to be a fit for purpose method for the identification of MPs and NPs from complex mixtures and matrices which have been deposited on PTFE membranes.Sun, Q., Jackson, C.A.L., Magee, C., Xie, X., 2020. Deeply buried ancient volcanoes control hydrocarbon migration in the South China Sea. Basin Research 32, 146-162. reflection data image now‐buried and inactive volcanoes, both onshore and along the submarine portions of continental margins. However, the impact that these volcanoes have on later, post‐eruption fluid flow events (e.g., hydrocarbon migration and accumulation) is poorly understood. Determining how buried volcanoes and their underlying plumbing systems influence subsurface fluid or gas flow, or form traps for hydrocarbon accumulations, is critical to de‐risk hydrocarbon exploration and production. Here, we focus on evaluating how buried volcanoes affect the bulk permeability of hydrocarbon seals, and channel and focus hydrocarbons. We use high‐resolution 3D seismic reflection and borehole data from the northern South China Sea to show how ca. <10 km wide, ca. <590 m high Miocene volcanoes, buried several kilometres (ca. 1.9 km) below the seabed and fed by a sub‐volcanic plumbing system that exploited rift‐related faults: (i) acted as long‐lived migration pathways, and perhaps reservoirs, for hydrocarbons generated from even more deeply buried (ca. 8–10 km) source rocks; and (ii) instigated differential compaction and doming of the overburden during subsequent burial, producing extensional faults that breached regional seal rocks. Considering that volcanism and related deformation are both common on many magma‐rich passive margins, the interplay between the magmatic products and hydrocarbon migration documented here may be more common than currently thought. Our results demonstrate that now‐buried and inactive volcanoes can locally degrade hydrocarbon reservoir seals and control the migration of hydrocarbon‐rich fluids and gas. These fluids and gases can migrate into and be stored in shallower reservoirs, where they may then represent geohazards to drilling and impact slope stability.Sun, Y., Amelung, W., Wu, B., Haneklaus, S., Maekawa, M., Lücke, A., Schnug, E., Bol, R., 2020. ‘Co-evolution’ of uranium concentration and oxygen stable isotope in phosphate rocks. Applied Geochemistry 114, 104476. rocks (PRs) used in fertilizer production contain uranium (U), which enters agricultural soils through phosphorus fertilization. However, our knowledge is still limited and cannot explain the different levels of U contamination found in agricultural systems. The paper reviewed the spatial and temporal U variations in PRs to obtain a comprehensive overview of U levels in various PRs worldwide and to investigate why U concentrations in igneous PRs are significantly lower compared to sedimentary PRs, and why less U is present in old sedimentary PRs (Precambrian-Cambrian) than in younger PRs (Ordovician-Neogene). In addition, the natural oxygen isotope compositions of phosphate (δ18Op) in various PRs were determined to identify their origins in relation to their U concentration. The δ18Op values differed among igneous PRs, old sedimentary PRs, and younger sedimentary PRs. Generally, the PRs with low δ18Op values had low U concentrations. In igneous PRs, low U concentrations were due to the lack of secondary U enrichment processes after rock formation, with low δ18Op values resulting from limited isotope fractionation at high temperature. Conversely, in sedimentary PRs, both U concentrations and δ18Op values were influenced by paleoclimate and paleogeographic features. Overall, there is a time-dependent coincidence of processes altering U concentration and δ18Op signatures of sedimentary PRs in a similar direction.Sun, Y., Yang, D., Shi, L., Wu, H., Cao, Y., He, Y., Xie, T., 2020. Properties of nanofluids and their applications in enhanced oil recovery: A comprehensive review. Energy & Fuels 34, 1202-1218. are stable mixtures of nanoscale particles dispersed in base fluids with good prospects in enhanced oil recovery in the petroleum industry. In this review, the mechanisms and evaluation methods of stable nanofluids were analyzed. The effects of nanoparticles on viscosity, electrical conductivity, and surface/interfacial tension of base fluids were discussed. The results of laboratory research and field tests revealed that nanofluids could improve the oil recovery through plugging and profile control, transformation of wettability of rock surface, changes in oil–water interface properties, and increases in the viscosity ratio between fluids. On the other hand, nanoparticles might stabilize oil–water emulsions produced during the extraction stage, adversely affecting subsequent oil–water separation processes, especially the electrical dehydration. However, careful analysis suggested lack of in-depth studies regarding the impacts of nanoparticles on droplet coalescence inside electro-dehydration plants. The present analyses will hopefully assist future investigations in nanofluidics.Syring, N., Stein, R., Fahl, K., Vahlenkamp, M., Zehnich, M., Spielhagen, R.F., Niessen, F., 2020. Holocene changes in sea-ice cover and polynya formation along the eastern North Greenland shelf: New insights from biomarker records. Quaternary Science Reviews 231, 106173. the processes controlling the natural variability of sea ice in the Arctic, one of the most dynamic components of the climate system, can help to constrain the effects of future climate change in this highly sensitive area. For the first time, a high-resolution biomarker study was carried out to reconstruct past sea-ice variability off eastern North Greenland. This area is strongly influenced by cold surface waters and drift ice transported via the East Greenland Current, meltwater pulses from the outlet glaciers of the Northeast Greenland Ice Stream and the build-up of landfast ice. The well-dated Holocene sedimentary section of Core PS93/025 provides insights into variations of the sea-ice conditions (regional and local sea-ice signal), oceanic and atmospheric circulation and the biotic response to these changes. These biomarker records show a reduced to variable sea-ice cover during the early Holocene between 10.2 and 9.3 ka, followed by a steady increase in sea-ice conditions during the mid Holocene. During the last 5–6 ka, sea-ice conditions remained more stable representing a seasonal to marginal sea-ice situation. Based on our biomarker records, stable sea-ice edge conditions, with a fully developed polynya situation occurred since the last 1 ka.Szopa, C., Freissinet, C., Glavin, D.P., Millan, M., Buch, A., Franz, H.B., Summons, R.E., Sumner, D.Y., Sutter, B., Eigenbrode, J.L., Williams, R.H., Navarro-González, R., Guzman, M., Malespin, C., Teinturier, S., Mahaffy, P.R., Cabane, M., 2020. First detections of dichlorobenzene isomers and trichloromethylpropane from organic matter indigenous to Mars mudstone in Gale Crater, Mars: Results from the sample analysis at Mars Instrument onboard the Curiosity rover. Astrobiology 20, 292–306. analysis of the Cumberland mudstone in Gale crater by the Sample Analysis at Mars (SAM) instrument revealed the detection of two to three isomers of dichlorobenzene. Their individual concentrations were estimated to be in the 0.5–17 ppbw range relative to the sample mass. We also report the first detection of trichloromethylpropane and the confirmation of the detection of chlorobenzene previously reported. Supporting laboratory experiments excluded the SAM internal background as the source of those compounds, thus confirming the organic carbon and chlorine of the newly detected chlorohydrocarbons are indigenous to the mudstone sample. Laboratory experiments also demonstrated that the chlorohydrocarbons were mainly produced from chemical reactions occurring in the SAM ovens between organic molecules and oxychlorines contained in the sample. The results we obtained show that meteoritic organics and tested chemical species (a polycyclic aromatic hydrocarbon, an amino acid, and a carboxylic acid) were plausible organic precursors of the chlorinated aromatic molecules detected with SAM, thus suggesting that they could be among the organic molecules present in the mudstone. Results from this study coupled with previously reported detections of chlorinated aromatics (<300 ppbw) indigenous to the same mudstone highlight that organics can be preserved from the harsh surface conditions even at shallow depth. The detection of new chlorohydrocarbons with SAM confirms that organic molecules should have been available in an environment favorable to life forms, strengthening the habitability aspect of Gale crater.Tacail, T., Le Houedec, S., Skulan, J.L., 2020. New frontiers in calcium stable isotope geochemistry: Perspectives in present and past vertebrate biology. Chemical Geology 537, 119471. their established uses in Earth and Planetary sciences, calcium (Ca) isotopes have a promising future in the study of the biology of present and past vertebrates, including humans. Early work paved the way to the ongoing research on the potential of Ca isotopes as relevant tools to disciplines other than geology, including palaeobiology, bioarchaeology and biomedical research. In this article, we first review the rationale behind the cycling of Ca isotopes in vertebrate organisms. We then summarize and discuss the use of Ca isotopes as dietary tracers from trophic reconstructions in past vertebrate ecosystems to the tracking of early life dietary transitions. Next, we review and examine the research outcomes on the potential of Ca isotopes as biomarkers of bone loss in physiological and pathological conditions such as bone cancers and osteoporosis. While emphasizing the needs of future research in each of these applications, we suggest new potential uses of Ca isotopes in vertebrate biology. Finally, we identify challenges and barriers faced when developing such interdisciplinary projects and suggest how these can be overcome.Tackie-Otoo, B.N., Ayoub Mohammed, M.A., Yekeen, N., Negash, B.M., 2019. Alternative chemical agents for alkalis, surfactants and polymers for enhanced oil recovery: Research trend and prospects. Journal of Petroleum Science and Engineering 187, 106828. Enhanced Oil Recovery (CEOR) techniques include alkaline, surfactant, and polymer flooding, as well as their binary and ternary combination such as alkali-surfactant (AS) and alkali-surfactant-polymer (ASP) flooding. However, the conventional synthetic chemical agents deployed in chemical flooding are confronted with several challenges, mainly the high cost and environmental related issues. Moreover, various technical limitations also affect the economic feasibility of the implementation of these methods. Green alternatives, such as organic alkalis, biopolymers and biosurfactants have been proposed and studied in literature as environmentally friendly and economically feasible options. They have also been proven to be stable in harsh reservoir conditions and in the presences of divalent cations. This review, therefore, presents an overview of available works on potential alternative chemical agents for conventional CEOR chemical agents. The various reports are compared to certify findings that are strong enough to facilitate field implementation. Then, recommendations are made on findings that require substantiation by further studies and areas that require more investigation. New research approaches are also recommended to improve the understanding of the flooding process of these alternative chemical agents. Reported works on organic alkalis show that ethanolamine proves to be the most effective alternative to inorganic alkalis. Plant oil-based surfactants that have been synthesized recently, outperform conventional synthetic surfactants in addition to their environmental friendliness. Ionic liquids, on the other hand, have enhanced functionality in harsh reservoir conditions contrary to conventional surfactants. Biopolymers are more stable and have reduced adsorption under harsh reservoir conditions. However, further studies are required to deepen the knowledge on wettability alteration by organic alkalis and the adsorption of biodegradable anionic surfactants. Studies are required to also improve the injectivity of biopolymers and suppress their biodegradability during flooding. This review will help improve the knowledge on alternatives chemicals to facilitate their field scale application.Tagesson, T., Schurgers, G., Horion, S., Ciais, P., Tian, F., Brandt, M., Ahlstr?m, A., Wigneron, J.-P., Ard?, J., Olin, S., Fan, L., Wu, Z., Fensholt, R., 2020. Recent divergence in the contributions of tropical and boreal forests to the terrestrial carbon sink. Nature Ecology & Evolution 4, 202-209. land use and land cover changes (LULCC) have a large impact on the global terrestrial carbon sink, but this effect is not well characterized according to biogeographical region. Here, using state-of-the-art Earth observation data and a dynamic global vegetation model, we estimate the impact of LULCC on the contribution of biomes to the terrestrial carbon sink between 1992 and 2015. Tropical and boreal forests contributed equally, and with the largest share of the mean global terrestrial carbon sink. CO2 fertilization was found to be the main driver increasing the terrestrial carbon sink from 1992 to 2015, but the net effect of all drivers (CO2 fertilization and nitrogen deposition, LULCC and meteorological forcing) caused a reduction and an increase, respectively, in the terrestrial carbon sink for tropical and boreal forests. These diverging trends were not observed when applying a conventional LULCC dataset, but were also evident in satellite passive microwave estimates of aboveground biomass. These datasets thereby converge on the conclusion that LULCC have had a greater impact on tropical forests than previously estimated, causing an increase and decrease of the contributions of boreal and tropical forests, respectively, to the growing terrestrial carbon sink.Táncsics, A., Farkas, M., Horváth, B., Maróti, G., Bradford, L.M., Lueders, T., Kriszt, B., 2020. Genome analysis provides insights into microaerobic toluene-degradation pathway of Zoogloea oleivorans BucT. Archives of Microbiology 202, 421-426. oleivorans, capable of using toluene as a sole source of carbon and energy, was earlier found to be an active degrader under microaerobic conditions in aquifer samples. To uncover the genetic background of the ability of microaerobic toluene degradation in Z. oleivorans, the whole-genome sequence of the type strain BucT was revealed. Metatranscriptomic sequence reads, originated from a previous SIP study on microaerobic toluene degradation, were mapped on the genome. The genome (5.68 Mb) had a mean G?+?C content of 62.5%, 5005 protein coding gene sequences and 80 RNA genes. Annotation predicted that 66 genes were involved in the metabolism of aromatic compounds. Genome analysis revealed the presence of a cluster with genes coding for a multicomponent phenol-hydroxylase system and a complete catechol meta-cleavage pathway. Another cluster flanked by mobile-element protein coding genes coded a partial catechol meta-cleavage pathway including a subfamily I.2.C-type extradiol dioxygenase. Analysis of metatranscriptomic data of a microaerobic toluene-degrading enrichment, containing Z?.? oleivorans as an active-toluene degrader revealed that a toluene dioxygenase-like enzyme was responsible for the ring-hydroxylation, while enzymes of the partial catechol meta-cleavage pathway coding cluster were responsible for further degradation of the aromatic ring under microaerobic conditions. This further advances our understanding of aromatic hydrocarbon degradation between fully oxic and strictly anoxic conditions.Tang, K., 2020. Chemical diversity and biochemical transformation of biogenic organic sulfur in the ocean. Frontiers in Marine Science 7, 68. doi: 10.3389/fmars.2020.00068. sulfur compounds are not only essential for organismal survival but also indispensable for the sulfur cycle. Over the past few decades, dimethylsulfoniopropionate (DMSP) and dimethyl sulfide (DMS) cycling in the upper ocean have been well characterized from the genetic to the ecosystem level. Recent advances in the study of marine sulfonate transformation have indicated that phytoplankton and microbes play key roles in oceanic sulfur and carbon fluxes. This review provides biochemical details of the major sulfur metabolites, and presents an interlinked reaction network with genetic information on the microbial transformation and mineralization of sulfur compounds. This review also discusses future prospects for the discovery and characterization of novel substrates and enzymes involved in organosulfur cycling, as well as for investigations of deep sea and sedimentary organic sulfur.Tang, L., Song, Y., Pang, X., Jiang, Z., Guo, Y., Zhang, H., Pan, Z., Jiang, H., 2020. Effects of paleo sedimentary environment in saline lacustrine basin on organic matter accumulation and preservation: A case study from the Dongpu Depression, Bohai Bay Basin, China. Journal of Petroleum Science and Engineering 185, 106669. Dongpu Depression has abundant oil and gas resources, but the distribution of hydrocarbon resources and enrichment degrees of organic matter (OM) in the northern and southern Dongpu Depression have significant differences due to the diverse sedimentary environment. To gain deep insight into the effects of sedimentary environment on OM accumulation and preservation, a series of experiments including element geochemistry, organic geochemistry and isotope geochemistry were performed on core samples collected from the fresh, brackish and saline regions of the third member of the Eocene Shahejie Formation (Es3). The lacustrine closure, paleo-salinity, redox conditions, hydrodynamic conditions, paleo-climate and paleo-productivity were quantitatively evaluated. Controlling factors and OM enrichment models were evaluated and established. The results show that the Es3 Formation was deposited as the lake experienced closed saline to transitional and then fresh lake stages. The lacustrine deposits were accompanied by climate changes from dry to humid and strongly rifting during Es3 deposition. The weak hydrodynamic conditions (Zr/Rb) and paleo climate indices (δ18O, climate index, Fe/Mn, Sr/Cu and Al/Mg) imply that moderate humid and dry climate can encourage OM development and preservation. The paleo productivity indices (δ13C, P/Al, P/Ti and P content) are positively related to TOC indicating that high productivity promotes OM accumulation. All the paleo salinity indices (Z value, Sr/Ba and B/Ga) have positive correlations with TOC content, suggesting that OM enrichment increases with salinity to some extent. The positive relationships between the redox indices (V/Cr, V/Sc, U/Th, and δU) and TOC indicate that redox conditions are the most important for OM preservation. This study not only advances the theory of OM enrichment mechanism in saline basins, but also provides guidance for predicting the distributions of high-quality source rocks in the Dongpu Depression.Tang, Y., Li, M., Zhu, Q., He, D., Jiang, X., Xiao, H., Shan, J., Kang, W., Leng, J., Wang, W., 2019. Geochemical characteristics and origin of hydrocarbons in the Mesoproterozoic reservoirs in the Liaoxi Depression, NE China. Energy Exploration & Exploitation 38, 333-347. reservoirs have been discovered in the Mesoproterozoic strata in the Liaoxi Depression, NE China. In order to determine the source of oil shows of the Mesoproterozoic Gaoyuzhuang Formation and their organic geochemical characteristics, eight source rocks and reservoir cores from the Mesoproterozoic Gaoyuzhuang Formation and four source rocks from the overlying Middle Jurassic Haifanggou Formation were geochemically analysed. The distribution patterns of normal alkanes, acyclic isoprenoids, hopanes, steranes and triaromatic steroids of the Mesoproterozoic hydrocarbons from Well N-1 are consistent with those of source rock extracts from the Mesoproterozoic Gaoyuzhuang Formation in the Well L-1. The molecular marker compositions of source rock extracts from the overlying Middle Jurassic Haifanggou Formation are distinctively different from those of the Mesoproterozoic hydrocarbons. The results suggest that the Mesoproterozoic source rocks have significant petroleum generation potential. The Mesoproterozoic paleo-reservoir may be prospecting exploration targets in the Liaoxi Depression, NE China.Tao, M.-J., Zhang, N.-N., Wen, P.-Y., Deng, F.-G., Ai, Q., Long, G.-L., 2020. Coherent and incoherent theories for photosynthetic energy transfer. Science Bulletin 65, 318-328. is a remarkable characteristic of photosynthesis in nature, that is, the energy transfer efficiency is close to 100%. Recently, due to the rapid progress made in the experimental techniques, quantum coherent effects have been experimentally demonstrated. Traditionally, the incoherent theories are capable of calculating the energy transfer efficiency, e.g., (generalized) F?rster theory and modified Redfield theory (MRT). However, in order to describe the quantum coherent effects in photosynthesis, one has to exploit coherent theories, such as hierarchical equation of motion (HEOM), quantum path integral, coherent modified Redfield theory (CMRT), small-polaron quantum master equation, and general Bloch-Redfield theory in addition to the Redfield theory. Here, we summarize the main points of the above approaches, which might be beneficial to the quantum simulation of quantum dynamics of exciton energy transfer (EET) in natural photosynthesis, and shed light on the design of artificial light-harvesting devices.Tarduno, J.A., Cottrell, R.D., Bono, R.K., Oda, H., Davis, W.J., Fayek, M., Erve, O.v.t., Nimmo, F., Huang, W., Thern, E.R., Fearn, S., Mitra, G., Smirnov, A.V., Blackman, E.G., 2020. Paleomagnetism indicates that primary magnetite in zircon records a strong Hadean geodynamo. Proceedings of the National Academy of Sciences 117, 2309-2318.: The age and early history of Earth’s geomagnetic field can provide insight into the evolution of the core and atmosphere. But measurement of Hadean zircons—the oldest known terrestrial materials—and the determination of the antiquity of their magnetizations are amongst the most challenging endeavors in paleomagnetism. New paleomagnetic, electron microscope, geochemical, and paleointensity data indicate the presence of primary magnetite inclusions in select zircons. These data support the presence of the geomagnetic field, and associated shielding of the atmosphere from the solar wind, ～4.2 billion years ago. A relatively strong field recorded by these zircons at ～4 billion years ago may be a signal that chemical precipitation in the core was powering the geodynamo.Abstract: Determining the age of the geomagnetic field is of paramount importance for understanding the evolution of the planet because the field shields the atmosphere from erosion by the solar wind. The absence or presence of the geomagnetic field also provides a unique gauge of early core conditions. Evidence for a geomagnetic field 4.2 billion-year (Gy) old, just a few hundred million years after the lunar-forming giant impact, has come from paleomagnetic analyses of zircons of the Jack Hills (Western Australia). Herein, we provide new paleomagnetic and electron microscope analyses that attest to the presence of a primary magnetic remanence carried by magnetite in these zircons and new geochemical data indicating that select Hadean zircons have escaped magnetic resetting since their formation. New paleointensity and Pb-Pb radiometric age data from additional zircons meeting robust selection criteria provide further evidence for the fidelity of the magnetic record and suggest a period of high geomagnetic field strength at 4.1 to 4.0 billion years ago (Ga) that may represent efficient convection related to chemical precipitation in Earth’s Hadean liquid iron core.Tarnovetskii, I.Y., Merkel, A.Y., Pimenov, N.V., 2019. Analysis of cultured methanogenic archaea from the Tarkhankut Peninsula Coastal methane seeps. Microbiology 88, 681-688. major substrates for methanogenesis were used for investigation of cultured methanogenic archaea from coastal methane seeps near the Tarkhankut Peninsula, Black Sea. Analysis of the 16S rRNA gene sequences revealed that growth of the classical methanogenic Euryarchaeota occurred in all enrichments but was absent in the controls without the substrates. Enrichments from the seep differed in microbial composition from those from the background point. The most numerous archaea belonged to the genera Methanolobus (medium with methanol and hydrogen), Methanosarcina (trimethylamine and hydrogen), Methanococcoides (trimethylamine), and Methanococcus (hydrogen and CO2). Syntrophic growth of hydrogenotrophic archaea of the genus Methanogenium with clostridia and members of the family Thermotogaceae probably occurred in enrichments with acetate. Relatively low similarity of the recovered 16S rRNA gene sequences with the closest cultured relatives (94% and lower) indicated that the Methanogenium phylotype belonged to a new species. The same was true for the Methanosarcina phylotype revealed in the culture with trimethylamine and hydrogen (97% and less similarity of the 16S rRNA gene sequences to those of the closest cultured relatives).Tegner, C., Marzoli, A., McDonald, I., Youbi, N., Lindstr?m, S., 2020. Platinum-group elements link the end-Triassic mass extinction and the Central Atlantic Magmatic Province. Scientific Reports 10, 3482. concentrations of iridium (Ir) and other platinum-group elements (PGE) have been reported in both terrestrial and marine sediments associated with the end-Triassic mass extinction (ETE) c. 201.5 million years ago. The source of the PGEs has been attributed to condensed vapor and melt from an extraterrestrial impactor or to volcanism. Here we report new PGE data for volcanic rocks of the Central Atlantic Magmatic Province (CAMP) in Morocco and show that their Pd/Ir, Pt/Ir and Pt/Rh ratios are similar to marine and terrestrial sediments at the ETE, and very different from potential impactors. Hence, we propose the PGEs provide a new temporal correlation of CAMP volcanism to the ETE, corroborating the view that mass extinctions may be caused by volcanism.Teske, A., 2020. 10 years of extreme microbiology: An interim reflection and future prospects. Frontiers in Microbiology 11, 131. doi: 10.3389/fmicb.2020.00131. into the crystal ball and predicting the future for the next 10 years for Extreme Microbiology can lead to equal shares of amusement and bewilderment down the road, best encapsulated in the exclamation “What were we thinking?” Keeping this caveat in mind while not worrying not too much about it will help coming up with a useful idea or two. Also, looking into what the Extreme Microbiology Section has become should be helpful; reality may contradict even the most elaborate prognosticating efforts, and point into new directions that even the very wise may not foresee.After surveying the Research Topics and most successful articles of the last 10 years, the first impression is that of a surprising diversity of themes, organisms, contributors, and, by implication, readers. The original “grand challenge article” (Teske, 2010) had certainly invited and welcomed this diversity, but could not foresee its encyclopedic scope. One thing is sure, “Extreme Microbiology” is not the enclave of a handful of specialists who cultivate a strange garden of extremophiles, or craft the Fabergé eggs of microbiology. Many research themes have turned out to be surprisingly popular, notably so in areas where extremophilic microbiology and applicability overlap. Looking through the Research Topics of the last 10 years, one could name investigations into acidophilic sulfur-or iron-oxidizing microorganisms and their importance in mining and bioleaching; the study of thermostable or cold-active enzymes with biotechnological potential; articles on facultative extremophiles and their uses; repeated focus on Actinobacteria, the hardy gram-positive, often thermophilic or thermotolerant bacteria that pervade the terrestrial and soil biosphere; the entire arc of halophile research from natural biodiversity to organism- or enzyme-specific studies; or astro-microbiology under different regimes of scientific gravity, from space station experiments that are actually being done to speculative scenarios of early Martian life. Purists may call this wide thematic range “eclectic” but it is evidence of the vitality of extremophile research that is proceeding in surprising directions. More accurately, they may be “surprising” primarily for senior editors but not so much for the scientists and their audiences who are driving these research efforts.Some areas of extremophile research integrate the habitats and their microbial inhabitants that reflect its special characteristics; the extreme microbial ecosystem always appears in the background, or shines through. Major habitat types such as hydrothermal vents, hydrocarbon seeps or the deep subsurface, provide the umbrella under which the respective microorganisms or microbial communities make their appearance. Extreme habitats require well-matched extreme microbial inhabitants, distinguished by uniquely adapted biochemistry and intriguing physiological capabilities that reflect the conditions of their existence. For many authors and readers [including this editor], this flavor of extreme microbiology—ultimately, extreme microbial ecosystem research—has drawn them into this field. For example, who would not be amazed by the complex biogeochemical layering and microscale architecture of a microbial mat from a hot spring or hydrothermal vent that may have existed in similar form already billions of years ago? Views and downloads for some articles of this type exceed 5,000 and 500, respectively, showing their enduring interest.However, it would be short-sighted to think that visually charismatic microbial ecosystems and expedition targets will necessarily define the attraction of Extreme Microbiology in the coming decade. Planet Earth, and perhaps not only planet Earth, will continue to be searched for extreme microbiomes, but this is not where the story ends. Now we come to the risky part of this short editorial, prognosticating. Be it! I think that the most exciting scientific advances of the next decade in the broadly defined “extremophile” area will target the uncharted depths of microbial evolution. I suggest (1) microbial dark matter and (2) archaea as key areas to watch and to cultivate in Frontiers, and I am very pleased to see that a brand-new specialty within Frontiers in Microbiology, “Biology of Archaea,” will now provide a permanent home for these new research developments. “Microbial dark matter” is shorthand for the vast diversity of uncultured microbial life that is out there (Rinke et al., 2013), and currently eludes laboratory cultivation or other forms of domestication. The outlines of the bacterial domain have changed dramatically, from a tree into a forest; and just as in a real forest, many lineages survive and thrive only by some form of symbiotic or parasitic association (Hug et al., 2016). The archaeal domain has changed from a collection of interesting specialties into a vast evolutionary frontier where all of a sudden everything seems possible. For example, hydrocarbon metabolism has proliferated throughout the archaeal domain in the last 2 or 3 years (Seitz et al., 2019); the proposal that archaeal lineages—the Asgard archaea—provided genetic and structural machinery for the ancient eukaryotic host cell has fired up the field of microbial evolution; the archaeal tree of life is at last emerging in full and draws attention to the biogeochemical and ecological roles of the archaeal biome (Spang et al., 2017). Elucidating microbial dark matter and charting the archaeal world will engage a new generation of investigators and introduce them to the Frontiers community. As chief specialty editor, I will launch a Research Topic on archaea in their environments—co-hosted with the “Biology of Archaea” section—as my contribution to celebrate the next 10 years of Frontiers in Microbiology.This editorial was written at sea on a research ship, the JOIDES Resolution, where a multidisciplinary team of geologists, geochemists and microbiologists is exploring microbial life in the layered hydrothermal sediments and basalts of a young oceanic spreading center, Guaymas Basin in the Gulf of California [expedition/385/]. Guaymas Basin is famous for its microbial diversity hosted by its hydrothermal vents, hydrocarbon seeps and organic-rich seafloor sediments (Figure 1) (Teske et al., 2014, 2016). The ship is a floating university with well-equipped labs for every research direction and a major drill rig riding midships, to recover sediment and basalt from the hydrothermal zone several hundred meters below the seafloor. Here, the wider geothermal and geochemical properties of this extreme subsurface environment, and the types of microbial life to be tracked are constantly evaluated in relation to each other. Finally, the microbiomes of this special place will illuminate the uncharted depths of microbial evolution.However, one example can go only so far. Authors who publish in Frontiers in Microbiology, and the Extreme Microbiology section, will continue to launch diverse investigations where physiological and genomic detail can ultimately be linked to organisms, communities, and entire ecosystems. In the future, I hope that the readers of Frontiers in Microbiology will find more examples of these exciting endeavors in the “Extreme Microbiology” section.ReferencesDombrowski, N., Teske, A. P., and Baker, B. J. (2018). Extensive microbial metabolic diversity and redundancy in Guaymas Basin hydrothermal sediments. Nat. Commun. 9:4999. doi: 10.1038/s41467-018-07418-0Hug, L. A., Baker, B. J., Anantharaman, K., Brown, C. T., Probst, A. J., Castelle, C. J., et al. (2016). A new view on the tree of life. Nat. Microbiol. 1:16048. doi: 10.1038/nmicrobiol.2016.48Rinke, C., Schwientek, P., Sczyrba, A., Ivanova, N. N., Anderson, I. J., Cheng, J. F., et al. (2013). Insights into the phylogeny and coding potential of microbial dark matter. Nature 499, 431–437. doi: 10.1038/nature12352Seitz, K. W., Dombrowski, N., Eme, L., Spang, A., Lombard, J., Sieber, J. R., et al. (2019). Asgard Archaea are capable of anaerobic hydrocarbon cycling. Nat. Commun. 10:1822. doi: 10.1038/s41467-019-09364-xSpang, A., Caceres, E. F., and Ettema, T. J. G. (2017). Genomic exploration of the diversity, ecology and evolution of the archaeal domain of life. Science 357:eaaf3883. doi: 10.1126/science.aaf3883Teske, A. (2010). Grand challenges in extreme microbiology. Front. Microbiol. 1:111. doi: 10.3389/fmicb.2010.00111Teske, A., Callaghan, A. V., and LaRowe, D. E. (2014). Biosphere frontiers of subsurface life in the sedimented hydrothermal system of Guaymas Basin. Front. Microbiol. 5:362. doi: 10.3389/fmicb.2014.00362Teske, A., de Beer, D., McKay, L. J., Tivey, M. K., Biddle, J. F., Hoer, D., et al. (2016). The Guaymas Basin hiking guide to hydrothermal mounds, chimneys and microbial mats: complex seafloor expressions of subsurface hydrothermal circulation. Front. Microbiol. 7:75. doi: 10.3389/fmicb.2016.00075Thalasso, F., Sepulveda-Jauregui, A., Gandois, L., Martinez-Cruz, K., Gerardo-Nieto, O., Astorga-Espa?a, M.S., Teisserenc, R., Lavergne, C., Tananaev, N., Barret, M., Cabrol, L., 2020. Sub-oxycline methane oxidation can fully uptake CH4 produced in sediments: case study of a lake in Siberia. Scientific Reports 10, 3423. is commonly assumed that methane (CH4) released by lakes into the atmosphere is mainly produced in anoxic sediment and transported by diffusion or ebullition through the water column to the surface of the lake. In contrast to that prevailing idea, it has been gradually established that the epilimnetic CH4 does not originate exclusively from sediments but is also locally produced or laterally transported from the littoral zone. Therefore, CH4 cycling in the epilimnion and the hypolimnion might not be as closely linked as previously thought. We utilized a high-resolution method used to determine dissolved CH4 concentration to analyze a Siberian lake in which epilimnetic and hypolimnetic CH4 cycles were fully segregated by a section of the water column where CH4 was not detected. This layer, with no detected CH4, was well below the oxycline and the photic zone and thus assumed to be anaerobic. However, on the basis of a diffusion-reaction model, molecular biology, and stable isotope analyses, we determined that this layer takes up all the CH4 produced in the sediments and the deepest section of the hypolimnion. We concluded that there was no CH4 exchange between the hypolimnion (dominated by methanotrophy and methanogenesis) and the epilimnion (dominated by methane lateral transport and/or oxic production), resulting in a vertically segregated lake internal CH4 cycle.Thiagarajan, N., Xie, H., Ponton, C., Kitchen, N., Peterson, B., Lawson, M., Formolo, M., Xiao, Y., Eiler, J., 2020. Isotopic evidence for quasi-equilibrium chemistry in thermally mature natural gases. Proceedings of the National Academy of Sciences 117, 3989-3995.: The mechanisms of natural gas formation are important to the carbon cycle and predicting where economical amounts of natural gas form. However, the formation mechanisms of natural gas are not clear, with hypotheses including both irreversible chemical processes such as thermal cracking of long-chain hydrocarbons and thermodynamic equilibrium processes such as transition metal catalysis. Here we show that hydrocarbon species in natural gases are initially produced by irreversible cracking chemistry, but, as thermal maturity increases, the H and C isotopic distributions within and among coexisting light n-alkanes approach thermodynamic equilibrium, either at the conditions of gas formation or during reservoir storage. Our finding has significant implications for natural gas exploration.Abstract: Natural gas is a key energy resource, and understanding how it forms is important for predicting where it forms in economically important volumes. However, the origin of dry thermogenic natural gas is one of the most controversial topics in petroleum geochemistry, with several differing hypotheses proposed, including kinetic processes (such as thermal cleavage, phase partitioning during migration, and demethylation of aromatic rings) and equilibrium processes (such as transition metal catalysis). The dominant paradigm is that it is a product of kinetically controlled cracking of long-chain hydrocarbons. Here we show that C2+ n-alkane gases (ethane, propane, butane, and pentane) are initially produced by irreversible cracking chemistry, but, as thermal maturity increases, the isotopic distribution of these species approaches thermodynamic equilibrium, either at the conditions of gas formation or during reservoir storage, becoming indistinguishable from equilibrium in the most thermally mature gases. We also find that the pair of CO2 and C1 (methane) exhibit a separate pattern of mutual isotopic equilibrium (generally at reservoir conditions), suggesting that they form a second, quasi-equilibrated population, separate from the C2 to C5 compounds. This conclusion implies that new approaches should be taken to predicting the compositions of natural gases as functions of time, temperature, and source substrate. Additionally, an isotopically equilibrated state can serve as a reference frame for recognizing many secondary processes that may modify natural gases after their formation, such as biodegradation.Tian, L., Song, H., Ye, Q., Hu, J., An, Z., Zhao, X., Bottjer, D., Tong, J., 2020. Recurrent anoxia recorded in shallow marine facies at Zhangcunping (western Hubei, China) throughout the Ediacaran to earliest Cambrian. Precambrian Research 340, 105617. order to reconstruct the redox history of surface seawater for Ediacaran shallow marine facies on the Yangtze Platform, as well as to understand its implications for geological events (oxidation and phosphatization) and early evolution of life, we have conducted a systematic high-resolution investigation on microfacies analyses, pyrite morphology as well as sulfur and carbon contents in a continuous carbonate Ediacaran–Cambrian succession (drilled 407-core) in the Zhangcunping area of western Hubei (South China). The framboidal pyrites and SNAV/TOC (NAV = non-acid volatile sulfur) based redox reconstruction show a dynamic history of recurrent shallow marine anoxia. The early aftermath of the Marinoan Glaciation (cap dolomite to phosphorites) was characterized by either absence of pyrite or dominated by large framboids, low TOC contents and phosphorite deposition as well as well-preserved microfossils, indicating a minor oxygenated (dysoxic to oxic) photic shallow marine ecosystem. Meanwhile, the uppermost Doushantuo and Dengying formations were potentially fully oxygenated due to the lack of pyrites as well as low SNAV and TOC contents. Correlating with macrofossil assemblages (Miaohe biota and Ediacara biota) found in western Hubei, a major oxygenated marine ecosystem can be outlined for the late Ediacaran. In addition, a complicated diagenetic microfabric overprints the fine microstructure of microfossils preserved in phosphorites, leaving remarkable taphonomic puzzles for future study.Tian, Y., Ju, B., Lü, G., Liu, N., Dong, Y., Ma, S., 2020. The comprehensive model for solvent assisted steam flooding in thin heavy oil reservoirs considering asphaltene deposition. Journal of Petroleum Science and Engineering 185, 106676. steam flooding has gained popularity in heavy oil reservoir during recent years. Calculating asphaltene deposition is a key issue in developing heavy oil reservoirs, because asphaltene deposition can significantly reduce permeability by blocking pore throats. In this work, a comprehensive model of solvent assisted steam flooding for thin heavy oil reservoirs considering the influence of asphaltene deposition was proposed. The model is solved by IMPES (Implicit Pressure and Explicit Saturations) method. The amount of deposition is calculated through three mechanisms of entrainment, plugging deposition and surface deposition. Then, the effects of asphaltene deposition on well performance and permeability reduction were analyzed. Furthermore, the solubility parameter is used to investigate the effect of different solvents on alleviating the damage of asphaltene deposition for reservoir. The damage of asphaltene deposition for reservoir can decrease with the increase of solvent concentration. Finally, based on the analysis of oil production, it is found that butane assisted steam flooding is the most effective thermal method to improve the oil recovery. And injection parameters of butane assisted steam are also determined for an oil field by analysis of oil production. Based on the results in this paper, it may be extensive applicability and practical significance for determining the best solvent and reasonable injection parameters during the development of heavy oil reservoirs considering asphaltene deposition to enhance oil recovery.Tian, Y., Zhan, Z.-W., Zou, Y.-R., Liao, Z., Peng, P.a., 2020. Separation of crocetane and phytane and measurement of their compound-specific carbon isotopic compositions. Journal of Chromatography A 1612, 460621. and phytane are two isoprenoids isomers with similar molecular structures and often present together in methane-seep sediments and some Palaeozoic crude oils. Their commonly co-elution on gas chromatography is challenging for quality and quantity analysis, making it impossible to determine their compound-specific isotopic composition, and thus, insight their geological and geochemical significance. A new gas chromatography method is reported here using a DB-17MS column (50%-phenyl-methyl polysiloxane as the stationary phase) that successfully achieved baseline separation of crocetane and phytane and can be used to accurately identify and quantify them on gas chromatography and gas chromatography–mass spectrometry. Routine steroids and terpenoids biomarkers can also be analysed simultaneously. Additionally, their compound-specific carbon isotopic compositions were also measured without matrix influence using this method. This is the first time that a simple chromatographic method for direct determination of compound-specific carbon isotopic composition of crocetane has been reported publicly.Tianhao, Z., Chen, Y., Liu, P., Zhou, L., Zhu, Q., Wang, J., Li, X., 2020. Investigation on the thermal cracking of n-decane under supercritical pressure by a developed online-sampling experimental method. Petroleum Chemistry 60, 39-44. this work, the thermal cracking of n-decane was carried out under supercritical pressure. To comprehensively investigate the thermal cracking, a developed online-sampling experimental method was constructed through the directly cooling of cracked fuel at high temperature. The results show, that the novel method can effectively terminate the subsequent cracking which occurred in the heat exchanger. Therefore, compared with the traditional offline-sampling method, lower gas product yields and conversions were obtained with this novel method. Besides, products composition and distribution were detected and analyzed in detail. In gas products, more alkanes and hydrogen were obtained while olefins were relatively less according to our novel method. For liquid products, similar composition and distribution can be obtained in both methods except that aromatic products decrease significantly by adopting the novel method. In general, this novel method can provide precise product yield and composition with little influence on the thermal cracking process.Totani, T., 2020. Emergence of life in an inflationary universe. Scientific Reports 10, 1671. emergence of ordered information stored in the form of RNA is an important unresolved problem concerning the origin of life. A polymer longer than 40–100 nucleotides is necessary to expect a self-replicating activity, but the formation of such a long polymer having a correct nucleotide sequence by random reactions seems statistically unlikely. However, our universe, created by a single inflation event, likely includes more than 10100 Sun-like stars. If life can emerge at least once in such a large volume, it is not in contradiction with our observations of life on Earth, even if the expected number of abiogenesis events is negligibly small within the observable universe that contains only 1022 stars. Here, a quantitative relation is derived between the minimum RNA length lmin required to be the first biological polymer, and the universe size necessary to expect the formation of such a long and active RNA by randomly adding monomers. It is then shown that an active RNA can indeed be produced somewhere in an inflationary universe, giving a solution to the abiotic polymerization problem. On the other hand, lmin must be shorter than ~20 nucleotides for the abiogenesis probability close to unity on a terrestrial planet, but a self-replicating activity is not expected for such a short RNA. Therefore, if extraterrestrial organisms of a different origin from those on Earth are discovered in the future, it would imply an unknown mechanism at work to polymerize nucleotides much faster than random statistical processes.Tranchida, P.Q., Mondello, L., 2020. Chapter 1.2 - Conventional GC-MS applications, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 75-108. present contribution is focused on the combination of gas chromatography with mass spectrometry (GC-MS), and its use in state-of-the-art applications. The first part of the subchapter contains introductive information related to GC-MS; state-of-the-art applications follow, with a subdivison made on the basis of the MS analyzer used (low resolution, high resolution, multiple analyzers). A wide variety of applications are described: food aroma, food contamination (pesticides, dioxins, flame retardants, etc.), petrochemicals, environmental contamination, and human fluid metabolomics. Greater focus is devoted to more recent forms of MS, rather than to more classical instrumentation.Tranchida, P.Q., Mondello, L., 2020. Chapter 2.2 - Comprehensive 2D Gas Chromatography, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 183-226. present contribution is focused on the combination of comprehensive two-dimensional gas chromatography with mass spectrometry (GC×GC-MS). The first part of the subchapter contains information related to the history and development of GC×GC (both with and without MS hyphenation), along with general principles, practical issues (i.e., modulation processes, method optimization, etc.), main forms of detection (non-MS devices), and some basic theory. The second part of the sub-chapter is based on state-of-the-art applications involving various forms of mass spectrometry, from more popular (low resolution, time-of-flight, single quadrupole) to less common (high resolution, time-of-flight, triple quadrupole) MS instrumentation.Tranchida, P.Q., Mondello, L., 2020. Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, p. 514. of Capillary Chromatography with Mass Spectrometry provides comprehensive coverage of capillary chromatography with mass spectrometry—both single and multidimensional approaches. The book examines nearly all capillary chromatography approaches, combined with a variety of MS forms, giving readers a wide and detailed view on current-day analytical strategies and applications. Of particular focus are novel developments in the field of MS, such as the Orbitrap, HR ToF, ToF MS with variable electron-impact energy, fast MS-MS and APGC technology.Junior scientists conducting research on mono-dimensional chromatography-MS fundamental relationships and experienced analytical chemists working in conventional capillary chromatography and classical multidimensional chromatography will find this an ideal application-based reference on the hyphenations of these bines mass spectrometry with a range of chromatographic approaches Emphasizes the importance of both capillary chromatography and mass spectrometry methods, thus stimulating separation scientists to fully exploit both analytical dimensions Authored by two of the world’s leading analytical chemists who have a total of more than 40 years of experience in research and instructionPart 1: Hyphenation of capillary gas chromatography with mass spectrometryChapter 1.1 - General principles and history, Marta P.B. Mour?o, Arend H.J. Kolk and Hans-Gerd Janssen, Pages 3-74Chapter 1.2 - Conventional GC-MS applications, Peter Q. Tranchida and Luigi Mondello, Pages 75-108Chapter 1.3 - High-speed GC-MS: Basic theory, practical aspects, and applications, Peter Q. Tranchida, Mariosimone Zoccali and Luigi Mondello, Pages 109-132Part 2: Two-dimensional capillary gas chromatography-based processes combined with mass spectrometryChapter 2.1 - Classical two-dimensional GC combined with mass spectrometry, Frank David, Pages 135-182Chapter 2.2 - Comprehensive 2D Gas Chromatography, Peter Q. Tranchida and Luigi Mondello, Pages 183-226Chapter 2.3 - Classical and comprehensive 2D LC-GC, Giorgia Purcaro, Pages 227-275Part 3: Hyphenation of oneand two-dimensional capillary liquid chromatography with mass spectrometryChapter 3.1 - History of liquid chromatography—mass spectrometry couplings, Chris G. de Koster and Peter J. Schoenmakers, Pages 279-295Chapter 3.2 - Theoretical and practical aspects of LC-MS analysis, Paola Donato, Paola Arena and Luigi Mondello, Pages 297-317Chapter 3.3 - Hyphenations of one-dimensional capillary liquid chromatography with mass spectrometry: State-of-the-art applications, Steven Ray Wilson, Henriette Engen Berg, Hanne Roberg-Larsen, Elsa Lundanes, Pages 319-36Chapter 3.4 - Hyphenations of 2D capillary-based LC with mass spectrometry, Francesco Cacciola, Domenica Mangraviti, Luigi Mondello, Paola Dugo, Pages 369-412Chapter 4 - Capillary electrophoresis-mass spectrometry: History, general principles, theoretical aspects, and state-of-the-art applications, Chiara Fanali, Giovanni D'Orazio and Salvatore Fanali, Pages 413-447Chapter 5 - Management and interpretation of capillary chromatography-mass spectrometry data, Brooke C. Reaser, Nathanial E. Watson, Sarah E. Prebihalo, David K. Pinkerton, Kristen J. Skogerboe, Robert E. Synovec, Pages 449-480Index, Pages 481-500Tranchida, P.Q., Zoccali, M., Mondello, L., 2020. Chapter 1.3 - High-speed GC-MS: Basic theory, practical aspects, and applications, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 109-132. gas chromatography, combined with mass spectrometry (GC-MS), is the focus of the present sub-chapter. Specifically, four of the most popular approaches to reduce GC separation times are herein reported: capillary columns with a reduced ID and film thickness (micro-bore columns), conditions of vacuum at the column outlet (low-pressure GC), very rapid (resistive) column heating, and (mostly short) narrow-bore capillary columns. Basic principles and theory, as well as practical aspects, in relation to each high-speed technology are described, along with advantages and drawbacks. A series of applications involving the use of such high-speed approaches, with various forms of mass spectrometry, are described and discussed. Focus is devoted in particular to the decade 2009–18.Trinklein, T.J., Gough, D.V., Warren, C.G., Ochoa, G.S., Synovec, R.E., 2020. Dynamic pressure gradient modulation for comprehensive two-dimensional gas chromatography. Journal of Chromatography A, 460488. report the discovery, preliminary investigation, and demonstration of a novel form of differential flow modulation for comprehensive two-dimensional (2D) gas chromatography (GC×GC). Commercially available components are used to apply a flow of carrier gas with a suitable applied auxiliary gas pressure (Paux) to a T-junction joining the first (1D) and second (2D) dimension columns. The 1D eluate is confined at the T-junction, and introduced for 2D separation with a cyclic rhythm, dependent upon the relationship of the modulation period (PM) to the pulse width (pw), where pw is defined as the time interval when the auxiliary gas flow at the T-junction is off. We refer to this flow modulation technique as “dynamic pressure gradient modulation” (DPGM) since a pressure gradient oscillates with the PM along the 1D and 2D column ensemble providing temporary stop-flow conditions and fast 2D flow rates, resulting in 100% duty cycle and full modulation. A 90-component test mixture was used to evaluate the technique with a pw of 60 ms and a PM of 750 ms. The resulting peaks were narrow, with 2Wb ranging from about 20-180 ms. With an average 1Wb of 3 s and a 2nc of 10, a 2D peak capacity, nc,2D, for the 25 min separation was 5000. The detector response enhancement factor (DREF) is reported, defined as the peak height of the highest modulated 2D peak divided by the unmodulated 1D peak height (DREF?=?2h/1h). The DREF ranged from about 7-87, depending on the 1Wb and 2Wb for a given analyte. A diesel sample was analyzed to demonstrate performance with a complex sample. Based upon the average 1Wb of 5 s and an average 2Wb of 168 ms, a nc,2D of 8640 was obtained for the 60 min diesel separation. Finally, the modulation principle was investigated as a function of PM, pw, and the volumetric flow rates, 1F and 2F. The measured 2Wb correlate well with the theoretical 2D injected width, given by 2Winj?=?(1F/2F) ?PM. However, the relevant 1F appears to be dictated by the 1D flow rate when no pressure is applied (during the pw interval), instead of 1F being the average flow rate on 1D (defined by the 1D dead time). The findings provide strong evidence for a differential flow modulation mechanism.Tromboni, F., Dodds, W.K., Chandra, S., Poulson, S.R., Pandey, A., Schechner, A., 2020. Respiration in rivers fractionates stable isotopes of dissolved oxygen; a global investigation on the influences of temperature and flow. Biogeochemistry 147, 199-210. ecosystem respiration remains challenging in aquatic ecosystems. Most investigators assume that nighttime and daytime respiration are equal. Recent studies suggest measuring dissolved oxygen isotopes during periods with and without photosynthesis can account for variations in daytime and nighttime respiration. These models are extremely sensitive to the oxygen isotopic fractionation factor (α) value used for respiration, yet almost nothing is known about the variability of α and factors driving that variability. We quantified how α varies with temperature and flow velocity using field measurements, laboratory experiments, and a modeling approach. We measured α in the field using sealed recirculating chambers in 16 rivers from different biomes (temperate, tropical, and sub-arctic) to assess a range of possible α values. The α values were widely variable, and variation was higher among sites in the same biome or ecoregion (e.g. 0.9780?±?0.005 to 0.9898?±?0.002 among six desert sites) than across different biomes. Our data revealed that both temperature, flow, and biofilm characteristics produced variations in α, with temperature decreasing and flow increasing it, until leveling off at high flow velocities. Biological and physical processes occurring in the diffusion boundary layer produced variations in α. Our results highlight that environmental conditions produce variable α values, the need for site-specific α measurements, and practical implications for consideration when measuring α in the field. More generally we illustrate an array of factors that can influence isotopic fractionation associated with metabolic activity of biologically active layers that could be important in any diffusion-limited environment.Trower, E.J., 2020. The enigma of Neoproterozoic giant ooids—fingerprints of extreme climate? Geophysical Research Letters 47, e2019GL086146.: Geologists have documented at least 14 occurrences of “giant ooids,” a geologically rare type of carbonate allochem, in Neoproterozoic successions at low paleolatitudes. Recent experiments and modeling demonstrated that ooid size reflects an equilibrium between precipitation and abrasion rates, such that ooid size could be used as a geological proxy for CaCO3 mineral saturation state (Ω). Here, the documented sizes of Neoproterozoic giant ooids were applied to estimate seawater Ω, which provided a novel approach to constraining temperature, partial pressure of CO2, and alkalinity preceding Neoproterozoic glaciations. The results suggest that giant ooid formation was most plausible with seawater alkalinity elevated over its present value by at least a factor of 2, and either much warmer (40 °C) or much colder (0 °C) climate than modern tropical carbonate platforms, which have important and divergent implications for climate states and ecosystem responses prior to the initiation of each Neoproterozoic glaciation.Plain Language Summary: Ooids are a type of calcium carbonate sediment grain composed of a set of concentric layers formed around a small particle. Although most ooids are sand‐size grains (<2 mm in diameter), rare cases, referred to as “giant ooids,” are much larger, with some >1 cm in diameter. Geologists have suggested that these giant ooids reflected unusual seawater chemistry, but the exact conditions required for their formation remained unknown. Although giant ooids are geologically rare, a surprising number of occurrences have been described from Neoproterozoic rocks (1,000–541 million years old) that underlie sedimentary layers deposited by low paleolatitude glaciations (i.e., “Snowball Earth” events). This study used the grain diameters of Neoproterozoic ooids to estimate the temperature and composition of seawater when they formed. The results showed that Neoproterozoic seawater must have been either very hot or very cold just prior to these glaciations, a finding that challenges either climate models of this era or conceptual models of common modes of carbonate sediment formation and deposition.Tsybin, Y.O., Nagornov, K.O., Kozhinov, A.N., 2019. Chapter 5 - Advanced fundamentals in Fourier transform mass spectrometry, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 113-132. transform mass spectrometry (FTMS) is an enabling technique to many challenging applications in molecular sciences. In this chapter we revisit FTMS fundamentals to further rationalize the selection of data acquisition and data processing approaches for the everyday FTMS practice. Whereas the FT-ICR MS fundamentals have been investigated and extensively reported for more than 40 years, the same level of understanding and description is not available for the teenager and rapidly evolving Orbitrap FTMS. Despite the widespread presence of the Orbitrap technology and its exponential development over the past decade, the associated data processing procedures are not always comprehensively described in the scientific literature. With this Chapter, we thus attempt to better inform the general user about the basics in mass spectra summation (averaging) and noise characteristics, as well as the benefits and consequences of using the data reduction approaches. For the latter, we describe the principles and compare the outcome of the full profile and the reduced profile mass spectra representation. To further bridge the knowledge gap, we compared ICR and Orbitrap FTMS techniques in regard to their resolution performance reflected through the theoretical didactic examples.Tumiati, S., Tiraboschi, C., Miozzi, F., Vitale-Brovarone, A., Manning, C.E., Sverjensky, D.A., Milani, S., Poli, S., 2020. Dissolution susceptibility of glass-like carbon versus crystalline graphite in high-pressure aqueous fluids and implications for the behavior of organic matter in subduction zones. Geochimica et Cosmochimica Acta 273, 383-402. matter, showing variable degrees of crystallinity and thus of graphitization, is an important source of carbon in subducted sediments, as demonstrated by the isotopic signatures of deep and ultra-deep diamonds and volcanic emissions in arc settings. In this experimental study, we investigated the dissolution of sp2 hybridized carbon in aqueous fluids at 1 and 3GPa, and 800?°C, taking as end-members (i) crystalline synthetic graphite and (ii) X-ray amorphous glass-like carbon. We chose glass-like carbon as an analogue of natural “disordered” graphitic carbon derived from organic matter, because unlike other forms of poorly ordered carbon, it does not undergo any structural modification at the investigated experimental conditions, allowing approach to thermodynamic equilibrium. Textural observations, Raman spectroscopy, synchrotron X-ray diffraction and dissolution susceptibility of char produced by thermal decomposition of glucose (representative of non-transformed organic matter) at the same experimental conditions support this assumption. The redox state of the experiments was buffered at ΔFMQ?≈?–0.5 using double capsules and either fayalite-magnetite-quartz (FMQ) or nickel-nickel oxide (NNO) buffers. At the investigated P–T–fO2 conditions, the dominant aqueous dissolution product is carbon dioxide, formed by oxidation of solid carbon. At 1GPa and 800?°C, oxidative dissolution of glass-like carbon produces 16–19?mol% more carbon dioxide than crystalline graphite. In contrast, fluids interacting with glass-like carbon at the higher pressure of 3GPa show only a limited increase in CO2 (fH2NNO) or even a lower CO2 content (fH2FMQ) with respect to fluids interacting with crystalline graphite. The measured fluid compositions allowed retrieval of the difference in Gibbs free energy (ΔG) between glass-like carbon and graphite, which is +1.7(1) kJ/mol at 1GPa–800?°C and +0.51(1) kJ/mol (fH2NNO) at 3GPa–800?°C. Thermodynamic modeling suggests that the decline in dissolution susceptibility at high pressure is related to the higher compressibility of glass-like carbon with respect to crystalline graphite, resulting in G–P curves crossing at about 3.4GPa at 800?°C, close to the graphite–diamond transition. The new experimental data suggest that, in the presence of aqueous fluids that flush subducted sediments, the removal of poorly crystalline “disordered” graphitic carbon is more efficient than that of crystalline graphite. This occurs especially at shallow levels of subduction zones, where the difference in free energy is higher and the availability of poorly organized metastable carbonaceous matter and of aqueous fluids produced by devolatilization of the downgoing slab is maximized. At depths greater than 110?km, the small differences in ΔG imply that there is minimal energetic drive for transforming “disordered” graphitic carbon to ordered graphite; “disordered” graphitic carbon could even be energetically slightly favored in a narrow P interval.Tupper, A.S., Pudritz, R.E., Higgs, P.G., 2019. Can the RNA World still function without cytidine? Molecular Biology and Evolution 37, 71-83. scenarios for the origin of life assume that RNA played a key role in both catalysis and information storage. The A, U, G, and C nucleobases in modern RNA all participate in secondary structure formation and replication. However, the rapid deamination of C to U and the absence of C in meteorite samples suggest that prebiotic RNA may have been deficient in cytosine. Here, we assess the ability of RNA sequences formed from a three-letter AUG alphabet to perform both structural and genetic roles in comparison to sequences formed from the AUGC alphabet. Despite forming less thermodynamically stable helices, the AUG alphabet can find a broad range of structures and thus appears sufficient for catalysis in the RNA World. However, in the AUG case, longer sequences are required to form structures with an equivalent complexity. Replication in the AUG alphabet requires GU pairing. Sequence fidelity in the AUG alphabet is low whenever G’s are present in the sequence. We find that AUG sequences evolve to AU sequences if GU pairing is rare, and to RU sequences if GU pairing is common (R denotes A or G). It is not possible to conserve a G at a specific site in either case. These problems do not rule out the possibility of an RNA World based on AUG, but they show that it wouldbe significantly more difficult than with a four-base alphabet.Turetsky, M.R., Abbott, B.W., Jones, M.C., Anthony, K.W., Olefeldt, D., Schuur, E.A.G., Grosse, G., Kuhry, P., Hugelius, G., Koven, C., Lawrence, D.M., Gibson, C., Sannel, A.B.K., McGuire, A.D., 2020. Carbon release through abrupt permafrost thaw. Nature Geoscience 13, 138-143. permafrost zone is expected to be a substantial carbon source to the atmosphere, yet large-scale models currently only simulate gradual changes in seasonally thawed soil. Abrupt thaw will probably occur in <20% of the permafrost zone but could affect half of permafrost carbon through collapsing ground, rapid erosion and landslides. Here, we synthesize the best available information and develop inventory models to simulate abrupt thaw impacts on permafrost carbon balance. Emissions across 2.5?million?km2 of abrupt thaw could provide a similar climate feedback as gradual thaw emissions from the entire 18?million?km2 permafrost region under the warming projection of Representative Concentration Pathway 8.5. While models forecast that gradual thaw may lead to net ecosystem carbon uptake under projections of Representative Concentration Pathway 4.5, abrupt thaw emissions are likely to offset this potential carbon sink. Active hillslope erosional features will occupy 3% of abrupt thaw terrain by 2300 but emit one-third of abrupt thaw carbon losses. Thaw lakes and wetlands are methane hot spots but their carbon release is partially offset by slowly regrowing vegetation. After considering abrupt thaw stabilization, lake drainage and soil carbon uptake by vegetation regrowth, we conclude that models considering only gradual permafrost thaw are substantially underestimating carbon emissions from thawing permafrost.Turney, C.S.M., Fogwill, C.J., Golledge, N.R., McKay, N.P., van Sebille, E., Jones, R.T., Etheridge, D., Rubino, M., Thornton, D.P., Davies, S.M., Ramsey, C.B., Thomas, Z.A., Bird, M.I., Munksgaard, N.C., Kohno, M., Woodward, J., Winter, K., Weyrich, L.S., Rootes, C.M., Millman, H., Albert, P.G., Rivera, A., van Ommen, T., Curran, M., Moy, A., Rahmstorf, S., Kawamura, K., Hillenbrand, C.-D., Weber, M.E., Manning, C.J., Young, J., Cooper, A., 2020. Early Last Interglacial ocean warming drove substantial ice mass loss from Antarctica. Proceedings of the National Academy of Sciences 117, 3996-4006. Significance: Fifty years ago, it was speculated that the marine-based West Antarctic Ice Sheet is vulnerable to warming and may have melted in the past. Testing this hypothesis has proved challenging due to the difficulty of developing in situ records of ice sheet and environmental change spanning warm periods. We present a multiproxy record that implies loss of the West Antarctic Ice Sheet during the Last Interglacial (129,000 to 116,000 y ago), associated with ocean warming and the release of greenhouse gas methane from marine sediments. Our ice sheet modeling predicts that Antarctica may have contributed several meters to global sea level at this time, suggesting that this ice sheet lies close to a “tipping point” under projected warming.Abstract: The future response of the Antarctic ice sheet to rising temperatures remains highly uncertain. A useful period for assessing the sensitivity of Antarctica to warming is the Last Interglacial (LIG) (129 to 116 ky), which experienced warmer polar temperatures and higher global mean sea level (GMSL) (+6 to 9 m) relative to present day. LIG sea level cannot be fully explained by Greenland Ice Sheet melt (～2 m), ocean thermal expansion, and melting mountain glaciers (～1 m), suggesting substantial Antarctic mass loss was initiated by warming of Southern Ocean waters, resulting from a weakening Atlantic meridional overturning circulation in response to North Atlantic surface freshening. Here, we report a blue-ice record of ice sheet and environmental change from the Weddell Sea Embayment at the periphery of the marine-based West Antarctic Ice Sheet (WAIS), which is underlain by major methane hydrate reserves. Constrained by a widespread volcanic horizon and supported by ancient microbial DNA analyses, we provide evidence for substantial mass loss across the Weddell Sea Embayment during the LIG, most likely driven by ocean warming and associated with destabilization of subglacial hydrates. Ice sheet modeling supports this interpretation and suggests that millennial-scale warming of the Southern Ocean could have triggered a multimeter rise in global sea levels. Our data indicate that Antarctica is highly vulnerable to projected increases in ocean temperatures and may drive ice–climate feedbacks that further amplify warming.Tye, R.S., Lowe, D.R., Hickey, J.J., 2020. Ediacaran (Vendian)-period alluvial and coastal geomorphology applied to development of Verkhnechonskoye and Yaraktinskoye fields, East Siberia, Russian Federation. Journal of Sedimentary Research 90, 67-101. (635–542 Ma) oil-bearing strata in the Yarakta Horizon at the Verkhnechonskoye and Yaraktinskoye fields, East Siberia, consist of conglomerate, sandstone, dolomitic sandstone, and mudstone overlying and onlapping igneous to metasedimentary highlands of the East Siberia craton. Initial drainage networks formed within structurally defined valleys, and early deposition occurred in localized alluvial to shallow-marine depositional systems. Base-level-controlled depositional cycles aggraded the valleys; thus, as valleys aggraded, they buried interfluves and coalesced forming broad alluvial and coastal plains.Three to seven bedsets of variable net-to-gross content constitute a genetic cycle. Depositional cycles varied locally, as nine and eight cycles separated by decimeter- to multi-meter-thick mudstones are defined at Verknechonskoye and Yaraktinskoye, respectively. Within one genetic cycle, facies associations grade basinward from alluvial (channel-bar, channel-fill, floodplain, playa, and crevasse-splay) to shallow marine (sabkha, tidal-flat, estuarine-channel, and poorly developed shoreface). Coarse-grained lithofacies are typically arranged in decimeter- to meter-scale bedsets with sharp to scoured bases. Bedsets commonly, but not always, show an upward decrease in grain size, bed thickness, and scale of sedimentary structure. Typically, medium-grained sandstones exhibit low-angle cross bedding and are gradationally overlain by fine-grained sandstones exhibiting scour-and-fill, cuspate-ripple lamination, climbing-ripple lamination, and parallel lamination. Clay clasts and small pebbles are accessories. Interbedded mudstones, siltstones, and sandstones show ripple cross bedding, wavy to lenticular bedding, abundant soft-sediment deformation (e.g., shear, fluid-escape, slump features), and slickensides. Thin-bedded sandstones are micaceous and contain granule-size mud chips. Some mudstones exhibit crinkled to parallel laminae indicative of algal growth. Sandstone fills mudcracks. Interbedded green and black mudstones, plus pyrite and siderite cements, indicate alternating redox conditions. Alluvial facies have patchy quartz, anhydrite, and carbonate cements. Marine-influenced facies show early and well-developed quartz cement as well as abundant halite. Gypsum and halite dissolution formed secondary pores. Calculated estimates of fluvial-channel dimensions and sinuosities indicate that despite the lack of vegetation, fluvial channels in the Yarakta Horizon were shallow and relatively narrow, moderately sinuous, and exhibited varying degrees of mud-prone overbank deposition.Recognition and correlation of flooding surfaces and channel diastems bounding genetically related strata identified multiple stratigraphic compartments in each field. Porosity loss at chronostratigraphic boundaries accounts for complex water, oil, and gas contacts. Economic field development is hampered by locally varying reservoir quality and sandstone continuity caused by its channelized and onlapping stratigraphy and diagenesis. Reservoir simulation of varying geostatistical models demonstrate that differing porosity-distribution methods had little effect on estimates of in-place hydrocarbon volumes. Model differences in porosity and permeability distribution and lithofacies connectivity show large variations in recovery factor and productivity/injectivity.Unglert, M., Bockey, D., Bofinger, C., Buchholz, B., Fisch, G., Luther, R., Müller, M., Schaper, K., Schmitt, J., Schr?der, O., Schümann, U., Tsch?ke, H., Remmele, E., Wicht, R., Winkler, M., Krahl, J., 2020. Action areas and the need for research in biofuels. Fuel 268, 117227. combustion of chemicals in engines is much more than a transformation of chemical energy into kinetic energy. Fuel, engine and exhaust gas treatment form a unit with mutual dependencies and optimisation potentials.Above all, the creation of diesel fuels with different biodiesel proportions or biocomponents (Hydrotreated Vegetable Oil, HVO) and raw material provenances is becoming one of the greatest challenges for the petroleum and vehicle industry from a global point of view.But also offers the potential of a timely, based on existing infrastructure, positive climate change. New regenerative fuels entail properties such as polarity, soot mitigation potential and strong solution properties that require optimal formulations, suitable combustion parameters, and chemical resistance of fuel-bearing components.The paper summarizes the most important findings on biofuels and describes the need for action and research, as well as future challenges for biofuels as a pure fuel and blend component from the point of view of business and science.Vagts, J., Weiten, A., Scheve, S., Kalvelage, K., Swirski, S., W?hlbrand, L., Neidhardt, J., Winklhofer, M., Rabus, R., 2020. Nanomolar responsiveness of an anaerobic degradation specialist to alkylphenol pollutants. Journal of Bacteriology 202, e00595-19.: Anaerobic degradation of p-cresol (4-methylphenol) by the denitrifying betaproteobacterium Aromatoleum aromaticum EbN1 is regulated with high substrate specificity, presumed to be mediated by the predicted σ54-dependent two-component system PcrSR. An unmarked, in-frame ΔpcrSR deletion mutant showed reduced expression of the genes cmh (21-fold) and hbd (8-fold) that encode the two enzymes for initial oxidation of p-cresol to p-hydroxybenzoate compared to their expression in the wild type. The expression of cmh and hbd was restored by in trans complementation with pcrSR in the ΔpcrSR background to even higher levels than in the wild type. This is likely due to ～200-/～30-fold more transcripts of pcrSR in the complemented mutant. The in vivo responsiveness of A. aromaticum EbN1 to p-cresol was studied in benzoate-limited anaerobic cultures by the addition of p-cresol at various concentrations (from 100?μM down to 0.1?nM). Time-resolved transcript profiling by quantitative reverse transcription-PCR (qRT-PCR) revealed that the lowest p-cresol concentrations just affording cmh and hbd expression (response threshold) ranged between 1 and 10?nM, which is even more sensitive than the respective odor receptors of insects. A similar response threshold was determined for another alkylphenol, p-ethylphenol, which strain EbN1 anaerobically degrades via a different route and senses by the σ54-dependent one-component system EtpR. Based on these data and theoretical considerations, p-cresol or p-ethylphenol added as a single pulse (10?nM) requires less than a fraction of a second to reach equilibrium between intra- and extracellular space (～20 molecules per cell), with an estimated Kd (dissociation constant) of <100?nM alkylphenol (p-cresol or p-ethylphenol) for its respective sensory protein (PcrS or EtpR).Importance: Alkylphenols (like p-cresol and p-ethylphenol) represent bulk chemicals for industrial syntheses. Besides massive local damage events, large-scale micropollution is likewise of environmental and health concern. Next to understanding how such pollutants can be degraded by microorganisms, it is also relevant to determine the microorganisms’ lower threshold of responsiveness. Aromatoleum aromaticum EbN1 is a specialist in anaerobic degradation of aromatic compounds, employing a complex and substrate-specifically regulated catabolic network. The present study aims at verifying the predicted role of the PcrSR system in sensing p-cresol and at determining the threshold of responsiveness for alkylphenols. The findings have implications for the enigmatic persistence of dissolved organic matter (escape from biodegradation) and for the lower limits of aromatic compounds required for bacterial growth.Vaiglova, P., Hartman, G., Marom, N., Ayalon, A., Bar-Matthews, M., Zilberman, T., Yasur, G., Buckley, M., Bernstein, R., Tepper, Y., Weissbrod, L., Erickson-Gini, T., Bar-Oz, G., 2020. Climate stability and societal decline on the margins of the Byzantine empire in the Negev Desert. Scientific Reports 10, 1512. past human settlement of inhospitable regions is one of the most intriguing puzzles in archaeological research, with implications for more sustainable use of marginal regions today. During the Byzantine period in the 4th century CE, large settlements were established in the arid region of the Negev Desert, Israel, but it remains unclear why it did so, and why the settlements were abandoned three centuries later. Previous theories proposed that the Negev was a “green desert” in the early 1st millennium CE, and that the Byzantine Empire withdrew from this region due to a dramatic climatic downturn. In the absence of a local climate archive correlated to the Byzantine/Early Islamic transition, testing this theory has proven challenging. We use stable isotopic indicators of animal dietary and mobility patterns to assess the extent of the vegetative cover in the desert. By doing so, we aim to detect possible climatic fluctuations that may have led to the abandonment of the Byzantine settlements. The findings show that the Negev Desert was not greener during the time period under investigation than it is today and that the composition of the animals’ diets, as well as their grazing mobility patterns, remained unchanged through the Byzantine/Early Islamic transition. Favoring a non-climatic explanation, we propose instead that the abandonment of the Negev Byzantine settlements was motivated by restructuring of the Empire’s territorial priorities.Verchovsky, A.B., Anand, M., Barber, S.J., Sheridan, S., Morgan, G.H., 2020. A quantitative evolved gas analysis for extra-terrestrial samples. Planetary and Space Science 181, 104830. gas analysis (EGA) has been successfully applied to the studies of meteorites and Apollo lunar samples. It consists of linear heating of a material with registration of the released volatile compounds, typically using a spectrometric technique. However, so far no quantitative comparison was possible of the amount of gases released during heating of a sample. To address this limitation, we have developed a Quantitative EGA (QEGA) technique using our custom-built Finesse mass spectrometry system. It is based on calibration of the quadrupole mass spectrometer with reference gases (e.g. CO2, CO, H2, O2, N2 or their mixtures with known relative abundances) with known flow rate. The method was tested using simple chemical compounds such as CaCO3, which give well-known amounts of pure gases during their thermal decomposition. We present initial QEGA data on two reference meteorites, Allende and Murchison. Our QEGA work is also informing the design and operation of ProSPA spaceflight instruments being developed to perform analogous experiments in situ on the lunar surface through the European Space Agency’s PROSPECT payload on Luna 27.Vinh, J., 2019. Chapter 17 - Proteomics and proteoforms: Bottom-up or top-down, how to use high-resolution mass spectrometry to reach the Grail, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 529-567. consists of the dynamic characterization of functional proteins within a biological model in a given environment at a given time. It relies on the use of biological mass spectrometry with upstream purification/fractionation strategies. The study of proteoforms can be done by considering either these intact entities (top-down approach) or the proteolytic peptides (bottom-up approach). A partial proteolysis allows to address more specific longer peptides, for an easier study (middle-down approach). High accuracy/high resolution improves the robustness of the study of complex samples. Metadata is processed using signal processing and deconvolution algorithms for protein inference, and sequences database searching and statistical analysis. Here, we will discuss the various proteomics strategies by referring to the latest and most recent review articles at the time of writing of this text. Despite the complementarity of discussed approaches, none of which seems to allow for exhaustive coverage of the proteome.Viúdez-Moreiras, D., Arvidson, R.E., Gómez-Elvira, J., Webster, C., Newman, C.E., Mahaffy, P., Vasavada, A.R., 2020. Advective fluxes in the martian regolith as a mechanism driving methane and other trace gas emissions to the atmosphere. Geophysical Research Letters 47, e2019GL085694.: Advective fluxes influence methane and CO2 soil emissions into the atmosphere on Earth and may drive trace gas emissions in the Mars atmosphere. However, their relevance in the Martian regolith has not been evaluated to date. Our regolith transport simulations show that advective fluxes can be relevant under Martian conditions and may drive the methane abundance detected by Mars Science Laboratory. Trace gas emissions would be highest in regions where winds interact with topography. Emissions in these regions may be further enhanced by time‐varying pressure fields produced by diurnal thermal tides and atmospheric turbulence. Trace gases such as methane should be emitted or produced from the first layers of regolith, or quickly transported to this region from a deeper reservoir through fractured media.Plain Language Summary: Regolith emissions are driven by diffusion and/or advection, depending on the scenario. Advective fluxes influence methane and CO2 soil emissions into the atmosphere on Earth and may drive trace gas emissions in the Mars atmosphere. However, their relevance in the Martian regolith has not been evaluated to date. Our regolith transport simulations show that advective fluxes produced by winds and atmospheric pressure fluctuations can be relevant under Martian conditions and may drive the methane abundance detected by Mars Science Laboratory. Trace gases such as methane should be emitted or produced from the first layers of regolith, or quickly transported to this region from a deeper reservoir through fractured media.Vo Thanh, H., Sugai, Y., Nguele, R., Sasaki, K., 2020. Robust optimization of CO2 sequestration through a water alternating gas process under geological uncertainties in Cuu Long Basin, Vietnam. Journal of Natural Gas Science and Engineering 76, 103208. study presents a robust optimization workflow to determine the optimal water alternating gas (WAG) process for CO2 sequestration in a heterogeneous fluvial sandstone reservoir. As depicted in this study, WAG injection could enhance CO2 residual and solubility trapping based on an integrated modeling workflow. First, continuous CO2 injection and WAG were compared to demonstrate the efficiency of the WAG process for CO2 trapping enhancement. To achieve this while highlighting the impact of reservoir heterogeneity, 200 geological realizations were generated considering a wide range of plausible geological conditions. The ranking of these realizations was performed by quantifying the CO2 cumulative injection (P10, P50, and P90 realizations) that represent the overall geological uncertainties. Then, an innovative robust workflow was used Artificial Intelligence optimizer to determine the optimal solution for CO2 trapping. For comparison, a nominal optimization workflow of P50 realization was also conducted. The proposed robust optimization workflow resulted in higher CO2 trapping than the nominal optimization workflow. Thus, this study demonstrates a fast and reliable workflow that can accurately represent for optimization the cycle length injection in the WAG process under geological uncertainties.Volger, R., Pettersson, G.M., Brouns, S.J.J., Rothschild, L.J., Cowley, A., Lehner, B.A.E., 2020. Mining Moon & Mars with microbes: Biological approaches to extract iron from Lunar and Martian regolith. Planetary and Space Science 184, 104850. logistical supply of terrestrial materials to space is costly and puts limitations on exploration mission scenarios. In-situ resource utilization (ISRU) can alleviate logistical requirements and thus enables sustainable exploration of space. In this paper, a novel approach to ISRU, utilizing microorganisms to extract iron from Lunar or Martian regolith, is presented. Process yields, and kinetics are used to verify the theoretical feasibility of applying four different microorganisms. Based on yields alone, three of the four organisms were not investigated further for use in biological ISRU. For the remaining organism, Shewanella oneidensis, the survivability impact of Martian regolith simulant JSC-MARS1 and Mars-abundant magnesium perchlorate were studied and found to be minimal. The payback time of the infrastructure installation needed for the process with S. oneidensis on Mars was analyzed and the sensitivity to various parameters was investigated. Water recycling efficiency and initial regolith concentration were found to be key to process performance. With a water recycling efficiency of 99.99% and initial regolith concentration of 300?g/L, leading to an iron concentration of approximately 44.7?g/L, a payback time of 3.3 years was found.Vu, T.H., Choukroun, M., Sotin, C., Mu?oz-Iglesias, V., Maynard-Casely, H.E., 2020. Rapid formation of clathrate hydrate from liquid ethane and water ice on Titan. Geophysical Research Letters 47, e2019GL086265.: Liquid ethane is present in the lakes and seas observed on Titan's surface by the Cassini‐Huygens mission. While interaction between liquid hydrocarbons and water ice is expected to result in the formation of clathrate hydrates, such reaction (and its kinetics) has not yet been demonstrated for cryogenic liquids under relevant planetary conditions. In this paper, we report the first experimental evidence for rapid formation of clathrates upon direct contact of liquid ethane with water ice at 1 bar using micro‐Raman spectroscopy. Kinetics experiments conducted in the temperature range 150–173 K yield an activation energy of 14.8 ± 2.2 kJ/mol, which is suggestive of a diffusion‐controlled mechanism for clathrate formation. This implies that a clathrate reservoir can form within seasonal time scales on Titan if liquid ethane comes into contact with a pre‐existing icy bedrock, which may hold important implications for the structure and dynamics of Titan's crust and its global evolution.Plain Language Summary: Saturn's moon Titan has a dense atmosphere and liquid lakes (of methane and ethane) on its surface. These organic compounds are the main constituents of natural gas on Earth. Water is completely frozen and comprises most of Titan's bedrock materials. Under the right conditions, it is common for water ice to form new solids that trap natural gas in their structures, called clathrate hydrates. On Earth, clathrate hydrates are often found in the permafrost and deep ocean. However, Titan is so much colder that these natural gases exist as liquids. We do not yet know if clathrates can form under such conditions, and if so, how quickly. In this study, we prepared small grains of water ice, bathed them in liquid ethane, and monitored the rate at which clathrate hydrates appear. Our data confirm that clathrates would indeed form on Titan from an ethane lake or rain event onto water ice, and they would do so very quickly (in just a few Earth years). This suggests that clathrate hydrates can be an important material on Titan that may be encountered by future missions there.Vyviurska, O., ?pánik, I., 2020. Novel sample preparation approaches in gas chromatographic analysis: Promising ideas. Journal of Separation Science 43, 174-188. development of sample preparation procedures is still a dynamic process despite a number of already proposed techniques. The main challenge in this research field is to fully replace classical procedures like liquid‐liquid extraction and solid‐phase extraction in gas chromatographic analysis. Some progress has been already achieved for the last 20 years when miniaturized techniques were incorporated in ISO standards. The current review is focused on novel approaches in sample treatment that appeared since 2010. It includes research studies describing non‐conventional instrumental design available to inspire future progress in the field. A combination of a few extraction principles and supporting with additional treatment are the main core suggested for improvement of sample preparation efficiency. This requires good compatibility of extraction media, assessment of multiple experimental parameters, and potential automatization possibilities.Wagner, J.K.S., Smart, C., German, C.R., 2020. Discovery and mapping of the Triton seep site, Redondo Knoll: Fluid flow and microbial colonization within an oxygen minimum zone. Frontiers in Marine Science 7, 108. doi: 10.3389/fmars.2020.00108. paper examines a deep-water (～900 m) cold-seep discovered in a low oxygen environment ～30 km off the California coast in 2015 during an E/V Nautilus telepresence-enabled cruise. This Triton site was initially detected from bubble flares identified via shipboard multibeam sonar and was then confirmed visually using the remotely operated vehicle (ROV) Hercules. High resolution mapping (to 1 cm resolution) and co-registered imaging has provided us with a comprehensive site overview – both of the geologic setting and the extent of the associated microbial colonization. The Triton site represents an active cold-seep where microorganisms can act as primary producers at the base of a chemosynthesis-driven food chain. But it is also located near the core of a local oxygen minimum zone (OMZ), averaging <0.75 μM oxygen, which is significantly below average ocean levels (180–270 μM) and, indeed, extreme even among OMZs as a whole which are defined to occur at all oxygen concentrations <22 μM. Extensive microbial mats, extending for >100 m across the seafloor, dominate the site, while typical seep-endemic macro-fauna were noticeably absent from our co-registered photographic and high-resolution mapping surveys – especially when compared to all adjacent seep sites within the same California Borderlands region. While such absences of abundant macro-fauna could be attributable to variations in the availability of dissolved oxygen in the overlying water column this need not necessarily be the case. An alternate possibility is that the zonation in microbial activity that is readily observable at the seafloor at Triton reflects, instead, a concentric pattern of radially diminishing fluxes of reductants from the underlying seafloor. This unusual but readily accessible discovery, in close proximity to Los Angeles harbor, provides an intriguing new natural laboratory at which to examine biogeochemical and microbiological interactions associated with the functioning of cold seep ecosystems within an OMZ.Wan, T., Wang, X., Jing, Z., Gao, Y., 2020. Gas injection assisted steam huff-n-puff process for oil recovery from deep heavy oil reservoirs with low-permeability. Journal of Petroleum Science and Engineering 185, 106613. primary objective of this paper is to evaluate the possibility of using gas assisted cyclic steam stimulation for enhanced oil recovery in Xinjiang low-permeability heavy oil reservoirs. Several attempts have been made in this paper to improve the recovery efficiency, which include hydraulic fracturing horizontal wells, flue-gas and CO2 assisted cyclic steam co-injection, alternating injection of steam and CO2 scheme.To reduce the heavy oil viscosity and heat losses, cyclic flue-gas/steam injection method was proposed to make the gas penetrate deep into the formation and expand the steam chamber. Numerical simulations were carried out to examine the thermal process recovery efficiency of gas assisted steam injection in producing low-permeability heavy oil.The numerical results indicated that gaseous additives such as CO2 or flue-gas were feasible to improve the performance of cyclic steam injection. Without a gas blanket filling the chamber, the heat losses would become significant. Our research results indicated that the CO2/steam coinjection yielded higher oil recovery than flue-gas/steam and pure cyclic steam injection process. The thermal recovery performance is largely dependent on the contacted area of the steam with the oil reservoir. One reason is that the cumulative injected enthalpy of the CO2/steam is higher than flue-gas/steam and pure steam. Another reason is that the addition of nitrogen or carbon dioxide acts a role as thermal isolation to reduce the heat losses along the wellbore due to their low conductivity. The interaction of CO2 injection with reservoir heavy oil under temperature effect was discussed. Compared with the case without considering the temperature effect, the oil rate and cumulative oil recovery was higher for the case including the temperature dependent relative permeability.Wanczek, K.P., Kanawati, B., 2019. Chapter 1 - Historical developments in Fourier transform ion cyclotron resonance mass spectrometry, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 3-33. this review, the technical developments of the Fourier transform ion cyclotron resonance (FT ICR) mass spectrometry as well as the developments of the ICR before the implementation of Fourier transform into this technique are described in historical order. Instrumentation, theory and applications are covered in ion chemistry, ion physics, and structural analysis of a very broad variety of compounds, from atoms and small molecules to biological and petrochemical analytes. For investigation, the ions can be generated inside or outside the ICR cell. They are trapped in the ICR cell, reacted with neutral molecules, photons, or ions. Finally, mass spectra of primary ions and ionic reaction products are produced with ultrahigh resolution and precision. From the many thousand publications in the field, the authors selected 221 publications for this review. The criterion was that a new development, a new aspect, a new extension, or a new application of the method was presented for the first time. In the first decades, many fundamental discoveries took place. However, the FT ICR technique has not reduced its dynamical development until today and will continue its success with many extended applications and instrumental developments in the future.Wanczek, K.P., Kanawati, B., 2019. Chapter 18 - Gas phase ion-molecule reactions of inorganic compounds in FT-ICR-MS, in: Kanawati, B., Schmitt-Kopplin, P. (Eds.), Fundamentals and Applications of Fourier Transform Mass Spectrometry. Elsevier, pp. 569-591. between ions and reactive neutrals in the gas phase at near thermal energy conditions are feasible, provided that means exist to trap ions for a couple of seconds for collisions between ions and reactive neutrals to occur. The ion cyclotron resonance (ICR) technique provides an excellent environment for such gas phase ion-molecule reactions to take place, giving also the opportunity to correlate both reactant and product ions and to determine sum formulae with ultra-high resolution. Moreover, ICR can also enable structure elucidation by several techniques like collision induced dissociation (CID) experiments. Acceleration of some reactive ions can also induce endothermic ion-molecule reactions to occur. The authors give a systematic overview of gas phase ion chemistry of non-metal main group elements, covering a wide spectrum of reactions, as well as their rate constant determinations and thermodynamic ion energetics.Wang, C., Yu, L., Zou, Y., Ji, L., Li, Y., 2020. Sources and historical sedimentary record: Temporal variability of n-alkane and PAHs from the Yellow River Estuary, China. Applied Geochemistry 114, 104475. composition and distribution of n-alkanes and polycyclic aromatic hydrocarbons (PAHs) in suspended particulate matter (SPM) from the Yellow River and a sedimentary core from the Yellow River Estuary, China, were measured in order to determine environmental changes in the Yellow River Estuary on a regional scale. The concentration of n-alkane in SPM increased along the upper-middle-lower reaches of the Yellow River. The total concentrations of n-alkanes and PAHs in the core ranged from 0.04 to 0.86 μg g?1 (avg. 0.21 μg g?1), and from 0.04 to 0.29 μg g?1 (avg. 0.15 μg g?1) on a dry wt. basis, respectively. Understanding the temporal evolution of n-alkanes provide information on terrigenous versus aquatic productivity, oil exploration at the Shengli Oilfield, and channel diversion in the Yellow River. n-Alkanes in SPM were mainly derived from mixed sources, with terrigenous inputs dominating. PAHs in the sediment core were predominantly derived from coal and biomass combustion. The variation in PAHs levels throughout the core determines changes in energy use and socio-economic development. The temporal variability in n-alkane and PAHs and their molecular diagnostic ratios revealed a trend of regional environmental change and the role of anthropogenic activity in that environmental change.Wang, F.C.-Y., 2020. GC × VUV study of diesel: A two-dimensional separation approach. Energy & Fuels 34, 1432-1437. characterization of complex hydrocarbon mixtures remains a challenging task. Advances in analytical characterization have been made in several fronts. One such advance is in gas chromatography–vacuum ultraviolet spectrometry (GC-VUV), which allows for sensitive, universal detection that is particularly well suited for characterizing petroleum and petroleum products. As complete VUV (125–430 nm) spectra are obtained continuously, there are advantages in being able to arrange and visualize data in a multidimensional way through a plot of elution time versus wavelength and absorption intensity, providing a new method of two-dimensional separation, namely, GC × VUV. All structural features are readily visualized in a manner complementary to two-dimensional gas chromatography, GC × GC. In this study, we demonstrate the advantages of the GC × VUV approach by comparing the analysis of a diesel sample to results obtained by GC-FID, GC-VUV, and GC × GC-FID.Wang, H., An, Z., Lu, H., Zhao, Z., Liu, W., 2020. Calibrating bacterial tetraether distributions towards in situ soil temperature and application to a loess-paleosol sequence. Quaternary Science Reviews 231, 106172. glycerol dialkyl glycerol tetraethers (brGDGTs) produced by soil-dwelling bacteria offer a promising tool for reconstructing terrestrial temperatures. However, in most previous studies, due to lack of soil temperature data, brGDGTs are calibrated to the air rather than the soil temperature. This may impede our understanding of the accurate response of brGDGTs to temperature, and thus affect the quantitative paleotemperature reconstruction using these lipids. Here, we investigated modern soil brGDGTs and the corresponding soil temperature across a large climatic gradient in China (mean annual soil temperature (MAST) range: ?2.7 to 26.2 °C). The results show that the MAST is higher than the mean annual air temperature (MAAT) by 0–6 °C, and the difference is related to vegetation coverage. This supports the idea that vegetation can modulate MAST and points to the necessity of exploring the direct response of brGDGTs to soil temperature. Employing stepwise regression (sr), we developed MASTsr and MAATsr calibrations, which improve accuracy and reduce the error compared with previous global MAAT calibrations. In Lantian loess-paleosols, the MASTsr calibration resulted in ～4 °C lower glacial temperatures and a ～10 °C deglacial warming comparable with other terrestrial records and climate models. However, the global MATmr and MBT’/CBT calibrations produced abnormally higher glacial temperatures, while the empirical MAATsr calibration overestimated MAAT during the deglacial period with low vegetation coverage. This demonstrates that the calibration with soil temperature is preferred for quantitative paleotemperature reconstruction. Nevertheless, soil brGDGTs might be useful for inferring MAAT if underlying surface conditions are sufficiently constrained.Wang, H., Li, G., Zheng, Y., Kamy, S., Shen, Z., Yang, B., Shi, L., 2020. Research status and prospects of supercritical CO2 fracturing technology. Acta Petrolei Sinica 41, 116-126 on the problems encountered in the development of unconventional oil and gas using water-based fracturing fluids, this paper summarizes the unique advantages, technical characteristics, technological processes and operating mechanisms of supercritical CO2 fracturing technology. Through comprehensively analyzing the current research and development status involving the origin of supercritical CO2 fracturing technology, fracture initiation mechanisms of rock during supercritical CO2 fracturing, proppant carrying laws in fractures, flow law and control mechanism of the wellbore, fracturing equipment and field tests, this paper puts forward the key issues for industrial application and further proposes corresponding countermeasures. The researches on the fracture initiation mechanisms of rock during supercritical CO2 fracturing are dominated by phenomenal descriptions. The future study should focus on the integration of theoretical analysis and simulation experiment, and set up the quantitative evaluation method. In research of the proppant carrying capacity during supercritical CO2 fracturing, in addition to strengthening the efforts in improving the adhesion performance of tackifiers, it is also useful to develop nanofibers for enhancing tackling ability by physical methods, develop new-type low-density proppants and optimize the technical parameters of equipment. Based on the single-layer fracturing of vertical wells, the supercritical CO2 fracturing technology will be gradually developed to achieve the multi-stage fracturing of horizontal wells; in combination with coiled tubing fracturing, it can gradually meet the demands for the large-scale development of unconventional resources, such as shale gas, coalbed methane, tight sandstone gas, and etc.Wang, H., Lu, L., Chen, H., McKenna, A.M., Lu, J., Jin, S., Zuo, Y., Rosario-Ortiz, F.L., Ren, Z.J., 2020. Molecular transformation of crude oil contaminated soil after bioelectrochemical degradation revealed by FT-ICR mass spectrometry. Environmental Science & Technology 54, 2500-2509. is a low-cost approach for crude oil spill remediation, but it is often limited by electron acceptor availability. In addition, the biodegradation products of crude oil contaminants are complex, and transformation pathways are difficult to decipher. This study demonstrates that bioelectrochemical systems (BESs) can be effective in crude oil degradation by integrating biological and electrochemical pathways, and more importantly, it provides the first understanding on the daughter products of bioelectrochemical hydrocarbon degradation. Using electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and two-dimensional gas chromatography (GC × GC), the results showed that the active BES reactor improved the total petroleum hydrocarbon (TPH) degradation by ～70% than open circuit control reactors. After separating the daughter products into nine fractions (MA1–MA9) according to the molecular weight (m/z 200–1000) by modified aminopropyl silica (MAPS) fractionation, we found that active BES remediation resulted in 50% more polar, oxygen-containing naphthenic (NAP) acids. The MA4 fraction (centered at ～550 Da) increased by 47%, and MA5 and MA7 fractions with higher molucular weight increased by a maximum of ～7- and 9-fold, respectively. These results are in accordance with the variation of bulk elemental compositions in O2 species, where daughter transformation products doubled relative to parent oil extract. The contribution of newly generated NAP acids was mainly from higher-order oxygen species (O5–O6) with increased hydrophobicity in conjunction with a decreased abundance in lower-order oxygen species (O1). Overall, the study suggests that n-alkane degradation occurred via β-oxidation to oxygenated transformation products with lower molecular weight, such as n-alcohols in O1 class and subsequently to n-fatty acids in O2 class.Wang, H., Zhao, W., Cai, Y., Wang, X., Ye, Y., Su, J., He, K., Zhang, W., Huang, L., Zhang, S., 2020. Oil generation from the immature organic matter after artificial neutron irradiation. Energy & Fuels 34, 1276-1287. shale often receives high doses of radiation from radionuclides, mostly uranium (U). Natural decay of U releases particles and energy simultaneously. Thermal stress is considered to be conducive to organic matter (OM) maturation and petroleum generation and has always been taken into account in the simulation of basin thermal evolution. However, for the particles and their bombardment, the effect is still unclear. The main reason is that the half-life of U is up to 4.5 billion years; it is impossible to monitor the effect of U natural decay in the laboratory. Here, we implemented a thermal neutron irradiation experiment in a nuclear reactor using immature Type-II organic matter, to activate and accelerate the natural decay of U. Radiogenic heat was designed to be removed with the circulating water at room temperature to reduce the potential effect of thermal degradation. Oil generated from the irradiated organic matter confirmed that particle bombardment from the U natural decay promoted oil production, with a maximum yield of 19.5 mg g–1 TOC. The oil produced was rich in asphaltene, aromatic compounds, and high-molecular-weight compounds, and also had abundant low-maturity and intermediate products (e.g., alkenes, prist-1-ene, C27-hop-17(21)-ene, and moretanes) in the saturated fraction. These results indicated that particle bombardment led to the radiolytic cracking of C–C bonds, different from the traditional thermal degradation processes. Therefore, as a function of time and content, the natural irradiation from U decay should be taken into account, when evaluating the petroleum resources of Paleozoic and Proterozoic U-rich source rocks.Wang, K., Zhang, B., Kang, T., 2020. Effect of geological depths on CH4 adsorption, diffusion, and swelling in kaolinite by molecular simulations. Energy & Fuels 34, 1620-1626. demand for energy in the world has increased dramatically, leading to an increase in the geological depth of unconventional natural gas development such as shale gas. Comprehension adsorption and diffusion of CH4 at different geological depths is extremely significant, especially in the case of large depths. In this study, the molecular simulations were utilized to investigate the CH4 adsorption, diffusion, and swelling in kaolinite up to 6 km. The outcomes show that the adsorption amount of CH4 on kaolinite increases to the maximum at 2 MPa, while it decreases with increasing geological depth. This phenomenon is explained by the total interaction energy and adsorption isosteric heat between CH4 and kaolinite. The hydrogen and oxygen atoms in kaolinite molecules are the strongly adsorbed sites of CH4. Because of the wall effect, two strong adsorption layers of CH4 molecules were formed adjacent to the kaolinite surface. The CH4 coefficient, including that of self-diffusion and Fick diffusion, increased linearly with the geological depth, and the CH4 diffusion activation energy in kaolinite is about 1.61 kJ/mol at 1–6 km. The kaolinite volume increases first, then slightly decreases, and finally obviously increases with increasing geological depth. By considering the results of adsorption, diffusion, and expansion, we infer that the optimal kaolinite-bearing shale gas reservoir is buried at a depth of 3–4 km.Wang, L.-G., Lam, T.T.-Y., Xu, S., Dai, Z., Zhou, L., Feng, T., Guo, P., Dunn, C.W., Jones, B.R., Bradley, T., Zhu, H., Guan, Y., Jiang, Y., Yu, G., 2019. Treeio: An R package for phylogenetic tree input and output with richly annotated and associated data. Molecular Biology and Evolution 37, 599-603. trees and data are often stored in incompatible and inconsistent formats. The outputs of software tools that contain trees with analysis findings are often not compatible with each other, making it hard to integrate the results of different analyses in a comparative study. The treeio package is designed to connect phylogenetic tree input and output. It supports extracting phylogenetic trees as well as the outputs of commonly used analytical software. It can link external data to phylogenies and merge tree data obtained from different sources, enabling analyses of phylogeny-associated data from different disciplines in an evolutionary context. Treeio also supports export of a phylogenetic tree with heterogeneous-associated data to a single tree file, including BEAST compatible NEXUS and jtree formats; these facilitate data sharing as well as file format conversion for downstream analysis. The treeio package is designed to work with the tidytree and ggtree packages. Tree data can be processed using the tidy interface with tidytree and visualized by ggtree. The treeio package is released within the Bioconductor and rOpenSci projects. It is available at , L., Guan, E., Wang, Y., Wang, L., Gong, Z., Cui, Y., Meng, X., Gates, B.C., Xiao, F.-S., 2020. Silica accelerates the selective hydrogenation of CO2 to methanol on cobalt catalysts. Nature Communications 11, 1033. reaction pathways on supported catalysts can be tuned by optimizing the catalyst structures, which helps the development of efficient catalysts. Such design is particularly desired for CO2 hydrogenation, which is characterized by complex pathways and multiple products. Here, we report an investigation of supported cobalt, which is known for its hydrocarbon production and ability to turn into a selective catalyst for methanol synthesis in CO2 hydrogenation which exhibits good activity and stability. The crucial technique is to use the silica, acting as a support and ligand, to modify the cobalt species via Co?O?SiOn linkages, which favor the reactivity of spectroscopically identified *CH3O intermediates, that more readily undergo hydrogenation to methanol than the C?O dissociation associated with hydrocarbon formation. Cobalt catalysts in this class offer appealing opportunities for optimizing selectivity in CO2 hydrogenation and producing high-grade methanol. By identifying this function of silica, we provide support for rationally controlling these reaction pathways.Wang, L., Xin, J., Nai, H., Zheng, T., Tian, F., Zheng, X., 2020. Sorption of DONs onto clay minerals in single-solute and multi-solute systems: Implications for DONs mobility in the vadose zone and leachability into groundwater. Science of The Total Environment 712, 135502. organic nitrogen (DON) with a mixture of various organic nitrogen (N) is recognized as an emerging groundwater contaminant. Investigating the behavior and mechanism of DON sorption onto clay minerals, which are key components of vadose zone media, is crucial to evaluating its leaching potential. Considering the interactions among multiple DON compounds (DONs) may influence their sorption behaviors, the sorption of three typical DONs (amino acid, protein and urea) to clay minerals in single-, binary- and ternary-solute systems were explored, respectively. In addition, a combination of multiple methods, including physiochemical characterization, Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD) and pH variation analysis, were used to provide insight into the governing mechanisms. Results indicated that the sorption kinetics and isotherms of single systems were well-fitted by pseudo-second-order and Freundlich isotherm models, respectively. The mechanisms involved in the sorption of DONs onto clay minerals varied with the sorption time. The dominant interactions included van der Waals forces, ligand exchange, and hydrogen bonding (H-bonding) in the initial phase of the sorption process, whereas electrostatic interactions were predominant in the later stage as H+ was released into the solution. In binary-solute systems, either cooperative or competitive sorption was observed depending on the co-solute combination. For instance, the sorption behaviors of amino acids and urea were simultaneously enhanced in the binary system because of the formation of highly charged complexes as new active sites. Proteins sorption, however, was inhibited by the coexistence of urea as a result of active site depletion and protein denaturation. In ternary-solute systems, the sorption of DONs was balanced by cooperative and competitive sorption processes. These findings elucidated the sorption behaviors of DONs onto clay minerals in multi-solute systems and contributed to the evaluation of the mobility of DONs in the vadose zone and their leachability into groundwater.Wang, N., Saidhareddy, P., Jiang, X., 2020. Construction of sulfur-containing moieties in the total synthesis of natural products. Natural Product Reports 37, 246-275.: January 2013 to September 2018 Sulfur-containing natural products are a large class of significant functional molecules. Many of these compounds exhibit potent biological activities and pharmacological properties; in fact, some of them have been developed into important drugs. The total synthesis of sulfur-containing natural products is a subject that has long attracted significant attention from synthetic organic chemists; to achieve this goal, various methods have been developed over the past years. This review surveys total syntheses of sulfur-containing natural products that introduce sulfur atoms using different sulfurization agents to construct related sulfur-containing moieties.Wang, N., Zhi, Y., Wei, Y., Zhang, W., Liu, Z., Huang, J., Sun, T., Xu, S., Lin, S., He, Y., Zheng, A., Liu, Z., 2020. Molecular elucidating of an unusual growth mechanism for polycyclic aromatic hydrocarbons in confined space. Nature Communications 11, 1079. and clustering of polycyclic aromatic hydrocarbons (PAHs) are key mechanistic steps for coking and deactivation in catalysis reactions. However, no unambiguous mechanistic picture exists on molecule-resolved PAHs speciation and evolution, due to the immense experimental challenges in deciphering the complex PAHs structures. Herein, we report an effective strategy through integrating a high resolution MALDI FT-ICR mass spectrometry with isotope labeling technique. With this strategy, a complete route for aromatic hydrocarbon evolution is unveiled for SAPO-34-catalyzed, industrially relevant methanol-to-olefins (MTO) as a model reaction. Notable is the elucidation of an unusual, previously unrecognized mechanistic step: cage-passing growth forming cross-linked multi-core PAHs with graphene-like structure. This mechanistic concept proves general on other cage-based molecule sieves. This preliminary work would provide a versatile means to decipher the key mechanistic step of molecular mass growth for PAHs involved in catalysis and combustion chemistry.Wang, P., Yin, S., 2020. Composition and origin of natural gases accumulated in the Upper Triassic tight sandstone reservoirs in the Western Sichuan depression, China: Gaseous hydrocarbons, noble gases and carbon dioxide. Petroleum Science and Technology 38, 361-367. this paper, the gas composition and isotopic characteristics of the tight sandstone of the Upper Triassic Xujiahe Formation in the western Sichuan depression were analyzed, and the origin of hydrocarbon gas, rare gas and CO2 in natural gas were determined. The hydrocarbon gas content in the tight sandstone gas of the Xujiahe Formation is the highest, ranging from 96.43% to 99.44?vol.%, while the non-hydrocarbon gas content is only 0.34–2.73?vol.%. The hydrocarbon gas has the highest content of CH4, which is distributed from 88.52% to 97.86?vol.%, and the content of other hydrocarbon gases is relatively low. The studied natural gas is mainly dry gas, and a small part is wet gas. According to the hydrocarbon gas component and carbon isotope analysis results, it showed that the natural gas of the Xujiahe Formation was a thermogenic gas, and there was no mixing of biogenetic gas. The natural gas was derived from the thermal degradation of the humus kerogen. Moreover, the rare gas in the natural gas of the Xujiahe Formation is a crustal origin organic gas, and there is no mantle origin gas, which indicates the lack of inorganic components in the natural gas. We also found that the CO2 in the natural gas is mainly inorganic gas, which is derived from the dissolution of carbonate minerals; and only a small part is organic thermogenic gas, which is derived from the thermal maturation process of organic matter.Wang, Q., Hou, J., Yuan, J., Wu, Y., Liu, W., Luo, Y., Christie, P., 2020. Evaluation of fatty acid derivatives in the remediation of aged PAH-contaminated soil and microbial community and degradation gene response. Chemosphere 248, 125983. this study, derivatives of two common fatty acids in plant root exudates, sodium palmitate and sodium linoleate (sodium aliphatates), were added to an aged Polycyclic aromatic hydrocarbons (PAHs) contaminated soil to estimate their effectiveness in the removal of PAHs. Sodium linoleate was more effective in lowering PAHs and especially high-molecular-weight (4–6 ring) PAHs (HMW-PAHs). Principal coordinates analysis (PCoA) indicates that both amendments led to a shift in the soil bacterial community. Moreover, linear discriminant effect size (LEfSe) analysis demonstrates that the specific PAHs degraders Pseudomonas, Arenimonas, Pseudoxanthomonas and Lysobacter belonging to the γ-proteobacteria and Nocardia and Rhodococcus belonging to the Actinobacteria were the biomarkers of, respectively, sodium linoleate and sodium palmitate amendments. Correlation analysis suggests that four biomarkers in the sodium linoleate amendment treatment from γ-proteobacteria were all highly linearly negatively related to HMW-PAHs residues (p < 0.01) while two biomarkers in the sodium palmitate amendment treatment from Actinobacteria were highly linearly negatively related to LMW-PAHs residues (p < 0.01). Higher removal efficiency of PAHs (especially HMW-PAHs) in the sodium linoleate amendment treatment than in the sodium palmitate amendment treatment might be ascribed to the specific enrichment of microbes from the γ-proteobacteria. The bacterial functional KEGG orthologs (KOs) assigned to PAHs metabolism and functional C23O and C12O genes related to cleavage of the benzene ring were both up-regulated. These results provide new insight into the mechanisms of the two sodium aliphatate amendments in accelerating PAHs biodegradation and have implications for practical application in the remediation of PAHs-contaminated soils.Wang, Q., Zietzschmann, F., Yu, J., Hofman, R., An, W., Yang, M., Rietveld, L.C., 2020. Projecting competition between 2-methylisoborneol and natural organic matter in adsorption onto activated carbon from ozonated source waters. Water Research 173, 115574. the ozone-activated carbon process has been widely applied for drinking water purification, little is known about how ozone-modified natural organic matter (NOM) competes with micropollutants in activated carbon adsorption. In this study, three natural waters and one synthetic water (standard humics solution) with highly heterogeneous NOM compositions were employed to investigate the interference of ozonated NOM with the adsorption of 2-methylisoborneol (MIB). Analysis using liquid chromatography with online carbon and UV254 detection (LC-OCD-UVD) revealed that ozonation led to various disintegration patterns of macromolecules in NOM, and UV absorbance was reduced markedly for nearly all NOM fractions. Powdered activated carbon (PAC) adsorption experiments showed that increasing ozone consumption coincided with reducing NOM competition against MIB in the three natural waters, as expressed by the fitted initial concentrations of the equivalent background compound (c0,EBC). In the synthetic water, in contrast, competition increased under low/moderate specific ozone consumptions and then decreased with further elevation of ozone consumptions. Regarding the significance on affecting ozonated NOM interference, aromaticity reduction outweighed formation of low molecular weight (LMW) organics in most cases, enhancing MIB adsorption capacity. However, disintegration of the humics fraction with larger molecular weight (1,103?g/mol, as compared to 546–697?g/mol in three natural waters) into smaller, more competitive fractions caused the observed initial deteriorated MIB adsorption in synthetic water. A superior correlation between c0,EBC and the UV absorbance of LMW organics (R2?=?0.93) over concentrations of LMW organics underlined the importance of the aromatic properties in competitive adsorption projection for ozone pretreated natural waters. Furthermore, the change of relative concentration of UV absorbing compounds during ozonation could help estimate the decrease of c0,EBC, which could be a promising tool.Wang, X., Cai, T., Wen, W., Ai, J., Ai, J., Zhang, Z., Zhu, L., George, S.C., 2020. Surfactin for enhanced removal of aromatic hydrocarbons during biodegradation of crude oil. Fuel 267, 117272. biodegradation studies using the powerful surfactant have mainly focused on saturated hydrocarbons or parent aromatic hydrocarbons, but not specifically on the position or degree of alkyl substitution of aromatic hydrocarbons. Removal of substituted aromatic hydrocarbons remains a controversial topic in biodegradation. In this study, the effect of surfactin addition on specific alkylated aromatic isomers and saturated hydrocarbons was observed in aerobic biodegradation experiments with four species of bacteria. The relative susceptibility of the individual alkylphenanthrene, alkyldibenzothiophene and methyltriaromatic steroid isomers to biodegradation was determined by their depletion rates. The results show that different bacteria induce removal of alkylated aromatic hydrocarbons and alteration of other petroleum hydrocarbons in various ways. Bacillus amyloliquefaciens strain BC is the best for biodegradation of general petroleum hydrocarbons, because it can convert n-alkanes, n-alkylcyclohexanes, isoprenoids, and aromatic hydrocarbons. Achromobacter strain J3 can degrade methylphenanthrenes, methyltriaromatic steroids, triaromatic steroids, and steranes better than other bacteria. Citrobacter sp strain J1 induces the highest degradation rate for dimethylphenanthrenes, trimethylphenanthrenes, and dimethyldibenzothiophenes, and Brucella melitensis strain J2 selectively degrades methyldibenzothiophenes. Surfactin addition increases the biodegradation rate of alkylaromatic hydrocarbons by 1.5–87.2%, and can significantly enhance the biodegradation of alkylphenanthrenes, alkyldibenzothiophenes and methyltriaromatic steroids. Alkyldibenzothiophenes can be used as markers for determining the levels of biodegradation of crude oils, and when used in conjunction with triaromatic steroids are a powerful indicator of the biodegradation of petroleum. The use of surfactin for enhancing the removal of aromatic hydrocarbons provides a wide range of applications in the environmental remediation and petroleum industry.Wang, Y., Cao, J., Tao, K., Gao, X., Li, E., Shi, C., 2020. Multivariate statistical analysis reveals the heterogeneity of lacustrine tight oil accumulation in the Middle Permian Jimusar Sag, Junggar Basin, NW China. Geofluids 2020, 1860219. oil and gas accumulation commonly has heterogeneities within the reservoir formation. This heterogeneity, however, is hard to investigate by conventional geological and (organic) geochemical tools and thus is critical and challenging to study. Here, we attempted multivariate statistical analysis to reveal the heterogeneity based on a case study in the lacustrine tight oil accumulation in the middle Permian Lucaogou Formation of the Jimusar sag, Junggar Basin, NW China. Clustering heat maps and multi-dimensional scaling analysis revealed the heterogeneity of tight oil accumulation. The heterogeneity is reflected by the complex relationship between the two reservoir sweet spots as well as the oil migration and accumulation vertically and spatially, rather than the previous thoughts that it is a closed system associated with proximal hydrocarbon accumulation patterns. Multiple biomarkers show that the source rocks and reservoirs have similar characteristics in the lower part of the formation, reflecting a proximal hydrocarbon accumulation pattern in the lower sweet spot (near-source accumulation, abbreviated as NA). This represents a relatively closed system. However, the upper sweet spot and the middle section mudstone sequence intervening the two sweet spots are not a completely closed system in a strict sense. These sequences can be divided into three tight oil segments, i.e., lower, middle, and upper from deep to shallow. The lower segment is sited in the lower part of the middle section mudstone sequence. The middle segment is composed of the upper part of the middle section mudstone sequence and the lower part of the upper sweet spot. The upper segment is composed of the upper part of the upper sweet spot and the overlying upper Permian Wutonggou Formation reservoirs. Oils generated in the lower segment migrated vertically to upper sweet spot reservoirs through faults/fractures, and laterally to distal reservoirs. Oils generated in the middle segment were preserved in reservoirs of the upper sweet spot. Oils in the upper segment require accumulation by vertical and lateral migration through faults/fractures. As such, the tight oil accumulation is complex in the Lucaogou Formation. From base to top, the accumulation mechanisms in the Lucaogou Formation were NA, VLMA (vertical and lateral migration and accumulation), NA and VLMA, thereby showing strong heterogeneities. Our data suggest that these processes might be typical of tight oil accumulations universally, and are important for future exploration and exploitation in the region to consider the heterogeneities rather than a closed system. The multivariate statistical analysis is an effective tool for investigating complex oil-source correlations and accumulation in petroleum basins.Wang, Y., Han, Y., Hu, W., Fu, D., Wang, G., 2020. Analytical strategies for chemical characterization of bio-oil. Journal of Separation Science 43, 360-371., produced by biomass pyrolysis, have become promising candidates for feedstocks of high value-added chemicals and alternative sources for transportation fuels. Bio-oil is such a complicated mixture that contains nonpolar hydrocarbons and polar components which cover almost all kinds of organic oxygenated compounds such as carboxylic acids, alcohols, aldehydes, ketones, esters, furfurals, phenolic compounds, sugar-like material, and lignin-derived compounds. Comprehensive characterization of bio-oil and its subfractions could provide insight into the conversion process of biomass processing, as well as its further utilization as transportation fuels or chemical raw materials. This review focuses on advanced analytical strategies on in-depth characterization of bio-oil, which is concerned with gas chromatography, high-resolution mass spectrometry, FTIR spectroscopy and NMR spectroscopy, offering complementary information for previous reviews.Wang, Y., Liu, D.Q., Zhao, Z.H., Wang, H.J., 2020. Investigation on the effect of confining pressure on the geomechanical and ultrasonic properties of black shale using ultrasonic transmission and post-test CT visualization. Journal of Petroleum Science and Engineering 185, 106630. of the influence of confining pressure on the geomechanical and ultrasonic characteristics is essential to exploration and development of gas shale reservoirs. In contrast to the extensive studies on the physical and mechanical properties of shale, the velocities of P-wave and S-wave during continuous deformation are not thoroughly understood. In this study, a suite of triaxial compression tests were done on the shale samples collected from the Sichuan Basin and were cored with horizontal bedding structure under various confining pressure. In-situ ultrasonic transmission technique combined with post-test CT imaging analysis was used to reveal the velocity-pressure characteristics and crack patterns. The experimental results indicate that strength, elastic parameter, P- and S-wave velocities, and failure pattern are influenced by the applied confining pressure. At the pre-peak stage on the stress-strain curve, the P-wave velocity increases with elevated stress; however, the S-wave velocity first increases and then decreases, which is related to the crack damage evolution. The meso-structural changes during deformation are considered to be the main factor controlling the pressure sensitivity of the velocities. Under compression, the relatively soft pores, micro-cracks and minerals were compacted gradually, and it is the primary reason leading to the increment of velocities. Based on the CT scanning technique, the crack pattern was obtained after triaxial testing, the crack pattern analysis suggests that the fractal dimension of fracture distribution almost increases with confining pressure. What is more, the stimulated fracture density increases with increasing confining pressure. It suggests that, for the Longmaxi black shale, a high confining pressure condition is beneficial to form a complex fracture network.Wang, Y., Liu, H., Zhang, Q., Chen, Z., Wang, J., Dong, X., Chen, F., 2020. Pore-scale experimental study on EOR mechanisms of combining thermal and chemical flooding in heavy oil reservoirs. Journal of Petroleum Science and Engineering 185, 106649. flooding is an important method for the development of heavy oil reservoirs, but steam channeling is an inevitable serious problem in the process of steam injection, which decreases the sweep efficiency of steam and leads to low oil recovery. Viscosity reducer (VR) flooding and nitrogen foam flooding are two effective methods of enhancing heavy oil recovery with satisfactory results. In this paper, a series of experiments were conducted to evaluate the effects of various factors on the performance of the novel viscosity reducer (VR-A). On this basis, A visualized model was adopted to investigate the synergistic development effect of thermal and chemical flooding, which vividly reflected the interaction of chemical agents with crude oil and their migration characteristics in porous media, as well as the mechanisms of enhancing oil recovery on the pore-scale. The results showed that VR-A could achieve excellent viscosity reduction effect on heavy oil under the influence of various factors, which could be combined with thermal flooding to effectively recover heavy oil. As for the pore-scale level, after the VR-A solution was injected, the interfacial tension between the oil and water was decreased, the wettability of the surface of the particle was changed, and two types of oil-in-water emulsions (spherical emulsions and flocculent emulsions) with a lower viscosity were formed, which were easy to flow with the fluid in pores and throats and could temporarily block the high-permeability area. In the process of foam flooding, the phenomena of bubble coalescence and breakup occurred constantly, and bubbles trapped in the porous media could improve the sweep efficiency of the subsequent fluid. The ultimate oil recovery of the development method combining thermal and chemical flooding in the visualized displacement experiment is 76.9%, 39.7% higher than that of pure thermal flooding. This article can provide an effective method to solve the problem of poor steam flooding performance in heavy oil reservoirs.Wang, Y., Liu, L., Hu, Q., Hao, L., Wang, X., Sheng, Y., 2020. Nanoscale pore network evolution of Xiamaling marine shale during organic matter maturation by hydrous pyrolysis. Energy & Fuels 34, 1548-1563. suite of hydrous pyrolysis experiments was conducted on low-maturity organic-rich shale samples (with a total organic carbon (TOC) content of 6.9 wt % and marine-derived type I kerogen) from Xiamaling Formation to investigate the pore network evolution across a maturation gradient. Scanning electron microscopy and low-pressure gas physisorption (CO2 and Ar) were applied to observe the pore morphology and quantify the pore structure. On the basis of the geochemical properties and yields of the pyrolysis products, organic matter (OM) thermal maturation includes the following four stages: bitumen generation (unheated to 350 °C), oil window (350–410 °C), oil cracking (410–480 °C), and wet gas cracking (480–550 °C). The nanoscale pore network evolution shows a good correspondence to stages of hydrocarbon generation. Overall, the total pore volume increased in the bitumen generation stage and the oil window, followed by a decrease in the oil cracking stage, but then again increased in the wet gas cracking stage, while the total surface area progressively increased after an obvious decrease in the bitumen generation stage. The dominant pores at the bitumen generation stage are associated with minerals. The presence of shrinkage OM pores and microfractures contributes to increased volumes of meso- (diameter range of 2–50 nm) and macropores (diameter > 50 nm), while the decrease in micropore (diameter < 2 nm) volume is mainly related to bitumen infilling. During the oil window, bubble-like OM pores are greatly developed, which contributes to an increase in the total pore volume. A lower amount of modified mineral pores with relic OM is observed. However, the high expulsion efficiency causes a limited decline in the pore volume due to bitumen infilling. During the oil cracking stage, modified mineral pores progressively increase. Transformation of large-size bubble-like OM pores to small-size spongy OM pores leads to an increased micropore volume, as well as decreased meso- and macropore volumes. During the wet gas cracking stage, a large abundance of spongy OM pores is developed in highly transformed OM, leading to progressive increases in pore volume. Overall, mineral-related pores decrease, while OM pores change from nondevelopment, shrinkage pores, bubble-like to spongy pores during thermal maturation. Furthermore, OM thermal maturation primarily impacts pores less than 20 nm in size, since pore structure parameters for those pores exhibit the most change after pyrolysis. The pore evolution model revealed in this study will provide an analog for that of the other marine shales.Wang, Y., Luo, C., Yang, M., Jianwei, R., Wang, W., Li, Y., Gao, G., Ren, L., Zou, X., 2020. Target quantification and semi-target screening of halogenated carboxylic acids in drinking water using ultra-high performance liquid chromatography-quadrupole Orbitrap high-resolution mass spectrometry. Journal of Chromatography A 1614, 460710. monitor the existing and emerging halogenated carboxylic acids (HCAs) in drinking water, a sensitive and rapid ultra-high performance liquid chromatography-quadrupole orbitrap high-resolution mass spectrometry method for simultaneous target quantification of 10 haloacetic acids (HAAs) and semi-target screening of 19 HCAs was developed. After filtration, drinking water samples were injected into the instrument. HCAs were separated on an HSS T3 column and detected by a type of non-target scan in the electrospray ionization negative mode. For target quantification of 10 HAAs, good linearity was obtained and the correlation coefficients were higher than 0.995. The limits of detection were in the range of 0.050-2.0 μg/L. The recoveries were in the range of 89.7%-108%, 83.4%-121%, 77.1%-116% and 80.2%-104% at levels of 2.5, 5.0, 10 and 20 μg/L, respectively, with relative standard deviations of 1.26%-16.9%. For semi-target screening of 19 HCAs, several criteria including accurate m/z, predicted retention time, deduced fragment ions and simulated isotope pattern were used for identification. The method was applied to analyzing 41 drinking water samples successfully. Five HAAs were detected by target quantification, with dichloroacetic acid and trichloroacetic acid exceeding the limits suggested by the U.S. Environmental Protection Agency and the World Health Organization. Eight HCAs were preliminary identified by semi-target screening, and three of them were further confirmed with reference standards purchased later.Wei, B., Liu, J., Zhang, X., Xiang, H., Zou, P., Cao, J., Bai, M., 2020. Nuclear Magnetic Resonance (NMR) mapping of remaining oil distribution during sequential rate waterflooding processes for improving oil recovery. Journal of Petroleum Science and Engineering 190, 107102. the conclusion of waterflooding phase, significant volume of oil still remains in reservoir formations. In this paper, waterflooding was performed at a designed sequential rate mode with an aim to further reduce the remaining oil saturation (Sor). Waterflooding process was monitored continuously by a low-field Nuclear Magnetic Resonance (NMR) spectrometer attempting to map pore-scale displacing behaviors and also quantify the reduction in Sor in-situ. The results showed that the main pore size of the cores ranged from 1.6 μm to 63.0 μm inferred by T2 (transverse relaxation time) distributions. The value of Sor in the cores increased towards the outlet face during waterflooding because of capillary end effect, which became more significant for heavy oil. At the termination of this waterflooding process, Sor was found to be further reduced by approximately 5.0% in the presence of thief water pathways as a result of the improved viscous forces. Water fingering and capillary imbibition effects were clearly visualized in the NMR images. These observations are expected to be useful for heavy oil waterflooding operations especially in post-breakthrough phase.Wei, S., He, S., Pan, Z., Zhai, G., Dong, T., Guo, X., Yang, R., Han, Y., Yang, W., 2020. Characteristics and evolution of pyrobitumen-hosted pores of the overmature Lower Cambrian Shuijingtuo Shale in the south of Huangling anticline, Yichang area, China: Evidence from FE-SEM petrography. Marine and Petroleum Geology 116, 104303. pores, one of the significant pore types in shale reservoir, can be formed in both primary organic matter (kerogen) and secondary organic matter such as solid bitumen and pyrobitumen. Compared to the primary organic pores that are mainly observed in immature kerogen, secondary organic pores in migrated organic matter (solid bitumen and pyrobitumen) are more abundant and well connected to the matrix. In this study, the petrographic characteristics between the organic matter and matrix as observed in field emission-scanning electron microscopy (FE-SEM) images were used to characterize the pore system in the overmature Lower Cambrian Shuijingtuo (Niutitang-equivalent) Shale in the south of Huangling anticline, Yichang area, China. Pyrobitumen-hosted pores were observed to be the predominant pore type in the organic-rich Shuijingtuo Shales. The porous pyrobitumen occurs primarily in the original interparticle pores filled with microcrystalline quartz, which is the primary petrographic evidence to identify the migrated organic matter. Pore-filling organic matter and precipitation of authigenic quartz, rather than mechanical compaction, resulted in further loss of a large number of interparticle pores. The porous organic matter that filled in the intraparticle space within the early-formed framboidal pyrite and the pre-existing dissolution pores within the quartz and pyrite grains is pyrobitumen. This pyrobitumen had migrated as a mobile phase into the aforementioned pores spaces in the initial phase of hydrocarbon emplacement during the petroleum expulsion and migration process. With increasing thermal maturity, this migrated organic matter thermally transformed into pyrobitumen, and nanoscale pores were developed with thermal cracking into gas. The results show that the pore volume and surface area are positively correlated with the total organic carbon (TOC) content, indicating that organic matter primarily controls shale porosity for the Shuijingtuo Shales.Wei, W., Frei, R., Gilleaudeau, G.J., Li, D., Wei, G.-Y., Huang, F., Ling, H.-F., 2020. Variations of redox conditions in the atmosphere and Yangtze Platform during the Ediacaran-Cambrian transition: Constraints from Cr isotopes and Ce anomalies. Palaeogeography, Palaeoclimatology, Palaeoecology 543, 109598. Ediacaran-Cambrian transition was characterized by the evolution from Ediacaran soft-body to Cambrian skeletal organisms, and fluctuations of the marine carbon cycle. Marine redox changes should have played an essential role in both ecological and environmental evolutions; however, temporary changes and spatial distribution of redox conditions in the Ediacaran-Cambrian oceans remain elusive and highly debated. In this study, we analyzed chromium (Cr) isotope and cerium (Ce) anomaly profiles in carbonates from the Upper Ediacaran-Lower Cambrian Dengying and Zhujiaqing formations at the Xiaotan section, South China, in an attempt to provide new insights helping unravel Earth's surface redox changes during the Ediacaran-Cambrian transition. Our results show that these carbonates record generally positive δ53Crauth values (up to 1.15‰) with fluctuations and prominent negative Ce anomalies (Ce/Ce? values down to 0.35), implying a broad increase in oxygenation in the atmosphere and the inner shelf of the Yangtze Platform during the Ediacaran-Cambrian transition. The first appearance and subsequent diversification of the Cambrian animals may have benefited from this oxygenation event. The pronounced fluctuations of δ53Crauth and δ13Ccarb values can be explained by episodic oxidation of a deep-water DOC pool in a stratified water column across the chemocline through upwelling, releasing light carbon isotopes and organic-matter-bound isotopically unfractionated Cr (III) into shallow waters.Weiss, G.M., Massalska, B., Hennekam, R., Reichart, G.-J., Sinninghe Damsté, J.S., Schouten, S., van der Meer, M.T.J., 2020. Alkenone distributions and hydrogen isotope ratios show changes in haptophyte species and source water in the Holocene Baltic Sea. Geochemistry, Geophysics, Geosystems 21, e2019GC008751.: The Baltic Sea, a dynamic, marginal marine basin, experienced a number of large changes in salinity during the Holocene as a result of fluctuations in global and local sea level related to melting of glacial ice sheets and subsequent isostatic rebound. These changes likely had pronounced effects on the species composition of haptophytes, a common phytoplankton group found in the Baltic Sea. This dynamic environment provides the ideal setting to study how species change impacts distribution and hydrogen isotope ratios of long‐chain alkenones (δ2HC37), haptophyte‐specific biomarkers. Here we analyzed the aforementioned parameters in Holocene sediments covering the contrasting hydrological phases of the Baltic Sea. Alkenone distributions changed with different Baltic Sea salinity phases, suggesting that species shifts coincide with salinity change. δ2HC37 values show two major shifts: one in the middle of the freshwater Ancylus Lake phase (10.6 to 7.7 ka) and a second at the transition from the brackish Littorina Sea phase (7.2 to 3 ka) into the fresher Modern Baltic (3 ka to the present). The first shift represents a significant enrichment of 50‰, which cannot be explained by salinity or species changes only. At this time, the isotopically depleted ice sheets had melted, and only the relatively enriched freshwater source remained. The second shift, coincident with a change in distribution, is likely caused by a change in species composition alone. These findings show that hydrogen isotope ratios of long‐chain alkenones, combined with their relative distribution, can be used to reconstruct changes in source water.Plain Language Summary: Algae record information about the water they grow in, for example, if the water is from the ocean or freshwater sources. This information is preserved in organic compounds and can be elucidated by measuring the stable hydrogen isotope composition of these molecules. The Baltic Sea is particularly suited to study hydrological changes preserved in organic compounds because it maintains a connection with the North Sea, encompassing a range of ocean to freshwater habitats, and this connection has fluctuated over time causing large salinity changes. We investigated hydrological changes in the Baltic Sea over the last 11,000 years. In the older part of the record, a major shift in isotopes of algal compounds occurred without a shift in the algal population. We interpret this as the melting of the last remnants of glacial‐aged ice at this time, leading to an abrupt shift to other freshwater sources. In the younger parts of the record, more ocean water entered the Baltic Sea, causing a change in the algal population along with isotopic change. Overall, these results contribute to our knowledge of how water source and salinity affect algal populations, which is important for understanding how ecosystems might respond to future climate change and hydrological budget.Wells, S.S., Kennedy, R.T., 2020. High-throughput liquid–liquid extractions with nanoliter volumes. Analytical Chemistry 92, 3189-3197. methods for liquid–liquid extractions generally require microliter to milliliter volumes of solvents and sample, long equilibration times, and manual procedures. Extraction methods for samples in microfluidic systems have been limited as this tool is difficult to implement on the nanoliter or smaller scale. We have developed slug-flow nanoextraction (SFNE), a method based on droplet microfluidics that allows multiple liquid–liquid extractions to be performed simultaneously in a capillary tube, using only 5 nL of sample and extraction solvent per extraction. Each two-phase slug is segmented from the others by immiscible carrier fluid. We found rapid extractions (<5 s), partition coefficients matching those achieved at larger scale extractions, and potential to preconcentrate samples through volume manipulation. This method was used to accurately and rapidly determine octanol–water partition coefficients (Kow), determining identical Kow as the shake-flask method for acetaminophen, Kow = 2.48 ± 0.02. The measurement, along with calibration and 12 replicates, was complete within 5 min, consuming under 150 nL of solvent and sample. The method was also applied to extract analytes from complex biological samples prior to electrospray ionization-tandem mass spectrometry (ESI-MS/MS) at a rate of 6 s per sample, allowing for simultaneous determination of five different drugs spiked into human plasma, synthetic urine (SU), and artificial cerebral spinal fluid (aCSF) using ethyl acetate as the extraction phase. The signal-to-noise (S/N) for analytes improved up to 19-fold compared to direct ESI-MS of single-phase droplets (aqueous plugs segmented by carrier fluid), with limits of detection down to 7 nM (35 amol).White, S.M., Ravelo, A.C., 2020. Dampened El Ni?o in the Early Pliocene Warm Period. Geophysical Research Letters 47, e2019GL085504.: El Ni?o‐Southern Oscillation (ENSO) is the strongest mode of interannual climate variability, and its predicted response to anthropogenic climate change remains unclear. Determining ENSO's sensitivity to climatic mean state and the strength of positive and negative feedbacks, notably the thermocline feedback, will help constrain its future behavior. To this end, we collected ENSO proxy data from the early and mid‐Pliocene, a time during which tropical Pacific zonal and vertical temperature gradients were much lower than today. We found that El Ni?o events had a reduced amplitude throughout the early Pliocene, compared to the late Holocene. By the mid‐Pliocene, El Ni?o amplitude was variable, sometimes reduced and sometimes similar to the late Holocene. This trend in Pliocene ENSO amplitude mirrors the long‐term strengthening of zonal and vertical temperature gradients and verifies model results showing dampened ENSO under reduced gradients due to a weaker thermocline feedback.Plain Language Summary: El Ni?o events are marked by anomalously warm sea‐surface temperatures and increased rainfall in the central and eastern equatorial Pacific and cause major changes in weather patterns across the Pacific. It is unclear whether El Ni?o events will strengthen or weaken with anthropogenic warming. To help elucidate El Ni?o's future behavior, we reconstructed changes in El Ni?o during the Pliocene, the most recent extended period that was warmer than today. We found that El Ni?o events were weaker ~3.5 to 5 Ma, compared to the late Holocene. By ~3.1 Ma, El Ni?o strength was sometimes weaker and sometimes similar to the late Holocene, varying on millennial timescales. The shift in El Ni?o behavior coincides with a long‐term cooling of tropical Pacific subsurface waters. The association between subsurface temperature and El Ni?o strength has also been observed for the Last Glacial Maximum and the Holocene and points to an important role of the subsurface in dictating El Ni?o strength.Wi?c?aw, D., Bilkiewicz, E., Kotarba, M.J., Lillis, P.G., Dziadzio, P.S., Kowalski, A., Kmiecik, N., Romanowski, T., Jurek, K., 2020. Origin and secondary processes in petroleum in the eastern part of the Polish Outer Carpathians. International Journal of Earth Sciences 109, 63-99. geochemical study of crude oil and natural gas from producing wells and seeps within the Lower Cretaceous–Oligocene sandstone reservoirs of the most eastern part of the Polish Outer Carpathians was conducted for the evaluation of their origin, migration pathways and the effects of secondary processes (biodegradation, water washing and evaporative fractionation). The petroleum was generated from mixed marine/terrigenous organic matter (type-II/III kerogen) occurring mostly in Oligocene Menilite beds in the Silesian and Skole nappes. Shales within Upper Cretaceous–Palaeocene Istebna and Lower Cretaceous Ve?ovice, Lgota and Spas beds are considered as an additional source of hydrocarbons (mainly gaseous). Biodegradation processes were recorded in numerous oils, especially occurring in seeps, but the extent of these processes is not severe, because steranes and terpanes were not affected. All oils are more-or-less water washed, while the evaporative fractionation processes are developed only on a minimal scale. The natural gases are primarily of thermogenic origin, usually co-genetic with oil and often contain components of secondary microbial degradation of both oil and natural gas (13C-enriched CO2 and 13C-depleted CH4). Gases with the highest microbial methane contribution have been recorded in petroleum accumulated in Dwernik and ?odyna fields.Wilson, S.R., Berg, H.E., Roberg-Larsen, H., Lundanes, E., 2020. Chapter 3.3 - Hyphenations of one-dimensional capillary liquid chromatography with mass spectrometry: State-of-the-art applications, in: Tranchida, P.Q., Mondello, L. (Eds.), Hyphenations of Capillary Chromatography with Mass Spectrometry. Elsevier, pp. 319-367. liquid chromatography-mass spectrometry (cLC-MS) is a powerful tool for a variety of applications in analytical chemistry. Key advantages of cLC-MS are its suitability for small-sample analysis and enhanced sensitivity. The cLC-MS approach is perhaps most associated with bioanalytical applications, particularly proteomics and gradually also metabolomics. Typical sample matrices include cells and other biotissues/fluids. Central applications of cLC-MS include fundamental research efforts such as the mapping of the human proteome, but the approach is increasingly approaching the clinical area. The cLC-MS approach has also been employed in numerous fields such as foodomics, doping analysis, drug studies, and environmental chemistry research. The chapter highlights the work of researchers that have employed cLC-MS in their applications, between 2010 and 2017.Wohl, C., Brown, I., Kitidis, V., Jones, A.E., Sturges, W.T., Nightingale, P.D., Yang, M., 2020. Underway seawater and atmospheric measurements of volatile organic compounds in the Southern Ocean. Biogeosciences Discussions 2020, 1-40. sulfide and volatile organic compounds and are important for atmospheric chemistry. The oceanic emissions of biogenically derived gases, including dimethyl sulfide and especially isoprene, are not well constrained. The role of the ocean in the global budgets of atmospheric methanol, acetone and acetaldehyde is even more poorly known. In order to quantify the air-sea fluxes of these gases we measured their seawater concentrations and air mixing ratios in the Atlantic sector of the Southern Ocean, along a ~?11?000?km long transect at approximately 60°?S in Feb–Apr 2019. Concentrations, oceanic saturations and estimated fluxes of several simultaneously sampled volatile organic compounds (methanol, acetone, acetaldehyde, dimethyl sulfide and isoprene) are presented here. Campaign mean (±?1σ) surface water concentrations of dimethyl sulfide, isoprene, methanol, acetone and acetaldehyde were 2.60 (±?3.94), 0.0133 (±?0.0063), 67 (±?35), 5.5 (±?2.5) and 2.6 (±?2.7)?nmol?dm?3 respectively. In this dataset, seawater isoprene and methanol concentrations correlated positively. Furthermore, seawater acetone, methanol and isoprene concentrations were found to correlate negatively with the fugacity of carbon dioxide, possibly due to a common biological origin. Campaign mean (±?1σ) air mixing ratios of methanol, acetone and acetaldehyde were relatively low at 0.17 (±?0.08), 0.081 (±?0.031) and 0.049 (±?0.040)?ppbv. We observed diel changes in averaged acetaldehyde concentrations in seawater and ambient air (and to a lesser degree also for acetone and isoprene), which suggest light-driven productions. Campaign mean (±?1σ) fluxes of 4.3 (±?7.4)??mol?m?2?d?1 DMS and 0.028 (±?0.021)??mol?m?2?d?1 isoprene are determined where a positive flux indicates from the ocean to the atmosphere. Methanol was largely undersaturated in the surface ocean with a mean (±?1σ) net flux of ?2.4 (±?4.7)??mol?m?2?d?1, but also had a few occasional episodes of outgassing This section of the Southern Ocean was found to be both a source and a sink for acetone and acetaldehyde this time of the year, depending on location, resulting in a mean flux of ?0.55 (±?1.15)??mol?m?2?d?1 for acetone and ?0.28 (±?1.22)??mol?m?2?d?1 for acetaldehyde. The data collected here will be important for constraining the oceanic source/sink of these gases and potentially help to elucidate the presence of common sources/sinks for these compounds.Wójcik, M., Kostowski, W., 2020. Environmental risk assessment for exploration and extraction processes of unconventional hydrocarbon deposits of shale gas and tight gas: Pomeranian and Carpathian region case study as largest onshore oilfields. Journal of Earth Science 31, 215-222. gas and tight gas exploration and extraction processes create potential threats to the environment. In Poland, no comprehensive guidelines for environmental risk assessment have been prepared so far. This paper presents a proposal of environmental risk assessment methodology which can be used for corporate risk management procedures during exploration and extraction of unconventional hydrocarbons in Poland. The most frequent environmental threats that may occur during the exploration and exploitation of unconventional hydrocarbon deposits include degradation of soils through construction of drilling rigs and access roads, landforms change, local soil pollution caused by fuels, cleaning agents and materials used to prepare drilling fluids, rubble, cement, gravel, pollution of surface and underground water as a result of emergency discharges of sewage, infiltration of pollution from waste reservoirs, disturbance of hydrogeological equilibrium through significant water intake, noise and atmospheric pollution resulting from the combustion of fuels. To check the level of these threats’ six exploration sites form Pomeranian and Carpathian region of Poland (3 wells of shale gas and 3 wells of tight gas) have been evaluated in detail, and the risk quantification has been made. Because of a local, short-term and reversible environment impact, the environmental risks for the exploration and extraction processes of unconventional hydrocarbons have been found to be medium or negligibly small. It is recommended that using the same methodology for other regions of Poland where we can find unconventional hydrocarbons and it can be enriched in dedicated application with spatial maps to give the investors a quick feedback on the potential environmental risks.Wright, R.J., Bosch, R., Gibson, M.I., Christie-Oleza, J.A., 2020. Plasticizer degradation by marine bacterial isolates: A proteogenomic and metabolomic characterization. Environmental Science & Technology 54, 2244-2256. commercial plasticizers are toxic endocrine-disrupting chemicals that are added to plastics during manufacturing and may leach out once they reach the environment. Traditional phthalic acid ester plasticizers (PAEs), such as dibutyl phthalate (DBP) and bis(2-ethyl hexyl) phthalate (DEHP), are now increasingly being replaced with more environmentally friendly alternatives, such as acetyl tributyl citrate (ATBC). While the metabolic pathways for PAE degradation have been established in the terrestrial environment, to our knowledge, the mechanisms for ATBC biodegradation have not been identified previously and plasticizer degradation in the marine environment remains underexplored. From marine plastic debris, we enriched and isolated microbes able to grow using a range of plasticizers and, for the first time, identified the pathways used by two phylogenetically distinct bacteria to degrade three different plasticizers (i.e., DBP, DEHP, and ATBC) via a comprehensive proteogenomic and metabolomic approach. This integrated multi-OMIC study also revealed the different mechanisms used for ester side-chain removal from the different plasticizers (esterases and enzymes involved in the β-oxidation pathway) as well as the molecular response to deal with toxic intermediates, that is, phthalate, and the lower biodegrading potential detected for ATBC than for PAE plasticizers. This study highlights the metabolic potential that exists in the biofilms that colonize plastics—the Plastisphere—to effectively biodegrade plastic additives and flags the inherent importance of microbes in reducing plastic toxicity in the environment.Wu, Y., Tahmasebi, P., Yu, H., Lin, C., Wu, H., Dong, C., 2020. Pore-scale 3D dynamic modeling and characterization of shale samples: Considering the effects of thermal maturation. Journal of Geophysical Research: Solid Earth 125, e2019JB018309. The development of shale gas necessitates accurate modeling and characterization of these complicated formations, at both small and large scales. At the small scale, the studies based on experimental techniques have uncovered that the components and pore types in shales vary dramatically. Several pore types are identified and varied when the thermal maturation of shales changes. Therefore, accurate modeling and characterization of shale samples require taking such dynamic variations into consideration. This study presents a novel, dynamic, and three-dimensional (3D) modeling technique considering pore-system variation when the thermal maturation changes. The technique can construct dynamic shale models based on quartet structure generation set algorithm and morphological operation. This method can include various elements available in the shale samples in a very accurate way when the dynamic processes are reproduced. To evaluate the performance of the presented technique, 12 dynamic 3D shale models of three cases are constructed. These models are then characterized by analyzing the fractions of components and pores, pore and throat size distributions, coordination number distribution, fractal dimension, and tortuosity. Besides, gas transport in these dynamic 3D shale models is also simulated using pore network modeling to demonstrate the permeability variation of these models. Moreover, the fractions of interparticle and intraparticle pores and cementation degree are changed to further illustrate the capability of the developed algorithm. This study reveals such a dynamic modeling technique is a robust tool to construct various porous media with complicated elements and pores, which is not limited to shale samples.Wu, Y., Tian, H., Gong, D., Li, T., Zhou, Q., 2020. Paleo-environmental variation and its control on organic matter enrichment of black shales from shallow shelf to slope regions on the Upper Yangtze Platform during Cambrian Stage 3. Palaeogeography, Palaeoclimatology, Palaeoecology 545, 109653. understand the evolution of oceanic redox conditions and organic matter (OM) accumulation in the shelf and slope regions of the Upper Yangtze Platform during Cambrian Stage 3, high-resolution geochemical data were obtained from two wells respectively representing shelf and slope environments. Based on redox proxies, widespread anoxic/euxinic waters with intermittent sulfidic water columns were formed from shallow shelf to deep water slope and basinal regions during Stage 2 and early Stage 3; then, widespread anoxic waters were reduced and oxic waters expanded during the middle Stage 3, after which fluctuating suboxic and oxic (occasionally anoxic) environments became predominant during late Stage 3. The presence of hyalophane and positive Eu anomalies suggest strong Ba-rich hydrothermal activities in the shelf and deep basin regions during early and middle Stage 3. The Ba-rich hydrothermal fluids and upwelling events enhanced the primary productivity in surface waters and subsequently promoted organic matter enrichment. During Stage 2 and early Stage 3, the high primary productivity driven by coastal upwelling and hydrothermal activity were the main factors controlling OM enrichment; during middle Stage 3, the local anoxic water condition became responsible for OM enrichment when oxic waters began to gradually expand; during late Stage 3, both primary productivity and redox conditions became the main control factors for OM enrichment. According to the analysis of primary productivity, redox conditions, hydrothermal activity and upwelling events, an evolution model is proposed to account for the paleo-environmental variation and the OM enrichment from shallow shelf to slope regions during Cambrian Stage 3.Xia, L., Li, Y., Liu, Y., Li, G., Xiao, X., 2020. Recent advances in sample preparation techniques in China. Journal of Separation Science 43, 189-201. preparation is the procedure before instrumental analysis and significant to its effectiveness and efficiency. However, this procedure is usually time‐consuming, labor intensive, and prone to error. In the last decade, the development of sample preparation techniques has received increasing attention, especially in complex sample application. To pretreat samples faster and more effectively, advanced materials, instrumentation, and methods have been combined with typical techniques, including extraction, membrane separation, and chemical conversion techniques. Researchers in China focused on the development of simple, efficient sample preparation methods with selective enrichment and rapid separation capabilities for target analysis in complicated sample matrix and contribute almost a half of the publications in this specific field. In this review, a panorama of sample preparation techniques in China has been composed from more than 140 references, and we highlight some promising methods developed during recent years and introduce different separation materials with respect to these methods.Xia, Y., Xing, Y., Li, M., Liu, M., Tan, J., Cao, Y., Gui, X., 2020. Studying interactions between undecane and graphite surfaces by chemical force microscopy and molecular dynamics simulations. Fuel 269, 117367. are often used to increase the hydrophobicity of valuable minerals during flotation. Hence, it is necessary to know the forces between them, especially the hydrophobic force, which closely associated with hydrophobic minerals floating, such as graphite, coal, and molybdenite. In the present study, graphite sheets were used as the hydrophobic mineral, and the force characteristics and interfacial adsorption structures of undecane (a model collector) on graphite surface with different hydrophobicities were investigated by chemical force microscopy and molecular dynamics simulations. Undecane experiences repulsive interactions as it approaches hydrophilic graphite; however, an obvious jump-in phenomenon driven by hydrophobic force was observed for hydrophobic graphite, which triggers their adhesion. Derjaguin–Landau–Verwey–Overbeek (DLVO) and extended DLVO fitting reveal that the hydrophobic force decays at 1.35?nm in a single-exponential manner. The adhesion force during retraction increases with increasing surface hydrophobicity. The hydrophilic surface adsorbs a large amount of water to form a dense and ordered hydration film that interferes with the adsorption of undecane, while a water-depletion layer exists on the hydrophobic surface with closely adsorbed undecane molecules. This study improves our understanding of the action mechanism of flotation collectors for hydrophobic minerals.Xiang, L., Zhang, H., Schoepfer, S.D., Cao, C.-q., Zheng, Q.-f., Yuan, D.-x., Cai, Y.-f., Shen, S.-z., 2020. Oceanic redox evolution around the end-Permian mass extinction at Meishan, South China. Palaeogeography, Palaeoclimatology, Palaeoecology 544, 109626. end-Permian marine extinction (EPME) eliminated >80% of species globally, making it the most severe extinction of the Phanerozoic. Anoxia and euxinia are potential kill mechanisms that may have contributed to this biotic crisis. However, redox changes in the atmosphere-ocean system are likely to have been complex, with both the vertical location of the oxic-anoxic boundary (in the water column or sediments), and the total area or volume of anoxic and euxinic water in the global ocean changing over time. In this study, we generated iron speciation and major and trace element data from 141 samples of the Meishan-1 core, which was drilled at a site 550?m to the west of the Meishan D section. Iron speciation results, in combination with authigenic concentrations and enrichment factors of redox-sensitive metals (Mo, V, and U), and previously published macrofossil, trace fossil, and bioturbation evidence, suggest that: 1) Beds 21-24d were deposited beneath a predominantly oxic water column, 2) Beds 24e-28 were deposited under a persistently anoxic watermass with intermittently euxinic bottom water, and 3) Beds 29–34 were deposited under primarily ferruginous conditions. Excess fractions and enrichment factors of U, V and Mo in the anoxic and euxinic intervals of the Meishan-1 core suggest that authigenic precipitation of redox-sensitive trace metals mainly occurred before and during the EPME, with nearly no detectable authigenic U, V, or Mo accumulating after the EPME. Our results, along with published U, V and Mo concentrations from across the Neotethys, Paleotethys, and Panthalassic Ocean basins, indicate that oceanic trace metal reservoirs were depleted before and during the main extinction interval. This depletion of oceanic trace elements suggests a spatial expansion of both anoxic and euxinic watermasses prior to and during the EPME. The apparent coincidence in timing between the mass extinction and the areal expansion of anoxic and euxinic watermasses suggests that these factors played important roles in the loss of marine biota around the Permian-Triassic boundary (PTB), through oxygen deprivation and H2S toxicity.Xing, W., Hu, H., Zhang, Y., Zhao, D., Wang, W., Pan, H., Zhang, S., Yan, L., 2020. Magnetotactic bacteria diversity of and magnetism contribution to sediment in Wudalianchi volcanic barrier lakes, NE China. Science of The Total Environment 718, 137348. bacteria (MTB), the members of sediment microorganisms, play an important role in geochemical iron-cycling and sediment magnetism. This study aimed to investigate the diversity and magnetism contribution of MTB in three volcanic barrier lakes with different waterbody types (open waterbody, YC; semi-enclosed waterbody, WB; and enclosed waterbody, YYP). High-throughput sequencing results showed that MTB affiliated to Alphaproteobacteria, Betaproteobacteria and Nitrospira distributed widely in these lakes. The genera of Magnetococcus (98.10%) and Candidatus Magnetoovum (1.47%) were endemic to YC and WB, respectively. The changes in frequency-dependent susceptibility (χfd) values before and after magnetic collection in YC, WB and YYP samples were ? 0.28%, 0.05% and ? 0.22%, respectively. The magnetic susceptibility was significantly associated with Chao1 (R2 = 0.637 to 0.763, p < .01) and Shannon index (R2 = 0.803 to 0.998, p < .01). The room- and low-temperature magnetic characteristics of sediment samples were analyzed by vibrating sample magnetometer (VSM) and radio-frequency superconducting quantum interference device (SQUID). Results indicated that the presence or absence of MTB could lead to the changes in the room- and low-temperature magnetism of volcanic lake sediments, which would extend our knowledge of MTB magnetism contribution to volcanic ecosystems.Xing, Z., Ya, Z., Wang, Z., Sun, B., Fu, H., Bénédicte, M.-C.J., 2020. Study on the effects of waves and dispersant on the submergence of spilled oil. Water Resources 47, 95-102. baffled flasks were used to simulate regular wave and breaking wave at different oscillation intensities to study the effects of wave strength, reaction time, and dispersant on the submergence of oil spill. It was found that the wave strength has the greatest impact on submerging rate and submergence stability of Liaohe crude oil and Fuel 180. The characteristics of the impacts of the wave strength and dispersant content are that there are thresholds, below which the impacts are not obvious; their coupling effects are obvious only when both the wave strength and the dispersant content exceed their threshold; the impacts can accumulate over time and have the maximum value; the submerging rate reaches maximum at 30 min for Liaohe crude oil and 60 min for Fuel 180; the submerging rate will decrease after the time of the maximum impact. Based on the experimental results, it is proposed that the submerging model should have different forms based on the thresholds of conditions and different phases of the time, which need more work to be determined for different oils.Xiong, W., Gong, Q., Duan, X., Zhu, W., Yi, W., Hu, Z., Chang, J., Shen, R., 2020. Pressure building-up methodology to measure gas content of shale samples. Journal of Petroleum Science and Engineering 186, 106678. canister method for testing shale gas has been adopted from coalbed methane content testing standard. However, the method is inaccurate and may underestimate the gas content of shale samples because of poor estimation to lost gas in the process of recovering cores from the bottom to the wellhead of a well. In this paper, a new pressure buildup method is proposed to measure gas content at formation pressure and temperature. Since it avoids estimation of lost gas, shale gas content can be measured accurately. First pump methane into the canister in which a core is placed, and then pressurize the core until the pressure reaches the known formation pressure at known formation temperature. Then, after the pressure is balanced, degas and measure the gas released from the core. And finally, measure the residual gas after crushing a small part of the core when degassing rate is very low. The sum of desorbed gas and residual gas is the total shale gas. At unknown formation pressure, a linear equation with two unknowns -- pore volume at in-situ water saturation and adsorbed gas volume, is set up. Two linear equations with two unknowns are formed when the total shale gas tested at 25?MPa and 30?MPa for the same core, following the procedures for the case of known formation pressure, are substituted into the linear equation. Pore volume at in-situ water saturation and adsorbed gas volume are gained by solving the group of equations. Total shale gas can be calculated simply when formation pressure is gained. Unlike traditional methods, adsorbed gas and free gas can be obtained at the same time in the case of unknown formation pressure. Shale gas content measured by the pressure buildup method is 2–7 times as much as the standard.Xu, H., George, S.C., Hou, D., Cao, B., Chen, X., 2020. Petroleum sources in the Xihu Depression, East China Sea: Evidence from stable carbon isotopic compositions of individual n-alkanes and isoprenoids. Journal of Petroleum Science and Engineering 190, 107073. order to better understand the relative contributions of various source rocks for petroleum in the Xihu Depression, East China Sea Basin, gas chromatography-mass spectrometry analyses of the saturated and aromatic fractions and carbon isotopic analyses of the purified n-alkanes and isoprenoids were performed. The molecular composition and individual n-alkane and isoprenoid carbon isotope compositions were determined for oils and extracts of Paleogene mudstones (TOC: 0.45–2.3%), carbonaceous mudstones (12.7–19.6%), and coals (48–60%) in the Xihu Depression, so as to discriminate the hydrocarbon sources of coals and associated mudstones to the petroleum generated in the basin. Abundant diterpanes (e.g., isopimarane, phyllocladane) are present in all the samples. The differences in the δ13C values of pristane and phytane indicate separate origins for the isoprenoids. A general negative sloping profile with increasing n-alkane carbon chain length was observed in coals, mudstones and oils from the Huangyan oilfield, with individual n-alkane δ13C values between ?25.6‰ and ?34.4‰. These values are characteristic of the isotopic compositions of C3 plants, and are also typical of fluvial/lacustrine depositional settings. The isotope compositions of individual n-alkanes from the extracts of coals and mudstones correlate with the relative concentration of terrigenous higher plant-derived diterpenoids, which suggests that plant phyla/classes (for example gymnosperm-derived diterpanes versus angiosperm-derived diterpanes) may be a control on the carbon isotope profiles of n-alkanes. For samples dominated by terrigenous organic matter, long chain n-alkanes with a large proportion of gymnosperm input are approximately 2–3‰ enriched in 13C relative to those with angiosperm input, regardless of lithology. The connections between the oils, coals, and mudstones allow determination of the patterns and variations for different hydrocarbon contributions, and provide a way of differentiating specific source contributions to petroleum in the Xihu Depression. Oils generated from the coals have heavier δ13C values with increasing chain length within a narrow range (approx. 2–3‰) and have more heterotrophic origins, whereas oils from the mudstones are more depleted in 13C with increasing carbon number (n-C20-31) and have a greater derivation from land plants. The 825B oils in the Huangyan oilfield have a greater angiosperm-sourced hydrocarbon contribution than those of the 825AD oils, which have a greater gymnosperm-sourced hydrocarbon contribution. The tricyclic and tetracyclic diterpanes and the isotopic compositions of individual n-alkanes and isoprenoids may be useful in differentiating contributions of coals and associated mudstones to petroleum.Xu, H., Lin, C., Shen, Z., Gao, L., Lin, T., Tao, H., Chen, W., Luo, J., Lu, C., 2020. Molecular characteristics of dissolved organic nitrogen and its interaction with microbial communities in a prechlorinated raw water distribution system. Environmental Science & Technology 54, 1484-1492. organic nitrogen (DON) represents a unique challenge in prechlorinated raw water distribution systems (PRWDSs) because of its contribution to the formation of harmful nitrogen-disinfection byproducts, influence upon biogeochemical processes, and unclear molecular characteristics. Here, Fourier transform ion cyclotron resonance mass spectrometry in combination with high-throughput sequencing was applied to elucidate the molecular changes of DON and biofilm microbial communities in a PRWDS in Yixing, China. Our study revealed that dynamic characteristics of DON are significantly correlated with the biofilm. The accumulation of refractory lignin-like compounds and CnHmOpN1 contributes to the higher recalcitrance molecular characteristics of DON in the effluent associated with Alphaproteobacteria, Planctomycetes, and Bacteroidetes. Additionally, with the help of prechlorination, the biofilm may change the DON characteristics and lead to higher oxygenation, higher m/z, and lower saturation during transportation. Despite the promotion of CnHmOpN1 and CnHmOpN3 at the early stage, we suggest that appropriate concentration of chlorine can add to the front end of raw water distribution pipes. Prechlorination may control the nitrification process and stabilize the rapid growth of diversity and concentration of low molecular weight DON, especially the refractory CnHmOpN1 in the effluent, which may help to improve treatment efficiency of drinking water treatment plants.Xu, Y., Zhou, N.-Y., 2020. MhpA Is a hydroxylase catalyzing the initial reaction of 3-(3-hydroxyphenyl)propionate catabolism in Escherichia coli. Applied and Environmental Microbiology 86, e02385-19.: Escherichia coli K-12 and some other strains have been reported to be capable of utilizing 3-(3-hydroxyphenyl)propionate (3HPP), one of the phenylpropanoids from lignin. Although other enzymes involved in 3HPP catabolism and their corresponding genes from its degraders have been identified, 3HPP 2-hydroxylase, catalyzing the first step of its catabolism, has yet to be functionally identified at biochemical and genetic levels. In this study, we investigated the function and characteristics of MhpA from E. coli strain K-12 (MhpAK-12). Gene deletion and complementation showed that mhpA was vital for its growth on 3HPP, but the mhpA deletion strain was still able to grow on 3-(2,3-dihydroxyphenyl)propionate (DHPP), the hydroxylation product transformed from 3HPP by MhpAK-12. MhpAK-12 was overexpressed and purified, and it was likely a polymer and tightly bound with an approximately equal number of moles of FAD. Using NADH or NADPH as a cofactor, purified MhpAK-12 catalyzed the conversion of 3HPP to DHPP at a similar efficiency. The conversion from 3HPP to DHPP by purified MhpAK-12 was confirmed using high-performance liquid chromatography and liquid chromatography-mass spectrometry. Bioinformatics analysis indicated that MhpAK-12 and its putative homologues belonged to taxa that were phylogenetically distant from functionally identified FAD-containing monooxygenases (hydroxylases). Interestingly, MhpAK-12 has approximately an extra 150 residues at its C terminus in comparison to its close homologues, but its truncated versions MhpAK-12400 and MhpAK-12480 (with 154 and 74 residues deleted from the C terminus, respectively) both lost their activities. Thus, MhpAK-12 has been confirmed to be a 3HPP 2-hydroxylase catalyzing the conversion of 3HPP to DHPP, the initial reaction of 3HPP degradation.Importance: Phenylpropionate and its hydroxylated derivatives resulted from lignin degradation ubiquitously exist on the Earth. A number of bacterial strains have the ability to grow on 3HPP, one of the above derivatives. The hydroxylation was thought to be the initial and vital step for its aerobic catabolism via the meta pathway. The significance of our research is the functional identification and characterization of the purified 3HPP 2-hydroxylase MhpA from Escherichia coli K-12 at biochemical and genetic levels, since this enzyme has not previously been expressed from its encoding gene, purified, and characterized in any bacteria. It will not only fill a gap in our understanding of 3HPP 2-hydroxylase and its corresponding gene for the critical step in microbial 3HPP catabolism but also provide another example of the diversity of microbial degradation of plant-derived phenylpropionate and its hydroxylated derivatives.Xu, Z., Lin, M., Jiang, W., Cao, G., Yi, Z., 2020. Identifying the comprehensive pore structure characteristics of a rock from 3D images. Journal of Petroleum Science and Engineering 187, 106764. of pore structure in reservoirs plays a significant role in predicting properties of rocks and classifying the reservoirs. The focus is on determining comprehensive geometric and topological parameters of pore structure. X-ray computerized tomography scanning provides a 3D image of the pore structure. However, these images cannot directly generate pore structure parameters without numerical characterization of the images. A new method is developed to determine comprehensive geometric and topological parameters of pore structure from images. These parameters were determined by utilizing common mathematical morphology operations to segment the entire pore space into a series of space blocks of different radii, subsequently identifying these blocks as pores and throats based on the proposed morphological features of pore and throat. The parallel scheme was also studied to obtain the highest efficiency. Thereafter, the characteristics of pore structures and the performance of the method were assessed for various samples. The results were compared to the results calculated by other methods. Results showed that the method produced reliable pore structure characteristics for a wide variety of rocks. Additionally, in order to discuss whether our results can be used as the basic input data for other researches, an example about two-phase flow simulation was made and a comparison of simulation results and experimental data was made. Our results were a competent choice for other studies. Also, after proposing the detection criteria of pore and throat, the subsequent detecting procedure is without artificial adjustable parameters, making the method convenient to use. This method can comprehensively, efficiently, accurately, and conveniently characterize the pore structure based only on images.Xu, Z., Wan, S., Colin, C., Li, T., Clift, P.D., Chang, F., Sun, R., Yu, Z., Lim, D., 2020. Enhanced terrigenous organic matter input and productivity on the western margin of the Western Pacific Warm Pool during the Quaternary sea-level lowstands: Forcing mechanisms and implications for the global carbon cycle. Quaternary Science Reviews 232, 106211. in terrigenous organic matter (OM) input, productivity and the associated bottom-water redox conditions, together with forcing mechanisms and global carbon cycle implications of such variations, on the western margin of the Western Pacific Warm Pool (WPWP) during the Quaternary remain controversial. In this study, we reconstructed the hydrological dynamics, terrigenous OM input, productivity, and deep-sea redox conditions using one core from the continental slope of the Philippine Sea. The new data were integrated with published proxies from the same core and two additional cores from the abyssal Philippine Sea. The results exhibited noticeable variations in the abovementioned indicators, in correspondence to changes in the supply of terrigenous material. The continental slope deposition featured signals of strong physical erosion and chemical weathering of unconsolidated sediments on the exposed continental shelf during the Quaternary sea-level lowstands, which significantly contributed to increased terrigenous OM input and productivity and, in turn, decreased bottom-water oxygenation and atmospheric CO2 concentrations. In the abyssal Philippine Sea, increased Asian dust-driven OM input and productivity also acted as a sink of atmospheric CO2 during sea-level lowstands. Analysis of the data suggested that the enhanced terrigenous OM input and biological pump and thus the decreased dissolved oxygen level of the bottom water on the western margin of the WPWP played important roles in modifying the global carbon cycle during sea-level lowstands. In contrast, the influence of hydrological dynamics on terrigenous OM input, productivity, and redox conditions therein during the Quaternary was limited.Xue-wu, W., Pufu, X., Zheng-ming, Y., Xue-wei, L., Zhi-zeng, X., Li-qiang, W., 2020. Laboratory and field-scale parameter optimization of CO2 huff–n–puff with the staged-fracturing horizontal well in tight oil reservoirs. Journal of Petroleum Science and Engineering 186, 106703. the help of large-scale physical simulation experiment technology, the physical simulation experiments of the CO2 huff–n-puff with the staged-fracturing horizontal well could be acheived. We studied the production process of CO2 huff–n–puff and influence of different parameters affect oil recovery during the CO2 huff-n-puff procedure, ultimately, the operation parameters were optimized by numerical simulation. The results show that CO2 can quickly enter the deep formation through the horizontal well and the fracture during the huff period and staged-fracturing horizontal well can greatly increase the contact area between CO2 and crude oil, which improves the efficiency of extraction, dissolution, reduction of viscosity between CO2 and crude oil. During the puff period, the horizontal well and fractures can reduce the flow resistance effectively, so as to improve the flow capacity of crude oil. After 3 cycles of CO2 huff and puff, the oil recovery can be enhanced by 11.13%~21.39% compared with that obtained by elastic flooding, which indicates that the exploitation method of CO2 huff–n–puff can improve the development effects of tight oil reservoirs. CO2 huff-n-puff injection parameters are optimized, the results show that the optimum time of injection is 1 year, the optimum soaking time is 30d, and the optimal injection pore volume is 0.18HCPV. This research can provide a certain technical support for effective development of tight oil reservoirs.Yan, G., Xu, Y., Liu, Y., He, W., Chang, X., Tang, P., 2020. The evolution of acids and neutral nitrogen-containing compounds during pyrolysis experiments on immature mudstone. Marine and Petroleum Geology 115, 104292. experiments were conducted on immature(Ro = 0.47%) organic-rich (TOC = 6.0%)mudstone, and the liquid products at 10 different temperature stages were detected by negative ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI? FT-ICR MS). Seven classes of acids and neutral nitrogen-containing compounds, namely, N1, N2, O1, O2, O3, O4 and N1O1, were detected in all the products. The O2 class accounted for the largest proportion (50.56 %–91.65%) among all the products, followed by the O1 class (1.70 %–28.80%). The % O1 and % N1 classes showed a clear upward trend with the increase in experimental temperature due to their organic resources, and the % O2 class showed the exact opposite trend, which could be explained by the chemical reactions that occurred during the maturation process, such as decarboxylation and dehydration. In addition, the relative abundances of the classes with high double bond equivalents (DBE) (≥9) and low DBE (≤7) showed a significant upward trend and a clear downward trend, respectively. The main reasons were aromatization and condensation during thermal evolution. This series of thermal evolution characteristics indicated that a set of new thermal parameters, such as ∑%DBE ≥9/∑%DBE≤8 (O2 compounds) = 0.0007T2 - 0.372T + 48.594(R2 = 0.9088) may be used as a new maturity parameter after further verified with crude oils.Yan, H., Mao, F., Wang, J., 2020. Thermogravimetric-mass spectrometric characterization of thermal decomposition of lignite with attention to the evolutions of small molecular weight oxygenates. Journal of Analytical and Applied Pyrolysis 146, 104781. coupled with electron impact mass spectrometry (TG-EI MS) was used to investigate the evolutions of gases and small molecular weight oxygenates during the pyrolysis of a raw lignite and a potassium (K)-impregnated lignite. By clarifying the effects of ionization on the fragmentations of various compounds, it was found that a low ionizing energy of 20 eV was better for detecting oxygenates. The study further proposed a unique approach of the installment of a cold trap between the TG-MS interfaces. This vapor trapping approach is useful to distinguish between some compounds of equal mass in terms of their different boiling points. The real-time release of various oxygenates during the pyrolysis of the raw lignite and the K-impregnated lignite were detected. It was found that some highly volatile oxygenates such as formic acid (46 m/z), acetone (58 m/z) and butanone (72 m/z) started to release at a temperature of 200 °C or lower. Many oxygenates such as furan (68 m/z), methylfuran (82 m/z), cyclopentenone (82 m/z), cyclopentanone (84 m/z), furfural (96 m/z), dimethylfuran (96 m/z), cyclohexenone (96 m/z) and dimethoxyphenol (154 m/z) could be explained as the products degraded from the preserved woody components in this low-maturity lignite. The K impregnation overall facilitated the formations of oxygenates, while it had an inhibitory effect on the formation of CO and an insignificant effect on the formations of some oxygenates such as acetic acid and phenol. The curves of differential thermogravimetry (DTG) were deconvoluted to correspond to the staged release characteristics of main gases and various oxygenates.Yang, H., Tang, J., Zhang, C., Dai, Y., Zhou, C., Xu, P., Perry, D.C., Chen, X., 2020. Enhanced carbon uptake and reduced methane emissions in a newly restored wetland. Journal of Geophysical Research: Biogeosciences 125, e2019JG005222. play an important role in reducing global warming potential in response to global climate change. Unfortunately, due to the effects of human disturbance and natural erosion, wetlands are facing global extinction. It is essential to implement engineering measures to restore damaged wetlands. However, the carbon sink capacity of restored wetlands is unclear. We examined the seasonal change of greenhouse gas emissions in both restored wetland and natural wetland and then evaluated the carbon sequestration capacity of the restored wetland. We found that (1) the carbon sink capacity of the restored wetland showed clear daily and seasonal change, which was affected by light intensity, air temperature, and vegetation growth, and (2) the annual daytime (8–18 hr) sustained‐flux global warming potential was ?10.32 ± 4.29 kg CO2 m?2 year?1, representing a much larger carbon sink than natural wetland (?0.76 ± 3.07 kg CO2 m?2 year?1) from April to December. In addition, the results showed that appropriate tidal flow management may help to reduce CH4 emission in wetland restoration. Thus, we proposed that the restored coastal wetland, via effective engineering measures, reliably acted as a large net carbon sink and has the potential to help mitigate climate change.Yang, J., Liu, L., He, Z., Wang, S., Mo, Y., Li, X., Tian, L., Xiao, J., 2020. A new visual test method for the toluene insolubles in petroleum fractions. Energy & Fuels 34, 1447-1452. toluene insolubles (TI) was recognized as coking precursors produced at the initial stage of thermal reaction. The traditional methods can only obtain the overall yield of TI, however, more detailed information, such as the size distribution, and the shape parameters of TI, cannot be provided. In the present work, a new visual test method for the toluene insolubles in petroleum fractions was developed, based on the digital microscopic image processing technology and statistical method. This method can obtain the overall yields of toluene insolubles, provide the particle size distribution and the shape parameters. The optimized test conditions were determined by investigating the influencing factors. The calibration results of this method showed that the relative error of volume concentration is 5%, and the overall error of particle size distribution is less than 5%. Moreover, the detectable concentration of this method is much lower than that of the traditional methods.Yang, L., Zhang, J., Liu, K., Yang, G.-P., 2020. Spatiotemporal variability, size and photoreactivity of chromophoric dissolved organic matter in the Bohai Sea and the northern Yellow Sea. Journal of Marine Systems 205, 103316. distribution, composition, and photoreactivity of chromophoric and fluorescent dissolved organic matter (CDOM and FDOM) in the Bohai Sea (BS) and the northern Yellow Sea (NYS) were investigated during three cruises (summer 2017, winter 2017, and spring 2018) by combining size fractionation through a series of micro- and ultra-filtrations and irradiation experiments. A total of 484 excitation-emission matrix spectra were modeled by parallel factor analysis to yield four humic-like (C1–3 and C5) and three protein-like (C4 and C6–7) fluorescent components. CDOM in the BS and the NYS was primarily affected by terrestrial inputs. Microbial degradation processes and autochthonous production were considered to be important factors driving the dynamics of fluorescence components. A total of 73 triple CDOM absorption and fluorescence spectra (n = 219) from the study regions were measured on 0.2, 0.45, and 0.7 μm filters in winter; water samples were also collected from the Yellow River Estuary (YRE) to the NYS, which was further size fractionated through ultrafiltration membranes (10 kDa and 1 kDa) to investigate variability between spectra of different filter pore sizes. The significant mean difference of absorption coefficient and fluorescence spectra, and no consistent trend between spectral slope (S275–295, S350–400), slope ratio (SR) from these filtrates suggested that the choice of different filter pore sizes considerably influenced the CDOM optical assessment. Higher values of CDOM and FDOM in the particulate phases (0.2–0.7 μm) fraction were more distributed in the NYS where terrestrial inputs were less and DOM dynamics were more linked with phytoplankton production. As pore size decreased, the percentage of humic-like fluorescence increased suggesting that humic-like components of CDOM were more dominated by low-molecular-weight (LMW) materials compared with the protein-like components. Consistent with its higher terrestrial CDOM content, photodegradation resulted in losses of CDOM and FDOM and increasing of the spectral slope ratios (SR). These finding suggested that CDOM molecules were photochemically degraded to LMW substances. Our results indicated that the proportion of the LMW CDOM decreased from estuary to open sea, which likely resulted from high-molecular-weight (HMW) organic material produced during phytoplankton production in off-shore regions, and LMW substances produced during CDOM photochemical processes in coastal waters.Yang, Y., Wang, C., Bendle, J.A., Yu, X., Gao, C., Lü, X., Ruan, X., Wang, R., Xie, S., 2020. A new sea surface temperature proxy based on bacterial 3-hydroxy fatty acids. Organic Geochemistry 141, 103975. fatty acids (3-OH-FAs), derived from Gram-negative bacterial outer membranes, have received recent attention for their potential as new terrestrial pH and temperature proxies for palaeoclimate studies. However, it is not known whether 3-OH-FA based proxies can be developed and applied to the marine environment. Here we analyze 3-OH-FAs from a latitudinal transect of marine surface sediments from the North Pacific Ocean (12°N to 61°N with a annual mean sea surface temperature (SST) range of 28.1–1.3?°C). The results show that distributions of 3-OH-FAs in marine sediments yield overall higher abundances of anteiso 3-OH-FA homologues compared to soils. Furthermore, 16S rRNA gene sequencing of the marine sediments and soils shows the Gram-negative bacterial community is dominated by Proteobacteria (ca. 94%) at the phylum level. In contrast, in regional soils the Gram-negative bacterial community is more diverse with significant contributions from Proteobacteria (ca. 50%), Acidobacteria (ca. 24%), Verrucomicrobia (6%), Bacteroidetes (6%) and other phyla. These distinct genomic and molecular differences suggest distinctly different aggregate compositions of bacteria that produce 3-OH-FAs in the marine realm vs soils. Moreover, we find that the ratio of anteiso to normal C13 3-OH-FA (RAN13) measured in surface sediments is highly correlated with annual mean SST throughout the temperature transect. When applied to a short sediment core from the East China Sea, the SST changes reconstructed by the RAN13 proxy are comparable to instrumental SST data. These findings demonstrate that RAN13 and potentially other, so far undiscovered, proxies based on 3-OH-FAs have potential for environmental and palaeoclimate applications in marine environments.Yang, Z., Bryant, S., Dong, M., 2020. A method of determining adsorptive-gas permeability in shale cores with considering effect of dynamic adsorption on flow. Fuel 268, 117340. is an essential parameter in characterizing gas storage and production in shale reservoirs. Most current transient methods for measuring shale permeability use helium instead of methane, which may lead to large errors due to the complexity of gas flow in nanopores of shale. Although some previous studies use methane as the test gas and consider the effect of gas adsorption on permeability measurement, very few studies consider the effect of gas dissolution on measurement. Gas dissolution in organic matter, such as kerogen, may lead to a dynamic adsorption process. This process can delay the gas adsorption equilibrium on kerogen. Investigations on the measurement of radial permeability are also very rare. In this study, a dynamic adsorption-diffusion (DAD) method is proposed to measure gas axial and radial permeability of shale. It presents a new insight into the critical effect of gas adsorption and dissolution on the measurement of permeability of shale. Radial and axial DAD models are based on designed radial and axial DAD experiments with a constant boundary pressure. The exact analytical solutions for these models are further derived to estimate the directional permeability of shale cores. The directional permeability measured by the DAD technique shows a distinct anisotropy for shale. The fitting results of DAD models show it can effectively determine the dominated gas transport in the experiments. The results of the commercial permeameter depict that gas permeability measured using helium can be over 50% larger than that measured using methane. It shows the importance of using methane in the gas permeability measurement of shale in practice.Yang, Z., Shah, K., Laforest, S., Hollebone, B.P., Situ, J., Crevier, C., Lambert, P., Brown, C.E., Yang, C., 2020. Occurrence and weathering of petroleum hydrocarbons deposited on the shoreline of the North Saskatchewan River from the 2016 Husky oil spill. Environmental Pollution 258, 113769. the 16TAN Husky oil spill along the North Saskatchewan River (NSR), the occurrence and natural attenuation of the petroleum hydrocarbons were assessed by analyzing the littoral zone sediments/oil debris collected from July 2016 to October 2017. Husky oil-free, mixed sediment-Husky oil, and Husky oil debris samples were identified for all the collected samples. Shoreline sediments were contaminated by mixed biogenic, pyrogenic and petrogenic inputs prior to the spill. Oil stranded on the shoreline of NSR was moved or buried due to the very dynamic conditions of the shoreline, or cleaned through a series of cleanup activities after the spill. Most normal alkanes were naturally weathered, whereas most of the branched alkanes and all of the saturated petroleum biomarkers remained. Some lighter molecular weight (e.g., 2 to 3-ring) polycyclic aromatic hydrocarbons (PAHs) were lost rapidly after the spill, whereas sulfur containing components, e.g., dibenzothiophenes and benzonaphthothiiophenes, and those having a heavier molecular weight did not change markedly even 15 months post-spill. Similarly, some light hydrocarbons (e.g., <C10) were lost over the first kilometers from the point of entry (POE), while heavier hydrocarbons did not show any major differences away from the POE. Very large inter-site and inter-survey discrepancies were found for samples. Evaporation into the air and dissolution into water, combined with biodegradation, were together or independently the main contributors to the loss of the light molecular hydrocarbons.Yao, P., Wang, X.C., Bianchi, T.S., Yang, Z.S., Fu, L., Zhang, X.H., Chen, L., Zhao, B., Morrison, E.S., Shields, M.R., Liu, Y.N., Bi, N.S., Qi, Y.Z., Zhou, S., Liu, J.W., Zhang, H.H., Zhu, C.J., Yu, Z.G., 2020. Carbon cycling in the world's deepest blue hole. Journal of Geophysical Research: Biogeosciences 125, e2019JG005307.: Blue holes are unique geomorphological features with steep biogeochemical gradients and distinctive microbial communities. Carbon cycling in blue holes, however, remains poorly understood. Here we describe potential mechanisms of dissolved carbon cycling in the world's deepest blue hole, the Yongle Blue Hole (YBH), which was recently discovered in the South China Sea. In the YBH, we found some of the lowest concentrations (e.g., 22 μM) and oldest ages (e.g., 6,810 years before present) of dissolved organic carbon, as well as the highest concentrations (e.g., 3,090 μM) and the oldest ages (e.g., 8,270 years before present) of dissolved inorganic carbon observed in oceanic waters. Sharp gradients of dissolved oxygen, H2S, and CH4 and changes in bacterially mediated sulfur cycling with depth indicated that sulfur‐ and/or methane‐based metabolisms are closely linked to carbon cycling in the YBH. Our results showed that the YBH is a unique and easily accessible natural laboratory for examining carbon cycling in anoxic systems, which has potential for understanding carbon dynamics in both paleo and modern oceans—particularly in the context of global change.Plain Language Summary: Here, we report for the first time concentrations and isotopic composition of dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) along with geomorphological and geochemical parameters in the Yongle Blue Hole (YBH), South China Sea, the world's deepest blue hole. We found some of the lowest concentrations of DOC and the highest concentrations of DIC observed in coastal waters, that were both very old (their 14C ages are 6,810 and 8,270 years, respectively). Such low DOC concentrations have not been observed in relatively shallow oceanic environments. DIC in surface waters of the YBH is mainly controlled by air‐sea exchange, which only impacts the upper 80 m. The decomposition of organic carbon and the sulfidic acid dissolution of carbonates in the YBH enhance the production of DIC in deep waters of the YBH. The profiles of physical, chemical, and microbial parameters in the YBH provide a natural laboratory for examining carbon cycling and other redox‐sensitive elements. Understanding the key mechanisms of biogeochemical pathways in anoxic systems is critical in our understanding of carbon cycling in both paleo and modern oceans.Yao, W., Xu, J., Xia, W., Wang, Q., Rao, D., Chen, Q., 2020. A characteristic analysis between acidolysis gas and absorbed gas and its application to gas source correlation in Mao 1 member, Fuling area, Sichuan Basin. Natural Gas Industry B 7, 24-29. acidolysis gas in source rocks is the desorbed hydrocarbon gas in non-connected pores and carbonate crystal lattice, while the absorbed gas lies in the connected pores and is absorbed by surface. It is controversial about whether to use absorbed gas or acidolysis gas in gas source correlation. Using the absorbed gas and acidolysis gas in the first member of the Middle Permian Maokou Fm (hereinafter referred to as Mao 1 member) of Fuling area in the Sichuan Basin, the differences of components and carbon isotopes between absorbed gas and acidolysis gas and their applicable conditions in gas source correlation were discussed. The results show that: (1) there are larger differences of components and isotopes between absorbed gas and acidolysis gas. The absorbed gas has more heavy hydrocarbons and heavier carbon isotope. This difference can be attributed to the easier diffusion of methane and light hydrocarbons in absorbed gas, leading to relatively enriched heavy hydrocarbons and heavier carbon isotope in absorbed gas; (2) acidolysis gas is a mixture of hydrocarbon gas formed during different stages, while absorbed gas is the result of equilibrium between diffusion and supply of hydrocarbon gas, which can result in the differences on carbon isotope sequences between them; (3) the characteristics of natural gas produced after acid fracturing in the Mao 1 member in Fuling area resembles those of acidolysis gas in source rocks, while the characteristics of natural gas produced without acid fracturing are more similar to those of adsorbed gas; (4) the natural gas pool of the Mao 1 member is a carbonate gas pool with self-generation and self-storage. It is concluded that for the gas pool formed after migration, its producing pays have not been processed by acid fracturing, the produced gas should be correlated with the adsorbed gas in source rocks; for the carbonate gas pool with self-generation and self-storage, acid fracturing is usually needed, and the produced gas should be correlated with the acidolysis gas in source rocks.Yi, L., Liu, Z., Chen, Z., Li, M., 2020. Thermal maturity, source characteristics, and migration directions for the Ordovician oil in the Central Tabei Uplift, Tarim Basin: Insight from biomarker geochemistry. Journal of Petroleum Science and Engineering 189, 106975. central of Tabei Uplift, Tarim Basin in western China, including Rewapu, Yueman, and Fuyuan (RYF) blocks, can offer biomarker geochemistry of Ordovician oils and their valuable information for deep petroleum system. Biomarker analysis was performed on the Ordovician oils from the RYF using gas chromatography–mass spectrometry to constrain thermal maturity, oil source, and possible oil migration directions. The homogenization temperature of fluid inclusions and the burial history corrected by vitrinite reflectivity were used to reflect the oil charging periods. The oil samples were characterized by the complete occurrence of n-alkanes, dominated C20–C21–C23 terpanes, low abundance of homohopanes in the m/z 191 mass spectrogram, and a dominance of C29 among C27–29 regular steranes in the m/z 217 mass spectrogram. A weak and negligible biodegradation indicated by the biomarker signatures suggested favorable preservative conditions for the oils. Biomarker maturity parameters indicated that the oils were mainly in the late “oil window.” The oils were suggested to be obtained from reducing marine sedimentary environments and belong to the same crude oil family. The ratios related to the triaromatic steroids indicated that the Cambrian–Lower Ordovician and Middle–Upper Ordovician source rocks contributed to the Ordovician petroleum system, and the Middle–Upper Ordovician source rocks were likely the major contributors for the current oil samples. The filling tracers suggested that the main oil migration was from southwest to northeast along the Shunbei No. 1 fault rather than from the Manjiaer Depression in the southeast.Yin, L., Meng, F., Kong, F., Niu, C., 2020. Microfossils from the Paleoproterozoic Hutuo Group, Shanxi, North China: Early evidence for eukaryotic metabolism. Precambrian Research 342, 105650. Paleoproterozoic Hutuo Group is well-developed and distributed in the Wutai Mountains in the Xinzhou area of Shanxi Province, North China. Its middle part - the Dongye Subgroup is more suitable for obtaining microfossils in deposited sediments characterized with sandstone or slate in the lower part, and upward into interbedded sandstone, carbonate with stromatolites and phyllite. Based on recent zircon dating, the Hutuo Group was deposited around 2150–1950 Ma. In this study, eight morphological genera of microfossils, including the spheroid and filamentous cyanobacteria Eoentophysalis, Sphaerophycus, Siphonophycus, Pseudodendron, and the acritarchs Dictyosphaera, Dongyesphaera gen. nov., Leiosphaeridia, Satka were identified from the Weshan, Hebiancun and Tianpengnao Formations of the Dongye Subgroup. The identified microfossils reveal that eukaryotic protists exercised metabolic activities rarely observed to have occurred in what are thought to have been suitable environments.Yin, T., Liu, D., Cai, Y., Liu, Z., Gutierrez, M., 2020. A new constructed macromolecule-pore structure of anthracite and its related gas adsorption: A molecular simulation study. International Journal of Coal Geology 220, 103415. microscopic analysis of methane (CH4) adsorption in the heterogeneous pore structure of coals is vital for the success of the coalbed methane (CBM) projects. In this work, to make up for the limitations of laboratory testing conditions, grand canonical Monte Carlo (GCMC) and molecular dynamics (MD) simulations were performed to systematically study the mechanism of CH4 adsorption on dry and moist coals under reservoir temperature and pressure conditions. A novel strategy, named the diamond-filling method, was proposed for the construction of macromolecular pores with specific diameter and morphology. The simulation results demonstrated that the state of CH4 molecules constrained in pores changes from homogeneous filling to multilayer adsorption with the increase of pore size. During the variation of the state of CH4 molecules, the interaction between CH4 and coals gradually weakened, resulting in a significant reduction in CH4 concentration, which stabilized after the pore size reached 5 nm. In addition, it was found that the spherical pore showed the highest adsorption capacity, followed by cylindrical pore and flat pore. In the case where the moisture content ranged from 1 to 3 wt%, the results showed that H2O molecules kept gathering towards the walls. Meanwhile, the CH4 molecules gradually moved towards the bulk interior part along with the declining concentration due to the deeper adsorption potential of H2O molecules in nanopores. The molecular simulation was shown to be a valuable and efficient tool for revealing the mechanism of CH4 adsorption in coal and producing results that have practical applications.Yoshida, R., Yoshimura, T., Hemmi, H., 2020. Reconstruction of the “archaeal” mevalonate pathway from the methanogenic archaeon Methanosarcina mazei in Escherichia coli cells. Applied and Environmental Microbiology 86, e02889-19.: The mevalonate pathway is a well-known metabolic route that provides biosynthetic precursors for myriad isoprenoids. An unexpected variety of the pathway has been discovered from recent studies on microorganisms, mainly on archaea. The most recently discovered example, called the “archaeal” mevalonate pathway, is a modified version of the canonical eukaryotic mevalonate pathway and was elucidated in our previous study using the hyperthermophilic archaeon Aeropyrum pernix. This pathway comprises four known enzymes that can produce mevalonate 5-phosphate from acetyl coenzyme A, two recently discovered enzymes designated phosphomevalonate dehydratase and anhydromevalonate phosphate decarboxylase, and two more known enzymes, i.e., isopentenyl phosphate kinase and isopentenyl pyrophosphate:dimethylallyl pyrophosphate isomerase. To show its wide distribution in archaea and to confirm if its enzyme configuration is identical among species, the putative genes of a lower portion of the pathway—from mevalonate to isopentenyl pyrophosphate—were isolated from the methanogenic archaeon Methanosarcina mazei, which is taxonomically distant from A. pernix, and were introduced into an engineered Escherichia coli strain that produces lycopene, a red carotenoid pigment. Lycopene production, as a measure of isoprenoid productivity, was enhanced when the cells were grown semianaerobically with the supplementation of mevalonolactone, which demonstrates that the archaeal pathway can function in bacterial cells to convert mevalonate into isopentenyl pyrophosphate. Gene deletion and complementation analysis using the carotenogenic E. coli strain suggests that both phosphomevalonate dehydratase and anhydromevalonate phosphate decarboxylase from M. mazei are required for the enhancement of lycopene production.Importance: Two enzymes that have recently been identified from the hyperthermophilic archaeon A. pernix as components of the archaeal mevalonate pathway do not require ATP for their reactions. This pathway, therefore, might consume less energy than other mevalonate pathways to produce precursors for isoprenoids. Thus, the pathway might be applicable to metabolic engineering and production of valuable isoprenoids that have application as pharmaceuticals. The archaeal mevalonate pathway was successfully reconstructed in E. coli cells by introducing several genes from the methanogenic or hyperthermophilic archaeon, which demonstrated that the pathway requires the same components even in distantly related archaeal species and can function in bacterial cells.You, L., Qu, X., Zhong, J., Li, C., Wu, S., Gao, Y., Cui, J., 2020. Physical simulation experiments on pore evolution in high-temperature and overpressure reservoirs. Natural Gas Industry B 7, 30-39. present, simulation on reservoir evolution under normal pressure is common while that under abnormal pressure is rare. In this paper, the Miocene “high-temperature and overpressure” reservoir in the Ledong–Lingshui Sag of the Qiongdongnan Basin was taken as the research object to quantitatively define the effects of high pressure and overpressure on the evolution of reservoir pores. After the temperature and pressure field in this area was divided in the setting of sedimentation and diagenesis, the evolution characteristics of pores in different temperature and pressure field were analyzed by means of natural analogy and physical simulation experiment. Then, the effects of overpressure and fluids on the evolution of reservoir pores were discussed. Finally, the main factors controlling the development of high-quality reservoirs were determined. And the following research results were obtained. First, the temperature and pressure field of the Miocene reservoir in the Ledong–Lingshui Sag can be divided into three zones, i.e., high temperature and normal pressure zone, high temperature and overpressure zone, and high temperature and super overpressure zone. Second, overpressure and super overpressure can provide some preservation on primary pores. In the same diagenetic stage, the plane porosity of overpressure and super overpressure reservoirs is 1.23–6.74% higher than that of normal pressure reservoirs. Once the reservoir pressure in overpressure and super overpressure areas is higher than hydrostatic pressure by 8?MPa and 4?MPa, respectively, about 1% primary pores are preserved. Third, the dissolution of organic acid makes greater contribution to the secondary pores in reservoirs and its plane porosity is 0.96–7.38% higher than that of normal compaction reservoirs. Fourth, the leaching effect of meteorological water on reservoir physical properties is slight, and its plane porosity is only 0.19% higher than that of normal compaction reservoirs. In conclusion, the dissolution of organic acid is the most constructive effect for the reservoirs in high temperature and normal pressure. In addition, preservation of primary pores by overpressure is the most constructive effect for the reservoirs in high temperature and (super) overpressure, and the higher the overpressure is, the more preservation effect it provides on pores.Yu, J., Gou, X., Yu, J., 2020. Comprehensive chemical kinetic model of 2,6,10-trimethyl dodecane. Energy & Fuels 34, 2366-2375. a novel alternative fuel and surrogate component, 2,6,10-trimethyl dodecane has received extensive attention. For designing and optimizing internal combustion engines and propulsion systems by computational fluid dynamics, and providing more choices for a branched surrogate component to develop a more accurate surrogate model, a comprehensive detailed chemical kinetic model for 2,6,10-trimethyl dodecane has been developed based on 35 reaction classes to numerically describe its experimental observations. The proposed detailed kinetic model for 2,6,10-trimethyl dodecane has been validated against a wide range of experimental data, including ignition delay time, flow reactor, and laminar flame speeds. A good agreement between the numerical and the experimental data is observed. Using the kinetic model reduction scheme, high-temperature and low-temperature chemical kinetic models were eventually obtained and validated against the detailed kinetic model. The successful implementation of a kinetic model construction based on 35 reaction classes has indicated the possibility of its application for the development of mechanisms for the larger hydrocarbon fuels with asymmetric and iso-paraffinic molecular structures.Yu, K., Gan, Y., Ju, Y., Shao, C., 2020. Influence of sedimentary environment on the brittleness of coal-bearing shale: Evidence from geochemistry and micropetrology. Journal of Petroleum Science and Engineering 185, 106603. brittleness of shale is an important index to evaluate the fracture system and reformability of a shale reservoir. This study provides geochemical and micropetrological parameters as proxies for the paleo-hydrodynamics, redox condition, paleosalinity, and paleoclimate of transitional coal-bearing shale in the Huainan coalfield, eastern China. Thus, combining these data with organic geochemistry parameters, this study aims to investigate the most important factors controlling shale brittleness during the sedimentary process. The results indicate that various important physical and chemical factors (sedimentary facies, hydrodynamics, redox condition, salinity, and climate) of the paleoenvironment have exerted an intense influence on shale brittleness involving complex mechanisms. Rare earth element indexes suggest that marine facies are conducive to the enrichment of carbonate minerals and quartz, thereby improving the brittleness of shale. Micropetrologyical evidence indicates that with an increase of hydrodynamic force, a large number of terrestrial materials are introduced, leading to increased clay mineral content and significantly reducing the brittleness of shale. U/Th, V/Cr, and Ni/Co ratios and Pyrite indexes suggest that reducing water condition accounts for the enrichment of pyrite and the preservation of biogenic quartz. Thus, this increases the content of brittle minerals, while an oxidative environment significantly decreases the brittleness of shale. B/Ga ratios indicate that higher salinity promotes the dissolution of CO2, leading to precipitation of carbonate minerals and thus increasing the content of brittle minerals in shale, which is supported by the salinity characteristics obtained by the B content. In addition, Ba content indicates that a warm climate (humid) is the best condition for the growth of marine life and the development of carbonate minerals, which promotes the enrichment of brittle minerals obviously. While a hot climate (dry) results in the import of more terrestrial clay minerals in the provenance, thereby inhibiting shale brittleness.Yu, T., Guan, G., Abudula, A., Wang, D., 2020. 3D visualization of methane hydrate production behaviors under actual wellbore conditions. Journal of Petroleum Science and Engineering 185, 106645. study aimed to give a better visualization of the hydrate dissociation and gas production behaviors during methane hydrate production under actual wellbore conditions via 3D images. A real 3D methane hydrate reservoir model was built in this study, and three different types of production methods using horizontal wells (depressurization or hot water injection) were designed. Meanwhile, the gas production and fluid flow behaviors under actual wellbore conditions were revealed through 3D visualization. The simulation results indicated that for the depressurization scenario, the pressure loss in the wellbore mainly affected gas production at the early stage of the depressurization process, while the effect on the long-term gas production behavior was not quite significant. However, for the hot water injection scenario, the heat and flow losses in the wellbore both had great influence on the gas production and fluid flow behaviors, which would cause the decrease in gas production and have a negative impact on the processes of heat transfer, hydrate dissociation, and gas-liquid two-phase flow in the reservoir. Especially, at the end of 1.5?yr, the decrease in total gas production caused by the flow loss (19.4%) was much larger than that caused by the heat loss (4.1%). Therefore, for the future field trials and further investigations on 3D visualization of the actual methane hydrate production process, such losses in the wellbore should be taken into account for the accurate prediction of the long-term gas production behavior.Yuan, J., Ma, J., Sun, Y., Zhou, T., Zhao, Y., Yu, F., 2020. Microbial degradation and other environmental aspects of microplastics/plastics. Science of The Total Environment 715, 136968. (MP) pollution is a significant environmental concern due to the persistence of MPs and their potential adverse effects on biota. Most scientific studies have examined the distribution, ingestion, fate, behavior, amount, and effect of MPs. However, few studies have described the development of methods for the removal and remediation of MPs. Therefore, in this review, we summarize the recent literature regarding the microbial-mediated degradation of MPs and discuss the associated degradation characteristics and mechanisms. Different types and combinations of microorganisms, such as bacteria, fungi, bacterial consortia, and biofilms, that can degrade different MPs are categorized. This article summarizes approximately 50 recent papers. Twelve and 6 papers reported that bacteria and fungi, respectively, can degrade MPs. Nine articles indicated that bacterial consortia have the ability to degrade MPs, and 6 articles found that biofilms can also utilize MPs. Furthermore, to evaluate their associated degradation effects, the corresponding structural changes (i.e., macro size, surface morphology, and functional groups) in MPs after microbial degradation are examined. In addition, MP biodegradation is affected by microbial characteristics and environmental factors; therefore, the environmental factors (i.e., temperature, pH and strain activity) influencing MP degradation and the associated degradation effects (i.e., weight loss, degradation rate, and molecular weight change) are generalized. Furthermore, the mechanisms associated with the microbial-mediated degradation of MPs are briefly discussed. Finally, prospects for the degradation of MPs using microbes and future research directions are envisioned. This review provides the first systematic summary of the microbial-mediated degradation of MPs and provides a reference for future studies investigating effective means of MP pollution control.Yuan, W., Zhou, H., Yang, Z., Hein, J.R., Yang, Q., 2020. Magnetite magnetofossils record biogeochemical remanent magnetization in hydrogenetic ferromanganese crusts. Geology 48, 298-302. of natural remanent magnetization (NRM) and geomagnetic polarity reversals preserved within ferromanganese (Fe-Mn) crusts, together with the application of fine-resolution magnetostratigraphic analysis, have been successfully demonstrated. However, because Fe-bearing precipitates or minerals are thought to be either oxides and/or hydroxides precipitated from ambient oxic seawater or detrital minerals, the magnetic properties of the ferromagnetic minerals and the genetic mechanisms remain controversial; moreover, the origin of the NRM is unclear. Here, we show that nanometer-scale magnetite crystals found in Fe-Mn crusts from the Pacific Ocean and South China Sea are magnetosome fossils based on their narrow size range, chain arrangement, chemical purity, and crystallographic perfection, as indicated by transmission electron microscopy. Furthermore, our new data from rock magnetic and electron paramagnetic resonance analyses, combined with a previously reported micro-magnetostratigraphic sequence, indicate that magnetotactic bacteria and their post-mortem remains contribute to a biogeochemical remanent magnetization of Fe-Mn crusts. In addition, the results provide evidence for a previously unappreciated pathway for the biogeochemical cycling of iron in the deep ocean.Zamani, H., Jafari, A., Mousavi, S.M., Darezereshki, E., 2020. Biosynthesis of silica nanoparticle using Saccharomyces cervisiae and its application on enhanced oil recovery. Journal of Petroleum Science and Engineering 190, 107002. nanotechnology to increase the recovery of oil reservoirs can be a good way to meet energy demand, in order to increase oil production and reduce production costs. Biotechnology of nanoparticles using microorganisms as an environmentally friendly research field in nanotechnology around the world is a rapid development and is considered as a substitute for conventional and physical chemical methods. Optimizing processes can lead to morphology, control of the size and speed of nanoparticle synthesis reactions. Therefore, the purpose of this research is to build a reflection on the current status and future projects, and in particular the feasibility and limitations of the biotechnology approach proposed in the oil industry. In this research, Saccharomyces cervisiae yeast has been used for biochemical production of silica nanoparticles. This yeast is cultivated in its own culture medium. This yeast solution made after the addition of Sodium Silicate Precursor placed in the proper conditions of growth, i.e., temperature of 29 °C, away from the types of contamination and the passage of time, reducing the silica nanoparticles from the initial precursor. In this research, after performing the silica nanoparticle production processes, identification tests such as FTIR, XRD, SEM, DLS and TGA are performed. Then, in order to investigate the effect of this nanoparticle on the production efficiency of the oil, these nanoparticles were added to injectable solutions to an oil-wet micro-model with different concentrations of 250 ppm, 500 ppm and 1000 ppm. It was observed that the difference in the effect of nanoparticles produced by the biochemical method and commercial nanoparticles purchased in the injection process and on the measurement of the production efficiency of oil was that biosynthesized nanoparticles increased oil production efficiency by about 5–7 percent relative to commercial nanoparticles.Zampolli, J., Di Canito, A., Cappelletti, M., Collina, E., Lasagni, M., Di Gennaro, P., 2020. Biodegradation of naphthenic acids: identification of Rhodococcus opacus R7 genes as molecular markers for environmental monitoring and their application in slurry microcosms. Applied Microbiology and Biotechnology 104, 2675-2689., the increase of the unconventional oil deposit exploitation and the amount of oil sands process-affected waters (OSPW) in tailing ponds emerges the importance of developing bio-monitoring strategies for the restoration of these habitats. The major constituents of such deposits are naphthenic acids (NAs), emerging contaminant mixtures with toxic and recalcitrant properties. With the aim of developing bio-monitoring strategies based on culture-independent approach, we identified genes coding for enzymes involved in NA degradation from Rhodococcus opacus R7 genome, after the evaluation of its ability to mineralize model NAs. R. opacus R7 whole-genome analysis unveiled the presence of pobA and chcpca gene clusters putatively involved in NAs degradation. Gene expression analysis demonstrated the specific induction of R7 aliA1 gene, encoding for a long-chain-fatty-acid-CoA ligase, in the presence of cyclohexanecarboxylic acid (CHCA) and hexanoic acid (HA), selected as representative compounds for alicyclic and linear NAs, respectively. Therefore, aliA1 gene was selected as a molecular marker to monitor the biodegradative potential of slurry-phase sand microcosms in different conditions: spiked with CHCA, in the presence of R. opacus R7, the autochthonous microbial community, and combining these factors. Results revealed that the aliA1-targeting culture-independent approach could be a useful method for bio-monitoring of NA degradation in a model laboratory system.Zamudio, G.S., Palacios-Pérez, M., José, M.V., 2020. Information theory unveils the evolution of tRNA identity elements in the three domains of life. Theory in Biosciences 139, 77-85. determined the identity elements of each tRNA isoacceptor for the three domains of life: Eubacteria, Archaea, and Eukarya. Our analyses encompass the most updated and curated available databases using an information theory approach. We obtained a collection of identity clusters for each of the isoacceptors of the 20 canonical amino acids for the three major domains of life. The identity clusters for all isoacceptors are compared within and among the three domains to determine their pattern of differentiation and to shed light on the evolution of the identity elements.Zhang, C., Shuai, J., Ran, Z., Zhao, J., Wu, Z., Liao, R., Wu, J., Ma, W., Lei, M., 2020. Structural insights into NDH-1 mediated cyclic electron transfer. Nature Communications 11, 888. is a key component of the cyclic-electron-transfer around photosystem I (PSI CET) pathway, an important antioxidant mechanism for efficient photosynthesis. Here, we report a 3.2-?-resolution cryo-EM structure of the ferredoxin (Fd)-NDH-1L complex from the cyanobacterium Thermosynechococcus elongatus. The structure reveals three β-carotene and fifteen lipid molecules in the membrane arm of NDH-1L. Regulatory oxygenic photosynthesis-specific (OPS) subunits NdhV, NdhS and NdhO are close to the Fd-binding site whilst NdhL is adjacent to the plastoquinone (PQ) cavity, and they play different roles in PSI CET under high-light stress. NdhV assists in the binding of Fd to NDH-1L and accelerates PSI CET in response to short-term high-light exposure. In contrast, prolonged high-light irradiation switches on the expression and assembly of the NDH-1MS complex, which likely contains no NdhO to further accelerate PSI CET and reduce ROS production. We propose that this hierarchical mechanism is necessary for the survival of cyanobacteria in an aerobic environment.Zhang, D., Ranjith, P.G., Perera, M.S.A., Ma, G., 2020. Laboratory evaluation of flow properties of Niutitang shale at reservoir conditions. Marine and Petroleum Geology 115, 104257. and water saturation dependent gas flow under reservoir conditions is important for the exploration of deep energy resources. Steady-state and various unsteady-state argon permeability tests were conducted on dry Niutitang shale during the confinement loading and unloading cycles, then different gases were used for steady-state permeability tests at the final confinement of 20?MPa. Permeability decreased by 36% with the confinement increasing from 5?MPa to 60?MPa, and around 66% of the permeability reductions was recovered after the unloading cycles. The apparent steady-state permeabilities were 38% higher than those derived by unsteady-state methods due to the enhanced slip flow. Two cycles of water imbibition and gas drainage tests were conducted with the long water evaporation process completed in the second gas drainage process. Argon to carbon dioxide permeability ratio ranged from 1.2 to 2.1, while the water permeability was 30–45% of the gas intrinsic permeability. The argon breakthrough pressure of water-saturated Niutitang shale sample was 8?MPa, and the permeability increased by 10 times after the long-term evaporation process. Argon permeability decreased by 90% and increased by 21.6%–29.6% respectively after the first and second gas drainage processes compared with that under dry condition with the residual water saturation being 29.7% and 11.3% respectively, which were caused by the water blockage and cracking respectively. Influences of carbon dioxide adsorption and induced swelling reached a minimum at residual water saturation.Zhang, D., Wang, L., Su, L., Wu, Y., Sun, R., Wu, C., Song, D., Tuo, J., 2020. The chemical kinetics of the semi-open hydrous pyrolysis system: Time series analysis of lithostatic pressure and fluid pressure. International Journal of Coal Geology 220, 103418. a problem that has plagued geochemists, the perspective of time has long been recognized as an important factor in organic matter evolution and hydrocarbon generation. This article discusses two time series analysis methods based on econometrics, damping trend and autoregressive integrated moving average (ARIMA), to mine the potential value of data and abstract useful information from pyrolysis experiments. The case studies use marine source rocks (depth of 3119–3230 m, in the LH29–2 well) from the Enping Formation in the Baiyun Sag, the deep-water area (depth of >300 m) of the northern South China Sea, which has a geological background of high temperature, high pressure and rapid burial in the late stage. A tubular plug flow microreactor is used to artificially mature the source rock in the laboratory, and the conditions of hydrous pyrolysis are listed as follows: temperatures of 250°C, 300°C, 350°C, 400°C, 450°C, and 500°C; lithostatic pressure of 33~89 MPa; fluid pressure of 16~38 MPa; and time duration of 72 h. The results revealed that as the degree of maturation increased (Ro from 0.27 to 2.04), the cumulative yield of hydrocarbon gas increased rapidly (max = 311.64 ml/g?TOC), the yield of the expelled oil increased first and then decreased (peak = 350.69 mg/g?TOC at 350°C), and the yield of residual oil extracted from residue decreased gradually. Although the kinetic parameters of kerogen can be calculated by conventional pyrolysis experiments, the long-term cumulative effect of episodic-hydrocarbon expulsion in real conditions is often neglected. The major contributions of our statistical approach for geological applications are described as follows: (1) the recognition of qualitative changes within hydrocarbon generation and expulsion; (2) the characterization of episodic-hydrocarbon expulsion that describes the evolution of the lithostatic pressure and fluid pressure; (3) the disclosure of new influencing factors abstracted from time series models to describe the frequency distribution of hydrocarbon expulsion; and (4) an evaluation of the dependency of new variables.Zhang, D., Yang, Y., Ran, M., 2020. Variations of surface soil δ13Corg in the different climatic regions of China and paleoclimatic implication. Quaternary International 536, 92-102. of relationships between organic carbon isotope composition (δ13Corg) of surface soils and climatic factors (precipitation and temperature) is very crucial to reconstruct the paleoclimate variations. Relationships relating δ13Corg and climatic factors remain relatively different in the regions influenced by various climatic systems. In this study, based on compiled 1394 surface soil δ13Corg data in China, the relationship between soil δ13Corg and precipitation and temperature are statistically investigated in the different climatic regions of China (i.e., Xinjiang region, Tibetan Plateau, northern China and southern China). The result show that, spatially, surface soil δ13Corg values in Xinjiang region are mainly controlled by temperature and precipitation, while that are mainly controlled by precipitation in Tibetan Plateau. Surface soil δ13Corg in northern China and in southern China are mainly influenced by temperature but with a contrary picture. Temporally, a decrease of Holocene δ13Corg in Xinjiang region was caused by reducing temperature and increasing precipitation, while an increase of δ13Corg in Tibetan Plateau was a response to reducing precipitation. A decrease of Holocene δ13Corg in northeast China resulted from temperature decreasing and that in Loess Plateau from temperature decreasing and C4 abundance reducing. In southern China, temperature decreasing since Holocene was responsible for an increasing trend of δ13Corg sequence. Our results can be considered as a basis for the past climate and vegetation interpretation of δ13Corg data inferred from various geological archives in the different climatic regions of China.Zhang, H., Diao, R., Chan, H.H., Mostofi, M., Evans, B., 2020. Deformation of shale and coal organic carbon slit micropores induced by CO2-enhanced gas recovery: A Monte Carlo simulation study. Energy & Fuels 34, 1564-1580. swelling of shale and coal induced by the CO2-enhanced gas recovery (CO2-EGR) has proved to reduce the reservoir permeability and the CH4 production. In this work, we have studied the adsorption-induced deformation of the organic carbon slit micropores during the displacement of CH4 by the injected CO2 using grand canonical Monte Carlo simulation. Particularly, we have investigated the effect of the injected CO2 ratio on the deformation strain for each pore width from 0.5 to 2.0 nm under a series of pressures and temperatures. The results showed that the pore deformation is distinct depending on the pore size and the injected CO2 ratio, which generally includes monotonic swelling and shrinkage followed by swelling with bulk pressure. The pores below 0.55 nm have no deformation, as these pores are too narrow for both CH4 and CO2. The maximum swelling in CO2-EGR occurs in the 0.55–0.59 nm pores, which contributes most in terms of the CO2 storage but has no contribution to CH4 recovery. The maximum shrinkage happens in the 0.66 nm pore, which provides most to the CH4 recovery. Besides, the maximum swelling and shrinkage is generally not affected by the CO2 ratio except the deformation at low pressures and even a small amount of CO2 injection could induce the maximum swelling for the corresponding pores in shale or coal. The bulk pressure has a more significant effect on the deformation of the 0.75–1.05 nm pores with the increase of CO2 ratio, and the pore width for the maximum swelling decreases with the increase of pressure. At 100 MPa, a second minor peak of swelling and shrinkage occurs in the 0.85–0.9 and 0.95–1.05 nm pores, respectively. Furthermore, temperature has no effect on the maximum swelling at 100 MPa,but the overall deformation generally decreases with the increase of temperature including the maximum shrinkage. The 1.4–2.0 nm pores only have slight deformation regardless of the CO2 ratio, pressure, and temperature. It is also found that the solvation pressure is the driving force for the deformation irrespective of the adsorbed gas species. However, the adsorbed CH4 and CO2 molecules exert different solvation pressures to the pores during the competitive adsorption. The local solvation pressure is heterogeneous across the pore space for both CH4 and CO2. The positive pressures are close to the pore walls, which tend to swell the pores, but negative pressures are in the pore interior, which incline to contract the pore.Zhang, J.-H., Xie, S.-M., Zi, M., Yuan, L.-M., 2020. Recent advances of application of porous molecular cages for enantioselective recognition and separation. Journal of Separation Science 43, 134-149. materials with well‐defined pore structures have received considerable attention in the past decades due to their unique structures and wide applications. Most porous materials such as zeolites, metal‐organic frameworks, covalent organic frameworks, and porous organic polymers are extended to infinite frameworks or networks by robust covalent or coordination bonds. Porous molecular cages composed of discrete molecules with permanent cavities are an emerging class of porous material and the discrete molecules assemble into solids by weak intermolecular interaction. In comparison to porous extended solids such as metal‐organic frameworks and covalent organic frameworks, porous molecular cage solids are generally soluble in organic solvents thus allowing solution processing, making them more convenient to apply in many fields. This review mainly focuses on the recent advances of application of porous molecular cages (porous organic cages and metal‐organic cages) for enantioselective recognition and separation from 2010 to present, including gas chromatography, capillary electrochromatography, chiral fluorescent recognition, chiral potentiometric sensing, and enantioselective adsorption. Furthermore, the two important family members of porous molecular cages, porous organic cages and metal‐organic cages, are also discussed.Zhang, L., Liu, C., Liu, Y., Li, Q., Cheng, Q., Cai, S., 2020. Transport property of methane and ethane in K-illite nanopores of shale: Insights from molecular dynamic simulations. Energy & Fuels 34, 1710-1719. gas is a multicomponent mixture stored in nanopores, which consists mainly of methane (CH4) and ethane (C2H6). The transport property of shale gas in clay nanopores is a fundamental issue not only for accelerating exploitation of shale gas but also for grasping the diffusivity mechanism of gas mixtures in nanostructures. In this work, the transport property of CH4 and C2H6 in K-illite nanopores of shale is investigated by molecular dynamics combined with Fick’s first law. The equilibrium molecular dynamics (EMD) is utilized to calculate the binary Onsager coefficients. The thermodynamics factor, the self-, Maxwell–Stefan (MS), and transport diffusion coefficients of CH4-C2H6 are estimated, and the effects of pressure, temperature, and apertures are analyzed. The results show that the diffusion of gas in a confined space satisfies the linear law. The self-diffusion coefficient of CH4 is greater than that of C2H6, owing to the fact that surface diffusivity of C2H6 is lower than that of CH4. The MS and transport diffusion coefficients of CH4 are lower than those of C2H6. A high pressure can inhibit the diffusivity of alkanes. The larger aperture and higher temperature can enhance the diffusivity property. The reduction rate of transport diffusion selectivity for C2H6 over CH4 decreases with increasing aperture width. With increasing width of apertures, C2H6 has better diffusivity owing to the interaction of gas molecules and the wall surface. The competitive diffusion of C2H6 and CH4 is more sensitive to the formation conditions of temperature and pressure, and the transport selectivity of C2H6 over CH4 can be used to assess the diffusivity capacity between binary gas mixtures in nanopores. It is expected that this work can accommodate the secure and efficient exploitation of shale gas in nanopores with significant insights and quantitative predictions regarding the formation conditions of temperature and pressure.Zhang, M., Huang, J.-C., Sun, S., Rehman, M.M.U., He, S., 2020. Molecular and stable isotopic evidence for anaerobic ammonium-oxidizing bacteria in tidal flow constructed wetlands. International Biodeterioration & Biodegradation 149, 104915. process of anaerobic ammonium oxidation (anammox) plays a significant part in global nitrogen cycling, yet its depth-specific distribution and importance in tidal flow constructed wetlands (TF CWs) remained unclear. Currently, the abundance, biodiversity, vertical distribution, rates and potential role of the anammox process in two TF CWs of the Yangtze Estuary, China, were explored. The results indicated that anammox bacteria were widely distributed in the TF CWs, and Candidatus Brocadia was the dominant group among the anammox genera. The widespread presence of the anammox bacteria was observed at different water depths of the soil cores, and the abundance of total bacterial 16S rRNA and hzsB genes was 4.47–20.08 × 109 and 0.81–5.91 × 105 copies per gram of dry soil (copies g?1 ds), respectively. The homogenized soils were incubated with stable nitrogen isotope to confirm the rates of anammox in the TF CWs, and the anammox activities were 2.38–6.72 nmol of N2 per gram of dry soil per day (nmol N2 g?1 dry soil d?1), with contributions of 2.7–7.5% nitrogen gas production and anammox that was more active in the deeper layer of the two TF CWs.Zhang, P., Meng, Q., Liu, Z., Hu, F., Xue, M., 2020. A comparative study of oil shale-bearing intervals in the Lower Cretaceous Jiufotang Formation in the Beipiao Basin, Northeast China based on sedimentary organic-facies theory. Oil Shale 37, 32-50. this paper, the sedimentary organic facies is defined as a stratigraphic unit that not only contains organic matter (OM) of particular abundance, genetic type and spatial distribution, but also is influenced by its sedimentary environment and preservation conditions. This study aims to reveal the characteristics of OM accumulation in sediments. In the current work, three sedimentary organic facies of oil shale (OS) in the Lower Cretaceous Jiufotang Formation in the Beipiao Basin, Northeast China were distinguished on the basis of OM content, source and sedimentary environment. The accumulation conditions and characteristics of oil shale in different sedimentary organic facies are divergent. Deep-lake sapropelic oil shale with a high alginate-originated total organic carbon (TOC) content is deposited in a strongly reducing environment and is featured by high oil yield, medium-high calorific value, medium to low ash content, and low sulfur content. Deposited in a moderately reducing environment and having a medium alginate- and sporinite-derived TOC content, deep-to-semi-deep-lake sapropel–humic sapropelic oil shale is characterized by medium oil yield, medium calorific value, high ash content, and medium sulfur content. Semi-deep-lake humic-sapropelic oil shale with a medium-low terrigenous and alginate-mixed originated TOC is deposited in a weakly reducing environment and is characterized by low oil yield, low calorific value, high ash content, and high sulfur content. The current study of sedimentary organic facies also contributes to predicting high-quality oil shale. The quality of oil shale is controlled by organic matter content and sedimentary environment. Strongly reducing deep lake water with abundant alginate is an ideal environment for the accumulation of high-quality oil shale.Zhang, Q., Liu, H., Dong, X., Liu, Y., Li, G., Wang, Y., 2020. A new comprehensive model to estimate the steam chamber expansion and recovery performance of entire SAGD process. Journal of Petroleum Science and Engineering 185, 106629. gravity drainage (SAGD) technique has been successfully applied to unlock the oilsands resources in Canada. But to accurately estimate the steam chamber expansion and productivity of the entire lifetime of a SAGD well pair is still challenging. In this paper, a new comprehensive model is proposed encompassing the different stages of SAGD. Firstly, for the rising stage, based on the theory of volumetric displacement, an analytical model is developed for the rise speed and oil rate. Thereafter, based on Butler's theory, a 2D numerical approach is modelled for predicting the lateral spreading and confinement stage of steam chamber. Thus, combining the two different mathematical models, the steam chamber shape and recovery performance of a SAGD process can be calculated. The calculation results are also compared against 3D experimental results and field data to confirm the accuracy of this model. Then, a sensitivity analysis is performed to discuss the effects of operation parameters on steam chamber expansion and recovery performance of SAGD process. Results indicate that the calculated results can match the experiment results and field date very well. The calculated peak oil production rate causes a large error and the plateau time of SAGD process obviously is shortened if the preheating stage is neglected. A higher steam chamber pressure results in a narrower inverted triangle interface shape in the rising stage and a more concave-like interface in the sideways expansion stage. In addition, the oil rate increases with steam chamber pressure allowing for varying steam injection rate, whereas the increasing trend of ultimate recovery decreases with the steam chamber pressure increases, which indicates that a proper steam chamber pressure to be chosen can not only achieve a preferable ultimate recovery but also benefit for project economics.Zhang, R., Marchal, L., Lebovka, N., Vorobiev, E., Grimi, N., 2020. Two-step procedure for selective recovery of bio-molecules from microalga Nannochloropsis oculata assisted by high voltage electrical discharges. Bioresource Technology 302, 122893. procedure with the initial aqueous extraction from raw microalgae Nannochloropsis oculata and secondary organic solvent extraction from vacuum dried (VD) microalgae were applied for selective recovery of bio-molecules. The effects of preliminary aqueous washing and high voltage electrical discharges (HVED, 40?kV/cm, 4?ms pulses) were tested. The positive effects of HVED treatment and washing on selectivity of aqueous extraction of ionics and other water-soluble compounds (carbohydrates, proteins and pigments) were observed. Moreover, the HVED treatment allowed improving the kinetic of vacuum drying, and significant effects of HVED treatment on organic solvent extraction of chlorophylls, carotenoids and lipids were determined. The proposed two-step procedure combining the preliminary washing, HVED treatment and aqueous/organic solvents extraction steps are useful for selective extraction of different bio-molecules from microalgae biomass.Zhang, W., Huang, Z., Guo, X., Pan, Y., Liu, B., 2020. A study on pore systems of Silurian highly mature marine shale in Southern Sichuan Basin, China. Journal of Natural Gas Science and Engineering 76, 103094. porosity system in shale, which is a combination of organic-hosted pore and inorganic pore, plays a pivotal role in adsorbing methane for gas shale reservoir. In order to identify the porosity system with different properties and to give a quantitative characterization of pore structure for each individual porosity system, the dual liquid NMR method was conducted on six shale samples from the Lower Silurian Longmaxi Formation in the Southern Sichuan Basin. In shale reservoir, hydrophilic pore and oleophilic pore are respectively related to hydrophilic minerals and oleophilic organic matter. The NMR method detected the signal of water penetrating the water-wetting porosity system when saturated with water, which can reflect the pore size distribution (PSD) of hydrophilic porosity. The PSD of oleophilic pore can also be reflected when saturated with kerosene, vice versa. Generally, the NMR T2 spectra of sample saturated with DI water and kerosene, T2_water and T2_kerosene exhibit bimodal pattern, a dominant peak with a relaxation time range of 0.1–10 ms and a minor peak with a relaxation time ranging 10–100 ms. Generally, higher TOC content corresponds to large amounts of cumulative organic nanoscale pore. The organic-rich shale shows high content of organic-hosted pores and large amounts of inorganic pores which are validated by plane porosity statistics from the observation of SEM photographs. By correlating the two pore structure characterizing methods, the relaxivity of shale can be calculated to be 0.055–0.092 μm/ms when saturated with water. The quantitative estimation of organic-hosted porosity system and inorganic porosity system in the shale will provide a pivotal basis for elucidating gas occurrence states in shale.Zhang, X.-Y., Wang, R.-Y., Ma, F.-Y., Wei, X.-Y., Fan, X., 2020. Structural characteristics of soluble organic matter in four low-rank coals. Fuel 267, 117230. low-rank coals, Zhaotong lignite, Dayan lignite, Wucaiwan sub-bituminous coal and Shenfu sub-bituminous coal were sequentially dissolved in cyclohexane, acetone and methanol at 300?°C. An Orbitrap mass spectrometry coupled with an atmospheric pressure chemical ionization ion source was used to analyze the 12 thermal dissolution (TD) extracts from coals to obtain and compare the molecular distribution of soluble organic matter. Two statistical methods, principal component analysis and hierarchical clustering analysis, were used to mine the effective information from a large number of mass spectral data. The statistical results showed that the degree of coalification had greater effects on the structure and composition of TD extracts compared to the solvent. In-source collision-activated dissociation further elucidated the characteristics of molecular structure and revealed that most of O atoms distribute on alky chains.Zhang, X., Li, J., Yao, M.-C., Fan, W.-Y., Yang, C.-W., Yuan, L., Sheng, G.-P., 2020. Unrecognized contributions of dissolved organic matter inducing photodamages to the decay of extracellular DNA in waters. Environmental Science & Technology 54, 1614-1622. DNA (eDNA), which is derived from lysis or secretion of cells, is ubiquitous in various environments and crucial for gene dissemination, bacterial metabolism, biofilm integrity, and aquatic monitoring. However, these processes are largely influenced by damage to eDNA. Photodamage to eDNA, one of the most important types of DNA damage in natural waters, thus far remains unclear. In particular, the roles of the ubiquitous dissolved organic matter (DOM) in this process have yet to be determined. In this study, eDNA photodamage, including both deoxynucleoside damage and strand breaks, proved to be significantly influenced by DOM. DOM competed with eDNA for photons to inhibit the direct photodamage of eDNA. Nevertheless, DOM was photosensitized to produce reactive oxygen species (ROS) (i.e., hydroxyl radicals (·OH) and singlet oxygen (1O2)) to enhance the indirect photodamage of eDNA. The ·OH induced damage to four deoxynucleosides and strand breaks, and the 1O2 substantially enhanced deoxyguanosine damage. The presence of DOM changed the main photodamage products of deoxynucleosides, additional oxidation products induced by ROS formed besides pyrimidine dimers caused by UV. Results indicate that DOM-mediated indirect photodamage contributed significantly to eDNA photodamage in most water bodies. This study revealed the previously unrecognized crucial role of DOM in the decay of eDNA in waters.Zhang, X., Shi, W., Hu, Q., Zhai, G., Wang, R., Xu, X., Meng, F., Liu, Y., Bai, L., 2020. Developmental characteristics and controlling factors of natural fractures in the lower Paleozoic marine shales of the upper Yangtze Platform, southern China. Journal of Natural Gas Science and Engineering 76, 103191. work elucidates the developmental characteristics and controlling factors of natural fractures, and their effects on the shale gas content in the lower Paleozoic marine shales of the upper Yangtze Platform, southern China. These objectives have been achieved by systematic observations and descriptions of fractures in outcrops and drilling cores, as well as experimental tests on samples from the corresponding fractured intervals. The types of natural macro-fractures observed in both the Niutitang and Wufeng-Longmaxi shales mainly include vertical tension fractures, high-angle shear fractures, bed-parallel slip fractures and bedding fractures, with bedding fractures accounting for the largest proportion. In addition, Field Emission-Scanning Electron Microscopy (FE-SEM) images show that interlayer, inter-particle, intra-particle and organic matter-associated fractures are the primary types of micro-fractures. Tectonism is one of the dominant factors in fracture development, but other factors also have a strong influence, such as TOC content, mineral composition and shale-bed thickness. Under similar tectonic settings, the development of fractures is mainly influenced by the TOC content. For the Wufeng-Longmaxi shale, fracture abundance is positively correlated with the TOC content. However, the TOC content in Niutitang shale displays a positive correlation with fracture density only when the TOC content is less than 6%; when the TOC content is greater than 6%, the correlation is shown to be negative. Shale with higher quartz or lower clay contents exhibits greater fracture development. Furthermore, the shale-bed thickness has a negative influence on the fracture development, which can be essentially attributed to the change in mineral composition of shale. Natural fractures provide reservoir spaces for free gas and are favorable for the desorption of adsorbed gas; therefore, the better shale fractures are developed, the greater the gas content will likely be.Zhang, X., Zhang, R., Kang, T., Hu, Y., 2020. The adsorption and desorption behavior of CH4 on Jincheng anthracite modified in Fe3+ and Cu2+ ion electrolytes. Energy & Fuels 34, 1251-1258. anthracite was electrochemically treated in Fe2(SO4)3 and CuSO4 electrolytes, and the adsorption capacity and desorption ratio of CH4 on the anthracite were investigated using adsorption and desorption tests. The experimental results demonstrated that the saturated adsorption capacity of CH4 on anthracite decreased from 41.49 to 38.31 mL g–1 after being modified by the Fe3+ ion electrolyte and further decreased to 34.84 mL g–1 after being modified by the Cu2+ ion electrolyte. The CH4 desorption ratio increased from 63.43 to 73.66% and 84.87% after modification in Fe3+ and Cu2+ ion electrolytes, respectively, and this improvement was caused by the enlargement of the diffusion coefficient D. The effect of the Cu2+ electrolyte on CH4 adsorption/desorption was better than that of the Fe3+ electrolyte, and the mechanism was analyzed by the changes in the surface energy, functional groups, and pore characteristics before and after modification. The results obtained from this work provide a basis for the optimization of ion electrolytes when accelerating methane extraction via an electrochemical method.Zhang, Y., Chen, B., Zhai, W.-d., 2020. Exploring sources and biogeochemical dynamics of dissolved methane in the Central Bohai Sea in summer. Frontiers in Marine Science 7, 79. doi: 10.3389/fmars.2020.00079. clarify the sources and biogeochemical dynamics of dissolved methane (CH4) in shallow-water coastal oceans, we investigated the concentrations, sea-to-air fluxes, and net cycling rate of CH4 in the central Bohai Sea in summer 2018. During the survey, both summertime stratification and dissolved oxygen (DO) deficit were observed. In the surface layer, CH4 concentration ([CH4]) ranged from 3.08 to 10.27 nmol kg–1. The average sea-to-air flux was estimated at 6.46 ± 3.32 μmol m–2 d–1, indicating that the Bohai Sea serves as a source of atmospheric CH4. In the bottom layer, [CH4] ranged from 4.29 to 31.04 nmol kg–1. The downward increase in [CH4] within the water column indicated substantial sources of CH4 in the seafloor. Based on the complex relationship between the saturation ratio of CH4 and DO, three types of CH4 release from the seafloor were identified, including diagenesis of buried organic matter, natural leakage from geological settings, and anthropogenic release from offshore oil/gas development. The saturation ratios of CH4 in bottom waters were positively correlated with the degree of stratification of the water column. Using a two-layer box model, sedimentary CH4 release rates at two oxygen-deficient stations were estimated to be 56.0–60.8 μmol m–2 d–1, which was much higher than the sea-to-air fluxes. The modeling results also indicated that the majority of seafloor released CH4 (>90%) was consumed in the water column of this shallow-water coastal sea. This is the first comprehensive study on CH4 cycling in the Bohai Sea. This work shows the indicative role of DO in identifying multiple CH4 sources and highlights the dominance of water stratification and microbial consumption in local CH4 dynamics.Zhao, H., Zhong, Z., Li, Z., Wang, W., 2019. Research on catalytic pyrolysis of algae based on Py-GC/MS. Royal Society Open Science 6, 191307. order to improve the quality of catalysis products of algae, composite molecular sieve catalyst was prepared by digestion and crystallization of HZSM-5 to reduce the oxygen content of the catalytic products. According to the analysis of the pyrolysis products, the best preparation conditions were chosen of tetra propylammonium hydroxide (TPAOH) solution 2.0 mol l?1, cetyltrimethylammonium bromide (CTAB) solution 10 wt%, crystallization temperature 110°C, digestion–crystallization time: 24–24 h. The results indicate that the main function of catalysts is to promote the conversion of alcohols into hydrocarbons by reducing energy barriers. Catalysed by the composite molecular sieve, the content of alcohols in the pyrolysis products decreased from more than 30% to less than 10%, the content of hydrocarbons increased from 20% to nearly 60%, while all the adverse components remained at a low level, which indicates that the catalytic pyrolysis products are of high quality. The great deoxidation effect of composite molecular sieves is not only due to the expansion of the range of organic matter during re-pyrolysis, but also the increasing of the residence time of pyrolysis products inside the structure for the external mesoporous structure.Zhao, K., Li, T., Zhu, G., Zhang, Z., Li, J., Wang, P., Yan, H., Chen, Y., 2020. Geochemical characteristics and formation mechanism of high-quality Lower Cambrian source rocks: A case study of the Tianzhushan profile in western Hubei. Acta Petrolei Sinica 41, 13-26. mudstones developed worldwide in Lower Cambrian strata are an important set of high-quality source rocks. Although this set of source rocks is widely distributed, its thickness and quality vary largely in different regions. Reconstruction of the sedimentary and developmental model for black mudstones is of great significance for predicting the distribution of high-quality source rocks and can provide guidance for shale gas exploration. The geochemical analyses of organic carbon, major elements, and trace elements were performed on source rock samples from Lower Cambrian strata in the Tianzhushan profile of western Hubei, aiming to explore the control effect of paleoclimate, paleoproductivity and paleo-marine environment on the formation of high-quality source rocks, to analyze the sedimentary model and development mechanism of Lower Cambrian high-quality source rocks and the coupling relationship between the changes of biological activities and marine environment and the formation of high-quality source rocks. The results show that the high-quality Cambrian source rock section of the Tianzhushan profile is characterized by high TOC content (2.63% -8.76%), high chemical index of alteration (68-76), high biogenic Ba content (average of 1 392×10-6) and high enrichment of redox sensitive elements (Mo, U and V). The V/Cr, U/Th and V/Sc ratios indicate that Lower Cambrian water in the Tianzhushan profile underwent changes from sulfurized anoxic environments to sub-oxidized environments and then to oxidized environments. This is consistent with the change characteristics of redox environment indicated by the ratio of Mo and U enrichment factors. The correlation between TOC and Al, Si, biogenic Ba contents indicates that terrestrial input made a contribution to source rocks. The change of δ13C reflects the influence of sea level eustacy on living environment. The study demonstrates that the sulfidation and anoxia of seawater and high marine productivity in Early Cambrian are key factors controlling the large-scale burial of organic matter and the formation of high-quality source rocks in western Hubei.Zhao, L., Wang, D., Chen, S., Li, L., Zhang, T., 2020. Remote detection of hydrocarbon microseepage in a loess covered area. Journal of Earth Science 31, 207-214. microseepage can result in related near-surface mineral alterations. In this study, we evaluated the potential of detecting these alterations with field measured and satellite acquired hyperspectral data. Fourteen soil samples and reflectance spectra were collected in the Xifeng Oilfield, a loess covered area. Soil samples were analyzed in the laboratory for calcite, dolomite, kaolinite, illite, and mixedlayer illite/smectite content, and we processed reflectance spectra for continuum removal to derive clay and carbonate mineral absorption depth (H). High correlation between absorption depth and mineral content was shown for clay and mineral carbonate with field measured spectra. Based on the result for the field spectra, we proposed and tested a fast index based on the absorption depth of clay and carbonate minerals with a hyperspectral image of the area. The detected hydrocarbon microseepage anomalies matched well with those shown in the geological map.Zhao, S., Xue, S., Zhang, J., Zhang, Z., Sun, J., 2020. Dissolved organic matter-mediated photodegradation of anthracene and pyrene in water. Scientific Reports 10, 3413. and transformation process of polycyclic aromatic hydrocarbons (PAHs) is strongly depended on the interaction between PAHs and dissolved organic matters (DOM). In this study, a 125W high-pressure mercury lamp was used to simulate the sunlight experiment to explore the inhibition mechanism of four dissolved organic matters (SRFA, LHA, ESHA, UMRN) on the degradation of anthracene and pyrene in water environment. Results indicated that the photodegradation was the main degradation approach of PAHs, which accorded with the first-order reaction kinetics equation. The extent of degradation of anthracene and pyrene was 36% and 24%, respectively. DOM influence mechanism on PAHs varies depending upon its source. SRFA, LHA and ESHA inhibit the photolysis of anthracene, however, except for SRFA, the other three DOM inhibit the photolysis of pyrene. Fluorescence quenching mechanism is the main inhibiting mechanism, and the binding ability of DOM and PAHs is dominantly correlated with its inhibiting effect. FTIR spectroscopies and UV–Visible were used to analyze the main structural changes of DOM binding PAHs. Generally, the stretching vibration of N–H and C–O of polysaccharide carboxylic acid was the key to affect its binding with anthracene and C–O–C in aliphatic ring participated in the complexation of DOM and pyrene.Zhao, W., Hu, S., Hou, L., Yang, T., Li, X., Guo, B., Yang, Z., 2020. Types and resource potential of continental shale oil in China and its boundary with tight oil. Petroleum Exploration and Development 47, 1-11. shale oil has two types, low-medium maturity and medium-high maturity, and they are different in terms of resource environment, potential, production methods and technologies, and industrial evaluation criteria. In addition, continental shale oil is different from the shale oil and tight oil in the United States. Scientific definition of connotations of these resource types is of great significance for promoting the exploration of continental shale oil from “outside source” into “inside source” and making it a strategic replacement resource in the future. The connotations of low-medium maturity and medium-high maturity continental shale oils are made clear in this study. The former refers to the liquid hydrocarbons and multiple organic matter buried in the continental organic-rich shale strata with a burial depth deeper than 300 m and a Ro value less than 1.0%. The latter refers to the liquid hydrocarbons present in organic-rich shale intervals with a burial depth that in the “liquid window” range of the Tissot model and a Ro value greater than 1.0%. The geological characteristics, resource potential and economic evaluation criteria of different types of continental shale oil are systematically summarized. According to evaluation, the recoverable resources of in-situ conversion technology for shale oil with low-medium maturity in China is about (700–900)×108 t, and the economic recoverable resources under medium oil price condition ($ 60–65/bbl) is (150–200)×108 t. Shale oil with low-medium maturity guarantees the occurrence of the continental shale oil revolution. Pilot target areas should be optimized and core technical equipment should be developed according to the key parameters such as the cumulative production scale of well groups, the production scale, the preservation conditions, and the economics of exploitation. The geological resources of medium-high maturity shale oil are about 100×108 t, and the recoverable resources can to be determined after the daily production and cumulative production of a single well reach the economic threshold. Continental shale oil and tight oil are different in lithological combinations, facies distribution, and productivity evaluation criteria. The two can be independently distinguished and coexist according to different resource types. The determination of China's continental shale oil types, resources potentials, and tight oil boundary systems can provide a reference for the upcoming shale oil exploration and development practices and help the development of China's continental shale oil.Zhao, Z., Yang, X., Lee, J., Tolentino, R., Mayorga, R., Zhang, W., Zhang, H., 2020. Diverse reactions in highly functionalized organic aerosols during thermal desorption. ACS Earth and Space Chemistry 4, 283-296. organic aerosols (OA) are complex mixtures of organic molecules that are usually highly functionalized through various oxidative processes. Understanding the volatilities and chemical compositions of OA are key to elucidating their environmental impacts. Thermal desorption coupling to mass spectrometry has been used as the main approach to examine both aspects of OA. In this work, we investigated the thermal desorption-induced chemical compositional change of OA from heterogeneous oxidation of glutaric acid and ?-pinene ozonolysis. Using an ion mobility spectrometry mass spectrometer, coupled with total peroxide analysis and a mass transfer evaporation model, we determined diverse reactions in the particle phase during rapid heating, under moderate desorption temperatures (less than 100 °C). These reactions include irreversible oligomer (e.g., esters and organic peroxides) decomposition into monomers and new oligomer formation from decarboxylation, CO elimination, decarbonylation, and dehydration. These chemical processes may effectively modify the volatility and chemical characteristics of the residual OA particles. Further, the monomeric products from the thermal decomposition could interfere quantification of known monomer products without isomer separation. These findings could help reconcile previously observed inconsistency of OA evaporation kinetics vs. volatility distribution. Further, the results from this study could help interpret and constrain thermal desorption-based measurements of OA volatility and compositions.Zheng, H., Yang, H., Zhang, W., Yang, R., Su, B., Zhao, X., Zhou, Y., Dai, X., 2020. Insight of silk relics of mineralized preservation in Maoling Mausoleum using two enzyme-linked immunological methods. Journal of Archaeological Science 115, 105089. textiles often unearthed along with metal objects, are textile residues in which the fibers are partially or completely replaced by minerals. Some textile fragments with intact fiber shapes but mineralization on the surface of a ring-shaped iron sword, had recently been found from Maoling Mausoleum in Shanxi province, China. In this study, three-dimension microscope, scanning electron microscope-energy disperse spectroscopy (SEM-EDS) and Raman spectroscopy were used to observe the morphology of fiber and analyze the mineral element information, and two immunology testing techniques would be used to determine whether the textile fragments included the silk protein. The results showed that the hilt string imprint (sample A) was a twill braiding with cinnabar remaining on the surface and the blade textile imprint (sample B) was a tabby fabric, and these fibers were mineralized by iron ions to form a cavity structure. The morphology of sample B was similar to that of mulberry silk with a smooth surface and a triangular cross section. At the same time, silk protein was successfully detected in a few milligrams of sample B using fibroin polyclonal antibody by Enzyme-linked Immunosorbent assay (ELISA) and immunofluorescence method (IFM). Thus, it can be inferred that the iron sword was covered or wrapped in silk at that time. This research provided a technical support for the identification of silk residues in mineralized textiles, which is of great significance for the study of early organic fabrics.Zheng, L., Huang, X., Ji, X., Deng, C., 2020. Paleoenvironmental implications of molecular and carbon isotopic distributions of n-alkanes in the hominoid-bearing upper Miocene sediments from the Zhaotong Basin, southwestern China. Palaeogeography, Palaeoclimatology, Palaeoecology 544, 109627. is crucial to understand the relationship between hominoid primates and their living environment. Located at the southeastern margin of the Tibetan Plateau, the Shuitangba (STB) outcrop from the Zhaotong Basin is famous for bearing the remains of the youngest known ape fossil in the terminal Miocene (~6.2 Ma). In this study, the molecular and carbon isotope compositions of n-alkanes, together with the loss on ignition and the bulk carbon isotope composition of total organic matter, were investigated in the STB outcrop to infer the paleoenvironmental conditions in this uppermost Miocene sedimentary sequence, with the emphasis on the habitat of the STB hominoid. In the hominoid-bearing peaty clay layer and the surrounding lignite layers, the n-alkane molecular and carbon isotope compositions support a primary contribution from terrestrial higher plants. In contrast, n-alkanes in the upper shallow lake sediments are derived from multiple origins, mainly from aquatic plants and bacteria. Both carbon preference index (CPI) and average chain length (ACL) vary closely with the lithology, but the CPI record shows the larger amplitude of change than the ACL and varies sharply during the lithological boundary. It is notable that the changes of the molecular and carbon isotope compositions of long-chain n-alkanes do not parallel with the abrupt increase of Poaceae pollen percentage during the STB hominoid appearing stage. Such an inconsistency between herb pollen percentage and n-alkane ratios may result from the different sources. Our results clearly support that these organic matter-based ratios have the potential to record the paleoenvironmental changes in ancient lacustrine sediments.Zheng, M., Pan, Y., Wang, Z., Li, X., Guo, L., 2020. Capturing the dynamic profiles of products in Hailaer brown coal pyrolysis with reactive molecular simulations and experiments. Fuel 268, 117290. work aims at exploring the possible applications of the state-of-the-art methods in uncover the dynamic product profiles in coal pyrolysis. A combination of pyrolysis with the synchrotron vacuum ultraviolet photoionization mass spectrometry (Py-SVUV-PIMS), flash pyrolysis technique with gas chromatography-mass spectrometry (Py-GC/MS) and reactive molecular dynamic simulations (ReaxFF MD) was employed in capturing product distributions in Hailaer brown coal pyrolysis. The consistent identification of the representative pyrolyzates obtained from simulations and experiments suggest that mono-aromatic hydrocarbons and alkyl-phenols are major tar products. It is clearly observed that dimethyl-phenol is most likely the primary product for Hailaer coal pyrolysis after analyzing the spectrograms of Py-SVUV-PIMS and Py-GC/MS experiments. The three phenol generation pathways first reveal that the hydrogen atoms to stabilize phenoxyl radicals can come from surrounding structures, CHO2 intermediates and large fragments to help CO2 generation and condensation reactions. These results indicate ReaxFF MD with a reasonable coal model can provide rich clues for reactions involved with important pyrolyzates. The combined pyrolysis approaches can complement each other in capturing dynamic profiles for major products in different pyrolysis stages, including primary pyrolyzates of Py-GC/MS, primary and secondary pyrolyzates of Py-SVUV-PIMS, and the underlying reaction pathways of ReaxFF MD simulations.Zheng, S., Clausen, S., Feng, Q., Servais, T., 2020. Review of organic-walled microfossils research from the Cambrian of China: Implications for global phytoplankton diversity. Review of Palaeobotany and Palynology 276, 104191. recent years, significant progress has been made in organic-walled microfossil research from the Paleozoic of China. In the present study, all palynological investigations from the Cambrian of China, including thin sections, are reviewed and a synthesis of the organic-walled microfossil record is presented. The stratigraphic ranges of the organic-walled microfossils for each geographical region of China are listed in chronological order according to the most recent international stratigraphic chart. The compilation reveals that 99 genera and 276 species of organic-walled microfossils have been documented so far. The localities of the investigated areas are mostly on the Cambrian Jiangnan slope and basin and the north continental shelf of the Yangtze plate, where the Ediacaran–Cambrian transition has been largely discussed. The compilation points out that some geographical areas and some stratigraphical intervals remain relatively unstudied. Further research on these intervals and areas needs to be carried out to fill some of the gaps in the record. The data from the literature on organic-walled microfossils in China are added to the previously published dataset of global acritarch diversity. The higher diversities in the early Cambrian Fortunian stage and Stage 2 in China point to a global diversification up to a diversity peak around the late early/early middle Cambrian reported in previous studies. The latest Cambrian diversification rise in China confirms the onset of the Ordovician plankton revolution.Zheng, S., Feng, Q., Tribovillard, N., Servais, T., Zhang, Y., Gao, B., 2020. New insight into factors controlling organic matter distribution in Lower Cambrian source rocks: A study from the Qiongzhusi Formation in South China. Journal of Earth Science 31, 181-194. organic matter (OM) is a major reservoir of organic carbon in the global carbon cycle. Despite many studies, there still exist many debates on the mechanism of OM accumulation and preservation in marine sediments. We present a new field study of a Lower Cambrian shallow marine shelf sequence in the northern edge of the Yangtze Plate, China. Our results show that palynological OM and biogenic silica (Bio-Si) could be used alongside more conventional redox and paleo-productivity proxies to study the distribution of OM in marine sediments. The qualitative and quantitative study of palynological OM provides more detailed information on the nature of sedimentary organic carbon, which can be helpful in the assessment of primary productivity and OM preservation. In addition, the presence of Bio-Si stimulates the physical preservation of OM. Further analysis indicates that an increase in Bio-Si can promote OM preservation. This case-study provides insight into the intertwined factors controlling OM accumulation in the Early Cambrian.Zheng, Y.-F., Zhao, G., 2020. Two styles of plate tectonics in Earth’s history. Science Bulletin 65, 329-334. plate tectonics started to occur on Earth and how it has evolved through time are two of the most fundamental questions in earth sciences. While gravity-driven subducting has been accepted as a critical condition for the operation of plate tectonics on Earth, it is intriguing how the dynamic regime and thermal state of subduction zones have affected the style of plate tectonics in Earth’s history. The metamorphic rocks of regional distribution along convergent plate boundaries record reworking of crustal rocks through dehydration and melting at lithospheric depths. The property of regional metamorphism is determined by both dynamic regime and thermal state of plate margins. The two variables have secularly evolved in Earth’s history, which is recorded by changes in the global distribution of metamorphic facies series through time. This results in two styles of plate tectonics. Modern-style plate tectonics has developed since the Neoproterozoic when plate margins were rigid enough for cold subducting, whereas ancient-style plate tectonics has developed since the Archean when plate margins were ductile enough for warm subducting. Such a difference is primarily dictated by higher mantle temperatures in the Archean than in the Phanerozoic. The development of plate subduction in both cold and warm realms is primarily dictated by the rheology of plate margins. This leads to a holistic model for the style of plate tectonics during different periods in Earth’s history.Zheng, Z., Zuo, Y., Jiang, S., Zhou, Y., Zhang, Y., Wu, W., Yan, K., Yang, M., 2020. Carbon isotope kinetics effect on the natural gas accumulation: A case study of the Baimiao area, Dongpu depression, North China. Energy & Fuels 34, 1608-1619. isotope kinetics is developed from hydrocarbon generation kinetics for studying the natural gas accumulation process. On the basis of the kerogen pyrolysis experiments conducted in a closed gold tube autoclave system, the hydrocarbon generation kinetic parameters and carbon isotope kinetic parameters of the Shahejie Formation source rocks in the Qianliyuan sag are obtained by the Kinetics software and Excel spreadsheet software. In combination with the thermal and burial histories of the Qianliyuan sag, the long-term cumulative curve and periodic cumulative curve starting from 28.6 Ma under geological conditions are established. In combination with the geochemical parameters of the Carboniferous–Permian gas source rocks, the gas source and natural gas accumulation process in the Baimiao area are revealed. The results show that (1) the oil–gas reservoirs in the Baimiao area are formed earlier, and their accumulation time occurred from 28.6 to 27–25.8 Ma, and (2) the natural gas accumulation process in the Baimiao area was revealed to progress from the Shahejie 1 Formation depositional period to the Dongying Formation depositional period, the coal-type gas generated by the Carboniferous–Permian source rocks was accumulated in the Paleogene traps along the Lanliao fault and its derived fault systems, and these traps were formed during the Shahejie 2 Formation depositional period. Approximately 28.6 Ma, some oil-type gas generated by the Paleogene source rocks in the Qianliyuan sag accumulated in the traps formed during the early stage of the structural wing. Other oil-type gas migrated to the central part of the structure along the Duzhai fault and along a series of secondary faults in the Baimiao area, which then mixed with coal-type gas that accumulated in the early stage. At the end of the Dongying Formation depositional period, hydrocarbon generation ceased and the oil-type gas accumulation process was blocked from 27 to 25.8 Ma, which terminated the coal-type gas accumulation process. This work may provide some insights into the natural gas accumulation process and distribution in the Dongpu depression.Zhou, J., Jin, Z., Luo, K.H., 2020. Insights into recovery of multi-component shale gas by CO2 injection: A molecular perspective. Fuel 267, 117247. the mechanism behind shale gas recovery is of great importance for achieving optimum shale gas productivity. In this work, we use Grand Canonical Monte Carlo (GCMC) simulations to investigate the adsorption and recovery mechanisms of ternary hydrocarbon mixtures comprising methane, ethane and propane in kerogen nanopores. For the adsorption of hydrocarbon mixtures in kerogen slit pores, density distributions of each component are analyzed and the results indicate that densities of methane and ethane in the first adsorption layer increase as pressure increases, while an opposite trend is observed for propane. A stronger confinement effect is observed on the heavier hydrocarbon components, increasing the difficulty of recovery. For the recovery of the multi-component shale gas, we propose a reference recovery route with pressure drawdown and CO2 injection combined and the recovery efficiency is compared to the condition with only pressure drawdown applied. Significant enhancement in recovery ratio for all three components is observed with the CO2 injection and a better performance is shown on heavier components and smaller pores. An increase of 60% and 40% in propane recovery ratio is achieved in the 2-nm and 4-nm kerogen slit pores, respectively. Recovery mechanisms of pressure drawdown and CO2 injection are investigated in detail. The pressure drawdown method recovers methane from the first adsorption layer and middle of slit pore simultaneously, while extracting ethane and propane mainly from the middle of slit pore; the recovery due to CO2 injection mainly takes place in the adsorption layers. Pressure drawdown tends to extract the lighter components and CO2 injection is efficient in the recovery of heavier hydrocarbons. As pore width increases, the recovery ratio of pressure drawdown increases, while that of CO2 injection decreases. Besides, the CO2 sequestration ratio is higher in smaller kerogen slit pores.Zhou, W., Liu, Y., Wang, J., Guo, Z., Shen, A., Liu, Y., Liang, X., 2020. Application of two-dimensional liquid chromatography in the separation of traditional Chinese medicine. Journal of Separation Science 43, 87-104. Chinese medicines have been widely used to prevent and cure diseases for thousands of years. For the purpose of better understanding the extremely complicated traditional Chinese medicines, powerful separation techniques are essential. Two‐dimensional liquid chromatography has been proven to be more powerful for the separation of complex traditional Chinese medicines due to its enhanced peak capacity and resolution compared with one‐dimensional liquid chromatography. Enormous efforts have been made on the coupling of independent separation mechanisms to improve the resolving power for complex traditional Chinese medicine samples, including the development and introduction of novel stationary phases. This review aims to give an overview on the applications of two‐dimensional liquid chromatography in traditional Chinese medicine research since 2008, including comprehensive two‐dimensional liquid chromatography, heart‐cutting two‐dimensional liquid chromatography both in on‐line, and off‐line mode. Different couplings of separation modes were respectively discussed based on specific studies, with emphasis on the applications of novel stationary phases in the two‐dimensional liquid chromatography.Zhu, C., Sheng, J.J., Ettehadtavakkol, A., Li, Y., Gong, H., Li, Z., Dong, M., 2019. Numerical and experimental study of enhanced shale-oil recovery by CO2 miscible displacement with NMR. Energy & Fuels 34, 1524-1536. miscible displacement is an efficient method for enhanced shale-oil recovery. Understanding the movability of shale oil in different states of occurrence is important for CO2 miscible displacement. Therefore, a nuclear magnetic resonance (NMR)-based CO2 miscible displacement experiment is conducted on oil-saturated shale and sandstone. To describe the processes involved in the measurements, a mathematical model based on the Maxwell–Stefan equation is developed; it considers the heterogeneity of shale and the competitive adsorption and absorption of CO2–oil mixtures in organic matter. The results show that the porosity of immobile oil in the shale samples (4.0% and 4.3%) is lower than the porosity of free oil (8.0% and 10.2%). Compared with sandstone, a larger CO2-injection time yields a smaller recovery factor in the case of shale, and the recovery factor of immobile oil is much less than that of free oil in the shale. According to the model, the order of oil production in the laminated shale during CO2 miscible displacement is as follows: free oil in the inclusions, free oil in organic matrix-clay, and adsorption and absorption of oil in organic matter. The oil production rate is associated with the heterogeneity of shale (R0) and the competitive adsorption and absorption of CO2-oil mixture in the organic matter (ω0, kads).Zhu, H., Xu, T., Zhu, Z., Yuan, Y., Tian, H., 2020. Numerical modeling of methane hydrate accumulation with mixed sources in marine sediments: Case study of Shenhu Area, South China Sea. Marine Geology 423, 106142. natural gas hydrates detected in Shenhu Area, South China Sea are considered to have great potential for exploitation and to become a research hotspot. However, details of the dynamic accumulation and evolution processes of gas hydrate over a long time in this area remain unclear. In this study, we developed a numerical model to predict the accumulation of gas hydrates in the marine sediments by introducing the biogenic methanogenesis module to the framework of the existing simulator TOUGH+HYDRATE. A one-dimensional dynamic model was applied to reproduce the formation of gas hydrate at site SH2 in Shenhu Area. The burial of sediments and associated phenomena (e.g., evolution of temperature, sediment compaction and consequent reduction in sediment porosity and permeability, fluid expulsion) are taken into account. Modeling results indicate that with the conventional conversion coefficient (CC) of organic carbon to methane of 0.15, the amount of in-situ biogenic methane is not sufficient to form the highly saturated hydrate detected at this location and the remaining methane (91.4%) is supplied by the upward flow of fluids. The tectonic movement that took place about 1.5 Ma created pathways for the fluids to migrate vertically. The pore water and methane gas fluxes in the upward fluids were determined as 2 × 10?10 kg/s·m2 and 1 × 10?11 kg/s·m2, respectively, using the proved hydrate saturation profile and measured pore water chlorinity from recovered core samples. The distribution of hydrate in the sediments is significantly influenced by pore water salinity. The inhibitory effect of salt on hydrate formation, which shifts the pressure of three-phase (i.e., solid hydrate, methane gas and pore water) equilibrium to actual pore water pressure, could be the major reason for the appearance of a three-phase co-existence zone in the hydrate concentrated zone. Additionally, the water flux and diffusivity of salt have a profound effect on the formation of gas hydrate by affecting the salinity of pore water in the gas hydrate concentrated zone. The results of this study are of great significance for guiding marine gas hydrate exploration and resource evaluation.Zhu, R., Tolu, J., Deng, L., Fiskal, A., Winkel, L.H.E., Lever, M.A., 2020. Improving the extraction efficiency of sedimentary carbohydrates by sequential hydrolysis. Organic Geochemistry 141, 103963. serve as structural materials, energy storage compounds, and energy carriers in organisms and provide insights into the dominant sources and the degradation state of organic matter (OM). Several studies have analyzed dissolved and/or particulate carbohydrates in the environment, often with the aim of studying particular carbohydrate groups of interest. These studies have often employed different acids and hydrolytic conditions, making comparisons across studies a challenge. Here, we introduce a sequential acid hydrolysis protocol for the comprehensive extraction, quantification and compositional investigation of carbohydrates in sediment samples. This protocol has four acid hydrolysis steps that sequentially increase in extraction strength, where each subsequent hydrolysis step is performed on the unextracted remains previously hydrolyzed. The four hydrolysis steps consist of 1 M HCl for 2 h at (1) room temperature, (2) 50 °C, and (3) 105 °C, followed by incubation for 8 h using (4) 6 M HCl and 105 °C. Based on tests using diverse carbohydrate standard compounds, the protocol recovers most di- and oligosaccharides and soluble polysaccharides during the initial hydrolysis steps, whereas the recovery of most insoluble polysaccharides is highest during the final extraction step. Applying this protocol to different sediment types shows that recoveries of neutral sugars, amino sugars and sugar alcohols are on average ~60% higher than with a reference one-step extraction method using only hydrolysis with hot 6 M HCl. This sequential extraction protocol thus provides an important new tool for the quantitative and compositional analysis of carbohydrates in aquatic sediments.Zhu, X., Cai, J., Wang, Y., Liu, H., Zhang, S., 2019. Evolution of organic-mineral interactions and implications for organic carbon occurrence and transformation in shale. GSA Bulletin 132, 784-792. interactions are pervasive in sedimentary environments; however, the extent of these interactions is not constant and has a significant impact on organic carbon (OC) occurrence and transformation. To understand the evolution of organic-mineral interactions and the implications for OC occurrence and transformation in fine-grained sediments, several shale samples were selected and subjected to physical and chemical sequential treatments. The samples were subjected to pyrolysis, Fourier transform infrared spectrophotometry (FTIR), and adsorption measurements to determine the organic parameters and the mineral surface area (MSA) of the shale samples. The results show that the organic fractions derived from sequential treatments have varying pyrolysis and FTIR characteristics. The correlation between the total OC content and MSA is positive, but it is split according to organic fractions with different attributes. Correlations between the different organic fractions and MSA indicate that the organic matter in shale is mainly adsorbed on mineral surfaces, while a certain portion of organic matter occurs in the pores and is adsorbed on the organic-mineral aggregates, suggesting variable interactions between the organic fractions with different attributes and minerals. From the pyrolysis and FTIR analysis, the organic fractions of different occurrence sites vary in their OC proportion, proclivity to form organic functional groups, and hydrocarbon generation potential. With increasing burial depth, the MSA and hydrogen index as well as OC loading per unit MSA are reduced, and the OC proportions of organic fractions with different attributes have regular trends. These observations indicate that the extent of organic-mineral interactions that can stabilize organic matter gradually decreases, resulting in transformation of the tightly mineral-combined OC into free OC. Our work reveals the heterogeneity in organic matter occurrence and the effect of the evolution of the organic-mineral interactions on OC occurrence and transformation, which is significant in the global carbon cycle and in petroleum systems.Zhurina, M.V., Gannesen, A.V., Martyanov, S.V., Plakunov, V.K., 2020. Express method for determining the relation between polyethylene biocorrosion by Chromobacterium violaceum biofilms and their ability to form extracellular matrix. Microbiology 89, 44-49. express method for measuring biocorrosion of the surface of polyethylene by mono- and multi-species microbial biofilms was developed. The method involves massive inoculation of polyethylene samples with pure microbial cultures or their mixtures, with subsequent incubation for 5?7 days providing for the biofilm development. The damage to the surface of polyethylene was determined both by the optical method described in this paper and based on measuring the intensity of scattered light and by the standard method using a profilometer. Both methods revealed a direct correlation of the results and may be recommended for practical measurement of the initial stages of biocorrosion of the polyethylene surface. The biocorrosion level was found to depend primarily upon the number of viable microbial cells in the biofilm, rather than upon accumulation of the extracellular polymer matrix.Zou, C., Pan, S., Jing, Z., Gao, J., Yang, Z., Wu, S., Zhao, Q., 2020. Shale oil and gas revolution and its impact. Acta Petrolei Sinica 41, 1-12 shale oil and gas revolution has prolonged the life cycle of oil industry in the world, and promoted the growth of global oil and gas reserves and production, thus having influences on the energy strategy of each country. The formation and evolution of organic-rich shale worldwide were controlled by the life explosion and mass extinction events in the past geological periods. In combination with the worldwide exploration and development of shale oil and gas, the shale oil and gas revolution involves scientific and technological revolution, management revolution and strategic revolution. Through the scientific and technological revolution, the resource-based view is expanded from a single resource type to a "source rock bearing oil and gas" system; the efficient and low-cost development of shale oil and gas are realized by the management revolution; a new map of the worldwide energy is reshaped by the strategic revolution. Through systematically introducing the industrial practices in terrestrial shale oil and marine/terrestrial shale gas, it is clear that the underground in-situ heating conversion technology represents the actual exploration of the large-scale development and utilization of shale oil resources with medium-low maturity, and the volume fracturing technology for horizontal well is an effective way to realize the low-cost development of shale oil resources with medium-high maturity. It is pointed out that the shale oil with medium-low maturity in the Member 7 of Yanchang Formation in Ordos Basin and that with medium-high maturity in the Daanzhai Member of Jurassic Ziliujing Formation of Sichuan Basin have great resource potential. At present, China has achieved a success in the development of marine shale gas shallower than 3500 m, and major breakthroughs have been made in the exploration of transitional and marine shale gas deeper than 3 500 m. The underground coal gasification test represents an exploration way for achieving clean and sustainable use of coal. The shale oil and gas revolution has a profound impact on China's energy development. It breaks through the traditional oil exploration theories by introducing "source rock bearing oil and gas" as a new petroleum system, drives the technological explosion, speeds up the energy type alternation, opens the development path of "depending on conventional petroleum, making a breakthrough in unconventional petroleum, and developing new energy", which is expected to achieve energy independence in China.Zou, D., Pan, J., Liu, Z., Zhang, C., Liu, H., Li, M., 2020. The distribution of Bathyarchaeota in surface sediments of the Pearl River estuary along salinity gradient. Frontiers in Microbiology 11, 285. doi: 10.3389/fmicb.2020.00285., a recently proposed archaeal phylum, is globally distributed and highly abundant in anoxic sediments. Metabolic pathways of the Bathyarchaeota members are diverse and, hence, this phylum has been proposed to play an important role in global biogeochemical cycles. Bathyarchaeota members are distributed in the estuarine environments. However, limited information is available about their detailed community structure, abundance, and functions in the Pearl River estuary (PRE). In the current study, we performed a comprehensive investigation of the archaeal community in the PRE surface sediments along a salinity gradient, with a focus on Bathyarchaeota. Bathyarchaeota was the dominant archaeal phylum, with the abundance of the bathyarchaeotal 16S rRNA gene ranging from 1.43 × 108 to 1.22 × 109 copies/g sediment dry weight (d.w.), and Bathy-8 was the dominant subgroup. Thaumarchaeota, Lokiarchaeota, and Euryarchaeota, including Thermoprofundales (MBG-D archaea), were the other major archaeal groups in the PRE. The differences of community distributions in the high- and low-salinity sediments were hence investigated. Statistical analysis revealed that besides salinity, ammonium, and total organic carbon were the most important environmental factors influencing the archaea community structure, including that of Bathyarchaeota, in the PRE. The archaeal network indicated the cooccurrence among Bathyarchaeota, Lokiarchaeota, and Euryarchaeota, while Bathy-6 presented unique correlations compared with other bathyarchaeotal subgroups. These observations indicate that Bathyarchaeota may play a role in ecosystem function through microbe–microbe interactions, revealing a possible different lifestyle for Bathy-6 in eutrophic estuarine sediments. ................
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