Eaogorg.files.wordpress.com



GEOCHEMISTRY ARTICLES – October 2018?Analytical ChemistryAzzouz, A., Kailasa, S.K., Lee, S.S., J. Rascón, A., Ballesteros, E., Zhang, M., Kim, K.-H., 2018. Review of nanomaterials as sorbents in solid-phase extraction for environmental samples. TrAC Trends in Analytical Chemistry 108, 347-369.Brereton, R.G., Jansen, J., Lopes, J., Marini, F., Pomerantsev, A., Rodionova, O., Roger, J.M., Walczak, B., Tauler, R., 2018. Chemometrics in analytical chemistry - Part II: modeling, validation, and applications. Analytical and Bioanalytical Chemistry 410, 6691-6704.Esrafili, A., Baharfar, M., Tajik, M., Yamini, Y., Ghambarian, M., 2018. Two-phase hollow fiber liquid-phase microextraction. TrAC Trends in Analytical Chemistry 108, 314-322.Gajdosechova, Z., Pagliano, E., Zborowski, A., Mester, Z., 2018. Headspace in-tube microextraction and GC-ICP-MS determination of mercury species in petroleum hydrocarbons. Energy & Fuels 32, 10493-10501.Ji, Y., Hou, Y., Ren, S., Yao, C., Wu, W., 2018. Tetraethylammonium amino acid ionic liquids and CO2 for separation of phenols from oil mixtures. Energy & Fuels 32, 11046-11054.Panchuk, V., Yaroshenko, I., Legin, A., Semenov, V., Kirsanov, D., 2018. Application of chemometric methods to XRF-data – A tutorial review. Analytica Chimica Acta 1040, 19-32.Radwan, O., Gunasekera, T.S., Ruiz, O.N., 2018. Robust multiplex quantitative polymerase chain reaction assay for universal detection of microorganisms in fuel. Energy & Fuels 32, 10530-10539.Gas Chromatography/GC×GC/GC-MSAnthony, I.G.M., Brantley, M.R., Floyd, A.R., Gaw, C.A., Solouki, T., 2018. Improving accuracy and confidence of chemical identification by gas chromatography/vacuum ultraviolet spectroscopy-mass spectrometry: Parallel gas chromatography, vacuum ultraviolet, and mass spectrometry library searches. Analytical Chemistry 90, 12307-12313.Castanheiro, A., Joos, P., Wuyts, K., De Wael, K., Samson, R., 2019. Leaf-deposited semi-volatile organic compounds (SVOCs): An exploratory study using GCxGC-TOFMS on leaf washing solutions. Chemosphere 214, 103-110.Causon, T.J., 2018. Chromatography: Multidimensional techniques, Reference Module in Chemistry, Molecular Sciences and Chemical Engineering. Elsevier.Cersoy, S., Daheur, G., Zazzo, A., Zirah, S., Sablier, M., 2018. Pyrolysis comprehensive gas chromatography and mass spectrometry: A new tool to assess the purity of ancient collagen prior to radiocarbon dating. Analytica Chimica Acta 1041, 131-145.de Souza, J.R.B., Dias, F.F.G., Caliman, J.D., Augusto, F., Hantao, L.W., 2018. Opportunities for green microextractions in comprehensive two-dimensional gas chromatography / mass spectrometry-based metabolomics – A review. Analytica Chimica Acta 1040, 1-18.Djokic, M.R., Muller, H., Ristic, N.D., Akhras, A.R., Symoens, S.H., Marin, G.B., Van Geem, K.M., 2018. Combined characterization using HT-GC?×?GC-FID and FT-ICR MS: A pyrolysis fuel oil case study. Fuel Processing Technology 182, 15-25.Forsythe, J.C., Kenyon-Roberts, S., O'Donnell, M., Betancourt, S.S., Masurek, N., Gisolf, A., Bennett, B., Nelson, R.K., Canas, J.A., Reddy, C.M., Peters, K.E., Zuo, J.Y., Mullins, O.C., 2019. Biodegradation and water washing in a spill-fill sequence of oilfields. Fuel 237, 707-719.Kanaujia, P.K., 2018. Gas chromatography - Petroleum and petrochemical applications☆, Reference Module in Chemistry, Molecular Sciences and Chemical Engineering. Elsevier.Lee, D.-M., Lee, D.-H., Hwang, I.-H., 2018. Gasoline quality assessment using fast gas chromatography and partial least-squares regression for the detection of adulterated gasoline. Energy & Fuels 32, 10556-10562.Lje?evi?, M., Gojgi?-Cvijovi?, G., Ieda, T., Hashimoto, S., Nakano, T., Bulatovi?, S., Ili?, M., Be?koski, V., 2019. Biodegradation of the aromatic fraction from petroleum diesel fuel by Oerskovia sp. followed by comprehensive GC×GC-TOF MS. Journal of Hazardous Materials 363, 227-232.Maleki, S., Hashemi, P., Rasolzadeh, F., Maleki, S., Ghiasvand, A.R., 2018. A needle trap device packed with nanoporous silica sorbents for separation and gas chromatographic determination of polycyclic aromatic hydrocarbons in contaminated soils. Journal of Chromatographic Science 56, 771-778.Mohd Hassan, F.W., Muggundha, R., Kamaruzaman, S., Sanagi, M.M., Yoshida, N., Hirota, Y., Nishiyama, N., Yahaya, N., 2018. Dispersive liquid–liquid microextraction combined with dispersive solid-phase extraction for gas chromatography with mass spectrometry determination of polycyclic aromatic hydrocarbons in aqueous matrices. Journal of Separation Science 41, 3751-3763.Nhuchhen, D.R., Afzal, M.T., Dreise, T., Salema, A.A., 2018. Characteristics of biochar and bio-oil produced from wood pellets pyrolysis using a bench scale fixed bed, microwave reactor. Biomass and Bioenergy 119, 293-303.Santos, L.C., da Cruz, G.F., ?vila, B.M.F., Pereira, V.B., Azevedo, D.A., 2018. Exploratory analysis of Campos Basin crude oils via geochemical parameters by comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry. Energy & Fuels 32, 10321-10332.Stupak, M., Goodall, I., Tomaniova, M., Pulkrabova, J., Hajslova, J., 2018. A novel approach to assess the quality and authenticity of Scotch Whisky based on gas chromatography coupled to high resolution mass spectrometry. Analytica Chimica Acta 1042, 60-70.Imaging: AFM/STEMQiao, P., Harbottle, D., Li, Z., Tang, Y., Xu, Z., 2018. Interactions of asphaltene subfractions in organic media of varying aromaticity. Energy & Fuels 32, 10478-10485.Zhang, J., Liu, F., Yang, H., Zhu, Y., Wang, X., Hua, Z., 2018. Effect of ion type on the interaction between polar model oil and mica substrate: A chemical force microscopy study. Energy & Fuels 32, 10486-10492.Imaging: SEM, TEM, HIMChen, Q., You, L., Kang, Y., Dou, L., Sheng, J.J., 2018. Gypsum-crystallization-induced fracturing during shale–fluid reactions and application for shale stimulation. Energy & Fuels 32, 10367-10381.Cui, J., Liu, D., Cai, Y., Pan, Z., Zhou, Y., 2019. Insights into fractures and minerals in subbituminous and bituminous coals by FESEM-EDS and X-ray μ-CT. Fuel 237, 977-988.Fardi, T., Pintus, V., Kampasakali, E., Pavlidou, E., Schreiner, M., Kyriacou, G., 2018. Analytical characterization of artist’s paint systems based on emulsion polymers and synthetic organic pigments. Journal of Analytical and Applied Pyrolysis 135, 231-241.Gao, Z., Hu, Q., 2018. Pore structure and spontaneous imbibition characteristics of marine and continental shales in China. American Association of Petroleum Geologists Bulletin 102, 1941-1961.Gu, Y., Wan, Q., Yu, W., Li, X., Yu, Z., 2018. The effects of clay minerals and organic matter on nanoscale pores in Lower Paleozoic shale gas reservoirs, Guizhou, China. Acta Geochimica 37, 791-804.Hazra, B., Wood, D.A., Kumar, S., Saha, S., Dutta, S., Kumari, P., Singh, A.K., 2018. Fractal disposition, porosity characterization and relationships to thermal maturity for the Lower Permian Raniganj basin shales, India. Journal of Natural Gas Science and Engineering 59, 452-465.?nan, S., Al Badairy, H., ?nan, T., Al Zahrani, A., 2018. Formation and occurrence of organic matter-hosted porosity in shales. International Journal of Coal Geology 199, 39-51.Jiang, S., Mokhtari, M., 2019. Characterization of marl and interbedded limestone layers in the Eagle Ford Formation, DeWitt county, Texas. Journal of Petroleum Science and Engineering 172, 502-510.Jing, Z., Mahoney, S.A., Rodrigues, S., Balucan, R.D., Underschultz, J., Esterle, J.S., Rufford, T.E., Steel, K.M., 2018. A preliminary study of oxidant stimulation for enhancing coal seam permeability: Effects of sodium hypochlorite oxidation on subbituminous and bituminous Australian coals. International Journal of Coal Geology 200, 36-44.Karayi?it, A.?., Mastalerz, M., Oskay, R.G., Buzkan, ?., 2018. Bituminous coal seams from underground mines in the Zonguldak Basin (NW Turkey): Insights from mineralogy, coal petrography, Rock-Eval pyrolysis, and meso-and microporosity. International Journal of Coal Geology 199, 91-112.Keighley, D., Boonsue, S., Hall, D., 2018. Phosphatized tungsten-metabolizing coccoid microbes interpreted from oil shale of an Eocene lake, Green River Formation, Utah, USA. Geobiology 16, 610-627.Li, Z., Fu, Y., Zhou, A., Zhu, C., Yang, C., Shen, N., Yang, C., 2019. Effect of multi-intensification on the liberation of maceral components in coal. Fuel 237, 1003-1012.Liu, D., Li, H., Zhang, C., Wang, Q., Peng, P.a., 2019. Experimental investigation of pore development of the Chang 7 member shale in the Ordos basin under semi-closed high-pressure pyrolysis. Marine and Petroleum Geology 99, 17-26.Liu, Y., Zhu, Y., Chen, S., Wang, Y., Song, Y., 2018. Evaluation of spatial alignment of kerogen in shale using high-resolution transmission electron microscopy, Raman spectroscopy, and Fourier transform infrared. Energy & Fuels 32, 10616-10627.Maleki, S., Hashemi, P., Rasolzadeh, F., Maleki, S., Ghiasvand, A.R., 2018. A needle trap device packed with nanoporous silica sorbents for separation and gas chromatographic determination of polycyclic aromatic hydrocarbons in contaminated soils. Journal of Chromatographic Science 56, 771-778.McCutcheon, J., Southam, G., 2018. Advanced biofilm staining techniques for TEM and SEM in geomicrobiology: Implications for visualizing EPS architecture, mineral nucleation, and microfossil generation. Chemical Geology 498, 115-127.Piane, C.D., Bourdet, J., Josh, M., Clennell, M.B., Rickard, W.D.A., Saunders, M., Sherwood, N., Li, Z., Dewhurst, D.N., Raven, M.D., 2018. Organic matter network in post-mature Marcellus Shale: Effects on petrophysical properties. American Association of Petroleum Geologists Bulletin 102, 2239-2265.Ploeger, R., Shugar, A., Smith, G.D., Chen, V.J., 2019. Late 19th century accounts of Indian yellow: The analysis of samples from the Royal Botanic Gardens, Kew. Dyes and Pigments 160, 418-431.Qiu, Z., Zou, C., Li, X., Wang, H., Dong, D., Lu, B., Zhou, S., Shi, Z., Feng, Z., Zhang, M., 2018. Discussion on the contribution of graptolite to organic enrichment and gas?shale reservoir: A case study of the Wufeng–Longmaxi shales in South?China. Journal of Natural Gas Geoscience 3, 147-156.Rimington, W.R., Pressel, S., Duckett, J.G., Field, K.J., Read, D.J., Bidartondo, M.I., 2018. Ancient plants with ancient fungi: liverworts associate with early-diverging arbuscular mycorrhizal fungi. Proceedings of the Royal Society B: Biological Sciences 285, Article 20181600.Rüffel, V., Maar, M., Dammbrück, M.N., Haur?der, B., Neu, T.R., Meier, J., 2018. Thermodesulfobium sp. strain 3baa, an acidophilic sulfate reducing bacterium forming biofilms triggered by mineral precipitation. Environmental Microbiology 20, 3717-3731.Sui, W., Tian, Y., Yao, C., 2018. Investigation of microscopic pore structure variations of shale due to hydration effects through SEM fixed-point observation experiments. Petroleum Exploration and Development 45, 955-962.Sungatullin, R.K., Bakhtin, A.I., Tsel’movich, V.A., Bakhmutov, V.G., Sungatullina, G.M., 2018. Middle Paleozoic impact event in the southwest of the East European Platform. Russian Geology and Geophysics 59, 1149-1160.Thompson, M.S., Loeffler, M.J., Morris, R.V., Keller, L.P., Christoffersen, R., 2019. Spectral and chemical effects of simulated space weathering of the Murchison CM2 carbonaceous chondrite. Icarus 319, 499-511.Vollnhals, F., Wirtz, T., 2018. Correlative microscopy in 3D: Helium ion microscopy-based photogrammetric topography reconstruction combined with in situ secondary ion mass spectrometry. Analytical Chemistry 90, 11989–11995.Watteau, F., Villemin, G., 2018. Soil microstructures examined through transmission electron microscopy reveal soil-microorganisms interactions. Frontiers in Environmental Science 6, 106. doi: 110.3389/fenvs.2018.00106.You, L., Cheng, Q., Kang, Y., Chen, Q., Dou, L., Zhou, Y., 2018. Imbibition of oxidative fluid into organic-rich shale: Implication for oxidizing stimulation. Energy & Fuels 32, 10457-10468.Zhang, Y., He, Z., Jiang, S., Lu, S., Xiao, D., Chen, G., Li, Y., 2019. Fracture types in the lower Cambrian shale and their effect on shale gas accumulation, Upper Yangtze. Marine and Petroleum Geology 99, 282-291.Zhao, D., Guo, Y., Zhu, Y., Wang, G., Liu, J., Chong, X., Zhang, J., 2018. Micropore characteristics and geological significance of pyrite in shale rocks of Longmaxi Formation. Acta Sedimentologica Sinica 26, 864-876.Zhuo, X., Yan, Q., Zhang, J., Zhang, L., Chen, X., Ma, L., 2018. Conceptual models for correlation between detrital particles contents and pore distribution of shale: Taking the Silurian Longmaxi Formation in northwestern Guizhou as an example. Acta Sedimentologica Sinica 26, 969-980.Imaging: Xray CTChen, Q., You, L., Kang, Y., Dou, L., Sheng, J.J., 2018. Gypsum-crystallization-induced fracturing during shale–fluid reactions and application for shale stimulation. Energy & Fuels 32, 10367-10381.Cui, J., Liu, D., Cai, Y., Pan, Z., Zhou, Y., 2019. Insights into fractures and minerals in subbituminous and bituminous coals by FESEM-EDS and X-ray μ-CT. Fuel 237, 977-988.Gu, X., Pu, C., Khan, N., Wu, F., Huang, F., Xu, H., 2019. The visual and quantitative study of remaining oil micro-occurrence caused by spontaneous imbibition in extra-low permeability sandstone using computed tomography. Fuel 237, 152-162.Meyer, D.W., Flemings, P.B., DiCarlo, D., 2018. Effect of gas flow rate on hydrate formation within the hydrate stability zone. Journal of Geophysical Research: Solid Earth 123, 6263-6276.Sadeq, D., Iglauer, S., Lebedev, M., Rahman, T., Zhang, Y., Barifcani, A., 2018. Experimental pore-scale analysis of carbon dioxide hydrate in sandstone via X-Ray micro-computed tomography. International Journal of Greenhouse Gas Control 79, 73-82.Liquid Chromatography/LC-MS/SFCKing, A.C.F., Giorio, C., Wolff, E., Thomas, E., Karroca, O., Roverso, M., Schwikowski, M., Tapparo, A., Gambaro, A., Kalberer, M., 2019. A new method for the determination of primary and secondary terrestrial and marine biomarkers in ice cores using liquid chromatography high-resolution mass spectrometry. Talanta 194, 233-242.Langley, G.J., Herniman, J., Carter, A., Wilmot, E., Ashe, M., Barker, J., 2018. Detection and quantitation of ACCUTRACE S10, a new fiscal marker used in low-duty fuels, using a novel ultrahigh-performance supercritical fluid chromatography–mass spectrometry approach. Energy & Fuels 32, 10580-10585.Mallik, A.K., Qiu, H., Takafuji, M., Ihara, H., 2018. High molecular-shape-selective stationary phases for reversed-phase liquid chromatography: A review. TrAC Trends in Analytical Chemistry 108, 381-404.Venter, P., Muller, M., Vestner, J., Stander, M.A., Tredoux, A.G.J., Pasch, H., de Villiers, A., 2018. Comprehensive three-dimensional LC × LC × ion mobility spectrometry separation combined with high-resolution MS for the analysis of complex samples. Analytical Chemistry 90, 11643-11650.Mass Spectroscopy/ICR-FTMS/OrbitrapCasillo, A., Ziaco, M., Lindner, B., Parrilli, E., Schwudke, D., Holgado, A., Beyaert, R., Lanzetta, R., Tutino, M.L., Corsaro, M.M., 2018. Lipid A structural characterization from the LPS of the Siberian psychro-tolerant Psychrobacter arcticus 273-4 grown at low temperature. Extremophiles 22, 955-963.Djokic, M.R., Muller, H., Ristic, N.D., Akhras, A.R., Symoens, S.H., Marin, G.B., Van Geem, K.M., 2018. Combined characterization using HT-GC?×?GC-FID and FT-ICR MS: A pyrolysis fuel oil case study. Fuel Processing Technology 182, 15-25.Heidke, I., Scholz, D., Hoffmann, T., 2018. Quantification of lignin oxidation products as vegetation biomarkers in speleothems and cave drip water. Biogeosciences 15, 5831-5845.Kew, W., Mackay, C.L., Goodall, I., Clarke, D.J., Uhrín, D., 2018. Complementary ionization techniques for the analysis of Scotch whisky by high resolution mass spectrometry. Analytical Chemistry 90, 11265-11272.Lv, J., Miao, Y., Huang, Z., Han, R., Zhang, S., 2018. Facet-mediated adsorption and molecular fractionation of humic substances on hematite surfaces. Environmental Science & Technology 52, 11660-11669.Mitchell, J.M., Flight, R.M., Wang, Q.J., Higashi, R.M., Fan, T.W.-M., Lane, A.N., Moseley, H.N.B., 2018. New methods to identify high peak density artifacts in Fourier transform mass spectra and to mitigate their effects on high-throughput metabolomic data analysis. Metabolomics 14, 125.Neumann, E.K., Comi, T.J., Spegazzini, N., Mitchell, J.W., Rubakhin, S.S., Gillette, M.U., Bhargava, R., Sweedler, J.V., 2018. Multimodal chemical analysis of the brain by high mass resolution mass spectrometry and infrared spectroscopic imaging. Analytical Chemistry 90, 11572-11580.Ning, J., Wei, B., Mao, R., Wang, Y., Shang, J., Sun, L., 2018. Pore-level observations of an alkali-induced mild O/W emulsion flooding for economic enhanced oil recovery. Energy & Fuels 32, 10595-10604.Smith, R.K., Stacey, R.J., Bergstr?m, E., Thomas-Oates, J., 2018. Detection of opium alkaloids in a Cypriot base-ring juglet. Analyst 143, 5127-5136.Strife, R.J., Wang, Y., Kuehl, D., 2018. Restricted spectral accuracy analysis to identify the single correct organic compound elemental-composition from Orbitrap accurate mass data lists obtained at very high resolution. Journal of Mass Spectrometry 53, 921-926.Textor, S.R., Guillemette, F., Zito, P.A., Spencer, R.G.M., 2018. An assessment of dissolved organic carbon biodegradability and priming in blackwater systems. Journal of Geophysical Research: Biogeosciences 123, 2998-3015.Trimpin, S., Pophristic, M., Adeniji-Adele, A., Tomsho, J.W., McEwen, C.N., 2018. Vacuum matrix-assisted ionization source offering simplicity, sensitivity, and exceptional robustness in mass spectrometry. Analytical Chemistry 90, 11188-11192.Zheng, F., Hsu, C.S., Zhang, Y., Sun, Y., Wu, Y., Lu, H., Sun, X., Shi, Q., 2018. Simultaneous detection of vanadyl, nickel, iron, and gallium porphyrins in marine shales from the Eagle Ford Formation, South Texas. Energy & Fuels 32, 10382-10390.Mass Spectroscopy/OtherJiang, H.-X., Li, J., Tang, J., Mo, Y.-Z., Zhang, G., 2018. Applications of high-resolution mass spectrometry in studies of brown carbon. Chinese Journal of Analytical Chemistry 46, 1528-1538.Kim, D., Lee, J., Kim, B., Kim, S., 2018. Optimization and application of paper-based spray ionization mass spectrometry for analysis of natural organic matter. Analytical Chemistry 90, 12027-12034.Novák, J., ?kríba, A., Zápal, J., Kuzma, M., Havlí?ek, V., 2018. CycloBranch: An open tool for fine isotope structures in conventional and product ion mass spectra. Journal of Mass Spectrometry 53, 1097-1103.Sero, R., Vidal, M., Bosch, J., Rodríguez, P., Galceran, M.T., Moyano, E., 2019. Desorption electrospray ionization-high resolution mass spectrometry for the analysis of unknown materials: the phytosanitary product case. Talanta 194, 350-356.Trindade, G.F., Abel, M.-L., Watts, J.F., 2018. simsMVA: A tool for multivariate analysis of ToF-SIMS datasets. Chemometrics and Intelligent Laboratory Systems 182, 180-187.Vikse, K.L., McIndoe, J.S., 2018. Ionization methods for the mass spectrometry of organometallic compounds. Journal of Mass Spectrometry 53, 1026-1034.Vollnhals, F., Wirtz, T., 2018. Correlative microscopy in 3D: Helium ion microscopy-based photogrammetric topography reconstruction combined with in situ secondary ion mass spectrometry. Analytical Chemistry 90, 11989–11995.Yang, J., Norris, J.L., Caprioli, R., 2018. Novel vacuum stable ketone-based matrices for high spatial resolution MALDI imaging mass spectrometry. Journal of Mass Spectrometry 53, 1005-1012.Zheng, X., Dupuis, K.T., Aly, N.A., Zhou, Y., Smith, F.B., Tang, K., Smith, R.D., Baker, E.S., 2018. Utilizing ion mobility spectrometry and mass spectrometry for the analysis of polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polybrominated diphenyl ethers and their metabolites. Analytica Chimica Acta 1037, 265-273.Metabolomics/LipidomicsAsakura, T., Date, Y., Kikuchi, J., 2018. Application of ensemble deep neural network to metabolomics studies. Analytica Chimica Acta 1037, 230-236.Aszyk, J., Byliński, H., Namie?nik, J., Kot-Wasik, A., 2018. Main strategies, analytical trends and challenges in LC-MS and ambient mass spectrometry–based metabolomics. TrAC Trends in Analytical Chemistry 108, 278-295.Cui, L., Lu, H., Lee, Y.H., 2018. Challenges and emergent solutions for LC-MS/MS based untargeted metabolomics in diseases. Mass Spectrometry Reviews 37, 772-792.de Souza, J.R.B., Dias, F.F.G., Caliman, J.D., Augusto, F., Hantao, L.W., 2018. Opportunities for green microextractions in comprehensive two-dimensional gas chromatography / mass spectrometry-based metabolomics – A review. Analytica Chimica Acta 1040, 1-18.Do, K.T., Wahl, S., Raffler, J., Molnos, S., Laimighofer, M., Adamski, J., Suhre, K., Strauch, K., Peters, A., Gieger, C., Langenberg, C., Stewart, I.D., Theis, F.J., Grallert, H., Kastenmüller, G., Krumsiek, J., 2018. Characterization of missing values in untargeted MS-based metabolomics data and evaluation of missing data handling strategies. Metabolomics 14, 128.Dubois, V., Viljoen, A., Laencina, L., Le Moigne, V., Bernut, A., Dubar, F., Blaise, M., Gaillard, J.-L., Guérardel, Y., Kremer, L., Herrmann, J.-L., Girard-Misguich, F., 2018. MmpL8MAB controls Mycobacterium abscessus virulence and production of a previously unknown glycolipid family. Proceedings of the National Academy of Sciences 115, E10147-E10156.Gao, Y., Chen, Y., Yue, X., He, J., Zhang, R., Xu, J., Zhou, Z., Wang, Z., Zhang, R., Abliz, Z., 2018. Development of simultaneous targeted metabolite quantification and untargeted metabolomics strategy using dual-column liquid chromatography coupled with tandem mass spectrometry. Analytica Chimica Acta 1037, 369-379.Ghosh, D., Bhadury, P., Routh, J., 2018. Coping with arsenic stress: Adaptations of arsenite-oxidizing bacterial membrane lipids to increasing arsenic levels. MicrobiologyOpen 7, Article e00594.Harwood, C.R., Mouillon, J.-M., Pohl, S., Arnau, J., 2018. Secondary metabolite production and the safety of industrially important members of the Bacillus subtilis group. FEMS Microbiology Reviews 42, 721-738.La Barbera, G., Antonelli, M., Cavaliere, C., Cruciani, G., Goracci, L., Montone, C.M., Piovesana, S., Laganà, A., Capriotti, A.L., 2018. Delving into the polar lipidome by optimized chromatographic separation, high-resolution mass spectrometry, and comprehensive identification with Lipostar: Microalgae as case study. Analytical Chemistry 90, 12230–12238.Li, Y., Li, L., 2018. Improving accuracy of peak-pair intensity ratio measurement in differential chemical isotope labeling LC–MS for quantitative metabolomics. International Journal of Mass Spectrometry 434, 202-208.Lindon, J.C., Nicholson, J.K., Holmes, E., 2019. The Handbook of Metabolic Phenotyping. Elsevier, p. 619.Liu, X., Xu, G., 2018. Recent advances in using mass spectrometry for mitochondrial metabolomics and lipidomics - A review. Analytica Chimica Acta 1037, 3-12.Mitchell, J.M., Flight, R.M., Wang, Q.J., Higashi, R.M., Fan, T.W.-M., Lane, A.N., Moseley, H.N.B., 2018. New methods to identify high peak density artifacts in Fourier transform mass spectra and to mitigate their effects on high-throughput metabolomic data analysis. Metabolomics 14, 125.Nierop, K.G.J., Brouwer, P., Dekker, R., Schluepmann, H., Reichart, G.-J., 2018. ω20-Hydroxy and ω9,ω10-dihydroxy biomarker lipids in ferns from the Salviniaceae family. Organic Geochemistry 125, 229-242.Peisl, B.Y.L., Schymanski, E.L., Wilmes, P., 2018. Dark matter in host-microbiome metabolomics: Tackling the unknowns–A review. Analytica Chimica Acta 1037, 13-27.Qiu, F., Lei, Z., Sumner, L.W., 2018. MetExpert: An expert system to enhance gas chromatography?mass spectrometry-based metabolite identifications. Analytica Chimica Acta 1037, 316-326.Salvatore, M.M., Nicoletti, R., Salvatore, F., Naviglio, D., Andolfi, A., 2018. GC–MS approaches for the screening of metabolites produced by marine-derived Aspergillus. Marine Chemistry 206, 19-33.Silva, A.S.C., Palmer, A., Kovalev, V., Tarasov, A., Alexandrov, T., Martens, L., Degroeve, S., 2018. Data-driven rescoring of metabolite annotations significantly improves sensitivity. Analytical Chemistry 90, 11636-11642.Sivaram, A.K., Subashchandrabose, S.R., Logeshwaran, P., Lockington, R., Naidu, R., Megharaj, M., 2019. Metabolomics reveals defensive mechanisms adapted by maize on exposure to high molecular weight polycyclic aromatic hydrocarbons. Chemosphere 214, 771-780.Sostare, J., Di Guida, R., Kirwan, J., Chalal, K., Palmer, E., Dunn, W.B., Viant, M.R., 2018. Comparison of modified Matyash method to conventional solvent systems for polar metabolite and lipid extractions. Analytica Chimica Acta 1037, 301-315.Tian, X., Zhang, G., Shao, Y., Yang, Z., 2018. Towards enhanced metabolomic data analysis of mass spectrometry image: Multivariate Curve Resolution and Machine Learning. Analytica Chimica Acta 1037, 211-219.Ulmer, C.Z., Jones, C.M., Yost, R.A., Garrett, T.J., Bowden, J.A., 2018. Optimization of Folch, Bligh-Dyer, and Matyash sample-to-extraction solvent ratios for human plasma-based lipidomics studies. Analytica Chimica Acta 1037, 351-357.Zheng, X., Dupuis, K.T., Aly, N.A., Zhou, Y., Smith, F.B., Tang, K., Smith, R.D., Baker, E.S., 2018. Utilizing ion mobility spectrometry and mass spectrometry for the analysis of polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polybrominated diphenyl ethers and their metabolites. Analytica Chimica Acta 1037, 265-273.Zhong, F., Xu, M., Metz, P., Ghosh-Dastidar, P., Zhu, J., 2018. A quantitative metabolomics study of bacterial metabolites in different domains. Analytica Chimica Acta 1037, 237-244.PuppyomicsDeane-Coe, P.E., Chu, E.T., Slavney, A., Boyko, A.R., Sams, A.J., 2018. Direct-to-consumer DNA testing of 6,000 dogs reveals 98.6-kb duplication associated with blue eyes and heterochromia in Siberian Huskies. PLOS Genetics 14, Article e1007648.Prichard, A., Cook, P.F., Spivak, M., Chhibber, R., Berns, G.S., 2018. Awake fMRI reveals brain regions for novel word detection in dogs. Frontiers in Neuroscience 12, 737. doi: 710.3389/fnins.2018.00737.Archaeological/Art Organic ChemistryCersoy, S., Daheur, G., Zazzo, A., Zirah, S., Sablier, M., 2018. Pyrolysis comprehensive gas chromatography and mass spectrometry: A new tool to assess the purity of ancient collagen prior to radiocarbon dating. Analytica Chimica Acta 1041, 131-145.Fardi, T., Pintus, V., Kampasakali, E., Pavlidou, E., Schreiner, M., Kyriacou, G., 2018. Analytical characterization of artist’s paint systems based on emulsion polymers and synthetic organic pigments. Journal of Analytical and Applied Pyrolysis 135, 231-241.Goude, G., Clarke, J., Webb, J.M., Frankel, D., Georgiou, G., Herrscher, E., Lorentz, K.O., 2018. Exploring the potential of human bone and teeth collagen from Prehistoric Cyprus for isotopic analysis. Journal of Archaeological Science: Reports 22, 115-122.Hendy, J., Colonese, A.C., Franz, I., Fernandes, R., Fischer, R., Orton, D., Lucquin, A., Spindler, L., Anvari, J., Stroud, E., Biehl, P.F., Speller, C., Boivin, N., Mackie, M., Jersie-Christensen, R.R., Olsen, J.V., Collins, M.J., Craig, O.E., Rosenstock, E., 2018. Ancient proteins from ceramic vessels at ?atalh?yük West reveal the hidden cuisine of early farmers. Nature Communications 9, Article 4064.Karakasidou, K., Nikolouli, K., Amoutzias, G.D., Pournou, A., Manassis, C., Tsiamis, G., Mossialos, D., 2018. Microbial diversity in biodeteriorated Greek historical documents dating back to the 19th and 20th century: A case study. MicrobiologyOpen 7, e00596.Mamede, A.P., Vassalo, A.R., Piga, G., Cunha, E., Parker, S.F., Marques, M.P.M., Batista de Carvalho, L.A.E., Gon?alves, D., 2018. Potential of bioapatite hydroxyls for research on archeological burned bone. Analytical Chemistry 90, 11556-11563.Mazow, L.B., Mitra, S., Kimmel, D.G., Grieve, S., 2018. Extraction and analysis of total lipids in late Iron Age bath-shaped basins from the Levant as a means of assessing vessel function. Journal of Archaeological Science: Reports 22, 193-201.Ploeger, R., Shugar, A., Smith, G.D., Chen, V.J., 2019. Late 19th century accounts of Indian yellow: The analysis of samples from the Royal Botanic Gardens, Kew. Dyes and Pigments 160, 418-431.Robinson, J.R., Wadley, L., 2018. Stable isotope evidence for (mostly) stable local environments during the South African Middle Stone Age from Sibudu, KwaZulu-Natal. Journal of Archaeological Science 100, 32-44.Smith, R.K., Stacey, R.J., Bergstr?m, E., Thomas-Oates, J., 2018. Detection of opium alkaloids in a Cypriot base-ring juglet. Analyst 143, 5127-5136.Waters, M.R., Keene, J.L., Forman, S.L., Prewitt, E.R., Carlson, D.L., Wiederhold, J.E., 2018. Pre-Clovis projectile points at the Debra L. Friedkin site, Texas—Implications for the Late Pleistocene peopling of the Americas. Science Advances 4, Article eaat4505.Wu, M., Zhang, B., Jiang, L., Wu, J., Sun, G., 2018. Natural lacquer was used as a coating and an adhesive 8000 years ago, by early humans at Kuahuqiao, determined by ELISA. Journal of Archaeological Science 100, 80-87.BiochemistryCasillo, A., Ziaco, M., Lindner, B., Parrilli, E., Schwudke, D., Holgado, A., Beyaert, R., Lanzetta, R., Tutino, M.L., Corsaro, M.M., 2018. Lipid A structural characterization from the LPS of the Siberian psychro-tolerant Psychrobacter arcticus 273-4 grown at low temperature. Extremophiles 22, 955-963.Ghosh, D., Bhadury, P., Routh, J., 2018. Coping with arsenic stress: Adaptations of arsenite-oxidizing bacterial membrane lipids to increasing arsenic levels. MicrobiologyOpen 7, Article e00594.Johnson, T.B., Mach, C., Grove, R., Kelly, R., Van Cott, K., Blum, P., 2018. Secretion and fusion of biogeochemically active archaeal membrane vesicles. Geobiology 16, 659-673.Nierop, K.G.J., Brouwer, P., Dekker, R., Schluepmann, H., Reichart, G.-J., 2018. ω20-Hydroxy and ω9,ω10-dihydroxy biomarker lipids in ferns from the Salviniaceae family. Organic Geochemistry 125, 229-242.Picone, N., Op den Camp, H.J.M., 2019. Role of rare earth elements in methanol oxidation. Current Opinion in Chemical Biology 49, 39-44.Salway, J.G., 2018. The Krebs uric acid cycle: A forgotten Krebs Cycle. Trends in Biochemical Sciences 43, 847-849.Tobimatsu, Y., Schuetz, M., 2019. Lignin polymerization: how do plants manage the chemistry so well? Current Opinion in Biotechnology 56, 75-81.BiodegradationArnosti, C., Reintjes, G., Amann, R., 2018. A mechanistic microbial underpinning for the size-reactivity continuum of dissolved organic carbon degradation. Marine Chemistry 206, 93-99.Chen, S., Zhao, C., Liu, Q., Zang, M., Liu, C., Zhang, Y., 2018. Thermophilic biodesulfurization and its application in oil desulfurization. Applied Microbiology and Biotechnology 102, 9089-9103.Cheng, G., Sun, L., Fu, J., 2018. Prediction of biodegradability for polycyclic aromatic hydrocarbons using various in silico modeling methods. Archives of Environmental Contamination and Toxicology 75, 607-615.Himmelberg, A.M., Brüls, T., Farmani, Z., Weyrauch, P., Barthel, G., Schrader, W., Meckenstock, R.U., 2018. Anaerobic degradation of phenanthrene by a sulfate-reducing enrichment culture. Environmental Microbiology 20, 3589-3600.Liao, X., Wu, Z., Li, Y., Luo, J., Su, C., 2018. Enhanced degradation of polycyclic aromatic hydrocarbons by indigenous microbes combined with chemical oxidation. Chemosphere 213, 551-558.Lje?evi?, M., Gojgi?-Cvijovi?, G., Ieda, T., Hashimoto, S., Nakano, T., Bulatovi?, S., Ili?, M., Be?koski, V., 2019. Biodegradation of the aromatic fraction from petroleum diesel fuel by Oerskovia sp. followed by comprehensive GC×GC-TOF MS. Journal of Hazardous Materials 363, 227-232.Mao, R., Li, S., 2019. Temporal controls on dissolved organic carbon biodegradation in subtropical rivers: Initial chemical composition versus stoichiometry. Science of The Total Environment 651, 3064-3069.Textor, S.R., Guillemette, F., Zito, P.A., Spencer, R.G.M., 2018. An assessment of dissolved organic carbon biodegradability and priming in blackwater systems. Journal of Geophysical Research: Biogeosciences 123, 2998-3015.Xu, D., Zhang, K., Li, B.-G., Mbadinga, S.M., Zhou, L., Liu, J.-F., Yang, S.-Z., Gu, J.-D., Mu, B.-Z., 2019. Simulation of in situ oil reservoir conditions in a laboratory bioreactor testing for methanogenic conversion of crude oil and analysis of the microbial community. International Biodeterioration & Biodegradation 136, 24-33.Xu, R., Zhang, K., Liu, P., Han, H., Zhao, S., Kakade, A., Khan, A., Du, D., Li, X., 2018. Lignin depolymerization and utilization by bacteria. Bioresource Technology 269, 557-566.Yu, L., Lu, Q., Qiu, L., Xu, G., Zeng, Y., Luo, X., Wang, S., Mai, B., 2018. Enantioselective dechlorination of polychlorinated biphenyls in Dehalococcoides mccartyi CG1. Applied and Environmental Microbiology 84, Article e01300-01318.Biodegradation Pathways/GenomicsRen, L., Jia, Y., Zhang, R., Lin, Z., Zhen, Z., Hu, H., Yan, Y., 2018. Insight into metabolic versatility of an aromatic compounds-degrading Arthrobacter sp. YC-RL1. Frontiers in Microbiology 9, 2438. doi: 2410.3389/fmicb.2018.02438.Wang, W., Wang, L., Shao, Z., 2018. Polycyclic aromatic hydrocarbon (PAH) degradation pathways of the obligate marine PAH degrader Cycloclasticus sp. Strain P1. Applied and Environmental Microbiology 84, Article e01261-01218.Zavarzina, A.G., Lisov, A.V., Leontievsky, A.A., 2018. The role of ligninolytic enzymes laccase and a versatile peroxidase of the white-rot fungus Lentinus tigrinus in biotransformation of soil humic matter: Comparative in vivo study. Journal of Geophysical Research: Biogeosciences 123, 2727-2742.Biofuels/BiomassArranz-Gibert, P., Vanderschuren, K., Isaacs, F.J., 2018. Next-generation genetic code expansion. Current Opinion in Chemical Biology 46, 203-211.Dien, V.T., Morris, S.E., Karadeema, R.J., Romesberg, F.E., 2018. Expansion of the genetic code via expansion of the genetic alphabet. Current Opinion in Chemical Biology 46, 196-202.Harwood, C.R., Mouillon, J.-M., Pohl, S., Arnau, J., 2018. Secondary metabolite production and the safety of industrially important members of the Bacillus subtilis group. FEMS Microbiology Reviews 42, 721-738.Kumar, V., Binod, P., Sindhu, R., Gnansounou, E., Ahluwalia, V., 2018. Bioconversion of pentose sugars to value added chemicals and fuels: Recent trends, challenges and possibilities. Bioresource Technology 269, 443-451.Li, F., Zhang, X., Renata, H., 2019. Enzymatic C–H functionalizations for natural product synthesis. Current Opinion in Chemical Biology 49, 25-32.Li, M., Liu, D., Cong, X.-S., Chen, Q.-T., Shi, N., Wu, J.-H., Yang, Y.-X., Zhang, X.-B., Wu, C.-C., 2018. Isolation and identification of six difunctional ethyl esters from bio-oil and their special mass spectral fragmentation pathways. Energy & Fuels 32, 10649-10655.Nhuchhen, D.R., Afzal, M.T., Dreise, T., Salema, A.A., 2018. Characteristics of biochar and bio-oil produced from wood pellets pyrolysis using a bench scale fixed bed, microwave reactor. Biomass and Bioenergy 119, 293-303.Sekoai, P.T., Ouma, C.N.M., du Preez, S.P., Modisha, P., Engelbrecht, N., Bessarabov, D.G., Ghimire, A., 2019. Application of nanoparticles in biofuels: An overview. Fuel 237, 380-397.Singh, N., Choudhury, B., 2018. Potential of Lentibacillus sp. NS12IITR for production of lipids with enriched branched-chain fatty acids for improving biodiesel properties along with hydrocarbon co-production. Extremophiles 22, 865-875.Xu, R., Zhang, K., Liu, P., Han, H., Zhao, S., Kakade, A., Khan, A., Du, D., Li, X., 2018. Lignin depolymerization and utilization by bacteria. Bioresource Technology 269, 557-566.BiogeochemistryAlcamán-Arias, M.E., Pedrós-Alió, C., Tamames, J., Fernández, C., Pérez-Pantoja, D., Vásquez, M., Díez, B., 2018. Diurnal changes in active carbon and nitrogen pathways along the temperature gradient in Porcelana hot spring microbial mat. Frontiers in Microbiology 9, 2353. doi: 2310.3389/fmicb.2018.02353.Arnosti, C., Reintjes, G., Amann, R., 2018. A mechanistic microbial underpinning for the size-reactivity continuum of dissolved organic carbon degradation. Marine Chemistry 206, 93-99.Bryce, C., Blackwell, N., Schmidt, C., Otte, J., Huang, Y.-M., Kleindienst, S., Tomaszewski, E., Schad, M., Warter, V., Peng, C., Byrne, J.M., Kappler, A., 2018. Microbial anaerobic Fe(II) oxidation – Ecology, mechanisms and environmental implications. Environmental Microbiology 20, 3462-3483.Chaignaud, P., Morawe, M., Besaury, L., Kr?ber, E., Vuilleumier, S., Bringel, F., Kolb, S., 2018. Methanol consumption drives the bacterial chloromethane sink in a forest soil. The ISME Journal 12, 2681-2693.Currie, B., Utne-Palm, A.C., Salvanes, A.G.V., 2018. Winning ways with hydrogen sulphide on the Namibian Shelf. Frontiers in Marine Science 5, 341. doi: 310.3389/fmars.2018.00341.Dulaquais, G., Waeles, M., Gerringa, L.J.A., Middag, R., Rijkenberg, M.J.A., Riso, R., 2018. The biogeochemistry of electroactive humic substances and its connection to iron chemistry in the North East Atlantic and the Western Mediterranean Sea. Journal of Geophysical Research: Oceans 123, 5481-5499.Ghosh, D., Bhadury, P., Routh, J., 2018. Coping with arsenic stress: Adaptations of arsenite-oxidizing bacterial membrane lipids to increasing arsenic levels. MicrobiologyOpen 7, Article e00594.Hu, S.K., Connell, P.E., Mesrop, L.Y., Caron, D.A., 2018. A hard day's night: Diel shifts in microbial eukaryotic activity in the North Pacific subtropical gyre. Frontiers in Marine Science 5, 351. doi: 310.3389/fmars.2018.00351.Hu, X., Liu, J., Liu, H., Zhuang, G., Xun, L., 2018. Sulfur metabolism by marine heterotrophic bacteria involved in sulfur cycling in the ocean. Science China Earth Sciences 61, 1369-1378.Johnson, T.B., Mach, C., Grove, R., Kelly, R., Van Cott, K., Blum, P., 2018. Secretion and fusion of biogeochemically active archaeal membrane vesicles. Geobiology 16, 659-673.Koebsch, F., Winkel, M., Liebner, S., Liu, B., Westphal, J., Schmiedinger, I., Spitzy, A., Gehre, M., Jurasinski, G., K?hler, S., Unger, V., Koch, M., Sachs, T., B?ttcher, M.E., 2018. Sulfate deprivation triggers high methane production in a disturbed and rewetted coastal peatland. Biogeosciences Discussions 2018, 1-37.Li, X., Gao, D., Hou, L., Liu, M., 2019. Salinity stress changed the biogeochemical controls on CH4 and N2O emissions of estuarine and intertidal sediments. Science of The Total Environment 652, 593-601.Lindsay, M.R., Amenabar, M.J., Fecteau, K.M., Debes, R.V., Fernandes Martins, M.C., Fristad, K.E., Xu, H., Hoehler, T.M., Shock, E.L., Boyd, E.S., 2018. Subsurface processes influence oxidant availability and chemoautotrophic hydrogen metabolism in Yellowstone hot springs. Geobiology 16, 674-692.Muller, F.L.L., 2018. Exploring the potential role of terrestrially derived humic substances in the marine biogeochemistry of iron. Frontiers in Earth Science 6, 159. doi: 110.3389/feart.2018.00159.Smith, H.J., Zelaya, A.J., De?León, K.B., Chakraborty, R., Elias, D.A., Hazen, T.C., Arkin, A.P., Cunningham, A.B., Fields, M.W., 2018. Impact of hydrologic boundaries on microbial planktonic and biofilm communities in shallow terrestrial subsurface environments. FEMS Microbiology Ecology 94, Article fiy191.Sorokin, D.Y., Messina, E., La Cono, V., Ferrer, M., Ciordia, S., Mena, M.C., Toshchakov, S.V., Golyshin, P.N., Yakimov, M.M., 2018. Sulfur respiration in a group of facultatively anaerobic natronoarchaea ubiquitous in hypersaline soda lakes. Frontiers in Microbiology 9, 2359. doi: 2310.3389/fmicb.2018.02359.Stamps, B.W., Nunn, H.S., Petryshyn, V.A., Oremland, R.S., Miller, L.G., Rosen, M.R., Bauer, K.W., Thompson, K.J., Tookmanian, E.M., Waldeck, A.R., Loyd, S.J., Johnson, H.A., Stevenson, B.S., Berelson, W.M., Corsetti, F.A., Spear, J.R., 2018. Metabolic capability and phylogenetic diversity of Mono Lake during a bloom of the eukaryotic phototroph Picocystis sp. Strain ML. Applied and Environmental Microbiology 84, Article e01171-01118.Tarnovetskii, I.Y., Merkel, A.Y., Kanapatskiy, T.A., Ivanova, E.A., Gulin, M.B., Toshchakov, S., Pimenov, N.V., 2018. Decoupling between sulfate reduction and the anaerobic oxidation of methane in the shallow methane seep of the Black sea. FEMS Microbiology Letters 365, Article fny235.Taylor, M.A., Celis, G., Ledman, J.D., Bracho, R., Schuur, E.A.G., 2018. Methane efflux measured by eddy covariance in Alaskan upland tundra undergoing permafrost degradation. Journal of Geophysical Research: Biogeosciences 123, 2695-2710.Valenzuela, E.I., Avenda?o, K.A., Balagurusamy, N., Arriaga, S., Nieto-Delgado, C., Thalasso, F., Cervantes, F.J., 2019. Electron shuttling mediated by humic substances fuels anaerobic methane oxidation and carbon burial in wetland sediments. Science of The Total Environment 650, 2674-2684.Vallino, J.J., Huber, J.A., 2018. Using maximum entropy production to describe microbial biogeochemistry over time and space in a meromictic pond. Frontiers in Environmental Science 6, 100. doi: 110.3389/fenvs.2018.00100.Biofilm/Microbial Induced CorrosionChiellini, C., Miceli, E., Bacci, G., Fagorzi, C., Coppini, E., Fibbi, D., Bianconi, G., Mengoni, A., Canganella, F., Fani, R., 2018. Spatial structuring of bacterial communities in epilithic biofilms in the Acquarossa river (Italy). FEMS Microbiology Ecology 94, Article fiy181.Grzegorczyk, M., Pogorzelski, S.J., Pospiech, A., Boniewicz-Szmyt, K., 2018. Monitoring of marine biofilm formation dynamics at submerged solid surfaces with multitechnique sensors. Frontiers in Marine Science 5, 363. doi: 310.3389/fmars.2018.00363.Makama, Z., Celikkol, S., Ogawa, A., Gaylarde, C., Beech, I., 2018. The issue with using DNA profiling as a sole method for investigating the role of marine biofilms in corrosion of metallic materials. International Biodeterioration & Biodegradation 135, 33-38.McCutcheon, J., Southam, G., 2018. Advanced biofilm staining techniques for TEM and SEM in geomicrobiology: Implications for visualizing EPS architecture, mineral nucleation, and microfossil generation. Chemical Geology 498, 115-127.Moura, V., Ribeiro, I., Moriggi, P., Cap?o, A., Salles, C., Bitati, S., Procópio, L., 2018. The influence of surface microbial diversity and succession on microbiologically influenced corrosion of steel in a simulated marine environment. Archives of Microbiology 200, 1447-1456.R?der, H.L., Herschend, J., Russel, J., Andersen, M.F., Madsen, J.S., S?rensen, S.J., Burm?lle, M., 2018. Enhanced bacterial mutualism through an evolved biofilm phenotype. The ISME Journal 12, 2608-2618.Rüffel, V., Maar, M., Dammbrück, M.N., Haur?der, B., Neu, T.R., Meier, J., 2018. Thermodesulfobium sp. strain 3baa, an acidophilic sulfate reducing bacterium forming biofilms triggered by mineral precipitation. Environmental Microbiology 20, 3717-3731.Smith, H.J., Zelaya, A.J., De?León, K.B., Chakraborty, R., Elias, D.A., Hazen, T.C., Arkin, A.P., Cunningham, A.B., Fields, M.W., 2018. Impact of hydrologic boundaries on microbial planktonic and biofilm communities in shallow terrestrial subsurface environments. FEMS Microbiology Ecology 94, Article fiy191.Microbial Mediation of Mineral Formation/DegradationDopffel, N., K?gler, F., Hartmann, H., Costea, P.I., Mahler, E., Herold, A., Alkan, H., 2018. Microbial induced mineral precipitations caused by nitrate treatment for souring control during microbial enhanced oil recovery (MEOR). International Biodeterioration & Biodegradation 135, 71-79.Geerlings, N.M.J., Zetsche, E.-M., Martinez, S.H., Middelburg, J.J., Meysman, F.J.R., 2018. Mineral formation induced by cable bacteria performing long-distance electron transport in marine sediments. Biogeosciences Discussions 2018, 1-25.Nudelman, H., Lee, Y.-Z., Hung, Y.-L., Kolusheva, S., Upcher, A., Chen, Y.-C., Chen, J.-Y., Sue, S.-C., Zarivach, R., 2018. Understanding the biomineralization role of magnetite-interacting components (MICs) from magnetotactic bacteria. Frontiers in Microbiology 9, 2480. doi: 2410.3389/fmicb.2018.02480.Rüffel, V., Maar, M., Dammbrück, M.N., Haur?der, B., Neu, T.R., Meier, J., 2018. Thermodesulfobium sp. strain 3baa, an acidophilic sulfate reducing bacterium forming biofilms triggered by mineral precipitation. Environmental Microbiology 20, 3717-3731.Sajjad, W., Zheng, G., Zhang, G., Ma, X., Xu, W., Khan, S., 2018. Bioleaching of copper- and zinc-bearing ore using consortia of indigenous iron-oxidizing bacteria. Extremophiles 22, 851-863.Carbon CycleChen, X., Zhang, F., Lao, Y., Wang, X., Du, J., Santos, I.R., 2018. Submarine groundwater discharge-derived carbon fluxes in mangroves: An important component of blue carbon budgets? Journal of Geophysical Research: Oceans 123, 6962-6979.Denfeld, B.A., Klaus, M., Laudon, H., Sponseller, R.A., Karlsson, J., 2018. Carbon dioxide and methane dynamics in a small boreal lake during winter and spring melt events. Journal of Geophysical Research: Biogeosciences 123, 2527-2540.Martínez-Mena, M., Almagro, M., García-Franco, N., de Vente, J., García, E., Fayos, C.B., 2018. Fluvial sedimentary deposits as carbon sinks: organic carbon pools and stabilization mechanisms across a Mediterranean catchment. Biogeosciences Discussions 2018, 1-32.Moore III, B., Crowell, S.M.R., Rayner, P.J., Kumer, J., O'Dell, C.W., O'Brien, D., Utembe, S., Polonsky, I., Schimel, D., Lemen, J., 2018. The potential of the Geostationary Carbon Cycle Observatory (GeoCarb) to provide multi-scale constraints on the carbon cycle in the Americas. Frontiers in Environmental Science 6, 109. doi: 110.3389/fenvs.2018.00109.Stephens, B.M., Porrachia, M., Dovel, S., Roadman, M., Goericke, R., Aluwihare, L.I., 2018. Nonsinking organic matter production in the California Current. Global Biogeochemical Cycles 32, 1386-1405.Wan, J., Tokunaga, T.K., Dong, W., Williams, K.H., Kim, Y., Conrad, M.E., Bill, M., Riley, W.J., Hubbard, S.S., 2018. Deep unsaturated zone contributions to carbon cycling in semiarid environments. Journal of Geophysical Research: Biogeosciences 123, 3045-3054.Wan, X., Xiang, W., Wan, N., Yan, S., Bao, Z., Wang, Y., 2018. Complexation and reduction of iron by phenolic substances: Implications for transport of dissolved Fe from peatlands to aquatic ecosystems and global iron cycling. Chemical Geology 498, 128-138.Zhang, X., Lin, H., Wang, X., Austin, B., 2018. Significance of Vibrio species in the marine organic carbon cycle—A review. Science China Earth Sciences 61, 1357-1368.Carbon SequestrationChen, M., Park, M., Kim, J.-H., Shinn, Y.J., Lee, Y.K., Hur, J., 2018. Exploring pore water biogeochemical characteristics as environmental monitoring proxies for a CO2 storage project in Pohang Basin, South Korea. Marine Pollution Bulletin 137, 331-338.Jahediesfanjani, H., Warwick, P.D., Anderson, S.T., 2018. Estimating the pressure-limited CO2 injection and storage capacity of the United States saline formations: Effect of the presence of hydrocarbon reservoirs. International Journal of Greenhouse Gas Control 79, 14-24.Climate ChangeKoll, D.D.B., Cronin, T.W., 2018. Earth’s outgoing longwave radiation linear due to H2O greenhouse effect. Proceedings of the National Academy of Sciences 115, 10293.Ormes, J.F., 2018. Cosmic rays and climate. Advances in Space Research 62, 2880-2891.Rae, J.W.B., Burke, A., Robinson, L.F., Adkins, J.F., Chen, T., Cole, C., Greenop, R., Li, T., Littley, E.F.M., Nita, D.C., Stewart, J.A., Taylor, B.J., 2018. CO2 storage and release in the deep Southern Ocean on millennial to centennial timescales. Nature 562, 569-573.Taylor, M.A., Celis, G., Ledman, J.D., Bracho, R., Schuur, E.A.G., 2018. Methane efflux measured by eddy covariance in Alaskan upland tundra undergoing permafrost degradation. Journal of Geophysical Research: Biogeosciences 123, 2695-2710.Tzedakis, P.C., Drysdale, R.N., Margari, V., Skinner, L.C., Menviel, L., Rhodes, R.H., Taschetto, A.S., Hodell, D.A., Crowhurst, S.J., Hellstrom, J.C., Fallick, A.E., Grimalt, J.O., McManus, J.F., Martrat, B., Mokeddem, Z., Parrenin, F., Regattieri, E., Roe, K., Zanchetta, G., 2018. Enhanced climate instability in the North Atlantic and southern Europe during the Last Interglacial. Nature Communications 9, Article 4235.Coal/Lignite/Peat GeochemistryChen, Y., Liu, D., Cai, Y., Gan, Q., 2018. Insights into fractal characteristics of pores in different rank coals by nuclear magnetic resonance (NMR). Arabian Journal of Geosciences 11, 578.Cui, J., Liu, D., Cai, Y., Pan, Z., Zhou, Y., 2019. Insights into fractures and minerals in subbituminous and bituminous coals by FESEM-EDS and X-ray μ-CT. Fuel 237, 977-988.Edokpa, D.A., Evans, M.G., Boult, S., Rothwell, J.J., 2018. Size fractionation of dissolved organic nitrogen in peatland fluvial systems. Environmental Science & Technology 52, 11198-11205.He, D., Hou, D., Huang, H., 2018. Geochemical characteristics of n-alkane and n-alkan-2-one in Mildred peat bog from the Athabasca Region, Canada. Acta Sedimentologica Sinica 26, 1049-1058.Karayi?it, A.?., Mastalerz, M., Oskay, R.G., Buzkan, ?., 2018. Bituminous coal seams from underground mines in the Zonguldak Basin (NW Turkey): Insights from mineralogy, coal petrography, Rock-Eval pyrolysis, and meso-and microporosity. International Journal of Coal Geology 199, 91-112.Li, Z., Fu, Y., Zhou, A., Zhu, C., Yang, C., Shen, N., Yang, C., 2019. Effect of multi-intensification on the liberation of maceral components in coal. Fuel 237, 1003-1012.Liu, Y., Zhu, Y., Liu, S., Chen, S., Li, W., Wang, Y., 2018. Molecular structure controls on micropore evolution in coal vitrinite during coalification. International Journal of Coal Geology 199, 19-30.Moroeng, O.M., Keartland, J.M., Roberts, R.J., Wagner, N.J., 2018. Characterization of coal using electron spin resonance: implications for the formation of inertinite macerals in the Witbank Coalfield, South Africa. International Journal of Coal Science & Technology 5, 385-398.Qin, X., Jiao, T., Zhang, Y., Yu, J., Liang, P., 2018. Effect of solvent pretreatment on pyrolysis characteristic of high-sulfur bituminous coal. Journal of Analytical and Applied Pyrolysis 135, 54-59.Sharma, A., Phukan, S., Saikia, B.K., Baruah, B.P., 2018. Geochemical evaluation of the hydrocarbon prospects of carbonaceous shale and coal of Barail Group, Upper Assam Basin. International Journal of Oil, Gas and Coal Technology 19, 263-282.Straka, P., S?korová, I., 2018. Coalification and coal alteration under mild thermal conditions. International Journal of Coal Science & Technology 5, 358-373.Strehse, R., Bohne, H., Amha, Y., Leinweber, P., 2018. The influence of salt on dissolved organic matter from peat soils. Organic Geochemistry 125, 270-276.Walpen, N., Lau, M.P., Fiskal, A., Getzinger, G.J., Meyer, S.A., Nelson, T.F., Lever, M.A., Schroth, M.H., Sander, M., 2018. Oxidation of reduced peat particulate organic matter by dissolved oxygen: Quantification of apparent rate constants in the field. Environmental Science & Technology 52, 11151-11160.Wang, G., Hou, B., Zhang, J., Wang, H., Gao, D., Chang, G., Thallada, B., 2018. Effect of pressure and H2 on the pyrolysis characteristics of lignite: Thermal behavior and coal char structural properties. Journal of Analytical and Applied Pyrolysis 135, 1-9.Yu, K., Qu, Z., Ju, Y., Xue, Z., 2018. Burial and thermal history of coal-bearing strata in Shengli coalfield, Erlian Basin. Acta Sedimentologica Sinica 26, 903-913.Zhou, S., Liu, D., Karpyn, Z.T., Cai, Y., Yao, Y., 2018. Effect of coalification jumps on petrophysical properties of various metamorphic coals from different coalfields in China. Journal of Natural Gas Science and Engineering 60, 63-76.Coal Bed MethaneChen, F., He, H., Zhao, S.-M., Yao, J.-h., Sun, Q., Huang, G.-h., Xiao, D., Tang, L.-F., Leng, Y.-w., Tao, X.-x., 2018. Analysis of microbial community succession during methane production from Baiyinhua lignite. Energy & Fuels 32, 10311-10320.Hou, H., Shao, L., Li, Y., Li, Y.-n., 2018. Physical properties of coalbed methane reservoirs and favourable exploration areas in the northern Qaidam Basin, NW China. International Journal of Oil, Gas and Coal Technology 19, 357-377.Jing, Z., Mahoney, S.A., Rodrigues, S., Balucan, R.D., Underschultz, J., Esterle, J.S., Rufford, T.E., Steel, K.M., 2018. A preliminary study of oxidant stimulation for enhancing coal seam permeability: Effects of sodium hypochlorite oxidation on subbituminous and bituminous Australian coals. International Journal of Coal Geology 200, 36-44.Liu, F., Guo, H., Wang, Q., Haider, R., Urynowicz, M.A., Fallgren, P.H., Jin, S., Tang, M., Chen, B., Huang, Z., 2019. Characterization of organic compounds from hydrogen peroxide-treated subbituminous coal and their composition changes during microbial methanogenesis. Fuel 237, 1209-1216.Ouyang, Y., Tian, W., Sun, B., Wang, B., Qi, L., Sun, Q., Yang, Q., Dong, H., 2018. Accumulation characteristics and exploration strategies of coal measure gas in China. Natural Gas Industry B 5, 444-451.Tang, Z., Yang, S., Xu, G., Sharifzadeh, M., Zhai, C., 2018. Evolution law of adsorption and desorption characteristics of CH4 in coal masses during coalbed methane extraction. Energy & Fuels 32, 10540-10548.Wang, C., Yang, S., Li, X., Li, J., Jiang, C., 2019. Comparison of the initial gas desorption and gas-release energy characteristics from tectonically-deformed and primary-undeformed coal. Fuel 238, 66-74.Zagor??ak, R., Thomas, H.R., 2018. Effects of subcritical and supercritical CO2 sorption on deformation and failure of high-rank coals. International Journal of Coal Geology 199, 113-123.Zhang, M., Fu, X., 2018. Characterization of pore structure and its impact on methane adsorption capacity for semi-anthracite in Shizhuangnan Block, Qinshui Basin. Journal of Natural Gas Science and Engineering 60, 49-62.Cosmochemistry/Planetary GeochemistryEyres, S.P.S., Evans, A., Zijlstra, A., Avison, A., Gehrz, R.D., Hajduk, M., Starrfield, S., Mohamed, S., Woodward, C.E., Wagner, R.M., 2018. ALMA reveals the aftermath of a white dwarf–brown dwarf merger in CK?Vulpeculae. Monthly Notices of the Royal Astronomical Society, Article sty2554.Kossacki, K.J., 2019. Sublimation of cometary ices in the presence of organic volatiles II. Icarus 319, 470-475.Potenti, S., Manini, P., Fornaro, T., Poggiali, G., Crescenzi, O., Napolitano, A., Brucato, J.R., Barone, V., d'Ischia, M., 2018. Solid state photochemistry of hydroxylated naphthalenes on minerals: Probing polycyclic aromatic hydrocarbon transformation pathways under astrochemically-relevant conditions. ACS Earth and Space Chemistry 2, 977–1000.Sossi, P.A., Moynier, F., van Zuilen, K., 2018. Volatile loss following cooling and accretion of the Moon revealed by chromium isotopes. Proceedings of the National Academy of Sciences 115, 10920.Sundararajan, P., Tsuge, M., Baba, M., Lee, Y.-P., 2018. Infrared spectrum of protonated corannulene H+C20H10 in solid para-hydrogen and its potential contribution to interstellar unidentified infrared bands. ACS Earth and Space Chemistry 2, 1001-1010.Thelen, A.E., Nixon, C.A., Chanover, N.J., Cordiner, M.A., Molter, E.M., Teanby, N.A., Irwin, P.G.J., Serigano, J., Charnley, S.B., 2019. Abundance measurements of Titan’s stratospheric HCN, HC3N, C3H4, and CH3CN from ALMA observations. Icarus 319, 417-432.Thompson, M.S., Loeffler, M.J., Morris, R.V., Keller, L.P., Christoffersen, R., 2019. Spectral and chemical effects of simulated space weathering of the Murchison CM2 carbonaceous chondrite. Icarus 319, 499-511.AstrobiologyBarbieri, R., Cavalazzi, B., 2018. Microterracettes in Sabkha Oum Dba (Western Sahara, Morocco): Physical and biological interactions in the formation of a surface micromorphology. Astrobiology 18, 1351-1367.Bendia, A.G., Araujo, G.G., Pulschen, A.A., Contro, B., Duarte, R.T.D., Rodrigues, F., Galante, D., Pellizari, V.H., 2018. Surviving in hot and cold: psychrophiles and thermophiles from Deception Island volcano, Antarctica. Extremophiles 22, 917-929.Grimaldi, C., Marcy, G.W., 2018. Bayesian approach to SETI. Proceedings of the National Academy of Sciences 115, E9755-E9764.Kereszturi, A., Kapui, Z., Ori, G.G., Taj-Eddine, K., Ujvari, G., 2018. Mars-relevant field experiences in Morocco: The importance of spatial scales and subsurface exploration. Astrobiology 18, 1329-1350.Kong, F., Zheng, M., Hu, B., Wang, A., Ma, N., Sobron, P., 2018. Dalangtan saline playa in a hyperarid region on Tibet Plateau: I. Evolution and environments. Astrobiology 18, 1243-1253.Manasvi, L., Abraham, L., 2018. Implications of captured interstellar objects for panspermia and extraterrestrial life. The Astronomical Journal 156, Article 193.Oberlin, E.A., Claire, M.W., Kounaves, S.P., 2018. Evaluation of the Tindouf basin region in southern Morocco as an analogue site for soil geochemistry on Noachian Mars. Astrobiology 18, 1318-1328.Puente-Sánchez, F., Arce-Rodríguez, A., Oggerin, M., García-Villadangos, M., Moreno-Paz, M., Blanco, Y., Rodríguez, N., Bird, L., Lincoln, S.A., Tornos, F., Prieto-Ballesteros, O., Freeman, K.H., Pieper, D.H., Timmis, K.N., Amils, R., Parro, V., 2018. Viable cyanobacteria in the deep continental subsurface. Proceedings of the National Academy of Sciences 115, 10702-10707.Raack, J., Reiss, D., Balme, M.R., Taj-Eddine, K., Ori, G.G., 2018. In situ sampling of relative dust devil particle loads and their vertical grain size distributions. Astrobiology 18, 1305-1317.Romano, I., De Angelis, A., Poli, A., Ragni, P., Lilla, L., Zito, G., Nicolaus, B., De Luca, A.C., Di Donato, P., 2018. Resistance and Raman spectroscopy analysis of Parageobacillus thermantarcticus spores after γ-ray exposure. Extremophiles 22, 931-941.Sobron, P., Wang, A., Mayer, D.P., Bentz, J., Kong, F., Zheng, M., 2018. Dalangtan saline playa in a hyperarid region of Tibet Plateau: III. Correlated multiscale surface mineralogy and geochemistry survey. Astrobiology 18, 1277-1304.Wang, A., Sobron, P., Kong, F., Zheng, M., Zhao, Y.-Y.S., 2018. Dalangtan saline playa in a hyperarid region on Tibet Plateau: II. Preservation of salts with high hydration degrees in subsurface. Astrobiology 18, 1254-1276.Ward, M.K., Pollard, W.H., 2018. A hydrohalite spring deposit in the Canadian high Arctic: A potential Mars analogue. Earth and Planetary Science Letters 504, 126-138.Yung, Y.L., Chen, P., Nealson, K., Atreya, S., Beckett, P., Blank, J.G., Ehlmann, B., Eiler, J., Etiope, G., Ferry, J.G., Forget, F., Gao, P., Hu, R., Kleinb?hl, A., Klusman, R., Lefèvre, F., Miller, C., Mischna, M., Mumma, M., Newman, S., Oehler, D., Okumura, M., Oremland, R., Orphan, V., Popa, R., Russell, M., Shen, L., Sherwood Lollar, B., Staehle, R., Stamenkovi?, V., Stolper, D., Templeton, A., Vandaele, A.C., Viscardy, S., Webster, C.R., Wennberg, P.O., Wong, M.L., Worden, J., 2018. Methane on Mars and habitability: Challenges and responses. Astrobiology 18, 1221-1242.Environmental GeochemistryDoerr, S.H., Santín, C., Merino, A., Belcher, C.M., Baxter, G., 2018. Fire as a removal mechanism of pyrogenic carbon from the environment: Effects of fire and pyrogenic carbon characteristics. Frontiers in Earth Science 6, 127. doi: 110.3389/feart.2018.00127.Feng, J., Hu, P., Su, X., Li, Q., Sun, J., Li, Y.-F., 2018. Impact of suspended sediment on the behavior of polycyclic aromatic hydrocarbons in the Yellow River: Spatial distribution, transport and fate. Applied Geochemistry 98, 278-285.Gao, Y., Zhao, X., Ju, Z., Yu, Y., Qi, Z., Xiong, D., 2018. Effects of the suspended sediment concentration and oil type on the formation of sunken and suspended oils in the Bohai Sea. Environmental Science: Processes & Impacts 20, 1404-1413.Gensch, I., Sang-Arlt, X.F., Laumer, W., Chan, C.Y., Engling, G., Rudolph, J., Kiendler-Scharr, A., 2018. Using δ13C of levoglucosan as a chemical clock. Environmental Science & Technology 52, 11094–11101.Green, H.S., Fuller, S.A., Meyer, A.W., Joyce, P.S., Aeppli, C., Nelson, R.K., Swarthout, R.F., Valentine, D.L., White, H.K., Reddy, C.M., 2018. Pelagic tar balls collected in the North Atlantic Ocean and Caribbean Sea from 1988 to 2016 have natural and anthropogenic origins. Marine Pollution Bulletin 137, 352-359.Li, F., Peng, Y., Fang, W., Altermatt, F., Xie, Y., Yang, J., Zhang, X., 2018. Application of environmental DNA metabarcoding for predicting anthropogenic pollution in rivers. Environmental Science & Technology 52, 11708-11719.Lv, J., Miao, Y., Huang, Z., Han, R., Zhang, S., 2018. Facet-mediated adsorption and molecular fractionation of humic substances on hematite surfaces. Environmental Science & Technology 52, 11660-11669.McMahon, P.B., Kulongoski, J.T., Vengosh, A., Cozzarelli, I.M., Landon, M.K., Kharaka, Y.K., Gillespie, J.M., Davis, T.A., 2018. Regional patterns in the geochemistry of oil-field water, southern San Joaquin Valley, California, USA. Applied Geochemistry 98, 127-140.Riddick, S.N., Mauzerall, D.L., Celia, M.A., Kang, M., Bressler, K., Chu, C., Gum, C.D., 2019. Measuring methane emissions from abandoned and active oil and gas wells in West Virginia. Science of The Total Environment 651, 1849-1856.Saide, P.E., Steinhoff, D.F., Kosovic, B., Weil, J., Downey, N., Blewitt, D., Hanna, S.R., Delle Monache, L., 2018. Evaluating methods to estimate methane emissions from oil and gas production facilities using LES simulations. Environmental Science & Technology 52, 11206-11214.Sivaram, A.K., Subashchandrabose, S.R., Logeshwaran, P., Lockington, R., Naidu, R., Megharaj, M., 2019. Metabolomics reveals defensive mechanisms adapted by maize on exposure to high molecular weight polycyclic aromatic hydrocarbons. Chemosphere 214, 771-780.Weller, Z.D., Roscioli, J.R., Daube, W.C., Lamb, B.K., Ferrara, T.W., Brewer, P.E., von Fischer, J.C., 2018. Vehicle-based methane surveys for finding natural gas leaks and estimating their size: Validation and uncertainty. Environmental Science & Technology 52, 11922-11930.BioremediationAchermann, S., Fal?s, P., Joss, A., Mansfeldt, C.B., Men, Y., Vogler, B., Fenner, K., 2018. Trends in micropollutant biotransformation along a solids retention time gradient. Environmental Science & Technology 52, 11601-11611.Bharagava, R.N., Purchase, D., Saxena, G., Mulla, S.I., 2019. Chapter 26 - Applications of metagenomics in microbial bioremediation of pollutants: From genomics to environmental cleanup, in: Das, S., Dash, H.R. (Eds.), Microbial Diversity in the Genomic Era. Academic Press, pp. 459-477.Cipullo, S., Negrin, I., Claveau, L., Snapir, B., Tardif, S., Pulleyblank, C., Prpich, G., Campo, P., Coulon, F., 2019. Linking bioavailability and toxicity changes of complex chemicals mixture to support decision making for remediation endpoint of contaminated soils. Science of The Total Environment 650, 2150-2163.de Souza Pohren, R., Rocha, J.A.V., Horn, K.A., Vargas, V.M.F., 2019. Bioremediation of soils contaminated by PAHs: Mutagenicity as a tool to validate environmental quality. Chemosphere 214, 659-668.Hellauer, K., Martínez Mayerlen, S., Drewes, J.E., Hübner, U., 2019. Biotransformation of trace organic chemicals in the presence of highly refractory dissolved organic carbon. Chemosphere 215, 33-39.Panigrahi, S., Velraj, P., Subba Rao, T., 2019. Chapter 21 - Functional microbial diversity in contaminated environment and application in bioremediation, in: Das, S., Dash, H.R. (Eds.), Microbial Diversity in the Genomic Era. Academic Press, pp. 359-385.Sudmalis, D., Da Silva, P., Temmink, H., Bijmans, M.M., Pereira, M.A., 2018. Biological treatment of produced water coupled with recovery of neutral lipids. Water Research 147, 33-42.Deepwater Horizon/Other Oil SpillsAune, M., Aniceto, A.S., Biuw, M., Daase, M., Falk-Petersen, S., Leu, E., Ottesen, C.A.M., Sagerup, K., Camus, L., 2018. Seasonal ecology in ice-covered Arctic seas - Considerations for spill response decision making. Marine Environmental Research 141, 275-288.Boniewicz-Szmyt, K., Pogorzelski, S.J., 2018. Influence of surfactant concentration and temperature gradients on spreading of crude-oil at sea. Frontiers in Marine Science 5, 388. doi: 310.3389/fmars.2018.00388.de Vries, P., Tamis, J., Hjorth, M., Jak, R., Falk-Petersen, S., van den Heuvel-Greve, M., Klok, C., Hemerik, L., 2018. How including ecological realism impacts the assessment of the environmental effect of oil spills at the population level: The application of matrix models for Arctic Calanus species. Marine Environmental Research 141, 264-274.Romero, I.C., Sutton, T., Carr, B., Quintana-Rizzo, E., Ross, S.W., Hollander, D.J., Torres, J.J., 2018. Decadal assessment of polycyclic aromatic hydrocarbons in mesopelagic fishes from the Gulf of Mexico reveals exposure to oil-derived sources. Environmental Science & Technology 52, 10985-10996.Salih, Y.M., Karim, A.R., Khorshid, I., 2018. Estimation the time of spill crude oil in deep soil by the detection of volatile organic compounds (VOCs). Petroleum Science and Technology 36, 1497-1502.Schwehr, K.A., Xu, C., Chiu, M.-H., Zhang, S., Sun, L., Lin, P., Beaver, M., Jackson, C., Agueda, O., Bergen, C., Chin, W.-C., Quigg, A., Santschi, P.H., 2018. Protein: Polysaccharide ratio in exopolymeric substances controlling the surface tension of seawater in the presence or absence of surrogate Macondo oil with and without Corexit. Marine Chemistry 206, 84-92.Wenning, R.J., Robinson, H., Bock, M., Rempel-Hester, M.A., Gardiner, W., 2018. Current practices and knowledge supporting oil spill risk assessment in the Arctic. Marine Environmental Research 141, 289-304.Wirth, M.A., Passow, U., Jeschek, J., Hand, I., Schulz-Bull, D.E., 2018. Partitioning of oil compounds into marine oil snow: Insights into prevailing mechanisms and dispersant effects. Marine Chemistry 206, 62-73.Xu, C., Zhang, S., Beaver, M., Lin, P., Sun, L., Doyle, S.M., Sylvan, J.B., Wozniak, A., Hatcher, P.G., Kaiser, K., Yan, G., Schwehr, K.A., Lin, Y., Wade, T.L., Chin, W.-C., Chiu, M.-H., Quigg, A., Santschi, P.H., 2018. The role of microbially-mediated exopolymeric substances (EPS) in regulating Macondo oil transport in a mesocosm experiment. Marine Chemistry 206, 52-61.Xu, C., Zhang, S., Beaver, M., Wozniak, A., Obeid, W., Lin, Y., Wade, T.L., Schwehr, K.A., Lin, P., Sun, L., Hatcher, P.G., Chin, W.-C., Chiu, M.-H., Knap, A.H., Dean, K., Quigg, A., Santschi, P.H., 2018. Decreased sedimentation efficiency of petro- and non-petro-carbon caused by a dispersant for Macondo surrogate oil in a mesocosm simulating a coastal microbial community. Marine Chemistry 206, 34-43.Zatsepa, S.N., Ivchenko, A.A., Korotenko, K.A., Solbakov, V.V., Stanovoy, V.V., 2018. The role of wind waves in oil spill natural dispersion in the sea. Oceanology 58, 517-524.Oil Sand Process Waters/Tailing PondsAlberts, M.E., Chua, G., Muench, D.G., 2019. Exposure to naphthenic acids and the acid extractable organic fraction from oil sands process-affected water alters the subcellular structure and dynamics of plant cells. Science of The Total Environment 651, 2830-2844.Mercier, P.H.J., Tyo, D.D., Zborowski, A., Kung, J., Patarachao, B., Kingston, D.M., Couillard, M., Robertson, G., McCracken, T., Ng, S., 2019. First quantification of <2?μm clay, <0.2?μm ultrafines and solids wettability in process streams from naphthenic froth treatment plant at commercial mined oil sands operations. Fuel 237, 961-976.Niasar, H.S., Das, S., Xu, C., Ray, M.B., 2019. Continuous column adsorption of naphthenic acids from synthetic and real oil sands process-affected water (OSPW) using carbon-based adsorbents. Chemosphere 214, 511-518.Xia, Z., Idowu, I., Marvin, C., Thomas, P.J., Johnson, W., Francisco, O., Stetefeld, J., Crimmins, B., Fry, M., Tomy, G.T., 2019. Identification of halogenated polycyclic aromatic hydrocarbons in biological samples from Alberta Oil-Sands Region. Chemosphere 215, 206-213.Zhang, L., Cho, S., Hashisho, Z., Brown, C., 2019. Quantification of fugitive emissions from an oil sands tailings pond by eddy covariance. Fuel 237, 457-464.UnconventionalShale Gas-CBM ResourcesLandis, J.D., Sharma, M., Renock, D., 2018. Rapid desorption of radium isotopes from black shale during hydraulic fracturing. 2. A model reconciling radium extraction with Marcellus wastewater production. Chemical Geology 500, 194-206.Sleep, S., Laurenzi, I.J., Bergerson, J.A., MacLean, H.L., 2018. Evaluation of variability in greenhouse gas intensity of Canadian oil sands surface mining and upgrading operations. Environmental Science & Technology 52, 11941-11951.Zhang, X., Zhang, D., Huang, Y., Zhang, K., Lu, P., 2018. Simultaneous removal of organic matter and iron from hydraulic fracturing flowback water through sulfur cycling in a microbial fuel cell. Water Research 147, 461-471.Evolution/Paleontology/PalynologyBotting, J.P., Nettersheim, B.J., 2018. Searching for sponge origins. Nature Ecology & Evolution 2, 1685-1686.Hara, Y., Yamaguchi, K., Onimaru, K., Kadota, M., Koyanagi, M., Keeley, S.D., Tatsumi, K., Tanaka, K., Motone, F., Kageyama, Y., Nozu, R., Adachi, N., Nishimura, O., Nakagawa, R., Tanegashima, C., Kiyatake, I., Matsumoto, R., Murakumo, K., Nishida, K., Terakita, A., Kuratani, S., Sato, K., Hyodo, S., Kuraku, S., 2018. Shark genomes provide insights into elasmobranch evolution and the origin of vertebrates. Nature Ecology & Evolution 2, 1761-1771.Keighley, D., Boonsue, S., Hall, D., 2018. Phosphatized tungsten-metabolizing coccoid microbes interpreted from oil shale of an Eocene lake, Green River Formation, Utah, USA. Geobiology 16, 610-627.Lewitus, E., Bittner, L., Malviya, S., Bowler, C., Morlon, H., 2018. Clade-specific diversification dynamics of marine diatoms since the Jurassic. Nature Ecology & Evolution 2, 1715-1723.Rimington, W.R., Pressel, S., Duckett, J.G., Field, K.J., Read, D.J., Bidartondo, M.I., 2018. Ancient plants with ancient fungi: liverworts associate with early-diverging arbuscular mycorrhizal fungi. Proceedings of the Royal Society B: Biological Sciences 285, Article 20181600.Sallan, L., Friedman, M., Sansom, R.S., Bird, C.M., Sansom, I.J., 2018. The nearshore cradle of early vertebrate diversification. Science 362, 460-464.Origins of Life/Microbial GenomicsAk?l, C., Robinson, R.C., 2018. Genomes of Asgard archaea encode profilins that regulate actin. Nature 562, 439-443.Becker, S., Schneider, C., Okamura, H., Crisp, A., Amatov, T., Dejmek, M., Carell, T., 2018. Wet-dry cycles enable the parallel origin of canonical and non-canonical nucleosides by continuous synthesis. Nature Communications 9, Article 163.Eme, L., Ettema, T.J.G., 2018. The eukaryotic ancestor shapes up. Nature 562, 352-353.Hendrickson, H.L., Poole, A.M., 2018. Manifold routes to a nucleus. Frontiers in Microbiology 9, 2604. doi: 2610.3389/fmicb.2018.02604.Lazcano, A., 2018. Prebiotic evolution and self-assembly of nucleic acids. ACS Nano 12, 9643-9647.Lind, A.E., Lewis, W.H., Spang, A., Guy, L., Embley, T.M., Ettema, T.J.G., 2018. Genomes of two archaeal endosymbionts show convergent adaptations to an intracellular lifestyle. The ISME Journal 12, 2655-2667.Roger, A.J., Susko, E., 2018. Molecular clocks provide little information to date methanogenic Archaea. Nature Ecology & Evolution 2, 1676-1677.Schneider, C., Becker, S., Okamura, H., Crisp, A., Amatov, T., Stadlmeier, M., Carell, T., 2018. Noncanonical RNA nucleosides as molecular fossils of an early Earth - generation by prebiotic methylations and carbamoylations. Angewandte Chemie International Edition 57, 5943-5946.Wolfe, J.M., Fournier, G.P., 2018. Reply to ‘Molecular clocks provide little information to date methanogenic Archaea’. Nature Ecology & Evolution 2, 1678-1678.Xian, H., Zhu, J., Tan, W., Tang, H., Liu, P., Zhu, R., Liang, X., Wei, J., He, H., Teng, H.H., 2019. The mechanism of defect induced hydroxylation on pyrite surfaces and implications for hydroxyl radical generation in prebiotic chemistry. Geochimica et Cosmochimica Acta 244, 163-172.Hominid Evolution Enard, D., Petrov, D.A., 2018. Evidence that RNA viruses drove adaptive introgression between Neanderthals and modern humans. Cell 175, 360-371.e313.Fluid InclusionsPeters, C.A., George, S.C., 2018. Hydrocarbon biomarkers preserved in carbonate veins of potentially Paleoproterozoic age, and implications for the early biosphere. Geobiology 16, 577-596.Straka, P., S?korová, I., 2018. Coalification and coal alteration under mild thermal conditions. International Journal of Coal Science & Technology 5, 358-373.GeologyGalloway, E., Hauck, T., Corlett, H., Pan?, D., Schultz, R., 2018. Faults and associated karst collapse suggest conduits for fluid flow that influence hydraulic fracturing-induced seismicity. Proceedings of the National Academy of Sciences 115, E10003-E10012.Huang, X., Hu, G., Meng, Q., Zheng, X., 2018. Impact performance optimization of a YDC valve-type double action hydraulic hammer. Natural Gas Industry B 5, 425-433.Jiang, S., Mokhtari, M., 2019. Characterization of marl and interbedded limestone layers in the Eagle Ford Formation, DeWitt county, Texas. Journal of Petroleum Science and Engineering 172, 502-510.Simakov, S.K., 2018. Nano- and micron-sized diamond genesis in nature: An overview. Geoscience Frontiers 9, 1849-1858.Yarbrough, L.D., Carr, R., Lentz, N., 2019. X-ray fluorescence analysis of the Bakken and Three Forks Formations and logging applications. Journal of Petroleum Science and Engineering 172, 764-775.Bolide Impacts/Crater GeochemistryRiller, U., Poelchau, M.H., Rae, A.S.P., Schulte, F.M., Collins, G.S., Melosh, H.J., Grieve, R.A.F., Morgan, J.V., Gulick, S.P.S., Lofi, J., Diaw, A., McCall, N., Kring, D.A., Morgan, J.V., Gulick, S.P.S., Green, S.L., Lofi, J., Chenot, E., Christeson, G.L., Claeys, P., Cockell, C.S., Coolen, M.J.L., Ferrière, L., Gebhardt, C., Goto, K., Jones, H., Kring, D.A., Xiao, L., Lowery, C.M., Ocampo-Torres, R., Perez-Cruz, L., Pickersgill, A.E., Poelchau, M.H., Rae, A.S.P., Rasmussen, C., Rebolledo-Vieyra, M., Riller, U., Sato, H., Smit, J., Tikoo-Schantz, S.M., Tomioka, N., Whalen, M.T., Wittmann, A., Yamaguchi, K., Fucugauchi, J.U., Bralower, T.J., IODP–ICDP Expedition 364 Science Party, 2018. Rock fluidization during peak-ring formation of large impact structures. Nature 562, 511-518.Sungatullin, R.K., Bakhtin, A.I., Tsel’movich, V.A., Bakhmutov, V.G., Sungatullina, G.M., 2018. Middle Paleozoic impact event in the southwest of the East European Platform. Russian Geology and Geophysics 59, 1149-1160.HydratesAn, S.H., Van, S.L., Chon, B.H., 2018. Production characteristics of gas hydrate reservoirs associated with steam injection and depressurisation rate. International Journal of Oil, Gas and Coal Technology 19, 296-315.Bavoh, C.B., Khan, M.S., Lal, B., Bt Abdul Ghaniri, N.I., Sabil, K.M., 2018. New methane hydrate phase boundary data in the presence of aqueous amino acids. Fluid Phase Equilibria 478, 129-133.?a?atay, M.N., Y?ld?z, G., Bayon, G., Ruffine, L., Henry, P., 2018. Seafloor authigenic carbonate crusts along the submerged part of the North Anatolian Fault in the Sea of Marmara: Mineralogy, geochemistry, textures and genesis. Deep Sea Research Part II: Topical Studies in Oceanography 153, 92-109.Du, J., Wang, X., Liu, H., Guo, P., Wang, Z., Fan, S., 2019. Experiments and prediction of phase equilibrium conditions for methane hydrate formation in the NaCl, CaCl2, MgCl2 electrolyte solutions. Fluid Phase Equilibria 479, 1-8.Grishkevich, V.F., 2018. Neocomian paleogeography, gas hydrate cementation of sediments, and abnormal sequences of the Bazhenov Formation (West Siberia). Russian Geology and Geophysics 59, 157-167.Hao, Y., Li, X., Li, S., Lü, G., Liu, Y., Wei, X., 2018. Heat conduction and thermal convection on thermal front movement during natural gas hydrate thermal stimulation exploitation. Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles 73, Article 40.Li, S., Wei, N., Li, H., Pang, W., Xi, Y., Zhen, L., Fu, Q., 2018. Migration characteristics of solid-phase particles in horizontal pipes in the exploitation of marine gas hydrate reservoirs through solid fluidization. Natural Gas Industry 38, 100-106.Merey, ?., 2019. Evaluation of drilling parameters in gas hydrate exploration wells. Journal of Petroleum Science and Engineering 172, 855-877.Meyer, D.W., Flemings, P.B., DiCarlo, D., 2018. Effect of gas flow rate on hydrate formation within the hydrate stability zone. Journal of Geophysical Research: Solid Earth 123, 6263-6276.Paganoni, M., King, J.J., Foschi, M., Mellor-Jones, K., Cartwright, J.A., 2019. A natural gas hydrate system on the Exmouth Plateau (NW shelf of Australia) sourced by thermogenic hydrocarbon leakage. Marine and Petroleum Geology 99, 370-392.?a?atay, M.N., Y?ld?z, G., Bayon, G., Ruffine, L., Henry, P., 2018. Seafloor authigenic carbonate crusts along the submerged part of the North Anatolian Fault in the Sea of Marmara: Mineralogy, geochemistry, textures and genesis. Deep Sea Research Part II: Topical Studies in Oceanography 153, 92-109.Sadeq, D., Iglauer, S., Lebedev, M., Rahman, T., Zhang, Y., Barifcani, A., 2018. Experimental pore-scale analysis of carbon dioxide hydrate in sandstone via X-Ray micro-computed tomography. International Journal of Greenhouse Gas Control 79, 73-82.Sangtam, B.T., Kumar Majumder, S., 2018. A new empirical correlation for prediction of gas hydrate dissociation equilibrium. Petroleum Science and Technology 36, 1432-1438.Song, G., Li, Y., Wang, W., Liu, S., Wang, X., Shi, Z., Yao, S., 2019. Experimental investigation on the microprocess of hydrate particle agglomeration using a high-speed camera. Fuel 237, 475-485.Wang, G., Huang, R., Zhong, L., Wang, L., Zhou, S., Liu, Q., 2018. An optimal design of crushing parameters of marine gas hydrate reservoirs in solid fluidization exploitation. Natural Gas Industry 38, 84-89.Wei, N., Zhao, J., Sun, W., Zhou, S., Zhang, L., Li, Q., Fu, Q., Lü, X., Zheng, L., 2018. Non-equilibrium multiphase wellbore flow characteristics in solid fluidization exploitation of marine gas hydrate reservoirs. Natural Gas Industry 38, 90-99.Wu, T., Sahling, H., Feseker, T., Rendle-Bühring, R., Wei, J., Wintersteller, P., Marcon, Y., Pape, T., R?mer, M., Bohrmann, G., 2019. Morphology and activity of the Helgoland Mud Volcano in the Sorokin Trough, Northern Black Sea. Marine and Petroleum Geology 99, 227-236.Zang, X., Liang, D., 2018. Experimental study on hydrate formation with synthesized CH4/CO2/N2 ternary mixtures. Energy & Fuels 32, 10745-10753.Zhang, H., Luo, X., Bi, J., He, G., Li, Z., 2018. Multi-component fractal representation of multi-scale structure of natural gas hydrate-bearing sediments. Journal of Natural Gas Science and Engineering 60, 144-152.Zhou, M., Soga, K., Yamamoto, K., 2018. Upscaled anisotropic methane hydrate critical state model for turbidite hydrate-bearing sediments at East Nankai Trough. Journal of Geophysical Research: Solid Earth 123, 6277-6298.Isotope GeochemistryCeia, F.R., Cherel, Y., Paiva, V.H., Ramos, J.A., 2018. Stable isotope dynamics (δ13C and δ15N) in neritic and oceanic waters of the North Atlantic inferred from GPS-tracked Cory’s shearwaters. Frontiers in Marine Science 5, 377. doi: 310.3389/fmars.2018.00377.Chen, G., Han, J., Mu, Y., Yu, H., Qin, L., 2019. Two-stage chromium isotope fractionation during microbial Cr(VI) reduction. Water Research 148, 10-18.Craine, J.M., Elmore, A.J., Wang, L., Aranibar, J., Bauters, M., Boeckx, P., Crowley, B.E., Dawes, M.A., Delzon, S., Fajardo, A., Fang, Y., Fujiyoshi, L., Gray, A., Guerrieri, R., Gundale, M.J., Hawke, D.J., Hietz, P., Jonard, M., Kearsley, E., Kenzo, T., Makarov, M., Mara?ón-Jiménez, S., McGlynn, T.P., McNeil, B.E., Mosher, S.G., Nelson, D.M., Peri, P.L., Roggy, J.C., Sanders-DeMott, R., Song, M., Szpak, P., Templer, P.H., Van der Colff, D., Werner, C., Xu, X., Yang, Y., Yu, G., Zmudczyńska-Skarbek, K., 2018. Isotopic evidence for oligotrophication of terrestrial ecosystems. Nature Ecology & Evolution 2, 1735-1744.Eley, Y., White, J., Dawson, L., Hren, M., Pedentchouk, N., 2018. Variation in hydrogen isotope composition among salt marsh plant organic compounds highlights biochemical mechanisms controlling biosynthetic fractionation. Journal of Geophysical Research: Biogeosciences 123, 2645-2660.Gensch, I., Sang-Arlt, X.F., Laumer, W., Chan, C.Y., Engling, G., Rudolph, J., Kiendler-Scharr, A., 2018. Using δ13C of levoglucosan as a chemical clock. Environmental Science & Technology 52, 11094–11101.Gerschlauer, F., Saiz, G., Costa, D.S., Kleyer, M., Dannenmann, M., Kiese, R., 2018. Stable carbon and nitrogen isotopic composition of leaves, litter, and soils of various tropical ecosystems along an elevational and land-use gradient at Mount Kilimanjaro, Tanzania. Biogeosciences Discussions 2018, 1-27.Gong, S., Peng, Y., Bao, H., Feng, D., Cao, X., Crockford, P.W., Chen, D., 2018. Triple sulfur isotope relationships during sulfate-driven anaerobic oxidation of methane. Earth and Planetary Science Letters 504, 13-20.Haverly, M.R., Fenwick, S.R., Patterson, F.P.K., Slade, D.A., 2019. Biobased carbon content quantification through AMS radiocarbon analysis of liquid fuels. Fuel 237, 1108-1111.Hofmann, L.C., Heesch, S., 2018. Latitudinal trends in stable isotope signatures and carbon-concentrating mechanisms of northeast Atlantic rhodoliths. Biogeosciences 15, 6139-6149.Maxwell, T.M., Silva, L.C.R., Horwath, W.R., 2018. Predictable oxygen isotope exchange between plant lipids and environmental water: Implications for ecosystem water balance reconstruction. Journal of Geophysical Research: Biogeosciences 123, 2941-2954.McRose, D.L., Lee, A., Kopf, S.H., Baars, O., Kraepiel, A.M.L., Sigman, D.M., Morel, F.M.M., Zhang, X., 2019. Effect of iron limitation on the isotopic composition of cellular and released fixed nitrogen in Azotobacter vinelandii. Geochimica et Cosmochimica Acta 244, 12-23.Mi, J., Wang, H., He, K., Bai, J., Liu, C., 2018. Demethylation as a mechanism for isotopic reversals of shale gas generated at over maturity. Journal of Analytical and Applied Pyrolysis 135, 361-368.Ye, F., Guo, W., Wei, G., Jia, G., 2018. The sources and transformations of dissolved organic matter in the Pearl River Estuary, China, as revealed by stable isotopes. Journal of Geophysical Research: Oceans 123, 6893-6908.Zhang, H.-Y., Hartmann, H., Gleixner, G., Thoma, M., Schwab, V.F., 2019. Carbon isotope fractionation including photosynthetic and post-photosynthetic processes in C3 plants: Low [CO2] matters. Geochimica et Cosmochimica Acta 245, 1-15.Clumped IsotopesHyland, E.G., Huntington, K.W., Sheldon, N.D., Reichgelt, T., 2018. Temperature seasonality in the North American continental interior during the Early Eocene Climatic Optimum. Climate of the Past 14, 1391-1404.Peterson, B.K., Formolo, M.J., Lawson, M., 2018. Molecular and detailed isotopic structures of petroleum: Kinetic Monte Carlo analysis of alkane cracking. Geochimica et Cosmochimica Acta 243, 169-185.Yang, W., Zuo, R., Wang, X., Song, Y., Jiang, Z., Luo, Q., Zhai, J., Wang, Q., Zhang, C., Zhang, Z., 2019. Sensitivity of lacustrine stromatolites to Cenozoic tectonic and climatic forcing in the southern Junggar Basin, NW China: New insights from mineralogical, stable and clumped isotope compositions. Palaeogeography, Palaeoclimatology, Palaeoecology 514, 109-123.Methods/InstrumentationCheng, L.-C., Shiao, J.-C., Hsiao, S.S.-Y., Wang, P.-L., 2018. Fractionation of otolith nitrogen stable isotopes measured by peroxodisulfate oxidation-bacterial conversion and isotope ratio mass spectrometry. Rapid Communications in Mass Spectrometry 32, 1905-1910.Ishikawa, N.F., Itahashi, Y., Blattmann, T.M., Takano, Y., Ogawa, N.O., Yamane, M., Yokoyama, Y., Nagata, T., Yoneda, M., Haghipour, N., Eglinton, T.I., Ohkouchi, N., 2018. Improved method for isolation and purification of underivatized amino acids for radiocarbon analysis. Analytical Chemistry 90, 12035-12041.Riedo, A., Rout, S., Wiesendanger, R., Wurz, P., Leya, I., 2018. EGT—A sensitive time-of-flight mass spectrometer for multielement isotope gas analysis. Journal of Mass Spectrometry 53, 1036-1045.Mathematical Geochemistry/Phase BehaviorMa, Y., Lu, G., Shao, C., Li, X., 2019. Molecular dynamics simulation of hydrocarbon molecule adsorption on kaolinite (0?0?1) surface. Fuel 237, 989-1002.Marshall, B.D., Bokis, C.P., 2018. A PC-SAFT model for hydrocarbons II: General model development. Fluid Phase Equilibria 478, 34-41.Microbiology/ExtremophilesCasillo, A., Ziaco, M., Lindner, B., Parrilli, E., Schwudke, D., Holgado, A., Beyaert, R., Lanzetta, R., Tutino, M.L., Corsaro, M.M., 2018. Lipid A structural characterization from the LPS of the Siberian psychro-tolerant Psychrobacter arcticus 273-4 grown at low temperature. Extremophiles 22, 955-963.Ji, Z., Zhang, H., Liu, H., Yaghi, O.M., Yang, P., 2018. Cytoprotective metal-organic frameworks for anaerobic bacteria. Proceedings of the National Academy of Sciences 115, 10582-10587.Kim, D.-U., Jang, J.H., Kang, M.-S., Kim, J.-Y., Zhang, J., Lim, S., Kim, M.K., 2018. Deinococcus irradiatisoli sp. nov., isolated from gamma ray-irradiated soil. International Journal of Systematic and Evolutionary Microbiology 68, 3232-3236.Králová, S., ?vec, P., Busse, H.-J., Staňková, E., Váczi, P., Sedlá?ek, I., 2018. Flavobacterium chryseum sp. nov. and Flavobacterium psychroterrae sp. nov., novel environmental bacteria isolated from Antarctica. International Journal of Systematic and Evolutionary Microbiology 68, 3132-3139.Li, Y., Liles, M.R., Halanych, K.M., 2018. Endosymbiont genomes yield clues of tubeworm success. The ISME Journal 12, 2785-2795.Mei, R., Nobu, M.K., Narihiro, T., Yu, J., Sathyagal, A., Willman, E., Liu, W.-T., 2018. Novel Geobacter species and diverse methanogens contribute to enhanced methane production in media-added methanogenic reactors. Water Research 147, 403-412.Otte, J.M., Blackwell, N., Soos, V., Rugh?ft, S., Maisch, M., Kappler, A., Kleindienst, S., Schmidt, C., 2018. Sterilization impacts on marine sediment – Are we able to inactivate microorganisms in environmental samples? FEMS Microbiology Ecology 94, Article fiy189.Romano, I., De Angelis, A., Poli, A., Ragni, P., Lilla, L., Zito, G., Nicolaus, B., De Luca, A.C., Di Donato, P., 2018. Resistance and Raman spectroscopy analysis of Parageobacillus thermantarcticus spores after γ-ray exposure. Extremophiles 22, 931-941.Rüffel, V., Maar, M., Dammbrück, M.N., Haur?der, B., Neu, T.R., Meier, J., 2018. Thermodesulfobium sp. strain 3baa, an acidophilic sulfate reducing bacterium forming biofilms triggered by mineral precipitation. Environmental Microbiology 20, 3717-3731.Wiegand, S., Jogler, M., Jogler, C., 2018. On the maverick Planctomycetes. FEMS Microbiology Reviews 42, 739-760.Zhang, X., Lin, H., Wang, X., Austin, B., 2018. Significance of Vibrio species in the marine organic carbon cycle—A review. Science China Earth Sciences 61, 1357-1368.Zhou, E.-M., Xian, W.-D., Mefferd, C.C., Thomas, S.C., Adegboruwa, A.L., Williams, N., Murugapiran, S.K., Dodsworth, J.A., Ganji, R., Li, M.-M., Ding, Y.-P., Liu, L., Woyke, T., Li, W.-J., Hedlund, B.P., 2018. Thermus sediminis sp. nov., a thiosulfate-oxidizing and arsenate-reducing organism isolated from Little Hot Creek in the Long Valley Caldera, California. Extremophiles 22, 983-991.Microbial EcosystemsBendia, A.G., Araujo, G.G., Pulschen, A.A., Contro, B., Duarte, R.T.D., Rodrigues, F., Galante, D., Pellizari, V.H., 2018. Surviving in hot and cold: psychrophiles and thermophiles from Deception Island volcano, Antarctica. Extremophiles 22, 917-929.Charniauskaya, M.I., Bukliarevich, A.A., Delegan, Y.A., Akhremchuk, A.E., Filonov, A.E., Titok, M.A., 2018. Biodiversity of hydrocarbon-oxidizing soil bacteria from various climatic zones. Microbiology 87, 699-711.Chen, F., He, H., Zhao, S.-M., Yao, J.-h., Sun, Q., Huang, G.-h., Xiao, D., Tang, L.-F., Leng, Y.-w., Tao, X.-x., 2018. Analysis of microbial community succession during methane production from Baiyinhua lignite. Energy & Fuels 32, 10311-10320.Cira, N.J., Pearce, M.T., Quake, S.R., 2018. Neutral and selective dynamics in a synthetic microbial community. Proceedings of the National Academy of Sciences 115, E9842-E9848.Coutinho, F.H., Gregoracci, G.B., Walter, J.M., Thompson, C.C., Thompson, F.L., 2018. Metagenomics sheds light on the ecology of marine microbes and their viruses. Trends in Microbiology 26, 955-965.Crognale, S., Venturi, S., Tassi, F., Rossetti, S., Rashed, H., Cabassi, J., Capecchiacci, F., Nisi, B., Vaselli, O., Morrison, H.G., Sogin, M.L., Fazi, S., 2018. Microbiome profiling in extremely acidic soils affected by hydrothermal fluids: the case of the Solfatara Crater (Campi Flegrei, southern Italy). FEMS Microbiology Ecology 94, Article fiy190.García-Maldonado, J.Q., Escobar-Zepeda, A., Raggi, L., Bebout, B.M., Sanchez-Flores, A., López-Cortés, A., 2018. Bacterial and archaeal profiling of hypersaline microbial mats and endoevaporites, under natural conditions and methanogenic microcosm experiments. Extremophiles 22, 903-916.Godoy-Lozano, E.E., Escobar-Zepeda, A., Raggi, L., Merino, E., Gutierrez-Rios, R.M., Juarez, K., Segovia , L., Licea-Navarro, A.F., Gracia, A., Sanchez-Flores, A., Pardo-Lopez, L., 2018. Bacterial diversity and the geochemical landscape in the southwestern Gulf of Mexico. Frontiers in Microbiology 9, 2528. doi: 2510.3389/fmicb.2018.02528.Lindh, M.V., Pinhassi, J., 2018. Sensitivity of bacterioplankton to environmental disturbance: A review of Baltic Sea field studies and experiments. Frontiers in Marine Science 5, 361. doi: 310.3389/fmars.2018.00361.Offord, C., 2018. Underworld. The Scientist 10.2018, 28-35.Ortmann, A.C., Brannock, P.M., Wang, L., Halanych, K.M., 2018. River flow impacts bacterial and archaeal community structure in surface sediments in the northern Gulf of Mexico. Microbial Ecology 76, 941-953.Puente-Sánchez, F., Arce-Rodríguez, A., Oggerin, M., García-Villadangos, M., Moreno-Paz, M., Blanco, Y., Rodríguez, N., Bird, L., Lincoln, S.A., Tornos, F., Prieto-Ballesteros, O., Freeman, K.H., Pieper, D.H., Timmis, K.N., Amils, R., Parro, V., 2018. Viable cyanobacteria in the deep continental subsurface. Proceedings of the National Academy of Sciences 115, 10702-10707.R?ttjers, L., Faust, K., 2018. From hairballs to hypotheses–biological insights from microbial networks. FEMS Microbiology Reviews 42, 761-780.Sibanda, T., Selvarajan, R., Msagati, T., Venkatachalam, S., Meddows-Taylor, S., 2019. Defunct gold mine tailings are natural reservoir for unique bacterial communities revealed by high-throughput sequencing analysis. Science of The Total Environment 650, 2199-2209.Smith, H.J., Zelaya, A.J., De?León, K.B., Chakraborty, R., Elias, D.A., Hazen, T.C., Arkin, A.P., Cunningham, A.B., Fields, M.W., 2018. Impact of hydrologic boundaries on microbial planktonic and biofilm communities in shallow terrestrial subsurface environments. FEMS Microbiology Ecology 94, Article fiy191.Sorokin, D.Y., Messina, E., La Cono, V., Ferrer, M., Ciordia, S., Mena, M.C., Toshchakov, S.V., Golyshin, P.N., Yakimov, M.M., 2018. Sulfur respiration in a group of facultatively anaerobic natronoarchaea ubiquitous in hypersaline soda lakes. Frontiers in Microbiology 9, 2359. doi: 2310.3389/fmicb.2018.02359.Wang, S., Lin, Y., Gifford, S., Eveleth, R., Cassar, N., 2018. Linking patterns of net community production and marine microbial community structure in the western North Atlantic. The ISME Journal 12, 2582-2595.Watteau, F., Villemin, G., 2018. Soil microstructures examined through transmission electron microscopy reveal soil-microorganisms interactions. Frontiers in Environmental Science 6, 106. doi: 110.3389/fenvs.2018.00106.Wong, H.L., White, R.A., Visscher, P.T., Charlesworth, J.C., Vázquez-Campos, X., Burns, B.P., 2018. Disentangling the drivers of functional complexity at the metagenomic level in Shark Bay microbial mat microbiomes. The ISME Journal 12, 2619-2639.Xu, D., Sun, P., Zhang, Y., Li, R., Huang, B., Jiao, N., Warren, A., Wang, L., 2018. Pigmented microbial eukaryotes fuel the deep sea carbon pool in the tropical Western Pacific Ocean. Environmental Microbiology 20, 3811-3824.Zablocki, O., van Zyl, L., Trindade, M., 2018. Biogeography and taxonomic overview of terrestrial hot spring thermophilic phages. Extremophiles 22, 827-837.Zhang, X., Xu, W., Liu, Y., Cai, M., Luo, Z., Li, M., 2018. Metagenomics reveals microbial diversity and metabolic potentials of seawater and surface sediment from a hadal biosphere at the Yap Trench. Frontiers in Microbiology 9, 2402. doi: 2410.3389/fmicb.2018.02402.Zhao, F., Filker, S., 2018. Characterization of protistan plankton diversity in ancient salt evaporation ponds located in a volcanic crater on the island Sal, Cape Verde. Extremophiles 22, 943-954.Petroleum DegradersChaudhary, D.K., Kim, J., 2018. Brevundimonas mongoliensis sp. nov., a novel psychrotolerant bacterium isolated from oil-contaminated soil. Current Microbiology 75, 1530-1536.Kim, D.-W., Lee, K., Lee, D.-H., Cha, C.-J., 2018. Comparative genomic analysis of pyrene-degrading Mycobacterium species: Genomic islands and ring-hydroxylating dioxygenases involved in pyrene degradation. Journal of Microbiology 56, 798-804.Li, G., Gao, P., Zhi, B., Fu, B., Gao, G., Chen, Z., Gao, M., Wu, M., Ma, T., 2018. The relative abundance of alkane-degrading bacteria oscillated similarly to a sinusoidal curve in an artificial ecosystem model from oil-well products. Environmental Microbiology 20, 3772-3783.Liao, X., Wu, Z., Li, Y., Luo, J., Su, C., 2018. Enhanced degradation of polycyclic aromatic hydrocarbons by indigenous microbes combined with chemical oxidation. Chemosphere 213, 551-558.Lje?evi?, M., Gojgi?-Cvijovi?, G., Ieda, T., Hashimoto, S., Nakano, T., Bulatovi?, S., Ili?, M., Be?koski, V., 2019. Biodegradation of the aromatic fraction from petroleum diesel fuel by Oerskovia sp. followed by comprehensive GC×GC-TOF MS. Journal of Hazardous Materials 363, 227-232.Ren, L., Jia, Y., Zhang, R., Lin, Z., Zhen, Z., Hu, H., Yan, Y., 2018. Insight into metabolic versatility of an aromatic compounds-degrading Arthrobacter sp. YC-RL1. Frontiers in Microbiology 9, 2438. doi: 2410.3389/fmicb.2018.02438.Wang, W., Wang, L., Shao, Z., 2018. Polycyclic aromatic hydrocarbon (PAH) degradation pathways of the obligate marine PAH degrader Cycloclasticus sp. Strain P1. Applied and Environmental Microbiology 84, Article e01261-01218.Wilhelm, R.C., Hanson, B.T., Chandra, S., Madsen, E., 2018. Community dynamics and functional characteristics of naphthalene-degrading populations in contaminated surface sediments and hypoxic/anoxic groundwater. Environmental Microbiology 20, 3543-3559.Xu, D., Zhang, K., Li, B.-G., Mbadinga, S.M., Zhou, L., Liu, J.-F., Yang, S.-Z., Gu, J.-D., Mu, B.-Z., 2019. Simulation of in situ oil reservoir conditions in a laboratory bioreactor testing for methanogenic conversion of crude oil and analysis of the microbial community. International Biodeterioration & Biodegradation 136, 24-33.Zhang, X., Tu, B., Dai, L.-r., Lawson, P.A., Zheng, Z.-z., Liu, L.-Y., Deng, Y., Zhang, H., Cheng, L., 2018. Petroclostridium xylanilyticum gen. nov., sp. nov., a xylan-degrading bacterium isolated from an oilfield, and reclassification of clostridial cluster III members into four novel genera in a new Hungateiclostridiaceae fam. nov. International Journal of Systematic and Evolutionary Microbiology 68, 3197-3211.Oil & Gas ExplorationCabello, P., Lopez, C., Gamba, N., Dussán, M.I., Torres, E., Ballesteros-Torres, C.I., Cantisano, M.T., Marfisi, N., Calvo, R., Vázquez-Taset, Y.M., Ramos, E., 2018. An integrated approach to define new plays in mature oil basins: The example from the Middle Magdalena Valley basin (Colombia). American Association of Petroleum Geologists Bulletin 102, 2201-2238.Fu, S., Fu, J., Yu, J., Yao, J., Zhang, C., Ma, Z., Yang, Y., Zhang, Y., 2018. Petroleum geological features and exploration prospect of Linhe Depression in Hetao Basin, China. Petroleum Exploration and Development 45, 803-817.Li, J., Wang, X., Wei, G., Yang, W., Xie, Z., Li, Z., Guo, J., Wang, Y., Ma, W., Li, J., Hao, A., 2018. New progresses in basic geological theories and future exploration domains of natural gas in China. Natural Gas Industry B 5, 434-443.Qu, H., Zhang, G., Chen, S., 2018. Distribution pattern and main factors controlling hydrocarbon accumulation of global oil and gas-rich deepwater basins. Journal of Natural Gas Geoscience 3, 135-145.Shen, W., Pang, X., Chen, J., Wang, Y., Zhang, K., Gao, Z., Jia, Y., Chen, Z., 2018. Accumulation model based on factors controlling Ordovician hydrocarbons migration and enrichment in the Tazhong Uplift, Tarim Basin, NW China. Acta Sedimentologica Sinica 26, 1008-1022.Snedden, J.W., Tinker, L.D., Virdell, J., 2018. Southern Gulf of Mexico Wilcox source to sink: Investigating and predicting Paleogene Wilcox reservoirs in eastern Mexico deep-water areas. American Association of Petroleum Geologists Bulletin 102, 2045-2074.Wang, Y., Hao, X., Hu, Y., 2018. Orderly distribution and differential enrichment of hydrocarbon in oil-rich sags: A case study of Dongying Sag, Jiyang Depression, Bohai Bay Basin, East China. Petroleum Exploration and Development 45, 840-850.Xu, S., Hao, F., Xu, C., Zou, H., Zhang, X., Zong, Y., Zhang, Y., Cong, F., 2019. Hydrocarbon migration and accumulation in the northwestern Bozhong subbasin, Bohai Bay Basin, China. Journal of Petroleum Science and Engineering 172, 477-488.Oil & Gas Generation/ExpulsionBaruah, B., Tiwari, P., Thakur, P., Kataki, R., 2018. TGA-FTIR analysis of Upper Assam oil shale, optimization of lab-scale pyrolysis process parameters using RSM. Journal of Analytical and Applied Pyrolysis 135, 397-405.Gong, S., Wang, Y., Wang, H., Zhang, X., Liu, G., 2018. High-pressure pyrolysis of isoprenoid hydrocarbon p-menthane in a tandem micro-reactor with online GC–MS/FID. Journal of Analytical and Applied Pyrolysis 135, 122-132.He, C., Li, T., 2018. Studying advances in effect of pressure on organic matters maturation. Acta Sedimentologica Sinica 26, 1040-1048.Nasyrova, Z., Aliev, A., Petrov, S., Safiulina, A., Mukhamatdinov, I., 2018. The catalytic effects of carbonate minerals on characteristics of heavy oil in hydrothermal reactions. Petroleum Science and Technology 36, 1439-1445.Peters, K.E., Hackley, P.C., Thomas, J.J., Pomerantz, A.E., 2018. Suppression of vitrinite reflectance by bitumen generated from liptinite during hydrous pyrolysis of artificial source rock. Organic Geochemistry 125, 220-228.Peterson, B.K., Formolo, M.J., Lawson, M., 2018. Molecular and detailed isotopic structures of petroleum: Kinetic Monte Carlo analysis of alkane cracking. Geochimica et Cosmochimica Acta 243, 169-185.Vega, B., Kovscek, A.R., 2019. A systematic study of internal gas generation in shale source rocks using analog experiments. Journal of Petroleum Science and Engineering 173, 209-221.Oil & Gas GeochemistryBennett, B., Larter, S.R., 2018. Geological controls on the heterogeneous hydrocarbon compositions of the biodegraded Grosmont Formation bitumen, Western Canada Sedimentary Basin. Organic Geochemistry 125, 243-259.Faboya, O.L., Sonibare, O.O., Faboya, O.T., Agrawal, U., Liao, Z., Ekundayo, O., 2018. Data modelling for crude oil migration studies using ranking method: a rapid geo-tracer technique for geochemists. Acta Geochimica 37, 901-910.Forsythe, J.C., Kenyon-Roberts, S., O'Donnell, M., Betancourt, S.S., Masurek, N., Gisolf, A., Bennett, B., Nelson, R.K., Canas, J.A., Reddy, C.M., Peters, K.E., Zuo, J.Y., Mullins, O.C., 2019. Biodegradation and water washing in a spill-fill sequence of oilfields. Fuel 237, 707-719.Golubev, Y.A., Martirosyan, O.V., Kuzmin, D.V., Isaenko, S.I., Makeev, B.A., Antonets, I.V., Utkin, A.A., 2019. Transformations of natural bitumens of different degrees of metamorphism at a low vacuum heating in the temperature range of 400–1000?°C. Journal of Petroleum Science and Engineering 173, 315-325.He, D., Hou, D., Chen, T., 2018. Geochemical characteristics and analysis of crude-oil source in the deep-water area of the Baiyun Sag, South China Sea. Russian Geology and Geophysics 59, 499-511.Ji, Y., Hou, Y., Ren, S., Yao, C., Wu, W., 2018. Tetraethylammonium amino acid ionic liquids and CO2 for separation of phenols from oil mixtures. Energy & Fuels 32, 11046-11054.Kashirtsev, V.A., 2018. Hydrocarbons occluded by asphaltenes. Russian Geology and Geophysics 59, 975-982.Kashirtsev, V.A., Parfenova, T.M., Golovko, A.K., Nikitenko, B.L., Zueva, I.N., Chalaya, O.N., 2018. Phenanthrene biomarkers in the organic matter of Precambrian and Phanerozoic deposits and in the oils of the Siberian Platform. Russian Geology and Geophysics 59, 1380-1388.Lambertsson, L., Lord, C.J., Frech, W., Bj?rn, E., 2018. Rapid dissolution of cinnabar in crude oils at reservoir temperatures facilitated by reduced sulfur ligands. ACS Earth and Space Chemistry 2, 1022-1028.Ma, A., Jin, Z., Zhu, C., Gu, Y., 2018. Detection and significance of higher thiadiamondoids and diamondoidthiols in oil from the Zhongshen 1C well of the Tarim Basin, NW China. Science China Earth Sciences 61, 1440-1450.Ping, H., Chen, H., Zhu, J., George, S.C., Mi, L., Pang, X., Zhai, P., 2018. Origin, source, mixing, and thermal maturity of natural gases in the Panyu lower uplift and the Baiyun depression, Pearl River Mouth Basin, northern South China Sea. American Association of Petroleum Geologists Bulletin 102, 2171-2200.Ren, Y., Liao, Z., Sun, J., Jiang, B., Wang, J., Yang, Y., Wu, Q., 2019. Molecular reconstruction: Recent progress toward composition modeling of petroleum fractions. Chemical Engineering Journal, 761-775.Santos, L.C., da Cruz, G.F., ?vila, B.M.F., Pereira, V.B., Azevedo, D.A., 2018. Exploratory analysis of Campos Basin crude oils via geochemical parameters by comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry. Energy & Fuels 32, 10321-10332.Smirnov, M.B., Fadeeva, N.P., Poludetkina, E.N., 2018. Identification of the genetic heterogeneity of Tatarstan oils based on the composition of alkyl-substituted aromatic compounds. Russian Geology and Geophysics 59, 1137-1148.Wang, P., Xu, C., Zhang, Y., Wang, M., Shi, Q., 2018. Identification of artifacts in the methylation process of sulfur compounds in petroleum. Energy & Fuels 32, 10571-10579.Xiao, H., Wang, T.G., Li, M., Lai, H., Liu, J., Mao, F., Tang, Y., 2019. Geochemical characteristics of Cretaceous Yogou Formation source rocks and oil-source correlation within a sequence stratigraphic framework in the Termit Basin, Niger. Journal of Petroleum Science and Engineering 172, 360-372.Paleoclimatology/PalaeocenographyAl-Mojel, A., Dera, G., Razin, P., Le Nindre, Y.-M., 2018. Carbon and oxygen isotope stratigraphy of Jurassic platform carbonates from Saudi Arabia: Implications for diagenesis, correlations and global paleoenvironmental changes. Palaeogeography, Palaeoclimatology, Palaeoecology 511, 388-402.Baroni, I.R., Pohl, A., Helmond, N.A.G.M., Papadomanolaki, N.M., Coe, A.L., Cohen, A.S., van de Schootbrugge, B., Donnadieu, Y., Slomp, C.P., 2018. Ocean circulation in the Toarcian (Early Jurassic): A key control on deoxygenation and carbon burial on the European shelf. Paleoceanography and Paleoclimatology 33, 994-1012.Fujisaki, W., Sawaki, Y., Matsui, Y., Yamamoto, S., Isozaki, Y., Maruyama, S., 2019. Redox condition and nitrogen cycle in the Permian deep mid-ocean: A possible contrast between Panthalassa and Tethys. Global and Planetary Change 172, 179-199.Hyland, E.G., Huntington, K.W., Sheldon, N.D., Reichgelt, T., 2018. Temperature seasonality in the North American continental interior during the Early Eocene Climatic Optimum. Climate of the Past 14, 1391-1404.Jones, M.T., Percival, L.M.E., Stokke, E.W., Frieling, J., Mather, T.A., Riber, L., Schubert, B.A., Schultz, B., Tegner, C., Planke, S., Svensen, H.H., 2018. Mercury anomalies across the Palaeocene-Eocene Thermal Maximum. Climate of the Past Discussions 2018, 1-35.Li, B.Y., Zhang, D.W., Pang, X.Q., Gao, P., Zhu, D.Y., Guo, K.Z., Zheng, T.Y., 2018. Paired δ13Ccarb and δ13Corg records of the Ordovician on the Yangtze platform, South China. Australian Journal of Earth Sciences 65, 809-822.McKay, D.I.A., Lenton, T.M., 2018. Reduced carbon cycle resilience across the Palaeocene–Eocene Thermal Maximum. Climate of the Past 14, 1515-1527.Miyazaki, Y., Planavsky, N.J., Bolton, E.W., Reinhard, C.T., 2018. Making sense of massive carbon isotope excursions with an inverse carbon cycle model. Journal of Geophysical Research: Biogeosciences 123, 2485-2496.Tarique, M., Rahaman, W., 2018. Assessment of paleo-ocean pH records from boron isotope ratio in the Pacific and Atlantic ocean corals: Role of anthropogenic CO2 forcing and oceanographic factors to pH variability. Biogeosciences Discussions 2018, 1-37.Yang, W., Zuo, R., Wang, X., Song, Y., Jiang, Z., Luo, Q., Zhai, J., Wang, Q., Zhang, C., Zhang, Z., 2019. Sensitivity of lacustrine stromatolites to Cenozoic tectonic and climatic forcing in the southern Junggar Basin, NW China: New insights from mineralogical, stable and clumped isotope compositions. Palaeogeography, Palaeoclimatology, Palaeoecology 514, 109-123.Yin, L., Li, J., Tian, H., Long, X., 2018. Rhenium–osmium and molybdenum isotope systematics of black shales from the Lower Cambrian Niutitang Formation, SW China: Evidence of a well oxygenated ocean at ca. 520?Ma. Chemical Geology 499, 26-42.Extinction EventsDunhill, A.M., Foster, W.J., Azaele, S., Sciberras, J., Twitchett, R.J., 2018. Modelling determinants of extinction across two Mesozoic hyperthermal events. Proceedings of the Royal Society B: Biological Sciences 285, 20180404; DOI: 20180410.20181098/rspb.20182018.20180404.Fujisaki, W., Sawaki, Y., Matsui, Y., Yamamoto, S., Isozaki, Y., Maruyama, S., 2019. Redox condition and nitrogen cycle in the Permian deep mid-ocean: A possible contrast between Panthalassa and Tethys. Global and Planetary Change 172, 179-199.Huang, Y., Chen, Z.-Q., Algeo, T.J., Zhao, L., Baud, A., Bhat, G.M., Zhang, L., Guo, Z., 2019. Two-stage marine anoxia and biotic response during the Permian–Triassic transition in Kashmir, northern India: pyrite framboid evidence. Global and Planetary Change 172, 124-139.Sibert, E., Friedman, M., Hull, P., Hunt, G., Norris, R., 2018. Two pulses of morphological diversification in Pacific pelagic fishes following the Cretaceous–Palaeogene mass extinction. Proceedings of the Royal Society B: Biological Sciences 285, Article 20181194.Song, H., Wignall, P.B., Dunhill, A.M., 2018. Decoupled taxonomic and ecological recoveries from the Permo-Triassic extinction. Science Advances 4, Article eaat5091.White, D.A., Elrick, M., Romaniello, S., Zhang, F., 2018. Global seawater redox trends during the Late Devonian mass extinction detected using U isotopes of marine limestones. Earth and Planetary Science Letters 503, 68-77.Xiao, Y., Wu, K., Tian, L., Benton, M.J., Du, Y., Yang, H., Tong, J., 2018. Framboidal pyrite evidence for persistent low oxygen levels in shallow-marine facies of the Nanpanjiang Basin during the Permian-Triassic transition. Palaeogeography, Palaeoclimatology, Palaeoecology 511, 243-255.Xie, S., 2018. The shift of biogeochemical cycles indicative of the progressive marine ecosystem collapse across the Permian-Triassic boundary: An analog to modern oceans. Science China Earth Sciences 61, 1379-1383.Zheng, W., Gilleaudeau, G.J., Kah, L.C., Anbar, A.D., 2018. Mercury isotope signatures record photic zone euxinia in the Mesoproterozoic ocean. Proceedings of the National Academy of Sciences 115, 10594-10599.Zou, C., Qiu, Z., Wei, H., Dong, D., Lu, B., 2018. Euxinia caused the Late Ordovician extinction: Evidence from pyrite morphology and pyritic sulfur isotopic composition in the Yangtze area, South China. Palaeogeography, Palaeoclimatology, Palaeoecology 511, 1-11.Precambrian GeochemistryLedevin, M., 2019. Chapter 37 - Archean cherts: Formation processes and paleoenvironments, in: Van Kranendonk, M.J., Bennett, V.C., Hoffmann, J.E. (Eds.), Earth's Oldest Rocks (Second Edition). Elsevier, pp. 913-944.Paiste, K., Lepland, A., Zerkle, A.L., Kirsim?e, K., Izon, G., Patel, N.K., McLean, F., Kreitsmann, T., M?nd, K., Bui, T.H., Romashkin, A.E., Rychanchik, D.V., Prave, A.R., 2018. Multiple sulphur isotope records tracking basinal and global processes in the 1.98?Ga Zaonega Formation, NW Russia. Chemical Geology 499, 151-164.Retallack, G.J., Noffke, N., 2019. Are there ancient soils in the 3.7?Ga Isua Greenstone Belt, Greenland? Palaeogeography, Palaeoclimatology, Palaeoecology 514, 18-30.Trail, D., Boehnke, P., Savage, P.S., Liu, M.-C., Miller, M.L., Bindeman, I., 2018. Origin and significance of Si and O isotope heterogeneities in Phanerozoic, Archean, and Hadean zircon. Proceedings of the National Academy of Sciences 1115, 10287-10292.Van Kranendonk, M.J., Bennett, V.C., Hoffmann, J.E., 2019. Earth's Oldest Rocks, 2nd Edition. Elsevier, p. anics/Microfossils/Microbial EvolutionGutiérrez-Preciado, A., Sagha?, A., Moreira, D., Zivanovic, Y., Deschamps, P., López-García, P., 2018. Functional shifts in microbial mats recapitulate early Earth metabolic transitions. Nature Ecology & Evolution 2, 1700-1708.Hickman-Lewis, K., Westall, F., Cavalazzi, B., 2019. Chapter 42 - Traces of early life from the Barberton Greenstone Belt, South Africa, in: Van Kranendonk, M.J., Bennett, V.C., Hoffmann, J.E. (Eds.), Earth's Oldest Rocks (Second Edition). Elsevier, pp. 1029-1058.Kashirtsev, V.A., Parfenova, T.M., Golovko, A.K., Nikitenko, B.L., Zueva, I.N., Chalaya, O.N., 2018. Phenanthrene biomarkers in the organic matter of Precambrian and Phanerozoic deposits and in the oils of the Siberian Platform. Russian Geology and Geophysics 59, 1380-1388.Nutman, A.P., Bennett, V.C., Friend, C.R.L., 2019. Chapter 39 - Eoarchean life From the Isua Supracrustal Belt (Greenland), in: Van Kranendonk, M.J., Bennett, V.C., Hoffmann, J.E. (Eds.), Earth's Oldest Rocks (Second Edition). Elsevier, pp. 965-983.Peters, C.A., George, S.C., 2018. Hydrocarbon biomarkers preserved in carbonate veins of potentially Paleoproterozoic age, and implications for the early biosphere. Geobiology 16, 577-596.Sander, R., Pan, Z., Connell, L.D., Camilleri, M., Grigore, M., Yang, Y., 2018. Controls on methane sorption capacity of Mesoproterozoic gas shales from the Beetaloo Sub-basin, Australia and global shales. International Journal of Coal Geology 199, 65-90.Shields, G.A., 2019. Chapter 36 - Implications of carbonate and chert isotope records for the Early Earth, in: Van Kranendonk, M.J., Bennett, V.C., Hoffmann, J.E. (Eds.), Earth's Oldest Rocks (Second Edition). Elsevier, pp. 901-912.Stanton, C.L., Reinhard, C.T., Kasting, J.F., Ostrom, N.E., Haslun, J.A., Lyons, T.W., Glass, J.B., 2018. Nitrous oxide from chemodenitrification: A possible missing link in the Proterozoic greenhouse and the evolution of aerobic respiration. Geobiology 16, 597-609.Sugitani, K., 2019. Chapter 41 - Early Archean (pre-3.0Ga) cellularly preserved microfossils and microfossil-like structures from the Pilbara Craton, Western Australia—A review, in: Van Kranendonk, M.J., Bennett, V.C., Hoffmann, J.E. (Eds.), Earth's Oldest Rocks (Second Edition). Elsevier, pp. 1007-1028.Van Kranendonk, M.J., Djokic, T., Poole, G., Tadbiri, S., Steller, L., Baumgartner, R., 2019. Chapter 40 - Depositional setting of the fossiliferous, c.3480Ma Dresser Formation, Pilbara Craton: A review, in: Van Kranendonk, M.J., Bennett, V.C., Hoffmann, J.E. (Eds.), Earth's Oldest Rocks (Second Edition). Elsevier, pp. 985-1006.van Zuilen, M.A., 2019. Chapter 38 - The significance of carbonaceous matter to understanding life processes on early Earth, in: Van Kranendonk, M.J., Bennett, V.C., Hoffmann, J.E. (Eds.), Earth's Oldest Rocks (Second Edition). Elsevier, pp. 945-963.Zumberge, J.A., Love, G.D., Cárdenas, P., Sperling, E.A., Gunasekera, S., Rohrssen, M., Grosjean, E., Grotzinger, J.P., Summons, R.E., 2018. Demosponge steroid biomarker 26-methylstigmastane provides evidence for Neoproterozoic animals. Nature Ecology & Evolution 2, 1709-1714.Paleoclimatology/PaleocenographyKochnev, B.B., Pokrovsky, B.G., Kuznetsov, A.B., Marusin, V.V., 2018. C and Sr isotope chemostratigraphy of Vendian-Lower Cambrian carbonate sequences in the central Siberian Platform. Russian Geology and Geophysics 59, 585-605.Zheng, W., Gilleaudeau, G.J., Kah, L.C., Anbar, A.D., 2018. Mercury isotope signatures record photic zone euxinia in the Mesoproterozoic ocean. Proceedings of the National Academy of Sciences 115, 10594-10599.Production/Engineering GeochemistryChen, J., Fang, Z., Qiu, T., 2018. Molecular reconstruction model based on structure oriented lumping and group contribution methods. Chinese Journal of Chemical Engineering 26, 1677-1683.Correa Pabón, R.E., Souza Filho, C.R.d., 2019. Crude oil spectral signatures and empirical models to derive API gravity. Fuel 237, 1119-1131.Djokic, M.R., Muller, H., Ristic, N.D., Akhras, A.R., Symoens, S.H., Marin, G.B., Van Geem, K.M., 2018. Combined characterization using HT-GC?×?GC-FID and FT-ICR MS: A pyrolysis fuel oil case study. Fuel Processing Technology 182, 15-25.El Aily, M., Mansour, E.M., Desouky, S.M., Helmi, M.E., 2019. Modeling viscosity of moderate and light dead oils in the presence of complex aromatic structure. Journal of Petroleum Science and Engineering 173, 426-433.Radwan, O., Gunasekera, T.S., Ruiz, O.N., 2018. Robust multiplex quantitative polymerase chain reaction assay for universal detection of microorganisms in fuel. Energy & Fuels 32, 10530-10539.Ren, Y., Liao, Z., Sun, J., Jiang, B., Wang, J., Yang, Y., Wu, Q., 2019. Molecular reconstruction: Recent progress toward composition modeling of petroleum fractions. Chemical Engineering Journal, 761-775.Spiegel, M.T., Anthony, I.G.M., Brantley, M.R., Hassell, A., Farmer, P.J., Solouki, T., 2018. Reactivities of aromatic protons in crude oil fractions toward Br2 tagging for structural characterization by nuclear magnetic resonance and electron paramagnetic resonance spectroscopy and mass spectrometry. Energy & Fuels 32, 10549-10555.Weigel, S., Stephan, D., 2018. Bitumen characterization with Fourier transform infrared spectroscopy and multivariate evaluation: Prediction of various physical and chemical parameters. Energy & Fuels 32, 10437-10442.Xu, Z.-X., Xu, L., Cheng, J.-H., He, Z.-X., Wang, Q., Hu, X., 2018. Investigation of pathways for transformation of N?heterocycle compounds during sewage sludge pyrolysis process. Fuel Processing Technology 182, 37-44.AsphaltenesAlrashidi, H., Afra, S., Nasr-El-Din, H.A., 2019. Application of natural fatty acids as asphaltenes solvents with inhibition and dispersion effects: A mechanistic study. Journal of Petroleum Science and Engineering 172, 724-730.Bagherzadeh, H., Mansourpour, Z., Dabir, B., 2019. A coupled DEM-CFD analysis of asphaltene particles agglomeration and fragmentation. Journal of Petroleum Science and Engineering 173, 402-414.Barreira, F.R., Reis, L.G., Nunes, R.d.C.P., Filipakis, S.D., Lucas, E.F., 2018. Asphaltenes precipitation onset: Influence of the addition of a second crude oil or its asphaltenes fractions (C3I and C5I). Energy & Fuels 32, 10391-10397.Cho, J., Kim, T.H., Chang, N., Lee, K.S., 2019. Effects of asphaltene deposition-derived formation damage on three-phase hysteretic models for prediction of coupled CO2 enhanced oil recovery and storage performance. Journal of Petroleum Science and Engineering 172, 988-997.Correa Pabón, R.E., Souza Filho, C.R.d., 2019. Crude oil spectral signatures and empirical models to derive API gravity. Fuel 237, 1119-1131.El Aily, M., Mansour, E.M., Desouky, S.M., Helmi, M.E., 2019. Modeling viscosity of moderate and light dead oils in the presence of complex aromatic structure. Journal of Petroleum Science and Engineering 173, 426-433.Esene, C., Rezaei, N., Aborig, A., Zendehboudi, S., 2019. Comprehensive review of carbonated water injection for enhanced oil recovery. Fuel 237, 1086-1107.Fakher, S., Imqam, A., 2019. Asphaltene precipitation and deposition during CO2 injection in nano shale pore structure and its impact on oil recovery. Fuel 237, 1029-1039.Fallah, F., Khabaz, F., Kim, Y.-R., Kommidi, S.R., Haghshenas, H.F., 2019. Molecular dynamics modeling and simulation of bituminous binder chemical aging due to variation of oxidation level and saturate-aromatic-resin-asphaltene fraction. Fuel 237, 71-80.Ghadimi, M., Amani, M.J., Ghaedi, M., Malayeri, M.R., 2019. Modeling of formation damage due to asphaltene deposition in near wellbore region using a cylindrical compositional simulator. Journal of Petroleum Science and Engineering 173, 630-639.Kashirtsev, V.A., 2018. Hydrocarbons occluded by asphaltenes. Russian Geology and Geophysics 59, 975-982.Khormali, A., Sharifov, A.R., Torba, D.I., 2018. Experimental and modeling study of asphaltene adsorption onto the reservoir rocks. Petroleum Science and Technology 36, 1482-1489.Mozes, E., Delgado-Linares, J.G., Cárdenas, A.L., Salazar, F., Pereira, J.C., Bullón, J., 2018. Behavior of asphaltene and asphaltene fractions films on a Langmuir–Blodgett trough and its relationship with proposed molecular structures. Petroleum Science and Technology 36, 1490-1496.Qiao, P., Harbottle, D., Li, Z., Tang, Y., Xu, Z., 2018. Interactions of asphaltene subfractions in organic media of varying aromaticity. Energy & Fuels 32, 10478-10485.Spiegel, M.T., Anthony, I.G.M., Brantley, M.R., Hassell, A., Farmer, P.J., Solouki, T., 2018. Reactivities of aromatic protons in crude oil fractions toward Br2 tagging for structural characterization by nuclear magnetic resonance and electron paramagnetic resonance spectroscopy and mass spectrometry. Energy & Fuels 32, 10549-10555.Weigel, S., Stephan, D., 2018. Bitumen characterization with Fourier transform infrared spectroscopy and multivariate evaluation: Prediction of various physical and chemical parameters. Energy & Fuels 32, 10437-10442.Zheng, C., Brunner, M., Li, H., Zhang, D., Atkin, R., 2019. Dissolution and suspension of asphaltenes with ionic liquids. Fuel 238, 129-138.Interfaces/EORBarbosa, N.S.V., Lima, E.R.A., Tavares, F.W., 2019. Wettability of rock, oil and brine system based on density functional theory. Fluid Phase Equilibria 479, 99-105.Bazyari, A., Soulgani, B.S., Jamialahmadi, M., Dehghan Monfared, A., Zeinijahromi, A., 2018. Performance of smart water in clay-rich sandstones: Experimental and theoretical analysis. Energy & Fuels 32, 10354-10366.Chen, M., Dai, J., Liu, X., Qin, M., Pei, Y., Wang, Z., 2018. Differences in the fluid characteristics between spontaneous imbibition and drainage in tight sandstone cores from nuclear magnetic resonance. Energy & Fuels 32, 10333-10343.Chen, Q., You, L., Kang, Y., Dou, L., Sheng, J.J., 2018. Gypsum-crystallization-induced fracturing during shale–fluid reactions and application for shale stimulation. Energy & Fuels 32, 10367-10381.Ding, M., Wang, Y., Han, Y., Gao, M., Wang, R., 2019. Interactions in bypassed oil-CO2 systems and their utilization in enhancing the recovery of bypassed oil. Fuel 237, 1068-1078.Dopffel, N., K?gler, F., Hartmann, H., Costea, P.I., Mahler, E., Herold, A., Alkan, H., 2018. Microbial induced mineral precipitations caused by nitrate treatment for souring control during microbial enhanced oil recovery (MEOR). International Biodeterioration & Biodegradation 135, 71-79.Esene, C., Rezaei, N., Aborig, A., Zendehboudi, S., 2019. Comprehensive review of carbonated water injection for enhanced oil recovery. Fuel 237, 1086-1107.Li, K., Wang, D., Jiang, S., 2018. Review on enhanced oil recovery by nanofluids. Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles 73, Article 37.Ning, J., Wei, B., Mao, R., Wang, Y., Shang, J., Sun, L., 2018. Pore-level observations of an alkali-induced mild O/W emulsion flooding for economic enhanced oil recovery. Energy & Fuels 32, 10595-10604.Raipuria, V., Rani, N., Sharma, V.P., Naiya, T.K., 2018. Use of nanoparticle derived from natural source and its application in drilling fluid. International Journal of Oil, Gas and Coal Technology 19, 283-295.Sun, L., Hao, X., Dou, H., Adenutsi, C.D., Li, Z., Zhang, Y., 2018. Co-optimization of oil recovery and CO2 storage for cyclic CO2 flooding in ultralow permeability reservoirs. Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles 73, Article 42.Wani, O.B., Lai, C.-Y., Quadri, S.M.R., Chiesa, M., Alhassan, S.M., 2018. Understanding the wettability of calcite (CaCO3) using higher spatial resolution. Energy & Fuels 32, 10344-10353.Yin, T., Yang, Z., Dong, Z., Lin, M., Zhang, J., 2019. Physicochemical properties and potential applications of silica-based amphiphilic Janus nanosheets for enhanced oil recovery. Fuel 237, 344-351.Zhang, J., Liu, F., Yang, H., Zhu, Y., Wang, X., Hua, Z., 2018. Effect of ion type on the interaction between polar model oil and mica substrate: A chemical force microscopy study. Energy & Fuels 32, 10486-10492.Heavy Oil ProductionCuijpers, M.C.M., Boot, M.D., Deen, N.G., Golombok, M., 2019. Sulphur and viscosity reductions in heavy hydrocarbons by subcritical water processing. Journal of Petroleum Science and Engineering 172, 1069-1076.Huang, S., Chen, X., Liu, H., Xia, Y., Jiang, J., Cao, M., Li, A., Yang, M., 2019. Experimental and numerical study of steam-chamber evolution during solvent-enhanced steam flooding in thin heavy-oil reservoirs. Journal of Petroleum Science and Engineering 172, 776-786.Mercier, P.H.J., Tyo, D.D., Zborowski, A., Kung, J., Patarachao, B., Kingston, D.M., Couillard, M., Robertson, G., McCracken, T., Ng, S., 2019. First quantification of <2?μm clay, <0.2?μm ultrafines and solids wettability in process streams from naphthenic froth treatment plant at commercial mined oil sands operations. Fuel 237, 961-976.Recent SedimentsBao, R., Voort, T.S., Zhao, M., Guo, X., Montlu?on, D.B., McIntyre, C., Eglinton, T.I., 2018. Influence of hydrodynamic processes on the fate of sedimentary organic matter on continental margins. Global Biogeochemical Cycles 32, 1420-1432.Currie, B., Utne-Palm, A.C., Salvanes, A.G.V., 2018. Winning ways with hydrogen sulphide on the Namibian Shelf. Frontiers in Marine Science 5, 341. doi: 310.3389/fmars.2018.00341.He, D., Simoneit, B.R.T., Cloutier, J.B., Jaffé, R., 2018. Early diagenesis of triterpenoids derived from mangroves in a subtropical estuary. Organic Geochemistry 125, 196-211.Heidke, I., Scholz, D., Hoffmann, T., 2018. Quantification of lignin oxidation products as vegetation biomarkers in speleothems and cave drip water. Biogeosciences 15, 5831-5845.Jongejans, L.L., Strauss, J., Lenz, J., Peterse, F., Mangelsdorf, K., Fuchs, M., Grosse, G., 2018. Organic matter characteristics in yedoma and thermokarst deposits on Baldwin Peninsula, west Alaska. Biogeosciences 15, 6033-6048.Kisand, V., Talas, L., Kisand, A., Stivrins, N., Reitalu, T., Alliksaar, T., Vassiljev, J., Liiv, M., Heinsalu, A., Sepp?, H., Veski, S., 2018. From microbial eukaryotes to metazoan vertebrates: Wide spectrum paleo-diversity in sedimentary ancient DNA over the last ~14,500?years. Geobiology 16, 628-639.Liao, W., Hu, J., Peng, P.a., 2018. Burial of organic carbon in the Taiwan Strait. Journal of Geophysical Research: Oceans 123, 6639-6652.Liao, W., Hu, J., Zhou, H., Hu, J., Peng, P.a., Deng, W., 2018. Sources and distribution of sedimentary organic matter in the Beibu Gulf, China: Application of multiple proxies. Marine Chemistry 206, 74-83.Liu, J., An, Z., Liu, H., 2018. Leaf wax n-alkane distributions across plant types in the central Chinese Loess Plateau. Organic Geochemistry 125, 260-269.M?nd, K., Kirsim?e, K., Lepland, A., Crosby, C.H., Bailey, J.V., Konhauser, K.O., Wirth, R., Schreiber, A., Lumiste, K., 2018. Authigenesis of biomorphic apatite particles from Benguela upwelling zone sediments off Namibia: The role of organic matter in sedimentary apatite nucleation and growth. Geobiology 16, 640-658.Mathews, R.P., Singh, B.D., Singh, V.P., 2018. Evaluation of organic matter, hydrocarbon source, and depositional environment of onshore Warkalli sedimentary sequence from Kerala-Konkan Basin, South India. Journal of the Geological Society of India 92, 407-418.Plancq, J., McColl, J.L., Bendle, J.A., Seki, O., Couto, J.M., Henderson, A.C.G., Yamashita, Y., Kawamura, K., Toney, J.L., 2018. Genomic identification of the long-chain alkenone producer in freshwater Lake Toyoni, Japan: implications for temperature reconstructions. Organic Geochemistry 125, 189-195.Sorokin, D.Y., Messina, E., La Cono, V., Ferrer, M., Ciordia, S., Mena, M.C., Toshchakov, S.V., Golyshin, P.N., Yakimov, M.M., 2018. Sulfur respiration in a group of facultatively anaerobic natronoarchaea ubiquitous in hypersaline soda lakes. Frontiers in Microbiology 9, 2359. doi: 2310.3389/fmicb.2018.02359.Weber, Y., Sinninghe Damsté, J.S., Zopfi, J., De Jonge, C., Gilli, A., Schubert, C.J., Lepori, F., Lehmann, M.F., Niemann, H., 2018. Redox-dependent niche differentiation provides evidence for multiple bacterial sources of glycerol tetraether lipids in lakes. Proceedings of the National Academy of Sciences 115, 10926-10931.Wik, M., Johnson, J.E., Crill, P.M., DeStasio, J.P., Erickson, L., Halloran, M.J., Fahnestock, M.F., Crawford, M.K., Phillips, S.C., Varner, R.K., 2018. Sediment characteristics and methane ebullition in three subarctic lakes. Journal of Geophysical Research: Biogeosciences 123, 2399-2411.Zhang, R., Li, T., Russell, J., Zhou, Y., Zhang, F., Liu, Z., Guan, M., Han, Q., 2018. High-resolution reconstruction of historical flood events in the Changjiang River catchment based on geochemical and biomarker records. Chemical Geology 499, 58-70.Zwiep, K.L., Hennekam, R., Donders, T.H., van Helmond, N.A.G.M., de Lange, G.J., Sangiorgi, F., 2018. Marine productivity, water column processes and seafloor anoxia in relation to Nile discharge during sapropels S1 and S3. Quaternary Science Reviews 200, 178-190.Atmospheric GeochemistryJiang, H.-X., Li, J., Tang, J., Mo, Y.-Z., Zhang, G., 2018. Applications of high-resolution mass spectrometry in studies of brown carbon. Chinese Journal of Analytical Chemistry 46, 1528-1538.Hydrosphere GeochemistryAndrews, M.G., Jacobson, A.D., Osburn, M.R., Flynn, T.M., 2018. Dissolved carbon dynamics in meltwaters from the Russell Glacier, Greenland Ice Sheet. Journal of Geophysical Research: Biogeosciences 123, 2922-2940.Arnosti, C., Reintjes, G., Amann, R., 2018. A mechanistic microbial underpinning for the size-reactivity continuum of dissolved organic carbon degradation. Marine Chemistry 206, 93-99.Attermeyer, K., Catalán, N., Einarsdottir, K., Freixa, A., Groeneveld, M., Hawkes, J.A., Bergquist, J., Tranvik, L.J., 2018. Organic carbon processing during transport through boreal inland waters: Particles as important sites. Journal of Geophysical Research: Biogeosciences 123, 2412-2428.Balzano, S., Lattaud, J., Villanueva, L., Rampen, S.W., Brussaard, C.P.D., van Bleijswijk, J., Bale, N., Sinninghe Damsté, J.S., Schouten, S., 2018. A quest for the biological sources of long chain alkyl diols in the western tropical North Atlantic Ocean. Biogeosciences 15, 5951-5968.Bartl, I., Hellemann, D., Rabouille, C., Schulz, K., Tallberg, P., Hietanen, S., Voss, M., 2018. Particulate organic matter controls benthic microbial N retention and N removal in contrasting estuaries of the Baltic Sea. Biogeosciences Discussions 2018, 1-37.Benk, S.A., Li, Y., Roth, V.-N., Gleixner, G., 2018. Lignin dimers as potential markers for 14C-young terrestrial dissolved organic matter in the critical zone. Frontiers in Earth Science 6, 168. doi: 110.3389/feart.2018.00168.Chen, X., Zhang, F., Lao, Y., Wang, X., Du, J., Santos, I.R., 2018. Submarine groundwater discharge-derived carbon fluxes in mangroves: An important component of blue carbon budgets? Journal of Geophysical Research: Oceans 123, 6962-6979.Cui, Q., He, X., Liu, Q., Bai, Y., Chen, C.-T.A., Chen, X., Pan, D., 2018. Estimation of lateral DOC transport in marginal sea based on remote sensing and numerical simulation. Journal of Geophysical Research: Oceans 123, 5525-5542.Edokpa, D.A., Evans, M.G., Boult, S., Rothwell, J.J., 2018. Size fractionation of dissolved organic nitrogen in peatland fluvial systems. Environmental Science & Technology 52, 11198-11205.Hemingway, J.D., Spencer, R.G.M., Podgorski, D.C., Zito, P., Sen, I.S., Galy, V.V., 2019. Glacier meltwater and monsoon precipitation drive Upper Ganges Basin dissolved organic matter composition. Geochimica et Cosmochimica Acta 244, 216-228.King, A.C.F., Giorio, C., Wolff, E., Thomas, E., Karroca, O., Roverso, M., Schwikowski, M., Tapparo, A., Gambaro, A., Kalberer, M., 2019. A new method for the determination of primary and secondary terrestrial and marine biomarkers in ice cores using liquid chromatography high-resolution mass spectrometry. Talanta 194, 233-242.Lee, M.-H., Osburn, C.L., Shin, K.-H., Hur, J., 2018. New insight into the applicability of spectroscopic indices for dissolved organic matter (DOM) source discrimination in aquatic systems affected by biogeochemical processes. Water Research 147, 164-176.Li, X., Ding, Y., Xu, J., He, X., Han, T., Kang, S., Wu, Q., Mika, S., Yu, Z., Li, Q., 2018. Importance of mountain glaciers as a source of dissolved organic carbon. Journal of Geophysical Research: Earth Surface 123, 2123-2134.Li, Y., Song, G., Massicotte, P., Yang, F., Li, R., Xie, H., 2018. Distribution, seasonality, optical characteristics, and fluxes of dissolved organic matter (DOM) in the Pearl River (Zhujiang) estuary, China. Biogeosciences Discussions 2018, 1-53.Luzius, C., Guillemette, F., Podgorski, D.C., Kellerman, A.M., Spencer, R.G.M., 2018. Drivers of dissolved organic matter in the vent and major conduits of the world's largest freshwater spring. Journal of Geophysical Research: Biogeosciences 123, 2775-2790.Mao, R., Li, S., 2019. Temporal controls on dissolved organic carbon biodegradation in subtropical rivers: Initial chemical composition versus stoichiometry. Science of The Total Environment 651, 3064-3069.Osmont, D., Sigl, M., Eichler, A., Jenk, T.M., Schwikowski, M., 2018. A Holocene black carbon ice-core record of biomass burning in the Amazon Basin from Illimani, Bolivia. Climate of the Past Discussions 2018, 1-21.Politova, N.V., Savvichev, A.S., Klyuvitkin, A.A., Kravchishina, M.D., Demidov, A.B., Lein, A.Y., Gladyshev, V.S., 2018. Biochemical characteristics of suspended particulate matter on a latitudinal transect in the North Atlantic. Oceanology 58, 573-582.Schwehr, K.A., Xu, C., Chiu, M.-H., Zhang, S., Sun, L., Lin, P., Beaver, M., Jackson, C., Agueda, O., Bergen, C., Chin, W.-C., Quigg, A., Santschi, P.H., 2018. Protein: Polysaccharide ratio in exopolymeric substances controlling the surface tension of seawater in the presence or absence of surrogate Macondo oil with and without Corexit. Marine Chemistry 206, 84-92.Stephens, B.M., Porrachia, M., Dovel, S., Roadman, M., Goericke, R., Aluwihare, L.I., 2018. Nonsinking organic matter production in the California Current. Global Biogeochemical Cycles 32, 1386-1405.Vidal, M., Aspillaga, E., Teixidor-Toneu, I., Delgado-Huertas, A., 2018. Lateral transport of N-rich dissolved organic matter strengthens phosphorus deficiency in western subtropical North Atlantic. Global Biogeochemical Cycles 32, 1350-1366.Wu, Y., Eglinton, T.I., Zhang, J., Montlucon, D.B., 2018. Spatiotemporal variation of the quality, origin, and age of particulate organic matter transported by the Yangtze River (Changjiang). Journal of Geophysical Research: Biogeosciences 123, 2908-2921.Ye, F., Guo, W., Wei, G., Jia, G., 2018. The sources and transformations of dissolved organic matter in the Pearl River Estuary, China, as revealed by stable isotopes. Journal of Geophysical Research: Oceans 123, 6893-6908.Zangrando, R., Corami, F., Barbaro, E., Grosso, A., Barbante, C., Turetta, C., Capodaglio, G., Gambaro, A., 2019. Free phenolic compounds in waters of the Ross Sea. Science of The Total Environment 650, 2117-2128.Zhao, Y., Song, K., 2018. Relationships between DOC and CDOM based on the total carbon-specific fluorescence intensities for river waters across China. Journal of Geophysical Research: Biogeosciences 123, 2353-2361.Soil GeochemistryChaignaud, P., Morawe, M., Besaury, L., Kr?ber, E., Vuilleumier, S., Bringel, F., Kolb, S., 2018. Methanol consumption drives the bacterial chloromethane sink in a forest soil. The ISME Journal 12, 2681-2693.Craine, J.M., Elmore, A.J., Wang, L., Aranibar, J., Bauters, M., Boeckx, P., Crowley, B.E., Dawes, M.A., Delzon, S., Fajardo, A., Fang, Y., Fujiyoshi, L., Gray, A., Guerrieri, R., Gundale, M.J., Hawke, D.J., Hietz, P., Jonard, M., Kearsley, E., Kenzo, T., Makarov, M., Mara?ón-Jiménez, S., McGlynn, T.P., McNeil, B.E., Mosher, S.G., Nelson, D.M., Peri, P.L., Roggy, J.C., Sanders-DeMott, R., Song, M., Szpak, P., Templer, P.H., Van der Colff, D., Werner, C., Xu, X., Yang, Y., Yu, G., Zmudczyńska-Skarbek, K., 2018. Isotopic evidence for oligotrophication of terrestrial ecosystems. Nature Ecology & Evolution 2, 1735-1744.Doerr, S.H., Santín, C., Merino, A., Belcher, C.M., Baxter, G., 2018. Fire as a removal mechanism of pyrogenic carbon from the environment: Effects of fire and pyrogenic carbon characteristics. Frontiers in Earth Science 6, 127. doi: 110.3389/feart.2018.00127.Gerschlauer, F., Saiz, G., Costa, D.S., Kleyer, M., Dannenmann, M., Kiese, R., 2018. Stable carbon and nitrogen isotopic composition of leaves, litter, and soils of various tropical ecosystems along an elevational and land-use gradient at Mount Kilimanjaro, Tanzania. Biogeosciences Discussions 2018, 1-27.Poggenburg, C., Mikutta, R., Liebmann, P., Koch, M., Guggenberger, G., 2018. Siderophore-promoted dissolution of ferrihydrite associated with adsorbed and coprecipitated natural organic matter. Organic Geochemistry 125, 177-188.Strehse, R., Bohne, H., Amha, Y., Leinweber, P., 2018. The influence of salt on dissolved organic matter from peat soils. Organic Geochemistry 125, 270-276.Watteau, F., Villemin, G., 2018. Soil microstructures examined through transmission electron microscopy reveal soil-microorganisms interactions. Frontiers in Environmental Science 6, 106. doi: 110.3389/fenvs.2018.00106.Zavarzina, A.G., Lisov, A.V., Leontievsky, A.A., 2018. The role of ligninolytic enzymes laccase and a versatile peroxidase of the white-rot fungus Lentinus tigrinus in biotransformation of soil humic matter: Comparative in vivo study. Journal of Geophysical Research: Biogeosciences 123, 2727-2742.Remote Sensing-Hydrocarbon SeepageCui, Q., He, X., Liu, Q., Bai, Y., Chen, C.-T.A., Chen, X., Pan, D., 2018. Estimation of lateral DOC transport in marginal sea based on remote sensing and numerical simulation. Journal of Geophysical Research: Oceans 123, 5525-5542.Green, H.S., Fuller, S.A., Meyer, A.W., Joyce, P.S., Aeppli, C., Nelson, R.K., Swarthout, R.F., Valentine, D.L., White, H.K., Reddy, C.M., 2018. Pelagic tar balls collected in the North Atlantic Ocean and Caribbean Sea from 1988 to 2016 have natural and anthropogenic origins. Marine Pollution Bulletin 137, 352-359.Ho, S., Imbert, P., Hovland, M., Wetzel, A., Blouet, J.-P., Carruthers, D., 2018. Downslope-shifting pockmarks: interplay between hydrocarbon leakage, sedimentations, currents and slope’s topography. International Journal of Earth Sciences 107, 2907-2929.Miyajima, Y., Ijiri, A., Miyake, A., Hasegawa, T., 2018. Origin of methane and heavier hydrocarbons entrapped within Miocene methane-seep carbonates from central Japan. Chemical Geology 498, 83-95.Miyakawa, K., Okumura, F., 2018. Improvements in drill-core headspace gas analysis for samples from microbially active depths. Geofluids 2018, Article 2436814.Paganoni, M., King, J.J., Foschi, M., Mellor-Jones, K., Cartwright, J.A., 2019. A natural gas hydrate system on the Exmouth Plateau (NW shelf of Australia) sourced by thermogenic hydrocarbon leakage. Marine and Petroleum Geology 99, 370-392.Rivard, B., Harris, N.B., Feng, J., Dong, T., 2018. Inferring total organic carbon and major element geochemical and mineralogical characteristics of shale core from hyperspectral imagery. American Association of Petroleum Geologists Bulletin 102, 2101-2121.Schmidt, C., Burwicz, E., Hensen, C., Wallmann, K., Martínez-Loriente, S., Gràcia, E., 2018. Genesis of mud volcano fluids in the Gulf of Cadiz using a novel basin-scale model approach. Geochimica et Cosmochimica Acta 243, 186-204.Wu, T., Sahling, H., Feseker, T., Rendle-Bühring, R., Wei, J., Wintersteller, P., Marcon, Y., Pape, T., R?mer, M., Bohrmann, G., 2019. Morphology and activity of the Helgoland Mud Volcano in the Sorokin Trough, Northern Black Sea. Marine and Petroleum Geology 99, 227-236.Active Seepage Sea of Marmara. Deep Sea Research Part II Volume 153Ruffine, L., ?a?atay, M.N., Géli, L., 2018. Fluids and processes at the seismically active fault zone in the Sea of Marmara. Deep Sea Research Part II: Topical Studies in Oceanography 153, 1-3.Gasperini, L., Polonia, A., ?a?atay, M.N., 2018. Fluid flow, deformation rates and the submarine record of major earthquakes in the Sea of Marmara, along the North-Anatolian Fault system. Deep Sea Research Part II: Topical Studies in Oceanography 153, 4-16.Grall, C., Henry, P., Dupré, S., Géli, L., Scalabrin, C., Zitter, T.A.C., Sengor, A.M.C., Namik Cagatay, M., Cifci, G., 2018. Upward migration of gas in an active tectonic basin: An example from the Sea of Marmara. Deep Sea Research Part II: Topical Studies in Oceanography 153, 17-35.Ruffine, L., Ondreas, H., Blanc-Valleron, M.-M., Teichert, B.M.A., Scalabrin, C., Rinnert, E., Birot, D., Croguennec, C., Ponzevera, E., Pierre, C., Donval, J.-P., Alix, A.-S., Germain, Y., Bignon, L., Etoubleau, J., Caprais, J.-C., Knoery, J., Lesongeur, F., Thomas, B., Roubi, A., Legoix, L., Burnard, P., Chevalier, N., Lu, H., Dupré, S., Fontanier, C., Dissard, D., Olgun, N., Yang, H., Strauss, H., ?zaksoy, V., Perchoc, J., Podeur, C., Tarditi, C., ?zbeki, E., Guyader, V., Marty, B., Madre, D., Pitel-Roudaut, M., Grall, C., Embriaco, D., Polonia, A., Gasperini, L., ?a?atay, M.N., Henry, P., Géli, L., 2018. Multidisciplinary investigation on cold seeps with vigorous gas emissions in the Sea of Marmara (MarsiteCruise): Strategy for site detection and sampling and first scientific outcome. Deep Sea Research Part II: Topical Studies in Oceanography 153, 36-47.Ruffine, L., Donval, J.-P., Croguennec, C., Burnard, P., Lu, H., Germain, Y., Legoix, L.N., Bignon, L., ?a?atay, M.N., Marty, B., Madre, D., Pitel-Roudaut, M., Henry, P., Géli, L., 2018. Multiple gas reservoirs are responsible for the gas emissions along the Marmara fault network. Deep Sea Research Part II: Topical Studies in Oceanography 153, 48-60.Fontanier, C., Dissard, D., Ruffine, L., Mamo, B., Ponzevera, E., Pelleter, E., Baudin, F., Roubi, A., Chéron, S., Boissier, A., Gayet, N., Bermell-Fleury, S., Pitel, M., Guyader, V., Lesongeur, F., Savignac, F., 2018. Living (stained) deep-sea foraminifera from the Sea of Marmara: A preliminary study. Deep Sea Research Part II: Topical Studies in Oceanography 153, 61-78.Teichert, B.M.A., Chevalier, N., Gussone, N., Bayon, G., Ponzevera, E., Ruffine, L., Strauss, H., 2018. Sulfate-dependent anaerobic oxidation of methane at a highly dynamic bubbling site in the Eastern Sea of Marmara (?inarcik Basin). Deep Sea Research Part II: Topical Studies in Oceanography 153, 79-91.?a?atay, M.N., Y?ld?z, G., Bayon, G., Ruffine, L., Henry, P., 2018. Seafloor authigenic carbonate crusts along the submerged part of the North Anatolian Fault in the Sea of Marmara: Mineralogy, geochemistry, textures and genesis. Deep Sea Research Part II: Topical Studies in Oceanography 153, 92-109.Akhoudas, C., Chevalier, N., Blanc-Valleron, M.M., Klein, V., Mendez-Millan, M., Demange, J., Dalliah, S., Rommevaux, V., Boudouma, O., Pierre, C., Ruffine, L., 2018. Methane-derived stromatolitic carbonate crust from an active fluid seepage in the western basin of the Sea of Marmara: mineralogical, isotopic and molecular geochemical characterization. Deep Sea Research Part II: Topical Studies in Oceanography 153, 110-120.Yang, H., Lu, H., Ruffine, L., 2018. Geochemical characteristics of iron in sediments from the Sea of Marmara. Deep Sea Research Part II: Topical Studies in Oceanography 153, 121-130.Henry, P., Grall, C., Kende, J., Viseur, S., ?zeren, M.S., ?eng?r, A.M.C., Dupré, S., Scalabrin, C., Géli, L., 2018. A statistical approach to relationships between fluid emissions and faults: The Sea of Marmara case. Deep Sea Research Part II: Topical Studies in Oceanography 153, 131-143.Source Rocks/Depositional EnvironmentsBaeten, J., Mees, F., Marinova, E., De Dapper, M., De Vos, D., Huyge, D., Van Strydonck, M., Vandenberghe, D., Linseele, V., 2018. Late Pleistocene coprolites from Qurta (Egypt) and the potential of interdisciplinary research involving micromorphology, plant macrofossil and biomarker analyses. Review of Palaeobotany and Palynology 259, 93-111.Belozerov, V.B., Krasnoshchekova, L.A., Merkulov, V.P., 2018. Shale strata development problems and origin of the Bazhenov Formation fractures in the southeast of the West Siberian Plate. Russian Geology and Geophysics 59, 88-95.Dong, D., Shi, Z., Sun, S., Guo, C., Zhang, C., Guo, W., Guan, Q., Zhang, M., Jiang, S., Zhang, L., Ma, C., Wu, J., Li, N., Chang, Y., 2018. Factors controlling microfractures in black shale: A case study of Ordovician Wufeng Formation–Silurian Longmaxi Formation in Shuanghe Profile, Changning area, Sichuan Basin, SW China. Petroleum Exploration and Development 45, 818-829.Ekoko Eric, B., Philip, F., Emile, E., Isaac Konfor, N., Salomon Betrant, B., Daniel Florent, A., Bessa Armel Zacharie, E., 2019. Geochemical characteristics of shales in the Mamfe Basin, South West Cameroon: Implication for depositional environments and oxidation conditions. Journal of African Earth Sciences 149, 131-142.Gentzis, T., Carvajal-Ortiz, H., Selim, S.S., Tahoun, S.S., El-Shafeiy, M., Ocubalidet, S., Ali, A.A.-M., 2018. Depositional environment and characteristics of Late Eocene carbonaceous swampy tidal flat facies in the Fayoum Basin, Egypt. International Journal of Coal Geology 200, 45-58.Grishkevich, V.F., 2018. Neocomian paleogeography, gas hydrate cementation of sediments, and abnormal sequences of the Bazhenov Formation (West Siberia). Russian Geology and Geophysics 59, 157-167.Hakimi, M.H., Alaug, A.S., Ahmed, A.F., Yahya, M.M.A., 2019. Sedimentary environmental conditions and petroleum source rock potential of the Late Jurassic Arwa Member shales in Al-Jawf sub-basin, Yemen. Journal of African Earth Sciences 149, 474-486.Hazra, B., Wood, D.A., Kumar, S., Saha, S., Dutta, S., Kumari, P., Singh, A.K., 2018. Fractal disposition, porosity characterization and relationships to thermal maturity for the Lower Permian Raniganj basin shales, India. Journal of Natural Gas Science and Engineering 59, 452-465.Hu, G., Yang, R., Wang, L., Hu, W., Cao, J., 2019. Hydrocarbon potential and depositional environment of the Lower Cretaceous black mudstones and shales in the coastal Guangdong Province, China. Marine and Petroleum Geology 99, 92-106.Hui, R., Ding, A., 2018. Role of microorganisms in oil generation (II): Hydrogen metabolism and organic matter input from many origins. Acta Sedimentologica Sinica 26, 1023-1031 Jiang, S., Wang, Y., Wang, S., Peng, P., Dong, D., Wu, W., Li, X., Guan, Q., 2018. Distribution prediction of graphitized organic matter areas in the lower Cambrian Qiongzhusi shale in the Central Sichuan paleo-uplift and its surrounding areas in the Sichuan Basin. Natural Gas Industry 38, 19-27.Jubb, A.M., Botterell, P.J., Birdwell, J.E., Burruss, R.C., Hackley, P.C., Valentine, B.J., Hatcherian, J.J., Wilson, S.A., 2018. High microscale variability in Raman thermal maturity estimates from shale organic matter. International Journal of Coal Geology 199, 1-9.Kashirtsev, V.A., Nikitenko, B.L., Peshchevitskaya, E.B., Fursenko, E.A., 2018. Biogeochemistry and microfossils of the Upper Jurassic and Lower Cretaceous, Anabar Bay, Laptev Sea. Russian Geology and Geophysics 59, 386-404.Kayukova, G.P., Mikhailova, A.N., Kosachev, I.P., Pronin, N.V., Sotnikov, O.S., Evdokimov, A.М., Khisamov, R.S., 2018. Hydrothermal transformations of organic matter of low permeability rocks from Domanic Formation of the Romashkino oil field. Petroleum Science and Technology 36, 1463-1470.Kayukova, G.P., Mikhailova, A.N., Kosachev, I.P., Sitnov, S.A., Sotnikov, O.S., Nazimov, N.A., 2018. Peculiarities of hydrocarbon generation in procsses of transformation of organic matter of Domanikovian rocks in various media of hydrothermal system. Chemistry and Technology of Fuels and Oils 54, 446-456.Keighley, D., Boonsue, S., Hall, D., 2018. Phosphatized tungsten-metabolizing coccoid microbes interpreted from oil shale of an Eocene lake, Green River Formation, Utah, USA. Geobiology 16, 610-627.Kingsley, O.K., Umeji, O.P., 2018. Oil shale prospects of Imo Formation Niger Delta Basin, southeastern Nigeria: Palynofacies, organic thermal maturation and source rock perspective. Journal of the Geological Society of India 92, 498-506.Kontorovich, A.E., Ponomareva, E.V., Burshtein, L.M., Glinskikh, V.N., Kim, N.S., Kostyreva, E.A., Pavlova, M.A., Rodchenko, A.P., Yan, P.A., 2018. Distribution of organic matter in rocks of the Bazhenov horizon (West Siberia). Russian Geology and Geophysics 59, 285-298.Liao, J., Lu, H., Feng, Q., Zhou, Y., Shi, Q., Peng, P.a., Sheng, G., 2018. Two novel decamethylhenicosanes (C31H64) identified in a Maoming Basin shale, China. Organic Geochemistry 125, 212-219.Liu, B., Shi, J., Fu, X., Lyu, Y., Sun, X., Gong, L., Bai, Y., 2018. Petrological characteristics and shale oil enrichment of lacustrine fine-grained sedimentary system: A case study of organic-rich shale in first member of Cretaceous Qingshankou Formation in Gulong Sag, Songliao Basin, NE China. Petroleum Exploration and Development 45, 884-894.Liu, J., Liu, Q., Zhu, D., Meng, Q., Liu, W., Qiu, D., Huang, Z., 2018. The role of deep fluid in the formation of organic-rich source rocks. Journal of Natural Gas Geoscience 3, 171-180.Liu, Y., Zhu, Y., Chen, S., Wang, Y., Song, Y., 2018. Evaluation of spatial alignment of kerogen in shale using high-resolution transmission electron microscopy, Raman spectroscopy, and Fourier transform infrared. Energy & Fuels 32, 10616-10627.Ma, P., Li, Y., Wang, C., Zheng, L., Lv, D., Zou, Y., Li, S., 2018. Oligocene-Miocene source rocks of the Zhongcang Basin: Implications for hydrocarbon potential differentiation between lake basins in Central Tibet. International Journal of Coal Geology 199, 124-137.Nikitenko, B.L., Devyatov, V.P., Lebedeva, N.K., Basov, V.A., Fursenko, E.A., Goryacheva, A.A., Peshchevitskaya, E.B., Glinskikh, L.A., Khafaeva, S.N., 2018. Jurassic and Cretaceous biostratigraphy and organic matter geochemistry of the New Siberian Islands (Russian Arctic). Russian Geology and Geophysics 59, 168-185.Pandey, B., Pathak, D.B., Mathur, N., Jaitly, A.K., Singh, A.K., Singh, P.K., 2018. A preliminary evaluation on the prospects of hydrocarbon potential in the carbonaceous shales of Spiti and Chikkim formations, Tethys Himalaya, India. Journal of the Geological Society of India 92, 427-434.Peters, K.E., Hackley, P.C., Thomas, J.J., Pomerantz, A.E., 2018. Suppression of vitrinite reflectance by bitumen generated from liptinite during hydrous pyrolysis of artificial source rock. Organic Geochemistry 125, 220-228.Rivard, B., Harris, N.B., Feng, J., Dong, T., 2018. Inferring total organic carbon and major element geochemical and mineralogical characteristics of shale core from hyperspectral imagery. American Association of Petroleum Geologists Bulletin 102, 2101-2121.Shah, S.B.A., Ahmed, A., 2018. Hydrocarbon source rock potential of Paleocene and Jurassic deposits in the Panjpir oilfield subsurface, Punjab Platform, Pakistan. Arabian Journal of Geosciences 11, Article 607.Sharma, A., Phukan, S., Saikia, B.K., Baruah, B.P., 2018. Geochemical evaluation of the hydrocarbon prospects of carbonaceous shale and coal of Barail Group, Upper Assam Basin. International Journal of Oil, Gas and Coal Technology 19, 263-282.Shukla, M.K., Sharma, A., 2018. Carbon isotope and REE characteristics of the Paleocene–Eocene shallow marine Subathu formation from the NW Himalaya (India) and their paleo-environmental implications. Chemie der Erde 78, 314-322.Wang, M., Chen, Y., Song, G., Steele-MacInnis, M., Liu, Q., Wang, X., Zhang, X., Zhao, Z., Liu, W., Zhang, H., Zhou, Z., 2018. Formation of bedding-parallel, fibrous calcite veins in laminated source rocks of the Eocene Dongying Depression: A growth model based on petrographic observations. International Journal of Coal Geology 200, 18-35.Wei, W., Algeo, T.J., Lu, Y., Lu, Y., Liu, H., Zhang, S., Peng, L., Zhang, J., Chen, L., 2018. Identifying marine incursions into the Paleogene Bohai Bay Basin lake system in northeastern China. International Journal of Coal Geology 200, 1-17.Wu, L., Lu, Y., Jiang, S., Liu, X., He, G., 2018. Effects of volcanic activities in Ordovician Wufeng–Silurian Longmaxi period on organic-rich shale in the Upper Yangtze area, South China. Petroleum Exploration and Development 45, 862-872.Xiao, H., Wang, T.G., Li, M., Lai, H., Liu, J., Mao, F., Tang, Y., 2019. Geochemical characteristics of Cretaceous Yogou Formation source rocks and oil-source correlation within a sequence stratigraphic framework in the Termit Basin, Niger. Journal of Petroleum Science and Engineering 172, 360-372.Zhang, M., Li, J., Chen, J., 2018. Thermal effect on the distribution of rearranged hopanes in hydrocarbon source rocks. Acta Sedimentologica Sinica 26, 1033-1039.Zheng, F., Hsu, C.S., Zhang, Y., Sun, Y., Wu, Y., Lu, H., Sun, X., Shi, Q., 2018. Simultaneous detection of vanadyl, nickel, iron, and gallium porphyrins in marine shales from the Eagle Ford Formation, South Texas. Energy & Fuels 32, 10382-10390.Zheng, Y., Liao, Y., Wang, Y., Xiong, Y., Peng, P.a., 2018. Organic geochemical characteristics, mineralogy, petrophysical properties, and shale gas prospects of the Wufeng–Longmaxi shales in Sanquan Town of the Nanchuan District, Chongqing. American Association of Petroleum Geologists Bulletin 102, 2239-2265.Zhu, G., Chen, F., Wang, M., Zhang, Z., Ren, R., Wu, L., 2018. Discovery of the lower Cambrian high-quality source rocks and deep oil and gas exploration potential in the Tarim Basin, China. American Association of Petroleum Geologists Bulletin 102, 2123-2151.Unconventional ResourcesAn, C., Killough, J., Mi, L., 2019. Stress-dependent permeability of organic-rich shale reservoirs: Impacts of stress changes and matrix shrinkage. Journal of Petroleum Science and Engineering 172, 1034-1047.Assef, Y., Kantzas, A., Pereira Almao, P., 2019. Numerical modelling of cyclic CO2 injection in unconventional tight oil resources; trivial effects of heterogeneity and hysteresis in Bakken formation. Fuel 236, 1512-1528.Cheng, Z., Ning, Z., Wang, Q., Zeng, Y., Qi, R., Huang, L., Zhang, W., 2019. The effect of pore structure on non-Darcy flow in porous media using the lattice Boltzmann method. Journal of Petroleum Science and Engineering 172, 391-400.Dong, D., Shi, Z., Guan, Q., Jiang, S., Zhang, M., Zhang, C., Wang, S., Sun, S., Yu, R., Liu, D., Peng, P., Wang, S., 2018. Progress, challenges and prospects of shale gas exploration in the Wufeng–Longmaxi reservoirs in the Sichuan Basin. Natural Gas Industry B 5, 415-424.El Sharawy, M.S., Gaafar, G.R., 2019. Pore - Throat size distribution indices and their relationships with the petrophysical properties of conventional and unconventional clastic reservoirs. Marine and Petroleum Geology 99, 122-134.Fakher, S., Imqam, A., 2019. Asphaltene precipitation and deposition during CO2 injection in nano shale pore structure and its impact on oil recovery. Fuel 237, 1029-1039.Gao, Z., Hu, Q., 2018. Pore structure and spontaneous imbibition characteristics of marine and continental shales in China. American Association of Petroleum Geologists Bulletin 102, 1941-1961.Gottardi, R., Mason, S.L., 2018. Characterization of the natural fracture system of the Eagle Ford Formation (Val Verde County, Texas). American Association of Petroleum Geologists Bulletin 102, 1963-1984.Gu, X., Pu, C., Khan, N., Wu, F., Huang, F., Xu, H., 2019. The visual and quantitative study of remaining oil micro-occurrence caused by spontaneous imbibition in extra-low permeability sandstone using computed tomography. Fuel 237, 152-162.Gu, Y., Wan, Q., Yu, W., Li, X., Yu, Z., 2018. The effects of clay minerals and organic matter on nanoscale pores in Lower Paleozoic shale gas reservoirs, Guizhou, China. Acta Geochimica 37, 791-804.Guo, S., Peng, Y., 2019. Determination method of shale gas content: A case study in the Ordos Basin, China. Journal of Petroleum Science and Engineering 173, 95-100.Guo, X., Hu, D., Liu, R., Wei, X., Wei, F., 2018. Geological conditions and exploration potential of Permian marine–continent transitional facies shale gas in the Sichuan Basin Natural Gas Industry 38, 11-18.Han, S., Cheng, Y., Gao, Q., Yan, C., Han, Z., 2018. Experimental study of the effect of liquid nitrogen pretreatment on shale fracability. Journal of Natural Gas Science and Engineering 60, 11-23.Hong, S.K., Shinn, Y.J., Choi, J., Lee, H.S., 2018. Estimation of original kerogen type and hydrogen index using inorganic geochemical proxies: Implications for assessing shale gas potential in the Devonian Horn River Formation of western Canada. American Association of Petroleum Geologists Bulletin 102, 2075-2099.Hu, D., Wei, Z., Liu, R., Fan, Z., Han, J., 2018. Development characteristics and shale gas exploration potential of the Lower Carboniferous black shale in the Guizhong Depression. Natural Gas Industry 38, 28-37.Huang, H., Sun, W., Ji, W., Chen, L., Jiang, Z., Bai, Y., Tang, X., Du, K., Qu, Y., Ouyang, S., 2018. Impact of laminae on gas storage capacity: A case study in Shanxi Formation, Xiasiwan Area, Ordos Basin, China. Journal of Natural Gas Science and Engineering 60, 92-102.?nan, S., Al Badairy, H., ?nan, T., Al Zahrani, A., 2018. Formation and occurrence of organic matter-hosted porosity in shales. International Journal of Coal Geology 199, 39-51.Li, Y., Hu, Z., Liu, X., Duan, X., Gao, S., Wang, W., Chang, J., 2019. Pressure-dependent equilibrium molecular simulation of shale gas and its distribution and motion characteristics in organic-rich nano-slit. Fuel 237, 1040-1049.Lijun, L., Jun, Y., Hai, S., Zhaoqin, H., Xia, Y., Longlong, L., 2019. Compositional modeling of shale condensate gas flow with multiple transport mechanisms. Journal of Petroleum Science and Engineering 172, 1186-1201.Liu, D., Li, H., Zhang, C., Wang, Q., Peng, P.a., 2019. Experimental investigation of pore development of the Chang 7 member shale in the Ordos basin under semi-closed high-pressure pyrolysis. Marine and Petroleum Geology 99, 17-26.Liu, Q.-g., Wang, W.-h., Liu, H., Zhang, G., Li, L.-x., Zhao, Y.-l., 2018. Production rate analysis of fractured horizontal well considering multitransport mechanisms in shale gas reservoir. Geofluids 2018, Article 3148298.Mi, J., Wang, H., He, K., Bai, J., Liu, C., 2018. Demethylation as a mechanism for isotopic reversals of shale gas generated at over maturity. Journal of Analytical and Applied Pyrolysis 135, 361-368.Morga, R., Kamińska, M., 2018. The chemical composition of graptolite periderm in the gas shales from the Baltic Basin of Poland. International Journal of Coal Geology 199, 10-18.Piane, C.D., Bourdet, J., Josh, M., Clennell, M.B., Rickard, W.D.A., Saunders, M., Sherwood, N., Li, Z., Dewhurst, D.N., Raven, M.D., 2018. Organic matter network in post-mature Marcellus Shale: Effects on petrophysical properties. American Association of Petroleum Geologists Bulletin 102, 2239-2265.Qi, Y., Ju, Y., Huang, C., Zhu, H., Bao, Y., Wu, J., Meng, S., Chen, W., 2019. Influences of organic matter and kaolinite on pore structures of transitional organic-rich mudstone with an emphasis on S2 controlling specific surface area. Fuel 237, 860-873.Qiu, Z., Zou, C., Li, X., Wang, H., Dong, D., Lu, B., Zhou, S., Shi, Z., Feng, Z., Zhang, M., 2018. Discussion on the contribution of graptolite to organic enrichment and gas?shale reservoir: A case study of the Wufeng–Longmaxi shales in South?China. Journal of Natural Gas Geoscience 3, 147-156.Sander, R., Pan, Z., Connell, L.D., Camilleri, M., Grigore, M., Yang, Y., 2018. Controls on methane sorption capacity of Mesoproterozoic gas shales from the Beetaloo Sub-basin, Australia and global shales. International Journal of Coal Geology 199, 65-90.Sui, W., Tian, Y., Yao, C., 2018. Investigation of microscopic pore structure variations of shale due to hydration effects through SEM fixed-point observation experiments. Petroleum Exploration and Development 45, 955-962.Takbiri-Borujeni, A., Fathi, E., Kazemi, M., Belyadi, F., 2019. An integrated multiscale model for gas storage and transport in shale reservoirs. Fuel 237, 1228-1243.Vega, B., Kovscek, A.R., 2019. A systematic study of internal gas generation in shale source rocks using analog experiments. Journal of Petroleum Science and Engineering 173, 209-221.Yang, F., Hu, B., Xu, S., Meng, Q., Krooss, B.M., 2018. Thermodynamic characteristic of methane sorption on shales from oil, gas, and condensate windows. Energy & Fuels 32, 10443-10456.You, L., Cheng, Q., Kang, Y., Chen, Q., Dou, L., Zhou, Y., 2018. Imbibition of oxidative fluid into organic-rich shale: Implication for oxidizing stimulation. Energy & Fuels 32, 10457-10468.Zhang, K., Jia, N., 2019. Confined fluid interfacial tension calculations and evaluations in nanopores. Fuel 237, 1161-1176.Zhang, W., Wang, Q., Ning, Z., Zhang, R., Huang, L., Cheng, Z., 2018. Relationship between the stress sensitivity and pore structure of shale. Journal of Natural Gas Science and Engineering 59, 440-451.Zhang, Y., He, Z., Jiang, S., Lu, S., Xiao, D., Chen, G., Li, Y., 2019. Fracture types in the lower Cambrian shale and their effect on shale gas accumulation, Upper Yangtze. Marine and Petroleum Geology 99, 282-291.Zhao, D., Guo, Y., Zhu, Y., Wang, G., Liu, J., Chong, X., Zhang, J., 2018. Micropore characteristics and geological significance of pyrite in shale rocks of Longmaxi Formation. Acta Sedimentologica Sinica 26, 864-876.Zhao, G., Wang, C., 2019. Influence of CO2 on the adsorption of CH4 on shale using low-field nuclear magnetic resonance technique. Fuel 238, 51-58.Zhao, J., Ren, L., Shen, C., Li, Y., 2018. Latest research progresses in network fracturing theories and technologies for shale gas reservoirs. Natural Gas Industry B 5, 533-546.Zhuo, X., Yan, Q., Zhang, J., Zhang, L., Chen, X., Ma, L., 2018. Conceptual models for correlation between detrital particles contents and pore distribution of shale: Taking the Silurian Longmaxi Formation in northwestern Guizhou as an example. Acta Sedimentologica Sinica 26, 969-980.AbstractsAchermann, S., Fal?s, P., Joss, A., Mansfeldt, C.B., Men, Y., Vogler, B., Fenner, K., 2018. Trends in micropollutant biotransformation along a solids retention time gradient. Environmental Science & Technology 52, 11601-11611. many polar organic micropollutants, biotransformation by activated sludge microorganisms is a major removal process during wastewater treatment. However, our current understanding of how wastewater treatment operations influence microbial communities and their micropollutant biotransformation potential is limited, leaving major parts of observed variability in biotransformation rates across treatment facilities unexplained. Here, we present biotransformation rate constants for 42 micropollutants belonging to different chemical classes along a gradient of solids retention time (SRT). The geometric mean of biomass-normalized first-order rate constants shows a clear increase between 3 and 15 d SRT by 160% and 87%, respectively, in two experiments. However, individual micropollutants show a variety of trends. Rate constants of oxidative biotransformation reactions mostly increased with SRT. Yet, nitrifying activity could be excluded as primary driver. For substances undergoing other than oxidative reactions, i.e., mostly substitution-type reactions, more diverse dependencies on SRT were observed. Most remarkably, characteristic trends were observed for groups of substances undergoing similar types of initial transformation reaction, suggesting that shared enzymes or enzyme systems that are conjointly regulated catalyze biotransformation reactions within such groups. These findings open up opportunities for correlating rate constants with measures of enzyme abundance such as genes or gene products, which in turn should help to identify enzymes associated with the respective biotransformation reactions.Akhoudas, C., Chevalier, N., Blanc-Valleron, M.M., Klein, V., Mendez-Millan, M., Demange, J., Dalliah, S., Rommevaux, V., Boudouma, O., Pierre, C., Ruffine, L., 2018. Methane-derived stromatolitic carbonate crust from an active fluid seepage in the western basin of the Sea of Marmara: mineralogical, isotopic and molecular geochemical characterization. Deep Sea Research Part II: Topical Studies in Oceanography 153, 110-120. seeps along the North Anatolian fault in the Sea of Marmara (Turkey) were explored during submersible dives of the Marsite cruise in November 2014 when sediments, pore waters and carbonate crusts were sampled at active fluid seeping sites. In this study, we investigate the mineralogy, carbon and oxygen isotopic compositions and the lipid biomarkers of a carbonate crust from the western Tekirda? basin of the Sea of Marmara. This crust exhibits a laminated domal structure that resembles stromatolite. The mineralogy of authigenic seep-carbonate is mostly represented by aragonite associated with minor amounts of high-magnesian calcite. The abundance of pyrite associated with the authigenic seep-carbonate points to very intense bacterial sulfate reduction. The carbon (?42.6‰ to ?34.4‰) and oxygen (?1.5‰ to +1.1‰) isotopic compositions of the authigenic seep-carbonate crust indicate that carbonate precipitation was related to anaerobic oxidation of methane and occurred in mixtures of bottom seawater with brackish water expelled from the underlying sediments. Abundant microbial lipid biomarkers with negative δ13C values (?121‰ to ?96‰), confirm that anaerobic oxidation of methane (AOM) coupled with sulfate reduction, was mediated by methanotrophic archaea (ANME) and sulfate reducing bacteria (SRB). Diagnostic lipid fingerprints indicate that ANME-2 archaea and associated SRB were the prevalent AOM-mediating consortia, which characterize moderate to high methane flow at this site. Moreover, changes in microbial lipid distribution within the carbonate crust suggest a variation in the intensity of methane emission.Ak?l, C., Robinson, R.C., 2018. Genomes of Asgard archaea encode profilins that regulate actin. Nature 562, 439-443. origin of the eukaryotic cell is unresolved. Metagenomics sequencing has recently identified several potential eukaryotic gene homologues in Asgard archaea, consistent with the hypothesis that the eukaryotic cell evolved from within the Archaea domain. However, many of these eukaryotic-like sequences are highly divergent and the organisms have yet to be imaged or cultivated, which brings into question the extent to which these archaeal proteins represent functional equivalents of their eukaryotic counterparts. Here we show that Asgard archaea encode functional profilins and thereby establish that this archaeal superphylum has a regulated actin cytoskeleton, one of the hallmarks of the eukaryotic cell. Loki profilin-1, Loki profilin-2 and Odin profilin adopt the typical profilin fold and are able to interact with rabbit actin—an interaction that involves proteins from species that diverged more than 1.2 billion years ago. Biochemical experiments reveal that mammalian actin polymerizes in the presence of Asgard profilins; however, Loki, Odin and Heimdall profilins impede pointed-end elongation. These archaeal profilins also retard the spontaneous nucleation of actin filaments, an effect that is reduced in the presence of phospholipids. Asgard profilins do not interact with polyproline motifs and the profilin–polyproline interaction therefore probably evolved later in the Eukarya lineage. These results suggest that Asgard archaea possess a primordial, polar, profilin-regulated actin system, which may be localized to membranes owing to the sensitivity of Asgard profilins to phospholipids. Because Asgard archaea are also predicted to encode potential eukaryotic-like genes involved in membrane-trafficking and endocytosis, imaging is now necessary to elucidate whether these organisms are capable of generating eukaryotic-like membrane dynamics that are regulated by actin, such as are observed in eukaryotic cell movement, podosomes and endocytosis.Al-Mojel, A., Dera, G., Razin, P., Le Nindre, Y.-M., 2018. Carbon and oxygen isotope stratigraphy of Jurassic platform carbonates from Saudi Arabia: Implications for diagenesis, correlations and global paleoenvironmental changes. Palaeogeography, Palaeoclimatology, Palaeoecology 511, 388-402. carbon cycle disturbances reflected by carbon isotope excursions (CIE) have been reported in the Jurassic successions of Euro-Boreal and Mediterranean basins. However, sedimentary and geochemical data from other domains are still required to unravel the global or regional nature of paleoenvironmental disturbances and identify the potential triggers. Here, we present biostratigraphically well-constrained (middle Toarcian to lower Kimmeridgian) bulk-rock δ13C and δ18O data from central Saudi Arabia. Five major negative δ18O excursions are identified in back-reef facies below sequence boundaries and disconformities (Aalenian-Bajocian boundary, upper Bajocian, middle Bathonian, upper Callovian and lower Kimmeridgian), suggesting that these carbonates underwent intense meteoric diagenesis during partial or major subaerial exposures of the Arabian Platform. The δ13C record is less altered and shows correlations with the regional relative sea-level changes influencing the productivity levels and inflows of fluvial (12C-enriched) or oceanic (12C-depleted) waters onto the platform. Overall, most of the δ13C variations recorded at the scale of the Arabian Platform within the lower and middle Jurassic are in agreement with NW Tethyan data. Among these variations, the increase in δ13C values recorded in the middle Toarcian, lower Bajocian, and lower Bathonian zigzag Zone indicate a considerable increase of productivity and 12Corg burial concomitant with global sea-level rises. Conversely, the occurrence of major but diachronous negative CIEs at the Aalenian-Bajocian boundary and around the lower-upper Bajocian transition are interpreted as accelerations of terrestrial 12Corg transfer to the ocean and atmosphere linked to regional but widespread emergences of landmasses. Whether global (eustatic) or regional (tectonic), all these sea-level changes and carbon transfers could be distal consequences of successive episodes of the Pangean breakup.Alberts, M.E., Chua, G., Muench, D.G., 2019. Exposure to naphthenic acids and the acid extractable organic fraction from oil sands process-affected water alters the subcellular structure and dynamics of plant cells. Science of The Total Environment 651, 2830-2844. sands surface mining generates vast quantities of oil sands process-affected water (OSPW) as a by-product of bitumen extraction. The acid extractable organic (AEO) fraction of OSPW contains several contaminants, including naphthenic acids (NAs). While responses of living organisms to NA and AEO exposure have been described at the developmental, physiological, metabolic and gene expression levels, the effects of these compounds at the cellular and subcellular level are limited. Using live cell fluorescence microscopy and a suite of fluorescent marker proteins, we studied the intracellular responses of the plant cell cytoskeleton and several membrane-bound organelles to NA and AEO treatments. A rapid disassembly of cortical microtubules and a decrease in dynamics associated with actin filaments was observed in response to these treatments. Concomitantly, the integrity and dynamics of mitochondria, peroxisomes, Golgi stacks, and endoplasmic reticulum were also altered. AEO treatments were the most toxic to cells and resulted in the accumulation reactive oxygen species. This study provides foundational evidence for intracellular responses to NA and AEO exposure using two evolutionarily diverse model plant cell types. This cellular assay could be used to identify the most toxic components of AEO sub-fractions, and assist in determining the effectiveness of OSPW remediation efforts.Alcamán-Arias, M.E., Pedrós-Alió, C., Tamames, J., Fernández, C., Pérez-Pantoja, D., Vásquez, M., Díez, B., 2018. Diurnal changes in active carbon and nitrogen pathways along the temperature gradient in Porcelana hot spring microbial mat. Frontiers in Microbiology 9, 2353. doi: 10.3389/fmicb.2018.02353., carbon and nitrogen uptake, and gene transcription of microbial mat communities in Porcelana neutral hot spring (Northern Chilean Patagonia) were analyzed using metagenomics, metatranscriptomics and isotopically labeled carbon (H13CO3) and nitrogen (15NH4Cl and K15NO3) assimilation rates. The microbial mat community included 31 phyla, of which only Cyanobacteria and Chloroflexi were dominant. At 58°C both phyla co-occurred, with similar contributions in relative abundances in metagenomes and total transcriptional activity. At 66°C, filamentous anoxygenic phototrophic Chloroflexi were >90% responsible for the total transcriptional activity recovered, while Cyanobacteria contributed most metagenomics and metatranscriptomics reads at 48°C. According to such reads, phototrophy was carried out both through oxygenic photosynthesis by Cyanobacteria (mostly Mastigocladus) and anoxygenic phototrophy due mainly to Chloroflexi. Inorganic carbon assimilation through the Calvin–Benson cycle was almost exclusively due to Mastigocladus, which was the main primary producer at lower temperatures. Two other CO2 fixation pathways were active at certain times and temperatures as indicated by transcripts: 3-hydroxypropionate (3-HP) bi-cycle due to Chloroflexi and 3-hydroxypropionate-4-hydroxybutyrate (HH) cycle carried out by Thaumarchaeota. The active transcription of the genes involved in these C-fixation pathways correlated with high in situ determined carbon fixation rates. In situ measurements of ammonia assimilation and nitrogen fixation (exclusively attributed to Cyanobacteria and mostly to Mastigocladus sp.) showed these were the most important nitrogen acquisition pathways at 58 and 48°C. At 66°C ammonia oxidation genes were actively transcribed (mostly due to Thaumarchaeota). Reads indicated that denitrification was present as a nitrogen sink at all temperatures and that dissimilatory nitrate reduction to ammonia (DNRA) contributed very little. The combination of metagenomic and metatranscriptomic analysis with in situ assimilation rates, allowed the reconstruction of day and night carbon and nitrogen assimilation pathways together with the contribution of keystone microorganisms in this natural hot spring microbial mat.Alrashidi, H., Afra, S., Nasr-El-Din, H.A., 2019. Application of natural fatty acids as asphaltenes solvents with inhibition and dispersion effects: A mechanistic study. Journal of Petroleum Science and Engineering 172, 724-730. precipitation, flocculation, and deposition may cause severe damages to reservoirs, wells, and production facilities. Asphaltenes precipitation may occur during all production stages, e.g., primary depletion, acidizing jobs, and the injection of rich gas or carbon dioxide. The organic deposition removal is considered a costly workover job with the current oil prices. The solvents that are usually used are toluene and xylene, which are considered carcinogenic and toxic chemicals. Also, the use of a dispersant to inhibit the organic deposition can be expensive, as it is required for the life of the well. The objective of the present study is to propose new types of chemicals that can be primarily used as asphaltenes solvents while they can exhibit asphaltenes inhibition and dispersion effects as well. The efficiencies of these natural fatty acids were compared with the effectiveness of the combination of nonylphenol formaldehyde resin as a synthetic dispersant and toluene, in terms of the inhibition of asphaltenes precipitation as well as dissolving and dispersion of deposited asphaltenes. A Kuwaiti crude oil sample was used in this study with an API of approximately 38° and asphaltenes content of 2?wt%, yet showing severe asphaltenes precipitation problem during production stage. The effects of the tested chemicals on the behavior of crude oil and its asphaltenes content were evaluated using infra-red spectroscopy, UV–vis spectroscopy, and dynamic light scattering. The results of this study show that the natural fatty acids can inhibit asphaltenes precipitation and disperse aggregates of asphaltenes. Asphaltenes size distribution was decreased from 10?μm in the neat sample to 1–2?μm in the treated solutions. Moreover, the asphaltenes precipitation onset point was delayed after the model oil was treated with these fatty acids. The primary advantages of these fatty acids when used as solvents are their high flash points, green nature, and abilities to inhibit asphaltenes precipitation and disperse asphaltenes aggregates. The main working mechanisms for these chemicals were determined to be acid-base reactions and steric hindrance through aliphatic side chains. Despite of their lower efficiencies compared to nonylphenol formaldehyde resin when used solely in the treatment, since these chemicals are naturally occurred, environmentally friendly, and cost effective, they would be proper substitutions for the commercial dispersants.An, C., Killough, J., Mi, L., 2019. Stress-dependent permeability of organic-rich shale reservoirs: Impacts of stress changes and matrix shrinkage. Journal of Petroleum Science and Engineering 172, 1034-1047. stress is gradually increased and permeability is gradually reduced during reservoir depletion caused by hydrocarbon production, while the organic-rich matrix might experience a shrinkage process that will boost the permeability. The main objective of this paper was to develop a mathematical simulator coupling gas flow process, geomechanics effects, and matrix shrinkage in order to evaluate their influences on reservoir permeability and production performance of organic-rich shale reservoirs. The mesh was divided into three different continuums: organic matter, non-organic matter, and natural fractures. Matrix shrinkage was only considered for organic matter because of gas desorption process, and the stress-dependent permeability was considered for all three sub-pore media. The flow and stress-equilibrium equations were solved by the fixed-stress sequential method, where the flow equations are solved first, followed by the mechanics equations. The displacements are solved for each grid node by finite element method, and the grid pressure is solved by the integral finite difference method. Different stress-dependent correlations are chosen to separately apply to these three sub-pore media. Based on the correlations, the porosity and permeability are updated at end of each time step. A synthetic reservoir model was built, where the permeability change and the cumulative gas production is calculated at each time step. Besides, the sensitivity analyses were investigated for Total Organic Carbon (TOC), matrix permeability, Young's modulus, Poisson's ratio, and bottom hole pressure. The coupled model was validated by comparing with the analytical solution of Mandel's consolidation problem. Numerical results show that the permeability and cumulative production is significantly reduced when the stress-dependent permeability is considered. The matrix shrinkage on organic matter could provide an obvious rebound on cumulative production at the late producing stage, because the permeability is boosted by the media shrinkage at low pressure. However, the production enhancement is highly related to bottom hole pressure and Total Organic Carbon. Due to large permeability decline, a higher TOC does not necessarily bring a higher cumulative production. When the stress-dependent permeability is considered, a larger matrix permeability encounters a bigger loss of production rate. A higher cumulative production is predicted from a lower either Young's modulus or Poisson's ratio. A large bottom hole pressure could offset certain production loss caused by the permeability decline. Overall, the triple-porosity coupled simulator can quantitatively interpret the impacts of matrix shrinkage and geomechanics on permeability change and gas production performance for organic-rich shale reservoirs. That provides more realistic production performance evaluation and economic assessment when the stress-dependent permeability needs to be considered. Additionally, this coupled flow-geomechanics model is also available to simulate the permeability change when water injection is performed to maintain reservoir pressure and prevent the permeability decline.An, S.H., Van, S.L., Chon, B.H., 2018. Production characteristics of gas hydrate reservoirs associated with steam injection and depressurisation rate. International Journal of Oil, Gas and Coal Technology 19, 296-315. study examined the gas production characteristics of gas hydrate using steam injection and depressurisation methods for representatives of unconsolidated reservoirs. The properties of the gas production rate were analysed at 20% depressurisation following the steam temperature (280 and 300°C) and steam injection time (30, 60, and 200 s) in an unconsolidated artificial reservoir in a 3D experiment. The dissociation time and gas production rate were analysed according to the depressurisation rate (40%, 50%, and 60%) under constant gas hydrate saturation in an unconsolidated artificial reservoir in a 1D experiment. The results showed that the production of methane gas increases with increasing gas saturation and longer steam injection time at a low temperature (280°C) compared to a high temperature (300°C). In addition, the use of hot water provided better efficiency than steam in terms of maintaining the heat for dissociation and production processes.Andrews, M.G., Jacobson, A.D., Osburn, M.R., Flynn, T.M., 2018. Dissolved carbon dynamics in meltwaters from the Russell Glacier, Greenland Ice Sheet. Journal of Geophysical Research: Biogeosciences 123, 2922-2940. of the Greenland Ice Sheet (GrIS) has accelerated in recent decades. Given the close association between the water and carbon (C) cycles, melting of the GrIS may also drive local and global C cycle feedback. However, few studies have quantified such feedback, which may have important implications for predicting future climate or understanding linkages between ice sheet destabilization and climate change in the geologic past. Here we investigate seasonal and interannual dissolved C cycling at the margin of the Russell Glacier, west Greenland. By synthesizing isotopic analyses of water (δ18O) and C (δ13C and Δ14C) with geomicrobiological observations, we present evidence for previously unknown connections between the GrIS's supraglacial and subglacial dissolved C cycles. Supraglacial streams have variable concentrations of dissolved organic carbon (DOC) and are the dominant source of DOC in subglacial discharge. Supraglacial stream dissolved inorganic carbon (DIC) concentrations are uniform and sourced from a spatially and temporally constant mixture of organic C (~25%) respired by aerobic heterotrophs inhabiting the GrIS surface and dissolved atmospheric C (~75%). Supraglacial inputs account for ~50% of subglacial discharge DIC. The remaining subglacial DIC derives from carbonate weathering and microbial CO2 production, with the latter attributable to abundant anaerobic heterotrophic communities observed in subglacial discharge. Furthermore, we find that supraglacial streams deliver young DOC to the subglacial environment during snowmelt and rain events. These pulses of organic C may drive heterotrophic microbial respiration, with the cumulative effect being a seasonal shift in the source of basal DIC, from microbial‐ to carbonate‐dominated. Anthony, I.G.M., Brantley, M.R., Floyd, A.R., Gaw, C.A., Solouki, T., 2018. Improving accuracy and confidence of chemical identification by gas chromatography/vacuum ultraviolet spectroscopy-mass spectrometry: Parallel gas chromatography, vacuum ultraviolet, and mass spectrometry library searches. Analytical Chemistry 90, 12307-12313. identification often relies on matching measured chemical properties and/or spectral “fingerprints” of unknowns against their precompiled libraries. Chromatography, absorption spectroscopy, and mass spectrometry are all among analytical approaches that provide chemical measurement databases amenable to library searching. Occasionally, using conventional single-library or single-domain searches can lead to misidentification of unknowns. To improve chemical identification, we present a tandem gas chromatography/vacuum ultraviolet-mass spectrometry (GC/VUV-MS) chemical identification approach that utilizes databases from GC, VUV spectroscopy, and mass spectrometry analyses for a “multidomain” library search. Using standard chemical mixtures as well as aroma compounds as test cases, we demonstrate that multidatabase library searches utilizing GC, VUV, and MS data results in fully correct identification of chemical mixtures examined here that could only be identified with a 69.2% or an 88.5% success rate with MS or VUV library searches alone, respectively. Additionally, we introduce a library- and data domain-independent metric for evaluating the confidence of library search results. Using multidomain library searches improves both the chemical assignment accuracy and confidence.Arnosti, C., Reintjes, G., Amann, R., 2018. A mechanistic microbial underpinning for the size-reactivity continuum of dissolved organic carbon degradation. Marine Chemistry 206, 93-99. reservoir of dissolved organic carbon (DOC) in the ocean is modified by multiple input and removal processes. Incubation experiments as well as measurements of oceanic DOC have demonstrated that the high molecular weight (HMW) fraction of DOC typically has a younger radiocarbon age and is more reactive biologically than the low molecular weight (LMW) fraction of DOC. These observations have been summarized as a ‘size-reactivity continuum’ of DOC reactivity, but mechanistic explanations for these observations have been lacking. Here we describe how our recent discovery of ‘selfish’ HMW organic matter uptake among bacteria in surface ocean waters may help explain the rapid removal of HMW DOC. ‘Selfish’ substrate uptake by bacteria encompasses rapid binding and partial hydrolysis of intact polysaccharides on the outer membrane of bacteria, seamlessly followed by the transport of large oligosaccharide fragments into the periplasm with little to no loss of LMW hydrolysis products. ‘Selfish’ bacteria therefore process HMW substrates in a manner distinct from bacteria that carry out extracellular hydrolysis that yields LMW hydrolysis products in the environment. Recognition of the presence and prevalence of selfish bacteria in the ocean has profound implications for carbon flow – the source and quantity of LMW substrates made available to non-extracellular-enzyme producing bacteria – as well as for efforts to model and measure bacterial interactions during organic matter degradation. This discovery also highlights the importance of targeted substrate binding and uptake as key (often understudied) factors in geochemical investigations of microbially driven carbon cycling in the ocean. We conclude with some speculative thoughts about the factors that may determine the prevalence of selfish substrate uptake in the environment.Arranz-Gibert, P., Vanderschuren, K., Isaacs, F.J., 2018. Next-generation genetic code expansion. Current Opinion in Chemical Biology 46, 203-211. of the translation apparatus has permitted the site-specific incorporation of nonstandard amino acids (nsAAs) into proteins, thereby expanding the genetic code of organisms. Conventional approaches have focused on porting tRNAs and aminoacyl-tRNA synthetases (aaRS) from archaea into bacterial and eukaryotic systems where they have been engineered to site-specifically encode nsAAs. More recent work in genome engineering has opened up the possibilities of whole genome recoding, in which organisms with alternative genetic codes have been constructed whereby codons removed from the genetic code can be repurposed as new sense codons dedicated for incorporation of nsAAs. These advances, together with the advent of engineered ribosomes and new molecular evolution methods, enable multisite incorporation of nsAAs and nonstandard monomers (nsM) paving the way for the template-directed production of functionalized proteins, new classes of polymers, and genetically encoded materials.Asakura, T., Date, Y., Kikuchi, J., 2018. Application of ensemble deep neural network to metabolomics studies. Analytica Chimica Acta 1037, 230-236. neural network (DNN) is a useful machine learning approach, although its applicability to metabolomics studies has rarely been explored. Here we describe the development of an ensemble DNN (EDNN) algorithm and its applicability to metabolomics studies. As a model case, the developed EDNN approach was applied to metabolomics data of various fish species collected from Japan coastal and estuarine environments for evaluation of a regression performance compared with conventional DNN, random forest, and support vector machine algorithms. This study also revealed that the metabolic profiles of fish muscles were correlated with fish size (growth) in a species-dependent manner. The performance of EDNN regression for fish size based on metabolic profiles was superior to that of DNN, random forest, and support vector machine algorithms. The EDNN approach, therefore, should be helpful for analyses of regression and concerns pertaining to classification in metabolomics studies.Assef, Y., Kantzas, A., Pereira Almao, P., 2019. Numerical modelling of cyclic CO2 injection in unconventional tight oil resources; trivial effects of heterogeneity and hysteresis in Bakken formation. Fuel 236, 1512-1528. impact of rock heterogeneity on the performance of cyclic gas injection is a key element in tight oil reservoir modeling. Dependency of relative permeability on saturation history during cyclic CO2 injection (CCI) in various operational constraints affects the oil recovery in different ways. Numerous studies exist on the hydraulically fractured horizontal wells in unconventional resources, especially on cyclic gas injection performance. However, because of simplifications, the uncertainty due to permeability heterogeneity and dependency of reservoir gas extent on saturation history has not been considered in simulation models. A poor understanding of the variables affecting CO2 injection efficiency might result in unsuccessful treatments and project failures. The aim of the present work is to numerically model the physical properties of matrix heterogeneity and relative permeability hysteresis, which are influential in reservoir performance and should not be ignored during CCI. In this work, a compositional simulation model is built based on the Bakken formation geological settings, well production and crude oil PVT data. To embody heterogeneity, matrix and natural fracture effective permeability fields are log-normally populated. Four permeability maps based on Dykstra-Parsons (DP) coefficients are generated and applied in a sector model. A relative permeability hysteresis model is incorporated within the simulator using the Killough’s method. Hence, the effect of hysteresis-induced gas retardation on oil recovery and CO2 retention can be studied during CCI in which strong flow reversals happens. A compositional field-scale simulation of CCI is conducted and recovery performance is investigated as well as retained CO2 saturation. The simulation results revealed that production is greatly affected by heterogeneity at early stages of reservoir life. Uneven flow in the presence of heterogeneity leads to lower recovery during primary depletion. This effect is more highlighted after implementing CCI since injected gas is prevented from uniform distribution further and deep into the reservoir. Dissolution gas trapping is also modeled with inclusion of relative permeability hysteresis. Recovered oil from the hysteretic model illustrates a minor effect on CO2 trapping at near-miscible conditions. However, CO2 retention improves oil recovery at immiscible injection. In this model shortcomings of uncertainties associated with the simplified reservoir models in terms of uniformity in absolute permeability and relative permeability are reduced. Our results highlight the underlying mechanisms of lower recovery induced by heterogeneity and of improved efficiency due to hysteresis.Aszyk, J., Byliński, H., Namie?nik, J., Kot-Wasik, A., 2018. Main strategies, analytical trends and challenges in LC-MS and ambient mass spectrometry–based metabolomics. TrAC Trends in Analytical Chemistry 108, 278-295. plethora of analytical LC-MS-based methods have been successfully applied to analyses of complex samples of various origin for metabolomics investigations. Over the last ten years, the substantial evolution of ambient mass spectrometry (AMS) techniques has highlighted their tremendous potential in metabolomic studies due to the minimal sample pretreatment requirement and the ability to analyse samples in their native state. This review illustrates the present state of the art in application of the LC-MS- and AMS-based techniques in various fields of metabolomics. We focused on the AMS-based techniques that have most commonly been applied in metabolomics studies. Our review covers the main strategies and challenges identified in the implementation of these approaches, as well as key limiting factors, such as sample preparation, ionization techniques and quantitation capabilities. We?believe that the present paper represents the first attempt to compare these two approaches and will be useful in future metabolomics studies.Attermeyer, K., Catalán, N., Einarsdottir, K., Freixa, A., Groeneveld, M., Hawkes, J.A., Bergquist, J., Tranvik, L.J., 2018. Organic carbon processing during transport through boreal inland waters: Particles as important sites. Journal of Geophysical Research: Biogeosciences 123, 2412-2428. degradation and transformation of organic carbon (C) in inland waters result in significant CO2 emissions from inland waters. Even though most of the C in inland waters occurs as dissolved organic carbon (DOC), studies on particulate organic carbon (POC) and how it influences the overall reactivity of organic C in transport are still scarce. We sampled 30 aquatic ecosystems following an aquatic continuum including peat surface waters, streams, rivers, and lakes. We report DOC and POC degradation rates, relate degradation patterns to environmental data across these systems, and present qualitative changes in dissolved organic matter and particulate organic matter during degradation. Microbial degradation rates of POC were approximately 15 times higher compared to degradation of DOC, with POC half‐lives of only 17 ± 3 (mean ± SE) days across all sampled aquatic ecosystems. Rapid POC decay was accompanied by a shift in particulate C:N ratios, whereas dissolved organic matter composition did not change at the time scale of incubations. The faster degradation of the POC implies a constant replenishment to sustain natural POC concentrations. We suggest that degradation of organic matter transported through the inland water continuum might occur to a large extent via transition of DOC into more rapidly cycling POC in nature, for example, triggered by light. In this way, particles would be a dominant pool of organic C processing across the boreal aquatic continuum, partially sustained by replenishment via flocculation of DOC. Aune, M., Aniceto, A.S., Biuw, M., Daase, M., Falk-Petersen, S., Leu, E., Ottesen, C.A.M., Sagerup, K., Camus, L., 2018. Seasonal ecology in ice-covered Arctic seas - Considerations for spill response decision making. Marine Environmental Research 141, 275-288. to retreating sea ice and predictions of undiscovered oil and gas resources, increased activity in Arctic shelf sea areas associated with shipping and oil and gas exploration is expected. Such activities may accidentally lead to oil spills in partly ice-covered ocean areas, which raises issues related to oil spill response. Net Environmental Benefit Analysis (NEBA) is the process that the response community uses to identify which combination of response strategies minimises the impact to environment and people. The vulnerability of Valued Ecosystem Components (VEC's) to oil pollution depends on their sensitivity to oil and the likelihood that they will be exposed to oil. As such, NEBA requires a good ecological knowledge base on biodiversity, species' distributions in time and space, and timing of ecological events. Biological resources found at interfaces (e.g., air/water, ice/water or water/coastline) are in general vulnerable because that is where oil can accumulate. Here, we summarize recent information about the seasonal, physical and ecological processes in Arctic waters and evaluate the importance these processes when considering in oil spill response decision making through NEBA. In spring-time, many boreal species conduct a lateral migration northwards in response to sea ice retraction and increased production associated with the spring bloom. However, many Arctic species, including fish, seabirds and marine mammals, are present in upper water layers in the Arctic throughout the year, and recent research has demonstrated that bioactivity during the Arctic winter is higher than previously assumed. Information on the seasonal presence/absence of less resilient VEC's such as marine mammals and sea birds in combination with the presence/absence of sea ice seems to be especially crucial to consider in a NEBA. In addition, quantification of the potential impact of different, realistic spill sizes on the energy cascade following the spring bloom at the ice-edge would provide important information for assessing ecosystem effects.Azzouz, A., Kailasa, S.K., Lee, S.S., J. Rascón, A., Ballesteros, E., Zhang, M., Kim, K.-H., 2018. Review of nanomaterials as sorbents in solid-phase extraction for environmental samples. TrAC Trends in Analytical Chemistry 108, 347-369. organic contaminants (AOCs) are found to exert significant impacts on the human ecosystem, even at low or trace-level concentrations. To meet the growing demand for their quantitation in diverse environmental media, the use of preconcentration approaches (such as solid phase extraction) has become an essential component to practically upgrade both procedural efficiency and the analytical sensitivity. Nanomaterials (NMs) are realized as excellent candidates for proper sorption media because of their unique structural and surface properties with noticeably enhanced sorption capability towards contaminants. This review explores the use of various NMs (metallic and mixed oxide nanoparticles (NPs), carbon NMs (fullerenes, carbon nanotubes, graphene, and graphene oxide), polymer-based nanocomposites (organic polymers, inorganic and hybrid polymers, molecularly imprinted polymers, and dendrimers), and silicon/magnetic NPs) as potential sorbents for analytical applications. In this review, the distinctive features of NM-based sorptive extraction techniques are examined comprehensively with the discussion on their future prospects and key challenges.Baeten, J., Mees, F., Marinova, E., De Dapper, M., De Vos, D., Huyge, D., Van Strydonck, M., Vandenberghe, D., Linseele, V., 2018. Late Pleistocene coprolites from Qurta (Egypt) and the potential of interdisciplinary research involving micromorphology, plant macrofossil and biomarker analyses. Review of Palaeobotany and Palynology 259, 93-111. part of a rock art dating project at Qurta (Upper Egypt), samples were collected from an organic deposit and from an accumulation of individual faecal pellets. Radiocarbon dating of these relatively well-preserved materials indicates an unexpectedly old age of ca. 45,000 BP or older. In order to identify the biogenic nature of these deposits and to reconstruct the palaeo-environment at the time of their formation, micromorphological, palaeobotanical, and biomarker analyses were carried out. All data indicate that the organic deposit and the pellets were produced by different species. The presence of a novel biomarker, which only occurs in animal urine (hippuric acid), contributed to the conclusion that the organic deposit most likely represents the remains of a rock hyrax (Procavia capensis) latrine, whereas the pellets stem from small bovids. Plant macroremains from the pellets indicate that the animals browsed in the more vegetated areas, presumably near the Nile, although the general environment was probably mainly arid and open. Combined with the dates, this suggests that the pellets date to MIS 3 or 4. Our results demonstrate the great potential of an interdisciplinary approach to the study of Quaternary coprolite deposits, allowing for more adequate and more complete interpretation.Bagherzadeh, H., Mansourpour, Z., Dabir, B., 2019. A coupled DEM-CFD analysis of asphaltene particles agglomeration and fragmentation. Journal of Petroleum Science and Engineering 173, 402-414. the present paper, a Discrete Element Method-Computational Fluid Dynamics (DEM-CFD) approach along with a new coalescence model is adopted to study agglomeration and fragmentation of asphaltene particles, thoroughly. The collisions of asphaltene particles are investigated in three categories: collisions between individual primary particles (P-P collisions), individual primary particles and flocs (P-F collisions) and between flocs (F-F collisions). In addition, corresponding collision efficiencies have been determined based on the proposed coalescence model. Moreover, the importance of three different fragmentation modes including binary flocs fragmentations (binary fragmentation), detachment of a primary particle from floc (erosion) and splitting of floc into smaller flocs (large-scale fragmentation) is comparatively assessed. Eventually, the effect of fluid velocity and primary particles concentration on the aforementioned processes as well as asphaltene flocs properties are examined. Simulation results reveal P-P collisions contribution decreases continuously to reach a plateau in steady state condition while the contribution of P-F collisions increases initially and then it shows a gentle downward trend. F-F collisions contribution grows constantly up to steady state condition. The P-P and P-F collision efficiencies approximately remain constant whereas F-F collision efficiency continuously increases. In terms of fragmentation modes, contributions of binary fragmentation and erosion gradually decrease while large-scale fragmentation contribution constantly increases before steady state condition.Balzano, S., Lattaud, J., Villanueva, L., Rampen, S.W., Brussaard, C.P.D., van Bleijswijk, J., Bale, N., Sinninghe Damsté, J.S., Schouten, S., 2018. A quest for the biological sources of long chain alkyl diols in the western tropical North Atlantic Ocean. Biogeosciences 15, 5951-5968. chain alkyl diols (LCDs) are widespread in the marine water column and sediments, but their biological sources are mostly unknown. Here we combine lipid analyses with 18S rRNA gene amplicon sequencing on suspended particulate matter (SPM) collected in the photic zone of the western tropical North Atlantic Ocean at 24 stations to infer relationships between LCDs and potential LCD producers. The C30 1,15-diol was detected in all SPM samples and accounted for ?>?95% of the total LCDs, while minor proportions of C28 and C30 1,13-diols, C28 and C30 1,14-diols, as well as C32 1,15-diol were found. The concentration of the C30 and C32 diols was higher in the mixed layer of the water column compared to the deep chlorophyll maximum (DCM), whereas concentrations of C28 diols were comparable. Sequencing analyses revealed extremely low contributions (?≈?0.1% of the 18S rRNA gene reads) of known LCD producers, but the contributions from two taxonomic classes with which known producers are affiliated, i.e. Dictyochophyceae and Chrysophyceae, followed a trend similar to that of the concentrations of C30 and C32 diols. Statistical analyses indicated that the abundance of 4 operational taxonomic units (OTUs) of the Chrysophyceae and Dictyochophyceae, along with 23 OTUs falling into other phylogenetic groups, were weakly (r?≤?0.6) but significantly (p value?<?0.01) correlated with C30 diol concentrations. It is not clear whether some of these OTUs might indeed correspond to C28?32 diol producers or whether these correlations are just indirect and the occurrence of C30 diols and specific OTUs in the same samples might be driven by other environmental conditions. Moreover, primer mismatches were unlikely, but cannot be excluded, and the variable number of rRNA gene copies within eukaryotes might have affected the analyses leading to LCD producers being undetected or undersampled. Furthermore, based on the average LCD content measured in cultivated LCD-producing algae, the detected concentrations of LCDs in SPM are too high to be explained by the abundances of the suspected LCD-producing OTUs. This is likely explained by the slower degradation of LCDs compared to DNA in the oxic water column and suggests that some of the LCDs found here were likely to be associated with suspended debris, while the DNA from the related LCD producers had been already fully degraded. This suggests that care should be taken in constraining biological sources of relatively stable biomarker lipids by quantitative comparisons of DNA and lipid abundances.Bao, R., Voort, T.S., Zhao, M., Guo, X., Montlu?on, D.B., McIntyre, C., Eglinton, T.I., 2018. Influence of hydrodynamic processes on the fate of sedimentary organic matter on continental margins. Global Biogeochemical Cycles 32, 1420-1432. the effects of hydrodynamic forcing on organic matter (OM) composition is important for assessment of organic carbon (OC) burial in marginal seas on regional and global scales. Here we examine the relationships between regional oceanographic conditions (bottom shear stress), and the physical characteristics (mineral surface area and grain size) and geochemical properties (OC content [OC%] and carbon isotope compositions [13C, 14C]) of a large suite of surface sediments from the Chinese marginal seas to assess the influence of hydrodynamic processes on the fate of OM on shallow continental shelves. Our results suggest that 14C content is primarily controlled by organo‐mineral interactions and hydrodynamically driven resuspension processes, highlighted by (i) positive correlations between 14C content and OC% (and surface area) and (ii) negative correlations between 14C content and grain size (and bottom shear stress). Hydrodynamic processes influence 14C content due to both OC aging during lateral transport and accompanying selective degradation of OM associated with sediment (re) mobilization, these effects being superimposed on the original 14C characteristics of carbon source. Our observations support the hypotheses of Blair and Aller (2012) and Leithold et al. (2016) that hydrodynamically driven sediment translocation results in greater OC 14C depletion in broad, shallow marginal seas common to passive margin settings than on active margins. On a global scale, this may influence the extent to which continental margins act as net carbon sources and sinks. Our findings thus suggest that hydrodynamic processes are important in shaping the nature, dynamics, and magnitude of OC export and burial in passive marginal seas.Barbieri, R., Cavalazzi, B., 2018. Microterracettes in Sabkha Oum Dba (Western Sahara, Morocco): Physical and biological interactions in the formation of a surface micromorphology. Astrobiology 18, 1351-1367. terracing (microterracettes) is a surface geomorphic feature that recurs under a range of environmental settings, such as those existing in high to low temperature geothermal springs and evaporitic environments, through the single or combined action of physicochemical agents and microbiological processes. Such morphology can also be observed in a confined sector of the Sabkha Oum Dba, which is an inland sabkha of the Western Sahara (Morocco), where field and laboratory investigations revealed that they primarily depend on the accumulation of naviculoid diatoms. Through their biofilm production ability, these benthic diatoms are able to stabilize surface morphologies and make organic alveolar frameworks where the precipitation of low Mg calcite occurs in areas subjected to active oxygenic photosynthesis. Because microterracettes arise in a specific set of environmental conditions, they have environmental significance and, thanks to a high fossilization potential due to mineral precipitation, they can be an effective source of biomorphological and chemical evidence for life. The relationship with aqueous environments, considered to be widespread on Mars especially during a period of intense hydrologic activity as in the late Noachian and Hesperian periods, make the understanding of surficial processes useful (such as the formation of microterracettes) whose formation is frequent in terrestrial analogues for martian environments, such as ephemeral saline continental lakes (sabkhas) and related to the products of bacterial and eukaryotic life, as in the case of biofilms, in search for similar life forms beyond Earth.Barbosa, N.S.V., Lima, E.R.A., Tavares, F.W., 2019. Wettability of rock, oil and brine system based on density functional theory. Fluid Phase Equilibria 479, 99-105. composition of an ionic aqueous solution can modify the wettability behavior of a liquid/liquid/solid system. This behavior is of great importance for oil extraction and some separation processes. Here we model the contact angle and wettability on the basis of a tridimensional classical density functional theory (DFT) and Young equation for a brine/oil/solid surface system. We propose the inclusion of dispersion interaction between surface-ion and oil-ion. The equilibrium contact angle is found through the minimization of the grand potential. The approach presented here is promising and due to its versatility can be expanded to systems with some peculiarities such as roughness and thin film.Baroni, I.R., Pohl, A., Helmond, N.A.G.M., Papadomanolaki, N.M., Coe, A.L., Cohen, A.S., van de Schootbrugge, B., Donnadieu, Y., Slomp, C.P., 2018. Ocean circulation in the Toarcian (Early Jurassic): A key control on deoxygenation and carbon burial on the European shelf. Paleoceanography and Paleoclimatology 33, 994-1012. Toarcian Oceanic Anoxic Event (T-OAE, ~183?Myr) was a long-lasting episode of ocean deoxygenation during the Early Jurassic. The event is related to a period of global warming and characterized by major perturbations to the hydrological and carbon cycles with high rates of organic matter burial in shelf seas. Ocean circulation during the Toarcian and its influence on marine biogeochemical cycles are still not fully understood. Here we assess the spatial extent of anoxia in the NW Tethys Ocean during the T-OAE, the relationship with ocean circulation and the impact on organic carbon burial, using new and existing sedimentary records from the European Epicontinental Shelf in combination with general circulation model results. We demonstrate that bottom waters on the southwestern part of the shelf were mainly oxic during the T-OAE, while those in the northeastern basins were mostly anoxic or even sulfidic. Results for two ocean-atmosphere models (Fast Ocean-Atmosphere Model and Massachusetts Institute of Technology general circulation model) suggest the presence of a strong clockwise gyre over the European Epicontinental Shelf, which brought oxygenated equatorial waters from the Tethys Ocean to the southern shelf. The northward limb of the gyre was significantly weakened due to the rough bathymetry of the northern shelf, making this relative small region highly sensitive to local ocean stratification. These sluggish ocean dynamics promoted bottom water anoxia and enhanced burial of organic carbon in the northeastern basins, which accounted for 3?5% of the total carbon extracted from the ocean-atmosphere system as recorded by the positive carbon isotope shift.Barreira, F.R., Reis, L.G., Nunes, R.d.C.P., Filipakis, S.D., Lucas, E.F., 2018. Asphaltenes precipitation onset: Influence of the addition of a second crude oil or its asphaltenes fractions (C3I and C5I). Energy & Fuels 32, 10391-10397. the asphaltene stability in crude oils from different production streams is very useful in the petroleum industry because it allows avoiding serious problems caused by formation of solid deposits during oil flow. That prediction can be carried out by applying the solubility parameter (δ) of each oil, as calculated by the asphaltene precipitation onset value, obtained by titration with n-heptane. However, many crude oils do not have a well-defined precipitation onset point, which can be overcome by adding a crude oil assumed as the standard. This article analyzes the influence of a crude oil (called APS) on the precipitation onset of two other petroleum samples (called APA and APB). For this purpose, the asphaltene fractions C3I and C5I were extracted from APS, and the influence of the addition of this crude oil as well as its asphaltenes fractions in samples of oils APA and APB was evaluated by tests involving titration of n-heptane with detection by near-infrared spectroscopy (NIR). The calculation of the solubility parameters of the oils without well-defined precipitation onset, by adding the oil with well-defined precipitation onset, led to varied errors in function of the type of oil in question. The smallest errors were obtained when using, as the solubility parameter of the mixture (δM), the solubility parameter of the solvent system at the precipitation onset of the asphaltene C3I fraction (extracted from the crude oil assumed as the standard) in toluene, determined by titration with n-heptane.Bartl, I., Hellemann, D., Rabouille, C., Schulz, K., Tallberg, P., Hietanen, S., Voss, M., 2018. Particulate organic matter controls benthic microbial N retention and N removal in contrasting estuaries of the Baltic Sea. Biogeosciences Discussions 2018, 1-37. worldwide are known to act as filters of land-derived N loads, yet their variable environmental settings can affect microbial nitrogen (N) retention and removal and thus the coastal filter function. We investigated microbial N-retention (nitrification, ammonium assimilation) and N-removal (denitrification, anammox) in the aphotic benthic systems (here defined as: bottom boundary layer [BBL] and sediment) of two Baltic Sea estuaries that differ in riverine N loads, trophic state, bottom topography, and sediment type. Contrary to our expectations, nitrification rates (5–227nmolL?1d?1) in the BBL neither differed between the eutrophied Vistula estuary and the oligotrophic ?re estuary, nor between seasons. Ammonium assimilation rates were slightly higher in the oligotrophic ?re estuary in spring but did not differ between estuaries in summer (9–704nmolL?1d?1). In the sediment, no anammox was found in either estuary and denitrification rates were higher in the eutrophied (349±117?molNm?2d?1) than in the oligotrophic estuary (138±47?molNm?2d?1). Irrespective of their differences, in both estuaries the quality of the mainly phytoplankton-derived particulate organic matter (POM) – evaluated by means of C:N and POC:Chl.a ratios – seemed to control N-cycling processes through the availability of particulate organic N and C as substrate sources. Our data suggest, that in stratified estuaries, phytoplankton-derived POM is an essential link between riverine N loads and benthic N cycling and may function as a temporary N reservoir via long particle residence time or coastal parallel transport. Even at low process rates, effective coastal filtering would thus be achieved by the increased time available for the recycling of N via microbial retention processes until its permanent removal via denitrification.Baruah, B., Tiwari, P., Thakur, P., Kataki, R., 2018. TGA-FTIR analysis of Upper Assam oil shale, optimization of lab-scale pyrolysis process parameters using RSM. Journal of Analytical and Applied Pyrolysis 135, 397-405. paper presents a comprehensive study on the in line analysis of products formed during pyrolysis of oil shale from Upper Assam, India and optimization of lab-scale pyrolysis parameters. Thermogravimetric analysis coupled with Fourier transform infrared spectroscopy (TGA-FTIR) was used to determine the decomposition zones and investigate the products evolved during pyrolysis. Study of the evolved gases showed the presence of C-H stretching, C=C aromatic bending, O-H, CO2, and SO2. Response surface methodology (RSM) was employed using central composite design (CCD) model to setup the lab-scale experiment using TGA data, and optimization of process parameters viz. heating rate, temperature and particle size. The pyrolytic shale oil obtained at optimum condition was subjected to characterization using gas chromatography and mass spectrometry (GC–MS) and nuclear magnetic resonance spectroscopy (NMR). The produced shale oil showed an abundance of aliphatic compounds corresponding to high energy density.Bavoh, C.B., Khan, M.S., Lal, B., Bt Abdul Ghaniri, N.I., Sabil, K.M., 2018. New methane hydrate phase boundary data in the presence of aqueous amino acids. Fluid Phase Equilibria 478, 129-133. there are few amino acids hydrate based thermodynamic studies compared to kinetic studies, thus, the thermodynamic effect of four amino acids on methane hydrate formation are presented herein. The amino acids (valine, threonine, asparagine, and phenylalanine) were tested as gas hydrate inhibitors using the isochoric pressure search method in a high pressure stirring reactor. They were tested at 1?wt% and 5?wt% in the temperature and pressure ranges of 275.71–286.10?K and 3.52–10.25?MPa, respectively. All studied amino acids thermodynamically inhibited methane gas hydrate formation, with valine exhibiting the best inhibition impact with an average depression temperature of 0.529?K?at 5?wt%. Amino acids side chain properties were found to cause the variations in their inhibition impact. This study is useful to fully understand the thermodynamic inhibition effect of amino acids on gas hydrate formation. Inferring from the results in this study and literature, amino acids are thermodynamic gas hydrate inhibitors, while most of them are kinetic promoters.Bazyari, A., Soulgani, B.S., Jamialahmadi, M., Dehghan Monfared, A., Zeinijahromi, A., 2018. Performance of smart water in clay-rich sandstones: Experimental and theoretical analysis. Energy & Fuels 32, 10354-10366. water (SW) has been recognized as an effective yet environmentally friendly technique for enhanced oil recovery in both carbonate and sandstone reservoirs. However, owing to complexities of oil properties, rock compositions, and ion characteristics, the performance of smart water is not well-understood. This paper attempts to derive insights on how smart water performs in clay-rich sandstones. A comprehensive mechanistic study is carried out on synthetic sandpacks that contain different clay types (kaolinite and montmorillonite) and clay concentrations (3 and 8 wt %), under injection of three SWs (0.3 wt % NaCl, 0.05 wt % NaCl, and 0.3 wt % CaCl2). Extensive experiments and modeling are utilized to investigate wettability alteration at microscopic and macroscopic scales, including swelling index test, zeta potential measurement, core-flooding test, contact angle measurement, particle analysis of effluent, differential pressure analysis across the sandpacks, and disjoining pressure isotherm analysis. The theoretical results of disjoining pressure isotherm analysis show that wettability alteration is more accurately indicated by the maximum peak of the disjoining pressure curve than by the area below the positive section of that curve. This is confirmed by contact angle measurements and recovery factors (RFs). In addition, monovalent cations are found to have stronger impact on changing wettability toward a water-wet state than are divalent cations. We also find that there might exist a minimum salinity below which the expansion of the double layer reaches its maximum. Decreasing the salinity below this minimum value is found not to affect the sample’s wettability. Coreflooding tests show that total RF in the montmorillonite sandpacks is higher than in those made up of kaolinite. In general, a direct relationship is found between clay concentration and RFs. Furthermore, it is found that fines migration and wettability alteration are the dominant mechanism in kaolinite sandpacks, while clay swelling, wettability alteration, and a salt-in effect have been reported to be more significant in montmorillonite sandpacks.Becker, S., Schneider, C., Okamura, H., Crisp, A., Amatov, T., Dejmek, M., Carell, T., 2018. Wet-dry cycles enable the parallel origin of canonical and non-canonical nucleosides by continuous synthesis. Nature Communications 9, Article 163. molecules of life were created by a continuous physicochemical process on an early Earth. In this hadean environment, chemical transformations were driven by fluctuations of the naturally given physical parameters established for example by wet–dry cycles. These conditions might have allowed for the formation of (self)-replicating RNA as the fundamental biopolymer during chemical evolution. The question of how a complex multistep chemical synthesis of RNA building blocks was possible in such an environment remains unanswered. Here we report that geothermal fields could provide the right setup for establishing wet–dry cycles that allow for the synthesis of RNA nucleosides by continuous synthesis. Our model provides both the canonical and many ubiquitous non-canonical purine nucleosides in parallel by simple changes of physical parameters such as temperature, pH and concentration. The data show that modified nucleosides were potentially formed as competitor molecules. They could in this sense be considered as molecular fossils.Belozerov, V.B., Krasnoshchekova, L.A., Merkulov, V.P., 2018. Shale strata development problems and origin of the Bazhenov Formation fractures in the southeast of the West Siberian Plate. Russian Geology and Geophysics 59, 88-95. strata development is one of the most promising trends for the hydrocarbon production increase within the West Siberian petroliferous province. The lack of understanding of fracturing mechanism, which is crucial for steady well production during hydraulic fracturing or drilling of horizontal wells, substantially restricts the choice of process capabilities for effective development of such horizons. This paper considers the Bazhenov Formation fractures based on the core data. The role of open and mineralized fractures (their slope angles, density, and specific surface) in the structure of bituminous shales is considered. Paleomagnetic orientation of the core samples with open fractures is implemented, and litho-petrographical description of the strata is made. The obtained results indicate that the planetary paleotension system of rocks controls the origin of open fractures in the Bazhenov Formation. Therefore, their spatial orientation and autogeneration capability can be used during the development of the bituminous shale strataBendia, A.G., Araujo, G.G., Pulschen, A.A., Contro, B., Duarte, R.T.D., Rodrigues, F., Galante, D., Pellizari, V.H., 2018. Surviving in hot and cold: psychrophiles and thermophiles from Deception Island volcano, Antarctica. Extremophiles 22, 917-929. volcanoes harbor unique conditions of extreme temperature gradients capable of selecting different types of extremophiles. Deception Island is a marine stratovolcano located at Maritime Antarctica that is notable for its pronounced temperature gradients over very short distances, reaching values up to 100?°C in the fumaroles, and subzero temperatures next to the glaciers. Due to these characteristics, Deception can be considered an interesting analogue of extraterrestrial environments. Our main goal in this study was to isolate thermophilic and psychrophilic bacteria from sediments associated with fumaroles and glaciers from two geothermal sites in Deception Island, comprising temperatures between 0 and 98?°C, and to evaluate their survivability to desiccation and UV-C radiation. Our results revealed that culturable thermophiles and psychrophiles were recovered among the extreme temperature gradient in Deception volcano, which indicates that these extremophiles remain alive even when the conditions do not comprise their growth range. The viability of culturable psychrophiles in hyperthermophilic environments is still poorly understood and our work showed the importance of future studies about their survival strategies in high temperatures. Finally, the spore-forming thermophilic isolates which we found have displayed good survival to desiccation and UV-C irradiation, which suggests their potential to be further explored in astrobiological studies.Benk, S.A., Li, Y., Roth, V.-N., Gleixner, G., 2018. Lignin dimers as potential markers for 14C-young terrestrial dissolved organic matter in the critical zone. Frontiers in Earth Science 6, 168. doi: 10.3389/feart.2018.00168. origin, molecular composition and fate of dissolved organic matter (DOM) provides essential information that links surface and subsurface processes and explores the functioning of the Critical Zone. Therefore it is important to identify specific marker compounds that provide information on the temporal and spatial linkages in the Critical Zone. Here, we used ultra-high resolution mass spectrometry and accelerator mass spectrometry in order to identify markers for fast transport of surface-derived DOM through the Critical Zone. We assessed the molecular composition and radiocarbon age of solid phase extracted DOM (SPE-DOM) from forest top soils. The 14C ages of SPE-DOM in our study were similar to that of bulk DOM. Calibrated ages ranged from 0 to 49 years and the within-site variability was larger than between sampling sites. Spearman rank correlation between the 14C ages and the DOM composition identified 129 sum formulae that were significantly correlated to 14C age. We found that molecular entities with younger 14C ages had lower molecular weight, higher unsaturation and less oxygen and heteroatoms than those associated with older 14C ages. A chemical library search suggested that phenylpropanoids and compounds, which are known to be lignin derived, are key molecular species for terrestrial DOM with young 14C ages. Among them, lignin dimers emerged as prominent surface-derived compounds that can potentially be used as markers for fast transport of water and DOM into the subsurface and groundwater.Bennett, B., Larter, S.R., 2018. Geological controls on the heterogeneous hydrocarbon compositions of the biodegraded Grosmont Formation bitumen, Western Canada Sedimentary Basin. Organic Geochemistry 125, 243-259. hydrocarbon composition of the Grosmont Formation bitumen was investigated in 51 core samples by gas chromatography–mass spectrometry (GC–MS). The bitumen composition is highly variable and is heavily to severely biodegraded. Molecular ratios based on biodegradation-resistant compounds are highly uniform laterally and vertically, even across shale barriers indicating the bitumens are genetically related. Biodegradation-resistant biomarker maturity parameters suggests the bitumen was likely sourced during the early oil window stage of petroleum generation. Biomarkers responding to biodegradation display strong lateral and vertical variations in composition with geochemical profiles based on concentration data, displaying dramatic offsets when shales are present indicating the reservoir units are compartmentalised. Considering the relationship between 25-norhopanes and hopanes, the hydrocarbon composition data indicate progressive hopane degradation, both with concomitant formation of 25-norhopanes and hopane degradation without the formation of 25-norhopanes. In wells 07-08-085-18W4 and 10-12-093-24W4, the degradation of hopanes occurs in Upper Grosmont unit 3 (UG3) without the formation of 25-norhopanes (unless 25-norhopanes have been synchronously consumed), whereas in unit UG2, hopane degradation occurs with the concomitant formation of the 25-norhopanes. Therefore, the shale compartmentalizes the reservoir creating two isolated environments whereby the biogeochemical setting contributing to 25-norhopane formation is found in the UG2 unit, whereas it is absent or inactive in unit UG3. The degradation of the 22R epimer prior to the 22S epimer in the C31–C33 17α-hopanes was recognized in well 16-05-088-19W4, which indicates that the consortia of microbes more readily biodegraded the epimer having the biological conformation.Bharagava, R.N., Purchase, D., Saxena, G., Mulla, S.I., 2019. Chapter 26 - Applications of metagenomics in microbial bioremediation of pollutants: From genomics to environmental cleanup, in: Das, S., Dash, H.R. (Eds.), Microbial Diversity in the Genomic Era. Academic Press, pp. 459-477. pollutants are of serious ecotoxicological and health concern worldwide. To cope with these, bioremediation technologies utilizing microorganisms is currently viewed as an excellent cost-effective and ecofriendly strategy for the environmental management. However, a strategic execution of the bioremediation technology requires the knowledge of microbial metabolism, key enzymes, and genes involved and nature, dynamics, and composition of microbial communities, which can be easily understood by applying molecular techniques. Conventional or culture-dependent molecular techniques are currently being applied to characterize the potential pollutants degrading/detoxifying microbes, but these techniques are sometimes biased and do not actually provide the accurate information. However, the currently emerging metagenomic approaches including next-generation sequencing technologies can provide the reliable information and reveal very useful information about the metagenome of environmental microorganisms, which play an important role in the biogeochemical cycles and degradation and detoxification of environmental pollutants using culture-independent molecular techniques. Therefore, this chapter provides an overview of the metagenomic approaches and their applications in microbial ecology and bioremediation.Boniewicz-Szmyt, K., Pogorzelski, S.J., 2018. Influence of surfactant concentration and temperature gradients on spreading of crude-oil at sea. Frontiers in Marine Science 5, 388. doi: 10.3389/fmars.2018.00388. kinetics measurements were carried out on crude oils surfactant-containing sea water of well-controlled thermo elastic surface properties in laboratory conditions. It was found that oil lens expansion rates, predicted from the classical surface tension-driven spreading theory, were higher by a factor of 6–9 than those experimentally derived for Baltic collected sea water. Previously, in order to explain such a discrepancy, the initial spreading coefficient S0–entering the lens radius vs. time dependence was replaced with the temporal one St dependent on the water phase surface viscoelasticity of Boniewicz-Szmyt and Pogorzelski (2008). Now, natural surfactant concentration and temperature gradients perpendicular to the surface were shown to drive a particular cell-like flow at the surface microlayer, as a result of the classic and thermal Marangoni phenomenon. The balance of interfacial forces was taken as: –μ?Us/?z = ?γ/?T·?T/?x+?γ/?c·?c/?x where: μ is the dynamic viscosity, Us—the velocity, z and x axes oriented perpendicularly and horizontally to the main flow direction, T, γ, c are the temperature, surface tension, and concentration of surfactants. Computations performed on original seawater (Baltic Sea) systems, shown that the natural surfactant concentration term ?γ/?c is several times lower than the thermal ?γ/?T one (Boniewicz-Szmyt and Pogorzelski, 2016). Such a surface tension gradients induce the Benard-Marangoni instability, for high enough the so-called Marangoni numbers that could significantly slow down the spreading process. On the basis of thermo-physical model liquids properties, the critical temperature difference ΔTc required to initiate the process under an evaporative cooling condition was evaluated. In this just concept study, the preliminary results suggest that the vertical processes are involved, and that a realistic model of oil dispersion should include vertical velocity shears appearing in the final surface tension-driven stage of oil pollution development.Botting, J.P., Nettersheim, B.J., 2018. Searching for sponge origins. Nature Ecology & Evolution 2, 1685-1686. are believed by many researchers to be the earliest living animal group, but there is conflicting evidence for the timing of their origin. A molecular fossil discovery supports the contention that sponges appeared very early, but starkly contradicts the body fossil record.Brereton, R.G., Jansen, J., Lopes, J., Marini, F., Pomerantsev, A., Rodionova, O., Roger, J.M., Walczak, B., Tauler, R., 2018. Chemometrics in analytical chemistry - Part II: modeling, validation, and applications. Analytical and Bioanalytical Chemistry 410, 6691-6704. contribution of chemometrics to important stages throughout the entire analytical process such as experimental design, sampling, and explorative data analysis, including data pretreatment and fusion, was described in the first part of the tutorial “Chemometrics in analytical chemistry.” This is the second part of a tutorial article on chemometrics which is devoted to the supervised modeling of multivariate chemical data, i.e., to the building of calibration and discrimination models, their quantitative validation, and their successful applications in different scientific fields. This tutorial provides an overview of the popularity of chemometrics in analytical chemistry.Bryce, C., Blackwell, N., Schmidt, C., Otte, J., Huang, Y.-M., Kleindienst, S., Tomaszewski, E., Schad, M., Warter, V., Peng, C., Byrne, J.M., Kappler, A., 2018. Microbial anaerobic Fe(II) oxidation – Ecology, mechanisms and environmental implications. Environmental Microbiology 20, 3462-3483. is the most abundant redox-active metal in the Earth's crust. The one electron transfer between the two most common redox states, Fe(II) and Fe(III), plays a role in a huge range of environmental processes from mineral formation and dissolution to contaminant remediation and global biogeochemical cycling. It has been appreciated for more than a century that microorganisms can harness the energy of this Fe redox transformation for their metabolic benefit. However, this is most widely understood for anaerobic Fe(III)-reducing or aerobic and microaerophilic Fe(II)-oxidizing bacteria. Only in the past few decades have we come to appreciate that bacteria also play a role in the anaerobic oxidation of ferrous iron, Fe(II), and thus can act to form Fe(III) minerals in anoxic settings. Since this discovery, our understanding of the ecology of these organisms, their mechanisms of Fe(II) oxidation and their role in environmental processes has been increasing rapidly. In this article, we bring these new discoveries together to review the current knowledge on these environmentally important bacteria, and reveal knowledge gaps for future research.Cabello, P., Lopez, C., Gamba, N., Dussán, M.I., Torres, E., Ballesteros-Torres, C.I., Cantisano, M.T., Marfisi, N., Calvo, R., Vázquez-Taset, Y.M., Ramos, E., 2018. An integrated approach to define new plays in mature oil basins: The example from the Middle Magdalena Valley basin (Colombia). American Association of Petroleum Geologists Bulletin 102, 2201-2238. integrated approach to detect new areas of potential interest associated with stratigraphic traps in mature basins is presented. The study was carried out in the Middle Magdalena Valley basin, Colombia. The workflow integrates outcrop and subsurface interpretations of facies, activity of faults, and distribution of depocenters and paleocurrents and makes use of them to construct a three-dimensional exploration-scale geocellular facies model of the basin. The outcrop and well log sedimentological analysis distinguished facies associations of alluvial fan, overbank, floodplain, and channel fill, the last one constituting the reservoir rock. The seismic analysis showed that tectonic activity was coeval with the deposition of the productive units in the basin and that the activity ended earlier (before the middle Miocene) along the western margin than along the eastern margin. Paleogeographic reconstructions depict transverse and longitudinal fluvial systems, alluvial fans adjacent to the active basin margins, and floodplain facies dominating the structural highs and the southwestern depositional limit. These reconstructions provided statistical data (lateral variograms) to construct the model. The exploration-scale facies model depicts the complete structure of the basin in three dimensions and the gross distribution of the reservoir and seal rocks. The predictive capability of the model was evaluated positively, and the model was employed to detect zones of high channel fill facies probability that form bodies that are isolated or that terminate upward in pinchouts or are truncated by a fault. Our approach can prove helpful in improving general exploration workflows in similar settings.?a?atay, M.N., Y?ld?z, G., Bayon, G., Ruffine, L., Henry, P., 2018. Seafloor authigenic carbonate crusts along the submerged part of the North Anatolian Fault in the Sea of Marmara: Mineralogy, geochemistry, textures and genesis. Deep Sea Research Part II: Topical Studies in Oceanography 153, 92-109. seafloor authigenic carbonate crusts occur as pavements, mounds and chimneys along the North Anatolian Fault System (NAFS) in the Sea of Marmara. They are often covered or surrounded by patches of black Fe-sulphide-rich sediments, and associated with hydrocarbon-rich gas and brackish-water emissions in the 1250 m-deep deep basins and with deep saline formation waters and hydrocarbons emissions from mud volcanoes and anticlines on the 350–650 m-deep compressional highs.The authigenic carbonate crusts are commonly porous with sinter-like, botryoidal and sugary- granular textures, and constructed from cementation of framework elements consisting mainly of bivalve shells and shell fragments, serpulid tubes, fibrous microbial organic matter and rarely pebbles. The authigenic cements consist mainly of aragonite in most sites, but high Mg-calcite occurs as a major carbonate cement at some basinal sites, where the brackish former Marmara “Lake” waters emerge. The buoyant emission of brackish waters in the deep Marmara basins and deeply sourced fluids from the Tertiary Thrace basin at the compressional highs are supported by relatively low δ18O values (+0.5‰ to +3.8‰ V-PDB, average = +2.1‰V-PDB, n = 24) of carbonates in the former and high values (+2.6‰ to +3.4‰ V-PDB, average = +3.0‰, n = 9) in the latter areas.Low δ13C values (?47.6‰ to ?13.7‰ V-PDB, average: ?34.9‰ V-PDB, n = 33) and close association with black reduced sediments indicate that the seafloor authigenic carbonates are formed by the anaerobic oxidation of methane (AOM) at or near the seafloor, as result of high methane flux, possibly during periods of high seismic activity. Authigenic carbonates from the Western and Central highs are relatively less depleted in 13C than those of the deep basin sites, suggesting both microbial and thermogenic methane source for the deep basins carbonates and mainly thermogenic hydrocarbon, with some contribution from the biodegradation of heavy hydrocarbons and gas hydrate dissociation, for carbonates from the compressional highs. U-Th ages of the authigenic carbonates range from less than 1 ka BP to 9.6 ka BP. The age distribution, together with the geochemical and mineralogical data, suggests that different processes such as seismo-tectonics and gas hydrates destabilization might have played important role in the authigenic carbonate formation in the Sea of Marmara over the last 10 ka.Casillo, A., Ziaco, M., Lindner, B., Parrilli, E., Schwudke, D., Holgado, A., Beyaert, R., Lanzetta, R., Tutino, M.L., Corsaro, M.M., 2018. Lipid A structural characterization from the LPS of the Siberian psychro-tolerant Psychrobacter arcticus 273-4 grown at low temperature. Extremophiles 22, 955-963. arcticus 273-4 is a Gram-negative bacterium isolated from a 20,000-to-30,000-year-old continuously frozen permafrost in the Kolyma region in Siberia. The survival strategies adopted to live at subzero temperatures include all the outer membrane molecules. A strategic involvement in the well-known enhancement of cellular membrane fluidity is attributable to the lipopolysaccharides (LPSs). These molecules covering about the 75% of cellular surface contribute to cold adaptation through structural modifications in their portions. In this work, we elucidated the exact structure of lipid A moiety obtained from the lipopolysaccharide of P. arcticus grown at 4?°C, to mimic the response to the real environment temperatures. The lipid A was obtained from the LPS by mild acid hydrolysis. The lipid A and its partially deacylated derivatives were exhaustively characterized by chemical analysis and by means of ESI Q-Orbitrap mass spectrometry. Moreover, biological assays indicated that P. arcticus 273-4 lipid A may behave as a weak TLR4 agonist.Castanheiro, A., Joos, P., Wuyts, K., De Wael, K., Samson, R., 2019. Leaf-deposited semi-volatile organic compounds (SVOCs): An exploratory study using GCxGC-TOFMS on leaf washing solutions. Chemosphere 214, 103-110. particulate matter (PM) includes semi-volatile organic compounds (SVOCs), which can be deposited on vegetation matrices such as plant leaves. In alternative to air-point measurements or artificial passive substrates, leaf monitoring offers a cost-effective, time-integrating means of assessing local air quality. In this study, leaf washing solutions from ivy (Hedera hibernica) leaves exposed during one-month at different land use classes were explored via comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GCxGC-TOFMS). The composition of leaf-deposited SVOCs, corrected for those of unexposed leaves, was compared against routinely monitored pollutants concentrations (PM10, PM2.5, O3, NO2, SO2) measured at co-located air monitoring stations. The first study on leaf-deposited SVOCs retrieved from washing solutions, herein reported, delivered a total of 911 detected compounds. While no significant land use (rural, urban, industrial, traffic, mixed) effects were observed, increasing exposure time (from one to 28 days) resulted in a higher number and diversity of SVOCs, suggesting cumulative time-integration to be more relevant than local source variations between sites. After one day, leaf-deposited SVOCs were mainly due to alcohols, N-containing compounds, carboxylic acids, esters and lactones, while ketones, diketones and hydrocarbons compounds gained relevance after one week, and phenol compounds after one month. As leaf-deposited SVOCs became overall more oxidized throughout exposure time, SVOCs transformation or degradation at the leaf surface is suggested to be an important phenomenon. This study confirmed the applicability of GCxGC-TOFMS to analyze SVOCs from leaf washing solutions, further research should include validation of the methodology and comparison with atmospheric organic pollutants.Causon, T.J., 2018. Chromatography: Multidimensional techniques, Reference Module in Chemistry, Molecular Sciences and Chemical Engineering. Elsevier. complexity of samples of natural origin provides a substantial challenge for analysts as separation of constituent components via techniques such as chromatography is a key analytical task. Conventional separation approaches typically provide a single dimension of separation according to a broad chemical property of the components (e.g., polarity or ionic character). However, combinations of separation approaches to achieve a multidimensional separation provide an enormous increase in the resolution of components. The theoretical benefits of multidimensional techniques must also be brought together with practical knowledge of the employed separation dimensions including their compatibility and overall suitability for a particular sample type. Successful development of multidimensional techniques is now feasible using commercially available options and provides a powerful means to address resolution of extremely complex samples.Ceia, F.R., Cherel, Y., Paiva, V.H., Ramos, J.A., 2018. Stable isotope dynamics (δ13C and δ15N) in neritic and oceanic waters of the North Atlantic inferred from GPS-tracked Cory’s shearwaters. Frontiers in Marine Science 5, 377. doi: 10.3389/fmars.2018.00377. markers, such as stable isotopes, are a powerful approach to trace wildlife movements because they do not require initial marking of the organism. The main limitation of the isotopic method is the lack of knowledge in spatio-temporal patterns and dynamics of stable isotopes in marine environments, especially at local scales. Here, we combine GPS-tracks and isotopic signatures from Cory’s shearwaters as a model species to define isoscapes in the North Atlantic, and assess δ13C and δ15N dynamics, from local to regional spatial scales. Tracking data and blood samples were collected seasonally (during pre-laying and chick-rearing periods) across 6 years (2010–2015) from a total of 191 birds breeding at both neritic and oceanic environments. Tracked birds encompassed a large latitudinal and longitudinal area of the mid-North Atlantic, from the Eastern to Central North Atlantic. Overall, the δ13C and δ15N values of birds’ plasma over the region ranged from -20.2 to -16.2‰, and from 10.8 to 15.5‰, respectively. As expected, strong biogeographic isotopic patterns were found in δ13C values at a regional scale, mostly driven by an inshore/offshore gradient and chlorophyll a concentration. Although a moderate expression of spatial isotopic gradients on δ15N values (i.e., latitudinal and inshore/offshore) in the whole region, these were primarily influenced by temporal drivers (i.e., annual variability). At a local scale (i.e., in a radius of 100 km around the colony, within the neritic environment), both δ13C and δ15N values were very influenced by temporal drivers, suggesting that wide-ranging top consumers are hard to trace locally. This study shows that the δ13C values of marine top consumers are good indicators of the foraging habitat at a regional scale in the mid-North Atlantic, especially in terms of inshore/offshore gradients and areas of higher productivity.Cersoy, S., Daheur, G., Zazzo, A., Zirah, S., Sablier, M., 2018. Pyrolysis comprehensive gas chromatography and mass spectrometry: A new tool to assess the purity of ancient collagen prior to radiocarbon dating. Analytica Chimica Acta 1041, 131-145. carbonaceous contaminants coming from sediments significantly bias the radiocarbon date of collagen samples extracted from archaeological bone and teeth. In this study, a new approach combining pyrolysis, comprehensive gas chromatography and mass spectrometry (Py-GC?×?GC/MS) was proposed to ensure their removal during the demineralization and bone collagen extraction. This approach permitted to identify hydrocarbon contaminants for archaeological samples from the Neolithic period, in 30–40?μg of collagen. The use of 2D GC improved importantly the separation, selectivity and resolution compared to 1D GC thus permitting to detect organic contaminants within the complex chromatograms issued from collagen pyrolysis. Moreover, efficiency of the extraction steps in collagen sample preparation for radiocarbon dating (acid and alkali treatments, filtration steps) could be evaluated for four different protocols on the basis of organic contaminant removal. Radiocarbon dating of the extracted collagen of four of the tested protocols corroborated the results of the Py GC?×?GC/MS data. This approach opens new perspectives for the use of comprehensive gas chromatography in the domain of archaeological sciences.Chaignaud, P., Morawe, M., Besaury, L., Kr?ber, E., Vuilleumier, S., Bringel, F., Kolb, S., 2018. Methanol consumption drives the bacterial chloromethane sink in a forest soil. The ISME Journal 12, 2681-2693. volatile organic compounds (VOCs) emitted by terrestrial ecosystems, such as chloromethane (CH3Cl), have pronounced effects on troposphere and stratosphere chemistry and climate. The magnitude of the global CH3Cl sink is uncertain since it involves a largely uncharacterized microbial sink. CH3Cl represents a growth substrate for some specialized methylotrophs, while methanol (CH3OH), formed in much larger amounts in terrestrial environments, may be more widely used by such microorganisms. Direct measurements of CH3Cl degradation rates in two field campaigns and in microcosms allowed the identification of top soil horizons (i.e., organic plus mineral A horizon) as the major biotic sink in a deciduous forest. Metabolically active members of Alphaproteobacteria and Actinobacteria were identified by taxonomic and functional gene biomarkers following stable isotope labeling (SIP) of microcosms with CH3Cl and CH3OH, added alone or together as the [13C]-isotopologue. Well-studied reference CH3Cl degraders, such as Methylobacterium extorquens CM4, were not involved in the sink activity of the studied soil. Nonetheless, only sequences of the cmuA chloromethane dehalogenase gene highly similar to those of known strains were detected, suggesting the relevance of horizontal gene transfer for CH3Cl degradation in forest soil. Further, CH3Cl consumption rate increased in the presence of CH3OH. Members of Alphaproteobacteria and Actinobacteria were also 13C-labeled upon [13C]-CH3OH amendment. These findings suggest that key bacterial CH3Cl degraders in forest soil benefit from CH3OH as an alternative substrate. For soil CH3Cl-utilizing methylotrophs, utilization of several one-carbon compounds may represent a competitive advantage over heterotrophs that cannot utilize one-carbon compounds.Charniauskaya, M.I., Bukliarevich, A.A., Delegan, Y.A., Akhremchuk, A.E., Filonov, A.E., Titok, M.A., 2018. Biodiversity of hydrocarbon-oxidizing soil bacteria from various climatic zones. Microbiology 87, 699-711. bacteria isolated from soil samples from different climatic zones (Belarus, Libya, Iraq, and Antarctica) were studied. Techniques of physiological, biochemical, and molecular genetic analysis were used to identify 18 strains, most of which belonged to nonmycelial actinomycetes. Informative genetic markers used for identification of bacteria of the genus Rhodococcus were the genes alkB (for R. pyridinivorans), rpoC and groES (for R. erythropolis), groEL (for R. opacus), and random chromosome fragments (for R. opacus and R. pyridinivorans). Bacteria isolated from Libyan sandy soil and Antarctic soil and identified as Dietzia sp. 10-15, Deinococcus sp. А2-6, Alkanindiges sp. A36-1, and Alkanindiges sp. A36-3 exhibited low similarity of their 16S rRNA gene sequences to those of the closely related species and differed from them in a number of physiological and biochemical characteristics, which supported their identification as members of new species. Comparative physiological, biochemical, and fingerprint analysis of the strains belonging to the same species revealed intraspecific polymorphism. Strains capable of growth at high and low temperatures, resistant to UV-irradiation, elevated NaCl concentration, and acidic or alkaline conditions were revealed. This is the first report of oil degradation by R. pyridinivorans 5Ар at elevated temperature (45°C) and by R. erythropolis A2-h2 at 4°C.Chaudhary, D.K., Kim, J., 2018. Brevundimonas mongoliensis sp. nov., a novel psychrotolerant bacterium isolated from oil-contaminated soil. Current Microbiology 75, 1530-1536. yellow-coloured, Gram-stain-negative, motile, and rod-shaped bacteria, designated strains R-10-10T and R-10-15 were isolated from oil-contaminated soil. Both strains were able to grow at 4–40 °C, pH 5.5–10.5, and 0–4% (w/v) NaCl concentration. These strains were taxonomically characterized by a polyphasic approach. Based on the 16S rRNA gene sequence analysis, both strains, R-10-10T and R-10-15, could be affiliated to the genus Brevundimonas and shared highest sequence similarity with Brevundimonas staleyi FWC43T (98.8%), Brevundimonas bullata TK0051T (98.6%), and Brevundimonas subvibrioides CB81T (98.3%). The pairwise sequence similarity between strains R-10-10T and R-10-15 was 99.9%. Both strains R-10-10T and R-10-15 contained phosphatidylglycerol, diphosphatidylglycerol, and four unidentified glycolipids as major polar lipids; ubiquinone-10 as sole respiratory quinone; and summed feature 8 (C18:1ω7c and/or C18:1ω6c), C16:0, summed feature 3 (C16:1ω7c and/or C16:1ω6c), and C18:1ω9c as major fatty acids. The genomic DNA G+C content values of strains R-10-10T and R-10-15 were 67.1 and 66.9 mol%, respectively. The DNA–DNA relatedness between R-10-10T and R-10-15 was higher than 70% but the values were less than 55% with closely related reference type strains. The morphological, physiological, chemotaxonomic, and phylogenetic data clearly distinguished strain R-10-10T from its closest phylogenetic neighbors. Thus, strain R-10-10T is considered to represent a novel species of the genus Brevundimonas, for which the name Brevundimonas mongoliensis sp. nov. is proposed. The type strain is R-10-10T (=KEMB 9005-696T?=?KACC 19387T?=?JCM 32172T), and strain R-10-15 is considered as an additional strain of the novel species. The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene sequence of strains R-10-10T and R-10-15 are MF436701 and MF436702, respectively. The Digital Protologue database TaxonNumber for type strain R-10-10T is TA00428.Chen, F., He, H., Zhao, S.-M., Yao, J.-h., Sun, Q., Huang, G.-h., Xiao, D., Tang, L.-F., Leng, Y.-w., Tao, X.-x., 2018. Analysis of microbial community succession during methane production from Baiyinhua lignite. Energy & Fuels 32, 10311-10320. production from coal via anaerobic fermentation has received much attention in recent years. In the present work, the methane generation with Baiyinhua lignite by mixed flora derived from the coal bed water and anaerobic tank were investigated. The microbial community succession and the coal characteristics before and after methane production were analyzed, combing with high-throughput sequencing, proximate analysis, elemental analysis, X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The results showed that the bacteria community diversity was abundant, and the dominant phyla of bacteria were Firmicutes, Proteobacteria, Bacteroidetes, Thermotogae, Deferribacteres, Synergistete, and Spirochaetae. In contrast, the archaea community had low diversity, of which the main phylum was Euryarchaeota. Generally, both the bacterial and archaea biodiversities presented an initially increasing and then decreasing trend (0–40 days); however, the archaea diversity increased after 40 days of culture. In the gas production process, three groups of bacteria, including iron-reducing bacteria and sulfate-reducing bacteria assigned to Geovibrio, Macellibacteroides, and Desulfovibrio, were the main components. The results of proximate and elemental analyses of coal showed that moisture (+1.57%), volatile matter (Vdaf, +1.64%), H (+0.1%), O (+1.35%), N (+0.28%), and S (+1.29%) increased and ash (?1.67%) and C (?3.02%) decreased. XRD showed that the anaerobic digestion of microorganisms mainly uses the organic carbon source in lignite. The FTIR results showed a significant increase in the hydroxyl group, ether oxygen bond and carboxyl and carbonyl groups decreasing, the aromatics basically invariant, and aliphatic functional groups dominated by saturated CH2 decreasing significantly.Chen, G., Han, J., Mu, Y., Yu, H., Qin, L., 2019. Two-stage chromium isotope fractionation during microbial Cr(VI) reduction. Water Research 148, 10-18. isotope fractionation analysis is a promising approach for the assessment of microbial Cr(VI) reduction in groundwater. Understanding the mechanisms and other parameters that control Cr isotope fractionation factors (between the product Cr(III) and reactant Cr (VI)) in microbial Cr(VI) reduction is critical to this application. To date, such studies are very limited. Here, the influence of critical factors on observed Cr isotope fractionation during Cr(VI) reduction by Shewanella oneidensis MR-1 under various conditions was investigated. The Cr(VI) concentration and Cr isotope ratio measurements were conducted on unreacted Cr(VI) remaining in solution to determine Cr isotope fractionation factors. The changes in ambient environmental conditions (e.g., pH, temperature) have limited influence on Cr isotope fractionation factors. However, as a result of Cr(VI) consumption as the experiments proceed, the change in bioavailability of Cr(VI) has a significant impact on Cr isotope fractionation factors. For example, in temperature-controlled experiments, Cr isotope fractionation showed two-stage behavior: during Stage I, the values of ε were ?2.81?±?0.19‰ and ?2.60?±?0.14‰ at 18?°C and 34?°C, respectively; during Stage II, as Cr(VI) reduction progressed, Cr isotope fractionation was significantly masked, and the ε values decreased to ?0.98?±?0.49‰ and ?1.01?±?0.11‰ at 18?°C and 34?°C, respectively. Similar two-stage isotope fractionation behaviors were observed in pH-controlled experiments (pH?=?6.0 and 7.2) and in experiments with and without the addition of a competing electron acceptor (nitrate). Masking of isotope fractionation in Stage II indicated restrictions on the bioavailability of Cr(VI) and mass-transfer limitations. This study provides an explanation for the variation in Cr isotope fractionation factors during microbial Cr(VI) reduction in the environment, furthering the viability of Cr isotope ratio analysis as an approach in understanding Cr biogeochemical cycling.Chen, J., Fang, Z., Qiu, T., 2018. Molecular reconstruction model based on structure oriented lumping and group contribution methods. Chinese Journal of Chemical Engineering 26, 1677-1683. management is a promising technology to face challenges in the refining industry, such as more stringent requirements for product oil and heavier crude oil, and to maximize the value of every molecule in petroleum fractions. To achieve molecular management in refining processes, a novel model that is based on structure oriented lumping (SOL) and group contribution (GC) methods was proposed in this study. SOL method was applied to describe a petroleum fraction with structural increments, and GC method aimed to estimate molecular properties. The latter was achieved by associating rules between SOL structural increments and GC structures. A three-step reconstruction algorithm was developed to build a representative set of molecules from partial analytical data. First, structural distribution parameters were optimized with several properties. Then, a molecular library was created by using the optimized parameters. In the final step, maximum information entropy (MIE) method was applied to obtain a molecular fraction. Two industrial samples were used to validate the method, and the simulation results of the feedstock properties agreed well with the experimental data.Chen, M., Dai, J., Liu, X., Qin, M., Pei, Y., Wang, Z., 2018. Differences in the fluid characteristics between spontaneous imbibition and drainage in tight sandstone cores from nuclear magnetic resonance. Energy & Fuels 32, 10333-10343. the water injected during hydraulic fracturing is imbibed and then displaced in the matrix of tight reservoirs, it is meaningful to characterize the fluid distributions and percolation dynamics during these two processes as they significantly affect production. In this study, 6 tight sandstone cores from the Chinese Ordos Basin were selected to experimentally study the fluid seepage and distributions during spontaneous imbibition and drainage using a low-field nuclear magnetic resonance (NMR) core analysis unit. Dry cores were first tested via cocurrent imbibition and then centrifuged from fully saturated to irreducible water saturation to simulate the imbibition and drainage processes, respectively. The weights and T2 spectra were measured concurrently for each step. The results showed that the volume of imbibed water increased rapidly during the first 3000 min and reached a constant value at the end of the experiment; the final imbibition water saturation Swim ranged from 48.52% to 89.20%. The irreducible water saturation Swir was reached after a centrifuge speed of 10?000 r/min and varied from 40.46% to 53.28%. The gas and water relative permeabilities were estimated by combining the T2 spectra for different water saturations, which indicated the effect of the capillary force and pore–throat structure on the different fluid seepage characteristics during spontaneous imbibition and drainage. The T2 time was converted to the corresponding pore–throat radius by combining the fully water-saturated T2 spectra and pore distributions from a constant-rate mercury injection. Micropores of 0–2 μm were identified as the dominant pore spaces for imbibed water during spontaneous imbibition and the water remained after centrifugation, whereas a small amount of water was imbibed or remained in pores larger than 20 μm. The physical properties, microstructure, and dispersed clay minerals were considered to be the three dominant factors of the fluid dynamics and distribution differences, and the effects were stronger during spontaneous imbibition.Chen, M., Park, M., Kim, J.-H., Shinn, Y.J., Lee, Y.K., Hur, J., 2018. Exploring pore water biogeochemical characteristics as environmental monitoring proxies for a CO2 storage project in Pohang Basin, South Korea. Marine Pollution Bulletin 137, 331-338. parameters of pore waters, including dissolved organic matter, nutrients, sulfate, alkalinity, and chloride are explored as convenient and sensitive proxies to monitor the CO2 geological storage sites. Five sites for a CO2 storage project in the Pohang Basin of the East Sea in South Korea were investigated for the pre-injection biogeochemical conditions of these sites. Higher dissolved organic carbon (~36?mg?L?1), chromophoric and fluorescent dissolved organic matter, nutrients, and alkalinity were observed in a fluvially affected acoustic blanking site with geological faults. A general increasing downcore trend of measured DOM parameters, nutrients, and alkalinity with depth was found at the acoustic blanking site affected by riverine runoff with significant correlations among the parameters (R2: ~0.4–0.8), highlighting the impact of geological features and external inputs on the downcore biogeochemical properties. The results presented in this study suggest that DOM could be utilized as a robust and complementary biogeochemical parameter.Chen, Q., You, L., Kang, Y., Dou, L., Sheng, J.J., 2018. Gypsum-crystallization-induced fracturing during shale–fluid reactions and application for shale stimulation. Energy & Fuels 32, 10367-10381. microfracture propagation caused by mineral crystallization or growth has been demonstrated in a variety of volume-increasing mineral replacement reactions. This brings a new look on the way microfractures may be generated in the shale formation. Because carbonates and pyrite are highly reactive minerals during shale–fluid reactions and may be the most common sources of replacement reactions, 10 wt?% sulfuric acid (H2SO4) and 10 wt?% ammonium persulfate ((NH4)2S2O8) solutions were used to react with the centimeter- and millimeter-sized shale samples, which have a reactive mineral composition of 2.2–4.7 wt?% calcite (CaCO3) and 4.3–4.8 wt?% dolomite (CaMg(CO3)2), and 1.8–2.7 wt?% pyrite (FeS2). A deionized water experiment was performed as a replacement-free control. We monitored the reaction-induced fractures using X-ray tomography and scanning electron microscopy imaging. The related mineral dissolution and new mineral precipitation were also examined. Experiments showed that reactions of the unconfined shale samples with H2SO4 and (NH4)2S2O8 solution have a great potential for generating chemically induced fractures, because of the replacement of carbonate minerals by gypsum (CaSO4·2H2O) crystal. The replacement process was supposed to occur via an interface-coupled dissolution–precipitation reaction. It allows the gypsum precipitation in the immediate vicinity of the dissolving carbonate mineral surfaces. Because gypsum has a higher molar volume (74.4 cm3/mol) than calcite (36.9 cm3/mol) and dolomite (64.3 cm3/mol), the local replacement reactions can generate internal swelling stress that drives fracturing of the surrounding shale matrix. The reaction-induced stress is on the grain scale and derived from the crystallization pressure. Based on the calculation from the degree of supersaturation of CaSO4 solution, the crystallization pressure can easily exceed 30 MPa, which may provide a sufficient local swelling stress to cause intensive shale microfracturing. This implies that the replacement of calcite and dolomite grains by calcium sulfate crystals could provide an additional driving force to generate microfractures during shale hydraulic fracturing.Chen, S., Zhao, C., Liu, Q., Zang, M., Liu, C., Zhang, Y., 2018. Thermophilic biodesulfurization and its application in oil desulfurization. Applied Microbiology and Biotechnology 102, 9089-9103. reduce the harm caused to the environment by fuel combustion and meet the increasingly stringent emission standards, the sulfur content of fuels should be reduced. Dibenzothiophene, benzothiophene, and their derivatives are sulfur-containing components of fuels that are difficult to desulfurize and can therefore cause great environmental damage. Biodesulfurization is a desulfurization method that has the advantage of being able to remove dibenzothiophene and its derivatives removed easily under conditions that are relatively mild when compared with hydrodesulfurization. This paper introduces the advantages of thermophilic biodesulfurization compared with mesophilic biodesulfurization; analyzes the desulfurization mechanism, including the desulfurization pathways and enzymic systems of desulfurization bacteria; and discusses the application of biodesulfurization in oil desulfurization. The main problems existing in biodesulfurization and possible solutions are also analyzed in this paper. Biological desulfurization is a promising method for desulfurization; accordingly, more studies investigating biodesulfurization of actual oil are needed to enable the industrialized application of biodesulfurization.Chen, X., Zhang, F., Lao, Y., Wang, X., Du, J., Santos, I.R., 2018. Submarine groundwater discharge-derived carbon fluxes in mangroves: An important component of blue carbon budgets? Journal of Geophysical Research: Oceans 123, 6962-6979. are blue carbon systems characterized by high soil carbon storage and sequestration. Soil carbon losses via groundwater or pore water pathways are potentially important yet poorly understood components of mangrove carbon budgets. Here we quantified submarine groundwater discharge (SGD) and associated dissolved inorganic carbon (DIC) and organic carbon (DOC) fluxes into a mangrove‐dominated tropical bay (Maowei Sea) using a radon (222Rn) mass balance model. The SGD fluxes in Maowei Sea were estimated to be 4.9 × 107 (0.36 ± 0.33 m/day) and 2.6 × 107 m3/day (0.20 ± 0.18 m/day) for the wet and dry seasons, respectively, implying that SGD may respond to precipitation. The SGD‐derived DIC and DOC fluxes (mol·m?2·day?1) in the wet season (DIC: 0.70 ± 0.82; DOC: 0.31 ± 0.30) were higher than those in the dry season (DIC: 0.25 ± 0.24; DOC: 0.25 ± 0.23). These SGD‐derived carbon fluxes exceed local river inputs and constituted >70% of the total DIC and DOC input into the bay. If scaled up to the global weighted mangrove area in combination with data from other 32 study sites, carbon fluxes via SGD into mangroves may be equivalent to 29–48% of the global riverine input into the ocean. Therefore, we suggest that SGD is a major component of coastal carbon budgets and that accounting for SGD helps to reduce uncertainties in mangrove blue carbon budgets. Chen, Y., Liu, D., Cai, Y., Gan, Q., 2018. Insights into fractal characteristics of pores in different rank coals by nuclear magnetic resonance (NMR). Arabian Journal of Geosciences 11, 578. nuclear magnetic resonance (NMR), as a nondestructive and time saving method, has been widely used to evaluate the petrophysical properties of coalbed methane (CBM) reservoirs. To better understand the impacts of pore structures on permeability, NMR T2 spectrums of different rank coals and their meaning to porosity and permeability were investigated. Fractal dimensions of coal pores with NMR T2 spectrum and their correlations with porosity, Ro,m, and permeability were synthetically analyzed. The results show that T2 spectrums can be divided into three types named as unimodal, bimodal, and trimodal based on the spectrum peaks. The percentage of spectrum peak P1 increases with increasing Ro, m and the connectivity of different peaks can effectively reflect the permeability. The irreducible fluid and movable fluid porosity have an opposite relationship with increasing percentage of centrifugal fluid and increasing Ro,m. Fractal dimensions of adsorption pores (D1, 0.82–1.94) and seepage pores (D2, 2.50–2.99) demonstrate that coal pores have multiple fractals. Due to the coalification jump, both D1 and D2 show binomial relationship with Ro,m at the inflection section of 1.3–1.5% Ro,m. Generally, movable fluid porosity, irreducible fluid porosity, and total porosity show exponentially decreased or binomial relationship with the increasing D1 and D2. The development of microfractures could be the main cause of abnormal tendency between D2 and total porosity in the high-rank coals. The movable fluid porosity that reflects the proportion of seepage pores decreases with the increasing D2, which have a significant impact on low permeability coals. Most seepage pores that contributed permeability is lower than 0.1 mD, which contributes less than 20% to total permeability. However, seepage pores that contributed permeability may have an important role on CBM production, especially at the middle to late stage.Cheng, G., Sun, L., Fu, J., 2018. Prediction of biodegradability for polycyclic aromatic hydrocarbons using various in silico modeling methods. Archives of Environmental Contamination and Toxicology 75, 607-615. aromatic hydrocarbons (PAHs) have attracted great concern as global environmental pollutants. In this work, the quantitative structure–biodegradability relationship (QSBR) study has been done to predict the biodegradability of PAHs and develop the correlation between the biodegradability and the molecular structures. The structural chemistry and quantum chemistry descriptors were used to represent molecular structures. Three in silico modeling methods, i.e., multiple linear regression (MLR), radial basis function neural network, and back-propagation artificial neural network (BPANN), are utilized to construct the linear and nonlinear prediction models and provide some insights into the structural characteristics affecting the biodegradability of PAHs. The stability of these QSBR models was tested by leave-one-out cross-validation, and the cross-validated correlation coefficients (q2) were 0.6109, 0.6887, and 0.6586, respectively. The correlation coefficients (R2) of the three models for the training set were 0.7811, 0.8883, and 0.9667, respectively. The comparison of the three models showed that the BPANN model produced a statistically more significant model than the other two models. On the basis of molecular structure, the dominant molecular structure descriptor affecting biodegradability of PAHs were analyzed and discussed.Cheng, L.-C., Shiao, J.-C., Hsiao, S.S.-Y., Wang, P.-L., 2018. Fractionation of otolith nitrogen stable isotopes measured by peroxodisulfate oxidation-bacterial conversion and isotope ratio mass spectrometry. Rapid Communications in Mass Spectrometry 32, 1905-1910.: Otoliths are usually used to estimate the age of fish and the chemical composition such as nitrogen stable isotope ratios (δ15N values) may record environmental information and ecological role of the fish. However, the isotopic fractionation of δ15N values between diets and otoliths has rarely been investigated and remains unclear. Methods: Nitrogen isotopic fractionation between five different diets (δ15Ndiet values) and otoliths (δ15Noto values) were elucidated in tilapia Oreochromis mossambica reared in controlled feeding experiments. The otoliths were dissolved with hydrogen chloride and peroxodisulfate was used to oxidize the total organic materials to nitrate, which was further converted into N2O gas by denitrification bacteria before the measurement of δ15Noto values by isotope ratio mass spectrometry. The δ15N values of muscles, gills, scales and livers of the tilapias were also measured by isotope ratio mass spectrometry. Results: The peroxodisulfate oxidation‐bacterial conversion method reduced the minimum mass of the otoliths required for analysis to as low as 2?mg, unlike past methods, which have required masses of 8–155?mg. The δ15Noto values were not significantly different from the δ15Ndiet values of the five diets. Furthermore, the somatic growth rate had no effect on the δ15Noto values. Nevertheless, the δ15N values of metabolically active tissues were significantly different from each other and higher than the δ15Ndiet values, due to the deamination of these tissues. Conclusions: These results suggest that diet was the main source of amino acids for the otolith organic matrix and there was no biochemical transamination during the assimilation of dietary amino acids to otoliths. The δ15Noto value can be used as a proxy of nitrogen sources of fishes and may have potential application in ecological studies such as the detection of diet shift, migration, trophic levels and environmental changes experienced by the fish population. Cheng, Z., Ning, Z., Wang, Q., Zeng, Y., Qi, R., Huang, L., Zhang, W., 2019. The effect of pore structure on non-Darcy flow in porous media using the lattice Boltzmann method. Journal of Petroleum Science and Engineering 172, 391-400. flows associated with high Reynolds numbers often occur in the near-wellbore regions of gas reservoirs or hydraulic fractures and thus should not be ignored. However, investigating non-Darcy flow in these porous rocks through laboratory experiments is always expensive and time-consuming. As such, this article sought an alternative method, and a lattice Boltzmann study of non-Darcy flow in various porous models was performed. The applicability of two non-Darcy correlations in porous media and the effect of pore structure on non-Darcy flow were examined. In addition, the reasons for the deviation from the linear Darcy flow and different flow patterns related to inertial effects of the fluid were also studied. The results showed that the characterization of non-Darcy flow in porous media with the cubic law can only be valid in a narrow range of Reynolds number beyond the Darcy regime, outside of which the strong inertia-dominated flow yields to the quadratic correction. On the whole, representing the non-Darcy flows using the quadratic correction is acceptable, especially for porous media with a higher complexity. The features of non-Darcy flow greatly depend on the pore structure of a porous medium, and more heterogeneous pore models always have a faster cessation for Darcy flow and a higher β factor. Furthermore, for simple porous media a small amount of parameters may be adequate for the prediction of the β factor; while the correlations involving more parameters would be needed to determine the β factor for more intricate porous models, although such correlations may not be widely used in various industries. Besides, the non-Darcy flow that occurs in porous media is collectively controlled by different mechanisms. At elevated velocities, the inertial core effect in a large channel will lead the flow to be more homogeneous and less tortuous, while in porous models with complicated pore space, the steady eddy and reversal flow resulting from drag force will make the flow paths more tortuous. As such, it is the hope of this study to provide some new insights into the non-Darcy flow in porous media.Chiellini, C., Miceli, E., Bacci, G., Fagorzi, C., Coppini, E., Fibbi, D., Bianconi, G., Mengoni, A., Canganella, F., Fani, R., 2018. Spatial structuring of bacterial communities in epilithic biofilms in the Acquarossa river (Italy). FEMS Microbiology Ecology 94, Article fiy181. river biofilms characterize the rock surfaces along the Acquarossa river (Viterbo, Italy); they are in part red and in part black colored, maintaining a well-defined borderline. This peculiarity has raised questions about the biotic and abiotic phenomena that might avoid the mixing of the two biofilms. In this study, the structuring of bacterial communities in black and red epilithic biofilm in the Acquarossa river has been investigated with both culture dependent and independent approaches. Data obtained highlighted a (very) different taxonomic composition of black and red epilithons bacterial communities, dominated by Acinetobacter sp. and iron-oxidizing bacteria, respectively. The chemical characterization of both river water and biofilms revealed a substantial heavy metals pollution of the environment; heavy metals were also differentially accumulated in red and black epilithons. Overall, our data revealed that the structuring of red and black epilithons might be affected mainly by the antagonistic interactions exhibited by bacterial genera dominating the two biofilms. These findings suggest that biotic factors might be responsible for the structuring of natural bacterial communities, suggesting that there is a selection of populations at very small scale, and that different populations might compete for different niches.Cho, J., Kim, T.H., Chang, N., Lee, K.S., 2019. Effects of asphaltene deposition-derived formation damage on three-phase hysteretic models for prediction of coupled CO2 enhanced oil recovery and storage performance. Journal of Petroleum Science and Engineering 172, 988-997., precipitated from oil due to pressure, temperature, or oil compositional changes, can affect not only the performance of CO2 enhanced oil recovery (EOR), but also carbon capture and storage (CCS) by reducing porosity and permeability and altering wettability. A comprehensive solid deposition model, which includes adsorption, pore throat plugging, and re-entrainment, was developed to predict the amount of precipitated asphaltene under dynamic conditions. In this study, a hysteretic three-phase fluid flow model was used to simulate residual and solubility trapping during the water alternating gas (WAG) process. Alteration of rock wettability during asphaltene deposition led to a decrease in oil and gas mobility and an increase in water mobility, increasing the amount of CO2 residual trapping to 39%, via a hysteresis effect. Residual trapped CO2 replaced liquids in the pore space; more water was substituted when asphaltene deposition was considered than that without it because of greater water mobility. Consequentially solubility and residual trapping were overestimated by 20% and underestimated by 39% when asphaltene deposition was not considered. Formation damage by asphaltene deposition increased water production by 14% and decreased oil recovery by 9% compared to a model without asphaltene deposition. These results indicate that asphaltene deposition affects CO2 trapping mechanisms and EOR performance during coupled CO2 EOR and storage processes.Cipullo, S., Negrin, I., Claveau, L., Snapir, B., Tardif, S., Pulleyblank, C., Prpich, G., Campo, P., Coulon, F., 2019. Linking bioavailability and toxicity changes of complex chemicals mixture to support decision making for remediation endpoint of contaminated soils. Science of The Total Environment 650, 2150-2163. six-month laboratory scale study was carried out to investigate the effect of biochar and compost amendments on complex chemical mixtures of tar, heavy metals and metalloids in two genuine contaminated soils. An integrated approach, where organic and inorganic contaminants bioavailability and distribution changes, along with a range of microbiological indicators and ecotoxicological bioassays, was used to provide multiple lines of evidence to support the risk characterisation and assess the remediation end-point. Both compost and biochar amendment (p?=?0.005) as well as incubation time (p?=?0.001) significantly affected the total and bioavailable concentrations of the total petroleum hydrocarbons (TPH) in the two soils. Specifically, TPH concentration decreased by 46% and 30% in Soil 1 and Soil 2 amended with compost. These decreases were accompanied by a reduction of 78% (Soil 1) and 6% (Soil 2) of the bioavailable hydrocarbons and the most significant decrease was observed for the medium to long chain aliphatic compounds (EC16–35) and medium molecular weight aromatic compounds (EC16–21). Compost amendment enhanced the degradation of both the aliphatic and aromatic fractions in the two soils, while biochar contributed to lock the hydrocarbons in the contaminated soils. Neither compost nor biochar affected the distribution and behaviour of the heavy metals (HM) and metalloids in the different soil phases, suggesting that the co-presence of heavy metals and metalloids posed a low risk. Strong negative correlations were observed between the bioavailable hydrocarbon fractions and the ecotoxicological assays suggesting that when bioavailable concentrations decreased, the toxicity also decreased. This study showed that adopting a combined diagnostic approach can significantly help to identify optimal remediation strategies and contribute to change the over-conservative nature of the current risk assessments thus reducing the costs associated with remediation endpoint.Cira, N.J., Pearce, M.T., Quake, S.R., 2018. Neutral and selective dynamics in a synthetic microbial community. Proceedings of the National Academy of Sciences 115, E9842-E9848.: We created a synthetic microbial community to help understand how evolution and selection pressure change the species diversity of an ecosystem. Our results show that there is a clear transition between neutral and selective regimes that depends on the rate of immigration as well as the fitness differences.Abstract: Ecologists debate the relative importance of selective vs. neutral processes in understanding biodiversity. This debate is especially pertinent to microbial communities, which play crucial roles in areas such as health, disease, industry, and the environment. Here, we created a synthetic microbial community using heritable genetic barcodes and tracked community composition over repeated rounds of subculture with immigration. Consistent with theory, we find a transition exists between neutral and selective regimes, and the crossover point depends on the fraction of immigrants and the magnitude of fitness differences. Neutral models predict an increase in diversity with increased carrying capacity, while our selective model predicts a decrease in diversity. The community here lost diversity with an increase in carrying capacity, highlighting that using the correct model is essential for predicting community response to change. Together, these results emphasize the importance of including selection to obtain realistic models of even simple systems.Correa Pabón, R.E., Souza Filho, C.R.d., 2019. Crude oil spectral signatures and empirical models to derive API gravity. Fuel 237, 1119-1131. spectroscopy is presented as a quick alternative method for establishing crude oil properties such as density (°API gravity) and content of saturates, aromatics, resins and asphaltenes (SARA). Here, thirty seven (37) samples of crude oils with different °API gravities and SARA fractions were measured in the visible, near infrared and short wave infrared (VIS – NIR – SWIR/350–2500?nm), and in the middle and longwave infrared (MWIR – LWIR/3000–15,000?nm) ranges. Main CH absorption bands and optimal intervals for the discrimination among oil types were identified in all spectral regions. Based on diffuse reflectance spectroscopy and equivalent wavelet spectra, Principal Component Analysis allowed distinguishing between three major groups of crude oils with varied densities. Partial Least Squares Regression analysis yielded sixteen predictive models tailored to estimate the °API of crude oils based on their spectral signatures in the NIR – SWIR – MWIR – LWIR intervals. These data and methods are swift and nondestructive ways to estimate the °API of crude oils, with latent applications in several chains of the petroleum industry, particularly to assess and manage the environmental impact caused by oil discharge, leakage and spill events. Additionally, considering that airborne and orbital sensor systems currently in operation can sense some of the crude oil absorption bands highlighted in this study, the oil signatures revealed here could be potentially used to map oil contamination in diverse settings and globally using remote sensing.Coutinho, F.H., Gregoracci, G.B., Walter, J.M., Thompson, C.C., Thompson, F.L., 2018. Metagenomics sheds light on the ecology of marine microbes and their viruses. Trends in Microbiology 26, 955-965. brought about by omics-based approaches have revolutionized our understanding of the diversity and ecological processes involving marine archaea, bacteria, and their viruses. This broad review discusses recent examples of how genomics, metagenomics, and ecogenomics have been applied to reveal the ecology of these biological entities. Three major topics are covered in this revision: (i) the novel roles of microorganisms in ecosystem processes; (ii) virus–host associations; and (iii) ecological associations of microeukaryotes and other microbes. We also briefly comment on the discovery of novel taxa from marine ecosystems; development of a robust taxonomic framework for prokaryotes; breakthroughs on the diversity and ecology of cyanobacteria; and advances on ecological modelling. We conclude by discussing limitations of the field and suggesting directions for future research.Craine, J.M., Elmore, A.J., Wang, L., Aranibar, J., Bauters, M., Boeckx, P., Crowley, B.E., Dawes, M.A., Delzon, S., Fajardo, A., Fang, Y., Fujiyoshi, L., Gray, A., Guerrieri, R., Gundale, M.J., Hawke, D.J., Hietz, P., Jonard, M., Kearsley, E., Kenzo, T., Makarov, M., Mara?ón-Jiménez, S., McGlynn, T.P., McNeil, B.E., Mosher, S.G., Nelson, D.M., Peri, P.L., Roggy, J.C., Sanders-DeMott, R., Song, M., Szpak, P., Templer, P.H., Van der Colff, D., Werner, C., Xu, X., Yang, Y., Yu, G., Zmudczyńska-Skarbek, K., 2018. Isotopic evidence for oligotrophication of terrestrial ecosystems. Nature Ecology & Evolution 2, 1735-1744. societies depend on an Earth system that operates within a constrained range of nutrient availability, yet the recent trajectory of terrestrial nitrogen (N) availability is uncertain. Examining patterns of foliar N concentrations and isotope ratios (δ15N) from more than 43,000 samples acquired over 37?years, here we show that foliar N concentration declined by 9% and foliar δ15N declined by 0.6–1.6‰. Examining patterns across different climate spaces, foliar δ15N declined across the entire range of mean annual temperature and mean annual precipitation tested. These results suggest declines in N supply relative to plant demand at the global scale. In all, there are now multiple lines of evidence of declining N availability in many unfertilized terrestrial ecosystems, including declines in δ15N of tree rings and leaves from herbarium samples over the past 75–150?years. These patterns are consistent with the proposed consequences of elevated atmospheric carbon dioxide and longer growing seasons. These declines will limit future terrestrial carbon uptake and increase nutritional stress for herbivores.Crognale, S., Venturi, S., Tassi, F., Rossetti, S., Rashed, H., Cabassi, J., Capecchiacci, F., Nisi, B., Vaselli, O., Morrison, H.G., Sogin, M.L., Fazi, S., 2018. Microbiome profiling in extremely acidic soils affected by hydrothermal fluids: the case of the Solfatara Crater (Campi Flegrei, southern Italy). FEMS Microbiology Ecology 94, Article fiy190. integrated geochemical and microbiological investigation of soils from the Solfatara Crater (Campi Flegrei, southern Italy) demonstrated that interstitial soil gases dominated by CO2 and other typical hydrothermal gaseous species (e.g. H2S, CH4, ethane, benzene, alkenes and S-bearing organic compounds) influenced the composition of microbial communities. The relatively high concentrations of hydrothermal fluids permeating the soil produced acidic conditions and whitish deposits that characterize the Solfatara Crater floor. Archaea and Bacteria showed almost equal cell abundance (up to 3.2 × 107 and 4.2 × 107 cell/g, respectively) with relatively low levels of biodiversity and equitability in sites characterized by elevated temperatures (up to 70°C), very low pH values (up to 2.2) and reducing conditions. In these sites, high-throughput sequencing showed the marked selection of microorganisms, mainly affiliated with the genera Thermoplasma, Ferroplasma and Acidithiobacillus. A relatively high biodiversity and concomitant distinctive structure of the microbial community were observed in soils poorly affected by fumarolic emissions that were oxic and rich in organic matter.Cui, J., Liu, D., Cai, Y., Pan, Z., Zhou, Y., 2019. Insights into fractures and minerals in subbituminous and bituminous coals by FESEM-EDS and X-ray μ-CT. Fuel 237, 977-988. are the main pathways for fluid transport, which constrain the coalbed methane (CBM) reservoir permeability. Permeability is one of the key petrophysical parameters for CBM production. The fractures in the low and middle rank coals usually filled with minerals, which can significantly reduce the reservoir permeability. In this study, X-ray μ-CT combined with field emission scanning electron microscopy (FESEM) together with energy dispersive spectrometry (EDS) were used to quantitatively evaluate the features of fractures and minerals of FK sample (Ro,max 0.65%) and ML sample (Ro,max 1.49%) including morphology, complexity, volume and 3D structure, and its impacts on permeability. The results showed that fractures are well developed as observed in the samples FK and ML by the 2D cross section of X-ray μ-CT. Dolomite and kaolinite are common in the samples FK and ML as confirmed by FESEM images with EDS. Moreover, the 3D fracture structure including the open fracture and mineral filled fracture were reconstructed. The quantitative structural parameters (e.g. length, width, area and volume) of the fractures for these two samples were acquired by the commercial software Avizo 9.0.1. The middle rank coal of sample ML has larger fracture density (181 fractures per mm3) than that of the low rank coal of sample FK (104 fractures per mm3). Based on the reconstructed 2D and 3D fracture structure, the fracture complexity was evaluated through fractal dimension. And the impacts of mineralization in coals on petrophysical properties were evaluated, which show that the connectivity of fractures, porosity and permeability were greatly improved after demineralization. Therefore, this study may have implications for enhanced CBM recovery through demineralization.Cui, L., Lu, H., Lee, Y.H., 2018. Challenges and emergent solutions for LC-MS/MS based untargeted metabolomics in diseases. Mass Spectrometry Reviews 37, 772-792. the past decade, advances in liquid chromatography-mass spectrometry (LC-MS) have revolutionized untargeted metabolomics analyses. By mining metabolomes more deeply, researchers are now primed to uncover key metabolites and their associations with diseases. The employment of untargeted metabolomics has led to new biomarker discoveries and a better mechanistic understanding of diseases with applications in precision medicine. However, many major pertinent challenges remain. First, compound identification has been poor, and left an overwhelming number of unidentified peaks. Second, partial, incomplete metabolomes persist due to factors such as limitations in mass spectrometry data acquisition speeds, wide-range of metabolites concentrations, and cellular/tissue/temporal-specific expression changes that confound our understanding of metabolite perturbations. Third, to contextualize metabolites in pathways and biology is difficult because many metabolites partake in multiple pathways, have yet to be described species specificity, or possess unannotated or more-complex functions that are not easily characterized through metabolomics analyses. From a translational perspective, information related to novel metabolite biomarkers, metabolic pathways, and drug targets might be sparser than they should be. Thankfully, significant progress has been made and novel solutions are emerging, achieved through sustained academic and industrial community efforts in terms of hardware, computational, and experimental approaches. Given the rapidly growing utility of metabolomics, this review will offer new perspectives, increase awareness of the major challenges in LC-MS metabolomics that will significantly benefit the metabolomics community and also the broader the biomedical community metabolomics aspire to serve.Cui, Q., He, X., Liu, Q., Bai, Y., Chen, C.-T.A., Chen, X., Pan, D., 2018. Estimation of lateral DOC transport in marginal sea based on remote sensing and numerical simulation. Journal of Geophysical Research: Oceans 123, 5525-5542. to high temporal and spatial dynamics and complex biological processes, it is difficult to estimate lateral transportations of the dissolved organic carbon (DOC) in marginal seas by conventional field observations and model simulations. Taking the East China Sea (ECS), for example, this study proposed a novel model for estimating the lateral DOC flux in marginal sea. Three‐dimensional distributions of DOC concentrations were retrieved by satellite remote sensing. Furthermore, three‐dimensional currents were simulated using the numerical model. Finally, the lateral DOC flux in the whole ECS was estimated based on the satellite‐derived DOC concentrations and the simulated currents. The results showed that despite seasonal variations, the unit area lateral DOC flux remained high throughout the year in the Changjiang River estuary, Zhejiang‐Fujian Coast, Taiwan Strait, and Kuroshio regions. There were three eastward transportation channels which were strong in summer half year and weak in winter half year. Moreover, a northward transport zone extending from north of Taiwan to the south of the Changjiang River estuary was detected. In terms of annually net flux, highest net DOC import (30.65 TgC yr?1) was from the Taiwan Strait, mainly through the eastern side of the strait. The second highest net DOC import (18.75 TgC yr?1) was from the shelf slope (200 m isobath), mainly through the south part of the slope between 26°N and 26.5°N. Most of the net DOC export (?52.75 TgC yr?1) from the ECS was observed through the northern boundary (32°N), particularly in the outer shelf with water depth of 100–200 m. Cuijpers, M.C.M., Boot, M.D., Deen, N.G., Golombok, M., 2019. Sulphur and viscosity reductions in heavy hydrocarbons by subcritical water processing. Journal of Petroleum Science and Engineering 172, 1069-1076. and sulphur content are two important properties of heavy hydrocarbons for downstream processing. Both properties can be significantly reduced in value by processing in subcritical water. Subcritical water has advantages over steam recovery methods in terms of viscosity and sulphur reduction as well as energy consumption. In order to understand the mechanism of subcritical water treatment, the chemical structure of pre- and post-processed heavy hydrocarbons are compared to each other. For subcritical water processing, viscosity reduction coincides with a reduction in average molecular weight, average carbon chain length between branching points, and sulphur content, along with an increase in volatility and H2S production. This suggests that not only are C–C bonds cracked, but also C–S-(C) bonds. Subsequent comparison of subcritical water results with those obtained for pyrolysis treatment shows that the former is faster and more effective.Currie, B., Utne-Palm, A.C., Salvanes, A.G.V., 2018. Winning ways with hydrogen sulphide on the Namibian Shelf. Frontiers in Marine Science 5, 341. doi: 10.3389/fmars.2018.00341. shelf sediments off Namibia are some of the most unusual and extreme marine habitats because of their extremely high hydrogen sulphide concentrations. High surface productivity of the northern Benguela upwelling system provides benthic life with so much carbon that biotic processes must rely on innovative mechanisms to cope with perennial anoxia and toxic hydrogen sulphide. Bottom dwelling communities are forced to adapt lifestyles to deal physiologically and behaviourally with these stressful conditions. The upside of hydrogen sulphide is that it fuels extensive mats of large sulphide-oxidizing bacteria on the seabed, which create detoxified habitat niches and food for the animals living there. The threat of hypoxic stress exacerbated by hydrogen sulphide is largely overcome in the water column by microbes that detoxify sulphide, allowing animals in the upper water layers to thrive in this productive upwelling area. The bearded goby Sufflogobius bibarbatus is a cornerstone species that successfully couples the inhospitable benthic environment with the pelagic. Benthic studies have as yet not characterized the sulphidic shelf communities, which have the potential to uncover biotic adaptations to toxic sulphide. This ancient shelf upwelling system has long operated under hypoxic pressure, balancing always the abundance of particulate food against oxygen limitation and hydrogen sulphide toxicity. Challenges faced by this unique system could include environmental changes related to climate change, or man-made physical disturbances of the anoxic, sulphide-rich seabed sediments.de Souza, J.R.B., Dias, F.F.G., Caliman, J.D., Augusto, F., Hantao, L.W., 2018. Opportunities for green microextractions in comprehensive two-dimensional gas chromatography / mass spectrometry-based metabolomics – A review. Analytica Chimica Acta 1040, 1-18. have become an attractive class of techniques for metabolomics. The most popular technique is solid-phase microextraction that revolutionized the field of modern sample preparation in the early nineties. Ever since this milestone, microextractions have taken on many principles and formats comprising droplets, fibers, membranes, needles, and blades. Sampling devices may be customized to impart exhaustive or equilibrium-based characteristics to the extraction method. Equilibrium-based approaches may rely on additional methods for calibration, such as diffusion-based or on-fiber kinetic calibration to improve bioanalysis. In addition, microextraction-based methods may enable minimally invasive sampling protocols and measure the average free concentration of analytes in heterogeneous multiphasic biological systems. On-fiber derivatization has evidenced new opportunities for targeted and untargeted analysis in metabolomics. All these advantages have highlighted the potential of microextraction techniques for in?vivo and on-site sampling and sample preparation, while many opportunities are still available for laboratory protocols. In this review, we outline and discuss some of the most recent applications using microextractions techniques for comprehensive two-dimensional gas chromatography-based metabolomics, including potential research opportunities.de Souza Pohren, R., Rocha, J.A.V., Horn, K.A., Vargas, V.M.F., 2019. Bioremediation of soils contaminated by PAHs: Mutagenicity as a tool to validate environmental quality. Chemosphere 214, 659-668. can be used as one of the decontamination techniques for areas contamined by polycyclic aromatic hydrocarbons (PAHs). However the effective biodegradation of these compounds must take into account the possible toxic and mutagenic effects that might persist. In this study the mutagenic potential of soil samples from an area contaminated by wood preservatives was evaluated. The area had already been submitted to a simulated bioremediation process in a microcosm, using two different inoculums (1 and 2), and comparing them to the decay of PAHs. Organic extracts were prepared before and after bioremediation, where the 16 PAHs considered a priority by USEPA were analyzed and tested using the Salmonella/microsome assay. The extracts were analyzed in strains TA98, TA97a and TA100 (+S9mix/-S9mix), YG1041 and YG1042. Considering Inoculum 1 only as bioaugmented and Inoculum 2 also stimulated and enriched, the concentrations of PAHs and mutagenic effect were different. The former identified a greater reduction of mutagenesis and a smaller decrease of PAHs while the latter showed greater mutagenic power even associated with the greatest reduction of PAHS. The possible generation of degradation byproducts with high mutagenic power after a partial biodegradation process can be considered. In strains YG1041 and YG 1042 the mutagenesis values before bioremediation were 747 and 567 rev/g soil, respectively. Although the efficiency of bioremediation was observed, the associated damage indicates that the analysis of contaminants and their relationship with mutagenic effects are a fundamental stage for the effective evaluation of the risks and efficiency of bioremediation processes.de Vries, P., Tamis, J., Hjorth, M., Jak, R., Falk-Petersen, S., van den Heuvel-Greve, M., Klok, C., Hemerik, L., 2018. How including ecological realism impacts the assessment of the environmental effect of oil spills at the population level: The application of matrix models for Arctic Calanus species. Marine Environmental Research 141, 264-274. oil spill responses, assessment of the potential environmental exposure and impacts of a spill is crucial. Due to a lack of chronic toxicity data, acute data is used together with precautionary assumptions. The effect on the Arctic keystone (copepod) species Calanus hyperboreus and Calanus glacialis populations is compared using two approaches: a precautionary approach where all exposed individuals die above a defined threshold concentration and a refined (full-dose-response) approach. For this purpose a matrix population model parameterised with data from the literature is used. Population effects of continuous exposures with varying durations were modelled on a range of concentrations. Just above the chronic No Observed Effect Concentration (which is field relevant) the estimated population recovery duration of the precautionary approach was more than 300 times that of the refined approach. With increasing exposure concentration and duration, the effect in the refined approach converges to the maximum effect assumed in the precautionary approach.Deane-Coe, P.E., Chu, E.T., Slavney, A., Boyko, A.R., Sams, A.J., 2018. Direct-to-consumer DNA testing of 6,000 dogs reveals 98.6-kb duplication associated with blue eyes and heterochromia in Siberian Huskies. PLOS Genetics 14, Article e1007648. genomics enables genetic discovery on an unprecedented scale by linking very large databases of personal genomic data with phenotype information voluntarily submitted via web-based surveys. These databases are having a transformative effect on human genomics research, yielding insights on increasingly complex traits, behaviors, and disease by including many thousands of individuals in genome-wide association studies (GWAS). The promise of consumer genomic data is not limited to human research, however. Genomic tools for dogs are readily available, with hundreds of causal Mendelian variants already characterized, because selection and breeding have led to dramatic phenotypic diversity underlain by a simple genetic structure. Here, we report the results of the first consumer genomics study ever conducted in a non-human model: a GWAS of blue eyes based on more than 3,000 customer dogs with validation panels including nearly 3,000 more, the largest canine GWAS to date. We discovered a novel association with blue eyes on chromosome 18 (P = 1.3x10-68) and used both sequence coverage and microarray probe intensity data to identify the putative causal variant: a 98.6-kb duplication directly upstream of the Homeobox gene ALX4, which plays an important role in mammalian eye development. This duplication is largely restricted to Siberian Huskies, is strongly associated with the blue-eyed phenotype (chi-square P = 5.2x10-290), and is highly, but not completely, penetrant. These results underscore the power of consumer-data-driven discovery in non-human species, especially dogs, where there is intense owner interest in the personal genomic information of their pets, a high level of engagement with web-based surveys, and an underlying genetic architecture ideal for mapping studies.Denfeld, B.A., Klaus, M., Laudon, H., Sponseller, R.A., Karlsson, J., 2018. Carbon dioxide and methane dynamics in a small boreal lake during winter and spring melt events. Journal of Geophysical Research: Biogeosciences 123, 2527-2540.: In seasonally ice‐covered lakes, carbon dioxide (CO2) and methane (CH4) emission at ice‐off can account for a significant fraction of the annual budget. Yet knowledge of the mechanisms controlling below lake‐ice carbon (C) dynamics and subsequent CO2 and CH4 emissions at ice‐off is limited. To understand the control of below ice C dynamics, and C emissions in spring, we measured spatial variation in CO2, CH4, and dissolved inorganic and organic carbon from ice‐on to ice‐off, in a small boreal lake during a winter with sporadic melting events. Winter melt events were associated with decreased surface water DOC in the forest‐dominated basin and increased surface water CH4 in the mire‐dominated basin. At the whole‐lake scale, CH4 accumulated below ice throughout the winter, whereas CO2 accumulation was greatest in early winter. Mass‐balance estimates suggest that, in addition to the CO2 and CH4 accumulated during winter, external inputs of CO2 and CH4 and internal processing during ice‐melt could represent significant sources of C gas emissions during ice‐off. Moreover, internal processing of CO2 and CH4 worked in opposition, with production of CO2 and oxidation of CH4 dominating at ice‐off. These findings have important implications for how small boreal lakes will respond to warmer winters in the future; increased winter melt events will likely increase external inputs below ice and thus alter the extent and timing of CO2 and CH4 emissions to the atmosphere at ice‐off. Plain Language Summary: Many lakes are ice‐covered for a portion of the year, where ice serves as a barrier to the atmosphere, trapping greenhouse gases, like carbon dioxide and methane. At ice‐off, these greenhouse gases are released into the atmosphere. Yet due to difficulties associated with sampling ice‐covered lakes, there is limited information about the factors that contribute to carbon dioxide and methane release at ice‐off. Moreover, projected warmer winters, with increased precipitation as rain and reduced duration of ice cover, suggest that the contributing factors may change in the future. To gain insight into greenhouse gas dynamics in ice‐covered lakes, we measured carbon dioxide and methane from ice‐on to ice‐off in a small boreal lake during a winter with sporadic melting events. We show that winter melt events alter carbon inputs below ice with implications for the timing and type of greenhouse gases released at ice‐off. Our study brings new insight to greenhouse gas dynamics in ice‐covered lakes and highlights challenges in understanding the implications of changing ice‐cover patterns as the climate warms.Dien, V.T., Morris, S.E., Karadeema, R.J., Romesberg, F.E., 2018. Expansion of the genetic code via expansion of the genetic alphabet. Current Opinion in Chemical Biology 46, 196-202. methods to expand the genetic code enable site-specific incorporation of non-canonical amino acids (ncAAs) into proteins in eukaryotic and prokaryotic cells. However, current methods are limited by the number of codons possible, their orthogonality, and possibly their effects on protein synthesis and folding. An alternative approach relies on unnatural base pairs to create a virtually unlimited number of genuinely new codons that are efficiently translated and highly orthogonal because they direct ncAA incorporation using forces other than the complementary hydrogen bonds employed by their natural counterparts. This review outlines progress and achievements made towards developing a functional unnatural base pair and its use to generate semi-synthetic organisms with an expanded genetic alphabet that serves as the basis of an expanded genetic code.Ding, M., Wang, Y., Han, Y., Gao, M., Wang, R., 2019. Interactions in bypassed oil-CO2 systems and their utilization in enhancing the recovery of bypassed oil. Fuel 237, 1068-1078. experimental study was conducted to improve understanding of the interactions between bypassed oil and CO2, and to investigate their contribution to bypassed oil recovery. First, experiments were carried out that focus on the interaction in terms of light-hydrocarbon extraction and dissolution-induced oil swelling. These were studied with respect to the simulated shallow/deep bypassed oil, according to their distribution in the bypassed region. Core flooding tests were designed to determine the level of bypassed oil recovery, which focus on the interaction-dominated, soaking, and ‘huff and puff’ (HnP) strategies (traditional methods for recovering non-bypassed oil). We find that, significant amounts of shallow bypassed oil could be extracted with a maximum extraction efficiency of 85.2% at 40?MPa, making it shrink instead of the more commonly observed expansion. Such deep bypassed oil could not be extracted to the same significant extent as shallow bypassed oil, mainly behaving in a dissolution-dominated expansive manner. Core flooding tests show that interactions occurring during soaking only allow a small amount of bypassed oil to be recovered (yielding a somewhat disappointing recovery factor of approximately 20%). It is likely that mainly shallow bypassed oil is activated in this case. Additionally, the transition of the dominating interactions during soaking was also observed by oil composition analysis. Lastly, but fortunately, HnP is able to enhance bypassed oil recovery to a more satisfying level of around 90%, removing the majority of the deep bypassed oil therewith.Djokic, M.R., Muller, H., Ristic, N.D., Akhras, A.R., Symoens, S.H., Marin, G.B., Van Geem, K.M., 2018. Combined characterization using HT-GC?×?GC-FID and FT-ICR MS: A pyrolysis fuel oil case study. Fuel Processing Technology 182, 15-25. this work the composition of a hydrotreated distilled crude oil fraction (HTAL-FEED) and its heaviest steam cracking product fraction, the so-called pyrolysis fuel oil (HTAL-PFO), have been characterized in detail using high-temperature comprehensive two-dimensional gas chromatography (HT-GC?×?GC) coupled to a flame ionization detector (FID) and Fourier Transform-Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS). Moreover, the HTAL-FEED and HTAL-PFO were characterized using elemental analysis and SARA fractionation to determine their bulk properties. Although the main compounds are saturates, the HTAL-FEED contains significant amounts of aromatic compounds, primarily mono- and di-aromatics but even up to penta-aromatics, which are responsible for the growth of large polycyclic aromatic hydrocarbons (PAH) formed during steam cracking that almost entirely make up the HTAL-PFO product. Quantitative results are obtained based on the HT-GC?×?GC-FID chromatograms and the use of well-chosen internal standards, allowing ~90?wt% of the feedstock and ~60?wt% of HTAL-PFO to be quantified. FT-ICR MS analyses confirmed the presence of molecules heavier than penta-aromatics in the HTAL-FEED, as well as the very heavy character of HTAL-PFO consisting of highly condensed aromatic molecules with up to 16 fused aromatic rings. The analytical methodology can be applied to other steam cracking products, providing a near-molecular level insight into conversion and coke formation precursors during steam cracking of wide boiling range hydrocarbons.Do, K.T., Wahl, S., Raffler, J., Molnos, S., Laimighofer, M., Adamski, J., Suhre, K., Strauch, K., Peters, A., Gieger, C., Langenberg, C., Stewart, I.D., Theis, F.J., Grallert, H., Kastenmüller, G., Krumsiek, J., 2018. Characterization of missing values in untargeted MS-based metabolomics data and evaluation of missing data handling strategies. Metabolomics 14, 128.: Untargeted mass spectrometry (MS)-based metabolomics data often contain missing values that reduce statistical power and can introduce bias in biomedical studies. However, a systematic assessment of the various sources of missing values and strategies to handle these data has received little attention. Missing data can occur systematically, e.g. from run day-dependent effects due to limits of detection (LOD); or it can be random as, for instance, a consequence of sample preparation.Methods: We investigated patterns of missing data in an MS-based metabolomics experiment of serum samples from the German KORA F4 cohort (n?=?1750). We then evaluated 31 imputation methods in a simulation framework and biologically validated the results by applying all imputation approaches to real metabolomics data. We examined the ability of each method to reconstruct biochemical pathways from data-driven correlation networks, and the ability of the method to increase statistical power while preserving the strength of established metabolic quantitative trait loci.Results: Run day-dependent LOD-based missing data accounts for most missing values in the metabolomics dataset. Although multiple imputation by chained equations performed well in many scenarios, it is computationally and statistically challenging. K-nearest neighbors (KNN) imputation on observations with variable pre-selection showed robust performance across all evaluation schemes and is computationally more tractable.Conclusion: Missing data in untargeted MS-based metabolomics data occur for various reasons. Based on our results, we recommend that KNN-based imputation is performed on observations with variable pre-selection since it showed robust results in all evaluation schemes.Doerr, S.H., Santín, C., Merino, A., Belcher, C.M., Baxter, G., 2018. Fire as a removal mechanism of pyrogenic carbon from the environment: Effects of fire and pyrogenic carbon characteristics. Frontiers in Earth Science 6, 127. doi: 10.3389/feart.2018.00127. carbon (PyC, charcoal) is produced during vegetation fires at a rate of ~116–385 Tg C yr?1 globally. It represents one of the most degradation-resistant organic carbon pools, but its long-term fate and the processes leading to its degradation remain subject of debate. A frequently highlighted potential loss mechanism of PyC is its consumption in subsequent fires. However, only three studies to date have tested this hypothesis with reported losses of <8–37%, with the effects of PyC chemical characteristics and fire conditions on PyC loss in wildfires remaining unexplored. To address this, we placed materials with different degrees of thermal and chemical recalcitrance (A: wildfire charcoal, B: slash-pile charcoal, C: pine wood and D: cedar wood) on the ground surface just prior to a high-intensity and a low-intensity boreal forest wildfire. Mass losses were highly variable and dependent on fire- and sample characteristics. Mass losses across both fires (as % of dry weight) were for A: 66.5 ± 25.2, B: 41.7 ± 27.2, C: 78.2 ± 14.9, and D: 83.8 ± 18.9. Mass loss correlated significantly with maximum temperature (Tmax) recorded on sample surfaces (r = 0.65, p = 0.01), but only weakly (r = 0.33) with time >300°C. Mass losses also showed a significant negative correlation (r = ?0.38, p = 0.05) with thermal recalcitrance (T50) determined using Differential Scanning Calorimetry (DSC) and Tmax with charcoal reflectance (Ro) determined after the fires (r = 0.46, p = 0.05). Losses in the high-intensity fire were significantly higher (p = 0.05) than in the low-intensity fire, but the latter had a higher rate of conversion of fuel to PyC. Our results demonstrate that exposure to fire can indeed be a significant removal mechanism for PyC that remains exposed on the ground after a previous fire. The losses found, however, are likely to represent an extreme upper range as most PyC produced in a fire would not remain exposed on the ground surface by the time the next fire occurs. Our data also demonstrate, for real wildfire conditions, the (i) contrasting resistance of different PyC types to combustion and (ii) contrasting net PyC losses between different fire intensities. The DSC and reflectance (Ro) results support the usefulness of these analyses in reflecting thermal degradation resistance and temperature exposure under actual wildfire conditions.Dong, D., Shi, Z., Guan, Q., Jiang, S., Zhang, M., Zhang, C., Wang, S., Sun, S., Yu, R., Liu, D., Peng, P., Wang, S., 2018. Progress, challenges and prospects of shale gas exploration in the Wufeng–Longmaxi reservoirs in the Sichuan Basin. Natural Gas Industry B 5, 415-424. Sichuan Basin is a major target for shale gas exploration in present China because of its rich gas stored in abundant black shales with multiple bed series. For further guidance or reference, field exploration and development practices in the shale reservoirs Upper Ordovician Wufeng–Lower Silurian Longmaxi shale reservoirs were studied in terms of development stages and progress, favorable conditions for shale gas accumulation, bottlenecking issues on theories and technologies related to shale gas development, and so on. The following findings were obtained. (1) Shale with rich organic matters originated from the deep shelf has a good quality and great thickness in the continuous beds. The relatively stable wide buffer zones in synclines (anticlines) provides favorable conditions for shale gas accumulation and preservation with well-developed micro-fractures and overpressure as necessary factors for a great potential of high shale gas productivity. (2) The bottlenecking technical issues restricting the shale gas industrial development in this study area include the following aspects: understandings of rich-organic matter shale sedimentary facies and modes, shale reservoir diagenetic process and evaluation systems, shale gas generation and accumulation mechanism, geophysical logging identification and prediction of shale gas layers, low resource utilization rate, great uncertainty of shale gas development, no technological breakthrough in the exploration of shale gas reservoirs buried deeper than 3500?m. In conclusion, this study area will be the major target for the shale gas exploration and development in China in a rather long period in the future.Dong, D., Shi, Z., Sun, S., Guo, C., Zhang, C., Guo, W., Guan, Q., Zhang, M., Jiang, S., Zhang, L., Ma, C., Wu, J., Li, N., Chang, Y., 2018. Factors controlling microfractures in black shale: A case study of Ordovician Wufeng Formation–Silurian Longmaxi Formation in Shuanghe Profile, Changning area, Sichuan Basin, SW China. Petroleum Exploration and Development 45, 818-829. dominant factors controlling development of microfractures in the black shale and the origin of microfractures in the sweet spot intervals were discussed of the Ordovician Wufeng Formation?Silurian Longmaxi Formation in Shuanghe outcrop profile, Changning, Sichuan Basin. For the target interval, holographic photograph statistics of microscopic composition of 203 big thin sections and 203 small thin sections, TOC content of 110 samples, 110 whole rock X-ray composition, and main trace elements of 103 samples were tested and analyzed. The results show that the microfractures include bedding microfractures and non-bedding microfractures. The bedding microfractures are mostly plane slip microfractures, lamellation microfractures and echelon microfractures. The non-bedding microfractures are largely shear microfractures and tension microfractures. Vertically, the density of microfractures is the highest in SLM1 Member of Longmaxi Formation, decreases from SLM2 Member to SLM5 Member gradually, and drops to the lowest in Wufeng Formation. The microfracture density is positively correlated with siliceous content and negatively correlated with the carbonate content. The finer the grain size of the black shale, the higher the density of the microfractures is. The microfracture density is controlled by biogenic silicon: the higher the content of biogenic silicon, the higher the microfracture density is. Under the effect of ground stress, microfractures appear first in the lamellar interfaces. Regional tectonic movements are the key factor causing the formation of microfractures in the sweet spot interval, diagenetic contraction is the main driving force for lamellation fractures, and the pressurization due to hydrocarbon generation is the major reason for the large-scale development of microcracks.Dopffel, N., K?gler, F., Hartmann, H., Costea, P.I., Mahler, E., Herold, A., Alkan, H., 2018. Microbial induced mineral precipitations caused by nitrate treatment for souring control during microbial enhanced oil recovery (MEOR). International Biodeterioration & Biodegradation 135, 71-79. active environments, like oil reservoirs, can suffer a range of problems due to the presence of sulfate-reducing microorganisms. These include, but are not limited to: H2S formation, souring and corrosion. To prevent biogenic sulfate reduction, nitrate can be used as an environmentally friendly alternative to biocides. However, side effects of nitrate injection are sometimes observed but not well understood. In our study, we used original water from an onshore reservoir, where a microbial enhanced oil recovery (MEOR) application is planned, and investigated the effects of nitrate addition on H2S generation, mineral precipitation and microbiology . We observed that nitrate did inhibit H2S formation in most, but not all cases. During nitrate reduction, iron and calcite minerals precipitated over short- and long-term (10 or 160 days) incubations. This was caused by a nitrate-reducing group of bacteria belonging to the family Deferribacteraceae. Using dynamic sandpack setups and numerical modeling approaches with the simulator TOUGHREACT, we observed significant reduction in permeabilities (～44×) suggesting injectivity issues over time in case nitrate is continuously added to the reservoir. Our study shows that nitrate-dependent processes, which were described separately for pure-cultures before, are also valid for natural mixed communities present in oil fields and underlines the complex interplay of microbial metabolisms associated with those communities.Du, J., Wang, X., Liu, H., Guo, P., Wang, Z., Fan, S., 2019. Experiments and prediction of phase equilibrium conditions for methane hydrate formation in the NaCl, CaCl2, MgCl2 electrolyte solutions. Fluid Phase Equilibria 479, 1-8. of gas hydrate cause a lot of problems for gas industry in the generation, transmission and processing which caused blockage in the equipment. One of the most common treatments is injection of electrolytes as chemical inhibitors. In this paper, hydrate formation conditions of methane gas in both water and NaCl, CaCl2, MgCl2 electrolyte solutions were measured and a new thermodynamic calculation method based on the original PR model and Chen-Guo model was proposed by introducing a water activity calculation equation. The comparison demonstrates that the inhibiting effect of MgCl2, NaCl, CaCl2 on the hydrate formation decrease respectively. The experimental results showed that the hydrate formation conditions are related to the electrolyte molecular mass and electrolyte concentration to a large extent, the deviation will increase as the temperature or the electrolyte concentration increases, so three parameters t1, t2, t3 (0.034, 0.15, 0.01) which are related to temperature, concentration and molecular weight of electrolyte are introduced in the new calculation method. The absolute average deviation of 41 sets of data is 7.98 and 1.96 respectively before and after the correction parameters were introduced, the accuracy has more than quadrupled.Dubois, V., Viljoen, A., Laencina, L., Le Moigne, V., Bernut, A., Dubar, F., Blaise, M., Gaillard, J.-L., Guérardel, Y., Kremer, L., Herrmann, J.-L., Girard-Misguich, F., 2018. MmpL8MAB controls Mycobacterium abscessus virulence and production of a previously unknown glycolipid family. Proceedings of the National Academy of Sciences 115, E10147-E10156.: One major defense mechanism of mycobacteria relies mainly on the synthesis and transport of specialized lipids, processes that reside in the cell wall. Among the transporters, Mycobacterial membrane protein Large (MmpL) plays an essential role. We describe the role of MmpL8 (MmpL8MAB) in the survival of Mycobacterium abscessus within eukaryotic hosts. We show that its absence slows the contact between M. abscessus and the host cell cytosol, an essential element in its resistance to the cell bactericidal mechanisms. The absence of MmpL8MAB leads to reduced production of a previously unknown glycolipid: a glycosyl diacylated nonadecyl diol (GDND). The glycolipid seems unique to the Mycobacterium chelonae complex, supporting the view that GDND might represent a typical signature of M. abscessus infection.Abstract: Mycobacterium abscessus is a peculiar rapid-growing Mycobacterium (RGM) capable of surviving within eukaryotic cells thanks to an arsenal of virulence genes also found in slow-growing mycobacteria (SGM), such as Mycobacterium tuberculosis. A screen based on the intracellular survival in amoebae and macrophages (MΦ) of an M. abscessus transposon mutant library revealed the important role of MAB_0855, a yet uncharacterized Mycobacterial membrane protein Large (MmpL). Large-scale comparisons with SGM and RGM genomes uncovered MmpL12 proteins as putative orthologs of MAB_0855 and a locus-scale synteny between the MAB_0855 and Mycobacterium chelonae mmpL8 loci. A KO mutant of the MAB_0855 gene, designated herein as mmpL8MAB, had impaired adhesion to MΦ and displayed a decreased intracellular viability. Despite retaining the ability to block phagosomal acidification, like the WT strain, the mmpL8MAB mutant was delayed in damaging the phagosomal membrane and in making contact with the cytosol. Virulence attenuation of the mutant was confirmed in vivo by impaired zebrafish killing and a diminished propensity to induce granuloma formation. The previously shown role of MmpL in lipid transport prompted us to investigate the potential lipid substrates of MmpL8MAB. Systematic lipid analysis revealed that MmpL8MAB was required for the proper expression of a glycolipid entity, a glycosyl diacylated nonadecyl diol (GDND) alcohol comprising different combinations of oleic and stearic acids. This study shows the importance of MmpL8MAB in modifying interactions between the bacteria and phagocytic cells and in the production of a previously unknown glycolipid family.Dulaquais, G., Waeles, M., Gerringa, L.J.A., Middag, R., Rijkenberg, M.J.A., Riso, R., 2018. The biogeochemistry of electroactive humic substances and its connection to iron chemistry in the North East Atlantic and the Western Mediterranean Sea. Journal of Geophysical Research: Oceans 123, 5481-5499. We present the zonal distribution of electroactive humic-like substances (eHS) along a section from Offshore Portugal in the North East Atlantic to the Sicily Channel in the Mediterranean Sea. The concentrations were normalized to Suwannee River Fulvic Acid and ranged from 11??g/L to 81??g/L. The vertical distributions were typical of those previously reported for dissolved organic carbon in the Mediterranean Sea. High eHS concentrations were measured in surface water and concentrations decreased with depth before increasing again toward benthic maxima measured at some stations. We estimate that eHS represented a relatively small fraction of the natural organic matter in the Mediterranean Sea (2?5%) but considering their important role in the complexation and the solubility of key trace elements (e.g., iron and copper), the eHS cycle could influence the entire biogeochemistry of these marine systems. We identified key processes controlling the concentration of eHS. While biologically mediated production was the major source of eHS, riverine and rain inputs as well as sediment release were also likely external sources. Low eHS concentrations at subsurface depths pointed to photodegradation as a possible sink of eHS, but degradation by heterotrophic bacteria seemed to be the main sink in the deep sea. Finally, we found a positive correlation between dissolved iron and eHS concentrations. Estimation of eHS contribution to iron binding ligand concentrations indicates the complexation of iron by eHS in the Mediterranean Sea. These observations suggest links between the cycles of eHS and iron in the Mediterranean Sea.Dunhill, A.M., Foster, W.J., Azaele, S., Sciberras, J., Twitchett, R.J., 2018. Modelling determinants of extinction across two Mesozoic hyperthermal events. Proceedings of the Royal Society B: Biological Sciences 285, 20180404; DOI: 10.1098/rspb.2018.0404. Late Triassic and Early Toarcian extinction events are both associated with greenhouse warming events triggered by massive volcanism. These Mesozoic hyperthermals were responsible for the mass extinction of marine organisms and resulted in significant ecological upheaval. It has, however, been suggested that these events merely involved intensification of background extinction rates rather than significant shifts in the macroevolutionary regime and extinction selectivity. Here, we apply a multivariate modelling approach to a vast global database of marine organisms to test whether extinction selectivity varied through the Late Triassic and Early Jurassic. We show that these hyperthermals do represent shifts in the macroevolutionary regime and record different extinction selectivity compared to background intervals of the Late Triassic and Early Jurassic. The Late Triassic mass extinction represents a more profound change in selectivity than the Early Toarcian extinction but both events show a common pattern of selecting against pelagic predators and benthic photosymbiotic and suspension-feeding organisms, suggesting that these groups of organisms may be particularly vulnerable during episodes of global warming. In particular, the Late Triassic extinction represents a macroevolutionary regime change that is characterized by (i) the change in extinction selectivity between Triassic background intervals and the extinction event itself; and (ii) the differences in extinction selectivity between the Late Triassic and Early Jurassic as a whole.Edokpa, D.A., Evans, M.G., Boult, S., Rothwell, J.J., 2018. Size fractionation of dissolved organic nitrogen in peatland fluvial systems. Environmental Science & Technology 52, 11198-11205. the nature and fate of nitrogen (N) in freshwater systems is crucial for assessing the risk of eutrophication. However, there is a paucity of information on the characterization of fluvial N in upland peat-dominated environments. Here, we employ a combination of field sampling and tangential flow ultrafiltration (TFU) to investigate the concentrations and fluxes of low molecular weight (LMW) and high molecular weight (HMW) dissolved organic N (DON) in a peatland stream-reservoir system in the south Pennines (UK). Our TFU results show that ～26% of DON concentration is LMW DON and represents an estimated fluvial flux of 3.07 ± 22 kg N ha–1 during the study period. Our mass balance results reveal that the reservoir retains 71% of LMW DON input, which accounts for ～25% retention of bioavailable (dissolved inorganic N + LMW DON) N. Our study suggests that current understanding of inorganic N as the sole source of bioavailable N with eutrophic significance in upland freshwaters requires a reappraisal. Evaluation of ecosystem response to increased loading of N needs to include a consideration of LMW DON.Ekoko Eric, B., Philip, F., Emile, E., Isaac Konfor, N., Salomon Betrant, B., Daniel Florent, A., Bessa Armel Zacharie, E., 2019. Geochemical characteristics of shales in the Mamfe Basin, South West Cameroon: Implication for depositional environments and oxidation conditions. Journal of African Earth Sciences 149, 131-142. and laboratory studies were carried out with the aim of characterizing the depositional environment and oxidation conditions during accumulation of shales in the Mamfe basin. Field studies denoted that the shales were black to dark grey in color, sub-tabular to tabular in occurrence, with some (n?=?20) reacting vigorously with dilute HCl, while others did not (n?=?5). Due to the carbonate content of the samples both whole rock dissolution and partial dissolution, using dilute acetic acid to target the carbonate fraction in the samples, were employed. The seven shale-rich units investigated have average whole rock Ni/Co, V/Cr, U/Th and Th/U ratios of 1.68–2.0, 1.13–2.95, 0.24–0.51 and?>?2, respectively. PAAS normalized rare earth elements in the whole rock samples display an enrichment of light rare earth elements (LREEs) over heavy rare earth elements (HREEs), middle rare earth elements (MREEs) over HREEs, positive Gd, Eu anomalies, no Ce anomalies, and an average Y/Ho ratio of 29.7?ppm. The carbonate fraction of the samples displays two different REE pattern types. Sites 1 and 6 have typical hat-shaped patterns with extensive MREE enrichment. The other locations are slightly HREE depleted and have weak MREE enrichment with negative Y anomalies. The trace element ratios and the REE patterns of the whole rock and carbonate fractions indicate that the sediments deposited in the Mamfe basin accumulated in non-marine environments. Furthermore, their coloration, MREE enrichment and lack of Ce anomalies in the carbonate fractions infers that the depositional area was in a vegetated, low-land lacustrine setting with limited oxygenation of the sediment, whereas the negative Ce anomalies in the whole rock shale samples is probably due to particulate scavenging of REEs from the fluid during transport. This would require the water to be deficient in Ce and, thus reflect oxidizing conditions in the source area and along the transport system.El Aily, M., Mansour, E.M., Desouky, S.M., Helmi, M.E., 2019. Modeling viscosity of moderate and light dead oils in the presence of complex aromatic structure. Journal of Petroleum Science and Engineering 173, 426-433. oil viscosity measurements are very crucial in the field of petroleum industries. Difficulties associated with obtaining accurate measured viscosity values for reservoir oils have turned the light to estimate viscosity through empirical correlations to alleviate these laboratory difficulties. This work is a supplementary study for a previous research work, done on Egyptian heavy crude oil samples, to cover all types of reservoir oils. The proposed work started with evaluating the previously published viscosity correlations that considered as a useful method to provide preliminary values for viscous oil reservoirs characterization. The obtained viscosity values showed poor performance of applying these correlations, as these correlations depend only on oil specific gravity and operating temperature. Therefore, there is a need for correlating a new effective viscosity model using asphaltene content as one of the main representative parameters. Asphaltene is considered as a complex aromatic structure which causes problems in reservoir oils. In this work, laboratory measurements have been made on five-hundred database points of Egyptian moderate and light dead oil samples obtained from different locations to build accurate viscosity correlation model. The best fit accurate empirical correlation has been found using multiple least-square nonlinear regression analysis for ranges of viscosity measurements from 23.06 to 43.18 OAPI. Testing of the new proposed viscosity model, with another set of laboratory measured viscosity data, shows high performance and accuracy in predicting Egyptian moderate and light dead crude oils viscosity as compared with literature viscosity correlations.El Sharawy, M.S., Gaafar, G.R., 2019. Pore - Throat size distribution indices and their relationships with the petrophysical properties of conventional and unconventional clastic reservoirs. Marine and Petroleum Geology 99, 122-134. injection capillary pressure (MICP) curves provide significant information about the pore size distribution (PSD), which controls and defines the main petrophysical properties, namely porosity, and permeability. Due to the importance of the PSD, several indices and parameters were introduced to quantify this property. 140 MICP curves for conventional and unconventional clastic reservoirs, representing different geographic localities, geologic ages, and depositional environments, were used to study these parameters and indices, as well as their relationships with porosity and permeability. This study indicated that the most popular indices, namely Thomeer pore geometrical factor (Fg) and Brooks and Corey pore size distribution index (λ), have poor relationships with both porosity and permeability. On the other hand, displacement pressure and Swanson parameter, and pore-throat radius corresponding to the 25th percentile of mercury saturation give the best relationships with them. Therefore, permeability prediction equations based on Thomeer and Brooks and Corey indices were modified. Additionally, several new equations relating PSD parameters and indices to porosity and permeability were introduced.Eley, Y., White, J., Dawson, L., Hren, M., Pedentchouk, N., 2018. Variation in hydrogen isotope composition among salt marsh plant organic compounds highlights biochemical mechanisms controlling biosynthetic fractionation. Journal of Geophysical Research: Biogeosciences 123, 2645-2660. isotopes of plant-derived biomarkers can vary by >100‰ at a single location. Isotope fractionation associated with the movement of water in plant leaves cannot account for this variability alone. Biochemical processes therefore must play a fundamental role in controlling hydrogen isotope fractionation during secondary compound biosynthesis. Different biosynthetic pathways utilize discrete hydrogen pools and occur within distinct cell compartments. We analyzed hydrogen isotope compositions of C16 and C18 fatty acids and phytol from seven salt marsh plants and compared these data with (i) leaf water and n-alkane δ2H, (ii) leaf carbon and nitrogen contents, and (iii) nitrogen isotopes of bulk tissue, to evaluate the relationship between biochemical processes, cellular compartmentalization, and hydrogen isotope fractionation. Interspecies variation in chloroplastic fatty acids and phytol δ2H exceeds leaf water δ2H, indicating that different commitments of metabolites among species at branching points in chloroplast metabolic processes may be important determinants of lipid δ2H values. Dominant osmoregulatory strategies, in particular, show strong correlation with leaf wax n-alkane δ2H. Species that preferentially produce nitrogenous compounds (dicots/shrubs) as protective solutes have 2H-enriched n-alkanes relative to species that produce mainly carbohydrates (monocots). n-Alkane δ2H values, in combination with δ15N data and elemental (C, N) composition, together provide information about biochemical environmental adaptations exhibited by different higher plant species in response to environmental stresses. Thus, while spatial and temporal integration of biomarkers may produce an isotopic record of ecosystem function, biomarkers from individual plant or microbial remains may hold additional details into biologic function and adaptation to ancient environments.Eme, L., Ettema, T.J.G., 2018. The eukaryotic ancestor shapes up. Nature 562, 352-353. archaea are the closest known relatives of nucleus-bearing organisms called eukaryotes. A study indicates that these archaea have a dynamic network of actin protein — a trait thought of as eukaryote-specific. Eukaryotic cells, which carry their DNA in a nucleus, are thought to have evolved from a merger between two other organisms — an archaeal host cell1–3 and a bacterium from which eukaryotic organelles called mitochondria emerged4. Some insights into the biological properties of the host have come from the closest known archaeal relatives of eukaryotes, the Asgard superphylum5,6. The genomes of organisms belonging to this archaeal group encode a suite of proteins typically involved in functions or processes thought to be eukaryote-specific. The functions of these ‘eukaryotic genes’ in Asgard archaea have been elusive, but in a paper in Nature, Ak?l and Robinson7 provide evidence that some of them encode proteins that are structurally and functionally similar to their eukaryotic counterparts.Apart from their nucleus and energy-producing mitochondria, eukaryotic cells are characterized by a complex internal system of membrane-bound compartments (the endomembrane system), and by a dynamic network of proteins such as actin, called the cytoskeleton. The latter gives the cells their shape and structure, but is also involved in a variety of cellular processes specific to eukaryotes8. These features are thought to have been present in the last common ancestor of all eukaryotes, which lived about 1.8 billion years ago9, but no life forms have been found that represent an intermediate between eukaryotes and their bacterial and archaeal ancestors. The seemingly sudden emergence of cellular complexity in the eukaryotic lineage is a conundrum for evolutionary biologists.Several of the proteins produced by Asgard archaea are evolutionarily related to proteins that in eukaryotes modulate complex cellular processes5,6. The identification of these proteins raised the question of whether Asgard archaea have some primitive versions of certain eukaryotic properties. If they do, it would suggest that the last archaeal ancestor of eukaryotes already displayed a certain — albeit probably limited — degree of cellular complexity reminiscent of eukaryotes.Experiments to support such ideas are complicated by the fact that evidence for the existence of the four known Asgard lineages (Lokiarchaeota, Odinarchaeota, Thorarchaeota and Heimdallarchaeota)5,6 is based solely on metagenomics analyses. The cells have yet to be observed under a microscope, and have not been cultured in vitro. Nevertheless, Ak?l and Robinson were determined to gain insight into the properties of Asgard proteins related to the eukaryotic proteins actin and profilin. In eukaryotes, profilin regulates the polymerization of actin into filaments of the cytoskeleton. These filaments have pivotal roles in processes that include vesicle and organelle movement, cell-shape formation and phagocytosis8, in which cells ingest foreign particles or other cells.To produce Asgard profilins, Ak?l and Robinson expressed these proteins in the bacterium Escherichia coli using a circular DNA molecule called a plasmid that harboured the profilin-encoding genes. They then purified the proteins and studied their structures using X-ray crystallography. Asgard profilins share limited amino-acid sequence identity with their eukaryotic counterparts. Nonetheless, the authors found that the structure of lokiarchaeal profilin is topologically similar to that of human profilin, although some structural divergences could be observed. This confirms that Asgard and eukaryotic profilins are indeed evolutionarily related, albeit distantly. Next, the researchers set out to investigate whether Asgard profilins could interact with Asgard actins. Unfortunately, despite considerable efforts, they were unable to produce functional Asgard actin. As an alternative, they therefore carried out in vitro and co-crystallization experiments to test whether Asgard profilins could interact with eukaryotic actins. Remarkably, despite being separated by 2 billion to 3 billion years of evolution9, several of the Asgard profilins bound to mammalian actin and regulated its polymerization kinetics. Asgard and mammalian profilins seem to have similar effects on mammalian actin, although the Asgard proteins act less efficiently. These results suggest that Asgard archaea harbour a profilin-regulated actin cytoskeleton — a cellular feature generally regarded as a defining characteristic of eukaryotic cells (Fig. 1).The inference of a primitive dynamic actin cytoskeleton in Asgard archaea sheds light on the biological properties of the ancestor of eukaryotes. In eukaryotic cells, the energy required to dynamically regulate actin is mainly provided by mitochondria10. Although the energetic and metabolic properties of Asgard archaea are currently unknown, they certainly lack the firepower that mitochondria provide. A profilin-regulated actin cytoskeleton in the archaeal ancestor of eukaryotes is therefore unlikely to sustain energy-consuming processes such as phagocytosis. But was the energy provided by mitochondria necessarily the ultimate driving force for the emergence of complex cellular features in eukaryotes? Archaea such as Ignicoccus hospitalis, along with several types of bacterium, have independently evolved endomembrane systems11. Because these lineages lack mitochondria, energetic constraints can be ruled out as a limiting factor in the emergence of such a system. It is therefore feasible that Asgard archaeal cells produce sufficient energy to harbour both a primitive endomembrane system and undergo actin-driven membrane and cell-shape deformation. Perhaps the latter ability could have facilitated the symbiotic interaction between the Asgard-related host cell and the bacterial ancestor of mitochondria, for example by optimizing the membrane surface area for metabolic exchange between the two cells. Once mitochondria became an intrinsic part of eukaryotic cells, their capacity for energy production could have conferred selective advantages on their host. However, the exact contribution of these organelles to the emergence of the complex features of eukaryotic cells remains unresolved. Future efforts to elucidate the biological and physiological properties of Asgard archaea will be essential to increase our understanding of the emergence of eukaryotes. Although biochemical and structural studies of individual Asgard proteins, such as those by Ak?l and Robinson, are likely to provide piecemeal insights, it is the ability to grow Asgard archaeal lineages in vitro that will ultimately unravel their obscure biology. References1. Williams, T. A., Foster, P. G., Cox, C. J. & Embley, T. M. Nature 504, 231–236 (2013).2. Raymann, K., Brochier-Armanet, C. & Gribaldo, S. Proc. Natl Acad. Sci. USA 112, 6670–6675 (2015).3. Eme, L., Spang, A., Lombard, J., Stairs, C. W. & Ettema, T. J. G. Nature Rev. Microbiol. 15, 711–723 (2017).4. Roger, A. J., Mu?oz-Gómez, S. A. & Kamikawa, R. Curr. Biol. 27, R1177–R1192 (2017).5. Spang, A. et al. Nature 521, 173–179 (2015).6. Zaremba-Niedzwiedzka, K. et al. Nature 541, 353–358 (2017).7. Ak?l, C. & Robinson, R. C. Nature 562, 439–443 (2018).8. Blanchoin, L., Boujemaa-Paterski, R., Sykes, C. & Plastino, J. Physiol. Rev. 94, 235–263 (2014).9. Betts, H. C. et al. Nature Ecol. Evol. 2, 1556–1562 (2018).10. Martin, W. F., Tielens, A. G. M., Mentel, M., Garg, S. G. & Gould, S. B. Microbiol. Mol. Biol. Rev. 81, e00008–17 (2017).11. Grant, C. R., Wan, J. & Komeili, A. Annu. Rev. Cell Dev. Biol. (2017).Enard, D., Petrov, D.A., 2018. Evidence that RNA viruses drove adaptive introgression between Neanderthals and modern humans. Cell 175, 360-371.e13. and modern humans interbred at least twice in the past 100,000 years. While there is evidence that most introgressed DNA segments from Neanderthals to modern humans were removed by purifying selection, less is known about the adaptive nature of introgressed sequences that were retained. We hypothesized that interbreeding between Neanderthals and modern humans led to (1) the exposure of each species to novel viruses and (2) the exchange of adaptive alleles that provided resistance against these viruses. Here, we find that long, frequent—and more likely adaptive—segments of Neanderthal ancestry in modern humans are enriched for proteins that interact with viruses (VIPs). We found that VIPs that interact specifically with RNA viruses were more likely to belong to introgressed segments in modern Europeans. Our results show that retained segments of Neanderthal ancestry can be used to detect ancient epidemics.Esene, C., Rezaei, N., Aborig, A., Zendehboudi, S., 2019. Comprehensive review of carbonated water injection for enhanced oil recovery. Fuel 237, 1086-1107. water injection (CWI) is a promising enhanced oil recovery (EOR) technique in which the dissolved CO2 can transfer to the oil phase to improve the oil mobility and to cause oil swelling, both enhancing the sweep efficiency. In addition to serving as an EOR method, CWI promotes a high storage capacity for geological CO2 storage. A number of laboratory tests and field applications have confirmed the effectiveness of CWI. This paper provides a comprehensive review of CWI to cover its important aspects/features such as displacement mechanisms and recovery performance at various conditions/properties. In this paper, carbonated water injection process and the properties of CO2-brine-oil systems are described. The influences of petrophysical properties, fluid properties, and operational parameters on the performance of CWI are also thoroughly addressed. The pore-scale investigations conducted by several researchers are reported in this review. The theoretical and practical challenges associated with the implementation of CWI are also discussed to unveil the fundamental mechanisms of transport phenomena in CWI. Some of the key points that are deduced from the previous theoretical and engineering works include: the exsolution of CO2 from carbonated water during pressure drop can provide additional energy for an extra oil recovery; detailed mathematical models capable of capturing the effects of dissolution, gravity, capillary pressure, and relative permeability hysteresis in 2-D and 3-D spatial orientation on the CWI performance have not been systematically developed yet; disparities between model results and experimental results are attributed to the instantaneous equilibrium assumptions in the model development; and the occurrence of asphaltene precipitation during CWI operations has not been highlighted in a majority of research works, while it is expected to happen during the CO2 exsolution due to the pressure decline.Esrafili, A., Baharfar, M., Tajik, M., Yamini, Y., Ghambarian, M., 2018. Two-phase hollow fiber liquid-phase microextraction. TrAC Trends in Analytical Chemistry 108, 314-322. fiber based liquid-phase microextraction technique (HF-LPME) was proposed in 1999 as an efficient alternative to the conventional sample preparation methods. Since its initiation, this technique have become increasingly popular due to their simplicity, low cost, possibility of for automation, and adaptability to a wide variety of sample matrices and analytes. The HF-LPME methods are mainly accomplished in two modes of two-phase and three-phase hollow fiber liquid-phase microextraction. This article covers the theoretical aspects and the developments of the two-phase hollow fiber liquid-phase microextraction technique as well as its applications to chemical analysis. Moreover, the pros and cons of this method and its advantages over other similar techniques are highlighted. More importantly, future directions and potential applications for a general implementation in routine/research laboratories are also prospected.Eyres, S.P.S., Evans, A., Zijlstra, A., Avison, A., Gehrz, R.D., Hajduk, M., Starrfield, S., Mohamed, S., Woodward, C.E., Wagner, R.M., 2018. ALMA reveals the aftermath of a white dwarf–brown dwarf merger in CK?Vulpeculae. Monthly Notices of the Royal Astronomical Society, Article sty2554. present Atacama Large Millimeter–Submillimeter Array (ALMA) observations of CK Vulpeculae which is identified with “Nova Vulpeculae 1670”. They trace obscuring dust in the inner regions of the associated nebulosity. The dust forms two cocoons, each extending ～5″ north and south of the presumed location of the central star. Brighter emission is in a more compact east–west structure (2″ × 1″) where the cocoons intersect. We detect line emission in NH2CHO, CN, four organic molecules and C17O. CN lines trace bubbles within the dusty cocoons; CH3OH a north–south S–shaped jet; and other molecules a central cloud with a structure aligned with the innermost dust structure. The major axis of the overall dust and gas bubble structure has a projected inclination of ～24° with respect to a 71″ extended “hourglass” nebulosity, previously seen in Hα. Three cocoon limbs align with dark lanes in the inner regions of the same Hα images. The central 2″ × 1″ dust is resolved into a structure consistent with a warped dusty disc. The velocity structure of the jets indicates an origin at the centre of this disc and precession with an unknown period. Deceleration regions at both the northern and southern tips of the jets are roughly coincident with additional diffuse dust emission over regions approximately 2″ across. These structures are consistent with a bipolar outflow expanding into surrounding high density material. We suggest that a white dwarf and brown dwarf merged between 1670 and 1672, with the observed structures and extraordinary isotopic abundances generated as a result.Faboya, O.L., Sonibare, O.O., Faboya, O.T., Agrawal, U., Liao, Z., Ekundayo, O., 2018. Data modelling for crude oil migration studies using ranking method: a rapid geo-tracer technique for geochemists. Acta Geochimica 37, 901-910. direction of oil charges within a field in the Niger Delta, Nigeria was determined by the sum of differences ranking method of carbazole concentrations after ascertaining other possible geological constraints on their compositional variations. The principle is that the smaller the sum, the closer the well to the source kitchen. The approach makes use of carbazoles’ interaction with the matrix, which leads to a reduction in their concentration with increasing distance from the source kitchen, allowing prediction of the charging direction. A wide range of compositional variations was observed for C1 (806.72–2152.90?μg/g) and C2 (767–2469.72?μg/g) carbazoles within the field. Based on these results, we inferred a filling pathway orientation from west to east. This suggests that the source kitchen—the most promising region for oil exploration—is located in the western part of the oil field.Fakher, S., Imqam, A., 2019. Asphaltene precipitation and deposition during CO2 injection in nano shale pore structure and its impact on oil recovery. Fuel 237, 1029-1039. dioxide (CO2) injection has been shown to improve oil recovery from conventional oil reservoirs, with a relatively high rate of success. Recently, it has also been applied in unconventional shale reservoirs, with hopes that it could improve oil recovery from them as well. The process proved successful in some shale plays, but failed in others. This research investigates the CO2 flow mechanism in nano-pores and its impact on asphaltene precipitation, which could lead to pore plugging and a reduction in oil recovery. Nano-composite filter membranes were used to conduct all experiments. The setup used was a specially designed filtration apparatus that could incorporate the nano filter membranes. The factors studied include the CO2 injection pressure, temperature, oil viscosity, CO2 soaking time, porous media thickness, nano-pore size, and pore size heterogeneity. Asphaltene wt% was quantified for all the experiments, both for the produced and bypassed oil. Increasing the CO2 injection pressure resulted in a higher oil recovery and a shorter CO2 breakthrough time. Also, the percentage of asphaltene in the recovered oil was higher for the higher CO2 injection pressure. Results indicated that increasing the temperature also resulted in a higher oil recovery, however, the asphaltene wt% in the bypassed oil also increased with temperature due to instability of the oil stabilizing agent, resin. It was found that the higher oil viscosity had a larger asphaltene weight percent. Increasing the thickness and heterogeneity resulted in a decrease in oil recovery and also a higher asphaltene weight percent. Increasing the nano-pore size resulted in a significantly higher oil recovery, and less pore plugging. This research investigates the flow mechanism of CO2 injection and asphaltene precipitation due to CO2 injection in nano-pores in order to better understand the main factors that will impact the success of CO2 injection in unconventional shale reservoirs.Fallah, F., Khabaz, F., Kim, Y.-R., Kommidi, S.R., Haghshenas, H.F., 2019. Molecular dynamics modeling and simulation of bituminous binder chemical aging due to variation of oxidation level and saturate-aromatic-resin-asphaltene fraction. Fuel 237, 71-80. binder’s chemical aging process leads to significant changes in its mechanical and rheological properties. The two main outcomes of chemical aging are the oxidation of molecules and changes in the binder’s saturate-aromatic-resin-asphaltene (SARA) fractions. The binder components’ reaction to oxygen results in the formation of polar viscosity-building molecules, while changes in the SARA fractions disturbs the binder’s balance, giving it brittle properties. As both of these factors affect the binder at the molecular level, molecular dynamics (MD) simulations can improve the fundamental understanding of binder aging. Therefore, nine MD models were built (one model that represents unaged binder and eight different aged binder models) in this study for two specific purposes: to compare the MD simulation results with the experimental results and to conduct a parametric analysis of the MD simulations to investigate the effect of each aging outcome on the properties of the binder. A comparison among binders with different aging levels showed that the MD simulations and experiments had the same rank order in viscosity values, but they had significantly different magnitudes, which may be partly attributed to the high shear rates used in the MD simulation. The parametric analysis indicated that the dominant aging mechanism in the laboratory aged binder was the disturbance of the SARA fractions, while the oxidation of the molecules appears to be a more dominant mechanism in the field aged binder.Fardi, T., Pintus, V., Kampasakali, E., Pavlidou, E., Schreiner, M., Kyriacou, G., 2018. Analytical characterization of artist’s paint systems based on emulsion polymers and synthetic organic pigments. Journal of Analytical and Applied Pyrolysis 135, 231-241. identification of artworks’ constituent materials is a prerequisite for the development of appropriate art conservation methodologies, as well as for addressing authenticity issues. The present study focuses on the characterization of acrylic emulsion paints, with the use of Pyrolysis coupled with Gas Chromatography / Mass Spectrometry (Py-GC/MS), in combination with Fourier Transform Infrared in ATR mode (FTIR-ATR) and Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (SEM-EDX). Commercial paints manufactured by Liquitex (USA) and Rembrandt series of Royal Talens (NL) were chosen for the study; the four paints selected contained the synthetic organic pigments, Hansa yellow (PY3), diketopyrrolopyrrole (PR264), phthalocyanine blue (PB15) or phthalocyanine green (PG7). The results provide clear evidence of recent changes in the paint formulations regarding the polymeric binder, with the addition of styrene to the co-polymer nBA/MMA. Furthermore, different dispersants/surfactants were detected within the paints from the two different brands. Additional information was acquired on the additives incorporated in the paint, such as UV absorbers, optical brighteners, antioxidants and biocides. With regards to the identification of the synthetic organic pigments, several new molecular fragments were recorded using the applied experimental set-up at 600?°C, as compared to previous works. The products formed by the pyrolysis of the pigments are presented and discussed, showing evidence of different thermal fragmentation pathways as regards the synthetic organic pigments, when mixed in the emulsion paints.Feng, J., Hu, P., Su, X., Li, Q., Sun, J., Li, Y.-F., 2018. Impact of suspended sediment on the behavior of polycyclic aromatic hydrocarbons in the Yellow River: Spatial distribution, transport and fate. Applied Geochemistry 98, 278-285. total of 150 samples were collected from 25 sites in the Yellow River of Henan Province during 2014 to demonstrate the impact of suspended sediment (SS) load on the behavior of semi-volatile organic compounds (SVOCs) in the Yellow River. The average concentrations of SS ranged from <0.01?g/L to 1.7?g/L and the total loading/removal of SS was 108?Mt in the Henan section of the Yellow River. The sixteen polycyclic aromatic hydrocarbons (PAHs) were detected with concentrations of 23-370?ng/L in the dissolved phase and 36–3700?ng/g dw in the particulate phase, respectively. The concentrations of ∑16PAHs (sum of PAHs in the dissolved and particulate phase) along the river flow showed a decreasing trend and then an increasingly varied SS concentration. In the SS-abundant section, PAHs were released from the particle phase to the dissolved phase. Based on the mass balance of water and SS, 43% of the total load of PAHs is ascribed to the scouring processes, indicating that PAHs release from river-bed soil to the Yellow River is significant.Fontanier, C., Dissard, D., Ruffine, L., Mamo, B., Ponzevera, E., Pelleter, E., Baudin, F., Roubi, A., Chéron, S., Boissier, A., Gayet, N., Bermell-Fleury, S., Pitel, M., Guyader, V., Lesongeur, F., Savignac, F., 2018. Living (stained) deep-sea foraminifera from the Sea of Marmara: A preliminary study. Deep Sea Research Part II: Topical Studies in Oceanography 153, 61-78. this preliminary study, we investigate living (stained) foraminifera from the Sea of Marmara. We focus on the faunal composition and geochemical signatures (trace elements, carbon and oxygen stable isotopes) in foraminiferal tests at two deep-sea sites (329 and ~ 1240 m depth respectively). Documented by ROV observations and sampling, both study areas are heterogeneous (including bacterial mats and carbonate concretions), proximal to cold seeps and consist of dysoxic bottom water (O2 < 20 ?mol/L). The prevailing dysoxia at both study areas restricts foraminiferal diversity to very low values (S < 9, H’ < 0.97). Stress-tolerant species Bolivina vadescens and Globobulimina affinis dominate living faunas at both sites. The highest foraminiferal standing stock is recorded at the shallowest site underneath a spreading bacterial mat. No benthic foraminifera from either site possess geochemical signatures of methane seepage. Our biogeochemical results show that use of foraminiferal Mn/Ca ratios as a proxy for bottom water oxygenation depends strongly on regional physiography, sedimentary processes and water column structure.Forsythe, J.C., Kenyon-Roberts, S., O'Donnell, M., Betancourt, S.S., Masurek, N., Gisolf, A., Bennett, B., Nelson, R.K., Canas, J.A., Reddy, C.M., Peters, K.E., Zuo, J.Y., Mullins, O.C., 2019. Biodegradation and water washing in a spill-fill sequence of oilfields. Fuel 237, 707-719. recent paper delineated the variations in crude oil in five oilfields (seven reservoirs); large differences in biodegradation and water washing were reported in accord with expectations of the spill-fill sequence of trap filling [1]. Here, the deepest oilfield, Catcher, with the best quality crude oil is examined in detail. Among different oilfields, the extent of water washing is tightly coupled to the extent of (ongoing) biodegradation. Moreover, in-reservoir gradients of biodegradation and water washing are also highly correlated supporting the previous finding that, for cases of ongoing biodegradation, water washing can be assisted by biodegradation. Further support for this process is obtained with a detailed analysis of alkylbenzenes and alkylnaphthalenes that show elimination in accordance with water solubility, yet scale with the extent of biodegradation. Ongoing biodegradation accelerates water washing; once water-soluble components enter the aquifer, they are consumed by microbes maintaining a flux of these components into the aquifer and eliminating the corresponding need for (slow) diffusion of these components away from the oil-water contact. In addition, the oil gradient in the Catcher oilfield is affected by the change in biodegradation of the crude oil spilling into Catcher from a deeper, subsiding reservoir causing a large gradient at the top of the oil column. Factors that determine oil type in charge are discussed. This paper extends the range of measurement of water washing in these reservoirs to a factor 10,000 in water solubility. All data herein are consistent with biodegradation and biodegradation-assisted water washing occurring in reservoir, not in migration.Fu, S., Fu, J., Yu, J., Yao, J., Zhang, C., Ma, Z., Yang, Y., Zhang, Y., 2018. Petroleum geological features and exploration prospect of Linhe Depression in Hetao Basin, China. Petroleum Exploration and Development 45, 803-817. over four decades of exploration, a major breakthrough has been made in the Hetao Basin recently, that is, commercial oil flow of 62.6 m3/d is tested from the Paleogene Linhe Formation in Well Song 5. A comprehensive study of petroleum geological features of the Linhe Depression reveals that the Langshan fault, Hangwu fault and Huanghe fault controlled the deposition and evolution of the depression and hydrocarbon generation center, and the basin experienced Early Cretaceous depression and Cenozoic faulting. There developed two sets of saline lake hydrocarbon source rocks, Cretaceous Guyang Formation and Paleogene Linhe Formation. The source rocks, dominantly type II1 and I, have high abundance of organic matter and large potential of hydrocarbon generation, and their maturity ranges from low mature to over mature owing to wide variation of burial depth. The Guyang Formation and Linhe Formation are the clastic reservoirs, which have good physical properties with burial depth less than 5 000 m. In the Jixi uplift, the weathering fractures in matrix also have storage capacity. Faulted block, faulted anticline and matrix fracture reservoirs are found through exploration. The low mature to mature oil, is generated from Guyang Formation and Linhe Formation. The study shows that the Linhe Depression has rich resources and huge exploration potential, where the main exploration targets are the Guyang and Linhe formations, the favorable exploration areas are the Hangwu fault belt, Jixi uplift belt and the deep sag in the north.Fujisaki, W., Sawaki, Y., Matsui, Y., Yamamoto, S., Isozaki, Y., Maruyama, S., 2019. Redox condition and nitrogen cycle in the Permian deep mid-ocean: A possible contrast between Panthalassa and Tethys. Global and Planetary Change 172, 179-199. constrain the redox conditions and related nitrogen cycles during the Middle Permian (Guadalupian) to latest Late Permian (Lopingian) deep mid-Panthalassa, we determined the abundances of major, trace, and rare earth elements along with the carbon and nitrogen isotope ratios in shales interbedded with deep-sea cherts that are well-exposed at the Gujo-Hachiman section in the Mino-Tanba belt, SW Japan. The positive Ce anomalies together with low Mo and U enrichment factors (MoEF?<?1.0; 0.7?<?UEF?<?2.5) during the Guadalupian and the most of the Lopingian indicate that the deep mid-Panthalassa was under oxic condition. On the other hand, the slightly higher MoEF (2.0?<?MoEF?<?9.2) and UEF (0.9?<?UEF?<?2.5) values in some of the middle-late Lopingian shales suggest deposition under intermittent suboxic condition. These new findings indicate that the redox condition in the deep mid-Panthalassa never reached an anoxic condition during the Guadalupian and Lopingian until the Permian-Triassic boundary (P-TB) interval. In view of the redox state from the Guadalupian to latest Lopingian, our newly obtained δ15NTN values (?0.12‰ to +2.57‰) indicate nitrate-rich conditions in the mid-Panthalassa along with large isotopic fractionation during nitrate assimilation. However, unlike the oxic and nitrate-rich deep-Panthalassa, we speculate that oxygen-depleted (i.e., anoxic/euxinic) and bioavailable nitrogen-poor conditions developed in the deep Tethys immediately before the Guadalupian-Lopingian boundary (G-LB). These environmental stresses were potentially driven by a global cooling episode (Kamura event) together with the unique paleogeography, i.e., no contact with polar ice caps in the Tethyan Ocean. Upwelling of the anoxic watermass accumulated in the deep Tethys during the global cooling episode likely triggered oceanic anoxia in the shallow-marine regions around the G-LB, which eventually resulted in the G-LB mass extinction.Gajdosechova, Z., Pagliano, E., Zborowski, A., Mester, Z., 2018. Headspace in-tube microextraction and GC-ICP-MS determination of mercury species in petroleum hydrocarbons. Energy & Fuels 32, 10493-10501. of mercury contamination in petroleum hydrocarbons (PHs) is necessary in order to assess the risk of corrosion of the processing infrastructure and to assess the level of human exposure to Hg-containing substances. Here we present an accurate and sensitive method for determination of Hg species in PHs by headspace sampling with a possibility of on-line pre-concentration using in-tube extraction (ITEX) combined with gas chromatography–inductively coupled plasma mass spectrometry (GC-ICP-MS) analysis. Mercury species were first extracted from the PHs matrix into an aqueous phase via dithizone chelation and subsequently converted with sodium tetrapropyl borate into volatile derivatives which could be sampled from the headspace prior to GC-ICP-MS analysis. For concentrations in the ng kg–1 range, the on-line ITEX method was applied, whereas the μg kg–1 range was accessible by static headspace. Quantitation of Hg species was carried out by a double isotope dilution method, with quantitative recoveries of methylmercury (MeHg, average 101 ± 5%) and inorganic mercury (InHg, average 97 ± 7%) by direct headspace injection. Average recoveries of Hg spikes after on-line ITEX pre-concentration were 95 ± 3% for MeHg and 98 ± 8% for InHg. The detection limits for MeHg and InHg were 428 and 46 ng kg–1 when measured by static headspace, and 2.4 ng kg–1 and 1.7 ng kg–1 by on-line ITEX pre-concentration. The accuracy of the pre-concentration method was demonstrated by analysis of a crude oil standard reference material (NIST 2722) certified for InHg.Galloway, E., Hauck, T., Corlett, H., Pan?, D., Schultz, R., 2018. Faults and associated karst collapse suggest conduits for fluid flow that influence hydraulic fracturing-induced seismicity. Proceedings of the National Academy of Sciences 115, E10003-E10012.: Induced earthquakes can be caused by hydraulic fracturing (HF). However, the exact means by which stress changes are transferred to seismogenic faults are unknown. This paper provides evidence that a case of induced earthquakes in southern Alberta responded to increased pore pressure on a fault in hydraulic communication with the HF operation. Reflection-seismic and drill core data provide evidence that fluid flow along this fault caused strata underlying the target reservoir to dissolve, causing a karst collapse in the geological past. We suggest that seismogenic and hydraulically active faults are geologically rare and that the injection of fluid directly into them is even rarer, potentially explaining the small percentage of HF wells that cause induced earthquakes.Abstract: During December 2011, a swarm of moderate-magnitude earthquakes was induced by hydraulic fracturing (HF) near Cardston, Alberta. Despite seismological associations linking these two processes, the hydrological and tectonic mechanisms involved remain unclear. In this study, we interpret a 3D reflection-seismic survey to delve into the geological factors related to these earthquakes. First, we document a basement-rooted fault on which the earthquake rupture occurred that extends above the targeted reservoir. Second, at the reservoir’s stratigraphic level, anomalous subcircular features are recognized along the fault and are interpreted as resulting from fault-associated karst processes. These observations have implications for HF-induced seismicity, as they suggest hydraulic communication over a large (vertical) distance, reconciling the discrepancy between the culprit well trajectory and earthquake hypocenters. We speculate on how these newly identified geological factors could drive the sporadic appearance of induced seismicity and thus be utilized to avoid earthquake hazards.Gao, Y., Chen, Y., Yue, X., He, J., Zhang, R., Xu, J., Zhou, Z., Wang, Z., Zhang, R., Abliz, Z., 2018. Development of simultaneous targeted metabolite quantification and untargeted metabolomics strategy using dual-column liquid chromatography coupled with tandem mass spectrometry. Analytica Chimica Acta 1037, 369-379. quantification and untargeted global profiling are the two mainstream approaches, a merging of which could provide enhanced analytical potential in metabolomics research. Here, a simultaneous targeted quantification and untargeted metabolomics (STQUM) strategy was developed for more efficient, accurate and comprehensive metabolomics research by using ultra-high-performance liquid chromatography coupled with high-resolution tandem mass spectrometry (UPLC-HRMS/MS). First, we selected 110 cancer-related metabolites as targets and established a dual LC sequential separation method for simultaneous analysis of strong and weak polar metabolites. In order to achieve efficient acquisition for synchronous qualitative and quantitative analysis, high-resolution, data-dependent parallel reaction monitoring (PRM) method and data-independent all ion fragmentation (AIF) method were established. Their performance in targeted confirmation and quantification, and untargeted analysis were systematically investigated and assessed. In total, 78 metabolites were confidently confirmed in positive ion mode in both PRM and AIF assays, in which 73 metabolites can be accurately quantified. In addition, simultaneously untargeted profiling of 4651 features of high reliability and validity were achieved. Both AIF and PRM methods revealed high confidence, sensitivity and accuracy. In the STQUM approach, another 15 metabolites could be accurately quantified in negative ion mode. The method offers a new perspective for merging the hypothesis-based targeted quantitative validation and untargeted biomarkers discovery in one run for improved analysis efficiency and integrity.Gao, Y., Zhao, X., Ju, Z., Yu, Y., Qi, Z., Xiong, D., 2018. Effects of the suspended sediment concentration and oil type on the formation of sunken and suspended oils in the Bohai Sea. Environmental Science: Processes & Impacts 20, 1404-1413. unsourced oil contamination on the coast of Bohai Sea has recently attracted scholars to study the formation of sunken and suspended oils (SSO) from oil slicks on the sea surface. In this research, batch experiments have been conducted to study the time-scale effect of the different concentrations of suspended sediments on the formation of sunken oils and suspended oils using three oils (Oman crude oil, Merey crude oil, and 380# fuel oil) and two sediments (sand and silt) at different temperatures. The results showed that the sunken and suspended oils formed quickly within the mixing time and reached a maximum at the equilibrium time, te, and that te had a wide range of variation with sediment concentration and type. The oil sinking and submerging efficiency could reach up to 6.33%, 43.82% and 44.44% for 380# fuel oil, Oman crude oil and Merey crude oil, respectively. It is noted that the increase in sediment concentration and environmental temperature could enhance the formation of SSO but that it had a close relationship with the oil type. Overall, hydrophobic sand had a significantly higher oil sedimentation effect than silt.Gao, Z., Hu, Q., 2018. Pore structure and spontaneous imbibition characteristics of marine and continental shales in China. American Association of Petroleum Geologists Bulletin 102, 1941-1961. pore structure of shale has a significant effect on hydrocarbon migration and the long-term gas supply of shale gas wells. The present study investigates the spontaneous imbibition characteristics to evaluate the pore connectivity and wettability of marine Longmaxi shale samples from the southeastern Chongqing area and continental Yanchang shale samples from the Ordos Basin. The pore-size distribution obtained from N2 adsorption and mercury intrusion porosimetry, field emission–scanning electron microscopy, and focused ion beam–scanning electron microscopy photos are used to interpret the imbibition behaviors. Our results show that the difference in dominant pore type between marine and continental samples, which is dominated by thermal maturity, controls on their imbibition behaviors as well as their wettability. Organic matter (OM) pores within Yanchang samples are poorly developed because of their low thermal maturity, and a large amount of water-wet inorganic pores are preserved in these samples because of relatively weak compaction. Oil-wet OM pores are well developed in Longmaxi samples with higher thermal maturity, and inorganic pores have been largely eliminated because of strong compaction. The low pore connectivity to water for both the Longmaxi and Yanchang samples is indicated by the low water imbibition slopes. Furthermore, the more oil-wet property of the Longmaxi samples and more water-wet characteristics of the Yanchang samples are obtained by comparing the directional water/oil imbibition slopes. In addition, the positive meaning of quartz in the protection of pore spaces is found in both the Longmaxi and the Yanchang samples used in this study.García-Maldonado, J.Q., Escobar-Zepeda, A., Raggi, L., Bebout, B.M., Sanchez-Flores, A., López-Cortés, A., 2018. Bacterial and archaeal profiling of hypersaline microbial mats and endoevaporites, under natural conditions and methanogenic microcosm experiments. Extremophiles 22, 903-916. and archaeal community structure of five microbial communities, developing at different salinities in Baja California Sur, Mexico, were characterized by 16S rRNA sequencing. The response of the microbial community to artificial changes in salinity–sulfate concentrations and to addition of trimethylamine was also evaluated in microcosm experiments. Ordination analyses of the microbial community structure showed that microbial composition was distinctive for each hypersaline site. Members of bacteria were dominated by Bacteroidetes and Proteobacteria phyla, while Halobacteria of the Euryarchaeota phylum was the most represented class of archaea for all the environmental samples. At a higher phylogenetic resolution, methanogenic communities were dominated by members of the Methanosarcinales, Methanobacteriales and Methanococcales orders. Incubation experiments showed that putative hydrogenotrophic methanogens of the Methanomicrobiales increased in abundance only under lowest salinity and sulfate concentrations. Trimethylamine addition effectively increased the abundance of methylotrophic members from the Methanosarcinales, but also increased the relative abundance of the Thermoplasmata class, suggesting the potential capability of these microorganisms to use trimethylamine in hypersaline environments. These results contribute to the knowledge of microbial diversity in hypersaline environments from Baja California Sur, Mexico, and expand upon the available information for uncultured methanogenic archaea in these ecosystems.Gasperini, L., Polonia, A., ?a?atay, M.N., 2018. Fluid flow, deformation rates and the submarine record of major earthquakes in the Sea of Marmara, along the North-Anatolian Fault system. Deep Sea Research Part II: Topical Studies in Oceanography 153, 4-16. submerged portions of the North-Anatolian Fault (NAF) in the Sea of Marmara and the NE-Aegean Sea are sites of large magnitude earthquakes, that leave diagnostic geological “signatures” in the sedimentary record in the form of mass-wasting deposits, turbidites, and fluid and gas escape features. This is due to the interplay of seismic-shaking, mass- and turbidit flows, sediment resuspension and fluids circulation in relatively small sub-basins with a complex paleo-oceanography, steep slopes, high rates of deformation, and diffuse fault-controlled gas and fluid seeps. To unravel the complex interrelations of these phenomena during earthquake cycles, we carried out paleoseismological studies at several key locations.Here, we report results of these studies, carried out onboard the R/V Urania over a decade, starting soon after the Mw 7.4, 1999 ?zmit earthquake. Our work included high resolution mapping of active faults through multibeam bathymetry and high resolution seismic reflection profiles, multi-parameter analysis of sediment cores, as well as seafloor observations using sensors mounted on remotely-operated vehicles (ROV). The main objectives were to map active faults, determine slip-rates and earthquake recurrence times along major fault strands, and assess connections between fault deformation and fluid activity. We mapped fault geometry in the gulfs of ?zmit, Gemlik and Saros, showing the trans-tensive nature of these depressions. The average slip-rates for the last ~ 10 ka was found to be 10?mm/y in the gulfs of ?zmit and Saros, at the eastern and the western ends of the NAF northern strand, and 3–4?mm/yr in the Gulf of Gemlik, along the middle strand of the NAF. These rates, integrated over 10 ka of NAF activity, are smaller than those determined by the GPS geodetic measurements.Submarine paleoseismological studies in the Gulf of ?zmit detected the sedimentary records of earthquakes for the last 2.4 ka, suggesting an average recurrence time of 300 years for major events.Multisensor observations and monitoring of the seafloor have shown widespread emissions of gas and fluids along the submerged part of the NAF, associated with reduced black sediments; we investigated their possible connection with the earthquake cycle.Geerlings, N.M.J., Zetsche, E.-M., Martinez, S.H., Middelburg, J.J., Meysman, F.J.R., 2018. Mineral formation induced by cable bacteria performing long-distance electron transport in marine sediments. Biogeosciences Discussions 2018, 1-25. bacteria are multicellular, filamentous microorganisms that are capable of transporting electrons over centimeter-scale distances. Although recently discovered, these bacteria appear to be widely present in the seafloor, and when active, they exert a strong imprint on the local geochemistry. In particular, their electrogenic metabolism induces unusually strong pH excursions in aquatic sediments, which induces considerable mineral dissolution, and subsequent mineral re-precipitation. However at present, it is unknown whether and how cable bacteria play an active or direct role in the mineral re-precipitation process. To this end we present an explorative study of the formation of sedimentary minerals in and near filamentous cable bacteria using a combined approach of electron microscopic and spectroscopic techniques. Our observations reveal three different types of biomineral formation directly associated with cable bacteria: (1) the formation of intracellular polyphosphate granules, which are associated with a localized accumulation of calcium and magnesium, (2) the attachment and incorporation of clay particles in a sheath surrounding the surface of the cable bacterium filaments, and (3) the encrustation of cable bacteria filaments by newly formed solid phases containing high amounts of iron. These findings suggest a complex interaction between cable bacteria and the surrounding sediment matrix, and a substantial imprint of the electrogenic metabolism on mineral diagenesis and sedimentary biogeochemical cycling. Particularly the encrustation process leaves many open questions for further research. For example, we hypothesize that the complete encrustation of filaments might create a diffusion barrier and negatively impact the metabolism of the cable bacteria.Gensch, I., Sang-Arlt, X.F., Laumer, W., Chan, C.Y., Engling, G., Rudolph, J., Kiendler-Scharr, A., 2018. Using δ13C of levoglucosan as a chemical clock. Environmental Science & Technology 52, 11094–11101. specific carbon isotopic measurements (δ13C) of levoglucosan were carried out for ambient aerosol sampled during an intensive biomass burning period at different sites in Guangdong province, China. The δ13C of ambient levoglucosan was found to be noticeably heavier than the average δ13C of levoglucosan found in source C3-plant-combustion samples. To estimate the photochemical age of sampled ambient levoglucosan, back trajectory analyses were done. The origin and pathways of the probed air masses were determined, using the Lagrangian-particle-dispersion-model FLEXPART and ECMWF meteorological data. On the other hand, the isotopic hydrocarbon clock concept was applied to relate the changes in the field-measured stable carbon isotopic composition to the extent of chemical processing during transport. Comparison of the photochemical age derived using these two independent approaches shows on average good agreement, despite a substantial scatter of the individual data pairs. These analyses demonstrate that the degree of oxidative aging of particulate levoglucosan can be quantified by combining laboratory KIE studies, observed δ13C at the source and in the field, as well as back trajectory analyses. In this study, the chemical loss of levoglucosan was found to exceed 50% in one-fifth of the analyzed samples. Consequently, the use of levoglucosan as a stable molecular tracer may underestimate the contribution of biomass burning to air pollution.Gentzis, T., Carvajal-Ortiz, H., Selim, S.S., Tahoun, S.S., El-Shafeiy, M., Ocubalidet, S., Ali, A.A.-M., 2018. Depositional environment and characteristics of Late Eocene carbonaceous swampy tidal flat facies in the Fayoum Basin, Egypt. International Journal of Coal Geology 200, 45-58. study addresses the stratigraphic and sedimentological characteristics of the Late Eocene carbonaceous shale-bearing Qasr El Sagha Formation in the Fayoum Basin, Egypt. The Qasr El Sagha succession is comprised of four facies types: coastal mudflat, tidal flat, swamp, and storm-affected tidal channels. The swamp facies contain the Fayoum carbonaceous shale facies, which have not been studied in the past. The present study reports the first publicly available sedimentological, palynological, and geochemical results for the Fayoum facies. Eight samples of the sequence were taken from a freshly exposed road cut and analyzed petrographically, geochemically, and palynologically in order to determine the paleoenvironment of deposition and prevailing conditions. The palynomorph assemblages show that the lower part of the sequence was deposited in a lowland-riparian environment with continued freshwater influx. The depositional regime in the upper part of the sequence was swampy and dominated by fresh water. Mixed angiosperms and pteridophytes dominated the woody forest vegetation and were the source for the formation of the Fayoum carbonaceous shale facies. The recovered palynomorph assemblage points to the prevalence of a tropical to a sub-tropical, warm, humid climate with heavy precipitation in the lowland, swampy areas that were in close proximity to the freshwater influx. The water table was above the fen surface, preventing oxidation of the vegetation. Intermittent flooding or fluctuation in paleo-water levels likely occurred in the peat paleo-mire. The Fayoum samples have Ro,ran values of ~0.40–0.50%, which is in very good agreement with the Tmax from Rock-Eval pyrolysis. Although a few of the samples have elevated S2 (15–24?mg HC/g rock) and HI values (125–140?mg HC/g TOC), they do not have any hydrocarbon generating potential in the sampled location as a result of their immaturity. Petrographically, the analyzed samples are dominated by huminite group macerals (up to 77%), with telohuminite (eu-eulminite B) being dominant. Liptinite content is up to 3.5%, whereas inertinite content is up to 6%, dominated by fungal sclerotia (funginite). The TOC of the facies samples does not exceed 40?wt%.Gerschlauer, F., Saiz, G., Costa, D.S., Kleyer, M., Dannenmann, M., Kiese, R., 2018. Stable carbon and nitrogen isotopic composition of leaves, litter, and soils of various tropical ecosystems along an elevational and land-use gradient at Mount Kilimanjaro, Tanzania. Biogeosciences Discussions 2018, 1-27. in the stable isotopic composition of carbon (δ13C) and nitrogen (δ15N) of fresh leaves, litter and topsoils were used to characterize soil organic matter dynamics of twelve tropical ecosystems in the Mount Kilimanjaro region, Tanzania. We studied a total of 60 sites distributed along five individual elevational transects (860–4550ma.s.l.), which define a strong climatic and land use gradient encompassing semi-natural and managed ecosystems. The combined effects of contrasting environmental conditions, vegetation, soil, and management practices had a strong impact on the δ13C and δ15N values observed in the different ecosystems. The relative abundance of C3 and C4 plants greatly determined the δ13C of a given ecosystem. In contrast, δ15N values were largely controlled by land-use intensification and climatic conditions. Both δ15N values and calculated δ15N-based enrichment factors (δ15Nlitter–δ15Nsoil) indicate tightest nitrogen cycling at high-elevation (>3000ma.s.l.) ecosystems, and more open nitrogen cycling both in grass-dominated and intensively managed cropping systems. The negative correlation of δ15N values with soil nitrogen content and the positive correlation with mean annual temperature suggest reduced mineralisation rates, and thus limited nitrogen availability, at least in high-elevation ecosystems. By contrast, intensively managed systems are characterized by lower soil nitrogen contents and warmer conditions, leading together with nitrogen fertilizer inputs to lower nitrogen retention, and thus, significantly higher soil δ15N values. A simple function driven by soil nitrogen content and mean annual temperature explained 68% of the variability in soil δ15N values across all sites. Based on our results, we suggest that in addition to land use intensification, increasing temperatures in a changing climate may promote soil carbon and nitrogen losses, thus altering the otherwise stable soil organic matter dynamics of Mt. Kilimanjaro’s forest ecosystems.Ghadimi, M., Amani, M.J., Ghaedi, M., Malayeri, M.R., 2019. Modeling of formation damage due to asphaltene deposition in near wellbore region using a cylindrical compositional simulator. Journal of Petroleum Science and Engineering 173, 630-639. deposition in surface facilities, wellbore and near wellbore region poses a chronic problem during oil production processes. It reduces permeability significantly by blocking pore throats as well as wettability alteration toward oil-wet. In this study, near wellbore damage due to asphaltene deposition is addressed. A numerical approach has been followed to investigate the impacts of asphaltene deposition in near wellbore region using an Iranian crude oil sample. An IMPEC (Implicit Pressure and Explicit Compositions) compositional simulator has been developed in cylindrical coordinates. Three mechanisms of asphaltene damage including porosity reduction, permeability reduction and wettability alteration are taken into account, and the impact of each mechanism is individually discerned. It is assumed precipitated asphaltene is a pure dense liquid and it is determined by LLE calculation using PR-EoS. The reduction in permeability is correlated with porosity reduction using a power law relation. To model wettability alteration, instantaneous wettability dependent properties (relative permeability, capillary pressure and residual saturations) are determined by a weight averaging between before/after deposition state. By assuming porous media is a bundle of capillary tubes, a weight factor is suggested which is sensitive to asphaltene particle size and their orientation on the surface and calculated dynamically during the simulation. Furthermore, sensitivity analysis is done to investigate the effect of model parameters. It is found that the wettability alteration is the main cause for the reduced production rate. Wettability alteration could reduce oil production even up to several times more than porosity and permeability reduction. The results also reveal that at early time of production, most deposition occurs in the vicinity of the well but as time elapses, the maximum deposition point expands gradually to farther areas from the wellbore.Ghosh, D., Bhadury, P., Routh, J., 2018. Coping with arsenic stress: Adaptations of arsenite-oxidizing bacterial membrane lipids to increasing arsenic levels. MicrobiologyOpen 7, Article e00594. levels of arsenic (As) in aquifers of South East Asia have caused diverse health problems affecting millions of people who drink As-rich groundwater and consume various contaminated agriculture products. The biogeochemical cycling and mobilization/immobilization of As from its mineral-bound phase is controlled by pH, oxic/anoxic conditions, and different microbial processes. The increased As flux generated from ongoing biogeochemical processes in the subsurface in turn affects the in situ microbial communities. This study analyzes how the indigenous arsenite-oxidizing bacteria combat As stress by various biophysical alterations and self-adaptation mechanisms. Fifteen arsenite-oxidizing bacterial strains were isolated and identified using a polyphasic approach. The bacterial strains isolated from these aquifers belong predominantly to arsenite-oxidizing bacterial groups. Of these, the membrane-bound phospholipid fatty acids (PLFA) were characterized in seven selected bacterial isolates grown at different concentrations of As(III) in the medium. One of the significant findings of this study is how the increase in external stress can induce alteration of membrane PLFAs. The change in fatty acid saturation and alteration of their steric conformation suggests alteration of membrane fluidity due to change in As-related stress. However, different bacterial groups can have different degrees of alteration that can affect sustainability in As-rich aquifers of the Bengal Delta Plain.Godoy-Lozano, E.E., Escobar-Zepeda, A., Raggi, L., Merino, E., Gutierrez-Rios, R.M., Juarez, K., Segovia , L., Licea-Navarro, A.F., Gracia, A., Sanchez-Flores, A., Pardo-Lopez, L., 2018. Bacterial diversity and the geochemical landscape in the southwestern Gulf of Mexico. Frontiers in Microbiology 9, 2528. doi: 10.3389/fmicb.2018.02528. sediments are an example of one of the most complex microbial habitats. These bacterial communities play an important role in several biogeochemical cycles in the marine ecosystem. In particular, the Gulf of Mexico has a ubiquitous concentration of hydrocarbons in its sediments, representing a very interesting niche to explore. Additionally, the Mexican government has opened its oil industry, offering several exploration and production blocks in shallow and deep water in the southwestern Gulf of Mexico (swGoM), from which there are no public results of conducted studies. Given the higher risk of large-scale oil spills, the design of contingency plans and mitigation activities before oil exploitation is of growing concern. Therefore, a bacterial taxonomic baseline profile is crucial to understanding the impact of any eventual oil spill. Here, we show a genus level taxonomic profile to elucidate the bacterial baseline, pointing out richness and relative abundance, as well as relationships with 79 abiotic parameters, in an area encompassing ～150,000 km2, including a region where the exploitation of new oil wells has already been authorized. Our results describe for the first time the bacterial landscape of the swGoM, establishing a bacterial baseline “core” of 450 genera for marine sediments in this region. We can also differentiate bacterial populations from shallow and deep zones of the swGoM based on their community structure. Shallow sediments have been chronically exposed to aromatic hydrocarbons, unlike deep zones. Our results reveal that the bacterial community structure is particularly enriched with hydrocarbon-degrading bacteria in the shallow zone, where a greater aromatic hydrocarbon concentration was determined. Differences in the bacterial communities in the swGoM were also observed through a comprehensive comparative analysis relative to various marine sediment sequencing projects, including sampled sites from the Deep Water Horizon oil spill. This study in the swGoM provides clues to the bacterial population adaptation to the ubiquitous presence of hydrocarbons and reveals organisms such as Thioprofundum bacteria with potential applications in ecological surveillance. This resource will allow us to differentiate between natural conditions and alterations generated by oil extraction activities, which, in turn, enables us to assess the environmental impact of such activities.Golubev, Y.A., Martirosyan, O.V., Kuzmin, D.V., Isaenko, S.I., Makeev, B.A., Antonets, I.V., Utkin, A.A., 2019. Transformations of natural bitumens of different degrees of metamorphism at a low vacuum heating in the temperature range of 400–1000?°C. Journal of Petroleum Science and Engineering 173, 315-325. results of studying the structural and chemical transformations of natural bitumens of different degrees of metamorphism under heating at a low vacuum (～8?kPa) in the temperature range 400–1000?°C are presented. Reducing of the size of supermolecular particles during heating was recorded. A sequent step-by-step transformation of the graphite-like phase in bitumen structure up to shungite stage according Raman spectra characteristics is shown. The samples acquire electrical conductivity through eliminating the hydrocarbon component, before their graphite-like structure of carbon was ordered up to the stage of the higher anthraxolite.Gong, S., Peng, Y., Bao, H., Feng, D., Cao, X., Crockford, P.W., Chen, D., 2018. Triple sulfur isotope relationships during sulfate-driven anaerobic oxidation of methane. Earth and Planetary Science Letters 504, 13-20. anaerobic oxidation of methane (SD-AOM) plays a critical role in regulating the global methane budget. Determination of the diagnostic triple isotope exponent 33θ (≡ln33α/ln34α) for SD-AOM can help to identify and quantify microbial sulfate reduction via SD-AOM in the environment. The history of Earth's surface redox conditions can also be examined through the measurement of triple sulfur isotope compositions in sedimentary rocks. Due to difficulties in both culturing anaerobic methanotrophs and sampling pore-water sulfate in SD-AOM-dominated environments, however, the 33θ values for the processes of SD-AOM have not been constrained. We propose that a set of modern cold-seep associated barite samples with low Δδ18O/Δδ34S values bear a record of residual pore-water sulfate during SD-AOM, and therefore the triple sulfur isotope composition of these barites can be used to deduce 33θ values. We applied a 1-D diagenetic reaction–transport model to fit Δ33S and δ′34S results from modern cold seep barites collected from five sites in the Gulf of Mexico. Based on revealed negative correlations (R2=0.77) between Δ33S and δ′34S values we calculated an upper-limit 33θ value of 0.5100 to 0.5112 (±0.0005) given a 1000ln34α value of ‰?30‰ to ‰?10‰. This 33θ value is distinctively lower than that of organoclastic sulfate reduction (OSR) in marine environments where the diagnostic isotope fractionation (1000ln34α) is typically more negative than that of SD-AOM. In addition, cold seep barite data display a negative Δ33S–δ′34S correlation whereas pore-water sulfates of all OSR-dominated settings show a positive one. Therefore, the diagnostic triple-sulfur isotope exponent and associated negative Δ33S–δ′34S correlation may allow for the identification of SD-AOM in sedimentary records.Gong, S., Wang, Y., Wang, H., Zhang, X., Liu, G., 2018. High-pressure pyrolysis of isoprenoid hydrocarbon p-menthane in a tandem micro-reactor with online GC–MS/FID. Journal of Analytical and Applied Pyrolysis 135, 122-132. have been synthesized in large quantities through metabolic engineering method using some microorganisms as hosts and biomass as carbon resources. An isoprenoid cyclic hydrocarbon, p-menthane, is considered as a promising “drop-in” fuel to substitute traditional cycloalkane components, however, its pyrolysis data is lacking so far which is a significant part of the fuel combustion chemistry, especially under high pressures. In this work, pyrolysis experiments of p-menthane were carried out in a tandem micro-reactor under temperature of 450–800?°C and pressure of 2?MPa. 39 species were identified and quantified by online GC–MS/FID, based on which some initial pyrolysis pathways were determined. The early production of 4-methyl-1-cyclohexene and 1-isopropyl-1-cyclohexene indicates that methyl and isopropyl scission happen at the initial stage followed by H-transfer reaction and dehydrogenation. The activation energy Ea and pre-exponential factor A of the overall reaction were calculated as 225?kJ?mol?1 and 1.17?×?1012?s?1, respectively. For secondary reactions, many conjugated dienes such as 1,3-butadiene and 2-methyl-1,3-butadiene and small olefins such as ethylene and propene are generated through the ring-opening pathways. Benzene and toluene are the most abundant products among aromatics detected which are formed through dehydrogenation and demethylation of some early species like 4-methyl-1-cyclohexene and side-chain scission of aromatics. A particular product 1,3-hexadien-5-yne was detected which is generated through ring-opening pathways followed by H-transfer and demethylation reactions and could isomerized to benzene. A lumped kinetic model was proposed to describe the pyrolysis of p-menthane which exhibited good agreement with the experimental data.Gottardi, R., Mason, S.L., 2018. Characterization of the natural fracture system of the Eagle Ford Formation (Val Verde County, Texas). American Association of Petroleum Geologists Bulletin 102, 1963-1984. Eagle Ford Formation has attracted considerable industry attention as a self-sourced unconventional shale reservoir. The productive interval in the Eagle Ford Formation is the transgressive systems tract, which contains parasequences whose lithologic content varies upward with increasing proportions of limestones. Optimum success in both exploration and production depends on the adequate characterization of fracture systems as a function of lithology. The outcrops present along US Highway 90 in Val Verde and Terrell Counties, Texas, provide considerable insight into the regional natural fracture system of the Eagle Ford Formation. Fracture-orientation analysis reveals two sets of conjugate hybrid shear fractures and two sets of regional fractures. Abutting relationships suggest that hybrid shear fractures formed first, followed by the thoroughgoing northeast-striking fracture set, and finally by a northwest-striking set, which tends to be confined to individual mechanical units. The orientation of these fractures suggests that they formed during post-Laramide stress relaxation and progressive exhumation. Spacing-frequency distribution analysis of the fracture population reveals a mature hypersaturated fracture system that likely formed at depth by overburden load and/or fluid pressure near maximum burial. Our results indicate that the Eagle Ford Formation displays a well-developed fracture network regionally distributed in the Val Verde Basin, and likely present in the productive Eagle Ford play. These observations provide evidence for pathways and vertical connectivity for potential fluid pathways throughout the Eagle Ford Formation.Goude, G., Clarke, J., Webb, J.M., Frankel, D., Georgiou, G., Herrscher, E., Lorentz, K.O., 2018. Exploring the potential of human bone and teeth collagen from Prehistoric Cyprus for isotopic analysis. Journal of Archaeological Science: Reports 22, 115-122. pilot study attempts to document the potential of Prehistoric human bone and teeth collagen from Cyprus (9th-2nd mill. BC), for isotopic analysis and palaeodietary reconstruction. We sampled archaeological human skeletons and some faunal remains coming from six sites located in different locations, with different burial modes. The analysis of carbon and nitrogen elemental compositions and stable isotope ratios (δ13C, δ15N), indicate an extremely poor preservation of collagen, probably in relationship with burying conditions. Although very few individuals were successfully analysed, stable isotope data from this study allow a discussion on different protein food resources intake by humans in comparison with some other published data in the Near East (Greece, Cyprus, Turkey) from the Neolithic to the Bronze Age. These diachronic data provide documentations for future studies, including palaeodietary and environmental field research.Grall, C., Henry, P., Dupré, S., Géli, L., Scalabrin, C., Zitter, T.A.C., Sengor, A.M.C., Namik Cagatay, M., Cifci, G., 2018. Upward migration of gas in an active tectonic basin: An example from the Sea of Marmara. Deep Sea Research Part II: Topical Studies in Oceanography 153, 17-35. of various sources were collected at the seafloor of the Marmara basin suggesting that the gases expelled have experienced multiple sequences of upward migration, from multiple sources. The pathways of upward migration of gas can be reconstructed by considering the distribution of gas seeps with respect to the near-surface geomorphostructure and the regional stratigraphic architecture of the Marmara Basin. Gas seeps appear to be more favourably localized within a 1–2km swath around active faults where sediment permeability is probably enhanced by deformation. In the fault zones, fault intersections between sets of transtensive and transpressive subsidiary faults, or between subsidiary faults and main faults, are the preferred gas pathways. These subsidiary structures localize methane seeps, observed as elongated black patches with bacterial mats, gas bubble emission sites, and chemoherms associated with buried mud volcanoes. Gas seeps are, however, rare along active faults segments crossing basin depocenters but focus along basin edges and along topographic highs. Considering the role of sedimentary layers as gas migration pathways can explain this characteristic of the distribution of gas seeps. Fault zones that cross updip gas migration pathways will vent comparatively more gas than fault zones on the downdip side. Moreover, gas accumulation and resulting overpressuring along the western fault segment crossing the Western High may be associated with aseismic fault creep and intense gas emissions at the seafloor. In contrast, the poorly focused seepage along the fault segment crossing the Central High may be linked to the locked state of this fault segment.Green, H.S., Fuller, S.A., Meyer, A.W., Joyce, P.S., Aeppli, C., Nelson, R.K., Swarthout, R.F., Valentine, D.L., White, H.K., Reddy, C.M., 2018. Pelagic tar balls collected in the North Atlantic Ocean and Caribbean Sea from 1988 to 2016 have natural and anthropogenic origins. Marine Pollution Bulletin 137, 352-359. balls are prevalent in oceans and the coastal environment; however, their origins are not well constrained on a global scale. To address this, we used gas chromatography to analyze the molecular composition of a unique set of 100 pelagic tar balls collected in the Western North Atlantic and Caribbean Sea between 1988 and 2016. Hierarchal cluster analysis (HCA) was employed to classify the samples into groups based on the relative proportions of resolved and unresolved hydrocarbon distributions. Additional analysis of polycyclic aromatic hydrocarbons revealed that 28% of samples originated from heavy fuel oils and therefore had anthropogenic origins consistent with the classifications based on HCA. Other samples examined could originate from anthropogenic or natural origins, such as natural seeps. This study provides a preliminary record of 100 classified pelagic tar ball samples and demonstrates an approach to determine their origin to the environment.Grimaldi, C., Marcy, G.W., 2018. Bayesian approach to SETI. Proceedings of the National Academy of Sciences 115, E9755-E9764. Significance: Ongoing and future initiatives in the search for extraterrestrial intelligence (SETI) will explore the Galaxy on an unprecedented scale to find evidence of communicating civilizations beyond Earth. Here, we construct a Bayesian formulation of SETI to infer the posterior probability of the mean number of radio signals crossing Earth, given a positive or a null outcome of all-sky searches for nonnatural radio emissions. We show that not detecting signals within ～40 ～40 kly from Earth is compatible with the absence in the entire Galaxy of detectable emitters of a wide range of radiated power. The discovery of even a single emission within ～1 ～1 kly implies instead that over 100 signals typically cross our planet from the Milky Way.Abstract: The search for technosignatures from hypothetical galactic civilizations is going through a new phase of intense activity. For the first time, a significant fraction of the vast search space is expected to be sampled in the foreseeable future, potentially bringing informative data about the abundance of detectable extraterrestrial civilizations or the lack thereof. Starting from the current state of ignorance about the galactic population of nonnatural electromagnetic signals, we formulate a Bayesian statistical model to infer the mean number of radio signals crossing Earth, assuming either nondetection or the detection of signals in future surveys of the Galaxy. Under fairly noninformative priors, we find that not detecting signals within about 1 kly from Earth, while suggesting the lack of galactic emitters or at best the scarcity thereof, is nonetheless still consistent with a probability exceeding 10% that typically over ～100 ～100 signals could be crossing Earth, with radiated power analogous to that of the Arecibo radar, but coming from farther in the Milky Way. The existence in the Galaxy of potentially detectable Arecibo-like emitters can be reasonably ruled out only if all-sky surveys detect no such signals up to a radius of about 40 kly, an endeavor requiring detector sensitivities thousands times higher than those of current telescopes. Conversely, finding even one Arecibo-like signal within ～1000 ～1000 light years, a possibility within reach of current detectors, implies almost certainly that typically more than ～100 ～100 signals of comparable radiated power cross the Earth, yet to be discovered.Grishkevich, V.F., 2018. Neocomian paleogeography, gas hydrate cementation of sediments, and abnormal sequences of the Bazhenov Formation (West Siberia). Russian Geology and Geophysics 59, 157-167. zones of the Bazhenov Formation originated in the Neocomian as a result of protobazhenite reworking by submarine slide and slump waste wedgings, which eroded and deformed slope toe protobazhenite. But gas hydrate (GH) cementation might restrict the rock ability for plastic deformation. The conditions for GH thermodynamic stability in protobazhenites are inferred from reconstructions of paleogeographic and paleo-oceanic evironments. Joint analysis of Neocomian marine paleodepths and deep water paleotemperatures provides an explanation of the Bazhenov abnormal-zone extension.Grzegorczyk, M., Pogorzelski, S.J., Pospiech, A., Boniewicz-Szmyt, K., 2018. Monitoring of marine biofilm formation dynamics at submerged solid surfaces with multitechnique sensors. Frontiers in Marine Science 5, 363. doi: 10.3389/fmars.2018.00363. on artificial and biotic solid substrata was studied in several locations in near-shore waters of the Baltic Sea (Gulf of Gdansk) during a three-year period with contact angle wettability, confocal microscopy and photoacoustic spectroscopy techniques. As a reference, the trophic state of water body was determined from chemical analyses according to the following parameters: pH, dissolved O2, phosphate, nitrite, nitrate, ammonium concentrations, and further correlated to the determined biofilm characterizing parameters by means of Spearman's rank correlation procedure. Biofilm adhesive surface properties (surface free energy, work of adhesion) were obtained with the contact angle hysteresis (CAH) approach using an automatic captive bubble solid surface wettability sensor assigned for in-situ, on-line, and quasi-continuous measurements of permanently submerged samples (Pogorzelski et al., 2013; Pogorzelski and Szczepanska, 2014). From confocal reflection microscopy (COCRM) data, characteristic biofilm structural signatures such as biovolume, substratum coverage fraction, area to volume ratio, spatial heterogeneity, mean thickness, and roughness) were determined at different stages of microbial colony development. Photosynthetic properties [photosynthetic energy storage (ES), photoacoustic amplitude and phase spectra] of biofilm communities exhibited a seasonal variation, as indicated by a novel closed-cell type photoacoustic spectroscopy (PAS) system. Mathematical modeling of a marine biofilm under steady state was undertaken with two adjustable parameters, of biological concern i.e., the specific growth rate and induction time, derived from simultaneous multitechnique signals. A set of the established biofilm structural and physical parameters could be modern water body trophic state indexes.Gu, X., Pu, C., Khan, N., Wu, F., Huang, F., Xu, H., 2019. The visual and quantitative study of remaining oil micro-occurrence caused by spontaneous imbibition in extra-low permeability sandstone using computed tomography. Fuel 237, 152-162. capillary imbibition plays a significant role in oil displacement mechanism during water flooding operation in extra-low permeability sandstone reservoirs. However, after long-term of waterflooding, most of the oil blobs still remain within the pore space. In this context, quantitative assessment of the micro-occurrence of remaining oil in pore space is indispensable to conduct for an efficient waterflooding operation. In this work, the core sample with 3?mm?×?10?mm dimensions was prepared from the southeast area of Ordos Basin Chang6 extra-low permeability formation. Subsequently, high-resolution X-rays CT scanning technology was employed to visualize the changes in fluid distribution during spontaneous imbibition process. By means of image segmentation and three-dimensional (3-D) image reconstruction technique, the images of the remaining oil in the 3-D pore space were obtained. After that, the shape factor and relative volume factor were used to quantify the micro-occurrence of remaining oil in the 3-D pore space. The experimental results show that the total volume of oil was declined to 2.27?×?107?μm3 from 4.25?×?107?μm3 after spontaneous imbibition in the core sample. Consequently, the continuous oil phase was disrupted by the water in pore space and segmented oil blocks were appeared. Meanwhile, the number of oil blocks was increased to 6027 from 958 that led to severe Jamin’s effect and spontaneous imbibition was resultantly came to an end. While in 3-D pore space, three different kinds of micro-occurrences of remaining oil were spotted, such as network (54.31%), cluster (35.28%), and isolated (10.51%). The network and cluster type of remaining oil micro-occurrences are considered as dominant types owing to the large volume and better communication. Because of abrupt capillary force reduction in suddenly enlarge channel and multiple Jamin’s effects, the network and cluster remaining oil would mainly be confined in large channels (over than peak pore radius). Therefore, our work provides some beneficial understanding of the remaining oil micro-occurrence in pore space after imbibition.Gu, Y., Wan, Q., Yu, W., Li, X., Yu, Z., 2018. The effects of clay minerals and organic matter on nanoscale pores in Lower Paleozoic shale gas reservoirs, Guizhou, China. Acta Geochimica 37, 791-804. organic-rich gas shales, clay minerals and organic matter (OM) have significant influences on the origin, preservation, and production of shale gas. Because of the substantial role of nanoscale pores in the generation, storage, and seepage of shale gas, we examined the effects of clay minerals and OM on nanoscale pore distribution characteristics in Lower Paleozoic shale gas reservoirs. Using the Niutitang and Longmaxi shales as examples, we determined the effects of clay minerals and OM on pores through sedimentation experiments. Field emission–scanning electron microscopy combined with low-pressure N2 adsorption of the samples before and after sedimentation showed significant differences in pore location and pore size distribution between the Niutitang and Longmaxi shales. Nanoscale pores mostly existed in OM in the Longmaxi shale and in clay minerals or OM–clay composites in the Niutitang shale. The distribution differences were attributed largely to variability in thermal evolution and tectonic development and might account for the difference in gas-bearing capacity between the Niutitang and Longmaxi reservoirs. In the nanoscale range, mesopores accounted for 61–76% of total nanoscale pore volume. Considerably developed nanoscale pores in OM were distributed in a broad size range in the Longmaxi shale, which led to good pore connectivity and gas production. Numerous narrow pores (i.e., pores?<?20?nm) in OM–clay composites were found in the Niutitang shale, and might account for this shale’s poor pore connectivity and low gas production efficiency. Enhancing the connectivity of the mesopores (especially pores?<?20?nm and those developed in OM–clay composites) might be the key to improving development of the Niutitang shale. The findings provide new insight into the formation and evolutionary mechanism of nanoscale pores developed in OM and clay minerals.Guo, S., Peng, Y., 2019. Determination method of shale gas content: A case study in the Ordos Basin, China. Journal of Petroleum Science and Engineering 173, 95-100. shale samples, which were from MF-1 well (a) and MF-2 well (b) in the northern Ordos Basin of China and Yan'an Formation of Jurassic coal measure strata of J601 well (c) in the western edge of the Ordos Basin, were taken for thermal simulation and rock pyrolysis experiments. The rules of hydrocarbon generation production and S2 varied with the increase in thermal maturity (Ro), and the relationship between S2 and gaseous hydrocarbon generation production were analyzed. The analytical results indicated that as the Ro increased, the liquid hydrocarbon production of the shale samples first increased and then decreased, while the gaseous hydrocarbon production and total hydrocarbon production increased, and the S2 gradually decreased. Gaseous hydrocarbon production increased as S2 decreased, and there was a two-stage negative linear correlation between S2 and gaseous hydrocarbon production. The gaseous hydrocarbon production increased slowly when the Ro value was below 0.8% and rapidly increased after this threshold was met. During the process of the hydrocarbon generation of the shale in the Ordos Basin, the evolution phase could be divided into three stages: the immature stage of producing liquid hydrocarbon, the mature stage of producing gaseous and liquid hydrocarbon, and the overmature stage of gaseous hydrocarbon thermal cracking. Considering the hydrocarbon expulsion efficiency of the shale samples, the total organic carbon (TOC) content had a positive logarithmic correlation with the shale gas content (the gaseous hydrocarbon production minus the expulsed gaseous hydrocarbon production). The hydrocarbon generation potential and gas content increased with the increase of TOC. With the knowledge of the shale samples' TOC content, the shale gas content of the sampling layer could be preliminarily determined based on the regression equations of TOC and gas content. The exploration potential of the shale layer could be evaluated according to the gas content calculation, after considering the standards for the shale gas favorable area and the target area gas content.Guo, X., Hu, D., Liu, R., Wei, X., Wei, F., 2018. Geological conditions and exploration potential of Permian marine–continent transitional facies shale gas in the Sichuan Basin Natural Gas Industry 38, 11-18. Marine–continent transitional facies shale of the Longtan Fm, Upper Permian is an important source rock stratum in the Sichuan Basin. The previous researches on it mainly focus more on source rock evaluation, but less on shale gas accumulation. In this paper, the test and analysis results of Well DYS1, the coring well of Longtan Fm were dissected. Combined with the drilling results of its adjacent area, the organic rich shale in the Longtan Fm were studied from the aspects of distribution, geochemical, reservoir, gas-bearing characteristics and roof and floor conditions, and then compared with the shale strata with similar sedimentary background and good shale gas shows. And accordingly, its geological conditions for the formation of Longtan shale gas and its exploration potential were made clear. And the following research results were obtained. First, in the southeastern Sichuan Basin, the organic rich shale of transitional facies of Longtan Fm is developed with a thickness of more than 40 m. It is characterized by high brittle mineral content, high porosity, high total organic carbon (TOC), moderate thermal evolution (Ro) and good gas-bearing property. Therefore, it is geologically favorable for the formation of shale gas. Second, compared with the existing transitional facies shales at home and abroad, the Longtan shale is better in terms of porosity, TOC, Ro, gas content and other key parameters. Third, the type of organic matters is the main reason for the low development degree of organic pores in the Longtan shale. And during its shale gas exploration and selection, the coal seam enriched sections shall be avoided. In conclusion, considering the development degree, interlayer thickness, depth and preservation conditions of organic rich shale comprehensively, the Qijiang–Chishui area is the best exploration area for the transitional facies shale gas of Longtan Fm in the Sichuan Basin.Gutiérrez-Preciado, A., Sagha?, A., Moreira, D., Zivanovic, Y., Deschamps, P., López-García, P., 2018. Functional shifts in microbial mats recapitulate early Earth metabolic transitions. Nature Ecology & Evolution 2, 1700-1708. microbial mats dominated terrestrial ecosystems for billions of years, largely causing, through cyanobacterial oxygenic photosynthesis, but also undergoing, the Great Oxidation Event approximately 2.5 billion years ago. Taking a space-for-time approach based on the universality of core metabolic pathways expressed at ecosystem level, we studied gene content and co-occurrence networks in high-diversity metagenomes from spatially close microbial mats along a steep redox gradient. The observed functional shifts suggest that anoxygenic photosynthesis was present but not predominant under early Precambrian conditions, being accompanied by other autotrophic processes. Our data also suggest that, in contrast to general assumptions, anoxygenic photosynthesis largely expanded in parallel with the subsequent evolution of oxygenic photosynthesis and aerobic respiration. Finally, our observations might represent space-for-time evidence that the Wood–Ljungdahl carbon fixation pathway dominated phototrophic mats in early ecosystems, whereas the Calvin cycle probably evolved from pre-existing variants before becoming the dominant contemporary form of carbon fixation.Hakimi, M.H., Alaug, A.S., Ahmed, A.F., Yahya, M.M.A., 2019. Sedimentary environmental conditions and petroleum source rock potential of the Late Jurassic Arwa Member shales in Al-Jawf sub-basin, Yemen. Journal of African Earth Sciences 149, 474-486. study is a part of the source rock geochemistry project in the onshore Sabatyen Basin, Yemen. The results of this study were used to improve our understanding of the petroleum resource potential of Al-Jawf sub-basin in the north-western part of the Sabatyen Basin. The shale samples of the Late Jurassic Arwa Member from two wells (Khyawan-01 and Himyar-01) were analyzed to evaluate the characterises of the organic richness, kerogen type, thermal maturity and petroleum generation potential in Al-Jawf sub-basin based on a compilation of geochemical and petrological data. The biomarker and stable isotope results were subsequently used to evaluate the organic source input and sedimentary environmental conditions during deposition of the Late Jurassic Arwa Member shales. The Arwa shales contain low to high organic matter, with variable TOC% values between 0.58 and 6.41, indicating fair to very good source rock generative potential. The Rock-Eval HI data are ranging from 73 to 816?mg HC/g TOC and display mainly Type III and II/III kerogens with a minor contribution of Types I/II kerogen, consistent with both oil and gas source rocks. The biological sources are predominately sapropelic organic matter, with significant contribution of higher plants input in the Arwa member shales as indicated from biomarkers and carbon isotope data and petrology study. The biomarker ratios of relatively low Pr/Ph, Pr/n-C17 and Ph/n-C18 values and relatively high values of HC34/HC35 indicate suboxic environmental conditions during deposition of the Arwa Member shales. The analyzed Arwa shale samples have temperatures of maximum pyrolysis yield (Tmax) in the range of 417–457?°C and vitrinite reflectance between 0.30 and 0.56 %Ro, consistent with immature to early-mature source rocks. It is interesting to know that the Arwa shale samples with high contents of TOC% (>1), HI (>300?mg HC/g TOC) and high thickness of more than 1000?m indicate that the Late Jurassic Arwa Member hold significant exploration potential for oil in the deeper locations. Therefore, the hydrocarbon exploration processes should be focused on the known deeper location of the Arwa Member for predicting the mature source rock.Han, S., Cheng, Y., Gao, Q., Yan, C., Han, Z., 2018. Experimental study of the effect of liquid nitrogen pretreatment on shale fracability. Journal of Natural Gas Science and Engineering 60, 11-23. cryogenic liquid nitrogen (LN2) comes into contact with deep reservoirs, it will bring about serious thermal damage to rock pore structure. Therefore, LN2 pretreatment on reservoirs can contribute to further improving the stimulated reservoir volume (SRV) during large-scale hydraulic fracturing. To investigate the effect of LN2 pretreatment on the SRV of shale reservoirs, a series of physical and mechanical experiments related to shale reservoir fracability were conducted. A quantitative fracability evaluation model suitable for different confining pressures was developed from the perspective of fracturing mechanisms. The changes in shale fracability due to LN2 pretreatment were discussed in detail. The responses in P-wave velocities and T2 spectrum curves demonstrate that shale pore structure is subjected to serious damage after freeze-thaw cycles, and some micro-pores are aggregated to form micro-cracks or even macro-cracks. The decreases in tensile, compressive and shear strength and elastic modulus show that the mechanical properties of shales are deteriorated due to cryogenic damage effect. The changes in physical and mechanical properties of shales reveal respectively that LN2 pretreatment can lead to a slight reduction in shale brittleness, a significant improvement in micro-crack development, a moderate decrease in stability of the bedding planes, a relative increase in the propagation ability of fractures. Based on the result of the analytic hierarchy process, it can be concluded that shale fracability is efficiently enhanced due to LN2 pretreatment, especially under high confining pressure condition. Finally, the hydraulic fracturing experiments under tri-axial stress were carried out to further validate the feasibility of LN2 pretreatment to improve the SRV of shale reservoirs. Compared with the experimental results without LN2 pretreatment, it is found that the initiation pressure and initiation time decline by about 54% and 60% respectively. Both the size and complexity of the SRV of shales are enhanced obviously.Hao, Y., Li, X., Li, S., Lü, G., Liu, Y., Wei, X., 2018. Heat conduction and thermal convection on thermal front movement during natural gas hydrate thermal stimulation exploitation. Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles 73, Article 40. Gas Hydrate (NGH) has attracted increasing attention for its great potential as clean energy in the future. The main heat transfer mode that controls the thermal front movement in the process of NGH exploitation by heat injection was discussed through NGH thermal stimulation experiments, and whether it is reliable that most analytical models only consider the heat conduction but neglect the effect of thermal convection was determined by the comparison results between experiments and Selim’s thermal model. And the following findings were obtained. First, the movement rate of thermal front increases with the rise of hot water injection rate but changes little with the rise of the temperature of the injected hot water, which indicated that thermal convection is the key factor promoting the movement of thermal front. Second, the thermal front movement rates measured in the experiments are about 10 times that by the Selim’s thermal model, the reason for which is that the Selim’s thermal model only takes the heat conduction into account. And third, theoretical calculation shows that heat flux transferred by thermal convection is 15.56 times that by heat conduction. It is concluded that thermal convection is the main heat transfer mode that controls the thermal front movement in the process of NGH thermal stimulation, and its influence should never be neglected in those analytical models.Hara, Y., Yamaguchi, K., Onimaru, K., Kadota, M., Koyanagi, M., Keeley, S.D., Tatsumi, K., Tanaka, K., Motone, F., Kageyama, Y., Nozu, R., Adachi, N., Nishimura, O., Nakagawa, R., Tanegashima, C., Kiyatake, I., Matsumoto, R., Murakumo, K., Nishida, K., Terakita, A., Kuratani, S., Sato, K., Hyodo, S., Kuraku, S., 2018. Shark genomes provide insights into elasmobranch evolution and the origin of vertebrates. Nature Ecology & Evolution 2, 1761-1771. cartilaginous fishes are divided into elasmobranchs (sharks, rays and skates) and chimaeras, and the lack of established whole-genome sequences for the former has prevented our understanding of early vertebrate evolution and the unique phenotypes of elasmobranchs. Here we present de novo whole-genome assemblies of brownbanded bamboo shark and cloudy catshark and an improved assembly of the whale shark genome. These relatively large genomes (3.8–6.7?Gbp) contain sparse distributions of coding genes and regulatory elements and exhibit reduced molecular evolutionary rates. Our thorough genome annotation revealed Hox C genes previously hypothesized to have been lost, as well as distinct gene repertories of opsins and olfactory receptors that would be associated with adaptation to unique underwater niches. We also show the early establishment of the genetic machinery governing mammalian homoeostasis and reproduction at the jawed vertebrate ancestor. This study, supported by genomic, transcriptomic and epigenomic resources, provides a foundation for the comprehensive, molecular exploration of phenotypes unique to sharks and insights into the evolutionary origins of vertebrates.Harwood, C.R., Mouillon, J.-M., Pohl, S., Arnau, J., 2018. Secondary metabolite production and the safety of industrially important members of the Bacillus subtilis group. FEMS Microbiology Reviews 42, 721-738. of the ‘Bacillus subtilis group’ include some of the most commercially important bacteria, used for the production of a wide range of industrial enzymes and fine biochemicals. Increasingly, group members have been developed for use as animal feed enhancers and antifungal biocontrol agents. The group has long been recognised to produce a range of secondary metabolites and, despite their long history of safe usage, this has resulted in an increased focus on their safety. Traditional methods used to detect the production of secondary metabolites and other potentially harmful compounds have relied on phenotypic tests. Such approaches are time consuming and, in some cases, lack specificity. Nowadays, accessibility to genome data and associated bioinformatical tools provides a powerful means for identifying gene clusters associated with the synthesis of secondary metabolites. This review focuses primarily on well-characterised strains of B. subtilis and B. licheniformis and their synthesis of non-ribosomally synthesised peptides and polyketides. Where known, the activities and toxicities of their secondary metabolites are discussed, together with the limitations of assays currently used to assess their toxicity. Finally, the regulatory framework under which such strains are authorised for use in the production of food and feed enzymes is also reviewed.Haverly, M.R., Fenwick, S.R., Patterson, F.P.K., Slade, D.A., 2019. Biobased carbon content quantification through AMS radiocarbon analysis of liquid fuels. Fuel 237, 1108-1111. production and use of renewable hydrocarbons has created a need for accurate quantification of the biobased carbon content of hydrocarbon fuels. The blend percentages of conventional biofuels (such as biodiesel and ethanol) can be quantified by numerous methods such as gas chromatography and infrared spectroscopy. Distinguishing the biobased content of a purely hydrocarbon fuel, however, is more difficult. In this study, a single-blind trial was conducted to assess the accuracy and precision of accelerator mass spectrometry (AMS) radiocarbon analysis of the biobased carbon content of hydrocarbon fuels. Test samples with known biobased carbon contents ranging from 0 to 10?wt% were sent to four labs for analysis by ASTM D6866-16 Method B. Blank correction of the test results was found to improve measurement accuracy through the reduction of lab-specific systematic error. Favorable precision, accuracy, and a limit of detection were determined. This study strongly supports radiocarbon analysis by AMS as an accurate and reliable method for quantifying the biobased carbon content of hydrocarbon transportation fuels.Hazra, B., Wood, D.A., Kumar, S., Saha, S., Dutta, S., Kumari, P., Singh, A.K., 2018. Fractal disposition, porosity characterization and relationships to thermal maturity for the Lower Permian Raniganj basin shales, India. Journal of Natural Gas Science and Engineering 59, 452-465. structural parameters of organic-rich shales control their gas storage properties and gas transport behaviors. In this work, pore structural parameters of selected organic-rich shale samples belonging to the Lower Permian Barakar Formation from Raniganj basin (India) are studied using low-pressure nitrogen adsorption combined with field emission scanning electron microscopy (FE-SEM), Rock-Eval pyrolysis and energy-dispersive X-ray spectroscopy (EDX). The samples are predominantly mesoporous and in the early to peak range of thermal maturity, with one late mature sample affected by a nearby igneous intrusion. The Brunauer, Emmett, and Teller specific surface area (BET SSA) of the samples display no correlation with total organic carbon (TOC), and a positive correlation with Rock-Eval Tmax. The average pore radii of the shale samples display a negative relationship with the BET SSA and Rock-Eval Tmax values. As thermal maturity advances finer pores are formed, which progressively increases the SSA of shales. A novel fractal-discriminating parameter, ΔS [(slope of the linear segment at P/P0 of 0.5–1.0) – (slope of the linear segment at P/P0 of 0–0.5), where S?=?D-3] displays a minimum value for a silty-shale sample, and a maximum value for the intrusion-affected shales. The less distinct fractal dimensions for the silty-shale, and the most distinct fractal dimension for the intrusion-affected shales shows influence of both the mineral composition and thermal maturity on fractal dimensions of shales. Among the samples studied, the intrusion-affected shales exhibited the highest BET SSA, pore volume, least average pore radius, larger ΔS and fractal dimensions (D1 and D2), all signifying the impact of high thermal maturity (thermal stress) on pore structural parameters.He, C., Li, T., 2018. Studying advances in effect of pressure on organic matters maturation. Acta Sedimentologica Sinica 26, 1040-1048. experiments are using gold bags to investigate the effect of pressure on maturation of organic matters, and no significant differences have been found in the majority of the results. However, the results from high-pressure fixed volume autoclave hydrous experiments usually showed pressure retardation on organic matters maturation. Although fixed volume autoclave hydrous pyrolysis may partly simulate the geological conditions under which hydrocarbons are being generated, the WYMN-3 HTHP instrument developed by Lanzhou Institute of Geology, Chinese Academy of Sciences or formation pore space pyrolysis built in Wuxi Research Institute of Petroleum Geology are better to investigate the organic matter maturation in overpressure basins because they also take into account of the lithostatic pressure. And high water pressure enhances the activation energy via increasing the pV work; it also reduces the entropy(ΔS) to decrease the pre-exponential factor(A). At present, using PreRoTM and T-P-Ro models would be better for overpressure basins, but both only take account of excess fluid pressure, rather than absolute fluid pressure. So a kinetic model incorporated absolute fluid pressure is needed in further studies. Given that it is hard to compare the results obtained from different experimental methods or instruments, it is quite necessary to establish a set of standard experimental rules to fully understand the pressure effect on organic matter maturation. In addition, the exploration and development of shale gas with high maturity levels provide valuable geological data for studying the effect of pressure on hydrocarbon generation at overmature stages, but this requires the accurate determination of thermal maturity levels of marine shales in which the vitrinite macerals are usually absent or rare.He, D., Hou, D., Chen, T., 2018. Geochemical characteristics and analysis of crude-oil source in the deep-water area of the Baiyun Sag, South China Sea. Russian Geology and Geophysics 59, 499-511. the Baiyun Sag, the oil relationship with possible source rocks is complicated, and little research on oil sources in the area has been performed. In this paper, geochemical studies of carbon isotopes, biomarkers, paleoenvironmental deposition, and crude oil maturity, carried out with the use of oil samples from the Baiyun Sag, demonstrate that the organic matter in crude oil has an oxidizing depositional environment and primarily lacustrine facies conditions, with a significantly higher plant input. The oil samples used are mature to highly mature. Crude oil in the northern area of the Baiyun Sag is more mature than samples in the eastern part of the sag. Despite limited source rock data, we were able to conclude that the crude oil samples were derived mainly from the Enping Formation; other potential source rocks of the Wenchang and Zhuhai Formations may also have contributed to the reservoirs in different parts of the sag. Furthermore, the source of crude oil in each structure in the Baiyun Sag was analyzed; for example, crude oil in the LH19-5 structure was generated from the organic matter of the Enping Formation, and crude oil in the LW3-1 structure was derived from the mixed organic matter of the Enping, Wenchang, and Zhuhai Formations. ? 2018, V.S. Sobolev IGM, Siberian Branch of the RAS. Published by Elsevier B.V. All rights reserved.He, D., Hou, D., Huang, H., 2018. Geochemical characteristics of n-alkane and n-alkan-2-one in Mildred peat bog from the Athabasca Region, Canada. Acta Sedimentologica Sinica 26, 1049-1058. geochemistry of n-alkane and n-alkan-2-one in the Mildred peat bog of the Athabasca region is systematically analyzed in order to determine the source material of organic matters in peat, and explore the genetic correlation between n-alkane and n-alkan-2-one, which reveals some biological information and vegetation evolution characteristics in the study peat bog. The distributions of n-alkane and n-alkan-2-one are characterized by high molecular weight and post peak pattern, with strong odd over even predominances, which indicates that the peat organic materials are primarily derived from in situ terrigenous higher plants, whereas the contribution from sphagnum and aquatic plants seems to be small. In accordance with principal component analysis (PCA) and n-alkane proxies distributions, the Mildred peat profile is divided into three intervals, the peat-forming plant in the upper interval (living layer to -17 cm) containing mainly Sphagnum fuscum; the middle interval (-17 cm to -41 cm) with woody plants, Ericaceae, piece needles and minor Cyperaceous as the in situ accumulated plants; and the deeper interval (-41 cm to the bottom) containing a number of Cyperaceous plants increased with some woody debris and Ericaceae grow. The similar distribution between n-alkane and n-alkan-2-one suggests microbial oxidation of related n-alkanes as the primary source of n-alkan-2-one in the Mildred peat bog. A direct input from peat-forming plants also contributes to n-alkan-2-one formation, particularly in the top profile. Microbial β-oxidation and decarboxylation of n-fatty acids can be also considered as an alternative origin of n-alkan-2-ones but its contribution is not significant.He, D., Simoneit, B.R.T., Cloutier, J.B., Jaffé, R., 2018. Early diagenesis of triterpenoids derived from mangroves in a subtropical estuary. Organic Geochemistry 125, 196-211. from three mangrove species, and surface and deeper soils along salinity gradients in the Shark River estuary, USA, were analyzed to determine numerous diagenetic degradation products and pathways for mangrove derived triterpenoids. The dehydration of pentacyclic triterpenols was observed in mangrove leaves, leading to pentacyclic triterpadienes with Δ2,12 and Δ2,14 unsaturations. Surprisingly, various mono-unsaturated triterpenes (with Δ12 and Δ14), nor-, bisnor- (24,25-bisnortaraxer-14-ene), trisnor-triterpenes (1,2,3-trisnortaraxera-5(10),14-diene and 1,2,3-trisnortaraxer-14-ene) and tetrakisnor- and pentakisnor-triterpenes were detected in Rhizophora mangle leaves, suggesting that reduction and later demethylation of triterpadienes can occur prior to mangrove leaf abscission or senescence/death. Most of the unsaturated and nortriterpenes were also found in mangrove stand soils (>100?years old), suggesting their relative stability. In addition, a high diversity of aliphatic and aromatic des-A-triterpenes from the taraxerane, oleanane, ursane, and lupane precursors were present in the surface and deeper soils of mangrove stands, suggesting that isomerization, rapid diagenetic loss of ring-A and further aromatization of triterpenoids occurred early during litter decay. The overall diagenetic transformations could be caused by a combination of photodegradation, microbial alteration (bacteria/fungi), anaerobic alteration (reduction), oxidation and secondary processes. Possible mechanisms of the early diagenesis of triterpenoids were proposed using taraxerol, a triterpenol, highly enriched in R. mangle, as an example. These results, coupled with the detection of various intermediate compounds, provide a better understanding of the diagenetic fate of mangrove derived triterpenoids.Heidke, I., Scholz, D., Hoffmann, T., 2018. Quantification of lignin oxidation products as vegetation biomarkers in speleothems and cave drip water. Biogeosciences 15, 5831-5845. we present a sensitive method to analyze lignin oxidation products (LOPs) in speleothems and cave drip water to provide a new tool for paleo-vegetation reconstruction. Speleothems are valuable climate archives. However, compared to other terrestrial climate archives, such as lake sediments, speleothems contain very little organic matter. Therefore, very few studies on organic biomarkers in speleothems are available. Our new sensitive method allows us to use LOPs as vegetation biomarkers in speleothems.Our method consists of acid digestion of the speleothem sample followed by solid-phase extraction (SPE) of the organic matter. The extracted polymeric lignin is degraded in a microwave-assisted alkaline CuO oxidation step to yield monomeric LOPs. The LOPs are extracted via SPE and finally analyzed via ultrahigh-performance liquid chromatography (UHPLC) coupled to electrospray ionization (ESI) and high-resolution Orbitrap mass spectrometry (HRMS). The method was applied to stalagmite samples with a sample size of 3–5g and cave drip water samples with a sample size of 100–200mL from the Herbstlabyrinth-Advent Cave in Germany. In addition, fresh plant samples, soil water, and powdered lignin samples were analyzed for comparison. The concentration of the sum of eight LOPs (Σ8) was in the range of 20–84ng?g?1 for the stalagmite samples and 230–440ng?L?1 for the cave drip water samples. The limits of quantification for the individual LOPs ranged from 0.3–8.2ng per sample or 1.5–41.0ng?mL?1 of the final sample solution.Our method represents a new and powerful analytical tool for paleo-vegetation studies and has great potential to identify the pathways of lignin incorporation into speleothems.Hellauer, K., Martínez Mayerlen, S., Drewes, J.E., Hübner, U., 2019. Biotransformation of trace organic chemicals in the presence of highly refractory dissolved organic carbon. Chemosphere 215, 33-39. studies demonstrated that the transformation of trace organic chemicals (TOrCs) in managed aquifer recharge (MAR) systems is favored under carbon-limited and oxic redox condition especially, if the dissolved organic (DOC) serving as primary substrate has a refractory character. Since co-metabolism is suggested to be the dominant removal mechanism, it is hypothesized that TOrCs transformation is controlled by the concentration of the refractory carbon under oxic redox conditions. A laboratory-scale soil column experiment mimicking MAR was established to investigate the influence of two different concentrations of highly refractory carbon sources on TOrCs transformation, namely drinking water (DW) and drinking water augmented with humic acid (DW + HA). Oxic redox conditions and carbon-limitation were present in both systems (ΔDOCDW+HA?≈?0.6–0.7?mg/L; ΔDOCDW?≈?0.1?mg/L). Of the 12 TOrCs investigated seven exhibited moderate to efficient transformation in both systems with only one compound (diclofenac) showing significantly enhanced (co-metabolic) biotransformation by adding humic acids as primary growth substrate. It is postulated that transformation of some TOrCs is characterized by metabolic degradation under starving conditions (ΔDOC?≤?0.1?mg/L). By comparing the transformation efficiency of selected TOrCs with previous studies operated under carbon-limited and oxic conditions, an inconsistent behavior of some compounds was observed. These results demonstrate that key factors triggering the transformation of TOrCs are still poorly understood and thus, further investigations regarding the biodegradation pathways of TOrCs, upregulation of key enzymes by the microbial community but also more detailed analysis of the composition of the biodegradable DOC are needed.Hemingway, J.D., Spencer, R.G.M., Podgorski, D.C., Zito, P., Sen, I.S., Galy, V.V., 2019. Glacier meltwater and monsoon precipitation drive Upper Ganges Basin dissolved organic matter composition. Geochimica et Cosmochimica Acta 244, 216-228. glaciers store dissolved organic carbon (DOC) that can be exported to river networks and subsequently respired to CO2. Despite this potential importance within the global carbon cycle, the seasonal variability and downstream transport of glacier-derived DOC in mountainous river basins remains largely unknown. To provide novel insight, here we present DOC concentrations and molecular-level dissolved organic matter (DOM) compositions from 22 nested, glaciated catchments (1.4–81.8% glacier cover by area) in the Upper Ganges Basin, Western Himalaya over the course of the Indian summer monsoon (ISM) in 2014. Aliphatic and peptide-like compounds were abundant in glaciated headwaters but were overprinted by soil-derived phenolic, polyphenolic and condensed aromatic material as DOC concentrations increase moving downstream. Across the basin, DOC concentrations and soil-derived compound class contributions decreased sharply from pre- to post-ISM, implying increased relative contribution of glaciated headwater signals as the monsoon progresses. Incubation experiments further revealed a strong compositional control on the fraction of bioavailable DOC (BDOC), with glacier-derived DOC exhibiting the highest bioavailability. We hypothesize that short-term (i.e. in the coming decades) increases in glacier melt flux driven by climate change will further bias exported DOM toward an aliphatic-rich, bioavailable signal, especially during the ISM and post-ISM seasons. In contrast, eventual decreases in glacier melt flux due to mass loss will likely lead to more a soil-like DOM composition and lower bioavailability of exported DOC in the long term.Hendrickson, H.L., Poole, A.M., 2018. Manifold routes to a nucleus. Frontiers in Microbiology 9, 2604. doi: 10.3389/fmicb.2018.02604. is widely assumed that there is a clear distinction between eukaryotes, with cell nuclei, and prokaryotes, which lack nuclei. This suggests the evolution of nuclear compartmentation is a singular event. However, emerging knowledge of the diversity of bacterial internal cell structures suggests the picture may not be as black-and-white as previously thought. For instance, some members of the bacterial PVC superphylum appear to have nucleus-like compartmentation, where transcription and translation are physically separated, and some jumbophages have recently been shown to create nucleus-like structures within their Pseudomonad hosts. Moreover, there is also tantalising metagenomic identification of new Archaea that carry homologues of genes associated with internal cell membrane structure in eukaryotes. All these cases invite comparison with eukaryote cell biology. While the bacterial cases of genetic compartmentation are likely convergent, and thus viewed by many as not germane to the question of eukaryote origins, we argue here that, in addressing the broader question of the evolution of compartmentation, other instances are at least as important: they provide us with a point of comparison which is critical for a more general understanding of both the conditions favouring the emergence of intracellular compartmentation of DNA and the evolutionary consequences of such cellular architecture. Finally, we consider three classes of explanation for the emergence of compartmentation: physical protection, crosstalk avoidance and nonadaptive origins.Hendy, J., Colonese, A.C., Franz, I., Fernandes, R., Fischer, R., Orton, D., Lucquin, A., Spindler, L., Anvari, J., Stroud, E., Biehl, P.F., Speller, C., Boivin, N., Mackie, M., Jersie-Christensen, R.R., Olsen, J.V., Collins, M.J., Craig, O.E., Rosenstock, E., 2018. Ancient proteins from ceramic vessels at ?atalh?yük West reveal the hidden cuisine of early farmers. Nature Communications 9, Article 4064. analysis of lipids (fats, oils and waxes) absorbed within archaeological pottery has revolutionized the study of past diets and culinary practices. However, this technique can lack taxonomic and tissue specificity and is often unable to disentangle signatures resulting from the mixing of different food products. Here, we extract ancient proteins from ceramic vessels from the West Mound of the key early farming site of ?atalh?yük in Anatolia, revealing that this community processed mixes of cereals, pulses, dairy and meat products, and that particular vessels may have been reserved for specialized foods (e.g., cow milk and milk whey). Moreover, we demonstrate that dietary proteins can persist on archaeological artefacts for at least 8000 years, and that this approach can reveal past culinary practices with more taxonomic and tissue-specific clarity than has been possible with previous biomolecular techniques.Henry, P., Grall, C., Kende, J., Viseur, S., ?zeren, M.S., ?eng?r, A.M.C., Dupré, S., Scalabrin, C., Géli, L., 2018. A statistical approach to relationships between fluid emissions and faults: The Sea of Marmara case. Deep Sea Research Part II: Topical Studies in Oceanography 153, 131-143. Sea of Marmara is traversed by the North Anatolian Fault system and also presents abundant emission sites of methane gas into the water column. In order to assess the spatial relationship between gas emissions and active faults, the distribution of distances between gas emission sites and the nearest fault is calculated and compared with the distribution of distances between a uniform random distribution of points (Poisson process representing the null hypothesis of an absence of relationship between gas emissions and faults) and the nearest fault. Interestingly, the distance distribution for the Poisson process is nearly exponential, indicating that the fault map does not have a characteristic scale other than that representing the intensity of the fault network. The distance distribution for the observed gas emissions is significantly narrower than that arising from the Poisson process, with a Kolmogorov distance of 0.25?±?0.02. The crossing point between the two distributions defines the characteristic half-width of the swath of gas emission sites around the mapped active faults. For the whole Sea of Marmara data set a characteristic half-width of 900–1000?m is found which matches the half-width of the seafloor deformation zone observed around the main active fault. When the same analysis is applied to zones covering the Western High and the Central High it is found that the swath of gas emissions is wider on the Central High (2?km half-width), and not clearly related to the seafloor deformation zone there. This difference is put in perspective with recent work showing that creep is occurring on the western segment of the Main Marmara Fault (this also causing microseismicity) while the central Istanbul-Silivri segment may have remained locked since the 1766 magnitude 7+ earthquake. This suggests that aseismic slip (and not only earthquake occurrence) effectively maintains high permeability conduits in fault zones in sediments.Hickman-Lewis, K., Westall, F., Cavalazzi, B., 2019. Chapter 42 - Traces of early life from the Barberton Greenstone Belt, South Africa, in: Van Kranendonk, M.J., Bennett, V.C., Hoffmann, J.E. (Eds.), Earth's Oldest Rocks (Second Edition). Elsevier, pp. 1029-1058. review the evidence for traces of Paleoarchean (3.47–3.2Ga) life in the Barberton Greenstone Belt (BGB), South Africa. Morphological, organic, geochemical, isotopic, and mineralogical biosignatures are preserved in massive and stratiform volcano-sedimentary cherts, in hydrothermal and chemical sedimentary rocks, and in quartz-rich sandstones. The well-preserved lithologies of the BGB record a broad diversity of features interpreted as the remnants of anaerobic life forms, including chemotrophs, benthic phototrophs, and possible planktonic organisms. Inferred photosynthetic fossils include planar to low-amplitude, finely laminated microbial mats and stromatolites from marine and terrestrial settings. Rarely preserved, putative, filamentous microfossils are very small compared with present-day phototrophs. Putative chemotrophic fossils are more enigmatic and generally restricted to nutrient-rich hydrothermal environments. Relatively large (up to some hundreds of microns) lenticular and spherical carbonaceous microfossils are interpreted as possible planktonic forms. Many proposed microfossils are of simple morphology and poorly preserved, thus it is difficult to completely discount abiogenic mechanisms for their formation.Himmelberg, A.M., Brüls, T., Farmani, Z., Weyrauch, P., Barthel, G., Schrader, W., Meckenstock, R.U., 2018. Anaerobic degradation of phenanthrene by a sulfate-reducing enrichment culture. Environmental Microbiology 20, 3589-3600. degradation processes are very important to attenuate polycyclic aromatic hydrocarbons (PAHs) in saturated, anoxic sediments. However, PAHs are poorly degradable, leading to very slow microbial growth and thus resulting in only a few cultures that have been enriched and studied so far. Here, we report on a new phenanthrene-degrading, sulfate-reducing enrichment culture, TRIP1. Genome-resolved metagenomics and strain specific cell counting with FISH and flow cytometry indicated that the culture is dominated by a microorganism belonging to the Desulfobacteraceae family (60% of the community) and sharing 93% 16S rRNA sequence similarity to the naphthalene-degrading, sulfate-reducing strain NaphS2. The anaerobic degradation pathway was studied by metabolite analyses and revealed phenanthroic acid as the major intermediate consistent with carboxylation as the initial activation reaction. Further reduced metabolites were indicative of a stepwise reduction of the ring system. We were able to measure the presumed second enzyme reaction in the pathway, phenanthroate-CoA ligase, in crude cell extracts. The reaction was specific for 2-phenanthroic acid and did not transform other isomers. The present study provides first insights into the anaerobic degradation pathways of three-ringed PAHs. The biochemical strategy follows principles known from anaerobic naphthalene degradation, including carboxylation and reduction of the aromatic ring system.Ho, S., Imbert, P., Hovland, M., Wetzel, A., Blouet, J.-P., Carruthers, D., 2018. Downslope-shifting pockmarks: interplay between hydrocarbon leakage, sedimentations, currents and slope’s topography. International Journal of Earth Sciences 107, 2907-2929. in Pliocene-Quaternary continental slope deposits offshore Angola show features related to: (1) fluid leakage craters that formed repeatedly, (2) authigenic methane-derived carbonates that indicate the (former) presence of hydrocarbons and (3) erosional–depositional structures that are clearly related to current activity. Depending on topography, the pockmarks show differing development: “Advancing Pockmarks” preferentially developed on regional slopes or inclined topography (>?2.5°–3°). They arranged in a chain-like pattern and mimic the outline of buried turbidite channels below. These pockmarks and their infill migrated downslope in response to shifting vents. “Nested Pockmarks” occur in gently sloping areas (<?2°). Their isolated conical infill records slope-parallel migration within a specific depth range pointing to the influence of contour currents. Both pockmark types are long-lived and they record preferential fluid migration along specific pathways, which developed at the downcurrent sidewalls of pockmarks due to flow separation initiating “cavity flow” within the pockmarks. The durable specific migration paths include pockmark sidewalls, vertically stacked erosional-interface of sediment waves, or entire pockmark bodies. The vertical extent of both pockmark types from End Miocene to the present-day seafloor documents various intensities of episodic fluid bursts followed by periods of quiescence and fill.Hofmann, L.C., Heesch, S., 2018. Latitudinal trends in stable isotope signatures and carbon-concentrating mechanisms of northeast Atlantic rhodoliths. Biogeosciences 15, 6139-6149. are free-living calcifying red algae that form extensive beds in shallow marine benthic environments (<250m), which provide important habitats and nurseries for marine organisms and contribute to carbonate sediment accumulation. There is growing concern that these organisms are sensitive to global climate change, yet little is known about their physiology. Considering their broad distribution along most continental coastlines, their potential sensitivity to global change could have important consequences for the productivity and diversity of benthic coastal environments. The goal of this study was to determine the plasticity of carbon-concentrating mechanisms (CCMs) of rhodoliths along a latitudinal gradient in the northeast Atlantic using natural stable isotope signatures. The δ13C signature of macroalgae can be used to provide an indication of the preferred inorganic carbon source (CO2 vs. HCO3?). Here we present the total (δ13CT) and organic (δ13Corg) δ13C signatures of northeast Atlantic rhodoliths with respect to changing environmental conditions along a latitudinal gradient from the Canary Islands to Spitsbergen. The δ13CT signatures (?11.9 to ?0.89) of rhodoliths analyzed in this study were generally higher than the δ13Corg signatures, which ranged from ?25.7 to ?2.8. We observed a decreasing trend in δ13CT signatures with increasing latitude and temperature, while δ13Corg signatures were only significantly correlated to dissolved inorganic carbon. These data suggest that high-latitude rhodoliths rely more on CO2 as an inorganic carbon source, while low-latitude rhodoliths likely take up HCO3? directly, but none of our specimens had ?13Corg signatures less than ?30, suggesting that none of them relied solely on diffusive CO2 uptake. However, depth also has a significant effect on both skeletal and organic δ13C signatures, suggesting that both local and latitudinal trends influence the plasticity of rhodolith inorganic carbon acquisition and assimilation. Our results show that many species, particularly those at lower latitudes, have CCMs that facilitate HCO3? use for photosynthesis. This is an important adaptation for marine macroalgae, because HCO3? is available at higher concentrations than CO2 in seawater, and this becomes even more extreme with increasing temperature. The flexibility of CCMs in northeast Atlantic rhodoliths observed in our study may provide a key physiological mechanism for potential adaptation of rhodoliths to future global climate change.Hong, S.K., Shinn, Y.J., Choi, J., Lee, H.S., 2018. Estimation of original kerogen type and hydrogen index using inorganic geochemical proxies: Implications for assessing shale gas potential in the Devonian Horn River Formation of western Canada. American Association of Petroleum Geologists Bulletin 102, 2075-2099. attention has been directed to the Devonian Horn River Formation in western Canada with respect to geochemical evaluation of gas-generation and storage potential. Because organic geochemical analyses are not always useful for characterizing the type and amount of original organic matter, we surmise the original kerogen type and original hydrogen index (HIo) and subsequently estimate a reliable original total organic carbon (TOCo) based on a combination of inorganic and organic geochemical data. Productivity (SiO2 and Ba) and terrestrial input (Al2O3, Hf, Nb, and Zr) proxies are used to estimate original kerogen types, which suggest that the Evie and Muskwa Members formed under conditions of high productivity and minor terrestrial input. These members also formed under reducing conditions, as indicated by the redox proxies (Mo, U, and Th/U). Under such conditions, primarily type II kerogen was preserved.By considering the fraction of biogenic silica, the estimated HIo values (400–500 mg hydrocarbon/g total organic carbon [TOC]) for the middle Otter Park Member are lower than that for Evie and Muskwa Members and higher than the upper and lower Otter Park Member. The stronger correlation between TOCo and trace elements suggests that HIo is useful for reconstructing the coherent variation in TOCo. Based on the original kerogen type and TOCo, the gas-generation and storage potentials of the Evie, middle Otter Park, and Muskwa Members are higher than those of other members. The source-rock potential is excellent for the Evie Member with an approximately 75% difference between TOCo and measured present-day TOC.Hou, H., Shao, L., Li, Y., Li, Y.-n., 2018. Physical properties of coalbed methane reservoirs and favourable exploration areas in the northern Qaidam Basin, NW China. International Journal of Oil, Gas and Coal Technology 19, 357-377. and coalbed methane (CBM) resources are abundant in the northern Qaidam Basin, northwestern China. Physical properties of a total of 57 coal samples were characterised utilising methods of low-temperature nitrogen adsorption, mercury porosimetries, and microfracture statistics. The results show that transitional pores, mesopores and macropores (10-104 nm in size) of the coal reservoir were found the most developed. Additionally, as maximum vitrinite reflectance (Ro,max) increases, the volume of micropores shows an increasing trend while the volume of transitional pores and other pores shows a decreasing trend. Microfracturing density of the coal reservoirs is generally more developed in deformed coal and higher brightness coal, which is also influenced by Ro,max and macerals. Centred on multi-level fuzzy optimisation, the Yuqia Coalfield is found to be the most suitable for CBM exploration and development in the northern Qaidam Basin, followed by the Saishiteng Coalfield, Quanji Coalfield, and Delingha Coalfield.Hu, D., Wei, Z., Liu, R., Fan, Z., Han, J., 2018. Development characteristics and shale gas exploration potential of the Lower Carboniferous black shale in the Guizhong Depression. Natural Gas Industry 38, 28-37. Carboniferous shale in the Guizhong Depression of central Guangxi presents good exploration potential of shale gas, but its exploration effectiveness is restricted by the unclear distribution, quality and potential of high-quality shale. In this paper, the Lower Carboniferous Luzhai shale was taken as the research object in order to guide the exploration of Carboniferous shale gas in the Guizhong Depression. Based on the field outcrops, well drilling, well logging and test data of the Guizhong Depression and its surrounding areas, the shale formation was studied systematically based on the characteristics of distribution, organic geochemistry and reservoir, and the preservation conditions. Then, the development characteristics of black shale were confirmed and the distribution laws of high-quality shale were summarized. Finally, shale gas exploration was analyzed and the favorable exploration areas were defined. And the following research results were obtained. First, the Luzhai Fm shale in the Guizhong Depression is mainly carbonaceous shale and siliceous shale of deepwater continental shelf facies. Second, the high-quality Luzhai shale is 20–60 m thick and it is characterized by high total organic carbon, good type of organic matters, moderate maturity of organic matter, high content of brittle minerals, good reservoir property and developed pores of organic matters. Third, regional caprocks and roofs & floors are well developed in the Liucheng Slope and the Yishan Sag. They are weakly deformed, suffer from less uplift and denudation, and are far away from the strong strike–slip reverse fault, so they have good preservation conditions. Fourth, shallow wells which were drilled in the surface structures of the Guizhong Depression in the early stage present abundant gas shows, and most of them produce gas flow, which reveals a promising prospect of shale gas exploration in this area. In conclusion, the wide and gentle synclines with large burial depth in the Liucheng Slope and the Yishan Sag are the favorable areas for shale gas exploration in the Guizhong Depression.Hu, G., Yang, R., Wang, L., Hu, W., Cao, J., 2019. Hydrocarbon potential and depositional environment of the Lower Cretaceous black mudstones and shales in the coastal Guangdong Province, China. Marine and Petroleum Geology 99, 92-106. Mesozoic (especially the Cretaceous) sequences in the northern South China Sea (SCS) are important potential targets of oil and gas exploration; however, they are currently poorly understood. We use organic petrology and geochemistry to evaluate the hydrocarbon potential and study depositional environment of the Cretaceous black mudstones and shales from the Dayawan Section in the Guangdong Province, China. These mudstones and shales yield total organic carbon (TOC) contents of 0.63%–2.76% and most samples meet the requirement for higher TOC source rocks. Organic matters in the mudstones and shales were sourced mainly from higher plants as well as subordinate benthic macroalgae. Organic petrology and geochemical data suggested that the organic matters were dominated by Type-III and minor Type-II, and generally have low thermal maturity. Thus, we evaluated the black mudstones and shales have a potential for hydrocarbon generation (especially gas prone). Pr/Ph, trace elements, and mixture source of organic matter suggested that these black mudstones and shales formed in a coastal–lacustrine environment, characterized by weakly oxidizing?weakly reducing conditions and low-salinity. A marine transgression developing in the middle part of the section was recognized. Generally, the northern SCS, which exhibits the more marine influence, likely contains source rocks with higher TOC contents and better organic matter types. The Cretaceous source rocks with higher liquid hydrocarbon generation potential may occur locally in the Pearl River Mouth Basin.Hu, S.K., Connell, P.E., Mesrop, L.Y., Caron, D.A., 2018. A hard day's night: Diel shifts in microbial eukaryotic activity in the North Pacific subtropical gyre. Frontiers in Marine Science 5, 351. doi: 10.3389/fmars.2018.00351. analysis revealed diel rhythmicity in the metabolic activity of single-celled microbial eukaryotes (protists) within an eddy in the North Pacific Subtropical Gyre (ca. 100 km NE of station ALOHA). Diel trends among different protistan taxonomic groups reflected distinct nutritional capabilities and temporal niche partitioning. Changes in relative metabolic activities among phototrophs corresponded to the light cycle, generally peaking in mid- to late-afternoon. Metabolic activities of protistan taxa with phagotrophic ability were higher at night, relative to daytime, potentially in response to increased availability of picocyanobacterial prey. Tightly correlated Operational Taxonomic Units throughout the diel cycle implicated the existence of parasitic and mutualistic relationships within the microbial eukaryotic community, underscoring the need to define and include these symbiotic interactions in marine food web descriptions. This study provided a new high-resolution view into the ecologically important interactions among primary producers and consumers that mediate the transfer of carbon to higher trophic levels. Characterizations of the temporal dynamics of protistan activities contribute knowledge for predicting how these microorganisms respond to environmental forcing factors.Hu, X., Liu, J., Liu, H., Zhuang, G., Xun, L., 2018. Sulfur metabolism by marine heterotrophic bacteria involved in sulfur cycling in the ocean. Science China Earth Sciences 61, 1369-1378. cycling in the biosphere is tightly interwoven with the cycling of carbon and nitrogen, through various biological and geochemical processes. Marine microorganisms, due to their high abundance, diverse metabolic activities, and tremendous adaptation potential, play an essential role in the functioning of global biogeochemical cycles and linking sulfur transformation to the cycling of carbon and nitrogen. Currently many coastal regions are severely stressed by hypoxic or anoxic conditions, leading to the accumulation of toxic sulfide. A number of recent studies have demonstrated that dissimilatory sulfur oxidation by heterotrophic bacteria can protect marine ecosystems from sulfide toxicity. Sulfur-oxidizing bacteria have evolved diverse phylogenetic and metabolic characteristics to fill an array of ecological niches in various marine habitats. Here, we review the recent findings on the microbial communities that are involved in the oxidation of inorganic sulfur compounds and address how the two elements of sulfur and carbon are interlinked and influence the ecology and biogeochemistry in the ocean. Delineating the metabolic enzymes and pathways of sulfur-oxidizing bacteria not only provides an insight into the microbial sulfur metabolism, but also helps us understand the effects of changing environmental conditions on marine sulfur cycling and reinforces the close connection between sulfur and carbon cycling in the ocean.Huang, H., Sun, W., Ji, W., Chen, L., Jiang, Z., Bai, Y., Tang, X., Du, K., Qu, Y., Ouyang, S., 2018. Impact of laminae on gas storage capacity: A case study in Shanxi Formation, Xiasiwan Area, Ordos Basin, China. Journal of Natural Gas Science and Engineering 60, 92-102. order to clarify the influence of laminae on the gas storage capacity of the delta?front shales, this study separates the bright laminae with the dark one in the six samples from the Lower Permian Shanxi Formation, Xiasiwan Area, Ordos Basin. Various analyses are subsequently implemented, including He?porosity test, XRD test, TOC test, N2 adsorption analysis, rock?eval pyrolysis analysis, free gas test and isothermal adsorption test. It is demonstrated that the dark laminae are muddy, while the bright ones are silty. Moreover, the total gas storage capacity reaches maximum when the bright laminae account for a proportion of about 46%. The free gas storage capacity increases with porosity, but decreases with water saturation, which is negatively correlated with TOC abundance and positively correlated with laminae thickness standard deviation. As for the absorbed gas storage capacity, it increases with TOC abundance. But in the muddy laminae, TOC abundance significantly varies. With the increasing proportion of silty laminae, the free gas storage capacity increases, and it is also controlled by water saturation influenced by the TOC abundance and the laminae thickness standard deviation. As the main factor controlling adsorbed gas storage capacity, TOC abundance tends to decrease with the increasing proportion of silty laminae. However, the decreasing trend of absorbed gas storage capacity with the increasing proportion of silty laminae is not that obvious due to the significantly varying TOC abundance per unit thickness of silty and muddy laminae.Huang, S., Chen, X., Liu, H., Xia, Y., Jiang, J., Cao, M., Li, A., Yang, M., 2019. Experimental and numerical study of steam-chamber evolution during solvent-enhanced steam flooding in thin heavy-oil reservoirs. Journal of Petroleum Science and Engineering 172, 776-786. flooding (SF) is an effective technology to exploit thin heavy-oil reservoirs. Long-term indoor experiments and field tests, however, show that SF has the problems of great heat loss and a limited steam-chamber affected area, which severely limits steam utility and the ultimate economic benefit of thin heavy-oil reservoirs. In this paper, based on a specific oil field in China, we designed a two-dimensional experimental model to investigate the effect of solvents on steam-chamber distribution and production dynamics, and the effect of heat-solvent coupling (molar ratio of steam and solvent) on steam-chamber front expansion. Then, based on the parameters of indoor experiments, we built a numerical model by CMG STARS to further study the influence of solvent migration in steam chambers under different injection molar ratios of steam and solvent. The results show that: i) According to experimental results, for SF, steam-chamber affected area is limited and oil recovery is low which is only 21.3%. After the solvent is added, steam-chamber affected area can be largely enlarged and displacement efficiency can be enhanced. Compared with SF, oil recovery of Solvent-Enhanced Steam Flooding (SESF) can be enhanced to 34.3%–58.3%; ii) According to the results of the numerical simulation, oil viscosity can be greatly reduced after the solvent is added. As a result, steam-chamber expansion can be improved, steam-chamber affected area can be enlarged, and displacement efficiency can be enhanced; iii) the optimal injection molar ratio of steam and solvent was around 8:1 for SESF.Huang, X., Hu, G., Meng, Q., Zheng, X., 2018. Impact performance optimization of a YDC valve-type double action hydraulic hammer. Natural Gas Industry B 5, 425-433. YDC type hydraulic hammer is a new valve-type double action hydraulic hammer suitable for oil and gas well drilling. It is hard to find out the optimal matching relationship among various factors based on experience and experiments, for the matching relationships of inner pressure is complex and the impact performance is influenced by many factors. In this paper, the operating principle of a YDC type hydraulic hammer was investigated, the force applied to the main moving components (valve core and hammer) was analyzed and a dynamic model of valve core and hammer in each operating stage was established. Then, a hydraulic hammer performance optimization design software was developed on the Matlab software platform, and the performance parameters calculated by the software were compared with the laboratory test results. The following research results were obtained. Firstly, single impact energy, impact frequency and impact power increase with the increase of pump displacement or the decrease of flow bean diameter, and they increase firstly and then decrease with the increase of area difference between the upper and lower chambers. Secondly, with the increase of hammer weight, single impact energy and impact power increase, but the impact frequency decreases slowly. Thirdly, with the increase of hammer travel, single impact energy presents an increasing trend, impact frequency presents a decreasing trend and impact power basically remains unchanged. Fourthly, with the increase of valve core weight, single impact energy presents an increasing trend, while both impact frequency and impact power decrease. Fifthly, the parameter combination corresponding to the optimal single impact energy and impact power is A5B1C5D4E3F2, and the effect of displacement on single impact energy and impact power is the greatest. It is concluded that under the existing displacement and pressure of drilling pumps, the impact performance of the hydraulic hammer can be increased effectively by improving the structure of the hydraulic hammer and thus increasing its work displacement.Huang, Y., Chen, Z.-Q., Algeo, T.J., Zhao, L., Baud, A., Bhat, G.M., Zhang, L., Guo, Z., 2019. Two-stage marine anoxia and biotic response during the Permian–Triassic transition in Kashmir, northern India: pyrite framboid evidence. Global and Planetary Change 172, 124-139. expanded ocean anoxia has long been believed to be a direct killing mechanism causing mortality of organisms during the Permian-Triassic mass extinction, little has been published on the extent and timing of this anoxia in Gondwana. The Guryul Ravine section in Kashmir, northern India, is a classic Permian–Triassic boundary (PTB) section containing high-quality marine sedimentary and fossil records, and thus provides a unique opportunity to study the redox conditions associated with the biotic crisis in the Gondwana region. Here, high-resolution biotic and redox data were generated from Kashmir to achieve an improved understanding of the nature of environmental stresses associated with the Earth's largest biocatastrophe. Our study, which evaluates pyrite framboid size and morphology, reveals two pronounced stages of oceanic oxygen deficiency, in the assigned latest Permian Hindeodus praeparvus–Clarkina meishanensis Zone and the earliest Triassic Isarcicella staeschei Zone. Updated marine invertebrate fossil records show three sharp species richness declines at Guryul Ravine. The first decline occurred within uppermost Permian storm beds and is interpreted to represent a facies control, in which a storm-agitated environment was inhospitable for benthos. The latter two biotic declines coincided with two marine anoxic events, as documented by pyrite framboid size distributions. The same two anoxic events are also recognized from PTB beds in the adjacent, relatively shallower Barus Spur section in Kashmir, in which newly obtained faunal data help to constrain placement of the PTB. The present study represents a new report of the two-stage pattern of oceanic anoxia during the Permian–Triassic transition. We propose that the two anoxic events at Guryul Ravine correlate precisely with anoxic events in the Meishan GSSP and some sections in South China, suggesting that this event sequence might have been characteristic of the Permian–Triassic transition in some specific geological settings. The close relationship between oxygen depletion and species richness decline suggests that the former were an important contributor to the latter. In addition, we find that many framboids exhibit surface oxidation, reducing their overall size. However, our statistical analysis suggests that the mean oxidation-related reduction in size is <2.2%, thus having little effect on redox interpretations based on pyrite framboid sizes. Our results demonstrate that, unlike many geochemical proxies, the pyrite framboid technique is still valid for redox interpretations of weathered samples.Hui, R., Ding, A., 2018. Role of microorganisms in oil generation (II): Hydrogen metabolism and organic matter input from many origins. Acta Sedimentologica Sinica 26, 1023-1031 discovery of H2-producing bacteria is a great advance in modern scientific research of microbiology. The hydrogen supersession (the generation and utilization of hydrogen) is the important link for microbially degradation of organic matters and generation of hydrocarbons in geological systems. During the progress of petroleum-formation, hydrogen is a middle product and also a major product. Addition of extra hydrogen is necessary all for the degradation of macromolecular compounds into low molecule ones, the elimination of oxygen-containing groups and also the transformation of alkenes into saturated hydrocarbons. If there are no hydrogen supersession, there would be no abundant petroleum formed. H2-producing bacteria contain hydrogenase with the ability to generate hydrogen. Some kinds of microbes produce H2 in the process of organic matter degradation while others utilize H2 for their living, thus for both the production and utilization of hydrogen can be always kept on a steady dynamic equilibrium. Only when H2-expending microbial existed, those of H2-producing can be grown up. H2-expending function of the bacteria can further improve the continuous reaction of hydrogen production. Those mutualistic symbioses can take place in every stage of petroleum formation. Hydrogen transformation is one of the most important characteristics to distinguish anaerobic decomposition of organic matters from aerobia ones.The growth and breeding of microbial are influenced under temperature, nutrient and sedimentary environments. Microbial populations are replaced unceasingly from shallow to deep layers, of which the primary population died and disappeared for the change of living conditions and new bacteria might be multiplied in a great quantity. Those died microorganisms can be deposited into sedimentary layers and then transformed into hydrocarbons.The enzyme is one protein with catalytic activity, from which all life actions of microbes can not be available. One kind of enzyme can only catalyze one certain reaction and/or complicate one kind of reactions, of which there is unique enzyme system at every stage. The enzyme might be also transformed into petroleum component after its special metabolism routing complicated. Such as chlorophyll can be transformed into F430-coenzyme of methanogen,and then converted to porphyrin compounds.The stratigraphic geothermal can promote the thermosplitting decomposition of organic matters and result in the breaking of C-C bond much more frequently. In addition, the degradation by anaerobic activity might also be able to improve the degradation of organic matters. Both two different pathways are unanimous, each other and cooperative to speed up the splitting decomposition of organic matters. The function of hydrocarbons formation through reform and/or transformation of organic matters by microbes also include the elimination of oxygen containing groups, the production and utilization of hydrogen to generate saturated hydrocarbons etc. and thus their significance could be much more important and comprehensive for discussion on the formation of crude oils and natural gases.Hyland, E.G., Huntington, K.W., Sheldon, N.D., Reichgelt, T., 2018. Temperature seasonality in the North American continental interior during the Early Eocene Climatic Optimum. Climate of the Past 14, 1391-1404. greenhouse climate equability has long been a paradox in paleoclimate research. However, recent developments in proxy and modeling methods have suggested that strong seasonality may be a feature of at least some greenhouse Earth periods. Here we present the first multi-proxy record of seasonal temperatures during the Paleogene from paleofloras, paleosol geochemistry, and carbonate clumped isotope thermometry in the Green River Basin (Wyoming, USA). These combined temperature records allow for the reconstruction of past seasonality in the continental interior, which shows that temperatures were warmer in all seasons during the peak Early Eocene Climatic Optimum and that the mean annual range of temperatures was high, similar to the modern value (?～?26°C). Proxy data and downscaled Eocene regional climate model results suggest amplified seasonality during greenhouse events. Increased seasonality reconstructed for the early Eocene is similar in scope to the higher seasonal range predicted by downscaled climate model ensembles for future high-CO2 emissions scenarios. Overall, these data and model comparisons have substantial implications for understanding greenhouse climates in general, and may be important for predicting future seasonal climate regimes and their impacts in continental regions.?nan, S., Al Badairy, H., ?nan, T., Al Zahrani, A., 2018. Formation and occurrence of organic matter-hosted porosity in shales. International Journal of Coal Geology 199, 39-51. within organic matter (OM) is considered to be the main site for gas storage (via fluid phase saturation of the pores and sorption on the pore walls) and thus its presence or absence is very critical for in-place gas assessment for organic-rich rocks. Numerous workers have suggested that OM-hosted porosity increases with thermal maturity mainly related to the process of bituminized organic matter cracking to gas. Comprehensive reviews of published literature enable us to conclude that organic porosity dominantly develops within bituminized organic matter (i.e., that portion that is petrographically identified, mainly based on its morphology, as solid bitumen (Mastalerz et al., 2018)) and primary (i.e, structured or amorphous) organic matter (kerogen) is mostly deficient in porosity. We show that in the same shale sample, structured kerogen shows no porosity whereas solid bitumen contains abundant porosity. It has been previously reported that sample preparation for SEM by ion milling may alter the organic matter. In this study, some adverse effects of ion milling have been observed by comparing SEM-visible pores of the same sample prepared by mechanical grind polish (MGP) and ion milling (IM) methods. Since solid bitumen is more labile, and probably more prone to chemical/physical alterations, we recommend that SEM observations of ion milled samples to be conducted with more attentiveness. We show that 1) MGP is a suitable sample preparation method for SEM observations, 2) the overwhelming majority of SEM-visible organic matter-hosted pores develop within solid bitumen and not in structured organic matter (kerogen), and 3) we reaffirm that shale mineral content is a key factor in preservation or destruction of solid bitumen-hosted porosity. Finally, we propose a conceptual model for the formation, preservation and destruction of OM-hosted porosity for shales. Accordingly, we suggest that, all other factors being equal, a quartz-rich brittle shale will preserve more SEM-visible solid bitumen-hosted (meso and micro) porosity compared to that of a clay-rich ductile shale. Therefore, gas storage capacity of a quartz-rich shale will be relatively high compared to that of a clay-rich shale.Ishikawa, N.F., Itahashi, Y., Blattmann, T.M., Takano, Y., Ogawa, N.O., Yamane, M., Yokoyama, Y., Nagata, T., Yoneda, M., Haghipour, N., Eglinton, T.I., Ohkouchi, N., 2018. Improved method for isolation and purification of underivatized amino acids for radiocarbon analysis. Analytical Chemistry 90, 12035-12041. have improved a method for isolation and purification of individual amino acids for compound-specific radiocarbon analysis (CSRA). To remove high-performance liquid chromatography (HPLC) eluent blanks from isolated amino acid fractions prior to the radiocarbon (Δ14C) measurement, each fraction was filtered through a membrane filter and then washed with diethyl ether twice. Radiocarbon measurements on standard amino acids processed and purified with the above method using elemental analyzer–accelerator mass spectrometry resulted in Δ14C values that were in strong agreement (R2 = 0.998) with the original Δ14C value of each amino acid standard. From these measurements, we calculate dead and modern carbon contamination contributions as 1.2 ± 0.2 and 0.3 ± 0.1 μgC, respectively, which are consistent with direct assessments of HPLC procedural blanks of 1.0 ± 0.8 μgC per sample. These contamination constraints allow correction of measured Δ14C values for accurate and precise CSRA and are widely applicable to future archeological and biogeochemical studies.Jahediesfanjani, H., Warwick, P.D., Anderson, S.T., 2018. Estimating the pressure-limited CO2 injection and storage capacity of the United States saline formations: Effect of the presence of hydrocarbon reservoirs. International Journal of Greenhouse Gas Control 79, 14-24. U.S. Geological Survey (USGS) national assessment of carbon dioxide (CO2) storage capacity evaluated 192 saline Storage Assessment Units (SAUs) in 33 U.S. onshore sedimentary basins that may be utilized for CO2 storage (see USGS Circular 1386). Similar to many other available models, volumetric analysis was utilized to estimate the initial CO2 injection and storage capacity of these SAUs based on aquifer characteristics and buoyant and residual trapping. The factor being almost always overlooked in most CO2 storage capacity models is that many of the evaluated SAUs contain large numbers of both conventional and unconventional discovered and undiscovered oil and gas reservoirs. The hydrocarbon production and pressure distribution of the resident oil and gas reservoirs may be negatively influenced by the propagated CO2 plume and pressure front resulting from a CO2 injection and storage operation in the surrounding SAU. To have a more realistic and accurate estimation of CO2 injection and storage capacity in saline formations, a model was previously developed that considers the CO2 injectivity of a given formation, underground pressure build-up limitations imposed by the rock fracturing pressure and the presence of hydrocarbon reservoirs within these aquifers. The developed method estimates the pre–brine extraction, pressure-limited CO2 injection and storage capacity of a saline formation by applying 3D numerical simulation only on the effective injection area (Aeff) surrounding each CO2 injection well utilizing TOUGH2-ECO2N simulation software.Ji, Y., Hou, Y., Ren, S., Yao, C., Wu, W., 2018. Tetraethylammonium amino acid ionic liquids and CO2 for separation of phenols from oil mixtures. Energy & Fuels 32, 11046-11054. have wide applications and much commercial value, and they are obtained from oil mixtures by separation. However, the previous separation agents have low separation efficiency or corrosive halide ions or are difficult to be regenerated. In this work, we designed several tetraethylammonium amino acid (TAAA) ionic liquids (ILs) without corrosive halide ions and found that the ILs could separate phenols from oil mixtures with much higher extraction efficiency and could be regenerated using CO2. The effects of separation time, initial phenol content, TAAA type, water content in TAAA, and phenol type on separation were investigated. It has been found that TAAA can separate phenols with high separation efficiencies, and the maximum separation efficiency of phenol can reach up to 99.0% at a TAAA:phenol mole ratio of 0.60. Meanwhile, ultimate phenol contents can reach as low as 1.40 g/dm3. The initial phenol content almost has no influence on the ultimate phenol contents. For real coal tar oil mixtures, the separation efficiency of phenols can reach up to 98.6%. The TAAAs can be regenerated and reused without significant decreases in separation efficiency of phenols. The separation mechanism has also been proposed based on chemical reactions.Ji, Z., Zhang, H., Liu, H., Yaghi, O.M., Yang, P., 2018. Cytoprotective metal-organic frameworks for anaerobic bacteria. Proceedings of the National Academy of Sciences 115, 10582-10587. Significance: Culturing bacteria to produce desired chemicals has long been practiced in human history, and has recently being taken as a promising approach to sustainable energy when this process is driven by sunlight and fed by CO2 as the only carbon source. Among these chemical-producing microbes are anaerobic bacteria, inherently susceptible to O2 and reactive oxygen species that are inevitably generated on anodes. Here, we provide cytoprotection against such oxidative stress by wrapping bacteria with an artificial material, metal-organic frameworks (MOFs), which significantly enhances the lifetime of anaerobes in the presence of O2, and maintains the continuous production of acetic acid from CO2. The ultrathin nature of the MOF layer allows for cell reproduction without loss of this cytoprotective material.Abstract: We report a strategy to uniformly wrap Morella thermoacetica bacteria with a metal-organic framework (MOF) monolayer of nanometer thickness for cytoprotection in artificial photosynthesis. The catalytic activity of the MOF enclosure toward decomposition of reactive oxygen species (ROS) reduces the death of strictly anaerobic bacteria by fivefold in the presence of 21% O2, and enables the cytoprotected bacteria to continuously produce acetate from CO2 fixation under oxidative stress. The high definition of the MOF–bacteria interface involving direct bonding between phosphate units on the cell surface and zirconium clusters on MOF monolayer, provides for enhancement of life throughout reproduction. The dynamic nature of the MOF wrapping allows for cell elongation and separation, including spontaneous covering of the newly grown cell surface. The open-metal sites on the zirconium clusters lead to 600 times more efficient ROS decomposition compared with zirconia nanoparticles.Jiang, H.-X., Li, J., Tang, J., Mo, Y.-Z., Zhang, G., 2018. Applications of high-resolution mass spectrometry in studies of brown carbon. Chinese Journal of Analytical Chemistry 46, 1528-1538. carbon is a hotspot in the field of atmospheric carbonaceous aerosol research. It has significant influence on regional radiative forcing and exerts climatic effects due to its apparent absorbance in the near ultraviolet-visible region. Brown carbon is mainly derived from incomplete combustion of biomass or coal, as well as secondary sources, such as a series of atmospheric photochemical reactions from volatile organic compounds. Although the composition of brown carbon is complex, high-resolution mass spectrometry, with its ultra-high mass resolution and precision, enables elucidation of the characteristics of the organic components of brown carbon at the molecular level. Here, high-resolution mass spectrometry combined with traditional analytical methods was used for the study of brown carbon. The development of high-resolution mass spectrometry for brown carbon separation is reviewed, as well as compositional analysis, source apportionment, and formation mechanism of brown carbon based on high-resolution data. In addition, the issues and prospects for the application of high-resolution mass spectrometry to evaluate brown carbon are discussed.Jiang, S., Mokhtari, M., 2019. Characterization of marl and interbedded limestone layers in the Eagle Ford Formation, DeWitt county, Texas. Journal of Petroleum Science and Engineering 172, 502-510. Eagle Ford Formation in Texas, USA is composed of marl and interbedded limestone sequences with intermittent layers of volcanic ash. To optimize hydrocarbon recovery from such a heterogeneous formation, it is necessary to have a better understanding of the effects of each individual marl and limestone layer on reservoir properties. The objective of this paper is to characterize and quantify properties of marl and limestone layers in the Eagle Ford Formation, in terms of spectral core gamma ray, elemental concentrations, lithology and organic richness. Moreover, the differences between these layers in micro-scale level were shown through the scanning electron microscope (SEM) images. XRF results show that concentrations of Al2O3, Fe2O3, Mo, and Zr in marl layers were more than 40% higher than in the interbedded limestone layers. The Eagle Ford samples fall into two groups in the ternary plot. Limestone layers contain calcite content ranging from 55% to 90% and clay content ranging from 5% to 30%, while marl layers contain 30%–70% calcite and around 20%–50% clay. Marl layers have better generative potential than the limestone layers in the Eagle Ford Formation. Moreover, estimation of total organic carbon of the Eagle Ford Formation using Passey's Δlog R method with a correction factor was provided and validated with lab measured data.Jiang, S., Wang, Y., Wang, S., Peng, P., Dong, D., Wu, W., Li, X., Guan, Q., 2018. Distribution prediction of graphitized organic matter areas in the lower Cambrian Qiongzhusi shale in the Central Sichuan paleo-uplift and its surrounding areas in the Sichuan Basin. Natural Gas Industry 38, 19-27. Organic matter graphitization is one of the main reasons for the poor results of shale gas exploration in some areas in China. At present, however, the graphitization degree of organic matter, the lower limit of depth and the main geological reasons for organic matter graphitization are still unclear. In this paper, the Lower Cambrian Qiongzhusi Fm in the central Sichuan paleo-uplift and its surrounding areas were taken as the main research objects. The electric characteristics study of organic matter graphitization were carried out on the Qiongzhusi shale by using resistivity log response and laser Raman spectroscopy. On this basis, the lower depth limit and distribution range of graphitized organic matter were predicted so as to provide a basis for the selection of shale gas exploration areas. And the following research results were obtained. First, The resistivity log of the shale in the high part of Central Sichuan paleo-uplift is normally flat, and there is no G' peak in Raman spectra of organic matter, indicating no organic matter is graphitized. Second, the resistivity of shale below 5 200 m in the Lower Cambrian aulacogen area is low, G' peak occurs in Raman spectra and Ro is over 3.5%. It is indicated that the organic matter below 5 200 m in this area has been graphitized, but its degree of graphitization is lower than that in the Changning area. Third, the lower depth limit of the graphitization of organic matter varies greatly (4 000–4 600 m) in Weiyuan–Ziyang area, but stays stable (about 5 200 m) in the Moxi–Gaoshiti area. In conclusion, the organic matter in Qiongzhusi Fm shale in the most parts of the Central Sichuan paleo-uplift in the Sichuan Basin has been graphitized, so it is unfavorable for shale gas exploration. In addition, the Weiyuan–Ziyang and Moxi–Gaoshiti areas are non-graphitized areas and they present good prospects of shale gas exploration.Jing, Z., Mahoney, S.A., Rodrigues, S., Balucan, R.D., Underschultz, J., Esterle, J.S., Rufford, T.E., Steel, K.M., 2018. A preliminary study of oxidant stimulation for enhancing coal seam permeability: Effects of sodium hypochlorite oxidation on subbituminous and bituminous Australian coals. International Journal of Coal Geology 200, 36-44. oxidation is proposed as an effective means to react and dissolve small regions of coal in the near wellbore region, thereby raising permeability for gas flow. In this study, we investigated the effect of sodium hypochlorite (NaClO) treatment on the structure of bituminous coal (Coal B) and subbituminous coal (Coal S) separately from the Bowen and Surat basins in Queensland, Australia. Swelling and leaching tests showed that both coals swelled, dissolved and broke in 5%wt. aqueous solutions of NaClO. Coal S reacted more vigorously in 5% NaClO, with 49% mass loss and 3840?mg/L of dissolved organic carbon (DOC) measured in the oxidant filtrate, than Coal B. The Coal B mass loss in 5% NaClO was 4.5% with 430?mg/L DOC measured in the filtrate. After NaClO treatment the total accessible pore volume of Coal S particles increased from 4.6% to 6.1%, and the porosity of Coal B increased from 8.6% to 8.9%. Pore size distributions determined from mercury intrusion porosimetry (MIP) indicated that oxidation enlarged the pores in Coal S more significantly than Coal B. Scanning electron microscopy (SEM) confirmed oxygen generated large pores on the surface of Coal S particles, but there were no significant changes on Coal B. We used a microfluidic cleat flow cell (CFC) to inject NaClO into artificial channels scribed in polished samples of Coal S and Coal B, and measured an increase in the widths of the channels after NaClO treatment. The increase in channel width observed in the CFC indicated that coal solubilisation was a more dominant mechanism than coal swelling. Similarly, the channel aperture of Coal S increased more than Coal B. CFC results also showed that NaClO etched dull coal bands (inertinite-rich) more significantly than bright coal bands (vitrinite-rich), and we proposed this result was due to the greater porosity in semi-fusinite, which allowed greater penetration of NaClO in dull coal bands than in bright coal bands. The low coal rank sample (Coal S) with higher liptinite content and more oxygen content was more susceptible to oxidisation by NaClO than Coal B.Johnson, T.B., Mach, C., Grove, R., Kelly, R., Van Cott, K., Blum, P., 2018. Secretion and fusion of biogeochemically active archaeal membrane vesicles. Geobiology 16, 659-673. belonging to the genus Metallosphaera oxidize sulfidic minerals. These organisms thrive at temperature extremes and are members of the archaeal phylum Crenarchaeota. Because they can employ a lithoautotrophic metabolism, energy availability likely limits their activity raising questions about how they conduct biogeochemical activity. Vesicles are membrane encapsulated structures produced by all biological lineages but using very different mechanisms. Across the Crenarchaeota, it has been proposed that a eukaryotic‐like Endosomal Sorting Complex Required for Transport system promotes formation of these structures but in response to unknown signals and for undefined purposes. To address such questions, Metallosphaera sedula vesicle formation and function were studied under lithoautotrophic conditions. Energy deprivation was evaluated and found to stimulate vesicle synthesis while energy excess repressed vesicle formation. Purified vesicles adhered rapidly to the primary copper ore, chalcopyrite, and formed compact monolayers. These vesicle monolayers catalyzed iron oxidation and solubilization of mineralized copper in a time‐dependent process. As these activities were membrane associated, their potential transfer by vesicle fusion to M. sedula cells was examined. Fluorophore‐loaded vesicles rapidly transferred fluorescence under environmentally relevant conditions. Vesicles from a related archaeal species were also capable of fusion; however, this process was species‐specific as vesicles from different species were incapable of fusion. In addition, vesicles produced by a copper‐resistant M. sedula cell line transferred copper extrusion capacity along with improved viability over mutant M. sedula cells lacking copper transport proteins. Membrane vesicles may therefore play a role in modulating energy‐related traits in geochemical environments by fusion‐mediated protein delivery. Jones, M.T., Percival, L.M.E., Stokke, E.W., Frieling, J., Mather, T.A., Riber, L., Schubert, B.A., Schultz, B., Tegner, C., Planke, S., Svensen, H.H., 2018. Mercury anomalies across the Palaeocene-Eocene Thermal Maximum. Climate of the Past Discussions 2018, 1-35. magmatic events like the emplacement of the North Atlantic Igneous Province (NAIP) are often coincident with periods of extreme climate change such as the Palaeocene–Eocene Thermal Maximum (PETM). One proxy for volcanism in the geological record that is receiving increased attention is the use of mercury (Hg) anomalies. Volcanic eruptions are among the dominant natural sources of Hg to the environment; thus, elevated Hg/TOC values in the sedimentary rock record may reflect an increase in volcanic activity at the time of deposition. Here we focus on five continental shelf sections located around the NAIP in the Paleogene. We measured Hg, total organic carbon (TOC) concentrations, and δ13C values to assess how Hg deposition fluctuated across the carbon isotope excursion (CIE). We find a huge variation in Hg anomalies between sites. The Grane field in the North Sea, the most proximal locality to the NAIP analyzed, shows Hg concentrations up to 90,100ppb (Hg/TOC = 95,700ppb/wt%) in the early Eocene. Significant Hg/TOC anomalies are also present in Danish (up to 324ppb/wt%) and Svalbard (up to 257ppb/wt%) sections prior to the onset of the PETM and during the recovery period, while the Svalbard section also shows a continuous Hg/TOC anomaly during the body of the CIE. The combination with other tracers of volcanism, tephra layers and unradiogenic Os isotopes, at these localities suggests that the Hg/TOC anomalies reflect pulses of magmatic activity. In contrast, we do not observe clear Hg anomalies on the New Jersey shelf (Bass River) or the Arctic Ocean (Lomonosov Ridge). This large spatial variance could be due to more regional Hg deposition. One possibility is that phreatomagmatic eruptions and hydrothermal vent complexes formed during the emplacement of sills led to submarine Hg release, which is observed to result in limited distribution in the modern. The Hg/TOC anomalies in strata deposited prior to the CIE may suggest that magmatism linked to the emplacement of the NAIP contributed to the initiation of the PETM. However, evidence for considerable volcanism in the form of numerous tephra layers and Hg/TOC anomalies post-PETM indicates a complicated relationship between LIP volcanism and climate. Factors such as climate system feedbacks, changes to the NAIP emplacement style, and/or varying magma production rates may be key to both the onset and cessation of hyperthermal conditions during the PETM.Jongejans, L.L., Strauss, J., Lenz, J., Peterse, F., Mangelsdorf, K., Fuchs, M., Grosse, G., 2018. Organic matter characteristics in yedoma and thermokarst deposits on Baldwin Peninsula, west Alaska. Biogeosciences 15, 6033-6048. Arctic warming continues and permafrost thaws, more soil and sedimentary organic matter (OM) will be decomposed in northern high latitudes. Still, uncertainties remain in the quality of the OM and the size of the organic carbon (OC) pools stored in different deposit types of permafrost landscapes. This study presents OM data from deep permafrost and lake deposits on the Baldwin Peninsula which is located in the southern portion of the continuous permafrost zone in west Alaska. Sediment samples from yedoma and drained thermokarst lake basin (DTLB) deposits as well as thermokarst lake sediments were analyzed for cryostratigraphical and biogeochemical parameters and their lipid biomarker composition to identify the belowground OC pool size and OM quality of ice-rich permafrost on the Baldwin Peninsula. We provide the first detailed characterization of yedoma deposits on Baldwin Peninsula. We show that three-quarters of soil OC in the frozen deposits of the study region (total of 68Mt) is stored in DTLB deposits (52Mt) and one-quarter in the frozen yedoma deposits (16Mt). The lake sediments contain a relatively small OC pool (4Mt), but have the highest volumetric OC content (93kgm?3) compared to the DTLB (35kgm?3) and yedoma deposits (8kgm?3), largely due to differences in the ground ice content. The biomarker analysis indicates that the OM in both yedoma and DTLB deposits is mainly of terrestrial origin. Nevertheless, the relatively high carbon preference index of plant leaf waxes in combination with a lack of a degradation trend with depth in the yedoma deposits indicates that OM stored in yedoma is less degraded than that stored in DTLB deposits. This suggests that OM in yedoma has a higher potential for decomposition upon thaw, despite the relatively small size of this pool. These findings show that the use of lipid biomarker analysis is valuable in the assessment of the potential future greenhouse gas emissions from thawing permafrost, especially because this area, close to the discontinuous permafrost boundary, is projected to thaw substantially within the 21st century.Jubb, A.M., Botterell, P.J., Birdwell, J.E., Burruss, R.C., Hackley, P.C., Valentine, B.J., Hatcherian, J.J., Wilson, S.A., 2018. High microscale variability in Raman thermal maturity estimates from shale organic matter. International Journal of Coal Geology 199, 1-9. spectroscopy has recently received attention as a means to estimate thermal maturity of organic matter in petroleum generating source rocks to complement more traditional approaches such as vitrinite reflectance and programmed pyrolysis. While many studies have observed positive correlations between source rock thermal maturity and Raman spectral parameters, little attention has been given to the degree of variation in the Raman response across individual organic grains, especially for shales or mudrocks with highly dispersed organic matter. Here the spatial variation in Raman estimates of thermal maturity within individual organic grains is assessed from shales from the Boquillas, Marcellus, Niobrara, and Woodford Formations. The thermal maturity parameters extracted from Raman spectra can vary widely across distances of ≤5?μm within the same organic grain. These results illustrate the high degree of chemical heterogeneity inherent to the organic matter within these source rocks. Additionally, the spatial pattern of the Raman parameters, as revealed by 2D Raman mapping, imply that organic matter structure is influenced by associations with mineral surfaces within the surrounding rock matrix. Chemical heterogeneity and matrix effects directly impact the Raman response from these types of materials and thus the extracted thermal maturity estimate. These findings highlight the care which must be adopted when making Raman measurements of organic matter within source rock matrices, especially for samples which feature highly dispersed, heterogeneous organic matter as found in petroliferous mudrocks.Kanaujia, P.K., 2018. Gas chromatography - Petroleum and petrochemical applications☆, Reference Module in Chemistry, Molecular Sciences and Chemical Engineering. Elsevier. all other analytical techniques, gas chromatography has established itself as a powerful tool for the analysis of petroleum, refined petroleum products, natural gas, LPG, and petrochemicals. For these applications, GC based characterization relies on the range of methods available as standard test procedures or as laboratory-developed methods intended for research activities. The upstream petroleum industry uses GC for determining the various factors governing the nature and thermal maturity of the explored oils. Analysis of gases and hydrocarbons evolved from sedimentary rocks reveals valuable information about their origin, formation and thermal maturity. The GC plays a significant role in the downstream refining sector primarily in the refinery process optimizations and quality control of the finished products. It is extensively employed in the determination of refinery gases composition, quality control/custody transfers of different petrochemical feedstock streams and LPG. One of the prominent applications of GC includes determination of boiling range distribution of varying petroleum products and crude oils. In the case of crude oils, boiling point distribution is essential information about their refining characteristics and product yields. The residue obtained towards the end is regarded as necessary for the determination of the economics of the refinery processes. Determination of the hydrocarbon types, additives, oxygenates and sulfur in gasoline is the most critical application of GC and aimed at ascertaining the molecular level information about the gasoline. Various standard methods are adopted to furnish this valuable information; however, the applicability of GC beyond gasoline, that is, above 225°C is still a challenge. Multicolumn and multidimensional GC coupled with high resolution mass spectrometric detectors have potential in revealing the hydrocarbon types in the middle distillates, and gas-oil range. GC, owing to its versatility, is also an essential analytical tool in studying the environmental implications of the petroleum industry. Oil spill source identification and bioremediation are some well-known research areas that enormously employ GC for monitoring the fate of hydrocarbons. The article is aimed at highlighting the role of gas chromatography in petroleum and petrochemical characterization. ASTM methods have been discussed mainly in addition to mentioning the relevant ISO and IP methods wherever available. The availability of standard practices in this area has resulted in their adoption by different countries and utilizing them for refinery process controls, quality checks and ensuring compliance with the regulatory specifications of various finished products.Karakasidou, K., Nikolouli, K., Amoutzias, G.D., Pournou, A., Manassis, C., Tsiamis, G., Mossialos, D., 2018. Microbial diversity in biodeteriorated Greek historical documents dating back to the 19th and 20th century: A case study. MicrobiologyOpen 7, e00596. documents in archives, libraries, and museums often undergo biodeterioration by microorganisms. Fungi and less often bacteria have been described to advance paper staining, so called “foxing” and degradation of paper substrates. In this study, for the first time, the fungal and bacterial diversity in biodeteriorated paper documents of Hellenic General State Archives dating back to the 19th and 20th century has been assessed by culture‐dependent and independent methods. The internally transcribed spacer (ITS) region and 16S rRNA gene were amplified by PCR from fungal and bacterial isolates and amplicons were sequenced. Sequence analysis and phylogeny revealed fungal phylotypes like Penicillium sp., Cladosporium sp., Penicillium citrinum, Alternaria infectoria, Alternaria alternata, Epicoccum nigrum, and Penicillium chrysogenum which are often implicated in paper deterioration. Bacterial phylotypes closely related to known biodeteriogenic bacteria such as Bacillus spp., Micrococcus spp., Kocuria sp. in accordance with previous studies were characterized. Among the fungal phylotypes described in this study are included well‐known allergens such as Penicillium spp., Alternaria spp., and Cladosporium spp. that impose a serious health threat on staff members and scholars. Furthermore, fungal isolates such as Chalastospora gossypii and Trametes ochracea have been identified and implicated in biodeterioration of historical paper manuscripts in this study for the first time. Certain new or less known fungi and bacteria implicated in paper degradation were retrieved, indicating that particular ambient conditions, substrate chemistry, or even location might influence the composition of colonizing microbiota. Karayi?it, A.?., Mastalerz, M., Oskay, R.G., Buzkan, ?., 2018. Bituminous coal seams from underground mines in the Zonguldak Basin (NW Turkey): Insights from mineralogy, coal petrography, Rock-Eval pyrolysis, and meso-and microporosity. International Journal of Coal Geology 199, 91-112. Zonguldak Basin contains the main bituminous coal reserves of Turkey (ca 1.4 Gt), and several coal seams are mined in underground coal mines within the basin. This study focuses on coal petrography, mineralogy, Rock-Eval pyrolysis, and the meso-and microporosity characteristics of the coal samples collected from several Late Carboniferous (Pennsylvanian) bituminous coal seams in the basin. Forty channel samples were collected from various coal seams in underground mines at the Armut?uk, Zonguldak, and Amasra coalfields in the Zonguldak Basin. The studied coal samples have low total moisture contents (avg. 2.3%, on as-received basis), low total S contents (avg. 0.5%, on dry basis), and relatively high ash yields (avg. 21.2%, on dry basis). The random vitrinite reflectance values (0.69–1.21%) and gross calorific values (avg. 33.0?MJ/kg, on dry, ash-free basis) indicate that the coal samples are of high-volatile C bituminous to medium-volatile bituminous coal. Minerals identified by XRD in bulk coal samples are clay minerals (mainly kaolinite and rarely illite and chlorite), quartz, and carbonates (calcite, dolomite, and siderite). In a few samples, pyrite and feldspar were also identified. The SEM-EDX analyses performed on the carbon-coated polished blocks imply that the carbonate minerals are mainly epigenetic, whereas the silicate minerals are generally syngenetic in origin. The results of low-pressure N2 adsorption analysis indicate that the BET surface areas (1.1–5.5?m2/g) and mesopore volumes (0.003–0.011?cm3/g) vary within a wide range. The results of the low-pressure CO2 adsorption analyses show that micropores are abundant in the coal samples; however, the BET surface areas (10.41–78.11?m2/g) and micropore volumes (0.010–0.049?cm3/g) vary widely among the three coal mines and different coal seams. Our results suggest that variations in the mesopore characteristics are mainly controlled by mineral matter, while microporosity is controlled by a combination of organic matter (maceral compositions) and coal rank of the studied coal seams.Kashirtsev, V.A., 2018. Hydrocarbons occluded by asphaltenes. Russian Geology and Geophysics 59, 975-982. series of n-alkenes and dimethylalkanes with the odd or even number of carbon atoms in the molecule have been identified in chloroform extracts from the organic matter of Upper Paleozoic deposits of the Vilyui syneclise penetrated by the superdeep well SV-27 at depths below 5 km. It is presumed that these unusual hydrocarbons resulted from the destruction of asphaltene occlusions under severe P-T conditions at great depths and that the hydrocarbon generation began in the zone of postdiagenetic transformations of sediments. This hypothesis was tested in the sections of deposits whose organic matter underwent catagenesis of different grades. On the basis of these results, zones of emergence, transition, and destruction of occlusions have been recognized.Kashirtsev, V.A., Nikitenko, B.L., Peshchevitskaya, E.B., Fursenko, E.A., 2018. Biogeochemistry and microfossils of the Upper Jurassic and Lower Cretaceous, Anabar Bay, Laptev Sea. Russian Geology and Geophysics 59, 386-404. detailed analysis of organic matter from the Oxfordian-Lower Valanginian interval of the Nordvik section (Anabar Bay) allows the definition of three geochemical horizons (terpane, diasterene, and hopane), which are characterized by specific geochemical compounds and their ratios. These horizons are correlated with several stages in the evolution of microfossils associated with ecological and geochemical changes in sea paleobasin. Our study shows a good correlation among the variation in many geochemical parameters, the composition of microfossil assemblages, and the transgressive-regressive phases of the paleobasin evolution. Moderately shallow-water facies was reconstructed using micropaleontological, palynological, and lithological data from the upper and lower parts of the section, where the terpane and hopane horizons were identified. Both horizons are characterized by a general dominance of hopanes over other polycyclic biomarkers, the presence of compounds with the biological configuration and organic matter of mixed terrestrial-marine origin, the presence of benzohopanes and retene, an indicator of the conifer resins. This is also reflected in the composition of palynological assemblages, which are dominated by terrestrial palynomorphs, with rare conifer pollen grains. Relatively deep-water facies were identified in the middle part of the section (diasterene horizon). A distinctive geochemical feature of this interval is high relative abundances of diasterenes and 4-methyldiasterenes. The lower subhorizon is characterized by the highest values of the pristane/n-C17 ratio and relatively light δ13C values of noncarbonate carbon. The aromatic fractions have anomalously high concentrations of methyltrimethyltridecylchromans (MTTCs), which are interpreted to be derived mostly from chlorophyll of prasinophytes. The terpenoid distribution is marked by the presence of neohop-13(18)-enes, which probably originated from the activity of methanotrophic bacteria. The above geochemical parameters indicate high photic zone productivity (which is confirmed by the composition of palynological assemblages with abundant dinocysts and prasinophytes) that favored the accumulation of organic matter in dysaerobic conditions, which periodically occurred in the bottom of paleobasin. The alternation of dysaerobic and low-oxic bottom water conditions is easily reconstructed from the analysis of microbenthic communities. The analysis of biogeochemical, micropaleontological, paleontological, and palynological data on the Upper Volgian-lowermost Berriasian organic-rich shales revealed a very good source rock potential for this part of the section, as indicated by relatively high concentrations of organic matter of mixed bacterial-algal genesis and stagnant conditions during deposition and diagenesis. However, this potential was not realized because of the extremely “mild” thermobaric conditions that existed within the Mesozoic strata of the present-day Anabar Bay. At the same time, our results and analysis of the available data allow an optimistic assessment of the hydrocarbon potential of Jurassic-Lower Cretaceous deposits on the Laptev Sea shelf.Kashirtsev, V.A., Parfenova, T.M., Golovko, A.K., Nikitenko, B.L., Zueva, I.N., Chalaya, O.N., 2018. Phenanthrene biomarkers in the organic matter of Precambrian and Phanerozoic deposits and in the oils of the Siberian Platform. Russian Geology and Geophysics 59, 1380-1388. composition and distribution of phenanthrenes (polyaromatic compounds) have been studied in chloroform extracts from dispersed organic matter (OM) of clayey, siliceous, carbonate, and terrigenous rocks of different ages and facies and from some oils of the Siberian Platform. Phenanthrenes have been analyzed by gas chromatography-mass spectrometry. High contents of 1,7,8-trimethylphenanthrene and 1,1,7,8-tetramethyl-1,2,3,4-tetrahydrophenanthrene are present in the OM of Vendian and Cambrian carbonate-shale deposits and in ancient oils of the Nepa-Botuobiya and Anabar anteclises. The OM of Permian continental deposits and oils of the Vilyui syneclise is dominated by 1-methyl-7-isopropylphenanthrene (retene). A triangular diagram for identification of the types of original OM of rocks and classification of genetically related oils has been constructed based on the assessment of phenanthrene biomarker distribution. Putative pathways of the formation of phenanthrene biomarkers are discussed.Kayukova, G.P., Mikhailova, A.N., Kosachev, I.P., Pronin, N.V., Sotnikov, O.S., Evdokimov, A.М., Khisamov, R.S., 2018. Hydrothermal transformations of organic matter of low permeability rocks from Domanic Formation of the Romashkino oil field. Petroleum Science and Technology 36, 1463-1470. oil generating potential of Domanic rocks from Dankov–Lebedyan horizon of the Zelenogorsk area of Romashkino oil field was evaluated by Rock-Eval pyrolysis technique. The result of given method depends on the content, composition, and thermal stability of organic matter in rocks. During hydrothermal processes, the distinctive conversion behavior of organic matter at temperatures of 200°С, 250°С, 300°С, and 350°С in CO2 environment was revealed. The yield of obtained aquathermolysis products and their quality were evaluated. The results of the studies suggest that low-permeability carbonate rocks of the Dankov–Lebedyan horizon contain productive beds with content of Corg 1.89–3.03%, which when developed using thermal methods, can become an additional source of liquid hydrocarbons.Kayukova, G.P., Mikhailova, A.N., Kosachev, I.P., Sitnov, S.A., Sotnikov, O.S., Nazimov, N.A., 2018. Peculiarities of hydrocarbon generation in procsses of transformation of organic matter of Domanikovian rocks in various media of hydrothermal system. Chemistry and Technology of Fuels and Oils 54, 446-456. influence of various media on the degree of transformation of kerogen of Domanikovian rocks in hydrothermal processes was studied in model experiments. Autoclave experiments were conducted with debituminized rock in inert, hydrogen, and carbon dioxide media. A common mechanism was observed for all the reaction media under the influence of hydrothermal factors: the kerogen content in the rocks decreases and the yield of free hydrocarbons extractable from the rocks by organic solvents increases. The saturated hydrocarbon content is higher in the group composition of the experiment products compared to the original extract due to decrease in resin and aromatic hydrocarbon content. In the original extract from the Domanikovian rock, as well as in the experiment products, there are two solid dispersed phases, namely, asphaltenes soluble in aromatic solvents and their modified structures of the type of carbenes and carboids insoluble in toluene due to their more condensed structure with a smaller number of aliphatic substituents. The most pronounced decrease in resin content is observed in carbon dioxide medium with a marked increase in asphaltene content in the experiment products relative to the original extract. In hydrogen medium, on the other hand, asphaltene content decreases in the experiment products, but, in comparison with the carbon dioxide medium, carbenes and carboids are formed more intensely due to decomposition of the kerogen structure. Asphaltenes and carbenes-carboids were found to differ in structure and paramagnetic properties. Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 4, pp. 36 – 41, July – August, 2018.Keighley, D., Boonsue, S., Hall, D., 2018. Phosphatized tungsten-metabolizing coccoid microbes interpreted from oil shale of an Eocene lake, Green River Formation, Utah, USA. Geobiology 16, 610-627. globular structures have been observed in some beds of oil shale from eastern Utah. These beds comprise carbonate-dominated mud that is interlaminated with variably thick and continuous organic-rich layers. Collectively they are enriched in phosphorus, REEs, and actinides. The beds are considered of lacustrine origin and assigned to the Eocene Green River Formation. The globules themselves are of microcrystalline carbonate fluorapatite (?CFA), often contain concentric internal structures, and usually group together in clusters of up to 80, possibly more. Detailed SEM and microprobe analyses have revealed tungsten (W) to be almost exclusively associated with the globular clusters found within the more organic-rich laminae, often at concentrations of over 200?ppm, two orders of magnitude above shale standards. The globular structures are present in freshly cut sections where they occasionally grade into a ?CFA matrix cement. This, together with the draping of the clusters by stringers of organic matter that would have accumulated in the Eocene lake, confirms that the structures are not a contaminant. The limited range of sizes and globular shapes is consistent with the morphology of coccoidal bacteria: Concentric internal structures may represent remnants of the nucleoid and cell wall. Paired concentric structures may indicate cell division (reproduction) processes were occurring until mineralization. The phosphate mineralization itself may have been promoted by release of phosphate from the stressed cells, bringing porewaters to supersaturation, or by the cells acting as nucleation sites. The recording of trace amounts of W almost exclusively in globular clusters preserved in the most organic-rich stringers (anoxia prone) further suggests facultative use of W-enzymes in a microbial metabolism. Combined, their context, morphology, and indication of biogenic process are strong evidence that the structures are fossilized (phosphatized) microbes, possibly sulfate-reducing bacteria, or methanogenic archaea.Kereszturi, A., Kapui, Z., Ori, G.G., Taj-Eddine, K., Ujvari, G., 2018. Mars-relevant field experiences in Morocco: The importance of spatial scales and subsurface exploration. Astrobiology 18, 1329-1350. field work at the Ibn Battuta Mars analogue sites, two research questions were analyzed: (1) How do we identify sampling sites using remote and local imaging and (2) what kind of information can be gained from shallow subsurface exploration? While remote images help in targeting field activities in general, the connection between observations at different spatial scales for different rocky desert terrain types is not well established; in this, focused comparison of remote in situ images of well-selected analogues would help a great deal. Dried up lake beds as discerned in remotely acquired data may not show signatures of past water activity, while shallow subsurface exploration could reveal the lacustrine period. Acquisition of several satellite images of the same terrain under different geometries would help to support the planning of such in situ work. The selection of appropriate sampling sites in fluvial settings could be improved by analyzing long, meter-high, open-air outcrops that formed during most recent fluvial episodes. Such settings are abundant on Earth and could be present on Mars but may be just below the resolution of available data. By using 20–30-cm-deep excavations, shallow subsurface exploration could reveal the last period of geological history that would have been unattainable by surface observation alone. Aggregates embedded in the original strata or from heavily pulverized samples could not be identified; only weakly fragmented samples viewed right after acquisition showed aggregates, and thus, the Close-Up Imager (CLUPI) on the ExoMover might provide information on cementation-related aggregation on the observing plate before crushing. The mechanical separation of different size grains (mainly clays and attached minerals) would also support the identification of individual components. To maximize context information during subsurface exploration, rover imaging should be accomplished before crushing; however, currently planned imaging may not be ideal for this.Kew, W., Mackay, C.L., Goodall, I., Clarke, D.J., Uhrín, D., 2018. Complementary ionization techniques for the analysis of scotch whisky by high resolution mass spectrometry. Analytical Chemistry 90, 11265-11272. transform mass spectrometry (FTMS) is widely used to characterize the chemical complexity of mixtures, such as natural organic matter (NOM), petroleum, and agri-food products (including Scotch whisky). Although electrospray ionization (ESI) is by far the most widely used ionization source in these studies, other ionization techniques are available and may offer complementary information. In a recent study, we found matrix free laser desorption/ionization (LDI) to be effective for the analysis of Suwannee river fulvic acid (SRFA), and to provide complementary chemical insights. In this study, LDI along with atmospheric pressure photoionization (APPI) and atmospheric pressure chemical ionization (APCI) were compared to ESI for the analysis of Scotch whisky. High mass accuracy (54 ppb, mean) allowed for the assignment of 86% of peaks, with 3993 unique molecular formulas identified from four representative samples analyzed. All four ionization techniques, performed in negative mode, identified thousands of formulas. Many were unique to each ionization source, while 699 formulas were common to all techniques. Ions were identified in both deprotonated and radical anion forms. Our study highlights the importance of a multi-ionization source approach; we recommend that analysis of complex mixtures, especially novel ones, should not be limited solely to ESI.Khormali, A., Sharifov, A.R., Torba, D.I., 2018. Experimental and modeling study of asphaltene adsorption onto the reservoir rocks. Petroleum Science and Technology 36, 1482-1489. this work, amount of asphaltene adsorption onto the carbonate and sandstone rock samples was investigated at various initial concentrations of asphaltene in oil. Asphaltene adsorption onto both types of the reservoir rocks was increased by increasing the initial concentration of asphaltene. The amount of asphaltene adsorption onto the rock samples was predicted using Langmuir and Freundlich isotherm models. The results showed that Langmuir model had a better accuracy for prediction of asphaltene adsorption onto the rock samples than Freundlich model. Furthermore, asphaltene adsorption onto the reservoir rocks was studied in the presence of a recently developed asphaltene inhibitor. The inhibitor significantly reduced asphaltene adsorption at any initial concatenation of asphaltene. Moreover, changes in the rock permeability due to asphaltene precipitation were determined in the presence and absence of the asphaltene inhibitor.Kim, D.-U., Jang, J.H., Kang, M.-S., Kim, J.-Y., Zhang, J., Lim, S., Kim, M.K., 2018. Deinococcus irradiatisoli sp. nov., isolated from gamma ray-irradiated soil. International Journal of Systematic and Evolutionary Microbiology 68, 3232-3236. 17bor-2T, a gamma-resistant, pink-to-red-coloured, aerobic, catalase-positive, oxidase-negative and Gram-stain-negative bacterium, was isolated from gamma ray-irradiated soil. The isolate grew aerobically at 18–37?°C (optimum, 28–30?°C), pH 6.0–8.0 (pH 6.5–7.5) and in the presence of 0–1?% (w/v) NaCl (0?% NaCl). Phylogenetic analysis based on its 16S rRNA gene sequence indicated that strain 17bor-2T belonged to the genus Deinococcus with a highest sequence similarity of 96.4?% to Deinococcus alpinitundrae ME-04-04-52T. The major fatty acids of the strain were summed feature 3 (C16?:?1 ω7c and/or C16?:?1 ω6c), C16?:?0 and cyclo C17?:?0. The only respiratory quinone was MK-8. The major polar lipids of the strain were phosphoglycolipid, aminophospholipid and an unknown glycolipid. The DNA G+C?content of strain 17bor-2T was 62.8?mol%. On the basis of its phenotypic, genotypic and chemotaxonomic characteristics, strain 17bor-2T should be classified as a novel species in the genus Deinococcus, for which the name Deinococcus irradiatisoli sp. nov. is proposed. The type strain is 17bor-2T (=KCTC 33907T=NBRC 113037T). The GenBank/EMBL/DDBJ accession number of the 16S rRNA gene sequence of strain 17bor-2T is KY939573.Kim, D.-W., Lee, K., Lee, D.-H., Cha, C.-J., 2018. Comparative genomic analysis of pyrene-degrading Mycobacterium species: Genomic islands and ring-hydroxylating dioxygenases involved in pyrene degradation. Journal of Microbiology 56, 798-804. genome sequences of two pyrene-degrading bacterial strains of Mycobacterium spp. PYR10 and PYR15, isolated from the estuarine wetland of the Han river, South Korea, were determined using the PacBio RS II sequencing platform. The complete genome of strain PYR15 was 6,037,017 bp in length with a GC content of 66.5%, and contained 5,933 protein-coding genes. The genome of strain PYR10 was 5,999,427 bp in length with a GC content of 67.7%, and contained 5,767 protein-coding genes. Based on the average nucleotide identity values, these strains were designated as M. gilvum PYR10 and M. pallens PYR15. A genomic comparison of these pyrene-degrading Mycobacterium strains with pyrene-non-degrading strains revealed that the genomes of pyrene-degrading strains possessed similar repertoires of ringhydroxylating dioxygenases (RHDs), including the pyrenehydroxylating dioxygenases encoded by nidA and nidA3, which could be readily distinguished from those of pyrenenon-degraders. Furthermore, genomic islands, containing catabolic gene clusters, were shared only among the pyrenedegrading Mycobacterium strains and these gene clusters contained RHD genes, including nidAB and nidA3B3. Our genome data should facilitate further studies on the evolution of the polycyclic aromatic hydrocarbon-degradation pathways in the genus Mycobacterium.Kim, D., Lee, J., Kim, B., Kim, S., 2018. Optimization and application of paper-based spray ionization mass spectrometry for analysis of natural organic matter. Analytical Chemistry 90, 12027-12034. this study, paper-based ionization techniques—paper spray ionization (PSI) and paper spray chemical ionization (PSCI)—were evaluated and applied for high-resolution mass spectrometry (MS)-based analysis of natural organic matter (NOM). Methanol:isopropyl alcohol (50:50, v/v) and ethanol emerged as good spray solvents for PSI, and hexane:dichloromethane (50:50, v/v) was a good spray solvent for PSCI. PSI-MS spectra could be obtained with NOM samples on the microgram scale, which is a critical advantage over conventional electrospray ionization (ESI)-MS when the amount of available sample is limited. In addition, PSI is more tolerant to salt contamination than ESI for NOM analysis. PSCI preferentially ionized less polar compounds, which may not be ionized well using ESI. Therefore, PSCI can be used as a complementary method to ESI or PSI. Comparison of the numbers of peaks obtained with ESI-, PSI-, and PSCI-MS showed that employing PSI and PSCI can increase the number of compounds that can be detected by high-resolution MS. In conclusion, the data presented in this study showed that PSI and PSCI are suitable ionization techniques for NOM analysis. To the best of our knowledge, this is the first study evaluating and applying PSI and PSCI for NOM analysis.King, A.C.F., Giorio, C., Wolff, E., Thomas, E., Karroca, O., Roverso, M., Schwikowski, M., Tapparo, A., Gambaro, A., Kalberer, M., 2019. A new method for the determination of primary and secondary terrestrial and marine biomarkers in ice cores using liquid chromatography high-resolution mass spectrometry. Talanta 194, 233-242. majority of atmospheric compounds measured in ice cores are inorganic, while analysis of their organic counterparts is a less well developed field. In recent years, understanding of formation, transport pathways and preservation of these compounds in ice and snow has improved, showing great potential for their use as biomarkers in ice cores. This study presents an optimised analytical technique for quantification of terrestrial and marine biosphere emissions of secondary organic aerosol (SOA) components and fatty acids in ice using HPLC-MS analysis. Concentrations of organic compounds in snow and ice are extremely low (typically ppb or ppt levels) and thus pre-concentration is required prior to analysis. Stir bar sorptive extraction (SBSE) showed potential for fatty acid compounds, but failed to recover SOA compounds. Solid phase extraction (SPE) recovered compounds across both organic groups but methods improving some recoveries came at the expense of others, and background contamination of fatty acids was high. Rotary evaporation was by far the best performing method across both SOA and fatty acid compounds, with average recoveries of 80%. The optimised preconcentration – HPLC-MS method achieved repeatability of 9% averaged for all compounds. In environmental samples, both concentrations and seasonal trends were observed to be reproducible when analysed in two different laboratories using the same method.Kingsley, O.K., Umeji, O.P., 2018. Oil shale prospects of Imo Formation Niger Delta Basin, southeastern Nigeria: Palynofacies, organic thermal maturation and source rock perspective. Journal of the Geological Society of India 92, 498-506. search for oil and gas in the Nigerian inland basins and efficacy of the unconventional oil shale in hydrocarbon generation have necessitated the palynofacies characterization, thermal maturation and source rock evaluation of the Imo Formation, updip Niger Delta basin to determine its palynofacies constituents and oil shale potential. The standard acid maceration technique, palynofacies description as well as palynomorph colour index chart systematically compared to thermal alteration index and vitrinite reflectance index values were utilized for the study.The palynofacies components of the Imo Formation is dominant of yellow and brown amorphous organic matter, marine taxa, opaque particles, with few dark brown structured phytoclasts and terrestrial microflora. The source rock content is interpreted as Kerogen Type II - oil prone with abundant marine palynomorphs, amorphous organic matter and few terrestrial microfossils. The spore/pollen colour of the strata is light brown signifying mature and oil generation zone. This correlates to thermal alteration index (TAI) 2+ to 3 and vitrinite reflectance index (%Ro) values of 0.5% to 1.0%.The abundance of the amorphous organic matter of marine origin suggests good source rock which indicates good oil shale prospects. The oil shale prospects of the Imo Formation in the study area are hindered by the low abundance of the palynofacies associations. Field evidence indicate that the grey to slightly light grey shales in hand specimen, as against black carbonaceous shales rich in organic matter suggests that the environmental conditions affected the quality of the organic kerogen. The oil yields may be compensated by the great volume of marine shale deposited in the formation and the abundance of amorphous organic matter of marine origin which is known to be an excellent indicator of oil. The palynofacies model enhances the understanding of palynofacies events and oil shale quality which can be tied to the development of unconventional oil shale, oil fields and subsequent exploration drive in the area.Kisand, V., Talas, L., Kisand, A., Stivrins, N., Reitalu, T., Alliksaar, T., Vassiljev, J., Liiv, M., Heinsalu, A., Sepp?, H., Veski, S., 2018. From microbial eukaryotes to metazoan vertebrates: Wide spectrum paleo-diversity in sedimentary ancient DNA over the last ~14,500?years. Geobiology 16, 628-639. studies that utilize ancient DNA have focused on specific groups of organisms or even single species. Instead, the whole biodiversity of eukaryotes can be described using universal phylogenetic marker genes found within well-preserved sediment cores that cover the post-glacial period. Sedimentary ancient DNA samples from Lake Lielais Sv?ti?u, eastern Latvia, at a core depth of 1,050?cm in ~150?year intervals were used to determine phylotaxonomy in domain Eukaryota. Phylotaxonomic affiliation of >1,200 eukaryotic phylotypes revealed high richness in all major eukaryotic groups?Alveolata, Stramenopiles, Cercozoa, Chlorophyta, Charophyta, Nucletmycea, and Holozoa. The share of organisms that originate from terrestrial ecosystems was about one third, of which the most abundant molecular operational taxonomic units were Fungi and tracheal/vascular plants, which demonstrates the usefulness of using lake sediments to reconstruct the terrestrial paleoecosystems that surround them. Phylotypes that originate from the lake ecosystem belonged to various planktonic organisms; phyto-, proto,- and macrozooplankton, and vascular aquatic plants. We observed greater richness of several planktonic organisms that can be associated with higher trophic status during the warm climate period between 4,000 and 8,000?years ago and an increase in eukaryotic richness possibly associated with moderate human impact over the last 2,000?years.Kochnev, B.B., Pokrovsky, B.G., Kuznetsov, A.B., Marusin, V.V., 2018. C and Sr isotope chemostratigraphy of Vendian-Lower Cambrian carbonate sequences in the central Siberian Platform. Russian Geology and Geophysics 59, 585-605. propose a detailed δ13C curve for the Vendian and Lower Cambrian (Tommotian) strata of the central Siberian Platform. Two positive carbon isotope excursions identified near the base of the Yuryakh Formation (up to 5.5‰) and in the lower Bilir Formation (up to 5‰) are assigned to the lowermost and middle Tommotian, respectively. This correlation is supported by paleontological data, specific 87Sr/86Sr values (0.70845-0.70856), and similar C isotope record in coeval Early Cambrian basins. The documented minor vertical oscillations (a few meters) of these isotope excursions relative to the formation boundaries in remote boreholes is presumably caused by the spatiotemporal migration of facies. A high-amplitude negative δ13C excursion (-8 to -11‰) in the upper Nepa Regional Stage putatively corresponds to the global Shuram-Wonoka negative carbon isotope excursion (Middle Ediacaran). Carbonates of the lower Nepa Regional Stage (Besyuryakh Formation) demonstrate positive δ13C values (up to 5‰) and minimum 87Sr/86Sr ratios of 0.70796-0.70832. The C and Sr isotope record of the Nepa Regional Stage provides its robust correlation with the Dal’nyaya Taiga and Zhuya Groups of the Patom Foredeep. Micropaleontological data herein reported and glacial diamictites documented at the base of the Vendian sedimentary cover both in the central Patom Foredeep and on its periphery suggest a full stratigraphic volume of the Ediacaran System in the most stratigraphically complete sections of the central Siberian Platform.Koebsch, F., Winkel, M., Liebner, S., Liu, B., Westphal, J., Schmiedinger, I., Spitzy, A., Gehre, M., Jurasinski, G., K?hler, S., Unger, V., Koch, M., Sachs, T., B?ttcher, M.E., 2018. Sulfate deprivation triggers high methane production in a disturbed and rewetted coastal peatland. Biogeosciences Discussions 2018, 1-37. natural coastal wetlands, high supplies of marine sulfate suppress methanogenesis. Coastal wetlands are, however, often subject to disturbance by dyking and drainage for agricultural use and it has been shown that they can turn to potent methane sources when rewetted for remediation, suggesting that the sulfate-related methane suppressing mechanisms were suspended by the preceding land use measures. Here, we unravel the hydrological relocation and biogeochemical S and C transformation processes that induced high methane emissions in a disturbed and rewetted peatland despite former brackish impact. The underlying processes were investigated along a transect of increasing distance to the coastline using a combination of concentration patterns, stable isotope partitioning and analysis of the microbial community structure. We found that dyking and freshwater rewetting caused a distinct freshening and an efficient depletion of the brackish sulfate reservoir by dissimilatory sulfate reduction (DSR). Despite some legacy effects of brackish impact expressed as high amounts of sedimentary S and elevated electrical conductivities, contemporary metabolic processes operated mainly under sulfate-limited conditions. This opened up favorable conditions for the establishment of a prospering methanogenic community in the top 30–40cm of peat, the structure and physiology of which resembles those of terrestrial organic-rich environments. Locally, high amounts of sulfate persisted in deeper peat layers through the suppression of DSR, probably by competitive electron acceptors of terrestrial origin, for example Fe(III), but did not interfere with high methane emissions on ecosystem scale. Our results indicate that the climate effect of disturbed and remediated coastal wetlands cannot simply be derived by analogy with their natural counterparts. From a greenhouse gas perspective, the re-exposure of dyked wetlands to natural coastal dynamics would literally open up the floodgates for a replenishment of the marine sulfate pool and constitute an efficient measure to reduce methane emissions.Koll, D.D.B., Cronin, T.W., 2018. Earth’s outgoing longwave radiation linear due to H2O greenhouse effect. Proceedings of the National Academy of Sciences 115, 10293.: Earth’s climate is set by a balance between incoming solar and outgoing infrared radiation. The physical processes that influence this balance are complex and nonlinear, yet models and satellite measurements counterintuitively show that Earth’s infrared radiation is simply a linear function of surface temperature. Here we explain why: Linearity is due to the cancellation of two nonlinear processes and always arises in an atmosphere dominated by a condensable greenhouse gas. Our work explains a fundamental property of Earth’s climate and has implications for climate change as well as the climates of extrasolar planets with exotic greenhouse gases.Abstract: Satellite measurements and radiative calculations show that Earth’s outgoing longwave radiation (OLR) is an essentially linear function of surface temperature over a wide range of temperatures (?60 K). Linearity implies that radiative forcing has the same impact in warmer as in colder climates and is thus of fundamental importance for understanding past and future climate change. Although the evidence for a nearly linear relation was first pointed out more than 50 y ago, it is still unclear why this relation is valid and when it breaks down. Here we present a simple semianalytical model that explains Earth’s linear OLR as an emergent property of an atmosphere whose greenhouse effect is dominated by a condensable gas. Linearity arises from a competition between the surface’s increasing thermal emission and the narrowing of spectral window regions with warming and breaks down at high temperatures once continuum absorption cuts off spectral windows. Our model provides a way of understanding the longwave contribution to Earth’s climate sensitivity and suggests that extrasolar planets with other condensable greenhouse gases could have climate dynamics similar to Earth’s.Kong, F., Zheng, M., Hu, B., Wang, A., Ma, N., Sobron, P., 2018. Dalangtan saline playa in a hyperarid region on Tibet Plateau: I. Evolution and environments. Astrobiology 18, 1243-1253. 2008, we have been studying a saline lake, Dalangtan (DLT) Playa, and its surroundings in a hyperarid region of the Qaidam Basin on the Tibetan Plateau as a potential Mars analog site. We describe the evolution of saline deposits in the Qaidam Basin (including DLT), based on investigative findings accumulated over the course of 60 years of geological surveys. In addition, we report regional meteorological patterns recorded for the past 32 years along with meteorological station recorded data at DLT since 2012. Overall, the DLT area on the Tibetan Plateau has low atmospheric pressure, high ultraviolet radiation, low annual mean temperatures (T) but large seasonal and diurnal T cycles, and extremely low relative humidity, all of which bear some similarities with the equatorial region on Mars. In addition, salt types similar to those found on Mars, such as magnesium-sulfates, chlorides, and perchlorates, are found at the surface and subsurface in the DLT area (and the other two playas in the Qaidam Basin), thus supporting DLT as a Mars analog in terms of mineralogy and geochemistry.Kontorovich, A.E., Ponomareva, E.V., Burshtein, L.M., Glinskikh, V.N., Kim, N.S., Kostyreva, E.A., Pavlova, M.A., Rodchenko, A.P., Yan, P.A., 2018. Distribution of organic matter in rocks of the Bazhenov horizon (West Siberia). Russian Geology and Geophysics 59, 285-298. studied the distribution of organic carbon in rocks of the Bazhenov horizon, a unique object of predominantly biogenic sedimentation in the West Siberian sedimentary basin. The contents of organic carbon in the rocks were determined using the data from 4094 core analyses and core-log relationships derived from 48,500 radioactive- and electrical-log measurements. For the Bazhenov and Tutleima Formations, both approaches gave the same results. The average content of organic carbon in the rocks is 7.7%. These data were used to compile a detailed map of the distribution of organic carbon contents in sedimentary rocks of the basin. It was shown that the average organic carbon content in the rocks increases from 2-4% on the periphery of the basin to 10-12% in its central, deepest part. The distribution of Corg values in the basin is highly asymmetric. The highest Corg values are observed in the southwestern part of the basin interior, where beds with > 10% Corg range in thickness from 5 to 12-15 m. In sections, the highest Corg values are observed in their middle and upper parts, composed predominantly of silicites and mixtites enriched in biogenic silica.Kossacki, K.J., 2019. Sublimation of cometary ices in the presence of organic volatiles II. Icarus 319, 470-475. of the surfaces of cometary nuclei is determined by the sublimation of ice. The rate of sublimation is commonly calculated using the simple Hertz–Knudsen formula, which should be corrected by a temperature dependent sublimation coefficient αs (Kossacki et?al., 1999; Gundlach et?al., 2011; Kossacki and Leliwa-Kopystynski, 2014). In Kossacki et?al. (2017) the temperature dependence of αs for water ice with acetone and methanol present in comets was analyzed. In this work the influence of propanal at the temperature ?~195–~230?K and formamide at the temperature ?~200–~235?K were investigated. Experiments were performed with slab ice and porous fine-grained ice. It is found, that the presence of propanal reduces the sublimation coefficient at T?<?207?K and enhances at T?>?208?K. The presence of formamide reduced the sublimation coefficient in the whole investigated temperature range. Porous fine-grained ice sublimed up to four times slower than non-porous one.Králová, S., ?vec, P., Busse, H.-J., Staňková, E., Váczi, P., Sedlá?ek, I., 2018. Flavobacterium chryseum sp. nov. and Flavobacterium psychroterrae sp. nov., novel environmental bacteria isolated from Antarctica. International Journal of Systematic and Evolutionary Microbiology 68, 3132-3139. group of rod-shaped, aerobic, Gram-stain-negative, gliding bacteria producing flexirubin-type pigment was isolated from environmental samples collected in Antarctica in 2009–2014. Phylogenetic analysis of the almost complete 16S rRNA gene sequences revealed two separated branches belonging to the genus Flavobacterium . Group I (n=8), represented by strain CCM 8826T, shared the highest sequence similarity to Flavobacterium collinsii 983-08T (98.8?%) and Flavobacterium saccharophilum DSM 1811T (98.4?%), and group II (n=4) represented by strain CCM 8827T shared the highest similarity to Flavobacterium aquidurense WB 1.1-56T (99.6?%). High genetic homogeneity of both groups, separation from each other and from phylogenetically close Flavobacterium species was verified by the rep-PCR fingerprinting method. DNA–DNA hybridization confirmed low genomic relatedness between strain CCM 8826T and F. collinsii 983-08T and F. saccharophilum DSM 1811T (18 and 28?%, respectively) and between strain CCM 8827T and F. aquidurense WB 1.1-56T (27?%). Chemotaxonomic analyses of strains CCM 8826T and CCM 8827T revealed the respiratory quinone to be MK-6, the major identified polar lipid was phosphatidylethanolamine and the predominant polyamine was sym-homospermidine. The common major fatty acids were C15?:?0 iso, C17?:?0 iso 3OH, C15?:?1 iso G, Summed Feature 3 (C16?:?1 ω7c/C16?:?1 ω6c), C15?:?0 iso 3OH and additionally, C15?:?0 anteiso among group II members. All analyses confirmed that strains of group I and II represent two novel species of the genus Flavobacterium , for which the names Flavobacterium chryseum sp. nov. (type strain CCM 8826T=P3160T=LMG 30615T) and Flavobacterium psychroterrae sp. nov. (type strain CCM 8827T=P3922T=LMG 30616T) are proposed. The GenBank/EMBL/DDBJ accession number for the near-complete 16S rRNA gene sequence of Flavobacterium chryseum (CCM 8826T) is MH100900 and for Flavobacterium psychroterrae (CCM 8827T) is MH100901.Kumar, V., Binod, P., Sindhu, R., Gnansounou, E., Ahluwalia, V., 2018. Bioconversion of pentose sugars to value added chemicals and fuels: Recent trends, challenges and possibilities. Bioresource Technology 269, 443-451. of the crop plants contain about 30% of hemicelluloses comprising D-xylose and D-arabinose. One of the major limitation for the use of pentose sugars is that high purity grade D-xylose and D-arabinose are yet to be produced as commodity chemicals. Research and developmental activities are going on in this direction for their use as platform intermediates through economically viable strategies. During chemical pretreatment of biomass, the pentose sugars were generated in the liquid stream along with other compounds. This contains glucose, proteins, phenolic compounds, minerals and acids other than pentose sugars. Arabinose is present in small amounts, which can be used for the economic production of value added compound, xylitol. The present review discusses the recent trends and developments as well as challenges and opportunities in the utilization of pentose sugars generated from lignocellulosic biomass for the production of value added compounds.La Barbera, G., Antonelli, M., Cavaliere, C., Cruciani, G., Goracci, L., Montone, C.M., Piovesana, S., Laganà, A., Capriotti, A.L., 2018. Delving into the polar lipidome by optimized chromatographic separation, high-resolution mass spectrometry, and comprehensive identification with Lipostar: Microalgae as case study. Analytical Chemistry 90, 12230–12238. work describes the chromatographic separation optimization of polar lipids on Kinetex-EVO, particularly focusing on sulfolipids in spirulina microalgae (Arthrospira platensis). Gradient shape and mobile-phase modifiers (pH and buffer) were tested on lipid standards. Different conditions were evaluated, and resolution, peak capacity, and peak shape were calculated both in negative mode, for sulfolipids and phospholipids, and in positive mode, for glycolipids. A high-confidence lipid identification strategy was also applied. In collaboration with software creators and developers, Lipostar was implemented to improve the identification of phosphoglycerolipids and to allow the identification of glycosylmonoradyl- and glycosyldiradyl-glycerols classes, the last being the main focus of this work. By this approach, an untargeted screening also for searching lipids not yet reported in the literature could be accomplished. The optimized chromatographic conditions and database search were tested for lipid identification first on the standard mixture, then on the polar lipid extract of spirulina microalgae, for which 205 lipids were identified.Lambertsson, L., Lord, C.J., Frech, W., Bj?rn, E., 2018. Rapid dissolution of cinnabar in crude oils at reservoir temperatures facilitated by reduced sulfur ligands. ACS Earth and Space Chemistry 2, 1022-1028. (Hg) is present in petrochemical samples, including crude oils, and the processing and use of petroleum products contribute to global Hg emissions. We present a refined theory on geochemical processes controlling Hg concentrations in crude oil by studying dissolution kinetics and solubility thermodynamics of cinnabar (α-HgS(s)) in different crude oils held at reservoir temperatures. In a black light crude oil, α-HgS(s) dissolved in an apparent zero-order reaction with a rate of 0.14–0.58 μmoles m–2 s–1 at 170–230 °C and an estimated activation energy of 43 kJ mol–1. For crude oil samples with a total sulfur concentration spanning 0.15–2.38% (w/w), the measured dissolution rate varied between 0.05 and 0.24 μmoles m–2 s–1 at 200 °C. Separate tests showed that thiols and, to a lesser extent, organic sulfides increased the solubility of α-HgS(s) in isooctane at room temperature compared to thiophenes, disulfides, and elemental sulfur. Long-term (14 days) α-HgS(s) solubility tests in a crude oil at 200 °C generated dissolved Hg concentrations in the 0.3% (w/w) range. The high α-HgS(s) dissolving capacity of the crude oils was more than 2 orders of magnitude greater than the highest reported Hg concentration in crude oils globally. On the basis of the kinetic and solubility data, it was further concluded that α-HgS(s) is not stable under typical petroleum reservoir conditions and would decompose to elemental mercury (Hg0). Our results suggest that source/reservoir temperature, abundance of reduced sulfur compounds in the crude oil, and dissolved Hg0 evasion processes are principal factors controlling the ultimate Hg concentration in a specific crude oil deposit.Landis, J.D., Sharma, M., Renock, D., 2018. Rapid desorption of radium isotopes from black shale during hydraulic fracturing. 2. A model reconciling radium extraction with Marcellus wastewater production. Chemical Geology 500, 194-206. in hydraulic fracturing wastewaters derives from two isotopically distinct end-members in the shale, labile 228Ra hosted by mineral surfaces (226Ra/228Ra atom ratio ~250) and exchangeable 226Ra hosted by organic surfaces (226Ra/228Ra ~10,000). Here we use mass balance and isotope mixing models to reconcile extraction of Ra from these phases with mechanisms of Marcellus wastewater production. Radium isotopic mass balance requires that the characteristic water-rock ratio between wastewater and shale is exceedingly low, on the order of 0.04, and that this ratio decreases with time during wastewater production. An evolving water-rock interaction drives increasing Ra concentrations (=[Ra]) and 226Ra/228Ra ratios during wastewater production, all mediated by increasing [Ca2+] that favors desorption of 226Ra from organics. Our observations and models of Ra isotope geochemistry are best reconciled with observations of water and salinity mass balance, δ18O, Na-Br-Cl, and 87Sr/86Sr if wastewater is produced by mixing of injected fluids with a limited volume of pore brine (on the order of 13% by volume), accompanied by contemporaneous extraction of excess alkaline earth elements by water-rock exchange. Validated using Ra isotope data, this model attributes the extreme salinity and [Ra] in wastewaters to the progressive, hydrologic enrichment of injected fluids during hydraulic fracturing.Langley, G.J., Herniman, J., Carter, A., Wilmot, E., Ashe, M., Barker, J., 2018. Detection and quantitation of ACCUTRACE S10, a new fiscal marker used in low-duty fuels, using a novel ultrahigh-performance supercritical fluid chromatography–mass spectrometry approach. Energy & Fuels 32, 10580-10585. salinity waterflooding is an effective approach to improving oil recovery, behind which the microscopic mechanisms have been debated over the past decade, and especially, the role of polar organic components of crude oil is almost ignored but proposed to dominate the adhesion force of oil-rock in specific cases. In this study, chemical force microscopy (CFM) was used to directly measure the adhesion forces between polar model oil and mineral surface in the presence of electrolyte solution with different ionic type and concentration. By the use of classic Derjaguin–Landau–Verwey–Overbeek (DLVO) theory, the van der Waals and electrostatic forces were calculated, and it was found that there were some additional interactions, denoted as structural forces, playing an important part in the resultant forces. By the aid of extended DLVO (EDLVO) theory, the adhesion force of polar tip–substrate was found to increase in the order: Na+ < Ca2+ < Mg2+, and the low salinity effect (LSE) potential shows the opposite order, attributed to the ligand bridging and strong solvation of multivalent cations enhancing the electrostatic attraction of the tip–surface pair. In the case of sulfate ion as the anion, the adhesion force was smaller than that in the case of chloride ion because the SO42– ion can favor the formation of electrostatic repulsion between the tip and surface and accordingly enhance the LSE potential. On the basis of the experimental results, we propose a molecular interaction model between oil and solid substrate, which will provide an in-depth understanding of the effect of brine composition and concentration on oil detaching from a solid surface at the molecular level.Lazcano, A., 2018. Prebiotic evolution and self-assembly of nucleic acids. ACS Nano 12, 9643-9647. evolution is the stage that is assumed to have taken place prior to the emergence of the first living entities, during which time the abiotic synthesis of monomers, oligomers, and supramolecular systems that led to the hypothesized RNA world occurred. In this Perspective, the success of one-pot Miller–Urey type synthesis of organic compounds is compared with the multipot syntheses developed within the framework of systems chemistry, which attempts to demonstrate that RNA could have been formed directly in the primitive environment. The prebiotic significance of liquid-crystal ordering of nucleic acid oligomers and self-organizing assemblages of RNA and DNA that are formed in the absence of membranes or mineral matrices is also addressed.Ledevin, M., 2019. Chapter 37 - Archean cherts: Formation processes and paleoenvironments, in: Van Kranendonk, M.J., Bennett, V.C., Hoffmann, J.E. (Eds.), Earth's Oldest Rocks (Second Edition). Elsevier, pp. 913-944. chapter uses examples from the Barberton Greenstone Belt (3.5-3.2 Ga), South Africa, to review the case of Archean cherts as indicators of the conditions prevailing on the early Earth. Key components of the Precambrian silica cycle are presented, from hydrothermal processes and Si-metasomatism of the oceanic crust to siliceous sedimentation at the seafloor. Recent models of chert genetic processes are discussed for volcaniclastic-rich deposits and pure chemical precipitates, the later providing valuable insights on the habitat for early life. The last part of this chapter is dedicated to the potential and limitations of geochemical and isotopic proxies used in Archean cherts to access the environmental conditions within primitive ecosystems.Lee, D.-M., Lee, D.-H., Hwang, I.-H., 2018. Gasoline quality assessment using fast gas chromatography and partial least-squares regression for the detection of adulterated gasoline. Energy & Fuels 32, 10556-10562. find out if gasoline is adulterated, it is essential to analyze the sample’s information efficiently; however, current official test methods are time consuming and costly. Much research has been conducted to supplement these difficulties using multivariable analysis and instruments such as spectrophotometers or gas chromatography (GC). However, spectrophotometers are unable to determine the chemical components, and conventional GC systems take more than 30 min to obtain sufficient data from gasoline samples. In this work, fast GC and a partial least-squares regression (PLSR) were used as analytical methods to determine research octane number (RON), aromatic compounds, methanol, and other oxygenates in under 6 min. The samples of gasoline unadulterated and adulterated with benzene, toluene, xylenes, and methanol were predicted using PLSR, which showed a good correlation between the reference values greater than 0.97. The methodology was validated, estimating specific figures of merit for quantitative multivariate analysis, showing a good value of the root-mean-square error of prediction (RMSEP) and good relative error of prediction (REP %) in the range 0.0–13.0%. Therefore, these results indicate that the fast GC and PLSR model could be an alternative analytical method to effectively manage the gasoline quality.Lee, M.-H., Osburn, C.L., Shin, K.-H., Hur, J., 2018. New insight into the applicability of spectroscopic indices for dissolved organic matter (DOM) source discrimination in aquatic systems affected by biogeochemical processes. Water Research 147, 164-176. numerous studies on changes to optical proxies of dissolved organic matter (DOM) by biogeochemical processing, the applicability of commonly-used spectroscopic indices has not been explored as DOM source tracking tools under conditions where biogeochemical processes may alter them. For this study, two contrasting DOM end members, Suwannee River fulvic acid (SRFA) and algogenic DOM (ADOM), and their mixtures, were used to examine the potential changes in the conservative mixing behaviors of several well-known optical indices via end member mixing analysis under the influence of biodegradation, UV irradiation, and clay mineral (kaolin) adsorption. Most of the source tracking indices exhibited large deviations from conservative mixing behavior between the two end-members. Biodegradation tended to lower the portions of labile and ADOM in the mixtures, while the allochthonous end member (SRFA) was reduced by a greater extent after the process of UV irradiation or adsorption. The extent of the variations in biological index (BIX) and fluorescence index (FI) was smaller for more allochthonous DOM mixtures under the processes of biodegradation and UV irradiation. Overall, the process-driven variations in ratios of humic-like: protein-like fluorescence (as modeled by parallel factor analysis, PARAFAC) were greater for the SRFA versus ADOM. Evaluation criteria used in this study suggested that BIX, specific UV absorbance (SUVA), and FI each could be the reliable discrimination parameter least affected by biodegradation, UV irradiation, and adsorption, respectively. This study provided criterion information for the choice and the interpretation of the optical indices for DOM source discrimination in aquatic environments after substantial biogeochemical processing.Lewitus, E., Bittner, L., Malviya, S., Bowler, C., Morlon, H., 2018. Clade-specific diversification dynamics of marine diatoms since the Jurassic. Nature Ecology & Evolution 2, 1715-1723. are one of the most abundant and diverse groups of phytoplankton and play a major role in marine ecosystems and the Earth’s biogeochemical cycles. Here we combine DNA metabarcoding data from the Tara Oceans expedition with palaeoenvironmental data and phylogenetic models of diversification to analyse the diversity dynamics of marine diatoms. We reveal a primary effect of variation in carbon dioxide partial pressure (pCO2) on early diatom diversification, followed by a major burst of diversification in the late Eocene epoch, after which diversification is chiefly affected by sea level, an influx of silica availability and competition with other planktonic groups. Our results demonstrate a remarkable heterogeneity of diversification dynamics across diatoms and suggest that a changing climate will favour some clades at the expense of others.Li, B.Y., Zhang, D.W., Pang, X.Q., Gao, P., Zhu, D.Y., Guo, K.Z., Zheng, T.Y., 2018. Paired δ13Ccarb and δ13Corg records of the Ordovician on the Yangtze platform, South China. Australian Journal of Earth Sciences 65, 809-822. the Ordovician, huge biological revolutions and environmental changes happened in Earth’s history, including the Great Ordovician Biodiversification Event, global cooling and so on, but the cause of these events remains controversial. Herein, we conducted a paired carbon isotopic analysis of carbonate (δ13Ccarb) and organic matter (δ13Corg) through the Ordovician in the Qiliao section on the Yangtze platform of South China. Our results showed that the δ13Ccarb trend of the Qiliao section can be correlated with local and global curves. The δ13Corg trend seems is less clear than the δ13Ccarb trend for stratigraphic correlations, but some δ13Corg positive excursions in the Middle and Upper Ordovician may be used for correlation studies. These carbon isotopic records may have global significance rather than local significance, revealing several fluctuations to the global carbon cycle during the Ordovician. Several known δ13Ccarb and δ13Corg negative and positive excursions have been recognised in this study, including the early Floian Negative Inorganic Carbon (δ13Ccarb) Excursion (EFNICE), as well as the early Floian Positive Organic Carbon (δ13Ccarb) Excursion, the mid-Darriwilian Inorganic Carbon (δ13Ccarb and δ13Corg) Excursion (MDICE), and the early Katian Guttenberg Inorganic Carbon (δ13Ccarb and δ13Corg) Excursion (GICE). These positive excursions and a smooth decline trend of δ13Corg values during the early to mid-Floian may imply multiple episodes of enhanced organic carbon burial that began at the early Floian stage, probably resulting in further decline in atmospheric pCO2 and then global cooling.Li, F., Peng, Y., Fang, W., Altermatt, F., Xie, Y., Yang, J., Zhang, X., 2018. Application of environmental DNA metabarcoding for predicting anthropogenic pollution in rivers. Environmental Science & Technology 52, 11708-11719. are among the most threatened freshwater ecosystems, and anthropogenic activities are affecting both river structures and water quality. While assessing the organisms can provide a comprehensive measure of a river’s ecological status, it is limited by the traditional morphotaxonomy-based biomonitoring. Recent advances in environmental DNA (eDNA) metabarcoding allow to identify prokaryotes and eukaryotes in one sequencing run, and could thus allow unprecedented resolution. Whether such eDNA-based data can be used directly to predict the pollution status of rivers as a complementation of environmental data remains unknown. Here we used eDNA metabarcoding to explore the main stressors of rivers along which community structure changes, and to identify the method’s potential for predicting pollution status based on eDNA data. We showed that a broad range of taxa in bacterial, protistan, and metazoan communities could be profiled with eDNA. Nutrients were the main driving stressor affecting communities’ structure, alpha diversity, and the ecological network. We specifically observed that the relative abundance of indicative OTUs was?significantly correlated with nutrient levels. These OTUs data could be used to predict the nutrient status up to 79% accuracy on testing data sets. Thus, our study gives a?novel approach to predicting the pollution status of rivers by eDNA data.Li, F., Zhang, X., Renata, H., 2019. Enzymatic C–H functionalizations for natural product synthesis. Current Opinion in Chemical Biology 49, 25-32. functionalization of C–H bond is rapidly becoming an indispensible tool in chemical synthesis. However, due to the ubiquity of C–H bonds, achieving site-selective functionalization remains an arduous task, especially on advanced synthetic intermediates or natural products. In contrast, Nature has evolved a multitude of enzymes capable of performing this task with extraordinary selectivity, and the use of these enzymes in organic synthesis may provide a viable solution to contemporary challenges in site-selective functionalization of complex molecules. This review covers recent applications of enzymatic C–H functionalization strategies in natural product synthesis, both in the context of key building block preparation and late-stage functionalization of advanced synthetic intermediates.Li, G., Gao, P., Zhi, B., Fu, B., Gao, G., Chen, Z., Gao, M., Wu, M., Ma, T., 2018. The relative abundance of alkane-degrading bacteria oscillated similarly to a sinusoidal curve in an artificial ecosystem model from oil-well products. Environmental Microbiology 20, 3772-3783. phylogenetic diversity and species interactions in natural ecosystems have been investigated extensively, but our knowledge about their ecological roles, community dynamics and succession patterns is far from complete. This knowledge is essential to understand the complicated interactions of microorganisms in natural ecosystems. Here, an artificial ecosystem model of microorganisms was constructed from oil-well products and cultivated in a chemostat to investigate the succession pattern of alkane-degrading bacteria, a functional population in oil reservoirs. Their abundance was quantified by an improved qPCR technique. Our results showed that the phylogenetic structure of this artificial ecosystem model is stable during most of the chemostat cultivation process, while the genotype structure of alkane-degrading bacteria containing alkB genes shifted and their relative abundance oscillated similarly to a sinusoidal curve, like the succession pattern of producers in the Lotka?Volterra model. These results suggest that some theoretical frameworks of macroecology may work well in microbial ecosystems and be an efficient tool to understand them.Li, J., Wang, X., Wei, G., Yang, W., Xie, Z., Li, Z., Guo, J., Wang, Y., Ma, W., Li, J., Hao, A., 2018. New progresses in basic geological theories and future exploration domains of natural gas in China. Natural Gas Industry B 5, 434-443. natural gas exploration expands to deep, ultra-deep and unconventional areas, more and more complex exploration targets are encountered. In this circumstance, it is necessary to improve the existing basic natural gas geological theories for guiding the exploration and discovery of more giant gas fields. In this paper, the researches on basic natural gas geological theories since the beginning of the 12th Five-Year Plan were engaged, and then the key exploration target zones were analyzed. Some results were obtained. (1) The theory of whole-process hydrocarbon generation of organic matters was improved and the geologic theories of organic matter hydrocarbon generation (e.g. the thermal evolution model of kerogen degradation and the successive gas generation of organic matters) were developed. (2) Multi-element natural gas genesis identification method, quantitative evaluation method for different types of seals/caprocks, tight sandstone gas accumulation theory for low hydrocarbon generation intensity region, and hydrocarbon accumulation theory for giant ancient carbonate gas field were established, and the geological theories of gas generation, genesis identification and hydrocarbon accumulation were developed to provide the effective guidance for the exploration breakthrough and discovery of giant gas fields in the key basins of China recently. Four conclusions were reached: (1) ancient carbonate rock, tight sandstone, foreland region, shale and volcanic rock are primary exploration targets for discovering giant gas fields; (2) craton and foreland basins are still the key exploration areas, and ancient uplift, gentle slope and thrust belt are the main enrichment zones; (3) ancient strata and deep formations are critical gas exploration targets in the future; (4) oil cracking gas in marine basins, tight sandstone gas and shale gas are the important replacement resources for future gas reserves and production growth.Li, K., Wang, D., Jiang, S., 2018. Review on enhanced oil recovery by nanofluids. Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles 73, Article 37. addition of nanoparticles into water based fluids (nanofluid) with or without other chemicals to Enhance Oil Recovery (EOR) has recently received intensive interest. Many papers have been published in this area and several EOR mechanisms have been proposed. The main EOR mechanisms include wettability alteration, reduction in InterFacial surface Tension (IFT), increase in the viscosity of aqueous solution, decrease in oil viscosity, and log-jamming. Some of these mechanisms may be associated with the change in disjoining pressure because of the addition of the nanoparticles. The experimental data and results reported by different researchers, however, are not all consistent and some even conflict with others. Many papers published in recent years have been reviewed and the associated experimental data have been analyzed in this paper in order to clarify the mechanisms of EOR by nanofluids. Wettability alteration may be one of the most accepted mechanisms for nanofluid EOR while reduction in IFT and other mechanisms have not been fully proven. The main reason for the inconsistency among the experimental data might be lack of control experiments in which the effect of nanoparticles on oil recovery would be singled out.Li, M., Liu, D., Cong, X.-S., Chen, Q.-T., Shi, N., Wu, J.-H., Yang, Y.-X., Zhang, X.-B., Wu, C.-C., 2018. Isolation and identification of six difunctional ethyl esters from bio-oil and their special mass spectral fragmentation pathways. Energy & Fuels 32, 10649-10655. difunctional ethyl esters (DFEEs), including ethyl 16-hydroxyhexadecanoate, ethyl (Z)-18-hydroxyoctadec-9-enoate, and diethyl (Z)-octadec-9-ene-1,18-dioate, were isolated as nearly pure compounds from sawdust-derived bio-oil. Their structures were tentatively identified by gas chromatography/mass spectrometry (GC/MS) and high-resolution mass spectrometry (HR-MS). Combination transesterification reaction of DFEEs to difunctional methyl esters (DFMEs) and determination of the GC/MS retention time differences of DFEEs and corresponding DFMEs is a simple method to determine the ester group number of unknown DFEEs. GC/MS results indicate that the fragment ions at mass-to-charge ratios (m/z) of 88 and 98 are typical ions for these DFEEs. The former ion is formed via well-known McLafferty rearrangement, whereas the formation pathway of the ion at m/z 98 is unreported before. HR-MS results show that the fragment ion at m/z 98 should be a cyclohexanone radical ion, which is possibly formed via a novel rearrangement initiated by remote hydrogen rearrangement. Besides long-chain DFEEs, long-chain difunctional carboxylic acids (including dicarboxylic acids, ω-hydroxy acids, diacid monomethyl ester, and diacid monoethyl ester) and DFMEs (including diacid dimethyl ester and ω-hydroxy methyl ester) are also typical of the fragment ion at m/z 98. Hence, it is a common characteristic to form the rearrangement ion at m/z 98 for long-chain difunctional carboxylic acids, DFEEs, and DFMEs, and this special mass spectral rearrangement could facilitate the identification of these classes of compounds. Using this rearrangement rule of DFEEs, three ω-hydroxy ethyl esters, including ethyl 22-hydroxydocosanoate, ethyl 24-hydroxytetracosanoate, and ethyl 26-hydroxyhexacosanoate, were tentatively identified by GC/MS.Li, S., Wei, N., Li, H., Pang, W., Xi, Y., Zhen, L., Fu, Q., 2018. Migration characteristics of solid-phase particles in horizontal pipes in the exploitation of marine gas hydrate reservoirs through solid fluidization. Natural Gas Industry 38, 100-106. paper aims to find out the migration law of solid phase particles in horizontal pipe sections in the exploitation of natural gas hydrate resources through solid fluidization. First, based on the liquid–solid two-phase flow model, the Fluent software was applied to couple with the EDEM software to simulate the migration of solid hydrate particles transported through horizontal pipe segments with different liquid phase velocities, various particle sizes and hydrate abundances. Then a large physical experimental simulator for solid fluidization exploitation was adopted to validate the results of numerical simulation. The following findings were obtained. (1) The main migration modes of single-particle hydrate in horizontal section are saltation and creep. And the migration pattern of hydrate particle clusters in horizontal pipe section was greatly affected by hydrate abundance, liquid phase velocity, pipe diameter and solid particle size; (2) When the hydrate abundance and the liquid phase velocity are higher and the pipe diameter is small, the migration modes of solid particles are dominated by saltation and creep movement; conversely, the migration mode is mainly suspension movement. (3) To increase the inlet liquid velocity is an efficient means to improve the purification effect in horizontal tube sections. It is concluded that choosing the secondary crushing device with better crushing effect can improve the purification effect of solid particle clusters in horizontal pipe section. Besides, the pressure drop in the horizontal pipe section is mainly affected by the liquid velocity. In the prerequisite of meeting the lifting pump equipment load, the liquid velocity should be adjusted to achieve the appropriate liquid phase flow rate.Li, X., Ding, Y., Xu, J., He, X., Han, T., Kang, S., Wu, Q., Mika, S., Yu, Z., Li, Q., 2018. Importance of mountain glaciers as a source of dissolved organic carbon. Journal of Geophysical Research: Earth Surface 123, 2123-2134. sheets and glaciers have been shown to deliver large amounts of labile dissolved organic carbon (DOC) to downstream aquatic ecosystems, but recent studies may underestimate the release of DOC from mountain glaciers. To date, continuous measurements of DOC from mountain glaciers throughout entire glacier melt season are very limited. Here we present high-density data on DOC from two Asian mountain glaciers over a full melt season in 2013 and compile a global data set of DOC from 42 mountain glaciers. Based on our study and previously published DOC data, we estimate the storage and release of DOC associated with Asian mountain glaciers to be 8.8 to 13.8?Tg?C and 0.19?Tg?C/a, respectively. Rough extrapolation of glacier runoff to a global scale suggests that DOC release from mountain glaciers is on the order of 0.8?Tg?C/a, which is 1.4 times higher than the most current estimates. The current release of DOC from mountain glaciers is therefore far more significant than previously thought and should be considered in future evaluation of the global carbon cycle.Li, X., Gao, D., Hou, L., Liu, M., 2019. Salinity stress changed the biogeochemical controls on CH4 and N2O emissions of estuarine and intertidal sediments. Science of The Total Environment 652, 593-601. salinity is expected to drive changes in biogeochemical cycling and microbial communities in estuarine and intertidal wetlands. However, limited information regarding the role of salinity in shaping biogeochemical controls and mediating greenhouse gas emissions is currently available. In this study, we used incubation experiment across salinity gradients of the estuarine and intertidal sediments to reveal the underlying interconnections of CH4 and N2O emissions, biogeochemical controls and salinity gradients. Our results indicated that sediment biogeochemical properties were significantly affected by the increasing salinity, which were attributed to the accelerated sediment enzyme activities. The increasing salinity promoted CH4 and N2O emission rates by stimulating organic carbon decomposition and nitrogen transformation rates. In addition, the copy number of mcrA, nirS and nirK genes increased along with the salinity gradients, which strongly mediated the CH4 and N2O emission rates. Stepwise regression analysis suggested that labile organic carbon and denitrification were the most crucial determinants of CH4 and N2O emission rates, respectively. Overall, salinity could enhance CH4 and N2O emission mainly by altering sediment geochemical variables, microbial activity and functional gene abundance in estuarine and intertidal environments. Furthermore, increasing salinity could enhance the carbon and nitrogen export, which may pose a threat to the ecological function of estuarine and intertidal ecosystems. This study may contribute to the knowledge about the importance of biogeochemical controls induced by salinity in mediating greenhouse gas emissions.Li, Y., Hu, Z., Liu, X., Duan, X., Gao, S., Wang, W., Chang, J., 2019. Pressure-dependent equilibrium molecular simulation of shale gas and its distribution and motion characteristics in organic-rich nano-slit. Fuel 237, 1040-1049. an unconventional natural gas resource, shale gas plays a significant role in satisfying increasing global energy demands. Because of the less costs and better repeatability of molecular simulation for nano-scale research, it’s becoming a nice way to study the distribution and motion characteristics of shale gas, which is the key to get insights into the nano-scale effects in shale matrix. In this paper, pressure-dependent equilibrium molecular simulation of shale gas in organic-rich nano-slit is conducted, where the gas is divided into clearly defined layers and the structural and motion characteristics of different parts are detailedly analyzed, making systematic observations and descriptions of nano-scale effects happen. By virtue of this, the variation law of shale gas in the nano-slit and the mechanical theory behind it are proposed. Results also reveal the main reason for the roundabout ascension variation of Knudsen layer (KL) thickness, the role of density gullies as “lubricant layers” to enhance the diffusion in adsorption layers, the evidence of the role of gas-gas interactions in controlling molecular motion in addition to gas-wall interactions, nano-scale effects on gas movability with pressure from the viewpoint of gas development, etc. The physical phenomena caused by nano-scale effects and their variations with pressure in organic-rich nano-slit have been explicitly clarified, which is expected to be a useful reference for shale gas evaluation and exploitation.Li, Y., Li, L., 2018. Improving accuracy of peak-pair intensity ratio measurement in differential chemical isotope labeling LC–MS for quantitative metabolomics. International Journal of Mass Spectrometry 434, 202-208. chemical isotope labeling (CIL) liquid chromatography mass spectrometry (LC–MS) has become a powerful platform for quantitative metabolomic analysis. With differential isotope labeling of individual samples (e.g., 12C2-labeling) and a control sample (e.g., 13C2-labeling), the resulting mixtures (12C2-labeled sample and 13C2-labeled control) can be analyzed using LC–MS to detect peak pairs of labeled metabolites from which the peak-pair intensity ratios can be measured to provide the basis of relative quantification of metabolites in different samples. Depending on the mass difference of the light and heavy reagents used and the number of reagent tags attached to a metabolite, the mass difference within a peak pair can be as low as 2?Da. With 2-Da difference, the natural isotopologue of the light labeled molecular ion can overlap with that of the heavy labeled molecular ion of the same metabolite, causing potential interference in the measurement of the heavy peak intensity. In this work, we report our study of the natural isotope relative peak intensity of the most common elements in human endogenous metabolites, including carbon, hydrogen, oxygen, nitrogen, phosphor and sulfur, and their contributions to the intensity of the 2-Da-heavier labeled peak. We propose a simple data processing method to estimate and remove the natural isotope interference for improving the measurement accuracy of peak-pair intensity ratios.Li, Y., Liles, M.R., Halanych, K.M., 2018. Endosymbiont genomes yield clues of tubeworm success. The ISME Journal 12, 2785-2795. years after discovery of chemosynthetic symbiosis in the tubeworm Riftia pachyptila, how organisms maintain their unique host–symbiont associations at the cellular level is still largely unknown. Previous studies primarily focus on symbionts associated with host lineages living in hydrothermal vents. To understand physiological adaptations and evolution in these holobiont systems in markedly different habitats, we characterized four novel siboglinid-symbiont genomes spanning deep-sea seep and sedimented environments. Our comparative analyses suggest that all sampled siboglinid chemoautotrophic symbionts, except for frenulate symbionts, can use both rTCA and Calvin cycle for carbon fixation. We hypothesize that over evolutionary time siboglinids have been able to utilize different bacterial lineages allowing greater metabolic flexibility of carbon fixation (e.g., rTCA) enabling tubeworms to thrive in more reducing habitats, such as vents and seeps. Moreover, we show that sulfur metabolism and molecular mechanisms related to initial infection are remarkably conserved across chemoautotrophic symbionts in different habitats. Unexpectedly, we find that the ability to use hydrogen, as an additional energy source, is potentially more widespread than previously recognized. Our comparative genomic results help elucidate potential mechanisms used to allow chemosynthetically dependent holobionts adapt to, and evolve in, different environments.Li, Y., Song, G., Massicotte, P., Yang, F., Li, R., Xie, H., 2018. Distribution, seasonality, optical characteristics, and fluxes of dissolved organic matter (DOM) in the Pearl River (Zhujiang) estuary, China. Biogeosciences Discussions 2018, 1-53. organic carbon concentration in the Pearl River estuary (PRE) of China was measured in May, August, and October 2015 and January 2016. Chromophoric and fluorescent dissolved organic matter (CDOM and FDOM) in the latter three seasons were characterized by absorption and fluorescence spectroscopy. Parallel factor analysis of the fluorescence spectra identified two protein-like, two humic-like, and one oxidized quinone-like FDOM components. The seasonality of average DOM abundance varied as follows: DOC: May (156μmolL?1)>January (114μmolL?1)≈August (112μmolL?1)>November (86μmolL?1); CDOM absorption at 330nm: August (1.76m?1)>November (1.39m?1)≈January (1.30m?1); FDOM expressed as the sum of the maximum fluorescence intensities of all FDOM components: November (1.77R.U.)>August (1.54R.U.)≈January (1.49R.U.). Average DOM abundance in surface water was higher than in bottom water, their difference being marginal (0.1–10%) for DOC in all seasons and for CDOM and FDOM in November and January, and moderate (16–21%) for CDOM and FDOM in August. DOC showed little cross-estuary variations in all seasons while CDOM and FDOM in January were higher on the west side of the estuary than in the middle and on the east side. All three variables exhibited large variations and/or rapid drawdowns at the head of the estuary (salinity<5) due to multiple freshwater endmembers and/or biotic losses. In the saltier zone, they declined linearly with salinity except relatively constant DOC in May and November. The decrease in FDOM was 5–35% faster than that in CDOM, which in turn was 2–3 times faster than that in DOC. Salinity and CDOM absorption coefficients can serve as indicators of DOC in August and January. Absorbance- and fluorescence-based indices demonstrate that freshwater endmembers in all seasons mainly contained fresh, protein-rich DOM of microbial origin, though the proportion of humic-like components was somewhat higher in August. Protein-like materials were preferentially consumed in the low-salinity section but the dominance of the microbial signature was maintained throughout the saltier zone. Exports of DOC and CDOM (in terms of a330) into the South China Sea were estimated as 195×109g and 266×109m2 for the PRE, and 362×109g and 493×109m2 for the entire Pearl River Delta. Compared to other world major estuaries, the PRE presents the lowest concentrations and export fluxes of DOC and CDOM. Nonetheless, DOM delivered by the PRE is protein-rich and thus may significantly impact the local ecosystem.Li, Z., Fu, Y., Zhou, A., Zhu, C., Yang, C., Shen, N., Yang, C., 2019. Effect of multi-intensification on the liberation of maceral components in coal. Fuel 237, 1003-1012. order to achieve high-quality coal resources in western China, this study focused on a coal sample from the Shangwan Coal Mine, owned by the China Shendong Group, and employed scanning electron microscopy (SEM), mineral liberation analysis (MLA), and maceral component quantitative analysis for investigating the coal sample’s liberation characteristics and crack distribution patterns after pre-grading and microwave processing. The results show that the physical properties of coal maceral components significantly affected the related enrichment performances, and many intra-group and inter-group cracks were produced under the induction of microwave radiation. The cracks then developed and stopped growing among the different maceral components and mineral components, thereby inducing selective and random pulverization along the crack growth direction in further pulverization process and effectively enhancing the liberation properties of different components. Using the Sandbox method, the fractal dimension of the cracks on the particle surface was calculated to be 1.01, which confirmed the self-similarity of the cracks on the coal surface. Multi-intensification maceral liberation also yielded favorable grading performances. The inertinite content was the highest (75.23%) in grade-3 product, while the vitrinite content was the highest (66.3%) in grade-1 product; the corresponding enrichment ratios were 2.15 and 1.59, respectively. Moreover, the ash content in grade-2 product was the lowest, which dropped by 3.61% compared with that in raw coal sample.Liao, J., Lu, H., Feng, Q., Zhou, Y., Shi, Q., Peng, P.a., Sheng, G., 2018. Two novel decamethylhenicosanes (C31H64) identified in a Maoming Basin shale, China. Organic Geochemistry 125, 212-219. new C31 branched alkanes (botryococcanes) presumably produced by the B race of Botryococcus braunii were isolated and purified from the Maoming Basin shales using column chromatography and preparative gas chromatography and structurally characterized with HR-EI-MS and 1D and 2D NMR. Interpretation of their EI mass spectral and 1D and 2D NMR (HMBC and HSQC) data led to the firm assignments of the two alkanes as diastereoisomeric 2,3,6,7,10,12,15,16,19,20-decamethylhenicosanes (DMHs). The structural assignments were further confirmed by the close match of the measured 13C NMR chemical shifts with those predicted by Lindeman-Adams 13C chemical shift modeling. The skeletons of these two DMHs are virtually identical to that of the recently identified C33 botryococcane/botryococcanone in the same sample. It is proposed that these two DMHs share a precursor C33 botryococcene biochemically formed by condensing two farnesyl diphosphates involving an unusual cyclobutanation, a retro-Prins reaction and a tetramethylation. A photo-mediated geochemical oxidation of the double bond in the ethenyl group connected to the sole quaternary carbon C-10 is also proposed to be responsible for the formation of the co-occurring DMHs and C33 botryococcane/botryococcanone.Liao, W., Hu, J., Peng, P.a., 2018. Burial of organic carbon in the Taiwan Strait. Journal of Geophysical Research: Oceans 123, 6639-6652. carbon (OC) burial in nondeltaic continental shelves is an important part of the global carbon cycle. Of these, the Taiwan Strait (TWS) is a typical, nondeltaic shelf region that is influenced by a variety of factors including strong ocean currents, coastal upwelling, and small river inputs. To better understand how these factors influence OC burial in the TWS, we measured total organic carbon and total nitrogen contents as well as the stable carbon isotopes of sedimentary organic matter (δ13Corg) from the TWS. We also measured glycerol dialkyl glycerol tetraethers in surface sediments collected from the TWS. The concentrations of sedimentary total organic carbon and total nitrogen along the coast were high but decreased in areas more central to the TWS. This gradient was controlled by both hydrological conditions and coastal upwelling. The calculated accumulation rate of organic carbon ranged from 1.9 to 47.2 g C/m2/year and was comparable to other areas of the Chinese marginal seas. The source contribution calculated from the three‐end‐member model revealed that mostly marine OC was buried in the upwelling regions. In comparison, OC derived from terrestrial plant and soil was buried in the estuaries. Collectively, these results showed that the TWS may serve as a CO2 sink in the global carbon cycle. This is due to the preservation of the labile portions of the OC derived from plant and marine source, which formed the main component of the buried OC in the TWS. Liao, W., Hu, J., Zhou, H., Hu, J., Peng, P.a., Deng, W., 2018. Sources and distribution of sedimentary organic matter in the Beibu Gulf, China: Application of multiple proxies. Marine Chemistry 206, 74-83. and biomarker methods were combined to investigate the sources of sedimentary organic matter (OM) and their spatial distribution in the Beibu Gulf, a subtropical estuary in southern China. We measured the total organic carbon (TOC) and total nitrogen (TN) content, the glycerol dialkyl glycerol tetraethers (GDGTs) concentration, as well as the isotopic composition of sedimentary OM (δ13Corg and δ15N) in surface sediments collected from the Beibu Gulf. The spatial distribution of the bulk organic parameters (TOC, TN, C/N ratio, δ13Corg, and δ15N) revealed a generally decreasing trend in terrestrial OM from the Maowei Sea to the outer Qinzhou Bay, and from the tributary rivers to the outer bay. The BIT (branched/isoprenoid tetraether) indices also decreased seaward from the Maowei Sea to the Qinzhou Bay, and from rivers to the outer bay, showing that soil OM was mainly delivered to the bay by rivers. The spatial patterns of these bulk parameters suggest that the terrigenous OC is constrained to the coast and adjacent regions. The relatively high GDGT-0/Crenarchaeol ratios and increasing δ15N values along the coast of the Maowei Sea indicate the anthropogenic nitrogen in the Beibu Gulf. Our results show how important a multiproxy approach can be to fully understand and quantify the relative contributions of terrestrial and marine OC components and the biogeochemical processes in the Beibu Gulf, especially in the context of growing anthropogenic activities.Liao, X., Wu, Z., Li, Y., Luo, J., Su, C., 2018. Enhanced degradation of polycyclic aromatic hydrocarbons by indigenous microbes combined with chemical oxidation. Chemosphere 213, 551-558. this study, the removal efficiency PAHs by chemical oxidation combined with microbe remediation was evaluated in two contaminated soils. The number of indigenous soil microbes decreased after the addition of chemical oxidants and then increased by nutrients addition. The total removal efficiencies of PAHs by chemical oxidation and nutrient addition followed the order: activated persulfate?>?potassium permanganate?>?modified Fenton reagent?>?Fenton reagent. There are 24.29–27.97%, 22.00–23.67%, 10.24–13.74% and 1.9–2.5% contributions separately due to nutrient treatment in Fenton, modified Fenton, activated persulfate and potassium permanganate treatment, which show significantly difference. The different chemical oxidants exhibited 78–90% removal efficiency for 5–6 rings PAHs, while 52–85% removal efficiency for 2–4 rings PAHs. With the addition of nutrients, the growth of indigenous microbes was enhanced significantly, and the contents of 2–4 rings PAHs in the soil were further decreased. Furthermore, the removal efficiencies of NAP and ANY were increased by more than 45%, while the removal efficiencies of ANE, FLE and PHE were about 30% at Fenton system. There was a complementary enhancing effect of microbial remediation for PAHs degradation after chemical oxidation.Lijun, L., Jun, Y., Hai, S., Zhaoqin, H., Xia, Y., Longlong, L., 2019. Compositional modeling of shale condensate gas flow with multiple transport mechanisms. Journal of Petroleum Science and Engineering 172, 1186-1201. condensate gas has gained great attention in recent years due to the production of profitable liquid hydrocarbons. The fluid flow in shale matrix is complex and influenced by multiple transport mechanisms, such as stress sensitivity, Knudsen diffusion, adsorption, molecular diffusion, and confined phase behavior. In addition, the coexistence of multiscale pore space, including hydraulic fractures, micro-fractures in simulated reservoir volume (SRV) and nanopores in matrix further increases the fluid flow complexity. Conventional models cannot commonly consider all the factors. In this work, we develop a hybrid model for condensate gas reservoir, where fluid flow is described by compositional model coupled with transport mechanisms, micro-fractures and hydraulic fractures are handled by multiple interacting continua (MINC) model and embedded discretized fracture model (EDFM). Then based on the proposed model, the effects of gas transport mechanisms on a multi-stage fractured horizontal well production are analyzed, where simulations are conducted with and without SRV to investigate the importance of SRV. Furthermore, some important reservoir parameters, such as SRV properties, hydraulic fracture length and bottom-hole pressure are also investigated with the proposed model.Lind, A.E., Lewis, W.H., Spang, A., Guy, L., Embley, T.M., Ettema, T.J.G., 2018. Genomes of two archaeal endosymbionts show convergent adaptations to an intracellular lifestyle. The ISME Journal 12, 2655-2667. is a widespread phenomenon in the microbial world and can be based on diverse interactions between endosymbiont and host cell. The vast majority of the known endosymbiotic interactions involve bacteria that have invaded eukaryotic host cells. However, methanogenic archaea have been found to thrive in anaerobic, hydrogenosome-containing protists and it was suggested that this symbiosis is based on the transfer of hydrogen. Here, we used culture-independent genomics approaches to sequence the genomes of two distantly related methanogenic endosymbionts that have been acquired in two independent events by closely related anaerobic ciliate hosts Nyctotherus ovalis and Metopus contortus, respectively. The sequences obtained were then validated as originating from the ciliate endosymbionts by in situ probing experiments. Comparative analyses of these genomes and their closest free-living counterparts reveal that the genomes of both endosymbionts are in an early stage of adaptation towards endosymbiosis as evidenced by the large number of genes undergoing pseudogenization. For instance, the observed loss of genes involved in amino acid biosynthesis in both endosymbiont genomes indicates that the endosymbionts rely on their hosts for obtaining several essential nutrients. Furthermore, the endosymbionts appear to have gained significant amounts of genes of potentially secreted proteins, providing targets for future studies aiming to elucidate possible mechanisms underpinning host-interactions. Altogether, our results provide the first genomic insights into prokaryotic endosymbioses from the archaeal domain of life.Lindh, M.V., Pinhassi, J., 2018. Sensitivity of bacterioplankton to environmental disturbance: A review of Baltic Sea field studies and experiments. Frontiers in Marine Science 5, 361. doi: 10.3389/fmars.2018.00361. communities regulate energy and matter fluxes fundamental to all aquatic life. The Baltic Sea offers an outstanding ecosystem for interpreting causes and consequences of bacterioplankton community composition shifts resulting from environmental disturbance. Yet, a systematic synthesis of the composition of Baltic Sea bacterioplankton and their responses to natural or human-induced environmental perturbations is lacking. We review current research on Baltic Sea bacterioplankton dynamics in situ (48 articles) and in laboratory experiments (38 articles) carried out at a variety of spatiotemporal scales. In situ studies indicate that the salinity gradient sets the boundaries for bacterioplankton composition, whereas regional environmental conditions at a within-basin scale, including the level of hypoxia and phytoplankton succession stages, may significantly tune the composition of bacterial communities. Also the experiments show that Baltic Sea bacteria are highly responsive to environmental conditions, with general influences of e.g. salinity, temperature and nutrients. Importantly, nine out of ten experiments that measured both bacterial community composition and some metabolic activities showed empirical support for the sensitivity scenario of bacteria – i.e. that environmental disturbance caused concomitant changes in both community composition and community functioning. The lack of studies empirically testing the resilience scenario, i.e. experimental studies that incorporate the long-term temporal dimension, precludes conclusions about the potential prevalence of resilience of Baltic Sea bacterioplankton. We also outline outstanding questions emphasizing promising applications in incorporating bacterioplankton community dynamics into biogeochemical and food-web models and the lack of knowledge for deep-sea assemblages, particularly bacterioplankton structure-function relationships. This review emphasizes that bacterioplankton communities rapidly respond to natural and predicted human-induced environmental disturbance by altering their composition and metabolic activity. Unless bacterioplankton are resilient, such changes could have severe consequences for the regulation of microbial ecosystem services.Lindon, J.C., Nicholson, J.K., Holmes, E., 2019. The Handbook of Metabolic Phenotyping. Elsevier, p. 619. Handbook of Metabolic Phenotyping is the definitive work on the rapidly developing subject of metabolic phenotyping. It explores in detail the wide array of analytical chemistry and statistical modeling techniques used in the field, coupled with surveys of the various application areas in human development, nutrition, disease, therapy, and epidemiology to create a comprehensive exploration of the area of study. It covers recent studies that integrate the various -omics data sets to derive a systems biology view. It also addresses current issues on standardization, assay and statistics validation, and data storage and sharing. Written by experts with many years of practice in the field who pioneered many of the approaches widely used today, The Handbook of Metabolic Phenotyping is a valuable resource for postgrads and research scientists studying and furthering the field of metabolomics.Key Features·Contains theoretical and practical explanations of all the main analytical chemistry techniques used in metabolic phenotyping ·Explores, in detail, the many diverse statistical approaches used in the field ·Offers practical tips for successfully conducting metabolic phenotyping studies ·Features reviews of all of the various fields of activity relating to human studiesChapter 1 - An Overview of Metabolic Phenotyping and Its Role in Systems Biology, Elaine Holmes, Ian D. Wilson and John C. Lindon, Pages 1-51Chapter 2 - NMR Spectroscopy Methods in Metabolic Phenotyping, John A. Parkinson, Pages 53-96Chapter 3 - The Role of Ultra Performance Liquid Chromatography-Mass Spectrometry in Metabolic Phenotyping, Warwick B. Dunn and Matthew R. Lewis, Pages 97-136Chapter 4 - GC-MS-Based Metabolic Phenotyping, Olga Deda, Helen Gika, Nikolaos Raikos, Georgios Theodoridis, Pages 137-169Chapter 5 - Metabolic Phenotyping Using Capillary Electrophoresis Mass Spectrometry, Joanna Godzien, ?ngeles López-Gonzálvez, Antonia García, Coral Barbas, Pages 171-204Chapter 6 - Supercritical Fluid Chromatography for Metabolic Phenotyping: Potential and Applications, Ian D. Wilson and Robert S. Plumb, Pages 205-217Chapter 7 - The iKnife: Development and Clinical Applications of Rapid Evaporative Ionization Mass Spectrometry, Babar Vaqas, Simon J. Cameron, James L. Alexander, Kevin S. O’Neill, James M. Kinross, Zoltan Takats, Pages 219-236Chapter 8 - Univariate Statistical Modeling, Multiple Testing Correction, and Visualization in Metabolome-Wide Association Studies, Rapha?le Castagné and Marc Chadeau-Hyam, Pages 237-260Chapter 9 - Multivariate Statistical Methods for Metabolic Phenotyping, Joram M. Posma, Pages 261-308Chapter 10 - Data-Driven Visualizations in Metabolic Phenotyping, Dieter Galea, Ivan Laponogov and Kirill Veselkov, Pages 309-328Chapter 11 - Big Data and Databases for Metabolic Phenotyping, Timothy M.D. Ebbels, Jake T.M. Pearce, Noureddin Sadawi, Jianliang Gao, Robert C. Glen, Pages 329-367Chapter 12 - Progress in Standardization of Metabolic Phenotyping Data, Reza M. Salek, Pages 369-384Chapter 13 - Conception, Implementation and Operation of Large-Scale Metabolic Phenotyping Centres: Phenome Centres, Frank W. Bonner, Lynn Maslen, John C. Lindon, Matthew R. Lewis, Jeremy K. Nicholson, Pages 385-405Chapter 14 - Applications of Metabolic Phenotyping in Pharmaceutical Research and Development, Jeremy R. Everett, Pages 407-447Chapter 15 - Metabolic Phenotyping in Nutrition Research, Lorraine Brennan. Pages 449-460Chapter 16 - Metabolic Phenotyping in Clinical Practice, James M. Kinross, Pages 461-489Chapter 17 - Applications of Metabolic Phenotyping in Epidemiology, Rui Climaco Pinto, Ibrahim Karaman, Julia C. Fussell, Evangelos Evangelou, Frank J. Kelly, Paul Elliott, Ioanna Tzoulaki, Pages 491-534Chapter 18 - Influence of the Human Gut Microbiome on the Metabolic Phenotype, Lesley Hoyles and Jonathan Swann, Pages 535-560Chapter 19 - Linking Metabolic Phenotyping and Genomic Information, Abbas Dehghan, Pages 561-569Chapter 20 - Metabolic Phenotyping: History, Status, and Prospects, John C. Lindon, Elaine Holmes and Jeremy K. Nicholson, Pages 571-583Index, Pages 585-597Lindsay, M.R., Amenabar, M.J., Fecteau, K.M., Debes, R.V., Fernandes Martins, M.C., Fristad, K.E., Xu, H., Hoehler, T.M., Shock, E.L., Boyd, E.S., 2018. Subsurface processes influence oxidant availability and chemoautotrophic hydrogen metabolism in Yellowstone hot springs. Geobiology 16, 674-692. geochemistry of hot springs and the availability of oxidants capable of supporting microbial metabolisms are influenced by subsurface processes including the separation of hydrothermal fluids into vapor and liquid phases. Here, we characterized the influence of geochemical variation and oxidant availability on the abundance, composition, and activity of hydrogen (H2)‐dependent chemoautotrophs along the outflow channels of two‐paired hot springs in Yellowstone National Park. The hydrothermal fluid at Roadside East (RSE; 82.4°C, pH 3.0) is acidic due to vapor‐phase input while the fluid at Roadside West (RSW; 68.1°C, pH 7.0) is circumneutral due to liquid‐phase input. Most chemotrophic communities exhibited net rates of H2 oxidation, consistent with H2 support of primary productivity, with one chemotrophic community exhibiting a net rate of H2 production. Abundant H2‐oxidizing chemoautotrophs were supported by reduction in oxygen, elemental sulfur, sulfate, and nitrate in RSW and oxygen and ferric iron in RSE; O2 utilizing hydrogenotrophs increased in abundance down both outflow channels. Sequencing of 16S rRNA transcripts or genes from native sediments and dilution series incubations, respectively, suggests that members of the archaeal orders Sulfolobales, Desulfurococcales, and Thermoproteales are likely responsible for H2 oxidation in RSE, whereas members of the bacterial order Thermoflexales and the archaeal order Thermoproteales are likely responsible for H2 oxidation in RSW. These observations suggest that subsurface processes strongly influence spring chemistry and oxidant availability, which in turn select for unique assemblages of H2 oxidizing microorganisms. Therefore, these data point to the role of oxidant availability in shaping the ecology and evolution of hydrogenotrophic organisms. Liu, B., Shi, J., Fu, X., Lyu, Y., Sun, X., Gong, L., Bai, Y., 2018. Petrological characteristics and shale oil enrichment of lacustrine fine-grained sedimentary system: A case study of organic-rich shale in first member of Cretaceous Qingshankou Formation in Gulong Sag, Songliao Basin, NE China. Petroleum Exploration and Development 45, 884-894. organic-rich shale in the first member of Cretaceous Qingshankou Formation in the Gulong Sag, northern Songliao Basin as an example, this study examined the lithofacies classification, petrological characteristics, pore size distribution and their implications on the enrichment of shale oil of lacustrine detrital fine-grained shale. The spatial variation of lithofacies, controlled by Milankovitch cycle and influenced by sediment provenance, has an obvious sequence. The fine-grained sedimentary rocks of studied section could be classified into seven lithofacies according to a three-step classification criterion that consists of total organic carbon (TOC), sedimentary structure and mineral composition. Among them, the laminated siliceous mudstone lithofacies with moderate TOC has high hydrocarbon generation potential and abundant reservoir space, making it the most favorable lithofacies for the enrichment of matrix shale oil. Under the background of abnormally high pressure, the laminated siliceous mudstone lithofacies with moderate TOC deposited between the top of SSC2 and the bottom of SSC3 is stable in lateral distribution in the delta-lacustrine transition zone, with continuous thickness greater than 30 m. The massive siliceous mudstone lithofacies with high and moderate TOC developed in the middle of the these two cycles can act as the roof and floor seal for shale oil, therefore, the study area has good conditions for forming matrix type shale oil reservoirs.Liu, D., Li, H., Zhang, C., Wang, Q., Peng, P.a., 2019. Experimental investigation of pore development of the Chang 7 member shale in the Ordos basin under semi-closed high-pressure pyrolysis. Marine and Petroleum Geology 99, 17-26. heat simulation experiments were conducted on cylindrical samples, and a series of residue samples of Chang7 shale heated to different temperature were acquired to characterize the evolution and controlling factors of shale reservoir structure. Low pressure adsorption experiments with carbon dioxide and nitrogen as the adsorbents were conducted to characterize the evolution of shale nanopores. Mercury intrusion capillary pressure (MICP) and He–Hg porosities of the raw and residue shale columns were measured to study the evolution of porosities with increasing maturity. Also, the morphology of nanopores and microfractures of Argon ion polished shales was examined using scanning electron microscopy. Decreasing trends of micro- and meso-pores with increasing temperature were mainly caused by masking or occupation of pores by generated oil and bitumens during the oil generation stage. Then the specific surface areas (SSAs) and volumes of micro- and meso-pores increase dramatically with increasing temperature as further nanopores were formed through secondary cracking of the generated oil and bitumens. Destruction of nanopores occurred at the over-maturation stage, and caused decreasing trends of SSAs and volumes of micro-pore, meso-pore and macro-pore from 450?°C, 489?°C and 500?°C, respectively. Shale porosity showed a generally positive correlation with temperature, suggesting that macro-pores and micro-fractures were the predominant reservoirs. That was also observed with focused ion beam scanning electron microscopy. The insights into the evolution of shale nanopores presented in this study are generally in accordance with previous research in North America and China on the properties of these structures in shales at different maturation level.Liu, F., Guo, H., Wang, Q., Haider, R., Urynowicz, M.A., Fallgren, P.H., Jin, S., Tang, M., Chen, B., Huang, Z., 2019. Characterization of organic compounds from hydrogen peroxide-treated subbituminous coal and their composition changes during microbial methanogenesis. Fuel 237, 1209-1216. gas burns cleaner than coal by reducing ～50% of the carbon footprint and emission of toxic substances and particulates. Coalbed natural gas can be produced from coal by indigenous microorganisms. Hydrogen peroxide treatment to coal has been shown to enhance the production of biogenic coalbed natural gas. In this study, we investigated methane generation from a subbituminous coal pretreated by hydrogen peroxide and the changes of the organic composition during gas production. We demonstrate that there is a great potential to produce natural gas from hydrogen peroxide-treated coal by microorganisms. The organic composition of the coal-derived compounds and the bulk organic profiling were changed because of the microbial degradation. The liquid samples before and after gas production were characterized by fluorescence spectrometer, GC/MS, HPLC, GPC, and TOCs. The results indicated that the chemical treatment has produced both labile organic components and compounds that are recalcitrant to microbial degradation. Labile compounds including short-chain carboxylic acids (C1 to C6) were found to contribute to the gas production. HPSEC analysis has shown shifts of molecular weight distributions, confirming organic composition changes. In addition, the analyses suggested that the labile organic compounds were conducive to shorten the lag phase of the gas production, whereas the presumed-recalcitrant constituents were surprisingly slightly biodegraded. The analysis also showed that the chemical treatment and biotransformation could produce compounds that are toxic to the environment. Environmental impacts should be fully evaluated before field applications.Liu, J., An, Z., Liu, H., 2018. Leaf wax n-alkane distributions across plant types in the central Chinese Loess Plateau. Organic Geochemistry 125, 260-269. ecosystems generally contain various plant types (e.g. dicots, monocots, gymnosperms), and an evaluation of the dominant plant type in an ecosystem is the key to understanding geological records in paleoenvironmental research. In this study, we examined n-alkane chain length distributions in terrestrial higher plants in the central Chinese Loess Plateau, and found that average chain length (ACL) could be utilized as an indicator for differentiating gymnosperms from angiosperms. ACL21–33 was less than 27 for gymnosperms, but more than 27 for angiosperms. Moreover, a derived Pv index from a selected n-alkane ratio, (i.e. (C31?+?C33)/ΣCn(n=27–33)), provided a relative criterion for distinguishing between dicots and monocots within the angiosperms. When Pv?<??0.1, the ecosystem was predominated by dicots, but those with Pv?>?0.1, were dominated by monocots. Discrimination of the dominant plant type in an ecosystem is important when leaf wax n-alkanes are used as a proxy for paleoenvironmental reconstructions.Liu, J., Liu, Q., Zhu, D., Meng, Q., Liu, W., Qiu, D., Huang, Z., 2018. The role of deep fluid in the formation of organic-rich source rocks. Journal of Natural Gas Geoscience 3, 171-180. inner basin has been the focus of organic-rich source rocks -related studies for a long time. In contrast, the effect brought by deep fluids on organic-rich source rocks has not received its much-deserved attention. As a belt connecting the inner and external parts of basins, deep fluids promote the formation of organic-rich source rocks by increasing the marine primary productivity and creating favorable conservation environment. In the productivity facet, deep fluids carry a significant amount of nutrients like NO3?, PO43?, NH4+, hydrothermal gases (i.e., CH4, CO2, H2, and NH3), minor metal elements (i.e., Fe, Mn, Zn, Co, and Cu), as well as microbes from the deep earth like Archaebacteria and thermophilic bacteria. The injection of deep fluids assists organisms to thrive in water and helps facilitate the enhancement of marine primary productivity. The results then create favorable conditions for the formation and enrichment of organic matter. In regards to the organic matter conservation facet, the eruption of deep fluids sends a great deal of CO2 into atmosphere and ocean. By connecting with the Ca2+ and Mg2+ in the water, the CO2 above transforms into carbonate and contribute to the ever increasing water salinity. As a consequence, it will cause the stratification and circulation suspension of the ocean as well as the formation of favorable hydrodynamic conditions and preservation environments. In addition, magma and hydrothermal fluids can also create a reductive environment by sending reductive gases like H2S and CO into the water. In summary, the eruption of deep fluids guarantees the production of essential substances and a favorable environment for the formation and preservation of organic-rich source rocks.Liu, Q.-g., Wang, W.-h., Liu, H., Zhang, G., Li, L.-x., Zhao, Y.-l., 2018. Production rate analysis of fractured horizontal well considering multitransport mechanisms in shale gas reservoir. Geofluids 2018, Article 3148298. gas reservoir has been aggressively exploited around the world, which has complex pore structure with multiple transport mechanisms according to the reservoir characteristics. In this paper, a new comprehensive mathematical model is established to analyze the production performance of multiple fractured horizontal well (MFHW) in box-shaped shale gas reservoir considering multiscaled flow mechanisms (ad/desorption and Fick diffusion). In the model, the adsorbed gas is assumed not directly diffused into the natural macrofractures but into the macropores of matrix first and then flows into the natural fractures. The ad/desorption phenomenon of shale gas on the matrix particles is described by a combination of the Langmuir’s isothermal adsorption equation, continuity equation, gas state equation, and the motion equation in matrix system. On the basis of the Green’s function theory, the point source solution is derived under the assumption that gas flow from macropores into natural fractures follows transient interporosity and absorbed gas diffused into macropores from nanopores follows unsteady-state diffusion. The production rate expression of a MFHW producing at constant bottomhole pressure is obtained by using Duhamel’s principle. Moreover, the curves of well production rate and cumulative production vs. time are plotted by Stehfest numerical inversion algorithm and also the effects of influential factors on well production performance are analyzed. The results derived in this paper have significance to the guidance of shale gas reservoir development.Liu, X., Xu, G., 2018. Recent advances in using mass spectrometry for mitochondrial metabolomics and lipidomics - A review. Analytica Chimica Acta 1037, 3-12. and lipidomics generally targets a huge number of intermediate and end products of cellular metabolism in body fluids, tissues, and cells etc. At present, mass spectrometry (MS) based metabolic or lipid profiling of routine biological specimens including the whole cells, tissues, plasma, serum and urine etc., can cover hundreds of metabolites or lipid species in one analysis, which has qualified deep elucidation of global metabolic and lipid networks. Mitochondria are important intracellular organelles and many critical biochemical reactions occur here, they provide building block for new cells, control redox balance, participate in apoptosis and behave as a signalling platform. Evidence suggests high prevalence of mitochondrial dysfunction occurs in a variety of cancers and other diseases, thus there is an urgent demand for investigating and clarifying mitochondrial metabolic and lipid alterations induced by diseases. Nevertheless, mitochondria contribute a small fraction to cellular contents, profiling of whole cell is probably unsuitable for monitoring alterations in mitochondria. Therefore, metabolomics and lipidomics analyses specially for mitochondria are necessary to understand disturbed metabolic and lipid pathways induced by environment and diseases. However, methods for comprehensively profiling metabolites and lipids in mitochondria have been limited at present. This review summarizes the current states and progress of MS-based mitochondrial metabolomics and lipidomics study. Details of mitochondrial isolation procedure, analytical methods and their applications are described. The challenges and opportunities are also given.Liu, Y., Zhu, Y., Chen, S., Wang, Y., Song, Y., 2018. Evaluation of spatial alignment of kerogen in shale using high-resolution transmission electron microscopy, Raman spectroscopy, and Fourier transform infrared. Energy & Fuels 32, 10616-10627. the three-dimensional (3D) molecular structure of kerogen plays important roles in further understanding of shale gas storage and transport, accurate characterization methods for 3D kerogen structures are attracting increasing attention. Spatial alignment is important information for 3D kerogen modeling, but was usually ignored in previous studies. In this work, seven kerogen samples with different maturities were isolated from organic-rich shale using a chemical method and high-resolution transmission electron microscopy (HRTEM) was employed to quantitatively characterize the spatial alignment of these seven kerogen samples. Raman spectroscopy was used to investigate the overall structural disorder of the kerogen molecules and Fourier transform infrared (FT-IR) was conducted to study the chemical structure of these kerogen samples. The results show that immature, mature, and overmature kerogen samples all show an obvious alignment on the scale of 20 nm × 20 nm. In the immature kerogen sample Yl-1 with equivalent vitrinite reflectance (VReqv) = 0.4%, 60% of total aromatic fringes align in the major direction (with a 60° range), while 87% of the total aromatic fringes align in the major direction for the overmature kerogen sample Lmx-3 (VReqv = 3.1%). However, unlike local alignment in the scale of 20 nm × 20 nm, the aromatic fringes in different regions may have different directions in larger scale. Meanwhile, based on FT-IR data, aliphatic carbons and oxygen containing functional groups contribute to a large proportion in immature, mature, and overmature kerogen samples. Thus, immature, mature and overmature kerogen samples all show overall disorder according to Raman data. In addition, the size of aromatic rings is also quantitatively characterized based on HRTEM images. In immature kerogen samples, the proportion of aromatic rings smaller than 3 × 3 is larger than 70%. In mature and overmature kerogen samples, 3 × 3 sized aromatic rings always occupy the largest proportion. This study provides the quantitative information on spatial alignment and the size of aromatic rings for kerogen samples, which contribute to an improved understanding of the 3D structure of kerogen.Liu, Y., Zhu, Y., Liu, S., Chen, S., Li, W., Wang, Y., 2018. Molecular structure controls on micropore evolution in coal vitrinite during coalification. International Journal of Coal Geology 199, 19-30. (<2?nm) play an important role in coalbed methane adsorption, desorption, and diffusion. However, the mechanisms of micropore formation and evolution still need further study. This study primarily focuses on molecular structure controls on micropore evolution during coalification. CO2 adsorption experiments were employed to characterize micropore structure in coals, and 13C nuclear magnetic resonance (13C NMR) and X-ray diffraction (XRD) were employed to characterize the molecular structures of those coal samples. The results demonstrated that micropore evolution during laboratory simulated coalification was similar to that in geo-time-scale natural maturation. This suggests that laboratory simulated coalification can be an effective method for studying micropore evolution during coalification. Micropore evolution in laboratory simulated coalification and natural maturation both exhibited a parabolic curvature with coal rank, with a minimum at ~1.4%. When vitrinite reflectance (Ro) was <1.4%, micropores were mainly controlled by the aliphatic part of the coal samples, and micropore volume decreased with decreasing aliphatic functional groups. When Ro varied from 1.4% to 4.0%, micropore structure was mainly controlled by aromatic parts and coal crystallite structure. In this coalification stage, micropore volume showed linear correlation with the fraction of aromatic bridgehead carbon, the fraction of protonated aromatic carbon, and the ratio of aromatic bridge carbon to aromatic peripheral carbon (XBP). Moreover, the increase in lateral sizes (La) and the decrease in interlayer spacing (d002) both resulted in the increase in micropore volume. In conclusion, the coal microporosity and its evolution were primarily determined by coal molecular structure. In different coalification stages, microporosity and its evolution were controlled by different sub-portions of the whole molecular structure. These findings can provide mechanistic insights of gas sorption and diffusion, as gas sorption and diffusion behaviors are simultaneously controlled by both pore structure and molecular structure.Lje?evi?, M., Gojgi?-Cvijovi?, G., Ieda, T., Hashimoto, S., Nakano, T., Bulatovi?, S., Ili?, M., Be?koski, V., 2019. Biodegradation of the aromatic fraction from petroleum diesel fuel by Oerskovia sp. followed by comprehensive GC×GC-TOF MS. Journal of Hazardous Materials 363, 227-232. aromatic hydrocarbons (PAHs) from petroleum and fossil fuels are one of the most dominant pollutants in the environment. Since aromatic fraction from petroleum diesel fuel is mainly composed of PAHs, it is important to discover new microorganisms that can biodegrade these compounds. This article describes the biodegradation of the aromatic fraction separated from petroleum diesel fuel using the strain Oerskovia sp. CHP-ZH25 isolated from petroleum oil-contaminated soil. The biodegradation was monitored by gravimetry and GC?×?GC-TOF MS. An innovative method was applied to visualize degraded compounds in the data provided by a GC?×?GC-TOF MS. It was shown that Oerskovia sp. CHP-ZH25 degraded 77.4 % based on gravimetric analysis within 30 days. Average rate of degradation was 14.4?mg/L/day, 10.5?mg/L/day and 4.0?mg/L/day from 0-10 day, 10-20 and 20-30 day, respectively. The order of PAH degradation based on decrease in peak volume after 30 days of incubation was as follows: dibenzothiophene derivatives?>?benzo[b]thiophene derivatives?>?naphthalene derivatives?>?acenaphthene derivatives?>?acenaphthylene/biphenyl derivatives?>?fluorene derivatives?>?phenanthrene/anthracene derivatives. Here we demonstrated that Oerskovia sp. CHP-ZH25 could potentially be a suitable candidate for use in bioremediation of environments polluted with different PAHs.Luzius, C., Guillemette, F., Podgorski, D.C., Kellerman, A.M., Spencer, R.G.M., 2018. Drivers of dissolved organic matter in the vent and major conduits of the world's largest freshwater spring. Journal of Geophysical Research: Biogeosciences 123, 2775-2790. Springs is the largest and deepest freshwater spring on Earth and has exhibited increased chromophoric dissolved organic matter (CDOM) inputs (i.e., browning) in recent decades. To examine the drivers of changing dissolved organic matter at the spring vent, we examined dissolved organic carbon concentrations and dissolved organic matter composition via optical parameters (i.e., absorbance and fluorescence) in the major conduits and a connecting spring over the course of 1?year. Sample sites separated clearly based on dissolved organic carbon concentration, CDOM absorbance, and optical parameters indicative of autochthonous (clear groundwater) versus allochthonous (terrestrial) dissolved organic matter. Seasonality was apparent in the allochthonous-dominated sites with increasing terrestrial contribution particularly with large precipitation events post dry periods. Principle component analysis highlights the ability of optical parameters to show the dominance of sample sites draining from the southwest (i.e., Apalachicola National Forest) as responsible for the CDOM-rich water at the vent, whereas water draining from the north was comparatively clear. Increasing CDOM-rich waters at the vent suggests that either input from conduits draining from the southwest has increased, or the relative dilution with clear groundwater has decreased in the conduit system prior to discharge from the vent. Sea level rise impacts in the region have been suggested to result in more blackwaters delivered to the vent, and ongoing extraction of clear groundwater reduces the dilution capacity on CDOM-rich waters. Thus, anthropogenic impacts in the region need to be addressed if the trend of increased CDOM inputs at Wakulla Springs is to be reversed.Lv, J., Miao, Y., Huang, Z., Han, R., Zhang, S., 2018. Facet-mediated adsorption and molecular fractionation of humic substances on hematite surfaces. Environmental Science & Technology 52, 11660-11669. between dissolved organic matter (DOM) and iron oxyhydroxides have important environmental and geochemical implications. The present study employed two hematite nanocrystals to investigate the adsorption and molecular fractionation of two typical humic substances (HSs) using electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR-MS). Hematite with a predominant exposure of {100} facets induced more pronounced adsorption and molecular fractionation of HSs than {001} facets, indicating that the interfacial adsorptive fractionation process of HSs was mediated by exposed facets of hematite. Further exploration of the surface OH groups of the two hematite nanocrystals confirms that the facet-mediated molecular fractionation of HSs was attributable to the abundance of singly iron-atom coordinated ?OH sites on the hematite surfaces. Molecules with a high oxidation state and high aromaticity such as oxidized black carbon, polyphenol-like, and tannic-like compounds preferentially formed ligand-exchange complexes with singly coordinated ?OH groups on the hematite surfaces, inducing the selective binding and molecular fractionation of HSs at the mineral–water interface. These results demonstrate that singly iron-atom coordinated ?OH sites determine DOM adsorption and mediate molecular fractionation on hematite surfaces, and this contributes substantially to our understanding of the molecular mechanisms of iron oxyhydroxide-mediated molecular exchange of DOM in soils and/or sediments.Ma, A., Jin, Z., Zhu, C., Gu, Y., 2018. Detection and significance of higher thiadiamondoids and diamondoidthiols in oil from the Zhongshen 1C well of the Tarim Basin, NW China. Science China Earth Sciences 61, 1440-1450. and gas breakthroughs have been achieved in the Zhongshen 1 (ZS1) and 1C (ZS1C) wells in Cambrian pre-salt from the Tarim Basin in northwest China. However, Middle and Lower Cambrian reservoirs reveal substantial differences in the geochemistry and secondary alteration characteristics between the oils collected from the two wells. High concentrations of thiadiamondoids and diamondoidthiols, including thiatetramantanes, tetramantanethiols, thiapentamantanes, and pentamantanethiols, are detected in the organic sulfur compound fraction of concentrated oil collected from the ZS1C well, which samples the Lower Cambrian Xiaoerbulake Formation. Higher diamondoids, such as tetramantanes, pentamantanes, hexamantanes, and cyclohexamantane, also occur in the saturate fractions of the concentrated ZS1C oil. The presence of these compounds is verified by mass spectra analysis and comparison with previous studies. During thermochemical sulfate reduction (TSR), the cage of higher diamondoids is interpreted to open because of sulfur radicals forming open-cage higher diamondoid-like thiols, followed by cyclization that leads to the formation of high thiadiamondoids. Using D16-adamantane as an internal standard, the concentrations of lower diamondoids and thiadiamondoids of non-concentrated Cambrian oil from well ZS1C are 83874 and 8578 μg/g, respectively, which are far higher than Cambrian oil from well ZS1 and most Ordovician oils in the Tarim Basin. The high concentrations of lower thiadiamondoids and occurrence of higher thiadiamondoids and diamondoidthiols support that the oil from well ZS1C is a product of severe TSR alteration.Ma, P., Li, Y., Wang, C., Zheng, L., Lv, D., Zou, Y., Li, S., 2018. Oligocene-Miocene source rocks of the Zhongcang Basin: Implications for hydrocarbon potential differentiation between lake basins in Central Tibet. International Journal of Coal Geology 199, 124-137. Oligocene-Miocene Dingqinghu Formation is widely distributed in lake basins of the Bangong-Nujiang suture zone (BNSZ), central Tibet and has been reported as an important source rock layer. However, limited works have been conducted in the Zhongcang Basin. To gain knowledge on hydrocarbon potential of this area and further investigate the organic matter (OM) accumulation mechanisms of source rocks in the BNSZ basins, samples collected along two measured sections from the Zhongcang Basin were subjected to sedimentological, organic geochemical and petrographic analyses. Sedimentological analyses indicate that all samples were deposited in prodeltic to deep lake environments. Total organic carbon (TOC) values and pyrolysis data suggest a poor to fair hydrocarbon source potential of the middle Dingqinghu Formation, with the exception of OM-rich samples locate in a marker bed of the upper part. Vitrinite reflectance (Ro) values of the upper part and middle-lower part samples range from 0.41 to 0.50 and 0.52 to 0.61, indicating immature and marginal mature stages, respectively. These maturity levels were also supported by specific maturity indices of sample extracts, such as ratios of C31 22S/(22S?+?22R) homohopanes and C29 ββ/(αα?+?ββ) steranes. Bulk geochemistry, maceral composition of kerogen, and extract biomarkers demonstrate that OM-rich samples were deposited in fresh to brackish waters with type II-III kerogen mainly derived from algae and higher plants; while poor to fair samples have less higher plant contribution, but relatively high bacterial content that probably originated from more saline environments. The paleoclimate-induced environmental reorganization is likely responsible for the differential OM accumulation in the Zhongcang Basin; relatively wet climates would facilitate primary productivity of the lake as well as development of swamps on the delta, resulting in deposition of mixed terrestrial and aquatic OM with higher TOC, whilst dry conditions would restrict the development of river systems and promote the establishment of saline environments, causing decreased total OM input but increased proportion of halophilic bacterial OM. In addition, we summarized published data of the Dingqinghu Formation in the BNSZ basins and preliminarily reconstructed paleogeography of central Tibet. Two types of drainage patterns were confirmed in this area. A long-lived hierarchical drainage system is developed in the Lunpola area, while single lake systems were prevalent in other basins, including the Zhongcang Basin. The hierarchical drainage pattern could minimize clastic dilution effects during tectonic active and/or relatively wet periods, and prevent the establishment of hypersaline environments during the dry period. The drainage center in this kind of hierarchical system has lower sedimentation accumulation rate and could receive much more aquatic OM at any climatic conditions. We argue that tectonic-induced drainage organization primarily controlled the hydrocarbon potential differentiation between lake basins of central Tibet.Ma, Y., Lu, G., Shao, C., Li, X., 2019. Molecular dynamics simulation of hydrocarbon molecule adsorption on kaolinite (0?0?1) surface. Fuel 237, 989-1002. dynamics simulation method was used to systematically study the adsorption configuration, density distribution and adsorption energy of H2O, CO2, CH4, N2, C8H18 and fluorocarbon molecules C3F8 and C5F12 on kaolinite (0?0?1) surface. The enrichment characteristics of fluid molecules and the stability of adsorption configuration under reservoir temperature and pressure conditions are analyzed and discussed. The study shows that under the condition of reservoir temperature and pressure, the fluid molecules exhibit stratified adsorption characteristics on kaolinite (0?0?1) surface, in which the first adsorption layer has a higher regional density and the adsorption molecules are arrested by a higher free energy potential well, and the temperature and pressure have no significant influence on the potential barrier, meaning a adsorption phase state with ordered structure and stable configuration. In second and third adsorption layers, it was found that the free energy potentials well are lower, and the fluid is in a transition phase state with lower stability. The adsorption energy and free energy calculation results of the adsorption system show that the seven kinds of fluids are adsorbed on the kaolinite (0?0?1) surface in the order of H2O?>?C3F8?>?C5F12?>?C8H18?>?CO2?>?CH4?>?N2. The water and fluorocarbon molecules, which have a much larger binding energy than the C8H18 and CH4 molecules, can displace oil and gas molecules in kaolinite reservoirs, while carbon dioxide can only displace methane molecules adsorbed on the kaolinite surface. It has been shown that as the increase of temperature and pressure, the binding energy of water molecules and C3F8 decreases significantly, but the binding energy of C5F12, C8H18, CO2 and methane molecules increases by 20%, 36%, 50% and 90% respectively, indicating that water flooding and C5F12 surfactant flooding can enhance oil recovery under high temperature and pressure conditions.Makama, Z., Celikkol, S., Ogawa, A., Gaylarde, C., Beech, I., 2018. The issue with using DNA profiling as a sole method for investigating the role of marine biofilms in corrosion of metallic materials. International Biodeterioration & Biodegradation 135, 33-38. community DNA profiles were obtained from surfaces of corroding carbon steel electrodes using next generation sequencing (NGS) Illumina technology. One electrode was exposed to the microbial population present in Key West seawater (KWS), Florida, USA, augmented with Marinobacter J5B1. Another electrode (control) was kept in sterile KWS with the KWS population enclosed within a dialysis tube to prevent biofilm development. Microscopy and culture confirmed sterility of the control electrode, yet DNA was extracted from biofilm-free corrosion deposits. While 16405 Operational Taxonomic Units (OTUs) represented the bioflmed electrode, 64016 OTUs were associated with sterile corrosion deposits. Sequences of Rhodobacteriaceae, a group known to release DNA externally, comprised 50.79% of the latter OTUs. Results demonstrate that in a marine environment corrosion deposits on ferrous alloys can harbour bacterial extracellular DNA (e-DNA). Care must be exercised when using DNA profiling as a sole tool in demonstrating the involvement of biofilms in carbon steel corrosion.Maleki, S., Hashemi, P., Rasolzadeh, F., Maleki, S., Ghiasvand, A.R., 2018. A needle trap device packed with nanoporous silica sorbents for separation and gas chromatographic determination of polycyclic aromatic hydrocarbons in contaminated soils. Journal of Chromatographic Science 56, 771-778. and MCM-41 nanoporous silica sorbents were synthesized and functionalized by amine groups and used, for the first time, for packing a needle trap device (NTD). The characteristics of the synthesized SBA-15 and MCM-41 sorbents were investigated by X-ray diffraction, scanning electron microscopy and Fourier transfer infrared spectroscopy. The NTD coupling to gas chromatography with a flame ionization detector (GC–FID) was carried out to extract and determine polycyclic aromatic hydrocarbons (PAHs) in contaminated soil samples. The performances of the sorbents for the extraction of PAHs were compared under identical conditions and the NH2-SBA-15 sorbent showed superior results. Extraction temperature, extraction time, recycling gas flow rate, sample moisture, desorption time and desorption temperature were evaluated and optimized for the system. Under the optimum conditions, detection limits of 0.0004–0.0035 μg g?1, quantitation limits of 0.001–0.01 μg g?1 and relative standard deviations of 7.4–14.9% were obtained for the PAHs. The results showed the more effectiveness of this sorbent for the extraction of the PAHs compared to that of a commercial sorbent. The method was successfully applied for the extraction and determination of PAHs in polluted soil samples collected from gas stations, with recoveries ranging from 64 to 112%.Mallik, A.K., Qiu, H., Takafuji, M., Ihara, H., 2018. High molecular-shape-selective stationary phases for reversed-phase liquid chromatography: A review. TrAC Trends in Analytical Chemistry 108, 381-404. liquid chromatography (RPLC) is the most popular separation mode in high-performance liquid chromatography (HPLC). The design and synthesis of new separation materials to meet growing demands has always been a major concern to enhance the selectivity of stationary phases. Therefore, variety of new organic stationary phases for columns has been a key factor in the development of HPLC as one of the major separation tool. This review summarized the development trend of stationary phases and their characterizations with improved shape selectivity especially for the separation of shape-constrained isomers. The design of several novel stationary phases, based on the molecular-shape recognition concept, is also briefly reviewed along with the applications. Up-to-date information about the newly developed phases and the driving forces for the high shape selectivity will also be focused in this review.Mamede, A.P., Vassalo, A.R., Piga, G., Cunha, E., Parker, S.F., Marques, M.P.M., Batista de Carvalho, L.A.E., Gon?alves, D., 2018. Potential of bioapatite hydroxyls for research on archeological burned bone. Analytical Chemistry 90, 11556-11563. estimation of the maximum temperature affecting skeletal remains was previously attempted via infrared techniques. However, fossilization may cause changes in the composition of bones that replicate those from burned bones. We presently investigated the potential of three OH/P indices (intensity ratios of characteristic infrared bands for OH and phosphate groups, respectively) to identify bones burned at high temperatures (>800 °C) and to discriminate between fossil and burned archeological bones, using vibrational spectroscopy: combined inelastic neutron scattering (INS) and FTIR-ATR. The INS analyses were performed on two unburned samples and 14 burned samples of human femur and humerus. FTIR-ATR focused on three different samples: (i) modern bones comprising 638 unburned and 623 experimentally burned (400–1000 °C) samples; (ii) archeological cremated human skeletal remains from the Bronze and Iron Ages comprising 25 samples; and (iii) fossil remains of the Reptilia class from the Middle Triassic to the Eocene. The OH/P indices investigated were 630 cm–1/603 cm–1, 3572 cm–1/603 cm–1, and 3572 cm–1/1035 cm–1. The OH signals became visible in the spectra of recent and archeological bones burned between 600 and 700 °C. Although they have episodically been reported in previous works, no such peaks were observed in our fossil samples thus suggesting that this may be a somewhat rare event. While high crystallinity index values should always correspond to clearly visible hydroxyl signals in burned bone samples, this is not always the case in fossils which may be used as a criterion to exclude burning as the agent responsible for high crystallinity ratios.Manasvi, L., Abraham, L., 2018. Implications of captured interstellar objects for panspermia and extraterrestrial life. The Astronomical Journal 156, Article 193. estimate the capture rate of interstellar objects by means of three-body gravitational interactions. We apply this model to the Sun–Jupiter system and the Alpha Centauri A&B binary system, and find that the radius of the largest captured object is a few tens of km and Earth-sized, respectively. We explore the implications of our model for the transfer of life by means of rocky material. The interstellar comets captured by the “fishing net” of the solar system can be potentially distinguished by their differing orbital trajectories and ratios of oxygen isotopes through high-resolution spectroscopy of water vapor in their tails.M?nd, K., Kirsim?e, K., Lepland, A., Crosby, C.H., Bailey, J.V., Konhauser, K.O., Wirth, R., Schreiber, A., Lumiste, K., 2018. Authigenesis of biomorphic apatite particles from Benguela upwelling zone sediments off Namibia: The role of organic matter in sedimentary apatite nucleation and growth. Geobiology 16, 640-658. phosphorites comprise a major phosphorus (P) ore, yet their formation remains poorly understood. Extant polyphosphate‐metabolizing bacterial communities are known to act as bacterial phosphate‐pumps, leading to episodically high dissolved phosphate concentrations in pore waters of organic‐rich sediment. These conditions can promote the precipitation of amorphous precursor phases that are quickly converted to apatite—usually in carbonate fluorapatite form [Ca10(PO4,CO3)6F2‐3]. To assess the mechanisms underpinning the nucleation and growth of sedimentary apatite, we sampled P‐rich sediments from the Namibian shelf, a modern environment where phosphogenesis presently occurs. The P‐rich fraction of the topmost centimetres of sediment mainly consists of pellets about 50–400 μm in size, which in turn are comprised of micron‐sized apatite particles that are often arranged into radial structures with diameters ranging from 2 to 4 μm, and morphologies that range from rod‐shapes to dumbbells to spheres that resemble laboratory‐grown fluorapatite–gelatin nanocomposites known from double‐diffusion experiments in organic matrices. The nucleation and growth of authigenic apatite on the Namibian shelf is likely analogous to these laboratory‐produced precipitates, where organic macromolecules play a central role in apatite nucleation and growth. The high density of apatite nucleation sites within the pellets (>109 particles per cm3) suggests precipitation at high pore water phosphate concentrations that have been reported from the Namibian shelf and may be attributed to microbial phosphate pumping. The intimate association of organic material with the apatite could suggest a possible role of biological substrata, such as exopolymeric substances (EPS), in the nucleation of apatite precursors. Importantly, we do not observe any evidence that the apatite particles are actual phosphatized microbes, contradicting some earlier studies. Nevertheless, these results further evidence the potential importance of microbially derived (extracellular) organic matter as a template for phosphatic mineral nucleation in both recent and ancient phosphorites. Mao, R., Li, S., 2019. Temporal controls on dissolved organic carbon biodegradation in subtropical rivers: Initial chemical composition versus stoichiometry. Science of The Total Environment 651, 3064-3069. organic carbon (DOC) plays an indispensable role in biogeochemical cycles and ecosystem services in rivers. However, little is known about the seasonal variations of DOC biodegradation in subtropical rivers. Here, we investigated the concentrations of DOC, dissolved total nitrogen (DTN), and dissolved total phosphorus (DTP), humification index (HIX), fluorescence index (FI), and DOC biodegradation in 57 rivers in the dry and wet seasons in the Three Gorges Reservoir area, China, and the aims were to clarify the temporal changes in DOC biodegradation and its driving factors in these subtropical rivers. Compared with dry season, DTN and DTP concentrations, and HIX value were greater, and FI value was lower in the wet season. However, DOC biodegradation remained unchanged across the two sampling seasons. Further, DOC biodegradation negatively correlated with DOC:DTP ratio, DTN:DTP ratio, and FI in the dry season, but only with HIX in the wet season. These findings emphasis that, despite unchanged DOC biodegradation, the key factors driving DOC biodegradation shift from C:N:P stoichiometry in the dry season to initial chemical composition in the wet season in subtropical rivers. Our results regarding the temporal patterns of DOC biodegradation and the underlying mechanisms bear important implications for a better understanding of C dynamics in subtropical river ecosystems.Marshall, B.D., Bokis, C.P., 2018. A PC-SAFT model for hydrocarbons II: General model development. Fluid Phase Equilibria 478, 34-41. is the second paper in a series which describes the development of a general PC-SAFT hydrocarbon model. In instalment I, a new treatment of aromaticity was included in the PC-SAFT equation of state by mapping aromatic π-π attractions onto a dipolar free energy. In this paper we include this aromatic-polar map into the development of a generalized thermodynamic model for hydrocarbons. The characterization model incorporates heteroatom polarity as well as aromaticity. The minimum level of input to the model is boiling point, molecular weight, and specific gravity. If a specific molecular structure is known, the model formalism accommodates inclusion of various aromatic and heteroatom functional groups. We demonstrate by comparison to pure component properties of defined hydrocarbon molecules that the new approach is of nearly quantitative accuracy. We also demonstrate how the use of the polarity contributions allows for accurate prediction of non-idealities in mixture phase equilibria.Martínez-Mena, M., Almagro, M., García-Franco, N., de Vente, J., García, E., Fayos, C.B., 2018. Fluvial sedimentary deposits as carbon sinks: organic carbon pools and stabilization mechanisms across a Mediterranean catchment. Biogeosciences Discussions 2018, 1-32. role of fluvial sedimentary areas as organic carbon sinks remains largely unquantified. Little is known about mechanisms of organic carbon (OC) stabilization in alluvial sediments in semiarid and sub-humid catchments where those mechanisms are quite complex because sediments are often redistributed and exposed to a range of environmental conditions in intermittent and perennial fluvial courses within the same catchment. The main goal of this study was to evaluate the contribution of transport and depositional areas as sources or sinks of CO2 at the catchment scale. We used physical and chemical organic matter fractionation techniques and basal respiration rates in samples representative of the three phases of the erosion process within the catchment: (i) detachment, representing the main sediment sources from forests and agricultural upland soils, as well as fluvial lateral banks; (ii) transport, representing the main channel as suspended load and bedload; and (iii) depositional areas along the channel, downstream in alluvial wedges and in the reservoir at the outlet of the catchment, representative of medium and long-term residence deposits, respectively. Our results show that most of the sediments transported and deposited downstream come from agricultural upland soils and fluvial lateral bank sources, where the physico-chemical protection of OC is much lower than that of the forest soils, which are less sensitive to erosion. The protection of OC in forest soils and medium-term depositional areas (alluvial wedges) was mainly driven by physical stabilization mechanisms, while chemical protection of OC was observed in the fluvial lateral banks. However, in the remaining sediment sources, in sediments during transport, and after deposition in long-term deposits (the reservoir), both mechanisms are equally relevant. Mineralization of the most labile OC, intra-aggregate particulate organic matter (MPOM), was predominant during transport. Aggregate formation and OC accumulation, mainly associated with macroaggregates and occluded microaggregates within macroaggregates, were predominant in depositional areas, being more protected than the OC from the most eroding sources (agricultural soils and fluvial lateral banks). Both temporary and permanent sediment deposits in the catchment have an important role in erosive areas, compensating OC losses from the eroded sources and functioning as C sinks.Mathews, R.P., Singh, B.D., Singh, V.P., 2018. Evaluation of organic matter, hydrocarbon source, and depositional environment of onshore Warkalli sedimentary sequence from Kerala-Konkan Basin, South India. Journal of the Geological Society of India 92, 407-418. analysis of the carbonaceous sediments of Warkalli Formation (Mio-Pliocene) from the Warkalli cliff section has been done to assess the source of organic matter, palaeodepositional settings and the hydrocarbon potential. The n-alkane distribution from n-C12 to n-C33 along with bimodal distribution indicates significant organic matter contribution from microbial activity and higher plants. The contribution from angiosperm source vegetation is indicated by the oleanane type of triterpenoids. The hopanes distribution indicates the immature stage of the organic matter, which is in agreement with the Tmax (av. 401 °C) and huminite reflectance (av. 0.28% Rr) values. The total organic carbon (TOC) contents vary between 0.8 and 6.72 wt. % in the studied sediments. Hydrogen index and oxygen index values range from 16 to106 mg HC/g TOC, and 113 to 344 mg CO2/g TOC, respectively. The maceral content is low, being dominated by the detrohuminite submaceral and the mineral matter accounts for 68 to 77% of the total composition. The phytoclast group (63–87%) is dominant with subordinate amorphous organic matter (4–35%). The study shows that the sediments were deposited in a marginal suboxic basin with intermittent variations. All the parameters unequivocally suggest that the studied sequence holds the potential to generate gaseous hydrocarbons.Maxwell, T.M., Silva, L.C.R., Horwath, W.R., 2018. Predictable oxygen isotope exchange between plant lipids and environmental water: Implications for ecosystem water balance reconstruction. Journal of Geophysical Research: Biogeosciences 123, 2941-2954. this study, we present the first evidence for predictable exchange of oxygen isotopes between water and lipid compounds. Using laboratory incubations with aliphatic alcohols, hexadecanol and eicosanol, and bulk soil lipid extracts in isotopically enriched water for 160?days, we determined the magnitude and direction of exchange rates for bulk and compound-specific lipid extracts. Our data show that δ18O ratios of long-chain aliphatic lipids that persist in hydrophobic portions of soil organic matter integrate the signature of plant water δ18O values, which can be used to reconstruct hydrologic shifts in terrestrial systems. For bulk lipid extracts, equilibrium was reached, indicating that 22% of its oxygen content is exchangeable with a half-life of 0.13?years. Incubations with the same bulk lipid extracts in contact with iron oxyhydroxide minerals showed no difference in exchange rates, although the exchangeable fraction decreases to 19% of the total. This result suggests that mineral surfaces can inhibit oxygen exchange for some oxygen-containing functional groups. In contrast, pure compounds showed stable oxygen isotope signatures with no exchange under the same conditions. Taken together, these findings represent a significant development in the mechanistic understanding and application of oxygen isotopes in plant- and soil-derived lipids, toward a path for the use of lipid extracts in reconstructions of ecosystem water balance.Mazow, L.B., Mitra, S., Kimmel, D.G., Grieve, S., 2018. Extraction and analysis of total lipids in late Iron Age bath-shaped basins from the Levant as a means of assessing vessel function. Journal of Archaeological Science: Reports 22, 193-201. Late Iron Age bath-shaped basins from three sites in the Southern Levant were subjected to organic residue analysis by gas chromatography–mass spectrometry (GC–MS) to test the hypothesis that the vessels were used for wool scouring and fulling. All lipid extracts of the samples contained saturated and unsaturated lipids. These were compared to the same compounds in a series of reference materials selected based on ethno-historical and literary documentation. A final comparison was made to lipids extracted from a bath-shaped basin from Turkey that had previously been found to contain a residue similar in compounds to date palm kernel oil. Results demonstrate that the total lipid extracts (TLEs) from the bath-shaped basins are more similar to each other and to date palm kernel oil than to the other comparative materials. This supports the accepted view that bath-shaped basins in the Levant, comparable in date and shape, had a common function, but suggests functional alternatives to traditional interpretations of human burial or bathing. While wool working is a viable hypothesis, it was not possible to identify the specific activity as several different behaviors could result in a similar organic residue.McCutcheon, J., Southam, G., 2018. Advanced biofilm staining techniques for TEM and SEM in geomicrobiology: Implications for visualizing EPS architecture, mineral nucleation, and microfossil generation. Chemical Geology 498, 115-127. biofilms and mats have long been studied for their role in mineral precipitation reactions in natural environments. Scanning electron microscopy (SEM) is often used to characterize biofilms and their associated precipitates, however, conventional SEM sample preparation methods do not typically preserve the structure of the extracellular polymeric substances (EPS), which account for a large portion of biofilm material and play crucial roles in biofilm function and mineral nucleation. In the present investigation, EPS preservation and visualization using transmission electron microscopy (TEM) was explored using three biofilm fixation and staining protocols. Although aspects of these protocols were developed for preserving complex eukaryotic tissue samples, the heterogeneous, three-dimensional nature of biofilms make them suitable candidates for these sample processing techniques. The results suggest that cryofixation provides the best preservation of cyanobacteria-dominated biofilm structures. A staining protocol including six different pre-embedding stains allowed for TEM visualization of the EPS matrix that encompasses biofilm cells and precipitates. Of the stains used, uranyl acetate appears to be important in avoiding biofilm deformation during sample processing. Using these staining protocols, cell-EPS-mineral relationships were observed, including the precipitation of hydromagnesite [Mg5(CO3)4(OH)2·4H2O] on the EPS adjacent to the exterior of cyanobacteria filaments. Beachrock-associated biofilms were characterized using both TEM of ultrathin sections, as well as SEM of resin embedded osmium stained biofilms prepared as petrographic thin sections. Combining these two approaches enabled characterization of both the micrometer-scale cell-carbonate mineral contacts, as well as the larger scale microbial colony-mineral cement relationships. These results suggest that sample preparation techniques developed for rapid preservation of eukaryotic tissue samples can be used to preserve and characterize biofilm architecture. These findings have applications to understanding mineral nucleation in biofilms, and the preservation of biofilms as microfossils in the rock record.McKay, D.I.A., Lenton, T.M., 2018. Reduced carbon cycle resilience across the Palaeocene–Eocene Thermal Maximum. Climate of the Past 14, 1515-1527. past episodes of rapid carbon cycle and climate change are hypothesised to be the result of the Earth system reaching a tipping point beyond which an abrupt transition to a new state occurs. At the Palaeocene–Eocene Thermal Maximum (PETM) at ?～?56Ma and at subsequent hyperthermal events, hypothesised tipping points involve the abrupt transfer of carbon from surface reservoirs to the atmosphere. Theory suggests that tipping points in complex dynamical systems should be preceded by critical slowing down of their dynamics, including increasing temporal autocorrelation and variability. However, reliably detecting these indicators in palaeorecords is challenging, with issues of data quality, false positives, and parameter selection potentially affecting reliability. Here we show that in a sufficiently long, high-resolution palaeorecord there is consistent evidence of destabilisation of the carbon cycle in the ?～?1.5Myr prior to the PETM, elevated carbon cycle and climate instability following both the PETM and Eocene Thermal Maximum 2 (ETM2), and different drivers of carbon cycle dynamics preceding the PETM and ETM2 events. Our results indicate a loss of resilience (weakened stabilising negative feedbacks and greater sensitivity to small shocks) in the carbon cycle before the PETM and in the carbon–climate system following it. This pre-PETM carbon cycle destabilisation may reflect gradual forcing by the contemporaneous North Atlantic Volcanic Province eruptions, with volcanism-driven warming potentially weakening the organic carbon burial feedback. Our results are consistent with but cannot prove the existence of a tipping point for abrupt carbon release, e.g. from methane hydrate or terrestrial organic carbon reservoirs, whereas we find no support for a tipping point in deep ocean temperature.McMahon, P.B., Kulongoski, J.T., Vengosh, A., Cozzarelli, I.M., Landon, M.K., Kharaka, Y.K., Gillespie, J.M., Davis, T.A., 2018. Regional patterns in the geochemistry of oil-field water, southern San Joaquin Valley, California, USA. Applied Geochemistry 98, 127-140. and isotopic data for water co-extracted with hydrocarbons in oil and gas fields are commonly used to examine the source of the formation water and possible impacts on groundwater in areas of oil and gas development. Understanding the geochemical variability of oil-field water could help to evaluate its origin and delineate possible contamination of shallow aquifers in cases where oil-field water is released to the environment. Here we report geochemical and multiple isotope (H, C, O, Sr, Ra) data from 22 oil wells, three sources of produced water that are disposed of in injection wells, and two surface disposal ponds in four oil fields in the southern San Joaquin Valley, California (Fruitvale, Lost Hills, North and South Belridge). Correlations between Cl and δ18O, as well as other ions, and gradual increases in salinity with depth, indicate dilution of one or more saline end-members by meteoric water. The saline end-members, represented by deep samples (610?m–2621?m) in three oil-bearing zones, are characterized by NaCl composition, near-seawater Cl concentrations (median 20,000?mg/L), enriched δ18OH2O (median 3.4‰), high ammonium (up to 460?mg-N/L), and relatively high radium activity (226Ra+228Ra?=?12.3 Bq/L). The deepest sample has low Na/Cl (0.74), high Ca/Mg (5.0), and low 87Sr/86Sr (0.7063), whereas the shallower samples have higher Na/Cl (0.86–1.2), Ca/Mg near 1, and higher 87Sr/86Sr (～0.7083). The data are consistent with an original seawater source being modified by various depth and lithology dependent diagenetic processes. Dilution by meteoric water occurs naturally on the east side of the valley, and in association with water-injection activities on the west side. Meteoric-water flushing, particularly on the east side, results in lower solute concentrations (minimum total dissolved solids 2730?mg/L) and total radium (minimum 0.27 Bq/L) in oil-field water, and promotes biodegradation of dissolved organic carbon and hydrocarbon gases like propane. Acetate concentrations and δ13C of dissolved inorganic carbon indicate biogenic methane production occurs in some shallow oil zones. Natural and human processes produce substantial variability in the geochemistry of oil-field water that should be considered when evaluating mixing between oil-field waters and groundwater. The variability could result in uncertainty as to detecting the potential source and impact of oil-field water on groundwater.McRose, D.L., Lee, A., Kopf, S.H., Baars, O., Kraepiel, A.M.L., Sigman, D.M., Morel, F.M.M., Zhang, X., 2019. Effect of iron limitation on the isotopic composition of cellular and released fixed nitrogen in Azotobacter vinelandii. Geochimica et Cosmochimica Acta 244, 12-23. biological nitrogen transformations have characteristic kinetic isotope effects used to track these processes in modern and past environments. The isotopic fractionation associated with nitrogen fixation, the only biological source of fixed nitrogen (N), provides a particularly important constraint for studies of nitrogen cycling. Nitrogen fixation using the ‘canonical’ Mo-nitrogenase produces biomass with a δ15N value of ca. ?1‰ (vs. atmospheric N2). If the ‘alternative’ V- and Fe-only nitrogenases are used, biomass δ15N can be between ?6‰ and ?7‰. These biomass values are assumed to be relatively invariant and to reflect the cellular level expressed isotope effect of nitrogen fixation. However, field and laboratory studies report wide ranges of diazotrophic biomass δ15N (from ?3.6‰ to +0.5‰ for Mo-based nitrogen fixation). This variation could be partly explained by the release of dissolved organic N (DON) that is isotopically distinct from biomass. The model nitrogen fixer Azotobacter vinelandii secretes siderophores, small molecules that aid in Fe uptake and can comprise >30% of fixed nitrogen. To test whether siderophores (and other released N) can decouple biomass δ15N from the isotope effect of nitrogen fixation we measured the isotopic composition of biomass and released N in Fe-limited A. vinelandii cultures fixing nitrogen with Mo- and V-nitrogenases. We report that biomass δ15N was elevated under Fe limitation with a maximum value of +1.2‰ for Mo-based nitrogen fixation. Regardless of the nitrogenase isozyme used, released nitrogen δ15N was also 2–3‰ lower than biomass δ15N. Siderophore nitrogen was found to have a slightly higher δ15N than the rest of the DON pool but was still produced in large enough concentrations to account for increases in biomass δ15N. The low δ15N of siderophores (relative to biomass) is consistent with what is known from compound specific isotope studies of the amino acids used in siderophore biosynthesis, and indicates that other amino-acid derived siderophores should also have a low δ15N. The implications for studies of nitrogen fixation are discussed.Mei, R., Nobu, M.K., Narihiro, T., Yu, J., Sathyagal, A., Willman, E., Liu, W.-T., 2018. Novel Geobacter species and diverse methanogens contribute to enhanced methane production in media-added methanogenic reactors. Water Research 147, 403-412. determine whether the addition of conductive materials could enhance methane production by direct interspecies electron transfer (DIET), we operated three anaerobic reactors amended with non-conductive (ceramic) or conductive materials (anthracite and granular activated carbon (GAC)). Throughout eight months of operation, ethanol was consistently detected as the major fermentation product. The specific yield in the anthracite and GAC-added reactors increased by 31.5% and 43.3%, respectively, compared to the ceramic-added reactor. 16S rRNA gene sequencing results indicated Geobacter was dominant (up to 55% of total sequences), whereas acids-degrading syntrophic bacteria were low in abundance (<2%). Using metagenomic analysis, the draft genome of the dominant Geobacter population (bin GAC1) was reconstructed and observed to possess genetic abilities of ethanol oxidation, hydrogen production, and extracellular electron transfer, and represented a phylogenetically novel Geobacter species. While Methanosaeta was the dominant methanogen </topics/earth-and-planetary-sciences/methanogens>, reactors containing conductive materials harbored more diverse and abundant archaeal populations, as revealed by FISH, qPCR, and metagenomics. Our findings suggested that a novel Geobacter population could oxidize ethanol and employed both hydrogen transfer and DIET depending on the accessibility of conductive materials. Thermodynamic advantages of DIET over hydrogen production could lead to enhanced methane production in reactors with conductive materials.Mercier, P.H.J., Tyo, D.D., Zborowski, A., Kung, J., Patarachao, B., Kingston, D.M., Couillard, M., Robertson, G., McCracken, T., Ng, S., 2019. First quantification of <2?μm clay, <0.2?μm ultrafines and solids wettability in process streams from naphthenic froth treatment plant at commercial mined oil sands operations. Fuel 237, 961-976. the first time in oil sands industry, the absolute amounts of <2?μm clay and <0.2?μm ultrafine solids were quantified in commercial streams from the naphthenic froth treatment (NFT) process used by mined oil sands operators. The sample suite studied comprised seven representative NFT streams collected at a commercial plant including: one bitumen froth feed (F1), two naphtha-diluted bitumen products (P1, P2) and four tailings (T1, T2, T3, T4). The solids present in each of the seven NFT streams were fractionated quantitatively based on particle size and solids wettability using three original quantitative separation techniques presented here. First, clay-ultrafines (CUF) separation technique allows to fractionate solids into four distinct particle-size fractions: coarser solids (CS), >2 μm; total clays (TC), <2?μm; coarse clays (CC), 0.2–2?μm; and ultrafines (UF), <0.2?μm. Second, toluene/water (T/W) interfacial wettability (WET) fraction separation technique enables separation of solids into four distinct fractions: Hydrophilic Solids (HPS) partitioning into the aqueous phase (carbon <5% w/w); Intermediate Solids (IS) only weakly held at the T/W interface (carbon 6–10% w/w); organic-rich solids (ORS) remaining strongly held at the T/W interface (carbon 15–20%?w/w); high speed centrifugation solids (HSCS) remaining dispersed in the bitumen-toluene phase (carbon >20%?w/w). And third, toluene/water interfacial total solids (TS) separation permits to isolate all-at-once the entire solids fraction comprised in a given sample. The analytical procedures developed to apply these three techniques are outlined in detail, and compared to two standard methods used in the oil sands industry: Soxhlet-Dean and Stark extraction method and COSIA Unified Fines Method for minus 44??m material and for Particle Size Distribution (PSD). From quantitative results obtained by CUF, WET and TS techniques and industry standard PSD methods, the following key results arise. Most notably, CUF technique developed here showed >10?wt% ultrafines in samples T4, P1 and P2, whereas industry standard PSD methods (laser diffraction PSD data) did not notice any significant differences between the seven samples. The UF contents per total solids increase in going from froth F1 (～2.5?wt%) through product P1 (～9.3?wt%) to product P2 (～11?wt%). Tailings T4 has the highest proportion of UF (～12?wt%) amongst the four tailings, and also has the highest amounts of HPS, TC, and CC of any streams. NFT stream T4 therefore likely results from a separation process which selectively removes the smaller hydrophilic solids. The ORS and HSCS proportions per total solids increase in going from froth F1 through product P1 to product P2. For product P2, the ORS and HSCS contents account respectively for ～70?wt% and ～10?wt% of the solids contained in this sample. By contrast, as ORS and HSCS increase, the HPS contents decrease correspondingly. This inverse behavior between HPS and ORS?+?HSCS contents demonstrates the preferential removal of hydrophilic solids by the NFT processes. X-ray diffraction patterns measured for HSCS fractions separated from froth F1 and products P1 and P2 are virtually the same. This suggests that HSCS solids are present in the inlet froth and go through the entire NFT circuit without being affected by any of the different separation unit operations integrated in the NFT process flowsheet.Merey, ?., 2019. Evaluation of drilling parameters in gas hydrate exploration wells. Journal of Petroleum Science and Engineering 172, 855-877. hydrates are crystalline ice-like structures formed from water and gas molecules at high pressure and low temperature conditions. They are considered as near-future energy resources. Recently, there have been many drilling activities in gas hydrates in both permafrost regions (mainly Mallik wells, Canada; Ignik Sikumi #1 well, Alaska; Mount Elbert #1, Alaska) and marine sediments (the wells drilled in Gulf of Mexico and India drilling expeditions). In this study, it is aimed to evaluate and analyze logging-while drilling data (LWD) and other drilling data of these drilling activities. Initially, all drilling parameters (i.e. rate of penetration, weight on bit, torques, mud logs, etc.) of these wells were collected and drawn to see the change in parameters with depths. In order to indicate the changes in drilling parameters in the sediments containing gas hydrates, gas hydrate saturations were estimated from resistivity logs and NMR logs in this study. High resistivity log values and methane peaks in drilling fluid were good indicators of gas hydrate existence. During the drilling of permafrost formations and gas hydrates deposited in coarse sands as pore filling, the rate of penetration generally decreased. Differently, there was not almost any change in the rate of penetration during the drilling of fracture-filling gas hydrates within silts/clay in India. Borehole enlargements (washouts) were commonly seen in the wells drilled in marine sediments (Gulf of Mexico and Indian expeditions). However, this effect was minimum during the drilling of the wells in permafrost regions. This difference is due to the loose sediments in marine environment. Furthermore, gamma and density logs were seriously affected by washouts, mainly in marine sediments. It was observed that pore-filling gas hydrates affect the rate of penetration and keep the sediments stable because well collapses mainly occurred in the sediments without any gas hydrates. However, the temperature of drilling fluid should be close to the temperature of gas hydrate zones to reduce the effect of drilling on gas hydrate dissociation for the wells both in permafrost and marine sediments. In Gulf Mexico and Indian drilling expeditions, riser and wellhead equipment were not used. However, the usage of surface casing might decrease the risk of borehole collapses due to very loose sediments close to sea floor. Another important outcome of this study is that the pressure gradient follows hydrostatic pressure gradients according to the pressure analysis within gas hydrate stability zones of marine sediments. Finally, the analyses of drilling parameters revealed that drilling through gas hydrate bearing strata is not as risky as it might have been considered. The key is hidden in appropriate drilling design.Meyer, D.W., Flemings, P.B., DiCarlo, D., 2018. Effect of gas flow rate on hydrate formation within the hydrate stability zone. Journal of Geophysical Research: Solid Earth 123, 6263-6276. form methane hydrate in brine-saturated, coarse-grained samples, under hydrate-stable conditions, by injecting methane vapor at various flow rates. Decreasing the flow rate results in higher hydrate saturation, lower brine saturation, a smaller affected volume, and larger average pressure differentials across the sample. We interpret that the longer execution times at lower flow rates allow for additional methane transport and hydrate formation at the hydrate-brine interface. As a result, the hydrate skin is thicker at lower flow rates and thus is capable of sustaining larger pressure differentials. In several experiments, we stop brine flow and supply methane gas to the sample for an additional 800?hrs. During this period, hydrate continues to form, pressure differentials develop, and the bulk density changes within the affected volume. We interpret that there is gas present in the sample that is disconnected from the gas source. Hydrate forms around the disconnected gas due to methane transport through the skin that surrounds it, causing the internal gas pressure to decline and leading to inward collapse and net volume decrease. This lowers the brine pressure and creates a differential pressure across the sample that induces gas flow. This study indicates that lower gas flow rates through the hydrate stability zone can produce very high saturations of hydrate but require a larger differential pressure to sustain flow. Ultimately, this process is an alternative mechanism for sustained upward gas flow and hydrate formation far above the base of the hydrate stability zone.Mi, J., Wang, H., He, K., Bai, J., Liu, C., 2018. Demethylation as a mechanism for isotopic reversals of shale gas generated at over maturity. Journal of Analytical and Applied Pyrolysis 135, 361-368. paper investigates demethylation as a possible mechanism leading to isotopic reversals of shale gas during the thermal degradation using a model compound representative of methylated monoaromatic hydrocarbons presented in over-mature organic matter. The model compound used is 1,3,5-Trimethylbenzene (TB), which was subjected to isothermal pyrolysis experiments at three temperatures of 400 °C, 425 °C and 450?°C holding from 24 to 480?h at 300?bar. During the process of TB pyrolysis, heavy hydrocarbon gas was generated in addition to methane and hydrogen. Some aromatic compounds-bearing ethyl and propyl were also detected in the liquid products. The series of carbon isotope of hydrocarbon gas shows a reversal feature (i.e. δ13C1 >δ13C2) at TB conversion below 80%. The reversal feature is replaced by normal isotopic distribution when the TB conversion is above 80%. According to the yields variation of different products during TB cracking, heavy hydrocarbon gas appears to have generated via two pathways, (1) combination among the CH3 radicals from demethylation and (2) cleavage of long aliphatic chains formed by combination between CH3 radicals and methyl linked on aromatic rings during TB cracking. The reversal of carbon isotope between CH4 and C2H6 was caused by carbon isotopic fractionation during the heavy hydrocarbon gas generation. The TB cracking experiments indicates that demethylation is one of the factors causing the isotopic reversals of shale gas generated at over maturity. The change of carbon isotope from reversal to normal distribution is attributed to the cracking of C2H6 generated at higher thermal dynamics. It is deduced that the phenomenon of isotopic reversal of shale gas would disappear and be replaced by normal isotopic distribution with further decreasing of natural gas wetness.Mitchell, J.M., Flight, R.M., Wang, Q.J., Higashi, R.M., Fan, T.W.-M., Lane, A.N., Moseley, H.N.B., 2018. New methods to identify high peak density artifacts in Fourier transform mass spectra and to mitigate their effects on high-throughput metabolomic data analysis. Metabolomics 14, 125.: Direct injection Fourier-transform mass spectrometry (FT-MS) allows for the high-throughput and high-resolution detection of thousands of metabolite-associated isotopologues. However, spectral artifacts can generate large numbers of spectral features (peaks) that do not correspond to known compounds. Misassignment of these artifactual features creates interpretive errors and limits our ability to discern the role of representative features within living systems.Objectives: Our goal is to develop rigorous methods that identify and handle spectral artifacts within the context of high-throughput FT-MS-based metabolomics studies.Results: We observed three types of artifacts unique to FT-MS that we named high peak density (HPD) sites: fuzzy sites, ringing and partial ringing. While ringing artifacts are well-known, fuzzy sites and partial ringing have not been previously well-characterized in the literature. We developed new computational methods based on comparisons of peak density within a spectrum to identify regions of spectra with fuzzy sites. We used these methods to identify and eliminate fuzzy site artifacts in an example dataset of paired cancer and non-cancer lung tissue samples and evaluated the impact of these artifacts on classification accuracy and robustness.Conclusion: Our methods robustly identified consistent fuzzy site artifacts in our FT-MS metabolomics spectral data. Without artifact identification and removal, 91.4% classification accuracy was achieved on an example lung cancer dataset; however, these classifiers rely heavily on artifactual features present in fuzzy sites. Proper removal of fuzzy site artifacts produces a more robust classifier based on non-artifactual features, with slightly improved accuracy of 92.4% in our example analysis.Miyajima, Y., Ijiri, A., Miyake, A., Hasegawa, T., 2018. Origin of methane and heavier hydrocarbons entrapped within Miocene methane-seep carbonates from central Japan. Chemical Geology 498, 83-95. examined the carbon isotopic and molecular compositions of residual gases within Miocene methane-derived carbonates collected in Japan. Methane, ethane, and propane were extracted by acid digestion of powdered carbonates. The isotopic and molecular compositions of the extracted hydrocarbons are inconsistent with conventional thermogenic and microbial gases. Despite a range of δ13C values from ?67‰ to ?38‰ (relative to Vienna Pee Dee Belemnite (VPDB)), the liberated hydrocarbons yielded consistently low methane to ethane?+?propane ratios (2–30). The extracted ethane and propane yielded anomalous δ13C values as low as ?84‰, lower than those of the coexisting methane. The ethane and propane were most likely produced through thermal cracking of organic compounds preserved within the seep carbonates during burial. The observed unusual isotopic trends may be explained by the mixing of two thermogenic gas components with different carbon isotopic and molecular compositions. Nevertheless, a positive correlation between δ13C values of methane and relatively immature carbonates at one study site (Nakanomata) indicates that while methane was oxidized to bicarbonate from which carbonates precipitated, it was preserved within the host carbonate cements. Such a scenario indicates that the residual methane at least partly originates from the Miocene seep fluid. Smaller amounts of methane were also released during heating and crushing of chipped samples. The results suggest that methane was entrapped mainly within intracrystal inclusions, which is supported by the observation of abundant nanometer-scale voids in an individual crystal.Miyakawa, K., Okumura, F., 2018. Improvements in drill-core headspace gas analysis for samples from microbially active depths. Geofluids 2018, Article 2436814. IsoJar? container is widely used in headspace gas analysis for gases adsorbed on cuttings or bore cores from oil and gas fields. However, large variations in the carbon isotopic ratios of CH4 and CO2 are often reported, especially for data obtained from depths of <1000?m. The IsoJar? method leaves air in the headspace that allows microbial oxidation of CH4 to CO2, meaning that isotopic fractionation occurs during storage. This study employed the IsoJar? method to investigate the causes of differences in δ13C data reported by previous studies in the Horonobe area of Japan. It was found that after 80?d storage, δ13CCO2 values decreased by ~2‰, while δ13CCH4 values increased by >30‰, whereas samples analyzed within a week of collection showed no such fluctuations. The conventional amount of microbial suppressant (~0.5?ml of 10% benzalkonium chloride (BKC) solution) is insufficient to suppress microbial activity if groundwater is used as filling water. The significant variations in carbon isotopic compositions previously reported were caused by microbial methane oxidation after sampling and contamination by groundwater from different depths. To avoid these problems, we recommend the following: (1) if long-term sample storage is necessary, >10?ml of 10% BKC solution should be added or >0.3% BKC concentration is required to suppress microbial activity; (2) analyses should be performed within one week of sampling; and (3) for CO2 analyses, it is important that samples are not contaminated by groundwater from different depths.Miyazaki, Y., Planavsky, N.J., Bolton, E.W., Reinhard, C.T., 2018. Making sense of massive carbon isotope excursions with an inverse carbon cycle model. Journal of Geophysical Research: Biogeosciences 123, 2485-2496. beginning and end of the Proterozoic Eon are marked by extreme variations in carbonate carbon isotope values that have been interpreted to record massive perturbations to the global carbon cycle. The lower Proterozoic contains an extended interval of strata characterized by positive carbonate δ13C values. Conversely, uppermost Proterozoic carbonate strata contain thick intervals with extremely negative δ13C values and multiple large swings in carbonate δ13C. Previous attempts to model these pronounced carbon isotope excursions as shifts in the global marine dissolved inorganic carbon (DIC) reservoir have proved to be problematic, as the direction and magnitude of these positive and negative carbon isotope excursions require unrealistic amounts of either organic carbon burial or organic carbon oxidation, respectively. Here we present a modified global carbon cycle model—coupled with oxygen and sulfur cycle mass balances—that includes a parameterization of the recycling of sedimentary isotope anomalies and allows the extent of organic carbon oxidation to vary as a function of atmospheric oxygen levels. Our model is designed to match carbon isotope records while maintaining redox and mass balance with a given set of initial conditions and carbon cycle parameterizations. Using this approach, we demonstrate that there is a range of plausible biogeochemical perturbations that could induce substantial δ13C excursions in the global marine DIC reservoir. However, we also find that there are multiple, nonunique Earth system states for any observed marine δ13C value. Mohd Hassan, F.W., Muggundha, R., Kamaruzaman, S., Sanagi, M.M., Yoshida, N., Hirota, Y., Nishiyama, N., Yahaya, N., 2018. Dispersive liquid–liquid microextraction combined with dispersive solid-phase extraction for gas chromatography with mass spectrometry determination of polycyclic aromatic hydrocarbons in aqueous matrices. Journal of Separation Science 41, 3751-3763. study describes a dispersive liquid–liquid microextraction combined with dispersive solid‐phase extraction method based on phenyl‐functionalized magnetic sorbent for the preconcentration of polycyclic aromatic hydrocarbons from environmental water, sugarcane juice, and tea samples prior to gas chromatography with mass spectrometry analysis. Several important parameters affecting the extraction efficiency were investigated thoroughly, including the mass of sorbent, type and volume of extraction solvent, extraction time, type of desorption solvent, desorption time, type and amount of salt‐induced demulsifier, and sample volume. Under the optimized extraction and gas chromatography‐mass spectrometric conditions, the method revealed good linearity (10–100000 ng/L) with coefficient of determination (R2) of ≥0.9951, low limits of detection (3–16 ng/L), high enrichment factors (61–239), and satisfactory analyte recoveries (86.3–109.1%) with the relative standard deviations < 10% (n = 5). The entire sample preparation procedure was simple, rapid and can be accomplished within 10 min. This method was applied (after pretreatment) to 30 selected samples, and the presence of studied analytes was quantified in 17 samples.Moore III, B., Crowell, S.M.R., Rayner, P.J., Kumer, J., O'Dell, C.W., O'Brien, D., Utembe, S., Polonsky, I., Schimel, D., Lemen, J., 2018. The potential of the Geostationary Carbon Cycle Observatory (GeoCarb) to provide multi-scale constraints on the carbon cycle in the Americas. Frontiers in Environmental Science 6, 109. doi: 10.3389/fenvs.2018.00109. second NASA Earth Venture Mission, Geostationary Carbon Cycle Observatory (GeoCarb), will provide measurements of atmospheric carbon dioxide (CO2), methane (CH4), carbon monoxide (CO), and solar-induced fluorescence (SIF) from Geostationary Orbit (GEO). The GeoCarb mission will deliver daily maps of column concentrations of CO2, CH4, and CO over the observed landmasses in the Americas at a spatial resolution of roughly 10 × 10 km. Persistent measurements of CO2, CH4, CO, and SIF will contribute significantly to resolving carbon emissions and illuminating biotic processes at urban to continental scales, which will allow the improvement of modeled biogeochemical processes in Earth System Models as well as monitor the response of the biosphere to disturbance. This is essential to improve understanding of the Carbon-Climate connection. In this paper, we introduce the instrument and the GeoCarb Mission, and we demonstrate the potential scientific contribution of the mission through a series of CO2 and CH4 simulation experiments. We find that GeoCarb will be able to constrain emissions at urban to continental spatial scales on weekly to annual time scales. The GeoCarb mission particularly builds upon the Orbiting Carbon Obserevatory-2 (OCO-2), which is flying in Low Earth Orbit.Morga, R., Kamińska, M., 2018. The chemical composition of graptolite periderm in the gas shales from the Baltic Basin of Poland. International Journal of Coal Geology 199, 10-18. graptolite shales from an exploration borehole within the Baltic Basin (N-Poland) were examined by the electron microprobe (for the first time) and micro-FTIR spectroscopy. The graptolite periderm of mean reflectance Rr?≈?1.30–1.80% (VRE?≈?1.10–1.50%) contains ~85–91?wt% of carbon, 2.5–8.5?wt% of oxygen, 1.5–3?wt% of nitrogen and (by difference) ~3.0–4.5?wt% of hydrogen. Aromatic structures predominate, with minor amounts of the aliphatic and carbonyl groups. Carbon content in the graptolite periderm increases and oxygen content decreases with the increasing depth and mean reflectance (Rr). This is accompanied by the increase in aromaticity of the structure and shortening of the aliphatic chains. The studied graptolites represent mostly kerogen type II and, partly, type III. Chemical structure of the graptolite periderm reveals many similarities to that of vitrinite of the adequate rank (considering the Vitrinite Reflectance Equivalent values).Moroeng, O.M., Keartland, J.M., Roberts, R.J., Wagner, N.J., 2018. Characterization of coal using electron spin resonance: implications for the formation of inertinite macerals in the Witbank Coalfield, South Africa. International Journal of Coal Science & Technology 5, 385-398. contains a significant concentration of free radicals as a result of the coalification process. One of the experimental methods sensitive to the presence of radicals is electron spin resonance (ESR), and differences in ESR spectra for different macerals may provide insight into coal-forming processes. In this study, ESR data along with the H/C atomic ratio (to infer the aromatic fraction) are used to characterize coal samples with the aim of assessing a fire-origin for dominant inertinite macerals. A medium rank C bituminous Witbank No. 4 Seam Upper coal (the parent) was density-fractionated to create vitrinite-rich and inertinite-rich samples. The parent sample consists of 42 vol% vitrinite and 49 vol% inertinite. The density-fractionated samples comprise of 81 vol% total vitrinite (dominated by collotelinite and collodetrinite), and 63 vol% total inertinite (dominated by fusinite, semifusinite, and inertodetrinite). The H/C ratio is 0.74 for the inertinite-rich sample, and 0.85 for the vitrinite-rich counterpart, suggesting the former sample is more aromatic. The ESR spectra obtained for the three samples were found to fit best using a Lorentzian distribution. The fit is noticeably better for the aromatic inertinite-rich sample, for which the spectrum is symmetric. This is attributed to pronounced electron mobility and exchange interactions. The higher radical content of the inertinite-rich and parent samples is attributed to the presence of specific inertinite macerals, namely: fusinite, semifusinite, and inertodetrinite. And, owing to the greater radical content of the inertinite-rich sample, the dominant inertinite macerals are interpreted to have formed through charring of plant matter.Moura, V., Ribeiro, I., Moriggi, P., Cap?o, A., Salles, C., Bitati, S., Procópio, L., 2018. The influence of surface microbial diversity and succession on microbiologically influenced corrosion of steel in a simulated marine environment. Archives of Microbiology 200, 1447-1456. explore how a succession of bacteria grown on steel coupons in a marine environment can influence their corrosion process, we designed a microcosm in laboratory to evaluate corrosion kinetics and microbial diversity over 30 days. The results described a clear influence of corrosion by a succession of different bacterial groups. During the initial period, 2–7?days, a sharp increase in the rate of corrosion was detected accompanied by the presence of Alteromonadaceae, Vibrionaceae, Oceanospirillaceae, Rhodobacteraceae, Rhodospirillaceae and Flavobacteriaceae bacteria families. After 15 days, representatives of families Piscirickettsiaceae and Pseudomonadaceae were also described, accompanied by a continuous corrosion process over the coupons. After 30 days, there was a sudden change in the profile of the bacteria present on the steel coupons, with a prevalence of Halomonadaceae family species, and establishment and continuity of the corrosion process by the biofilm grown on the coupons. The results describe differences in microbial diversity over the time, highlighting certain bacterial lithotrophic species that persisted for most of the experiment, through a complex association between bacteria and metal surfaces, which can be a new starting point for development and maintenance of a favorable microenvironment to accelerate corrosion processes.Mozes, E., Delgado-Linares, J.G., Cárdenas, A.L., Salazar, F., Pereira, J.C., Bullón, J., 2018. Behavior of asphaltene and asphaltene fractions films on a Langmuir–Blodgett trough and its relationship with proposed molecular structures. Petroleum Science and Technology 36, 1490-1496. were precipitated from a Venezuelan Ayacucho crude oil and separated into two fractions (A1 and A2) by the p-nitrophenol method. The asphaltenes and the fractions A1 and A2, as well as mixtures of the two fractions were tested in a Langmuir?Bodgett trough. It was found that the asphaltenes and the fraction A2 had similar behavior and higher compressibility than the fraction A1. This is because the molecules of A2 are more flexible than the molecules of A1 as they have aliphatic chains that bond aromatic structures while the A1 has an aromatic nucleus.Muller, F.L.L., 2018. Exploring the potential role of terrestrially derived humic substances in the marine biogeochemistry of iron. Frontiers in Earth Science 6, 159. doi: 10.3389/feart.2018.00159. is a widely recognized link between iron bioavailability and phytoplankton growth in large tracts of the World Ocean. Iron bioavailability is thus pivotal to the removal of atmospheric carbon via the ocean’s ‘biological pump.’ To evaluate future scenarios of global climate change, we must therefore understand better how the bioavailability of iron in seawater is linked to processes controlling its supply, chemical speciation and removal from the water column. Much of the research on iron inputs to the open ocean has focused on atmospheric, benthic (shelf sediments) and hydrothermal (mid-ocean) sources of iron. The conventional wisdom has been that riverine iron sources are negligible because many of the major world rivers exhibit extensive removal of dissolved iron by flocculation processes during estuarine mixing. However, recent studies have revealed that a fraction of iron associated with peatland-derived humic and fulvic acids may survive aggregation processes in the freshwater-seawater mixing zone, and thus be exported offshore. This review is a synthesis of available data and information for and against the hypothesis that land-derived humic substances exert a significant control on the marine biogeochemical cycle of iron. From the outset, it is shown that this hypothesis can neither be verified nor disproved at present, in part due to analytical difficulties in characterizing the all-important marine colloidal phase. Evidence is then presented on the likely chemical nature and structure of iron-binding humic ligands along with implications for the lateral transport of iron in surface waters and its participation in carbon stabilization in marine sediments. This is followed by a discussion of photochemically and microbially mediated processes acting on terrestrial humic substances and a discussion of how terrestrial humic substances may influence the biological availability of iron. The review finishes with a presentation of measurement technologies and approaches that could be used to assess (i) how iron-binding ligands in seawater relate to land-derived humic substances and (ii) how terrestrial humics may influence the global carbon cycle indirectly by influencing the processes that control the supply and maintain the pool of ‘dissolved’ iron in the ocean.Nasyrova, Z., Aliev, A., Petrov, S., Safiulina, A., Mukhamatdinov, I., 2018. The catalytic effects of carbonate minerals on characteristics of heavy oil in hydrothermal reactions. Petroleum Science and Technology 36, 1439-1445. influences on heavy oil were simulated in laboratory conditions. The experimental model was composed of oil, calcite, dolomite, and manganese oxide. Oil to dominant mineral ratio was 1:1, where the content of manganese oxide was 5%. The hydrothermal reactions were carried out under the reservoir temperatures of 250?300°? and a pressure of 1?2?MPa. As a result of treatment, aromaticity of oil increased, while H:C ratio decreased from 1.92 to 1.61. The structures of newly formed light fractions were characterized by low molecular aromatic compounds, which were the destruction products of resins. The treatment provided removal of nitrogen and sulfur from crude oil, hence, decreasing the viscosity of products. The genotype of crude oil did not change. The quantitative changes in the ratio of isoprenoid alkanes to the linear ones were evaluated via geochemical coefficients of group composition.Neumann, E.K., Comi, T.J., Spegazzini, N., Mitchell, J.W., Rubakhin, S.S., Gillette, M.U., Bhargava, R., Sweedler, J.V., 2018. Multimodal chemical analysis of the brain by high mass resolution mass spectrometry and infrared spectroscopic imaging. Analytical Chemistry 90, 11572-11580. brain functions through chemical interactions between many different cell types, including neurons and glia. Acquiring comprehensive information on complex, heterogeneous systems requires multiple analytical tools, each of which have unique chemical specificity and spatial resolution. Multimodal imaging generates complementary chemical information via spatially localized molecular maps, ideally from the same sample, but requires method enhancements that span from data acquisition to interpretation. We devised a protocol for performing matrix-assisted laser desorption/ionization (MALDI)-Fourier transform ion cyclotron resonance-mass spectrometry imaging (MSI), followed by infrared (IR) spectroscopic imaging on the same specimen. Multimodal measurements from the same tissue provide precise spatial alignment between modalities, enabling more advanced image processing such as image fusion and sharpening. Performing MSI first produces higher quality data from each technique compared to performing IR imaging before MSI. The difference is likely due to fixing the tissue section during MALDI matrix removal, thereby preventing analyte degradation occurring during IR imaging from an unfixed specimen. Leveraging the unique capabilities of each modality, we utilized pan sharpening of MS (mass spectrometry) ion images with selected bands from IR spectroscopy and midlevel data fusion. In comparison to sharpening with histological images, pan sharpening can employ a plethora of IR bands, producing sharpened MS images while retaining the fidelity of the initial ion images. Using Laplacian pyramid sharpening, we determine the localization of several lipids present within the hippocampus with high mass accuracy at 5 μm pixel widths. Further, through midlevel data fusion of the imaging data sets combined with k-means clustering, the combined data set discriminates between additional anatomical structures unrecognized by the individual imaging approaches. Significant differences between molecular ion abundances are detected between relevant structures within the hippocampus, such as the CA1 and CA3 regions. Our methodology provides high quality multiplex and multimodal chemical imaging of the same tissue sample, enabling more advanced data processing and analysis routines.Nhuchhen, D.R., Afzal, M.T., Dreise, T., Salema, A.A., 2018. Characteristics of biochar and bio-oil produced from wood pellets pyrolysis using a bench scale fixed bed, microwave reactor. Biomass and Bioenergy 119, 293-303. pyrolysis of wood pellets was investigated in a pilot scale fixed bed microwave reactor at various biomass loadings and microwave power levels. A fixed proportion of biochar (10% of biomass loading) was used as a microwave absorber in each test conditions. Effect of biomass loading and the power level on the product yields and on the characteristics of biochar and bio-oil products were examined. While the bio-oil yield decreased when the biomass loading was increased from 1500?g to 3500?g, the biochar and gaseous product yields increased with the biomass loading. However, the microwave power level shows an opposite trend. Biochar exhibited good higher heating value (31?MJ/kg) and possessed a fine pore size (<1?nm), which can be used as a fuel or a source of porous carbon. Higher heating value of bio-oil was found in the range 12–14?MJ/kg. Kinematic viscosities of bio-oils were estimated in the range 1.8–6.1?mm2/s at 40?°C that is similar to the viscosity requirement for the gas turbine applications. Moisture content in bio-oils was found in the range of 57.3–69.3%, which is higher than the upper limit of water content (30% wt.). Only a few chemicals, including furfural, phenol, 3-Methyl-1,2-Cyclipentanedione, 3-Methylphenol, and 4-Methylguaiacol were found in the bio-oils because of the high moisture content. Results of product characterization of biochar and bio-oils confirm that both microwave power level and biomass loading does not have any significant impacts. Further research can be carried out to find out the measures to reduce the moisture content in the bio-oil.Niasar, H.S., Das, S., Xu, C., Ray, M.B., 2019. Continuous column adsorption of naphthenic acids from synthetic and real oil sands process-affected water (OSPW) using carbon-based adsorbents. Chemosphere 214, 511-518. this study, activated petroleum coke (APC) and commercial activated carbon (CAC) were used in a continuous adsorption column for removal of model naphthenic acids and organics from real oil sands process-affected water (OSPW). Diphenylacetic acid and 2-naphthoic acid, two model naphthenic acid (NA) compounds, were removed completely by the APC in a continuous column operation. Due to the complex nature of organics in OSPW, total organic carbon (TOC) was measured to determine the effectiveness of OSPW treatment by APC. The removal of TOC from OSPW at its natural pH 8 by APC was only 25%, whereas acidification at pH 4 followed by APC adsorption removed 96% of the initial TOC. When compared to a commercial activated carbon, the APC showed an average of 20% higher organics removal. The experimental breakthrough curves were better fitted by Thomas model in comparison to Adams-Bohart and Yoon-Nelson models. The regeneration of APC was conducted using methanol with 0.01?wt% NaOH (pH?=?11.7) and a total of four cycles of adsorption and regeneration were conducted with marginal loss of adsorption sites.Nierop, K.G.J., Brouwer, P., Dekker, R., Schluepmann, H., Reichart, G.-J., 2018. ω20-Hydroxy and ω9,ω10-dihydroxy biomarker lipids in ferns from the Salviniaceae family. Organic Geochemistry 125, 229-242. seven species of floating ferns from the genus Azolla (family Salviniaceae) produce a unique series of long chain mid-chain ω20-hydroxy compounds (ω20-alkanols, 1,ω20-diols, ω20-hydroxy fatty acids) and structurally related ω9,ω10-dihydroxy compounds (ω9,ω10-diols, 1,ω9,ω10-triols and ω9,ω10-dihydroxy fatty acids). These very long chain fatty acid (VLCFA) derivatives occur in the ferns’ waxes in free and esterified form. The specific distribution of these lipids differed between species belonging to each of the two sections in the Azolla genus: in species of the section Azolla and Rhizosperma, the ratio of C31 over C35 ω20-alkanols averaged 7.0 and 0.40, and the ratio of C26 over C28 ω20-hydroxy fatty acids averaged 2.7 and 1.0, respectively. Similar compounds were identified in species of another genus in the Salviniaceae family, Salvinia, suggesting that their biosynthetic pathway evolved early during Salviniaceae evolution (>89?Ma). Salvinia species contain ω20-hydroxy and ω9,ω10-dihydroxy compounds in smaller concentrations and in a much different distribution compared to Azolla; the C31 1,ω20-diol is unique to Salvinia species. Closely related fern species from the genera Marsilea, Pilularia and Regnellidium did not contain these compounds, nor did unrelated aquatic plants from the genera Lemna and Pistia. All mid-chain hydroxy compounds detected in extant Azolla have been traced previously in Arctic Eocene sediments from the so-called ‘Azolla Event’ (48.5?Ma), implying that they are well preserved in the geological record and may therefore serve as Azolla biomarkers. Our findings indicate that ω20-hydroxy and ω9,ω10-dihydroxy compounds in sediments could be used as biomarkers of the whole Salviniaceae family. Subsequently, the clear differences in compound distribution between the Azolla and Salvinia genera and the more subtle ones between the two Azolla sections, may allow assigning the compound’s origin at the genus (and possibly section) level, depending on the preservation of compound classes in the sediment and the timing of the Azolla or Salvinia deposition. This is exemplified by a sediment interval of the so-called ‘Salvinia bed’ (Eemian), which contained trace amounts of the C31 1,ω20-diol, but none of the ω20-hydroxy and ω9,ω10-dihydroxy compounds common to Azolla, indicating the value of C31 1,ω20-diol as a biomarker for distinguishing Salvinia from Azolla.Nikitenko, B.L., Devyatov, V.P., Lebedeva, N.K., Basov, V.A., Fursenko, E.A., Goryacheva, A.A., Peshchevitskaya, E.B., Glinskikh, L.A., Khafaeva, S.N., 2018. Jurassic and Cretaceous biostratigraphy and organic matter geochemistry of the New Siberian Islands (Russian Arctic). Russian Geology and Geophysics 59, 168-185. Jurassic-Cretaceous terrigenous complex of the Laptev and East Siberian Seas is of considerable interest as a potential exploration target. However, the key Jurassic and Cretaceous sections of the New Siberian Islands have been poorly studied. The results of this study were used to provide a detailed micropaleontological description of these sections and substantiation of the previous lithostratigraphic subdivision. We first identified a series of Boreal standard zones in the Jurassic and Cretaceous sections, based on the foraminifers, ostracods, dinocysts, and terrestrial palynomorphs. Our results, along with the published data on ammonites, bivalves, and terrestrial palynomorphs and the results of radiometric dating, provide more precise constraints on the stratigraphic position of the identified lithostratigraphic units. The results of this study can be corroborated by seismic data to explore offshore areas of the Laptev and East Siberian Seas. We also present detailed data on the geochemistry of organic matter from the Pestsovaya Formation (Hettangian-lowermost Upper Pliensbachian).Ning, J., Wei, B., Mao, R., Wang, Y., Shang, J., Sun, L., 2018. Pore-level observations of an alkali-induced mild O/W emulsion flooding for economic enhanced oil recovery. Energy & Fuels 32, 10595-10604. depression of the current global oil market makes the majority of chemical EOR projects worldwide nearly unprofitable, especially in China. Therefore, economic alternative methods and technologies must be quickly developed. This proof of concept research evaluates a chemical flooding method using pre-formed mild O/W emulsions, which were produced by saponification between a low-cost alkali (NaOH) and a petroleum acid-rich oil. Our focus was first given to the dynamics of the saponification with an aim to quantify alkali consumption. Afterward, the composition of the crude oil before and after the reaction was characterized using a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) to determine the preferred compounds in saponification. The physiochemical properties of the generated emulsions were further investigated through direct measurements of rheology, morphology, particle size distribution, and stability. Particular attention was placed on the oil displacement mechanisms of the emulsions at pore level. The results showed that fatty acids, naphthenic acids, and aromatic acids were clearly partitioned on the FT-ICR MS spectra of the crude oil, while the C16 and C18 fatty acids (DBE = 1, DBE represents equivalent double bond number) were predominantly saponified, which accordingly produced mild O/W emulsions (pH ≈ 7.0). The viscosity, morphology, and stability of the emulsions were found to strongly depend on the oil–water ratio. The displacement dynamics of three stable emulsions observed in a visual micromodel revealed that the O/W emulsion flooding can enlarge the sweep area and also notably reduce the residual oil saturation when employed as an EOR mode. Emulsification/entrainment, blocking, and stripping were three dominant pore level driving forces for this emulsion flooding. Phase inverse from O/W to W/O occurred when the emulsion of O/W = 3:7 was used and finally caused injectivity issue.Novák, J., ?kríba, A., Zápal, J., Kuzma, M., Havlí?ek, V., 2018. CycloBranch: An open tool for fine isotope structures in conventional and product ion mass spectra. Journal of Mass Spectrometry 53, 1097-1103. the growing community of Fourier transform mass spectrometry users, the identification of fine isotope structure has become an indispensable method for molecular formula determination. In this work, the fine isotope envelopes for accessing the mutual ratio of 2 closely related pyoverdines in a mixture were used. Bacterial siderophores pyoverdines D and E cannot be easily separated via liquid chromatography-mass spectrometry because their structures differ in (de)amidation at the respective chromophore parts only. Their mutual ratio was determined in a mixture via nuclear magnetic resonance spectroscopy and semiquantitative mass spectrometry using our open-source software CycloBranch, which represents a genuine free tool supporting the determination of fine isotope structures in both conventional and product ion mass spectra. Native Bruker, Thermo, and Waters data formats are supported in addition to XML and plain text formats. , H., Lee, Y.-Z., Hung, Y.-L., Kolusheva, S., Upcher, A., Chen, Y.-C., Chen, J.-Y., Sue, S.-C., Zarivach, R., 2018. Understanding the biomineralization role of magnetite-interacting components (MICs) from magnetotactic bacteria. Frontiers in Microbiology 9, 2480. doi: 10.3389/fmicb.2018.02480. is a process that takes place in all domains of life and which usually helps organisms to harden soft tissues by creating inorganic structures that facilitate their biological functions. It was shown that biominerals are under tight biological control via proteins that are involved in nucleation initiation and/or which act as structural skeletons. Magnetotactic bacteria (MTB) use iron biomineralization to create nano-magnetic particles in a specialized organelle, the magnetosome, to align to the geomagnetic field. A specific set of magnetite-associated proteins (MAPs) is involved in regulating magnetite nucleation, size, and shape. These MAPs are all predicted to contain specific 17 to 22 residue-long sequences involved in magnetite formation. To understand the mechanism of magnetite formation, we focused on three different MAPs, MamC, Mms6 and Mms7, and studied the predicted iron-binding sequences. Using nuclear magnetic resonance (NMR), we differentiated the recognition mode of each MAP based on ion specificity, affinity, and binding residues. The significance of critical residues in each peptide was evaluated by mutation followed by an iron co-precipitation assay. Among the peptides, MamC showed weak ion binding but created the most significant effect in enhancing magnetite particle size, indicating the potency in controlling magnetite particle shape and size. Alternatively, Mms6 and Mms7 had strong binding affinities but less effect in modulating magnetite particle size, representing their major role potentially in initiating nucleation by increasing local metal concentration. Overall, our results explain how different MAPs affect magnetite synthesis, interact with Fe2+ ions and which residues are important for the MAPs functions.Nutman, A.P., Bennett, V.C., Friend, C.R.L., 2019. Chapter 39 - Eoarchean life From the Isua Supracrustal Belt (Greenland), in: Van Kranendonk, M.J., Bennett, V.C., Hoffmann, J.E. (Eds.), Earth's Oldest Rocks (Second Edition). Elsevier, pp. 965-983. contrast to the majority of Eoarchean terranes, the 3800–3700Ma Isua supracrustal belt (Greenland) contains tectonic slices with maximum metamorphic temperatures below 550°C and rare domains where deformation is low, resulting in the preservation of Eoarchean sedimentary structures. In the 1970s, globular structures in metacherts were interpreted as relict microfossils, but subsequent investigations have reinterpreted these as younger abiogenic structures. Also in the 1970s, bulk graphite analysis revealed negative δ13CVPDB values, and debate surrounded whether this signature was biogenic carbon or formed during metamorphism by the reaction 6FeCO3?2Fe2O4+5CO2+C. To avoid possible metamorphic graphite, subsequent studies analyzed silicate rocks devoid of carbonate, and graphite from graywackes, which yielded negative δ13CVPDB values with nanoscale morphologies consistent with pyrolyzation of structurally heterogeneous organic compounds during metamorphism. Iron isotopic signatures in Isua banded iron formations show isotope fractionations compatible with both biogenic and abiogenic processes. Units of Isua massive dolomite have seawater-like rare earth element+yttrium signatures, indicating a sedimentary origin. Given that low-temperature dolomite is only known to form by microbial mediation, this is simple, robust evidence for early life. In a low-strain domain, ～3700Ma dolomitic rocks preserve shallow water sedimentary structures and stromatolites with δ13CVPDB values of?+1. Thus, five decades of Isua investigations have resulted in increasing and diverse lines of evidence for Eoarchean life. The weight of evidence is affirmative, and future research should focus on the diversity of the ecological niches it occupied and its metabolic pathways.Oberlin, E.A., Claire, M.W., Kounaves, S.P., 2018. Evaluation of the Tindouf basin region in southern Morocco as an analogue site for soil geochemistry on Noachian Mars. Astrobiology 18, 1318-1328. on Earth that provide insights into processes that may be occurring or may have occurred throughout martian history are often broadly deemed “Mars analog environments.” As no single locale can precisely represent a past or present martian environment, it is important to focus on characterization of terrestrial processes that produce analogous features to those observed in specific regions of Mars or, if possible, specific time periods during martian history. Here, we report on the preservation of ionic species in soil samples collected from the Tindouf region of Morocco and compare them with the McMurdo Dry Valleys of Antarctica, the Atacama Desert in Chile, the martian meteorite EETA79001, and the in situ Mars analyses from the Phoenix Wet Chemistry Laboratory (WCL). The Moroccan samples show the greatest similarity with those from Victoria Valley, Beacon Valley, and the Atacama, while being consistently depleted compared to University Valley and enriched compared to Taylor Valley. The NO3/Cl ratios are most similar to Victoria Valley and Atacama, while the SO4/Cl ratios are similar to those from Beacon Valley, Victoria Valley, and the Atacama. While perchlorate concentrations in the Moroccan samples are typically lower than those found in samples of other analog sites, conditions in the region are sufficiently arid to retain oxychlorines at detectable levels. Our results suggest that the Tindouf Basin in Morocco can serve as a suitable analogue for the soil geochemistry and subsequent aridification of the Noachian epoch on Mars.Offord, C., 2018. Underworld. The Scientist 10.2018, 28-35. journeys into mines to explorations of volcanoes on the ocean floor, deep voyages reveal the richness of the planet’s deep biosphere.About a 20-minute drive north of the industrial town of Timmins, Ontario, the ground gives way to a gaping pit stretching more than 100 meters across. This pit is the most recognizable feature of Kidd Creek Mine, the deepest copper and zinc mine in the world. Below the Earth’s surface, a maze of underground tunnels and shafts pierces 3 kilometers of ancient volcanic rock. Were it not for a huge ventilation system keeping the passages cool, the air temperature at this depth would be 34 °C (93 °F).It’s here that Barbara Sherwood Lollar, a hydrogeologist at the University of Toronto, journeys into the planet’s crust to hunt for signs of life. “You get into a small truck or vehicle and go down a long, winding roadway that corkscrews down into the Earth,” she tells The Scientist. By the time she and her fellow passengers clamber out into the corridors at the end of the roadway, “we are literally walking along what was the ocean floor 2.7 billion years ago,” she says. “It’s an utterly fascinating and magical place to visit.”Unlike miners, who navigate these tunnels in search of metal ores, Sherwood Lollar and her colleagues are on the lookout for pools of salty water. “These aren’t waters you’d pump into your cottage and drink or spread on your crops,” Sherwood Lollar says. “These are waters that have been in contact with the rock for long geochemical timescales—they’re full of dissolved cations and anions that they’ve leached out of the minerals.” So full, in fact, that they give off a distinctive, musty odor. “As we’re walking along these tunnels, if I get a whiff of that stenchy smell, then we head in that direction.”Where there’s water, there’s the potential for life. In 2006, Sherwood Lollar was part of a team led by Tullis Onstott at Princeton University that discovered an anaerobic, sulfate-reducing bacterium thriving in the sulfate-rich fracture waters of Mponeng gold mine in South Africa, 2.8 kilometers underground.1 A few years later, a different group described a diverse microbial community living at a similar depth in the Earth’s crust, accessed via a borehole drilled into the ground in Finland.2 With the recent discovery of 2-billion-year-old, hydrogen- and sulfate-rich water seeping out of the rock in Kidd Mine, Sherwood Lollar and her colleagues are hoping they might again find life.3These expeditions are just one part of a rapidly expanding field of research focused on documenting microbial and even eukaryotic life dwelling hundreds of meters deep in the Earth’s crust—the vast sheath of rock encasing the planet’s mantle. Researchers are now exploring this living underworld, or deep biosphere, not only in the ancient, slow-changing continental crust beneath our feet, but in the thinner, more dynamic oceanic crust under the seafloor. (See illustration on page 32.) Such habitats have become more accessible thanks to the last two decades’ expansion of scientific drilling projects—whereby researchers haul up cores of rock to study on the surface—as well as a growing number of expeditions into the Earth via mines or cracks in the ocean floor.Studies of these dark—and often anoxic and hot—environments are challenging scientists to rethink the limits of life, at the same time highlighting how little we know about the world beneath our feet. “It’s a really good field if you don’t mind not knowing all the answers,” says Jason Sylvan, a geomicrobiologist at Texas A&M University. “For some people, that freaks them out. For me, a field is more exciting when you can ask really big questions.”Holes in the groundA desire to explore the deep biosphere has led Julie Huber, a microbial oceanographer at Woods Hole Oceanographic Institution in Massachusetts, to some of the remotest places on Earth. Huber is interested in the huge volumes of water swilling around between rock particles in the oceanic crust, and the extent and diversity of microbial life within them. One way to access that water is via expensive drilling projects, many organized by the International Ocean Discovery Program (IODP), that bore through marine sediments to the crust. In 2013, this approach revealed bacteria living in 3.5-million-year-old basalt rock underneath the Pacific Ocean.4The other way, Huber explains, “is to find where that water is naturally leaking out through the seafloor, and then try to capture it just as it’s coming out.” For that purpose, Huber has not only worked with teams of engineers to guide remotely operated vehicles down to the bottom of the ocean, she’s also joined the ranks of scientists who have taken the plunge with Alvin, a three-person submersible research vehicle owned by the US Navy that can dive down as far as 4,500 meters. “Claustrophobic people don’t do well in there,” Huber acknowledges—adding that anyone planning to dive is invited to try sitting in the sub before it leaves the boat deck to avoid “a full-on panic being launched into the ocean.”These technologies allow Huber to collect samples of the fluids seeping, or sometimes exploding, out of the oceanic crust from underwater volcanoes and hydrothermal vents. In the early 2000s, she and her colleagues used 16S rRNA gene sequencing to analyze subseafloor microbial diversity following multiple eruptions of Axial Seamount, an underwater volcano about 480 kilometers west of Oregon and nearly 1.5 kilometers under the water’s surface. Compared to background seawater, samples collected at the vent site revealed multiple unique bacterial5 and archaeal6 taxa that appeared to have been blasted out of the crust, pointing to a diverse microbial community thriving below the seafloor. More recently, Huber’s group carried out a detailed survey at the world’s deepest hydrothermal vent field—a site known as Piccard, after Swiss deep-sea adventurer Jacques Piccard—and turned up thousands of vent-specific microbial taxa in fluids exiting the crust at temperatures of up to 108 °C (226 °F).7Such findings are becoming typical of this young research field. To date, studies of crustal sites all over the world—both oceanic and continental—have documented all sorts of organisms getting by in environments that, until recently, were deemed inhospitable, with some theoretical estimates now suggesting life might survive at least 10 kilometers into the crust. And the deep biosphere doesn’t just comprise bacteria and archaea, as once thought; researchers now know that the subsurface contains various fungal species,8 and even the occasional animal. Following the 2011 discovery of nematode worms in a South African gold mine, an intensive two-year survey turned up members of four invertebrate phyla—flatworms, rotifers, segmented worms, and arthropods—living 1.4 kilometers below the Earth’s surface.9Unsurprisingly, as researchers explore these unusual habitats, they’re finding a number of organisms that were until recently unknown to science. The discovery of “extremophile” archaea species in the last decade has led scientists to rethink the entire domain’s phylogeny. (See “Archaea Family Tree Blossoms, Thanks to Genomics,” The Scientist, June 2018.) And while many of the bacteria and archaea discovered in the deep biosphere have analogs or close relatives on the surface, some are unlike anything found anywhere else.One example is Candidatus Desulforudis audaxviator, first found by Onstott’s team in Mponeng gold mine in 2006. (“Audax viator,” which translates from Latin to “bold traveler,” is a reference to a line in Jules Verne’s Journey to the Center of the Earth.) Researchers have since identified bacteria resembling this species in other sites a kilometer or more into the crust, but haven’t yet found any close relatives in surface communities. Another bacterial species, unearthed more than 1,000 meters down in the Henderson molybdenum mine in Colorado, shows faint phylogenetic links to members of the phylum Nitrospirae, but is otherwise unlike anything on the surface.10A key area of research now is understanding how such life survives. Devoid of sunlight, “these systems are typically energy-poor,” says Sherwood Lollar. Compared to surface communities, microbes in the deep biosphere are thought to be relatively slow-growing and sparsely distributed, she adds. While surface soil may contain in excess of 10 billion microbes per gram, oceanic crust usually contains around 10,000 cells per gram, and continental crust—where water is unsurprisingly in shorter supply—holds fewer than 1,000 cells per gram.Working with such low-biomass samples presents a challenge of its own, but researchers are using a combination of techniques, including metagenomic analyses and incubation of subsurface rocks or fluids with different potential food sources in the lab, to probe the function of subsurface microbes. Such studies are revealing genes for metabolic enzymes that suggest these organisms can gain energy from a suite of sources—particularly hydrogen and other molecules that are released by chemical reactions between water and rock. When geomicrobiologist Lotta Purkamo of the University of St Andrews and her colleagues characterized the ecosystem of a 600-meter-deep borehole in northern Finland, for example, they found evidence of metabolic pathways based on reducing or oxidizing sulfate, nitrate, methane, ammonia, and iron, as well as fixation reactions involving carbon.11Additionally, thanks to metatranscriptomic analyses, “we’re learning that these organisms have a lot of potential metabolisms that they could be expressing,” says Huber, who recently carried out this sort of assay on the Axial Seamount community.12 “But depending on the conditions and the geological setting, just a small subset of those genes are being used.” Such results hint at flexible and opportunistic lifestyles, she adds, where microbes make use of whatever they can, whenever they can.These findings are chipping away at some of the big questions about the diversity and uniqueness of life in the deep biosphere. But the insights afforded by a single drill core or fluid sample can be frustratingly fleeting, says University of Bergen geobiologist Steffen J?rgensen. One sample “doesn’t give us any understanding of the dynamics of the system and how it evolves over time,” he says. For a longer-term view of life deep in the Earth, researchers are taking their experiments underground. The fourth dimensionLast summer, J?rgensen stepped out of a helicopter onto a tiny basalt island about 30 kilometers from the south coast of Iceland. Too rocky to access by boat, the island of Surtsey is the tip of a huge mound of magma blown out of the seafloor by an under-water volcanic eruption that went on for nearly four years in the mid-1960s. This newly formed oceanic crust “gives us a huge advantage,” J?rgensen says. “We can actually drill into what is a marine system, but from land.”Using equipment flown to Surtsey by helicopter, J?rgensen and a large team of engineers drilled down into the basalt. They didn’t just remove cores from the island; rather, the researchers set up a mini observatory to take in situ measurements of the deep biosphere. Into a 190-meter-deep hole in the rock, the team installed a series of 10-meter-long aluminum tubes, several with a number of small slits to allow fluids to trickle through from the surrounding rock. Then, into the tubes the team lowered a cable with various bits of equipment—temperature and pressure loggers, and microbial incubators—attached at specific intervals, until the equipment lined up with the slits. Since then, the instruments in the observatory have been collecting data from the oceanic crust, and next summer, J?rgensen and his colleagues will go back to see what they’ve found.The Surtsey installation is now one of a handful of deep observatories around the world and part of a larger effort to establish long-term studies in both oceanic and continental crust. Such sites offer a window into the activity of the deep biosphere, as well as an opportunity to collect time-series data that are critical to understand how that biosphere changes over time. “It’s the only way that we can . . . make observations that are more than ‘I went to this place, one time in the history of the world, and I grabbed a bunch of rocks, and here’s what I saw,’” says Sylvan.Data coming out of long-term studies of the deep biosphere paint a dynamic picture. This July, a team that included Onstott and Sherwood Lollar published metagenomic, metatranscriptomic, and metaproteomic analyses of data collected over a period of two and a half years at a depth of 1,339 meters from a borehole drilled into South Africa’s Beatrix gold mine.13 Over the course of the study, the microbial community structure shifted in concert with natural fluctuations in the groundwater’s geochemistry—in particular, the availability of electron-accepting compounds such as nitrates and sulfates.Meanwhile, Huber’s group published an analysis of data gathered over two years from two so-called CORK (circulation obviation retrofit kits) observatories installed in the oceanic crust below North Pond, a site on the Mid-Atlantic Ridge, through which circulates well-oxygenated and—at less than 15 °C (59 °F)—relatively cold water.14 Metagenomics showed that the microbial communities, which were substantially different from those of warmer and anoxic environments, went through substantial shifts over time—with one phylum dominating one month, and another taking over the next—despite only minor fluctuations in the water’s geochemistry.Such underground observatories can also act as in situ laboratories. By incubating rocks inside these sites for years at a time, researchers can study how microbial communities colonize new material in their natural environments rather than in the lab, and how the mineralogical composition of the crust influences who grows where.15 The sites might even reveal subsurface dynamics on much longer timescales, by helping scientists identify signs of ancient life. To date, many of the clues about deep microbial communities throughout geological history come from what look like fossilized or mineralized remains of bacteria and archaea on rocks retrieved from the crust. But given how little researchers know about the processes of mineralization in the deep subsurface, the authenticity of at least some of these remains is in question.“It’s quite difficult to tell whether you’re actually looking at a fossil of an organism that lived in the deep biosphere billions of years ago,” explains University of Edinburgh geobiologist Sean McMahon. “Not only is it difficult in general to recognize fossil bacteria, which look very much like minerals at that size scale, it’s difficult to show, if it really is a fossil bacterium, that the organism lived below the surface at the time it was living billions of years ago.”To get a better grip on the long-term dynamics of the deep biosphere, groups such as McMahon’s are trying to recreate deep mineralization in the lab. They do this by inoculating rocks with bacteria, McMahon explains, then tweaking physical and chemical conditions to trigger fossilization. “The idea is to try and find the sweet spot where the microbes are able to live happily, but you only have to change a small thing for them to become entombed in minerals and fossilized,” he says.Underground observation stations such as the one at Surtsey will soon be able to complement this research, says J?rgensen. “By having the observatory, we can hopefully clarify whether these [fossil-like] structures can be produced abiotically, or if we only see them where there’s microbes present,” he says. “It is a very difficult question to get to the bottom of.”Missing piecesDespite the infancy of research into the deep biosphere, it’s clear to many in the field that science has long held a warped view of what constitutes life in our universe. Researchers are far from agreeing on the extent of this underworld—one 1990s paper controversially suggested that deep life constituted 50 percent of the Earth’s current biomass,16 though most estimates are now below 15 percent. Before the rise of land plants around 400 million years ago, though, deep biomass could have outweighed life on the surface by an order of magnitude, according to calculations published this summer by McMahon and the University of Aberdeen’s John Parnell.17However much life exists below the Earth’s surface, its mere presence is forcing a reevaluation of biological normalcy, not only on Earth but deep within other planets such as Mars. After all, in the Earth’s crust, “we had made an assumption that there was no life,” notes Purkamo, who has also been affiliated with St Andrews’s Centre for Exoplanet Science. “And then, tada!”Findings from the underground frontier are also pushing scientists to consider how subsurface microbes—and the reactions they carry out—influence global processes occurring above the surface. “I’m quite sure that people don’t really think about that,” notes J?rgensen. “That they’re walking on this enormous biosphere that could have a really significant impact on how the system works.” The same goes for attempts to understand physical and biological evolution throughout the planet’s history. “When we think about how life on Earth has changed over time, and how it’s interacted with the chemistry of rocks, sediments, groundwater, oceans, atmosphere, we shouldn’t be thinking just about charismatic animals and plants,” says McMahon. “We should be thinking about this huge quantity of microorganisms, most of which are living on the surfaces of mineral grains and interacting with them.”That’s exactly the view today’s deep biosphere researchers are trying to expand, and to most in the field, it’s an exciting journey. “It’s like: Damn, there’s so much we do not know about what is happening down there,” says Huber, whose team is currently exploring the deep biosphere at an active underwater volcano known as Loihi, about 35 kilometers off the coast of Hawaii’s Big Island. “And what a privilege to be able to ask these questions and to do this type of science and try to figure it out.” References1. L.-H. Lin et al., “Long-term sustainability of a high-energy, low-diversity crustal biome,” Science, 314:479–82, 2006.2. M. It?vaara et al., “Characterization of bacterial diversity to a depth of 1500 m in the Outokumpu deep borehole, Fennoscandian Shield,” FEMS Micro Ecol, 77:295–309, 2011.3. L. Li et al., “Sulfur mass-independent fractionation in subsurface fracture waters indicates a long-standing sulfur cycle in Precambrian rocks,” Nat Commun, 7:13252, 2016.4. M.A. Lever et al., “Evidence for microbial carbon and sulfur cycling in deeply buried ridge flank basalt,” Science, 339:1305–08, 2013.5. J.A. Huber et al., “Bacterial diversity in a subseafloor habitat following a deep-sea volcanic eruption,” FEMS Microbiol Ecol, 43:393–409, 2003. 6. J.A. Huber et al., “Temporal changes in archaeal diversity and chemistry in a mid-ocean ridge subseafloor habitat,” Appl Env Microbiol, 68:1585–94, 2002.7. J. Reveillaud et al., “Subseafloor microbial communities in hydrogen-rich vent fluids from hydrothermal systems along the Mid-Cayman Rise,” Env Microb, 18:1970–87, 2016.8. H. Drake et al., “Anaerobic consortia of fungi and sulfate reducing bacteria in deep granite fractures,” Nat Commun, 8:55, 2017.9. G. Borgonie et al., “Eukaryotic opportunists dominate the deep-subsurface biosphere in South Africa,” Nat Commun, 6:8952, 2015.10. J.W. Sahl et al., “Subsurface microbial diversity in deep-granitic-fracture water in Colorado,” Appl Environ Microbiol, 74:143–52, 2008.11. L. Purkamo et al., “Diversity and functionality of archaeal, bacterial and fungal communities in deep Archaean bedrock groundwater,” FEMS Microbiol Ecol, 94:fiy116, 2018.12. C.S. Fortunato, J.A. Huber, “Coupled RNA-SIP and metatranscriptomics of active chemolithoautotrophic communities at a deep-sea hydrothermal vent,” ISME, 10:1925–38, 2016.13. C. Magnabosco et al., “Fluctuations in populations of subsurface methane oxidizers in coordination with changes in electron acceptor availability,” FEMS Microbiol Ecol, 94:fiy089, 2018.14. B.J. Tully et al., “A dynamic microbial community with high functional redundancy inhabits the cold, oxic subseafloor aquifer,” ISME J, 12:1–16, 2018.15. A.R. Smith et al., “Deep crustal communities of the Juan de Fuca Ridge are governed by mineralogy,” Geomicrobiol J, 34:147–56, 2017.16. T. Gold, “The deep, hot biosphere,” PNAS, 89:6045–49, 1992.17. S. McMahon, J. Parnell, “The deep history of Earth’s biomass,” J Geol Soc, doi:10.1144/jgs2018-061, 2018.Ormes, J.F., 2018. Cosmic rays and climate. Advances in Space Research 62, 2880-2891. change and global warming is generally attributed to increases in greenhouse gases in the atmosphere. Other possible contributing effects are constantly being sought. Because of the importance of solar irradiance as a driver of climate, and because the widely known effect of the solar cycle on cosmic rays, it has been speculated for more than 50years that cosmic ray variations may have an impact on climate. The question has been how. A proposed mechanism would be through the effect of ionization from cosmic rays on the rates of nucleation of cloud condensation nuclei. The result would be an impact of the rate of cosmic rays on cloud formation that would subsequently impact the reflection of incoming short wavelengths and the trapping of outgoing long radiation; more cosmic rays would lead to more clouds and a net cooling of the planet (and visa-versa). This paper concludes that while the effect may operate, it is not sufficiently robust to be a significant contributor to the current warming of the planet.Ortmann, A.C., Brannock, P.M., Wang, L., Halanych, K.M., 2018. River flow impacts bacterial and archaeal community structure in surface sediments in the northern Gulf of Mexico. Microbial Ecology 76, 941-953. community structure in the northern Gulf of Mexico has been shown to be driven by geographical differences due to inshore–offshore gradients and location relative to river discharge. Samples collected along three transects spanning Mobile Bay, Alabama, showed significant differences in meiobenthic communities east of the bay compared to those sampled from the west. In contrast, analysis of bacterial and archaeal communities from the same sediment samples shows that the inshore–offshore gradient has minimal impact on their community structure. Significant differences in community structure were observed for Bacteria and Archaea between the east and west samples, but there was no difference in richness or diversity. Grouped by sediment type, higher richness was observed in silty samples compared to sandy samples. Significant differences were also observed among sediment types for community structure with bacteria communities in silty samples having more anaerobic sulfate reducers compared to aerobic heterotrophs, which had higher abundances in sandy sediments. This is likely due to increased organic matter in the silty sediments from the overlying river leading to low oxygen habitats. Most archaeal sequences represented poorly characterized high-level taxa, limiting interpretation of their distributions. Overlap between groups based on transect and sediment characteristics made determining which factor is more important in structuring bacterial and archaeal communities difficult. However, both factors are driven by discharge from the Mobile River. Although inshore–offshore gradients do not affect Bacteria or Archaea to the same extent as the meiobenthic communities, all three groups are strongly affected by sediment characteristics.Osmont, D., Sigl, M., Eichler, A., Jenk, T.M., Schwikowski, M., 2018. A Holocene black carbon ice-core record of biomass burning in the Amazon Basin from Illimani, Bolivia. Climate of the Past Discussions 2018, 1-21. Amazon Basin is one of the major contributors to global biomass burning emissions. However, regional paleofire trends remain partially unknown. Due to their proximity to the Amazon Basin, Andean ice cores are suitable to reconstruct paleofire trends in South America and improve our understanding of the complex linkages between fires, climate and humans. Here we present the first refractory black carbon (rBC) ice-core record from the Andes as a proxy for biomass burning emissions in the Amazon Basin, derived from an ice core drilled at 6300ma.s.l. from Illimani glacier in the Bolivian Andes and spanning the entire Holocene back to the last deglaciation 13000 years ago. The Illimani rBC record displays a strong seasonality with low values during the wet season and high values during the dry season due to the combination of enhanced biomass burning emissions in the Amazon Basin and less precipitation at the Illimani site. Significant positive (negative) correlations were found with reanalyzed temperature (precipitation) data, respectively, for regions in Eastern Bolivia and Western Brazil characterized by a substantial fire activity. rBC long-term trends indirectly reflect regional climatic variations through changing biomass burning emissions as they show higher (lower) concentrations during warm/dry (cold/wet) periods, respectively, in line with climate variations such as the Younger Dryas, the 8.2ka event, the Holocene Climatic Optimum, the Medieval Warm Period or the Little Ice Age. The highest rBC concentrations of the entire record occurred during the Holocene Climatic Optimum between 7000 and 3000BC, suggesting that this outstanding warm and dry period caused an exceptional biomass burning activity, unprecedented in the context of the past 13000 years. Recent rBC levels, rising since 1730 AD in the context of increasing temperatures and deforestation, are similar to those of the Medieval Warm Period. No decrease was observed in the 20th century, in contradiction with the global picture (broken fire hockey stick hypothesis).Otte, J.M., Blackwell, N., Soos, V., Rugh?ft, S., Maisch, M., Kappler, A., Kleindienst, S., Schmidt, C., 2018. Sterilization impacts on marine sediment – Are we able to inactivate microorganisms in environmental samples? FEMS Microbiology Ecology 94, Article fiy189. distinguish between biotic and abiotic processes in laboratory experiments with environmental samples, an effective sterilization method is required that prevents biological activity but does not change physico-geochemical properties of samples. We compared standard sterilization methods with respect to their impact on microbial abundance and activity. We exposed marine sediment to (i) autoclaving, (ii) gamma-radiation or (iii) sodium azide (NaN3) and determined how nucleic acids, microbial productivity, colony forming units (CFUs) and community composition of microorganisms, fungi, unicellular protists and protozoa were affected. In autoclaved and gamma-sterilized sediments, only few colonies formed within 16 days. After addition of NaN3 to the sediment, numerous CFUs (>50) but lower 3H-leucine incorporation rates, i.e. lower protein biosynthesis rates, were found compared to the other two sterilization techniques. Extractable RNA was detected immediately after all sterilization treatments (0.2–17.9 ng/g dry sediment) but decreased substantially by 84%–98% after 16 days of incubation. The total organic carbon content increased from 18 mg L?1 to 220 mg L?1 (autoclaving) and 150 mg L?1 (gamma-radiation) after sterilization. We compare advantages and disadvantages for each tested sterilization method and provide a helpful decision-making resource for choosing the appropriate sterilization technique for environmental studies, particularly for marine sediments.Ouyang, Y., Tian, W., Sun, B., Wang, B., Qi, L., Sun, Q., Yang, Q., Dong, H., 2018. Accumulation characteristics and exploration strategies of coal measure gas in China. Natural Gas Industry B 5, 444-451. measure gas is broadly defined as all natural gas occurring in coal measure strata while narrowly defined as the coalbed methane (CBM) in coal beds and the natural gas in the adjacent tight sandstone reservoirs. In this paper, the accumulation characteristics and control factors of narrowly defined coal measure gas in China were analyzed from the aspects of source rock distribution, coal–sandstone combination type, sedimentary facies and closed system to improve CBM development benefit. And the following research results were obtained. First, there are various coal–sandstone combination relationships in coal measure strata of coal bearing basins in China. Second, the widely-distributed source rocks provide sufficient gas sources for the enrichment of coal measure gas. Third, sedimentary facies dominate the combination relationships of source–reservoir–caprock assemblages of coal measure gas, so the inborn material base of coal measure gas accumulation is formed. The sedimentary systems of fluvial facies and delta facies are the most favorable sedimentary facies for the paragenesis and accumulation of coal measure gas for their coal beds and sandstones are developed. Fourth, the closed system controls the whole process of generation, enrichment and accumulation of CBM (coal measure gas). Three types of coal measure gas reservoirs are identified: self-source and self-reservoir CBM reservoirs, paragenetic CBM–sandstone gas reservoirs, coal-derived sandstone gas reservoirs, among which the first type is currently the main target of CBM exploration and development. Finally, the next exploration direction of coal measure gas was pointed out as follows. First, the exploration and evaluation of coal measure gas shall be focused on the giant basins with abundant coal measure gas, such as Qinshui, Ordos, Junggar, Hailar and Jixi. Second, coal measure gas reservoirs shall be explored specifically based on different types. It is necessary to carry out CBM exploration in the self-source and self-reservoir CBM enriched zones in the shallow layers, integrated exploration of CBM and sandstone gas in the paragenetic CBM–sandstone gas reservoirs in the deep layers, and sandstone gas exploration in coal-derived sandstone gas reservoirs.Paganoni, M., King, J.J., Foschi, M., Mellor-Jones, K., Cartwright, J.A., 2019. A natural gas hydrate system on the Exmouth Plateau (NW shelf of Australia) sourced by thermogenic hydrocarbon leakage. Marine and Petroleum Geology 99, 370-392. identification of natural gas hydrates and shallow free gas in sedimentary basins is critical for understanding the organic carbon cycle dynamics in the shallow geosphere, as well as for geohazard studies related to the development of commercial hydrocarbon fields. In this study, we report for the first time the evidence for the potential occurrence of a natural gas hydrate system along the continental margin of Australia, on the Exmouth Plateau (NW Shelf). By the use of high-quality 3D seismic data, calibrated by downhole data from ODP and industry boreholes, we interpret a series of shallow high-amplitude anomalies, including patchy bottom-simulating reflections, as the seismic expression of localised accumulations of free gas beneath the base of hydrate stability, and overlying high-saturation hydrates or authigenic carbonates. The hydrate-bearing reservoir is constituted by Neogene and Quaternary fine-grained carbonate nannofossil and foraminifera-rich oozes. The patchy distribution of the shallow free gas and hydrate accumulations, which reflects the geometry of deeper fault blocks, is hypothesised to result from the leakage of thermogenic gas from deeper reservoirs. The interpretation of a thermogenic origin for the hydrate-forming gases is supported by (1) the existence in the study area of several thermogenic gas discoveries within Late Triassic reservoirs, (2) seismic evidence of cross-stratal and stratal pathways for migrating gases in the overburden, (3) the presence of free gas accumulations at depths intermediate between the deep reservoirs and shallow gas hydrate systems, and (4) geochemical and lithological evidence that the conditions which favour the generation of shallow microbial gas are not present in the area. The acquisition of downhole log and sample data through the observed seismic amplitude anomalies is necessary to test the interpretations and hypotheses presented in this manuscript.Paiste, K., Lepland, A., Zerkle, A.L., Kirsim?e, K., Izon, G., Patel, N.K., McLean, F., Kreitsmann, T., M?nd, K., Bui, T.H., Romashkin, A.E., Rychanchik, D.V., Prave, A.R., 2018. Multiple sulphur isotope records tracking basinal and global processes in the 1.98?Ga Zaonega Formation, NW Russia. Chemical Geology 499, 151-164. exceptionally organic-rich rocks of the 1.98?Ga Zaonega Formation deposited in the Onega Basin, NW Russia, have refined our understanding of Earth System evolution during the Paleoproterozoic rise in atmospheric oxygen. These rocks were formed in vent- or seep-influenced settings contemporaneous with voluminous mafic volcanism and contain strongly 13C-depleted organic matter. Here we report new isotopic (δ34S, Δ33S, Δ36S, δ13Corg) and mineralogical, major element, total sulphur and organic carbon data for the upper part of the Zaonega Formation, which was deposited shortly after the termination of the Lomagundi-Jatuli positive carbon isotope excursion. The data were collected on a recently obtained 102?m drill-core section and show a δ13Corg shift from ?38‰ to ?25‰. Sedimentary sulphides have δ34S values typically between +15‰ and +25‰ reflecting closed-system sulphur isotope </topics/earth-and-planetary-sciences/sulfur-isotopes> behaviour driven by high rates of microbial sulphate reduction, high sulphate demand, hydrothermal activity and hydrocarbon seepage </topics/earth-and-planetary-sciences/seepage>. Four intervals record δ34S values that exceed +30‰. We interpret these unusually 34S-enriched sulphides to be a result of limited sulphate diffusion into pore waters due to changes in sedimentation and/or periods of basinal restriction. Additionally, there are four negative δ34S excursions that are interpreted to reflect changes in the open/closed-system behaviour of sulphate reduction or availability of reactive iron. Our findings highlight the influence of basinal processes in regulating sulphur isotope records and the need for care before interpreting such signals as reflecting global conditions.Panchuk, V., Yaroshenko, I., Legin, A., Semenov, V., Kirsanov, D., 2018. Application of chemometric methods to XRF-data – A tutorial review. Analytica Chimica Acta 1040, 19-32. fluorescence (XRF) spectrometry is a modern method of element analysis, widely applied in forensic science, archeology, geochemistry and other fields. Chemometric data processing tools and approaches may help XRF to become even more informative. These tools allow for convenient data visualization, exploration of hidden relations in the data, classification of samples and quantitative treatment of noisy and overlapped spectra. This review describes the most popular chemometric techniques employed in XRF studies and provides typical examples of such applications.Pandey, B., Pathak, D.B., Mathur, N., Jaitly, A.K., Singh, A.K., Singh, P.K., 2018. A preliminary evaluation on the prospects of hydrocarbon potential in the carbonaceous shales of Spiti and Chikkim formations, Tethys Himalaya, India. Journal of the Geological Society of India 92, 427-434. the present investigation, an attempt has been made to explore the possibility of hydrocarbon prospects in the carbonaceous shale deposits of Spiti and Chikkim formations exposed in the Spiti valley of the Tethys Himalaya. Twenty samples, collected from successive levels of these litho-units, have been subjected to maceral analysis, Rock-Eval Pyrolysis and six samples to Fourier Transform Infra-red Spectroscopy (FTIR) and nuclear magnetic resonance (NMR) analyses. The study reveals the presence of mainly kerogen-III type of organic matter but some of the shale samples have shown a good amount of total organic carbon (TOC) to the tune of 3.19% which is sufficient to produce hydrocarbon. The results indicate the presence of methane occurring as free and fixed hydrocarbon in the shale samples. Few levels are especially rich in hydrocarbon. They have shown encouraging results with potential for generating liquid as well as lighter hydrocarbon. The data is also supported by the FTIR and NMR studies.Panigrahi, S., Velraj, P., Subba Rao, T., 2019. Chapter 21 - Functional microbial diversity in contaminated environment and application in bioremediation, in: Das, S., Dash, H.R. (Eds.), Microbial Diversity in the Genomic Era. Academic Press, pp. 359-385. of pollution and contamination from the natural environment has taken a center stage in the activities of the environmental managers and researchers. In the recent days, rapid emergence of contaminated sites in the world environment needs a sustainable effort and technique for the survival of the aquatic and terrestrial habitats. Elimination of natural and xenobiotic pollutants can be achieved by the process of bioremediation in an economic and ecofriendly manner. An array of abiotic and biotic components along with the functional characteristics of the inhibiting organisms is crucial in the process of bioremediation in a natural system. Microorganisms are present ubiquitously in the world ecosystem and are the versatile players in the bioremediation of contaminated sites. Information on their catabolic potential, genetic, and functional diversity is the foremost requirement during the bioremediation application. To perform a comprehensive assessment of the biodegradation potential of a contaminated site and changes in the structure and functional activities of microbial communities involved in bioremediation processes, sensitive, molecular techniques are essential. Analysis of nucleic acids, proteins, and lipids from environmental samples by molecular approaches such as genetic fingerprinting, metagenomics, metaproteomics, metatranscriptomics, and proteogenomics are vital for discovering and characterizing the vast microbial diversity and in understanding their interactions with biotic and abiotic environmental factors. In this chapter, we discuss the use of novel molecular techniques that offer new insights into the phylogenetic and functional diversity of microbial assemblages and their demonstrated application to assess biotreatment of contaminated environments.Peisl, B.Y.L., Schymanski, E.L., Wilmes, P., 2018. Dark matter in host-microbiome metabolomics: Tackling the unknowns–A review. Analytica Chimica Acta 1037, 13-27. “dark matter” in metabolomics (unknowns) represents an exciting frontier with significant potential for discovery in relation to biochemistry, yet it also presents one of the largest challenges to overcome. This focussed review takes a close look at the current state-of-the-art and future challenges in tackling the unknowns with specific focus on the human gut microbiome and host-microbe interactions. Metabolomics, like metabolism itself, is a very dynamic discipline, with many workflows and methods under development, both in terms of chemical analysis and post-analysis data processing. Here, we look at developments in the mutli-omic analyses and the use of mass spectrometry to investigate the exchange of metabolites between the host and the microbiome as well as the environment within the microbiome. A case study using HuMiX, a microfluidics-based human-microbial co-culture system that enables the co-culture of human and microbial cells under controlled conditions, is used to highlight opportunities and current limitations. Common definitions, approaches, databases and elucidation techniques from both the environmental and metabolomics fields are covered, with perspectives on how to merge these, as the boundaries blur between the fields. While reflecting on the number of unknowns remaining to be conquered in typical complex samples measured with mass spectrometry (often orders of magnitude above the “knowns”), we provide an outlook on future perspectives and challenges in elucidating the relevant “dark matter”.Peters, C.A., George, S.C., 2018. Hydrocarbon biomarkers preserved in carbonate veins of potentially Paleoproterozoic age, and implications for the early biosphere. Geobiology 16, 577-596. on the early rise of oxygenic photosynthesis and eukaryotes has recently encountered a major pitfall, as some hopane and sterane biomarkers reported in Archaean rocks are the results of contamination. Following an extensive petrological framework in the Pilbara Craton, Western Australia, oil‐bearing fluid inclusions and solid bitumens were identified in replacement and hydrothermal carbonate veins cross‐cutting Archaean metasedimentary rocks. The 2.55–2.63 billion years old metasedimentary rocks were found to be depleted of indigenous biomarkers. Here we show novel biomarker results from the solvent extraction of the carbonate veins. Volcanic rock blanks, outside rinses, and instrumental blanks showed no biomarkers, and the surrounding rocks were metamorphosed to a sufficiently high extent to not yield any biomarkers, but the biomarkers found in the veins are most likely indigenous. Biomarkers detected include C21?22 ααα‐ and αββ‐steranes (pregnanes), C27?29 αββ‐steranes, C19?26 tricyclic terpanes, C29?30,34 αβ‐hopanes, C30 17α‐diahopane, and trisnorhopanes, which are in the range 2–180 pg/g. The extracted organic matter is highly mature, based on the biomarker configurations and calculated vitrinite reflectance that ranges from 2.4–3.0 (methylphenanthrene index), 1.4–1.9 (methyladamantane index), and 1.4–2.3 (methyldiamantane index). As the biomarkers are highly mature and the biomarker assemblages have a distinctive pattern to each vein type the likelihood of sample contamination by recent, less mature, biomarkers from a different assemblage is unlikely. The detection of steranes suggests that molecular oxygen was available when the veins were formed, possibly between 2.2 and 1.8 billion years ago, but no evidence for oxygenic photosynthesis in the form of cyanobacterial biomarkers has been found. Carbonate minerals that seem to better preserve biomarkers, such as concretions or veins, show the growing importance of new and exciting opportunities to seek biomarkers in the early Earth rock record, and potentially on other planets. Our results demonstrate for that first time that biomarkers can be found in veins cutting through highly metamorphosed Archaean rocks, and gives an insight into ancient environments.Peters, K.E., Hackley, P.C., Thomas, J.J., Pomerantz, A.E., 2018. Suppression of vitrinite reflectance by bitumen generated from liptinite during hydrous pyrolysis of artificial source rock. Organic Geochemistry 125, 220-228. random vitrinite reflectance (Ro) is the most widely accepted method to determine thermal maturity of coal and other sedimentary rocks. However, oil-immersion Ro of polished rock or kerogen samples is commonly lower than Ro values measured in samples from adjacent vitrinite-rich coals that have undergone the same level of thermal stress. So-called suppressed Ro values have also been observed in hydrous pyrolysis experiments designed to simulate petroleum formation. Various hypotheses to explain Ro suppression, such as sorption of products generated from liptinite during maturation, diagenetic formation of perhydrous vitrinite or overpressure, remain controversial. To experimentally test for suppression of vitrinite reflectance, artificial rock was prepared using silica and a calcined blend of limestone and clay with various proportions of thermally immature vitrinite-rich Wyodak-Anderson coal and liptinite-rich kerogen isolated from the oil-prone Parachute Creek Member of the Green River Formation. The samples were subjected to hydrous pyrolysis for 72?h. at isothermal temperatures of 300?°C, 330?°C, and 350?°C to simulate burial maturation. Compared to artificial rock that contains only coal, samples with different proportions of oil-prone kerogen show distinct suppression of calibrated Ro at 300?°C and 330?°C. The reflectance of solid bitumen generated during heating of the samples is lower than that of the associated vitrinite and does not interfere with the Ro measurements. These results provide the first experimental evidence that Ro suppression occurs in vitrinite mixed with liptinite-rich kerogen in a rock matrix. Although the precise chemical mechanism for Ro suppression by liptinite remains unclear, free radicals generated from solid bitumen and associated volatile products during maturation of liptinite may contribute to termination reactions that slow the aromatization and rearrangement of polyaromatic sheets in vitrinite, thus suppressing Ro. This mechanism does not preclude Ro suppression that might result from overpressure or differences in redox conditions during diagenesis.Peterson, B.K., Formolo, M.J., Lawson, M., 2018. Molecular and detailed isotopic structures of petroleum: Kinetic Monte Carlo analysis of alkane cracking. Geochimica et Cosmochimica Acta 243, 169-185. compositional and bulk isotopic signatures of hydrocarbon compounds are routinely characterized to constrain the origin of oils and natural gases in sedimentary basins. Recent developments in clumped isotope geochemistry have given rise to a suite of measurements that provide new information on the thermal history of low molecular weight hydrocarbon gases. However, to date no study has linked these compositional, bulk and clumped isotope constraints to any mechanistic understanding of how these signatures develop and evolve. In this study, we developed a kinetic Monte Carlo method to predict consistent and simultaneous molecular distributions, bulk isotopic content, and detailed (multiply substituted and site-specific) isotopic structures of hydrocarbons from a cracking model. The detailed isotopic structure of the source (initially modeled as long alkanes), the intermediates, and the product molecules is followed as a function of the level of conversion due to cracking reactions. The bulk 13C content of gaseous alkane products generated via the model is shown to follow the linear natural gas plot at low conversion, but to deviate at high conversions. As examples of the information generated, the populations of center vs. terminal 13C-substituted propane are reported as a function of the starting alkane chain length and conversion and the population of doubly-13C-substituted ethane is described as a function of conversion and for different 13C substitution patterns in the source. The results are compared to experiment where possible and highlight the possibility of constraining hydrocarbon source isotopic structure and the nature of the generation processes leading to the formation of natural hydrocarbon deposits.Piane, C.D., Bourdet, J., Josh, M., Clennell, M.B., Rickard, W.D.A., Saunders, M., Sherwood, N., Li, Z., Dewhurst, D.N., Raven, M.D., 2018. Organic matter network in post-mature Marcellus Shale: Effects on petrophysical properties. American Association of Petroleum Geologists Bulletin 102, 2239-2265. samples of the Marcellus Shale from a well drilled in northeastern Pennsylvania were used to study diagenetic effects on the mineral and organic matter and their impact on petrophysical response. We analyzed an interval of high gamma ray and anomalously low electrical resistivity from a high thermal maturity (mean maximum vitrinite reflectance > 4%) part of the shale&hyphen;gas play. A suite of microanalytical techniques was used to study features of the shale down to the nanoscale and assess the level of thermal alteration of the mineral and organic phases.The samples are organic rich, with total organic carbon contents of 3–7 wt. %; the vast majority of the organic matter was identified as highly porous pyrobitumen. Matrix porosity is also present, especially within the clay aggregates and at the interface between rigid clasts and clay minerals.Mineral- and organic-based thermal maturity indices suggest that during burial the sediment had been exposed to temperatures as high as 285°C (545°F). Under these conditions, the residual, migrated organic matter assumed a partially crystalline habit as confirmed by the identification of turbostratic structures via electron microscopy imaging. Experimental dielectric measurements on organic matter–rich samples confirm that the anomalous electrical properties observed in the wire-line logs can be ascribed to the presence of an electrically conductive interconnected network of partially graphitized organic matter. The preservation of porosity suggests that this organic network can contribute not only to the electrical properties but also to the gas flow properties within the Marcellus Shale.Picone, N., Op den Camp, H.J.M., 2019. Role of rare earth elements in methanol oxidation. Current Opinion in Chemical Biology 49, 39-44. decades rare earth elements (or lanthanides) were considered not to be involved in biological processes, until their discovery in the active site of the XoxF-type methanol dehydrogenase of the methanotrophic bacterium Methylacidiphilum fumariolicum SolV. Follow-up studies revealed the presence of lanthanides in other pyrroloquinoline quinone-containing enzymes involved in alcohol metabolism. This review discusses the biochemistry of the lanthanide-dependent enzymes and the ability of these metals of influencing the gene expression and the type of methanol dehydrogenase used by microorganisms. Furthermore, it highlights novel insights on the uptake mechanism of rare earth elements into bacterial cells.Ping, H., Chen, H., Zhu, J., George, S.C., Mi, L., Pang, X., Zhai, P., 2018. Origin, source, mixing, and thermal maturity of natural gases in the Panyu lower uplift and the Baiyun depression, Pearl River Mouth Basin, northern South China Sea. American Association of Petroleum Geologists Bulletin 102, 2171-2200. natural gas fields have been discovered in the Baiyun depression and the adjoining Panyu lower uplift in the Pearl River Mouth Basin, northern South China Sea. The natural gases are associated with condensate and are characterized by relatively heavy carbon isotopes, with methane and ethane δ13C values ranging from –44.2‰ to –33.6‰ and –30.0‰ to –25.4‰, respectively. Nearly all methane and ethane are derived from oil-prone type II kerogen in the Wenchang Formation source rock, whereas the heavy hydrocarbon gases (propane, butanes, and pentanes) are derived from both the Wenchang and Enping (type III kerogen) Formations, based on an integrated comparison of carbon isotopic compositions of the natural gases, typical type I/II and type III kerogen-derived gases, and the Enping and Wenchang kerogens. The gases from the eastern parts of the Baiyun depression and the Panyu lower uplift mainly originate from secondary oil cracking and primary kerogen cracking, respectively. The gases from the northern slope of the Baiyun depression are a mixture of oil-cracking and kerogen-cracking gases. Both oil-cracking and kerogen-cracking gases were mainly generated from the Wenchang Formation source rock in the maturity range of 1.5%–2.5% vitrinite reflectance, with a corresponding present-day depth range of 5400–6500 m (17,700–21,300 ft). The apparent contribution of the Wenchang Formation to the discovered gas accumulations demonstrates that it is the most important source rock in the area, instead of the Enping Formation. The search for more gas derived from oil cracking will be the next natural gas exploration direction in the Baiyun depression.Plancq, J., McColl, J.L., Bendle, J.A., Seki, O., Couto, J.M., Henderson, A.C.G., Yamashita, Y., Kawamura, K., Toney, J.L., 2018. Genomic identification of the long-chain alkenone producer in freshwater Lake Toyoni, Japan: implications for temperature reconstructions. Organic Geochemistry 125, 189-195. the lacustrine haptophyte species that produce long-chain alkenones (LCAs) is essential prior to down-core temperature reconstructions. Here, we investigated the identity of LCA-producing species from Lake Toyoni, Japan using 18S ribosomal DNA (rDNA) and organic geochemical analyses. The rDNA analyses identified eighteen operational taxonomic units (OTUs) of which only one fell within the haptophyte phylotype. This haptophyte belongs to the Group I phylotype, as supported by the LCA distribution found in surface and down-core sediments, and is closely related to a haptophyte found in Lake BrayaS? (Greenland). The inferred temperature using the Greenland calibration is very close to the Lake Toyoni surface temperature recorded during the spring/early summer season, when the LCA-producing haptophyte is likely to bloom. We therefore suggest that the temperature calibration from the Lake BrayaS?, Greenland is a suitable calibration for down-core temperature reconstructions at Lake Toyoni.Ploeger, R., Shugar, A., Smith, G.D., Chen, V.J., 2019. Late 19th century accounts of Indian yellow: The analysis of samples from the Royal Botanic Gardens, Kew. Dyes and Pigments 160, 418-431. yellow has always been a mysterious pigment. In 1883, an eye-witness account of its production described it as a urinary sediment from cows fed a mango leaves rich diet; this same account describes a set of manufacturing materials and samples sent to the Royal Botanic Gardens, Kew (England). Most of these original materials were recovered in 2016 from the Economic Botany Collection at Kew, and analyzed alongside known reference materials, to characterize the pigment materials, and to search for evidence of an animal origin. Component characterization and identification was performed using py (TMAH)-GC-MS, LC-MS, FTIR, Raman Spectroscopy, SEM-EDS, UVA-induced visible fluorescence, and polarized light microscopy. All the materials were shown to contain variable ratios of reported components of Indian yellow (euxanthic acid, euxanthone, and a sulfo-derivative of euxanthone), and some presented hippuric acid, a ruminant metabolite found in urine. This is the first substantial link between animal urine and the pigment Indian yellow. When possible, the interior and exterior of the pigment-balls were characterized, and a higher amount of euxanthone was consistently detected on the exposed exterior of the ball. It is proposed, that euxanthone may be a chemical marker for the degradation of Indian yellow. A laboratory prepared euxanthone was used for comparison; this paper presents the characterization data for euxanthone, much of which is the first time it has been reported in the literature.Poggenburg, C., Mikutta, R., Liebmann, P., Koch, M., Guggenberger, G., 2018. Siderophore-promoted dissolution of ferrihydrite associated with adsorbed and coprecipitated natural organic matter. Organic Geochemistry 125, 177-188. of Fe(III) from hardly soluble Fe oxyhydroxides by bacteria, fungi and plants in soil is often facilitated by Fe(III)-chelating siderophores. While the siderophore-promoted dissolution of pure Fe oxyhydroxides and the influence of defined low molecular weight organic acids has been investigated meticulously, studies examining Fe oxyhydroxides coated with more complex adsorbed organic matter (OM) or Fe-OM coprecipitates have been sparse. This study therefore explored the impact of the composition of both adsorbed and coprecipitated OM on the siderophore-promoted dissolution of ferrihydrite (Fh) in relation to (i) surface site coverage and pore blockage, (ii) aggregation state, (iii) charge characteristics and (iv) crystallinity. In addition to pure Fh, Fh-OM adsorption complexes and Fe-OM coprecipitates were synthesized using OM of different origins (extracellular polymeric substances of Bacillus subtilis, natural OM (NOM) extracted from soil Oi and Oa horizons). The Fe-organic associations were characterized by N2 gas adsorption, X-ray photoelectron spectroscopy (XPS), electrophoretic mobility, particle size measurements and desorption experiments. Siderophore-mediated dissolution experiments with desferrioxamine-B (DFOB) were conducted at pH 4 and 7. At pH 4, adsorbed OM provided a more effective protection against DFOB due to its larger sorption affinity. At pH 7, the surface site blockage by adsorbed OM at comparable C loadings was less effective, while less aggregated particles were more prone to dissolution. For OM coprecipitated with Fe, there was no distinct accelerating or inhibiting effect on DFOB-promoted dissolution to be found. Initial Fe dissolution rates at given soil conditions were thus affected by both the type of OM and the sorption procedure. Our results therefore corroborate the importance of considering the heterogeneous composition of soil OM when investigating the mobilization of Fe-organic associations.Politova, N.V., Savvichev, A.S., Klyuvitkin, A.A., Kravchishina, M.D., Demidov, A.B., Lein, A.Y., Gladyshev, V.S., 2018. Biochemical characteristics of suspended particulate matter on a latitudinal transect in the North Atlantic. Oceanology 58, 573-582. sedimentary matter was studied along the latitudinal transect 59°30′ N from Great Britain to Greenland on cruise 49 of the R/V Akademik Ioffe in June 2015. The concentrations of suspended particulate matter (SPM) along the transect were low, increasing from 0.24 to 1.07 mg/L in the surface layer (0–5 m), from 0.24 to 0.99 mg/L in the pycnocline (thermocline) zone, and appreciably decreasing toward the bottom layer, fluctuating from 0.10 to 0.56 mg/L. The isotopic composition of organic carbon in SPM was determined in 18 samples. The δ13C-Corg values vary from –17 to –24.6‰. Judging from the chlorophyll a content, the isotopic composition of water masses, and their remoteness from the coast, the carbon in SPM is mainly represented by autochthonous organic matter of phytoplanktonic origin. The presence of SPM with a heavy isotopic composition in the surface layer of the water column can serve as evidence for the current processes of phytoplankton bloom. In this case, differences in the intensity of these processes can be observed, creating a mosaic bloom pattern even within a distance of 150 NM.Potenti, S., Manini, P., Fornaro, T., Poggiali, G., Crescenzi, O., Napolitano, A., Brucato, J.R., Barone, V., d'Ischia, M., 2018. Solid state photochemistry of hydroxylated naphthalenes on minerals: Probing polycyclic aromatic hydrocarbon transformation pathways under astrochemically-relevant conditions. ACS Earth and Space Chemistry 2, 977–1000. derivatives of polycyclic aromatic hydrocarbons (PAHs), or oxyPAHs, recently captured the interest of the scientific community for their photochemical reactivity in a water ice matrix mimicking the interstellar medium. Furthermore, oxyPAHs are interesting molecules for the study of the origin of life for their prebiotic potential. However, their stability and transformation pathways under astrophysically relevant conditions have remained largely unexplored. Herein we report the photochemical behavior of 1-naphthol (1-HN), 1,6- and 1,8-dihydroxynaphthalene (DHN) either as pure powdered solids or adsorbed on forsterite or anatase surface. All the compounds showed an extensive decrease of main vibrational bands, accompanied in the case of DHNs by the formation of new molecular species. Irradiation of 1,8-DHN at 80 K resulted in the IR-detectable generation of CO2 (2340 cm?1), a process reported by other authors following irradiation of PAHs in water ice analogues at 14 K. These results, when compared to model autoxidation experiments, indicated a high susceptibility of hydroxylated naphthalene derivatives to UV radiation leading to free radical and carbonyl-containing extended quinone intermediates (preliminary DFT calculations) with partial degradation and decarboxylation. Based on these results, oxyPAH formation and photoprocessing on minerals is proposed as a plausible pathway of PAHs transformation under astrochemical conditions of prebiotic relevance.Prichard, A., Cook, P.F., Spivak, M., Chhibber, R., Berns, G.S., 2018. Awake fMRI reveals brain regions for novel word detection in dogs. Frontiers in Neuroscience 12, 737. doi: 10.3389/fnins.2018.00737. do dogs understand human words? At a basic level, understanding would require the discrimination of words from non-words. To determine the mechanisms of such a discrimination, we trained 12 dogs to retrieve two objects based on object names, then probed the neural basis for these auditory discriminations using awake-fMRI. We compared the neural response to these trained words relative to “oddball” pseudowords the dogs had not heard before. Consistent with novelty detection, we found greater activation for pseudowords relative to trained words bilaterally in the parietotemporal cortex. To probe the neural basis for representations of trained words, searchlight multivoxel pattern analysis (MVPA) revealed that a subset of dogs had clusters of informative voxels that discriminated between the two trained words. These clusters included the left temporal cortex and amygdala, left caudate nucleus, and thalamus. These results demonstrate that dogs’ processing of human words utilizes basic processes like novelty detection, and for some dogs, may also include auditory and hedonic representations.Puente-Sánchez, F., Arce-Rodríguez, A., Oggerin, M., García-Villadangos, M., Moreno-Paz, M., Blanco, Y., Rodríguez, N., Bird, L., Lincoln, S.A., Tornos, F., Prieto-Ballesteros, O., Freeman, K.H., Pieper, D.H., Timmis, K.N., Amils, R., Parro, V., 2018. Viable cyanobacteria in the deep continental subsurface. Proceedings of the National Academy of Sciences 115, 10702-10707. Significance: Cyanobacteria were responsible for the origin of oxygenic photosynthesis, and have since come to colonize almost every environment on Earth. Here we show that their ecological range is not limited by the presence of sunlight, but also extends down to the deep terrestrial biosphere. We report the presence of microbial communities dominated by cyanobacteria in the continental subsurface using microscopy, metagenomics, and antibody microarrays. These cyanobacteria were related to surface rock-dwelling lineages known for their high tolerance to environmental and nutritional stress. We discuss how these adaptations allow cyanobacteria to thrive in the dark underground, a lifestyle that might trace back to their nonphotosynthetic ancestors.Abstract: Cyanobacteria are ecologically versatile microorganisms inhabiting most environments, ranging from marine systems to arid deserts. Although they possess several pathways for light-independent energy generation, until now their ecological range appeared to be restricted to environments with at least occasional exposure to sunlight. Here we present molecular, microscopic, and metagenomic evidence that cyanobacteria predominate in deep subsurface rock samples from the Iberian Pyrite Belt Mars analog (southwestern Spain). Metagenomics showed the potential for a hydrogen-based lithoautotrophic cyanobacterial metabolism. Collectively, our results suggest that they may play an important role as primary producers within the deep-Earth biosphere. Our description of this previously unknown ecological niche for cyanobacteria paves the way for models on their origin and evolution, as well as on their potential presence in current or primitive biospheres in other planetary bodies, and on the extant, primitive, and putative extraterrestrial biospheres.Qi, Y., Ju, Y., Huang, C., Zhu, H., Bao, Y., Wu, J., Meng, S., Chen, W., 2019. Influences of organic matter and kaolinite on pore structures of transitional organic-rich mudstone with an emphasis on S2 controlling specific surface area. Fuel 237, 860-873. networks in organic-rich mudstone play a key role in providing pore space, surface area and channels for gas storage and migration. Controls of nanopore development are still poorly understood, especially for transitional mudstone. Differing from marine and lacustrine mudstone, transitional mudstone is characterized by high kaolinite and low illite contents, and complex organic input. Six transitional mudstones in Linxing Area, eastern Ordos Basin were selected to figure out the influence of kaolinite and organic matter (OM) on pore structures. Sample preparation (OM-removal and kerogen isolation), mineralogical, organic petrographic and geochemical analyses and textural analysis (low-pressure Ar and CO2 adsorption) were performed. Data in other publications were used to test and perfect our conclusion of specific surface area changing with S2 (second peak in Rock-Eval pyrolysis). Our study demonstrates the pores within 5–50?nm are mainly controlled by quartz contents and are negatively correlated with kaolinite or clay mineral contents. Kaolinite content has little influence on specific surface area, but organic pores, most of which are within 0.3 to ～5?nm, contribute much to specific surface area. Higher proportion of marine OM has larger organic pores. “Quasi-parabolic +” was used to describe the firstly increasing, secondly decreasing and then uncertain relationship between specific surface area and S2 values. The relationship was found in both transitional and marine mudstones. Surface area changing with S2 is because TOC, thermal maturity and organic input affect organic pore development and also control S2 values. Micropore specific area of kerogen has a firstly increasing and secondly decreasing trend with hydrogen index (HI) values while S2 affects micropore surface area of mudstones. Our findings can be used to estimate pore parameters of organic-rich mudstone.Qiao, P., Harbottle, D., Li, Z., Tang, Y., Xu, Z., 2018. Interactions of asphaltene subfractions in organic media of varying aromaticity. Energy & Fuels 32, 10478-10485. asphaltenes were fractionated by extended-saturates, aromatics, resins, and asphaltenes (E-SARA) analysis into four asphaltene subfractions: toluene-extracted interfacially active asphaltenes (T-IAA), toluene-extracted remaining asphaltenes (T-RA), Heptol 50/50-extracted interfacially active asphaltenes (HT-IAA), and Heptol 50/50-extracted remaining asphaltenes (HT-RA). The aggregation kinetics of fractionated asphaltenes measured by dynamic light scattering (DLS) showed that decreasing solvent aromaticity promoted asphaltene aggregation for all subfractions. In a given solvent, T-IAA exhibited the strongest aggregation tendency, followed by HT-IAA, then T-RA, and HT-RA. Such differences were attributed to the higher oxygen and sulfur contents (highlighted in sulfoxide content) in IAA subfractions than RA subfractions, as confirmed by elemental analysis and X-ray photoelectron spectroscopy (XPS). The interaction forces between immobilized fractionated asphaltenes were measured using an atomic force microscope (AFM) to obtain a fundamental understanding of asphaltene interactions in organic media of varying aromaticity. The results showed that decreasing solvent aromaticity reduced steric repulsion and increased adhesion between asphaltenes with asphaltenes adopting a more compressed conformation. IAA subfractions, in particular T-IAA, exhibited higher adhesion forces than RA subfractions during separation of two asphaltene films in contact. The results of AFM colloidal force measurements were in good agreement with the DLS data. In spite of the small sulfoxide content in asphaltenes, the sulfoxide groups are believed to play a critical role in enhancing asphaltene aggregation in the bulk oil phase.Qin, X., Jiao, T., Zhang, Y., Yu, J., Liang, P., 2018. Effect of solvent pretreatment on pyrolysis characteristic of high-sulfur bituminous coal. Journal of Analytical and Applied Pyrolysis 135, 54-59. this study, high-sulfur bituminous coal was extracted with n-hexane, acetone, carbon disulfide, tetrahydrofuran and pyridine, respectively. The effect of solvent pretreatment on pyrolysis characteristic of high-sulfur coal was studied in a fixed-bed reactor. The heterocyclic aromatic hydrocarbons such as tetrahydrofuran and pyridine got higher extraction yields than other solvents. Oxygenated compounds could be selectively extracted by tetrahydrofuran with a maximum relative content of 9.09%, and nitrogen-containing compounds by pyridine with its content of 5.61%. However, all the solvents did not exhibit the selective extraction ability of sulfur-containing compounds. Compared with raw coal, the phenols content in pyrolysis tar from residues of pyridine and tetrahydrofuran increased significantly, and the sulfur compounds all exhibited lower content tendency. The solvent pretreatment can inhibit the radical condensation reaction effectively, and result in the reduction of high carbon number tar components, which is beneficial to the upgradation of pyrolysis tar. In addition, solvent pretreatment can be able to increase the oil yield, especially pyridine of 17.63%.Qiu, F., Lei, Z., Sumner, L.W., 2018. MetExpert: An expert system to enhance gas chromatography?mass spectrometry-based metabolite identifications. Analytica Chimica Acta 1037, 316-326. chromatography?mass spectrometry (GCMS) is an important analytical technique in metabolomics studies and has been routinely used for metabolite profiling of biological samples. Spectral matching to databases of authentic compounds are the preferred tools for metabolite identifications; however, the metabolic coverage of these databases is still limited compared to the number of known metabolites. Several computational tools have been developed to facilitate the interpretation of MS data but unfortunately most of them have limited applicability to GCMS-based metabolite identification. In this paper, we introduce a computer-aided, metabolite expert system called MetExpert which emulates the metabolite-identification ability of a human expert using orthogonal datasets including molecular formulas, retention indices, and EI-MS spectra to characterize the molecular structures. This system integrates four modules including in silico derivatization, metabolite-likeness evaluation, retention prediction, and substructure prediction. In silico derivatization increases the searchable chemical space for TMS-derivatized metabolites many of which are absent in molecular structure databases. Metabolite-likeness evaluations are an efficient approach to select metabolite-like molecules when querying large databases such as PubChem. An artificial neutral network then establishes the quantitative structure?retention relationships for the accurate prediction of RIs that further refines the candidate molecules. In addition, PLS-DA models establish quantitative structure?spectra relationships for the prediction of metabolite substructures. Finally, weighted scoring of three orthogonal evaluations increases the identification rates. MetExpert outperformed current state-of-the-art methods such as MetFrag and CFM-ID for ranking the correct identifications. While spectral comparisons with chemical standards or de novo structural elucidations are necessary to validate the predictions, MetExpert provides an efficient and effective approach to prioritize the candidates.Qiu, Z., Zou, C., Li, X., Wang, H., Dong, D., Lu, B., Zhou, S., Shi, Z., Feng, Z., Zhang, M., 2018. Discussion on the contribution of graptolite to organic enrichment and gas?shale reservoir: A case study of the Wufeng–Longmaxi shales in South?China. Journal of Natural Gas Geoscience 3, 147-156. graptolitic shale of the Wufeng–Longmaxi Formations is widely deposited across the Ordovician and Silurian transition in South China, which is the target of shale gas exploration and development within China. The contribution of graptolites to organic enrichment and reservoir of gas shale is discussed below based on the statistics of nearly 1000 shale samples from the Wufeng Formation and the bottom part of the Longmaxi Formation in the southern and northern margins of the Yangtze plate. The assessment involves graptolites abundance, the total organic carbon (TOC) content analyses, and the different scales of scanning electron microscopy analyses of related samples. The TOC content of the Wufeng–Longmaxi graptolitic shales (including graptolites and non-graptolites, i.e., the host shale) is mainly controlled by that of its host shale, while less affected by the graptolites abundance, indicating that the graptolites barely influence the organic enrichment. Graptolites consist of a large number of organic matter with reticular biological tissue structure; they account for 20%–50% of the graptolitic area. The aforementioned also developed honeycomb-shaped pores with pore sizes ranging 110 nm-1.7?μm (an average of about 500?nm), which are higher than those of the organic pores in the host shale (108–770?nm, average 330?nm), proving that graptolites have an important contribution to shale gas storage space. Since there are a large number of graptolites within the shales from the Wufeng Formation and the bottom part of the Longmaxi Formation, the laminated and stacked local pattern of their distribution provides abundant storage space for shale gas. Moreover, the feature also serves as the predominant channel for shale gas flow. Therefore, the widely developed graptolites should be considered as one of the essential factors controlling enrichment and high productivity of shale gas in the Wufeng–Longmaxi Formations.Qu, H., Zhang, G., Chen, S., 2018. Distribution pattern and main factors controlling hydrocarbon accumulation of global oil and gas-rich deepwater basins. Journal of Natural Gas Geoscience 3, 135-145. is observed from distribution of oil and gas-rich basins as well as summary and analysis of main control factor for hydrocarbon accumulation in global deepwater that oil and gas-rich basins in deepwater in the world shows “one horizontal and two vertical” in distribution pattern and that “one vertical” of deepwater basin group chiefly distributed in Atlantic Ocean from north to south of deepwater oil rich-basin group in the world is under the influence of fault basin group and that deepwater gas-rich basin group along Neo-tethyan tectonic domain and epicontinental basin group in East Africa shows “one horizontal and one vertical” in distribution, being under the influence of “fault basin group in transitional facies”; Comparative analysis and research of main factors for hydrocarbon accumulation in main deepwater oil and gas-rich basins in the world in a systemic way show that main control factors for hydrocarbon accumulation in deepwater oil and gas-rich basin in the world can be reduced to following five types: (1) Reservoir under common control of salt structure, passage system and large turbidite fan; (2) Reservoir under control of source control area and large reservoir body; (3) Reservoir under control of source rock and cap rock control area and large delta; (4) Reservoir under control of source and cover control zone and reef flat; (5) Reservoir under control of source heat control zone, passage system and trap.Raack, J., Reiss, D., Balme, M.R., Taj-Eddine, K., Ori, G.G., 2018. In situ sampling of relative dust devil particle loads and their vertical grain size distributions. Astrobiology 18, 1305-1317. a field campaign in the Sahara Desert in southern Morocco, spring 2012, we sampled the vertical grain size distribution of two active dust devils that exhibited different dimensions and intensities. With these in situ samples of grains in the vortices, it was possible to derive detailed vertical grain size distributions and measurements of the lifted relative particle load. Measurements of the two dust devils show that the majority of all lifted particles were only lifted within the first meter (～46.5% and ～61% of all particles; ～76.5?wt % and ～89?wt % of the relative particle load). Furthermore, ～69% and ～82% of all lifted sand grains occurred in the first meter of the dust devils, indicating the occurrence of “sand skirts.” Both sampled dust devils were relatively small (～15?m and ～4–5?m in diameter) compared to dust devils in surrounding regions; nevertheless, measurements show that ～58.5% to 73.5% of all lifted particles were small enough to go into suspension (<31?μm, depending on the used grain size classification). This relatively high amount represents only ～0.05 to 0.15?wt % of the lifted particle load. Larger dust devils probably entrain larger amounts of fine-grained material into the atmosphere, which can have an influence on the climate. Furthermore, our results indicate that the composition of the surface, on which the dust devils evolved, also had an influence on the particle load composition of the dust devil vortices. The internal particle load structure of both sampled dust devils was comparable related to their vertical grain size distribution and relative particle load, although both dust devils differed in their dimensions and intensities. A general trend of decreasing grain sizes with height was also detected.Radwan, O., Gunasekera, T.S., Ruiz, O.N., 2018. Robust multiplex quantitative polymerase chain reaction assay for universal detection of microorganisms in fuel. Energy & Fuels 32, 10530-10539. detection of microbial contamination in conventional and alternative fuels is hampered by the lack of sensitive and cost-effective assays to detect total and specific microorganisms in fuels. Here, we report a simple and highly sensitive TaqMan quantitative polymerase chain reaction (qPCR) assay for universal detection and quantification of fungi, bacteria, and archaea in fuel in a single multiplexed reaction. Universal primers and probes targeting conserved regions of the 16S and 18S rRNA genes were designed and validated for specific amplification of total fungi, bacteria, and archaea in fuel. The assay is able to detect as low as 10 pg of fungal and bacterial DNA. The combination of a simple liquid–liquid extraction to recover cells from fuel with a freeze-and-heat method to release DNA for direct qPCR amplification eliminates the need for DNA extractions from contaminated samples, thus making the assay much faster, inexpensive, and less laborious. The universal microbial multiplex qPCR assay demonstrated a high capacity to detect and quantify a wide range of microbial contaminants. The assay was validated to accurately detect and quantify the intended microorganisms in the presence of high levels of nontarget DNA and in fuel from field samples. This robust microbial qPCR assay can be applied to microbial detection in environmental and industrial settings to facilitate risk assessment and mitigation of microbial contamination.Rae, J.W.B., Burke, A., Robinson, L.F., Adkins, J.F., Chen, T., Cole, C., Greenop, R., Li, T., Littley, E.F.M., Nita, D.C., Stewart, J.A., Taylor, B.J., 2018. CO2 storage and release in the deep Southern Ocean on millennial to centennial timescales. Nature 562, 569-573. cause of changes in atmospheric carbon dioxide (CO2) during the recent ice ages is yet to be fully explained. Most mechanisms for glacial–interglacial CO2 change have centred on carbon exchange with the deep ocean, owing to its large size and relatively rapid exchange with the atmosphere. The Southern Ocean is thought to have a key role in this exchange, as much of the deep ocean is ventilated to the atmosphere in this region. However, it is difficult to reconstruct changes in deep Southern Ocean carbon storage, so few direct tests of this hypothesis have been carried out. Here we present deep-sea coral boron isotope data that track the pH—and thus the CO2 chemistry—of the deep Southern Ocean over the past forty thousand years. At sites closest to the Antarctic continental margin, and most influenced by the deep southern waters that form the ocean’s lower overturning cell, we find a close relationship between ocean pH and atmospheric CO2: during intervals of low CO2, ocean pH is low, reflecting enhanced ocean carbon storage; and during intervals of rising CO2, ocean pH rises, reflecting loss of carbon from the ocean to the atmosphere. Correspondingly, at shallower sites we find rapid (millennial- to centennial-scale) decreases in pH during abrupt increases in CO2, reflecting the rapid transfer of carbon from the deep ocean to the upper ocean and atmosphere. Our findings confirm the importance of the deep Southern Ocean in ice-age CO2 change, and show that deep-ocean CO2 release can occur as a dynamic feedback to rapid climate change on centennial timescales.Raipuria, V., Rani, N., Sharma, V.P., Naiya, T.K., 2018. Use of nanoparticle derived from natural source and its application in drilling fluid. International Journal of Oil, Gas and Coal Technology 19, 283-295. inefficiency of drilling fluid in performing certain functional properties like proper cutting lifting, pressure maintenance, forming thin mud cake around borehole wall is mainly because of lack in particular rheological or filtrate loss properties. Hence, the industry is looking for new kind of additives which can be helpful in maintaining these properties in desired range even under extreme conditions. This paper describes the preparation of silica nanoparticles from abundantly available agricultural waste rice husk and its use in drilling fluid. Silica nanoparticle were synthesised from rice husk by treating it with 1N HCl and calcinating at 600°C. Nano silica particles prepared are characterised by FTIR, FESEM and EDX studies. Effect of temperature on rheological and filtration loss properties was studied for the drilling fluids with and without silica nanoparticles. It was observed that drilling fluid with silica nanoparticles maintains its properties at even high temperature of 100°C. Ren, L., Jia, Y., Zhang, R., Lin, Z., Zhen, Z., Hu, H., Yan, Y., 2018. Insight into metabolic versatility of an aromatic compounds-degrading Arthrobacter sp. YC-RL1. Frontiers in Microbiology 9, 2438. doi: 10.3389/fmicb.2018.02438. genus Arthrobacter is ubiquitously distributed in different natural environments. Many xenobiotic-degrading Arthrobacter strains have been isolated and described; however, few have been systematically characterized with regard to multiple interrelated metabolic pathways and the genes that encode them. In this study, the biodegradability of seven aromatic compounds by Arthrobacter sp. YC-RL1 was investigated. Strain YC-RL1 could efficiently degrade p-xylene (PX), naphthalene, phenanthrene, biphenyl, p-nitrophenol (PNP), and bisphenol A (BPA) under both separated and mixed conditions. Based on the detected metabolic intermediates, metabolic pathways of naphthalene, biphenyl, PNP, and BPA were proposed, which indicated that strain YC-RL1 harbors systematic metabolic pathways toward aromatic compounds. Further, genomic analysis uncovered part of genes involved in the proposed pathways. Both intradiol and extradiol ring-cleavage dioxygenase genes were identified in the genome of strain YC-RL1. Meanwhile, gene clusters predicted to encode the degradation of biphenyl (bph), para-substituted phenols (npd) and protocatechuate (pca) were identified, and bphA1A2BCD was proposed to be a novel biphenyl-degrading gene cluster. The complete metabolic pathway of biphenyl was deduced via intermediates and functional gene analysis (bph and pca gene clusters). One of the these genes encoding ring-cleavage dioxygenase in bph gene cluster, a predicted 2,3-dihydroxybiphenyl 1,2-dioxygenase (BphC) gene, was cloned and its activity was confirmed by heterologous expression. This work systematically illuminated the metabolic versatility of aromatic compounds in strain YC-RL1 via the combination of metabolites identification, genomics analysis and laboratory experiments. These results suggested that strain YC-RL1 might be a promising candidate for the bioremediation of aromatic compounds pollution sites.Ren, Y., Liao, Z., Sun, J., Jiang, B., Wang, J., Yang, Y., Wu, Q., 2019. Molecular reconstruction: Recent progress toward composition modeling of petroleum fractions. Chemical Engineering Journal, 761-775. reconstruction is popular in current oil refinery modelling. It aims to understand the refining process from the molecular level, to predict product properties accurately, to optimize the processes, and to increase the value of each molecule. Molecular reconstruction technology determines the detailed molecular composition of petroleum fractions through obtainable bulk properties and chemical details. In this paper, the existing molecular reconstruction models involving models with a set of predefined deterministic molecules, stochastic reconstruction method, structure-oriented lumping method, molecular type-homologous series matrix method, reconstruction by entropy maximization method, stochastic reconstruction-entropy maximization method and state space representation method are reviewed and compared. The credibility of the simulated composition and the drawbacks of molecular reconstruction technique are also discussed.Retallack, G.J., Noffke, N., 2019. Are there ancient soils in the 3.7?Ga Isua Greenstone Belt, Greenland? Palaeogeography, Palaeoclimatology, Palaeoecology 514, 18-30. lens of black schist within 3.7?Ga quartzites of Greenland may be Earth's oldest known alluvial paleosol. The suspect metamorphic rock is a lens in orthoquartzite of berthierine schist with crystals of ripidolite, but it has a truncated top above dark gray grading down to gray color, ptygmatically folded surface cracks filled with silt grains, and large sand crystals, unusual for sedimentary or metamorphic rocks. The paleosol hypothesis was tested with thin sections showing plausible mineral weathering trends, and by chemical analysis showing molar weathering ratios and REE distribution like those of soils. The schist is deeply weathered and at the culmination of weathering trends from analysis of other metasediments of the Isukasia area. The protolith can be reconstructed as a saponite clay with a salt-rich horizon of kieserite, like other acid-sulfate paleosols of the early Earth. Models for proton and electron consumption of paleosols applied to the profile reveal an atmosphere with only 36?±?510?ppm O2 and 820?±?201?ppm CO2, and humid, cool temperate paleoclimate. The profile has organic δ13CPDB consistently of ?24.2 to ?27.4‰, and modest Raleigh distillation near the top. Similar consistent values and trends are produced by decay of organic matter in living soils, but biotic carbon isotopic composition of sediments is erratic from bed to bed, and abiotic carbon compounds of meteorites differ dramatically for each kerogen particle. Thus life in this very ancient soil is not precluded by our analyses, but ultrastructural and geochemical testing of carbon particles would further test this hypothesis.Riddick, S.N., Mauzerall, D.L., Celia, M.A., Kang, M., Bressler, K., Chu, C., Gum, C.D., 2019. Measuring methane emissions from abandoned and active oil and gas wells in West Virginia. Science of The Total Environment 651, 1849-1856. studies have reported methane (CH4) emissions from abandoned and active oil and gas infrastructure across the United States, where measured emissions show regional variability. To investigate similar phenomena in West Virginia, we measure and characterize emissions from abandoned and active conventional oil and gas wells. In addition, we reconcile divergent regional CH4 emissions estimates by comparing our West Virginia emissions estimates with those from other states in the United States. We find the CH4 emission factors from 112 plugged and 147 unplugged wells in West Virginia are 0.1?g?CH4?h?1 and 3.2?g?CH4?h?1, respectively. The highest emitting unplugged abandoned wells in WV are those most recently abandoned, with the mean emission of wells abandoned between 1993 and 2015 of 16?g?CH4?h?1 compared to the mean of those abandoned before 1993 of 3?×?10?3?g?CH4?h?1. Using field observations at a historic mining area as a proxy for state-wide drilling activity in the late 19th/early 20th century, we estimate the number of abandoned wells in WV at between 60,000 and 760,000 wells. Methane emission factors from active conventional wells were estimated at 138?g?CH4?h?1. We did not find an emission pattern relating to age of wells or operator for active wells, however, the CH4 emission factor for active conventional wells was 7.5 times larger than the emission factor used by the EPA for conventional oil and gas wells. Our results suggest that well emission factors for active and abandoned wells can vary within the same geologic formation and may be affected by differences in state regulations. Therefore, accounting for state-level variations is critical for accuracy in greenhouse gas emissions inventories, which are used to guide emissions reduction strategies.Riedo, A., Rout, S., Wiesendanger, R., Wurz, P., Leya, I., 2018. EGT—A sensitive time-of-flight mass spectrometer for multielement isotope gas analysis. Journal of Mass Spectrometry 53, 1036-1045. principles of operation and figures of merit of a novel, compact (324 mm × ? 114 mm; volume approximately 1000 cm3) reflectron‐type time‐of‐flight mass spectrometer designed for simultaneous multielement isotope gas analysis is presented. The system, which consists of a pulsed electron impact ion source, is designed either to directly analyse gas samples collected and stored in a compartment or samples extracted from solids using a CW laser system (fibre‐coupled diode laser, <75 W, λ = 808 ± 10 nm). In latter case, laser pulses are focussed onto the sample surface to spot sizes of approximately 400 μm in diameter that allows for direct ablation and vaporisation of solid sample material and releasing of trapped gases. A cleaning and trapping system that consists of various cold stages and getters is used before the gas enters the mass analyser. Measurements on various gases were conducted for performance evaluation, ranging from standard gases (Ar, Kr, and Xe) to trapped gases extracted from a sample of the Millbillillie meteorite. At optimised instrument settings, mass spectrometric measurements can be conducted with a mass resolution m/?m of up to approximately 1200 (16O and CH4 can be resolved), with a dynamic range of approximately 6 orders of magnitude and a mass calibration accuracy of approximately 100 ppm. The high detection sensitivity of the system allows the detection of gas species at partial pressures down to the low 10?16 mbar level (corresponding to <10 particles/cm3 at standard temperature and pressure, including an ion transmission of approximately 80%). Measurements using standard gases demonstrated that the isotope ratios for a given element can be measured with an accuracy at the per mill level (relative to terrestrial values). Measurements of Ar extracted from the meteorite Millbillillie gave a 36Ar/38Ar ratio of approximately 1.6, which is in good agreement with literature values. Riller, U., Poelchau, M.H., Rae, A.S.P., Schulte, F.M., Collins, G.S., Melosh, H.J., Grieve, R.A.F., Morgan, J.V., Gulick, S.P.S., Lofi, J., Diaw, A., McCall, N., Kring, D.A., Morgan, J.V., Gulick, S.P.S., Green, S.L., Lofi, J., Chenot, E., Christeson, G.L., Claeys, P., Cockell, C.S., Coolen, M.J.L., Ferrière, L., Gebhardt, C., Goto, K., Jones, H., Kring, D.A., Xiao, L., Lowery, C.M., Ocampo-Torres, R., Perez-Cruz, L., Pickersgill, A.E., Poelchau, M.H., Rae, A.S.P., Rasmussen, C., Rebolledo-Vieyra, M., Riller, U., Sato, H., Smit, J., Tikoo-Schantz, S.M., Tomioka, N., Whalen, M.T., Wittmann, A., Yamaguchi, K., Fucugauchi, J.U., Bralower, T.J., IODP–ICDP Expedition 364 Science Party, 2018. Rock fluidization during peak-ring formation of large impact structures. Nature 562, 511-518. meteorite impact structures on the terrestrial bodies of the Solar System contain pronounced topographic rings, which emerged from uplifted target (crustal) rocks within minutes of impact. To flow rapidly over large distances, these target rocks must have weakened drastically, but they subsequently regained sufficient strength to build and sustain topographic rings. The mechanisms of rock deformation that accomplish such extreme change in mechanical behaviour during cratering are largely unknown and have been debated for decades. Recent drilling of the approximately 200-km-diameter Chicxulub impact structure in Mexico has produced a record of brittle and viscous deformation within its peak-ring rocks. Here we show how catastrophic rock weakening upon impact is followed by an increase in rock strength that culminated in the formation of the peak ring during cratering. The observations point to quasi-continuous rock flow and hence acoustic fluidization as the dominant physical process controlling initial cratering, followed by increasingly localized faulting.Rimington, W.R., Pressel, S., Duckett, J.G., Field, K.J., Read, D.J., Bidartondo, M.I., 2018. Ancient plants with ancient fungi: liverworts associate with early-diverging arbuscular mycorrhizal fungi. Proceedings of the Royal Society B: Biological Sciences 285, Article 20181600. mycorrhizas are widespread in land plants including liverworts, some of the closest living relatives of the first plants to colonize land 500 million years ago (MYA). Previous investigations reported near-exclusive colonization of liverworts by the most recently evolved arbuscular mycorrhizal fungi, the Glomeraceae, indicating a recent acquisition from flowering plants at odds with the widely held notion that arbuscular mycorrhizal-like associations in liverworts represent the ancestral symbiotic condition in land plants. We performed an analysis of symbiotic fungi in 674 globally collected liverworts using molecular phylogenetics and electron microscopy. Here, we show every order of arbuscular mycorrhizal fungi colonizes early-diverging liverworts, with non-Glomeraceae being at least 10 times more common than in flowering plants. Arbuscular mycorrhizal fungi in liverworts and other ancient plant lineages (hornworts, lycopods, and ferns) were delimited into 58 taxa and 36 singletons, of which at least 43 are novel and specific to liverworts. The discovery that early plant lineages are colonized by early-diverging fungi supports the hypothesis that arbuscular mycorrhizas are an ancestral symbiosis for all land plants.Rivard, B., Harris, N.B., Feng, J., Dong, T., 2018. Inferring total organic carbon and major element geochemical and mineralogical characteristics of shale core from hyperspectral imagery. American Association of Petroleum Geologists Bulletin 102, 2101-2121. systems that image drill core can capture detail mineralogical information at the millimeter scale and thus have the potential to enable investigators to characterize shale composition and heterogeneity, complementing the direct chemical and x-ray diffraction analysis of core samples and guiding detailed sampling. This method provides insight into petrophysical and geomechanical properties because these properties are significantly correlated to rock composition. We tested this approach on a continuous long core from the shale sequence of the Horn River Group in the Horn River Basin, British Columbia, sampled at a spacing of 1 m (40 in.) and analyzed for geochemical composition. These data enable the calibration of spectral imagery to rock composition and specifically predict total organic carbon (TOC) and the abundance of SiO2, Al2O3, K2O, and CaO. We then imaged nine samples from the Woodford Shale from the Permian Basin, Texas, for a blind test to assess the predictive models. The models were then used to predict TOC and geochemical data over detailed imagery of 300 m (984 ft) of Horn River Group shale core and portray their spatial variability downhole as images and profiles. In its simplest form, hyperspectral imagery can be enhanced to highlight fabric in shale core that otherwise is difficult to visualize because of low brightness. In addition, we show that spectral imagery of shale can also be processed to either convey mineralogical (quartz, clay, and carbonate) or geochemical information. The resulting views can readily be used to guide the selection of samples and may provide tools for scaling reservoir properties from individual plugs to reservoir volumes.Robinson, J.R., Wadley, L., 2018. Stable isotope evidence for (mostly) stable local environments during the South African Middle Stone Age from Sibudu, KwaZulu-Natal. Journal of Archaeological Science 100, 32-44. environmental and climatic records are crucial to our understanding of human behavior and cognition during the African Middle Stone Age. This is particularly true of the South African Middle Stone Age record with its enigmatic and relatively short lived Still Bay and Howieson's Poort industries. Existing environmental models for the South African Middle Stone Age are primarily contingent on global climatic data which are temporally, spatially, and/or stratigraphically separated from archaeological sites. The well-dated and extensive Middle Stone Age sequence of Sibudu provides a rare opportunity to gather the high-resolution on-site data which are sorely needed to evaluate behavior-environment links ‘on the ground.’ Stable carbon and oxygen isotope data were collected from faunal tooth enamel samples spanning the entire Sibudu sequence excavated by Wadley from >77 to ～38 thousand years ago (ka). Two periods of habitat change are identified at Sibudu. The pre-Still Bay (>73 ka) is characterized by more closed, likely forested, and mesic conditions than the rest of the sequence. Late and final Middle Stone Age industries (～48–38 ka) at Sibudu are associated with more open and likely drier conditions than earlier. No major environmental or habitat changes based on stable isotope data, however, are identified in the Sibudu record concordant with the Still Bay, Howieson's Poort, or post-Howieson's Poort techno-complexes. These results suggest that social and demographic changes were presumably as significant as environmental conditions, if not more so, in behavioral transitions at Sibudu.R?der, H.L., Herschend, J., Russel, J., Andersen, M.F., Madsen, J.S., S?rensen, S.J., Burm?lle, M., 2018. Enhanced bacterial mutualism through an evolved biofilm phenotype. The ISME Journal 12, 2608-2618. communities primarily consist of multiple species that affect one another’s fitness both directly and indirectly. This study showed that the cocultivation of Paenibacillus amylolyticus and Xanthomonas retroflexus exhibited facultative mutualistic interactions in a static environment, during the course of which a new adapted phenotypic variant of X. retroflexus appeared. Although the emergence of this variant was not directly linked to the presence of P. amylolyticus, its establishment in the coculture enhanced the productivity of both species due to mutations that stimulated biofilm formation. The mutations were detected in genes encoding a diguanylate cyclase predicted to synthesise cyclic-di-GMP. Examinations of the biofilm formed in cocultures of P. amylolyticus and the new variant of X. retroflexus revealed a distinct spatial organisation: P. amylolyticus only resided in biofilms in association with X. retroflexus and occupied the outer layers. The X. retroflexus variant therefore facilitated increased P. amylolyticus growth as it produced more biofilm biomass. The increase in X. retroflexus biomass was thus not at the expense of P. amylolyticus, demonstrating that interspecies interactions can shape diversification in a mutualistic coculture and reinforce these interactions, ultimately resulting in enhanced communal performance.Roger, A.J., Susko, E., 2018. Molecular clocks provide little information to date methanogenic Archaea. Nature Ecology & Evolution 2, 1676-1677.. No AbstractRomano, I., De Angelis, A., Poli, A., Ragni, P., Lilla, L., Zito, G., Nicolaus, B., De Luca, A.C., Di Donato, P., 2018. Resistance and Raman spectroscopy analysis of Parageobacillus thermantarcticus spores after γ-ray exposure. Extremophiles 22, 931-941. of the genus Bacillus are able to resist ionizing radiations and therefore they are a suitable biological model for studies in Astrobiology, i.e. the multidisciplinary approach to the study of the origin and evolution of life on Earth and in the universe. The resistance to γ-radiation is an important issue in Astrobiology in relation to the search for bacterial species that could adapt to life in space. This study investigates the resistance of spores of the thermophilic bacteria Parageobacillus thermantarcticus to γ-rays. The analysis of spores’ response to irradiation at a molecular level is performed by means of Raman spectroscopy that allows to get insights in the sequence of events taking place during inactivation. The role of the γ-rays’ dose in the inactivation of spores is also investigated, allowing to highlight the mechanism(s) of inactivation including DNA damage, protein denaturation and calcium dipicolinate levels.Romero, I.C., Sutton, T., Carr, B., Quintana-Rizzo, E., Ross, S.W., Hollander, D.J., Torres, J.J., 2018. Decadal assessment of polycyclic aromatic hydrocarbons in mesopelagic fishes from the Gulf of Mexico reveals exposure to oil-derived sources. Environmental Science & Technology 52, 10985-10996. study characterizes a decadal assessment of polycyclic aromatic hydrocarbons (PAHs) in the muscle tissues of mesopelagic fish species as indicators of the environmental health of the Gulf of Mexico (GoM) deep-pelagic ecosystem. Mesopelagic fishes were collected prior to the Deepwater Horizon (DWH) oil spill (2007), immediately post-spill (2010), 1 year after the spill (2011), and 5–6 years post-spill (2015–2016) to assess if the mesopelagic ecosystem was exposed to, and retained, PAH compounds from the DWH spill. Results indicated that a 7- to 10-fold increase in PAHs in fish muscle tissues occurred in 2010–2011 (4972 ± 1477 ng/g) compared to 2007 (630 ± 236 ng/g). In 2015–2016, PAH concentrations decreased close to the levels measured in 2007 samples (827 ± 138 ng/g); however, the composition of PAHs still resembles a petrogenic source similar to samples collected in 2010–2011. PAH composition in muscle samples indicated that natural sources (e.g., Mississippi River and natural seeps) or spatial variability within the GoM do not explain the temporal variability of PAHs observed from 2007 to 2016. Furthermore, analysis of different fish tissues indicated the dietary intake and maternal transfer of PAHs as the primary mechanisms for bioaccumulation in 2015–2016, explaining the elevated levels and composition of PAHs in ovarian eggs.R?ttjers, L., Faust, K., 2018. From hairballs to hypotheses–biological insights from microbial networks. FEMS Microbiology Reviews 42, 761-780. networks are an increasingly popular tool to investigate microbial community structure, as they integrate multiple types of information and may represent systems-level behaviour. Interpreting these networks is not straightforward, and the biological implications of network properties are unclear. Analysis of microbial networks allows researchers to predict hub species and species interactions. Additionally, such analyses can help identify alternative community states and niches. Here, we review factors that can result in spurious predictions and address emergent properties that may be meaningful in the context of the microbiome. We also give an overview of studies that analyse microbial networks to identify new hypotheses. Moreover, we show in a simulation how network properties are affected by tool choice and environmental factors. For example, hub species are not consistent across tools, and environmental heterogeneity induces modularity. We highlight the need for robust microbial network inference and suggest strategies to infer networks more reliably.Rüffel, V., Maar, M., Dammbrück, M.N., Haur?der, B., Neu, T.R., Meier, J., 2018. Thermodesulfobium sp. strain 3baa, an acidophilic sulfate reducing bacterium forming biofilms triggered by mineral precipitation. Environmental Microbiology 20, 3717-3731. reducing prokaryotes are promising candidates for the remediation of acidic metal-rich waste waters. However, only few acidophilic species have been described to date. Chemolithoautotrophic strain 3baa was isolated from sediments of an acidic mine pit lake. Based on its 16S-rRNA gene sequence it belongs to the genus Thermodesulfobium. It was identified as an acidophile growing in artificial pore water medium in the range of pH 2.6?6.6. Though the highest sulfate reduction rates were obtained at the lower end of this range, elongated cells and extended lag phases demonstrated acid stress. Sulfate reduction at low pH was accompanied by the formation of mineral precipitates strongly adhering to solid surfaces. A structural investigation by laser scanning microscopy, electron microscopy and X-ray microanalysis revealed the formation of Al hydroxides and Fe sulfides which were densely populated by cells. Al hydroxides precipitated first, enabling initial cell attachment. Colonization of solid surfaces coincided with increased sulfate reducing activity indicating more favourable growth conditions within biofilms compared with free-living cells. These findings point out the importance of cell?mineral interaction for biofilm formation and contribute to our understanding how sulfate reducing prokaryotes thrive in both natural and engineered systems at low pH.Ruffine, L., ?a?atay, M.N., Géli, L., 2018. Fluids and processes at the seismically active fault zone in the Sea of Marmara. Deep Sea Research Part II: Topical Studies in Oceanography 153, 1-3.. IntroductionUnderstanding the relationships between fluid origin and migration, fault dynamics and the seismicity of the Marmara Region involves answering key questions. Amongst them, questions on earthquake cycles, seismic event occurrences, gas emission distribution at locked or creeping fault segments, as well as the fate of fluids in both the sedimentary and water columns systematically arise. The occurrence of cold seeps at the seafloor is a clear visual expression of shallow fluid migration, which are widely observed in the Sea of Marmara (SoM). Cold seeps are mostly located along the North Anatolian Fault (NAF) system and inherited faults (Zitter et al., 2008). They were first detected during the R/V Meteor Cruise Leg M44/1 in February 1999 (Halbach et al., 2002) but visually observed for the first time during the Marmarascarps cruise (2002) using the ROV (Remotely Operated Vehicle)-Victor 6000. However, the Marmarascarps expedition was devoted to the investigation of the submarine morphology of the SoM, without specific attention to fluid seepage (Armijo et al., 2005). Since this expedition, the idea of possible links between fluid expulsion from the seafloor at cold seeps and the functioning of the Marmara Fault System became apparent (Zitter et al., 2008), and two fluid-oriented scientific cruises, Marnaut in 2007 and MarmEsonet in 2009, were consequently undertaken.The Marnaut expedition, with the manned submersible Nautile, was conducted in May-June 2007 onboard the R/V Atalante ( <;). It was dedicated to the mapping of gas emissions, and the sampling and analysis of fluids and carbonate crusts along the submerged NAF system. The main objective was to study the origin of the fluids and the possible relationships between fluid emissions and fault activity (Bourry et al., 2009, Burnard et al., 2012, Dupré et al., 2012, Dupré et al., 2015, Géli et al., 2008). Three active venting sites were sampled at which the collected gases were significantly different in their composition and origin. The gases were of thermogenic origin on the Western and Central highs and genetically related to the Thrace hydrocarbon Basin, whereas microbial gases were predominant in the easternmost ??narc?k Basin (Bourry et al., 2009, Ruffine et al., 2012). Gas hydrates were discovered and recovered for the first time on the Western High, the analysis of which revealed s-II structure with a high content of heavy hydrocarbons. The recovered samples were the most propane-enriched hydrates ever collected (Bourry et al., 2009, Ruffine et al., 2012). The pore fluids were very diverse and complex in composition, reflecting mixing of fluids from different sources (Ruffine et al., 2015, Tryon et al., 2010, Zitter et al., 2008) as well as variations with time (Tryon et al., 2012). Such fluid emissions favored the development of microbial chemosynthetic communities (Ritt et al., 2010); especially those involved in the anaerobic oxidation of methane (AOM) and other heavier hydrocarbons. The AOM at the cold seep sites was also associated with deposition of carbonate crusts (Crémière et al., 2013, Crémiere et al., 2012).Two years later, the MarmEsonet ( <;) cruise was conducted in November-December 2009 on board the R/V Le Suroit. Given the multitude of gas seeps observed during the Marnaut-cruise dives, priority was given to (1) the mapping of gas plumes for the entire Sea of Marmara by both shipborne multibeam and AUV-driven acoustic surveys of the water column, and (2) the characterization of the plumbing system by 3D seismics. The main results of the cruise were fittingly summarized in Dupré et al. (2015) as: “Gas emissions are spatially controlled by a combination of factors, including fault and fracture networks in connection to the Main Marmara Fault system and inherited faults, the nature and thickness of sediments (e.g., occurrence of impermeable or gas-bearing sediments and landslides), and the connectivity between the seafloor and gas sources, particularly in relation to the Eocene Thrace Basin. The relationship between seepage and fault activity is not linear, as active faults do not necessarily conduct gas, and scarps corresponding to deactivated fault strands may continue to channel fluids. Within sedimentary basins, gas is not expelled at the seafloor unless faulting, deformation, or erosional processes affect the sediments. On topographic highs, gas flares occur along the main fault scarps but are also associated with sediment deformation.” Thus, undoubtedly, the occurrence of seeps in the SoM is influenced by the dynamics of fault networks and geological processes affecting the sedimentary column. These factors control their inception, intensity and lifetime as well as the chemical composition of fluids via source mixing.Based on the outcomes of these two cruises, the MarsiteCruise expedition ( <;) was scheduled in November 2014. The main objective was to improve our understanding of the relationships between fault activity, fluid migration and seismicity in the Marmara region. This marine expedition was divided into three legs with three scientific aims. The first was devoted to the deployment of submarine instrumentation to collect long period series of geodetic and geophysical data to determine correlations between fault motion, intermittent fluid discharge and micro-seismicity (Sakic et al., 2016). The second leg was dedicated to ROV-Victor 6000 dives to investigate the geochemical dynamics of selected cold-seep sites. The third leg allowed the recovery of long-gravity cores for dating some seismic reflector surfaces to establish chronostratigraphy for the last few thousand years and obtain fault slip rates.The present Special Issue, entitled “Fluids and processes at the seismically active fault zone in the Sea of Marmara”, provides new insights into the aforementioned topics. The questions on the links between fluids, faults and seismicity in the SoM are debated in the 10 contributions composing this special issue. The first article summarizes the earthquake geological studies carried out since the Mw 7.4 and 7.3 1999 eastern Marmara earthquakes under collaborative studies between Italian and Turkish scientists (Gasperini et al., 2018). The main objectives were to map active faults and determine slip-rates, earthquake recurrence times, and possible relationships between fluid emissions and fault activity. The average slip-rates for the last ~ 10 kyrs were found to be 10 mm/yr on the northern strand and 3–4 mm/yr along the middle strand of the NAF (Gasperini et al., 2018). Submarine paleoseismological studies in the Gulf of ?zmit suggested an average recurrence time of 300 years over the late Holocene. The work of Grall et al. (2018) deals with the gas distribution in relation to geological characteristics of the sea such as geomorphology and stratigraphy of the sedimentary column. This study demonstrates that gas seeps appear to be localized within 1–2 km of the active fault zones, fault intersections between subsidiary faults and main faults, along basin edges that cross updip gas migration pathways and topographic highs, where the fault appears to be creeping. On the contrary, the seeps are rare along active fault segments crossing basin depocenters and the Central High segment which appears to be locked (Grall et al., 2018).MarsiteCruise provided the opportunity to develop a new strategy for gas-seep detection, and this is described in detail in the Special Issue (Ruffine et al., 2018b). Such a strategy allowed us to detect and sample 18 gas seeps. It has been shown that the gas bubbles emitted at the seafloor are mixtures of primary and secondary microbial gases with thermogenic and mantle-derived gases with very asymmetric contribution of each source (Ruffine et al., 2018a). The sediments in the vicinity of the seeps host living benthic Foraminifera, and a study from samples collected on the Central High and the ??narc?k Basin show that Bolivina vadescens and Globobulimina affinis are the two dominant species at the study areas (Fontanier et al., 2018). Three articles (Akhoudas et al., 2018, ?a?atay et al., 2018, Teichert et al., 2018) deal specifically with the texture, mineralogical and isotopic compositions and genesis of authigenic carbonate crusts associated with cold seeps in the SoM. These studies demonstrate the use of crusts as archives of past fluid activity and possibly of earthquake activity. The study by ?a?atay et al. (2018) shows that the authigenic carbonates and black sulfidic sediments were formed by the AOM at or near the seafloor during less than 1 kyr BP to 9.6 kyr BP, as a result of high methane flux, possibly associated with high seismic activity and gas hydrate destabilization due to global warming. ?a?atay et al. (2018) also discuss the problems using authigenic carbonate crusts as archives of paleoseismic activity. However, the high-resolution multi-proxy study carried out by Teichert et al. (2018) provides a promising example of the use of authigenic carbonates as archives of past seismic activity. Iron has also been investigated as proxy for tracing the migration of fluids within the sedimentary column and their discharge at the seafloor (Yang et al., 2018). The presence of metastable ferromagnetic iron sulfide minerals on the Western High indicates a more reducing environment resulting from the degradation of heavy hydrocarbons and organic matter. The last article (Henry et al., 2018) links fluid emission and fault activity. It has been shown that most of the gas emissions are located within a distance shorter than 750 m from the faults, and irrespective of creeping or locked segments.Ruffine, L., Donval, J.-P., Croguennec, C., Burnard, P., Lu, H., Germain, Y., Legoix, L.N., Bignon, L., ?a?atay, M.N., Marty, B., Madre, D., Pitel-Roudaut, M., Henry, P., Géli, L., 2018. Multiple gas reservoirs are responsible for the gas emissions along the Marmara fault network. Deep Sea Research Part II: Topical Studies in Oceanography 153, 48-60. continental margins, upward migration of fluids from various sources and various subsurface accumulations, through the sedimentary column to the seafloor, leads to the development of cold seeps where chemical compounds are discharged into the water column. MarsiteCruise was undertaken in November 2014 to investigate the dynamics of cold seeps characterized by vigorous gas emissions in the Sea of Marmara (SoM).A previous paper published by Bourry et al. (2009) presented the gas geochemistry of three seeps sampled along three different segments in the SoM. Their findings showed that the seeps were sourced by three different reservoirs. In this paper, seventeen seeps were investigated to determine the gas sources, unravel reservoir contributions, and estimate their level of mixing. The molecular and stable isotope compositions of the gas compounds were determined to establish the empirical diagrams that usually allow to delineate source domains. The results provide insights into the complexities of source mixing within the sedimentary column of the SoM before emission of the gases into the water column. The seep gases originate from deep thermogenic or microbial hydrocarbon sources, or from a CO2-rich source. Microbial sources producing methane from primary methanogenesis have been identified in the Tekirda? and the ??narc?k basins. In addition, six different thermogenic reservoirs or six different pathways of migration are responsible for the supply of gas to the seeps on the highs and in the western basin. Five of them are undergoing biodegradation followed by secondary methanogenesis, thereby providing additional sources of microbial methane to the seeps. Overall, the gases emitted by the seventeen seeps consist of variable mixtures of different components from two or three sources.Ruffine, L., Ondreas, H., Blanc-Valleron, M.-M., Teichert, B.M.A., Scalabrin, C., Rinnert, E., Birot, D., Croguennec, C., Ponzevera, E., Pierre, C., Donval, J.-P., Alix, A.-S., Germain, Y., Bignon, L., Etoubleau, J., Caprais, J.-C., Knoery, J., Lesongeur, F., Thomas, B., Roubi, A., Legoix, L., Burnard, P., Chevalier, N., Lu, H., Dupré, S., Fontanier, C., Dissard, D., Olgun, N., Yang, H., Strauss, H., ?zaksoy, V., Perchoc, J., Podeur, C., Tarditi, C., ?zbeki, E., Guyader, V., Marty, B., Madre, D., Pitel-Roudaut, M., Grall, C., Embriaco, D., Polonia, A., Gasperini, L., ?a?atay, M.N., Henry, P., Géli, L., 2018. Multidisciplinary investigation on cold seeps with vigorous gas emissions in the Sea of Marmara (MarsiteCruise): Strategy for site detection and sampling and first scientific outcome. Deep Sea Research Part II: Topical Studies in Oceanography 153, 36-47. was undertaken in October/November 2014 in the Sea of Marmara to gain detailed insight into the fate of fluids migrating within the sedimentary column and partially released into the water column. The overall objective of the project was to achieve a more global understanding of cold-seep dynamics in the context of a major active strike-slip fault. Five remotely operated vehicle (ROV) dives were performed at selected areas along the North Anatolian Fault and inherited faults.To efficiently detect, select and sample the gas seeps, we applied an original procedure. It combines sequentially (1) the acquisition of ship-borne multibeam acoustic data from the water column prior to each dive to detect gas emission sites and to design the tracks of the ROV dives, (2) in situ and real-time Raman spectroscopy analysis of the gas stream, and (3) onboard determination of molecular and isotopic compositions of the collected gas bubbles. The in situ Raman spectroscopy was used as a decision-making tool to evaluate the need for continuing with the sampling of gases from the discovered seep, or to move to another one. Push cores were gathered to study buried carbonates and pore waters at the surficial sediment, while CTD-Rosette allowed collecting samples to measure dissolved-methane concentration within the water column followed by a comparison with measurements from samples collected with the submersible Nautile during the Marnaut cruise in 2007.Overall, the visited sites were characterized by a wide diversity of seeps. CO2- and oil-rich seeps were found at the westernmost part of the sea in the Tekirdag Basin, while amphipods, anemones and coral populated the sites visited at the easternmost part in the Cinarcik Basin. Methane-derived authigenic carbonates and bacterial mats were widespread on the seafloor at all sites with variable size and distributions. The measured methane concentrations in the water column were up to 377 μmol, and the dissolved pore-water profiles indicated the occurrence of sulfate depleting processes accompanied with carbonate precipitation. The pore-water profiles display evidence of biogeochemical transformations leading to the fast depletion of seawater sulfate within the first 25-cm depth of the sediment. These results show that the North Anatolian Fault and inherited faults are important migration paths for fluids for which a significant part is discharged into the water column, contributing to the increase of methane concentration at the bottom seawater and favoring the development of specific ecosystems.Sadeq, D., Iglauer, S., Lebedev, M., Rahman, T., Zhang, Y., Barifcani, A., 2018. Experimental pore-scale analysis of carbon dioxide hydrate in sandstone via X-Ray micro-computed tomography. International Journal of Greenhouse Gas Control 79, 73-82. dioxide geo-sequestration (CGS) into sediments in the form of (gas) hydrates is one proposed method for reducing anthropogenic carbon dioxide emissions to the atmosphere and, thus reducing global warming and climate change. However, there is a serious lack of understanding of how such CO2 hydrate forms and exists in sediments. We thus imaged 2hydrate distribution in sandstone, and investigated the hydrate morphology and cluster characteristics via x-ray micro-computed tomography in 3D in-situ. A substantial amount of gas hydrate (～17% saturation) was observed, and the stochastically distributed hydrate clusters followed power-law relations with respect to their size distributions and surface area-volume relationships. The layer-like hydrate configuration is expected to reduce 2mobility in the reservoir, and the smaller than expected hydrate surface-area/volume ratio will reduce methane production and 2storage capacities. These findings will aid large-scale implementation of industrial CGS projects via the hydrate route.Saide, P.E., Steinhoff, D.F., Kosovic, B., Weil, J., Downey, N., Blewitt, D., Hanna, S.R., Delle Monache, L., 2018. Evaluating methods to estimate methane emissions from oil and gas production facilities using LES simulations. Environmental Science & Technology 52, 11206-11214. simulations (LES) coupled to a model that simulates methane emissions from oil and gas production facilities are used to generate realistic distributions of meteorological variables and methane concentrations. These are sampled to obtain simulated observations used to develop and evaluate source term estimation (STE) methods. A widely used EPA STE method (OTM33A) is found to provide emission estimates with little bias when averaged over six time periods and seven well pads. Sixty-four percent of the emissions estimated with OTM33A are within ±30% of the simulated emissions, showing a slightly larger spread than the 72% found previously using controlled release experiments. A newly developed method adopts the OTM33A sampling strategy and uses a variational or a stochastic STE approach coupled to an LES to obtain a better fit to the sampled meteorological conditions and to account for multiple sources within the well pad. This method can considerably reduce the spread of the emissions estimates compared to OTM33A (92–95% within ±30% percent error), but it is associated with a substantial increase in computational cost due to the LES. It thus provides an alternative when the additional costs can be afforded to obtain more precise emission estimates.Sajjad, W., Zheng, G., Zhang, G., Ma, X., Xu, W., Khan, S., 2018. Bioleaching of copper- and zinc-bearing ore using consortia of indigenous iron-oxidizing bacteria. Extremophiles 22, 851-863. iron-oxidizing bacteria were isolated on modified selective 9KFe2+ medium from Baiyin copper mine stope, China. Three distinct acidophilic bacteria were isolated and identified by analyzing the sequences of 16S rRNA gene. Based on published sequences of 16S rRNA gene in the GenBank, a phylogenetic tree was constructed. The sequence of isolate WG101 showed 99% homology with Acidithiobacillus ferrooxidans strain AS2. Isolate WG102 exhibited 98% similarity with Leptospirillum ferriphilum strain YSK. Similarly, isolate WG103 showed 98% similarity with Leptospirillum ferrooxidans strain L15. Furthermore, the biotechnological potential of these isolates in consortia form was evaluated to recover copper and zinc from their ore. Under optimized conditions, 77.68?±?3.55% of copper and 70.58?±?3.77% of zinc were dissolved. During the bioleaching process, analytical study of pH and oxidation–reduction potential fluctuations were monitored that reflected efficient activity of the bacterial consortia. The FTIR analysis confirmed the variation in bands after treatment with consortia. The impact of consortia on iron speciation within bioleached ore was analyzed using M?ssbauer spectroscopy and clear changes in iron speciation was reported. The use of indigenous bacterial consortia is more efficient compared to pure inoculum. This study provided the basic essential conditions for further upscaling bioleaching application for metal extraction.Salih, Y.M., Karim, A.R., Khorshid, I., 2018. Estimation the time of spill crude oil in deep soil by the detection of volatile organic compounds (VOCs). Petroleum Science and Technology 36, 1497-1502. of volatile organic compounds (VOCs) was done by a large number of studies in different methods and techniques among them are passive samplers because of their unique specifications technically and economically. In this study, passive sampler technique was used for monitoring of VOCs from spill crude oils in deep soil. Mathematical equations were achieved for the determination of time spill crude oil which depends on soil moisture content, soil temperature, and wind speed. The mathematical equations were driven from monitoring VOCs during three months. The results illustrated that the concentrations of n-Pentane was inversely diffused when compared with n-Nonane.Sallan, L., Friedman, M., Sansom, R.S., Bird, C.M., Sansom, I.J., 2018. The nearshore cradle of early vertebrate diversification. Science 362, 460-464.. Ancestral vertebrate habitats are subject to controversy and obscured by limited, often contradictory paleontological data. We assembled fossil vertebrate occurrence and habitat datasets spanning the middle Paleozoic (480 million to 360 million years ago) and found that early vertebrate clades, both jawed and jawless, originated in restricted, shallow intertidal-subtidal environments. Nearshore divergences gave rise to body plans with different dispersal abilities: Robust fishes shifted shoreward, whereas gracile groups moved seaward. Fresh waters were invaded repeatedly, but movement to deeper waters was contingent upon form and short-lived until the later Devonian. Our results contrast with the onshore-offshore trends, reef-centered diversification, and mid-shelf clustering observed for benthic invertebrates. Nearshore origins for vertebrates may be linked to the demands of their mobility and may have influenced the structure of their early fossil record and diversification.Editor's Summary: Shallow-water diversification. Most of what we know about the relationship between diversification and environment in ancient marine environments has come from invertebrates. The influence of habitat on vertebrate diversification thus remains a persistent question. Sallan et al. studied fossil vertebrates spanning the mid-Paleozoic, including both jawed and jawless fish (see the Perspective by Pimiento). They found that diversification occurred primarily in nearshore environments, with diversified forms later colonizing deeper marine or freshwater habitats. Furthermore, more robust forms remained in the nearshore, whereas more gracile forms moved to deeper waters. This split is similar to current relationships between form and environment in aquatic habitats.Salvatore, M.M., Nicoletti, R., Salvatore, F., Naviglio, D., Andolfi, A., 2018. GC–MS approaches for the screening of metabolites produced by marine-derived Aspergillus. Marine Chemistry 206, 19-33. the last decades the increasing awareness by the scientific community of the importance to exploit natural resources for the finding of new bioactive products has stimulated a huge research activity concerning the marine biological resources, and advanced strategies have been developed for investigations on microbial metabolomics. Gas chromatography coupled to mass spectrometry represents a valuable technology in this respect. The present review considers general GC–MS approaches to be adopted in investigations on fungal metabolomics, and more particularly the outcomes concerning marine-derived strains of Aspergillus, representing the most widespread genus of Ascomycetes fungi reported from the sea.Salway, J.G., 2018. The Krebs uric acid cycle: A forgotten Krebs Cycle. Trends in Biochemical Sciences 43, 847-849. Kornberg wrote a paper entitled ‘Krebs and his trinity of cycles' commenting that every school biology student knows of the Krebs cycle, but few know that Krebs discovered two other cycles. These are (i) the ornithine cycle (urea cycle), (ii) the citric acid cycle (tricarboxylic acid or TCA cycle), and (iii) the glyoxylate cycle that was described by Krebs and Kornberg. Ironically, Kornberg, codiscoverer of the ‘glyoxylate cycle’, overlooked a fourth Krebs cycle – (iv) the uric acid cycle.Sander, R., Pan, Z., Connell, L.D., Camilleri, M., Grigore, M., Yang, Y., 2018. Controls on methane sorption capacity of Mesoproterozoic gas shales from the Beetaloo Sub-basin, Australia and global shales. International Journal of Coal Geology 199, 65-90. in the Beetaloo Sub-basin in Australia's Northern Territory has indicated gas-saturated, quartz-rich source rocks that are gas mature and laterally continuous over large areas. In the Sub-basin shale targets have been identified within the Velkerri Formation and the Kyalla Formation. These shales are of Mesoproterozoic age and thus significantly older than any of the North American shale plays and most other shales currently under investigation for their gas production potential.In this work, we characterise two sets of drill cutting samples from the Beetaloo Sub-basin for their composition, pore structure, and CH4 adsorption capacity. The objective of this study is to assess the adsorption potential of these shales and investigate the properties controlling this. Measurements from other researchers are included in the analysis to determine to what degree commonly characterised properties such as bulk clay and total organic carbon (TOC) content control gas adsorption capacity on a larger scale and thus provide an indication of the range of adsorption behaviours that may be expected.The adsorption measurements are carried out at reservoir conditions - that is high pressures (up to 30?MPa) and high temperatures (up to 110?°C). The results show that the organic-rich (TOC: 3.7–6.2%) middle Velkerri shale samples have a significantly higher adsorption capacity (expressed by the Langmuir volume) than the clay-rich, organic-lean (TOC: 0.85–1.8%) lower Kyalla shale samples: 2.89–3.38?m3/t compared to 1.88–2.81?m3/t. This is in agreement with the higher average micropore volume of the middle Velkerri shale samples.Results of our analysis demonstrate that, depending on a shale's composition, different properties control gas adsorption in shale, though in the organic-rich middle Velkerri B shale samples the controlling paramters cannot be clearly determined. A positive correlation between TOC and CH4 adsorption capacity is observed, but only up to a TOC of 4.5%. Above this point the adsorption capacity appears to decrease again. The lack of a strictly positive correlation between TOC and adsorption capacity is likely caused by other parameters affecting sorption behaviour, in particular variations in organic matter type and thermal maturity. However, analysis of a global adsorption data set of marine shales of non-differentiated maturity nevertheless indicates that, on a larger scale, the TOC content can provide a reasonable first estimate of a shale's CH4 adsorption capacity.In the organic-lean lower Kyalla shale samples clay minerals control microporosity and CH4 adsorption. It is the high illite/muscovite content (30–40%) in particular that is indicated to be the main contributor to microporosity and gas adsorption capacity. Results from the analysis of the global shale adsorption data set are in agreement with these findings, showing that for organic-lean shales with a TOC?<?2% clay may be the primary control on CH4 adsorption.Sangtam, B.T., Kumar Majumder, S., 2018. A new empirical correlation for prediction of gas hydrate dissociation equilibrium. Petroleum Science and Technology 36, 1432-1438. prevent the plug of hydrate it is important to study the relationship between temperature and pressure at which hydrate form and dissociate. An empirical correlation was developed to predict the equilibrium condition to form the gas hydrate with and without presence of inhibitors. Overall 600 data points of equilibrium, to form gas hydrate have used to obtain the empirical correlation. The overall average absolute deviations are found to have good agreement with the experimental data. The present study may be helpful for further understanding the correlation of gas hydrate formation equilibrium condition.Santos, L.C., da Cruz, G.F., ?vila, B.M.F., Pereira, V.B., Azevedo, D.A., 2018. Exploratory analysis of Campos Basin crude oils via geochemical parameters by comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry. Energy & Fuels 32, 10321-10332. two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC–TOFMS) was used for geochemical characterization of 18 oil samples from Campos Basin, Brazil. Conventional analyses were also performed on these oils (API gravity and GC-FID) and in the maltenic fraction (saturated, aromatic, and polar analysis) after asphaltene precipitation, aiming the oil screening for a rapid assessment of general characteristics. The results from principal component analysis with the biomarker parameters of source, maturity, and biodegradation obtained by GC×GC–TOFMS separated the oils into two groups, mainly explained by gammacerane content. The higher sensitivity and resolution of GC×GC–TOFMS allowed the identification of unusual compounds in oils from this basin, such as methylhopanes (whose calculated ratios allowed the oils in this work to be classified as having a marine, lacustrine, or “mixed” source, the same interpretation obtained by statistical analysis), moretanes (with results that reinforce the hypothesis of same thermal evolution for the studied samples), and short-chain steranes (C21 and C22), detected in very low concentrations in all of the samples. This study is the first to show the presence of these compounds in Campos Basin crude oils.Schmidt, C., Burwicz, E., Hensen, C., Wallmann, K., Martínez-Loriente, S., Gràcia, E., 2018. Genesis of mud volcano fluids in the Gulf of Cadiz using a novel basin-scale model approach. Geochimica et Cosmochimica Acta 243, 186-204. Volcanism and fluid seepage are widespread phenomena in the Gulf of Cadiz (SW Iberian Margin). In this seismically active region located at the boundary between the African and Eurasian plates, fluid flow is typically focused on deeply rooted active strike-slip faults. The geochemical signature of emanating fluids from various mud volcanoes (MVs) has been interpreted as being largely affected by clay mineral dehydration and recrystallization of Upper Jurassic carbonates. Here we present the results of a novel, fully-coupled 1D basin-scale reactive-transport model capable of simulating major fluid forming processes and related geochemical signatures by considering the growth of the sediment column over time, compaction of sediments, diffusion and advection of fluids, as well as convective and conductive heat flow. The outcome of the model is a realistic approximation to the development of the sediment pore water system over geological time scales in the Gulf of Cadiz. Combined with a geochemical reaction transport model for clay mineral dehydration and calcium carbonate recrystallization, we were able to reproduce measured concentrations of Cl, strontium and 87Sr/86Sr of emanating mud volcano fluids. These results support previously made qualitative interpretations and add further constraints on fluid forming processes, reaction rates and source depths. The geochemical signature at Porto MV posed a specific problem, because of insufficient constraints on non-radiogenic 87Sr/86Sr sources at this location. We favour a scenario of basement-derived fluid injection into basal Upper Jurassic carbonate deposits (Hensen et al., 2015). Although the mechanism behind such basement-derived flow, e.g. along permeable faults, remains speculative at this stage, it provides an additional source of low 87Sr/86Sr fluids and offers an idea on how formation water from the deepest sedimentary strata above the basement can be mobilized and eventually initiate the advection of fluids feeding MVs at the seafloor.The dynamic reactive-transport model presented in this study provides a new tool addressing the combined simulation of complex physical-geochemical processes in sedimentary systems. The model can easily be extended and applied to similar geological settings, and thus help us to provide a fundamental understanding of fluid dynamics and element recycling in sedimentary basins.Schneider, C., Becker, S., Okamura, H., Crisp, A., Amatov, T., Stadlmeier, M., Carell, T., 2018. Noncanonical RNA nucleosides as molecular fossils of an early Earth - generation by prebiotic methylations and carbamoylations. Angewandte Chemie International Edition 57, 5943-5946. RNA-world hypothesis assumes that life on Earth started with small RNA molecules that catalyzed their own formation. Vital to this hypothesis is the need for prebiotic routes towards RNA. Contemporary RNA, however, is not only constructed from the four canonical nucleobases (A, C, G, and U), it also contains many chemically modified (noncanonical) bases. A still open question is whether these noncanonical bases were formed in parallel to the canonical bases (chemical origin) or later, when life demanded higher functional diversity (biological origin). Here we show that isocyanates in combination with sodium nitrite establish methylating and carbamoylating reactivity compatible with early Earth conditions. These reactions lead to the formation of methylated and amino acid modified nucleosides that are still extant. Our data provide a plausible scenario for the chemical origin of certain noncanonical bases, which suggests that they are fossils of an early Earth.Schwehr, K.A., Xu, C., Chiu, M.-H., Zhang, S., Sun, L., Lin, P., Beaver, M., Jackson, C., Agueda, O., Bergen, C., Chin, W.-C., Quigg, A., Santschi, P.H., 2018. Protein: Polysaccharide ratio in exopolymeric substances controlling the surface tension of seawater in the presence or absence of surrogate Macondo oil with and without Corexit. Marine Chemistry 206, 84-92. substances can interact with oil in the water to form emulsions and aggregates; dispersants are designed to form emulsions to prevent oil droplets from coalescing and stabilize them in a suspension. Amphiphilic extracellular polymeric substances (EPS) concentrated at the air-water interface where surface tension was measured to determine their propensity for formation of emulsions and/or aggregates. Here we investigated mechanisms governing the self-assembly and phase separation for protein-polysaccharide-oil-dispersant interactions through measurements of surface tension, chemical composition, and confocal microscopy. EPS colloid fractions from treatments of WAF (water accommodated fraction of oil), CEWAF (chemically enhanced WAF using the dispersant Corexit), and a control mesocosm were examined. In analyzing the size fractions of water column samples, it was found that treatments with oil and/or Corexit showed EPS with enhanced protein:polysaccharide carbon-based ratios and lower surface tension (SFT), suggesting the effective bioemulsifying effects of proteins. In addition, EPS model constituents of protein slightly increased SFT at low concentrations of less than a few mg/L, but decreased it at higher concentrations of 8?mg/L or more. These model molecules appear to be more efficient than Corexit in inducing the self-assembly of micelles in the seawater even when only very low concentrations of these constituents are present. Our results suggest that EPS are more efficient than Corexit at forming micelles. Results from this study provides mechanistic insights into the fate and distribution of oil in the surface ocean.Sekoai, P.T., Ouma, C.N.M., du Preez, S.P., Modisha, P., Engelbrecht, N., Bessarabov, D.G., Ghimire, A., 2019. Application of nanoparticles in biofuels: An overview. Fuel 237, 380-397. are fast advancing as alternative sources of renewable energy due to their non-polluting features and cost-competitiveness in comparison to fossil fuels. However, in order to fast-track their development, focus is shifting towards the use of technologies that will maximize their yields. Nanoparticles are gaining increasing interest amongst researchers due to their exquisite properties, which enable them to be applied in diverse fields such as agriculture, electronics, pharmaceuticals and food industry. They are also being explored in biofuels in order to improve the performance of these bioprocesses. This review critically examines the various studies in literature that have explored nanoparticles in biofuel processes such as biohydrogen, biogas, biodiesel and bioethanol production, towards enhancing their process yields. Furthermore, it elucidates the different types of nanomaterials (metallic, nanofibers and nanotubes) that have been used in these bioprocesses. It also evaluates the effects of immobilized nanoparticles on biofuels such as biodiesel, and the ability of nanoparticles to effectively suppress inhibitory compounds under certain conditions. A short section is included to discuss the factors that influence the performance of nanoparticles on biofuels production processes. Finally, the review concludes with suggestions on improvements and possible further research aspects of these bioprocesses using nanoparticles.Sero, R., Vidal, M., Bosch, J., Rodríguez, P., Galceran, M.T., Moyano, E., 2019. Desorption electrospray ionization-high resolution mass spectrometry for the analysis of unknown materials: the phytosanitary product case. Talanta 194, 350-356. this work, we tested the potential of desorption electrospray ionization-high resolution mass spectrometry (DESI-HRMS) for the analysis of unknown materials. To this end, our study focused on analyzing an unknown complex sample suspected of being an adulterated phytosanitary product or a fraud. A simple and fast sample manipulation procedure (filter paper impregnated with the sample) was used for the chemical characterization of the phytosanitary product by DESI-HRMS(/MS). Kendrick Mass Defect (KMD) analysis was used to process the DESI high-resolution mass spectral data, allowing the identification of a low molecular weight polymer (polyethylene glycol) and the detection of other ions, which did not follow polymer distributions. The characteristic isotope patterns of these ions suggested the presence of organometallic compounds. Accurate mass measurements, isotope pattern fits and the structural information obtained by DESI-MS/HRMS (wide isolation window) allowed identifying the presence of triphenyltin, a biocide extensively used for agricultural purposes and restricted by the European Commission, in the phytosanitary product. The concentration of triphenyltin in the sample was 35%, which corresponds to ～12% expressed as weight of tin, 120 times higher than the maximum legislated level.Shah, S.B.A., Ahmed, A., 2018. Hydrocarbon source rock potential of Paleocene and Jurassic deposits in the Panjpir oilfield subsurface, Punjab Platform, Pakistan. Arabian Journal of Geosciences 11, Article 607. source rock potential of three formations in Panjpir oilfield in Punjab Platform in the eastern part of the Middle Indus Basin, namely Ranikot (Paleocene), Samanasuk (Jurassic), and Shinwari (Jurassic) was investigated by using total organic carbon (TOC) and Rock-Eval pyrolysis analysis measurements. Nine samples were obtained from producing well. The analyzed samples contain TOC ranging between 0.98 and 2.45?wt.%. S2 values of Rock-Eval show poor potential with values ranging from 0.02 to 0.27?mg HC/g rock. The samples have low hydrogen index values ranging from 3 to 27?mg HC/g TOC and also having low Tmax values ranging from 427 to 431?°C. On the basis of analysis performed, only three studied samples have early maturity, two from Ranikot and one from Samana Suk formation, whereas rest of the samples are in immature zones as indicated by HI vs Tmax plot; no samples from Shinwari Formation lie in maturity window. All of the samples have kerogen Type III and have poor generation potential. Hence, from the result, some minor gas could be expected to have been generated in the study area.Sharma, A., Phukan, S., Saikia, B.K., Baruah, B.P., 2018. Geochemical evaluation of the hydrocarbon prospects of carbonaceous shale and coal of Barail Group, Upper Assam Basin. International Journal of Oil, Gas and Coal Technology 19, 263-282. Upper Assam Basin is an important onshore petroleum province in India. The petroleum generation potential of Barail coal and carbonaceous shale in the different oil fields has been assessed to determine the source rock quality of the coal/shale unit or the argillaceous unit in the Upper Assam Shelf of Barail Group. Organic geochemical analyses involving elemental analysis, TOC and Rock-Eval pyrolysis were carried out on some selected subsurface core samples from different oil fields of Upper Assam to characterise their sedimentary organic matter. Rock-Eval pyrolysis showed good organic carbon richness, i.e., TOC (1.00%-69.21%), thus indicating good generative potential for petroleum. The Tmax data span of the studied samples is 396°C-433°C. Low Tmax values (<430°C) of the studied samples indicate that the organic matter in the coal and carbonaceous shale samples of Barail strata are either immature or less mature with respect to liquid hydrocarbon generation. The Rock-Eval pyrolysis results indicate the mixed type II and III kerogen, which is of good source rock quality, but thermally immature to generate petroleum.Shen, W., Pang, X., Chen, J., Wang, Y., Zhang, K., Gao, Z., Jia, Y., Chen, Z., 2018. Accumulation model based on factors controlling Ordovician hydrocarbons migration and enrichment in the Tazhong Uplift, Tarim Basin, NW China. Acta Sedimentologica Sinica 26, 1008-1022. order to further clarify the role of different geological conditions on hydrocarbons accumulation process, the major controlling factors of Ordovician hydrocarbons accumulation in the Tazhong Uplift, Tarim Basin are studied based on the view points of diverse geological conditions and their relationship in space. The results showed that the vertical hydrocarbons migration distance and accumulation layers were controlled by vertical source-reservoir distribution, faults, and caprocks. Structures played a major role in lateral direction of hydrocarbons migration. The lateral migration pathways were governed by unconformities, transport faults, and porous permeable carrier beds. Apart from the excellent reservoir controls, hydrocarbons enrichment was controlled by tectonic events. Based on the analysis of factors mentioned above and coupled with oil sources conditions and excellent reservoirs, two types of hydrocarbon accumulation models could be retained based on the vertical hydrocarbon migration distance, including a multi-sourced area model and a single-sourced area model. In addition, the accumulation models could be also classified into near source accumulation and far source accumulation based on the lateral hydrocarbons migration distance.Shields, G.A., 2019. Chapter 36 - Implications of carbonate and chert isotope records for the Early Earth, in: Van Kranendonk, M.J., Bennett, V.C., Hoffmann, J.E. (Eds.), Earth's Oldest Rocks (Second Edition). Elsevier, pp. 901-912. existence of marine sedimentary rocks through three-and-a-half billion years of Earth history provides us with important insight into the early Earth. The strontium isotopic evolution of seawater is consistent with an increase in the influence of continental weathering associated with a major crustal building episode before the Archean-Proterozoic boundary. Although the weathering of newly emergent terrains could have helped to fuel the subsequent Great Oxidation Event, contemporaneous carbon and oxygen isotope records do not clearly record this tectonic upheaval but can be used instead to demonstrate the antiquity of life, a smaller biomass and temperatures that typically did not exceed 55°C as far back as 3.5 Ga.Shukla, M.K., Sharma, A., 2018. Carbon isotope and REE characteristics of the Paleocene–Eocene shallow marine Subathu formation from the NW Himalaya (India) and their paleo-environmental implications. Chemie der Erde 78, 314-322. isotope (δ13C) and rare earth element (REE) concentrations in representative samples of the shallow marine Subathu Formation, explored from the Neelkanth and Dogadda sections of Northwestern Himalaya (India) were determined to infer the palaeo-environmental condition during the late Paleocene and middle Eocene. δ13C values show variation of ～5.0‰ with maximum excursion (?27.34‰) in calcareous sandstone at the basal part and minimum (?22‰) in red shale towards the terminal end. Total REE concentration varies (due to lithology) from 27.23?ppm to 564.35?ppm with an average of 187.60?ppm. The chondrite and PAAS normalized patterns exhibit positive Ce anomaly (0.95–4.45), enriched LREE, and depleted HREE, medium Y/Ho ratio (～30–45) along with positive correlation between Y/Dy and Y/Ho ratio. In addition, calcite veins present in some shale samples indicate redox sensitive trace elements. The overall REE abundance and distribution suggests highly oxygenated environment under the shallow marine regressive phase of deposition. The depositional setting, biostratigraphical constrained age along with δ13C values and lower TOC suggested an intense warm period, that might be coeval with the Paleocene-Eocene Thermal Maxima event (PETM).Sibanda, T., Selvarajan, R., Msagati, T., Venkatachalam, S., Meddows-Taylor, S., 2019. Defunct gold mine tailings are natural reservoir for unique bacterial communities revealed by high-throughput sequencing analysis. Science of The Total Environment 650, 2199-2209. tailing dumps are arguably one of the leading sources of environmental degradation with often both public health and ecologically consequences. The present study investigated the concentration of heavy metals in gold mine tailings, and used high throughput sequencing techniques to determine the microbial community diversity of these tailings using 16S rRNA gene based amplicon sequence analysis. The concentration of detected metals and metalloids followed the order Si?>?Al?>?Fe?>?K?>?Ca?>?Mg. The 16S rRNA gene based sequence analysis resulted in a total of 273,398 reads across the five samples, represented among 7 major phyla, 41 classes, 77 orders, 142 families and 247 major genera. Phylum Actinobacteria was the most dominant, followed by Proteobacteria, Firmicutes, Chloroflexi, Cyanobacteria, Bacteroidetes, Acidobacteria and Planctomycetes. Redundancy analysis (RDA) and pairwise correlation analysis positively correlated the distribution of Alphaproteobacteria and Gammaproteobacteria to Al and K; Actinobacteria to Cr and Chloroflexi to Si. Negative correlations were observed in the distribution of Bacteroidetes with respect to As concentrations, Actinobacteria to Al, and Alphaproteobacteria and Gammaproteobacteria to high As and Te content of the soils. Predictive functional analysis showed the presence of putative biosynthetic and degradative pathways across the five sample sites. The study concludes that mine tailing sites harbour diverse and unique microbial assemblages with potentially biotechnologically important genes for biosynthesis and biodegradation.Sibert, E., Friedman, M., Hull, P., Hunt, G., Norris, R., 2018. Two pulses of morphological diversification in Pacific pelagic fishes following the Cretaceous–Palaeogene mass extinction. Proceedings of the Royal Society B: Biological Sciences 285, Article 20181194. phylogenies suggest some major radiations of open-ocean fish clades occurred roughly coincident with the Cretaceous–Palaeogene (K/Pg) boundary, however the timing and nature of this diversification is poorly constrained. Here, we investigate evolutionary patterns in ray-finned fishes across the K/Pg mass extinction 66 million years ago (Ma), using microfossils (isolated teeth) preserved in a South Pacific sediment core spanning 72–43 Ma. Our record does not show significant turnover of fish tooth morphotypes at the K/Pg boundary: only two of 48 Cretaceous tooth morphotypes disappear at the event in the South Pacific, a rate no different from background extinction. Capture–mark–recapture analysis finds two pulses of origination in fish tooth morphotypes following the mass extinction. The first pulse, at approximately 64 Ma, included short-lived teeth, as well as forms that contribute to an expansion into novel morphospace. A second pulse, centred at approximately 58 Ma, produced morphotype novelty in a different region of morphospace from the first pulse, and contributed significantly to Eocene tooth morphospace occupation. There was no significant increase in origination rates or expansion into novel morphospace during the early or middle Eocene, despite a near 10-fold increase in tooth abundance during that interval. Our results suggest that while the K/Pg event had a minor impact on fish diversity in terms of extinction, the removal of the few dominant Cretaceous morphotypes triggered a sequence of origination events allowing fishes to rapidly diversify morphologically, setting the stage for exceptional levels of ray-finned fish diversity in the Cenozoic.Silva, A.S.C., Palmer, A., Kovalev, V., Tarasov, A., Alexandrov, T., Martens, L., Degroeve, S., 2018. Data-driven rescoring of metabolite annotations significantly improves sensitivity. Analytical Chemistry 90, 11636-11642. analyzing mass spectrometry imaging data sets, assigning a molecule to each of the thousands of generated images is a very complex task. Recent efforts have taken lessons from (tandem) mass spectrometry proteomics and applied them to imaging mass spectrometry metabolomics, with good results. Our goal is to go a step further in this direction and apply a well established, data-driven method to improve the results obtained from an annotation engine. By using a data-driven rescoring strategy, we are able to consistently improve the sensitivity of the annotation engine while maintaining control of statistics like estimated rate of false discoveries. All the code necessary to run a search and extract the additional features can be found at and to rescore the results from a search in , S.K., 2018. Nano- and micron-sized diamond genesis in nature: An overview. Geoscience Frontiers 9, 1849-1858. are four main types of natural diamonds and related formation processes. The first type comprises the interstellar nanodiamond particles. The second group includes crustal nano- and micron-scale diamonds associated with coals, sediments and metamorphic rocks. The third one includes nanodiamonds and microndiamonds associated with secondary alteration and replacing of mafic and ultramafic rocks. The fourth one includes macro-, micron- and nano-sized mantle diamonds which are associated with kimberlites, mantle peridotites and eclogites. Each diamond type has its specific characteristics. Nano-sized diamond particles of lowest nanometers in size crystallize from abiotic organic matter at lower pressures and temperatures in space during the stages of protoplanetary disk formation. Nano-sized diamonds are formed from organic matter at P-T exceeding conditions of catagenesis stage of lithogenesis. Micron-sized diamonds are formed from fluids at P-T exceeding supercritical water stability. Macrosized diamonds are formed from metal-carbon and silicate-carbonate melts and fluids at P-T exceeding 1150?°C and 4.5?GPa. Nitrogen and hydrocarbons play an important role in diamond formation. Their role in the formation processes increases from macro-sized to nano-sized diamond particles. Introduction of nitrogen atoms into the diamond structure leads to the stabilization of micron- and nano-sized diamonds in the field of graphite stability.Singh, N., Choudhury, B., 2018. Potential of Lentibacillus sp. NS12IITR for production of lipids with enriched branched-chain fatty acids for improving biodiesel properties along with hydrocarbon co-production. Extremophiles 22, 865-875. environment is inhabited by array of microbes which have the potential to produce industrially important products. This study explored biomass and lipid production potential of the halophilic bacterium, strain NS12IITR which was isolated from Sambhar Lake, Rajasthan. Sequencing and phylogenetic analysis revealed that the bacterium belonged to genus Lentibacillus. The salient feature of the isolate is its ability to accumulate total cellular lipid up to 18.9?±?0.45% of dry cell weight. In addition, trans-esterification of extracted lipid yielded 77.6?±?5.56% of total esters as methyl ester of branched-chain fatty acids (BCFAs). To assess the nature of extracted lipid, lipid sample was fractionated on the silicic acid column, which demonstrated that 49.03?±?1.35% of the total lipids was neutral in nature. Trans-esterification of the neutral lipid fraction yielded 60.62?±?4.88% of total esters as methyl ester of BCFAs. Methyl esters of BCFAs were present in trans-esterified products of neutral as well as polar lipid fractions. Furthermore, the isolate produced hydrocarbons both extracellularly (C10–C30) and intra-cellularly (C15–C28). The concentration of extracellular hydrocarbon (21.11?±?0.78 mg/L) synthesized by strain NS12IITR is in close agreement with the yield reported from other hydrocarbon producing bacteria. This is hereby a first report on the co-production of lipids and hydrocarbon from a halophilic bacterium. The production of neutral lipid with high percentage of BCFAs and co-production of hydrocarbons makes the isolate NS12IITR a potential claimant for biofuel production.Sivaram, A.K., Subashchandrabose, S.R., Logeshwaran, P., Lockington, R., Naidu, R., Megharaj, M., 2019. Metabolomics reveals defensive mechanisms adapted by maize on exposure to high molecular weight polycyclic aromatic hydrocarbons. Chemosphere 214, 771-780. aromatic hydrocarbons are an important group of persistent organic pollutants. Using plants to remediate PAHs has been recognized as a cost-effective and environmentally friendly technique. However, the overall impact of PAHs on the regulation of plant metabolism has not yet been explored. In this study, we analyzed the alteration in the maize (Zea mays L.) metabolome on exposure to high molecular weight PAHs such as benzo[a]pyrene (BaP) and pyrene (PYR) in a hydroponic medium, individually and as a mixture (BaP?+?PYR) using GC-MS. The differences in the metabolites were analyzed using XCMS (an acronym for various forms (X) of chromatography-mass spectrometry), an online-based data analysis tool. A significant variation in metabolites was observed between treatment groups and the unspiked control group. The univariate, multivariate and pathway impact analysis showed there were more significant alterations in metabolic profiles between individual PAHs and the mixture of BaP and PYR. The marked changes in the metabolites of galactose metabolism and aminoacyl tRNA biosynthesis in PAHs treated maize leaves exhibit the adaptive defensive mechanisms for individual and PAHs mixture. Therefore, the metabolomics approach is essential for an understanding of the complex biochemical responses of plants to PAHs contaminants. This knowledge will shed new light in the field of phytoremediation, bio-monitoring, and environmental risk assessment.Sleep, S., Laurenzi, I.J., Bergerson, J.A., MacLean, H.L., 2018. Evaluation of variability in greenhouse gas intensity of Canadian oil sands surface mining and upgrading operations. Environmental Science & Technology 52, 11941-11951. present a statistically enhanced version of the GreenHouse gas emissions of current Oil Sands Technologies model that facilitates characterization of variability of greenhouse gas (GHG) emissions associated with mining and upgrading of bitumen from Canadian oil sands. Over 30 years of publicly available project-specific operating data are employed as inputs, enabling Monte Carlo simulation of individual projects and the entire industry, for individual years and project life cycles. We estimate that median lifetime GHG intensities range from 89 to 137 kg CO2eq/bbl synthetic crude oil (SCO) for projects that employ upgrading. The only project producing dilbit that goes directly to a refinery has a median lifetime GHG intensity of 51 kg CO2eq/bbl dilbit. As SCO and dilbit are distinct products with different downstream processing energy requirements, a life cycle assessment (“well to wheel”) is needed to properly compare them. Projects do not reach steady-state in terms of median GHG intensity. Projects with broader distributions of annual GHG intensities and higher median values are linked to specific events (e.g., project expansions). An implication for policymakers is that no specific technology or operating factor can be directly linked to GHG intensity and no particular project or year of operation can be seen as representative of the industry or production technology.Smirnov, M.B., Fadeeva, N.P., Poludetkina, E.N., 2018. Identification of the genetic heterogeneity of Tatarstan oils based on the composition of alkyl-substituted aromatic compounds. Russian Geology and Geophysics 59, 1137-1148. study presents data on concentrations of n-alkylbenzenes, n-alkylnaphthalenes, phytanylnaphthalene, and methylphytanylnaphthalene in representative crude oils of Tatarstan. The results of the study reveal the elevated concentrations of C19, C21, and C23 homologues of n-alkylbenzenes and n-alkylnaphthalenes, which can be considered as biomarkers. The proposed procedure for comprehensive quantification of this group of biomarkers can be used as an efficient tool to study oils from the major petroleum basins of Russia. Based on the results of the study, four genetic groups of oils in Tatarstan have been distinguished: (1) oils from the north and northwest (Bir saddle, Lower Kama system of linear faults, and Saraily saddle), (2) oils from Devonian terrigenous reservoirs within the South Tatar arch and Melekes depression, (3) oils from Carboniferous reservoirs, and (4) oils from Devonian carbonate reservoirs. All these oils belong to the same genetic macrotype. Based on the results of this study, the sedimentary sections of the Melekes depression cannot be regarded as potential source rocks. It is assumed that oil has migrated to the northern part of the region from the north or east. Some of the possible migration routes for oils from the remaining part of Tatarstan are from the southeast and/or south.Smith, H.J., Zelaya, A.J., De?León, K.B., Chakraborty, R., Elias, D.A., Hazen, T.C., Arkin, A.P., Cunningham, A.B., Fields, M.W., 2018. Impact of hydrologic boundaries on microbial planktonic and biofilm communities in shallow terrestrial subsurface environments. FEMS Microbiology Ecology 94, Article fiy191. environments contain a large proportion of planetary microbial biomass and harbor diverse communities responsible for mediating biogeochemical cycles important to groundwater used by human society for consumption, irrigation, agriculture and industry. Within the saturated zone, capillary fringe and vadose zones, microorganisms can reside in two distinct phases (planktonic or biofilm), and significant differences in community composition, structure and activity between free-living and attached communities are commonly accepted. However, largely due to sampling constraints and the challenges of working with solid substrata, the contribution of each phase to subsurface processes is largely unresolved. Here, we synthesize current information on the diversity and activity of shallow freshwater subsurface habitats, discuss the challenges associated with sampling planktonic and biofilm communities across spatial, temporal and geological gradients, and discuss how biofilms may be constrained within shallow terrestrial subsurface aquifers. We suggest that merging traditional activity measurements and sequencing/-omics technologies with hydrological parameters important to sediment biofilm assembly and stability will help delineate key system parameters. Ultimately, integration will enhance our understanding of shallow subsurface ecophysiology in terms of bulk-flow through porous media and distinguish the respective activities of sessile microbial communities from more transient planktonic communities to ecosystem service and maintenance.Smith, R.K., Stacey, R.J., Bergstr?m, E., Thomas-Oates, J., 2018. Detection of opium alkaloids in a Cypriot base-ring juglet. Analyst 143, 5127-5136. method has been developed for extracting poppy alkaloids from oily matrices, specifically lipid residues associated with archaeological ceramics. The protocol has been applied to fresh and artificially aged poppyseed oil and to residue from a Late Bronze Age Cypriot juglet in the collections of the British Museum. The juglet is of a type that has been linked with ancient trade in opium due to its poppy-head shape and wide distribution; it is a rare example of an intact vessel with contents sealed inside. Bulk analysis of the residue by GC-EI-MS and pyGC-EI-MS indicated a degraded plant oil and possible presence of papaverine. Analysis of the alkaloid extracts by HPLC-ESI-MS using both triple quadrupole and FTICR mass spectrometers detected the five primary opium alkaloids in fresh poppyseed oil and papaverine in most of the aged samples. Papaverine and thebaine were detected in the juglet residue, providing the first rigorous chemical evidence to support a link between this vessel type and opium, or at least poppies. The association of opium with oil raises new questions about the ancient purpose of the commodities within these vessels, and the low levels (ng g?1) of opiates detected in this unusually well-preserved residue shed doubt on the scope for their detection in more fragmentary ceramic remains (potsherds). Papaverine was found to exhibit challenging carryover behaviour in all the analytical methods used in this study. The phenomenon has not been reported before and should be considered in future analyses of this analyte in all application areas.Snedden, J.W., Tinker, L.D., Virdell, J., 2018. Southern Gulf of Mexico Wilcox source to sink: Investigating and predicting Paleogene Wilcox reservoirs in eastern Mexico deep-water areas. American Association of Petroleum Geologists Bulletin 102, 2045-2074. analyses show that northern Gulf of Mexico (GOM) Wilcox Group siliciclastic deep-water systems are linked to transport of sediments from the Laramide tectonic belt into the deep basin. Less is known, however, about southern GOM sedimentation. New drilling and discoveries in the Mexican deep water have generated considerable interest since the opening of Mexico to international exploration. To investigate Paleogene deposition in Mexico’s offshore areas, a three-phased approach was employed: (1) seismic mapping of deep-water depocenters, (2) regional stratigraphic analysis of potential basin entry points, and (3) prediction of submarine-fan dimensions using empirical scaling relationships. Isochore and structural mapping of the Wilcox depocenters used available well and seismic data. Potential basin entry points were identified by evaluation of Wilcox fluvial–deltaic systems and tectonic elements. Empirical scaling relationships previously established between fluvial and deep-water segments provide first-order predictions of submarine-fan dimensions.Paleogene Wilcox source-to-sink systems of the greater GOM basin change north to south as a function of varied tectonics and sedimentary accommodation. The United States sector was a passive margin: continental-scale drainage systems fed a broad, gently dipping shelf. By contrast, the southern GOM basin was a tectonically active margin: smaller-scale fluvial systems sourced from the Hidalgoan uplands flowed directly into foreland basins located on the slope. Results presented here indicate that several systems rimming the southern GOM were able to effectively transfer sediment from the mountain belt into the basin. Regional observations and semiquantitative predictions of fan dimensions provide a context for future detailed work based on new well and seismic information.Sobron, P., Wang, A., Mayer, D.P., Bentz, J., Kong, F., Zheng, M., 2018. Dalangtan saline playa in a hyperarid region of Tibet Plateau: III. Correlated multiscale surface mineralogy and geochemistry survey. Astrobiology 18, 1277-1304. report the first multiscale, systematic field-based testing of correlations between orbital scale advanced spaceborne thermal emission and reflection radiometer visible near-infrared (VNIR)/shortwave infrared (SWIR) reflectance and thermal infrared relative emissivity and outcrop scale Raman spectroscopy, VNIR reflectance, X-ray diffraction (XRD), and laser-induced breakdown spectroscopy (LIBS) mineralogy and chemistry in a saline dry lakebed. This article is one of three reports describing the evolution of salt deposits, meteorological record, and surface and subsurface salt mineralogy in Dalangtan, Qaidam Basin, a hyperarid region of the Tibet Plateau, China, as potential environmental, mineralogical, and biogeochemical analogs to Mars. We have successfully bridged remote sensing data to fine scale mineralogy and chemistry data. We have defined spectral end-members in the northwestern Qaidam Basin and classified areas within the study area on the basis of their spectral similarity to the spectral end-members. Results of VNIR/SWIR classification reveal zonation of spectral units within three large anticlinal domes in the study area that can be correlated between the three structures. Laboratory Raman, VNIR reflectance, XRD, and LIBS data of surface mineral samples collected along a traverse over Xiaoliangshan (XLS) indicate that the surface is dominated by gypsum, Mg sulfates, Na sulfates, halite, and carbonates, with minor concentrations of illite present in most samples as well. Our results can be used as a first step toward better characterizing the potential of orbital reflectance spectroscopy as a method for mineral detection and quantification in salt-rich planetary environments, with the benefit that this technique can be validated on the ground using instruments onboard rovers.Song, G., Li, Y., Wang, W., Liu, S., Wang, X., Shi, Z., Yao, S., 2019. Experimental investigation on the microprocess of hydrate particle agglomeration using a high-speed camera. Fuel 237, 475-485. investigate the microprocess of hydrate particle agglomeration, a high-pressure visual cell was used for repeated experiments of hydrate particle formation and flow from methane?+?water systems at an experimental temperature of 275.15?K, an initial pressure of 6?MPa and a rotation rate of 200?rpm. During the experiments, a high-speed camera was used to capture the micromorphologies and micro flow behavior of hydrate particles. Based on the experimental data obtained by the high-speed camera, three types of micromorphologies were identified for hydrate particles. Then, the variation in the average diameter of hydrate particles and the characteristics of hydrate particle size distribution were investigated by calculating the equivalent projection area diameter of hydrate particles. During the experiments, particle collision, particle agglomeration and particle breakage were the three main micro flow behaviors of hydrate particles captured by the high-speed camera. The whole process of hydrate agglomeration under flow conditions was also captured by the high-speed camera. Finally, according to the variation in the average diameter of hydrate particles and the micro flow behavior of hydrate particles, a physical model for the whole process of hydrate particle “agglomeration” was established.Song, H., Wignall, P.B., Dunhill, A.M., 2018. Decoupled taxonomic and ecological recoveries from the Permo-Triassic extinction. Science Advances 4, Article eaat5091. Permian-Triassic mass extinction was the worst crisis faced by life; it killed >90% of marine species in less than 0.1 million years (Ma). However, knowledge of its macroecological impact over prolonged time scales is limited. We show that marine ecosystems dominated by non-motile animals shifted to ones dominated by nektonic groups after the extinction. In Triassic oceans, animals at high trophic levels recovered faster than those at lower levels. The top-down rebuilding of marine ecosystems was still underway in the latest Triassic, ~50 Ma after the extinction, and contrasts with the ~5-Ma recovery required for taxonomic diversity. The decoupling between taxonomic and ecological recoveries suggests that a process of vacant niche filling before reaching the maximum environmental carrying capacity is independent of ecosystem structure building.Sorokin, D.Y., Messina, E., La Cono, V., Ferrer, M., Ciordia, S., Mena, M.C., Toshchakov, S.V., Golyshin, P.N., Yakimov, M.M., 2018. Sulfur respiration in a group of facultatively anaerobic natronoarchaea ubiquitous in hypersaline soda lakes. Frontiers in Microbiology 9, 2359. doi: 10.3389/fmicb.2018.02359. ubiquity of strictly anaerobic sulfur-respiring haloarchaea in hypersaline systems with circumneutral pH has shaken a traditional concept of this group as predominantly aerobic heterotrophs. Here, we demonstrated that this functional group of haloarchaea also has its representatives in hypersaline alkaline lakes. Sediments from various hyprsaline soda lakes showed high activity of sulfur reduction only partially inhibited by antibiotics. Eight pure cultures of sulfur-reducing natronoarchaea were isolated from such sediments using formate and butyrate as electron donors and sulfur as an electron acceptor. Unlike strict anaerobic haloarchaea, these novel sulfur-reducing natronoarchaea are facultative anaerobes, whose metabolic capabilities were inferred from cultivation experiments and genomic/proteomic reconstruction. While sharing many physiological traits with strict anaerobic haloarchaea, following metabolic distinctions make these new organisms be successful in both anoxic and aerobic habitats: the recruiting of heme-copper quinol oxidases as terminal electron sink in aerobic respiratory chain and the utilization of formate, hydrogen or short-chain fatty acids as electron donors during anaerobic growth with elemental sulfur. Obtained results significantly advance the emerging concept of halo(natrono)archaea as important players in the anaerobic sulfur and carbon cycling in various salt-saturated habitats.Sossi, P.A., Moynier, F., van Zuilen, K., 2018. Volatile loss following cooling and accretion of the Moon revealed by chromium isotopes. Proceedings of the National Academy of Sciences 115, 10920.: With the exception of volatile elements, which are strongly depleted and isotopically fractionated, the Moon has chemical and isotopic signatures that are indistinguishable from Earth’s mantle. Reconciliation of these properties with Moon formation in a high-energy giant impact invokes evaporative loss of volatile elements, but at conditions that are poorly known. Chromium isotopic fractionation is sensitive to temperature variations and liquid–gas equilibration during evaporation. We measure an isotopic difference between Earth’s mantle and the Moon, consistent with the loss of a Cr-bearing, oxidized vapor phase in equilibrium with the proto-Moon. Temperatures of vapor loss required are much lower than predicted by recent models, implying that volatile elements were removed from the Moon following cooling rather than during a giant impact.Abstract: Terrestrial and lunar rocks share chemical and isotopic similarities in refractory elements, suggestive of a common precursor. By contrast, the marked depletion of volatile elements in lunar rocks together with their enrichment in heavy isotopes compared with Earth’s mantle suggests that the Moon underwent evaporative loss of volatiles. However, whether equilibrium prevailed during evaporation and, if so, at what conditions (temperature, pressure, and oxygen fugacity) remain unconstrained. Chromium may shed light on this question, as it has several thermodynamically stable, oxidized gas species that can distinguish between kinetic and equilibrium regimes. Here, we present high-precision Cr isotope measurements in terrestrial and lunar rocks that reveal an enrichment in the lighter isotopes of Cr in the Moon compared with Earth’s mantle by 100 ± 40 ppm per atomic mass unit. This observation is consistent with Cr partitioning into an oxygen-rich vapor phase in equilibrium with the proto-Moon, thereby stabilizing the CrO2 species that is isotopically heavy compared with CrO in a lunar melt. Temperatures of 1,600–1,800 K and oxygen fugacities near the fayalite–magnetite–quartz buffer are required to explain the elemental and isotopic difference of Cr between Earth’s mantle and the Moon. These temperatures are far lower than modeled in the aftermath of a giant impact, implying that volatile loss did not occur contemporaneously with impact but following cooling and accretion of the Moon.Sostare, J., Di Guida, R., Kirwan, J., Chalal, K., Palmer, E., Dunn, W.B., Viant, M.R., 2018. Comparison of modified Matyash method to conventional solvent systems for polar metabolite and lipid extractions. Analytica Chimica Acta 1037, 301-315. the last decade, metabolomics has experienced significant advances in the throughput and robustness of analytical methodologies. Yet the preparation of biofluids and low-mass tissue samples remains a laborious and potentially inconsistent manual process, and a significant bottleneck for high-throughput metabolomics. To address this, we have compared three different sample extraction solvent systems in three diverse sample types with the purpose of selecting an optimum protocol for subsequent automation of sample preparation. We have investigated and re-optimised the solvent ratios in the recently introduced methyl tert-butyl ether (MTBE)/methanol/water solvent system (here termed modified Matyash; 2.6/2.0/2.4, v/v/v) and compared it to the original Matyash method (10/3/2.5, v/v/v) and the conventional chloroform/methanol/water (stepwise Bligh and Dyer, 2.0/2.0/1.8, v/v/v) using two biofluids (human serum and urine) and one tissue (whole Daphnia magna). This is the first report of the use of the Matyash method for extracting metabolites from the US National Institutes of Health (NIH) model organism D.?magna. Extracted samples were analysed by non-targeted direct infusion mass spectrometry metabolomics or LC-MS metabolomics. Overall, the modified Matyash method yielded a higher number of peaks and putatively annotated metabolites compared to the original Matyash method (1–29% more peaks and 1–30% more metabolites) and the Bligh and Dyer method (4–20% more peaks and 1–41% more metabolites). Additionally the modified Matyash method was superior when considering metabolite intensities. The reproducibility of the modified Matyash method was higher than other methods (in 10 out of 12 datasets, compared to the original Matyash method; and in 8 out of 12 datasets, compared to the Bligh and Dyer method), based upon the observation of a lower mRSD of peak intensities. In conclusion, the modified Matyash method tended to provide a higher yield and reproducibility for most sample types in this study compared to two widely used methods.Spiegel, M.T., Anthony, I.G.M., Brantley, M.R., Hassell, A., Farmer, P.J., Solouki, T., 2018. Reactivities of aromatic protons in crude oil fractions toward Br2 tagging for structural characterization by nuclear magnetic resonance and electron paramagnetic resonance spectroscopy and mass spectrometry. Energy & Fuels 32, 10549-10555. characterization and structural elucidation of specific chemical subclasses within a complex mixture often require analyte separation, a variety of spectroscopic techniques, and inquiry into reactivity patterns. Crude oil is one of the most challenging and highly complex mixtures, and for classification purposes, it is typically separated into low-weight n-heptane-soluble and high-weight toluene-soluble (or asphaltene) fractions. Both fractions of crude oil have been studied previously using various spectroscopic methods, but their complete characterization remains elusive. In this work, we use selective functional group derivatization of both n-heptane and asphaltene fractions of crude oil for unprecedented identification of chemical functional groups by a combination of high-resolution mass spectrometry, 1H and 13C nuclear magnetic resonance, and electron paramagnetic resonance spectroscopy methods. Chemical tagging with elemental bromine suggests that the aromatic protons within the asphaltene fraction are less abundant and more sterically hindered than previous models might suggest. An efficient column purification was used to remove paramagnetic metals and allow for the identification of crude oil functional groups via analysis of spectrometry and spectroscopy data combined with chemical reactivity studies.Stamps, B.W., Nunn, H.S., Petryshyn, V.A., Oremland, R.S., Miller, L.G., Rosen, M.R., Bauer, K.W., Thompson, K.J., Tookmanian, E.M., Waldeck, A.R., Loyd, S.J., Johnson, H.A., Stevenson, B.S., Berelson, W.M., Corsetti, F.A., Spear, J.R., 2018. Metabolic capability and phylogenetic diversity of Mono Lake during a bloom of the eukaryotic phototroph Picocystis sp. Strain ML. Applied and Environmental Microbiology 84, Article e01171-18.: Algal blooms in lakes are often associated with anthropogenic eutrophication; however, they can occur without the human introduction of nutrients to a lake. A rare bloom of the alga Picocystis sp. strain ML occurred in the spring of 2016 at Mono Lake, a hyperalkaline lake in California, which was also at the apex of a multiyear-long drought. These conditions presented a unique sampling opportunity to investigate microbiological dynamics and potential metabolic function during an intense natural algal bloom. We conducted a comprehensive molecular analysis along a depth transect near the center of the lake from the surface to a depth of 25 m in June 2016. Across sampled depths, rRNA gene sequencing revealed that Picocystis-associated chloroplasts were found at 40 to 50% relative abundance, greater than values recorded previously. Despite high relative abundances of the photosynthetic oxygenic algal genus Picocystis, oxygen declined below detectable limits below a depth of 15 m, corresponding with an increase in microorganisms known to be anaerobic. In contrast to previously sampled years, both metagenomic and metatranscriptomic data suggested a depletion of anaerobic sulfate-reducing microorganisms throughout the lake's water column. Transcripts associated with photosystem I and II were expressed at both 2 m and 25 m, suggesting that limited oxygen production could occur at extremely low light levels at depth within the lake. Blooms of Picocystis appear to correspond with a loss of microbial activity such as sulfate reduction within Mono Lake, yet microorganisms may survive within the sediment to repopulate the lake water column as the bloom subsides.Importance: Mono Lake, California, provides a habitat to a unique ecological community that is heavily stressed due to recent human water diversions and a period of extended drought. To date, no baseline information exists from Mono Lake to understand how the microbial community responds to human-influenced drought or algal bloom or what metabolisms are lost in the water column as a consequence of such environmental pressures. While previously identified anaerobic members of the microbial community disappear from the water column during drought and bloom, sediment samples suggest that these microorganisms survive at the lake bottom or in the subsurface. Thus, the sediments may represent a type of seed bank that could restore the microbial community as a bloom subsides. Our work sheds light on the potential photosynthetic activity of the halotolerant alga Picocystis sp. strain ML and how the function and activity of the remainder of the microbial community responds during a bloom at Mono Lake.Stanton, C.L., Reinhard, C.T., Kasting, J.F., Ostrom, N.E., Haslun, J.A., Lyons, T.W., Glass, J.B., 2018. Nitrous oxide from chemodenitrification: A possible missing link in the Proterozoic greenhouse and the evolution of aerobic respiration. Geobiology 16, 597-609. potent greenhouse gas nitrous oxide (N2O) may have been an important constituent of Earth's atmosphere during Proterozoic (~2.5–0.5 Ga). Here, we tested the hypothesis that chemodenitrification, the rapid reduction of nitric oxide by ferrous iron, would have enhanced the flux of N2O from ferruginous Proterozoic seas. We empirically derived a rate law, d[N2O]/dt = 7.2 x 10-5 [Fe+2]0.3 [NO]1, and measured an isotopic site preference of +16‰ for the reaction. Using this empirical rate law, and integrating across an oceanwide oxycline, we found that low nM NO and μM‐low mM Fe2+ concentrations could have sustained a sea‐air flux of 100–200 Tg N2O–N year?1, if N2 fixation rates were near‐modern and all fixed N2 was emitted as N2O. A 1D photochemical model was used to obtain steady‐state atmospheric N2O concentrations as a function of sea‐air N2O flux across the wide range of possible pO2 values (0.001–1 PAL). At 100–200 Tg N2O–N year?1 and >0.1 PAL O2, this model yielded low‐ppmv N2O, which would produce several degrees of greenhouse warming at 1.6 ppmv CH4 and 320 ppmv CO2. These results suggest that enhanced N2O production in ferruginous seawater via a previously unconsidered chemodenitrification pathway may have helped to fill a Proterozoic “greenhouse gap,” reconciling an ice‐free Mesoproterozoic Earth with a less luminous early Sun. A particularly notable result was that high N2O fluxes at intermediate O2 concentrations (0.01–0.1 PAL) would have enhanced ozone screening of solar UV radiation. Due to rapid photolysis in the absence of an ozone shield, N2O is unlikely to have been an important greenhouse gas if Mesoproterozoic O2 was 0.001 PAL. At low O2, N2O might have played a more important role as life's primary terminal electron acceptor during the transition from an anoxic to oxic surface Earth, and correspondingly, from anaerobic to aerobic metabolisms. Stephens, B.M., Porrachia, M., Dovel, S., Roadman, M., Goericke, R., Aluwihare, L.I., 2018. Nonsinking organic matter production in the California Current. Global Biogeochemical Cycles 32, 1386-1405. eastern boundary upwelling systems such as the California Current Ecosystem (CCE) are important regions for supporting both local and remote food webs. Several studies have reported on the temporal and spatial variability of primary production and gravitational export in the CCE. However, few studies have quantified the partitioning of net primary and new production into other reservoirs of detrital organic matter. This study tested the hypothesis that nonsinking detrital reservoirs are an exportable reservoir of new production in the CCE with samples collected by the California Cooperative Oceanic Fisheries Investigation survey between 2008 and 2010. Water column gradients in nitrate (NO3?) and total organic carbon (TOC; which excludes sinking particulate organic carbon) were used to estimate potential rates of new production (PNew) and TOC production (PTOC), respectively. The PTOC:PNew varied between 0.16 and 0.56 and often increased with indicators of enhanced autotrophic production. At times, surface stratification was also correlated with elevated PTOC:PNew. In the most productive, inshore region, PTOC exceeded previously reported sinking export rates, which identified TOC as a quantitatively significant repository of exportable carbon in the CCE. However the sum of PTOC and sinking export for these productive regions was less than both PNew and oxygen‐based estimates of net community production. These results imply that nonsinking reservoirs alone are not sufficient to explain observed imbalances between production and export for the most productive CCE regions. Straka, P., S?korová, I., 2018. Coalification and coal alteration under mild thermal conditions. International Journal of Coal Science & Technology 5, 358-373. temperatures are often considered to be approximately 100–170?°C for bituminous coal and 170–275?°C for anthracite. However, our micropetrographic observations, solid state 27Al magic-angle spinning nuclear magnetic resonance measurements, interpretation of δ13C values for whewellite in pelosiderite concretions from Carboniferous sediments, and assessment of whewellite thermal stability show that coalification temperatures can be significantly lower. Also the temperatures of coal alteration may be substantially lower than is stated. Ordinarily, high-temperature alteration is reported, but microthermometric measurements of fluids temperatures and micropetrographic observations show that the coal alteration can take place at low temperatures. For this reason, coals from the Kladno–Rakovník Basin, part of Late Paleozoic continental basins of the Czech Republic, were analyzed. Regarding coalification, micropetrographic characterizations of unaltered coals, the presence of thermally unstable Al complexes in the coal organic mass documented using 27Al MAS NMR method, and proven occurrence of whewellite in pelosiderite concretions suggest a lower coalification temperature, max. ~?70?°C. Regarding coal alteration, micropetrographic observations revealed (a) the weaker intensity of fluorescence of liptinite, (b) mylonitic structures and microbreccia with carbonate fluid penetration, and (c) high oxygen content in coals (37–38?wt.%). These phenomena are typical for thermal and oxidative alteration of coal. As the temperature of carbonate fluids inferred from fluid inclusion analysis was evaluated as ~?100–113?°C, the temperature of coal alteration was suggested as ~?113?°C; the alteration was caused by hot hydrothermal fluids.Strehse, R., Bohne, H., Amha, Y., Leinweber, P., 2018. The influence of salt on dissolved organic matter from peat soils. Organic Geochemistry 125, 270-276. the influence of salt on the release and transformations of dissolved organic matter (DOM) is crucial for developing management strategies for coastal wetlands. We hypothesize that salt causes distinct changes in certain compound classes of DOM, distinguishable from the impact of other factors such as peat origin and decomposition degree. Therefore, the DOM composition was investigated in freshwater and saltwater extracts of nine peat samples of varying origin and decomposition degree. Samples were analyzed for carbon and nitrogen concentrations and pH values, and organic matter composition by temperature-resolved pyrolysis-field ionization mass spectrometry (Py-FIMS). The data revealed larger abundances of phenols/lignin monomers, peptides, carbohydrates, (mainly heterocyclic) N-compounds/nitriles and alkylaromatics in the saltwater extracts. The thermal release curves in Py-FIMS indicated a precipitation of fractions of alkylaromatics, N-compounds/nitriles and phenols/lignin monomers and a release of lipids, alkylaromatics and free fatty acids n-C16 to n-C34 in the saltwater extracts. Coagulation/precipitation, cation exchange and, for free fatty acids, the formation of micelles seem to be key mechanisms of the salt impact. Due to the stronger direct and indirect influences of saltwater on less decomposed peat an adapted management should be directed to preferentially protect rather pristine peatlands from saltwater intrusions that can be expected as a result of rising ocean levels under climate change.Strife, R.J., Wang, Y., Kuehl, D., 2018. Restricted spectral accuracy analysis to identify the single correct organic compound elemental-composition from Orbitrap accurate mass data lists obtained at very high resolution. Journal of Mass Spectrometry 53, 921-926. spectral accuracy is applied to Orbitrap data (240?000 resolution at m/z 400) to more clearly break out the scoring and ranking of allowable elemental compositions (ECs) in a candidate list. The correct EC is usually top ranked and separated from other answers by 10 to 40% within the dimensionless 0 to 100% scale, providing a single, definitive EC. The A?+?2 position (where A denotes the monoisotopic line position) is especially advantageous in restricted spectral accuracy. It has enough intensity and more complexity than (A?+?1) fine lines and is like a fingerprint. Avoidance of coalescence phenomena and careful ion population control are essential.Stupak, M., Goodall, I., Tomaniova, M., Pulkrabova, J., Hajslova, J., 2018. A novel approach to assess the quality and authenticity of Scotch Whisky based on gas chromatography coupled to high resolution mass spectrometry. Analytica Chimica Acta 1042, 60-70. is one of the most popular spirit drinks in the world. Unfortunately, this highly valued commodity is vulnerable to fraud. To detect fraudulent practices and document quality parameters, a number of laboratory tests based on various principles including chromatography and spectroscopy have been developed. In most cases, the analytical methods are based on targeted screening strategies. Non-targeted screening (metabolomics fingerprinting) of (semi)volatile substances was used in our study. Following the pre-concentration of these compounds, either by solid phase microextraction (SPME) or by ethyl acetate extraction, gas chromatography (GC) coupled to tandem mass spectrometry (Q-TOF mass analyser) was employed. Unsupervised principal component analysis (PCA) and supervised partial least squares discriminant analysis (PLS–DA) were used for evaluation of data obtained by analysis of a unique set of 171 authentic whisky samples provided by the Scotch Whisky Research Institute. Very good separation of malt whiskies according to the type of cask in which they were matured (bourbon versus bourbon and wine) was achieved, and significant ?markers' for bourbon and wine cask maturation, such as N-(3-methylbutyl) acetamide and 5-oxooxolane-2-carboxylic acid, were identified. Subsequently, the unique sample set was used to construct a statistical model for distinguishing malt and blended whiskies. In the final phase, 20 fake samples were analysed and the data processed in the same way. Some differences could be observed in the (semi)volatile profiles of authentic and fake samples. Employing the statistical model developed by PLS-DA for this purpose, marker compounds that positively distinguish fake samples were identified.Sudmalis, D., Da Silva, P., Temmink, H., Bijmans, M.M., Pereira, M.A., 2018. Biological treatment of produced water coupled with recovery of neutral lipids. Water Research 147, 33-42. water (PW) is the largest waste stream generated by oil and gas industry. It is commonly treated by physical-chemical processes due to high salt content and poor biodegradability of water insoluble compounds, such as n-alkanes. N-alkanes can represent a major fraction of organic contaminants within PW. In this study the possibility of simultaneous n – alkane biodegradation and production of neutral lipids in a concentrated PW stream with A. borkumenis SK2 as the sole reactor inoculum was investigated. N-alkane removal efficiency up to 99.6%, with influent alkane COD of 7.4?g/L, was achieved in a continuously operated reactor system. Gas chromatography results also showed that the majority of other non-polar compounds present in the PW were biodegraded. Biodegradation of n-alkanes was accompanied by simultaneous production of neutral lipids, mostly wax ester (WE)-alike compounds. We demonstrate, that under nutrient limited conditions and 108.9?±?3.3?mg/L residual n-alkane concentration the accumulation of extracellular WE-alike compounds can be up to 12 times higher compared to intracellular, reaching 3.08 grams per litre of reactor volume?(g/Lreactor) extracellularly and 0.28?g/Lreactor intracellularly. With residual n-alkane concentration of 311.5?±?34.2?mg/L accumulation of extracellular and intracellular WE-alike compounds can reach up to 6.15 and 0.91?g/Lreactor, respectively. To the best of our knowledge simultaneous PW treatment coupled with production of neutral lipids has never been demonstrated before.Sugitani, K., 2019. Chapter 41 - Early Archean (pre-3.0Ga) cellularly preserved microfossils and microfossil-like structures from the Pilbara Craton, Western Australia—A review, in: Van Kranendonk, M.J., Bennett, V.C., Hoffmann, J.E. (Eds.), Earth's Oldest Rocks (Second Edition). Elsevier, pp. 1007-1028. cellularly preserved microfossils and microfossil-like structures from the Pilbara Craton, Western Australia are reviewed. Various morphological types of microfossils and possible microfossils identified from five formations over the period 3.5–3.0Ga include rods, spheroids, lenses, and filaments (and their subtypes). Depositional environments of the host rocks range from shallow marine, or even terrestrial, to deep-sea. Evidence for input of hydrothermal fluids to the habitat is common. Although biological affinities of Archean microfossils are still poorly constrained, their diversity in morphology and interpreted habitat suggest biotic diversity. Recently accumulated data of large microfossils (>20μm in diameter), morphologically similar to cyanobacteria, sulfur bacteria, and even eukaryotes, could provide a new framework for the early evolution of life.Sui, W., Tian, Y., Yao, C., 2018. Investigation of microscopic pore structure variations of shale due to hydration effects through SEM fixed-point observation experiments. Petroleum Exploration and Development 45, 955-962. paper conducted the shale hydration experiments by using four different types of shale outcrop samples. The microscopic pore structure variations before and after hydration were recorded, compared and analyzed through Field Emission Scanned Electronic Microscope (FESEM) with fixed-point observation technique. The results showed that higher content of montmorillonite and carbonate minerals would contribute to the form of dissolution pores and looseness of mineral grains; some critical factors also include original alignment and cementation of mineral grains, and distribution of natural microfractures. Hydration doesn't change the organic pore structure. Almost all dissolution pores originated from mineral intergranular and intragranular pores in matrix, and the dissolution of matrix pores also lead to mineral particles to loose and fall off. When the mineral grains are aligned and compacted along with the bedding-parallel planes, the density of dissolution pores and the number of dissolution pores of small size in bedding-vertical specimens are usually larger than that in bedding-parallel specimens. For the shale samples with few natural microfractures, carbonate minerals may contribute to the generation and propagation of microfractures during hydration.Sun, L., Hao, X., Dou, H., Adenutsi, C.D., Li, Z., Zhang, Y., 2018. Co-optimization of oil recovery and CO2 storage for cyclic CO2 flooding in ultralow permeability reservoirs. Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles 73, Article 42. CO2 flooding is an efficient method to enhance oil recovery in ultralow permeability reservoirs. As the demand for low carbon economy development, co-optimization of CO2 storage and utilization should be considered. In this research, initially a comprehensive optimization method was proposed, which co-optimize oil recovery and CO2 storage by different weighting factors. Then, a series of core flooding experiments were performed using the core samples collected from Changqing oilfield, which is a ultralow permeability reservoir with heterogeneity and micro-cracks, CO2 injection parameters of slug size and Injection-Soaking Time Ratio (ISR) were optimized. The results revealed that the optimal injection parameters changed for different optimization objectives. In the case where equal important to oil recovery and CO2 storage were considered, the optimum CO2 injection parameters in the ultralow permeability reservoirs were 0.03PV for slug size and 1:1 for ISR. Comparing the method of oil recovery optimization (ω 1 = 1) to co-optimization of oil recovery and CO2 storage (ω 1 = ω 2 = 0.5), oil recovery was reduced by 8.93%, CO2 storage was significantly increased by 25.85%. The results provide an insight into parameter optimization of CO2 enhanced oil recovery design.Sundararajan, P., Tsuge, M., Baba, M., Lee, Y.-P., 2018. Infrared spectrum of protonated corannulene H+C20H10 in solid para-hydrogen and its potential contribution to interstellar unidentified infrared bands. ACS Earth and Space Chemistry 2, 1001-1010. aromatic hydrocarbons (PAH) and their derivatives, including protonated and cationic species, are suspected to be carriers of the unidentified infrared (UIR) emission bands observed from the galactic and extragalactic sources. We extended our investigations of infrared (IR) spectra of protonated planar PAH to a nonplanar PAH, corannulene (C20H10), which is regarded as a fragment of a fullerene, C60. The protonated corannulene H+C20H10 was produced on bombarding a mixture of corannulene and para-hydrogen (p-H2) with electrons during deposition at 3.2 K. During maintenance of the electron-bombarded matrix in darkness the intensities of IR lines of protonated corannulene decreased because of neutralization by electrons that were slowly released from the trapped sites. The observed lines were classified into two groups according to their responses to secondary irradiation at 365 nm. Eighteen lines in one group are assigned to the lowest-energy species among five possible isomers, hub-H+C20H10, and 17 in another group to rim-H+C20H10, the species of second lowest energy. Spectral assignments were derived based on a comparison of the observed spectra with those predicted with the B3PW91/6-311++G(2d,2p) method. The observed IR spectrum of hub-H+C20H10 resembles several bands of the Class-A UIR bands.Sungatullin, R.K., Bakhtin, A.I., Tsel’movich, V.A., Bakhmutov, V.G., Sungatullina, G.M., 2018. Middle Paleozoic impact event in the southwest of the East European Platform. Russian Geology and Geophysics 59, 1149-1160. zone with high remanent magnetization and magnetic susceptibility has been identified at the boundary between Lower Devonian gray- and red-colored deposits in the basin of the Dniester River in the southwest of Ukraine (in the southwest of the East European Platform). The microparticles of native iron and nickel and iron-nickel intermetallic compounds found here might be markers of an impact event in the Lochkovian (~415 Ma). Electron microscope examination and probe microanalysis of the chemical composition, morphology, structures, and textures of specific microobjects showed that they are the product of melting of meteoritic substance and target rocks caused by an impact explosion. Explosive dispersion and deposition of microparticles on the Earth’s surface result in a rapid differentiation of their substance. The obtained data can be used as evidence of a reference impact event during the fall of an iron-stone meteorite, and a characteristic set of minerals and geochemical parameters can help to identify catastrophic events in the geologic history.Takbiri-Borujeni, A., Fathi, E., Kazemi, M., Belyadi, F., 2019. An integrated multiscale model for gas storage and transport in shale reservoirs. Fuel 237, 1228-1243. paper presents a multi-scale modeling of gas transport in shale where techniques from micro- to macro-scale (Molecular dynamic simulations, lattice Boltzmann and multi-continuum) are integrated to achieve more accurate and robust simulation and prediction results. The formulation is then applied to pulse decay experiment to obtain shale core plug transport and storage parameters such as inorganic permeability and organic porosity and effective diffusion coefficient. The formulations governing gas transport and storage in dual porosity, single permeability shale model is validated in wide range of Knudsen number and flow regimes. In this new approach, shale organic matter is modeled using four different 3D molecular structure of type II Kerogen A, B, C, and D and a type III Kerogen A, with different Kerogen porosities and densities. The Equilibrium Molecular dynamics (EMD) simulations and Grand Canonical Monte Carlo (GCMC) are used to obtain the gas transport and adsorption parameters in different Kerogen structures, respectively. Meso-scale Lattice Boltzmann simulation is used to obtain gas transport parameters in inorganic matter of shale samples and the regularized 13-moment method is used for both inorganic matrix and natural fractures transport parameters and compared with LBM simulations. Next, the multi-continuum approach is used to integrate and describe gas transport and storage in multi-scale shale samples. The multi-continuum model developed is then used to history-match and predict Marcellus shale sample transport and storage parameters using pulse decay technique. The average parameters obtained from experiments and GCMC and EMD simulations will be used as external knowledge in our simulation based history-matching algorithm of pulse decay experiment to obtain shale organic and inorganic transport and storage parameters. Shale matrix permeability will be corrected for gas slippage using LBM and R13 AP results. The new formulation is compared with the previously published models simulating the gas dynamics in shale reservoirs. In this study, we show that gas transport and storage in micro-scale organic pores of shale matrix are nontrivial and significantly impact cumulative gas recovery from these unconventional reservoirs. Our unique integrated multiscale study (i.e., micro-scale molecular dynamics, meso-scale lattice Boltzmann simulation and multi-continuum macro-scale approach) showed the importance of developing external knowledge on different scales to obtain realistic parameter domains for gas transport and storage in shale reservoirs. This study is an important step for development of integrated multi-scale shale gas reservoir flow simulators and it has a practical importance on shale reservoir characterization specially quantifying the shale transport parameters using pulse decay technique.Tang, Z., Yang, S., Xu, G., Sharifzadeh, M., Zhai, C., 2018. Evolution law of adsorption and desorption characteristics of CH4 in coal masses during coalbed methane extraction. Energy & Fuels 32, 10540-10548. low-temperature oxidation of coal during coalbed methane extraction is inevitable. To study the evolution of the CH4 adsorption and desorption characteristics in coal masses during the low-temperature oxidation of coal, starting from the evolution of physical and chemical adsorption of CH4 in coal masses during the low-temperature oxidation of coal and combining it with the evolution of free radicals, we constructed a physical model of CH4 adsorption and desorption in the coalbed methane extraction process. This model provides the theoretical basis for improving the efficiency and quantity of coalbed methane extraction. Our results indicate that during coalbed methane extraction, the mesopores, macropores, and overall porosity increase with the rise in oxidation temperature. However, the number of micropores first increases and then decreases during the process, leading to the CH4 physical adsorption capacity showing a trend of first increasing and then decreasing with increasing oxidation temperature; however, the number of ?COOH groups shows the opposite trend to that of the number of micropores, resulting in the CH4 chemical adsorption capacity first decreasing and then increasing with the increase of the oxidation temperature; meanwhile, the free radical content increases gradually with the increasing oxidation temperature, leading to the continuous consumption of O2 adsorbed on the coal surface and the reinforcement of the CH4 adsorption capacity. To maximize coalbed methane extraction efficiency, it is necessary to take measures to avoid the low-temperature oxidation of coal at the initial stage.Tarique, M., Rahaman, W., 2018. Assessment of paleo-ocean pH records from boron isotope ratio in the Pacific and Atlantic ocean corals: Role of anthropogenic CO2 forcing and oceanographic factors to pH variability. Biogeosciences Discussions 2018, 1-37. isotopes (δ11B) records from tropical ocean corals have been used to reconstruct paleo-pH of ocean for the past several decades to few centuries which are comparable to the resolution of instrumental records. In most of the studies, attempts have been made to decipher the role of anthropogenic CO2 forcing to recent trend of ocean acidification based on δ11B derived paleo-pH records. However, such attempts in past were often hindered by limited knowledge of oceanographic factors that contributed to past pH variability and changes. In this study, we have evaluated pH records reconstructed using δ11B records from the Pacific and the Atlantic Oceans corals and investigated major forcing factors that contributed to sub annual-decadal scale pH variability and changes since the industrial era ~1850AD.To the best of our knowledge, total eight δ11B records from the Pacific and two from the Atlantic Oceans are available in published literatures. The compilations of these records show large variability; range between 26.27–20.82‰ which corresponds to pH range 8.40–7.63 respectively. Our investigation of pH records from the Pacific ocean based on principal component analysis (PCA) reveals that atmospheric CO2 can explains maximum up to ~26% of the total pH variability during 1950–2004AD, followed by the ocean-climate oscillations (i.e. ENSO and PDO) driven oceanographic factors up to ~17%. The remaining large variability (~57%) could not be explained by above forcing factors and hence we invoke possible influence of metabolic processes of corals and/or changes in micro-environments within the reefs which are often neglected in interpreting paleo-pH records. Therefore, we highlight the need for detailed investigation in future studies to understand about the exact mechanism, processes/factors that controlled boron isotope fractionations in coral reef environments. Further, our investigation reveals that amplitude of the ENSO driven pH variability shows fivefold increase during 1980–2000AD compared to the previous three decades (1950–1980AD). This observation is consistent with the historical records of global coral bleaching events and therefore underscores role of ENSO driven environmental stress responsible for coral bleaching events. Considering model based projections of increasing frequency and amplitude of extreme ENSO events in the backdrop of recent global warming, bleaching events are likely to increase in the next decades/centuries.Tarnovetskii, I.Y., Merkel, A.Y., Kanapatskiy, T.A., Ivanova, E.A., Gulin, M.B., Toshchakov, S., Pimenov, N.V., 2018. Decoupling between sulfate reduction and the anaerobic oxidation of methane in the shallow methane seep of the Black sea. FEMS Microbiology Letters 365, Article fny235. seepages are widespread in the Black Sea. However, microbiological research has been carried out only at the continental shelf seeps. The present work dealt with coastal gas seepages of the Kalamit Bay (Black Sea). High-throughput 16S rRNA gene sequencing and radiotracer analysis (14С and 35S) were used to determine the composition of the microbial community and the rates of microbial sulfate reduction and methane oxidation. The phylum Proteobacteria, represented mainly by sulfate reducers of the class Deltaproteobacteria, was the predominant in sequence dataset. Bacteroidetes and Planctomycetes were other numerous phyla. Among archaea, the phylum Woesearchaeota and Marine Benthic Group B were predominant in the upper horizons. Relative abundance of Euryarchaeota of the families Methanomicrobiaceae and Methanosarcinaceae (including ANME-3 archaea) increased in deeper sediment layers. Sulfate reduction rate (up to 2.9 mmol/L × day) was considerably higher than the rate of anaerobic methane oxidation (up to 43.4 μmol/L × day), which indicated insignificant contribution of anaerobic methane oxidation to the total sulfide production.Taylor, M.A., Celis, G., Ledman, J.D., Bracho, R., Schuur, E.A.G., 2018. Methane efflux measured by eddy covariance in Alaskan upland tundra undergoing permafrost degradation. Journal of Geophysical Research: Biogeosciences 123, 2695-2710. gas emissions from thawing permafrost in arctic ecosystems may amplify global warming, yet estimates of the rate of carbon release, and the proportion of carbon released as methane (CH4) or carbon dioxide (CO2), have a high degree of uncertainty. There are many areas where no measurements exist, and few year‐round or long‐term records. Existing year‐round eddy covariance measurements of arctic CH4 fluxes suggest that nongrowing season emissions make up a significant proportion of tundra systems emissions on an annual basis. Here we present continuous CH4 flux measurements made at Eight Mile Lake, an upland tundra ecosystem undergoing permafrost degradation in Interior Alaska. We found net CH4 emissions throughout the year (1.2 ? 0.011 g C‐CH4 m2/yr) that made up 61% of total radiative forcing from annual C emissions (CO2 and CH4; 32.3 g C m2/yr) when taking into account the greenhouse warming potential of CH4 relative to CO2. Nongrowing season emissions accounted for 50% of the annual CH4 budget, characterized by large pulse emissions. These were related to abrupt increases in air and shallow soil temperatures rather than consistent emissions during the zero curtain—a period of the fall/early winter season when subsurface soil temperatures remain near the 0 °C freezing point. Weekly growing season CH4 emissions in 2016 and 2017 were significantly related with thaw depth, and the magnitude of CH4 emissions between these seasons was proportional to the rate of active layer thaw throughout the season. Teichert, B.M.A., Chevalier, N., Gussone, N., Bayon, G., Ponzevera, E., Ruffine, L., Strauss, H., 2018. Sulfate-dependent anaerobic oxidation of methane at a highly dynamic bubbling site in the Eastern Sea of Marmara (?inarcik Basin). Deep Sea Research Part II: Topical Studies in Oceanography 153, 79-91. the MARSITECruise expedition in November 2014 on board the RV Pourquoi Pas?, multidisciplinary sampling was carried out with the ROV Victor 6000 in order to investigate biogeochemical processes taking place at cold seep environments in the Sea of Marmara. Pore water, bottom water, sediment and authigenic carbonate samples were collected from two short push cores (MRS-DV5-PC04 ? 8 cm, MRS-DV5-PC01 ? 12.5 cm) at an active methane bubbling site in the southeastern part of the ?inarcik Basin. Sulfate sulfur and oxygen isotope data as well as sulfide isotope data indicate that sulfate-dependent anaerobic oxidation of methane is the dominant process in the sediments. This is confirmed by archaeal lipids diagnostic for anaerobic methane oxidizers detected with strong 13C-depletions. The available data even allows to distinguish the dominant AOM assemblages. Specific lipid patterns are consistent with a dominance of ANME-2 archaea within the microbial community. Abundant authigenic carbonates (mostly aragonite), found at all depths, show a narrow range in δ13C values between ?27.69‰ and ?33.40‰. The carbon isotopic composition of the dissolved inorganic carbon as well as strontium and calcium isotopes confirm that the current reaction zone (sulfate-methane transition zone) starts at the bottom of the core. All shallower carbonates are witnesses of paleo seepage activity. U-Th dating of four pure aragonite samples show the short time span that is preserved in core MRS-DV5-PC01 (235 ± 60 yr B.P.). Two major earthquakes of 1766 AD and 1754 AD in the ?inarcik Basin might potentially have triggered the increased seepage of methane at this location.Textor, S.R., Guillemette, F., Zito, P.A., Spencer, R.G.M., 2018. An assessment of dissolved organic carbon biodegradability and priming in blackwater systems. Journal of Geophysical Research: Biogeosciences 123, 2998-3015. deliver approximately 260?Tg of dissolved organic carbon (DOC) to the ocean annually, yet there is little evidence of terrigenous DOC (tDOC) in the ocean. While tDOC was historically believed to be stable and resistant to microbial degradation, it has recently been shown that freshwater systems mineralize more tDOC than originally thought. The priming effect is a possible mechanism by which inputs of biolabile DOC enhance the bioavailability of stable DOC components in aquatic systems, resulting in higher rates of microbial remineralization. Here we investigate tDOC biodegradability by conducting bioincubation experiments and utilizing ultrahigh resolution mass spectrometry to characterize the chemical composition of blackwater and leachate dissolved organic matter (DOM) samples. The role of priming in blackwater ecosystems was assessed through the inclusion of bioincubation treatments amended with a variety of simple biolabile OC substrates. Blackwaters lost 6.10?±?3.85% DOC within 1?month, while leachates lost 38.10?±?16.74% DOC. There were no significant differences between DOC remineralization in control and primed treatments, indicating that priming is not an important factor in the biodegradation of DOC in blackwater ecosystems. However, the proportion of biodegradable DOC and DOM composition were significantly correlated, mostly driven by the contribution of aliphatic compounds (H/C?≥?1.5, O/C?<?0.9) that were abundant (9.3?±?5.2%) in leachate DOM. The molecular signature of biodegraded leachate DOM resembled that of stable blackwater DOM, indicating that bioavailable DOM components leached from plant litter are rapidly utilized and stable DOM is exported downstream.Thelen, A.E., Nixon, C.A., Chanover, N.J., Cordiner, M.A., Molter, E.M., Teanby, N.A., Irwin, P.G.J., Serigano, J., Charnley, S.B., 2019. Abundance measurements of Titan’s stratospheric HCN, HC3N, C3H4, and CH3CN from ALMA observations. Icarus 319, 417-432. investigations have employed more than 100 close observations of Titan by the Cassini orbiter to elucidate connections between the production and distribution of Titan’s vast, organic-rich chemical inventory and its atmospheric dynamics. However, as Titan transitions into northern summer, the lack of incoming data from the Cassini orbiter presents a potential barrier to the continued study of seasonal changes in Titan’s atmosphere. In our previous work (Thelen et al., 2018), we demonstrated that the Atacama Large Millimeter/submillimeter Array (ALMA) is well suited for measurements of Titan’s atmosphere in the stratosphere and lower mesosphere (～100?500 km) through the use of spatially resolved (beam sizes ?<?1′′) flux calibration observations of Titan. Here, we derive vertical abundance profiles of four of Titan’s trace atmospheric species from the same 3 independent spatial regions across Titan’s disk during the same epoch (2012–2015): HCN, HC3N, C3H4, and CH3CN. We find that Titan’s minor constituents exhibit large latitudinal variations, with enhanced abundances at high latitudes compared to equatorial measurements; this includes CH3CN, which eluded previous detection by Cassini in the stratosphere, and thus spatially resolved abundance measurements were unattainable. Even over the short 3-year period, vertical profiles and integrated emission maps of these molecules allow us to observe temporal changes in Titan’s atmospheric circulation during northern spring. Our derived abundance profiles are comparable to contemporary measurements from Cassini infrared observations, and we find additional evidence for subsidence of enriched air onto Titan’s south pole during this time period. Continued observations of Titan with ALMA beyond the summer solstice will enable further study of how Titan’s atmospheric composition and dynamics respond to seasonal changes.Thompson, M.S., Loeffler, M.J., Morris, R.V., Keller, L.P., Christoffersen, R., 2019. Spectral and chemical effects of simulated space weathering of the Murchison CM2 carbonaceous chondrite. Icarus 319, 499-511. performed pulsed-laser irradiation of a chip of the CM2 Murchison carbonaceous chondrite meteorite to simulate micrometeorite impacts on carbonaceous asteroids. Optical reflectance spectroscopy and transmission electron microscopy were performed to characterize the unirradiated and irradiated samples and vapor and melt deposits collected on a glass slide ～7?mm from the surface of the sample. The spectrum of the deposit on the glass slide shows a red slope between 0.35–2.5 ??m, while the irradiated surface of the meteorite shows only slight darkening over the same spectral range. We identified predominant melt products and vesiculated textures in the glass slide deposit, in the fine-grained matrix of the meteorite, and in individual mineral phases of the meteorite chip. Extracted focused ion beam (FIB) sections from the matrix material, an olivine grain, a pentlandite grain, and from the glass slide deposit were analyzed by scanning transmission electron microscopy (STEM). Microstructural and chemical analyses based on the STEM observations show widespread melting and the formation of Fe-bearing nanoparticles (including prevalent Fe–Ni–sulfides) across the surface of the meteorite. The section extracted from the glass slide revealed nanoparticles embedded in a chemically and microstructurally complex deposit, which likely formed as a result of both melting and vaporization processes. These analyses reveal a significantly more compositionally diverse population of nanoparticles compared to what is observed in lunar or ordinary chondritic space weathered samples. We discuss the implications these results have for the space weathering of carbonaceous asteroids and their importance for understanding the surface processes on primitive bodies.Tian, X., Zhang, G., Shao, Y., Yang, Z., 2018. Towards enhanced metabolomic data analysis of mass spectrometry image: Multivariate Curve Resolution and Machine Learning. Analytica Chimica Acta 1037, 211-219. amounts of data are generally produced from mass spectrometry imaging (MSI) experiments in obtaining the molecular and spatial information of biological samples. Traditionally, MS images are constructed using manually selected ions, and it is very challenging to comprehensively analyze MSI results due to their large data sizes and highly complex data structures. To overcome these barriers, it is obligatory to develop advanced data analysis approaches to handle the increasingly large MSI data. In the current study, we focused on the method development of using Multivariate Curve Resolution (MCR) and Machine Learning (ML) approaches. We aimed to effectively extract the essential information present in the large and complex MSI data and enhance the metabolomic data analysis of biological tissues. Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) algorithm was used to obtain major patterns of spatial distribution and grouped metabolites with the same spatial distribution patterns. In addition, both supervised and unsupervised ML methods were established to analyze the MSI data. In the supervised ML approach, Random Forest method was selected, and the model was trained using the selected datasets based on the distribution pattern obtained from MCR-ALS analyses. In the unsupervised ML approach, both DBSCAN (Density-based Spatial Clustering of Applications with Noise) and CLARA (Clustering Large Applications) were applied to cluster the MSI datasets. It is worth noting that similar patterns of spatial distribution were discovered through MSI data analysis using MCR-ALS, supervised ML, and unsupervised ML. Our protocols of data analysis can be applied to process the data acquired using many other types of MSI techniques, and to extract the overall features present in MSI results that are intractable using traditional data analysis approaches.Tobimatsu, Y., Schuetz, M., 2019. Lignin polymerization: how do plants manage the chemistry so well? Current Opinion in Biotechnology 56, 75-81. final step of lignin biosynthesis is the polymerization of monolignols in apoplastic cell wall domains. In this process, monolignols secreted by lignifying cells, or occasionally neighboring non-lignifying and/or other lignifying cells, are activated by cell-wall-localized oxidation systems, such as laccase/O2 and/or peroxidase/H2O2, for combinatorial radical coupling to make the final lignin polymers. Plants can precisely control when, where, and which types of lignin polymers are assembled at tissue and cellular levels, but do not control the polymers’ exact chemical structures per se. Recent studies have begun to identify specific laccase and peroxidase proteins responsible for lignin polymerization in specific cell types and during different developmental stages. The coordination of polymerization machinery localization and monolignol supply is likely critical for the spatio-temporal patterning of lignin polymerization. Further advancement in this research area will continue to increase our capacity to manipulate lignin content/structure in biomass to meet our own biotechnological purposes.Trail, D., Boehnke, P., Savage, P.S., Liu, M.-C., Miller, M.L., Bindeman, I., 2018. Origin and significance of Si and O isotope heterogeneities in Phanerozoic, Archean, and Hadean zircon. Proceedings of the National Academy of Sciences 1115, 10287-10292. Significance: The crust or its chemically weathered derivatives likely served as a substrate for the origin of life, which could have occurred by 4.1 Ga. Yet no known bona fide terrestrial rocks from this time remain. Studies have thus turned to geochemical signatures within detrital zircons from this time. While zircons do not directly record low-temperature weathering processes, they inherit isotopic information upon recycling and remelting of sediment. We developed a method to fingerprint the identity of material involved in water–rock interactions >4 Ga, bolstered by a large Si and O isotopic dataset of more modern zircon samples. The data presented here provide evidence for chemical sediments, such as cherts and banded iron formations on Earth >4 Ga.Abstract: Hydrosphere interactions and alteration of the terrestrial crust likely played a critical role in shaping Earth’s surface, and in promoting prebiotic reactions leading to life, before 4.03 Ga (the Hadean Eon). The identity of aqueously altered material strongly depends on lithospheric cycling of abundant and water-soluble elements such as Si and O. However, direct constraints that define the character of Hadean sedimentary material are absent because samples from this earliest eon are limited to detrital zircons (ZrSiO4). Here we show that concurrent measurements of Si and O isotope ratios in Phanerozoic and detrital pre-3.0 Ga zircon constrain the composition of aqueously altered precursors incorporated into their source melts. Phanerozoic zircon from (S)edimentary-type rocks contain heterogeneous δ18O and δ30Si values consistent with assimilation of metapelitic material, distinct from the isotopic character of zircon from (I)gneous- and (A)norogenic-type rocks. The δ18O values of detrital Archean zircons are heterogeneous, although yield Si isotope compositions like mantle-derived zircon. Hadean crystals yield elevated δ18O values (vs. mantle zircon) and δ30Si values span almost the entire range observed for Phanerozoic samples. Coupled Si and O isotope data represent a constraint on Hadean weathering and sedimentary input into felsic melts including remelting of amphibolites possibly of basaltic origin, and fractional addition of chemical sediments, such as cherts and/or banded iron formations (BIFs) into source melts. That such sedimentary deposits were extensive enough to change the chemical signature of intracrustal melts suggests they may have been a suitable niche for (pre)biotic chemistry as early as 4.1 Ga.Trimpin, S., Pophristic, M., Adeniji-Adele, A., Tomsho, J.W., McEwen, C.N., 2018. Vacuum matrix-assisted ionization source offering simplicity, sensitivity, and exceptional robustness in mass spectrometry. Analytical Chemistry 90, 11188-11192. matrix-assisted ionization (vMAI) uses select matrix compounds which when exposed to the vacuum of a mass spectrometer produce gas-phase ions from associated volatile or nonvolatile analyte without external energy input. Here, a vMAI source was constructed to replace the commercial inlet of a Thermo Orbitrap mass spectrometer. This allowed for rapid introduction of the matrix/analyte sample by a probe, contrary to vacuum matrix-assisted laser desorption/ionization (MALDI) sources. The matrix/analyte sample is inserted into a region of the “S-lens” entrance, where the spontaneously formed ions can be effectively transferred to the mass analyzer. This specifically designed ion source requires no laser, high voltage, heat, or nebulizing gases. A low voltage is used to transmit the ions through the commercial “S-lens” assembly and airflow can be used to modulate the ionization event. A few picograms of the drug erythromycin, assisted by the 3-nitrobenzonitrile vMAI matrix, is sufficient to produce mass spectra for over 1 min with the MH+ ion as the base peak in each mass spectrum. There is minimal carryover when loading high concentration samples and complex mixtures, contrary to direct infusion electrospray ionization, providing the probe is thoroughly cleaned between each new sample acquisition. Analyses of biological fluids, bacterial extracts, tissue, and high concentration samples have so far shown no indication of inlet or instrument contamination with these samples. The typical ultrahigh resolution and mass accuracy of the mass spectrometer are achieved, and a path forward to potential high throughput acquisitions demonstrated. It is expected that robustness can be introduced to any mass spectrometer through implementation of such a simple source.Trindade, G.F., Abel, M.-L., Watts, J.F., 2018. simsMVA: A tool for multivariate analysis of ToF-SIMS datasets. Chemometrics and Intelligent Laboratory Systems 182, 180-187. mass spectrometry datasets are every year larger and more complex, with unsupervised multivariate analysis (MVA) becoming a routine procedure for most researchers. Moreover, the increasing interdisciplinarity of the field demands the development of software for rapid and accessible MVA for researchers of various backgrounds. This paper presents a MATLAB-based software for performing principal component analysis (PCA), non-negative matrix factorisation (NMF) and k-means clustering of large analytical chemistry datasets with a particular focus on of time-of-flight secondary ions mass spectrometry (ToF-SIMS). All five modes of operation (spectra, profiles, images, 3D and multi) are described with a few examples of typical applications at The Surface Analysis Laboratory of the University of Surrey: point spectra analysis of wood growth regions, depth profiling of a metallic multi-layered sample, imaging of an organic coating on a metal substrate and 3D characterisation of an automotive grade polypropylene.Tzedakis, P.C., Drysdale, R.N., Margari, V., Skinner, L.C., Menviel, L., Rhodes, R.H., Taschetto, A.S., Hodell, D.A., Crowhurst, S.J., Hellstrom, J.C., Fallick, A.E., Grimalt, J.O., McManus, J.F., Martrat, B., Mokeddem, Z., Parrenin, F., Regattieri, E., Roe, K., Zanchetta, G., 2018. Enhanced climate instability in the North Atlantic and southern Europe during the Last Interglacial. Nature Communications 9, Article 4235. ambiguity remains over the extent and nature of millennial/centennial-scale climate instability during the Last Interglacial (LIG). Here we analyse marine and terrestrial proxies from a deep-sea sediment sequence on the Portuguese Margin and combine results with an intensively dated Italian speleothem record and climate-model experiments. The strongest expression of climate variability occurred during the transitions into and out of the LIG. Our records also document a series of multi-centennial intra-interglacial arid events in southern Europe, coherent with cold water-mass expansions in the North Atlantic. The spatial and temporal fingerprints of these changes indicate a reorganization of ocean surface circulation, consistent with low-intensity disruptions of the Atlantic meridional overturning circulation (AMOC). The amplitude of this LIG variability is greater than that observed in Holocene records. Episodic Greenland ice melt and runoff as a result of excess warmth may have contributed to AMOC weakening and increased climate instability throughout the LIG.Ulmer, C.Z., Jones, C.M., Yost, R.A., Garrett, T.J., Bowden, J.A., 2018. Optimization of Folch, Bligh-Dyer, and Matyash sample-to-extraction solvent ratios for human plasma-based lipidomics studies. Analytica Chimica Acta 1037, 351-357. order to profile the lipidome for untargeted lipidomics applications, analysis by ultra-high performance liquid chromatography – high resolution mass spectrometry (UHPLC-HRMS) typically requires the extraction of lipid content from sample matrices using matrix-specific conditions. The Folch, Bligh-Dyer, and Matyash extraction methods, while promising approaches, were originally tailored to specific matrices (brain tissue, fish muscle, and E.?coli, respectively). Each of these methods have specific solvent ratios that must be adhered to achieve optimal extraction. Thus, the sample-to-solvent ratios for these methods should be optimized for the sample matrix of interest prior to employment. This study evaluated the appropriate sample-to-extraction solvent ratios for human plasma-based lipidomics studies. An advantage of employing biphasic lipid extractions is the ability to investigate both the aqueous and organic layers for increased analyte coverage in untargeted studies. Therefore, this work also evaluated the multi-omic capability of each lipid extraction method for plasma in an effort to provide a workflow capable of increasing analyte coverage in a single extraction, thus providing a more complete understanding of complex biological systems. In plasma, a decrease in sample-to-solvent ratios from 1:4, 1:10, 1:20, to 1:100 (v/v) resulted in a gradual increase in the peak area of a diverse range of metabolite (aqueous layer) and lipid (organic layer) species for each extraction method up to the 1:20(v/v) sample-to-solvent ratio. The Bligh-Dyer and Folch methods yielded the highest peak areas at every plasma sample-to-solvent ratios for both metabolite and lipid species. Depending on the lipid class of interest, the Folch or Bligh-Dyer method is best suited for analysis of human plasma at a 1:20 (v/v) sample to total solvent ratio.Valenzuela, E.I., Avenda?o, K.A., Balagurusamy, N., Arriaga, S., Nieto-Delgado, C., Thalasso, F., Cervantes, F.J., 2019. Electron shuttling mediated by humic substances fuels anaerobic methane oxidation and carbon burial in wetland sediments. Science of The Total Environment 650, 2674-2684. pathways for the anaerobic oxidation of methane (AOM) have remained elusive, particularly in organic rich ecosystems. In this work, the occurrence of AOM driven by humus-catalyzed dissimilatory iron reduction was investigated in sediments from a coastal mangrove swamp. Anoxic sediment incubations supplied with both goethite (α-FeOOH) and leonardite (humic substances (HS)) displayed an average AOM rate of 10.7?±?0.8?μmol?CH4?cm?3?day?1, which was 7 and 3 times faster than that measured in incubations containing only goethite or HS, respectively. Additional incubations performed with 13C-methane displayed Pahokee Peat HS-mediated carbonate precipitation linked to 13CH4 oxidation and ferrihydrite reduction (~1.3?μmol?carbonate?cm?3?day?1). These results highlight the role of HS on mitigating greenhouse gases released from wetlands, not only by mediating the AOM process, but also by enhancing carbon sequestration as inert minerals (calcite, aragonite and siderite).Vallino, J.J., Huber, J.A., 2018. Using maximum entropy production to describe microbial biogeochemistry over time and space in a meromictic pond. Frontiers in Environmental Science 6, 100. doi: 10.3389/fenvs.2018.00100. how microbial communities organize and function at the ecosystem level is essential to understanding and predicting how they will respond to environmental change. Mathematical models can be used to describe these communities, but properly representing all the biological interactions in extremely diverse natural microbial ecosystems in a mathematical model is challenging. We examine a complementary approach based on the maximum entropy production (MEP) principle, which proposes that systems with many degrees of freedom will likely organize to maximize the rate of free energy dissipation. In this study, we develop an MEP model to describe biogeochemistry observed in Siders Pond, a phosphate limited meromictic system located in Falmouth, MA that exhibits steep chemical gradients due to density-driven stratification that supports anaerobic photosynthesis as well as microbial communities that catalyze redox cycles involving O, N, S, Fe and Mn. The MEP model uses a metabolic network to represent microbial redox reactions, where biomass allocation and reaction rates are determined by solving an optimization problem that maximizes entropy production over time, and a 1D vertical profile constrained by an advection-dispersion-reaction model. We introduce a new approach for modeling phototrophy and explicitly represent oxygenic photoautotrophs, photoheterotrophs and anoxygenic photoautotrophs. The metabolic network also includes reactions for aerobic organoheterotrophic bacteria, sulfate reducing bacteria, sulfide oxidizing bacteria and aerobic and anaerobic grazers. Model results were compared to observations of biogeochemical constituents collected over a 24 hour period at 8 depths at a single 15 m deep station in Siders Pond. Maximizing entropy production over long (3 day) intervals produced results more similar to field observations than short (0.25 day) interval optimizations, which support the importance of temporal strategies for maximizing entropy production over time. Furthermore, we found that entropy production must be maximized locally instead of globally where energy potentials are degraded quickly by abiotic processes, such as light absorption by water. This combination of field observations and modeling results indicate that natural microbial systems can be modeled by using the maximum entropy production principle applied over time and space using many fewer parameters than conventional models.Van Kranendonk, M.J., Bennett, V.C., Hoffmann, J.E., 2019. Earth's Oldest Rocks, 2nd Edition. Elsevier, p. 1112.Earth’s Oldest Rocks, Second Edition, is the only single reference source for geological research of early Earth. This new edition is an up-to-date collection of scientific articles on all aspects of the early history of the Earth, from planetary accretion at 4.567 billion years ago (Ga), to the onset of modern-style plate tectonics at 3.2 Ga. Since the first edition was published, significant new advances have been made in our understanding of events and processes on early Earth that correspond with new advances in technology. The book includes contributions from over 100 authors, all of whom are experts in their respective fields.The research in this reference concentrates on what is directly gleaned from the existing rock record to understand how our planet formed and evolved during the planetary accretion phase, formation of the first crust, the changing dynamics of the mantle and style of tectonics, life’s foothold and early development, and mineral deposits. It is an ideal resource for academics, students and the general public alike.Key FeaturesFeatures more than 150 pages of new material, including new chapters on topics like early solar system materials, oldest evidence of life on Earth, and modelling early tectonicsContains comprehensive reviews of areas of ancient lithosphere on Earth, of planetary accretion processes, and of meteoritesFocuses on specific aspects of early Earth, including the oldest putative life forms, evidence of the composition of the ancient atmosphere-hydrosphere, and the oldest evidence for subduction-accretionPresents an overview of geological processes and a model of the tectonic framework of early EarthSection I: Getting StartedChapter 1 - Early Solar System Materials, Processes, and Chronology. Yuri Amelin, Pages 3-26Chapter 2 - Origin of the Earth and the Late Heavy Bombardment, Marc D. Norman, Pages 27-47Chapter 3 - Early Earth Atmosphere and Oceans, James F. Kasting, Pages 49-61Section II: Overviews of Early Earth ProcessesChapter 4 - Modeling Early Earth Tectonics: The Case for Stagnant Lid Behavior, Craig O'Neill, Siqi Zhang, Pages 65-80Chapter 5 - The Earliest Subcontinental Lithospheric Mantle, William L. Griffin, Suzanne Y. O'Reilly, Pages 81-102Chapter 6 - Distribution and Geochemistry of Komatiites and Basalts Through the Archean, Stephen J. Barnes, Nicholas T. Arndt, Pages 103-132Chapter 7 - The Formation of Tonalites–Trondjhemite–Granodiorites in Early Continental Crust, J. Elis Hoffmann, Chao Zhang, Jean-Francois Moyen, Thorsten J. Nagel, Pages 133-168Chapter 8 - Archean Asteroid Impacts on Earth: Stratigraphic and Isotopic Age Correlations and Environmental Consequences, Alexandra Krull Davatzes, Steven Goderis, Bruce M. Simonson, Pages 169-185Chapter 9 - Paleoarchean (3.6–3.2 Ga) Mineral Systems in the Context of Continental Crust Building and the Role of Mantle Plumes, Franco Pirajno, David L. Huston, Pages 187-209Chapter 10 - Origin of Paleoarchean Sulfate Deposits, Pascal Philippot, Elodie Muller Claire Rollion-Bard, Pages 211-235Section III: The Most Ancient RemnantsChapter 11 - Earth's Oldest Rocks and Minerals, Kent C. Condie, Pages 239-253Chapter 12 - The Oldest Terrestrial Mineral Record: Thirty Years of Research on Hadean Zircon From Jack Hills, Western Australia, Aaron J. Cavosie, John W. Valley, Simon A. Wilde, Pages 255-278Chapter 13 - Evidence of Hadean to Paleoarchean Crust in the Youanmi and South West Terranes, and Eastern Goldfields Superterrane of the Yilgarn Craton, Western Australia, Stephen Wyche, Yongjun Lu, Michael T.D. Wingate, Pages 279-292Chapter 14 - Hadean to Paleoarchean Rocks and Zircons in China, Yusheng Wan, Hangqiang Xie, Chunyan Dong, Alfred Kr?ner, Simon A. Wilde, Wenqian Bai, Shoujie Liu, Shiwen Xie, Mingzhu Ma, Yuan Li, Dunyi Liu, Pages 293-327Chapter 15 - The Acasta Gneiss Complex, Jesse R. Reimink, Ann M. Bauer, Thomas Chacko, Pages 329-347Chapter 16 - The Nuvvuagittuq Greenstone Belt: A Glimpse of Earth's Earliest Crust, Jonathan O'Neil, Richard W. Carlson, Dominic Papineau, Evelyn Y. Levine, Don Francis, Pages 349-374Chapter 17 - The 3.9–3.6 Ga Itsaq Gneiss Complex of Greenland, Allen P. Nutman, Vickie C. Bennett, Pages 375-399Chapter 18 - The Narryer Terrane, Yilgarn Craton, Western Australia: Review and Recent Developments, Allen P. Nutman, Vickie C. Bennett, Pages 401-433Section IV: Well-Preserved Granitoid- Greenstone TerrainsChapter 19 - Paleoarchean Development of a Continental Nucleus: The East Pilbara Terrane of the Pilbara Craton, Western Australia, Martin J. Van Kranendonk, Robert H. Smithies, David C. Champion, Pages 437-462Chapter 20 - The Oldest Well-Preserved Felsic Volcanic Rocks on Earth: Geochemical Clues to the Early Evolution of the Pilbara Supergroup and Implications for the Growth of a Paleoarchean Protocontinent, Robert H. Smithies, David C. Champion, Martin J. Van Kranendonk, Pges 463-486Chapter 21 - Geochemistry of Paleoarchean Granites of the East Pilbara Terrane, Pilbara Craton, Western Australia: Implications for Early Archean Crustal Growth, David C. Champion, Robert H. Smithies, Pages 487-518Chapter 22 - Paleoarchean Mineral Deposits of the Pilbara Craton: Genesis, Tectonic Environment, and Comparisons With Younger Deposits, David L. Huston, Franco Pirajno, Peter Morant, Brendan Cummins, Darcy Baker, Terrence P. Mernagh, Pges 519-551Chapter 23 - Early Archean Crustal Evolution in Southern Africa—An Updated Record of the Ancient Gneiss Complex of Swaziland, J. Elis Hoffmann, Alfred Kr?ner, Pages 553-567Chapter 24 - Geologic Evolution of the Barberton Greenstone Belt—A Unique Record of Crustal Development, Surface Processes, and Early Life 3.55–3.20 Ga, Gary R. Byerly, Donald R. Lowe, Christoph Heubeck, Pages 569-613Chapter 25 - TTG Plutons of the Barberton Granitoid-Greenstone Terrain, South Africa, Jean-Francois Moyen, Gary Stevens, Alexander F.M. Kisters, Richard W. Belcher, Baptiste Lemirre, Pages 615-653Chapter 26 - Tectonometamorphic Controls on Archaean Gold Mineralization in the Barberton Greenstone Belt, South Africa, Annika Dziggel, Alexander F.M. Kisters, Pages 655-674Section V: Filling the GapsChapter 27 - Paleoarchean Gneisses in the Minnesota River Valley and Northern Michigan, USA, Marion E. Bickford, Aaron M. Satkoski, Scott D. Samson, Joseph L. Wooden, Robert L. Bauer, Mark D. Schmitz, Paul A. Mueller, George D. Kamenov, Pages 677-702Chapter 28 - The Assean Lake Complex: Ancient Crust at the Northwestern Margin of the Superior Craton, Manitoba, Canada, Christian O. B?hm, Russell P. Hartlaub, Larry M. Heaman, Nicole Cates, Martin Guitreau, Bernard Bourdon, Antoine S.G. Roth, Stephen J. Mojzsis, Janne Blichert-Toft, Pages 703-722Chapter 29 - Oldest Rocks of the Wyoming Craton, Kevin R. Chamberlain, Paul A. Mueller, Pages 723-739Chapter 30 - Early Crustal Evolution as Recorded in the Granitoids of the Singhbhum and Western Dharwar Cratons, Sukanta Dey, Aniruddha Mitra, Jinia Nandy, Sudipto Mondal, Abhishek Topno, Yongsheng Liu,Keqing Zong, Pages 741-792Chapter 31 - Paleoarchean Crustal Evolution of the Bundelkhand Craton, North Central India, Pritam Nasipuri, Lopamudra Saha, Xie Hangqiang, Jayanta K. Pati, Manavan Satyanaryanan, Saheli Sarkar, Ankit Bhandari, Yashvardhan Gaur, Pages 793-817Chapter 32 - Paleoarchean Rocks in the Fennoscandian Shield, Pentti H?ltt?, Esa Heilimo, Hannu Huhma, Asko Kontinen, Laura Lauri, Alexandr Slabunov, Pges 819-835Chapter 33 - Archean Crustal Evolution in the Ukrainian Shield, Stefan Claesson, Gennadiy Artemenko, Svetlana Bogdanova, Leonid Shumlyanskyy, Pages 837-854Chapter 34 - The Paleoarchean Record of the Zimbabwe Craton, Axel Hofmann, Godfrey Chagondah, Pages 855-864Chapter 35 - Ancient Antarctica: The Archean of the East Antarctic Shield, Simon L. Harley, Nigel M. Kelly, Monika A. Kusiak, Pages 865-897Section VI: LifeChapter 36 - Implications of Carbonate and Chert Isotope Records for the Early Earth, Graham A. Shields, Pages 901-912Chapter 37 - Archean Cherts: Formation Processes and Paleoenvironments, Morgane Ledevin, Pages 913-944Chapter 38 - The Significance of Carbonaceous Matter to Understanding Life Processes on Early Earth, Mark A. van Zuilen, Pages 945-963Chapter 39 - Eoarchean Life From the Isua Supracrustal Belt (Greenland), Allen P. Nutman, Vickie C. Bennett, Clark R.L. Friend, Pages 965-983Chapter 40 - Depositional Setting of the Fossiliferous, c.3480 Ma Dresser Formation, Pilbara Craton: A Review, Martin J. Van Kranendonk, Tara Djokic, Greg Poole, Sahand Tadbiri, Luke Steller, Raphael Baumgartner, Pages 985-1006Chapter 41 - Early Archean (Pre-3.0Ga) Cellularly Preserved Microfossils and Microfossil-Like Structures From the Pilbara Craton, Western Australia—A Review, Kenichiro Sugitani, Pages 1007-1028Chapter 42 - Traces of Early Life From the Barberton Greenstone Belt, South Africa, Keyron Hickman-Lewis, Frances Westall, Barbara Cavalazzi, Pages 1029-1058Van Kranendonk, M.J., Djokic, T., Poole, G., Tadbiri, S., Steller, L., Baumgartner, R., 2019. Chapter 40 - Depositional setting of the fossiliferous, c.3480Ma Dresser Formation, Pilbara Craton: A review, in: Van Kranendonk, M.J., Bennett, V.C., Hoffmann, J.E. (Eds.), Earth's Oldest Rocks (Second Edition). Elsevier, pp. 985-1006. this chapter we summarize the depositional setting and occurrences of life traces within the 3.48Ga Dresser Formation of the Pilbara Craton, Western Australia. All fossiliferous and chemical traces of life occur with the lowermost of two chert units within the Dresser Formation, known as the North Pole chert. This is separated from an overlying, nonfossiliferous chert unit of the formation by a unit of pillowed and massive basalt. Highly morphologically varied stromatolites of assemblage 2 occur in shallow water conditions, including lacustrine, fluvial, and terrestrial hot spring settings. The recent discovery of geyserite and other sinter deposits containing biosignatures shows that life inhabited a terrestrial setting much earlier than previously thought. A range of evidence points to diverse life at this time that occupied several distinct niches using, probably, a variety of metabolisms.van Zuilen, M.A., 2019. Chapter 38 - The significance of carbonaceous matter to understanding life processes on early Earth, in: Van Kranendonk, M.J., Bennett, V.C., Hoffmann, J.E. (Eds.), Earth's Oldest Rocks (Second Edition). Elsevier, pp. 945-963. material (CM) found in metamorphosed Archean rocks may represent the altered remains of ancient (i.e., syndepositional) organisms, the product of abiologic synthesis, migrated bitumen from younger rocks, or the degraded remnants of modern endolithic microorganisms. Here, a general summary is presented of CM formation processes that can generate abiotic CM, followed by a description of three well-known controversies on the origin of Archean CM. These include CM found in the 3.9Ga Akilia association in southern West Greenland, the 3.7Ga Isua supracrustal belt (ISB)of southern West Greenland, and the 3.5Ga Apex chert, Pilbara, Western Australia. Based on these controversies, a set of criteria are presented for identification of biogenic CM in Archean rocks. Biogenic CM should be syngenetic with the rock (e.g.,?be completely enclosed in a microcrystalline matrix, have a degree of structure in line with the metamorphic grade) and should display compositional characteristics (e.g.,?δ13C, heteroatoms such as N, P, S) in line with a biologic source material.Vega, B., Kovscek, A.R., 2019. A systematic study of internal gas generation in shale source rocks using analog experiments. Journal of Petroleum Science and Engineering 173, 209-221. two-dimensional Hele-Shaw cell was created to study and visualize hydrocarbon source rock (i.e., shale) elastic-brittle fracture and fracture network propagation mechanisms triggered by internal gas generation and gas build up during maturation of organic components. An analog immature source rock was created using a mixture of gelatin, sugar, and live yeast in pre-determined proportions. This mixture was poured into the Hele-Shaw cell and allowed to gel. The internal gas generated as a result of sugar fermentation by yeast caused pressure build up within the gel that ultimately resulted in the activation of dissipation mechanisms such as gas diffusion and deformation of the gel matrix. These mechanisms are analogous to shale maturation and fluid generation. Image analysis was employed to study and characterize key events such as fracture nucleation, propagation, and coalescence versus time. Derivative parameters such as fracture growth rate, fracture tip pressure, and fracture spatial distribution, among others, were calculated using the image-sourced data and applying Linear Elastic Fracture Mechanics (LEFM) principles. Results showed that the experiments are repeatable within a consistent response range and additional parameters were identified to be useful input for numerical modelling, including nucleation sites, fracture merging angle, merging to nucleation ratio, and fracture connectivity. For a volume of about 100?cm3 of 11.6% wt. food-grade gelatin solution with 0.25% wt. yeast and a sugar/yeast ratio of 3, measured average total gas production was 35?cm3 (at standard conditions). On an average gelatin matrix area of 400?cm2, the average total fracture length and fracture density are 106?cm and 0.15 fractures/cm2, respectively. Average maximum calculated fracture tip pressure and maximum fracture velocity are 0.92 psi and 5.85?×?10?4?cm/s, respectively. Fracture connectivity was more frequent in the second half of the gas generation process and greater for the older and longer fractures. Average final fracture spacing was 4.42?cm. Connection angles between fractures tended to be closer to 0° than to 90°. Photoelasticity imaging techniques were applied to the experimental setup to visualize the stress field within the sample. The difference of principal stresses was estimated at 3.70?×?103?Pa for the tested material late in the maturation process. Results suggest interdependence of gas pressure, gas diffusion, and transient stress field states. The range of laboratory-scaled data are useful as benchmarking parameters for numerical modelling of source rock maturation including geomechanics.Venter, P., Muller, M., Vestner, J., Stander, M.A., Tredoux, A.G.J., Pasch, H., de Villiers, A., 2018. Comprehensive three-dimensional LC × LC × ion mobility spectrometry separation combined with high-resolution MS for the analysis of complex samples. Analytical Chemistry 90, 11643-11650. two-dimensional liquid chromatography (LC × LC) and ion mobility spectrometry–mass spectrometry (IMS–MS) are increasingly being used to address challenges associated with the analysis of highly complex samples. In this work, we evaluate the potential of the combination of these techniques in the form of a comprehensive three-dimensional LC × LC × IMS separation system. As application, hydrophilic interaction chromatography (HILIC) × reversed phase LC (RP-LC) × IMS–high-resolution MS (HR-MS) was used to analyze a range of phenolic compounds, including hydrolyzable and condensed tannins, flavonoids, and phenolic acids in several natural products. A protocol for the extraction and visualization of the four-dimensional data obtained using this approach was developed. We show that the combination of HILIC, RP-LC, and IMS offers excellent separation of complex phenolic samples in three dimensions. Benefits associated with the incorporation of IMS include improved MS sensitivity and mass-spectral data quality. IMS also provided separation of trimeric procyanidin isomeric species that could not be differentiated by HILIC × RP-LC or HR-MS. On the traveling wave IMS (TWIMS) system used here, both IMS separation performance and the extent of second dimension (2D) undersampling depend on the upper mass scan limit, which might present a limitation for the analysis of larger molecular ions. The performance of the LC × LC × IMS system was characterized in terms of practical peak capacity and separation power, using established theory and taking undersampling and orthogonality into account. An average increase in separation performance by a factor of 13 was found for the samples analyzed here when IMS was incorporated into the HILIC × RP-LC–MS workflow.Vidal, M., Aspillaga, E., Teixidor-Toneu, I., Delgado-Huertas, A., 2018. Lateral transport of N-rich dissolved organic matter strengthens phosphorus deficiency in western subtropical North Atlantic. Global Biogeochemical Cycles 32, 1350-1366. ability of the subtropical North Atlantic to sustain export production despite the lack of available nutrients is fascinating. Subtropical gyres are expected to expand under a global warming scenario, so it is important to understand the mechanisms supplying the required nutrients. Current issues for the region concern the nutrient and metabolic balance, the origin of excess nitrogen and phosphorus shortage, and the maintenance of nitrogen fixation. We report data on the allocation of nitrogen and phosphorus in dissolved and suspended pools, the isotopic δ15N of suspended nitrogen, and the lability of dissolved organic phosphorus (DOP) along a section crossing the eastern seasonally stratified North Atlantic and the western subtropical North Atlantic (NASW). We find extreme P‐deficiency in the NASW, with the highest dissolved inorganic N:P ratios located within the upperthermocline isopycnals (σ? = 26.3–26.8). Our data indicate an important role of the midlatitude northeast seasonally stratified North Atlantic bringing dissolved organic matter (DOM) to the thermocline of the North Atlantic. The mineralization of N‐rich DOM contributes to the N excess (P deficit) of the upperthermocline of NASW. We find lower concentrations of more reactive DOP in the western than in the eastern part of the transect, indicating an active role of DOP in the nutrition of microbial communities. Our results support recent hypotheses concerning the environmental controls of marine nitrogen fixation identifying the key role of DOP utilization.Vikse, K.L., McIndoe, J.S., 2018. Ionization methods for the mass spectrometry of organometallic compounds. Journal of Mass Spectrometry 53, 1026-1034. rapid development of new ionization methods has greatly expanded the ability of mass spectrometry to target diverse areas of chemistry. Synthetic organometallic and inorganic chemists often find themselves with interesting characterization problems that mass spectrometry could potentially find the answer for, but without a guide for choosing the appropriate method of analysis. This tutorial review seeks to provide that guidance via a simple flow chart followed by a brief description of how each common ionization method works. It covers all of the commonly used ionization techniques as well as promising variants and aims to be a resource of first resort for organometallic chemists and analysts tackling a new problem.Vollnhals, F., Wirtz, T., 2018. Correlative microscopy in 3D: Helium ion microscopy-based photogrammetric topography reconstruction combined with in situ secondary ion mass spectrometry. Analytical Chemistry 90, 11989–11995. chemical or elemental analysis of samples with complex surface topography is challenging for secondary ion mass spectrometry (SIMS), if the three-dimensional structure of the sample is not taken into account. Conventional 3D reconstruction of SIMS data assumes a flat surface and uniform sputtering conditions, which is not the case for many analytical applications involving micro- and nanosized particles, composites, or patterned materials. Reliable analysis of such samples requires knowledge of the actual 3D surface structure to correctly reconstruct the SIMS 3D maps. To this end, we introduce the use of photogrammetric 3D topography reconstruction from scanning helium ion microscopy (HIM) correlated with in situ SIMS data for the reconstruction of 3D SIMS data. The HIM and SIMS data are acquired under in situ conditions in a Zeiss ORION NanoFab HIM using a novel SIMS analyzer. We successfully tested the applicability of the approach to generate 3D models of different samples and show that the combination of SIMS and 3D topography is able to provide insights into the influence of the sample topography in a single instrument and with a single ion column and hence without the need for ex-situ sample analysis or additional instrumentation. These findings offer a path toward ion-based correlative 3D spectromicroscopy (3D-HIM-SIMS) and suggest that many combinations of charged particle based P3D (SEM, HIM) and analytical microscopy techniques, such as SIMS, energy-dispersive X-ray spectroscopy (EDX), or ionoluminescence/cathodoluminescence (IL/CL), can be used for correlative microscopy in 3D.Walpen, N., Lau, M.P., Fiskal, A., Getzinger, G.J., Meyer, S.A., Nelson, T.F., Lever, M.A., Schroth, M.H., Sander, M., 2018. Oxidation of reduced peat particulate organic matter by dissolved oxygen: Quantification of apparent rate constants in the field. Environmental Science & Technology 52, 11151-11160. particulate organic matter (POM) is an important terminal electron acceptor for anaerobic respiration in northern peatlands provided that the electron-accepting capacity of POM is periodically restored by oxidation with O2 during peat oxygenation events. We employed push–pull tests with dissolved O2 as reactant to determine pseudo-first-order rate constants of O2 consumption (kobs) in anoxic peat soil of an unperturbed Swedish ombrotrophic bog. Dissolved O2 was rapidly consumed in anoxic peat with a mean kobs of 2.91 ± 0.60 h–1, corresponding to an O2 half-life of ～14 min. POM dominated O2 consumption, as evidenced from approximately 50-fold smaller kobs in POM-free control tests. Inhibiting microbial activity with formaldehyde did not appreciably slow O2 consumption, supporting abiotic O2 reduction by POM moieties, not aerobic respiration, as the primary route of O2 consumption. Peat preoxygenation with dissolved O2 lowered kobs in subsequent oxygen consumption tests, consistent with depletion of reduced moieties in POM. Finally, repeated oxygen consumption tests demonstrated that anoxic peat POM has a high reduction capacity, in excess to 20 μmol electrons donated per gram POM. This work demonstrates rapid abiotic oxidation of reduced POM by O2, supporting that short-term oxygenation events can restore the capacity of POM to accept electrons from anaerobic respiration in temporarily anoxic parts of peatlands.Wan, J., Tokunaga, T.K., Dong, W., Williams, K.H., Kim, Y., Conrad, M.E., Bill, M., Riley, W.J., Hubbard, S.S., 2018. Deep unsaturated zone contributions to carbon cycling in semiarid environments. Journal of Geophysical Research: Biogeosciences 123, 3045-3054. terrestrial carbon cycling has relied primarily on studies of topsoils that are typically characterized to depths shallower than 0.5?m. At a semiarid site instrumented down to 7?m, we measured seasonal- and depth-resolved carbon inventories and fluxes and groundwater and unsaturated zone flow rates. Measurements showed that ~30% of the CO2 efflux to the atmosphere (60% in winter) originates from below 1?m, contrary to predictions of less than 1% by Earth System Model land modules. Respiration from deeper roots and deeper microbial communities is supported by favorable subsurface temperatures, moisture, and oxygen availability. Below 1?m, dissolved organic carbon fluxes from the overlying soil and C from deep roots and exudates are expected to be important in sustaining microbial respiration. Because these conditions are characteristic of semiarid climate regions, we contend that Earth System Model land modules should incorporate such deeper soil processes to improve CO2 flux predictions.Wan, X., Xiang, W., Wan, N., Yan, S., Bao, Z., Wang, Y., 2018. Complexation and reduction of iron by phenolic substances: Implications for transport of dissolved Fe from peatlands to aquatic ecosystems and global iron cycling. Chemical Geology 498, 128-138. (Fe) is among the limiting nutrients in marine environments and mainly originates from terrigenous sources. Dissolved organic carbon (DOC), an important natural organic ligand, plays a key role in the dissolution and transport of terrestrial iron. Peat-derived DOC contains a large number of phenolics, and a systematic study of the geochemical interaction between DOC and Fe will contribute to the understanding of the global carbon and iron cycles. Phenolics, including phenolic acids, are secondary metabolites from plants and fungi. These compounds possess an aromatic ring bearing one or more hydroxyl groups and their structures may range from that of a simple phenolic molecule to that of a complex high-molecular weight polymer. Despite the extensive literature describing the biological effects of phenolic acids, the effect of phenolics on the iron cycle in peatlands is not known very well. Zoige peatland, the world's largest plateau peat wetland, was studied through field investigation and laboratory simulated experiments. The content of phenolics, filterable Fe and some physicochemical parameters in the rivers of the area were investigated. The waters are generally alkaline, with an average pH of 8.04, and aqueous Fe(III) and Fe(II) concentrations are higher than most of the common rivers in the world. The results of our experiments suggested that the high iron solubility was closely related to the phenolic content of the DOC. In particular, phenolics with catechol or galloy moieties forming complexes with iron and significantly impede the oxidation of complexed Fe(II). In addition, some phenolic substances are able to reduce ferric iron to ferrous iron. The combination of complexation and reduction in Fe by phenolics effectively increased the proportion of ferrous iron to total iron and slowed the oxidation and precipitation in the waters, maintaining a high content of “soluble iron” in the peatland. This mechanism has great implications for the effective transport of soluble iron from peatlands to aquatic ecosystems and the global coupled iron and carbon cycles.Wang, A., Sobron, P., Kong, F., Zheng, M., Zhao, Y.-Y.S., 2018. Dalangtan saline playa in a hyperarid region on Tibet Plateau: II. Preservation of salts with high hydration degrees in subsurface. Astrobiology 18, 1254-1276. on a field expedition to the Dalangtan (DLT) saline playa located in a hyperarid region (Qaidam Basin) on the Tibet Plateau and follow-up investigations, we report the mineralogy and geochemistry of the salt layers in two vertical stratigraphic cross sections in the DLT playa. Na-, Ca-, Mg-, KCaMg-sulfates; Na-, K-, KMg-chlorides; mixed (K, Mg)-chloride–sulfate; and chlorate and perchlorate were identified in the collected samples. This mineral assemblage represents the last-stage precipitation products from Na-K-Mg-Ca-Cl-SO4 brine and the oxychlorine formation from photochemistry reaction similar to other hyperarid regions on Earth. The spatial distributions of these salts in both stratigraphic cross sections suggest very limited brine volumes during the precipitation episodes in the Holocene era. More importantly, sulfates and chlorides with a high degree of hydrations were found preserved within the subsurface salt-rich layers of DLT saline playa, where the environmental conditions at the surface are controlled by the hyperaridity in the Qaidam Basin on the Tibet Plateau. Our findings suggest a very different temperature and relative humidity environment maintained by the hydrous salts in a subsurface salty layer, where the climatic conditions at surface have very little or no influence. This observation bears some similarities with four observations on Mars, which implies not only a large humidity reservoir in midlatitude and equatorial regions on Mars but also habitability potential that warrants further investigation.Wang, C., Yang, S., Li, X., Li, J., Jiang, C., 2019. Comparison of the initial gas desorption and gas-release energy characteristics from tectonically-deformed and primary-undeformed coal. Fuel 238, 66-74. and gas outbursts (hereinafter, collectively referred to as ‘outbursts’) often last for just a few tens of seconds and occur mostly in gas-bearing tectonically-deformed (TD) coal. It has been proved that, in comparison to primary-undeformed (PU) coal, TD coal is more susceptible to outbursts due to its lower mechanical strength, stronger gas-adsorption capability, and faster gas-desorption rate. At the same time, the energy required for the outburst process is mainly provided by the gas. However, the characteristics of the gas-desorption behavior and gas-release energy in TD and PU coal during the first dozen seconds or so have rarely been studied. In this study, gas desorption experiments were carried out on TD and PU coal at different gas pressures using self-assembled desorption equipment. The experiments focus on roughly the first 13?s. The results show that the drop rate of gas pressure is lower with TD coal compared to PU coal, while the gas desorption rate is higher for TD coal compared to PU coal. Most of the gas is released from the two types of coal in the first few seconds. For both TD and PU coal, the time taken to release 90% of the total gas expansion energy (TGEE) is shorter than that to release 90% of the total gas energy (TGE). At the different gas pressures used, the TGEE of the two types of coal accounts for about 14–16% of the TGE. The higher the gas pressure is, the greater the TGEE released by the coal samples gets, and thus the larger the TGEE: TGE ratio becomes. Although the TGEE released from the TD coal is about 3 times that released from the PU coal, it accounts for a slightly smaller proportion of the TGE compared to that in the PU coal samples.Wang, G., Hou, B., Zhang, J., Wang, H., Gao, D., Chang, G., Thallada, B., 2018. Effect of pressure and H2 on the pyrolysis characteristics of lignite: Thermal behavior and coal char structural properties. Journal of Analytical and Applied Pyrolysis 135, 1-9. aim of the present work was to investigate the effect of pressure and H2 on the pyrolysis characteristics of lignite. Thermogravimetric behavior during lignite pyrolysis was studied under different Ar or H2 pressures using a pressurized thermogravimetric analyzer (P-TGA). Structural properties of coal chars obtained from P-TGA were investigated by the application of elemental analyzer, Fourier transform infrared spectroscopy, X-ray diffraction analyzer, and gas sorption surface area and pore size analyzer. CO2 gasification reactivity of coal chars was also evaluated by TGA tests. The results demonstrated that the weight loss for lignite pyrolysis increased in the presence of H2 and it became more remarkable with rising pressure. Meanwhile, conversion of C and H during pressurized hydropyrolysis was promoted to a higher level considerably. Aromaticity as well as graphitization degree for coal chars were both intensified with addition of H2, especially under elevated pressures. As to the mesopore structure, BET specific surface area of coal chars from hydropyrolysis increased obviously in comparison with that of coal chars obtained in Ar atmosphere, especially under pressurized conditions. Moreover, coal chars from hydropyrolysis exhibited higher CO2 gasification reactivity.Wang, G., Huang, R., Zhong, L., Wang, L., Zhou, S., Liu, Q., 2018. An optimal design of crushing parameters of marine gas hydrate reservoirs in solid fluidization exploitation. Natural Gas Industry 38, 84-89. select reasonable excavating and crushing process parameters and nozzle structure parameters is one of the key factors to realize commercial excavation of marine natural gas hydrate (hereinafter "hydrate" for short) in solid fluidization exploitation. For analyzing the factors influencing jet crushing efficiency of hydrate in actual engineering, nozzle diameter, pump pressure and other parameters were simulated and analyzed in k–ε turbulence model based on the laboratory experiments and the field production test data at Liwan 3 Station in the northern South China Sea with a gas production rate of 12×104 m3/d as the target of commercial hydrate exploitation. And the following research results were obtained. First, the relationship curves of nozzle diameter, pump pressure and displacement are determined when the critical jet speed for crushing hydrate is 24 m/s. Second, the crushing rate to satisfy the daily hydrate sediment excavation of commercial exploitation is 2.48 m3/min and its corresponding jet crushing diameter is 800 mm. Third, when the nozzle diameter is fixed, other parts in the process will be damaged if jet displacement and pump pressure are increased directly. In conclusion, these selected design parameters for commercially excavating and crushing marine non-diagenetic hydrate by means of solid fluidization are conducive to the optimal design of crushing parameters of hydrate in solid fluidization exploitation.Wang, M., Chen, Y., Song, G., Steele-MacInnis, M., Liu, Q., Wang, X., Zhang, X., Zhao, Z., Liu, W., Zhang, H., Zhou, Z., 2018. Formation of bedding-parallel, fibrous calcite veins in laminated source rocks of the Eocene Dongying Depression: A growth model based on petrographic observations. International Journal of Coal Geology 200, 18-35., fibrous calcite veins (commonly referred to as “beefs”) are widely developed within Eocene, lacustrine, laminated organic-rich source rocks in the Dongying Depression of Bohai Bay Basin, East China. Understanding the formation of this type vein is essential to elucidate the diagenetic evolution and fluid migration in muddy source rocks. This study investigates the mechanism(s) of growth of bedding-parallel veins in hydrocarbon source rocks of the Es4 upper and the Es3 lower units in the Dongying Depression, based on systematic observations of macro- and micro-scale features both in veins and their wall-rocks, combined with X-ray diffraction and analyses of geochemical indicators.The source rocks are heterogeneous in both composition and structure. The beefs mainly occur in laminated rocks consisting of organic-rich laminae, which occur together with horizontally-continuous banded lamalginites and rare carbonate-rich laminae, overall corresponding to high TOC, low carbonate contents, and low maturity (average Ro?=?0.57%). Most beefs are embedded in the neighboring lamalginites of organic-rich laminae with low clay-mineral contents. The beefs are products of diagenesis accompanying burial, and both the initial fracture opening and subsequent dilation represent early stages of hydrocarbon generation and expulsion. The presence of bedding-parallel bituminite veins and the median plane (or “parting”) is evidence for horizontally oriented hydrofracturing due to fluid overpressure. In turn, fluid overpressure reflects the generation and primary migration of hydrocarbon-bearing fluids. Hydrocarbon generation (organic matter evolution) and clay-mineral dehydration (illitization of smectite) were responsible for the fluid overpressure. Crystal growth within the beefs was a continuous process with an antitaxial growth direction, and there was no growth competition between adjacent fibres. These observations indicate that the crystal growth and fracture dilation were synchronous and growth space was limited. The force exerted by crystallizing vein fill contributed to the high fluid pressure, suggesting that fibrous vein minerals actively promoted further dilation as the veins grew. Vein dilation accompanied the migration of hydrocarbon-bearing fluids, evinced by the occurrence of primary hydrocarbon inclusions found in the fibrous calcites. Therefore, the hydrocarbon-bearing fluids were present at the time of horizontal fluid flow, from the start of fracture opening to the end of the dilation.Wang, P., Xu, C., Zhang, Y., Wang, M., Shi, Q., 2018. Identification of artifacts in the methylation process of sulfur compounds in petroleum. Energy & Fuels 32, 10571-10579. of sulfides and thiophenes into methyl sulfonium salts for electrospray ionization (ESI) mass spectrometry analysis has been a widely used approach for molecular characterization of sulfur-containing compounds in fossil fuels. In this study, we found a series of artifacts in the methylation products of crude oils, which could lead to incorrect assignment of sulfur compounds, severe ionization suppression of S1 species with a high double bond equivalent value, and OxSx species with low abundance. The terminal products from the Friedel–Craft methylation of toluene and its methyl homologues were identified as 1,1,2,3,4,5,6-heptamethylbenzenonium, which showed high abundance in the positive-ion ESI mass spectrum. These compounds associate with Ag+, leading to the formation of abundant Ag-cationized monomer and homo- and hetero-Ag-cationized dimer complexes. In-source high-energy collisional dissociation (HCD) of the homo- and hetero-Ag-cationized dimer complexes [M1 + Ag + M1]+ and [M1 + Ag + M2]+ yielded the monomer complexes [M1 + Ag]+, which further fragmented to yield the molecular ion [M1]+. The abundant Ag-cationized complexes seriously interfered with the identification of sulfur compounds. Feasible suggestions are made to eliminate the interference by Ag-cationized complexes.Wang, S., Lin, Y., Gifford, S., Eveleth, R., Cassar, N., 2018. Linking patterns of net community production and marine microbial community structure in the western North Atlantic. The ISME Journal 12, 2582-2595. net community production (NCP) tracks uptake of carbon by plankton communities and its potential transport to depth. Relationships between marine microbial community composition and NCP currently remain unclear despite their importance for assessing how different taxa impact carbon export. We conducted 16 and 18S rRNA gene (rDNA) sequencing on samples collected across the Western North Atlantic in parallel with high-resolution O2/Ar-derived NCP measurements. Using an internal standard technique to estimate in-situ prokaryotic and eukaryotic rDNA abundances per liter, we employed statistical approaches to relate patterns of microbial diversity to NCP. Taxonomic abundances calculated using internal standards provided valuable context to traditional relative abundance metrics. A bloom in the Mid-Atlantic Bight featured high eukaryote abundances with low eukaryotic diversity and was associated with the harmful algal bloom-forming Aureococcus anophagefferens, phagotrophic algae, heterotrophic flagellates, and particle-associated bacteria. These results show that coastal Aureococcus blooms host a distinct community associated with regionally significant peaks in NCP. Meanwhile, weak relationships between taxonomy and NCP in less-productive waters suggest that productivity across much of this region is not linked to specific microplankton taxa.Wang, W., Wang, L., Shao, Z., 2018. Polycyclic aromatic hydrocarbon (PAH) degradation pathways of the obligate marine PAH degrader Cycloclasticus sp. Strain P1. Applied and Environmental Microbiology 84, Article e01261-18.: Bacteria play an important role in the removal of polycyclic aromatic hydrocarbons (PAHs) from polluted environments. In marine environments, Cycloclasticus is one of the most prevalent PAH-degrading bacterial genera. However, little is known regarding the degradation mechanisms for multiple PAHs by Cycloclasticus. Cycloclasticus sp. strain P1 was isolated from deep-sea sediments and is known to degrade naphthalene, phenanthrene, pyrene, and other aromatic hydrocarbons. Here, six ring-hydroxylating dioxygenases (RHDs) were identified in the complete genome of Cycloclasticus sp. P1 and were confirmed to be involved in PAH degradation by enzymatic assays. Further, five gene clusters in its genome were identified to be responsible for PAH degradation. Degradation pathways for naphthalene, phenanthrene, and pyrene were elucidated in Cycloclasticus sp. P1 based on genomic and transcriptomic analysis and characterization of an interconnected metabolic network. The metabolic pathway overlaps in many steps in the degradation of pyrene, phenanthrene, and naphthalene, which were validated by the detection of metabolic intermediates in cultures. This study describes a pyrene degradation pathway for Cycloclasticus. Moreover, the study represents the integration of a PAH metabolic network that comprises pyrene, phenanthrene, and naphthalene degradation pathways. Taken together, these results provide a comprehensive investigation of PAH metabolism in Cycloclasticus.Importance: PAHs are ubiquitous in the environment and are carcinogenic compounds and tend to accumulate in food chains due to their low bioavailability and poor biodegradability. Cycloclasticus is an obligate marine PAH degrader and is widespread in marine environments, while the PAH degradation pathways remain unclear. In this report, the degradation pathways for naphthalene, phenanthrene, and pyrene were revealed, and an integrated PAH metabolic network covering pyrene, phenanthrene, and naphthalene was constructed in Cycloclasticus. This overlapping network provides streamlined processing of PAHs to intermediates and ultimately to complete mineralization. Furthermore, these results provide an additional context for the prevalence of Cycloclasticus in oil-polluted marine environments and pelagic settings. In conclusion, these analyses provide a useful framework for understanding the cellular processes involved in PAH metabolism in an ecologically important marine bacterium.Wang, Y., Hao, X., Hu, Y., 2018. Orderly distribution and differential enrichment of hydrocarbon in oil-rich sags: A case study of Dongying Sag, Jiyang Depression, Bohai Bay Basin, East China. Petroleum Exploration and Development 45, 840-850. on fine geological modeling and taking the evolution of key reservoir-forming elements as the main line, the mechanism of orderly distribution and differential enrichment of hydrocarbon was revealed by studying the joint evolution and coupling effect of pressure, fluid and reservoir properties. Orderly development of sedimentary systems in a rift basin is the base of orderly distribution of reservoirs, and the continuity of pressure structure is the key to controlling orderly distribution of reservoir. From the sag center to the margin, in the sag, second-order sequence and large-scale sedimentary system, the reservoirs appear in an orderly distribution from lithologic reservoir to structural reservoir to stratigraphic reservoir. Alternative acid and alkaline actions controlled the development of high quality reservoirs in the mid-fan sandy conglomerate bodies in the steep slope, resulting in the oil and gas accumulation pattern of sealing at the root fan and enrichment at the mid-fan, in which the breakthrough pressure difference between root fan and mid-fan determines the reservoir enrichment level. The action of acidic fluid controlled the development of high quality reservoirs in beach bar sand and turbidite. The pressure difference between high-pressure source rock caused by pressurization of hydrocarbon generation and low-pressure reservoir caused by reservoir improvement provided driving force for oil and gas charging, giving rise to the pressing-absorbing oil and gas charging mechanism controlled by source rock overpressure. The research results have guidance and reference significance for fine exploration in mature exploration areas.Wani, O.B., Lai, C.-Y., Quadri, S.M.R., Chiesa, M., Alhassan, S.M., 2018. Understanding the wettability of calcite (CaCO3) using higher spatial resolution. Energy & Fuels 32, 10344-10353. alteration of carbonate rocks from an oil-wet state to a water wet or mixed-wet state during water flooding is known to enhance the recovery of oil from the reservoirs. Previously, the wettability of porous mediums has been extensively investigated using numerous macroscopic methods. Among those, the contact angle is a highly employed method for wettability measurements; however, this technique, because of its lower spatial resolution, fails to provide a complete chemical understanding of all the factors affecting the reservoir wettability. In an attempt to overcome this, we employed a multiscale approach involving macro-, micro-, and nanoscopic analytical techniques to investigate the wettability of calcite. Studies were performed by aging two different planes of freshly cleaved calcite in ambient atmosphere and with deionized (DI) water. Contact angle measurements and AFM force profiles were recorded at the macroscale and nanoscale, respectively. Wettability transition was observed from super hydrophilic to hydrophobic nature in ambient atmosphere and super hydrophilic to hydrophilic nature in DI water. When AFM studies were performed on samples aged in DI water there were always patches of water present, which were observed only at the nanoscale. These water patches affect the contact angle measurements and make the macroscopic wettability results inherently ambiguous. This work has shown that the contact angle measurements should not be taken as the absolute measurement of wettability.Ward, M.K., Pollard, W.H., 2018. A hydrohalite spring deposit in the Canadian high Arctic: A potential Mars analogue. Earth and Planetary Science Letters 504, 126-138. Axel Heiberg Island in the Canadian High Arctic, low temperature perennial saline springs occur despite thick permafrost and cold polar desert conditions marked by a mean annual air temperature close to ?20?°C. We present the first comprehensive geomorphic study of the Stolz Diapir Spring (79°04′30″N; 87°04′30″W), a unique groundwater system due to its known fresh water source and sodium chloride-dominated chemistry. During winter, spring discharge precipitates hydrohalite (NaCl?2H2O) by freezing fractionation that forms a pool and barrage system morphologically similar to carbonate travertines and tufas found in temperate climates. The deposit is the largest hydrohalite accumulation on Earth based on published sources. This system experiences dramatic seasonal differences in hydrology and mineralogy marked by a switch from winter regime of salt deposition and cascading surface flow from pool to pool to a summer regime marked by chemical and mechanical erosion and deposit subsurface flow. The warmer temperatures also cause the decomposition of hydrohalite to halite. Accordingly, this site is a useful analogue for similar structures identified on Mars located in areas rich in evaporite minerals and lacking evidence of volcanic activity.Waters, M.R., Keene, J.L., Forman, S.L., Prewitt, E.R., Carlson, D.L., Wiederhold, J.E., 2018. Pre-Clovis projectile points at the Debra L. Friedkin site, Texas—Implications for the Late Pleistocene peopling of the Americas. Science Advances 4, Article eaat4505. projectile points of the Clovis complex and stemmed projectile points of the Western Stemmed Tradition first appeared in North America by ~13 thousand years (ka) ago. The origin, age, and chronological superposition of these stemmed and lanceolate traditions are unclear. At the Debra L. Friedkin site, Texas, below Folsom and Clovis horizons, we find stemmed projectile points dating from ~13.5 to ~15.5 ka ago, with a triangular lanceolate point form appearing ~14 ka ago. The sequential relationship of stemmed projectile points followed by lanceolate forms suggests that lanceolate points are derived from stemmed forms or that they originated from two separate migrations into the Americas.Watteau, F., Villemin, G., 2018. Soil microstructures examined through transmission electron microscopy reveal soil-microorganisms interactions. Frontiers in Environmental Science 6, 106. doi: 10.3389/fenvs.2018.00106. over the last few decades has shown that the characterization of microaggregates at the micrometer scale using Transmission Electron Microscopy (TEM) provides useful information on the influence of microorganisms on soil functioning. By taking soil heterogeneity into account, TEM provides qualitative information about the state of bacteria and fungi (e.g., intact state of living organisms, spores, residues) at the sampling date within organo-mineral associations, from the soil-root interface to the bulk soil, and in biogenic structures such as casts. The degree of degradation of organic matter can be related to the visualized enzymatic potential of microorganisms that degrade them, thus indicating organic matter dynamics within soil aggregates. In addition, analytical TEM characterization of microaggregates by EELS (Electron Energy Loss Spectroscopy) or EDX (Energy Dispersive X-rays spectroscopy) provides in situ identification of microbial involvement in the biogeochemical cycles of elements. Furthermore, micrometer characterization associated with other methodologies such as Nanoscale Secondary Ion Mass Spectrometry (NanoSIMS) or soil fractionation, enables monitoring both incorporation of biodegraded litter within soil aggregates and impacts of microbial dynamics on soil aggregation, particularly due to production of extracellular polymeric substances. The present focused review suggests that such an approach using micrometer characterization of soil microhabitats provides relevant qualitative and quantitative information when monitoring and modelling microbial processes in dynamics of organo-mineral associations.Weber, Y., Sinninghe Damsté, J.S., Zopfi, J., De Jonge, C., Gilli, A., Schubert, C.J., Lepori, F., Lehmann, M.F., Niemann, H., 2018. Redox-dependent niche differentiation provides evidence for multiple bacterial sources of glycerol tetraether lipids in lakes. Proceedings of the National Academy of Sciences 115, 10926-10931.: Reliable prediction of future climate conditions requires a thorough understanding of climate variability throughout Earth’s history. Microbial molecular fossils, such as bacterial membrane-spanning tetraether lipids [branched glycerol dialkyl glycerol tetraethers (brGDGTs)], have proven to be particularly useful for the assessment of past climatic conditions, because they occur ubiquitously in the environment and show compositional changes related to temperature. However, the identity and ecology of brGDGT-producing bacteria is largely unknown, and a mechanistic basis for brGDGT-based paleoclimate reconstruction is still lacking. Here, we present insights into the ecological parameters that affect brGDGT synthesis in lakes, demonstrating that eutrophic lakes with oxygen-deprived bottom waters are the preferred sites for brGDGT-based reconstructions of continental climate.Abstract: Terrestrial paleoclimate archives such as lake sediments are essential for our understanding of the continental climate system and for the modeling of future climate scenarios. However, quantitative proxies for the determination of paleotemperatures are sparse. The relative abundances of certain bacterial lipids, i.e., branched glycerol dialkyl glycerol tetraethers (brGDGTs), respond to changes in environmental temperature, and thus have great potential for climate reconstruction. Their application to lake deposits, however, is hampered by the lack of fundamental knowledge on the ecology of brGDGT-producing microbes in lakes. Here, we show that brGDGTs are synthesized by multiple groups of bacteria thriving under contrasting redox regimes in a deep meromictic Swiss lake (Lake Lugano). This niche partitioning is evidenced by highly distinct brGDGT inventories in oxic vs. anoxic water masses, and corresponding vertical patterns in bacterial 16S rRNA gene abundances, implying that sedimentary brGDGT records are affected by temperature-independent changes in the community composition of their microbial producers. Furthermore, the stable carbon isotope composition (δ13C) of brGDGTs in Lake Lugano and 34 other (peri-)Alpine lakes attests to the widespread heterotrophic incorporation of 13C-depleted, methane-derived biomass at the redox transition zone of mesotrophic to eutrophic lake systems. The brGDGTs produced under such hypoxic/methanotrophic conditions reflect near-bottom water temperatures, and are characterized by comparatively low δ13C values. Depending on climate zone and water depth, lake sediment archives predominated by deeper water/low-13C brGDGTs may provide more reliable records of climate variability than those where brGDGTs derive from terrestrial and/or aquatic sources with distinct temperature imprints.Wei, N., Zhao, J., Sun, W., Zhou, S., Zhang, L., Li, Q., Fu, Q., Lü, X., Zheng, L., 2018. Non-equilibrium multiphase wellbore flow characteristics in solid fluidization exploitation of marine gas hydrate reservoirs. Natural Gas Industry 38, 90-99. the core process of fractured marine gas hydrate (hereinafter referred to as hydrate) particles being transported up to the surface platform by airtight pipeline in the solid fluidization exploitation of marine gas hydrate reservoirs, influenced by the rising temperature and the dropping pressure, the solid hydrates will decompose and produce a large amount of gas at a certain critical point, causing the liquid-solid two-phase flow in the wellbore to change into complicated gas-liquid-solid multiphase non-equilibrium flow, which further aggravate well control, solid phase transportation and other safety risks. In view of this, the dynamic hydrate decomposition law in the above process was studied in this paper by establishing multiphase wellbore flow mathematical models of wellbore temperature and pressure field, hydrate phase equilibrium, hydrate dynamic decomposition in multiphase riser pipe flow, wellbore multiphase flow coupled hydrate dynamic decomposition, and a numerical calculation method was proposed and verified. The following results were obtained. First, by numerical model analysis, the effects of liquid phase displacement, solid throughput (daily gas production rate) and wellhead back pressure under different construction parameters on multi-phase non-equilibrium pipe flow were obtained. In addition, the field construction guidance measures were put forward based on multiphase non-equilibrium pipe flow characteristics as follows: to properly increase the solid throughput so as to increase the natural gas production, to appropriately increase the liquid-phase displacement and the wellhead back pressure so as to ensure well control safety. This study provides not only a theoretical basis for the prediction of multiphase non-equilibrium pipe flow in the solid fluidization exploitation, but a technical support for the field construction parameter optimization and well control safety. Wei, W., Algeo, T.J., Lu, Y., Lu, Y., Liu, H., Zhang, S., Peng, L., Zhang, J., Chen, L., 2018. Identifying marine incursions into the Paleogene Bohai Bay Basin lake system in northeastern China. International Journal of Coal Geology 200, 1-17. extent of marine influence on the Paleogene Bohai Bay Basin in northeastern China, which accumulated mainly continental (e.g., fluvial and lacustrine) facies, remains under debate. Evidence from geochemical, paleontological, and lithological data have documented several marine incursions, but no systematic study has been conducted to investigate their timing and frequency and their significance for understanding the Paleogene tectonic evolution of northeastern China. In order to address the marine influence on sediment accumulation and to identify variations in paleosalinity during deposition of the mid-Eocene lower Es3 (Es3L) Member of the Shahejie Formation, this study analyzed multiple paleosalinity proxies (B/Ga, Sr/Ba, and S/TOC) in fine-grained siliciclastic (argillaceous) sediments of the Luo-69 drillcore from the Dongying Depression. All three proxies yielded similar paleosalinity interpretations, with peak salinity and marine influence (i.e., maximum B/Ga, Sr/Ba, and S/TOC values) occurring at the base of the Es3L Member, and progressively declining salinities, representing a shift toward brackish conditions, upsection over an interval of 185.5?m representing ~2.2 Myr of sedimentation. This paleosalinity record suggests gradual long-term variations that were probably due to changes in tectonically controlled gateways linking the Bohai Bay Basin to the Yellow Sea. In addition to analysis of the mid-Eocene Es3L Member, published data on the stratigraphic distribution of marine fossils, glauconite, and elemental paleosalinity proxies are applied to evaluate the history of marine incursions into the Bohai Bay lake system throughout the mid to late Paleogene (~50–24?Ma). This analysis revealed four intervals of probable major marine incursions dating to the early Eocene, the middle Eocene, the early Oligocene, and the late Oligocene.Weigel, S., Stephan, D., 2018. Bitumen characterization with Fourier transform infrared spectroscopy and multivariate evaluation: Prediction of various physical and chemical parameters. Energy & Fuels 32, 10437-10442. the aim of this work, the characterization of bitumen based on Fourier transform infrared spectroscopy combined with multivariate evaluation was investigated. For this, 90 bitumen samples were analyzed using the attenuated total reflection technology with multiple reflections. The gained spectra were divided into two partial spectra with the relevant peaks and pre-processed with a standard normal variate transformation and the first derivative. For a comprehensive evaluation, a multivariate analysis method in terms of the partial least square regression was used. On the basis of this procedure, models could be determined allowing for the description and prediction of different bitumen parameters, including the penetration, the complex shear modulus, the phase angle, and the asphaltene content. Further, the softening point can be estimated roughly. In contrast, the description of the flexural stiffness a well as the m value capturing the low-temperature behavior and the description of the content of the different maltene fractions are not possible. Concerning the structural relationships, increasing hardness, viscosity, stiffness, and elastic behavior are associated with an increase of the aromatic and oxygen-containing compounds and changes in the structure of the aromatics and alkenes.Weller, Z.D., Roscioli, J.R., Daube, W.C., Lamb, B.K., Ferrara, T.W., Brewer, P.E., von Fischer, J.C., 2018. Vehicle-based methane surveys for finding natural gas leaks and estimating their size: Validation and uncertainty. Environmental Science & Technology 52, 11922-11930. leaks in urban natural gas (NG) distribution systems is important for reducing methane emissions and costly waste. Mobile surveying technologies have emerged as a new tool for monitoring system integrity, but this new technology has not yet been widely adopted. Here, we establish the efficacy of mobile methane surveys for managing local NG distribution systems by evaluating their ability to detect and locate NG leaks and quantify their emissions. In two cities, three-quarters of leak indications from mobile surveys corresponded to NG leaks, but local distribution companies’ field crews did not find most of these leaks, indicating that the national CH4 activity factor for leaks in local NG distribution pipelines is underestimated by a factor of 2.4. We found the median distance between mobile-estimated leak locations and actual leak locations was 19 m. A comparison of emission quantification methods (mobile-based, surface enclosure, and tracer ratio) found that the mobile method overestimated leak magnitude for the smallest leaks but accurately estimated size for the largest leaks that are responsible for the majority of total emissions. Across leak sizes, mobile methods adequately rank relative emission rates for repair prioritization, and they are easily deployed and offer efficient spatial coverage.Wenning, R.J., Robinson, H., Bock, M., Rempel-Hester, M.A., Gardiner, W., 2018. Current practices and knowledge supporting oil spill risk assessment in the Arctic. Marine Environmental Research 141, 289-304. spill response (OSR) in the Arctic marine environment conducted as part of operational planning and preparedness supporting exploration and development is most successful when knowledge of the ecosystem is readily available and applicable in an oil spill risk assessment framework. OSR strategies supporting decision-making during the critical period after a spill event should be explicit about the environmental resources potentially at risk and the efficacy of OSR countermeasures that best protect sensitive and valued resources. At present, there are 6 prominent methods for spill impact mitigation assessment (SIMA) in the Arctic aimed at supporting OSR and operational planning and preparedness; each method examines spill scenarios and identifies response strategies best suited to overcome the unique challenges posed by polar ecosystems and to minimize potential long-term environmental consequences. The different methods are grounded in classical environmental risk assessment and the net environmental benefit analysis (NEBA) approach that emerged in the 1990s after the Exxon Valdez oil spill. The different approaches share 5 primary assessment elements (oil physical and chemical properties, fate and transport, exposure, effects and consequence analysis). This paper highlights how the different Arctic methods reflect this common risk assessment framework and share a common need for oil spill science relevant to Arctic ecosystems. An online literature navigation portal, developed as part of the 5-year Arctic Oil Spill Response Technologies Joint Industry Programme, complements the different approaches currently used in the Arctic by capturing the rapidly expanding body of scientific knowledge useful to evaluating exposure, vulnerability and recovery of the Arctic ecosystem after an oil spill.White, D.A., Elrick, M., Romaniello, S., Zhang, F., 2018. Global seawater redox trends during the Late Devonian mass extinction detected using U isotopes of marine limestones. Earth and Planetary Science Letters 503, 68-77. Late Devonian extinction ranks as one of the ‘big five’ Phanerozoic extinctions affecting up to 80% of marine species and is characterized by two major extinction events that are separated by <3 My. The leading hypotheses explaining both extinction events are global cooling and/or widespread marine anoxia. We test the marine anoxia hypothesis by analyzing uranium isotopes (δ238U) across a ～7 My interval of well-dated Upper Devonian marine limestones from the Devil's Gate Formation in Nevada, USA. The measured δ238U curve shows no co-variation with local sediment-derived redox trends, water-depth dependent facies changes, redox-sensitive metals, TOC, or diagnostic elemental ratios. From these relationships, we infer that the δ238U curve represents global seawater redox conditions. Two negative δ238U excursions (indicating more reducing seawater) are observed with durations of ～3.8 My (late Frasnian) and ～1.1 My (early Famennian), respectively. Steady-state modeling of the observed ?0.2 to ?0.3‰ shifts in δ238U points to a ～5–15% increase in the total area of anoxic seafloor during these excursions. The late Frasnian negative excursion is broadly coincident with the first extinction event (late rhenana Zone or lower Kellwasser event), whereas the early Famennian negative excursion (lower-middle triangularis zones) occurs after the most intense Frasnian–Famennian boundary (F–F) extinction event (upper Kellwasser event). Compilations of local sediment redox conditions from Upper Devonian marine deposits with conodont zone-level age control indicates that the extinction events were coincident with widespread anoxic deposits accumulating in subtropical epeiric sea and some open ocean settings, supporting previous interpretations that widespread marine anoxia had an important influence on the Late Devonian extinctions. The temporal relationships between global-ocean redox trends represented by the δ238U curve and the newly compiled subtropical marine redox sediment trends indicates that local epeiric seawaters carried a similar U-isotopic composition as the open ocean for the majority of the studied interval except for a brief interval (<500 ky) spanning the F–F boundary.Wiegand, S., Jogler, M., Jogler, C., 2018. On the maverick Planctomycetes. FEMS Microbiology Reviews 42, 739-760. are ubiquitous, environmentally and biotechnologically important bacteria that are key players in global carbon and nitrogen cycles. Ever since their first discovery in the 1920s they seemed to blur the prokaryote?/eukaryote dichotomy. After initially being described as fungi and reclassified as bacteria later, they were still thought to feature a nucleus-like compartment surrounding their highly condensed DNA. Also, an endocytosis-like uptake mechanism for macromolecules was described. Besides these eukaryotic hallmark traits, Planctomycetes seemed to lack typical bacterial features such as a peptidoglycan cell wall or the universal bacterial cell division protein FtsZ, while mostly dividing by polar budding instead of binary fission. Thus, Planctomycetes were speculated to be ancestral to both, bacteria and eukaryotes. With the advent of novel microscopic techniques, along with the development of genetic tools for Planctomycetes, some of these hypotheses were revisited. Surprisingly, Planctomycetes were found to possess a peptidoglycan cell wall and to comprise a cell plan comparable to other Gram-negative bacteria as the nucleus-like structure is rather an invagination of the cytoplasmic membrane than a cohesive compartment. These finding challenge the idea of a eukaryotic ancestry of the phylum, as Planctomycetes now appear similar, yet distinct to other bacteria.Wik, M., Johnson, J.E., Crill, P.M., DeStasio, J.P., Erickson, L., Halloran, M.J., Fahnestock, M.F., Crawford, M.K., Phillips, S.C., Varner, R.K., 2018. Sediment characteristics and methane ebullition in three subarctic lakes. Journal of Geophysical Research: Biogeosciences 123, 2399-2411. (bubbling) from climate‐sensitive northern lakes remains an unconstrained source of atmospheric methane (CH4). Although the focus of many recent studies, ebullition is rarely linked to the physical characteristics of lakes. In this study we analyze the sediments of subarctic postglacial lakes and investigate how sediment properties relate to the large spatial variation in CH4 bubble flux, quantified over multiple years using bubble traps. The results show that the sediments from our lakes are rich in total organic carbon, containing 37 kg/m3 on average. This number is roughly 40% higher than the average for yedoma deposits, which have been identified as high CH4 emitters. However, the quantity of total organic carbon is not a useful indicator of high emissions from the study lakes. Neither is the amount of CH4 in the sediment a reliable measure of ebullition potential. Instead, our data point to coarse detritus, partly from buried submerged aquatic vegetation and redeposited peat as spatial controls on fluxes, often in combination with previously established effects of incoming solar radiation and water depth. The results once again highlight the climate sensitivity of northern lakes, indicating that biological responses to warmer waters and increased energy input and heating of organic sediments during longer ice‐free seasons can substantially alter future CH4 emissions. Wilhelm, R.C., Hanson, B.T., Chandra, S., Madsen, E., 2018. Community dynamics and functional characteristics of naphthalene-degrading populations in contaminated surface sediments and hypoxic/anoxic groundwater. Environmental Microbiology 20, 3543-3559. research on the biogeochemical factors affecting natural attenuation in coal‐tar contaminated groundwater, at South Glens Falls, NY, revealed the importance of anaerobic metabolism and trophic interactions between degrader and bacterivore populations. Field‐based characterizations of both phenomena have proven challenging, but advances in stable isotope probing (SIP), single‐cell imaging and shotgun metagenomics now provide cultivation‐independent tools for their study. We tracked carbon from 13C‐labelled naphthalene through microbial populations in contaminated surface sediments over 6 days using respiration assays, secondary ion mass spectrometry imaging and shotgun metagenomics to disentangle the contaminant‐based trophic web. Contaminant‐exposed communities in hypoxic/anoxic groundwater were contrasted with those from oxic surface sediments to identify putative features of anaerobic catabolism of naphthalene. In total, six bacteria were responsible for naphthalene degradation. Cupriavidus, Ralstonia and Sphingomonas predominated at the earliest stages of SIP incubations and were succeeded in later stages by Stenotrophomonas and Rhodococcus. Metagenome‐assembled genomes provided evidence for the ecological and functional characteristics underlying these temporal shifts. Identical species of Stenotrophomonas and Rhodococcus were abundant in the most contaminated, anoxic groundwater. Apparent increases in bacterivorous protozoa were observed following exposure to naphthalene, though insignificant amounts of carbon were transferred between bacterial degraders and populations of secondary feeders.Wirth, M.A., Passow, U., Jeschek, J., Hand, I., Schulz-Bull, D.E., 2018. Partitioning of oil compounds into marine oil snow: Insights into prevailing mechanisms and dispersant effects. Marine Chemistry 206, 62-73. sedimentation of oil via marine snow was observed during and after the Deepwater Horizon oil spill in 2010. We conducted laboratory experiments to characterize the chemical composition of oil associated with marine oil snow (MOS), identify mechanisms responsible for the incorporation of oil compounds into MOS, and describe the impact of the dispersant Corexit on oil incorporation into MOS. Phytoplankton was incubated in roller tanks in the presence or absence of Macondo crude oil and Corexit and the partitioning of n-alkanes and PAHs between MOS?>?1?mm, the dissolved phase and particles <1?mm was analyzed. Oil incorporation into MOS depended largely on the physiochemical properties of the respective oil compounds. Insoluble compounds, namely n-alkanes and high molecular weight (HMW) PAHs, were integrated into MOS within entire oil droplets that were scavenged by phytoplankton. The water-soluble fraction of the oil, namely low molecular weight PAHs, was sorbed by cells in MOS. Droplet incorporation took place immediately, while sorption only occurred after an experimental period longer than 1?day. The dispersant Corexit significantly increased the amount of oil trapped in MOS, and caused MOS to be enriched in HMW oil compounds, of which many act as toxins. Alteration of the chemical composition of oil in MOS after an experimental period of 4?days suggests biodegradation of oil compounds, especially in the presence of Corexit. These results allow further insights into processes affecting MOS formation and sedimentation and assist future research and spill response planning.Wolfe, J.M., Fournier, G.P., 2018. Reply to ‘Molecular clocks provide little information to date methanogenic Archaea’. Nature Ecology & Evolution 2, 1678-1678.. No abstract.Wong, H.L., White, R.A., Visscher, P.T., Charlesworth, J.C., Vázquez-Campos, X., Burns, B.P., 2018. Disentangling the drivers of functional complexity at the metagenomic level in Shark Bay microbial mat microbiomes. The ISME Journal 12, 2619-2639. functional metagenomic potential of Shark Bay microbial mats was examined for the first time at a millimeter scale, employing shotgun sequencing of communities via the Illumina NextSeq 500 platform in conjunction with defined chemical analyses. A detailed functional metagenomic profile has elucidated key pathways and facilitated inference of critical microbial interactions. In addition, 87 medium-to-high-quality metagenome-assembled genomes (MAG) were assembled, including potentially novel bins under the deep-branching archaeal Asgard group (Thorarchaetoa and Lokiarchaeota). A range of pathways involved in carbon, nitrogen, sulfur, and phosphorus cycles were identified in mat metagenomes, with the Wood–Ljungdahl pathway over-represented and inferred as a major carbon fixation mode. The top five sets of genes were affiliated to sulfate assimilation (cysNC cysNCD, sat), methanogenesis (hdrABC), Wood–Ljungdahl pathways (cooS, coxSML), phosphate transport (pstB), and copper efflux (copA). Polyhydroxyalkanoate (PHA) synthase genes were over-represented at the surface, with PHA serving as a potential storage of fixed carbon. Sulfur metabolism genes were highly represented, in particular complete sets of genes responsible for both assimilatory and dissimilatory sulfate reduction. Pathways of environmental adaptation (UV, hypersalinity, oxidative stress, and heavy metal resistance) were also delineated, as well as putative viral defensive mechanisms (core genes of the CRISPR, BREX, and DISARM systems). This study provides new metagenome-based models of how biogeochemical cycles and adaptive responses may be partitioned in the microbial mats of Shark Bay.Wu, L., Lu, Y., Jiang, S., Liu, X., He, G., 2018. Effects of volcanic activities in Ordovician Wufeng–Silurian Longmaxi period on organic-rich shale in the Upper Yangtze area, South China. Petroleum Exploration and Development 45, 862-872. on the corresponding relationship between the paleoproductivity, redox conditions and volcanism within a chronostratigraphic framework, the effects of volcanic events in the Wufeng–Longmaxi period on organic abundance of shale were examined. Bentonite layers were mostly developed in the transgressive systems tract 1 (TST1, Wufeng Formation) and transgressive systems tract 2 (TST2, Longmaxi Formation), and the two systems tracts corresponded to favorite shale lithofacies with high silica and total organic carbon (TOC) contents. According to the stratigraphic characteristics of bentonite rich interval, TST1 is classified as the interval with dense bentonite layers with the frequency of bentonite layer (bentonite layers/time) of more than 1.5 layers/Ma and the cumulative thickness ratio of bentonite layers (thickness of bentonite layers/thickness of shale) of more than 1%; TST2 is classified as the interval with sparse bentonite layers (frequency < 1.5 layers/Ma; cumulative thickness ratio < 1%). TST1 (dense interval) witnessed more intense and high-frequency volcanic activities than TST2 (sparse interval), so the TST1 has generally higher TOC than TST2. The intense and frequent volcanic activities had dual effects on organic-rich shale: on one hand, volcanic ash provided a sufficient supply of nutrients, which triggered high marine productivity; on the other hand, the extremely anoxic environment caused by volcanic activity enhanced the burial amount and preservation rate of organic matter.Wu, M., Zhang, B., Jiang, L., Wu, J., Sun, G., 2018. Natural lacquer was used as a coating and an adhesive 8000 years ago, by early humans at Kuahuqiao, determined by ELISA. Journal of Archaeological Science 100, 80-87. lacquer is one of the first polymeric materials used by humans and has both functional and aesthetic uses. It has been used as coating by human since the Neolithic Age. It was discovered that lacquer was not only used as a coating but also an adhesive at the Kuahuqiao site 8000 calibrated years before present. This site, a Neolithic settlement, is located in the Chinese Yangtze River Delta. The three lacquered relics obtained there consisted of a mulberry bow, the earliest known canoe-like boat, and a broken pottery fragment. The mulberry bow coated with lacquer film has been reported. There is a hole at the bottom of the canoe-like boat and it was repaired by a timber and an adhesive, recently. And the pottery fragment was also repaired by an adhesive, 8000 years ago. The analysis of infrared showed that the coating of the bow and the adhesives of the boat and the pottery are likely to be natural lacquer. However, the coating of the bow and the adhesive of the boat are impure, because of burial conditions and post-processing. They don't meet the requirements of Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), the common method to identify lacquer. Therefore, enzyme-linked immune sorbent assay (ELISA) was selected as the main analytical method. Detection of lacquer by ELISA is almost no requirements for samples, therefore it can be used to search for earlier lacquerwares and identify the lacquerwares in poor condition. It was determined that the coating of the bow and the adhesives of the boat and the pottery were all the natural lacquer from Toxicodendron vernicifluum by ELISA. Only the adhesive of the pottery was analyzed by Py-GC/MS, and it determined that it was natural lacquer, consistent with the result of ELISA. These discoveries prove that natural lacquer was widely used as a coating and an adhesive by Neolithic humans at the Kuahuqiao site, 8000 years ago.Wu, T., Sahling, H., Feseker, T., Rendle-Bühring, R., Wei, J., Wintersteller, P., Marcon, Y., Pape, T., R?mer, M., Bohrmann, G., 2019. Morphology and activity of the Helgoland Mud Volcano in the Sorokin Trough, Northern Black Sea. Marine and Petroleum Geology 99, 227-236. change and activity of submarine mud volcanoes are still poorly understood. In this study, we integrated Autonomous Underwater Vehicle (AUV) high resolution bathymetric and backscatter data, Remotely Operated Vehicle (ROV) seafloor observation, Bottom Water Temperature (BWT), gas samples and PARASOUND acoustic profiles collected from three research expeditions to study the morphology and activity of the Helgoland Mud volcano (Helgoland MV) in the Sorokin Trough of the Black Sea. Based on the high resolution bathymetric and backscatter maps, the Helgoland MV is classified into five fields, which are active center, inner crest, inner moat, outer crest, and outer moat. Special seafloor features, such as gas bubble emission, mud breccia, fluid flow and mud pools, were observed in different fields by ROV observation, indicating heterogeneous distribution of materials and activities of the Helgoland MV. BWT elevation (up to 1.652?°C) show the same direction as the fault (NW-SE), indicating active mud extrusion from the active center. Methane carbon stable isotope (?58.1～ ?63.6‰) and gas composition (C1/C2+?=?2836, CH4?=?99.545%, C2H6?=?0.033%, C3H8?=?0.002%, CO2?=?0.417%) indicate biogenic source with admixture of thermogenic gas. The circular faults surrounding the Helgoland MV, as observed in the sub-bottom profiles, are speculated to be formed due the subsidence of the caldera and gravity driven sediment movement. A conception model is proposed to explain the interrelation between the seafloor morphology and activity of the Helgoland MV. Multidisciplinary data, especially the application of ROV and AUV, broaden the capability to investigate the activity and morphology of the submarine mud volcanoes.Wu, Y., Eglinton, T.I., Zhang, J., Montlucon, D.B., 2018. Spatiotemporal variation of the quality, origin, and age of particulate organic matter transported by the Yangtze River (Changjiang). Journal of Geophysical Research: Biogeosciences 123, 2908-2921. on the age dynamics of particulate organic matter (POM) in large river systems is currently sparse and represents an important knowledge gap in our understanding of the global carbon cycle. Here we examine variations in organic geochemical characteristics of suspended sediments from the Changjiang (Yangtze River) system collected between 1997 and 2010. Higher particulate organic carbon content (POC%) values were observed in the middle reach, especially after 2003, and are attributed to the increase of in situ (aquatic) primary production associated with decreased total suspended matter concentrations. Corresponding Δ14C values from depth profiles taken in 2009 and 2010 indicate spatial and temporal variations in POC sources within the basin. Two isotopic mass balance approaches were explored to quantitatively apportion different sources of Changjiang POM. Results indicate that contributions of biomass and pre‐aged soil organic matter are dominant, regardless of hydrological conditions, with soil‐derived organic carbon comprising 17–56% of POC based on a Monte Carlo three‐end‐member mixing model. In contrast, binary mixing model calculations suggest that up to 80% of POC (2009 samples only) derived from biospheric sources. The emplacement of the Three Gorges Dam and resulting trapping of sediment from the upper reach of the watershed resulted in a modification of POM 14C ages in the reservoir. With the resulting decline in sediment load and increase in the proportion of modern POC in the lower reach, these changes in POM flux and composition of the Changjiang have significant implications for downstream carbon cycle processes.Xia, Z., Idowu, I., Marvin, C., Thomas, P.J., Johnson, W., Francisco, O., Stetefeld, J., Crimmins, B., Fry, M., Tomy, G.T., 2019. Identification of halogenated polycyclic aromatic hydrocarbons in biological samples from Alberta Oil-Sands Region. Chemosphere 215, 206-213. polycyclic aromatic hydrocarbons (HPAHs) were identified in biological samples from the Alberta Oil-Sands Region (AOSR) using gas chromatography coupled with high-resolution time-of-flight mass spectrometry (GC-HRTOF-MS) at a resolving power of 25,000. Knowledge of the electron ionization (EI) fragmentation behavior of individual HPAH isomers, achieved by injecting authentic standards in full-scan MS mode, was paramount in identifying a suite of HPAHs in samples from the AOSR. Confirmation of compounds in biological samples was based on the measured mass accuracy (±3?ppm) of 2 characteristic ions prominent in the EI mass spectra of each compound. Numerous compounds were detected in the high resolution total ion chromatogram in liver extracts of 4 biological species from the AOSR: river otter (Lontra Canadensis), northern pike (Esox lucius), lake whitefish (Coregonus clupeaformis) and snails (Gastropod sp.) many of which remain unidentified. Careful examination of the high-resolution accurate mass data suggests that dichloro-anthracene/phenanthrene, bromo-anthracene/phenanthrene and dibromo-fluorene were present in the biological samples. Lipid corrected concentrations of dichloro-PAHs were estimated to be 16.3?±?11.4 (n?=?4) and 5.5 (n?=?1) ng/g in lake whitefish and river otter, respectively. Concentrations of mono-bromo-PAHs were an order of magnitude greater in snails (170.5?ng/g) than in northern pike (12.5?ng/g) while concentrations of dibromo-PAHs were 4 times greater in snails than in northern pike. The detection of these compounds in biota implies that these compounds are bioaccumulative. The liver-based biomagnification factor of the dichloro-PAH congener in the river otter/lake whitefish feeding relationship is much smaller than 1 implying that this compound does not biomagnify.Xian, H., Zhu, J., Tan, W., Tang, H., Liu, P., Zhu, R., Liang, X., Wei, J., He, H., Teng, H.H., 2019. The mechanism of defect induced hydroxylation on pyrite surfaces and implications for hydroxyl radical generation in prebiotic chemistry. Geochimica et Cosmochimica Acta 244, 163-172. generation of reactive oxygen species H2O2 and OH? from pyrite in anaerobic environments plays an important role in the evolution of early Earth. What remains debatable is the underlying mechanism leading to the OH? generation reactions. Using a comprehensive approach combining X-ray photoelectron spectroscopy and ab initio calculations, we investigated binding energies and valence band structures of defective pyrite surfaces in an attempt to interrogate pyrite-mediated H2O dissociation in the presence and absence of crystal defects. The results show that, while energetically inhibited on perfect crystal faces, H2O dissociation is thermodynamically favored at defective sites. Furthermore, the formation of surface defects can lead to an energy shift in valence bands and thereby forming two defect states. Simultaneously, interaction between both defect states and water molecules makes the hydroxylation energetically favored on the pyrite surface. The hydroxylation occurs through proton transfer from water to a defective S monomer, resulting in an =FeO(H)···HS structure. These findings provide new insight into pyrite-assisted OH? formation processes in anaerobic conditions and may be important for understanding prebiotic chemistry and the evolution of early Earth.Xiao, H., Wang, T.G., Li, M., Lai, H., Liu, J., Mao, F., Tang, Y., 2019. Geochemical characteristics of Cretaceous Yogou Formation source rocks and oil-source correlation within a sequence stratigraphic framework in the Termit Basin, Niger. Journal of Petroleum Science and Engineering 172, 360-372. study investigated the geochemical characteristics of source rocks in each sequence and studied on the oil-source correlation under a sequence stratigraphic framework of the Upper Cretaceous Yogou Formation. The Yogou Formation as the most primary and productive source bed in the Termit Basin (Niger), was further divided into three third-order sequences (i.e. YSQ1, YSQ2 and YSQ3, from bottom to top) in the study. On the basis of the geochemical analysis of a total of 35 rock samples from YSQ3, YSQ2 and YSQ1, the variation of the organic matter abundances, types and maturity of source rocks within different sequences were compared. The TOC content of YSQ2 and YSQ1 source rocks ranges from 0.76% to 1.69% with mature to high mature thermal evaluation stage (Ro: 0.63%–1.29%), while the TOC content of YSQ3 source rocks is much higher (1.11%–6.63%) with a relatively lower maturation levels (Ro: 0.59%–0.91%). All source rocks are dominated by Type II2–III kerogen. Moreover, in order to determine the oil-source correlation under a sequence stratigraphic framework, the composition of biomarkers in 35 source rocks and 25 crude oils were analyzed systematically. Various non-biomarker and biomarker parameters were applied involving source-related, maturity-related and environment-related parameters. The YSQ3 source rocks are typically characterized by relatively higher Pr/Ph ratio, higher concentration of dibenzofurans (DBFs) and lower gammacerane index indicating a suboxic transitional environment, and the relatively higher values of oleanane index and C24TeT/(C24TeT + C26TT) ratio reflecting a significant terrigenous organic matter input. Conversely, the YSQ2, YSQ1 source rocks and studied oils have relatively lower Pr/Ph ratios, higher content of gammacerane and dibenzothiophenes (DBTs) suggesting suboxic to anoxic conditions under shallow marine depositional environment, and low values of oleanane index and C24TeT/(C24TeT + C26TT) ratios indicating predominant algal aquatic organisms input. In addition, other molecular parameters in crude oils, including OEP, CPI, TAR, nC21-/nC22+, (nC21+nC22)/(nC28+nC29), Pr/nC17, Ph/nC18 ratios and the distribution patterns and relevant parameters of tricyclic terpane series, also have the obviously similar characteristics to YSQ2 and YSQ1 source rocks, rather than YSQ3 source rocks. The result of oil-source correlation shows that the discovered oils are dominantly derived from YSQ2 and YSQ1 source rocks, with minor contribution of YSQ3 source rocks. Therefore, the oil-source correlation within a sequence stratigraphic framework can provide a practical model for source rock assessment and petroleum system study.Xiao, Y., Wu, K., Tian, L., Benton, M.J., Du, Y., Yang, H., Tong, J., 2018. Framboidal pyrite evidence for persistent low oxygen levels in shallow-marine facies of the Nanpanjiang Basin during the Permian-Triassic transition. Palaeogeography, Palaeoclimatology, Palaeoecology 511, 243-255. studies suggested that anoxia was a causal factor in the end-Permian mass extinction (EPME), marked by abrupt enrichment of pyrite framboids in the post-EPME microbialites of the earliest Triassic on shallow platforms, and that this dysoxic–anoxic phase followed a time of well?oxygenated seafloors. Here, we report persistent dysoxia throughout the latest Permian and euxinia just before the EPME, based on a new redox history reconstruction study using framboidal pyrite size distribution as well as sulfur isotopic compositions of pyrites, from the Taiping section on the Pingguo Platform in the Nanpanjiang Basin in China. Further, we show that the EPME was followed here by rapid oxygenation, not an anoxic incursion. This revised redox history might be an unusual localized phenomenon when compared to other platforms, or it could be solid sedimentary evidence for redox oscillations outside the bioclast-enriched photic zone, which broadens our understanding of terrestrial–marine ecosystem interactions before and during the EPME.Xie, S., 2018. The shift of biogeochemical cycles indicative of the progressive marine ecosystem collapse across the Permian-Triassic boundary: An analog to modern oceans. Science China Earth Sciences 61, 1379-1383. warming, the most severe faunal mass extinction and the shift of biogeochemical cycles were observed in the ocean across the Permian-Triassic boundary about 252 million years ago, providing an analog to understanding the modern oceans. Along with the progressive global warming, the biogeochemical cycle was documented to show a shift from the decoupled processes of carbon, nitrogen and sulfur prior to the mass extinction to the coupled biogeochemical processes during faunal mass extinction. The coupled biogeochemical cycle was further observed to shift from the coupled C-N processes during the first episode of the faunal mass extinction to the coupled C-N-S processes during the second episode, diagnostic of the progressive development of more deteriorated marine environmental conditions and the more severe biotic crisis across the Permian-Triassic boundary. The biogeochemical cycles could thus be an indication to the progressive collapse of marine ecosystems triggered by the global warming in Earth history. In modern oceans, the coupled C-N cycle triggered by the global warming was observed in some regions. If these local C-N processes develop and expand to the global oceans, the coupled C-N-S processes might be brought into existence and the marine ecosystems are inevitable to suffer from complete collapse as observed at 252 million years ago.Xu, C., Zhang, S., Beaver, M., Lin, P., Sun, L., Doyle, S.M., Sylvan, J.B., Wozniak, A., Hatcher, P.G., Kaiser, K., Yan, G., Schwehr, K.A., Lin, Y., Wade, T.L., Chin, W.-C., Chiu, M.-H., Quigg, A., Santschi, P.H., 2018. The role of microbially-mediated exopolymeric substances (EPS) in regulating Macondo oil transport in a mesocosm experiment. Marine Chemistry 206, 52-61. exopolymeric substances (EPS) formation was observed in contaminated surface waters of the Gulf of Mexico, after the Deepwater Horizon oil spill. The conditions under which EPS are produced can cause variations in their physico-chemical properties, affecting the fate of the oil through either emulsification or coagulation with particles, followed by aggregation and marine oil snow (MOS) sedimentation. Here, we report results from a four-day mesocosm experiment that examined EPS production, the change in the bulk chemical composition (mainly polysaccharides and proteins), as well as the partitioning into different size fractions (suspended particulate matter (SPM), colloidal fraction, and sinking MOS). The treatments included 1) natural coastal seawater (Control), 2) a water accommodated fraction of oil (WAF), 3) a chemically-enhanced WAF with addition of oil dispersant Corexit (CEWAF), and 4) a diluted CEWAF (DCEWAF). Generally, the presence of WAF stimulated more extracellular polysaccharide production, whereas the addition of Corexit promoted more protein production. Moreover, marine aggregates changed from a terrestrial signature (higher aromaticity, lower EPS content and more uniform monosaccharide distribution) in the early stages of the experiment, to a fresher autochthonous signature (less aromatic, higher EPS content and glucose-dominated monosaccharide distribution) in the later stage of the mesocosm experiment. Corexit promoted the association between oil and proteins, assisting to emulsify the oil in colloids and SPM and delay the settling of EPS and oil (MOS) for the duration of the mesocosm. Furthermore, when oil, especially Corexit-dispersed oil, was present, extracellular polysaccharides were preferentially incorporated into sinking MOS relative to proteins, as evidenced from a lower protein-C/carbohydrate-C ratio of the sinking MOS than those of SPM and colloidal fraction in WAF, CEWAF and DCEWAF, respectively. This is in contrast to a higher protein-C/carbohydrate-C ratio in the sinking marine snow than those of SPM and colloidal fraction in the control. Likely, microbially-mediated extracellular polysaccharides are the key component that anchors the mineral ballast until the aggregates become dense enough and overcome the buoyancy added to the aggregates as a result of their association with oil/Corexit. We conclude that interactions between Corexit and EPS components regulate petroleum hydrocarbon distribution between the water column and sinking MOS.Xu, C., Zhang, S., Beaver, M., Wozniak, A., Obeid, W., Lin, Y., Wade, T.L., Schwehr, K.A., Lin, P., Sun, L., Hatcher, P.G., Chin, W.-C., Chiu, M.-H., Knap, A.H., Dean, K., Quigg, A., Santschi, P.H., 2018. Decreased sedimentation efficiency of petro- and non-petro-carbon caused by a dispersant for Macondo surrogate oil in a mesocosm simulating a coastal microbial community. Marine Chemistry 206, 34-43. amounts of mucous-rich oil-containing marine snow formed in surface waters adjacent to the Deepwater Horizon spill. This marine oil snow (MOS) was implicated in oil delivery to the seafloor. Whether the use of chemical dispersants increased or decreased MOS sedimentation remains controversial. We conducted mesocosm experiments testing the effects of oil and oil plus a dispersant on MOS formation and sedimentation, in coastal seawater. The four treatments used were a surrogate Macondo oil water accommodated fraction (“WAF”), two concentrations of chemically-enhanced WAF (“CEWAF” and diluted CEWAF, “DCEWAF”) containing a dispersant and oil, and Controls (no additions). Based on radiocarbon and 13C NMR results, the presence of dispersants enhanced the amounts of petro-carbon being incorporated into the sinking oil-carrying aggregates (aka MOS). However, most of the chemically-dispersed oil preferentially partitioned into the colloidal and suspended particulate fractions rather than into the rapidly forming MOS. Thus the oil and non-petro-carbon sedimentation efficiency in treatments with a dispersant was much lower, compared to those in the Control and WAF treatments, during the four-day mesocosm experiment. Formation of MOS and its subsequent sinking sequestered the oil in two stages: first via terrestrial-derived detritus containing humic compounds, and subsequently via freshly produced material, such as exopolymeric substances produced by phytoplankton and bacteria.Xu, D., Sun, P., Zhang, Y., Li, R., Huang, B., Jiao, N., Warren, A., Wang, L., 2018. Pigmented microbial eukaryotes fuel the deep sea carbon pool in the tropical Western Pacific Ocean. Environmental Microbiology 20, 3811-3824. microbial eukaryotes dominate primary production over large oceanic regions. Due to their small sizes and slow sinking rates, it is assumed they contribute relatively little to the downward export of organic carbon via the biological pump. Therefore, the community structure of phototrophic cells in the deep ocean has long been overlooked and remains largely unknown. In this study, we used an integrative approach, including epifluorescence microscopy, sequencing of 18S rRNA and photosystem‐II psbA gene transcripts, to investigate phototrophic microbial eukaryotes in samples collected from the tropical Western Pacific Ocean. It was found that: (i) pigmented nano‐sized eukaryotes (PNEs) are ubiquitous in the deep Western Pacific Ocean down to 5000 m depth; (ii) the PNE community is dominated by cells 2–5 μm in size; (iii) their abundance is significant, averaging 4 ± 1 (± s.e.) cells ml?1 in waters below 1000 m which is comparable to that of heterotrophic nanoflagellates; (iv) the active pigmented microbial eukaryotes in the deep waters are highly diverse and dominated by Haptophyta followed by Chlorophyta and Bacillariophyta; (v) PNEs in deep waters were likely transported from surface ocean by various fast‐sinking mechanisms, thus contributing to the biological pump and fuelling the deep‐sea communities by supplying fresh organic carbon.Xu, D., Zhang, K., Li, B.-G., Mbadinga, S.M., Zhou, L., Liu, J.-F., Yang, S.-Z., Gu, J.-D., Mu, B.-Z., 2019. Simulation of in situ oil reservoir conditions in a laboratory bioreactor testing for methanogenic conversion of crude oil and analysis of the microbial community. International Biodeterioration & Biodegradation 136, 24-33. bioreactor was designed and established to simulate in situ oil reservoir conditions for investigating methanogenic conversion of crude oil by microbial community derived from production water of a high-temperature oilfield. The continuous incubation and culturing were divided into two phases (Phase I, day 0–341; and Phase II, day 341–520) to allow sampling and supplement of fresh culture medium on day 341 and 520, respectively. The average methane production rate was 4.9 and 20.8?mmol CH4·day?1?m?3 pore volume during the Phase I and Phase II, respectively. Degradation intermediates of fatty acids were detected in the culture fluids indicating the transformation of crude oil. The 16S rRNA gene sequence analysis revealed that the major bacterial community shifted from Deferribacteres to Aminicenantes and unclassified Bacteria, as well as Thermotogae and Synergistetes. The predominant methanogenic community shifted from methylotrophic methanogen (Methanolobus) to hydrogenotrophic methanogens (Methanothermobacter and Methanocalculus) and acetoclastic methanogen (Methanothrix) after 341 days of incubation, and was subsequently dominated by hydrogenotrophic methanogen (Methanothermobacter) after 520 days of incubation. This study expanded our understandings of methanogenic oil-degrading processes and the key microorganisms involved in laboratory simulation bioreactor over time of incubation. In addition, it further provides valuable insights on the microbial conversion of hydrocarbons to methane for enhancing the energy recovery from residual oil in petroleum reservoirs.Xu, R., Zhang, K., Liu, P., Han, H., Zhao, S., Kakade, A., Khan, A., Du, D., Li, X., 2018. Lignin depolymerization and utilization by bacteria. Bioresource Technology 269, 557-566. compound wastes are generated as a result of agricultural and industrial practices. Microorganism-mediated bio-catalytic processes can depolymerize and utilize lignin eco-friendly. Although fungi have been studied since several decades for their ability to depolymerize lignin, strict growth conditions of fungus limit it’s industrial application. Compared with fungi, bacteria can tolerate wider pH, temperature, oxygen ranges and are easy to manipulate. Several studies have focused on bacteria involved in the process of lignin depolymerization and utilization. Pseudomonas have been used for paper mill wastewater treatment while Rhodococcus are widely reported to accumulate lipid. In this review, the recent studies on bacterial utilization in paper wastewater treatment, lignin conversion to biofuels, bioplastic, biofertilizers and other value-added chemicals are summarized. As bacteria possess remarkable advantages in industrial production, they may play a promising role in the future commercial lignin utilization.Xu, S., Hao, F., Xu, C., Zou, H., Zhang, X., Zong, Y., Zhang, Y., Cong, F., 2019. Hydrocarbon migration and accumulation in the northwestern Bozhong subbasin, Bohai Bay Basin, China. Journal of Petroleum Science and Engineering 172, 477-488. important exploration breakthrough has been achieved in the western subsag of the Bozhong subbasin, but the hydrocarbon accumulation mechanism was not clear. The hydrocarbon migration and accumulation mechanism of the western subsag of the Bozhong subbasin is discussed based on the modeling of hydrocarbon migration pathways and the study of late-stage reactivation of neotectonic faults. Three processes for lateral petroleum migration and accumulation can be recognized in the studied area: 1) migration and accumulation along the T8 unconformity; 2) migration and accumulation within the Guantao Formaiton (N1g); and 3) interaction of migration and accumulation along the T8 unconformity and Guantao Formation (N1g). The reactivation of faults in the studied area began 5.1?Ma. Following hydrocarbon lateral migration, late-stage reactivated neotectonic faults serve as effective vertical conduits for hydrocarbon migration and accumulation into the shallow Minghuazhen Formation (N1m) reservoirs. The modeling results of preferential petroleum migration pathways (PPMPs) and favorable accumulation areas are consistent with the actual exploration results. Two kinds of potential exploration targets can be predicted in the northwestern Bozhong subbasin: the first kind is hydrocarbon accumulation areas near or within generative kitchens (e.g. Target 1); the other kind is hydrocarbon accumulation areas removed from the generative kitchens, but with hydrocarbon sourcing from multiple generative kitchen and numerous PPMPs (e.g. Target 2). Studying preferential petroleum migration pathways will help reduce exploration risk.Xu, Z.-X., Xu, L., Cheng, J.-H., He, Z.-X., Wang, Q., Hu, X., 2018. Investigation of pathways for transformation of N?heterocycle compounds during sewage sludge pyrolysis process. Fuel Processing Technology 182, 37-44. study investigated the transformation of N?heterocycle compounds during sewage sludge pyrolysis process. The reaction pathways for evolution of the products especially the N-containing organics such as amino acids?N were analyzed in detail. NH3 is the main N-containing gaseous product during the pyrolysis and its concentration was increased with the increasing temperature. Phenolic compounds, hydrocarbons and heterocyclic compounds were the main component in liquid products. The in situ FT-IR study showed that the labile inorganic ammonium salt decomposition proceeded to completion below 500?°C. Above 500?°C N?heterocycle compound was formed and then it was decomposed, while above 600?°C nitrile started to decompose. NH3 formation main originates from the decomposition of N?heterocyclic compounds and nitrile. Proteins during the pyrolysis, as verified by XPS, were mainly converted into inorganic nitrogen. In addition, the Py-GC–MS results showed that large amount of N?heterocyclic compounds were found in amino acid?N pyrolysis products. The transformation paths for the amino acids with different chemical structures were distinct. Except N?heterocyclic amino acids, long chain aliphatic amino acid also can form N?heterocyclic compounds through cyclization. In addition, the decomposition of the intermediates of N?heterocyclic compounds form small molecular compounds or while the polymerization of the intermediates forms macromolecule compounds. The amino acids with heterocycle structure were disrupted to form heterocycle and aliphatic intermediate. The plausible mechanism of sewage sludge pyrolysis was proposed.Yang, F., Hu, B., Xu, S., Meng, Q., Krooss, B.M., 2018. Thermodynamic characteristic of methane sorption on shales from oil, gas, and condensate windows. Energy & Fuels 32, 10443-10456. methane sorption isotherms at 40–101 °C and pressures up to 25 MPa were measured on Jurassic lacustrine and Silurian marine shales from China. Shale samples span a thermal maturity range from low mature (oil window) to overmature (dry gas window). Low-pressure CO2 and N2 adsorption techniques were used to quantify specific surface area, pore volume, and pore size distributions. The thermodynamic characteristic of methane sorption on shales was assessed based on the experimental multitemperature isotherms. The effects of physical and chemical properties of shales on thermodynamic properties were analyzed and discussed. Finally, standard enthalpy of sorption was first introduced to evaluate the sorption affinity of methane on shales, and a general pattern describing the evolution of methane sorption as a function of thermal maturity was proposed. The Langmuir sorption capacity of these shales varies from 0.09 to 0.16 mmol/g. The low total organic matter carbon, clay-rich lacustrine shales have comparable methane sorption capacities as those of organic-rich, high thermal maturity marine shales, though high thermal maturity shale samples tend to have larger micropore volume than low mature shales. Clay minerals, especially I/S mixed layer minerals, contribute a lot to methane sorption of lacustrine shales in oil window. The isosteric heat of methane sorption on these shales decreases with increasing absorbed amount. The commonly used Clausius–Clapeyron equation, which neglects the real gas behavior and adsorbed volume, tends to overvalue the isosteric heat. The standard enthalpy of sorption reflects the comprehensive effect of physical and chemical properties of shales on gas sorption and shows a parabolic-like pattern with thermal maturity. The standard enthalpy of sorption first decreases with increasing thermal maturity up to the condensate window shales (late mature, equilibrated vitrinite reflectance 1.0–1.1%) and subsequently increases toward the overmature shales.Yang, H., Lu, H., Ruffine, L., 2018. Geochemical characteristics of iron in sediments from the Sea of Marmara. Deep Sea Research Part II: Topical Studies in Oceanography 153, 121-130. ~1000?cm long sediment cores were recovered from the Sea of Marmara, one with the occurrence of gas hydrates in the Western High, and the other without hydrates in the Cinarcik Basin. Differences in mineralogical and chemical compositions have been identified between the two sediment cores. Based on the results of the mineralogical and geochemical analyses, the main sources of the sediments are quite similar for both investigated areas, but the authigenic components are different, particularly iron sulfides and carbonates. Authigenic Fe(II) carbonate are much higher in Core MRS-CS-05 in the Western High, while crystalline Fe(III) phases are more abundant in Core MRS-CS-16 in the Cinarcik Basin. Notably, the enrichments of greigite (Fe3S4), a metastable ferromagnetic iron sulfide mineral and intermediate polysulfide, as well as iron carbonates are identified at 400 cmbsf with the maximum iron content in Core MRS-CS-05. These indicate the presence of a more reducing and acidic environment in the Western High, mainly due to higher organic matter content and seepage of heavy hydrocarbons in the sediments.Yang, J., Norris, J.L., Caprioli, R., 2018. Novel vacuum stable ketone-based matrices for high spatial resolution MALDI imaging mass spectrometry. Journal of Mass Spectrometry 53, 1005-1012. We describe the use of aromatic ketones and cinnamyl ketones that have high vacuum stability for analyzing tissue sections using matrix-assisted laser desorption/ionization imaging mass spectrometry. Specifically, the matrix, (E)-4-(2,5-dihydroxyphenyl)but-3-en-2-one (2,5-cDHA) provides high sensitivity and high vacuum stability while producing small size crystals (1-2??m). A high throughput and highly reproducible sample preparation method was developed for these matrices that first involves using an organic spray solution for small matrix crystal seeding followed by spraying of the matrix in a 30% acetonitrile/70% water solution on the tissue surface to obtain a homogeneous coating of small crystals, suitable for high spatial resolution imaging.Yang, W., Zuo, R., Wang, X., Song, Y., Jiang, Z., Luo, Q., Zhai, J., Wang, Q., Zhang, C., Zhang, Z., 2019. Sensitivity of lacustrine stromatolites to Cenozoic tectonic and climatic forcing in the southern Junggar Basin, NW China: New insights from mineralogical, stable and clumped isotope compositions. Palaeogeography, Palaeoclimatology, Palaeoecology 514, 109-123. stromatolites serve as high-resolution and sensitive archives of palaeoenvironmental settings and palaeoclimatic conditions. An exceptionally well-developed stromatolite bed was discovered within nearshore shallow lacustrine sediments of the Lower Miocene Taxihe Formation on the southern margin of the Junggar Basin, north of the Tian Shan Range. We investigated the morphology, mineralogy, clumped and traditional stable isotope geochemistry of the stromatolites by using a multi-method approach with the application of X-ray diffraction analysis, advanced mineral identification and characterization (AMICSCAN), a clumped isotope palaeothermometer and modelling. The overall positive excursions and covariance of δ18O (varying from +10.61‰ to ?5.82‰ V-PDB) and δ13C (ranging between ?1.27‰ and +2.08‰ V-PDB) values are interpreted as the result of deposition in a closed-basin system under local progressive evaporation conditions during an episode of aridification. Clumped isotope proxy records display a significant decrease in water δ18O values and a decline of lake water temperature from ~38 to ~32?°C, suggesting a shift towards more arid and relatively cooler conditions during the course of stromatolite accretion. This interpretation agrees with lake volume and water level decreases inferred from isotope modelling results. The Late Cenozoic aridification of the southern margin of the Junggar Basin is thus interpreted from a new and unique perspective to have prevailed since the Early Miocene, driven by renewed uplift of the northern Tian Shan Range. The investigated stromatolite records reflect a snapshot of the local palaeoclimatic and palaeoenvironmental evolution, and our work provides references for potential studies of future discoveries of lacustrine microbialites in northwestern China.Yarbrough, L.D., Carr, R., Lentz, N., 2019. X-ray fluorescence analysis of the Bakken and Three Forks Formations and logging applications. Journal of Petroleum Science and Engineering 172, 764-775. ability to characterize subsurface lithology downhole is critical for hydrocarbon identification and subsequent production. Well logging methods frequently used in industry are gamma ray, spontaneous potential, and resistivity principles. Few publications have addressed the feasibility of using X-ray fluorescence (XRF) as a logging method. The exploitation of deep shale petroleum systems will demand greater stratigraphic resolution; X-ray fluorescence well logging (XRFWL) may accurately and efficiently identify geochemical signatures in rock samples, which could give information about hydrocarbon bearing strata in both vertical and horizontal drilling applications when depth matching core data to wells is performed. This case study analyzed eight core sections from the lower Bakken and Three Forks Formation of the Williston Basin in North Dakota using X-ray fluorescence. The Charlotte 1-22H core sequence from Continental Resources, Inc. (Continental Resources) was also included to assess the elemental composition of the stratigraphic interval spanning the Lodgepole, Bakken, Pronghorn, and Three Forks Formations. Core sections were exposed to X-ray at 45-keV excitation voltages to provide fluorescence spectra; count rate values were obtained and elemental ratios were calculated to assess the geochemical composition of each stratigraphic interval. From these XRF analyses we created chemostratigraphic logs representing the subsurface lithology of the Williston Basin diagenetic processes in the host unit were then assessed based on elemental ratio quantity. This novel case study of the Bakken and Three Forks Formations in North Dakota may not necessarily be dispositive for identifying other geologic units. Understanding the spatial distribution of lightweight, mid-range, and trace metal elements in the Bakken hydrocarbon system might lead to a better comprehension of what affects the accuracy and precision of typical industry logs. The ability to measure the elemental composition of core samples and drill cuttings precisely and accurately will allow for further insight into how elemental composition changes can be correlated with diagenetic changes of the Bakken Petroleum System. Using a portable XRF (pXRF) brings this analysis method closer to the drilling operations and provides quick turnaround of samples.Ye, F., Guo, W., Wei, G., Jia, G., 2018. The sources and transformations of dissolved organic matter in the Pearl River Estuary, China, as revealed by stable isotopes. Journal of Geophysical Research: Oceans 123, 6893-6908. investigate the sources and transformation processes of bulk marine dissolved organic matter (DOM), seasonally collected water samples from the Pearl River Estuary (PRE), south China, were analyzed for concentration and stable isotopic ratios (δ13C and δ15N) of DOM. The δ13C values clearly indicated a shift of dissolved organic carbon (DOC) sources from terrigenous material in the river to predominantly plankton in the lower estuary. The distribution of δ13C during the estuarine mixing, in combination with the notable deviation of DOC concentration, provided strong evidence for a substantial DOC removal in the salinity range of 5 to 22. In contrast to δ13C, the δ15N of DOM exhibits a strong seasonality, implying a clear decoupling of estuarine DOC and dissolved organic nitrogen (DON) dynamics. During dry periods with low river discharge, sewage‐derived DON contributed significantly to the riverine loading. While freshwater‐saltwater mixing is important in regulating the distribution of DON, the distribution of δ15N along the salinity gradient provided strong evidence for active sediment‐water interaction and adsorption/desorption processes at the middle to high salinities. During wet periods, severe soil loss and erosion, and/or in situ biological production, adsorption onto suspended particles dominate the riverine DON fluxes, whereas the DON dynamics might be governed by different biogeochemical processes between spring and summer, as reflected by distinct δ15DON patterns in the estuarine zone. In spring, highly degraded DON originating from soil experienced little further biological alternation during estuarine mixing, whereas there was a tight coupling of DON production and consumption in summer. Yin, L., Li, J., Tian, H., Long, X., 2018. Rhenium–osmium and molybdenum isotope systematics of black shales from the Lower Cambrian Niutitang Formation, SW China: Evidence of a well oxygenated ocean at ca. 520?Ma. Chemical Geology 499, 26-42. Early Cambrian was a key period in Earth's history, and the reconstruction of ancient ocean chemistry on spatial and temporal scales can contribute to a better understanding of events during that period. New Early Cambrian data for Re–Os and Mo isotopic compositions and redox-sensitive elements (RSE) are reported here for the Niutitang Formation, SE Chongqin, SW China. A Re–Os age of 520?±?30?Myr (Model 3, 2σ, n?=?21, MSWD?=?62) and a (187Os/188Os)i ratio of 0.79?±?0.11 were obtained, consistent with previously reported data for equivalent strata from other areas. Separate regression of samples with (187Os/188Os)i of 0.72–0.79 and 0.81–0.89 produce more precise ages of 520.1?±?9.5?Myr (Model1, 2σ, n?=?7, MSWD?=?1.0) and 513?±?10?Myr (Model 1, 2σ, n?=?8 MSWD?=?0.96) respectively, suggesting heterogeneity in the primary source of Os as the dominant cause of scatter and uncertainty. High initial 187Os/188Os of 0.79?±?0.11 may indicate a high Os input from oxidative weathering of upper continental crust for Early Cambrian ocean.Based on RSE data such as Mo, U, V enrichment and Ni/Co, V/Cr, V/(V?+?Ni), MoEF/UEF, Re/Mo ratios, two geochemically distinct zones (upper and lower) can be delineated in the sedimentary sequence, as reflected in drillcore sections. The upper section (n?=?9) is characterized by low total organic carbon (TOC) contents (mean 1.8?±?1.5?wt%), low RSE contents (Mo (0.008?±?0.006)?×?10?3?g/g; V (0.22?±?0.15)?×?10?3?g/g; U (0.008?±?0.004)?×?10?3?g/g), and low V/Cr (2.0?±?1.7), Ni/Co (5.9?±?3.5), MoEF/UEF (2.6?±?1.8), and Mo/TOC (6.0?±?3.9) ratios; in contrast, the lower core section (n?=?13) is characterized by high TOC contents (4.4?±?2.2?wt%), high RSE contents (Mo (0.10?±?0.08)?×?10?3?g/g; V (1.0?±?1.0)?×?10?3?g/g; U (0.05?±?0.04)?×?10?3?g/g), high V/Cr (6?±?5), Ni/Co (24?±?14), MoEF/UEF (6.3?±?2.2), and Mo/TOC (21?±?9) ratios (uncertainties are ±1SD here). Significantly decreasing trends of those redox proxies from lower to upper sections suggest that the depositional conditions evolved from anoxic/euxinic to oxic condition. All samples display extremely low Re/Mo ratios of 0.2?×?10?3–1.9?×?10?3, indicating the absence of intermediate reducing conditions, possibly reflecting rapid ocean oxygenation.The Mo isotopic composition in the sedimentary succession of the YC9 core exhibits a large variation, with δ98/95Mo values of 0.04–2.00‰. Upper section δ98/95Mo values display an opposite trend to Mn content and negative correlation with Mo/TOC ratios, indicating Mo fractionation associated with adsorption on Mn oxides or oxyhydroxides. Lower section δ98/95Mo values are positively correlated with Mo/TOC ratios and negatively with Re/Mo ratios, suggesting incomplete conversion of molybdates to tetrathiomolybdates under weakly euxinic conditions.High δ98/95Mo of 2.00‰ and high average Mo/TOC ratios of 21 (10?6?g/g)/wt% were observed in euxinic shales in the Niutitang Formation, suggesting extensive ocean oxygenation may have taken place at ca. 520?Ma.Yin, T., Yang, Z., Dong, Z., Lin, M., Zhang, J., 2019. Physicochemical properties and potential applications of silica-based amphiphilic Janus nanosheets for enhanced oil recovery. Fuel 237, 344-351. flooding has recently garnered significant attention as a novel enhanced oil recovery (EOR) technology; however, there are limitations to the current simple nanofluid flooding. Compared with the commonly used homogeneous spherical nanoparticles, amphiphilic Janus nanosheets have a higher interfacial activity and greater application potential for EOR. In this paper, a carboxyl/alkyl composite silica-based amphiphilic Janus nanosheets (CSAJN) were prepared by a bottom-up synthesis strategy, and the physicochemical properties and EOR potential were systematically investigated. The results showed that the CSAJN displayed a distinct ultrathin flake-like morphology and a lateral size in the range of hundreds of nanometres. More specifically, the CSAJN had two different sides, one side containing a carboxyl group that was hydrophilic, and the other side containing an alkyl group that was hydrophobic. Because of the amphiphilic and Janus nature, the CSAJN could be dispersed in different polar solvents, reduce the oil-water interfacial tension and enhance the oil-water interfacial film strength. Core displacement experiments showed that the CSAJN nanofluid could significantly increase the efficiency of oil recovery to ～18.31% even at an ultralow concentration of 0.005?wt% and cause minimal impairment to the permeability. By observing and analysing the interfacial behaviour of CSAJN in a toluene/brine system, it was found that the formation of a climbing film and high-strength elastic oil-water interfacial film by CSAJN may play an important role in EOR mechanism. This work reveals the physicochemical properties of silica-based amphiphilic Janus nanosheets and provides a novel efficient nanofluid system for EOR.You, L., Cheng, Q., Kang, Y., Chen, Q., Dou, L., Zhou, Y., 2018. Imbibition of oxidative fluid into organic-rich shale: Implication for oxidizing stimulation. Energy & Fuels 32, 10457-10468. large amount of fracturing fluid enters a well of a shale gas reservoir to create a fracture network, but the recovery of fracturing fluid is generally less than 30%. Fracturing fluid from the hydraulic fractures usually invades the microfractures and matrix by spontaneous imbibition during the shut-in. Recent studies show that the water–rock interaction may induce shale structure failures, which can significantly affect imbibition rate. Due to the presence of oxidizable compositions (e.g., pyrite and organic matter (OM)), oxidation easily induced the structure failures and dissolution pores. However, its effects on imbibition of water into the shale is poorly understood. In this study, imbibition experiments of deionized water (DI water) and oxidative fluid under no confining pressure conditions were conducted to determine the imbibition characteristics; shale cubes (1 cm × 1 cm × 1 cm) and crushed samples (380–830 μm) were treated by DI water and oxidative fluid for revelation of the change in the composition and the associated dissolution structures and explanation of the imbibition characteristics of oxidative fluid in shale. The results show that the final amount of oxidative fluid imbibed is higher than that of DI water; oxidation-induced microfractures during the imbibition lead to a “phase step” of the normalized imbibed volume vs time curve and “S” characteristic of the normalized imbibed volume vs square root of time (sqrt time) curve. These differences are mainly caused by the improvement of the imbibition pathway and the increase of water retention space by oxidation. After the oxidation treatment of crushed shale samples for 48 h, lots of oxidation-induced microfractures and dissolution pores were observed by field-emission scanning electron microscopy. Combining the analysis of X-ray diffraction (XRD) and atomic absorption spectroscopy (AAS) found that the dissolution pores seemed to strongly contribute to the loss of calcite, dolomite, and pyrite. Results from mercury injection capillary pressure analysis showed that the oxidative dissolution could lead to a high porosity and good connectivity of nanoscale pores networks in shale cubes. Moreover, oxidative dissolution decreased the barriers of microfracture propagation according to the decrease of zeta potential in the shale–water system and, meanwhile, accelerated the release of clay hydration forces to induce microfractures. The results indicate that the coordinative effect between spontaneous imbibition and oxidative dissolution may play a significant role in increasing the gas supply ability of nanoscale pores and microfractures, thus achieving oxidizing stimulation of shale formation to enhance shale gas recovery.Yu, K., Qu, Z., Ju, Y., Xue, Z., 2018. Burial and thermal history of coal-bearing strata in Shengli coalfield, Erlian Basin. Acta Sedimentologica Sinica 26, 903-913. to the stratigraphic lithologic data and thermal physical parameters, we use 50 sets of vitrinite reflectance data, 46 sets of mudstone sonic slowness data and geothermal data of 3 boreholes to reconstruct the burial history, thermal evolution history and hydrocarbon generation history of the Shengli coalfield since Late Cretaceous period. The result shows: 1) The burial characteristics of "the subsidence of the study area was accompanied by uplifting in the early stage and stopped in the late stage" are expressed in the Shengli coalfield. From Aershan period to early Duhongmu period, the study area entered the accelerated rapid subsidence progress, and the first stage of uplifting and erosion occurred at the end of this sedimentary period. The amount of denudation was about 410 m. From late Duhongmu period to Saihantala period, the study area once again entered the rapid subsidence progress, and then it was in the second stage of uplifting, and the denudation amount was about 580 m. Since late deposition of the Saihantala period, the study area was in a slow-ending subsidence period; 2) From Aershan period to early Duhongmu period, the geotemperature of the study area gradually increased. At the end of early Duhongmu period, the geotemperature reached a peak value of about 90 ℃, and then entered the first stage of uplifting, the temperature decreased rapidly. In the Saihantala period, the geotemperature increased rapidly and reached the peak of 120 ℃ at the end of the deposition, in abnormally high temperature state, and then entered the second stage of uplifting, the geotemperature decreased. After that it was in the stable stage in study area; 3)The maturity of source rocks was controlled by paleo geotemperature. The hydrocarbons source rocks of the Aershan Formation and the Tenggeer Formation were in a low to medium maturity stage and had a certain potential for hydrocarbons generation. The Duhongmu Formation and Saihantala Formation should be in immature stage and had almost no hydrocarbon generating potential.Yu, L., Lu, Q., Qiu, L., Xu, G., Zeng, Y., Luo, X., Wang, S., Mai, B., 2018. Enantioselective dechlorination of polychlorinated biphenyls in Dehalococcoides mccartyi CG1. Applied and Environmental Microbiology 84, Article e01300-18.: Reductive dehalogenation mediated by organohalide-respiring bacteria plays a critical role in the global cycling of organohalides. Nonetheless, information on the dehalogenation enantioselectivity of organohalide-respiring bacteria remains limited. In this study, we report the enantioselective dechlorination of chiral polychlorinated biphenyls (PCBs) by Dehalococcoides mccartyi CG1. CG1 preferentially removed halogens from the (?)-enantiomers of the three major environmentally relevant chiral PCBs (PCB174, PCB149, and PCB132), and the enantiomer compositions of the dechlorination products depended on their parent organohalides. The in vitro assays with crude cell extracts or concentrated whole cells and the in vivo experiments with living cells showed similar enantioselectivities, in contrast with the distinct enantiomeric enrichment factors (εER) of the substrate chiral PCBs. Additionally, these results suggest that concentrated whole cells might be an alternative to crude cell extracts in in vitro tests of reductive dehalogenation activities. The enantioselective dechlorination of other chiral PCBs that we resolved via gas chromatography further confirmed the preference of CG1 for the (?)-enantiomers.Importance: A variety of agrochemicals and pharmaceuticals are chiral. Due to the enantioselectivity in biological processes, enantiomers of chiral compounds may have different environmental occurrences, fates, and ecotoxicologies. Many chiral organohalides exist in anaerobic or anoxic soils and sediments, and organohalide-respiring bacteria play a major role in the environmental attenuation and global cycling of these chiral organohalides. Therefore, it is important to investigate the dehalogenation enantioselectivity of organohalide-respiring bacteria. This study reports the discovery of enantioselective dechlorination of chiral PCBs by Dehalococcoides mccartyi CG1, which provides insights into the dehalogenation enantioselectivity of Dehalococcoides and may shed light on future PCB bioremediation efforts to prevent enantioselective biological side effects.Yung, Y.L., Chen, P., Nealson, K., Atreya, S., Beckett, P., Blank, J.G., Ehlmann, B., Eiler, J., Etiope, G., Ferry, J.G., Forget, F., Gao, P., Hu, R., Kleinb?hl, A., Klusman, R., Lefèvre, F., Miller, C., Mischna, M., Mumma, M., Newman, S., Oehler, D., Okumura, M., Oremland, R., Orphan, V., Popa, R., Russell, M., Shen, L., Sherwood Lollar, B., Staehle, R., Stamenkovi?, V., Stolper, D., Templeton, A., Vandaele, A.C., Viscardy, S., Webster, C.R., Wennberg, P.O., Wong, M.L., Worden, J., 2018. Methane on Mars and habitability: Challenges and responses. Astrobiology 18, 1221-1242. measurements of methane (CH4) by the Mars Science Laboratory (MSL) now confront us with robust data that demand interpretation. Thus far, the MSL data have revealed a baseline level of CH4 (～0.4 parts per billion by volume [ppbv]), with seasonal variations, as well as greatly enhanced spikes of CH4 with peak abundances of ～7?ppbv. What do these CH4 revelations with drastically different abundances and temporal signatures represent in terms of interior geochemical processes, or is martian CH4 a biosignature? Discerning how CH4 generation occurs on Mars may shed light on the potential habitability of Mars. There is no evidence of life on the surface of Mars today, but microbes might reside beneath the surface. In this case, the carbon flux represented by CH4 would serve as a link between a putative subterranean biosphere on Mars and what we can measure above the surface. Alternatively, CH4 records modern geochemical activity. Here we ask the fundamental question: how active is Mars, geochemically and/or biologically? In this article, we examine geological, geochemical, and biogeochemical processes related to our overarching question. The martian atmosphere and surface are an overwhelmingly oxidizing environment, and life requires pairing of electron donors and electron acceptors, that is, redox gradients, as an essential source of energy. Therefore, a fundamental and critical question regarding the possibility of life on Mars is, “Where can we find redox gradients as energy sources for life on Mars?” Hence, regardless of the pathway that generates CH4 on Mars, the presence of CH4, a reduced species in an oxidant-rich environment, suggests the possibility of redox gradients supporting life and habitability on Mars. Recent missions such as ExoMars Trace Gas Orbiter may provide mapping of the global distribution of CH4. To discriminate between abiotic and biotic sources of CH4 on Mars, future studies should use a series of diagnostic geochemical analyses, preferably performed below the ground or at the ground/atmosphere interface, including measurements of CH4 isotopes, methane/ethane ratios, H2 gas concentration, and species such as acetic acid. Advances in the fields of Mars exploration and instrumentation will be driven, augmented, and supported by an improved understanding of atmospheric chemistry and dynamics, deep subsurface biogeochemistry, astrobiology, planetary geology, and geophysics. Future Mars exploration programs will have to expand the integration of complementary areas of expertise to generate synergistic and innovative ideas to realize breakthroughs in advancing our understanding of the potential of life and habitable conditions having existed on Mars. In this spirit, we conducted a set of interdisciplinary workshops. From this series has emerged a vision of technological, theoretical, and methodological innovations to explore the martian subsurface and to enhance spatial tracking of key volatiles, such as CH4.Zablocki, O., van Zyl, L., Trindade, M., 2018. Biogeography and taxonomic overview of terrestrial hot spring thermophilic phages. Extremophiles 22, 827-837. viruses (“phages”) play important roles in the regulation and evolution of microbial communities in most ecosystems. Terrestrial hot springs typically contain thermophilic bacterial communities, but the diversity and impacts of its associated viruses (“thermophilic phages”) are largely unexplored. Here, we provide a taxonomic overview of phages that have been isolated strictly from terrestrial hot springs around the world. In addition, we placed 17 thermophilic phage genomes in a global phylogenomic context to detect evolutionary patterns. Thermophilic phages have diverse morphologies (e.g., tailed, filamentous), unique virion structures (e.g., extremely long tailed siphoviruses), and span five taxonomic families encompassing strictly thermophilic phage genera. Within the phage proteomic tree, six thermophilic phage-related clades were identified, with evident genomic relatedness between thermophilic phages and archaeal viruses. Moreover, whole proteome analyses showed clustering between phages that infect distinct host phyla, such as Firmicutes and Deinococcus–Thermus. The potential for discovery of novel phage-host systems in terrestrial hot springs remain mostly untapped, thus additional emphasis on thermophilic phages in ecological prospecting is encouraged to gain insights into the microbial population dynamics of these environments.Zagor??ak, R., Thomas, H.R., 2018. Effects of subcritical and supercritical CO2 sorption on deformation and failure of high-rank coals. International Journal of Coal Geology 199, 113-123. paper presents the results of an extensive experimental analysis aimed at establishing the effects of subcritical and supercritical CO2 sorption on deformation and failure of coals. Two high-rank anthracitic coals from the South Wales coalfield, obtained from different locations and depths of 150?m and 550?m, are employed for that purpose. The investigations include i) determination of unconfined compressive strengths and elastic moduli of the cores both non-saturated and saturated with CO2 at 2.1?MPa, 4.3?MPa and 8.5?MPa, ii) assessing the dependence of the parameters obtained on CO2 pressure, iii) analysing the effect of CO2 saturation on failure patterns of the samples tested and iv) determination of the particle size distribution after the failure of the samples. Based on the results of twenty coal specimens tested, it is demonstrated that CO2 sorption reduces the uniaxial compressive strengths and elastic moduli by between 29% and 83% for the range of pressures studied. The reductions observed increase gradually up to 4.3?MPa and then reach a plateau. By accommodating the effect of effective stress on compressive strength values, it is shown that chemical weakening of high rank coals is mostly associated with sorption of subcritical CO2, with negligible impact of supercritical CO2 on further parameter reduction. Inspection of failure patterns during uniaxial compression suggests that non-saturated coal specimens fail through axial splitting with rapid crack propagation and high outburst of coal pieces while the failure of cores subjected to CO2 injection occurs through multiple fractures with negligible material outburst. The post-failure analysis demonstrates that CO2 treated samples disintegrate on smaller particles than non-saturated specimens, as up to 5.6 more CO2 saturated coal pieces passed through the sieves considered in this study than non-saturated pieces. It is claimed that this study presents novel insights into the geomechanical response of high rank anthracitic coals to high pressure CO2 injection.Zang, X., Liang, D., 2018. Experimental study on hydrate formation with synthesized CH4/CO2/N2 ternary mixtures. Energy & Fuels 32, 10745-10753. variations in the equilibrium conditions of the hydrate phase between different gas components can be employed for gas separation. The use of hydrate-based gas separation technologies for CH4 recovery from biogas has gained prominence. In this study, the formation of a ternary mixture gas hydrate with CH4, CO2, and N2 was studied. The amount of gas consumed and the hydrate formation rate were calculated using pressure and temperature variations during the reaction. Gas composition changes, the CH4 recovery factor, and CO2 split ratio were the key parameters considered to evaluate the technical feasibility of HBGS. Results indicated that the formation of the mixture gas hydrate depends on the driving force between the hydrate equilibrium conditions and operating conditions. The process of hydrate formation can be divided into two stages: Most of the CO2 formed the hydrate in the first stage, and both CH4 and N2 may have entered the hydrate structure in the second stage. For a given gas, the CO2 separation and CH4 recovery could not be optimized for one specific P–T condition. The powder X-ray diffraction measurements indicated that the ternary mixture gas hydrate was an structure I. The experimental results herein can provide data and theoretical support for CH4 purification and CO2 separation from biogas.Zangrando, R., Corami, F., Barbaro, E., Grosso, A., Barbante, C., Turetta, C., Capodaglio, G., Gambaro, A., 2019. Free phenolic compounds in waters of the Ross Sea. Science of The Total Environment 650, 2117-2128. presence of free phenolic compounds (PC) in Antarctic sea water has been investigated to explain their source and particle size distribution in the atmospheric aerosols, as determined in our previous research. The sea water samples were filtered to distinguish the PC concentrations in the particulate and dissolved fractions. Two sample preparation procedures were developed to quantify nine PC in both fractions. The highest concentrations were found in the dissolved fraction of Ross Sea water, with vanillin, vanillic acid, acetovanillone and p-coumaric acid being the most abundant PC. Dissolved PC were mainly found in the upper part of water column. This facilitated the sea water-air exchange by bubble busting processes. In the aerosol, they were mainly found in the fine fraction, where these compounds have a higher degree of oxidation than PC detected in seawater, suggesting that they were newly emitted and they have been not yet oxidized. These results supported our previous hypothesis that PC were locally emitted into the atmosphere from the Ross Sea. Three different possible sources of PC are hypothesized for Antarctic sea waters: 1) from the intrusion of Modified Circumpolar Deep Water that may transport oceanic lignin; 2) from phytoplankton biomass that may be a source of PC in Antarctic waters since diatoms produce exudates that contain vanillic acid, p-coumaric acid and syringic acid; 3) from the melting of glaciers and sea ice: glaciers contain lignin that can be degraded, while in the sea ice there are diatoms that may release PC. Statistical analysis and the low value of vanillic acid/vanillin ratio indicated that the most plausible source for PC in the dissolved fraction was the senescence of phytoplankton. As a contrast, particulate PC with higher vanillic acid/vanillin ratios were ascribed to degraded lignin or the sorption of diagenically oxidized material on particles.Zatsepa, S.N., Ivchenko, A.A., Korotenko, K.A., Solbakov, V.V., Stanovoy, V.V., 2018. The role of wind waves in oil spill natural dispersion in the sea. Oceanology 58, 517-524. paper analyzes the available parametrizations for calculating oil dispersion in water. A new parametrization of oil droplet flux into water has been elaborated based on a number of recent experimental studies on wind waves and oil droplet dispersion during wave breaking. The turnover rate (TOR) of the sea surface is proposed to determine the primary flux of oil droplets into water. The parameter of lognormal distribution (median) of oil droplets is calculated versus their sizes in a wide range of oil density, viscosity, interfacial tension, and wind speed.Zavarzina, A.G., Lisov, A.V., Leontievsky, A.A., 2018. The role of ligninolytic enzymes laccase and a versatile peroxidase of the white-rot fungus Lentinus tigrinus in biotransformation of soil humic matter: Comparative in vivo study. Journal of Geophysical Research: Biogeosciences 123, 2727-2742. organic matter (SOM) turnover by ligninolytic fungi is a large‐scale process that controls organic carbon geochemistry in terrestrial ecosystems. However, the role of certain oxidative enzymes (e.g., laccase) in humus degradation remains unclear, as well as the molecular structure and recalcitrance of SOM components. In order to address these questions, the degradation of forest soil humic acid (HA) in the presence of laccase and a versatile peroxidase (VP) has been studied in the liquid culture of Lentinus tigrinus. Contrary to the evolving views on humus structure, we have found that alkali‐extractable and acid‐insoluble constituents of SOM (HA) contain true macromolecular components, stable in the presence of 0.1% sodium dodecyl sulfate but degradable/resynthesizable by oxidative enzymes acting on covalent linkages. The HA degradation in the presence of laccase (high N medium) occurs at slower initial rate than in the presence of VP (low N medium). However, each of the enzymes caused about 60% color loss and almost complete degradation of HA into smaller molecules (gel‐filtration data) within 2 weeks of cultivation. Depolymerization of HA in the culture liquid in the presence of laccase was accompanied by polymerization of degradation products on mycelium. Our results show that (1) humus macromolecules are not stable to oxidative enzymes once desorbed from the mineral phase, (2) laccase of Lentinus tigrinus is comparable by its degradation potential to VP, and (3) interfacial secondary synthesis reactions occur during humus decay in the presence of laccase. Our results highlight the important role of laccases in SOM sequestration in soils. Zhang, H.-Y., Hartmann, H., Gleixner, G., Thoma, M., Schwab, V.F., 2019. Carbon isotope fractionation including photosynthetic and post-photosynthetic processes in C3 plants: Low [CO2] matters. Geochimica et Cosmochimica Acta 245, 1-15. isotope ratios of plants are highly informative for the reconstruction of ancient environments and for the interpretation of plant physiological processes to climate, but their responses to changing atmospheric CO2 concentration are currently debated. Moreover, plants in the geological past have experienced long-term low CO2 concentration (LC). However, the effects of LC on the plant C isotope ratios are still elusive.To investigate effects of atmospheric CO2 concentration ([CO2]) and drought on isotope ratios of plant metabolites we grew winter wheat (Triticum aestivum) in climate-controlled chambers under different [CO2] covering glacial, pre-industrial, and present concentrations (170, 280, and 400?ppm) and water regimes (well-watered and drought).First, we quantified total C isotope discrimination between plant and atmosphere (Δ) using 13C on-line measurements of plant gas exchange and 13C values of plant metabolites, i.e., cellulose, n-alkane, and phospholipid fatty acids (PLFA). We found that LC yielded a higher Δ regardless of water regime, i.e. more 13C-depleted values were found under LC; the effect was stronger for n-C29 alkane (1.5‰/100?ppm) and C16:0 PLFA (1.1‰/100?ppm) than that for cellulose (0.6‰/100?ppm). We then calculated post-photosynthetic C isotope shift (?) between specific metabolites and plant bulk isotope values. δ13Cn-C29 alkane and δ13CPLFA were 8.3‰ and 7.3‰ lighter than the δ13Cbulk under 400?ppm; these depletions became higher (9.8‰ and 8.2‰ lighter than the δ13Cbulk for n-C29 alkane and PLFA, respectively) under 170?ppm. In contrast, δ13Ccellulose was 1.2‰ heavier than the δ13Cbulk under 400?ppm while this enrichment became higher (1.6‰) under 170?ppm.Changes in atmospheric [CO2] affected C fractionation not only via photosynthetic but also post-photosynthetic processes and thus must be taken into account when interpreting C isotopes for paleoclimate reconstruction and future global C cycle predictionZhang, H., Luo, X., Bi, J., He, G., Li, Z., 2018. Multi-component fractal representation of multi-scale structure of natural gas hydrate-bearing sediments. Journal of Natural Gas Science and Engineering 60, 144-152. is a set owning an infinitely fine structure in a self-similar or self-affine way covering all scales, and is widely used to model the structure of porous media. Hydrate-bearing sediments belong to porous media, so this paper attempts to construct a structure model of hydrate-bearing sediments with the three-component fractal extended from the two-component fractal. The three-component fractal is capable to display structural details at arbitrarily small scale. Additionally, in the three-component fractal, any parameter defined as the ratio (such as porosity and hydrate saturation) of two different volumes approaches a determined value when considering the infinitesimal scale. The interface between hydrate elements and pore elements is suggested to be a potential way to classify the hydrate-bearing sediments. Using the proposed three-component fractal model to calculate the interface between one arbitrary hydrate particle and surrounding pores, we obtain the theoretical solutions of the amount of substance, the dissociation rate and maximal dissociation time of one arbitrary hydrate element in sediments. It is found that the effective reacting surface of one hydrate element in sediments could be equal to even greater than that of the pure hydrate element in the late period of hydrate dissociation, during which the amount of substance of one hydrate element in sediments is still greater though. Finally, we further extend the three-component fractal to any-component fractal, and show how to model more complex porous media by using a suitable generator.Zhang, J., Liu, F., Yang, H., Zhu, Y., Wang, X., Hua, Z., 2018. Effect of ion type on the interaction between polar model oil and mica substrate: A chemical force microscopy study. Energy & Fuels 32, 10486-10492. salinity waterflooding is an effective approach to improving oil recovery, behind which the microscopic mechanisms have been debated over the past decade, and especially, the role of polar organic components of crude oil is almost ignored but proposed to dominate the adhesion force of oil-rock in specific cases. In this study, chemical force microscopy (CFM) was used to directly measure the adhesion forces between polar model oil and mineral surface in the presence of electrolyte solution with different ionic type and concentration. By the use of classic Derjaguin–Landau–Verwey–Overbeek (DLVO) theory, the van der Waals and electrostatic forces were calculated, and it was found that there were some additional interactions, denoted as structural forces, playing an important part in the resultant forces. By the aid of extended DLVO (EDLVO) theory, the adhesion force of polar tip–substrate was found to increase in the order: Na+ < Ca2+ < Mg2+, and the low salinity effect (LSE) potential shows the opposite order, attributed to the ligand bridging and strong solvation of multivalent cations enhancing the electrostatic attraction of the tip–surface pair. In the case of sulfate ion as the anion, the adhesion force was smaller than that in the case of chloride ion because the SO42– ion can favor the formation of electrostatic repulsion between the tip and surface and accordingly enhance the LSE potential. On the basis of the experimental results, we propose a molecular interaction model between oil and solid substrate, which will provide an in-depth understanding of the effect of brine composition and concentration on oil detaching from a solid surface at the molecular level.Zhang, K., Jia, N., 2019. Confined fluid interfacial tension calculations and evaluations in nanopores. Fuel 237, 1161-1176. this paper, confined fluid interfacial tensions (IFTs) in nanopores and their influential factors are studied. First, a new generalized equation of state (EOS) considering the pore radius, intermolecular interactions, and wall effect is developed analytically for calculating the thermodynamic phase behaviour of confined pure and mixing fluids in nanopores. Second, the modified model based on the new EOS and coupled with the parachor model, which also takes account for the capillary pressure and shifts of critical properties, is applied to calculate the IFTs in nanopores at different conditions. Third, the following four important factors are specifically studied to evaluate their effects on the IFTs in nanopores: feed gas to liquid ratio (FGLR), temperature, pore radius, and wall-effect distance. The newly-developed model is found to be accurate for vapour–liquid equilibrium (VLE) and IFT calculations in bulk phase and nanopores by comparing with the measured and calculated data in the literature. The IFTs in bulk phase of the pure and mixing hydrocarbon (HC) systems are always higher than those in nanopores. At low pressures, the calculated IFTs in nanopores from the new model are higher than those from the previously modified EOS, whereas they become almost equivalent at high pressures. The calculated IFTs of the simple HC systems in nanopores keep constant at different FGLRs while they are decreased by reducing the FGLRs for a multicomponent mixing HC system. Moreover, at low pressures, the gaseous CO2–mixing HC IFTs in bulk phase and nanopores are inferred to be lowered by increasing the temperature while the liquid/supercritical CO2–mixing HC IFTs may be increased. The temperature effect on the IFTs are weakened in nanopores at most pressures except for some extremely high pressure cases. The IFTs in nanopores are decreased with the reduction of pore radius but keep constant at δp/rp?≥?1.0.Zhang, L., Cho, S., Hashisho, Z., Brown, C., 2019. Quantification of fugitive emissions from an oil sands tailings pond by eddy covariance. Fuel 237, 457-464. sands tailings ponds are sources of greenhouse gasses (GHG) and air pollutants. The flux chamber technique, typically used to measure emissions from tailings ponds, samples a small area for a short duration, which may not account for the spatial and temporal variability of emissions from oil sands tailings ponds. The eddy covariance (EC) technique, with large spatial coverage and better temporal resolution, is a promising method to improve the accuracy of emission flux quantification. A field campaign was conducted to measure emissions from an oil sands tailings pond in Alberta using an EC system. Average CH4 and CO2 emission fluxes were 4.56?×?10?2?g/(m2-d) and 3.59?g/(m2-d), respectively. Diurnal and daily variations of CH4 and CO2 emission fluxes were strong with relative standard deviations of 97–158%. Nighttime (18:30 to 8:00, inclusive) CH4 average emission flux (6.55?×?10?2?g/(m2-d)) was 2.8 times daytime (8:30 to 18:00, inclusive) CH4 flux (2.32?×?10?2?g/(m2-d)) while nighttime CO2 average emission flux (2.97?g/(m2-d)) was 0.7 times daytime CO2 emission flux (4.29?g/(m2-d)). Pearson correlation test results suggest that short-term (i.e., days to weeks) variations of CH4 and CO2 emission fluxes measured in this study were not strongly (but can be weakly) correlated with meteorological variables or the 90% cumulative flux contour distance. The CH4 and CO2 emission fluxes determined in this study were of the same order of magnitude as those from a previous study that used the EC technique at the same tailings pond. CO2 fluxes in this study were similar while CH4 fluxes in this study were more than an order of magnitude lower than fluxes based on flux chamber measurements conducted by a 3rd party at the same location and in the same month and year as part of routine regulatory monitoring requirements. Continuous, real-time, and long-term monitoring of tailings ponds emissions is necessary to reduce uncertainty and improve representativeness and accuracy of emission flux quantification.Zhang, M., Fu, X., 2018. Characterization of pore structure and its impact on methane adsorption capacity for semi-anthracite in Shizhuangnan Block, Qinshui Basin. Journal of Natural Gas Science and Engineering 60, 49-62. determine the pore structure characteristics and its effect on the adsorption capacity of semi-anthracite, high pressure mercury injection (HPMI), Low pressure nitrogen gas adsorption (LP-N2GA), Low pressure carbon dioxide gas adsorption (LP-CO2GA) and isotherm adsorption experiments were carried out on eight coal samples collected from the Shizhuangnan Block. The results show that the semi-anthracite reservoirs predominantly developed semi-open pores with poor connectivity and various pore morphology. The combined pore size distribution (PSD) from results of HPMI, LP-N2GA and LP-CO2GA indicated that the super-micropores in semi-anthracite reservoirs are most developed, providing the main storage space, accounting for 80.75% of the total TPV and 99.69% of the total SSA, followed by macropores. Additionally, the pore volume and SSA distributions of semi-anthracite reservoirs are unimodal with peak values present at 0.5–0.6?nm, indicating that pores with pore diameter between 0.5 and 0.6?nm are the largest contributors to TPV and SSA, accounting for 40.09% of the TPV and 56.95% of the total SSA. The super-micropores have a controlling factor on the adsorption capacity of semi-anthracite reservoirs. Vitrinite-rich coals developed stronger adsorption capacity as the vitrinite is rich in super-micropores whereas there are no obvious correlations between inertinite content with super-micropore SSA and VL. Additionally, mineral has a negative effect on the adsorption capacity of coals by inhibiting the development level of super-micropores. The combination application of HPMI, LP-N2GA and LP-CO2GA can more accurately reflect the pore structure of coal reservoir, especially for super-micropores.Zhang, M., Li, J., Chen, J., 2018. Thermal effect on the distribution of rearranged hopanes in hydrocarbon source rocks. Acta Sedimentologica Sinica 26, 1033-1039. molecular geochemical characteristics of a total 87 samples of lacustrine and coal measure hydrocarbon source rocks collected from the Songliao Basin and Ordos Basin are systematically analyzed in order to evaluate thermal effect on the distribution characteristics of rearranged hopanes in hydrocarbon source rocks. The results indicate that both lacustrine and coal measure hydrocarbon source rocks contain abundantly four series of rearranged hopanes and their distributions in geological bodies from different depositional environments or parent material sources show similar variation trends. The relatively lower abundant rearranged hopanes are distributed from low mature to high mature stages, whereas the abnormally high or higher abundant rearranged hopanes are mainly presented in mature stage. The linear correlations between the 17α(H)-diahopane series and other three series of rearranged hopanes including 18α(H)-neohopane series, the early-eluting rearranged hopane series and 21-methyl-28-nor-hopane series, are diverse clearly. In addition, the variations of relative abundance of rearranged hopanes from the two sets of samples show similar trend. For example, the relative abundances of 17α(H)-diahopane and 18α(H)-neohopane display an initial increase and a following decrease with increasing maturity and the highest amounts appear to be distributed in the range of maturity 0.8%-0.9% Ro. On the other hand, the absolute concentrations of rearranged hopanes have consistent variation for the hydrocarbon source rocks derived from different sedimentary environments with increasing maturity. Rearranged hopanes are formed at immature to mature stage corresponding to Ro=0.5%-0.7%. With the source rocks into mature stage (Ro=0.7%-0.8%), the absolute concentration decreases remarkably with the decreasing extent more than 90%. The consistency of variation of relative abundance and absolute concentration of rearranged hopanes in different depositional systems indicate that thermal effect has much more important impact on the distribution and composition of rearranged hopanes compared with sedimentary environments and biological sources.Zhang, R., Li, T., Russell, J., Zhou, Y., Zhang, F., Liu, Z., Guan, M., Han, Q., 2018. High-resolution reconstruction of historical flood events in the Changjiang River catchment based on geochemical and biomarker records. Chemical Geology 499, 58-70. hydrologic events such as floods have caused catastrophic losses to modern human society, especially in highly developed coastal areas. However, high-resolution reconstructions of extreme flood events are scarce due to a paucity of suitable proxies in marginal seas. Here we present a high-resolution record of extreme flood events in the Changjiang River catchment during the last 110?years using samples from the subaqueous delta of Changjiang River estuary. We used a multi-proxy approach including Sr-Nd isotopes, Zr/Rb ratio and biomarkers (branched GDGTs, i.e. brGDGTs, and crenarchaeol, and the ratio of the two as calculated by the BIT index) as proxies for the evolution of extreme floods in the Changjiang River catchment. Rapid shifts in these proxies agreed with the timing of floods on the Changjiang River. We also tested the reliability of biomarker indices to reconstruct paleoflood events in this area. The results indicated that the abundances of GDGTs fluctuated in concert with historical floods. Cross-spectral analyses revealed that historical floods in the Changjiang River catchment were consistent with ENSO variance.Zhang, W., Wang, Q., Ning, Z., Zhang, R., Huang, L., Cheng, Z., 2018. Relationship between the stress sensitivity and pore structure of shale. Journal of Natural Gas Science and Engineering 59, 440-451. pore structure of shale changes with variations in the effective stress, greatly affecting the gas production of shale. The relationship between pore structure and stress sensitivity has remained unclear to date. The porosity sensitivity exponent and pore compressibility are two crucial parameters for describing the stress sensitivity and relate to the pore structure of shale. In this study, expressions of the porosity sensitivity exponent and pore compressibility were deduced based on a dual-porosity model. The results show that the scale and quantity of the micro-fractures and matrix pores play an important role in determining the porosity sensitivity exponent and pore compressibility. Regarding the pore structure of shale, a low ratio of the porosity of the matrix pores to the porosity of the micro-fractures causes the porosity sensitivity exponent to be low and the pore compressibility to be high; consequently, the shale shows strong stress sensitivity. The results regarding the porosity sensitivity exponent and pore compressibility indicate that the pore compressibility is the dominant factor influencing the stress sensitivity. The pore compressibility is affected by not only the pore structure of shale but also the mechanical properties of shale. Young's modulus is negatively correlated with pore compressibility, while Poisson's ratio shows a positive relationship and can be neglected. The effect of tortuosity on the stress sensitivity was also studied. The fitting results for the Walsh model illustrate that the tortuosity increases the degree of stress sensitivity. The results of this study identified the relationship between stress sensitivity and pore structure of shale, which will enable reservoir engineers to accurately predict stress sensitivity and investigate the permeability and porosity of shale based on its pore structure.Zhang, X., Lin, H., Wang, X., Austin, B., 2018. Significance of Vibrio species in the marine organic carbon cycle—A review. Science China Earth Sciences 61, 1357-1368. genus Vibrio, belonging to Gammaproteobacteria of the phylum Proteobacteria, is a genetically and ecologically diverse group of heterotrophic bacteria, that are ubiquitous in marine environments, especially in coastal areas. In particular, vibrios dominate, i.e. up to 10% of the readily culturable marine bacteria in these habitats. The distribution of Vibrio spp. is shaped by various environmental parameters, notably temperature, salinity and dissolved organic carbon. Vibrio spp. may utilize a wide range of organic carbon compounds, including chitin (this may be metabolized by most Vibrio spp.), alginic acid and agar. Many Vibrio spp. have very short replication times (as short as ~10 min), which could facilitate them developing into high biomass content albeit for relatively short durations. Although Vibrio spp. usually comprise a minor portion (typically ~1% of the total bacterioplankton in coastal waters) of the total microbial population, they have been shown to proliferate explosively in response to various nutrient pulses, e.g., organic nutrients from algae blooms and iron (Fe+) from Saharan dust. Thus, Vibrio spp. may exert large impacts on marine organic carbon cycling especially in marginal seas. Genomics and related areas of investigation will reveal more about the molecular components and mechanisms involved in Vibrio-mediated biotransformation and remineralization processes.Zhang, X., Tu, B., Dai, L.-r., Lawson, P.A., Zheng, Z.-z., Liu, L.-Y., Deng, Y., Zhang, H., Cheng, L., 2018. Petroclostridium xylanilyticum gen. nov., sp. nov., a xylan-degrading bacterium isolated from an oilfield, and reclassification of clostridial cluster III members into four novel genera in a new Hungateiclostridiaceae fam. nov. International Journal of Systematic and Evolutionary Microbiology 68, 3197-3211. rod-shaped, Gram-stain-positive, obligately anaerobic, xylan-degrading bacterium, SK-Y3T, was isolated from oily-sludge of Shengli oilfield, China. Optimum growth occurred at 50?°C, at pH 7.5 and without addition of NaCl. The predominant cellular fatty acids of strain SK-Y3T were iso-C15?:?0, anteiso-C15?:?0 and iso-C17?:?0, and the main polar lipids were glycolipids (GL), lipids (L), phosphatidylglycerol (PG) and diphosphatidylglycerol (DPG); no respiratory quinones were detected. The genomic DNA G+C content was 37.2?mol%. Phylogenetic analysis of 16S rRNA gene sequences showed that strain SK-Y3T belongs to clostridial cluster III, exhibiting 91–92% sequence similarity to the most closely related species, namely Clostridium clariflavum , Clostridium straminisolvens and Acetivibrio cellulolyticus . Based on distinct physiological and phylogenetic differences from the aforementioned described taxa, strain SK-Y3T (=DSM 103557T=ACCC 19952T) is proposed as the type strain of a novel species of a new genus, Petroclostridium xylanilyticum gen. nov., sp. nov. Furthermore, analysis through 16S rRNA gene, ribosomal protein and whole genome sequences indicated that clostridial cluster III members should be reclassified into four novel genera for which the names Hungateiclostridium gen. nov., Thermoclostridium gen. nov., Ruminiclostridium gen. nov. and Pseudoclostridium gen. nov. are proposed. In combination with the genera Anaerobacterium , Cellulosibacter, Ercella , Fastidiosipila , Mageeibacillus , Pseudobacteroides, Petroclostridium and Saccharofermentans , clostridial cluster III members formed a monophyletic clade within the order Clostridiales but that was clearly distinguished from other Ruminococcaceae members, which is proposed as a novel family, Hungateiclostridiaceae fam. nov. The GenBank/EMBL/DDBJ accession numbers of the 16S rRNA gene and whole-genome sequences for strain SK-Y3T are KT630605 and GCA_002252565 .1, respectively.Zhang, X., Xu, W., Liu, Y., Cai, M., Luo, Z., Li, M., 2018. Metagenomics reveals microbial diversity and metabolic potentials of seawater and surface sediment from a hadal biosphere at the Yap Trench. Frontiers in Microbiology 9, 2402. doi: 10.3389/fmicb.2018.02402. biosphere represents the deepest part of the ocean with water depth greater than 6,000 m. Accumulating evidence suggests the existence of unique microbial communities dominated by heterotrophic processes in this environment. However, investigations of the microbial diversity and their metabolic potentials are limited because of technical constraints for sample collection. Here, we provide a detailed metagenomic analysis of 3 seawater (5,000-6,000 mbsl) and 3 surface sediments (4,435-6,578 mbsl) from a hadal biosphere at the Yap Trench of the western Pacific. Distinct microbial community compositions were observed in seawater and sediment samples, with the dominance of Gammaproteobacteria and Thaumarchaeota, respectively. Comparative analysis of the genes involved in carbon, nitrogen and sulfur metabolisms revealed that heterotrophic processes (i.e., degradation of carbohydrates, hydrocarbons, and aromatics) are the most common microbial metabolisms in the seawater, while chemolithoautotrophic metabolisms such as ammonia oxidation with the HP/HB cycle for CO2 fixation probably dominated the surface sediment communities of the Yap Trench. Furthermore, abundant genes involved in stress response and metal resistance were both detected in the seawater and sediments, thus the enrichment of metal resistance genes is further hypothesized as characteristic of the hadal microbial communities. Overall, this study sheds light on the metabolic versatility of microorganisms in the Yap Trench, their roles in carbon, nitrogen, and sulfur biogeochemical cycles, and how they have adapted to this unique hadal environment.Zhang, X., Zhang, D., Huang, Y., Zhang, K., Lu, P., 2018. Simultaneous removal of organic matter and iron from hydraulic fracturing flowback water through sulfur cycling in a microbial fuel cell. Water Research 147, 461-471. high volume of flowback water (FW) generated during shale gas exploitation is highly saline, and contains complex organics, iron, heavy metals, and sulfate, thereby posing a significant challenge for the environmental management of the unconventional natural gas industry. Herein, the treatment of FW in a sulfur-cycle-mediated microbial fuel cell (MFC) is reported. Simultaneous removal efficiency for chemical oxygen demand (COD) and total iron from a synthetic FW was achieved, at 72?±?7% and 90.6?±?8.7%, respectively, with power generation of 2667?±?529?mW/m3 in a closed-circuit MFC (CC-MFC). However, much lower iron removal (38.5?±?4.5%) occurred in the open-circuit MFC (OC-MFC), where the generated FeS fine did not precipitate because of sulfide supersaturation. Enrichment of both sulfur-oxidizing bacteria (SOB), namely Helicobacteraceae in the anolyte and the electricity-producing bacteria, namely Desulfuromonadales on the anode likely accelerated the sulfur cycle through the biological and bioelectrochemical oxidation of sulfide in the anodic chamber, and effectively increased the molar ratio of total iron to sulfide, thus alleviating sulfide supersaturation in the closed circuitry. Enrichment of SOB in the anolyte might be attributed to the formation of FeS electricity wire and likely contributed to the stable high power generation. Bacteroidetes, Firmicutes, Proteobacteria, and Chloroflexi enriched in the anodic chamber were responsible for degrading complex organics in the FW. The treatment of real FW in the sulfur-cycle-mediated MFC also achieved high efficiency. This research provides a promising approach for the treatment of wastewater containing organic matters, heavy metals, and sulfate by using a sulfur-cycle-mediated MFC.Zhang, Y., He, Z., Jiang, S., Lu, S., Xiao, D., Chen, G., Li, Y., 2019. Fracture types in the lower Cambrian shale and their effect on shale gas accumulation, Upper Yangtze. Marine and Petroleum Geology 99, 282-291. reveal the characteristics of fractures in high quality shale reservoir and to find regions that are favorable for shale gas accumulation, the characteristics of fractures and their effect on the shale gas content in the lower Cambrian marine shale from 2 typical shale gas wells in the Upper Yangtze have been analyzed in detail by observing the shale cores, scanning electron microscope photographs and rock slice pictures associated with various geochemical data. Five types of macrofractures (high-angle shearing fracture, tension-shearing fracture, compresso-shearing fracture, low-angle slip fracture, and bedding fracture) and 4 types of microfractures (interlayer fracture, inter-particle fracture, intra-particle fracture, and organic matter-associated fracture) have been identified in the lower Cambrian shale. The fractures in lower Cambrian shale have 5 possible origins: 1 generated by tectonic tension and shearing stresses; 2 cracking due to loading pressure relief; 3 corroded by acidic fluids during hydrocarbon generation; 4 induced by overpressured fluid; 5 formed due to diagenesis-associated shrinkage of mineral crystals. In general, the shale in Sichuan Basin contains more nonstructural fractures (including bedding fractures and microfractures), whereas shale outside the basin contains more structural fractures (including high-angle shearing fractures, tension-shearing fractures, and low-angle slip fractures). Three controlling factors of fracture development be summarized as follows: 1 tectonic setting; 2 mineral components; 3 organic matter content and maturity. In conclusion, structural fractures can be considered as destructive, and nonstructural fractures can be considered as favorable. Shale gas reservoirs can be divided into 3 types: type A with a shale gas content >2?m3/t, destructive/structural fractures <20/m, and favorable/nonstructural fractures >100/m; type B with a shale gas content of 1?m3/t - 2?m3/t, destructive/structural fractures <20/m, and favorable/nonstructural fractures 50/m ?100/m; (3) type C with a shale gas content?<?1?m3/t, destructive/structural fractures >20/m, or destructive/structural fractures <20/m, and favorable/nonstructural fractures <50/m.Zhao, D., Guo, Y., Zhu, Y., Wang, G., Liu, J., Chong, X., Zhang, J., 2018. Micropore characteristics and geological significance of pyrite in shale rocks of Longmaxi Formation. Acta Sedimentologica Sinica 26, 864-876. study on shale gas reservoirs has become much more meticulously and quantitatively along with the rapid improvement of shale gas geological theories. As a common material composition of shale gas reservoirs, the mineralogical and pore development characteristics as well as geological significance of pyrite has drawn a lot of attention, especially the nanoscale pores in framboidal pyrite. By using Argon Ion Polishing-Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive Spectroscopy (EDS), and X-ray Diffraction (XRD) combined with Image Processing technology to study on the mineralogical characteristics of different types of pyrite in reservoir rocks and to make quantitative characterization and evaluation of nanoscale pore characteristics as well as the reservoir significance of pyrite in high quality shale reservoir rocks of middle-lower Longmaxi Formation in Southeast Chongqing area, the results showed that the framboidal pyrite was the most developed type of pyrite in the shale matrix of Longmaxi Formation with aggregate diameter ranging between 3-10 μm. The pores in the framboidal pyrite aggregate were mainly nanoscale pores developed in organic matter filling among the crystallites with diameters mainly concentrated below 100 nm. The pores in framboidal pyrite provided the reservoir with 0.7%-7% proportion of pore network in shale matrix and should be classified into Organic-Matter pores. Characterization and evaluation of classified pores based on Image Processing might provide a new approach to study on reservoir pores, being a feasible method to quantitatively study on different types of pores in different compositions. In addition to the reservoir space contributed by framboidal pyrite to the reservoir, the favorable conditions of organic matter preservation under reducing environments provided a basis for the study of high-quality reservoir formation mechanism and the prediction of high-quality reservoirs. Thus, pyrite, especially framboidal pyrite developed in shale matrix, has important geological significance for shale gas in both reservoir study and the exploration of high-quality reservoirs.Zhao, F., Filker, S., 2018. Characterization of protistan plankton diversity in ancient salt evaporation ponds located in a volcanic crater on the island Sal, Cape Verde. Extremophiles 22, 943-954. is an important factor when exploring the limits known for life. Therefore, hypersaline systems have attracted much attention in recent years. In this study, we investigated the protistan diversity and community composition in two natural salt evaporation ponds (27–30% salinity) located in an ancient volcanic crater on the Cape Verde island Sal using high-throughput DNA sequencing. Our study revealed a broad range of protistan taxa and a high taxonomic diversity within the Ciliophora, Dinophyceae, and Chlorophyta. We detected a total of 23 Dinophyceae families, although Dinophyceae were generally considered to be only this diverse in aquatic environments of less than 10% salinity. Moreover, we uncovered a high degree of genetic novelty in this habitat. The mean similarity of all detected OTUs to previously described sequences was only 93.6%. These findings strongly dispute the traditional view that extreme hypersaline environments generally maintain low protistan diversity. A meta-analysis covering our and previously published data from other inland and coastal salt ponds clearly showed that our samples clustered according to salinity and not biogeography. This result further supports the claim that salinity is a major transition boundary for protistan communities, regardless of their biogeographic origin.Zhao, G., Wang, C., 2019. Influence of CO2 on the adsorption of CH4 on shale using low-field nuclear magnetic resonance technique. Fuel 238, 51-58. to the higher adsorption capacity, CO2 can efficiently replace the adsorbed CH4 from shale surface. To understand the effect of CO2 on the adsorption of CH4 on shale is significant for comprehending the mechanisms of enhanced shale methane recovery using CO2 method in shale gas reservoirs. In this work, the low-field nuclear magnetic resonance (NMR) technique is employed to quantitatively investigate the influence of CO2 on the CH4 adsorption on typical shale samples. CH4 is first introduced to “saturate” the shale samples at given pressures; based on the measured T2 spectrum for the “CH4-saturated” shale samples, the states that CH4 exists in shale samples are identified. CO2 is then introduced into the “CH4-saturated” shale samples at higher pressures. By comparing the measured T2 spectrum before and after CO2 introduction, the change of CH4 adsorption of due to the presence of CO2 is comprehensively analyzed. According to the measured T2 spectrum, CH4 exists on shale samples in three different states, i.e., the adsorbed CH4 on pore surface, the free-state CH4 in pore center, and the free-state CH4 among shale particles. Compared to the free-state CH4, the “CH4-saturated” shale samples are dominated by the adsorbed CH4. As pressure increases, the adsorbed amount of CH4 first increases and then tends to level off. After introducing CO2 into the “CH4-saturated” shale samples, the adsorbed CH4 is firstly reduced, suggesting the more affinity of CO2 to the organic shale surface, and then tends to level off, achieving the adsorption/desorption equilibrium. CO2 can replace the adsorbed CH4 from pore surface, decreasing the adsorbed molar amount of CH4. However, the replaced CH4 seems to only become free-state CH4 in pore center and hardly escape from the organic pores. Thereby, other stimulating methods, such as secondary hydraulic fracturing, should be supplemented with the CO2 injection for further development of the shale gas reservoirs.Zhao, J., Ren, L., Shen, C., Li, Y., 2018. Latest research progresses in network fracturing theories and technologies for shale gas reservoirs. Natural Gas Industry B 5, 533-546. view of the bottleneck of shale gas development technologies, the latest progresses in such theories on the fields like fracture network fracability evaluation, fracture network propagation mechanism, stimulated reservoir volume (SRV) evaluation and fracturing fluid research & development were analyzed comprehensively in reference to the existing achievements and experiences in North American shale gas reservoir development and based on the probes, practices and cognitions of shale gas development technologies in China since 2005. First, the study on the shale brittleness develops from the definition of mineral and mechanical semi-quantitative threshold measurement to a comprehensive evaluation which integrates rock constituents, elastic mechanics and development characteristics of natural fractures together. Second, the study on the fracture network development develops from the directional extension theory to the simulation of fracture network formation in the stochastic distribution pattern of natural fractures. Third, the study on SRV develops from the micro-seismic monitoring based instrument and technology to the mathematical theory evaluation method dependent on the discrete fracture network and extended finite element. And fourth, the study on fracturing fluids develops from the wide application of slick water (drag reducing water) and a linear gel fracturing fluid system to the development and application of novel fracturing fluids with little or no water. Then, the theoretical and technological challenges were pointed out, including the comprehensive fracability evaluation of reservoir fracture networks, the deep seated shale gas fracturing, the operation curve diagnosis of shale gas fracturing, the shale gas refracturing theory, and the research & development and flowback control of novel fracturing fluids. Finally, the development trend of related technologies was predicted so as to provide a theoretical and technical guidance for the efficient shale gas development in China in the future.Zhao, Y., Song, K., 2018. Relationships between DOC and CDOM based on the total carbon-specific fluorescence intensities for river waters across China. Journal of Geophysical Research: Biogeosciences 123, 2353-2361. correlations between chromophoric dissolved organic matter (CDOM) absorption coefficient a(440) and dissolved organic carbon (DOC) were observed due to weak absorption for river waters especially in the Qinghai‐Tibetan Plateau, and thus, it is impossible to estimate DOC concentrations by CDOM absorption across China. Therefore, it is necessary to estimate DOC concentrations through the fluorescent fraction of CDOM (i.e., FDOM). FDOM was proposed as a new method for estimation of large‐scale DOC concentrations in river waters across China. A total of 301 water samples from eight river basins across China were selected to assess FDOM by excitation‐emission matrix (EEM) fluorescence. Five fluorescent regions were obtained by EEM coupled with fluorescence regional integration (FRI) (EEM‐FRI) method. However, weak correlations between the fluorescence intensities FR(1–5), FSUM, and DOC concentrations were observed for all water samples, respectively. Therefore, the total carbon‐specific fluorescence intensities FSUM/DOC were used to establish relationships between DOC and FDOM. All 301 water samples excluding five outliers with FSUM/DOC higher than 8,000 nm/(mg/L)) were divided into four groups based on the threshold values for FSUM/DOC, and strong positive correlations between FSUM and DOC were observed in each group (R2 = 0.843, FSUM/DOC < 1,000 nm/(mg/L); R2 = 0.928, 1,000 < FSUM/DOC < 2,000 nm/(mg/L); R2 = 0.964, 2,000 < FSUM/DOC < 3,000 nm/(mg/L); and R2 = 0.953, 3,000 < FSUM/DOC < 8,000 nm/(mg/L)), respectively. This result indicated that the riverine DOC concentrations on large‐scale across China can be estimated directly by FDOM properties. Zheng, C., Brunner, M., Li, H., Zhang, D., Atkin, R., 2019. Dissolution and suspension of asphaltenes with ionic liquids. Fuel 238, 129-138., which comprise polycyclic aromatic hydrocarbon cores with attached short aliphatic side chains, are the most polar fraction of crude oils. Asphaltenes are prone to precipitation, which requires expensive cleaning procedures using solvents like toluene or xylene. The toxicity and high vapour pressures of toluene and xylene means there is an urgent need for new liquids that are able to dissolve or suspend asphaltenes but are less environmentally problematic. This study reports treatment results of asphaltenes with 16 different ionic liquids covering three different types of cation charge groups, namely, cholinium, imidazolium and phosphonium with a wide variety of anions. The two oil-miscible ionic liquids, trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylphentyl)phosphinate and trihexyl(tetradecyl)phosphonium bis(2-ethylhexyl)phosphate, solubilised or suspended a significant fraction of raw asphaltenes. Elemental analysis, TGA and FTIR revealed that asphaltenes recovered from these ionic liquids had increased aliphatic and oxygen content compared to the raw material, and decomposed at lower temperatures during TGA test. The relative hydrophobicity of the ionic liquid is the major factor controlling the asphaltene mass in the ionic liquid, followed by the strength of interactions between ionic liquid and asphaltene alkyl groups. These findings provide a platform for the development of new ionic liquid based cleaners for asphaltene deposits.Zheng, F., Hsu, C.S., Zhang, Y., Sun, Y., Wu, Y., Lu, H., Sun, X., Shi, Q., 2018. Simultaneous detection of vanadyl, nickel, iron, and gallium porphyrins in marine shales from the Eagle Ford Formation, South Texas. Energy & Fuels 32, 10382-10390. in immature shales of the Late Cretaceous Eagle Ford Formation from South Texas were analyzed by positive-ion electrospray ionization (ESI) Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Vanadyl, nickel, iron, and gallium porphyrins were detected in a single mass spectrum. The iron porphyrins were most abundant, followed by vanadyl, nickel, and gallium porphyrins, consistent with the metal contents determined by elemental analysis. The distribution of porphyrins shows that deoxophylloerythroetio (DPEP) porphyrins, dicyclic-deoxophylloerythroetio (di-DPEP) porphyrins, and porphyrins containing oxygen functional groups are the main components. The detection of oxygen-containing porphyrins, such as iron porphyrins with formulas of CnHmN4FeO, CnHmN4FeO2, and CnHmN5FeO2, would offer new clues of petroporphyrins formation mechanism from biological sources, such as chlorophylls and hemes. To our knowledge, this reports for the first time the presence of oxygen-containing iron porphyrins and gallium porphyrins in geological samples other than coals and lignites. The discovery of these petroporphyrins could provide additional insights into the diagenetic pathway of petroporphyrins and novel applications in petroleum geochemistry/exploration and oil refining. The composition of metalloporphyrins may potentially provide clues to decipher the redox conditions during deposition in the Eagle Ford Formation and provide better understanding of the Oceanic Anoxic Event 2 (OAE-2).Zheng, W., Gilleaudeau, G.J., Kah, L.C., Anbar, A.D., 2018. Mercury isotope signatures record photic zone euxinia in the Mesoproterozoic ocean. Proceedings of the National Academy of Sciences 115, 10594-10599. Significance: The occurrence of toxic H2S-rich water in the photic zone of the ocean, a phenomenon called photic zone euxinia (PZE), had profound negative impacts on ancient biological evolution and modern marine ecosystems. We explore the possibility of using mercury (Hg) stable isotopes as a new proxy for PZE. We found that Hg-isotope compositions in sedimentary rocks deposited under oxic versus H2S-rich conditions are distinguishable. The difference in Hg isotopes is most likely caused by contrasting Hg chemical behavior in response to changes in surface ocean redox states. Thus, our data demonstrate that Hg isotopes in marine sediments are a promising proxy of PZE, useful in future studies to refine our understanding on PZE and its impact on life.Abstract: Photic zone euxinia (PZE) is a condition where anoxic, H2S-rich waters occur in the photic zone (PZ). PZE has been invoked as an impediment to the evolution of complex life on early Earth and as a kill mechanism for Phanerozoic mass extinctions. Here, we investigate the potential application of mercury (Hg) stable isotopes in marine sedimentary rocks as a proxy for PZE by measuring Hg isotope compositions in late Mesoproterozoic (～1.1 Ga) shales that have independent evidence of PZE during discrete intervals. Strikingly, a significantly negative shift of Hg mass-independent isotope fractionation (MIF) was observed during euxinic intervals, suggesting changes in Hg sources or transformations in oceans coincident with the development of PZE. We propose that the negative shift of Hg MIF was most likely caused by (i) photoreduction of Hg(II) complexed by reduced sulfur ligands in a sulfide-rich PZ, and (ii) enhanced sequestration of atmospheric Hg(0) to the sediments by thiols and sulfide that were enriched in the surface ocean as a result of PZE. This study thus demonstrates that Hg isotope compositions in ancient marine sedimentary rocks can be a promising proxy for PZE and therefore may provide valuable insights into changes in ocean chemistry and its impact on the evolution of life.Zheng, X., Dupuis, K.T., Aly, N.A., Zhou, Y., Smith, F.B., Tang, K., Smith, R.D., Baker, E.S., 2018. Utilizing ion mobility spectrometry and mass spectrometry for the analysis of polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polybrominated diphenyl ethers and their metabolites. Analytica Chimica Acta 1037, 265-273. aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) are persistent environmental pollutants originating from incomplete combustion of organic materials and synthetic sources. PAHs, PCBs, and PBDEs have all been shown to have a significant effect on human health with correlations to cancer and other diseases. Therefore, measuring the presence of these xenobiotics in the environment and human body is imperative for assessing their health risks. To date, their analyses require both gas chromatography and liquid chromatography separations in conjunction with mass spectrometry measurements for detection of both the parent molecules and their hydroxylated metabolites, making their studies extremely time consuming. In this work, we characterized PAHs, PCBs, PBDEs and their hydroxylated metabolites using ion mobility spectrometry coupled with mass spectrometry (IMS-MS) and in combination with different ionization methods including electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI). The collision cross section and m/z trend lines derived from the IMS-MS analyses displayed distinct trends for each molecule type. Additionally, the rapid isomeric and molecular separations possible with IMS-MS showed great promise for quickly distinguishing the parent and metabolized PAH, PCB, and PDBE molecules in complex environmental and biological samples.Zheng, Y., Liao, Y., Wang, Y., Xiong, Y., Peng, P.a., 2018. Organic geochemical characteristics, mineralogy, petrophysical properties, and shale gas prospects of the Wufeng–Longmaxi shales in Sanquan Town of the Nanchuan District, Chongqing. American Association of Petroleum Geologists Bulletin 102, 2239-2265. marine shales occur in the Wufeng Formation and Longmaxi Formation of Sanquan Town of the Nanchuan District, Chongqing Municipality, which is located on the southeast margin of the Sichuan Basin. However, few details of the characteristics of the Wufeng–Longmaxi shales in this area have been reported. In this study, a well approximately 100 m (～328 ft) deep was drilled. A high-quality shale (total organic carbon [TOC] >2.0 wt. %, clay <40%) interval that was approximately 24 m (～79 ft) thick with an average TOC value of 3.0 wt. % mainly occurs in the Ordovician Wufeng Formation (Katian and Hirnantian) and base of the Silurian Longmaxi Formation (Rhuddanian). Shales with higher TOC values commonly have a higher porosity and specific surface area. Tectonic movements may also have been very important factors that influenced the petrophysical properties of the shales. For example, a detachment layer that resulted from complex tectonic movements is extensive in the Wufeng Formation. The cracks and microcracks in the detachment layer can result in good pore connectivity. Consequently, the detachment layer can be an effective migration pathway. The Longmaxi–Wufeng shales of Sanquan Town are also compared with those of the famous Jiaoye 1 well in the Jiaoshiba shale gas field in the eastern Sichuan Basin. Although the shales in Sanquan Town have considerable shale gas generation potential, the shale gas resource potential in Sanquan Town is probably poor because the escape of shale gas may be accelerated by the detachment layer in destroyed anticlines and synclines.Zhong, F., Xu, M., Metz, P., Ghosh-Dastidar, P., Zhu, J., 2018. A quantitative metabolomics study of bacterial metabolites in different domains. Analytica Chimica Acta 1037, 237-244. metabolite concentrations are essential information for quantitative metabolomics studies, as concentrations are closely related to metabolic reactions, enzyme kinetics and other important biological activities. A well-performed metabolites extraction procedure, a reliable detection method, and a robust quantitative approach are all critical factors for obtaining absolute metabolite concentrations. Here, we used a HPLC-MS/MS based platform to successfully develop a 13C-labeled quantitative metabolomics approach, and applied this novel method to quantify bacterial metabolite concentrations in three different domains (i.e., intracellularly, extracellularly and to the whole culture), with high accuracy for a model Escherichia coli bacteria. The bacterial culture was grown in universal 12C-labeled medium and the metabolites were extracted by 40/40/20/methanol/ACN/H2O with 0.1% formic acid. One hundred and twenty-five metabolites were initially screened and one hundred and six 12C metabolites were confidently detected from the model bacteria grown in 12C-labeled medium. A subset of twenty-one metabolites was subsequently quantified using 12C-metabolite chemical standards to assist the calculation of 12C metabolite concentration. This rigorous 12C-labled quantitative method was then applied to characterize the metabolic profile changes in three domains of E.?coli going through antibiotic treatment. Our results demonstrated that metabolites from all three domains can be used to significantly differentiate the ampicillin treatment group and control group (without ampicillin). In conclusion, our work demonstrated that the quantitative metabolomics approach can be used as a valuable tool to study bacterial metabolism in different domains and to understand their response to environmental perturbations.Zhou, E.-M., Xian, W.-D., Mefferd, C.C., Thomas, S.C., Adegboruwa, A.L., Williams, N., Murugapiran, S.K., Dodsworth, J.A., Ganji, R., Li, M.-M., Ding, Y.-P., Liu, L., Woyke, T., Li, W.-J., Hedlund, B.P., 2018. Thermus sediminis sp. nov., a thiosulfate-oxidizing and arsenate-reducing organism isolated from Little Hot Creek in the Long Valley Caldera, California. Extremophiles 22, 983-991. species are widespread in natural and artificial thermal environments. Two new yellow-pigmented strains, L198T and L423, isolated from Little Hot Creek, a geothermal spring in eastern California, were identified as novel organisms belonging to the genus Thermus. Cells are Gram-negative, rod-shaped, and non-motile. Growth was observed at temperatures from 45 to 75?°C and at salinities of 0–2.0% added NaCl. Both strains grow heterotrophically or chemolithotrophically by oxidation of thiosulfate to sulfate. L198T and L423 grow by aerobic respiration or anaerobic respiration with arsenate as the terminal electron acceptor. Values for 16S rRNA gene identity (≤?97.01%), digital DNA–DNA hybridization (≤?32.7%), OrthoANI (≤?87.5%), and genome-to-genome distance (0.13) values to all Thermus genomes were less than established criteria for microbial species. The predominant respiratory quinone was menaquinone-8 and the major cellular fatty acids were iso-C15:0, iso-C17:0 and anteiso-C15:0. One unidentified phospholipid (PL1) and one unidentified glycolipid (GL1) dominated the polar lipid pattern. The new strains could be differentiated from related taxa by β-galactosidase and β-glucosidase activity and the presence of hydroxy fatty acids. Based on phylogenetic, genomic, phenotypic, and chemotaxonomic evidence, the novel species Thermus sediminis sp. nov. is proposed, with the type strain L198T (=?CGMCC 1.13590T?=?KCTC XXX).Zhou, M., Soga, K., Yamamoto, K., 2018. Upscaled anisotropic methane hydrate critical state model for turbidite hydrate-bearing sediments at East Nankai Trough. Journal of Geophysical Research: Solid Earth 123, 6277-6298.: Turbidite formation is a common feature of natural hydrate‐bearing sediments that has been observed and reported at several hydrate exploration sites. It is therefore important to incorporate this anisotropic geological feature into the constitutive modeling when evaluating the geomechanical risks involved during hydrate‐based gas production. To date, a number of constitutive models have been proposed to capture the isotropic geomechanical behavior of homogeneous hydrate‐bearing sediments. Since the turbidite formation contains soil layers at a scale much smaller than the size of the numerical element used for reservoir scale simulations, it is necessary to upscale the geomechanical behavior of a layered system to an equivalent anisotropic continuum model by adopting some homogenization techniques. In this study, an anisotropic methane hydrate critical state model is developed by modifying the original isotropic version of Uchida et al. (2012). The calibration methodology of the anisotropic model parameters for a given set of hydrate heterogeneity and the turbidite formation at the Eastern Nankai Trough is proposed and demonstrated. The upscaled parameters are calibrated by curve fitting the numerically simulated stress‐strain curves of the layered system with the original isotropic constitutive model at the layered scale. Forty‐two sets of model parameters are calibrated from different site element models of this site. They are used to develop empirical correlations between the model parameters and the site input properties within the turbidite formation. This paper presents the details of the new anisotropic constitutive model and the performance of the proposed upscaling procedure for the Eastern Nankai Trough case. Plain Language Summary: The prospects for gas production from methane hydrates have greatly improved since hydrate deposits were found to exist in sandy sediments. Heterogeneity is a very important feature of natural hydrate‐bearing sediments. In order to carry out accurate numerical simulations of the Eastern Nankai Trough gas production test, an advanced soil model is proposed in this study to better represent heterogeneous structure of the hydrate‐bearing sediments. The numerical simulations using the advanced model suggested more accurate results than the results determined from previous models. This study, as part of MH21 research program, Japan, offered important insights for offshore methane hydrate gas production in Eastern Nankai Trough, Japan.Zhou, S., Liu, D., Karpyn, Z.T., Cai, Y., Yao, Y., 2018. Effect of coalification jumps on petrophysical properties of various metamorphic coals from different coalfields in China. Journal of Natural Gas Science and Engineering 60, 63-76. effect of coalification jumps on petrophysical properties, and the evolution of porosity and permeability of metamorphic coals are poorly understood, which significantly influences coalbed methane extraction. We estimated pore throat diameter, specific surface area, connectivity, moveable fluid space, heterogeneity, porosity and permeability in a series of 41 coal samples (maximum reflectance of vitrinite </topics/earth-and-planetary-sciences/vitrinite> in 0.34–4.24%) over six coalification jumps, by processing low temperature nitrogen adsorption, mercury intrusion porosimetry and nuclear magnetic resonance (NMR) measurements. Each coalification jump generally leads to abrupt change of petrophysical properties from dehydration to graphitization. Connectivity parameters (efficiency mercury withdrawal and the ratio of movable fluid to bounded fluid) and fractal dimensions (DNA1, DNA2, DMIP, DNMRS and DNMRM) present binomial function with vitrinite reflectance. Generations of thermogenic gas and fractures growth are attributed to increasing pore-fracture connectivity in bituminization and debituminization. Fractures begin healing and compaction, as well as reduced connectivity, at the fourth jump in graphitization. Heterogeneous pore-structures (high DMIP and DNMRM) usually have low connectivity. Moveable fluid space and its porosity from NMR are negatively correlated with the increase in coal rank. The evolution and origin of porosity and permeability (<1 mD) during coalification is proposed. Coal permeability (>1 mD) has no relation with coal rank and is related to fracture characteristics. Unlike the origin of porosity, which intrinsically inherits from progressive coalification, the origin of permeability is attributed to both progressive coalification and tectonic stresses. This study reveals the complex pore-fracture structures variation and the effect of stages in coal maturation on petrophysical properties of coalbed methane reservoirs.Zhu, G., Chen, F., Wang, M., Zhang, Z., Ren, R., Wu, L., 2018. Discovery of the lower Cambrian high-quality source rocks and deep oil and gas exploration potential in the Tarim Basin, China. American Association of Petroleum Geologists Bulletin 102, 2123-2151. global Precambrian–Cambrian system includes an important series of hydrocarbon-bearing strata. However, because rocks of this age are typically deeply buried, few petroleum exploration breakthroughs have been made, and the presence of source rocks remains somewhat controversial. Recently, commercial condensate and gas were discovered from the deep (～6900 m [～22,600 ft]) Zhongshen 1C (ZS1C) exploratory well drilled in the Tazhong uplift of the Tarim Basin, China, leading to renewed interest in the development of Cambrian source rocks in the basin. On the basis of outcrop reconnaissance and sample testing from around the Tarim Basin, we show that a set of high-quality source rocks were developed within the lower Cambrian Yuertusi Formation (?1y), at the base of the lower Cambrian. These rocks are black shales and typically have a total organic carbon content between 2% and 6% but extending as high as 17% in selected regions. This marine sequence is 10–15 m (33–49 ft) thick in some outcrops along the margins of the basin. Seismic data indicate that these high-quality source rocks may cover an area as large as 260,000 km2 (100,000 mi2). Their main organic parent material was benthic multicellular algae. On the basis of high-temperature thermal simulations conducted on these source rocks, we show that the gas composition and carbon isotopes from the ZS1C well are similar to the products generated at a thermal evolution stage corresponding to a vitrinite reflectance of between 2.2% and 2.5%. Late-stage natural gas accumulated within these rocks over time. The δ34S correlation of organic sulfur compounds in the condensate with Cambrian sulfates provides further evidence for a &Jukcy;1y source rock origin of the ZS1C condensate and gas. The Cambrian dolomites in association with a salt seal exhibit favorable geological conditions for large-scale hydrocarbon accumulation. A new set of deep exploration strata can, therefore, be developed, guiding future deep Cambrian hydrocarbon exploration in the Tarim Basin.Zhuo, X., Yan, Q., Zhang, J., Zhang, L., Chen, X., Ma, L., 2018. Conceptual models for correlation between detrital particles contents and pore distribution of shale: Taking the Silurian Longmaxi Formation in northwestern Guizhou as an example. Acta Sedimentologica Sinica 26, 969-980. composition, structure and particles arrangement of rocks determine the developmental characteristics of pores. However, there are few researches performed on the influence of detrital particles content and its arrangement patterns on the pore distribution of shale from the structural-genetic perspectives by far. The black shale of the Silurian Longmaxi Formation in northwestern Guizhou Province was taken as an example for the analysis of thin section, XRD and scanning electron microscopy (SEM), and two types of shales were divided as the "particle dispersal" and "lamellar" according to the arrangement patterns of detritus particles. The conceptual models of pore structure of shales were abstracted and the influence of detrital particles content on the pore development was analyzed. For the particle dispersed shale, the main type of pore is micro pores of clay minerals while the content of clastic particles is less than 52.4%, and the porosity decreases with increase of particles content. When the content of clastic particles reaches 52.4%, the porosity becomes the lowest and the interpartical pores are filled with clay. The interpartical pores will increase with the clastic particles content increasing, and the porosity will increase rapidly. For the laminar shale, the increase of grain content leads to the increase of intergranular pores and the increase of porosity in sand strip, and then result in the transformation of shale reservoir to conventional clastic reservoir gradually. These models can be helpful for a deepen understanding of the development mechanism of porosity in shale, tight sandstone and conventional sandstone, and also important implications to predict and evaluate unconventional reservoirs.Zou, C., Qiu, Z., Wei, H., Dong, D., Lu, B., 2018. Euxinia caused the Late Ordovician extinction: Evidence from pyrite morphology and pyritic sulfur isotopic composition in the Yangtze area, South China. Palaeogeography, Palaeoclimatology, Palaeoecology 511, 1-11. Late Ordovician mass extinction (LOME) was a severe biocrisis during the Phanerozoic and in this extinction, trilobites, brachiopods, mollusks, graptolites, conodonts and other types suffered severe mortality, and 85% of marine invertebrate species were eliminated. The potential cause of this mass extinction remains unclear, although glaciation and marine anoxia have received the greatest attention. Herein, we present findings on pyrite morphology, pyritic sulfur isotopic composition and total organic carbon content (TOC) to analyze the evolution of redox conditions across the Ordovician-Silurian boundary in the Yangtze area of South China. Our results show that long-term euxinic conditions interrupted by episodic dysoxic/oxic events occurred from the upper Katian stage to the lower Rhuddanian stage. The two extinction pulses of LOME were coincident with euxinic conditions, suggesting that marine euxinia may have been the main cause of this mass extinction event.Zumberge, J.A., Love, G.D., Cárdenas, P., Sperling, E.A., Gunasekera, S., Rohrssen, M., Grosjean, E., Grotzinger, J.P., Summons, R.E., 2018. Demosponge steroid biomarker 26-methylstigmastane provides evidence for Neoproterozoic animals. Nature Ecology & Evolution 2, 1709-1714. biomarkers preserved in ancient sedimentary rocks hold promise for tracking the diversification and ecological expansion of eukaryotes. The earliest proposed animal biomarkers from demosponges (Demospongiae) are recorded in a sequence around 100?Myr long of Neoproterozoic–Cambrian marine sedimentary strata from the Huqf Supergroup, South Oman Salt Basin. This C30 sterane biomarker, informally known as 24-isopropylcholestane (24-ipc), possesses the same carbon skeleton as sterols found in some modern-day demosponges. However, this evidence is controversial because 24-ipc is not exclusive to demosponges since 24-ipc sterols are found in trace amounts in some pelagophyte algae. Here, we report a new fossil sterane biomarker that co-occurs with 24-ipc in a suite of late Neoproterozoic–Cambrian sedimentary rocks and oils, which possesses a rare hydrocarbon skeleton that is uniquely found within extant demosponge taxa. This sterane is informally designated as 26-methylstigmastane (26-mes), reflecting the very unusual methylation at the terminus of the steroid side chain. It is the first animal-specific sterane marker detected in the geological record that can be unambiguously linked to precursor sterols only reported from extant demosponges. These new findings strongly suggest that demosponges, and hence multicellular animals, were prominent in some late Neoproterozoic marine environments at least extending back to the Cryogenian period.Zwiep, K.L., Hennekam, R., Donders, T.H., van Helmond, N.A.G.M., de Lange, G.J., Sangiorgi, F., 2018. Marine productivity, water column processes and seafloor anoxia in relation to Nile discharge during sapropels S1 and S3. Quaternary Science Reviews 200, 178-190. Mediterranean sapropels S1 (～10.5–6.1 kyr BP) and S3 (～85.8–80.8 kyr BP) formed respectively under full interglacial and glacial inception conditions. Consequently, the environmental factors preconditioning and leading to sapropel formation (e.g., global sea level and monsoonal forcing) were different. These factors must have differently influenced processes such as marine productivity, water column processes, and related seafloor anoxia. Here we investigate these differences through an interdisciplinary approach using dinoflagellate cyst and pollen/spore assemblages and sedimentary (redox-sensitive) trace-metal concentrations from a core in the central Nile delta area. Comparing S1 to S3, we demonstrate that (1) Nile discharge appears to be stronger during S3 than S1, as shown by δ18Oresiduals, higher ratio of pollen and spores, and the higher abundance of coastal dinocysts and freshwater palynomorphs, (2) Ba/Al, Corg, and dinocyst accumulation rates indicate that marine productivity was similar at least during the first phase of their deposition and started prior to the onset of both sapropels, (3) bottom water conditions were more reducing during S3, resulting in higher Mo/Al, S, and Corg/Ptot values, but preservation was high and similar for both sapropels, and (4) Sedimentary Mo-U covariation indicates that the depth of water-column ventilation during deposition of S3 was shallower than during S1 (～1000?m versus ～1800m, respectively). We attribute the observed differences to slightly enhanced precessional-forced monsoon intensity and potentially lower global sea level, resulting not only in increased North-African run-off, but also in reduced ventilation during S3 compared to S1. ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download