Gas Chromatography/GC×GC/GC-MS



GEOCHEMISTRY ARTICLES – April 2019?Analytical ChemistryBauer, A.E., Frank, R.A., Headley, J.V., Milestone, C.B., Batchelor, S., Peru, K.M., Rudy, M.D., Barrett, S.E., Vanderveen, R., Dixon, D.G., Hewitt, L.M., 2019. A preparative method for the isolation and fractionation of dissolved organic acids from bitumen-influenced waters. Science of The Total Environment 671, 587-597.Brewer, P.J., Brown, R.J.C., Mussell Webber, E.B., van Aswegen, S., Ward, M.K.M., Hill-Pearce, R.E., Worton, D.R., 2019. Breakthrough in negating the impact of adsorption in gas reference materials. Analytical Chemistry 91, 5310-5315.Fedotov, P.S., Malofeeva, G.I., Savonina, E.Y., Spivakov, B.Y., 2019. Solid-phase extraction of organic substances: Unconventional methods and approaches. Journal of Analytical Chemistry 74, 205-212.Felz, S., Vermeulen, P., van Loosdrecht, M.C.M., Lin, Y.M., 2019. Chemical characterization methods for the analysis of structural extracellular polymeric substances (EPS). Water Research 157, 201-208.Grootveld, M., Percival, B., Gibson, M., Osman, Y., Edgar, M., Molinari, M., Mather, M.L., Casanova, F., Wilson, P.B., 2019. Progress in low-field benchtop NMR spectroscopy in chemical and biochemical analysis. Analytica Chimica Acta 1067, 11-30.Nsibande, S.A., Montaseri, H., Forbes, P.B.C., 2019. Advances in the application of nanomaterial-based sensors for detection of polycyclic aromatic hydrocarbons in aquatic systems. TrAC Trends in Analytical Chemistry 115, 52-69.Rezaei, M., Gieleciak, R., Michaelian, K.H., 2019. Determination of olefin contents in liquid hydrocarbons using a quantum cascade laser and a photoacoustic detector. Energy & Fuels 33, 2859-2866.Ver?an K?k, M., Varfolomeev, M.A., Nurgaliev, D.K., 2019. Determination of SARA fractions of crude oils by NMR technique. Journal of Petroleum Science and Engineering 179, 1-6.Zeinali, S., Khalilzadeh, M., Bagheri, H., 2019. Generic extraction medium: From highly polar to non-polar simultaneous determination. Analytica Chimica Acta 1066, 1-12.Gas Chromatography/GC×GC/GC-MSBiagini, D., Lomonaco, T., Ghimenti, S., Onor, M., Bellagambi, F.G., Salvo, P., Di Francesco, F., Fuoco, R., 2019. Using labelled internal standards to improve needle trap micro-extraction technique prior to gas chromatography/mass spectrometry. Talanta 200, 145-155.Chen, X., Hua, L., Jiang, J., Hu, F., Wan, N., Li, H., 2019. Multi-capillary column high-pressure photoionization time-of-flight mass spectrometry and its application for online rapid analysis of flavor compounds. Talanta 201, 33-39.Duemichen, E., Eisentraut, P., Celina, M., Braun, U., 2019. Automated thermal extraction-desorption gas chromatography mass spectrometry: A multifunctional tool for comprehensive characterization of polymers and their degradation products. Journal of Chromatography A 1592, 133-142.Franchina, F.A., Purcaro, G., Burklund, A., Beccaria, M., Hill, J.E., 2019. Evaluation of different adsorbent materials for the untargeted and targeted bacterial VOC analysis using GC×GC-MS. Analytica Chimica Acta 1066, 146-153.Guo, Q., Yu, J., Zhao, Y., Liu, T., Su, M., Jia, Z., Zhao, Y., Mu, Z., Yang, M., 2019. Identification of fishy odor causing compounds produced by Ochromonas sp. and Cryptomonas ovate with gas chromatography-olfactometry and comprehensive two-dimensional gas chromatography. Science of The Total Environment 671, 149-156.Já?ová, J., Gardlo, A., Dimandja, J.-M.D., Adam, T., Friedeck?, D., 2019. Impact of sample dimensionality on orthogonality metrics in comprehensive two-dimensional separations. Analytica Chimica Acta 1064, 138-149.Mako?, P., Przyjazny, A., Boczkaj, G., 2019. Methods of assaying volatile oxygenated organic compounds in effluent samples by gas chromatography – a review. Journal of Chromatography A 1592, 143-160.Mao, F., Fan, H., Wang, J., 2019. Biogenic oxygenates in lignite pyrolysis tars and their thermal cracking revealed by two-dimensional gas chromatography/time-of-flight mass spectrometry (GC×GC-TOFMS). Journal of Analytical and Applied Pyrolysis 139, 213-223.Marathe, P.S., Juan, A., Hu, X., Westerhof, R.J.M., Kersten, S.R.A., 2019. Evaluating quantitative determination of levoglucosan and hydroxyacetaldehyde in bio-oils by gas and liquid chromatography. Journal of Analytical and Applied Pyrolysis 139, 233-238.Pesesse, R., Stefanuto, P.H., Schleich, F., Louis, R., Focant, J.F., 2019. Multimodal chemometric approach for the analysis of human exhaled breath in lung cancer patients by TD-GC?×?GC-TOFMS. Journal of Chromatography B 1114-1115, 146-153.Shan, C., Ye, J., Scarlett, A., Grice, K., 2019. Molecular and isotopic characteristics of mature condensates from the East China Sea shelf basin using GC×GC-TOFMS and GC-IRMS. Journal of Earth Science 30, 376-386.Souza, I.D., Nan, H., Queiroz, M.E.C., Anderson, J.L., 2019. Tunable silver-containing stationary phases for multidimensional gas chromatography. Analytical Chemistry 91, 4969-4974.Strangl, M., Ortner, E., Buettner, A., 2019. Evaluation of the efficiency of odor removal from recycled HDPE using a modified recycling process. Resources, Conservation and Recycling 146, 89-97.Wang, L., Li, J., Chen, Y., Yang, H., Shao, J., Zhang, X., Yu, H., Chen, H., 2019. Investigation of the pyrolysis characteristics of guaiacol lignin using combined Py-GC?×?GC/TOF-MS and in-situ FTIR. Fuel 251, 496-505.Wilde, M.J., Cordell, R.L., Salman, D., Zhao, B., Ibrahim, W., Bryant, L., Ruszkiewicz, D., Singapuri, A., Free, R.C., Gaillard, E.A., Beardsmore, C., Thomas, C.L.P., Brightling, C.E., Siddiqui, S., Monks, P.S., 2019. Breath analysis by two-dimensional gas chromatography with dual flame ionisation and mass spectrometric detection – Method optimisation and integration within a large-scale clinical study. Journal of Chromatography A 1594, 160-172.Imaging: AFMBlowey, P.J., Maurer, R.J., Rochford, L.A., Duncan, D.A., Kang, J.H., Warr, D.A., Ramadan, A.J., Lee, T.-L., Thakur, P.K., Costantini, G., Reuter, K., Woodruff, D.P., 2019. The structure of VOPc on Cu(111): Does V=O point up, or down, or both? The Journal of Physical Chemistry C 121, 8101-modo, M., Kaiser, K., De Falco, G., Minutolo, P., Schulz, F., D'Anna, A., Gross, L., 2019. On the early stages of soot formation: Molecular structure elucidation by high-resolution atomic force microscopy. Combustion and Flame 205, 154-164.Korolkov, V.V., Summerfield, A., Murphy, A., Amabilino, D.B., Watanabe, K., Taniguchi, T., Beton, P.H., 2019. Ultra-high resolution imaging of thin films and single strands of polythiophene using atomic force microscopy. Nature Communications 10, Article 1537.Misra, S., Varma, A.K., Hazra, B., Biswas, S., Samad, S.K., 2019. The influence of the thermal aureole asymmetry on hydrocarbon generative potential of coal beds: Insights from Raniganj Basin, West Bengal, India. International Journal of Coal Geology 206, 91-105.Solyanikova, I.P., Golovleva, L.A., 2019. Hexadecane and hexadecane-degrading bacteria: Mechanisms of interaction. Microbiology 88, 15-26.Xu, M., Yi, J., Qi, P., Wang, H., Marasteanu, M., Feng, D., 2019. Improved chemical system for molecular simulations of asphalt. Energy & Fuels 33, 3187-3198.Imaging: SEM, TEM, HIMBoruah, A., Rasheed, A., Mendhe, V.A., Ganapathi, S., 2019. Specific surface area and pore size distribution in gas shales of Raniganj Basin, India. Journal of Petroleum Exploration and Production Technology 9, 1041-1050.Chen, L., Jiang, Z., Liu, Q., Jiang, S., Liu, K., Tan, J., Gao, F., 2019. Mechanism of shale gas occurrence: Insights from comparative study on pore structures of marine and lacustrine shales. Marine and Petroleum Geology 104, 200-216.Dong, T., Harris, N.B., McMillan, J.M., Twemlow, C.E., Nassichuk, B.R., Bish, D.L., 2019. A model for porosity evolution in shale reservoirs: An example from the Upper Devonian Duvernay Formation, Western Canada Sedimentary Basin. American Association of Petroleum Geologists Bulletin 103, 1017-1044.Fu, X., Zhang, Q., Gao, Y., Wu, Y., Xiao, X., Li, L., Xue, J., Liu, B., 2019. Degradation potential of petroleum hydrocarbon-degrading bacteria immobilized on different carriers in marine environment. Petroleum Science and Technology 37, 1417-1424.Ganai, J.A., Rashid, S.A., 2019. Anoxia and fluctuating climate recorded from the Devonian–Carboniferous black shales, Tethys Himalaya, India: a multi-proxy approach. International Journal of Earth Sciences 108, 863-883.Khishvand, M., Oraki Kohshour, I., Alizadeh, A.H., Piri, M., Prasad, S., 2019. A multi-scale experimental study of crude oil-brine-rock interactions and wettability alteration during low-salinity waterflooding. Fuel 250, 117-131.Long, Y., Huang, X., Gao, Y., Chen, L., Song, F., Zhang, H., 2019. Swelling mechanism of core–shell polymeric nanoparticles and their application in enhanced oil recovery for low-permeability reservoirs. Energy & Fuels 33, 3077-3088.Maraschin, A.J., da Cruz, G.F., Martins, L.L., Severiano Ribeiro, H.J.P., Augustin, A.H., 2019. Relationship between diagenesis and the emplacement of bitumen in the Lower Triassic Piramboia Formation sandstones, Paraná Basin, SW Brazil. Journal of South American Earth Sciences 92, 435-447.Mayayo, M.J., Yuste, A., Luzón, A., Corzo, A., Mu?oz, A., Pérez, A., Soriano, A., 2019. Fe-rich microspheres pseudomorphs after pyrite framboids in Holocene fluvial deposits from NE Spain: Relationship with environmental conditions and bacterial activity. Sedimentary Geology 386, 103-117.Othman, F., Naufaliansyah, M.A., Hussain, F., 2019. Effect of water salinity on permeability alteration during CO2 sequestration. Advances in Water Resources 127, 237-251.Ragsdale, S.W., 2019. Elusive microbe that consumes ethane found under the sea. Nature 568, 40-41.Tian, T., Zhou, S., Fu, D., Yang, F., Li, J., 2019. Characterization and controlling factors of pores in the Lower Cambrian Niutitang shale of the Micangshan Tectonic Zone, SW China. Arabian Journal of Geosciences 12, 251.Walton, E.L., Timms, N.E., Hauck, T.E., MacLagan, E.A., Herd, C.D.K., 2019. Evidence of impact melting and post-impact decomposition of sedimentary target rocks from the Steen River impact structure, Alberta, Canada. Earth and Planetary Science Letters 515, 173-186.Wang, Y., Wang, L., Wang, J., Jiang, Z., Wang, C.-C., Fu, Y., Song, Y.-F., Wang, Y., Liu, D., Jin, C., 2019. Multiscale characterization of three-dimensional pore structures in a shale gas reservoir: A case study of the Longmaxi shale in Sichuan basin, China. Journal of Natural Gas Science and Engineering 66, 207-216.Zeyen, N., Benzerara, K., Menguy, N., Brest, J., Templeton, A.S., Webb, S.M., Gérard, E., Moreira, D., López-García, P., Tavera, R., Morin, G., 2019. Fe-bearing phases in modern lacustrine microbialites from Mexico. Geochimica et Cosmochimica Acta 253, 201-230.Zhang, X., Lin, B., Zhu, C., Yan, F., Liu, T., Liu, T., Li, Y., 2019. Petrophysical variation of coal treated by cyclic high-voltage electrical pulse for coalbed methane recovery. Journal of Petroleum Science and Engineering 178, 795-804.Zhong, C., Qin, Q., Fan, C., Hu, D., 2019. Effect of nanometer pore structure on methane adsorption capacity in organic-rich shale. Petroleum Science and Technology 37, 1243-1250.Imaging: Xray CTLi, C., Liu, C., Hu, G., Sun, J., Hao, X., Liu, L., Meng, Q., 2019. Investigation on the multiparameter of hydrate-bearing sands using nano-focus X-ray computed tomography. Journal of Geophysical Research: Solid Earth 124, 2286-2296.Liu, N.-Z., Zou, Y.-S., Ma, X.-F., Li, N., Wu, S., 2019. Study of hydraulic fracture growth behavior in heterogeneous tight sandstone formations using CT scanning and acoustic emission monitoring. Petroleum Science 16, 396-408.Maraschin, A.J., da Cruz, G.F., Martins, L.L., Severiano Ribeiro, H.J.P., Augustin, A.H., 2019. Relationship between diagenesis and the emplacement of bitumen in the Lower Triassic Piramboia Formation sandstones, Paraná Basin, SW Brazil. Journal of South American Earth Sciences 92, 435-447.Struchkov, I.A., Rogachev, M.K., Kalinin, E.S., Roschin, P.V., 2019. Laboratory investigation of asphaltene-induced formation damage. Journal of Petroleum Exploration and Production Technology 9, 1443-1455.Wang, Y., Wang, L., Wang, J., Jiang, Z., Wang, C.-C., Fu, Y., Song, Y.-F., Wang, Y., Liu, D., Jin, C., 2019. Multiscale characterization of three-dimensional pore structures in a shale gas reservoir: A case study of the Longmaxi shale in Sichuan basin, China. Journal of Natural Gas Science and Engineering 66, 207-216.Wu, N.-y., Liu, C.-l., Hao, X.-l., 2018. Experimental simulations and methods for natural gas hydrate analysis in China. China Geology 1, 61-71.Liquid Chromatography/LC-MS/SFCFu, Q., Jiang, D., Xin, H., Dai, Z., Cai, J., Ke, Y., Jin, Y., Liang, X., 2019. Design, synthesis and evaluation of a series of alkylsiloxane-bonded stationary phases for expanded supercritical fluid chromatography separations. Journal of Chromatography A 1593, 127-134.Gil-Ramirez, A., Al-Hamimi, S., Rosmark, O., Hallgren, O., Larsson-Callerfelt, A.-K., Rodríguez-Meizoso, I., 2019. Efficient methodology for the extraction and analysis of lipids from porcine pulmonary artery by supercritical fluid chromatography coupled to mass spectrometry. Journal of Chromatography A 1592, 173-182.Já?ová, J., Gardlo, A., Dimandja, J.-M.D., Adam, T., Friedeck?, D., 2019. Impact of sample dimensionality on orthogonality metrics in comprehensive two-dimensional separations. Analytica Chimica Acta 1064, 138-149.King, A.C.F., Giorio, C., Wolff, E., Thomas, E., Roverso, M., Schwikowski, M., Tapparo, A., Bogialli, S., Kalberer, M., 2019. Direct injection liquid chromatography high-resolution mass spectrometry for determination of primary and secondary terrestrial and marine biomarkers in ice cores. Analytical Chemistry 91, 5051-5057.Knolhoff, A.M., Kneapler, C.N., Croley, T.R., 2019. Optimized chemical coverage and data quality for non-targeted screening applications using liquid chromatography/high-resolution mass spectrometry. Analytica Chimica Acta 1066, 93-101.Marathe, P.S., Juan, A., Hu, X., Westerhof, R.J.M., Kersten, S.R.A., 2019. Evaluating quantitative determination of levoglucosan and hydroxyacetaldehyde in bio-oils by gas and liquid chromatography. Journal of Analytical and Applied Pyrolysis 139, 233-238.Mechelke, J., Longrée, P., Singer, H., Hollender, J., 2019. Vacuum-assisted evaporative concentration combined with LC-HRMS/MS for ultra-trace-level screening of organic micropollutants in environmental water samples. Analytical and Bioanalytical Chemistry 411, 2555-2567.Nouara, A., Panagiotopoulos, C., Balesdent, J., Violaki, K., Bard, E., Fagault, Y., Repeta, D.J., Sempéré, R., 2019. Liquid chromatographic isolation of individual carbohydrates from environmental matrices for stable carbon analysis and radiocarbon dating. Analytica Chimica Acta 1067, 137-146.Sakai, M., Hayakawa, Y., Funada, Y., Ando, T., Fukusaki, E., Bamba, T., 2019. Development of a practical online supercritical fluid extraction–supercritical fluid chromatography/mass spectrometry system with an integrated split-flow method. Journal of Chromatography A 1592, 161-172.Sanz Rodriguez, E., Plummer, C., Nation, M., Moy, A., Curran, M., Haddad, P.R., Paull, B., 2019. Sub-1 mL sample requirement for simultaneous determination of 17 organic and inorganic anions and cations in Antarctic ice core samples by dual capillary ion chromatography. Analytica Chimica Acta 1063, 167-177.Schwab, V.F., Nowak, M.E., Trumbore, S.E., Xu, X., Gleixner, G., Muhr, J., Küsel, K., Totsche, K.U., 2019. Isolation of individual saturated fatty acid methyl esters derived from groundwater phospholipids by preparative high-pressure liquid chromatography for compound-specific radiocarbon analyses. Water Resources Research 55, 2521-2531.West, C., Lemasson, E., 2019. Unravelling the effects of mobile phase additives in supercritical fluid chromatography—Part II: Adsorption on the stationary phase. Journal of Chromatography A 1593, 135-146.Wu, Y., Gao, S., Liu, Z., Zhao, J., Ji, B., Zeng, X., Yu, Z., 2019. The quantification of chlorinated paraffins in environmental samples by ultra-high-performance liquid chromatography coupled with Orbitrap Fusion Tribrid mass spectrometry. Journal of Chromatography A 1593, 102-109.Zatirakha, A.V., Uzhel, A.S., Loshin, A.A., Chernobrovkina, A.V., Smolenkov, A.D., Shpigun, O.A., 2019. Novel stationary phases for ion chromatography and hydrophilic interaction liquid chromatography. Journal of Analytical Chemistry 74, 12-20.Mass Spectroscopy/ICR-FTMS/OrbitrapCriscuolo, A., Zeller, M., Cook, K., Angelidou, G., Fedorova, M., 2019. Rational selection of reverse phase columns for high throughput LC-MS lipidomics. Chemistry and Physics of Lipids 221, 120-127.Echavarri-Bravo, V., Tinzl, M., Kew, W., Cruickshank, F., Mackay, C.L., Clarke, D.J., Horsfall, L.E., 2019. High resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) for the characterisation of enzymatic processing of commercial lignin. New Biotechnology 52, 1-8.Fang, Z., Li, L., Jiang, B., He, C., Li, Y., Xu, C., Shi, Q., 2019. Molecular composition and transformation of dissolved organic matter (DOM) in coal gasification wastewater. Energy & Fuels 33, 3003-3011.Knolhoff, A.M., Kneapler, C.N., Croley, T.R., 2019. Optimized chemical coverage and data quality for non-targeted screening applications using liquid chromatography/high-resolution mass spectrometry. Analytica Chimica Acta 1066, 93-101.Kostyukevich, Y., Vlaskin, M., Zherebker, A., Grigorenko, A., Borisova, L., Nikolaev, E., 2019. High-resolution mass spectrometry study of the bio-oil samples produced by thermal liquefaction of microalgae in different solvents. Journal of The American Society for Mass Spectrometry 30, 605-614.Li, L., Fang, Z., He, C., Shi, Q., 2019. Separation and characterization of marine dissolved organic matter (DOM) by combination of Fe(OH)3 co-precipitation and solid phase extraction followed by ESI FT-ICR MS. Analytical and Bioanalytical Chemistry 411, 2201-2208.Li, Y., Xu, H., He, C., Shen, Z., Chen, W., Gao, L., Lin, C., Lin, T., Lu, C., Shi, Q., Luo, J., Wang, W., 2019. Transformation and fate of dissolved organic nitrogen in drinking water supply system: A full scale case study from Yixing, China. Science of The Total Environment 673, 435-444.Nguyen, M.-T., Pirngruber, G.D., Chainet, F., Albrieux, F., Tayakout-Fayolle, M., Geantet, C., 2019. Molecular-level insights into coker/straight-run gas oil hydrodenitrogenation by Fourier transform ion cyclotron resonance mass spectrometry. Energy & Fuels 33, 3034-3046.Orrego-Ruiz, J.A., Medina-Sandoval, C.F., Hinds, C.C., ?lvaro, V.-G., Rojas-Ruiz, F.A., 2019. FT-ICR MS determination of the role of naphthenic acids on the stabilization of alkali/surfactant/polymer emulsified effluents: A field study. Journal of Petroleum Science and Engineering 179, 192-198.Selliez, L., Briois, C., Carrasco, N., Thirkell, L., Thissen, R., Ito, M., Orthous-Daunay, F.R., Chalumeau, G., Colin, F., Cottin, H., Engrand, C., Flandinet, L., Fray, N., Gaubicher, B., Grand, N., Lebreton, J.P., Makarov, A., Ruocco, S., Szopa, C., Vuitton, V., Zapf, P., 2019. Identification of organic molecules with a laboratory prototype based on the Laser Ablation-CosmOrbitrap. Planetary and Space Science 170, 42-51.Sowers, T.D., Holden, K.L., Coward, E.K., Sparks, D.L., 2019. Dissolved organic matter sorption and molecular fractionation by naturally occurring bacteriogenic iron (oxyhydr)oxides. Environmental Science & Technology 53, 4295-4304.Stopka, S.A., Samarah, L.Z., Shaw, J.B., Liyu, A.V., Veli?kovi?, D., Agtuca, B.J., Kukolj, C., Koppenaal, D.W., Stacey, G., Pa?a-Toli?, L., Anderton, C.R., Vertes, A., 2019. Ambient metabolic profiling and imaging of biological samples with ultrahigh molecular resolution using laser ablation electrospray ionization 21 Tesla FTICR mass spectrometry. Analytical Chemistry 91, 5028-5035.Thieme, L., Graeber, D., Hofmann, D., Bischoff, S., Schwarz, M.T., Steffen, B., Meyer, U.-N., Kaupenjohann, M., Wilcke, W., Michalzik, B., Siemens, J., 2019. Dissolved organic matter characteristics of deciduous and coniferous forests with variable management: different at the source, aligned in the soil. Biogeosciences 16, 1411-1432.Vanryckeghem, F., Huysman, S., Van Langenhove, H., Vanhaecke, L., Demeestere, K., 2019. Multi-residue quantification and screening of emerging organic micropollutants in the Belgian part of the North Sea by use of Speedisk extraction and Q-Orbitrap HRMS. Marine Pollution Bulletin 142, 350-360.Wozniak, A.S., Prem, P.M., Obeid, W., Waggoner, D.C., Quigg, A., Xu, C., Santschi, P.H., Schwehr, K.A., Hatcher, P.G., 2019. Rapid degradation of oil in mesocosm simulations of marine oil snow events. Environmental Science & Technology 53, 3441-3450.Wu, Y., Gao, S., Liu, Z., Zhao, J., Ji, B., Zeng, X., Yu, Z., 2019. The quantification of chlorinated paraffins in environmental samples by ultra-high-performance liquid chromatography coupled with Orbitrap Fusion Tribrid mass spectrometry. Journal of Chromatography A 1593, 102-109.Zhang, B., Shan, C., Hao, Z., Liu, J., Wu, B., Pan, B., 2019. Transformation of dissolved organic matter during full-scale treatment of integrated chemical wastewater: Molecular composition correlated with spectral indexes and acute toxicity. Water Research 157, 472-482.Mass Spectroscopy/OtherBen Faleh, A., Warnke, S., Rizzo, T.R., 2019. Combining ultrahigh-resolution ion-mobility spectrometry with cryogenic infrared spectroscopy for the analysis of glycan mixtures. Analytical Chemistry 91, 4876-4882.Chamberlain, C.A., Rubio, V.Y., Garrett, T.J., 2019. Strain-level differentiation of bacteria by paper spray ionization mass spectrometry. Analytical Chemistry 91, 4964-4968.Chen, X., Hua, L., Jiang, J., Hu, F., Wan, N., Li, H., 2019. Multi-capillary column high-pressure photoionization time-of-flight mass spectrometry and its application for online rapid analysis of flavor compounds. Talanta 201, 33-39.Drze?d?on, J., Jacewicz, D., Sielicka, A., Chmurzyński, L., 2019. MALDI-MS for polymer characterization – Recent developments and future prospects. TrAC Trends in Analytical Chemistry 115, 121-128.Feider, C.L., Krieger, A., DeHoog, R.J., Eberlin, L.S., 2019. Ambient ionization mass spectrometry: Recent developments and applications. Analytical Chemistry 91, 4266-4290.Johnson, J.T., Lee, K.W., Bhanot, J.S., McLuckey, S.A., 2019. A miniaturized Fourier transform electrostatic linear ion trap mass spectrometer: Mass range and resolution. Journal of The American Society for Mass Spectrometry 30, 588-594.Kadesch, P., Quack, T., Gerbig, S., Grevelding, C.G., Spengler, B., 2019. Lipid topography in Schistosoma mansoni cryosections, Revealed by microembedding and high-resolution atmospheric-pressure matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging. Analytical Chemistry 91, 4520-4528.Liem-Nguyen, V., Huynh, K., Gallampois, C., Bj?rn, E., 2019. Determination of picomolar concentrations of thiol compounds in natural waters and biological samples by tandem mass spectrometry with online preconcentration and isotope-labeling derivatization. Analytica Chimica Acta 1067, 71-78.Revel’skii, I.A., Yashin, Y.S., Revel’skii, A.I., 2019. Atmospheric pressure photoionization mass spectrometry: New capabilities for the determination of the numbers of components in complex mixtures and their identification. Journal of Analytical Chemistry 74, 192-197.Shimizu, N., 2019. Big picture geochemistry from microanalyses – My four-decade odyssey in SIMS. Geochemical Perspectives 8, 1-104.Wei, J.N., Belanger, D., Adams, R.P., Sculley, D., 2019. Rapid prediction of electron–ionization mass spectrometry using neural networks. ACS Central Science 5, 700-708.Metabolomics/LipidomicsBatstone, D.J., Hülsen, T., Oehmen, A., 2019. Metabolic modelling of mixed culture anaerobic microbial processes. Current Opinion in Biotechnology 57, 137-144.Bell, M., Blais, J.M., 2019. “-Omics” workflow for paleolimnological and geological archives: A review. Science of The Total Environment 672, 438-455.Benham, K., Fernández, F.M., Orlando, T.M., 2019. Sweep jet collection laser-induced acoustic desorption atmospheric pressure photoionization for lipid analysis applications. Journal of The American Society for Mass Spectrometry 30, 647-658.Chamberlain, C.A., Rubio, V.Y., Garrett, T.J., 2019. Strain-level differentiation of bacteria by paper spray ionization mass spectrometry. Analytical Chemistry 91, 4964-4968.Criscuolo, A., Zeller, M., Cook, K., Angelidou, G., Fedorova, M., 2019. Rational selection of reverse phase columns for high throughput LC-MS lipidomics. Chemistry and Physics of Lipids 221, 120-127.Da, W., Shao, J., Li, Q., Shi, G., Wang, T., Wu, D., Wang, C., 2019. Extraction of extracellular matrix in static and dynamic Candida biofilms using cation exchange resin and untargeted analysis of matrix metabolites by ultra-high-performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). Frontiers in Microbiology 10, 752. doi: 710.3389/fmicb.2019.00752.Deng, J., Yang, Y., Liu, Y., Fang, L., Lin, L., Luan, T., 2019. Coupling Paternò-Büchi reaction with surface-coated probe nanoelectrospray ionization mass spectrometry for in vivo and microscale profiling of lipid C═C location isomers in complex biological tissues. Analytical Chemistry 91, 4592-4599.Dong, X., Greening, C., Rattray, J.E., Chakraborty, A., Chuvochina, M., Mayumi, D., Dolfing, J., Li, C., Brooks, J.M., Bernard, B.B., Groves, R.A., Lewis, I.A., Hubert, C.R.J., 2019. Metabolic potential of uncultured bacteria and archaea associated with petroleum seepage in deep-sea sediments. Nature Communications 10, Article 1816.Gika, H., Virgiliou, C., Theodoridis, G., Plumb, R.S., Wilson, I.D., 2019. Untargeted LC/MS-based metabolic phenotyping (metabonomics/metabolomics): The state of the art. Journal of Chromatography B 1117, 136-147.Goff, J., Terry, L., Mal, J., Schilling, K., Pallud, C., Yee, N., 2019. Role of extracellular reactive sulfur metabolites on microbial Se(0) dissolution. Geobiology 17, 320-329.Hutchins, P.D., Russell, J.D., Coon, J.J., 2019. Mapping lipid fragmentation for tailored mass spectral libraries. Journal of The American Society for Mass Spectrometry 30, 659-668.Jeanne Dit Fouque, K., Ramirez, C.E., Lewis, R.L., Koelmel, J.P., Garrett, T.J., Yost, R.A., Fernandez-Lima, F., 2019. Effective liquid chromatography–trapped ion mobility spectrometry–mass spectrometry separation of isomeric lipid species. Analytical Chemistry 91, 5021-5027.Ju, R., Liu, X., Zheng, F., Zhao, X., Lu, X., Zeng, Z., Lin, X., Xu, G., 2019. Removal of false positive features to generate authentic peak table for high-resolution mass spectrometry-based metabolomics study. Analytica Chimica Acta 1067, 79-87.Knolhoff, A.M., Kneapler, C.N., Croley, T.R., 2019. 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Characteristics of the palynomorphs and hydrocarbon potential in the continental Permian Raniganj Formation, Banespetali Nala, West Bengal. Journal of the Geological Society of India 93, 431-436.Sousa, E.d.S., Júnior, G.R.S., Silva, A.F., Reis, F.d.A.M., de Sousa, A.A.C., Cioccari, G.M., Capilla, R., de Souza, I.V.A.F., Imamura, P.M., Rodrigues, R., Lopes, J.A.D., de Lima, S.G., 2019. Biomarkers in Cretaceous sedimentary rocks from the Codó Formation - Parnaíba Basin: Paleoenvironmental assessment. Journal of South American Earth Sciences 92, 265-281.Xia, L., Cao, J., Hu, S., Li, S., 2019. How marine incursion influences the quality of lacustrine source rocks: The Paleogene Nanxiang Basin, eastern China. American Association of Petroleum Geologists Bulletin 103, 1071-1096.Yang, F., Xue, L., Yang, S., Chen, G., Bi, G., Lv, C., Ma, M., Su, L., Zhang, D., Zhou, Q., 2019. Characteristics of organic acids in lacustrine organic-rich shale, Ordos Basin, China. 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Petroleum 5, 13-29.Bao, S.-j., Zhai, G.-y., Zhou, Z., Yu, S.-f., Chen, K., Wang, Y.-f., Wang, H., Liu, Y.-m., 2018. The evolution of the Huangling uplift and its control on the accumulation and preservation of shale gas. China Geology 1, 346-353.Boruah, A., Rasheed, A., Mendhe, V.A., Ganapathi, S., 2019. Specific surface area and pore size distribution in gas shales of Raniganj Basin, India. Journal of Petroleum Exploration and Production Technology 9, 1041-1050.Cai, C., Kang, Y., Wang, X., Hu, Y., Huang, M., Liu, Y., Liu, J., Chen, H., Li, X., 2019. Experimental study on shale fracturing enhancement by using multi-times pulse supercritical carbon dioxide (SC-CO2) jet. Journal of Petroleum Science and Engineering 178, 948-963.Cai, J., Lin, D., Singh, H., Zhou, S., Meng, Q., Zhang, Q., 2019. A simple permeability model for shale gas and key insights on relative importance of various transport mechanisms. Fuel 252, 210-219.Cai, L., Xiao, G., Lu, S., Wang, J., Wu, Z., 2019. Spatial-temporal coupling between high-quality source rocks and reservoirs for tight sandstone oil and gas accumulations in the Songliao Basin, China. International Journal of Mining Science and Technology 29, 387-397.Cao, Y., Han, H., Liu, H.-w., Jia, J.-c., Zhang, W., Liu, P.-w., Ding, Z.-g., Chen, S.-j., Lu, J.-g., Gao, Y., 2019. Influence of solvents on pore structure and methane adsorption capacity of lacustrine shales: An example from a Chang 7 shale sample in the Ordos Basin, China. Journal of Petroleum Science and Engineering 178, 419-428.Chai, D., Fan, Z., Li, X., 2019. A new unified gas-transport model for gas flow in nanoscale porous media. SPE Journal 24, 698-719.Chen, D., Zhang, J., Lan, B., Wang, X., Wang, Z., 2019. Influence of sedimentary environment on the shale gas reservoir of Sahai formation in Fuxin Basin, northeast China. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects 41, 1949-1959.Chen, J.-H., Althaus, S.M., Liu, H.-H., Sun, Q., 2019. Shale gas transport in rock matrix: Diffusion in the presence of surface adsorption and capillary condensation. Journal of Natural Gas Science and Engineering 66, 18-25.Chen, L., Jiang, Z., Liu, Q., Jiang, S., Liu, K., Tan, J., Gao, F., 2019. Mechanism of shale gas occurrence: Insights from comparative study on pore structures of marine and lacustrine shales. Marine and Petroleum Geology 104, 200-216.Chen, X.-h., Luo, S.-y., Liu, A., Li, H., 2018. The oldest shale gas reservoirs in southern margin of Huangling uplift, Yichang, Hubei, China. China Geology 1, 158-159.Civan, F., 2019. Can gas permeability of fractured shale be determined accurately by testing core plugs, drill cuttings, and crushed samples? SPE Journal 24, 720-732.Cui, J., 2019. Oil transport in shale nanopores and micro-fractures: Modeling and analysis. Journal of Petroleum Science and Engineering 178, 640-648.Cui, J., Li, S., Mao, Z., 2019. Oil-bearing heterogeneity and threshold of tight sandstone reservoirs: A case study on Triassic Chang7 member, Ordos Basin. Marine and Petroleum Geology 104, 180-189.Das, S., Adeoye, J., Dhiman, I., Bilheux, H.Z., Ellis, B.R., 2019. Imbibition of mixed-charge surfactant fluids in shale fractures. Energy & Fuels 33, 2839-2847.Dong, T., Harris, N.B., McMillan, J.M., Twemlow, C.E., Nassichuk, B.R., Bish, D.L., 2019. A model for porosity evolution in shale reservoirs: An example from the Upper Devonian Duvernay Formation, Western Canada Sedimentary Basin. American Association of Petroleum Geologists Bulletin 103, 1017-1044.Gorynski, K.E., Tobey, M.H., Enriquez, D.A., Smagala, T.M., Dreger, J.L., Newhart, R.E., 2019. Quantification and characterization of hydrocarbon-filled porosity in oil-rich shales using integrated thermal extraction, pyrolysis, and solvent extraction. American Association of Petroleum Geologists Bulletin 103, 723-744.Han, H., Guo, C., Zhong, N.-n., Pang, P., Chen, S.-j., Lu, J.-g., Gao, Y., 2019. Pore structure evolution of lacustrine shales containing Type I organic matter from the Upper Cretaceous Qingshankou Formation, Songliao Basin, China: A study of artificial samples from hydrous pyrolysis experiments. Marine and Petroleum Geology 104, 375-388.Kang, Y., Rao, Q., Zhao, Q., Wang, H., 2019. Exploration and development potential of the low-maturity continental shale gas in the Fuxin Basin Natural Gas Industry 39, 21-31.Li, R., Wu, K., Li, J., Xu, J., Chen, Z., 2019. Shale gas transport in wedged nanopores with water films. Journal of Natural Gas Science and Engineering 66, 217-232.Li, S., Zhang, D., 2019. How effective is carbon dioxide as an alternative fracturing fluid? SPE Journal 24, 857-876.Li, Y., Hu, Z., Duan, X., Wang, X., Shi, J., Zhan, H., 2019. The general form of transport diffusivity of shale gas in organic-rich nano-slits—A molecular simulation study using Darken approximation. Fuel 249, 457-471.Liu, H., Zhang, S., Song, G., Xuejun, W., Teng, J., Wang, M., Bao, Y., Yao, S., Wang, W., Zhang, S., Hu, Q., Fang, Z., 2019. Effect of shale diagenesis on pores and storage capacity in the Paleogene Shahejie Formation, Dongying Depression, Bohai Bay Basin, east China. Marine and Petroleum Geology 103, 738-752.Liu, J., Xie, H., Wang, Q., Chen, S., Hu, Z., 2019. The effect of pore size on shale gas recovery with CO2 sequestration: Insight into molecular mechanisms. Energy & Fuels 33, 2897-2907.Liu, K., Ostadhassan, M., 2019. The impact of pore size distribution data presentation format on pore structure interpretation of shales. Advances in Geo-Energy Research 3, 187-197.Liu, N.-Z., Zou, Y.-S., Ma, X.-F., Li, N., Wu, S., 2019. Study of hydraulic fracture growth behavior in heterogeneous tight sandstone formations using CT scanning and acoustic emission monitoring. Petroleum Science 16, 396-408.Long, S., Zhang, Y., Li, J., Sun, Z., Shang, X., Dai, C., 2019. Comprehensive geological modeling technology for shale gas reservoirs Natural Gas Industry 39, 47-55.Luo, P., Zhong, N., Khan, I., Wang, X., Wang, H., Luo, Q., Guo, Z., 2019. Effects of pore structure and wettability on methane adsorption capacity of mud rock: Insights from mixture of organic matter and clay minerals. Fuel 251, 551-561.Ma, Q., Yang, S., Lv, D., Wang, M., Chen, J., Kou, G., Yang, L., 2019. Experimental investigation on the influence factors and oil production distribution in different pore sizes during CO2 huff-n-puff in an ultra-high-pressure tight oil reservoir. Journal of Petroleum Science and Engineering 178, 1155-1163.Merey, ?., 2019. Analysis of the effect of experimental adsorption uncertainty on CH4 production and CO2 sequestration in Dadas shale gas reservoir by numerical simulations. Journal of Petroleum Science and Engineering 178, 1051-1066.Sheng, G., Javadpour, F., Su, Y., 2019. Dynamic porosity and apparent permeability in porous organic matter of shale gas reservoirs. Fuel 251, 341-351.Sun, F., Yao, Y., Li, G., Dong, M., 2019. Transport behaviors of real gas mixture through nanopores of shale reservoir. Journal of Petroleum Science and Engineering 177, 1134-1141.Talbi, R., Lakhdar, R., Smati, A., Spiller, R., Levey, R., 2019. Aptian–Albian shale oil unconventional system as registration of Cretaceous oceanic anoxic sub-events in the southern Tethys (Bir M’Cherga basin, Tunisia). Journal of Petroleum Exploration and Production Technology 9, 1007-1022.Tian, T., Zhou, S., Fu, D., Yang, F., Li, J., 2019. Characterization and controlling factors of pores in the Lower Cambrian Niutitang shale of the Micangshan Tectonic Zone, SW China. Arabian Journal of Geosciences 12, 251.Torghabeh, A.K., Rezaee, R., Pimentel, N., Johnson, L., Alshakhs, M., 2019. Petroleum geochemistry, burial history and shale gas potential of the Goldwyer Formation - Canning Basin, Western Australia. International Journal of Oil, Gas and Coal Technology 20, 420-440.Wang, J.-q., Gong, J.-m., Zhang, L., Cheng, H.-y., Liao, J., Chen, J.-w., Su, J., Yang, C.-s., 2018. Discussion on “sandwich” structures and preservation conditions of shale gas in the South Yellow Sea Basin. China Geology 1, 485-492.Wang, M., Guo, Z., Jiao, C., Lu, S., Li, J., Xue, H., Li, J., Li, J., Chen, G., 2019. Exploration progress and geochemical features of lacustrine shale oils in China. Journal of Petroleum Science and Engineering 178, 975-986.Wang, Y., Wang, L., Wang, J., Jiang, Z., Wang, C.-C., Fu, Y., Song, Y.-F., Wang, Y., Liu, D., Jin, C., 2019. Multiscale characterization of three-dimensional pore structures in a shale gas reservoir: A case study of the Longmaxi shale in Sichuan basin, China. Journal of Natural Gas Science and Engineering 66, 207-216.Wu, H., Xiong, L., Ge, Z., Shi, H., Wang, T., Fan, L., 2019. Fine characterization and target window optimization of high-quality shale gas reservoirs in the Weiyuan area, Sichuan Basin Natural Gas Industry 39, 11-20.Wu, J., Liang, C., Jiang, Z., Zhang, C., 2019. Shale reservoir characterization and control factors on gas accumulation of the Lower Cambrian Niutitang shale, Sichuan Basin, South China. Geological Journal 54, 1604-1616.Wu, M., Ding, M., Yao, J., Li, C., Li, X., Zhu, J., 2019. Development of a multi-continuum quadruple porosity model to estimate CO2 storage capacity and CO2 enhanced shale gas recovery. Journal of Petroleum Science and Engineering 178, 964-974.Xie, X., Amann-Hildenbrand, A., Littke, R., Krooss, B.M., Li, M., Li, Z., Huang, Z., 2019. The influence of partial hydrocarbon saturation on porosity and permeability in a palaeogene lacustrine shale-hosted oil system of the Bohai Bay Basin, Eastern China. International Journal of Coal Geology 207, 26-38.Yang, Y., Wang, K., Zhang, L., Sun, H., Zhang, K., Ma, J., 2019. Pore-scale simulation of shale oil flow based on pore network model. Fuel 251, 683-692.Yuan, Y., Rezaee, R., 2019. Impact of paramagnetic minerals on NMR-converted pore size distributions in Permian Carynginia shales. Energy & Fuels 33, 2880-2887.Zhai, G.-y., Wang, Y.-f., Zhou, Z., Liu, G.-h., Yang, Y.-r., Li, J., 2018. “Source-Diagenesis-Accumulation” enrichment and accumulation regularity of marine shale gas in southern China. China Geology 1, 319-330.Zhai, G.-y., Wang, Y.-f., Zhou, Z., Yu, S.-f., Chen, X.-l., Zhang, Y.-x., 2018. Exploration and research progress of shale gas in China. China Geology 1, 257-272.Zhang, K., Tontiwachwuthikul, P., Jia, N., Li, S., 2019. Four nanoscale-extended equations of state: Phase behaviour of confined fluids in shale reservoirs. Fuel 250, 88-97.Zheng, D., Wang, W., Reza, Z., 2019. Integrated pore-scale characterization of mercury injection/imbibition and isothermal adsorption/desorption experiments using dendroidal model for shales. Journal of Petroleum Science and Engineering 178, 751-765.Zhong, C., Qin, Q., Fan, C., Hu, D., 2019. Effect of nanometer pore structure on methane adsorption capacity in organic-rich shale. Petroleum Science and Technology 37, 1243-1250.Zhong, C., Qin, Q., Fan, C., Hu, D., 2019. Geochemical characteristics of shale gas and its response to thermal maturity (Ro) in the Longmaxi formation, Dingshan area, Southeast Sichuan. Petroleum Science and Technology 37, 1270-1278.Zhou, J., Liu, M., Xian, X., Jiang, Y., Liu, Q., Wang, X., 2019. Measurements and modelling of CH4 and CO2 adsorption behaviors on shales: Implication for CO2 enhanced shale gas recovery. Fuel 251, 293-306.Zhou, Z., Bao, S.-j., Chen, X.-l., Yu, S.-f., Chen, K., Guo, T.-x., Xu, Q.-f., 2018. A discovery of Silurian tight shale gas in Jianshi, Hubei, China. China Geology 1, 160-161.Stauffer, P.H., Rahn, T., Ortiz, J.P., Salazar, L.J., Boukhalfa, H., Behar, H.R., Snyder, E.E., 2019. Evidence for high rates of gas transport in the deep subsurface. Geophysical Research Letters 46, 3773-3780.AbstractsAbarca, E., Idiart, A., Grandia, F., Rodríguez-Morillas, N., Pellan, C., Zen, M., A?t-Ettajer, T., Fontanelli, L., 2019. 3D reactive transport modeling of porosity evolution in a carbonate reservoir through dolomitization. Chemical Geology 513, 184-199. of carbonate reservoirs is considered a major process for porosity enhancement and is therefore of great relevance in hydrocarbon exploration. Despite the ubiquitous occurrence of massive dolostones, the question of whether reasonable amounts of dolomitizing fluid and Mg supply are capable of substantial porosity generation remains. In this work, a model of hydrothermal dolomitization of a carbonate reservoir is assessed by means of 3D reactive transport simulations implemented in iCP, an interface between Comsol Multiphysics and PHREEQC. The model is based on a currently producing carbonate reservoir with large regions of high porosity values deduced through seismic inversion. The model geometry and parameterization are based on the present-day configuration of the basin. Using an embedded model approach, the geochemical reactions in the reservoir have been coupled to the thermo-hydrogeological behavior of the entire basin. The results indicate that, after 100?kyr, dolomitization of limestone by fluids with high Mg/Ca ratio is restricted to areas around faults. Predicted volumes affected by dolomitization are consistent with dolomite bodies observed in nature. However, the intensity of dolomitization (up to 20% of limestone replacement) and the corresponding porosity enhancement (up to 3%) is not in agreement with the observed porosity values in the studied area. Even considering uncertainties in the fluid chemistry and in the hydrological conditions, numerical predictions suggest that times much longer than 100?kyr of recurrent water-rock interaction are needed to account for the generation of massive dolostones formed from limestone replacement. However, longer periods of time are not consistent with the tectonic evolution of the basin. Therefore, additional or alternative porosity generation mechanisms must be involved, such as compaction and late diagenetic corrosion.Abarghani, A., Ostadhassan, M., Bubach, B., Zhao, P., 2019. Estimation of thermal maturity in the Bakken source rock from a combination of well logs, North Dakota, USA. Marine and Petroleum Geology 105, 32-44. attempts have been conducted to construct a reliable model to relate petrophysical and geomechanical characteristics of shale to geochemical properties. In this study, continuous logs were built to predict the thermal maturity of the Bakken Formation from a set of petrophysical logs. First, dynamic modulus (Ed) was created from shear and compressional sonic and, density logs and then converted to Ei (nanoindentation based Young's modulus) using the existing experimental relationship between Ed and Ei. Next, continuous TOC logs were generated for the Bakken Shales based on an empirical relationship between well log derived Ei and TOC contents that were measured in the lab. There was found an acceptable difference between estimated log-based TOC and measured values in three separate wells. Solid bitumen reflectance as a reliable indicator of thermal maturity was measured on all samples from the same wells in the scarcity/absence of vitrinite maceral. The relationships between GR/NPHI/RHOZ wireline logs versus solid bitumen reflectance (BRO%) as the maturity index was then investigated in twelve wells. Based on the strength or weight of the relationship between each log and BRO%, a new parameter “?” was defined to represent thermal maturity from well logs. A good agreement between parameter ? and BRO% values was observed which provided an empirical equation to make the estimation of BRO% values for the whole length of the shale members possible. Ultimately, the continuity of BRO% values, would enable us to establish a relationship between BRO% and measured Tmax values to generate continuous Tmax logs for the Bakken Shale members. Using these newly developed well logs, it would become possible to make a 3D property models for BRO% and Tmax (the thermal maturity property cube) for an accurate petroleum system evaluation based on GR/NPHI/RHOZ logs.Abhishek, R., Hamouda, A.A., Abdulhameed, F.M., 2019. Adsorption kinetics and enhanced oil recovery by silica nanoparticles in sandstone. Petroleum Science and Technology 37, 1363-1369. study addresses adsorption kinetics of silica nanoparticles on sandstone mineral surfaces and Enhanced oil recovery (EOR) by nanoparticles. It was shown that nanoparticle adsorption on quartz which is the major constituent of sandstone reservoirs was best described as second order process. Both rate and equilibrium adsorption increases with salinity. However, salinity reduces Intraparticle diffusion while enhancing film diffusion. Spontaneous imbibition with nanoparticles dispersed in low salinity water showed higher incremental recovery which may be due to increased structural disjoining pressure. This was supported by surface forces analysis based on particle size and zeta potential measurements of the nanofluids.Abolhasan, A., Esmaeilzadeh, F., Mowla, D., 2019. Effect of brine on asphaltene precipitation at high pressures in oil reservoirs. Petroleum Chemistry 59, 57-65. this study, the effect of NaCl, KCl, CaCl2, MgCl2, MgSO4, and CaCl2 salts in brine in the range of low (1000?5000 ppm) and intermediate (5000?40?000 ppm) salinity water on the amount and offset pressure of asphaltene precipitation was investigated. The measurements were performed at reservoir temperature (350.15 K) and high pressures (0?100 bar). The IFT (Interfacial Tension) values increased with pressure and a sudden increase was observed at a specific pressure namely, an offset pressure of asphaltene precipitation in APE (Asphaltene Precipitation Envelope). For all brines, the amount of IFT with increasing concentration was in descending order and after a minimum value it changed to uptrend. Likewise, similar results were obtained for the precipitated asphaltene amount. All the brines intensified the asphaltene precipitation. Monovalent cations like Na+ and K+ showed higher values of IFT and hence more asphaltene precipitation, however, MgCl2 showed the least IFT, offset pressure and the amount of asphaltene precipitation.Abraham, J.S., Sripoorna, S., Maurya, S., Makhija, S., Gupta, R., Toteja, R., 2019. Techniques and tools for species identification in ciliates: a review. International Journal of Systematic and Evolutionary Microbiology 69, 877-894. are highly divergent unicellular eukaryotic organisms with nuclear dualism and a highly specialized ciliary pattern. They inhabit all biotopes and play crucial roles in regulating microbial food webs as they prey on bacteria, protists and even on microscopic animals. Nevertheless, subtle morphological differences and tiny sizes hinder proper species identification for many ciliates. In the present review, an attempt has been made to elaborate the various approaches used by modern day ciliate taxonomists for species identification. The different approaches involved in taxonomic characterization of ciliates such as classical (using live-cell observations, staining techniques, etc.), molecular (involving various marker genes) and statistical (delimitation of cryptic species) methods have been reviewed. Ecological and behavioural aspects in species identification have also been discussed. In present-day taxonomy, it is important to use a ‘total evidence’ approach in identifying ciliates, relying on both classical and molecular information whenever possible. This integrative approach will help in the mergence of classical methods with modern-day tools for comprehensive species description in future.Acharya, K., Werner, D., Dolfing, J., Barycki, M., Meynet, P., Mrozik, W., Komolafe, O., Puzyn, T., Davenport, R.J., 2019. A quantitative structure-biodegradation relationship (QSBR) approach to predict biodegradation rates of aromatic chemicals. Water Research 157, 181-190. objective of this work was to develop a QSBR model for the prioritization of organic pollutants based on biodegradation rates from a database containing globally harmonized biodegradation tests using relevant molecular descriptors. To do this, we first categorized the chemicals into three groups (Group 1: simple aromatic chemicals with a single ring, Group 2: aromatic chemicals with multiple rings and Group3: Group 1 plus Group 2) based on molecular descriptors, estimated the first order biodegradation rate of the chemicals using rating values derived from the BIOWIN3 model, and finally developed, validated and defined the applicability domain of models for each group using a multiple linear regression approach. All the developed QSBR models complied with OECD principles for QSAR validation. The biodegradation rate in the models for the two groups (Group 2 and 3 chemicals) are associated with abstract molecular descriptors that provide little relevant practical information towards understanding the relationship between chemical structure and biodegradation rates. However, molecular descriptors associated with the QSBR model for Group 1 chemicals (R2?=?0.89, Q2loo?=?0.87) provided information on properties that can readily be scrutinised and interpreted in relation to biodegradation processes. In combination, these results lead to the conclusion that QSBRs can be an alternative tool to estimate the persistence of chemicals, some of which can provide further insights into those factors affecting biodegradation.Afolabi, R.O., Yusuf, E.O., 2019. Nanotechnology and global energy demand: challenges and prospects for a paradigm shift in the oil and gas industry. Journal of Petroleum Exploration and Production Technology 9, 1423-1441. exploitation of new hydrocarbon discoveries in meeting the present global energy demand is a function of the availability and application of new technologies. The relevance of new technologies is borne out of the complex subsurface architecture and conditions of offshore petroleum plays. Conventional techniques, from drilling to production, for exploiting these discoveries may require adaption for such subsurface conditions as they fail under conditions of high pressure and high temperature. The oil and gas industry over the past decades has witnessed increased research into the use of nanotechnology with great promise for drilling operations, enhanced oil recovery, reservoir characterization, production, etc. The prospect for a paradigm shift towards the application of nanotechnology in the oil and gas industry is constrained by evolving challenges with its progression. This paper gave a review of developments from nano-research in the oil and gas industry, challenges and recommendations.Agatova, A.I., Torgunova, N.I., Serebryanikova, E.A., Dukhova, L.K., 2019. Space and time variations of organic matter in Caspian Sea water. Water Resources 46, 76-86. analysis of data on the space and time variations of the concentrations and element composition of organic matter dissolved in Caspian Sea water over 2010–2015 showed that the average concentrations of Corg and Norg did not changed over the last 5 years of sea level drop relative to the period of level rise, while the concentrations of Porg decreased more than three times, i.e., qualitative changes had taken place in the organic matter. According to the average data, the concentrations of Corg, Norg, and Porg in the southern waters were slightly higher than those in the Northern and Middle Caspian waters. In deep-water regions, the concentrations Corg, Norg, and Рorg increase at the boundary of hydrogen sulfide appearance. The presence of hydrogen sulfide in deep waters of the Derbentskaya and Southern Caspian depressions, accompanied by an increase in OM, suggests that no radical increase in vertical seawater mixing took place in these regions during the eight-year regression. The distribution of carbohydrates demonstrates a considerable contribution of petroleum hydrocarbon OM to the total pool.Aghajanzadeh, M.R., Ahmadi, P., Sharifi, M., Riazi, M., 2019. Wettability modification of oil-wet carbonate reservoirs using silica-based nanofluid: An experimental approach. Journal of Petroleum Science and Engineering 178, 700-710. is an important factor which controls oil recovery and fluids displacement efficiency in the porous media. Wettability alteration (WA) from strongly oil-wet towards water wet or neutral states is one of the most effective methods of oil recovery increment. Many studies have shown that nanofluid can change the wettability of rock surface towards a desirable state and base on literature structural disjoining pressure is the main mechanism of wettability alteration via nano-treatment. However, there is a lack of information regarding the impact of salinity on nanofluid performance in porous media. Therefore, in this work, the effects of salinity, nanofluid concentration and rock type (i.e. limestone and dolomite surfaces) on wettability alteration of oil wet carbonate substrates under ambient condition were investigated. For this purpose, various static and dynamic experiments including contact angle, imbibition and core flood tests have been performed. The results on contact angle measurements showed that by increasing nanoparticles and electrolyte concentration the wettability alteration from oil wet to water wet was significantly enhanced. Moreover, the wettability alteration of dolomite substrate is much more than that of limestone substrate. In the following, the impact of nanofluid on the spontaneous imbibition for strongly oil-wet carbonate cores was closely examined. Finding results showed an increase as much as 15% of oil recovery for nanofluid imbibition in comparison to that of formation brine. Final evaluation of the nanofluid treatment in terms of its effectiveness was measured by core flood experimental runs. Comparison of relative permeability curves before and after treating have outlined that after the treatment process, the relative permeability curve has shifted to the right and the water relative permeability has reduced from 0.43 mD to 0.23 mD at the residual oil saturation due to wettability alteration of rock surface from strongly oil wet to water wet state.Ahmad, S., Ahmad, F., Ullah, A., Eisa, M., Ullah, F., Kaif, K., Khan, S., 2019. Integration of the outcrop and subsurface geochemical data: implications for the hydrocarbon source rock evaluation in the Lower Indus Basin, Pakistan. Journal of Petroleum Exploration and Production Technology 9, 937-951. present study details the hydrocarbon source rock geochemistry and organic petrography of the outcrop and subsurface samples of the Middle Jurassic Chiltan Formation and the Lower Cretaceous Sembar Formation from the Sann #1 well Central and Southern Indus Basin, Pakistan. The total organic carbon (TOC), Rock–Eval pyrolysis, vitrinite reflectance (Ro) % and Maceral analysis techniques were used and various geochemical plots were constructed to know the quality of source rock, type of kerogen, level of maturity and migration history of the hydrocarbons. The outcrop and Sann #1 well data on the Sembar Formation reveals poor, fair, good and very good quality of the TOC, type II–III kerogen, immature–mature organic matter and an indigenous hydrocarbon generation potential. The outcrop and Sann #1 well data on the Chiltan Formation show a poor–good quality of TOC, type II–III kerogen, immature–mature source rock quality and having an indigenous hydrocarbon generation potential. The vitrinite reflectance [Ro (%)] values and Maceral types [fluorescent amorphous organic matter, exinite, alginite and inertnite] demonstrate that maturity in both Sembar and the Chiltan formation at surface and subsurface fall in the oil and gas generation zone to cracking of oil to gas condensate zone. Recurrence of organic rich and poor intervals within the Sembar and Chiltan formation are controlled by the Late Jurassic thermal uplift preceding the Indo-Madagascar separation from the Afro-Arabian Plate and Early Cretaceous local transgressive–regressive cycles. From the current study, it is concluded that both Sembar and Chiltan formation can act as a potential hydrocarbon source rock in the study area.Ahmed, O.E., Eldesoky, A.M., El Nady, M.M., 2019. The use of polycyclic aromatic in the assessment of marine life and the impact on petroleum pollution in the Suez Gulf, Egypt. Petroleum Science and Technology 37, 1400-1409. study represents the concentrations of 16 PAHs in a commercial aquatic species Sauridaund squamis; Euthynnus affinis; Rhabdosargus haffara; Argyrops Spinifer; Nemipterus Japonicus, Oreochromis Niloticus; Trachurus Indicus; Peneus Japonicas; Scomber Japonicus; and Pomadasys Stridens, which were collected from the coastal area of the Suez Gulf waters. The analyses of polycyclic aromatic hydrocarbons (PAHs) were determined using HPLC to identify the sources of PAHs. The results revealed that low molecular weight of PAHs were more than high molecular weight in aquatic species, Benzo(a)Anthracene/(Benzo(a)Anthracene?+?Chrysene) BaA/(BaA?+?Chr), Indeno (1,2,3-cd) pyrene/(Indeno (1,2,3-cd) pyrene?+?Benzo (ghi) perylene) IP/(IP?+?BP) and Fluoranthene/Pyrene (Fl/Pyr), they reflected that the PAHs sources in aquatic species are petrogenic as a main sources, pyrogenic sources. The study area was generally contaminated with hydrocarbons and continuous consumption of food from this area may pose public health hazards.Ai, J., Lü, X.-b., Li, Z.-w., Wu, Y.-l., 2018. A super-large graphite deposit discovered in granite rocks at Huangyangshan, Xinjiang, China. China Geology 1, 164-166.. Objective: A graphite deposit has been discovered in Sujiquan, Xinjiang in 1980s, which provides detailed geological settings for the super-large graphite deposit discovered in Huangyangshan pluton with total reserves up to 7.264×109 t in 2017. Outcrops of igneous rocks in the study area include Middle Devonian plagioclase granite and Late Carboniferous alkali feldspar granite that is referred to the Huangyangshan pluton, which includes the Lower Carboniferous Heishantou Formation and Jiangbasi Formation, both of which consist of volcanic-sedimentary rocks (Fig. 1). Sujiquan fault provided passage for the migration of volcanic intrusions. Graphite deposits are usually hosted by metamorphic rocks, but Huangyanshan deposits are hosted by granite rocks, which are rarely known. The Huangyangshan graphite deposit hosted by granite pluton at Huangyangshan area was discovered by Xinjiang Branch of China National Geological Exploration Center of Building Materials Industry since 2015. The graphite deposit is 160 km away from Qitai, Changji, Xinjiang, China. 8 crystalline graphite ore deposits are recognized, which has super large reserves up to 7.264×109 t. The lithology of the Huangyangshan pluton is composed of 5 types: medium grained biotite granite, fine grained biotite granite, hornblende granite, medium grained arfvedsonite granite, and fine grained arfvedsonite granite. Currently, there are few studies of Huangyangshan deposit. This paper mainly introduces geological characteristics of the Huangyangshan deposit to help further researches and exploitations.2. Methods: This project combines field investigation and sample analyzing methods. Rock samples are systematically taken from the geological sections in the field. Detailed geological characteristics of the samples are described in the field as well. Petrology and petrography studies on graphite ores and host rocks are carried out to identify lithology and mineral compositions. This paper will discuss the genesis of Huangyangshan graphite deposit with all the results in the end.3. Results: Huangyangshan graphite deposit is consisted of 8 ore bodies. No.1 and No.2 ore bodies are hosted by hornblende granite (Table 1). The upper wall rock of these two ore bodies is hornblende granite, while the lower wall rock is fine grained biotite granite. The boundary between ore bodies and wall rocks is distinctive. No.3 and No.4 ore bodies are hosted by fine grained biotite granite. No.5 to No.8 ore bodies are hosted by medium grained biotite granite (Fig. 1).The lithology of ore body is alkali feldspar granite, which consists of 60%–70% alkali feldspar, 5%–10% plagioclase, 20%–25% quartz, and minor hornblende, biotite and clinopyroxene. Graphite occurs in spherulitic, nodular and veinlet structures (Fig. 2). Graphite crystals occur in flaky and colloform textures. Metallic minerals associated with graphite include pyrrhotite, chalcopyrite and ilmenite. Ore bodies were altered under strong chloritization and sericitization. Stratum inclusions were recognized in graphite ores. They are identified as sandstone and tuff under microscope, displaying resemblance to the lithology of Heishantou Formation. Graphite veins traverse graphite spherulites and nodules, implying that graphite is formed by two stages of mineralization. The first stage is magmatic hydrothermal mineralization, and the second stage is hydrothermal superimposition mineralization period. The first stage is the primary mineralization stage.Stratum inclusions are remained in the ores, indicating that the carbons involved in the formation of graphite is derived from the upper stratum. Magma assimilated carbonaceous matters from stratum during its ascending. As magmatic hydrothermal fluids separated from the magmatic melts, large amount of carbon was migrated into hydrothermal fluids. As temperature and pressure declined, crystalline graphite was precipitated from magmatic hydrothermal fluids. Therefore, Huangyangshan graphite deposit is a magmatic hydrothermal deposit rather than a magmatic deposit.In comparison with Serrania de Ronda (Spain), Beni Bousera (Morocco), Botogol and Pogranichnoe (Russia), which are hosed by mafic-ultramafic rocks and containing few small (diameter≤5 cm) graphite spherulites, Huangyangshan super large deposit is hosted by acid rocks, containing abundant (about 90%) large (diameter≤20 cm) graphite spherulites.4. Conclusions: Huangyangshan crystalline graphite deposit with reserves up to 7.264×109 t, which is a unique super-large deposit so far.The carbons that are consisted of graphite in Huangyangshan deposit is derived from stratum. As magma was ascending, carbonaceous matters were assimilated from stratum. Crystalline graphite was precipitated from magmatic hydrothermal fluids. Therefore, this deposit is a magmatic hydrothermal deposit instead of a magmatic deposit.Al-Abri, H., Pourafshary, P., Mosavat, N., Al Hadhrami, H., 2019. A study of the performance of the LSWA CO2 EOR technique on improvement of oil recovery in sandstones. Petroleum 5, 58-66. salinity water is an emerging enhanced oil recovery (EOR) method that causes wettability alteration towards a favorable state to reduce residual oil saturation, while water alternating gas (WAG) is a proven EOR process that enhances oil recovery by controlling mobility of both water and gas. Therefore, combining the two EOR processes as low salinity water-alternating CO2 EOR injection (LSWA CO2) can further improve oil recovery by promoting the synergy of the mechanisms underlying these two methods.Core flooding experiments, contact angle, interfacial tension (IFT), and CO2 solubility measurement in oil and brine were conducted to investigate the viability and performance of LSWA CO2 in sandstone reservoirs. A favorable wettability alteration, along with IFT reduction and mobility control, are the mechanisms that contribute to residual oil mobilization efficiencies during the LSWA CO2 EOR process. In addition, LSWA CO2 core flooding experiments result in a significant incremental oil recovery.Three smart waters were tested in our research, to examine the impact of changing cationic composition on oil recovery. The solutions are designed brines as NaCl (SW1), MgCl2 (SW2), and KCl (SW3). Of the three solutions, SW1 yields the highest incremental oil recovery and highest IFT reduction. In addition, it results in a favorable wettability alteration towards a more water-wet state.In all cases, introducing CO2 to the brine/oil system shows a great advantage in terms of enhancing wettability modification, promoting IFT reduction, and controlling the displacement front of the injected fluid through mobility control.Al-Khafaji, A.J., Sadooni, F., Hindi, M.H., 2019. Contribution of the Zubair source rocks to the generation and expulsion of oil to the reservoirs of the Mesopotamian Basin, Southern Iraq. Petroleum Science and Technology 37, 940-949. huge quantities of oil and gas reserved in the fields of southern Iraq must be matched by enough source rocks that can generate and expel equivalent amounts of hydrocarbons. This study is an attempt to evaluate the potential and efficiency of the Zubair Formation strata as potential source rocks that contributed to the hydrocarbon budget. A Multiproxy investigation including TOC, pyrolysis, palynofacies, carbon isotope and biomarker analysis were used to investigate such possibility. Results indicate that Zubair rocks were ranging from poor to excellent source rocks, early to moderate maturity, and generated and expelled much hydrocarbons to the Cretaceous reservoirs of the Basin.Al-Mudhafar, W.J., Rao, D.N., Srinivasan, S., 2019. Geological and production uncertainty assessments of the cyclic CO2-assisted gravity drainage EOR process: a case study from South Rumaila oil field. Journal of Petroleum Exploration and Production Technology 9, 1457-1474. or uncertainty assessment in the reservoir flow modeling, especially in real field-scale evaluation, is essential to make a trustful decision regarding the future development plans. This paper presents an efficient uncertainty assessment workflow of geological and production data through the cyclic CO2-assisted gravity drainage (GAGD) process in South Rumaila oil field in Southern Iraq. First, the sequential Gaussian simulation created a large number of reservoir stochastic realizations that capture the entire geological uncertainty space. Second, ranking was applied to select the quartiles (P10,P20,…,P90) of reservoir permeability and anisotropy ratio to quantify the geological uncertainty. Next, the equation of state-compositional flow model was constructed to evaluate these realizations by calculating the reservoir flow response. Then, 81 designed simulations were created by factorial design considering the combined realizations of permeability and anisotropy ratio. In a successive step, the most-likely model was considered for the uncertainty quantification of the operational decision parameters through the cyclic GAGD process to restrict the uncertainty space, which leads to obtain the true optimal scenario. The cyclic GAGD operational parameters include durations of injection, soaking, and production and the minimum bottom hole pressure in production wells. The compositional reservoir flow model was again used to evaluate the multiple simulations created by the proxy-based Box–Behnken design and Monte Carlo simulation. The combined geological and production uncertainty workflow gave an idea about the uncertainty or risk space of the predicted reservoir flow response in the future cyclic GAGD process performance.Albright, M.B.N., Timalsina, B., Martiny, J.B.H., Dunbar, J., 2019. Comparative genomics of nitrogen cycling pathways in bacteria and archaea. Microbial Ecology 77, 597-606. the explosion of metagenomic sequencing data, using -omics data to predict environmental biogeochemistry remains a challenge. One or a few genes (referred to as marker genes) in a metabolic pathway of interest in meta-omic data are typically used to represent the prevalence of a biogeochemical reaction. This approach often fails to demonstrate a consistent relationship between gene abundance and an ecosystem process rate. One reason this may occur is if a marker gene is not a good representative of a complete pathway. Here, we map the presence of 11 nitrogen (N)-cycling pathways in over 6000 complete bacterial and archaeal genomes using the Integrated Microbial Genomes database. Incomplete N-cycling pathways occurred in 39% of surveyed archaeal and bacterial species revealing a weakness in current marker-gene analyses. Furthermore, we found that most organisms have limited ability to utilize inorganic N in multiple oxidation states. This suggests that inter-organism exchange of inorganic N compounds is common, highlighting the importance of both community composition and spatial structure in determining the extent of recycling versus loss in an ecosystem.Alexander, C.M.O.D., 2019. Quantitative models for the elemental and isotopic fractionations in chondrites: The carbonaceous chondrites. Geochimica et Cosmochimica Acta 254, 277-309. quantitative understanding of the elemental and isotopic fractionations recorded in the compositions of the chondritic meteorites would provide fundamental constraints for astrophysical models of early Solar System evolution. Here it is shown through least squares fitting that almost all features of the bulk elemental and isotopic compositions of the main carbonaceous chondrite (CC) groups, as well as the ungrouped Tagish Lake (C2) meteorite, can be reproduced using mixtures of the same four components. The fractionations amongst the non-CCs (ordinary, Rumuruti and enstatite chondrites) are distinctly different to those in the CCs and are the subject of a separate study (Alexander, 2019). The four CC components are: (1) a ‘chondrule’ (or chondrule precursor) component that partially lost Fe,Ni metal and volatiles, but is otherwise CI-like, (2) the cc-RI component that has a refractory inclusion-like bulk composition and is largely responsible for the refractory element enrichments and nucleosynthetic isotope anomalies in the bulk CCs, (3) anhydrous and reduced but otherwise CI-like matrix that accounts for almost all of the most volatile element (e.g., Zn, Se and C) contents of the CCs, and (4) water with relatively high Δ17O and δ18O values. Comparison of the inferred component compositions to additional meteoritic constraints produces some notable results. The ε48Ca?≈?8 and ε50Ti?≈?8 values for the cc-RI component are consistent with the average values for refractory inclusions. On the other hand, the ε54Cr?≈??10 is not, but is required by the negative correlation between ε50Ti and ε54Cr amongst the bulk CCs. The cc-RI component may be comprised of a more CAI-like sub-component that carries the ε48Ca and ε50Ti anomalies, and a more ferromagnesian sub-component that carries the negative ε54Cr anomalies. The compositions of the volatile and metal subcomponents lost from the ‘chondrule’ component are consistent with condensation models, suggesting that the fractionations predated chondrule formation. The isotopic compositions of chondrules from the more cc-RI-rich CC groups (e.g., CV, CO and CM) seem to require the addition of some of the cc-RI component to their precursors. The assumption that matrix is CI-like is inconsistent with chondrule-matrix complementarity, but is justified by the success of the fits and the relatively uniform and CI-like abundances of organics and presolar grains in the matrices of the most primitive CCs. The inferred Δ17O?=?3.5‰ for the water component is consistent with most constraints from secondary phases in the CCs. The large O isotopic mass fractionation (δ18O?≈?18–21‰) of the water is consistent with ～89–95% condensation of ice from a vapor under Rayleigh conditions at 150–170?K. The water was entirely accreted with the matrix with fairly constant (0.32?±?0.06 by wt.) and CI-like (～0.38 by wt.) water/matrix ratios. These water/matrix ratios are much less than the water/rock ratio of one that is often cited for a nebula of solar composition, but can be explained if much of the C in the CC formation regions was present as CO and CO2, and the abundance of CH4 was low.Alizadeh, B., Saadati, H., Tarhandeh, E., 2019. Geochemical characteristics of Upper Jurassic carbonate reservoir bitumen in the eastern Kopeh-Dagh, NE Iran. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects 41, 1928-1937. characteristics of solid bitumen in Upper Jurassic carbonate reservoir are investigated. Aromatic maturity parameters indicate peak to late oil window level of maturity for the bitumen samples. Regular sterane distributions, conical variable (CV), plots of δ13CSat versus δ13CAro and Pr/nC17 against Ph/nC18, predominance of C23 tricyclic terpane, ratios of steranes/hopanes and C23/C21 tricyclic terpane indicate charging from clastic-rich anoxic marine source rocks. Ratios of C29/C30 hopane, Ts/Ts+?Tm, C24 tetracyclic terpane/C20-26 tricyclic terpanes and plot of C22/C21 versus C24/C23 tricyclic terpanes show influences of carbonate/marl facies. All these would throw crucial guiding light on the interpretation of the future exploration.Allemann, M.N., Shulse, C.N., Allen, E.E., 2019. Linkage of marine bacterial polyunsaturated fatty acid and long-chain hydrocarbon biosynthesis. Frontiers in Microbiology 10, 702. doi: 710.3389/fmicb.2019.00702. marine gamma-proteobacteria produce omega-3 polyunsaturated fatty acids, such as eicosapentaenoic acid (20:5, EPA) and docosahexaenoic acid (22:6, DHA), which are incorporated into membrane phospholipids. Five genes, designated pfaABCDE, encode the polyketide/fatty acid synthase necessary for production of these long-chain fatty acids. In addition to de novo biosynthesis of EPA and DHA, the “Pfa synthase” is also involved with production of a long-chain polyunsaturated hydrocarbon product (31:9, PUHC) in conjunction with the oleABCD hydrocarbon biosynthesis pathway. In this work, we demonstrate that OleA mediates the linkage between these two pathways in vivo. Co-expression of pfaA-E along with oleA from Shewanella pealeana in Escherichia coli yielded the expected product, a 31:8 ketone along with a dramatic ~10-fold reduction in EPA content. The decrease in EPA content was independent of 31:8 ketone production as co-expression of an OleA active site mutant also led to identical decreases in EPA content. We also demonstrate that a gene linked with either pfa and/or ole operons in diverse bacterial lineages, herein designated pfaT, plays an accessory role in maintaining optimal production of Pfa synthase derived products in Photobacterium and Shewanella species.Almenningen, S., Fotland, P., Fern?, M.A., Ersland, G., 2019. An experimental investigation of gas-production rates during depressurization of sedimentary methane hydrates. SPE Journal 24, 522-530. methane hydrates contain a vast amount of untapped natural gas that can be produced through pressure depletion. Several field pilots have proved the concept with days to weeks of operation, but the longer-term response remains uncertain. This paper investigates the parameters affecting the rate of gas recovery from methane-hydrate-bearing sediments. The recovery of methane gas from hydrate dissociation through pressure depletion was studied at different initial hydrate saturations and different constant production pressures in cylindrical sandstone cores. Core-scale dissociation patterns were mapped with magnetic resonance imaging (MRI), and pore-scale dissociation events were visualized in a high-pressure micromodel. Key findings from the gas-production-rate analysis are that the maximum rate of recovery is only to a small extent affected by the magnitude of the pressure reduction below the dissociation pressure, and that the hydrate saturation directly affects the rate of recovery, where intermediate hydrate saturations (0.30 to 0.50) give the highest initial recovery rate. These results are of interest to anyone who evaluates the production performance of sedimentary hydrate accumulations and demonstrate how important accurate saturation estimates are to prediction of both the initial rate of gas recovery and the ultimate-recovery efficiency.Alshakhs, M., Rezaee, R., 2019. Sweet-spot mapping through formation evaluation and property modelling using data from the Goldwyer Formation of the Barbwire Terrace, Canning Basin. Petroleum 5, 13-29. Goldwyer Formation of the Canning Basin has been regarded as a highly prospective shale play. This study assesses the potential prospectivity of this source rock as an unconventional hydrocarbon resource. Considering the sparsity of wells penetrating the Middle Ordovician Goldwyer across the vast under-explored area of the Canning Basin, a basin-wide study of the source rock is not warranted. Goldwyer assessment of the Barbwire Terrace, a subdivision of the Canning Basin, is carried out instead.This assessment includes the estimation of key shale play properties, such as, total organic carbon, total porosity, water saturation, and brittleness index. Each property was estimated from available well data by testing multiple estimation methods. TOC values were derived from multiple regressions of different well data. A simplified Archie's equation was used to estimate water saturation. Density porosity method was primarily used for total porosity estimations. Sonic data along with density were utilized to estimate brittleness index.Each property was then modelled across the Goldwyer Formation within the terrace. This provided geostatistical estimates on the propagation of such properties. In order to generate sweet spot maps for the Barbwire Terrace, averaged maps of different properties were combined in a weighted manner. This approach attempts to simplify the complexity of unconventional resource assessment, which therefore has provided a single product evaluating the prospectivity of the Goldwyer as a hydrocarbon resource.Results have shown that TOC and porosity are mostly the deciding factors for the prospectivity of this source rock, given that their values can be too small where the Goldwyer is deemed non-prospective. Nonetheless, sweet-spot maps show that most prospective zone is the Upper Goldwyer (Goldwyer I), followed by the upper parts of the Lower Goldwyer (Goldwyer III). More specifically, southern flanks of north-western and middle regions of the Barbwire Terrace tend to be more prospective. A stricter approach where cut-off values were applied for each property showed that sweet-spot maps are only prospective in the southern flanks of the middle Barbwire Terrace of Goldwyer I.Aminnaji, M., Anderson, R., Tohidi, B., 2019. Anomalous KHI-Induced dissociation of gas hydrates inside the hydrate stability zone: Experimental observations & potential mechanisms. Journal of Petroleum Science and Engineering 178, 1044-1050. the past decade, the low dosage hydrate inhibitors (LDHIs) - which include kinetic hydrate inhibitors (KHIs) and anti-agglomerants (AAs) - have seen increasing use for gas hydrate prevention in hydrocarbon production operations, offering significant CAPEX/OPEX advantages over traditional thermodynamic inhibitors (e.g. methanol, glycols). Typically dosed at < 2.5% in produced water, KHIs were historically considered primarily as hydrate nucleation inhibitors, although in recent years focus has shifted towards their powerful crystal growth inhibition properties. Beginning at low aqueous concentrations, KHI polymers induce a number of highly repeatable, well-defined, hydrate crystal growth inhibition (CGI) regions as a function of subcooling, varying from complete inhibition, through long induction times and reduced growth rates, to final failure/uninhibited growth. This behaviour can be used to robustly assess KHIs for field use, as we have previously demonstrated through development of the KHI CGI evaluation method, which is now used as standard by a number of laboratories. During CGI testing, it is not uncommon to observe anomalous (should be stable thermodynamically) hydrate dissociation in the presence of KHIs, although very little is understood regarding this phenomenon. In this work, we present the initial findings of experimental studies aimed at investigating this anomalous dissociation for different commercial base polymers. Results demonstrate that, in addition to inhibiting hydrate growth/nucleation, low dosages (e.g. 0.5% and 0.25%) of KHI polymers can induce partial or complete hydrate dissociation, with this process largely generic to different KHIs. However, some KHI polymers cause catastrophic hydrate growth after nucleation begins and these polymers show no ability to dissociate hydrates, so this hydrate dissociation ability is not universal to all KHI Polymers. The cause of this dissociation is unclear, although it is postulated to result from interactions between the KHI and inherent hydrate morphological and/or structural changes. In addition to improving confidence in KHI field use, findings potentially have novel applications with respect to hydrate plug remediation and gas production from naturally occurring hydrates in oceanic/permafrost sediments.Anderson, R.F., Sachs, J.P., Fleisher, M.Q., Allen, K.A., Yu, J., Koutavas, A., Jaccard, S.L., 2019. Deep-sea oxygen depletion and ocean carbon sequestration during the last ice age. Global Biogeochemical Cycles 33, 301-317.: Enhanced ocean carbon storage during the Pleistocene ice ages lowered atmospheric CO2 concentrations by 80 to 100 ppm relative to interglacial levels. Leading hypotheses to explain this phenomenon invoke a greater efficiency of the ocean's biological pump, in which case carbon storage in the deep sea would have been accompanied by a corresponding reduction in dissolved oxygen. We exploit the sensitivity of organic matter preservation in marine sediments to bottom water oxygen concentration to constrain the level of dissolved oxygen in the deep central equatorial Pacific Ocean during the last glacial period (18,000–28,000 years BP) to have been within the range of 20–50 μmol/kg, much less than the modern value of ~168 μmol/kg. We further demonstrate that reduced oxygen levels characterized the water column below a depth of ~1,000 m. Converting the ice age oxygen level to an equivalent concentration of respiratory CO2, and extrapolating globally, we estimate that deep‐sea CO2 storage during the last ice age exceeded modern values by as much as 850 Pg C, sufficient to balance the loss of carbon from the atmosphere (~200 Pg C) and from the terrestrial biosphere (~300–600 Pg C). In addition, recognizing the enhanced preservation of organic matter in ice age sediments of the deep Pacific Ocean helps reconcile previously unexplained inconsistencies among different geochemical and micropaleontological proxy records used to assess past changes in biological productivity of the ocean.Plain Language Summary: Carbon dioxide (CO2) in Earth's atmosphere was lower during cold glacial periods of the last 800,000 years than during warm interglacial periods, by an amount equivalent to about one third of the preindustrial CO2 content of the atmosphere. It is thought that the ocean absorbed the CO2 missing from the atmosphere, but determining where and how the CO2 was stored in the ocean has remained a challenge. Photosynthesis in the surface ocean converts CO2 to organic matter, a portion of which sinks into the deep sea, where it is subsequently converted back to CO2 by respiration of the organisms that consume the organic matter. Stimulation of the biological uptake of CO2 in surface water, inhibition of the physical processes that raise deep waters back to the surface where they exchange gases with the atmosphere, or any combination of the two would enhance the storage of CO2 in the deep ocean while also reducing the concentration there of dissolved oxygen. Here we show that the oxygen concentration in deep waters of the Pacific Ocean was much lower during the last glacial period than today. The difference is sufficient to accommodate the CO2 removed from the atmosphere during the ice ages.Artemieva, N., Shuvalov, V.V., Khazins, V.M., 2019. Upper atmosphere effects after the entry of small cosmic bodies: Dust trains, plumes, and atmospheric disturbances. Icarus 327, 60-71. this paper we present the results of numerical modeling of the Chelyabinsk dust train during the first 3?min after the meteoroid entry which are in qualitative agreement with observations. Then we analyze the possibility of plume formation after impacts of small cosmic bodies and make some calculations for the Tunguska event which, unfortunately, cannot be compared directly with observations. We also estimate long-lasting disturbances in the upper atmosphere caused by the plume formation.Ash, J.L., Egger, M., Treude, T., Kohl, I., Cragg, B., Parkes, R.J., Slomp, C.P., Sherwood Lollar, B., Young, E.D., 2019. Exchange catalysis during anaerobic methanotrophy revealed by 12CH2D2 and 13CH3D in methane. Geochemical Perspectives Letters 10, 26-30. anaerobic oxidation of methane (AOM) is a crucial component of the methane cycle, but quantifying its role in situ under dynamic environmental conditions remains challenging. We use sediment samples collected during IODP Expedition 347 to the Baltic Sea to show that relative abundances of 12CH2D2 and 13CH3D in methane remaining after microbial oxidation are in internal, thermodynamic isotopic equilibrium, and we attribute this phenomenon to the reversibility of the initial step of AOM. These data suggest that 12CH2D2 and 13CH3D together can identify the influence of anaerobic methanotrophy in environments where conventional bulk isotope ratios are ambiguous, and these findings may lead to new insights regarding the global significance of enzymatic back reaction in the methane cycle. ?vila, M.P., Brand?o, L.P.M., Brighenti, L.S., Tonetta, D., Reis, M.P., St?hr, P.A., Asmala, E., Amado, A.M., Barbosa, F.A.R., Bezerra-Neto, J.F., Nascimento, A.M.A., 2019. Linking shifts in bacterial community with changes in dissolved organic matter pool in a tropical lake. Science of The Total Environment 672, 990-1003. communities have a pivotal role in the global carbon cycle. Still the interaction between microbial community and dissolved organic matter (DOM) in freshwater ecosystems remains poorly understood. Here, we report results from a 12-day mesocosm study performed in the epilimnion of a tropical lake, in which inorganic nutrients and allochthonous DOM were supplemented under full light and shading. Although the production of autochthonous DOM triggered by nutrient addition was the dominant driver of changes in bacterial community structure, temporal covariations between DOM optical proxies and bacterial community structure revealed a strong influence of community shifts on DOM fate. Community shifts were coupled to a successional stepwise alteration of the DOM pool, with different fractions being selectively consumed by specific taxa. Typical freshwater clades as Limnohabitans and Sporichthyaceae were associated with consumption of low molecular weight carbon, whereas Gammaproteobacteria and Flavobacteria utilized higher molecular weight carbon, indicating differences in DOM preference among clades. Importantly, Verrucomicrobiaceae were important in the turnover of freshly produced autochthonous DOM, ultimately affecting light availability and dissolved organic carbon concentrations. Our findings suggest that taxonomically defined bacterial assemblages play definite roles when influencing DOM fate, either by changing specific fractions of the DOM pool or by regulating light availability and DOC levels.Backes, S., Garg, S.G., Becker, L., Peleh, V., Glockshuber, R., Gould, S.B., Herrmann, J.M., 2019. Development of the mitochondrial intermembrane space disulfide relay represents a critical step in eukaryotic evolution. Molecular Biology and Evolution 36, 742-756. mitochondrial intermembrane space evolved from the bacterial periplasm. Presumably as a consequence of their common origin, most proteins of these compartments are stabilized by structural disulfide bonds. The molecular machineries that mediate oxidative protein folding in bacteria and mitochondria, however, appear to share no common ancestry. Here we tested whether the enzymes Erv1 and Mia40 of the yeast mitochondrial disulfide relay could be functionally replaced by corresponding components of other compartments. We found that the sulfhydryl oxidase Erv1 could be replaced by the Ero1 oxidase or the protein disulfide isomerase from the endoplasmic reticulum, however at the cost of respiration deficiency. In contrast to Erv1, the mitochondrial oxidoreductase Mia40 proved to be indispensable and could not be replaced by thioredoxin-like enzymes, including the cytoplasmic reductase thioredoxin, the periplasmic dithiol oxidase DsbA, and Pdi1. From our studies we conclude that the profound inertness against glutathione, its slow oxidation kinetics and its high affinity to substrates renders Mia40 a unique and essential component of mitochondrial biogenesis. Evidently, the development of a specific mitochondrial disulfide relay system represented a crucial step in the evolution of the eukaryotic cell.Baghban, A., Piri, A., Lakzaei, M., Janghorban Lariche, M., Baghban, M., 2019. On the prediction of solubility of alkane in carbon dioxide using the LSSVM algorithm. Petroleum Science and Technology 37, 1231-1237. increasing global energy demand and declination of oil reservoir in recent years cause the researchers attention focus on the enhancement of oil recovery approaches. One of the extensive applicable methods for enhancement of oil recovery, which has great efficiency and environmental benefits, is carbon dioxide injection. The CO2 injection has various effects on the reservoir fluid, which causes enhancement of recovery. One of these effects is extraction of lighter components of crude oil, which straightly depends on solubility of hydrocarbons in carbon dioxide. In order to better understand of this parameter, in this study, Least squares support vector machine (LSSVM) algorithm was developed as a novel predictive tool to estimate solubility of alkane in CO2 as function of carbon number of alkane, carbon dioxide density, pressure, and temperature. The predicting model outputs were compared with the extracted experimental solubility from literature statistically and graphically. The comparison showed the great ability and high accuracy of developed model in prediction of solubility.Bahn, P.R., 2018. The Equations of Life: How Physics Shapes Evolution by Charles S. Cockell, Basic Books, 2018 (Review). Origins of Life and Evolution of Biospheres 48, 421-422. first became acquainted with the work of British astrobiologist Charles Cockell twelve years ago, when I wrote a highly favorable review of a discussion meeting issue of the Philosophical Transactions of the Royal Society, which was co-edited by Cockell and entitled Conditions for the Emergence of Life on the Early Earth. So, it was with great expectations of something excellent that I read Cockell’s book The Equations of Life. Cockell did not disappoint me. He has written a superb book.Cockell’s main thesis in this work is that biogenesis and evolution on Earth and elsewhere in the Universe is largely predictable based on the laws of physics and chemistry. He gives a number of physics equations that constrain the structural characteristics of various animals on Earth and would constrain life elsewhere where it may exist. Thus, he posits carbon as the only viable element central to the building of informational biopolymers on Earth and on other planets or moons. Water, which is...Bak, E.N., Larsen, M.G., Jensen, S.K., N?rnberg, P., Moeller, R., Finster, K., 2019. Wind-driven saltation: An overlooked challenge for life on Mars. Astrobiology 19, 497-505. studies have demonstrated that the martian surface environment is hostile to life because of its rough radiation climate and the reactive chemistry of the regolith. Physical processes such as erosion and transport of mineral particles by wind-driven saltation have hitherto not been considered as a life hazard. We report a series of experiments where bacterial endospores (spores of Bacillus subtilis) were exposed to a simulated saltating martian environment. We observed that 50% of the spores that are known to be highly resistant to radiation and oxidizing chemicals were destroyed by saltation-mediated abrasion within one minute.Scanning electron micrographs show that the spores were not only damaged by abrasion but were eradicated during the saltation process. We suggest that abrasion mediated by wind-driven saltation should be included as a factor that defines the habitability of the martian surface environment. The process may efficiently protect the martian surface from forward contamination with terrestrial microbial life-forms. Abrasion mediated by wind-driven saltation should also be considered as a major challenge to indigenous martian surface life if it exists/existed.Bale, N.J., Rijpstra, W.I.C., Sahonero-Canavesi, D.X., Oshkin, I.Y., Belova, S.E., Dedysh, S.N., Sinninghe Damsté, J.S., 2019. Fatty acid and hopanoid adaption to cold in the methanotroph Methylovulum psychrotolerans. Frontiers in Microbiology 10, 589. doi: 510.3389/fmicb.2019.00589. strains of aerobic psychrotolerant methanotrophic bacteria Methylovulum psychrotolerans, isolated from geographically remote low-temperature environments in Northern Russia, were grown at three different growth temperatures, 20°C, 10°C and 4°C and were found to be capable of oxidizing methane at all temperatures. The three M. psychrotolerans strains adapted their membranes to decreasing growth temperature by increasing the percent of unsaturated fatty acid (FAs), both for the bulk and intact polar lipid (IPL)-bound FAs. Furthermore, the ratio of βOH-C16:0 to n-C16:0 increased as growth temperature decreased. The IPL head group composition did not change as an adaption to temperature. The most notable hopanoid temperature adaptation of M. psychrotolerans was also an increase in unsaturated hopanols with decreasing temperature. As the growth temperature decreased from 20 to 4°C, the percent of unsaturated M. psychrotolerans bulk-FAs increased from 79 to 89 % while the total percent of unsaturated hopanoids increased from 27 to 49 %. While increased FA unsaturation in response to decreased temperature is a commonly observed response in order to maintain the liquid-crystalline character of bacterial membranes, hopanoid unsaturation upon cold exposition has not previously been described. In order to investigate the mechanisms of both FA and hopanoid cold-adaption in M. psychrotolerans we identified genes in the genome of M. psychrotolerans that potentially code for FA and hopanoid desaturases. The unsaturation of hopanoids represents a novel membrane adaption to maintain homeostasis upon cold adaptation.Bao, H., Niggemann, J., Huang, D., Dittmar, T., Kao, S.-J., 2019. Different responses of dissolved black carbon and dissolved lignin to seasonal hydrological changes and an extreme rain event. Journal of Geophysical Research: Biogeosciences 124, 479-493. Hydrology, especially extreme hydrological events, has been recognized as an important driver of the land-to-ocean export of terrigenous dissolved organic matter (tDOM). Nevertheless, how various types of tDOM that differ in source and reactivity respond to changes in hydrology is not known. Seasonal and event exports of dissolved organic carbon (DOC), dissolved black carbon (DBC), and dissolved lignin were studied in a small subtropical river. We found that seasonal variations in DBC concentration were significantly related to hydrology, while DOC and dissolved lignin were not. In contrast, DOC, DBC, and dissolved lignin changed similarly during an extreme rain event. The variation magnitudes of DOC, DBC, and dissolved lignin concentrations were in the lower end compared to other rivers, which may be related to the limited coverage of wetlands and riparian vegetation and poor development of organic-rich soil. Dilution effects were observed when the runoff exceeded 0.4?mm/hr, and the fluxes of both DBC and dissolved lignin decreased during the runoff peak, which was caused by surface flow and potentially by removal processes during peak discharge. Our results suggest that the influence of hydrology varies with tDOM source and reactivity and that high enough runoff (e.g., 0.7?mm/hr in the Jiulong River) may not enhance the export rate of tDOM. However, our study was carried out in a small watershed with limited wetlands and riparian vegetation, and more studies are needed to verify whether this trend is consistent among global rivers.Bao, S.-j., Zhai, G.-y., Zhou, Z., Yu, S.-f., Chen, K., Wang, Y.-f., Wang, H., Liu, Y.-m., 2018. The evolution of the Huangling uplift and its control on the accumulation and preservation of shale gas. China Geology 1, 346-353. There are plenty of Sinian and Cambrian potential shale gas resources in South China, which is characterized by high thermal evolution degrees, poor drilling performances and only occurs in local areas. Taking the principle “high to find low” is the key issue to achieving a breakthrough in older shale. China Geological Survey drilled in the periphery of the Proterozoic basement, i.e. the Huangling anticline, in the western Hubei, and Hannan paleocontinent in the southern Shanxi. It received high-quality gas-bearing shale with relatively low Ro in the in Lower Cambrian Niutitang formation and Sinian Doushantuo formation. Based on geological conditions of shale gas reservoirs in the Huangling anticline, this paper puts forward the new model named “Control over reservoirs by periphery of basement” about shale gas accumulation, suggesting that the shale deposited in a deepwater continental shelf in the periphery of the basement is characterized by shallow burial, a short burial time, stable tectonics, relatively low thermal evolution degrees, and shale gas reservoirs in a good condition. The shale of the Sinian-Cambrian strata deposited in deepwater continental shelves in the periphery of Chuanzhong paleo-uplift in Sichuan, Hannan paleocontinent in the southern Shanxi, Huangling anticline in western Hubei and Jiangnang-Xuefeng paleo-uplift in Hunan and Guizhou province have good shale gas exploration potential.Barras, C., 2019. Does fossil site record dino-killing impact? Science 364, 10-11. fossil site in North Dakota records a stunningly detailed picture of the devastation minutes after an asteroid slammed into Earth about 66 million years ago, a paper out this week argues. Geologists have theorized that the impact played a role in the mass extinction at the end of the Cretaceous period, when all the dinosaurs (except birds) vanished. At the site, 3000 kilometers from the impact in Mexico, the researchers say they have discovered the chaotic debris left when tsunamilike waves surged up a river valley. The jumbled mess of fossils includes freshwater sturgeon that apparently choked to death on glassy particles raining out of the sky from the impact fireball. If accepted, the find would be the first direct evidence of the killing and might settle the debate about whether dinosaurs were thriving right up until the cataclysm. But some researchers are skeptical.Barry, P.H., de Moor, J.M., Giovannelli, D., Schrenk, M., Hummer, D.R., Lopez, T., Pratt, C.A., Segura, Y.A., Battaglia, A., Beaudry, P., Bini, G., Cascante, M., d’Errico, G., di?Carlo, M., Fattorini, D., Fullerton, K., Gazel, E., González, G., Halldórsson, S.A., Iacovino, K., Kulongoski, J.T., Manini, E., Martínez, M., Miller, H., Nakagawa, M., Ono, S., Patwardhan, S., Ramírez, C.J., Regoli, F., Smedile, F., Turner, S., Vetriani, C., Yücel, M., Ballentine, C.J., Fischer, T.P., Hilton, D.R., Lloyd, K.G., 2019. Forearc carbon sink reduces long-term volatile recycling into the mantle. Nature 568, 487-492. and other volatiles in the form of gases, fluids or mineral phases are transported from Earth’s surface into the mantle at convergent margins, where the oceanic crust subducts beneath the continental crust. The efficiency of this transfer has profound implications for the nature and scale of geochemical heterogeneities in Earth’s deep mantle and shallow crustal reservoirs, as well as Earth’s oxidation state. However, the proportions of volatiles released from the forearc and backarc are not well constrained compared to fluxes from the volcanic arc front. Here we use helium and carbon isotope data from deeply sourced springs along two cross-arc transects to show that about 91 per cent of carbon released from the slab and mantle beneath the Costa Rican forearc is sequestered within the crust by calcite deposition. Around an additional three per cent is incorporated into the biomass through microbial chemolithoautotrophy, whereby microbes assimilate inorganic carbon into biomass. We estimate that between 1.2?×?108 and 1.3?×?1010 moles of carbon dioxide per year are released from the slab beneath the forearc, and thus up to about 19 per cent less carbon is being transferred into Earth’s deep mantle than previously estimated.Basafa, M., Hawboldt, K., 2019. Reservoir souring: sulfur chemistry in offshore oil and gas reservoir fluids. Journal of Petroleum Exploration and Production Technology 9, 1105-1118. injection of sulfate-containing seawater into an oil reservoir, for maintaining the reservoir pressure, can promote the growth of sulfate reducing bacteria and archaea near the injection wells, leading to the formation of sulfides such as hydrogen sulfide. However, intermediate sulfur species with different valence states, such as polythionates and polysulfides have been detected in several produced water samples, likely a result of phase partitioning, and chemical and microbial reactions. These sulfur species could affect the microbial communities (e.g., microbially influenced corrosion) and will impact the efficiency of souring mitigation methods. In addition, the presence of these sulfur species can result in operational, environmental, and treatment problems. Therefore, development and implementation of souring control strategies during production cycle of oil and gas reservoirs require identifying the origins, reactivity, and the partitioning behaviour of these compounds. This paper presents an overview of the known mechanisms responsible for reservoir souring and then focuses on the chemical reactions and sulfur species associated with production and consumption of hydrogen sulfide. In this work we highlight complexity of the sulfur chemistry and that the assumption that all the sulfate is reduced to hydrogen sulfide can lead to inappropriate souring management methods. The paper also reviews the detection and analysis methods used for sulfur compounds. The review demonstrates that there is a gap in the current souring models and methods due to the exclusion of key sulfur compounds and challenges in identifying and quantifying these compounds with respect to speed of analysis and sample stability.Batstone, D.J., Hülsen, T., Oehmen, A., 2019. Metabolic modelling of mixed culture anaerobic microbial processes. Current Opinion in Biotechnology 57, 137-144. culture anaerobic processes are important to environmental systems, including the global carbon cycle, and industrial and environmental biotechnology. Mixed culture metabolic modelling (MM) is an essential tool to analyse these systems. MM predicts microbial function based on knowledge or assumption of cellular metabolism. It may be developed based on observations at the process level – biochemical process modelling (BPM) or fundamental knowledge of the cell being modelled – cellular level modelling (CLM). There is a substantial gap between these two fields, with BPM not considering genetic constraints, particularly where this may be important to interspecies interactions (e.g. amino acid transfer), and CLM commonly not considering mass transfer principles, such as advection/diffusion/migration. No unified approach is useful for all applications, but there is an increasing need to consider genetic information and constraints in developing BPM, and translate BPM principles (including mass-transfer and inorganic chemistry) for application to CLM.Bauer, A.E., Frank, R.A., Headley, J.V., Milestone, C.B., Batchelor, S., Peru, K.M., Rudy, M.D., Barrett, S.E., Vanderveen, R., Dixon, D.G., Hewitt, L.M., 2019. A preparative method for the isolation and fractionation of dissolved organic acids from bitumen-influenced waters. Science of The Total Environment 671, 587-597. surface mining of oil sands north of Fort McMurray, Alberta produces considerable tailings waste that is stored in large tailings ponds on industrial lease sites. Viable strategies for the detoxification of oil sands process affected water (OSPW) are under investigation. In order to assess the toxic potential of the suite of dissolved organics in OSPW, a method for their extraction and fractionation was developed using solid phase extraction. The method successfully isolated organic compounds from 180?L of an aged OSPW source. Using acidic- or alkaline-conditioned non-polar ENV+ resin and soxhlet extraction with ethyl acetate and methanol, three fractions (F1–F3) were generated. Chemical characterization of the generated fractions included infusion to electrospray ionization ultrahigh-resolution mass spectrometry (ESI-UHRMS), liquid chromatography quadrupole time-of-flight mass spectrometry, gas chromatography triple quadrupole time-of-flight mass spectrometry, and synchronous fluorescence spectroscopy (SFS). Additionally, ESI-UHRMS class distribution data and SFS identified an increased degree of oxygenation and aromaticity, associated with increased polarity. Method validation, which included method and matrix spikes with surrogate and labelled organic mono carboxylic acid standards, confirmed separation according to acidity and polarity with generally good recoveries (average 76%). Because this method is capable of extracting large sample volumes, it is amenable to thorough chemical characterization and toxicological assessments with a suite of bioassays. As such, this protocol will facilitate effects-directed analysis of toxic components within bitumen-influenced waters from a variety of sources.Bava, Y.B., Geronés, M., Buceta, D., de la Iglesia Rodríguez, D., López-Quintela, M.A., Erben, M.F., 2019. Elucidation of the average molecular structure of Argentinian asphaltenes. Energy & Fuels 33, 2950-2960. asphaltenes were separated from three different Argentinian crude oils. The asphaltene fractions were extracted by precipitation employing n-pentane and n-heptane solvents, and the coprecipitated resins were removed via Soxhlet extraction. The asphaltenes were characterized by elemental analysis, thermogravimetric analysis, laser desorption ionization mass spectrometry, Fourier-transform infrared spectroscopy, proton nuclear magnetic resonance, powder X-ray diffraction, and Raman spectroscopy. It was found that the asphaltene fractions present both a higher content of heteroatoms and a major degree of aromaticity, when n-heptane is employed. Average structural parameters were obtained by a comprehensive analysis of the experimental data, including those describing the central polycyclic aromatic hydrocarbon (PAH) cores and lateral chains. Thus, a hypothetical average molecular structure is proposed for the Argentinian asphaltenes. The average model molecules have a nucleus of PAHs arranged as pericondensed systems of 4–6 fused aromatic rings, with naphthenic groups and/or alkyl chains of 5–10 carbon long attached.Baydjanova, S., George, S.C., 2019. Depositional environment, organic matter sources, and variable 17α(H)-diahopane distribution in Early Permian samples, southern Sydney Basin, Australia. Organic Geochemistry 131, 60-75. Permian strata exposed in the southern part of the Sydney Basin, NSW, Australia, include the Pebbley Beach Formation, the Snapper Point Formation and the Wandrawandian Siltstone. These formations were deposited during the Late Paleozoic Ice Age, when Australia was close to the South Pole. The Pebbley Beach and Snapper Point formations were deposited in shallow marine to coastal environments, while the Wandrawandian Siltstone was deposited in deeper water following a marine transgression. However, opinions differ on the precise environmental and climatic conditions that prevailed during their deposition. Sixteen outcrop samples from these formations were collected and analysed to determine their depositional conditions and the source(s) of their organic matter.The biomarker and aromatic hydrocarbon distributions show that the rocks are in the early to mid-oil window. Some aromatic parameters show that the stratigraphically younger Wandrawandian Siltstone is more thermally mature than the older Pebbley Beach Formation, which is interpreted to be due to the geographic position of these outcrops in the Sydney Basin. The samples have low to intermediate pristane/phytane ratios (from 1.4 to 3.4), showing variation from oxic to suboxic depositional conditions. Most of the mudstones and siltstones sampled were deposited in a marine environment, with some fluvial-deltaic or estuarine influence, and contain mixed type II and type III organic matter. The Pebbley Beach formation is characterised by terpane distributions dominated by the C24 tetracyclic terpane, and to a lesser extent the C19 tricyclic terpane. The Snapper Point Formation has a mix of C19 and C23 tricyclic terpanes and C24 tetracyclic terpane, while the Wandrawandian Siltstone is dominated by C19, C21, and C23 tricyclic terpanes. The sterane distribution follows a C29?>?C28?>?C27 pattern in the majority of the samples, including in the marine deposited Wandrawandian Siltstone. The three formations have very variable relative amounts of diahopanes and other rearranged hopanes, with the highest C30*/C30 αβ hopane ratio (6.9) in the Wandrawandian Siltstone. This formation also has high amounts of diasteranes compared to the other two formations, but the relative amounts of diasteranes are not as high as for the diahopanes. Classically, this suggests a clay-rich sediment in an oxic or suboxic, acid-catalysed depositional environment, with enhanced diagenetic alteration of the biomarkers. The Wandrawandian Siltstone was deposited in suboxic conditions, not unusual to many rocks that contain much less rearranged hopanes. Unusual characteristics of the Wandrawandian Siltstone include significant slumping and soft sediment deformation, and deposition under periglacial-glacial conditions. The occurrence of the slumps on the continental slope led to significant sediment overturn, and this may have resulted in enhanced diagenetic and catalytic rearrangement reactions, leading to the elevated levels of diahopanes and other rearranged hopanes. The disequilibrium between the relative abundances of diahopanes and diasteranes suggests different formation mechanisms for these biomarkers.Bell, M., Blais, J.M., 2019. “-Omics” workflow for paleolimnological and geological archives: A review. Science of The Total Environment 672, 438-455.“-Omics” is a powerful screening method with applications in molecular biology, toxicology, wildlife biology, natural product discovery, and many other fields. Genomics, proteomics, metabolomics, and lipidomics are common examples included under the “-omics” umbrella. This screening method uses combinations of untargeted, semi-targeted, and targeted analyses paired with data mining to facilitate researchers' understanding of the genome, proteins, and small organic molecules in biological systems. Recently, however, the use of “-omics” has expanded into the fields of geology, specifically petrology, and paleolimnology. Specifically, untargeted analyses stand to transform these fields as petroleomics, and sediment-“omics” become more prevalent. “-Omics” facilitates the visualization of small molecule profiles from environmental matrices (i.e. oil and sediment). Small molecule profiles can provide improved understanding of small molecules distributions throughout the environment, and how those compositions can change depending on conditions (i.e. climate change, weathering, etc.). “-Omics” also facilities discovery of next-generation biomarkers that can be used for oil source identification and as proxies for reconstructing past environmental changes. Untargeted analyses paired with data mining and multivariate statistical analyses represents a powerful suite of tools for hypothesis generation, and new method development for environmental reconstructions. Here we present an introduction to “-omics” methodology, technical terms, and examples of applications to paleolimnology and petrology. The purpose of this review is to highlight the important considerations at each step in the “-omics” workflow to produce high quality and statistically powerful data for petrological and paleolimnological applications.Ben Faleh, A., Warnke, S., Rizzo, T.R., 2019. Combining ultrahigh-resolution ion-mobility spectrometry with cryogenic infrared spectroscopy for the analysis of glycan mixtures. Analytical Chemistry 91, 4876-4882. isomeric complexity of glycans make their analysis by traditional techniques particularly challenging. While the recent combination of ion mobility spectrometry (IMS) with cryogenic IR spectroscopy has demonstrated promise as a new technique for glycan analysis, this approach has been limited by the modest resolution of the ion mobility stage. In this work we report results from a newly developed instrument that combines ultrahigh-resolution IMS with cryogenic IR spectroscopy for glycan analysis. This apparatus makes use of the recent development in traveling-wave IMS called structures for lossless ion manipulation. The IMS stage allows the selection of glycan isomers that differ in collisional cross section by as little as 0.2% before injecting them into a cryogenic ion trap for IR spectral analysis. We compare our results to those using drift-tube IMS and highlight the advantages of the substantial increase in resolution. Application of this approach to glycan mixtures demonstrates our ability to isolate individual components, measure a cryogenic IR spectrum, and identify them using a spectroscopic database.Benham, K., Fernández, F.M., Orlando, T.M., 2019. Sweep jet collection laser-induced acoustic desorption atmospheric pressure photoionization for lipid analysis applications. Journal of The American Society for Mass Spectrometry 30, 647-658. acoustic desorption coupled to microplasma-based atmospheric pressure photoionization (LIAD-APPI) using a nebulized sweep jet to aid in dopant introduction and ion transmission has been applied to the analysis of model, apolar lipid compounds. Specifically, several sterols, sterol esters, and triacylglycerols were detected using dopants such as anisole and toluene. Additionally, several triacylglycerols, sterols, carboxylic acids, and hopanoids were detected from complex mixtures of olive oil and Australian shale rock extract as a first demonstration of the applicability of LIAD-APPI on real-world samples. Detection limits using a sweep jet configuration for α-tocopherol and cholesterol were found to be 609?±?61 and 292?±?29?fmol, respectively. For sterol esters and triacylglycerols with a large number of double bonds in the fatty acid chain, LIAD-APPI was shown to yield greater molecular ion or [M+NH4]+ abundances than those with saturated fatty acid chains. Dopants such as anisole and toluene, with ionization potentials (IPs) of 8.2 and 8.8?eV, respectively, were tested. A greater degree of fragmentation with several of the more labile test compounds was observed using toluene. Overall, LIAD-APPI with a nebulized sweep jet requires minimal sample preparation and is a generally useful and sensitive analysis technique for low-polarity mixtures of relevance to biochemical assays and geochemical profiling.Bertrand, T., Forget, F., Umurhan, O.M., Moore, J.M., Young, L.A., Protopapa, S., Grundy, W.M., Schmitt, B., Dhingra, R.D., Binzel, R.P., Earle, A.M., Cruikshank, D.P., Stern, S.A., Weaver, H.A., Ennico, K., Olkin, C.B., 2019. The CH4 cycles on Pluto over seasonal and astronomical timescales. Icarus 329, 148-165.'s surface is covered in numerous CH4 ice deposits, that vary in texture and brightness, as revealed by the New Horizons spacecraft as it flew by Pluto in July 2015. These observations suggest that CH4 on Pluto has a complex history, involving reservoirs of different composition, thickness and stability controlled by volatile processes occurring on different timescales. In order to interpret these observations, we use a Pluto volatile transport model able to simulate the cycles of N2 and CH4 ices over millions of years. By assuming fixed solid mixing ratios, we explore how changes in surface albedos, emissivities and thermal inertias impact volatile transport. This work is therefore a direct and natural continuation of the work by Bertrand et al. (2018), which only explored the N2 cycles. Results show that bright CH4 deposits can create cold traps for N2 ice outside Sputnik Planitia, leading to a strong coupling between the N2 and CH4 cycles. Depending on the assumed albedo for CH4 ice, the model predicts CH4 ice accumulation (1) at the same equatorial latitudes where the Bladed Terrain Deposits are observed, supporting the idea that these CH4-rich deposits are massive and perennial, or (2) at mid-latitudes (25°? 70°), forming a thick mantle which is consistent with New Horizons observations. In our simulations, both CH4 ice reservoirs are not in an equilibrium state and either one can dominate the other over long timescales, depending on the assumptions made for the CH4 albedo. This suggests that long-term volatile transport exists between the observed reservoirs. The model also reproduces the formation of N2 deposits at mid-latitudes and in the equatorial depressions surrounding the Bladed Terrain Deposits, as observed by New Horizons. At the poles, only seasonal CH4 and N2 deposits are obtained in Pluto's current orbital configuration. Finally, we show that Pluto's atmosphere always contained, over the last astronomical cycles, enough gaseous CH4 to absorb most of the incoming Lyman-α flux.Bi, C.-q., Lin, Z.-k., Tian, Y., Du, Z.-l., Chen, Y., 2018. Three source rocks discovered in the Mid-Lower Jurassic, Dunhuang Basin in China. China Geology 1, 162-163.. Objective:Dunhuang Basin is the largest area and the third hydrocarbon resources potential basin among the basins of Hexi Corridor, and also a low exploration degree basin. The source rock position, characteristics and hydrocarbon generating potential of residual Mid-Lower Jurassic are still unknown. The project is to ascertain the source rock development and hydrocarbon generating capacity of Mid-Lower Jurassic, to find out the resource potential, to delineate the resource prospect area and to optimize the favorable areas. It may direct the petroleum exploration in Dunhuang Basin.2. Methods: By the surveys over Dunhuang Basin and its peripheral areas in Lower Jurassic, and by the comparison and comprehensive study of the data from Well XC1, 2D seismic, gravity, magnetics and electrics, Mid-Lower Jurassic was correlated and subdivided. And Zhongjiangou Formation in Middle Jurassic and Dashankou Formation in Lower Jurassic were confirmed the main source rock intervals. The carboniferous shale and dark mudstone samples taken from the outcrops and core were made geochemical test and analysis. The hydrocarbon generating potential was evaluated by the abundance, type and maturity of organic matter. Moreover, the hydrocarbon resources potential is integratedly assessed by the source thickness, buried depth and extension.3. Results: The outcrops indicate the dark mudstone and carboniferous shale in Dashankou Formation of Lower Jurassic in Dunhuang Basin (Jiang P and Fan XL, 2005), which are medium-poor source rocks and up to mature totally (Fig. 1). The samples taken from Heidaban section, mainly dark mudstone, are mature, medium source rocks with the mean TOC 1.39% and the organic matter type II1 or Ⅲ. The samples taken from Lucaogou section, mainly carboniferous shale, are maturated or highly maturated, medium source rocks with the organic matter type II2. The organic matter type of Daba and Hongliugou sections is III. And no source rock has been identified in Duobagou and Qingtainan sections. It is noteworthy that these samples are generally taken from the basin margin facies and subjected to long-term weathering, which may result in lower soluble organic matter content and lower transformational ratio of the organics.Well XC1 located on the margins of Wudun Sag was drilled three sets of source rocks (Liu ZQ et al., 2016), added up to 101.5 m and up to premium-good source rocks (Table 1) (Zhang XC et al., 2017). Respectively, the upper part of Zhongjiangou Formation of Middle Jurassic, mainly dark mudstone, is integratedly assessed premium to good source rock, of which the kerogen type is I and II1, TOC is from 0.17% to 5.69% and 3.03% averagely, the mean of S1+S2, Ro and Tmax is 12.07 mg/g, 0.67 and 447 °C respectively. The lower part of Zhongjiangou Formation of Middle Jurassic, mainly sand and mudstone thin interbeds, is good source rock, of which the kerogen type is II2-III, and the mean of TOC, S1+S2, Ro and Tmax is 3.81%, 9.34 mg/g, 0.70 and 449 °C respectively. Dashankou Formation of Lower Jurassic, mainly sand and shale interbeds, is totally assessed medium source rock, of which the karogen type is II2-III, and TOC, S1+S2, and Tmax is averagely 1.62%, 2.19 mg/g and 461 °C.It is integratedly assessed three most exploration potential areas totally 2230 km2, respectively the eastern subsag of Qingtai Sag, Southern subsag of Wudun Sag and north-western part of Hongliugou Sag, based on the source rock test and analysis, residual thickness of Mid-Lower Jurassic and buried depth for secondary hydrocarbon generation.4. Conclusion: The dark mudstone and carboniferous shale in Zhongjiangou Formation of Middle Jurassic and Dashankou Formation of Lower Jurassic are the source rocks in Dunhuang Basin. The source rock of Dashankou Formation is totally mature and medium-poor based on the outcrop samples. However, three sets of source rock are drilled. Two sets of source rock developed in Zhongjiangou Formation are mature, premium-good source rocks, of which the organic matter type is I-II1 and the mean of Ro is 0.8. The source rock of Dashankou Formation is medium and the organic matter type is II2-III. It is integratedly assessed that the most exploration potential areas of Dunhuang Basin are the eastern subsag of Qingtai Sag, southern subsag of Wudun Sag and north-western part of Hongliugou Sag.Biagini, D., Lomonaco, T., Ghimenti, S., Onor, M., Bellagambi, F.G., Salvo, P., Di Francesco, F., Fuoco, R., 2019. Using labelled internal standards to improve needle trap micro-extraction technique prior to gas chromatography/mass spectrometry. Talanta 200, 145-155. working with humid gaseous samples, the amount of water vapour collected in a needle trap along with volatile analytes may vary from sample to sample and decrease during the storage. This has a major impact on desorption efficiency and recovery. We propose the addition of a labelled internal standards to nullify the effect of variable humidity on the analytical performance of needle trap micro-extraction combined with gas chromatography mass spectrometry. Triple-bed (Divinylbenzene/Carbopack X/Carboxen 1000) and single-bed (Tenax GR) needles were tested with standard gaseous mixtures prepared at different relative humidity levels (85%, 50% and 10%). The standard mixtures contained twenty-five analytes representative of breath and ambient air constituents, including hydrocarbons, ketones, aldehydes, aromatics, and sulphurs, in the concentration range 0.1–700 ppbv. The two needles showed different behaviours, as recovery was independent of humidity for single-beds, whereas a low recovery (10–20%) was observed when triple-beds trapped very volatile compounds at low humidity (e.g. pentane and ethanol, 10% relative humidity. Triple-beds showed an almost quantitative recovery (>90%) of all the analytes at 50% and 85% relative humidity. This big difference was probably due to the reduced action of water vapour pressure during the desorption step. The addition of 6D-acetone and 8D-toluene to the sorbent material before gas sampling and the normalization of raw data nullified this effect, thereby lowering the variations of analyte recovery at different humidity levels down to 20%. Internal standards were also exploited to limit within 10–20% alterations in peak areas of very volatile compounds during needle storage at room temperature. This variation may results from a loss of water vapour either retained from the sorbent material and/or condensed on triple-bed needle walls. After normalization, the inter- and intra-day precision were halved to 5% and 10% in the case of single-beds, respectively, and to 15% and 20% with three-beds. The addition of an internal standard to the sorbent helps to keep the overall analytical procedure under control and improves the reliability of needle trap micro-extraction for the analysis of volatile organic compounds at ultra-trace levels.Bian, X.-Q., Huang, J.-H., Wang, Y., Liu, Y.-B., Kasthuriarachchi, D.T.K., Huang, L.-J., 2019. Prediction of wax disappearance temperature by intelligent models. Energy & Fuels 33, 2934-2949. is well-known that reservoir hydrocarbon fluids contain heavy paraffins that may form solid phases of wax at low temperatures. Problems associated with wax formation and deposition are a major concern in production and transportation of hydrocarbon fluids. Thus, testing of wax disappearance temperature (WDT) is essential in high-efficiency development of crude oil. For the sake of reduction of time and improvement of accuracy, four metaheuristic models called gray wolf optimizer-based support vector machine (GWO-SVM), least-squares support vector machine, genetic algorithm-based adaptive network-based fuzzy inference system, and particle swarm optimization-based adaptive network-based fuzzy inference system were used for the prediction of WDT in binary, ternary, and multicomponent systems in the range of 0.1–100 MPa. The input parameters are molar mass and pressure, and the output is the WDT at every point. The comparison between the four models shows that the GWO-SVM gets the best accordance with experimental data sets with the minimum average absolute relative deviation (AARD = 0.7128%), maximum determination coefficient (R2 = 0.9546), and minimum root-mean-squared error (RMSE = 2.4208) in all 272 data points. And outliers detection using the leverage approach to detect the doubt points, where only 6 data points in all 272 data points.Blouin, A., Imbert, P., Sultan, N., Callot, J.-P., 2019. Evolution model for the Absheron mud volcano: From in situ observations to numerical modeling. Journal of Geophysical Research: Earth Surface 124, 766-794.: The morphology of mud volcanoes (MVs) has been extensively studied over the last few decades. Although recent research has begun to focus on deep processes and structures, little is known about mud generation mechanisms. This study aims to investigate the feeder system and formation of an active kilometer‐scale MV by relying on a 3‐D seismic survey and an in situ data set on the Absheron anticline (South Caspian Basin). Seismic data show a depleted area in the Anhydritic Surakhany Formation (ASF), whose mineralogical composition fits with surface mud. Well data show that the ASF is a succession of evaporitic beds and low‐temperature shales near its fracture pressure. Biostratigraphic analysis confirms a Pliocene origin for the mud, suggesting that the ASF may be the source. Numerical modeling of sedimentation coupled with laboratory test results and well sonic logs fairly reproduces the observed in situ overpressure trend. Two‐dimensional methane diffusion coupled with overpressure caused by rapid sedimentation highlights the superposition of critical fracturing conditions with methane‐saturated sediments at the base of the studied MV. The present study demonstrates the predominant role of fluid overpressure due to sedimentation and gas saturation in the formation of the Absheron MV, and this is shown to occur as follows: (1) methane migration through the thrust‐related faults reaching the ASF, accompanied by (2) lateral overpressure, caused by rapid sedimentation, diffusing along the ASF leading to (3) hydro‐fracturing of overpressured and methane‐saturated sediments resulting in an important decrease in overpressure, causing (4) gas exsolution and expansion triggering sediment remobilization.Plain Language Summary: Mud volcanoes have proved to be a real risk for people living near them (e.g., Lusi catastrophe, Indonesia) and for infrastructures. While their surface morphology is well understood and their plumbing system is correctly imaged by high‐resolution seismic technology, their formation mechanisms and their trigger is yet to be understood. The South Caspian Basin is known for the presence of a large number of active structures. On the Absheron anticline, a giant active mud volcano is surrounded and covered by a large data set from seismic imaging to sediment cores. From the analysis of the seismic data, and from diverse measurements on sediments, we were able to locate the source of the mud, which is shallower than the source for many mud volcanoes in the region. We developed a numerical model able to reproduce the pore pressure trends recorded at the wells, and it shows that the interaction between methane‐saturated areas and potential rupture zones is able to explain the mud volcano location. Finally, based on the different results and observations, a formation model is proposed where hydrofracturing is the initial trigger for the subsequent gas exsolution and expansion that disaggregate and remobilize weak sedimentary layers.Blowey, P.J., Maurer, R.J., Rochford, L.A., Duncan, D.A., Kang, J.H., Warr, D.A., Ramadan, A.J., Lee, T.-L., Thakur, P.K., Costantini, G., Reuter, K., Woodruff, D.P., 2019. The structure of VOPc on Cu(111): Does V=O point up, or down, or both? The Journal of Physical Chemistry C 121, 8101-8111. local structure of the non-planar phthalocyanine, vanadyl phthalocyanine (VOPc), adsorbed on Cu(111) at a coverage of approximately one half of a saturated molecular layer, has been investigated by a combination of normal-incidence X-ray standing waves (NIXSW), scanned-energy mode photoelectron diffraction (PhD) and density-functional theory (DFT), complemented by scanning tunnelling microscopy (STM). Qualitative assessment of the NIXSW data clearly shows that both ‘up’ and ‘down’ orientations of the molecule (with V=O pointing out of, and into, the surface) must coexist on the surface. O 1s PhD proves to be inconclusive regarding the molecular orientation. DFT calculations, using two different dispersion correction schemes, show good quantitative agreement with the NIXSW structural results for equal co-occupation of the two different molecular orientations and clearly favour the Many Body Dispersion (MBD) method to deal with long-range dispersion forces. The calculated relative adsorption energies of the differently-oriented molecules at the lowest coverage show a strong preference for the ‘up’ orientation, but at higher local coverages, this energetic difference decreases and mixed orientation phases are almost energetically equivalent to pure ‘up’ oriented phases. DFT-based Tersoff-Hamann simulations of STM topographs for the two orientations cast some light on the extent to which such images provide a reliable guide to molecular orientation.Bobrovskiy, I., Krasnova, A., Ivantsov, A., Luzhnaya, E., Brocks, J.J., 2019. Simple sediment rheology explains the Ediacara biota preservation. Nature Ecology & Evolution 3, 582-589. soft-bodied Ediacara biota (571–541?million years ago) represents the oldest complex large organisms in the fossil record, providing a bridge between largely microbial ecosystems of the Precambrian and the animal-dominated world of the Phanerozoic, potentially holding clues about the early evolution of Metazoa. However, the nature of most Ediacaran organisms remains unresolved, partly due to their enigmatic non-actualistic preservation. Here, we show that Flinders-style fossilization of Ediacaran organisms was promoted by unusually prolonged conservation of organic matter, coupled with differences in rheological behaviour of the over- and underlying sediments. In contrast with accepted models, cementation of overlying sand was not critical for fossil preservation, which is supported by the absence of cement in unweathered White Sea specimens and observations of soft sediment deformation in South Australian specimens. The rheological model, confirmed by laboratory simulations, implies that Ediacaran fossils do not necessarily reflect the external shape of the organism, but rather the morphology of a soft external or internal organic ‘skeleton’. The rheological mechanism provides new constraints on biological interpretations of the Ediacara biota.Borruel-Abadía, V., Barrenechea, J.F., Galán-Abellán, A.B., De la Horra, R., López-Gómez, J., Ronchi, A., Luque, F.J., Alonso-Azcárate, J., Marzo, M., 2019. Could acidity be the reason behind the Early Triassic biotic crisis on land? Chemical Geology 515, 77-86. recent years there is growing evidence of the importance of the Smithian-Spathian (Early Triassic) ecological crisis to explain the delayed recovery of life after the Permian-Triassic Boundary mass extinction. This study focuses on sedimentary continental rocks of middle Permian to Middle Triassic age from four different Peritethys basins in subequatorial latitudes. Similar distribution patterns of aluminum phosphate-sulfate (APS) minerals contents in these rocks in the four studied basins provide evidence of increased acidity during the Smithian-Spathian transition, coinciding with a lack of indicators of organic activity in the same interval. Thus, this period of high acidity on land, may have been one of the causes of this biological crisis. Based on the quantification of APS minerals in the studied sedimentary sequences, we propose that it was not until acidity in the environment diminished, that biotic recovery was possible. APS data may also be useful to interpret other past biotic crises.Boruah, A., Rasheed, A., Mendhe, V.A., Ganapathi, S., 2019. Specific surface area and pore size distribution in gas shales of Raniganj Basin, India. Journal of Petroleum Exploration and Production Technology 9, 1041-1050. of multiscale transports of shale gas is important for shale gas exploration and exploitation. Traditional porosity determining approaches normally underrate the shale gas transport capacity as these techniques do not include adsorb gas in nanometer-sized slit pores. Silty shale, carbonaceous shale, claystone and ironstone shale unit of Barren Measures Formation was examined to understand the pore system at various scales. The pores are intergranular, intragranular, interlayer, dissolved pore and fracture pores where gas molecules are present as free state and/or adsorbed gas in the internal structure of the pores and at the edge of their structures. Here, we used the Brunauer–Emmett–Teller technique with scanning electron microscopy for considering the adsorption mechanism to understand the gas transport in micro and nano pores in shales. The adsorption parameters between organic wall and grain surface were observed to be controlled by clay mineralogy. SEM, X-ray diffraction and BET manifest significant information about role of clays, organic matter and mineral composition in development of pore network, which also governs the gas storage and transport properties. A large portion of pores in Barren Measures shales ranges between 20 and 55?nm and the pore size diameter ranges from 5.49 to 29.75?nm.Bougi, M.S.M., Baklouti, S., Rasheed, M.A., Rao, P.L.S., Hasan, S.Z., Gharbi, J., Ksibi, M., 2019. Evidence of signatures for recognition of hydrocarbon microseepage in El Hajeb oilfield, eastern Tunisia. Geomicrobiology Journal 36, 348-358. prospecting technique was applied in El Hajeb oilfield, Tunisia for potential hydrocarbon resource exploration by examining the anomalous abundance of hydrocarbon oxidizing bacteria. The method depends on the seepage of light gaseous hydrocarbons such as C1 - C5 from the petroleum pools to the shallow surface giving the reasonable conditions to the development of highly specialized bacterial population. A total of 51 soil samples were collected from 1.5 m depth. Bacterial counts for n-propane utilizing bacteria ranged between nil and 2.44 x 105 cfu/gm. The light gaseous hydrocarbons analysis showed that their concentrations were 102, 55, 41, 20, 21, 19, 10 and 141 ppb for C1, C2, C3, iC4, nC4, iC5, nC5 and ΣC2+, respectively. The gas concentration maps showed the presence of dynamic hydrocarbons micro-seepage from petroleum systems. The integrated geomicrobial and adsorbed soil gas results demonstrated that the anomalous hydrocarbon zones spread in all territory which could presumably help to evaluate highpotentialareas. In conclusion, our study confirms that the use of microbial data and adsorbed gas analyses of soil samples is a low cost tool for hydrocarbon exploration. This technique has been confirmed and can be applied successfully in frontier basins.Boyd, P.W., Claustre, H., Levy, M., Siegel, D.A., Weber, T., 2019. Multi-faceted particle pumps drive carbon sequestration in the ocean. Nature 568, 327-335. ocean’s ability to sequester carbon away from the atmosphere exerts an important control on global climate. The biological pump drives carbon storage in the deep ocean and is thought to function via gravitational settling of organic particles from surface waters. However, the settling flux alone is often insufficient to balance mesopelagic carbon budgets or to meet the demands of subsurface biota. Here we review additional biological and physical mechanisms that inject suspended and sinking particles to depth. We propose that these ‘particle injection pumps’ probably sequester as much carbon as the gravitational pump, helping to close the carbon budget and motivating further investigation into their environmental control.Brace, S., Diekmann, Y., Booth, T.J., van Dorp, L., Faltyskova, Z., Rohland, N., Mallick, S., Olalde, I., Ferry, M., Michel, M., Oppenheimer, J., Broomandkhoshbacht, N., Stewardson, K., Martiniano, R., Walsh, S., Kayser, M., Charlton, S., Hellenthal, G., Armit, I., Schulting, R., Craig, O.E., Sheridan, A., Parker Pearson, M., Stringer, C., Reich, D., Thomas, M.G., Barnes, I., 2019. Ancient genomes indicate population replacement in Early Neolithic Britain. Nature Ecology & Evolution 3, 765-771. roles of migration, admixture and acculturation in the European transition to farming have been debated for over 100?years. Genome-wide ancient DNA studies indicate predominantly Aegean ancestry for continental Neolithic farmers, but also variable admixture with local Mesolithic hunter-gatherers. Neolithic cultures first appear in Britain circa 4000?bc, a millennium after they appeared in adjacent areas of continental Europe. The pattern and process of this delayed British Neolithic transition remain unclear. We assembled genome-wide data from 6 Mesolithic and 67?Neolithic individuals found in Britain, dating 8500–2500?bc. Our analyses reveal persistent genetic affinities between Mesolithic British and Western European hunter-gatherers. We find overwhelming support for agriculture being introduced to Britain by incoming continental farmers, with small, geographically structured levels of hunter-gatherer ancestry. Unlike other European Neolithic populations, we detect no resurgence of hunter-gatherer ancestry at any time during the Neolithic in Britain. Genetic affinities with Iberian Neolithic individuals indicate that British Neolithic people were mostly descended from Aegean farmers who followed the Mediterranean route of dispersal. We also infer considerable variation in pigmentation levels in Europe by circa 6000?bc.Breecker, D.O., Horton, B.K., Jackson, L.J., Beate, B.O., Bright, J., 2019. Testing stable isotope paleoaltimetry with Quaternary volcanic glasses from the Ecuadorian Andes. Geology 47, 411-414. provides critical constraints on orogenic processes. Validation of paleoaltimeters enhances confidence in their application to geologic problems and requires investigations of proxy materials formed at known elevations over known time frames. We evaluated isotope-elevation relationships for late Pleistocene to Holocene (220–0 ka) hydrated volcanic glasses deposited over a 4 km elevation range spanning the Pacific coastal forearc and Andean magmatic arc of Ecuador (0°–1.5°S). Reconstructed δD values of paleometeoric water (δDpw) in the glasses decrease systematically with elevation. Holocene δDpw values are similar to δD values of modern meteoric water (δDmw), whereas late Pleistocene δDpw values are 10‰–30‰ lower than both Holocene δDpw values and δDmw values at high (>2 km) elevations. An elevation reconstruction based on δD differences from a modern or late Pleistocene low-elevation datum (ΔδDmw or ΔδDpw, respectively) using a one-dimensional thermodynamic Rayleigh distillation model parameterized with modern temperature accurately predicts Holocene sample elevations but overpredicts elevations of volcanic glass samples that were deposited during glacial marine isotope stage (MIS) 6 by 1–1.5 km. Late Pleistocene sample elevations are accurately predicted by applying a realistic correction for estimated lower air temperature (by ～5 °C) during glacial MIS 6. This study validates the applicability of volcanic glass δD values in paleoaltimetry studies, underscores the importance of accounting for climate-induced changes in isotope lapse rates when calculating paleoelevations, and suggests that ΔδDpw might be a sensitive proxy for climate change when applied on time scales over which elevation change was minimal.Brewer, P.J., Brown, R.J.C., Mussell Webber, E.B., van Aswegen, S., Ward, M.K.M., Hill-Pearce, R.E., Worton, D.R., 2019. Breakthrough in negating the impact of adsorption in gas reference materials. Analytical Chemistry 91, 5310-5315. have shown that an exchange dilution preparation method reduces the impact of surface adsorption of the target component in high-pressure gas mixtures used for underpinning measurements of amount-of-substance fraction. Gas mixtures are diluted in the same cylinder by releasing an aliquot of the parent mixture. Additional matrix gas is then added to the cylinder. This differs from conventional methods where dilutions are achieved by transferring the parent mixture to another cylinder, which then stores the final reference material. The benefit of this revolutionary approach is that losses due to adsorption to the walls of the cylinder and the valve are reduced as the parent mixture pacifies the surface with only a negligible relative change in amount-of-substance fraction. This development allows for preparation of gas reference materials with unprecedented uncertainties beyond the existing state of the art. It has significant implications for the preparation of high accuracy gas reference materials which underpin a broad range of requirements, particularly in atmospheric monitoring of carbon dioxide, where understanding the adsorption effects is the major obstacle to advancing the measurement science. It has the potential to remove the reliance on proprietary surface pretreatments as the method provides an in situ and consistent alternative.Brolly, C., Parnell, J., Bowden, S., 2019. Surface mineral crusts: a potential strategy for sampling for evidence of life on Mars. International Journal of Astrobiology 18, 91-101. mineral crusts on Earth are highly diverse and usually, contain microbial life. Crusts constitute an attractive target to search for life: they require water for their formation, they efficiently entrap organic matter and are relatively easy to sample and process. They hold a record of life in the form of microbial remains, biomolecules and carbon isotope composition. A miniaturized Raman spectrometer is included in the ExoMars 2020 payload as it is sensitive to a range of photosynthetic pigments. Samples from the Haughton Impact Structure, Canadian High Arctic and others, shows the preservation of pigments in a range of crust types, especially supra-permafrost carbonate crusts and cryptogamic crusts. The Raman spectral signatures of these crusts are shown along with biomarker analysis to showcase these techniques prior to the ExoMars 2020 mission. Carotenoids and other photoprotective microbial pigments are identified in the Haughton surface crusts using Raman spectroscopy. Gas chromatography-mass spectrometry analyses show a distribution of fatty acids which are most likely from a cyanobacterial source. The successful demonstration of these analyses in the Haughton Impact structure shows the biosignature of surface mineral crusts can be easily extracted and provides an excellent target for sampling evidence of life on Mars.Brown, D.R., Johnston, S.G., Santos, I.R., Holloway, C.J., Sanders, C.J., 2019. Significant organic carbon accumulation in two coastal acid sulfate soil wetlands. Geophysical Research Letters 46, 3245-3251.: Restoring degraded freshwater wetlands may help to maximize soil carbon sequestration. In this study, we use 18 210Pb‐dated sediment cores to determine the organic carbon (OC) accumulation rates from two hydrologically restored freshwater coastal acid sulfate soil (CASS) wetlands. Recent OC accumulation rates (from ~1980 to present) were estimated to be 251 ± 26 g·m?2·year?1 in the seasonally inundated CASS and 227 ± 50 g·m?2·year?1 in the permanently inundated CASS. The average OC accumulation during the previous century (190 ± 20 g·m?2·year?1) was within the range of blue carbon ecosystems (saltmarshes, mangroves, and seagrasses). Considering their large area and carbon accumulation rate, we estimate that Australian CASS wetlands sequester approximately 7.8 ± 0.8 Tg of carbon annually, which is equivalent to ~8% of the CO2 emission from fossil fuels in Australia. Hence, preserving or restoring CASS may be a good climate change mitigation strategy.Plain Language Summary: Coastal freshwater wetlands are highly productive and can sequester large amounts of carbon. The carbon accumulation rates here suggest that coastal acid sulfate soils (CASS) are also a substantial sink of CO2. By extrapolating our observations, we show that approximately 7.79 Tg of carbon is sequestered in Australian CASS wetlands annually which is equivalent to ~8% of the CO2 emission from fossil fuels in Australia. Hence, managing CASS wetlands to protect their soil carbon store function may help offset anthropogenic sources of greenhouse gasses and their hydrological remediation could be an important component to the global carbon cycle.Burger, B.J., Vargas Estrada, M., Gustin, M.S., 2019. What caused Earth's largest mass extinction event? New evidence from the Permian-Triassic boundary in northeastern Utah. Global and Planetary Change 177, 81-100. discovery of a Permian-Triassic boundary section in northeastern Utah provided an opportunity to study the chemistry and geology associated with this event that led to one of the greatest mass extinctions on the planet. From 83% to 97% of the species living on the planet went extinct during this relatively short interval of geological time that defines the major geological boundary between the Paleozoic and Mesozoic Eras. The cause and resulting sequence of events that led to this extinction have puzzled geologists for years. The new stratigraphic section in Utah provided a framework for reconstruction of the chemistry that was in the ocean during the mass extinction. Geochemical analysis of the section demonstrates, moving across the boundary from the Paleozoic to the Mesozoic, a significant drop in carbonate and total organic carbon, and a delayed occurrence of pyrite. Carbon isotope ratios (δ13C) show a negative excursion in carbonate with ratios dropping from 2.59‰ to ?3.63‰. Elevated mercury is present at the boundary with a 4-fold increase from background levels. The boundary layer also has elevated zinc, lead, strontium, and nickel, but not at high enough levels to indicate a volcanic ash source. There is no evidence in concentrations of siderophile and chalcophile elements for an extraterrestrial impact. The stratigraphic section in Utah supports the theory of a massive release of carbon dioxide, resulting in the acidification of the oceans. High levels of mercury, as well as elevated levels of zinc and lead, implicate a coal source triggered by the contemporary Siberian Traps sill complex. The delay of enriched sulfur and barium content in the stratigraphic record indicates an anoxic ocean and upwelling of methane hydrates from depth. Further study of this stratigraphic section will aid our understanding of the global impact these catastrophic events had on life.Burnham, A.K., 2019. Kinetic models of vitrinite, kerogen, and bitumen reflectance. Organic Geochemistry 131, 50-59. reflectance is perhaps the most widely used property to calibrate paleothermal histories, and the most common model for that purpose is Easy%Ro. This paper reviews the origin of Easy%Ro as a simplification of Vitrimat. Weaknesses of the original versions are discussed, as are historical attempts to improve them. New versions of Vitrimat and Easy%Ro are presented that use substantially higher frequency factors and activation energies, and variations of these versions are derived for vitrinite itself and hydrogen-rich macerals and bitumen. The Vitrimat models are based on the original premise that reflectance correlates primarily with H/C ratio and secondarily with O/C ratio. With this approach, the reflectance of different types of organic matter is automatically calculated based on the initial composition of that organic matter. This general approach may also serve as a pathway with appropriate cross-reaction terms to calculate suppression of true vitrinite reflectance matured in oil-prone rocks containing significant concentrations of liptinite.But, S.Y., Egorova, S.V., Khmelenina, V.N., Trotsenko, Y.A., 2019. Serine-glyoxylate aminotranferases from methanotrophs using different C1-assimilation pathways. Antonie van Leeuwenhoek 112, 741-751. indicator enzyme of the serine pathway of assimilation of reduced C1 compounds, serine-glyoxylate aminotransferase (Sga), has been purified from three methane-oxidizing bacteria, Methylomicrobium alcaliphilum 20Z, Methylosinus trichosporium OB3b and Methylococcus capsulatus Bath. The native enzymes were shown to be dimeric (80?kDa, strain 20Z), tetrameric (~?170?kDa, strain OB3b) or trimeric (~?120?kDa, strain Bath). Sga from the three methanotrophs catalyse the pyridoxal phosphate-dependent transfer of an amino group from serine to glyoxylate and pyruvate; the enzymes from strains 20Z and Bath also transfer an amino group from serine to α-ketoglutarate and from alanine to glyoxylate. No other significant differences between the Sga from the three methanotrophs were found. The three methanotrophic Sga have their highest catalytic efficiencies in the reaction between glyoxylate and serine, which is in agreement with their function to provide circulation of the serine assimilation pathway.The disruption of the sga gene in Mm. alcaliphilum resulted in retardation of growth rate of the mutant cells and in a prolonged lag-phase after passaging from methane to methanol. In addition, the growth of the mutant strain is accompanied by formaldehyde accumulation in the culture liquid. Hence, Sga is important in the serine cycle of type I methanotrophs and this pathway could be related to the removal of excess formaldehyde and/or energy regulation.Caetano-Anollés, D., Nasir, A., Kim, K.M., Caetano-Anollés, G., 2019. Testing empirical support for evolutionary models that root the tree of life. Journal of Molecular Evolution 87, 131-142. of life (ToLs) can only be rooted with direct methods that seek optimization of character state information in ingroup taxa. This involves optimizing phylogenetic tree, model and data in an exercise of reciprocal illumination. Rooted ToLs have been built from a census of protein structural domains in proteomes using two kinds of models. Fully-reversible models use standard-ordered (additive) characters and Wagner parsimony to generate unrooted trees of proteomes that are then rooted with Weston’s generality criterion. Non-reversible models directly build rooted trees with unordered characters and asymmetric stepmatrices of transformation costs that penalize gain over loss of domains. Here, we test the empirical support for the evolutionary models with character state reconstruction methods using two published proteomic datasets. We show that the reversible models match reconstructed frequencies of character change and are faithful to the distribution of serial homologies in trees. In contrast, the non-reversible models go counter to trends in the data they must explain, attracting organisms with large proteomes to the base of the rooted trees while violating the triangle inequality of distances. This can lead to serious reconstruction inconsistencies that show model inadequacy. Our study highlights the aprioristic perils of disposing of countering evidence in natural history reconstruction.Cai, C., Kang, Y., Wang, X., Hu, Y., Huang, M., Liu, Y., Liu, J., Chen, H., Li, X., 2019. Experimental study on shale fracturing enhancement by using multi-times pulse supercritical carbon dioxide (SC-CO2) jet. Journal of Petroleum Science and Engineering 178, 948-963. Carbon Dioxide (SC-CO2) fracturing can increase shale gas production and reduce carbon dioxide (CO2) emission. In order to enhance shale fracturing, a new method of multi-times pulse SC-CO2 jet fracturing is proposed and comprehensively studied. The results demonstrate there are more initiation positions and more complex fracture network after pulse SC-CO2 jet fracturing due to strong impingement and pressurization. Furthermore, three types of main fracture and four types of fracture branch are observed. The main fractures mostly initiate from perforation and propagate with irregular path to the specimen edge. CO2 absorption and fracture volume increase 77.72% and 2283%, respectively, more than that of single-pulse SC-CO2 jet fracturing. The comparison indicates that SC-CO2 creates more complex fracture morphology, larger fracture volume and CO2 absorption than that of water. Moreover, the effect of influential factors, including pulse jet frequency, pulse jet pressure and pulse jet distance, are discussed thoroughly. Thus, this study provides a method of jet fracturing enhancement, and is instructive for understanding and tackling pulse jet fracturing issue related to CO2 utilization and fracturing of shale reservoir.Cai, J., Lin, D., Singh, H., Zhou, S., Meng, Q., Zhang, Q., 2019. A simple permeability model for shale gas and key insights on relative importance of various transport mechanisms. Fuel 252, 210-219. transport mechanism in a shale nanopore is investigated by considering convective flow, gas diffusion, and surface diffusion. A common practice in modeling shale gas permeability is to use Knudsen diffusion coefficient when calculating diffusive flux, but the use of Knudsen diffusion coefficient would be incorrect if the shale gas flow regime is lying either in the transition diffusion or Fick’s diffusion, in which case the diffusion coefficient must correspond to that regime. This study proposes an apparent permeability model of shale based on a unified diffusion coefficient that transforms its value per the flow regime, including the effect of molecular diffusion, viscous flow, and surface diffusion of adsorbed gas through linear superposition. The proposed model is verified by comparing against other models for shale gas permeability. Results of sensitivity analysis indicate that permeability of gas due to diffusive transport is independent of pressure and pore size when pressure is larger than 6.895?MPa, but is dominant at lower pressures and increases with pore size. For pore diameters larger than 100?nm, the permeability due to surface diffusion is independent of pressure or pore size, indicating negligible gas transport due to surface diffusion in relatively larger pores (>100?nm) at any pressure, but it is dominant in small pore sizes when pressure is below 10?MPa. Permeability of gas (with or without surface diffusion) increases with the decrease of pressure when the pore diameters are smaller than 100?nm, whereas for pore diameters larger than 300?nm it is not affected by pressure, but increases with the increase of pore size, indicating that Darcy’s law is applicable in pores with the diameters larger than 300?nm.Cai, L., Xiao, G., Lu, S., Wang, J., Wu, Z., 2019. Spatial-temporal coupling between high-quality source rocks and reservoirs for tight sandstone oil and gas accumulations in the Songliao Basin, China. International Journal of Mining Science and Technology 29, 387-397. spatial-temporal relationship between high-quality source rocks and reservoirs is a key factor when evaluating the formation, occurrence, and prospectivity of tight oil and gas reservoirs. In this study, we analyze the fundamental oil and gas accumulation processes occurring in the Songliao Basin, contrasting tight oil sand reservoirs in the south with tight gas sand reservoirs in the north. This is done using geochemical data, constant-rate and conventional mercury injection experiments, and fluid inclusion analyses. Our results demonstrate that as far as fluid mobility is concerned, the expulsion center coincides with the overpressure zone, and its boundary limits the occurrence of tight oil and gas accumulations. In addition, the lower permeability limit of high-quality reservoirs, controlled by pore-throat structures, is 0.1?×?10?3 μm2 in the fourth member of the Lower Cretaceous Quantou Formation (K1q4) in the southern Songliao Basin, and 0.05?×?10?3 μm2 in the Lower Cretaceous Shahezi Formation (K1sh) in the northern Songliao Basin. Furthermore, the results indicate that the formation of tight oil and gas reservoirs requires the densification of reservoirs prior to the main phase of hydrocarbon expulsion from the source rocks. Reservoir “sweet spots” develop at the intersection of high-quality source rocks (with high pore pressure) and reservoirs (with high permeability).Campeau, A., Bishop, K., Amvrosiadi, N., Billett, M.F., Garnett, M.H., Laudon, H., ?quist, M.G., Wallin, M.B., 2019. Current forest carbon fixation fuels stream CO2 emissions. Nature Communications 10, Article 1876. CO2 emissions contribute significantly to atmospheric climate forcing. While there are strong indications that groundwater inputs sustain these emissions, the specific biogeochemical pathways and timescales involved in this lateral CO2 export are still obscure. Here, via an extensive radiocarbon (14C) characterisation of CO2 and DOC in stream water and its groundwater sources in an old-growth boreal forest, we demonstrate that the 14C-CO2 is consistently in tune with the current atmospheric 14C-CO2 level and shows little association with the 14C-DOC in the same waters. Our findings thus indicate that stream CO2 emissions act as a shortcut that returns CO2 recently fixed by the forest vegetation to the atmosphere. Our results expose a positive feedback mechanism within the C budget of forested catchments, where stream CO2 emissions will be highly sensitive to changes in forest C allocation patterns associated with climate and land-use changes.Cao, J.-h., Wu, X., Huang, F., Hu, B., Groves, C., Yang, H., Zhang, C.-l., 2018. Global significance of the carbon cycle in the karst dynamic system: evidence from geological and ecological processes. China Geology 1, 17-27. the basis of proposing the existence of a karst carbon cycle and carbon sink at a watershed scale, this paper provides four pieces of evidence for the integration of geology and ecology during the carbon cycle processes in the karst dynamic system, and estimated the karst carbon sink effect using the methods of comparative monitoring of paired watersheds and the carbon stable isotope tracer technique. The results of the soil carbon cycle in Maocun, Guilin, showed that the soil carbon cycle in the karst area, the weathering and dissolution of carbonate rocks under the soil, resulted in a lower soil respiration of 25% in the karst area than in a non-karst area (sandstone and shale), and the carbon isotope results indicated that 13.46% of the heavy carbon of the limestone is involved in the soil carbon cycle. The comparative monitoring results in paired watersheds, suggesting that the HCO3- concentration in a karst spring is 10 times that of a rivulet in a non-karst area, while the concentration of inorganic carbon flux is 23.8 times. With both chemical stoichiometry and carbon stable isotopes, the proportion of carbon in karst springs derived from carbonate rocks was found to be 58.52% and 37.65% respectively. The comparison on carbon exchange and isotopes at the water-gas interface between the granite and carbonate rock basins in the Li River showed that the CO2 emission of the karst water is 10.92 times that of the allogenic water from the non-karst area, while the carbon isotope of HCO3- in karst water is lighter by 8.62‰. However, this does not mean that the karst water body has a larger carbon source effect. On the contrary, it means the karst water body has a greater karst carbon sink effect. When the karst subterranean stream in Zhaidi, Guilin, is exposed at the surface, carbon-rich karst water stimulated the growth of aquatic plants. The values of carbon stable isotopes in the same species of submerged plants gradually becomes heavier and heavier, and the 512 m flow process has a maximum range of 15.46‰. The calculation results showed that 12.52% of inorganic carbon is converted into organic carbon. According to the data that has been published, the global karst carbon sink flux was estimated to be 0.53-0.58 PgC/a, equivalent to 31.18%-34.41% of the global forest carbon sink flux. In the meanwhile, the karst carbon sink flux in China was calculated to be 0.051 PgC/a, accounting for 68% of its forest carbon sink flux.Cao, K., 2018. Cretaceous terrestrial deposits in China. China Geology 1, 402-414. an important part of an epidermic system, terrestrial deposits can provide a good record of major geological events in the Cretaceous epidemic system. This article is a review of the geological background, paleogeography, paleoclimate, basin evolution and sedimentary characteristics in China through the Cretaceous period, in order to provide a comprehensive understanding for interested researchers. During the Berriasian-Hauterivian age, red-mainly fluvial and shallow lacustrine deposition developed under arid and semi-arid climates in westen China when eastern China had been occupied by the “East Plateau”. During the Barremian-Albian, age coal-bearing depositions occurred to the north of the Yanshan Mountain under the wet and warm climate. However, mainly red fluvial and shallow lacustrine depositions prevailed in most of the south to the Yanshan Mountain except basins where seawater could enter and caused mostly green depositions. During the Cenomanian-Santonian age, high land uplift took place in northwestern China. Mainly red deposition with developed alluvial plains occupied southwestern China and South China when the Songliao Basin was filled by black deep lacustrine mud shale caused by transgression. Mainly red deposition under an arid and semi-arid climate occupied all basins in China during the Campanian-Maastrichtian age.Cao, Y., Han, H., Liu, H.-w., Jia, J.-c., Zhang, W., Liu, P.-w., Ding, Z.-g., Chen, S.-j., Lu, J.-g., Gao, Y., 2019. Influence of solvents on pore structure and methane adsorption capacity of lacustrine shales: An example from a Chang 7 shale sample in the Ordos Basin, China. Journal of Petroleum Science and Engineering 178, 419-428. dissolution of soluble organic matter by solvents can increase the porosity and pore connectivity of shale, which is conducive to the exploitation of shale gas. To explore the influence of solvents on the pore structure and methane adsorption capacity of extracted shale, a sample of the Chang 7 shales from the Ordos Basin, China is extracted using acetone, tetrahydrofuran (THF), carbon disulfide (CS2), and benzene, respectively. Low pressure gas (CO2 and N2) adsorptions and methane adsorption experiments were carried out on the studied sample before and after extraction. The results indicate that the extraction yields of THF, CS2, benzene and acetone were 0.84%, 0.63%, 0.34%, and 0.31%, respectively, which is jointly influenced by the molecular dynamics diameter, aromaticity, boiling point, and polarity. The extraction yield of acetone (0.31%) is the lowest, which may be attributed to its low boiling point. The extraction yield of CS2 is about 2 times higher than acetone. It may be related to that the CS2 can destroy ionic crosslinks in organic matter, improving the extraction yield significantly. The highest extraction yield (0.84%) of THF is consistent with its aromatic structure, high boiling point, and strong polarity. The extraction yield (0.34%) of benzene is relatively low among the used solvents, which may be aroused by its larger dynamic diameter and weak polarity. Interestingly, the size ranges of pores that increased after extraction are strongly controlled by solvents. Acetone is easier to enter the micropores due to its smaller dynamics diameter. Therefore, the organic matters in micropores were more easily dissolved in acetone, which results in the significant increases in micropore volume and surface area. Comparably, mesopore volume and surface area increased greatly after CS2 extraction. One possibility is that CS2 mainly dissolved the organic matters in mesopores. Another possibility is that a part of micropores were enlarged to mesopores by extraction. The macropore volumes of the sample extracted by benzene and THF obviously increased due to their larger dynamics diameters. The methane adsorption capacity of the extracted sample is stronger than the raw sample. The type of adsorption isotherm was not changed. The acetone extracted sample has the highest methane adsorption capacity, followed by THF, CS2, and benzene, which is positively related with their micropore surface areas.Cappello, S., Cruz Viggi, C., Yakimov, M., Rossetti, S., Matturro, B., Molina, L., Segura, A., Marqués, S., Yuste, L., Sevilla, E., Rojo, F., Sherry, A., Mejeha, O.K., Head, I.M., Malmquist, L., Christensen, J.H., Kalogerakis, N., Aulenta, F., 2019. Combining electrokinetic transport and bioremediation for enhanced removal of crude oil from contaminated marine sediments: Results of a long-term, mesocosm-scale experiment. Water Research 157, 381-395. sediments represent an important sink of harmful petroleum hydrocarbons after an accidental oil spill. Electrobioremediation techniques, which combine electrokinetic transport and biodegradation processes, represent an emerging technological platform for a sustainable remediation of contaminated sediments. Here, we describe the results of a long-term mesocosm-scale electrobioremediation experiment for the treatment of marine sediments contaminated by crude oil. A dimensionally stable anode and a stainless-steel mesh cathode were employed to drive seawater electrolysis at a fixed current density of 11 A/m2. This approach allowed establishing conditions conducive to contaminants biodegradation, as confirmed by the enrichment of Alcanivorax borkumensis cells harboring the alkB-gene and other aerobic hydrocarbonoclastic bacteria. Oil chemistry analyses indicated that aromatic hydrocarbons were primarily removed from the sediment via electroosmosis and low molecular weight alkanes (nC6 to nC10) via biodegradation.Cardona, T., 2019. Thinking twice about the evolution of photosynthesis. Open Biology 9, Article 180246. Granick opened his seminal 1957 paper titled ‘Speculations on the origins and evolution of photosynthesis’ with the assertion that there is a constant urge in human beings to seek beginnings (I concur). This urge has led to an incessant stream of speculative ideas and debates on the evolution of photosynthesis that started in the first half of the twentieth century and shows no signs of abating. Some of these speculative ideas have become commonplace, are taken as fact, but find little support. Here, I review and scrutinize three widely accepted ideas that underpin the current study of the evolution of photosynthesis: first, that the photochemical reaction centres used in anoxygenic photosynthesis are more primitive than those in oxygenic photosynthesis; second, that the probability of acquiring photosynthesis via horizontal gene transfer is greater than the probability of losing photosynthesis; and third, and most important, that the origin of anoxygenic photosynthesis pre-dates the origin of oxygenic photosynthesis. I shall attempt to demonstrate that these three ideas are often grounded in incorrect assumptions built on more assumptions with no experimental or observational support. I hope that this brief review will not only serve as a cautionary tale but also that it will open new avenues of research aimed at disentangling the complex evolution of photosynthesis and its impact on the early history of life and the planet.Carrizo, D., Sánchez-García, L., Menes, R.J., García-Rodríguez, F., 2019. Discriminating sources and preservation of organic matter in surface sediments from five Antarctic lakes in the Fildes Peninsula (King George Island) by lipid biomarkers and compound-specific isotopic analysis. Science of The Total Environment 672, 657-668. are important paleoenvironmental archives retaining abundant information due to their typical high sedimentation rates and susceptibility to environmental changes. Here, we scrutinize the organic matter (OM) composition, origin and preservation state in surface sediments from five lakes in a remote, warming-sensitive, and poorly explored region partially covered by the retreating Collins Glacier in King George Island (Antarctica), the Fildes Peninsula. Lipid biomarkers of terrestrial origin (i.e. high-molecular weight n-alkanes, n-alkanoic acids, and n-alkanols; β-sitosterol, campesterol, and stigmasterol) were detected in the five Fildes Lakes, with the smallest basin (i.e., Meltwater) showing a particularly strong moss imprint. Aquatic source indicators such as low C/N and terrestrial over aquatic ratios (TAR), or less negative δ13C values were preferentially found in the mid-sized lakes (i.e., Drake and Ionospheric). Sedimentary carbon in the larger lakes (i.e., Uruguay and Kitezh) displayed a largely biogenic origin (i.e., values of carbon preference index, CPI, ?1), whereas the three lakes close to Collins Glacier (i.e., Drake, Meltwater, and Ionospheric) showed certain contribution from petrogenic sources (CPI?~?1). The results suggest that the geochemical signature of the surface sediments in the five Fildes lakes is determined by factors such as the distance to the retreating Collins Glacier, the proximity to the coast, or the lake depth. This study illustrates the forensic interest of combining lipid biomarkers, compound-specific isotopic analysis, and bulk geochemistry to reconstruct paleoenvironments and study climate-sensitive regions.Cavalazzi, B., Barbieri, R., Gómez, F., Capaccioni, B., Olsson-Francis, K., Pondrelli, M., Rossi, A.P., Hickman-Lewis, K., Agangi, A., Gasparotto, G., Glamoclija, M., Ori, G.G., Rodriguez, N., Hagos, M., 2019. The Dallol geothermal area, northern Afar (Ethiopia)—An exceptional planetary field analog on Earth. Astrobiology 19, 553-578. Dallol volcano and its associated hydrothermal field are located in a remote area of the northern Danakil Depression in Ethiopia, a region only recently appraised after decades of inaccessibility due to severe political instability and the absence of infrastructure. The region is notable for hosting environments at the very edge of natural physical-chemical extremities. It is surrounded by a wide, hyperarid salt plain and is one of the hottest (average annual temperatureDallol: 36–38°C) and most acidic natural systems (pHDallol ≈0) on Earth. Spectacular geomorphologies and mineral deposits produced by supersaturated hydrothermal waters and brines are the result of complex interactions between active and inactive hydrothermal alteration of the bedrock, sulfuric hot springs and pools, fumaroles and geysers, and recrystallization processes driven by hydrothermal waters, degassing, and rapid evaporation.The study of planetary field analog environments plays a crucial role in characterizing the physical and chemical boundaries within which life can exist on Earth and other planets. It is essential for the definition and assessment of the conditions of habitability on other planets, including the possibility for biosignature preservation and in situ testing of technologies for life detection. The Dallol area represents an excellent Mars analog environment given that the active volcanic environment, the associated diffuse hydrothermalism and hydrothermal alteration, and the vast acidic sulfate deposits are reminiscent of past hydrothermal activity on Mars. The work presented in this paper is an overview of the Dallol volcanic area and its hydrothermal field that integrates previous literature with observations and results obtained from field surveys and monitoring coupled with sample characterization. In so doing, we highlight its exceptional potential as a planetary field analog as well as a site for future astrobiological and exploration programs.Caye, K., Jumentier, B., Lepeule, J., Fran?ois, O., 2019. LFMM 2: Fast and accurate inference of gene-environment associations in genome-wide studies. Molecular Biology and Evolution 36, 852-860. association (GEA) studies are essential to understand the past and ongoing adaptations of organisms to their environment, but those studies are complicated by confounding due to unobserved demographic factors. Although the confounding problem has recently received considerable attention, the proposed approaches do not scale with the high-dimensionality of genomic data. Here, we present a new estimation method for latent factor mixed models (LFMMs) implemented in an upgraded version of the corresponding computer program. We developed a least-squares estimation approach for confounder estimation that provides a unique framework for several categories of genomic data, not restricted to genotypes. The speed of the new algorithm is several order faster than existing GEA approaches and then our previous version of the LFMM program. In addition, the new method outperforms other fast approaches based on principal component or surrogate variable analysis. We illustrate the program use with analyses of the 1000 Genomes Project data set, leading to new findings on adaptation of humans to their environment, and with analyses of DNA methylation profiles providing insights on how tobacco consumption could affect DNA methylation in patients with rheumatoid arthritis.Software availability: Software is available in the R package lfmm at álvez, E., Casal, P., Lundin, D., Pi?a, B., Pinhassi, J., Dachs, J., Vila-Costa, M., 2019. Microbial responses to anthropogenic dissolved organic carbon in the Arctic and Antarctic coastal seawaters. Environmental Microbiology 21, 1466-1481. of semi-volatile hydrophobic organic pollutants (OPs) reach open oceans through atmospheric deposition, causing a chronic and ubiquitous pollution by anthropogenic dissolved organic carbon (ADOC). Hydrophobic ADOC accumulates in cellular lipids, inducing harmful effects on marine biota, and can be partially prone to microbial degradation. Unfortunately, their possible effects on microorganisms, key drivers of global biogeochemical cycles, remain unknown. We challenged coastal microbial communities from Ny-?lesund (Arctic) and Livingston Island (Antarctica) with ADOC concentrations within the range of oceanic concentrations in 24 h. ADOC addition elicited clear transcriptional responses in multiple microbial heterotrophic metabolisms in ubiquitous groups such as Flavobacteriia, Gammaproteobacteria and SAR11. Importantly, a suite of cellular adaptations and detoxifying mechanisms, including remodelling of membrane lipids and transporters, was detected. ADOC exposure also changed the composition of microbial communities, through stimulation of rare biosphere taxa. Many of these taxa belong to recognized OPs degraders. This work shows that ADOC at environmentally relevant concentrations substantially influences marine microbial communities. Given that emissions of organic pollutants are growing during the Anthropocene, the results shown here suggest an increasing influence of ADOC on the structure of microbial communities and the biogeochemical cycles regulated by marine microbes.Chai, D., Fan, Z., Li, X., 2019. A new unified gas-transport model for gas flow in nanoscale porous media. SPE Journal 24, 698-719. new unified gas-transport model has been developed to characterize single-component real-gas flow in nanoscale organic and inorganic porous media by modifying the Bravo (2007) model. More specifically, a straight capillary tube is characterized by a conceptual layered model consisting of a viscous-flow zone, a Knudsen-diffusion zone, and a surface-diffusion zone. To specify the contributions of the viscous flow and the Knudsen diffusion to the gas transport, the virtual boundary between the viscous-flow and Knudsen-diffusion zones is first determined using an analytical molecular-kinetics approach. As such, the new unified gas-transport model is derived by integrating the weighted viscous flow and Knudsen diffusion, and coupling surface diffusion. The model is also comprehensively scaled up to the bundles-of-tubes model considering the roughness, rarefaction, and real-gas effect. Nonlinear programming methods have been used to optimize the empirical parameters in the newly proposed gas-transport model. Consequently, the newly proposed gas-transport model yields the most accurate molar fluxes compared with the Bravo (2007) model and four other analytical models. One of the advantages of the new unified gas-transport model is its great flexibility, because the Knudsen number is included as an independent variable, which also endows the newly proposed model with the capability to cover the full-flow regimes. In addition, the apparent permeability has been mathematically derived from the new unified gas-transport model. A series of simulations has been implemented using methane gas. It is found through sensitivity analysis that apparent permeability is strongly dependent on pore size, porosity, and tortuosity, and weakly dependent on the surface-diffusivity coefficient and pore-surface roughness. The increased viscosity can reduce the total molar flux in the inorganic pores up to 66.0% under the typical shale-gas-reservoir conditions. The viscous-flow mechanism cannot be neglected at any pore sizes under reservoir conditions, whereas the Knudsen diffusion is found to be important when pore size is smaller than 2 nm and pressure is less than 35.0 MPa. The contribution of surface diffusion cannot be ignored when the pore size is smaller than 10 nm and the pressure is less than 15.0 MPa.Chamberlain, C.A., Rubio, V.Y., Garrett, T.J., 2019. Strain-level differentiation of bacteria by paper spray ionization mass spectrometry. Analytical Chemistry 91, 4964-4968. spray ionization mass spectrometry (PSI-MS) is a relatively new analytical technique allowing for rapid mass spectrometric analysis of biological samples with little or no sample preparation. The expeditious nature of the analysis and minimal requirement for sample preparation make PSI-MS a promising avenue for future clinical assays with one potential application in the identification of different types of bacteria. Although past PSI-MS studies have demonstrated the ability to distinguish between bacteria of different species and morphological classes, achieving within-species strain-level differentiation has never been performed. In this report, we demonstrate the first strain-level bacterial differentiation by PSI-MS with the mammalian intestinal bacterium Oxalobacter formigenes (Oxf). This novel application holds promising clinical significance as it could be used to differentiate between pathogenic bacteria and their harmless, commensal relatives, saving time and money in clinical diagnostics. Both whole cells and cell lysates of Oxf strains HC1 and OxWR were analyzed using the Prosolia Velox 360TM PSI source coupled to a Thermo Scientific Q Exactive high-resolution mass spectrometer with a rapid 30 s analytical method. Multivariate statistical analysis followed by examination of significant features provided for and confirmed differentiation between Oxf HC1 and OxWR. We report a panel of strain-exclusive metabolites that could serve as potential strain-indicating biomarkers.Chandrasekharan Nair, V., Gupta, P., Sangwai, J.S., 2019. Natural gas production from a marine clayey hydrate reservoir formed in seawater using depressurization at constant pressure, depressurization by constant rate gas release, thermal stimulation, and their implications for real field applications. Energy & Fuels 33, 3108-3122. depressurization approach of methane production from a natural gas hydrate reservoir has been identified as the most energy-efficient production approach. However, some of the field-scale studies involving constant pressure depressurization (CPD) did not yield significant success. To address this, the constant rate gas release (CRD) depressurization approach was used to overcome the drawbacks of the CPD approach. The experimental investigations of these methods with and without thermal stimulation (TS) have not yet been investigated in detail for marine clayey hydrate reservoirs formed in seawater to understand their comparative effectiveness for methane gas recovery. Although common production approaches have been studied by many researchers on hydrate-bearing sand sediments, energy recovery from hydrate-rich clayey sediments has not yet been investigated in detail, which form the major dominant hydrate reservoirs of the hydrate resource pyramid across the globe. This work investigates in detail the potency of five different natural gas production techniques such as CRD, CPD, TS, and their combination to produce natural gas out of the marine clayey hydrate system. To simulate marine conditions, mud samples with 3 wt % of bentonite clay in seawater have been used for methane hydrate formation at an initial pressure of 8 ± 0.2 MPa and a temperature of 278.15 ± 1 K. The thermodynamic phase equilibrium study of methane hydrate in the marine clayey system has also been conducted to understand the phase stability of hydrates. Subsequently, a study on five different methane recovery approaches to recover natural gas from marine clayey hydrate systems has been carried out to understand their efficacy. For CRD depressurization, two rates, viz., 10 and 20 mL/min, have been used, whereas for CPD, two set pressures of 3.5 and 2.3 MPa have been used. TS was carried out by increasing the hydrate reservoir temperature from 278.15 to 298.15 K. Field implications of these five production schemes have also been discussed in detail for their real field applications.Charles, C.J., Rout, S.P., Wormald, R., Laws, A.P., Jackson, B.R., Boxall, S.A., Humphreys, P.N., 2019. In-situ biofilm formation in hyper alkaline environments. Geomicrobiology Journal 36, 405-411. manufacture in the UK has resulted in the generation of a number of alkaline sites (>pH 11.0) with complex indigenous microbial populations. Within the present study, retrievable cotton samples were used to investigate the fate of cellulose, the primary carbon source, within three sites aged from ≈25 to 140?years. Following 3 months incubation in situ, biofilms had formed on all cotton samples in these extreme pH conditions; with matrices comprised of carbohydrates, proteins, lipids and eDNA. Biofilms from the older sites contained greater amounts of eDNA, a structural component that aids the production of a denser biofilm. The age of the sites correlated with a shift from polysaccharides composed of β 1,4 and β 1,3 linked sugars to those composed of pyranosyl sugars within the older sites. These changes were reflected in the active biofilm communities which shifted from being Clostridiales dominated in the youngest site to Proteobacteria dominated in the older sites. The study demonstrates that the microbial communities resident in anthropogenic alkaline sites are able to form biofilms at pH values?>?pH 11.0 and that these biofilms evolve toward Proteobacteria dominated communities employing eDNA and pyranosyl sugar based polysaccharides to build the biofilm matrix.Chen, D., Ye, Z., Pan, Z., Tan, Y., Li, H., 2019. Theoretical models to predict gas adsorption capacity on moist coal. Energy & Fuels 33, 2908-2914. impact of moisture on gas adsorption capacity reduction on coal has been well recognized, and empirical correlations are widely used to quantitatively evaluate the moisture effect. However, few studies are found on fundamental modeling of the moisture effect on gas adsorption capacity. In this work, two theoretical models on the basis of the extended Langmuir theory (EL-based) and the ideal adsorbed solution theory (IAS-based) were developed to account for the gas adsorption capacity with different pressures and moisture contents. With the parameters determined from the gas adsorption on dry samples and water adsorption on samples under atmospheric conditions, both models are able to predict the gas adsorption capacity under combined effects of gas pressure and moisture content. The models were verified through a set of experimental data from a coal sample from Australia, and they were further applied to describe the methane adsorption behavior on a coal sample from New Zealand. The results demonstrate that both models can reasonably predict the gas adsorption capacity on moist coal samples. Although one more parameter is required, the IAS-based model could match the experimental data with higher accuracy. The research findings in this work contribute to a better understanding of the fundamentals of gas adsorption characteristics on moist coal.Chen, D., Zhang, J., Lan, B., Wang, X., Wang, Z., 2019. Influence of sedimentary environment on the shale gas reservoir of Sahai formation in Fuxin Basin, northeast China. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects 41, 1949-1959. Basin is a continental faulted lacustrine basin in northeast China with significant shale gas resources. The shale reservoir mainly developed in the sedimentary environment of the deep and semi-deep lake, swamp, and the interdistributary bay. Deep and semi-deep lake shale has considerable thickness, high clay content, dominant type II1 kerogen, and more pyrite framboid pores; swamp shale has the highest TOC content, type III kerogen, high clay content, and more organic pores; interdistributary bay shale shows high brittle mineral contents, type II2 kerogen, and more intergranular pores. The methane adsorption capacity is highest in swamp shale, followed by the deep and semi-deep lake and interdistributary bay.Chen, H., 2019. Performance of a simple backtracking method for marine oil source searching in a 3D ocean. Marine Pollution Bulletin 142, 321-334. of a simple backtracking method in searching for a potential spill source for offshore detected oil is investigated through a series of idealized numerical experiments, in which either sea surface source in a 2D case or underwater source in a 3D case is considered. Numerical result shows that, generally, backtracking time is an important input for 2D version of the backtracking method, whereas an accurate ocean dynamic background and an accurate field measurement of oil droplet size are crucial for 3D version. Reducing the uncertainty in oil detection site or accurately measuring the oil droplet size can effectively improve the efficiency of method implementation. External information like satellite images, offshore oil facilities and navigation information is helpful for improving the method efficiency.Chen, J.-H., Althaus, S.M., Liu, H.-H., Sun, Q., 2019. Shale gas transport in rock matrix: Diffusion in the presence of surface adsorption and capillary condensation. Journal of Natural Gas Science and Engineering 66, 18-25. characteristic of unconventional shale rock is the abundance of nanoscale pores and pore throats. For many shale reservoirs, these are the dominant factors controlling the total reserve, production rate, and overall production. Accordingly, many new phenomenon related to nanopore physics need to be considered for shale reservoir. A key mechanism controlling hydrocarbon gas transport from pores to fractures in shale reservoirs is molecular diffusion. As a result, the diffusion coefficient of light hydrocarbon becomes an important parameter in reservoir simulation to estimate production rate, especially for the long-term or late time production. The diffusion coefficient is also a key parameter in nuclear magnetic resonance (NMR) logging for fluid typing in determining hydrocarbon-in-place.Diffusion in nanopore systems is complicated by two important factors. First, the gas molecules collide more with pore surfaces than with each other; therefore, simple diffusion theory based on gas molecule collision is not applicable. Second, the occurrence of capillary condensation in small pores or pore throats and the adsorption to the pore surface makes the hydrocarbon transport a mixed process of liquid diffusion and gas diffusion in the reservoir.We derived a theoretical model for mixed phase diffusion under fast exchange for shale gas reservoirs. We obtained that the effective diffusion coefficient of mixed fluid is a fractional average of the liquid and gas diffusivity. We verified this model using NMR to measure n-hexane diffusion in a well-characterized hierarchical carbon with both nanometer pores and micrometer pores so that both gas and liquid can be prepared to exist in the sample simultaneously. We found that the diffusion coefficient of hexane in these hydrophobic nanopores is approximately one magnitude of order larger than the bulk liquid value. The effective diffusion coefficient in this study can be used in reservoir simulation and interpretation of NMR logs for shale gas reservoirs.Chen, L., Jiang, Z., Liu, Q., Jiang, S., Liu, K., Tan, J., Gao, F., 2019. Mechanism of shale gas occurrence: Insights from comparative study on pore structures of marine and lacustrine shales. Marine and Petroleum Geology 104, 200-216. exploration practices of marine and lacustrine shale gas in the Upper Yangtze Platform, South China show that there is a huge difference in gas content, which is mainly related to the difference of pore structure. This study is focused on marine Longmaxi and lacustrine Da'anzhai shales in the Upper Yangtze Platform, and their pore structure characteristics were compared and the mechanism of shale gas occurrence were discussed. First, the pore structures of marine and lacustrine shales were characterized and the effects of organic matter abundance, maturity and inorganic minerals on porosity were investigated. Then the contributions of different components to porosity were evaluated and the occurrence mode of methane in the pores of marine and lacustrine shales was established. The results show that (1) Three pore types can be observed in both marine and lacustrine shales: organic matter-hosted pores (OM pores), framework minerals-associated pores (FM pores), and clay minerals-associated pores (CM pores). OM pores are more developed in marine shale and CM pores are more developed in lacustrine shale. (2) Low pressure gas adsorption (LPGA) results show that the micropores of marine shale are dominated by pores of 0.4–0.7?nm and the micropores of lacustrine shale are dominated by pores of 0.5–0.9?nm, while the mesopores of marine shale are dominated by pores of 2–10?nm and the mesopores of lacustrine shale are dominated by pores of 3–30?nm, which are consistent with MIP results. (3) Organic matter has an impact on porosity of marine and continental shales but is not the most important controlling factor. And the contribution of organic matter to porosity in marine shale is greater than the contribution of organic matter to porosity in lacustrine shale. Shale porosity increases first and then decreases with the increase of maturity, which may be related to the carbonization of organic matter. (4) OM pores and CM pores tend to be preserved due to the presence of rigid grains that form rigid frameworks preventing these pores from collapsing. FM pores are mainly related to the dissolution of framework minerals by organic acids, and these dissolution pores can greatly improve the porosity and permeability of shale. (5) Quantification of porosity as related to mineralogy shows that OM pores contribute approximately 37% to total porosity of marine shale and 24% to total porosity of lacustrine shale and CM pores contribute approximately 53% to total porosity of marine shale and 67% to total porosity of lacustrine shale. (6) Shale gas occurrence is mainly controlled by the distribution mode of pore systems which are composed of OM pores, FM pores and CM pores. It is due to higher percentage on OM pores and lower percentage on CM pores that gas content of marine shale is generally higher than that of lacustrine shale.Chen, S.-C., Musat, N., Lechtenfeld, O.J., Paschke, H., Schmidt, M., Said, N., Popp, D., Calabrese, F., Stryhanyuk, H., Jaekel, U., Zhu, Y.-G., Joye, S.B., Richnow, H.-H., Widdel, F., Musat, F., 2019. Anaerobic oxidation of ethane by archaea from a marine hydrocarbon seep. Nature 568, 108-111. is the second most abundant component of natural gas in addition to methane, and—similar to methane—is chemically unreactive. The biological consumption of ethane under anoxic conditions was suggested by geochemical profiles at marine hydrocarbon seeps, and through ethane-dependent sulfate reduction in slurries. Nevertheless, the microorganisms and reactions that catalyse this process have to date remained unknown8. Here we describe ethane-oxidizing archaea that were obtained by specific enrichment over ten years, and analyse these archaea using phylogeny-based fluorescence analyses, proteogenomics and metabolite studies. The co-culture, which oxidized ethane completely while reducing sulfate to sulfide, was dominated by an archaeon that we name ‘Candidatus Argoarchaeum ethanivorans’; other members were sulfate-reducing Deltaproteobacteria. The genome of Ca. Argoarchaeum contains all of the genes that are necessary for a functional methyl-coenzyme M reductase, and all subunits were detected in protein extracts. Accordingly, ethyl-coenzyme M (ethyl-CoM) was identified as an intermediate by liquid chromatography–tandem mass spectrometry. This indicated that Ca. Argoarchaeum initiates ethane oxidation by ethyl-CoM formation, analogous to the recently described butane activation by ‘Candidatus Syntrophoarchaeum’. Proteogenomics further suggests that oxidation of intermediary acetyl-CoA to CO2 occurs through the oxidative Wood–Ljungdahl pathway. The identification of an archaeon that uses ethane (C2H6) fills a gap in our knowledge of microorganisms that specifically oxidize members of the homologous alkane series (CnH2n+2) without oxygen. Detection of phylogenetic and functional gene markers related to those of Ca. Argoarchaeum at deep-sea gas seeps suggests that archaea that are able to oxidize ethane through ethyl-CoM are widespread members of the local communities fostered by venting gaseous alkanes around these seeps.Chen, S., Sun, S., Zhao, C., Liu, Q., Zang, M., 2019. Biodesulfurization of model oil using growing cells of Gordonia sp. SC-10. Petroleum Science and Technology 37, 907-912. biodesulfurization capacity of Gordonia sp. SC-10 in a biphasic reaction system was investigated in this study. Model oil containing dibenzothiophene was used as the sole sulfur source of bacterium. The results showed that 81.43% of the sulfur in model oil with initial sulfur content of 174?mg/l could be removed within 5?days. Gordonia sp. SC-10 had high desulfurization rate for model oils with low sulfur contents, which would reduce sulfur concentration to below 5?mg/l. Biodesulfurization process might be a potential method to obtain fuels with ultra-low sulfur contents.Chen, X.-h., Luo, S.-y., Liu, A., Li, H., 2018. The oldest shale gas reservoirs in southern margin of Huangling uplift, Yichang, Hubei, China. China Geology 1, 158-159.. Objective: Large-scale commercial production of shale gas started in Fuling, Changning and Weiyuan areas of the Sichuan Basin (Zou et al., 2016) since 2010. The most notable shale gas success is the Longmaxi organic rich Shale in Jiaoshiba field, Sichuan Basin. The Yichang slope is located in the north of middle Yangtze region. This eastward dipping slope is a new prospective area for shale gas exploration in recent 5 years. The gas-bearing shale system in the Yichang slope is underlain by the granite basement. The outcrop is exposed in the center of the Huangling Anticline. Early Paleozoic conventional natural gas was explored in Weiyuan and Gaoshiti in the north Sichuan Basin. The Precambrian Doushantuo shale in Yichang area is another prolific shale gas exploration target. The Doushantuo shale gas in Yichang slope is the earliest marine shale gas resource in the world, whose source rock was deposited between 635 and 551 Ma ago (Condon et al., 2005). Although the Yiye-1 well is finished recently, it is a significant innovation in shale gas exploration. The exploration of Doushantuo shale gas increases the unconventional hydrocarbon resources from Sichuan Basin to its adjacent areas (i.e. the Middle Yangtze Platform).The marine-deposited Donshantuo shale contains large thickness, potentially favorable thermal maturity, and continuous features of seismic reflection co-axial. Lower Doushantuo units in the middle Yangtze area of China are the target strata for shale gas exploration. The lithology of Doushantuo unit is mainly comprised of microcrystalline limestone interbedded with black shale with abundant phosphatic nodules. Those strata were deeply buried in the early Mesozoic, and being uplifted during the late Mesozoic and Cenozoic.The purpose of this project is to investigate the shale gas distribution and gas-bearing system of the Doushantuo Formation, and to identify the characteristics of shale gas capacities integrating with geological and geochemical data. This project provides the basic data for future exploration and development of the regional shale gas.2. Methods: A geological investigation well (Well Yiye-1) was drilled by Wuhan Centre of China Geological Survey (CGS) in the southeast of Huangling Anticline in 2015-2016. Yiye-1well is located 25 km northwest to the Yichang city in Hubei province. The well was drilled from the Cretaceous Shimen Formation (Shimen F.M) to Neoproterozoic Formation with a total depth of 2418 meters in September 2016. Public drilling information on the shale formations in this area is quite limited. Data includes a 272 km 2-D seismic line, 4 geological survey wells, and limited geochemical test data (Fig. 1a). It helps identify the regional stratigraphy and structural characteristics, as well as the distribution and thickness variation. Standard core drilling, special logging and field analytical experiments are also carried out on the Yiye-1Well.3. Results: The Doushantuo Formation is overlain by the Upper Sinian Dengying carbonate rock, and underline by the late Neoproterozoic glacial deposition, which is about 206 m thick in Yiye-1 well (Figure 1b). Shale member of Doushantuo Formation (Z1d2) is confined as the shelf deposits in sub-depressions of the continental margins corresponding to the lower part of a first marine transgression cycle, which aggregates 145 meter in thickness. Organic matter within Doushantuo shale is dominated by oil-prone type Ⅰ marine kerogen that contains an average of 2.79 wt. % total organic carbon (TOC), with present-day thermal maturity between 2.06 and 2.66 % equivalent vitrinite reflectance (Ro). The mineral composition of shale consists of 18.4% clay minerals, 25.2% quartz, 4.5% calcite, 43.23% dolomite/ankerite, 2.28% pyrite, 6.4% feldspar and minor pyrite in some sample. Illite smectite mixed layer is the major clay mineral (Fig. 1c).Measurement of total hydrocarbon and methane through mud logging indicates anomaly in depth from 2244 m to 2389 m. Total shale gas content is tested with core in the field analytical experiment. 47 measured samples within 145 m shows that the gas content of the Doushantuo shale in Yiye-1 well is ranging from 0.39 m3/t to 2.00 m3/t, averaging 1.08 m3/t. It reached the lower limit of commercial exploitation. In terms of its chemical composition, shale gas is typically a dry gas with more than 90% methane.The reservoirs of Doushantuo shale are preserved in normal pressure, which differs from the large-scale commercial shale gas intervals of Fuling and Weiyuan areas of the Sichuan Basin. Large amount of geological information for natural gas were obtained from nearby geological investigation wells, which provided clear evidences for gas potential. Overall the Yichang area, with less complicated structural and faulting, is favorable for unconventional natural gas preserved.4. Conclusion: The Precambrian Doushantuo shale in the Middle Yangtze is an important strata for shale gas exploration. Canister desorption shale gas from 47 samples shows that total gas content typically ranged from 0.39 m3/t to 2.00 m3/t. The Doushantuo shale gas in Yichang slope area is the earliest marine shale gas resource in the world, which represents an enormous potential gas resource and a new prospective area for shale gas exploration outside the Sichuan hydrocarbon bearing basin.Chen, X., Hua, L., Jiang, J., Hu, F., Wan, N., Li, H., 2019. Multi-capillary column high-pressure photoionization time-of-flight mass spectrometry and its application for online rapid analysis of flavor compounds. Talanta 201, 33-39. photoionization time-of-flight mass spectrometry (HPPI-TOFMS) is a versatile and highly sensitive analytical technique for online and real-time analysis of trace volatile organic compounds in complex mixtures. However, discrimination of isomers is usually a great challenge for the soft ionization method, and matrix effect is also inevitable under high pressure in the HPPI source. In this work, we describe a first attempt to develop a two-dimensional (2D) hyphenated instrument by coupling of a multi-capillary column (MCC) with a HPPI-TOFMS to overcome these problems. The capability of the MCC-HPPI-TOFMS for discrimination of isomeric compounds and elimination of the matrix effect was demonstrated by analyzing flavor mixtures. With the merits of fast separation, soft ionization and high detection sensitivity, satisfactory effects in the 2D analysis were achieved, despite the relatively low chromatographic resolution of MCC. As a result, three isomers, eucalyptol, l-menthone and linalool, in a flavor mixture were successfully categorized within 90?s, and the matrix effect caused by solvent ethanol was significantly eliminated as well. The limits of detection (LODs) down to sub-ppbv level were achieved for the investigated five flavor compounds without any enrichment process, and an excellent repeatability was obtained with the relative standard deviations (RSDs) of signal intensities ≤5%. The MCC-HPPI-TOFMS system was preliminarily applied for rapid and online analysis of flavor compounds in the exhaled gas of a volunteer after mouth rinsing with a gargle product. The rapid changes of the three flavor compounds, as well as the steady endogenous metabolite acetone, in the exhaled gas were successfully determined with a time-resolution of only 1.5?min.Chen, Y., Qin, Y., Luo, Z., Yi, T., Wei, C., Wu, C., Li, G., 2019. Compositional shift of residual gas during desorption from anthracite and its influencing factors. Fuel 250, 65-78. attention has been paid to the factors influencing compositional shifts in residual gas during the desorption process from coal. Two anthracite samples were collected from the Zhina Coalfield in China to study compositional shifts in residual gas. The entire desorption process was divided into five stages, comprising thirteen substages. Low-pressure N2 adsorption tests showed that mesopore and macropore volumes and surface areas increased continuously as the particle size of pulverized coal decreased. The increase in porosity with decreasing particle size is attributable to the existence of many closed pores in the coal. The residual gas contents of the two samples were 8.34 and 7.22?cm3/g (“as-received” basis). The desorption rate of residual gas gradually declined with time in a 95?°C thermostatic water bath. Measured concentrations of the chemical gas components CH4, C2+, N2, and CO2 show distinct variations during the desorption process. The factors influencing compositional shifts in residual gas are ambient temperature, heating time, and pulverized coal particle size. N2 concentrations were highest during the pulverization process and relatively low during the heating process, which is in contrast with the variation trend of C2+ and CO2 concentrations. CH4 and N2 concentrations decreased steadily with heating time in a 95?°C thermostatic water bath, whereas C2+ and CO2 concentrations showed the opposite trend. This is because C2+ and CO2 have stronger adsorption affinities than CH4 and N2 do, and a large proportion of N2 and CH4 could desorb preferentially from coal. C2+ and CO2 concentrations increased with decreasing coal particle size, whereas CH4 and N2 concentrations showed the opposite trend. Relatively high concentrations of CO2 and C2+ in closed pores may be related to the sealing effect of closed pores, which prevents the escape of early generated products. In addition, increased pressure in closed coal pores should retard C2+ cracking at high temperatures. Thus, it is necessary to focus on the compositional shifts in residual gas and its influencing factors. Failure to account for these aspects may lead to typical analytical errors, which will propagate in the assessment of CH4 abundance in coalbeds.Chen, Y., Ye, Q., Jiang, H., Wignall, P.B., Yuan, J., 2019. Conodonts and carbon isotopes during the Permian-Triassic transition on the Napo Platform, South China. Journal of Earth Science 30, 244-257. Permian-Triassic boundary (PTB) sections (Pojue and Dala) are well exposed in an isolated carbonate platform (Napo Platform) on the southwestern margin of the Nanpanjiang Basin, South China. These sections provide an insight into the transition across the PTB and a detailed investigation of the conodont biostratigraphy and inorganic carbon isotopes is presented. The PTB at the Pojue Section is placed at the base of Bed 10B (a dolomitized mudstone found below a microbialite horizon), defined by the first occurrence of Hindeodus parvus. At the Dala Section, four conodont zones occur. They are, in ascending order, the Hindeodus parvus Zone, Isarcicella staeschei Zone, Isarcicella isarcica Zone and Clarkina planata Zone. Comparison with the Pojue Section suggests the PTB at Dala also occurs at the base of dolomitized mudstone below a microbialite horizon, although the first occurrence of Hindeodus parvus is near the top of a microbialite bed: an occurrence that is also seen in other platform sections. The succeeding microbialite beds developed during the ongoing PTB mass extinction phase. This time was characterized by low carbon isotope values, and a microbialite ecosystem that provided a refuge for selected groups (bivalves, ostracods and microgastropods) that were likely tolerant of extremely high temperatures.Cheng, Q., Zhang, M., Huang, G., Zhang, W., 2019. The contribution of bacteria to organic matter in coal-measure source rocks. Acta Geochimica 38, 364-375. the basis of GC–MS analysis, a suite of nine coal-measure source rocks (Ro 0.51%–0.63%) from the southern margin of Junggar basin was found to contain many biomarkers for bacterially-generated hydrocarbons: hopane, sesquiterpene, C23+ monomethyl alkanes (even carbon predominance), and C24+ alkyl cyclohexane. Rock–eval and microscope analysis indicate that vitrinite (especially desmocollinite and homocollinite) plays a significant role in the generation of hydrocarbons in coal-measure source rocks. Vitrinite performs this role by absorbing ultramicroscopic organic matter, generally in the form of resins or bacterial plastids. C23+ monomethyl alkanes (even carbon predominance) and C24+ alkyl cyclohexane series compounds are derived from bacterial metabolites of higher plants. The ultramicro organic matter adsorbed by vitrinite source rocks in the study area is probably ultramicro bacterial plastids. Because the organic matter of higher plants with low hydrogen content has been transformed into organic matter rich in hydrogen by bacteria, the hydrocarbon generation capacity of source rocks is greatly improved. In other words, in coal-measure source rocks, bacteria play an important role in hydrocarbon generation.Cheng, S., Li, S., Tsona, N.T., George, C., Du, L., 2019. Alterations in the surface properties of sea spray aerosols introduced by the presence of sterols. Science of The Total Environment 671, 1161-1169. mixed stearic acid (SA)/sterol systems were used as sea spray aerosol mimics to get more insights into the alterations in surface properties of aerosols induced by sterols. By means of surface pressure (π)–area (A) isotherms and polarization modulation-infrared reflection absorption spectroscopy (PM-IRRAS), the effect of cholesterol (chol), stigmasterol (stig) and ergosterol (erg) on the lateral packing and chain conformation of SA monolayer was explored. The fact that the excess areas of mixing of the mixed monolayers exhibit significant deviations from ideally mixed film proves that, the sterols are miscible with SA throughout all the monolayer compositions and surface pressures examined. The lift-off areas in π–A isotherms were found to increase with increasing mole fraction of sterols, indicating that expulsive interactions exist between SA and sterols, which are more pronounced when the mole fraction of sterols is 0.7. In addition, the peak intensities of νa(CH2) and νs(CH2) in IRRAS spectra decrease with increasing sterols levels, which is consistent with our findings in the π–A isotherms, that the addition of sterols leads to a looser chain packing in SA monolayer. The proportion of gauche defects in SA monolayer induced by the sterols follows the order cholesterol?<?stigmasterol?<?ergosterol at a certain sterol level, as reflected by the decreasing peak intensities of νa(CH2) and νs(CH2). Consequently, the sterols generally give rise to considerable expanding effects on SA monolayer, which are particularly pronounced for stigmasterol and ergosterol, suggesting that the additional alkyl side chains and double bonds of the sterols play a role on disordering SA monolayer. The present study is likely to shed light on many boundary processes take place at the interface of SSAs, in particular, transport processes of water and trace gases across the interface.Cheng, S., Li, S., Tsona, N.T., George, C., Du, L., 2019. Insights into the headgroup and chain length dependence of surface characteristics of organic-coated sea spray aerosols. ACS Earth and Space Chemistry 3, 571-580. structure of sea spray aerosols (SSAs) has been described as a saline core coated by organic surfactants. The presence of surface-active compounds at the interface can exert significant effect on physical, chemical, and optical properties of SSAs. The surfactant molecules chosen for this study, palmitic acid (PA), stearic acid (SA), arachidic acid (AA), methyl palmitate (MP), methyl stearate (MS), and methyl arachidate (MA), were used to explore the effect of alkyl chain length, headgroups, and sea salts on the surface properties of these monolayers. Surface pressure–area (π–A) isotherms obtained with a Langmuir trough was used for revealing macroscopic phase behavior of the monolayers. Moreover, infrared reflection absorption spectroscopy (IRRAS) was employed to investigate the interfacial organization at the molecular level. The π–A isotherms indicated that sea salts, present in the subphase, have an intense condensing effect on fatty acid monolayers while exerting an expanding effect on fatty acid methyl ester monolayers, which was confirmed by results from IRRAS experiments. IRRAS further uncovered the all-trans conformation of the hydrocarbon chains, which can be evidenced by the relatively low νa(CH2) and νs(CH2) stretching vibrations. The conformational order changes in the alkyl chains of different film-forming species (C16 < C18 < C20) were directly revealed by analyzing the intensity ratios of the νa(CH2) and νs(CH2) bands. Thus, all three factors alter the phase behavior and molecular packing of the monolayers at the air–aqueous interface.Chugaev, A.V., Chernyshev, I.V., Budyak, A.E., Mandzhieva, G.V., Sadasyuk, A.S., Gareev, B.I., 2019. Variations of the 238U/235U isotope ratio in metasedimentary rocks and evidence of changes in sedimentation conditions during the Ediacarian Period of the Neoproterozoic. Doklady Earth Sciences 484, 167-172. isotopic composition of uranium is a new geochemical indicator that facilitates reconstruction of the redox conditions of geological processes. In this paper the results of study of the 238U/235U isotope ratio in the Neoproterozoic metasedimentary rocks of the Baikal–Patom fold belt (Northern Transbaikalia) were obtained using the MC-ICP-MS method and 235U + 236U double spike. The scale of 238U/235U ratio variations (δ238U = –0.37 to –0.11‰) is within the range of (–0.39 to +0.15‰), typical of metasedimentary terrigenous rocks of marine origin. In terms of the δ238U values, uranium of the BPB rocks studied is heavier than seawater uranium (δ238U = –0.41 ± 0.03). There is a correlation between the δ238U value in the rocks and their position in the stratigraphic section. Variations of the 238U/235U ratio in the terrigenous-carbonate sequences of BPB indicate that the sedimentation conditions changed and euxinic conditions were established in the course of evolution of the paleobasin in the Late Ediacarian period.Ciais, P., Tan, J., Wang, X., Roedenbeck, C., Chevallier, F., Piao, S.L., Moriarty, R., Broquet, G., Le Quéré, C., Canadell, J.G., Peng, S., Poulter, B., Liu, Z., Tans, P., 2019. Five decades of northern land carbon uptake revealed by the interhemispheric CO2 gradient. Nature 568, 221-225. global land and ocean carbon sinks have increased proportionally with increasing carbon dioxide emissions during the past decades. It is thought that Northern Hemisphere lands make a dominant contribution to the global land carbon sink; however, the long-term trend of the northern land sink remains uncertain. Here, using measurements of the interhemispheric gradient of atmospheric carbon dioxide from 1958 to 2016, we show that the northern land sink remained stable between the 1960s and the late 1980s, then increased by 0.5?±?0.4 petagrams of carbon per year during the 1990s and by 0.6?±?0.5 petagrams of carbon per year during the 2000s. The increase of the northern land sink in the 1990s accounts for 65% of the increase in the global land carbon flux during that period. The subsequent increase in the 2000s is larger than the increase in the global land carbon flux, suggesting a coincident decrease of carbon uptake in the Southern Hemisphere. Comparison of our findings with the simulations of an ensemble of terrestrial carbon models over the same period suggests that the decadal change in the northern land sink between the 1960s and the 1990s can be explained by a combination of increasing concentrations of atmospheric carbon dioxide, climate variability and changes in land cover. However, the increase during the 2000s is underestimated by all models, which suggests the need for improved consideration of changes in drivers such as nitrogen deposition, diffuse light and land-use change. Overall, our findings underscore the importance of Northern Hemispheric land as a carbon sink.Civan, F., 2019. Can gas permeability of fractured shale be determined accurately by testing core plugs, drill cuttings, and crushed samples? SPE Journal 24, 720-732. the nanodarcy gas permeability and other parameters of naturally and hydraulically induced fractured shale formations by testing the pressure transmission of core plugs, drill cuttings, and crushed samples is discussed. The author reviewed and modified the available methods for interpreting pressure tests with an emphasis on the differences between intrinsic and apparent permeability, and the generally overlooked temperature effects. It is significant to note that the temperature of gas varies during transport through porous rock samples and various dead-volumes when testing equipment used for permeability measurement is involved; this is because of unavoidable viscous dissipation and Joule-Thomson effects. Improved formulations and analysis methods that honor the relevant physics of gas transport and interactions with shale are presented, for both the generally assumed isothermal conditions and the realistic case of nonisothermal conditions. These improved formulations provide valuable insights when comparing and evaluating the currently available equations used for permeability calculations with the experimental data obtained by various testing methods. Better design and analysis of experiments for simultaneously determining several unknown parameters that impact the transport calculations, including deformation, adsorption, diffusion, viscous dissipation, Joule-Thomson effect, and deviation from Darcy flow, are described. It is recommended that the permeability and other parameters of shale samples be determined by simultaneous analysis of multiple pressure tests conducted under different conditions to accommodate temporally and spatially variable conditions by consideration of the temperature effect. The inherent limitations of the methods that rely on analytical solutions of the diffusivity equation on the basis of Darcy’s law are also explained.Close, R.A., Benson, R.B.J., Alroy, J., Behrensmeyer, A.K., Benito, J., Carrano, M.T., Cleary, T.J., Dunne, E.M., Mannion, P.D., Uhen, M.D., Butler, R.J., 2019. Diversity dynamics of Phanerozoic terrestrial tetrapods at the local-community scale. Nature Ecology & Evolution 3, 590-597. fossil record provides one of the strongest tests of the hypothesis that diversity within local communities is constrained over geological timescales. Constraints to diversity are particularly controversial in modern terrestrial ecosystems, yet long-term patterns are poorly understood. Here we document patterns of local richness in Phanerozoic terrestrial tetrapods using a global data set comprising 145,332 taxon occurrences from 27,531 collections. We show that the local richness of non-flying terrestrial tetrapods has risen asymptotically since their initial colonization of land, increasing at most threefold over the last 300 million years. Statistical comparisons support phase-shift models, with most increases in local richness occurring: (1) during the colonization of land by vertebrates, concluding by the late Carboniferous; and (2) across the Cretaceous/Paleogene boundary. Individual groups, such as mammals, lepidosaurs and dinosaurs also experienced early increases followed by periods of stasis often lasting tens of millions of years. Mammal local richness abruptly tripled across the Cretaceous/Paleogene boundary, but did not increase over the next 66 million years. These patterns are consistent with the hypothesis that diversity is constrained at the local-community scale.Cockell, C.S., Holt, J., Campbell, J., Groseman, H., Josset, J.-L., Bontognali, T.R.R., Phelps, A., Hakobyan, L., Kuretn, L., Beattie, A., Blank, J., Bonaccorsi, R., McKay, C., Shirvastava, A., Stoker, C., Willson, D., McLaughlin, S., Payler, S., Stevens, A., Wadsworth, J., Bessone, L., Maurer, M., Sauro, F., Martin-Torres, J., Zorzano, M.-P., Bhardwaj, A., Soria-Salinas, A., Mathanlal, T., Nazarious, M.I., Ramachandran, A.V., Vaishampayan, P., Guan, L., Perl, S.M., Telling, J., Boothroyd, I.M., Tyson, O., Realff, J., Rowbottom, J., Lauernt, B., Gunn, M., Shah, S., Singh, S., Paling, S., Edwards, T., Yeoman, L., Meehan, E., Toth, C., Scovell, P., Suckling, B., 2019. Subsurface scientific exploration of extraterrestrial environments (MINAR 5): analogue science, technology and education in the Boulby Mine, UK. International Journal of Astrobiology 18, 157-182. deep subsurface of other planetary bodies is of special interest for robotic and human exploration. The subsurface provides access to planetary interior processes, thus yielding insights into planetary formation and evolution. On Mars, the subsurface might harbour the most habitable conditions. In the context of human exploration, the subsurface can provide refugia for habitation from extreme surface conditions. We describe the fifth Mine Analogue Research (MINAR 5) programme at 1 km depth in the Boulby Mine, UK in collaboration with Spaceward Bound NASA and the Kalam Centre, India, to test instruments and methods for the robotic and human exploration of deep environments on the Moon and Mars. The geological context in Permian evaporites provides an analogue to evaporitic materials on other planetary bodies such as Mars. A wide range of sample acquisition instruments (NASA drills, Small Planetary Impulse Tool (SPLIT) robotic hammer, universal sampling bags), analytical instruments (Raman spectroscopy, Close-Up Imager, Minion DNA sequencing technology, methane stable isotope analysis, biomolecule and metabolic life detection instruments) and environmental monitoring equipment (passive air particle sampler, particle detectors and environmental monitoring equipment) was deployed in an integrated campaign. Investigations included studying the geochemical signatures of chloride and sulphate evaporitic minerals, testing methods for life detection and planetary protection around human-tended operations, and investigations on the radiation environment of the deep subsurface. The MINAR analogue activity occurs in an active mine, showing how the development of space exploration technology can be used to contribute to addressing immediate Earth-based challenges. During the campaign, in collaboration with European Space Agency (ESA), MINAR was used for astronaut familiarization with future exploration tools and techniques. The campaign was used to develop primary and secondary school and primary to secondary transition curriculum materials on-site during the campaign which was focused on a classroom extra vehicular activity simulation.Colcord, D.E., Shilling, A.M., Freeman, K.H., Njau, J.K., Stanistreet, I.G., Stollhofen, H., Schick, K.D., Toth, N., Brassell, S.C., 2019. Aquatic biomarkers record Pleistocene environmental changes at Paleolake Olduvai, Tanzania. Palaeogeography, Palaeoclimatology, Palaeoecology 524, 250-261. hypotheses invoke climatic variability as a driving force for hominin evolution. Thus, high-resolution records of climate and environmental variability from anthropologically significant locations can help test these hypotheses. Sedimentary sequences recovered by the Olduvai Gorge Coring Project (OGCP) help evaluate climatic and environmental changes at Olduvai Gorge, Tanzania through the analyses of various biogeochemical proxies. The stratigraphic sequence of OGCP Core 2A can be correlated with horizons associated with hominins and is chronologically constrained by distinctive dated horizons, such as the Bed I Basalt and Tuff IB. The lacustrine interval from 76.6 to 86.9?m depth is ideally suited for high-resolution analyses of biogeochemical proxies as it is rich in organic carbon (>1%TOC). The hydrogen isotopic composition of nC31 in this interval of OGCP Core 2A records the effects of precession-driven wet-dry cycles on the terrestrial environment that led to alternations between woodland and grassland ecosystems, comparable to those documented by previous investigations of outcrop analogues at Olduvai. Here, we examine stratigraphic variations in the abundance of biomarkers (C28 steradienes, C17 and C23 n-alkanes, C27 and C28 A-norsteranes, fern-8-ene, and chromans) derived from aquatic organisms (algae, cyanobacteria, sponges, macrophytes, etc.) to determine the response of Paleolake Olduvai to climate variability. In general, these aquatic biomarkers reflect the productivity of the lake environment and exhibit the same precession-driven wet-dry cycles recorded by terrestrial biogeochemical signatures. However, they also provide evidence of abrupt (<~300?yr) changes in lake level and corresponding aquatic communities superimposed on the longer-term Milankovitch cycles. Thus, evidence for climatic variability is manifested through the pacing and intensity of changes in both terrestrial and aquatic ecosystems, but the different rates of the responses on land and in the aquatic environment potentially had a complex influence on water and food resources that were important factors for hominin habitation and evolution.Collins, T., Margesin, R., 2019. Psychrophilic lifestyles: mechanisms of adaptation and biotechnological tools. Applied Microbiology and Biotechnology 103, 2857-2871. microorganisms inhabiting permanently low-temperature environments were initially just a biological curiosity but have emerged as rich sources of numerous valuable tools for application in a broad spectrum of innovative technologies. To overcome the multiple challenges inherent to life in their cold habitats, these microorganisms have developed a diverse array of highly sophisticated synergistic adaptations at all levels within their cells: from cell envelope and enzyme adaptation, to cryoprotectant and chaperone production, and novel metabolic capabilities. Basic research has provided valuable insights into how these microorganisms can thrive in their challenging habitat conditions and into the mechanisms of action of the various adaptive features employed, and such insights have served as a foundation for the knowledge-based development of numerous novel biotechnological tools. In this review, we describe the current knowledge of the adaptation strategies of cold-adapted microorganisms and the biotechnological perspectives and commercial tools emerging from this knowledge. Adaptive features and, where possible, applications, in relation to membrane fatty acids, membrane pigments, the cell wall peptidoglycan layer, the lipopolysaccharide component of the outer cell membrane, compatible solutes, antifreeze and ice-nucleating proteins, extracellular polymeric substances, biosurfactants, chaperones, storage materials such as polyhydroxyalkanoates and cyanophycins and metabolic adjustments are presented and modo, M., Kaiser, K., De Falco, G., Minutolo, P., Schulz, F., D'Anna, A., Gross, L., 2019. On the early stages of soot formation: Molecular structure elucidation by high-resolution atomic force microscopy. Combustion and Flame 205, 154-164. early stages of soot formation, namely inception and growth, are highly debated and central to many ongoing studies in combustion research. Here, we provide new insights into these processes from studying different soot samples by atomic force microscopy (AFM). Soot has been extracted from a slightly sooting, premixed ethylene/air flame both at the onset of the nucleation process, where the particle size is of the order of 2–4?nm, and at the initial stage of particle growth, where slightly larger particles are present. Subsequently, the molecular constituents from both stages of soot formation were investigated using high-resolution AFM with CO-functionalized tips. In addition, we studied a model compound to confirm the atomic contrast and AFM-based unambiguous identification of aliphatic pentagonal rings, which were frequently observed on the periphery of the aromatic soot molecules. We show that the removal of hydrogen from such moieties could be a pathway to resonantly stabilized π-radicals, which were detected in both investigated stages of the soot formation process. Such π-radicals could be highly important in particle nucleation, as they provide a rational explanation for the binding forces among aromatic molecules.Cordier, T., Frontalini, F., Cermakova, K., Apothéloz-Perret-Gentil, L., Treglia, M., Scantamburlo, E., Bonamin, V., Pawlowski, J., 2019. Multi-marker eDNA metabarcoding survey to assess the environmental impact of three offshore gas platforms in the North Adriatic Sea (Italy). Marine Environmental Research 146, 24-34. environmental DNA (eDNA) metabarcoding represents a new promising tool for biomonitoring and environmental impact assessment. One of the main advantages of eDNA metabarcoding, compared to the traditional morphotaxonomy-based methods, is to provide a more holistic biodiversity information that includes inconspicuous morphologically non-identifiable taxa. Here, we use eDNA metabarcoding to survey marine biodiversity in the vicinity of the three offshore gas platforms in North Adriatic Sea (Italy). We isolated eDNA from 576 water and sediment samples collected at 32 sampling sites situated along four axes at increasing distances from the gas platforms. We obtained about 46 million eDNA sequences for 5 markers from nuclear 18S V1V2, 18S V4, 18S 37F and mitochondrial 16S and COI genes that cover a wide diversity of benthic and planktonic eukaryotes. Our results showed some impact of platform activities on benthic and pelagic communities at very close distance (<50?m), while communities for intermediate (125?m, 250?m, 500?m) and reference (1000?m, 2000?m) sites did not show any particular biodiversity changes that could be related to platforms activities. The most significant community change along the distance gradient was obtained with the 18S V1V2 marker targeting benthic eukaryotes, even though other markers showed similar trends, but to a lesser extent. These results were congruent with the AMBI index inferred from the eDNA sequences assigned to benthic macrofauna. We finally explored the relation between various physicochemical parameters, including hydrocarbons, on benthic community in the case of one of the platforms. Our results showed that these communities were not significantly impacted by most of hydrocarbons, but rather by macro-elements and sediment texture.Cordier, T., Lanzén, A., Apothéloz-Perret-Gentil, L., Stoeck, T., Pawlowski, J., 2019. Embracing environmental genomics and machine learning for routine biomonitoring. Trends in Microbiology 27, 387-397. is fast becoming a routine tool in medical diagnostics and cutting-edge biotechnologies. Yet, its use for environmental biomonitoring is still considered a futuristic ideal. Until now, environmental genomics was mainly used as a replacement of the burdensome morphological identification, to screen known morphologically distinguishable bioindicator taxa. While prokaryotic and eukaryotic microbial diversity is of key importance in ecosystem functioning, its implementation in biomonitoring programs is still largely unappreciated, mainly because of difficulties in identifying microbes and limited knowledge of their ecological functions. Here, we argue that the combination of massive environmental genomics microbial data with machine learning algorithms can be extremely powerful for biomonitoring programs and pave the way to fill important gaps in our understanding of microbial ecology.Cramwinckel, M.J., Woelders, L., Huurdeman, E.P., Peterse, F., Gallagher, S.J., Pross, J., Burgess, C., Reichart, G.-J., Sluijs, A., Bijl, P.K., 2019. Surface-circulation change in the Southern Ocean across the Middle Eocene Climatic Optimum: inferences from dinoflagellate cysts and biomarker paleothermometry. Climate of the Past Discussions 2019, 1-34. climate cooled from the early Eocene hothouse (~?52–50?Ma) to the latest Eocene (~?34?Ma). At the same time, the tectonic evolution of the Southern Ocean was characterized by the opening and deepening of circum-Antarctic gateways, which affected both surface- and deep-ocean circulation. The Tasman Gateway played a key role in regulating ocean throughflow between Australia and Antarctica. Southern Ocean surface currents through and around the Tasman Gateway have left recognizable tracers in the spatiotemporal distribution of plankton fossils, including organic-walled dinoflagellate cysts. This spatiotemporal distribution depends on physico-chemical properties of the water masses in which these organisms thrived. The degree to which the geographic path of surface currents (primarily controlled by tectonism) or their physico-chemical properties (significantly impacted by climate) have controlled the composition of the fossil assemblages has, however, remained unclear. In fact, it is yet poorly understood to what extent oceanographic response as a whole was dictated by climate change, independent of tectonics-induced oceanographic changes that operate on longer time scales. To disentangle the effects of tectonism and climate in the southwest Pacific Ocean, we target a climatic deviation from the long-term Eocene cooling trend, a 500 thousand year long global warming phase termed the Middle Eocene Climatic Optimum (MECO; ~?40?Ma). The MECO warming is unrelated to regional tectonism, and thus provides a test case to investigate the oceans physiochemical response to climate change only. We reconstruct changes in surface-water circulation and temperature in and around the Tasman Gateway during the MECO through new palynological and organic geochemical records from the central Tasman Gateway (Ocean Drilling Program Site 1170), the Otway Basin (southeastern Australia) and the Hampden Section (New Zealand). Our results confirm that dinocyst communities track tectonically driven circulation patterns, yet the variability within these communities can be driven by superimposed temperature change. Together with published results from the east of the Tasman Gateway, our results suggest that as surface-ocean temperatures rose, the East Australian Current extended further southward during the peak of MECO warmth. Simultaneous with high sea-surface temperatures in the Tasman Gateway area, pollen assemblages indicate warm temperate rainforests with paratropical elements along the southeastern margin of Australia. Finally, based on new age constraints we suggest that a regional southeast Australian transgression might have been caused by sea-level rise during MECO.Crann, C.A., Grant, T., 2019. Radiocarbon age of consolidants and adhesives used in archaeological conservation. Journal of Archaeological Science: Reports 24, 1059-1063. and adhesives used to conserve archaeological artifacts must be carefully removed prior to radiocarbon dating of the artifact, otherwise the radiocarbon signature will be compromised. It is therefore paramount to understand how the artifact was conserved and which conservation products were used in order to determine: (1) the best location on the artifact to sample; (2) how to remove the consolidant physically and/or chemically; and subsequently (3) whether or not the consolidant was successfully removed. The first two considerations are a matter of communication between the archaeologist, the conservator, and the radiocarbon laboratory, but the third consideration can be a bit tricky to determine. The archaeologist usually knows the approximate time period of the artifact given the context in which it was found so when the age is not as expected, it is possible the consolidant was not completely removed. However, it can be purely speculation unless the radiocarbon signature of the consolidant (old or young) is known. Here we present results from the radiocarbon and stable isotope analyses of 21 consolidants and adhesives commonly used for archaeological conservation. The consolidants and adhesives cover both natural (animal and fish glues, tree resins, starches) and synthetic materials (acrylics, poly(vinyl acetate), poly(vinyl butyral), polyethylene glycol, glycerol, cellulose ethers, cellulose esters, cyanoacrylates and soluble nylon) and are selected from those commonly in use now, as well as a few that were used historically but are now avoided due to poor aging qualities. This paper will present data that may indicate in which direction – young or old – conservation treatments may skew radiocarbon dates, the importance of knowing the conservation history of older samples and how these results should be interpreted. Stable isotope signatures of the consolidants and glues are also provided as the analysis is inexpensive and complimentary to the radiocarbon analysis and could be used to corroborate suspicions of contamination gleaned from offset radiocarbon ages of archaeological samples. Finally, we present the case study that motivated this project: the analysis of carbonized residuals vacuum impregnated with PVA glue.Criscuolo, A., Zeller, M., Cook, K., Angelidou, G., Fedorova, M., 2019. Rational selection of reverse phase columns for high throughput LC-MS lipidomics. Chemistry and Physics of Lipids 221, 120-127. lipidomes are characterized by extremely high complexity and dynamic range of lipid concentrations. Furthermore, high diversity of lipid physicochemical properties requires high resolving powers for both chromatographic and mass spectrometric analytical platforms. Reverse-phase chromatography coupled with data-dependent MS/MS acquisition is one of the most popular techniques in untargeted lipidomics. Optimal method should provide good chromatographic separation and resolution, reproducibility, selectivity and sensitivity. Here, we developed and set-up a RPLC-MS/MS workflow capable of resolving complex mixtures of lipids in 32?minutes of analysis. Human blood plasma was chosen as a representative complex natural lipidome with large variance of lipid classes, species and lipid concentrations. Lipids were separated by RPLC on five different reverse phase columns with different types of stationary phase particles, size and chemistry. High mass accuracy MS analysis and data-dependent MS/MS analysis were performed using a Q Exactive? HF Hybrid Quadrupole-Orbitrap? Mass Spectrometer to identify individual lipid molecular species. This workflow was applied to evaluate the separation capability of each column and to identify the lipidomics profile in highly complex biological samples. As a result, we report more than 600 lipid species covering 18 lipid classes in human blood plasma and provide suggestions to the selection of the appropriate reverse phase column for the analysis of specific lipidomes.Crockford, P.W., Kunzmann, M., Bekker, A., Hayles, J., Bao, H., Halverson, G.P., Peng, Y., Bui, T.H., Cox, G.M., Gibson, T.M., W?rndle, S., Rainbird, R., Lepland, A., Swanson-Hysell, N.L., Master, S., Sreenivas, B., Kuznetsov, A., Krupenik, V., Wing, B.A., 2019. Claypool continued: Extending the isotopic record of sedimentary sulfate. Chemical Geology 513, 200-225. Proterozoic Eon spans Earth's middle age during which many important transitions occurred. These transitions include the oxygenation of the atmosphere, emergence of eukaryotic organisms and growth of continents. Since the sulfur and oxygen cycles are intricately linked to most surface biogeochemical processes, these transitions should be recorded in changes to the isotopic composition of marine and terrestrial sulfate minerals. Here we present oxygen (?17O, δ18O) and sulfur (?33S, δ34S) isotope records of Proterozoic sulfate from currently available data together with new measurements of 313 samples from 33 different formations bearing Earth's earliest unambiguous evaporites at 2.4?Ga through to Ediacaran aged deposits. This record depicts distinct intervals with respect to the expression of sulfate isotopes that are not completely captured by established intervals in the geologic timescale. The most salient pattern is the muted ?17O signatures across the GOE, late Proterozoic and Ediacaran with values that are only slightly more negative than modern marine sulfate, contrasting with highly negative values across the mid-Proterozoic and Cryogenian. We combine these results with estimates of atmospheric composition to produce a gross primary production (GPP) curve for the Proterozoic. Through these results we argue that changes in GPP across Earth history likely help account for many of the changes in the Proterozoic Earth surface environment such as rising atmospheric oxygen, large fluctuations in the size of the marine sulfate reservoir and variations in the isotopic composition of sedimentary sulfate.Cui, J.-W., Zhu, R.-K., Luo, Z., Li, S., 2019. Sedimentary and geochemical characteristics of the Triassic Chang 7 Member shale in the southeastern Ordos Basin, Central China. Petroleum Science 16, 285-297. Ordos Basin is the largest petroliferous basin in China, where the Chang 7 Member shale serves as the major source rock in the basin, with an area of more than 100,000?km2. So far, sedimentary and geochemical characterizations have rarely been conducted on the shale in shallow (<?1000?m) areas in the southeastern part of the basin, but such characterizations can help identify the genesis of organic-rich shale and promote the prediction and recovery of shale oil. In this paper, several outcrop sections of the Chang 7 Member in the Tongchuan area were observed and sampled, and sedimentary and geochemical characterizations were conducted for the well-outcropped YSC section. The study results show that the Chang 7 Member shale is widely distributed laterally with variable thickness. The organic-rich shale is 7–25?m thick in total and exhibits obvious horizontal variation in mineral composition. In the eastern sections, the shale contains organic matter of Type II2–III and is low in thermal maturity, with high clay mineral content, low K-feldspar content, and no pyrite. In the western sections, the shale contains Type II1 organic matter and is low in thermal maturity, with high clay mineral, K-feldspar, and pyrite contents. The YSC section reveals three obvious intervals in vertical mineral composition and organic abundance. The Chang 7 Member organic-rich shale (TOC?>?10%) contains mainly sapropelite and liptinite, with Type II kerogen. It is generally characterized by a hydrocarbon potential of more than 70?mg/g, low maturity, and shallow–semideep lacustrine facies. In the western sections, the shale, still in a low maturity stage, has a higher hydrocarbon potential and is optional for shale oil recovery. However, the Chang 7 Member shale in the study area is highly heterogeneous and its shale oil recovery is practical only in the organic-rich intervals.Cui, J., 2019. Oil transport in shale nanopores and micro-fractures: Modeling and analysis. Journal of Petroleum Science and Engineering 178, 640-648. mathematical modeling and analysis for the apparent permeability of shale oil with complicated compositions in dual-wettability shales (superior to existing single-component or single-wettability analysis), which is the core of this work, will help understand the detailed contributions of the considered mechanisms. Based on a previously established flow enhancement model, the effects of the mixed wettability and those triggered by asphaltenes, namely, the wettability alteration, the pore radius reduction, and the viscosity increment, are taken into account by respective corrections of the variables in the model. The effect of the mixed wettability is quantified by the water-wet area ratio, while the surface coverage, the adsorption thickness, and the volume fraction in the free phase are utilized to quantify the effects of asphaltenes. The volume fraction of asphaltenes in the free phase is related to that in both phases by the volume conservation equation. The full mathematical model and its several simplifications are achieved. Comprehensive sensitivity analysis and comparisons are carried out to demonstrate the effects of each variable (i.e., the pore radius, the initial water-wet surface ratio, the relative adsorption thickness, and the surface coverage) on: (1) the flow enhancement; (2) the relative importance of all mechanisms; (3) the differences among organic pores/inorganic pores/micro-fractures; and (4) the overall contribution of asphaltenes. The effect of different adsorption patterns (characterized by the relative adsorption thickness and the surface coverage) is also discussed.Cui, J., Li, S., Mao, Z., 2019. Oil-bearing heterogeneity and threshold of tight sandstone reservoirs: A case study on Triassic Chang7 member, Ordos Basin. Marine and Petroleum Geology 104, 180-189. Ordos Basin is the foremost tight-oil reservoir in China with respect to location and production, where tight-oil reservoirs are characterized by low porosity, low permeability, low pressure, and high heterogeneity. Until now, the cause of the oil-bearing heterogeneity of such reservoirs has not been reported. In this study, the cause of the oil-bearing heterogeneity and threshold of tight sandstone reservoirs in the seventh member of the Triassic Yanchang Formation (Chang7 Member), Ordos Basin, were investigated by core and thin-section observations using a fluorescence microscope, cathodoluminescence microscope, isotope ratio mass spectrometer, and thermal stage, among other devices. The results revealed that calcitic cementation is the major genetic mechanism for the oil-bearing heterogeneity of tight sandstone reservoirs in the study area, and that it is mainly in Phase 1. The clumped isotope revealed that the calcitic cements in Phase I were formed at 18–42?°C during the Middle–Late Triassic to Middle Jurassic periods; thus, they are the diagenetic products, and may be related to the early small-scale tectonic movements in the basin. The synchronous brine inclusions associated with the hydrocarbon inclusions correspond to a homogenization temperature of 90–120?°C. In conjunction with the basin simulation, this suggests that the hydrocarbons were charged in one phase in the Early Cretaceous period (100–130?Ma). Moreover, the modified cements in the Chang7 oil-free tight sandstone were formed earlier than the period in which the oil was charged in the oil-bearing sandstone. The tight sandstone reservoirs mainly contain nanoscale throats (diameter?<?1?μm). With respect to the residual oil saturation, average size of mesopores, and the correlation between the oil saturation and porosity, it was concluded that tight oil may be present above the threshold characterized by a 15?mm mesopore average size and 2% porosity. It is first specified that the formation of oil-free calcitic-cemented sandstone is the diagenetic response of the early tectonic movement, which provides a basis for the determination of the influence of calcitic-cemented sandstone on hydrocarbon accumulation. Moreover, the results of the study on the oil-bearing threshold can be helpful in selection of the exploration zone and the resource estimation of unconventional tight-oil reservoirs.Cui, Y.Y., Henze, D.K., Brioude, J., Angevine, W.M., Liu, Z., Bousserez, N., Guerrette, J., McKeen, S.A., Peischl, J., Yuan, B., Ryerson, T., Frost, G., Trainer, M., 2019. Inversion estimates of lognormally distributed methane emission rates from the Haynesville-Bossier oil and gas production region using airborne measurements. Journal of Geophysical Research: Atmospheres 124, 3520-3531.: Quantifying methane (CH4) emissions from the oil and natural gas (O/NG) production sector is an important regulatory challenge in the United States. In this study, we conduct a set of inversion calculations using different methods to quantify lognormal distributed CH4 surface fluxes in the Haynesville‐Bossier O/NG production basin in Texas and Louisiana, combining three statistical cost functions, four meteorological configurations, and two days of aircraft measurements from a 2013 field campaign. We aggregate our posterior flux estimates to derive our best estimate of the basin‐wide CH4 emissions, 76 metric tons/hr, with a 95% highest density interval of 51–104 metric tons/hr, in agreement with previous estimates using mass balance and eddy covariance approaches with the same aircraft measurements. Our inversion estimate of basin‐wide CH4 emissions is 133% (89%–182%, 95% highest density interval) of a gridded Environmental Protection Agency's inventory for 2012, and the largest discrepancies between our study and this inventory are located in the northeastern quadrant of the basin containing active unconventional O/NG wells. Our inversion approach provides a new spatiotemporal characterization of CH4 emissions in this O/NG production region and shows the usefulness of inverse modeling for improving O/NG CH4 emission estimates.Plain Language Summary: Oil and natural gas (O/NG)‐related methane (CH4) emission estimates have drawn great concern because activity in this industry has increased dramatically over the past decade. However, estimating CH4 emissions from O/NG production regions is very challenging because the emission rates are highly heterogeneous. To properly characterize the CH4 emissions in the Haynesville oil and gas production region, we develop an inverse modeling system to handle different ways of characterizing the highly skewed (i.e., lognormally distributed) CH4 sources in Haynesville. The inverse model calculations are driven by high‐frequency, high‐precision CH4 mixing ratios measured on a National Oceanic and Atmospheric Administration aircraft during a field study in the summer of 2013. We use a variety of meteorological simulations to define the transport errors in our inversions, and we take advantage of a resampling method to characterize the posterior uncertainties. Our results suggest that Haynesville's CH4 emissions are likely underestimated in the U.S. Environmental Protection Agency's national CH4 inventory and particularly in the subdomain where many active unconventional wells are located; day‐to‐day variability in Haynesville's overall CH4 emissions likely exists. Our work offers an extensive characterization of inversions' uncertainties and demonstrate the feasibility of improving CH4 emission estimates from O/NG production regions using high quality aircraft observations.Cumming, E.A., Rietze, A., Morrissey, L.S., Cook, M.C., Rhim, J.H., Ono, S., Morrill, P.L., 2019. Potential sources of dissolved methane at the Tablelands, Gros Morne National Park, NL, CAN: A terrestrial site of serpentinization. Chemical Geology 514, 42-53. Tablelands massif in Western Newfoundland is part of a Phanerozoic ophiolite sequence and is a terrestrial site of serpentinization. Similar to other Phanerozoic ophiolite sequences, the Tablelands possess environmental conditions that are conducive to all three established pathways of methanogenesis – abiogenic, microbial, and thermogenic – or a combination thereof. Sourcing methane from the Tablelands has thus far been limited because of the low dissolved methane concentrations. We tested dissolved gas extraction and concentration methods (vacuum extraction and gas stripping) for their effect on isotopic fractionation, and we applied these methods to sample dissolved methane for carbon and hydrogen isotopes (δ13CCH4 and δDCH4) as well as doubly substituted “clumped” isotopologue (13CH3D) analyses. Clumped isotope thermometry of methane estimated an apparent temperature of 85?±?7?°C. The carbon isotope value of methane (δ13CCH4) for samples collected in 2017 was ?27.9?±?0.5‰, consistent with previously measured values (?27.3?±?0.5‰) dating back to 2009. The hydrogen isotope value of methane (δDCH4) in 2017 was ?175?±?5‰. On a carbon deuterium (CD) plot, the Tablelands methane data plotted outside of the microbial field, but within an area where abiogenic and thermogenic fields overlap. A conclusive discrimination between abiogenic and thermogenic methanogenic pathways remains challenging. Nevertheless, a combination of sedimentary organic matter characterization of the underlying sedimentary units and comparison of geochemical characteristics with those described in experimental and theoretical studies suggest that the methane extracted from the Tablelands is likely a result of slow production of methane at ~85?°C from background organic sources.Cunningham, A.B., Class, H., Ebigbo, A., Gerlach, R., Phillips, A.J., Hommel, J., 2019. Field-scale modeling of microbially induced calcite precipitation. Computational Geosciences 23, 399-414. biogeochemical process known as microbially induced calcite precipitation (MICP) is being investigated for engineering and material science applications. To model MICP process behavior in porous media, computational simulators must couple flow, transport, and relevant biogeochemical reactions. Changes in media porosity and permeability due to biomass growth and calcite precipitation, as well as their effects on one another must be considered. A comprehensive Darcy-scale model has been developed by Ebigbo et al. (Water Resour. Res. 48(7), W07519, 2012) and Hommel et al. (Water Resour. Res. 51, 3695–3715, 2015) and validated at different scales of observation using laboratory experimental systems at the Center for Biofilm Engineering (CBE), Montana State University (MSU). This investigation clearly demonstrates that a close synergy between laboratory experimentation at different scales and corresponding simulation model development is necessary to advance MICP application to the field scale. Ultimately, model predictions of MICP sealing of a fractured sandstone formation, located 340.8 m below ground surface, were made and compared with corresponding field observations. Modeling MICP at the field scale poses special challenges, including choosing a reasonable model-domain size, initial and boundary conditions, and determining the initial distribution of porosity and permeability. In the presented study, model predictions of deposited calcite volume agree favorably with corresponding field observations of increased injection pressure during the MICP fracture sealing test in the field. Results indicate that the current status of our MICP model now allows its use for further subsurface engineering applications, including well-bore cement sealing and certain fracture-related applications in unconventional oil and gas production.Currie, A., 2019. Mass extinctions as major transitions. Biology & Philosophy 34, Article 29. paleobiology and investigations of ‘major evolutionary transitions’ are intimately concerned with the macroevolutionary shape of life. It is surprising, then, how little studies of major transitions are informed by paleontological perspectives and. I argue that this disconnect is partially justified because paleobiological investigation is typically ‘phenomena-led’, while investigations of major transitions (at least as commonly understood) are ‘theory-led’. The distinction turns on evidential relevance: in the former case, evidence is relevant in virtue of its relationship to some phenomena or hypotheses concerning those phenomena; in the latter, evidence is relevant in virtue of providing insights into, or tests of, an abstract body of theory. Because paleobiological data is by-and-large irrelevant to the theory which underwrites the traditional conception of major transitions, it is of limited use to that research program. I suggest that although the traditional conception of major transitions is neither ad-hoc or problematically incomplete, its promise of providing unificatory explanations of the transitions is unlikely to be kept. Further, examining paleobiological investigations of mass extinctions and organogenesis, I further argue that (1) whether or not transitions in paleobiology count as ‘major’ turns on how we conceive of major transitions (that is, the notion is sensitive to investigative context); (2) although major transitions potentially have a unified theoretical basis, recent developments suggest that investigations are becoming increasingly phenomena-led; (3) adopting phenomena-led investigations maximizes the evidence available to paleobiologists.Curto, A., Mahoney, P., Maurer, A.-F., Barrocas-Dias, C., Fernandes, T., Fahy, G.E., 2019. Diet and disease in Tomar, Portugal: Comparing stable carbon and nitrogen isotope ratios between skeletons with and without signs of infectious disease. Journal of Archaeological Science 105, 59-69.: This study explored the correspondence between stable isotope ratios and indicators of non-specific (periostitis and/or osteomyelitis) and specific (venereal syphilis) disease in a sample of human skeletons from a Portuguese archaeological collection. Additionally, this study examined stable carbon (δ13C) and nitrogen (δ15N) isotope ratios between individuals at different disease stages.Materials and methods: δ13C and δ15N data from previously analysed skeletons without signs of infectious disease or physiological stress (n?=?32) were compared to new data from skeletons with active (n?=?6), healed (n?=?7) or a combination of both lesions (n?=?10). Skeletons with lesions (n?=?23) were also grouped as having only healed tibial periostitis (n?=?7), generalised non-specific (n?=?5) and generalised specific infections (n?=?2). The skeletons with lesions that did not fit into these groups (n?=?9) were not used in this analysis.Results: The δ15N from skeletons with non-specific generalised infections in several bones differed significantly when compared to skeletons that had either only healed tibial periostitis or were without lesions. Skeletons with venereal syphilis had similar mean δ13C and δ15N to either skeletons without signs of disease or those with only healed tibial periostitis.Discussion: These results suggest different diets may be linked into an individual's susceptibility to these pathogens. Diet influences resistance to infectious disease, while infections decrease nutrient availability, increase malabsorption and resting energy expenditure. Potentially therefore, combining isotopic evidence of diet with pathology may contribute to a new understanding of health and lifestyle in the past.Da, W., Shao, J., Li, Q., Shi, G., Wang, T., Wu, D., Wang, C., 2019. Extraction of extracellular matrix in static and dynamic Candida biofilms using cation exchange resin and untargeted analysis of matrix metabolites by ultra-high-performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). Frontiers in Microbiology 10, 752. doi: 710.3389/fmicb.2019.00752. infections caused by Candida albicans is posing a great threat to human health. The ability of biofilm formation is believed to be associated with resistance-related Candida infections. Currently, the knowledge on extracellular matrix (EM) of C. albicans biofilm is limited. In this study, we introduced ion exchange resin, i.e. cation exchange resin (CER) and anion exchange resin (AER), in EM extraction of C. albicans biofilm as well as several non-albicans Candida (NAC) biofilms under static and dynamic states in combination with vortexing and ultrasonication (VU). The metabolites extracted from the dynamic C. albicans biofilm matrix using the CER-VU and VU were identified with ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) via untargeted filtration. Compared with other physical and chemical extraction methods used, the CER-VU was demonstrated to be an ideal approach with the high-yield acquisitions of the EM constituents including proteins, triglycerides and carbohydrates and low-level damages on the fungal cell viability and integrity. The untargeted MS analysis further showed the high efficacy of CER-VU, as a large quantity of metabolites (217 versus 198) was matched comprising a great number of lipids, carbohydrates, amino acids, nucleic acids and their derivatives together with a high involvement of signaling pathways compared with the VU alone. However, combining the results from both the CER-VU and VU methods could generate more metabolites. In summary, the EM analysis of the dynamic C. albicans biofilm expands our understanding upon a comprehensive depiction of matrix components and provides another effective approach for EM extraction.Danise, S., Clémence, M.-E., Price, G.D., Murphy, D.P., Gómez, J.J., Twitchett, R.J., 2019. Stratigraphic and environmental control on marine benthic community change through the early Toarcian extinction event (Iberian Range, Spain). Palaeogeography, Palaeoclimatology, Palaeoecology 524, 183-200. the Early Jurassic (~183?Ma ago) global warming and associated environmental changes coincided with an extinction event in the marine realm (early Toarcian extinction event). Anoxia was previously considered to have been the main cause of extinction, but extinctions also occur at localities that remained oxygenated throughout the event, suggesting that other factors, such as temperature, may have played a major role. To test this hypothesis, we integrated quantitative analyses of benthic macro-invertebrates with high-resolution geochemical proxies on the bulk rock (TOC, δ13C, δ18O) and on belemnites and brachiopod shells (δ13C, δ18O) from two sections from the Iberian Range, Spain, with no black shale deposition. The sections are orientated SE-NW along an onshore-offshore gradient deepening to the north. The dominant benthic groups, bivalves and brachiopods, show a different response to the extinction: brachiopods go through a complete species-level turnover, while many bivalve species range through the event. In the shallower section, changes in richness and evenness correlate with TOC (Total Organic Carbon), suggesting that variations in nutrient input from runoff, and the possible local onset of low-redox conditions (TOC?>?4?wt%), controlled faunal diversity. In contrast, at the deeper section, community change correlates with changes in δ18O, indicating that temperature variations might have influenced faunal change. Different stratigraphic patterns of extinction occur between the two localities, with last-occurrences clustering at the maximum flooding surface in the shallower section, and at the transgressive surface in the deeper one. The observed differences between the two localities highlight the important role of local sedimentary and stratigraphic processes in controlling the shape of the geochemical and fossil record, and the need for studying multiple sections along onshore-offshore gradients in order to extrapolate regional and global patterns.Das, S., Adeoye, J., Dhiman, I., Bilheux, H.Z., Ellis, B.R., 2019. Imbibition of mixed-charge surfactant fluids in shale fractures. Energy & Fuels 33, 2839-2847. fracturing of shale reservoirs often requires millions of gallons of water, but only a fraction of the injected water returns to the surface. Shale gas production has been demonstrated to be positively correlated with the amount of water imbibed by the shale. In this study, neutron radiography is used to evaluate the effect of two commonly used surfactants in hydraulic fracturing fluids on the rate of capillary water uptake in shale fractures. Cationic n-octadecyl trimethylammonium chloride (OTAC) and anionic ammonium dodecyl sulfate (ADS) were added to deionized water at a 1:1 molar ratio at different concentrations and imbibed into a 200 μm Marcellus shale saw-cut fracture. The correlations between the surfactant concentration and fracture aperture with the capillary pressure and water uptake were examined in detail to understand water imbibition during hydraulic fracturing. The effect of wettability alteration during aging of the reservoir on the water uptake rate was studied by comparing water imbibition rates into shale fractures pre-exposed to the surfactant solutions to those of unexposed shale fractures. A 51% reduction in the rate of water uptake into the unexposed shale fracture was observed when the 1:1 mixed ADS/OTAC surfactant concentration was increased from 0.1 to 0.9 mM. This decrease in imbibition rate is attributed to changes in interfacial tension and not wettability alteration of the fracture surface. For the pre-exposed sample, surfactants have sufficient time to adsorb to the shale and alter the surface wettability. The rate of water uptake for pre-exposed shale fractures was reduced by 96% compared to that of unexposed shale fractures for 0.1 mM ADS/OTAC mixture. These experimental observations suggest that natural gas production may be improved after a well shut-in period when mixed-charge surfactants are included in hydraulic fracturing fluid formulations and have sufficient time to alter shale wettability toward a more oil-wet state.de Bar, M.W., Ullgren, J.E., Thunnell, R.C., Wakeham, S.G., Brummer, G.-J.A., Stuut, J.-B.W., Sinninghe Damsté, J.S., Schouten, S., 2019. Long-chain diols in settling particles in tropical oceans: insights into sources, seasonality and proxies. Biogeosciences 16, 1705-1727. this study we analyzed sediment trap time series from five tropical sites to assess seasonal variations in concentrations and fluxes of long-chain diols (LCDs) and associated proxies with emphasis on the long-chain diol index (LDI) temperature proxy. For the tropical Atlantic, we observe that generally less than 2?% of LCDs settling from the water column are preserved in the sediment. The Atlantic and Mozambique Channel traps reveal minimal seasonal variations in the LDI, similar to the two other lipid-based temperature proxies TEX86 and UK'37. In addition, annual mean LDI-derived temperatures are in good agreement with the annual mean satellite-derived sea surface temperatures (SSTs). In contrast, the LDI in the Cariaco Basin shows larger seasonal variation, as do the TEX86 and UK'37. Here, the LDI underestimates SST during the warmest months, which is possibly due to summer stratification and the habitat depth of the diol producers deepening to around 20–30?m. Surface sediment LDI temperatures in the Atlantic and Mozambique Channel compare well with the average LDI-derived temperatures from the overlying sediment traps, as well as with decadal annual mean SST. Lastly, we observed large seasonal variations in the diol index, as an indicator of upwelling conditions, at three sites: in the eastern Atlantic, potentially linked to Guinea Dome upwelling; in the Cariaco Basin, likely caused by seasonal upwelling; and in the Mozambique Channel, where diol index variations may be driven by upwelling from favorable winds and/or eddy migration.De, S., Kumar Vikram, V., Sengupta, D., 2019. Application of support vector regression analysis to estimate total organic carbon content of Cambay shale in Cambay basin, India – a case study. Petroleum Science and Technology 37, 1155-1164. objective of the present study is to estimate total organic carbon (TOC) content over the entire thickness of Cambay Shale, in the boreholes of Jambusar–Broach block of Cambay Basin, India. To achieve this objective, support vector regression (SVR), a supervised data mining technique, has been utilized using five basic wireline logs as input variables. Suitable SVR model has been developed by selecting epsilon-SVR algorithm and varying three different kernel functions and parameters like gamma and cost on a sample dataset. The best result is obtained when the radial-basis kernel function with gamma = 1 and cost = 1, are used. Finally, the performance of developed SVR model is compared with the ΔlogR method. The TOC computed by SVR method is found to be more precise than the ΔlogR method, as it has better agreement with the core-TOC. Thus, in the present study area, the SVR method is found to be a powerful tool for estimating TOC of Cambay Shale in a continuous and rapid manner.Deis, D.R., Mendelssohn, I.A., Fleeger, J.W., Bourgoin, S.M., Lin, Q., 2019. Legacy effects of Hurricane Katrina influenced marsh shoreline erosion following the Deepwater Horizon oil spill. Science of The Total Environment 672, 456-467. interactions occur when one perturbation influences the severity and perhaps the baseline state of succeeding disturbances. Natural and anthropogenic disturbances are frequent in dynamic coastal ecosystems and can often be linked. We evaluated potential for disturbance interactions associated with the 2010 Deepwater Horizon (DWH) oil spill, which was preceded by disturbance from Hurricane Katrina in 2005, by quantifying marsh shoreline retreat across both events. Our goal was to determine the degree to which Hurricane Katrina altered baseline rates of erosion prior to the DWH spill. We quantified erosion rate and fetch from aerial images of northern Barataria Bay, Louisiana marsh shorelines classified as reference, moderately-oiled, and heavily-oiled over three pre-spill time periods (1998–2004, prior to Hurricane Katrina; 2004–2005, during Katrina; 2005–2010, post-Katrina but pre-oil spill) and a post-spill period from 2010 to 2013. Prior to Hurricane Katrina, marsh shoreline erosion rates were low (from 0.38 to 1.10?m?yr?1). In contrast during Hurricane Katrina (2004–2005), erosion increased by 661% and 756%, respectively, for shorelines that would subsequently become moderately and heavily-oiled; reference shoreline erosion increased by 59%. These high erosion rates were associated with increased fetch and higher wave action due to loss of protective geomorphic features such as small islands and spits and persisted during the post-Katrina/pre-spill period of 2005–2010 (0.62, 1.38, and 2.07?m?yr?1 for reference, moderately, and heavily-oiled shorelines, respectively). Erosion rates increased modestly after the DWH event (reference?=?1.13?m?yr?1, moderate oiling?=?1.45?m?yr?1; heavy oiling?=?2.77?m?yr?1), but not significantly, compared to the post-Katrina period. Consequently, we could not detect a post-spill increase in marsh shoreline erosion. Rather, we concluded that Hurricane Katrina reset the erosion baseline, thereby connecting the two disturbances, and was the major driver of marsh shoreline erosion at our research sites during the study period.Deng, J., Yang, Y., Liu, Y., Fang, L., Lin, L., Luan, T., 2019. Coupling Paternò-Büchi reaction with surface-coated probe nanoelectrospray ionization mass spectrometry for in vivo and microscale profiling of lipid C═C location isomers in complex biological tissues. Analytical Chemistry 91, 4592-4599. are important structural components of biological systems, and lipid C═C locations play important roles in their biophysical and biochemical properties. Rapid, in vivo, in situ, and microscale lipidomics investigation (including precise identification of lipid C═C locations and isomers) of biological specimen has great potential for clinical diagnosis, biological studies, and biomarker discovery. Here we report a novel lipidomics methodology by coupling Paternò-Büchi (PB) reaction with surface-coated probe nanoelectrospray ionization mass spectrometry (SCP-nanoESI-MS) for in vivo, in situ, and microscale analysis of lipid species and C═C location isomers in complex biological tissues. The proposed SCP-PB-nanoESI-MS method was performed by application of a biocompatible solid-phase microextraction (SPME) probe for in vivo, in situ, and microscale sampling and extraction of lipids from biological tissues, and then some spray solvent containing PB reagent was applied to desorb lipid species enriched on SPME probe within a nanospray tip. Subsequently, ultraviolet irradiation was employed to initiate PB reaction for unsaturated lipids within the nanospray tip. After that, a high voltage was applied on the SPME probe to induce nanoESI for MS analysis under ambient and open-air conditions, and collision-induced dissociation was performed to the PB reaction product ions for determination of lipid C═C locations and isomers. By using our proposed SCP-BP-nanoESI-MS method, microscale investigation of lipid compositions and C═C location isomers for lipid droplet of Perilla seed and human intestinal tissue were successfully achieved, and in vivo analysis of lipid species and C═C locations for zebrafish was accomplished.DePalma, R.A., Smit, J., Burnham, D.A., Kuiper, K., Manning, P.L., Oleinik, A., Larson, P., Maurrasse, F.J., Vellekoop, J., Richards, M.A., Gurche, L., Alvarez, W., 2019. A seismically induced onshore surge deposit at the KPg boundary, North Dakota. Proceedings of the National Academy of Sciences 116, 8190-8199.: The Chicxulub impact played a crucial role in the Cretaceous–Paleogene extinction. However the earliest postimpact effects, critical to fully decode the profound influence on Earth’s biota, are poorly understood due to a lack of high-temporal-resolution contemporaneous deposits. The Tanis site, which preserves a rapidly deposited, ejecta-bearing bed in the Hell Creek Formation, helps to resolve that long-standing deficit. Emplaced immediately (minutes to hours) after impact, Tanis provides a postimpact “snapshot,” including ejecta accretion and faunal mass death, advancing our understanding of the immediate effects of the Chicxulub impact. Moreover, we demonstrate that the depositional event, calculated to have coincided with the arrival of seismic waves from Chicxulub, likely resulted from a seismically coupled local seiche.Abstract: The most immediate effects of the terminal-Cretaceous Chicxulub impact, essential to understanding the global-scale environmental and biotic collapses that mark the Cretaceous–Paleogene extinction, are poorly resolved despite extensive previous work. Here, we help to resolve this by describing a rapidly emplaced, high-energy onshore surge deposit from the terrestrial Hell Creek Formation in Montana. Associated ejecta and a cap of iridium-rich impactite reveal that its emplacement coincided with the Chicxulub event. Acipenseriform fish, densely packed in the deposit, contain ejecta spherules in their gills and were buried by an inland-directed surge that inundated a deeply incised river channel before accretion of the fine-grained impactite. Although this deposit displays all of the physical characteristics of a tsunami runup, the timing (<1 hour postimpact) is instead consistent with the arrival of strong seismic waves from the magnitude Mw ～10 to 11 earthquake generated by the Chicxulub impact, identifying a seismically coupled seiche inundation as the likely cause. Our findings present high-resolution chronology of the immediate aftereffects of the Chicxulub impact event in the Western Interior, and report an impact-triggered onshore mix of marine and terrestrial sedimentation—potentially a significant advancement for eventually resolving both the complex dynamics of debris ejection and the full nature and extent of biotic disruptions that took place in the first moments postimpact.Desmond, D.S., Saltymakova, D., Neusitzer, T.D., Firoozy, N., Isleifson, D., Barber, D.G., Stern, G.A., 2019. Oil behavior in sea ice: Changes in chemical composition and resultant effect on sea ice dielectrics. Marine Pollution Bulletin 142, 216-233. has been increasing urgency to develop methods for detecting oil in sea ice owing to the effects of climate change in the Arctic. A multidisciplinary study of crude oil behavior in a sea ice environment was conducted at the University of Manitoba during the winter of 2016. In the experiment, medium-light crude oil was injected underneath young sea ice in a mesocosm. The physical and thermodynamic properties of the oil-infiltrated sea ice were monitored over a three-week time span, with concomitant analysis of the oil composition using analytical instrumentation. A resonant perturbation technique was used to measure the oil dielectric properties, and the contaminated sea ice dielectric properties were modeled using a mixture model approach. Results showed that the interactions between the oil and sea ice altered their physical and thermodynamic properties. These changes led to an overall decrease in sea ice dielectrics, potentially detectable by remote sensing systems.Détroit, F., Mijares, A.S., Corny, J., Daver, G., Zanolli, C., Dizon, E., Robles, E., Grün, R., Piper, P.J., 2019. A new species of Homo from the Late Pleistocene of the Philippines. Nature 568, 181-186. hominin third metatarsal discovered in 2007 in Callao Cave (Northern Luzon, the Philippines) and dated to 67?thousand years ago provided the earliest direct evidence of a human presence in the Philippines. Analysis of this foot bone suggested that it belonged to the genus Homo, but to which species was unclear. Here we report the discovery of twelve additional hominin elements that represent at least three individuals that were found in the same stratigraphic layer of Callao Cave as the previously discovered metatarsal. These specimens display a combination of primitive and derived morphological features that is different from the combination of features found in other species in the genus Homo (including Homo floresiensis and Homo sapiens) and warrants their attribution to a new species, which we name Homo luzonensis. The presence of another and previously unknown hominin species east of the Wallace Line during the Late Pleistocene epoch underscores the importance of island Southeast Asia in the evolution of the genus Homo.Dick, G.J., 2019. The microbiomes of deep-sea hydrothermal vents: distributed globally, shaped locally. Nature Reviews Microbiology 17, 271-283. discovery of chemosynthetic ecosystems at deep-sea hydrothermal vents in 1977 changed our view of biology. Chemosynthetic bacteria and archaea form the foundation of vent ecosystems by exploiting the chemical disequilibrium between reducing hydrothermal fluids and oxidizing seawater, harnessing this energy to fix inorganic carbon into biomass. Recent research has uncovered fundamental aspects of these microbial communities, including their relationships with underlying geology and hydrothermal geochemistry, interactions with animals via symbiosis and distribution both locally in various habitats within vent fields and globally across hydrothermal systems in diverse settings. Although ‘black smokers’ and symbioses between microorganisms and macrofauna attract much attention owing to their novelty and the insights they provide into life under extreme conditions, habitats such as regions of diffuse flow, subseafloor aquifers and hydrothermal plumes have important roles in the global cycling of elements through hydrothermal systems. Owing to sharp contrasts in physical and chemical conditions between these various habitats and their dynamic, extreme and geographically isolated nature, hydrothermal vents provide a valuable window into the environmental and ecological forces that shape microbial communities and insights into the limits, origins and?evolution of microbial life.Dieudonné, A., Pignol, D., Prévéral, S., 2019. Magnetosomes: biogenic iron nanoparticles produced by environmental bacteria. Applied Microbiology and Biotechnology 103, 3637-3649. scientific community’s interest in magnetotactic bacteria has increased substantially in recent decades. These prokaryotes have the particularity of synthesizing nanomagnets, called magnetosomes. The majority of research is based on several scientific questions. Where do magnetotactic bacteria live, what are their characteristics, and why are they magnetic? What are the molecular phenomena of magnetosome biomineralization and what are the physical characteristics of magnetosomes? In addition to scientific curiosity to better understand these stunning organisms, there are biotechnological opportunities to consider. Magnetotactic bacteria, as well as magnetosomes, are used in medical applications, for example cancer treatment, or in environmental ones, for example bioremediation. In this mini-review, we investigated all the aspects mentioned above and summarized the currently available knowledge.Dineen, A.A., Roopnarine, P.D., Fraiser, M.L., 2019. Ecological continuity and transformation after the Permo-Triassic mass extinction in northeastern Panthalassa. Biology Letters 15, 20180902. Permo-Triassic mass extinction (PTME) is often implicated in the transition from the Paleozoic evolutionary fauna (PEF) to the modern evolutionary fauna (MEF). However, the exact timing and details of this progression are unknown, especially regarding the vacating and filling of functional ecological space after the PTME. Here, we quantify the functional diversity of middle Permian and Early Triassic marine paleocommunities in the western US to determine functional re-organization in the aftermath of the PTME. Results indicate that while the PTME was selective in nature, many new Triassic taxa either re-filled functional roles of extinct Permian taxa or performed the same functional roles as Permian survivors. Despite this functional overlap, Permian survivors and new Triassic taxa differed significantly in their relative abundances within those overlapping functions. This shift in numerical emphasis, driven by an increase in abundance towards more MEF-style traits, may represent a first step in the transition between the PEF and MEF. We therefore suggest that the extreme impact of the PTME had significant and permanent re-organizational effects on the intrinsic structure of marine ecosystems. Early Triassic ecosystems likely bridged the gap between the Paleozoic and modern evolutionary faunas, as newly originated Triassic taxa shared ecospace with Permian survivors, but shifted functional emphasis.Ding, X., Liu, G., Imin, A., Rexit, M., Gao, C., Jiang, H., 2019. Relationship between source rock development and petroleum accumulation in the Erlian Basin, northern China. Geological Journal 54, 1730-1744. The Wuli and Saihan sags in the Erlian Basin, the most petroliferous basin in northern China, were analysed with bulk geochemical analysis, carbon isotopic composition, microthermometry of fluid inclusions, and basin modelling to characterize the organic matter abundance and composition, to construct source rock development models, and to reveal the relationship between source rock development and hydrocarbon accumulation. The samples display wide variations in total organic carbon content and Rock-Eval indices, suggesting heterogeneity of organic matter richness and type. The Wuli Sag has oxic depositional environment, high productivity, and high total organic carbon content; the effective oil source rocks are mainly distributed in the deep sag where the productivity is high; and there is plenty of organic matter left and preserved after degradation. In the Saihan Sag, there is a small amount of organic matter deposited because of low productivity; the effective oil source rocks are mainly distributed in the slope by the deep sag where the reducing degree is the strongest. The source rock development models controlled the geochemical characteristics and distribution of source rocks, which are the keys to hydrocarbon potential and accumulation. The oil of Wuli Sag is mainly distributed in the deep sag, whereas the oil of Saihan Sag is mainly distributed in the slope by deep sag, which is in agreement with the previously effective oil source rocks distribution. In the strong division sags, the region where source rock distributed is beneficial to hydrocarbon accumulation. The conclusions may have important implications for petroleum exploration in other small lacustrine depositional systems.Ding, Y., Bi, R., Sachs, J., Chen, X., Zhang, H., Li, L., Zhao, M., 2019. Lipid biomarker production by marine phytoplankton under different nutrient and temperature regimes. Organic Geochemistry 131, 34-49. ocean’s biological pump strongly influences atmospheric CO2 and regulates Earth’s climate. Determining the contribution of different phytoplankton groups to the biological pump over geological timescales remains an important, yet elusive, goal in biogeochemistry and organic geochemistry. Towards that end, source-specific lipid biomarkers can be used, but this approach requires the quantification of the biomarker-to-carbon ratio in different phytoplankton species, and under differing environmental conditions. We investigated responses of brassicasterol, dinosterol and C37 alkenones to three temperatures (15, 20 and 25?°C) and three N:P supply ratios (10:1, 24:1 and 63:1 mol mol?1) in three diatoms, three dinoflagellates and one coccolithophore, in laboratory experiments. Brassicasterol was produced by one diatom species, three dinoflagellates and the coccolithophore Emiliania huxleyi, while dinosterol and C37 alkenones were produced by dinoflagellates and E. huxleyi, respectively. Overall, carbon-normalized contents of lipid biomarkers varied by about a factor of three over the wide ranges of temperature and N:P supply ratios, in all species. Within the factor of three, brassicasterol was highest under the balanced N:P condition in diatoms, but under N and P deficiency in dinoflagellates. Brassicasterol in E. huxleyi was highest at lower temperatures. Dinosterol in dinoflagellates and C37 alkenones in E. huxleyi varied with temperature and N:P supply ratios, but not systematically. Compared to those in our experiments, smaller ranges are expected of N:P ratios and temperature and hence carbon-normalized biomarker contents at individual locations over time. Thus, our results imply that lipid biomarkers can be used to estimate taxon-specific carbon fluxes through time.do Nascimento-Dias, B.L., 2019. Combination between Ca, P and Y in the Martian Meteorite NWA 6963 could be used as a strategy to indicate liquid water reservoirs on ancient Mars? International Journal of Astrobiology 18, 151-156. we have learned much about the geological characteristics and history of Mars, the gaps in our knowledge certainly exceed what we understand. Martian meteorites, such as Northwest Africa (NWA) 6963, can be excellent materials for understanding the present and past of Mars, as part of the records of the planet's evolution is preserved in these extraterrestrial rocks. Micro X-ray fluorescence provided data, in which it was possible to verify the presence of Ca, P and Y elements, which are call attention because they were detected superimposed in certain regions. The way these elements were detected indicates the formation of minerals composed by the combination of these elements, such as, for example, Calcite (CaCO3), Apatite [Ca5(PO4)3(OH, F, Cl)], Merrilite [Ca9NaMg (PO4)7] and Xenotime (YPO4). These minerals are great indicators of aqueous environments. In general, the formation of these minerals is due to processes involving hydrothermal fluids or sources (>100 °C). Some geological indications suggest that in the past there might have been a large amount of liquid water, which could have accumulated large reservoirs below the Martian surface. Thus, the laboratory study of Martian meteorites and interpretations of minerals present in these samples can contribute in a complementary way to the existing results of telescopic observations and/or missions of space probes as a strategy to indicate reservoirs of liquid water.Dodge, G.J., Patel, A., Jaremko, K.L., McCammon, J.A., Smith, J.L., Burkart, M.D., 2019. Structural and dynamical rationale for fatty acid unsaturation in Escherichia coli. Proceedings of the National Academy of Sciences 116, 6775-6783.: The production of unsaturated fatty acids (UFAs) is essential to all life. Escherichia coli produces UFAs during fatty acid biosynthesis, requiring the action of two dehydratases, FabA and FabZ. While both enzymes can prepare α,β-trans unsaturated fatty acid intermediates via dehydration, only FabA can further isomerize an intermediate to produce a β,γ-cis unsaturated species, the precursor to E. coli UFAs. Through the combined application of chemical biology tools, structural biology, and computer simulations, we have developed a more complete understanding of the divergent activity and substrate selectivities of FabA and FabZ. This work reveals the structure of E. coli FabZ and clarifies the molecular mechanisms responsible for the introduction of cis unsaturation in fatty acids, a long-standing mechanistic uncertainty.Abstract: Fatty acid biosynthesis in α- and γ-proteobacteria requires two functionally distinct dehydratases, FabA and FabZ. Here, mechanistic cross-linking facilitates the structural characterization of a stable hexameric complex of six Escherichia coli FabZ dehydratase subunits with six AcpP acyl carrier proteins. The crystal structure sheds light on the divergent substrate selectivity of FabA and FabZ by revealing distinct architectures of the binding pocket. Molecular dynamics simulations demonstrate differential biasing of substrate orientations and conformations within the active sites of FabA and FabZ such that FabZ is preorganized to catalyze only dehydration, while FabA is primed for both dehydration and isomerization.Dong, T., Harris, N.B., McMillan, J.M., Twemlow, C.E., Nassichuk, B.R., Bish, D.L., 2019. A model for porosity evolution in shale reservoirs: An example from the Upper Devonian Duvernay Formation, Western Canada Sedimentary Basin. American Association of Petroleum Geologists Bulletin 103, 1017-1044. influence of thermal maturity on porosity in shale samples from the Upper Devonian Duvernay Formation is examined. The samples span a maturity range from immature to the wet gas window. Porosity decreases from immature to the oil window, primarily because of compaction. Relatively high porosity of wet gas window samples is ascribed to formation of secondary organic pores, feldspar dissolution pores, and primary pore preservation by the quartz framework. The final decline in the porosity of the dry gas window samples is explained by greater compaction, the disappearance of secondary organic pores, and feldspar dissolution pores.Porosity correlates positively to quartz content and negatively to carbonate content; no relationship was evident between porosity and clay or total organic carbon content. No obvious correlations exist between rock composition and permeability except that SiO2 content shows a weakly positive correlation to permeability. Permeability is highest in immature samples, which have the greatest pore and pore-throat sizes. Nitrogen adsorption and mercury injection analysis show that pore and pore-throat sizes decrease with increasing maturity.Visible pores, imaged by scanning electron microscopy and helium ion microscopy, exist as organic pores, including bubblelike pores developed within organic matter (OM) and fissure-type pores, intraparticle pores mainly developed within carbonate grains, and interparticle pores either within a clay-rich matrix or between rigid mineral grains. In immature samples, the primary pores are interparticle pores between clay minerals and other mineral grains. The OM fissures are ubiquitous in oil window samples, and secondary bubblelike OM–hosted pores are well developed within gas window samples.Dong, X., Greening, C., Rattray, J.E., Chakraborty, A., Chuvochina, M., Mayumi, D., Dolfing, J., Li, C., Brooks, J.M., Bernard, B.B., Groves, R.A., Lewis, I.A., Hubert, C.R.J., 2019. Metabolic potential of uncultured bacteria and archaea associated with petroleum seepage in deep-sea sediments. Nature Communications 10, Article 1816. lack of microbial genomes and isolates from the deep seabed means that very little is known about the ecology of this vast habitat. Here, we investigate energy and carbon acquisition strategies of microbial communities from three deep seabed petroleum seeps (3?km water depth) in the Eastern Gulf of Mexico. Shotgun metagenomic analysis reveals that each sediment harbors diverse communities of chemoheterotrophs and chemolithotrophs. We recovered 82 metagenome-assembled genomes affiliated with 21 different archaeal and bacterial phyla. Multiple genomes encode enzymes for anaerobic oxidation of aliphatic and aromatic compounds, including those of candidate phyla Aerophobetes, Aminicenantes, TA06 and Bathyarchaeota. Microbial interactions are predicted to be driven by acetate and molecular hydrogen. These findings are supported by sediment geochemistry, metabolomics, and thermodynamic modelling. Overall, we infer that deep-sea sediments experiencing thermogenic hydrocarbon inputs harbor phylogenetically and functionally diverse communities potentially sustained through anaerobic hydrocarbon, acetate and hydrogen metabolism.Dorrell, R.G., Azuma, T., Nomura, M., Audren de Kerdrel, G., Paoli, L., Yang, S., Bowler, C., Ishii, K.-i., Miyashita, H., Gile, G.H., Kamikawa, R., 2019. Principles of plastid reductive evolution illuminated by nonphotosynthetic chrysophytes. Proceedings of the National Academy of Sciences 116, 6914-6923.: Photosynthesis has been gained many times in eukaryotic evolution via endosymbiosis. It has also been lost many times, including multiple occasions in the chrysophyte algae, a lineage of unicellular algae related to diatoms. This study reveals the functions of nonphotosynthetic chrysophyte plastids in six lineages that have lost photosynthesis independently. We see a remarkable degree of convergence in retained functions among these chrysophyte lineages. Moreover, the retained functions are highly similar to those of apicomplexans such as the malaria parasite Plasmodium. The shared losses of function provide insight into the principles of and constraints on plastid reductive evolution, not only within chrysophytes, but across photosynthetic and secondarily nonphotosynthetic eukaryotes.Abstract: The division of life into producers and consumers is blurred by evolution. For example, eukaryotic phototrophs can lose the capacity to photosynthesize, although they may retain vestigial plastids that perform other essential cellular functions. Chrysophyte algae have undergone a particularly large number of photosynthesis losses. Here, we present a plastid genome sequence from a nonphotosynthetic chrysophyte, “Spumella” sp. NIES-1846, and show that it has retained a nearly identical set of plastid-encoded functions as apicomplexan parasites. Our transcriptomic analysis of 12 different photosynthetic and nonphotosynthetic chrysophyte lineages reveals remarkable convergence in the functions of these nonphotosynthetic plastids, along with informative lineage-specific retentions and losses. At one extreme, Cornospumella fuschlensis retains many photosynthesis-associated proteins, although it appears to have lost the reductive pentose phosphate pathway and most plastid amino acid metabolism pathways. At the other extreme, Paraphysomonas lacks plastid-targeted proteins associated with gene expression and all metabolic pathways that require plastid-encoded partners, indicating a complete loss of plastid DNA in this genus. Intriguingly, some of the nucleus-encoded proteins that once functioned in the expression of the Paraphysomonas plastid genome have been retained. These proteins were likely to have been dual targeted to the plastid and mitochondria of the chrysophyte ancestor, and are uniquely targeted to the mitochondria in Paraphysomonas. Our comparative analyses provide insights into the process of functional reduction in nonphotosynthetic plastids.dos Santos, A.C., Ximenes, E., Kim, Y., Ladisch, M.R., 2019. Lignin–enzyme interactions in the hydrolysis of lignocellulosic biomass. Trends in Biotechnology 37, 518-531. is central to overcoming recalcitrance in the enzyme hydrolysis of lignocellulose. While the term implies a physical barrier in the cell wall structure, there are also important biochemical components that direct interactions between lignin and the hydrolytic enzymes that attack cellulose in plant cell walls. Progress toward a deeper understanding of the lignin synthesis pathway – and the consistency between a range of observations over the past 40 years in the very extensive literature on cellulose hydrolysis – is resulting in advances in reducing a major impediment to cellulose conversion: the cost of enzymes. This review addresses lignin and its role in the hydrolysis of hardwood and other lignocellulosic residues.Drollinger, S., Kuzyakov, Y., Glatzel, S., 2019. Effects of peat decomposition on δ13C and δ15N depth profiles of Alpine bogs. CATENA 178, 1-10. of organic substances is one of the main processes responsible for the signatures of stable carbon and nitrogen isotopes (δ13C and δ15N) in soils and peats. However, the applicability of δ13C and δ15N signatures at the natural abundance level as indicators of the degree of peat decomposition is still debatable. We evaluated δ13C and δ15N depth patterns of peat cores sampled at nine sites in two nearby Alpine peat bogs with varying degree of organic matter degradation. Based on water table depths and past drainage intensities, the peat cores were divided into three degradation classes. We found similar overall depths patterns of δ13C and δ15N across the nine depth profiles and distinct differences between aerobic and anaerobic peat layers. Considerable differences in stable C and N isotope signatures of same depths were detected between profiles of the three classes, whereas depth profiles of peat cores with similar degree in peatland degradation were nearly identical. In the aerobic peat layers, δ13C and δ15N increased with depths at all study sites from 2.6‰ to 4.9‰ for δ13C and 3.2‰ to 7.0‰ for δ15N compared to the initial signatures of the plant biomass. Standardised δ13C of aerobic layers differ distinctly between slightly degraded peats at the open peat bog area, intermediately degraded peats at the tree-covered edge areas and strongly degraded peats at the former peat-cutting site. δ13C signatures of aerobic layers of strongly degraded peats were markedly more negative compared to the slightly degraded peats because of the selective 12C losses by microbial respiration. δ15N were more positive at strongly degraded than at slightly degraded sites in both, aerobic and anaerobic peat layers. The uniform stable isotope ratios in the anaerobic layers deeper than the local maxima of the isotopic signatures support the assumption that minor 13C fractionation occurs under anaerobic conditions. δ13C slightly declining with depth in the waterlogged layers of strongly degraded peat reflects the preferential utilisation and loss of labile organic compounds enriched in 13C. δ15N of strongly degraded peats was higher compared to well-conserved peat. The close relationship between the measured δ15N to δ15N modelled based on C:N ratios and bulk densities supports the assumption that the δ15N signature is the result of isotopic fractionation by peat decomposition. We conclude that peat decomposition strongly affects the δ13C and δ15N depth profiles of peat bogs and most likely overrides other factors, such as differences between plant species, litter components, atmospheric δ13C shift during peat formation, temperature effects, or type of mycorrhizal symbiosis.Drozdova, O.Y., Ilina, S.M., Anokhina, N.A., Zavgorodnyaya, Y.A., Demin, V.V., Lapitskiy, S.A., 2019. Organic matter transformation in the conjugate series of surface water in northern Karelia. Water Resources 46, 52-58. composition of organic matter in the conjugated series of natural water (soil, bog, creek, and lake water) has been considered. The composition of aliphatic and aromatic carboxylic acids and humic substances has been determined. Humic substances have been found to account for the major portion of dissolved organic carbon (from 28 in lake water to 57% in bog water with weight-averaged molecular masses of the order of 1 kDa); and the amounts of aliphatic and aromatic carboxylic acids, to account for ≤2% of the total concentration of carbon of water-soluble organic compounds. Transformation of dissolved organic matter have been shown to take place in the series of the examined water: the composition and its characteristics have been shown to change; and the share of the fraction with molecular mass <1 kDa, to increase because of photo- and biodegradation of high-molecular organic compounds.Druhan, J.L., Winnick, M.J., 2019. Reactive transport of stable isotopes. Elements 15, 107-110. have a rich history as tracers of biogeochemical processes, but they are commonly interpreted using distillation models that lump multiple compounding effects, including advection, diffusion, and complex chemical transformations. Today, as our ability to measure small differences in relative mass continues to improve, a new generation of process-based models are being developed that explicitly track individual isotopes across an increasingly diverse range of environments. Advances in isotopic reactive transport models are now yielding new insight into fundamental questions across the Earth sciences, including the relationships between experiments and natural systems and the conditions under which isotopes record past environments.Drze?d?on, J., Jacewicz, D., Sielicka, A., Chmurzyński, L., 2019. MALDI-MS for polymer characterization – Recent developments and future prospects. TrAC Trends in Analytical Chemistry 115, 121-128. development of new polymerization methods and, consequently, the generation of new polymeric materials, is associated with the development of methods for testing the properties of these materials.The matrix assisted laser desorption and ionization - mass spectrometry method (MALDI-MS) is the technique used to study various polymers. The most important advantages of this method include the ability to determine the distribution of the molecular mass of polymers, identify the components of the polymer chain, and examine the surfaces of the polymers. The investigations using MALDI-MS are conducted on different types of samples, e. g. environmental samples, synthetic polymers, colony-cultured and blood-cultured samples.In this review the main recent developments of the MALDI-MS method for studies of polymers have been summarized. The future prospects in field of MALDI-MS and its application to different types of polymeric materials have been described.Duan, X.-y., Li, Y.-x., Li, X.-g., Yin, P., 2018. Historical records and the sources of polycyclic aromatic hydrocarbons in the East China Sea. China Geology 1, 505-511. coastal cities are the most advanced regions in China. In the past few decades, the environment changed very significantly due to large scale human activities in the coastal regions. Polycyclic aromatic hydrocarbons (PAHs) in three dated sediment cores from the west coast of the Yellow Sea (core A01), the Yangtze River estuary (YRE; core A02) and the Oujiang River estuary (ORE; core A03) were analyzed to reconstruct the environmental evolutionary process of the east China coastal region over the past century. In the three cores, PAHs concentrations were increased rapidly. Lower concentrations of PAHs were measured in core A02 than in cores A01 and A03. The vertical variation of PAHs in the YRE was dominated by the petrogenic sources. Historical records of PAHs in the ORE were controlled by pyrolytic sources. PAHs on the west coast of the Yellow Sea were contributed by the two sources.Duemichen, E., Eisentraut, P., Celina, M., Braun, U., 2019. Automated thermal extraction-desorption gas chromatography mass spectrometry: A multifunctional tool for comprehensive characterization of polymers and their degradation products. Journal of Chromatography A 1592, 133-142. TED-GC–MS analysis is a two-step method. A sample is first decomposed in a thermogravimetric analyzer (TGA) and the gaseous decomposition products are then trapped on a solid-phase adsorber. Subsequently, the solid-phase adsorber is analyzed with thermal desorption gas chromatography mass spectrometry (TDU-GC–MS). This method is ideally suited for the analysis of polymers and their degradation processes. Here, a new entirely automated system is introduced which enables high sample throughput and reproducible automated fractioned collection of decomposition products.The fractionated collection together with low temperatures reduces the risk of contamination, improves instrumental stability and minimizes maintenance efforts. Through variation of the two main parameters (purge gas flow and heating rate) it is shown how the extraction process can be optimized. By measuring the decomposition products of polyethylene it is demonstrated that compounds with masses of up to 434?Da can be detected. This is achieved despite the low temperature (?40?°C) of the solid-phase adsorber and the low thermal desorption temperature of 200?°C in the TDU unit.It is now shown that automated TED-GC–MS represents a new flexible multi-functional method for comprehensive polymer analyses. Comparable polymer characterization was previously only achievable through a combination of multiple independent analytical methods. This is demonstrated by three examples focused on practical challenges in materials analysis and identification: The first one is the analysis of wood plastic composites for which the decomposition processes of the polymer and the bio polymer (wood) could be clearly distinguished by fractionated collection using sequential adsorbers. Secondly, a fast quantitative application is shown by determining the weight concentrations of an unknown polyolefin blend through comparison with a reference material. Additionally, the determination of microplastic concentrations in environmental samples is becoming an increasingly important analytical necessity. It is demonstrated that with TED-GC–MS calibration curves showing good linearity for the most important precursors for microplastic, even complex matrix materials (suspended particulate matter) can be successfully analyzed.Dunn, F.S., Liu, A.G., 2019. Viewing the Ediacaran biota as a failed experiment is unhelpful. Nature Ecology & Evolution 3, 512-514. organisms from the late Ediacaran period have often been described as failed experiments in the history of life. We argue that the field of Ediacaran palaeobiology should dispense with unhelpful historical classification schemes and embrace phylogenetic systematics if we are to establish the evolutionary relevance of these fossils.Dunn, J.B., 2019. Biofuel and bioproduct environmental sustainability analysis. Current Opinion in Biotechnology 57, 88-93. cycle analysis (LCA) is a key tool in the evaluation of biofuel and bioproduct sustainability. Recent advances in these analyses include increased incorporation of spatially explicit elements of feedstock growth including changes in soil carbon and fertilization rates. Furthermore, new evaluations of processes to convert biomass to fuels (ethanol, algal-derived fuels, jet fuels, and others) and products have been conducted that examine emerging conversion technologies. Co-product allocation among co-produced biofuels and bioproducts continues to raise LCA methodological challenges; approaches to allocation can drive LCA results. Given the variations in feedstocks, spatially explicit factors, conversion process design, and LCA methodological choices (e.g. co-product allocation), transparency in reporting biofuel LCA methodology and results is critical to enable cross-comparison of studies.Dwivedi, A., Kumar, A., Bhat, J.L., 2019. Production and characterization of biosurfactant from corynebacterium species and its effect on the growth of petroleum degrading bacteria. Microbiology 88, 87-93. study was carried out to isolate the effective bacterial strains for the degradation of petroleum hydrocarbons and biosurfactant production. The bacterial strains were screened for production of biosurfactant by CTAB methylene blue agar assay, hemolytic activity assay and drop collapse assay. The selected strain was identified as Corynebacterium species by 16S rRNA sequence analysis. Biosurfactant was characterized using thin layer chromatographic analysis revealed that the biosurfactant may be glycolipids which have different functional groups viz: alkenes, carboxylic acids and aliphatic amines. GC-MS analysis confirmed that the biosurfactant was 13-docosenamide (z). Biosurfactant also induces the growth of petroleum degrading bacteria i.e. Corynebacterium species. The results proved that the maximum growth was found at 96 h with biosurfactant (13-docosenamide (z)) and 144 h without biosurfactant. The study reflected the potential use of this biosurfactant for petroleum degradation and its application for in situ bioremediation of petroleum hydrocarbons contaminated sites.Ebrahim, T., Mohsen, V.S., Mahdi, S.M., Esmaeel, K.T., Saeb, A., 2019. Performance of low-salinity water flooding for enhanced oil recovery improved by SiO2 nanoparticles. Petroleum Science 16, 357-365. water injection has been utilized as a promising method for oil recovery in recent years. Low-salinity water flooding changes the ion composition or brine salinity for improving oil recovery. Recently, the application of nanoparticles with low-salinity water flooding has shown remarkable results in enhanced oil recovery (EOR). Many studies have been performed on the effect of nanofluids on EOR mechanisms. Their results showed that nanofluids can improve oil recovery when used in low-salinity water flooding. In this work, the effects of injection of low-salinity water and low-salinity nanofluid (prepared by adding SiO2 nanoparticles to low-salinity water) on oil recovery were investigated. At first, the effects of ions were investigated with equal concentrations in low-salinity water flooding. The experimental results showed that the monovalent ions had better performance than the divalent ions because of them having more negative zeta potential and less ionic strength. Also, low-salinity water flooding recovered 6.1% original oil in place (OOIP) more than the high-salinity flooding. Contact angle measurements demonstrated that low-salinity water could reduce the contact angle between oil and water. Then in the second stage, experiments were continued by adding SiO2 nanoparticles to the K+ solution which had the highest oil recovery at the first stage. The experimental results illustrated that the addition of SiO2 nanoparticles up to 0.05 wt% increased oil recovery by about 4% OOIP more than the low-salinity water flooding.Echavarri-Bravo, V., Tinzl, M., Kew, W., Cruickshank, F., Mackay, C.L., Clarke, D.J., Horsfall, L.E., 2019. High resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) for the characterisation of enzymatic processing of commercial lignin. New Biotechnology 52, 1-8. and lignin components of woody biomass have been identified as an attractive alternative to fossil fuels. However, the complex composition of this plant polymer is one of the drawbacks that limits its exploitation. Biocatalysis of lignin to produce platform chemicals has been receiving great attention as it presents a sustainable approach for lignin valorisation. Aligned with this area of research, in the present study we have applied ultra-high-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to identify the preferred lignin substrates of a ligninolytic enzyme, a laccase produced by the terrestrial fungus Trametes versicolor. A commercial lignin was incubated with the laccase and acetosyringone (a laccase mediator) for up to 168?h and direct infusion electrospray FT-ICR MS enabled the identification of thousands of molecular species present in the complex lignin sample at different incubation time points. Significant changes in the chemical composition of lignin were detected upon laccase treatment, which resulted in a decrease in the molecular mass distribution of assigned species, consistent with laccase lytic activity. This reduction was predominantly in species classified as lignin-like (based on elemental ratios) and polymeric in nature (>400?Da). Of particular note was a fall in the number of species assigned containing sulfur. Changes in the chemical composition/structure of the lignin polymer were supported by FT-IR spectroscopy. We propose the use of FT-ICR MS as a rapid and efficient technique to support the biotechnological valorisation of lignin as well as the development and optimization of laccase-mediator systems for treating complex mixtures.Elster, H., 2019. 3. Easier access to “fossil gelatin” and quality check by amino acid racemization. Palaeogeography, Palaeoclimatology, Palaeoecology 526, 43-52. in fossil bones is the most important source for radiocarbon, stable isotopes, ZooMS (Zooarchaeology by Mass Spectrometry) and Amino Acid Racemization (AAR) studies. The isolation and cleaning of fossil gelatin is a time consuming procedure and can introduce contaminations, which, as a consequence, can produce erroneous results.By synthesizing and optimizing a “Molecularly Imprinted Polymer” (MIP) for gelatin this isolation procedure can be faster and more specific.This first application of MIP on fossil gelatin is described. By optimizing the sample preparation over all steps from getting fossil bone powder (ca. 20?mg), isolating the fossil gelatin by MIP, and analyzing the amino acids, especially the enantiomers of aspartic acid from the fossil gelatin by gas chromatography (GC), results are available within one day.These results include a measure of the quality of the fossil gelatin by the pattern of the single amino acids and the ratios of defined amino acids from the GC chromatogram. At the same time, the AAR can give an estimate of the relative age of the fossil bones.Estapa, M.L., Feen, M.L., Breves, E., 2019. Direct observations of biological carbon export from profiling floats in the subtropical North Atlantic. Global Biogeochemical Cycles 33, 282-300. complex interplay of biological and physical mechanisms comprising the ocean's biological carbon pump has not been well characterized to date, due to the difficulty of observing these mechanisms in situ at adequate spatial and temporal resolution. An annual time series is presented of direct measurements of export production and particle properties collected using optical sediment trap‐equipped profiling floats cycling every 1.5–2.5 days. The observations indicate strong variability in particle export and bio‐optical properties, influenced by the spring bloom, mesoscale eddy activity, and the mixed layer pump. Temporal and vertical decoupling of fluxes at depths ranging from 150 to 1,000 m was also observed, and remineralization length scales were more variable than predicted by temperature‐ and oxygen‐based models. Net primary production was computed from float observations using a modification of the Carbon‐based Productivity Model and used to estimate export and export (e‐) ratios, which were compared to predictions of literature export models. Mechanistic models explicitly incorporating ecosystem processes and their depth dependence may perform better at reproducing regional observations collected at high temporal resolution.Etu-Sihvola, H., Bocherens, H., Drucker, D.G., Junno, A., Mannermaa, K., Oinonen, M., Uusitalo, J., Arppe, L., 2019. The dIANA database – Resource for isotopic paleodietary research in the Baltic Sea area. Journal of Archaeological Science: Reports 24, 1003-1013. research is a complex field, which requires large sets of background information. Owing to increasing interest and activity in the field, a substantial amount of archaeological isotope baseline data exist for Northern Europe, consisting mainly of animal bone collagen δ13C, δ15N, and δ34S values. However, the data are scattered into dozens of publications written in multiple languages and less-accessible formats, making the data laborious to use. This article presents the first compilation work of this data, the open access dIANA database (Dietary Isotopic baseline for the Ancient North; ), aimed to support (paleo)dietary research in the Baltic Sea area. The database work is complemented with new analyses of archaeological and (pre-)modern domestic and wild fauna from Finland and Russia broadening the selection of analysed species in the database. We present and discuss data examples, which on one hand show existing spatiotemporal isotope patterns related to diet and differences in the environmental carbon sources and on the other, also visualize the current status of baseline research and the need for further analyses in the circum-Baltic area.Fang, Z., Li, L., Jiang, B., He, C., Li, Y., Xu, C., Shi, Q., 2019. Molecular composition and transformation of dissolved organic matter (DOM) in coal gasification wastewater. Energy & Fuels 33, 3003-3011. gasification process generates a huge amount of highly concentrated industrial wastewater. A better understanding of molecular compositions of dissolved organic matter (DOM) is necessary for the design and optimization of coal gasification wastewater (CGW) treatment processes. In this study, we analyzed the chemical compositions of DOM in a Lurgi coal gasification wastewater treatment plant by three-dimensional excitation–emission matrix (3D-EEM) fluorescence spectroscopy and Fourier-transform ion cyclotron resonance mass spectrometry. Six samples were collected from several specific treatment processes, including raw CGW, effluent of hydrolytic acidification, effluent of sequencing batch reactor, effluent of contact oxidation, and influent and effluent of NaClO bleaching process. The CGW DOM was separated into organic and aqueous phases using liquid–liquid extraction (hydrophobic part) and following solid-phase extraction (hydrophilic part). The concentration of DOM decreased along the whole process, whereas its hydrophilicity increased. The 3D-EEM results reveal that three distinct fluorophores: protein-like organic matter, fulvic acid-like organic matter, and humic acid-like organic matter exist in raw CGW. The intensity of the three fluorophores significantly reduced along these treatment processes, and only fulvic acid-like organic matter can be identified in the end effluent. The molecular compositions of DOM in organic and aqueous phase show different patterns; CHO formulas were the dominant species in the organic phase, where CHOS formulas were predominant in the aqueous phase. The chemical diversity of DOM increased with different treatment processes; especially, potential disinfection by-products like CHOCl compounds are formed during NaClO bleaching process. Semiquantitative analysis using stearic-d35 acid (C18D35O2H) revealed the decreasing trend of different species, providing detailed information of molecular transformation in the water treatment processes.Fazeli, H., Patel, R.A., Ellis, B.R., Hellevang, H., 2019. Three-dimensional pore-scale modeling of fracture evolution in heterogeneous carbonate caprock subjected to CO2-enriched brine. Environmental Science & Technology 53, 4630-4639. in caprocks overlying CO2 storage reservoirs can adversely affect the sealing capacity of the rocks. Interactions between acidified fluid and minerals with different reactivities along a fracture pathway can affect the chemically induced changes in hydrodynamic properties of fractures. To study porosity and permeability evolution of small-scale (millimeter scale) fractures, a three-dimensional pore-scale reactive transport model based on the lattice Boltzmann method has been developed. The model simulates the evolution of two different fractured carbonate-rich caprock samples subjected to a flow of CO2-rich brine. The results show that the existence of nonreactive minerals along the flow path can restrict the increase in permeability and the cubic law used to relate porosity and permeability in monomineral fractured systems is therefore not valid in multimineral systems. Moreover, the injection of CO2-acidified brine at high rates resulted in a more permeable fractured media in comparison to the case with lower injection rates. The overall rate of calcite dissolution along the fracture decreased over time, confirming similar observations from previous continuum scale models. The presented 3D pore-scale model can be used to provide inputs for continuum scale models, such as improved porosity–permeability relationships for heterogeneous rocks, and also to investigate other reactive transport processes in the context of CO2 leakage in fractured seals.Feakins, S.J., Wu, M.S., Ponton, C., Tierney, J.E., 2019. Biomarkers reveal abrupt switches in hydroclimate during the last glacial in southern California. Earth and Planetary Science Letters 515, 164-172. of past hydroclimate provide a means to understand precipitation responses to global ocean-atmosphere climate dynamics beyond the scope of that in the instrumental record. Late glacial climate was characterized by abrupt variability in ice and ocean dynamics, however the implications for hydroclimate are not as well known. Here we present organic geochemical proxy evidence for precipitation isotopes based on plant leaf wax hydrogen isotopic compositions (δDwax) and temperature proxy evidence based upon the branched glycerol dialkyl glycerol tetraethers (brGDGTs), that derive from the membrane lipids of bacteria, each extracted from a sedimentary archive in Lake Elsinore, California spanning 32–9 ka. We add proxy evidence for vegetation and salinity from additional biomarker analyses and compare to prior pollen and sedimentological evidence from the same core. Our record indicates a strong deglacial warming of 10°C in Lake Elsinore (beginning at 14.5 ka) that accompanied a D-enrichment of precipitation of +90‰ and more C4 vegetation (12–10 ka), after a cold, wet and C3-dominated phase (20–14.5 ka), indicating winter-dominated precipitation during the Last Glacial Maximum and Heinrich Stadial 1. During the late glacial (32–20 ka) we find abrupt variability, with precipitation isotopic shifts (～70‰) that are independent of temperature swings implicating changes in storm track, rather than local temperature as drivers of the precipitation isotope signal. Temperature is however not irrelevant for hydroclimate: we find extreme warmth at 29.4 ka and 26.8 ka, the latter coincident with existing reports of an extended dry period (27.5–25.5 ka), suggesting a long hot and dry interlude during the generally cooler glacial period. We compare δDwax with speleothem δ18O from Nevada, also within the winter-dominated precipitation region. Our results corroborate the Last Glacial Maximum and deglacial signals, and fill gaps revealing storm-track instability from 32–20 ka, however the pacing and magnitude of the biomarker signals merit cautious interpretation.Fedotov, P.S., Malofeeva, G.I., Savonina, E.Y., Spivakov, B.Y., 2019. Solid-phase extraction of organic substances: Unconventional methods and approaches. Journal of Analytical Chemistry 74, 205-212. developing “unconventional” methods for the solid-phase extraction (SPE) of organic substances, for example, solid-phase microextraction, solid-phase dynamic extraction, dispersive solid-phase extraction, matrix solid-phase dispersion, microextraction in a packed syringe, etc., are characterized. The main distinctive features of the methods and the fields and prospects for their application are considered. Solid-phase microextraction is most popular, mainly because of a possibility of the full automation of the separation and determination of analytes and the ease of combination with gas and liquid chromatography, as well as with other analytical methods.Feider, C.L., Krieger, A., DeHoog, R.J., Eberlin, L.S., 2019. Ambient ionization mass spectrometry: Recent developments and applications. Analytical Chemistry 91, 4266-4290., S., Vermeulen, P., van Loosdrecht, M.C.M., Lin, Y.M., 2019. Chemical characterization methods for the analysis of structural extracellular polymeric substances (EPS). Water Research 157, 201-208. structure and functionality depend on extracellular polymeric substances (EPS), but analytical methods for EPS often lack specificity which limits progress of biofilm research. EPS were extracted from aerobic granular sludge and analyzed with frequently applied colorimetric methods. The colorimetric methods were evaluated based on their applicability for EPS analysis. EPS fractions of interest were proteins, sugars, uronic acids and phenolic compounds. The applied methods (Lowry method, bicinchoninic acid assay, phenol sulfuric acid method, carbazole sulfuric acid method) were investigated in terms of their sensitivity towards the selected standard compound. Interference of compounds present in EPS with the colorimetric methods was further evaluated. All methods showed to be highly depending on the choice of standard compound and susceptible towards interference by compounds present in EPS. This study shows that currently used colorimetric methods are not capable of accurately characterizing EPS. More advanced methods are needed to be able to draw conclusions about biofilm composition, structure and functionality.Fernández-Castro, B., ?lvarez, M., Nieto-Cid, M., Zunino, P., Mercier, H., ?lvarez-Salgado, X.A., 2019. Dissolved organic nitrogen production and export by meridional overturning in the eastern subpolar North Atlantic. Geophysical Research Letters 46, 3832-3842. organic matter (DOM) is produced in the surface and exported towards the deep ocean, adding ～2 PgC/year to the global carbon export. Due to its central role in the Meridional Overturning Circulation, the eastern subpolar North Atlantic (eSPNA) contributes largely to this export. Here we quantify the transport and budget of dissolved organic nitrogen (DON) in the eSPNA, in a box delimited by the OVIDE 2002 section and the Greenland‐Iceland‐Scotland sills. The Meridional Overturning Circulation exports >15.9 TgN/year of DON downward and, contrary to the extended view that these are materials of subtropical origin, up to 33% of the vertical flux derives from a net local DON production of 7.1?±?2.6 TgN/year. The low C:N molar ratio of DOM production (7.4?±?4.1) and the relatively short transit times in the eSPNA (3?±?1 year) suggest that local biogeochemical transformations result in the injection of fresh bioavailable DOM to the deep ocean.Fernández-López de Pablo, J., Gutiérrez-Roig, M., Gómez-Puche, M., McLaughlin, R., Silva, F., Lozano, S., 2019. Palaeodemographic modelling supports a population bottleneck during the Pleistocene-Holocene transition in Iberia. Nature Communications 10, Article 1872. change lies at the core of debates on genetic inheritance and resilience to climate change of prehistoric hunter-gatherers. Here we analyze the radiocarbon record of Iberia to reconstruct long-term changes in population levels and test different models of demographic growth during the Last Glacial-Interglacial transition. Our best fitting demographic model is composed of three phases. First, we document a regime of exponential population increase during the Late Glacial warming period (c.16.6-12.9 kya). Second, we identify a phase of sustained population contraction and stagnation, beginning with the cold episode of the Younger Dryas and continuing through the first half of the Early Holocene (12.9-10.2 kya). Finally, we report a third phase of density-dependent logistic growth (10.2-8 kya), with rapid population increase followed by stabilization.?Our results support a population bottleneck hypothesis during the Last Glacial-Interglacial transition, providing a demographic context to interpret major shifts of prehistoric genetic groups in south-west Europe.Ferrari, V.B., Cesar, A., Cay?, R., Choueri, R.B., Okamoto, D.N., Freitas, J.G., Favero, M., Gales, A.C., Niero, C.V., Saia, F.T., de Vasconcellos, S.P., 2019. Hexadecane biodegradation of high efficiency by bacterial isolates from Santos Basin sediments. Marine Pollution Bulletin 142, 309-314. aim of the study was the investigation of bacterial diversity from sediments collected at Santos Estuarine System, regarding to their abilities for hexadecane biotransformation. Hexadecane is a medium-chain linear alkane, considered as a model molecule for hydrocarbon biodegradation studies. It is a component from aliphatic fraction of crude petroleum, commonly related to environmental contamination by diesel oil. Santos Basin is an area with historical petroleum contamination. In the present work, sediment samples from this area were inoculated in artificial seawater (ASW), containing hexadecane as carbon source. Six bacterial isolates were selected as resistant to hexadecane. Chromatographic results showed biodegradation indexes above 97%. After 48?h of culture, five of them could degrade >80% of the initial hexadecane added. These isolates were characterized by 16S rDNA gene sequencing analysis. The following species were found: Bacillus amyloliquefaciens, Staphylococcus epidermidis, Micrococcus luteus, Nitratireductor aquimarinus, and Bacillus pumilus.Filippidi, A., De Lange, G.J., 2019. Eastern Mediterranean deep water formation during sapropel S1: A reconstruction using geochemical records along a bathymetric transect in the adriatic outflow region. Paleoceanography and Paleoclimatology 34, 409-429. Mediterranean thermohaline circulation is directly influenced by middle‐ and low‐latitude climate systems. The dramatic paleoclimate changes during the last African Humid Period (~10–6 ka BP) were captured in Mediterranean sediments as the distinctly organic‐rich unit sapropel S1. Here, deepwater formation variability during S1 deposition is reconstructed. We use geochemical records of three cores along a bathymetric transect (775‐, 1,359‐, and 1,908‐m water depths), at the transition between the Adriatic DW‐ formation area and the Eastern Mediterranean. In all three cores, sedimentation rates are distinctly higher during S1, corresponding with enhanced runoff emanating from the Adriatic hinterland. Hence, major runoff did not only come from southern but also from northern borderlands in this period. During sapropel formation, enhanced levels of primary productivity occurred in the surface waters and oxygen‐depleted conditions in the bottom waters for all sites. Conditions for sediment and bottom‐water below ~1.4 km water depth were sulfidic throughout S1, but for intermediate depth (775 m) were anoxic only during the first part (S1a). Bottom‐water oxygenation interrupted S1 formation at water depths down to ~1.4 km, during two brief episodes, at 8.2 and 7.4 cal. ka BP. From the 7.4 cal. ka BP ventilation onward, the transition to more oxygenated bottom‐water conditions was more progressive for the intermediate water depth site (775 m) than for the deeper sites. Conditions remained fully oxic for all water depths following the S1‐MarkerBed ventilation event. Possibly, the onset of continuously oxic conditions started slightly earlier at intermediate depth (775 m; 6.6 ± 0.3 cal. ka BP) than at greater depths (1,359 m, 1,908 m; 6.0 ± 0.3 cal. ka BP).Franchina, F.A., Purcaro, G., Burklund, A., Beccaria, M., Hill, J.E., 2019. Evaluation of different adsorbent materials for the untargeted and targeted bacterial VOC analysis using GC×GC-MS. Analytica Chimica Acta 1066, 146-153. analysis of bacterial volatile organic compounds has gained attraction as a non-invasive way to identify disease-causing organisms, given that bacteria have unique metabolisms and volatile metabolic byproducts. In the present research, different adsorbent materials (Carbopack Y, X, B, Carboxen 1000 and Tenax TA), packed singularly or in combination, were compared in terms of sampling performance (sensitivity, repeatability and selectivity) for the extraction of standards and bacterial volatile metabolites in?vitro (from Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli). After extraction, bacterial volatile organic compounds were desorbed and analyzed in a comprehensive two-dimensional gas chromatography system coupled to a time-of-flight mass spectrometer (GC?×?GC-ToF MS). The results show that Tenax has the greater ability to extract the standard mix as well as volatile organic compounds with better repeatability (4–26 RSD%), higher sensitivity (on average ～24 fold) compared to Carbopack Y, X and Carboxen 1000 tube, which followed in terms of performance. In addition, Tenax confirmed the best sensitivity and discriminatory power with no misclassification in the untargeted and unsupervised analysis for the differentiation of the bacterial species.French, K.L., Birdwell, J.E., Whidden, K.J., 2019. Geochemistry of a thermally immature Eagle Ford Group drill core in central Texas. Organic Geochemistry 131, 19-33. Upper Cretaceous Eagle Ford Group displays significant lateral and vertical geochemical variability. Much of the work on the Eagle Ford Group has been focused southwest of the San Marcos arch. To more fully characterize the Eagle Ford across the entire region, a thermally immature drill core was acquired north of the San Marcos arch that recovered the Pepper Shale and the Eagle Ford Group. Molecular and isotopic analyses of rock extracts were combined with bulk organic and inorganic geochemistry and mineralogy to track the variability in organic matter source and depositional environment, as well as to identify drivers of organic enrichment. The Pepper Shale received significant terrigenous organic matter in its distal deltaic or prodeltaic setting compared to the more distally deposited Eagle Ford Group that primarily hosts marine organic matter. The upper Eagle Ford contains two chemofacies. The older upper Eagle Ford chemofacies has similar mineralogy and organic matter to the underlying lower Eagle Ford, and both intervals display good to excellent source rock potential. In contrast, the younger upper Eagle Ford chemofacies has a different sterane assemblage, a larger terrigenous component, and a higher clay mineral abundance. However, anoxic to euxinic depositional conditions distinguish the lower Eagle Ford from the upper Eagle Ford, which was deposited under oxic to dysoxic conditions. Redox chemistry and organic matter source are two important variables that determine source rock quality, but they did not change in parallel during Eagle Ford deposition. Differences in organic facies explain the Tmax variability, and depositional redox conditions governed organic-richness in the Eagle Ford Group in central Texas.Fu, D., Zhou, S., Ma, Y., Li, J., Xu, G., Tian, T., Yang, F., 2019. Petroleum accumulation history of Nanbaxian belt — Study of gas generation and fluid phase, northern margin of Qaidam Basin, West of China. Journal of Petroleum Science and Engineering 178, 449-458. study the phase evolution and the fluid accumulation history of Nanbaxian petroleum field, in this study, a series of anhydrous closed-system gold-tube thermal simulation experiments have been performed on a carbonaceous mudstone (type Ⅱ kerogen) from the northern margin of the Qaidam Basin in the Xiaomeigou Formation (J1x). The hydrocarbon generation kinetics research was used to simulate the gas generation history of Yiliping depression, and the phase characteristics of the evolution were analysed by PVTsim. The influence of kerogen generated CO2 on the fluid phase was discussed that CO2 has a significant influence on the fluid phase at low maturity stage that the fluid phase could be a gas phase under geological condition. As a result, the fluid was migrated to Lower Ganchaigou Formation as gas phase, in the early stage of hydrocarbon accumulation. The fluid phase was gradually transformed into oil phase with the CO2 loss and accumulated as primary reservoir. With the increase of the maturity, the effect of CO2 on the fluid phase gradually decrease. During the Shizigou Formation depression, the tectonic action and the hydrocarbon generated from Yiliping depression led to the evaporation fractionation of the primary reservoir and the gas washing which cause the reconstructed of the primary reservoir in Lower Ganchaigou Formation and form of the secondary reservoir in Shizigou Formation.Fu, Q., Jiang, D., Xin, H., Dai, Z., Cai, J., Ke, Y., Jin, Y., Liang, X., 2019. Design, synthesis and evaluation of a series of alkylsiloxane-bonded stationary phases for expanded supercritical fluid chromatography separations. Journal of Chromatography A 1593, 127-134. fluid chromatography (SFC) today represents an alternative technique in analytical chemistry due to its obvious benefits in kinetic performance and its complementarity to liquid chromatography. In this paper, a series of alkylsiloxane-bonded stationary phases were synthesized and evaluated to expand their SFC applications. Five kinds of non-endcapped C8 stationary phases (C8-1 to C8-5) with increasing bonding density were synthesized, and the carbon content was 3.91%, 6.07%, 7.97%, 8.65% and 9.10% respectively. Retention mechanism of the C8 phases in SFC in SFC was investigated by the use of a linear solvation energy relationship (LSER) model. Results underlined a close relationship between the bonding density of alkyl chain and the dispersion and polar interactions of the stationary phase. Complementary evaluation was studied based on the calculation of vector angle (θ), and the widest θ of 123° was found between silica and C8 with the highest bonding density. Selective diversity also existed between the two C8 phases with the highest and lowest bonding densities. In addition, the effect of modifier on the SFC mechanism was investigated. Modifiers (methanol, ethanol, isopropanol and acetonitrile) had insignificant influence on the dispersion interaction but they mainly affected the hydrogen bonding interaction by changing the LSER parameters a and b. Finally, C8 and silica columns were applied for separation of eight amide alkaloids of Piper kadsura. Silica provided better retention but limited selectivity while C8 can distinguish alkaloids different in alkyl chain, double bond and cis-trans structure. This research further contributed to demonstrate the potential of alkylsiloxane-bonded stationary phase in improving selectivity of SFC.Fu, X., Zhang, Q., Gao, Y., Wu, Y., Xiao, X., Li, L., Xue, J., Liu, B., 2019. Degradation potential of petroleum hydrocarbon-degrading bacteria immobilized on different carriers in marine environment. Petroleum Science and Technology 37, 1417-1424. technology is a method for restoring the ecological environment of oil-polluted areas. In this paper, the performance and degradation characteristics of immobilized microorganisms on different carriers were systematically studied starting with the selection of immobilized carriers. The results showed that cinnamon shell was the best carrier for screened Pseudomonas YT-11 to prepare immobilized microorganisms (diesel degradation rate was 69.57% in 5 days). On the basis of the determination of diesel degradability and SEM structure, the degradation mechanism of immobilized microspheres was concluded: diesel was adsorbed on the surface of microspheres and then entered the interior to be degraded by microorganisms.Gan, Y., Cheng, Q., Wang, Z., Yang, J., Sun, W., Liu, Y., 2019. Molecular dynamics simulation of the microscopic mechanisms of the dissolution, diffusion and aggregation processes for waxy crystals in crude oil mixtures. Journal of Petroleum Science and Engineering 179, 56-69. ensure the safe and economic operation of a waxy crude oil production process, the microdynamic mechanism and thermodynamic characteristics of the wax gelation process need to be revealed at nanoscale. The molecular dynamics model was established to characterize the phase transition and gelation behavior of waxy molecules in a multiphase system (including oil, asphaltene and water). The relative error between the simulated results and experimental data measured by Dutour et al. (2002) was less than 5%. Under the coupling effect of different operation parameters, the molecular dynamics simulation was employed. The simulated results showed that the spherical paraffin crystals underwent the processes of dissolution, diffusion and aggregation. After which waxy cluster crystals with larger amount but smaller volume were formed, which would be deposited on the inner wall under the concentration gradient. The influence mechanisms of different operating parameters on wax gelation were analyzed. And it was found that the increase in temperature and water cut decrease the wax precipitation, while the increase in pressure enhance the wax precipitation rate. Furthermore, by means of hydrogen bonding and the effect of similar dissolution, water and asphaltene molecules also affect the wax precipitation process at the molecular scale. The investigations in this study provide theoretical support for the paraffin removal and control in a waxy crude oil production system.Ganai, J.A., Rashid, S.A., 2019. Anoxia and fluctuating climate recorded from the Devonian–Carboniferous black shales, Tethys Himalaya, India: a multi-proxy approach. International Journal of Earth Sciences 108, 863-883. to inaccessibility and tough conditions (high-altitude low-oxygen region) very less information is available about the Indian Tethys Himalayan sequences, particularly geochemical data are scarce. An attempt is made in the present study to evaluate the sediment geochemistry and paleo-redox conditions of Devonian–Carboniferous black shales from the Spiti region, Tethys Himalaya, using multi proxy approach. Besides black shales, this paper also provides the first in-depth study of the geochemistry of phosphatic nodules (hosted by the black shales) that will allow primary and secondary processes to be understood. Geochemical investigations, particularly redox-sensitive trace element ratios (for e.g. V/(V?+?Ni)?>?0.5; Ni/Co?=?4.3–7.2; V/Cr?>?2 and positive Ce anomalies), suggest deposition of these black shales under sub-oxic to anoxic marine conditions, thus recording an ocean anoxic event in the region. These ocean anoxic events of Devonian–Carboniferous Spiti black shales, which possess distinctive geochemical signatures, can very well be correlated with global events such as Hangenberg Events and the Lower Alum Shale Event. The span of the chemical index of alteration (CIA) values (54–78), variation of ?4Si% parameter (82–3) and C values (0.1–0.6) recorded in the black shales strongly indicate varying degrees of weathering conditions in the source area, which in turn reflect fluctuating climatic conditions prevailing during the deposition of these sediments in Devonian–Carboniferous period in the Spiti region. The distinct geochemical characteristics such as Y, Sr and rare earth element (REE) enrichments (particularly middle REE enrichments with a “hat-shaped” pattern) with high P2O5 contents (up to 14 wt%) distinguish the nodules from the host rocks (black shales). SEM (scanning electron microscope) results, supplemented by XRD (X-ray diffraction) studies of the nodules, show the dominance of calcium, silica and phosphatic phases. The diversity of clay minerals, significant variations in mineralogical composition and lack of any continuous vertical trend in the nodules suggest a relatively low impact on the primary environmental signal by burial diagenesis.Gao, H., Tong, X., Wen, Z., Wang, Z., 2019. The tectonic evolution of the eastern Mediterranean basin and its control on hydrocarbon distribution. Journal of Petroleum Science and Engineering 178, 389-407. discoveries of giant, deep-water gas fields in the Eastern Mediterranean Basin (EMB) have revealed abundant hydrocarbon resources and significant exploration potential in turbidite and reef reservoirs (e.g., in the Tamar and Levantine fields, and the Zohr and Calypso fields, respectively). However, further exploration is currently constrained by the lack of detailed knowledge on the development of the basin. This paper presents a systematic model of the tectonic evolution of the EMB based on an analysis of new 2D seismic data and relevant published literature, assesses the main petroleum systems operating in the basin, and identifies prospective zones for future exploration. The modeling of a sequence of 12 prototype basins, restored from the seismic data, enable the tectonic evolution of the EMB to be divided into three stages: a rift stage, a ‘drift’ stage (including post-rift thermal subsidence), and a ‘convergence and transformation’ stage. This latest stage can be divided into four chronologically and geographically distinct sub-stages.The structural and stratigraphic architecture of the EMB, and hence the hydrocarbon distribution in the basin, evolved during the rifting of continental fragments from Gondwana (e.g., the Tauride–Anatolian plate, and the Kyrenia, Troodos, and Eratosthenes micro-plates), followed by their northward drift and collision with Eurasia. Six hydrocarbon plays are identified in this paper, two of which are previously unrecognized: the Mesozoic intra-platform reef play in the Eratosthenes Seamount, and the Mesozoic and Miocene ‘double-stacked’ platform-margin reef play in the ‘high–low structure belt’ south of the Eratosthenes Seamount. These two high-quality reef plays, together with stratigraphic and fault-block traps in the northern Levant Basin, are identified as the most prospective hydrocarbon exploration targets in the EMB.Gao, M., Li, X., Ren, C., Wang, Z., Pan, Y., Guo, L., 2019. Construction of a multicomponent molecular model of Fugu coal for reaxFF-MD pyrolysis simulation. Energy & Fuels 33, 2848-2858. description of chemical structure diversity is necessary for a coal model in exploring the coal pyrolysis mechanism by reactive molecular dynamics (ReaxFF-MD) simulation. This paper presents a strategy for constructing large and reasonable coal models manually with varied chemical structures. A multicomponent molecular model containing 23,898 atoms was constructed for Fugu subbituminous coal following the proposed strategy on the basis of characterization data obtained from the proximate and ultimate analysis, 13C NMR, and solvent extraction experiments. The model consists of 75 macromolecules of 20 varied average structures for structural diversity and 29 varied small compounds to capture the mobile phase. The elemental composition and key structural parameters of the multicomponent model agree with the analytical data of Fugu coal sample on the whole. The weight loss profile obtained from slow heat-up (2 K/ps) ReaxFF-MD simulations agrees fairly with the observations from thermogravimetric experiments reported in the literature. The temporal evolution of a representative product (C2H4) from long-time (2000 ps) isothermal ReaxFF-MD simulations shows qualitative agreement with the results of the synchrotron radiation vacuum ultraviolet photoionization time-of-flight mass spectrometry (SVUV-PI-TOF-MS) pyrolysis experiments. These examinations indicate the applicability of the constructed model in ReaxFF-MD simulations to explore the coal pyrolysis mechanism. The proposed strategy suggests a feasible approach for manually constructing reasonable large coal models based on limited conventional characterization data.Gao, Y., Tang, X., Chu, J., He, J., 2019. Microbially induced calcite precipitation for seepage control in sandy soil. Geomicrobiology Journal 36, 366-375. induced calcite precipitation (MICP) can reduce the permeability of soil by reducing the pore volumes. A MICP-based soil improvement method to control water leakage in irrigation channels and reservoirs built on sandy soil grounds is presented in this article. Using this method, a low-permeable hard crust can be formed at the soil surfaces. An experimental study was carried out to evaluate the effect of this method. Sandy soil samples were treated using four different schemes, namely, (1) surface spray, (2) surface spray with the addition of fibers, (3) surface spray and bulk stabilization, and (4) immersion stabilization. By applying around 2.6?L treatment liquid (consisting of ureolytic bacteria, 0.5?mol/L calcium chloride and 0.5?mol/L urea) to the top 2-cm thick soil, the seepage rates of the samples treated by the four different schemes could be reduced by up to 379 times. The conversion rates of calcium source in the tests were up to 89.7%. The results showed that a method of treating the soil in bulk before the formation of a crust on top of the soil layer was effective in reducing the seepage rates. After the bio-treatment, the formed low-permeable hard crust layer was 10 to 20?mm thick with a calcite content higher than 5%. Below the hard crusts, the calcite content was less than 5% and the soil was not properly cemented. Using the mercury intrusion test, it was found that both pore volumes and pore sizes of the bio-treated soil reduced significantly as compared with the untreated soil. Penetration tests using a flat-bottom penetrometer were used to assess the mechanical behavior of the bio-treated soil. The results indicated that the penetration resistance of the bio-treated soil layer was much higher than that of the untreated soil.Garcés-Ruiz, M., Senés-Guerrero, C., Declerck, S., Cranenbrouck, S., 2019. Community composition of arbuscular mycorrhizal fungi associated with native plants growing in a petroleum-polluted soil of the Amazon region of Ecuador. MicrobiologyOpen 8, Article e00703. mycorrhizal fungi (AMF) are worldwide distributed plant symbionts. However, their occurrence in hydrocarbon‐polluted environments is less investigated, although specific communities may be present with possible interest for remediation strategies. Here, we investigated the AMF community composition associated with the roots of diverse plant species naturally recolonizing a weathered crude oil pond in the Amazon region of Ecuador. Next generation 454 GS‐Junior sequencing of an 800 bp LSU rRNA gene PCR amplicon was used. PCR amplicons were affiliated to a maximum‐likelihood phylogenetic tree computed from 1.5 kb AMF reference sequences. A high throughput phylogenetic annotation approach, using an evolutionary placement algorithm (EPA) allowed the characterization of sequences to the species level. Fifteen species were detected. Acaulospora species were identified as dominant colonizers, with 73% of relative read abundance, Archaeospora (19.6%) and several genera from the Glomeraceae (Rhizophagus, Glomus macrocarpum‐like, Sclerocystis, Dominikia and Kamienskia) were also detected. Although, a diverse community belonging to Glomeraceae was revealed, they represented <10% of the relative abundance in the Pond. Seventy five % of the species could not be identified, suggesting possible new species associated with roots of plants under highly hydrocarbon‐polluted conditions.Garel, M., Bonin, P., Martini, S., Guasco, S., Roumagnac, M., Bhairy, N., Armougom, F., Tamburini, C., 2019. Pressure-retaining sampler and high-pressure systems to study deep-sea microbes under in situ conditions. Frontiers in Microbiology 10, 453. doi: 410.3389/fmicb.2019.00453. pelagic realm of the dark ocean is characterized by high hydrostatic pressure, low temperature, high-inorganic nutrients and low organic carbon concentrations. Measurements of metabolic activities of bathypelagic bacteria are often underestimated due to the technological limitations in recovering samples and maintaining them under in situ environmental conditions. Moreover, most of the pressure-retaining samplers, developed by a number of different labs, able to maintain seawater samples at in situ pressure during recovery have remained at the prototype stage, and therefore not available to the scientific community. In this paper, we will describe a ready-to-use pressure-retaining sampler, which can be adapted to use on a CTD-carousel sampler. As well as being able to recover samples under in situ pressure, we propose a sample processing in equi-pressure mode. Using a piloted pressure generator, we present how to perform sub-sampling and transfer of samples in equi-pressure mode to obtain replicates and perform hyperbaric experiments safely and efficiently (with less than 2% pressure variability). As proof of concept, we describe a field application (prokaryotic activity measurements and incubation experiment) with samples collected at 3000m-depth in the Mediterranean Sea. Sampling, sub-sampling, transfer and incubations were performed under in situ pressure conditions and compared to those performed following decompression and incubation at atmospheric pressure. Three successive incubations were made for each condition using direct dissolved-oxygen concentration measurements to determine the incubation times. Subsamples were collected at the end of each incubation to monitor the prokaryotic diversity, using 16S-rDNA/rRNA high-throughput sequencing. Our results demonstrated that oxygen consumption by prokaryotes is always higher under in situ conditions than after decompression and incubation at atmospheric pressure. In addition, over time, the variations in the prokaryotic community composition and structure are seen to be driven by the different experimental conditions. Finally, within samples maintained under in situ pressure conditions, the active (16S rRNA) prokaryotic community was dominated by sequences affiliated with rare families containing piezophilic isolates, such as Oceanospirillaceae or Colwelliaceae. These results demonstrate the biological importance of maintaining in situ conditions during and after sampling in deep-sea environments.Garrett-Bakelman, F.E., Darshi, M., Green, S.J., Gur, R.C., Lin, L., Macias, B.R., McKenna, M.J., Meydan, C., Mishra, T., Nasrini, J., Piening, B.D., Rizzardi, L.F., Sharma, K., Siamwala, J.H., Taylor, L., Vitaterna, M.H., Afkarian, M., Afshinnekoo, E., Ahadi, S., Ambati, A., Arya, M., Bezdan, D., Callahan, C.M., Chen, S., Choi, A.M.K., Chlipala, G.E., Contrepois, K., Covington, M., Crucian, B.E., De Vivo, I., Dinges, D.F., Ebert, D.J., Feinberg, J.I., Gandara, J.A., George, K.A., Goutsias, J., Grills, G.S., Hargens, A.R., Heer, M., Hillary, R.P., Hoofnagle, A.N., Hook, V.Y.H., Jenkinson, G., Jiang, P., Keshavarzian, A., Laurie, S.S., Lee-McMullen, B., Lumpkins, S.B., MacKay, M., Maienschein-Cline, M.G., Melnick, A.M., Moore, T.M., Nakahira, K., Patel, H.H., Pietrzyk, R., Rao, V., Saito, R., Salins, D.N., Schilling, J.M., Sears, D.D., Sheridan, C.K., Stenger, M.B., Tryggvadottir, R., Urban, A.E., Vaisar, T., Van Espen, B., Zhang, J., Ziegler, M.G., Zwart, S.R., Charles, J.B., Kundrot, C.E., Scott, G.B.I., Bailey, S.M., Basner, M., Feinberg, A.P., Lee, S.M.C., Mason, C.E., Mignot, E., Rana, B.K., Smith, S.M., Snyder, M.P., Turek, F.W., 2019. The NASA Twins Study: A multidimensional analysis of a year-long human spaceflight. Science 364, Article eaau8650.'s summary: What to expect after a year in space? Space is the final frontier for understanding how extreme environments affect human physiology. Following twin astronauts, one of which spent a year-long mission on the International Space Station, Garrett-Bakelman et al. examined molecular and physiological traits that may be affected by time in space (see the Perspective by L?brich and Jeggo). Sequencing the components of whole blood revealed that the length of telomeres, which is important to maintain in dividing cells and may be related to human aging, changed substantially during space flight and again upon return to Earth. Coupled with changes in DNA methylation in immune cells and cardiovascular and cognitive effects, this study provides a basis to assess the hazards of long-term space habitation.Science, this issue p. eaau8650; see also p. 127Structured AbstractIntroduction: To date, 559 humans have been flown into space, but long-duration (>300 days) missions are rare (n = 8 total). Long-duration missions that will take humans to Mars and beyond are planned by public and private entities for the 2020s and 2030s; therefore, comprehensive studies are needed now to assess the impact of long-duration spaceflight on the human body, brain, and overall physiology. The space environment is made harsh and challenging by multiple factors, including confinement, isolation, and exposure to environmental stressors such as microgravity, radiation, and noise. The selection of one of a pair of monozygotic (identical) twin astronauts for NASA’s first 1-year mission enabled us to compare the impact of the spaceflight environment on one twin to the simultaneous impact of the Earth environment on a genetically matched subject.Rationale: The known impacts of the spaceflight environment on human health and performance, physiology, and cellular and molecular processes are numerous and include bone density loss, effects on cognitive performance, microbial shifts, and alterations in gene regulation. However, previous studies collected very limited data, did not integrate simultaneous effects on multiple systems and data types in the same subject, or were restricted to 6-month missions. Measurement of the same variables in an astronaut on a year-long mission and in his Earth-bound twin indicated the biological measures that might be used to determine the effects of spaceflight. Presented here is an integrated longitudinal, multidimensional description of the effects of a 340-day mission onboard the International Space Station.Results: Physiological, telomeric, transcriptomic, epigenetic, proteomic, metabolomic, immune, microbiomic, cardiovascular, vision-related, and cognitive data were collected over 25 months. Some biological functions were not significantly affected by spaceflight, including the immune response (T cell receptor repertoire) to the first test of a vaccination in flight. However, significant changes in multiple data types were observed in association with the spaceflight period; the majority of these eventually returned to a preflight state within the time period of the study. These included changes in telomere length, gene regulation measured in both epigenetic and transcriptional data, gut microbiome composition, body weight, carotid artery dimensions, subfoveal choroidal thickness and peripapillary total retinal thickness, and serum metabolites. In addition, some factors were significantly affected by the stress of returning to Earth, including inflammation cytokines and immune response gene networks, as well as cognitive performance. For a few measures, persistent changes were observed even after 6 months on Earth, including some genes’ expression levels, increased DNA damage from chromosomal inversions, increased numbers of short telomeres, and attenuated cognitive function.Conclusion: Given that the majority of the biological and human health variables remained stable, or returned to baseline, after a 340-day space mission, these data suggest that human health can be mostly sustained over this duration of spaceflight. The persistence of the molecular changes (e.g., gene expression) and the extrapolation of the identified risk factors for longer missions (>1 year) remain estimates and should be demonstrated with these measures in future astronauts. Finally, changes described in this study highlight pathways and mechanisms that may be vulnerable to spaceflight and may require safeguards for longer space missions; thus, they serve as a guide for targeted countermeasures or monitoring during future missions.Abstract: To understand the health impact of long-duration spaceflight, one identical twin astronaut was monitored before, during, and after a 1-year mission onboard the International Space Station; his twin served as a genetically matched ground control. Longitudinal assessments identified spaceflight-specific changes, including decreased body mass, telomere elongation, genome instability, carotid artery distension and increased intima-media thickness, altered ocular structure, transcriptional and metabolic changes, DNA methylation changes in immune and oxidative stress–related pathways, gastrointestinal microbiota alterations, and some cognitive decline postflight. Although average telomere length, global gene expression, and microbiome changes returned to near preflight levels within 6 months after return to Earth, increased numbers of short telomeres were observed and expression of some genes was still disrupted. These multiomic, molecular, physiological, and behavioral datasets provide a valuable roadmap of the putative health risks for future human spaceflight.Garwood, R.J., Spencer, A.R.T., Sutton, M.D., 2019. REvoSim: Organism-level simulation of macro and microevolution. Palaeontology 62, 339-355. processes dictate the generation and loss of biodiversity. Understanding them is a key challenge when interrogating the earth–life system in deep time. Model‐based approaches can reveal important macroevolutionary patterns and generate hypotheses on the underlying processes. Here we present and document a novel model called REvoSim (Rapid Evolutionary Simulator) coupled with a software implementation of this model. The latter is available here as both source code (C++/Qt, GNU General Public License) and as distributables for a variety of operating systems. REvoSim is an individual‐based model with a strong focus on computational efficiency. It can simulate populations of 105–107 digital organisms over geological timescales on a typical desktop computer, and incorporates spatial and temporal environmental variation, recombinant reproduction, mutation and dispersal. Whilst microevolutionary processes drive the model, macroevolutionary phenomena such as speciation and extinction emerge. We present results and analysis of the model focusing on validation, and note a number potential applications. REvoSim can serve as a multipurpose platform for studying both macro and microevolution, and bridges this divide. It will be continually developed by the authors to expand its capabilities and hence its utility.Garzón-Cardona, J.E., Martínez, A., Pantoja, S., Guinder, V., Koch, B., Krock, B., Barrera, F., Lara, R., 2019. Linking optical and chemical signatures of dissolved organic matter in the southern Argentine shelf: Distribution and bioavailability. Journal of Marine Systems 195, 74-82. spectroscopy is commonly used to investigate the distribution and dynamics of dissolved organic matter (DOM) in marine systems. However, the direct comparison with chemical signatures is essential to substantiate the molecular composition of specific fluorescent components. Here we report the relation between optical and chemical signatures of DOM in waters of the Beagle Channel (BCW) (south-east of Tierra del Fuego, in the southern Argentine shelf) at the Pacific-Atlantic connection and neighboring coastal (CW) and oceanic (OW) waters (54.75–55.75°S, 64–68°W). The relationships among concentrations of total dissolved carbohydrates (TDCHO) and amino acids (TDAA), and fluorescent DOM (FDOM), including terrestrial “humic-like” (FDOMC) and “protein-like” compounds (FDOMT), and bioavailability of DOM components were assessed from field measurements acquired in the austral summer 2012. The maximal concentrations of TDCHO, dissolved organic carbon (DOC) and FDOMc intensities were found in BCW, while the minima in OW, displaying a negative correlation with salinity. This spatial distribution of biogeochemical signals suggests that humic compounds contributed by continental runoff contain refractory carbohydrates, and FDOMC resulted as a reliable tracer of carbon pathways in the Pacific-Atlantic connection. Conversely, TDAA and FDOMT showed the opposite distributional trend, with minimal concentrations in BCW and the maxima in CW and OW. The significant positive correlation of TDAA with salinity suggests open water sources of these components, however, phytoplankton biomass (Chla) in CW and OW was significantly lower than in BCW, ruling out the assumption of autochthonous source in open waters. TDAA were negatively correlated with the abundance of heterotrophic bacteria (HB), which displayed a consistent decrease from BCW towards OW, suggesting high bacterial uptake of TDAA in the BCW. This bacterial uptake is supported by the observed variation in carbon contribution of TDAA to DOC (amino acids carbon yield, in %), which is an indicator of DOM lability. The negative correlation found between amino acids carbon yield and HB abundance reflects intense bacterial activity in BCW, where phytoplankton biomass was maximum. Hence, higher DOM “freshness” occurs in the BCW, suggesting a tight coupling between microbial production and consumption.Gibbons, A., 2019. Moderns said to mate with late-surviving Denisovans. Science 364, 12-13. elusive Denisovans, the extinct cousins of Neanderthals, are known only from a handful of bones and teeth they left in Siberia's Denisova Cave in Russia and the genetic legacy they bequeathed to living people across Asia. A new study of that legacy in people from New Guinea now suggests that, far from being a single group, these mysterious humans were so diverse that their populations were as distantly related to each other as they were to Neanderthals. In another startling suggestion, the study implies that one of those groups may have survived and encountered modern humans as recently as 15,000 to 30,000 years ago—tens of thousands of years later than researchers had thought.Gika, H., Virgiliou, C., Theodoridis, G., Plumb, R.S., Wilson, I.D., 2019. Untargeted LC/MS-based metabolic phenotyping (metabonomics/metabolomics): The state of the art. Journal of Chromatography B 1117, 136-147. chromatography (LC) hyphenated to mass spectrometry is currently the most widely used means of determining metabolic phenotypes via both untargeted and targeted analysis. At present a range of analytical separations, including reversed-phase, hydrophilic interaction and ion-pair LC are employed to maximise metabolome coverage with ultra (high) performance liquid chromatography (UHPLC) increasingly displacing conventional high performance liquid chromatography because of the need for short analysis times and high peak capacity in such applications. However, it is widely recognized that these methodologies do not entirely solve the problems facing researchers trying to perform comprehensive metabolic phenotyping and in addition to these “routine” approaches there are continuing investigations of alternative separation methods including 2-dimensional/multi column approaches. These involve either new stationary phases or multidimensional combinations of the more conventional materials currently used, as well as application of miniaturization or “new” approaches such as supercritical HP and UHP- chromatographic separations. There is also a considerable amount of interest in the combination of chromatographic and ion mobility separations, with the latter providing both an increase in resolution and the potential to provide additional structural information via the determination of molecular collision cross section data. However, key problems remain to be solved including ensuring quality, comparability across different laboratories and the ever present difficulty of identifying unknowns.Gil-Ramirez, A., Al-Hamimi, S., Rosmark, O., Hallgren, O., Larsson-Callerfelt, A.-K., Rodríguez-Meizoso, I., 2019. Efficient methodology for the extraction and analysis of lipids from porcine pulmonary artery by supercritical fluid chromatography coupled to mass spectrometry. Journal of Chromatography A 1592, 173-182. artery grafts are needed as cardiovascular bioprosthetics. For successful tissue recellularization after transplantation, lipids have to be removed from the donor artery. Developing a selective process to remove lipids without damaging the extracellular matrix greatly depends on knowing the amount and type of lipid compounds in the specific tissue. Here we present an efficient methodology for the study of lipids present in porcine pulmonary arteries. The performance of six extraction methods to recover lipids from artery was evaluated. For this purpose, a supercritical fluid chromatography method coupled to quadrupole time-of-flight mass spectrometry detection (UHPSFC/QTOF-MS) was adapted. The method enabled separation of lipids of a wide range of polarity according to lipid class in less than 7?min. One dichloromethane-based extraction method was shown to be the most efficient one for the recovery of lipids from pulmonary artery. However, one MTBE-based extraction method was able to show the highest fatty acid extraction yields (to the expense of longer extraction times). Lipids were relative quantified according to class, and the major species within each class were identified. Triacylglycerols and glycerophospholipids were the most abundant classes, followed by sphingomyelins, monoacylglycerols and fatty acyls. The matrix effect exerted no interference on the analytical method, except for some few combinations of extraction method and lipid class. These results are of relevance for lipidomic studies from solid tissue, in particular for studies on pulmonary and cardiovascular diseases. Finally, our work sets the basis for the further development of a selective processes to remove lipids from pulmonary artery without damaging the tissue prior to transplantation.Gilbert, A., Sherwood Lollar, B., Musat, F., Giunta, T., Chen, S., Kajimoto, Y., Yamada, K., Boreham, C.J., Yoshida, N., Ueno, Y., 2019. Intramolecular isotopic evidence for bacterial oxidation of propane in subsurface natural gas reservoirs. Proceedings of the National Academy of Sciences 116, 6653-6658.: Microorganisms can oxidize hydrocarbons anaerobically, but the detection and quantification of this process in natural settings remains difficult, impeding reliable estimation of these processes at the global scale. We have used the technique of position-specific isotope analysis of propane and show that anaerobic biological degradation of propane leads to a specific signature that differs from that of propane produced from thermal decomposition of higher hydrocarbons. When applied to natural gas reservoirs, we show that anaerobic bacterial oxidation of propane can be detected and quantified, which is not the case with the use of conventional methods. Our findings are thus of importance for the detection of subsurface biology, for the understanding of the carbon cycle, and more broadly for environmental sciences.Abstract: Microbial anaerobic oxidation of hydrocarbons is a key process potentially involved in a myriad of geological and biochemical environments yet has remained notoriously difficult to identify and quantify in natural environments. We performed position-specific carbon isotope analysis of propane from cracking and incubation experiments. Anaerobic bacterial oxidation of propane leads to a pronounced and previously unidentified 13C enrichment in the central position of propane, which contrasts with the isotope signature associated with the thermogenic process. This distinctive signature allows the detection and quantification of anaerobic oxidation of hydrocarbons in diverse natural gas reservoirs and suggests that this process may be more widespread than previously thought. Position-specific isotope analysis can elucidate the fate of natural gas hydrocarbons and provide insight into a major but previously cryptic process controlling the biogeochemical cycling of globally significant greenhouse gases.Gingerich, P.D., 2019. Temporal scaling of carbon emission and accumulation rates: Modern anthropogenic emissions compared to estimates of PETM onset accumulation. Paleoceanography and Paleoclimatology 34, 329-335.: The Paleocene‐Eocene thermal maximum (PETM) was caused by a massive release of carbon to the atmosphere. This is a benchmark global greenhouse warming event that raised temperatures to their warmest since extinction of the dinosaurs. Rates of carbon emission today can be compared to those during onset of the PETM in two ways: (1) projection of long‐term PETM rates for comparison on an annual time scale and (2) projection of short‐term modern rates for comparison on a PETM time scale. Both require temporal scaling and extrapolation for comparison on the same time scale. PETM rates are few and projection to a short time scale is poorly constrained. Modern rates are many, and projection to a longer PETM time scale is tightly constrained—modern rates are some 9–10 times higher than those during onset of the PETM. If the present trend of anthropogenic emissions continues, we can expect to reach a PETM‐scale accumulation of atmospheric carbon in as few as 140 to 259 years (about 5 to 10 human generations).Plain Language Summary: The Paleocene‐Eocene thermal maximum (PETM) is a global greenhouse warming event that happened 56 million years ago, causing extinction in the world's oceans and accelerated evolution on the continents. It was caused by release of carbon dioxide and other greenhouse gases to the atmosphere. When we compare the rate of release of greenhouse gases today to the rate of accumulation during the PETM, we must compare the rates on a common time scale. Projection of modern rates to a PETM time scale is tightly constrained and shows that we are now emitting carbon some 9–10 times faster than during the PETM. If the present trend of increasing carbon emissions continues, we may see PETM‐magnitude extinction and accelerated evolution in as few as 140 years or about five human generations.Glynn, D.S., McMahon, K.W., Guilderson, T.P., McCarthy, M.D., 2019. Major shifts in nutrient and phytoplankton dynamics in the North Pacific Subtropical Gyre over the last 5000 years revealed by high-resolution proteinaceous deep-sea coral δ15N and δ13C records. Earth and Planetary Science Letters 515, 145-153. North Pacific Subtropical Gyre (NPSG) is the largest continuous ecosystem on Earth and is a critical component of global oceanic biogeochemical cycling and carbon sequestration. We report here multi-millennial-scale, sub-decadal-resolution records of bulk stable nitrogen (δ15N) and carbon (δ13C) isotope records from proteinaceous deep-sea corals. Data from three Kulamanamana haumeaae specimens from the main Hawaiian Islands extend the coral-based time-series back ～5000 yrs for the NPSG and bypass constraints of low resolution sediment cores in this oligotrophic ocean region. We interpret these records in terms of shifting biogeochemical cycles and plankton community structure, with a main goal of placing the extraordinarily rapid ecosystem biogeochemical changes documented by recent coral records during the Anthropocene in a context of broader Late-Holocene variability. During intervals where new data overlaps with previous records, there is strong correspondence in isotope values, indicating that this older data represents a direct extension of Anthropocene records. These results reveal multiple large isotopic shifts in both δ15N and δ13C values similar to or larger in magnitude to those reported in the last 150 yrs. This shows that large fluctuations in the isotopic composition of export production in this region are not unique to the recent past, but have occurred multiple times through the Mid- to Late-Holocene. However, these earlier isotopic shifts occurred over much longer time intervals (～millennial vs. decadal timescales). Further, the δ15N data confirm that the extremely low present day δ15N values recorded by deep sea corals (～8‰) are unprecedented for the NPSG, at least within the past five millennia. Together these records reveal centennial to millennial-scale oscillations in NPSG biogeochemical cycles. Further, these data also suggest a number of independent biogeochemical regimes during which δ15N and δ13C trends were synchronous (similar to recent coral records) or distinctly decoupled. We propose that phytoplankton species composition and nutrient source changes are the dominant mechanisms controlling the coupling and de-coupling of δ15N and δ13C values, likely primarily influenced by changing oceanographic conditions (e.g., stratification vs. entrainment). The decoupling observed in the past further suggests that oceanographic forcing and ecosystem responses controlling δ15N and δ13C values of export production have been substantially different earlier in the Holocene compared to mechanisms controlling the present day system.Goff, J., Terry, L., Mal, J., Schilling, K., Pallud, C., Yee, N., 2019. Role of extracellular reactive sulfur metabolites on microbial Se(0) dissolution. Geobiology 17, 320-329. dissolution of elemental selenium [Se(0)] during chemical weathering is an important step in the global selenium cycle. While microorganisms have been shown to play a key role in selenium dissolution in soils, the mechanisms of microbial selenium solubilization are poorly understood. In this study, we isolated a Bacillus species, designated as strain JG17, that exhibited the ability to dissolve Se(0) under oxic conditions and neutral pH. Growth of JG17 in a defined medium resulted in the production and accumulation of extracellular compounds that mediated Se(0) dissolution. Analysis of the spent medium revealed the presence of extracellular sulfite, sulfide, and thiosulfate. Abiotic Se(0) dissolution experiments with concentrations of sulfite, sulfide, and thiosulfate relevant to our system showed similar extents of selenium solubilization as the spent medium. Together, these results indicate that the solubilization of Se(0) by JG17 occurs via the release of extracellular inorganic sulfur compounds followed by chemical dissolution of Se(0) by the reactive sulfur metabolites. Our findings suggest that the production of reactive sulfur metabolites by soil microorganisms and the formation of soluble selenosulfur complexes can promote selenium mobilization during chemical weathering.Goldman, M.J., Vandewiele, N.M., Ono, S., Green, W.H., 2019. Computer-generated isotope model achieves experimental accuracy of filiation for position-specific isotope analysis. Chemical Geology 514, 1-9. isotope analysis (PSIA) can aid in understanding the origins of molecules. Destructive PSIA requires a model to track isotope substitution through reaction pathways. We present a general method based on the Reaction Mechanism Generator software to construct quantitative kinetic models with atom-specific isotope tracking and kinetic isotope effects during thermal decomposition of model compounds. A propane mechanism produced with this method is compared to experiments. Without tuning kinetic or thermodynamic parameters to experimental data, the mechanism replicated, within experimental uncertainty, the relationship between the parent molecule's position-specific values and the fragments' enrichments. These isotope-specific models can serve as an in silico platform to quantitatively assess secondary isotopic reactions which can scramble position-specific enrichments, design and optimize experimental conditions, and test feasibility of PSIA for new compounds. The proposed methodology creates new opportunities for applications in isotope analysis for a range of chemical compounds.Go?i, M.A., Corvi, E.R., Welch, K.A., Buktenica, M., Lebon, K., Alleau, Y., Juranek, L.W., 2019. Particulate organic matter distributions in surface waters of the Pacific Arctic shelf during the late summer and fall season. Marine Chemistry 211, 75-93. change is leading to marked decreases in the extent, thickness and persistence of sea ice in Polar Regions, especially during the later summer and fall seasons. The expanded open water domain during this period has the potential to drastically affect the hydrography, biogeochemistry and ecology of Arctic seas. In view of these rapid changes, the distributions of particulate organic matter in surface waters from the Pacific Arctic shelf were determined during the late summer and early fall months (August–October) over four different years (2012, 2015, 2016, and 2017). Utilizing surface underway systems of research vessels in combination with a semi-automated filtration system, over a thousand individual samples from surface waters were collected along the northern Bering Sea and Chukchi Sea shelves. Particulate organic carbon (POC) concentrations and molar carbon:nitrogen ratios ([C:N]) were determined to investigate the distribution and provenance of organic matter in surface waters at a high spatial resolution along the research vessels' navigational paths. Corrections for sorption of dissolved carbon and nitrogen were possible at high frequency because of our sampling techniques. The resulting blank-corrected POC concentrations in surface waters ranged from <2 to 35?μM, with several samples collected earlier (August) in the open water season displaying much higher concentrations (>60?μM). Large spatial and temporal variability characterized measurements throughout the study area, with maxima in POC concentration often measured in association with physical features (e.g., straits, capes, fronts, shoals) and strong wind events. Hydrographically, POC distributions displayed significant variability among water masses in the region. Alaska Coastal Water, which was predominant along the southern section of the study area (between Bering Strait and Pt. Hope), displayed the highest POC concentrations whereas Bering-Chukchi Shelf Water and especially Melt Water, which occupied the northern section of the study area (Pt. Hope to Utquiagvik) were characterized by the lowest POC concentrations. Earlier periods (August–September) also were characterized by higher average POC concentrations than later periods (September–October). Overall, most of the samples collected exhibited [C:N] ratios that ranged from 6 to 8?mol:mol, and were consistent with a predominant marine provenance. Our findings indicate POC distributions reflect patterns of wind forcing and physical circulation and identify regions of localized high standing stocks that suggest spatially and temporarily variable production in this area during the late open-water season.González-Fuenzalida, R.A., Herráez-Hernández, R., Verdú-Andrés, J., Bouzas-Blanco, A., Seco-Torrecillas, A., Campíns-Falcó, P., 2019. Establishing the occurrence and profile of polycyclic aromatic hydrocarbons in marine sediments: The eastern Mediterranean coast of Spain as a case study. Marine Pollution Bulletin 142, 206-215., cost-effective analysis, diagnosis of sources of pollution and assessment of potential toxicological effects were included in the case study. Marine sediments collected from 24 points along the eastern Mediterranean coast of Spain (Comunitat Valenciana region) in 2010, 2011, 2012 and 2015 have been analysed for polycyclic aromatic hydrocarbons. Fluoranthene, pyrene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene were the most found. An analysis of the relative abundance of selected PAHs revealed that petrogenic and mixed petrogenic/pyrogenic sources are predominant in the area. The total concentrations of the target compounds ranged from 14.7 to 615.3?ng/g dry weight. The effects range-low (ERL) guideline values were used to assess potential toxicological effects. Rarely adverse biological effects can be expected in the tested area. The level of pollution by PAHs in the area can be considered low, although occasionally high values can be found, particularly in areas with high population or ship traffic.Gorynski, K.E., Tobey, M.H., Enriquez, D.A., Smagala, T.M., Dreger, J.L., Newhart, R.E., 2019. Quantification and characterization of hydrocarbon-filled porosity in oil-rich shales using integrated thermal extraction, pyrolysis, and solvent extraction. American Association of Petroleum Geologists Bulletin 103, 723-744. oil-rich shales, current solvent extraction– and thermal extraction–based methods inaccurately measure hydrocarbon-filled porosity (φHC). Moreover, the hydrocarbon composition is not characterized by either method. Here, we show how open-system programmed thermal extraction and pyrolysis, LECO total organic carbon, Archimedes bulk density, and helium pycnometry measurements are integrated to calculate oil and gas pore volumes, characterize their composition, and estimate mobility. Use of a modified multiramp, slow-heating thermal extract, and pyrolysis temperature program further subdivides the φHC. Saturate–aromatic–resin–asphaltene (SARA) separation and gas chromatography of solvent-extracted organic matter and thermally extracted oils are used to compositionally classify the φHC. The segregated bulk compositions of gas- and oil-filled porosity measured via this method are shown to overlap and are broken into the following categories: gas-filled porosity (～C1–C14), light oil–filled porosity (～C6–C36), and heavy oil–filled porosity (～C32–C36+). Furthermore, slow-heating multiramp thermal extraction can subdivide the light oil–filled porosity into four components capturing the C11–C13, C12–C16, C14–C20, and C17–C36 ranges of the extractable organic matter. Analysis of solvent-extracted oils by SARA identifies abundant saturates and aromatics in the light oil–filled porosity and abundant resins and asphaltenes in the heavy oil–filled porosity. Low-maturity shales can be dominated by heavy (C32+) oils rich in asphaltene and resin fractions not observed in the produced fluid. The ratios of SARA components in the C15+ fraction of produced fluid and core extract can be used to better estimate the potentially mobile φHC.Goulden, S.K.E., Ohkouchi, N., Freeman, K.H., Chikaraishi, Y., Ogawa, N.O., Suga, H., Chadwick, O., Houlton, B.Z., 2019. Strong correspondence between nitrogen isotope composition of foliage and chlorin across a rainfall gradient: Implications for paleo-reconstruction of the nitrogen cycle. Biogeosciences Discussions 2019, 1-26. (N) availability influences patterns of terrestrial productivity and global carbon cycling, imparting strong but poorly resolved feedbacks on Earth's climate system. Central questions concern the timescale of N cycle response to elevated CO2 concentration in the atmosphere, and whether availability of this limiting nutrient increases or decreases with climate change. Nitrogen isotopic composition of bulk plant leaves provides information on large-scale patterns of N availability in the modern environment. Here we examine the utility of chlorins, degradation products of chlorophylls, hypothesized to persist in soil subsequent to plant decay, as proxies for reconstructing past plant δ15N. Specifically, we test the hypothesis that δ15N of plant leaves (δ15Nleaf) is recorded in δ15N of pheophytin a (δ15Npheo) along the leaf-litter-soil continuum across an array of ecosystem climate conditions and plant functional types (C3, C4, legumes, and woody plants). The δ15N of live foliage and bulk soil display marked declines with increasing rainfall, consistent with past studies in Hawaii and patterns worldwide. We find measurable chlorin concentrations along soil-depth profiles at all sites, with pheophytin a present in amounts required for isotopic analysis (>?10?nmol). δ15Npheo in leaves, litter, and soil track δ15Nleaf of plant leaves. We find potential for δ15Npheo records from soil to provide proxy information on δ15Nleaf.Grootveld, M., Percival, B., Gibson, M., Osman, Y., Edgar, M., Molinari, M., Mather, M.L., Casanova, F., Wilson, P.B., 2019. Progress in low-field benchtop NMR spectroscopy in chemical and biochemical analysis. Analytica Chimica Acta 1067, 11-30. employment of spectroscopically-resolved NMR techniques as analytical probes have previously been both prohibitively expensive and logistically challenging in view of the large sizes of high-field facilities. However, with recent advances in the miniaturisation of magnetic resonance technology, low-field, cryogen-free “benchtop” NMR instruments are seeing wider use. Indeed, these miniaturised spectrometers are utilised in areas ranging from food and agricultural analyses, through to human biofluid assays and disease monitoring. Therefore, it is both intrinsically timely and important to highlight current applications of this analytical strategy, and also provide an outlook for the future, where this approach may be applied to a wider range of analytical problems, both qualitatively and quantitatively.Guo, Q., Yu, J., Zhao, Y., Liu, T., Su, M., Jia, Z., Zhao, Y., Mu, Z., Yang, M., 2019. Identification of fishy odor causing compounds produced by Ochromonas sp. and Cryptomonas ovate with gas chromatography-olfactometry and comprehensive two-dimensional gas chromatography. Science of The Total Environment 671, 149-156. fishy odor problems have become a major concern in drinking water quality, and are commonly related to algal proliferation in source water. Unlike the typical musty/earthy odorants 2-methylisoborneol (MIB) and geosmin, identification of the corresponding fishy odorants is still a big challenge. In this study, two species of fishy-odor-producing algae, Ochromonas sp. and Cryptomonas ovate, were cultured to explore the odor production characteristics and typical odorants. When algae were ruptured in the stationary and decline phases, fishy odor intensities of 4 to 8 characterized by FPA were produced. However, some frequently reported aldehydes that could cause fishy odor, including n-hexanal, 2-octenal, heptanal, 2,4-heptanal and 2,4-decadienal, were not detected in either of the cultured algae. The possible fishy odor-causing compounds were further identified by combining gas chromatography-olfactometry (GC-O/MS) and comprehensive two-dimensional gas chromatography (GC?×?GC-TOFMS) using retention indices (RIs). From GC-O/MS analysis, twelve and six olfactometry peaks with various odor characteristics were identified in Ochromonas sp. and Cryptomonas ovate, respectively, of which three and two olfactometry peaks showed fishy odor characteristics. 2-Nonenal, 2,4-octadienal, fluorene and 2-tetradecanone were identified as fishy odorants in Ochromonas sp., and 1-octen-3-ol, 6-methyl-5-hepten-2-one, 1-octen-3-one, 2-nonenal and 2,4-octadienal were identified in Cryptomonas ovate. Other identified compounds, including butyl butanoate (fragrant odor), ionone (fragrant odor), bis (2-chloroisopropyl) ether (chemical odor) etc., did not show fishy features. Therefore, the fishy odor might be a synthetic and comprehensive odor, which resulted from the combination of different odorants and their synergistic effects. The results of this study will be helpful for understanding fishy odor problems, which will provide support for fishy odor management and control in the drinking water industry.Guo, X., Chen, J., Huang, Z., Jin, Y., Chen, C., Li, T., Ding, C., Wang, R., 2019. Geochemical characteristics and accumulation of hydrocarbon in Lower Jurassic tight sandstone in Wenjisang area, Turpan Basin, NW China. Petroleum Science and Technology 37, 853-861. order to investigate the geochemical characteristics, sources and accumulation process of Lower-Jurassic Sangonghe Formation tight sandstone oil, multiple geochemical analyses were performed on source rocks, oil samples and sandstone particles from Wenjisang area in Turpan Basin. The results show that coal-measure source rocks have relatively higher organic matter abundance and type-II organic matter for Xishanyao and Badaowan Formations, with the potential of liquid hydrocarbon generation. Oil samples of Sangonghe Formation have the characteristics of coal-measure-formed oil. Higher maturity indicate the oil may be mainly generated by Lower-Jurassic Badaowan Formation source rocks. Quantitative fluorescence parameters also reflect that hydrocarbons charged into Sangonghe Formation through continuous migration from the bottom of sand body to the top gradually. In down dip direction of Wenjisang area may develope continuous tight oil and gas reservoirs in Lower Jurassic.Guo, X., Huang, Z., Zhao, L., Zhang, T., Han, W., Sun, X., Yang, X., Ding, C., 2019. Hydrocarbon accumulation period and geochemical discrimination of gas-bearing properties of deep tight sandstone in Kuqa depression, China. Petroleum Science and Technology 37, 1387-1393. order to clarify the hydrocarbon accumulation period of deep tight sandstone in Dabei-Keshen area of Kuqa depression, and to develop identification methods of reservoir fluid properties, a series of experiments were carried out. The results show that hydrocarbon inclusions are less distributed, and gaseous hydrocarbon is mainly methane. Hydrocarbon has been continuously charged since 12?Ma in Dabei gas field, and one main period of accumulation took place during 6–4?Ma for Keshen gas field. Late accumulation may limit the application of hydrocarbon inclusions abundance, rock soluble salt components to distinguish reservoir fluid properties. Carbon isotope composition of carbonate cement in tight sandstone is an effective indicator for gas-bearing properties. For gas layer, the carbon isotope is lighter than ?1.5‰ and ?2.5‰ for Dabei and Keshen gas field receptively.Guo, X., Liu, Z., Xiao, Y., Xu, X., Xue, X., Liu, Q., Li, X., 2019. Simulations on pyrolysis of different coals by the Boltzmann–Monte Carlo percolation (BMCP) model. Energy & Fuels 33, 3144-3154. modeling researches on coal pyrolysis either make predictions with empirical parameters under limited conditions or simulate reactions occurs on a nanosecond scale that cannot be compared with experimental data due to the complexity of pyrolysis. The Boltzmann–Monte Carlo percolation (BMCP) model from a covalent bond perspective followed the “dissociation–coupling” mechanism can provide both products’ distribution and bonds’ population qualitatively. In this work, by introducing a universal method for calculating the average molecular weight of radicals and a correlation method between cycles and the actual residence time, the results of the BMCP model can be used for comparison with actual experimental data. The BMCP model with different assumptions on coupling of radicals is used to simulate pyrolysis with different coals under different temperatures and different pressures. The results of the BMCP model accord well with experimental data not only on a microscale for bonds but also on a macroscale for products under various conditions; the quantitative prediction ability of the BMCP model has been proved, and this indicates that the “dissociation coupling” mechanism can reflect some chemical nature of coal pyrolysis. Furthermore, although apparent activation energies seemed to be different under different assumptions, the minor deviations in various conditions indicate that assumptions on the “coupling” step can hardly affect simulation results and the bond “dissociation” step may be the rate-determining step in the dissociation–coupling mechanism.Hakimi, M.H., Alaug, A.S., Afify, W.E., El Nady, M.M., Lashin, A.A., 2019. Investigating gas resource potentiality from Late Jurassic Madbi Formation in the NW –Say’Un-Masila Basin, Eastern Yemen. Petroleum Science and Technology 37, 1355-1362. Jurassic Madbi shale samples from Al-Qarn-01 well in the NW Say’un-Masila Basin, Eastern Yemen are analyzed using conventional geochemical data such as total organic carbon (TOC) content and Rock-Eval pyrolysis. The results in this study are used to evaluate the gas resource potentiality in the basin. The analyzed shales have high TOC content between 1.00% and 3.12%, and their HIs range from 77 to 177?mg HC/g TOC. These values indicate that the investigated Madbi shale intervals contain Type III kerogen and are considered to be very good gas-source rocks. Furthermore, the relatively high Rock-Eval pyrolysis Tmax (447–459?°C) and PI (0.09–0.44) values indicate mainly peak to late mature oil window.Hakimi, M.H., Ismail, I.M., Lashin, A.A., Ibrahim, E.-K.H., 2019. Physical and geochemical properties of crude oils in relation to their source rocks, Alif field, Marib Sub-basin, Yemen. Petroleum Science and Technology 37, 899-906. and geochemical properties were performed on three crude oils from Alif-01 well in the Marib sub-basin. The analyzed samples comprise medium specific gravity (37° API), reflecting mature source rocks. The thermal maturity of the analyzed oils is also indicated from the high content of aliphatic hydrocarbons (HC). The compositions of HC further suggest that analyzed oils belong to paraffinic oils. The n-alkane and isoprenoid distributions reveal that the analyzed oils are derived from marine source rock, containing mixed organic matter, with some terrestrial input and deposited under relatively reducing conditions. The features of the analyzed oils are consistent with the Madbi source rock characteristics in the basin.Han, H., Guo, C., Zhong, N.-n., Pang, P., Chen, S.-j., Lu, J.-g., Gao, Y., 2019. Pore structure evolution of lacustrine shales containing Type I organic matter from the Upper Cretaceous Qingshankou Formation, Songliao Basin, China: A study of artificial samples from hydrous pyrolysis experiments. Marine and Petroleum Geology 104, 375-388. characterize the pore evolution of lacustrine shales containing Type I organic matter, we performed hydrous pyrolysis experiments on a lacustrine shale sample to make it reach various maturities. The samples with various maturities were then extracted using dichloromethane. Total organic carbon content, Rock-Eval pyrolysis, and low-pressure gas (CO2 and N2) adsorption analyses were performed on the samples before and after extraction. The results showed that the volumes and surface areas of micropores (<2?nm) of the extracted samples were much higher than those of the artificial samples, but the parameters of mesopores (2–50?nm) of the extracted samples were close to the samples before extraction, indicating that liquid hydrocarbons are mainly stored in micropores. There were no any obvious correlations between pore volumes and mineral contents for the extracted samples, suggesting maturity is the dominant control of pore structure. The pore evolution of the extracted samples is similar to that of the artificial samples. During maturation, micropore volumes initially decreased over the interval 0.71%–0.97% EASY%Ro before increasing at EASY%Ro values exceeding 1.08%. The changes in micropore volume of the extracted samples may be related to the formation and cracking of insoluble organic matter. During this process, mesopore volumes kept increasing, which is mainly aroused by kerogen decomposition or carbon loss. Our results could improve the understanding of pore evolution of lacustrine shales and provide some implications for shale oil storage.Han, W.-C., Chen, L., Liu, C.-S., Berndt, C., Chi, W.-C., 2019. Seismic analysis of the gas hydrate system at Pointer Ridge offshore SW Taiwan. Marine and Petroleum Geology 105, 158-167. Ridge is a gas hydrate prospect on the South China Sea continental slope offshore SW Taiwan. It is characterized by densely distributed bottom simulating reflections (BSRs), active gas seepage, and potential sandy gas hydrate reservoirs. To understand how the fluids have migrated toward the seafloor, and the role of geological processes in the gas hydrate system, we have collected and analyzed high-quality 2D and 3D reflection seismic data. We first mapped the spatial distribution of the BSRs, and interpreted a major normal fault, Pointer Ridge Fault (PR Fault). The NE-SW trending fault dips to the east, and separates the erosional regime to the west from the depositional regime to the east. One active vent site was identified directly above the PR Fault, while another is located on a topographic high to the west of the fault. On the hanging block of the fault we found at least one major unconformity. The seismic data indicate refilled channels with coarser-grained sediments in the hanging wall of the normal fault. Seismic attribute analysis shows subsurface fluid conduits and potential gas hydrate reservoirs. We propose two types of gas chimneys, which are separated by the fault. Gas plumes derived from hydroacoustic data are mostly from the footwall block of the fault. We infer that fluid flow is more active in the erosional environment compared to the depositional one, and that this is the result of reduced overburden. The methane-bearing fluids migrate upward along the PR Fault and chimneys and form hydrates above the base of the gas hydrate stability zone. Based on seismic interpretation and seismic attribute analysis, we postulate that the channel infill constitutes the most promising hydrate reservoirs in this geological setting. In the surveyed area of Pointer Ridge these channels occur mainly below the gas hydrate stability zone.Han, W., Chang, X., Tao, S., Hou, L., Ma, W., Yao, J., Meng, S., 2019. Geochemical characteristics and genesis of pre-salt gases in the Ordos Basin, China. Journal of Petroleum Science and Engineering 179, 92-103. geochemical characteristics, genesis and accumulation mechanism of the pre-salt gases of Ordos Basin have been rarely studied in China. Components and carbon isotope values of pre-salt gases are investigated and compared with those of the Upper Paleozoic and post-salt gases. Homogenization temperatures and carbon isotope values of gases of the pre-salt fluid inclusions were also measured. Based on the geochemical parameters, combined with the geological conditions, the genesis and accumulation mechanism of pre-salt gases are studied. The components, carbon isotope values and the first two homogenization temperature ranges (90–120?°C and 120–160?°C) of the pre-salt gases contain those of the Upper Paleozoic and post-salt gases. The pre-salt inclusions have an extra homogenization temperature range (160–200?°C) and the pre-salt rocks also have some hydrocarbon generation capacity, which means the pre-salt rocks may also generate some gases. The pre-salt gases are mixed gases generated from the Upper Paleozoic coal strata, the post-salt and pre-salt Lower Paleozoic Majiagou Formation, which is confirmed by the geochemical characteristics and the geological settings.Hansen, A.K., Thairu, M.W., 2019. It's a small, small world: unravelling the role and evolution of small RNAs in organelle and endosymbiont genomes. FEMS Microbiology Letters 366, Article fnz049. and host-restricted bacterial symbionts are characterized by having highly reduced genomes that lack many key regulatory genes and elements. Thus, it has been hypothesized that the eukaryotic nuclear genome is primarily responsible for regulating these symbioses. However, with the discovery of organelle- and symbiont-expressed small RNAs (sRNAs) there is emerging evidence that these sRNAs may play a role in gene regulation as well. Here, we compare the diversity of organelle and bacterial symbiont sRNAs recently identified using genome-enabled ‘-omic’ technologies and discuss their potential role in gene regulation. We also discuss how the genome architecture of small genomes may influence the evolution of these sRNAs and their potential function. Additionally, these new studies suggest that some sRNAs are conserved within organelle and symbiont taxa and respond to changes in the environment and/or their hosts. In summary, these results suggest that organelle and symbiont sRNAs may play a role in gene regulation in addition to nuclear-encoded host mechanisms.Hao, J., Mohammadkhani, S., Shahverdi, H., Esfahany, M.N., Shapiro, A., 2019. Mechanisms of smart waterflooding in carbonate oil reservoirs - A review. Journal of Petroleum Science and Engineering 179, 276-291. goal of the present paper is to provide a comprehensive review of the literature describing the physical and chemical mechanisms for enhanced oil recovery under smart waterflooding in carbonate reservoirs. Advanced, or smart waterflooding is a term denoting directed alteration of the ionic composition of the injected brine in order to achieve a better oil recovery, in particular, the low salinity flooding. While injection of a low salinity brine in sandstones is well described, the acting mechanisms of advanced waterflooding are not fully clarified, and only few reservoir-scale tests have been carried out. Demonstration and comparison of the different phenomena explaining the effect of smart waterflooding are the goals of the present review. Unlike the previous such reviews, we do not only concentrate on the phenomena occurring on the rock-brine-oil interfaces, but also address dynamic phenomena caused by flow, like fluid diversion and emulsification. The paper comprises an up-to-date information, classification and guidance and, consequently, is intended to serve advancing the research in the area of smart waterflooding in carbonates.Harp, D.R., Oldenburg, C.M., Pawar, R., 2019. A metric for evaluating conformance robustness during geologic CO2 sequestration operations. International Journal of Greenhouse Gas Control 85, 100-108. metric for quantifying the robustness of a designation of conformance of a geologic CO2 sequestration (GCS) project during its operational phase is developed and demonstrated. Conformance in this context is a measure of the degree to which the sequestration system is understood and can be accurately modeled along with the degree to which the storage system is performing as designed. The robustness of conformance quantifies the degree to which parameter values can deviate from their current nominal estimates and still produce model forecasts that meet the performance criteria for the GCS operation. We develop and demonstrate the approach on a simplified scenario to illustrate the concept using a single uncertain parameter (homogeneous reservoir permeability) and a single performance criterion (critical pressure at a monitoring well in the reservoir; i.e., one that may displace brine from the reservoir to an overlying drinking water aquifer for example). Increased confidence in conformance assessment as more monitoring data are obtained is incorporated through the standard error of the coefficient (reservoir permeability in the case presented here), which we designate as the concordance metric. As more monitoring data become available during the course of the GCS operation, the standard error of the coefficient decreases (in general), thereby leading to increased conformance robustness as a larger deviation from nominal is required to fail to meet performance criteria. Increasing conformance robustness over time builds confidence that a GCS project will continue to meet performance criteria during the life-span of the project, thereby supporting designations of conformance. A lack of conformance robustness provides a critical warning that the performance criteria of the GCS operation are not robust against probabilistic and non-probabilistic uncertainty in model conceptualization and/or model parameters.Harrison, A.L., Tutolo, B.M., DePaolo, D.J., 2019. The role of reactive transport modeling in geologic carbon storage. Elements 15, 93-98. engineered storage of CO2 in Earth's subsurface provides one of the most promising means of reducing net greenhouse gas emissions. Paramount to the success of this method is ensuring that CO2 injected into the subsurface is securely stored. Reactive transport models can be used to answer the key question regarding CO2 storage, “Will the injected CO2 be secure, and over what timescale?” Here, we explore examples of how reactive transport models have been used to simulate the range of geochemical and hydrologic processes that will take place over thousands of years and across many spatial scales to answer that key question.Hartmann, J., 2019. Plate tectonics, carbon, and climate. Science 364, 126-127. the past 541 million years (the Phanerozoic eon), Earth's climate has been relatively stable compared to preceding eons. However, there have been periods of longer glaciations, which have been attributed to changes in the balance between CO2 sources and sinks. The major CO2 sources are thought to be mantle degassing at hotspot volcanoes, mid-ocean ridges, and rifts; subduction zone volcanoes; metamorphosis of carbonate rocks into silicate rocks; and oxidative weathering (see the figure) (1). The main CO2 sink is chemical weathering and the subsequent transfer of carbon to the ocean, where carbonate sediments lock up CO2 for long periods of time. During arc-continent collisions, rocks from volcanic arcs are accreted to continents. On page 181 of this issue, Macdonald et al. (2) propose that weathering can rise after the accreted rocks are exposed at Earth's surface. This mechanism may explain the glaciations seen during the Phanerozoic.Harvey, V.L., Egerton, V.M., Chamberlain, A.T., Manning, P.L., Sellers, W.I., Buckley, M., 2019. Interpreting the historical terrestrial vertebrate biodiversity of Cayman Brac (Greater Antilles, Caribbean) through collagen fingerprinting. The Holocene 29, 531-542. Brac (Cayman Islands) lies within the Caribbean Islands Biodiversity Hotspot, an epicenter of high biodiversity and endemism. However, all endemic terrestrial mammals on the Cayman Islands are now extinct, following post-1500 AD human colonization of the islands. Introduced rodents and domesticated mammals now exclusively represent this facet of terrestrial fauna on the Cayman Islands, and are a likely cause of endemic species loss on the islands. Cayman Brac has numerous caves and rock fissures that offer protection to a naturally accumulated ensemble of vertebrate sub-fossil bone remains, documenting modifications in island biodiversity through the Holocene. In this study, we showcase the first molecular faunal survey undertaken on sub-fossil remains from the Cayman Islands, using collagen fingerprinting for taxonomic identification of the cave skeletal deposits collected from a single cave system, Green Cave on Cayman Brac. Collagen type (I) extracts from 485 bone fragments were analyzed to determine faunal identity and assemblage composition. A total of 76% of the collagen fingerprint-yielding samples were mammalian in origin, 67% of which were identified as invasive murid rodents. Here, we present mass spectral biomarkers for the endemic terrestrial mammal fauna of Cayman Brac, including the extinct capromyid rodents, Capromys and Geocapromys (Rodentia: Capromyidae), alongside commentary on the composition of the sub-fossil bone assemblage between the five distinct depositional chambers that comprise Green Cave. Collagen (I) provides a key service in taxonomic identification and mapping of macroevolutionary trends, and these results suggest a pivotal role for murid rodents in the competition and extinction of terrestrial endemic mammals from the Cayman Islands.Hatayama, K., Saito, K., 2019. Calcite formation induced by Ensifer adhaerens, Microbacterium testaceum, Paeniglutamicibacter kerguelensis, Pseudomonas protegens and Rheinheimera texasensis. Antonie van Leeuwenhoek 112, 711-721. wide range of bacterial species are able to induce calcium carbonate precipitation. Using our own laboratory-preserved strains, we have newly discovered that Ensifer sp. MY11e, Microbacterium sp. TMd9a1, Paeniglutamicibacter sp. MSa1a, Pseudomonas sp. GTc3, and Rheinheimera sp. ATWe6 can induce the formation of calcite crystals on an agar medium. Type strains of their closely related species (Ensifer adhaerens, Microbacterium testaceum, Paeniglutamicibacter kerguelensis, Pseudomonas protegens, and Rheinheimera texasensis) could also induce calcite formation. Although the initial pH value of the agar medium was 6.1, the pH of the agar media containing calcite, induced by cultivation of the 10 bacterial strains, increased to 8.0–8.4. The ammonification (oxidative deamination) of amino acids may been responsible for this increase in pH. The crystals formed both on and around the bacterial colonies. Furthermore, when these strains (excepting two Microbacterium strains) were cultivated on a cellulose acetate membrane filter (0.20?μm pore size) resting on the surface of the agar medium (i.e., in the membrane filter culture method), the crystals formed on the agar medium separate from the bacterial cells. These results indicate that the bacterial cells did not necessarily become nucleation sites for these crystals. We also investigated whether the studied strains could be applied to the biocementation of sand, and found that only two Ensifer strains were able to form large sand lumps.He, F., Zhu, R., Jin, A., Li, M., Cao, J., Lou, Z., 2019. Hydrocarbon preservation and formation water geochemistry in abnormal pressure system in the Bawu area of Lishu depression, Songliao Basin, China. Petroleum Science and Technology 37, 1176-1183. hydrocarbon production in the Bawu area of Lishu Depression is high. However, the Bawu area has undergone three main tectonic movements, the strata were strongly uplifted and eroded, and the fractures were extremely developed. The conditions of hydrocarbon preservation have become intricate. In this study, by analyzing isotopes compositions and geochemical features of formation water, and the characteristics of formation pressure, the hydrocarbon preservation can be deduced. The subnormal and lower normal pressure zones (away from Xiaokuan Fault) of Yingcheng and Shahezi Formations are relatively closed and more conducive to hydrocarbon preservation.He, K., Zhang, S., Mi, J., Ma, Q., Tang, Y., Fang, Y., 2019. Experimental and theoretical studies on kinetics for thermochemical sulfate reduction of oil, C2–5 and methane. Journal of Analytical and Applied Pyrolysis 139, 59-72. address the kinetic parameters for thermochemical sulfate reduction (TSR) of oil and hydrocarbon gases, hydrothermal experiments involving oil or methane and sulfate at 50?MPa were conducted by a gold tube pyrolysis system. By determination of gas yields in non-isothermal pyrolysis of oil with gypsum and water, it was found that the generation of H2S can be divided into two stages, including TSR of liquid oil and C2-5 hydrocarbon gases. The average activation energies (Ea) for TSR of oil and C2-5 were fitted to be 58.1 and 65.9?kcal/mol, respectively. By isothermal pyrolysis of methane-dominated gas with aqueous MgSO4 at 500–600?°C, the reaction rates for TSR of methane at elevated temperature was determined. Meanwhile, theoretical calculations based on density functional theory (DFT) and transition state (TS) were carried out to obtain the thermodynamic parameters for the oxidation of methane by different sulfate species. It is revealed that the energy barriers for reactions between methane and HSO4? or [MgSO4]CIP at 0–600?°C were much lower than those for free SO42?. Combined the experimental results and theoretical calculations, the Ea for TSR of methane involving SO42?, HSO4? and [MgSO4]CIP were calculated to be 67.0, 52.1 and 54.9?kcal/mol, respectively. Finally, the conversion for TSR of oil, ethane and methane in the subsurface were addressed by geological extrapolation and their onset temperatures in different geological conditions were proposed. It is implied that the onset temperature of methane TSR may be as higher as 200?°C when no catalysts (i.e. S, H2S and S3?) and high concentration of MgSO4 were presented.He, M., Wang, J., Fan, X., Liu, X., Shi, W., Huang, N., Zhao, F., Miao, M., 2019. Genetic basis for the establishment of endosymbiosis in Paramecium. The ISME Journal 13, 1360-1369. single-celled ciliate Paramecium bursaria is an indispensable model for investigating endosymbiosis between protists and green-algal symbionts. To elucidate the mechanism of this type of endosymbiosis, we combined PacBio and Illumina sequencing to assemble a high-quality and near-complete macronuclear genome of P. bursaria. The genomic characteristics and phylogenetic analyses indicate that P. bursaria is the basal clade of the Paramecium genus. Through comparative genomic analyses with its close relatives, we found that P. bursaria encodes more genes related to nitrogen metabolism and mineral absorption, but encodes fewer genes involved in oxygen binding and N-glycan biosynthesis. A comparison of the transcriptomic profiles between P. bursaria with and without endosymbiotic Chlorella showed differential expression of a wide range of metabolic genes. We selected 32 most differentially expressed genes to perform RNA interference experiment in P. bursaria, and found that P. bursaria can regulate the abundance of their symbionts through glutamine supply. This study provides novel insights into Paramecium evolution and will extend our knowledge of the molecular mechanism for the induction of endosymbiosis between P. bursaria and green algae.He, Q., Chen, S., Li, Y., Lu, J., Xiao, Z., Qiu, W., 2019. The study of the oil source in Xiaoliangshan Sag, Northwestern Qaidam Basin, China. Petroleum Science and Technology 37, 1201-1207. geochemical characteristics of the crude oil in the northwestern and southwestern Qaidam Basin and the Tertiary source rocks of Xiaoliangshan Sag were compared and analyzed. The results show that the Tertiary source rocks of N1 and E32 are the best two sets of source rocks in Xiaoliangshan Sag. The crude oil of the northwestern Qaidam Basin is sourced from nearby Xiaoliangshan Sag rather than Mangya Sag. The crude oil of N22 in the shallow strata of Nanyishan, Jiandingshan and Xiaoliangshan are mainly sourced from the source rocks of N1, while the crude oil of E32 in the deep strata is mainly sourced from the source rocks of E32.He, Q., Jiang, Q., Xing, L., Zhang, S., Pang, W., Hu, H., Lu, S., Yin, Q., 2019. Geochemical characteristics of newly discovered Elongatoolithidae eggs from the Upper Cretaceous of Jiangxi Province, southern China: Palaeoenvironmental and palaeoclimatic inferences. Cretaceous Research 99, 352-364. analyzed identified oospecies and associated geochemical characteristics of newly discovered dinosaur eggs from the Cretaceous Hekou Formation in Yudu District, Jiangxi Province, China. Results reveal that the Yudu eggs can be identified as representatives of the known oospecies Macroolithus rugustus within Elongatoolithidae based on external shape, size, ornamentation, and internal microstructure between the columnar and cone layers. The major element found in Macroolithus rugustus shells is Ca, while trace elements mainly include Sr, Ba, As, Cr, Mn, Pb, Cd, La, and Ir, characterised by Ir and Sr abnormalities, as well as the toxic elements As and Pb. Enrichment of trace elements in shells might be due to the diet of dinosaurs and subsequent deposition in eggs, consistent with global Ir anomalies and the regional enrichment of trace elements. δ13C values for Macroolithus rugustus ranging between??8.81‰ and??7.65‰ are indicative of C3 plants with relatively high CO2 concentration and low mean annual precipitation (MAP), while δ18O values ranging between??8.51‰ and 3.14‰ indicate relatively low humidity and the alteration of water sources of female dinosaur. The Sr and Ca contents as well as δ18O values of eggshells could be associated with the drinking water and food materials together with dissolved bone apatite. In light of the red-brown colour of surrounding rocks, high Fe composition revealed by macroelement analysis, and the presence of a C3 vegetation with low MAP, the palaeoenvironment of Yudu dinosaur nesting area was most likely to be fluvial and the palaeoclimate was semi-arid to arid, which is conducive to the preservation of eggs.Hepp, J., Wüthrich, L., Bromm, T., Bliedtner, M., Sch?fer, I.K., Glaser, B., Rozanski, K., Sirocko, F., Zech, R., Zech, M., 2019. How dry was the Younger Dryas? Evidence from a coupled δ2H–δ18O biomarker paleohygrometer applied to the Gemündener Maar sediments, Western Eifel, Germany. Climate of the Past 15, 713-733. of the Late Glacial to Early Holocene transition phase and particularly the Younger Dryas period, i.e. the major last cold spell in central Europe during the Late Glacial, are considered to be keys for understanding rapid natural climate change in the past. The sediments from maar lakes in the Eifel, Germany, have turned out to be valuable archives for recording such paleoenvironmental changes.For this study, we investigated a Late Glacial to Early Holocene sediment core that was retrieved from the Gemündener Maar in the Western Eifel, Germany. We analysed the hydrogen (δ2H) and oxygen (δ18O) stable isotope composition of leaf-wax-derived lipid biomarkers (n-alkanes C27 and C29) and a hemicellulose-derived sugar biomarker (arabinose), respectively. Both δ2Hn-alkane and δ18Osugar are suggested to reflect mainly leaf water of vegetation growing in the catchment of the Gemündener Maar. Leaf water reflects δ2H and δ18O of precipitation (primarily temperature-dependent) modified by evapotranspirative enrichment of leaf water due to transpiration. Based on the notion that the evapotranspirative enrichment depends primarily on relative humidity (RH), we apply a previously introduced “coupled δ2Hn-alkane–δ18Osugar paleohygrometer approach” to reconstruct the deuterium excess of leaf water and in turn Late Glacial–Early Holocene RH changes from our Gemündener Maar record.Our results do not provide evidence for overall markedly dry climatic conditions having prevailed during the Younger Dryas. Rather, a two-phasing of the Younger Dryas is supported, with moderate wet conditions at the Aller?d level during the first half and drier conditions during the second half of the Younger Dryas. Moreover, our results suggest that the amplitude of RH changes during the Early Holocene was more pronounced than during the Younger Dryas. This included the occurrence of a “Preboreal Humid Phase”. One possible explanation for this unexpected finding could be that solar activity is a hitherto underestimated driver of central European RH changes in the past.Hill, L.L., Czolowski, E.D., DiGiulio, D., Shonkoff, S.B.C., 2019. Temporal and spatial trends of conventional and unconventional oil and gas waste management in Pennsylvania, 1991–2017. Science of The Total Environment 674, 623-636. significant development of oil and gas from the Marcellus Shale and other geological formations in Pennsylvania over the last decade has generated large volumes of liquid and solid waste. In this paper we use data reported to the Pennsylvania Department of Environmental Protection (PADEP) to examine temporal and spatial trends in generation and management of liquid and solid waste from both conventional and unconventional oil and gas activities in Pennsylvania between 1991 and 2017. While previous assessments have examined this waste inventory in part, no complete assessment of waste quantity, waste types, waste handling practices, and spatial waste tracking has been undertaken using all currently available years of Pennsylvania oil and gas waste data. In 2017 more than half of oil and gas wastewater by volume was reused at well pads to facilitate more hydrocarbon production while the majority of solid waste by volume was disposed of at in-state landfills. The spatial resolution of wastewater generation and handling from unconventional operations has improved substantially with recent regulations and reporting requirements; however, conventional oil and gas development was not held to more stringent reporting requirements and thus spatially-explicit data on wastewater generation and handling from conventional oil and gas development is still lacking. In addition, a third of the liquid waste across all years in the inventory lack a reported final destination. Spatially explicit cradle-to-grave reporting of waste generation and waste handling from both conventional and unconventional oil and gas development is critical to assess potential environmental and human health hazards and risks associated with oil and gas development.Hong, T., Liu, W., Li, M., Chen, C., 2019. Recent advances in the fabrication and application of nanomaterial-based enzymatic microsystems in chemical and biological sciences. Analytica Chimica Acta 1067, 31-47. enzymatic microsystems have strong prospects in chemical and biological analysis due to their low consumption of reagents, fast analysis time, easy manipulation and satisfactory portability. Nanomaterials (NMs) provide a favorable platform for integrating enzymes into microsystems with enhanced selectivity and sensitivity. Various NM-enzyme immobilization strategies applied in the fabrication of capillary-based and chip-based enzymatic microsystems are summarized in this manuscript. We focus on highlighting the advantages of employing NM-based enzymatic microsystems for enantioseparation, inhibitor screening, bioreaction and biosensing. Innovative nanocomposites and NM-functionalized monoliths used to construct multienzymatic microsystems are also illustrated. The general development trend identified in this review indicates that the application of NMs has significantly improved enzymatic microsystem performance.Hooker, C.A., Lee, K.Z., Solomon, K.V., 2019. Leveraging anaerobic fungi for biotechnology. Current Opinion in Biotechnology 59, 103-110. anaerobic fungi are critical for hydrolyzing untreated lignocellulose in the digestive tracts of large herbivorous animals. While these fungi were discovered more than 40 years ago, they remain understudied and underexploited. Recent advances in -omics technologies, however, have enabled studies that reveal significant biosynthetic potential within anaerobic fungal genomes for diverse biotechnological applications. Applications range from enhanced second-generation bioenergy platforms to improved animal health. However, developing gut fungi for these applications will require significant advances in genome engineering technologies for these organisms. Here, we review the biotechnological abilities of anaerobic fungi and highlight challenges that must be addressed to develop them for a range of biotechnological applications.Hotaling, S., Quackenbush, C.R., Bennett-Ponsford, J., New, D.D., Arias-Rodriguez, L., Tobler, M., Kelley, J.L., 2019. Bacterial diversity in replicated hydrogen sulfide-rich streams. Microbial Ecology 77, 559-573. environments typically require costly adaptations for survival, an attribute that often translates to an elevated influence of habitat conditions on biotic communities. Microbes, primarily bacteria, are successful colonizers of extreme environments worldwide, yet in many instances, the interplay between harsh conditions, dispersal, and microbial biogeography remains unclear. This lack of clarity is particularly true for habitats where extreme temperature is not the overarching stressor, highlighting a need for studies that focus on the role other primary stressors (e.g., toxicants) play in shaping biogeographic patterns. In this study, we leveraged a naturally paired stream system in southern Mexico to explore how elevated hydrogen sulfide (H2S) influences microbial diversity. We sequenced a portion of the 16S rRNA gene using bacterial primers for water sampled from three geographically proximate pairings of streams with high (>?20?μM) or low (~?0?μM) H2S concentrations. After exploring bacterial diversity within and among sites, we compared our results to a previous study of macroinvertebrates and fish for the same sites. By spanning multiple organismal groups, we were able to illuminate how H2S may differentially affect biodiversity. The presence of elevated H2S had no effect on overall bacterial diversity (p?=?0.21), a large effect on community composition (25.8% of variation explained, p?<?0.0001), and variable influence depending upon the group—whether fish, macroinvertebrates, or bacteria—being considered. For bacterial diversity, we recovered nine abundant operational taxonomic units (OTUs) that comprised a core H2S-rich stream microbiome in the region. Many H2S-associated OTUs were members of the Epsilonproteobacteria and Gammaproteobacteria, which both have been implicated in endosymbiotic relationships between sulfur-oxidizing bacteria and eukaryotes, suggesting the potential for symbioses that remain to be discovered in these habitats.Hou, H.-s., Wang, C.-s., Zhang, J.-d., Ma, F., Fu, W., Wang, P.-j., Huang, Y.-j., Zou, C.-c., Gao, Y.-f., Gao, Y., Zhang, L.-m., Yang, J., Guo, R., 2018. Deep Continental Scientific Drilling Engineering Project in Songliao Basin: progress in Earth Science research. China Geology 1, 173-186. Songke No.2 well (eastern hole) (referred to as Well SK-2), one of the “two wells and four holes” of the Deep Continental Scientific Drilling Engineering Project in the Songliao Basin, is in Anda City, Heilongjiang Province, and was officially completed on May 26, 2018. The scientific goals of Well SK-2 cover four aspects: paleoclimate research, resource and energy exploration, primary geological research, and development of deep earth exploration techniques. Since the official commencement of drilling in 2014, the Well SK-2 scientific drilling engineering team has organized and implemented drilling for coring, in situ logging, chemical analysis of core elements, and deep structural exploration around the well. Currently, the following preliminary scientific research progress has been made: 4334.81 m in situ core data has been obtained; the centimeter-level high-resolution characterization of the most complete and continuous Cretaceous continental strata ever unearthed has been completed, and the standard profile of continental strata has been initially established; the unconventional natural gas resources and basin-type hot dry rocks in the deep Songliao Basin were found to have good prospects for exploration and development; the climatic evolutionary history of the Cretaceous continental strata was rebuilt for the first time, covering hundreds of thousands to millions of years, and the major events of Cretaceous climate fluctuations have been discovered; all these reveal strong evidence for the subduction and aggregation of paleo-ocean plates, providing a theoretical basis for the re-recognition of the genesis of the Songliao Basin and for deep earth oil and gas exploration. The implementation of the Deep Continental Scientific Drilling Engineering Project in the Songliao Basin is of great significance for exploring the mysteries of the Earth and solving major problems such as those related to the deep energy environment. It is a solid step along the road of “going deep into the Earth”.Houseknecht, D.W., 2019. Petroleum systems framework of significant new oil discoveries in a giant Cretaceous (Aptian–Cenomanian) clinothem in Arctic Alaska. American Association of Petroleum Geologists Bulletin 103, 619-652. oil discoveries in an Aptian–Cenomanian clinothem in Arctic Alaska demonstrate the potential for hundred-million- to billion-barrel oil accumulations in Nanushuk Formation topsets and Torok Formation foresets–bottomsets. Oil-prone source rocks and the clinothem are draped across the Barrow arch, a structural hinge between the Colville foreland basin and Beaufort Sea rifted margin. Stratigraphic traps lie in a favorable thermal maturity domain along multiple migration pathways across more than 30,000 km2 (10,000 mi2). Sediment from the Chukotkan orogen (Russia) filled the western Colville basin and spilled over the Beaufort rift shoulder, forming east- and north-facing shelf margins. Progradational shelf margin trajectories change abruptly to “sawtooth” trajectories at midclinothem, the result of reduction in sediment influx. Two stratigraphic trap types are inferred in Nanushuk basal topsets in the eastern part of the clinothem: (1) lowstand systems tracts, inferred to reflect forced regression, include a narrow, thick progradational stacking pattern perched on a sequence boundary on the upper slope; and (2) highstand-progradational systems tracts include a broad, thin wedge of shingled parasequences above a toplap surface. Both include stratigraphically isolated sandstone sealed by mudstone. Trap geometries in Torok foreset and bottomset facies in the same area include basin-floor fan, slope-apron, and slope-channel deposits that pinch out upslope and are sealed by mudstone. Significant potential exists for the discovery of additional oil accumulations in these stratigraphic trap types in the eastern part of the clinothem. Less potential may exist in the western part because reservoir–seal pairs may not be well developed.Howarth, R.W., 2019. Is shale gas a major driver of recent increase in global atmospheric methane? Biogeosciences Discussions 2019, 1-23. has been rising rapidly in the atmosphere over the past decade, contributing to global climate change. Unlike the late 20th Century when the rise in atmospheric methane was accompanied by an enrichment in the heavier carbon stable isotope (13C) of methane, methane in recent years has become more depleted in 13C. This depletion has been widely interpreted to indicate a primarily biogenic source for the increased methane. Here we show that the change may instead be associated with emissions from shale gas and shale oil development. While methane in conventional natural gas is enriched in 13C relative to the atmospheric mean, shale gas is depleted in 13C relative to this atmospheric level. Correcting for this difference, we conclude that emissions from shale gas production in North America over the past decade may well be the leading cause of the increased flux of methane to the atmosphere. Increased fluxes from biogenic sources such as animal agriculture and wetlands are far less important than indicated by some other recent papers using 13C data.Hu, G., Li, Y., Ye, C., Liu, L., Chen, X., 2019. Engineering microorganisms for enhanced CO2 sequestration. Trends in Biotechnology 37, 532-547. CO2 sequestration not only provides a green and sustainable approach for ameliorating global warming but also simultaneously produces biofuels and chemicals. However, the efficiency of microbial CO2 fixation is still very low. In addition, concomitant microbial CO2 emission decreases the carbon yield of desired chemicals. To address these issues, strategies including engineering CO2-fixing pathways and energy-harvesting systems have been developed to improve the efficiency of CO2 fixation in autotrophic and heterotrophic microorganisms. Furthermore, metabolic pathways and energy metabolism can be rewired to reduce microbial CO2 emissions and increase the carbon yield of value-added products. This review highlights the potential of biotechnology to promote microbial CO2 sequestration and provides guidance for the broader use of microorganisms as attractive carbon sinks.Hu, S., Xiao, C., Liang, X., Cao, Y., Wang, X., Li, M., 2019. The influence of oil shale in situ mining on groundwater environment: A water-rock interaction study. Chemosphere 228, 384-389. shale samples were obtained from Nong'an oil shale ore-bearing area which was located in the southeastern uplift of Songliao basin, China. The XRD test for oil shale identified the minerals in it and a series of water-rock interaction experiment between oil shale-water and oil shale ash-water were carried out to the study the release of organic matter from groundwater during oil shale in-situ exploitation. The content of phenol, BTEX, TOC and TPH in oil shale and oil shale ash aqueous solution were determined. The phenol and TOC in oil shale aqueous solution were higher than that of oil shale ash aqueous solution, conversely, more BTEX and TPH were existed in oil shale ash aqueous solution. The reaction temperature had significant influence on phenol, TOC and TPH in oil shale aqueous solution, which was not obvious in oil shale ash aqueous solution. Besides, the TOC average content in oil shale aqueous solution gradually increased along with the reaction time. The results show that not only oil shale in situ mining process make groundwater organic pollution aggravate but also continuous pollution of groundwater caused by the residual oil shale ash still exist.Huang, R., Wang, C., Chelme-Ayala, P., Fang, Z., Shi, Q., Xu, C., Gamal El-Din, M., 2019. Ferrate oxidation of distinct naphthenic acids species isolated from process water of unconventional petroleum production. Science of The Total Environment 672, 906-915. naphthenic acid (NA) species were isolated from oil sands process water (OSPW) into 20 fractions via silver-ion solid phase extraction, prior to treatment using potassium ferrate(VI). Untreated and treated fractions F1–F20 were characterized using ultra performance liquid chromatography traveling-wave ion mobility time-of-flight mass spectrometry to identify classical NAs (aliphatic O2–NAs mainly found in fractions F1–F4), aromatic NAs (aromatic O2–NAs in F6–F9), oxidized NAs (O3–, O4–, and O5–NAs in F14–F17), and sulfur-containing NAs (F16–F19). The Fe(VI) oxidation reactivity of individual NA species was studied with minimized confounding effects from the complicated OSPW matrix. Aliphatic and aromatic O2–NAs were found to have different reactivity towards Fe(VI) oxidation, with removals ranging from <50% up to 90% at 200?mg/L ferrate dose. The O3–NAs and O4–NAs from raw OSPW were recalcitrant species with slight degradation under Fe(VI) oxidation conditions. The Fe(VI) oxidation of O2–NAs generated new O3–NAs as byproducts or intermediate byproducts which finally resulted in more oxygen-rich Ox–NAs as the final byproducts depending on the Fe(VI) doses. Besides the obtained knowledge on chemical reactivity, current methodology (i.e., treatment of Ag-ion fractions of OSPW versus raw OSPW) could be applied to evaluate other treatment approaches as well as toxicity of distinct NA species for environmental applications.Huang, X., Li, T., Zhao, J., Wang, C., 2019. Rigorous modeling of solubility of normal alkanes in supercritical CO2. Petroleum Science and Technology 37, 1008-1015. this contribution, ANFIS approaches are developed for the prediction of normal alkane solubility in supercritical carbon dioxide. Regarding the economic and environmental benefits of carbon dioxide injection, it introduced as a well-known procedure of EOR. With this in mind that solubility of normal alkanes followed by CO2 injection affected by various operational condition, in this article functionality of solubility of normal alkanes in supercritical carbon dioxide from operational condition was investigated using Adaptive Neuro Fuzzy Interface System (ANFIS). Results demonstrate that the model is precise. The model shows an overall R2 and AARD% estimations of 0.9921 and 0.89%, respectively.Hudson-Edwards, K.A., Byrne, P., Bird, G., Brewer, P.A., Burke, I.T., Jamieson, H.E., Macklin, M.G., Williams, R.D., 2019. Origin and fate of vanadium in the Hazeltine Creek catchment following the 2014 Mount Polley mine tailings spill in British Columbia, Canada. Environmental Science & Technology 53, 4088-4098. from the analysis of aqueous and solid-phase V speciation within samples collected from the Hazeltine Creek catchment affected by the August 2014 Mount Polley mine tailings dam failure in British Columbia, Canada, are presented. Electron microprobe and X-ray absorption near-edge structure (XANES) analysis found that V is present as V3+ substituted into magnetite and V3+ and V4+ substituted into titanite, both of which occur in the spilled Mount Polley tailings. Secondary Fe oxyhydroxides forming in inflow waters and on creek beds have V K-edge XANES spectra exhibiting E1/2 positions and pre-edge features consistent with the presence of V5+ species, suggesting sorption of this species on these secondary phases. PHREEQC modeling suggests that the stream waters mostly contain V5+ and the inflow and pore waters contain a mixture of V3+ and V5+. These data, and stream, inflow, and pore water chemical data, suggest that dissolution of V(III)-bearing magnetite, V(III)- and V(IV)-bearing titanite, V(V)-bearing Fe(-Al-Si-Mn) oxhydroxides, and V-bearing Al(OH)3 and/or clay minerals may have occurred. In the circumneutral pH environment of Hazeltine Creek, elevated V concentrations are likely naturally attenuated by formation of V(V)-bearing secondary Fe oxyhydroxide, Al(OH)3, or clay mineral colloids, suggesting that the V is not bioavailable. A conceptual model describing the origin and fate of V in Hazeltine Creek that is applicable to other river systems is presented.Hui, R., Ding, A., 2019. Generation of petroleum and natural gas in the transformation of organic matter by microbia at different evolution stages. Acta Sedimentologica Sinica 37, 424-431. is produced through biogeological action. Oil generation follows regularity in the deposition of marine or terrestrial facies. The composition and structure of the organic matter exert an influence on the formation of petroleum and natural gas in sediments. For example, materials that easily dissolve in water and have low molecular weight, join with simple compounds in the petroleum formation first. Source materials of lower-maturation oils mainly include algae, low aquatic organisms, low plants, and twigs, leaves, fruits, etc. from terrestrial plants. Their compositions mainly consist of carbohydrates, starch, hemicelluloses, chlorophyll, etc., as well as the short chain and easily dissolved fatty acids and proteins. Microbia mainly include amylolytic bacteria, carbohydrate-splitting bacteria hydrogen-producing bacteria, and others.The organic matter of mature oils mainly originates from the lopoid and protein in organisms and algae, or from the carbohydrates in terrestrial organic matter, in which fat-decomposing bacteria, protelytic bacteria, H2-producing bacteria, etc. grow. In the early stages, fatty acids cannot be dissolved in water. Only when no other superior carbon materials existed in the environment could the microbia grow by using and decomposing lipoids. Fatty acid takes the linear bonding of carbon and hydrogen as the dominant structure within the carboxyl group. Oxygen-containing groups are eliminated, and petroleum can be generated in great quantity. Amino acids are also mainly straight chain structures, and eliminated end carboxyl groups might form hydrocarbons. Fatty acids and protein are transformed to petroleum at the same time, and therefore, the high peak of the generated oil is formed. Source rocks containing abundant organisms are excellent hydrocarbon-generating materials.Thermophile and superthermophilic methanogens subsist at high evolutional stages with great quantity. Their methane-generating model is H2+CO2. Cellulose, xylem, high polymers, and others from terrestrial plants were degraded at the mature stage with difficulty, and yet they might be decomposed and provide carbon for forming CO2 at a high evolutional stage.Microbia degrade organic matter to form petroleum and natural gas. Not only is there a successively settled basin, but also abundant organic matter from source rocks, and oil-generation might take place, which will require the degradation of original materials, elimination of oxygen-containing group, H2-producing bacteria to generate hydrogen H2-expending bacteria to use hydrogen, and other processes, which is more complicated than natural gas formation. Natural gas might be formed at a depth of 10 m in Quaternary reserves, but oil reserves need to be buried below 1 000 m depth within Tertiary strata for formation to occur.Hujslová, M., Bystriansk?, L., Benada, O., Gryndler, M., 2019. Fungi, a neglected component of acidophilic biofilms: do they have a potential for biotechnology? Extremophiles 23, 267-275. from extreme environments, including acidophilic ones, belong to biotechnologically most attractive organisms. They can serve as a source of enzymes and metabolites with potentially uncommon properties and may actively participate within bioremediation processes. In respect of their biotechnological potential, extremophilic fungi are mostly studied as individual species. Nevertheless, microorganisms rarely live separately and they form biofilms instead. Living in biofilms is the most successful life strategy on the Earth and the biofilm is the most abundant form of life in extreme environments including highly acidic ones. Compared to bacterial fraction, fungal part of acidophilic biofilms represents a largely unexplored source of organisms with possible use in biotechnology and especially data on biofilms of highly acidic soils are missing. The functioning of the biofilm results from interactions between organisms whose metabolic capabilities are efficiently combined. When we look on acidophilic fungi and their biotechnological potential we should take this fact into account as well. The practical problem to be resolved in connection with extensive studies of exploitable properties and abilities of acidophilic fungi is the methodology of isolation of strains from the nature. In this respect, novel isolation techniques should be developed.Huo, F., Wang, X., Xu, W., Yang, X., Huang, H., 2019. Comparative analysis of characteristics and genesis of crude oils of the Zs block in the Tazhong area and the Ha 6 block in the Tabei area, Tarim basin. Petroleum Science and Technology 37, 1082-1089. block is located in the north of the Tarim Basin. In this study, the characteristics of the Ordovician crude oil in the Ha6 block were analyzed by the gas chromatography-mass spectrometry (GC-MS) method on the basis of exploration and development data. The results show that C7 compounds are produced by type-I kerogen. According to the comparison, the medium-molecular-weight hydrocarbon fingerprint of the Cambrian crude oil in the Zs block is consistent with that of the Ordovician crude oil in the Ha6 block, which means that their sources are the same. In the two blocks, biological marker compounds of crude oil are also very similar: C27R, C28R, and C29R steranes are in a V-shaped pattern; the Ts/Tm ratio and the content of tricyclic terpanes are both high; and the presence of a large amount of aromatized isoprenoid indicates the crude oil was generated in a strong-reducing environment. In addition, the crude oil single molecule carbon isotope curve is similar with that of Wells Zs1 and Zs5. Therefore, it is comprehensively concluded that the crude oil in the Ordovician reservoirs in the Repu area is mainly supplied by the Cambrian source rock.Huo, F., Wang, X., Xu, Z., Huang, H., Qiang, W., 2019. Cambrian crude oil in ZS well field, Tazhong area: characteristics, genesis, and comparison with Ordovician crude oil. Petroleum Science and Technology 37, 1059-1066. this paper, the Cambrian crude oil and source-rock geochemistry in the ZS well field of Tazhong area, Tarim Basin, was analyzed using the gas chromatography-mass spectrometry (GC-MC). Moreover, the hydrocarbon source in the Tazhong was identified through oil?source correlation. The analysis of light hydrocarbons and biomarkers indicates that the Cambrian and Ordovician protokerogens are of marine sapropelic type formed in a strongly reducing environment. The result of oil-source correlation shows that both Cambrian crude oil in the ZS well field and Ordovician crude oil in the Tazhong area originated in the Cambrian-Lower Ordovician source rocks.Hupp, C.R., Kroes, D.E., Noe, G.B., Schenk, E.R., Day, R.H., 2019. Sediment trapping and carbon sequestration in floodplains of the Lower Atchafalaya Basin, LA: Allochthonous versus autochthonous carbon sources. Journal of Geophysical Research: Biogeosciences 124, 663-677. Recent studies suggest that about 2?Pg of organic C is stored on floodplains worldwide. The present study indicates the Atchafalaya River, fifth largest river in the United States in terms of discharge, traps 30?mm/year of sediment on average within its floodplain, which is the highest average nonepisodic rate of fluvial deposition on the U.S. Coastal Plain. We installed sediment sampling stations at 23 sites, normally in transect, in the Atchafalaya Basin; these sites represent the range of hydrogeomorphic conditions on the floodplain based on hydrologic connectivity with the river main stem. The rate of sedimentation translates into about 12.5?Tg/year and includes 694?Mg/year of organic C. Highest sedimentation rates are associated with areas of high connectivity to channels and prograding deltaic processes. The δ13C content suggests that 35% of deposited C is derived from river-suspended sediment compared to litterfall in the basin. Thus, much of the organic C sequestered is allochthonous material. However, isolated interior sites with limited connectivity to the channel may generate and sequester large amounts of autochthonous C. The substantial trapping of both autochthonous and allochthonous C (392?Mg/year) make this freshwater-forested floodplain critical in storage of material before reaching the coastal delta and estuary. This C deposition rate (340?g C·m-2·yr-1) exceeds all other rates reported in recent Blue Carbon and Tidal Freshwater Forested Wetland studies. Atchafalaya C sequestration occurs in/near areas with tidal influence and like other coastal systems is an important site for trapping mineral and organic sediment and in global C cycling.Hurai, V., ?ernu?ák, I., Randive, K., 2019. Raman spectroscopic study of polysulfanes (H2Sn) in natural fluid inclusions. Chemical Geology 508, 15-29. methane inclusions with up to 68?mol% H2S in metamorphic quartzite from Bastar Craton (India) exhibit common ν1 vibration modes of H2S and CH4 at 2609?cm?1 and 2919?cm?1, respectively, associated with unknown Raman bands at 2488, 2503, 2574, and 2899?cm?1. The fluid inclusions generate molecular hydrogen and surplus sulfur during irradiation with a 532?nm, 25?mW laser, thus indicating photolytic breakdown of polysulfanes – H2Sn. Quantum chemistry modeling based on the density functional theory was conducted to better understand the origin of the unusual Raman bands in the SH-stretching region. Vibrations of simple H2S, H2S2, H2S3, H2S4, H2S5, and S6–8 molecules were simulated together with selected complexes of n?=?1–4 polysulfanes with the crown-shaped, orthorhombic cycloocta-sulfur identified in the fluid inclusions according to intense Raman bands at 60–62, 79–80, 149–151, 218–220, 441–442, and 472–474?cm?1. Theoretical calculations confirmed that the vibrations at 2488, 2503, and 2574?cm?1 reflect symmetric and asymmetric, H-bonded and non-H-bonded H2S2…S8…H2S2, H2S2…S8 and H2S…S8…H2S complexes in the crystallized sulfur melt. A small band at 2899?cm?1 is tentatively attributed to CH3–S8– and/or –CH2–S8– bonds, which also diminished during irradiation with green laser. “Phantom” bands occasionally occurring at >2580?cm?1 were identified as artificial bands, resulting from an imprecise angle of incidence of laser beam to rotatable holographic grating. Another small 2579?±?1?cm?1 band in Raman spectra recorded using longer acquisition times represents a combination band of host quartz, rather than the A12ν4 resonant vibration of CH4 located at the same frequency.Hutchings, J.A., Bianchi, T.S., Kaufman, D.S., Kholodov, A.L., Vaughn, D.R., Schuur, E.A.G., 2019. Millennial-scale carbon accumulation and molecular transformation in a permafrost core from Interior Alaska. Geochimica et Cosmochimica Acta 253, 231-248. carbon stored in high-latitude permafrost represents a potential positive feedback to climate warming as well as a valuable store of paleoenvironmental information. The below-freezing conditions have effectively removed permafrost organic material from the modern carbon cycle and preserved its pre-freezing bulk and molecular states. The conditions that lead to efficient burial of organic carbon (OC) within permafrost were investigated by measuring OC stocks, past accumulation rates, and biogeochemical composition of a permafrost core taken from Interior Alaska dating back to 40?ka. The post-glacial Marine Isotope Stage 1 is represented by the top 1.2?m of the core and contains 64.7?kg?OC/m2 with an accumulation rate of 4.3?g?OC/m2/yr. The sediments that accumulated around the Last Glacial Maximum contain 9.9?kg?OC/m2 with an accumulation rate of 0.5?g OC/m2/yr. Carbon storage (144.7?kg?OC/m2) and accumulation (26.1 g OC/m2/yr) are both observed to be greatest between 35 and 40?ka, late during the Marine Isotope Stage 3 global interstadial. The extent of OC degradation was assessed using lignin and amino acid biomarkers with both approaches indicating well-preserved contemporary active layer and interstadial OC, whereas stadial OC was highly degraded. Lignin compositional indices throughout the core appear altered by sorptive processes that confounded some expected trends in the overall organic matter composition, while amino acids provided a more integrated pattern of change. Significant correlations between carbon-normalized hydroxyproline and total lignin concentrations further support the usefulness of hydroxyproline as an indicator for the abundance of plant organic matter. A novel amino acid plant-microbial index of the ratio of microbial-specific muramic acid and diaminopimelic acid biomarkers to the plant-specific hydroxyproline biomarker, indicate a transition from plant-dominated organic matter in fresh organic soils (index values of 0.01–0.20) to more microbial-dominated organic matter in degraded mineral soils (index values of 0.50–2.50). The branched glycerol dialkyl glycerol tetraether composition is complex and is not immediately compatible with existing temperature transfer functions. Residence time within the active layer is interpreted to integrate key factors such as primary productivity, inorganic sediment delivery, and other climate factors that control soil organic matter degradation. The Marine Isotope Stage 3, mid-Wisconsin interstadial period at this locality was forest-dominated and suggests the currently prevailing tundra ecotone is sensitive to environmental change. The majority of buried permafrost OC is high in degradability and if thawed, would be expected to be highly vulnerable to microbial decomposition.Hutchins, P.D., Russell, J.D., Coon, J.J., 2019. Mapping lipid fragmentation for tailored mass spectral libraries. Journal of The American Society for Mass Spectrometry 30, 659-668. of simulated lipid fragmentation spectra enable the identification of hundreds of unique lipids from complex lipid extracts, even when the corresponding lipid reference standards do not exist. Often, these in silico libraries are generated through expert annotation of spectra to extract and model fragmentation rules common to a given lipid class. Although useful for a given sample source or instrumental platform, the time-consuming nature of this approach renders it impractical for the growing array of dissociation techniques and instrument platforms. Here, we introduce Library Forge, a unique algorithm capable of deriving lipid fragment mass-to-charge (m/z) and intensity patterns directly from high-resolution experimental spectra with minimal user input. Library Forge exploits the modular construction of lipids to generate m/z transformed spectra in silico which reveal the underlying fragmentation pathways common to a given lipid class. By learning these fragmentation patterns directly from observed spectra, the algorithm increases lipid spectral matching confidence while reducing spectral library development time from days to minutes. We embed the algorithm within the preexisting lipid analysis architecture of LipiDex to integrate automated and robust library generation within a comprehensive LC-MS/MS lipidomics workflow.Igun, O.T., Meynet, P., Davenport, R.J., Werner, D., 2019. Impacts of activated carbon amendments, added from the start or after five months, on the microbiology and outcomes of crude oil bioremediation in soil. International Biodeterioration & Biodegradation 142, 1-10. use of activated carbon (AC) amendments to reduce exposure risks for hydrophobic contaminants like polycyclic aromatic hydrocarbons (PAHs) by adsorption is an innovative soil remediation approach. However, AC amendment side-effects on the pollution biodegradation are poorly understood. This study assessed for optimized nutrient ratio conditions, effects of 5% soil wet weight AC amendments, if added from the beginning or after five months, on the outcomes of one year of crude oil polluted soil bioremediation. CO2, residual hydrocarbon concentrations and microbial community structure analysis revealed how AC amendment hindered crude oil biodegradation much more, if added from the start, as compared to after 5 months, i.e. after the initial phase of biodegradation. Putative crude oil degrading microorganisms from the genera Marinobacter, Parvibaculum, Salinibacterium, Muricauda, and Alcanivorax were more sensitive to the AC amendment than those from the genus Rhodococcus. Rhodococci possess hydrophobic cell walls which may enable them to accumulate hydrocarbons in the AC amended soil, despite of their reduced availability. AC amendment from the start had the highest alkane and total US EPA PAH residues, but was more effective than one year of bioremediation, with or without AC amendment after 5 months, in reducing PAH availability in the soil.Iraji, S., Ayatollahi, S., 2019. Experimental investigation on asphaltene biodegradability using microorganism: cell surface properties’ approach. Journal of Petroleum Exploration and Production Technology 9, 1413-1422. precipitation is known to be responsible for serious challenges in oil industry such as wellbore damage, oil flow reduction, and plugging of transportation lines. The traditional methods to remove asphaltene deposition are mostly based on chemical solvent. One of the recent proposed green and cost–effect remedial methods is the application of microorganisms capable of consuming the heavy hydrocarbon chains. The cell surface hydrophobicity among others effectively manipulates the efficiency of the microorganism for asphaltene degradation. Besides, surface active agents would affect the microorganism adhesion and cell surface properties, and alters its hydrophobicity. Investigating the effect of these parameters on biodegradability of asphaltene leads to a better understanding of the microorganism effects on asphaltenic oil. In the current investigation, different asphaltenic solutions with the concentration of 2, 4, and 10?g/l are prepared using different southern Iranian crude oil sources, namely Ahwaz-Bangestan and Kuh-e-Mond oil fields. To estimate asphaltene biodegradability, the solutions were used as a carbon source for three different microorganisms namely Enterobacter cloacae, Enterobacter cloacae, and Pseudomonas aeruginosa for a period of 10 days, while the temperature and rotational speed were kept constant under 40?°C and 150?rpm, respectively. The tests were also repeated using sodium dodecyl benzene sulfonate as surface active agent to evaluate the effect of surfactant on microorganism adhesion and cell surface hydrophobicity. The results pointed to the direct effects of the initial concentration of asphaltene in the solution as well as the presence of surfactant which alters the cells hydrophobicity and leads to more asphaltene biodegradability up to 49%.Isidorova, A., Mendon?a, R., Sobek, S., 2019. Reduced mineralization of terrestrial OC in anoxic sediment suggests enhanced burial efficiency in reservoirs compared to other depositional environments. Journal of Geophysical Research: Biogeosciences 124, 678-688. Freshwater reservoirs are important sites of organic carbon (OC) burial, but the extent to which reservoir OC burial is a new anthropogenic carbon sink is currently unclear. While burial of aquatic OC (by, e.g., phytoplankton) in reservoirs may count as a new C sink, the burial of terrestrial OC in reservoirs constitutes a new C sink only if the burial is more efficient in reservoirs than in other depositional environments. We carried out incubation experiments that mimicked the environmental conditions of different depositional environments along the land-sea continuum (oxic and anoxic freshwater, oxic and anoxic seawater, oxic river bedload, and atmosphere-exposed floodplain) to investigate whether reservoirs bury OC more efficiently compared to other depositional environments. For sediment OC predominantly of terrestrial origin, OC degradation rates were significantly lower, by a factor of 2, at anoxic freshwater and saltwater conditions compared to oxic freshwater and saltwater, river, and floodplain conditions. However, the transformation of predominantly terrestrial OC to methane was one order of magnitude higher in anoxic freshwater than at other conditions. For sediment OC predominantly of aquatic origin, OC degradation rates were uniformly high at all conditions, implying equally low burial efficiency of aquatic OC (76% C loss in 57?days). Since anoxia is more common in reservoirs than in the coastal ocean, these results suggest that reservoirs are a depositional environment in which terrestrial OC is prone to become buried at higher efficiency than in the ocean but where also the terrestrial OC most efficiently is transformed to methane.J?ckle, O., Seah, B.K.B., Tietjen, M., Leisch, N., Liebeke, M., Kleiner, M., Berg, J.S., Gruber-Vodicka, H.R., 2019. Chemosynthetic symbiont with a drastically reduced genome serves as primary energy storage in the marine flatworm Paracatenula. Proceedings of the National Academy of Sciences 116, 8505-8514.: Animals typically store their primary energy reserves in specialized cells. Here, we show that in the small marine flatworm Paracatenula, this function is performed by its bacterial chemosynthetic symbiont. The intracellular symbiont occupies half of the biomass in the symbiosis and has a highly reduced genome but efficiently stocks up and maintains carbon and energy, particularly sugars. The host rarely digests the symbiont cells to access these stocks. Instead, the symbionts appear to provide the bulk nutrition by secreting outer-membrane vesicles. This is in contrast to all other described chemosynthetic symbioses, where the hosts continuously digest full cells of a small and ideally growing symbiont population that cannot provide a long-term buffering capacity during nutrient limitation.Abstract: Hosts of chemoautotrophic bacteria typically have much higher biomass than their symbionts and consume symbiont cells for nutrition. In contrast to this, chemoautotrophic Candidatus Riegeria symbionts in mouthless Paracatenula flatworms comprise up to half of the biomass of the consortium. Each species of Paracatenula harbors a specific Ca. Riegeria, and the endosymbionts have been vertically transmitted for at least 500 million years. Such prolonged strict vertical transmission leads to streamlining of symbiont genomes, and the retained physiological capacities reveal the functions the symbionts provide to their hosts. Here, we studied a species of Paracatenula from Sant’Andrea, Elba, Italy, using genomics, gene expression, imaging analyses, as well as targeted and untargeted MS. We show that its symbiont, Ca. R. santandreae has a drastically smaller genome (1.34 Mb) than the symbiont?s free-living relatives (4.29–4.97 Mb) but retains a versatile and energy-efficient metabolism. It encodes and expresses a complete intermediary carbon metabolism and enhanced carbon fixation through anaplerosis and accumulates massive intracellular inclusions such as sulfur, polyhydroxyalkanoates, and carbohydrates. Compared with symbiotic and free-living chemoautotrophs, Ca. R. santandreae’s versatility in energy storage is unparalleled in chemoautotrophs with such compact genomes. Transmission EM as well as host and symbiont expression data suggest that Ca. R. santandreae largely provisions its host via outer-membrane vesicle secretion. With its high share of biomass in the symbiosis and large standing stocks of carbon and energy reserves, it has a unique role for bacterial symbionts—serving as the primary energy storage for its animal host.Já?ová, J., Gardlo, A., Dimandja, J.-M.D., Adam, T., Friedeck?, D., 2019. Impact of sample dimensionality on orthogonality metrics in comprehensive two-dimensional separations. Analytica Chimica Acta 1064, 138-149. is a key parameter in the evaluation of the performance of a 2D chromatography-based separation system. Two different perspectives on orthogonality are determined: the extent of the separation space utilized (global orthogonality) and the uniformity of the coverage of the separation space (local orthogonality). This work aims to elucidate the impact of sample dimensionality (the number of separation processes involved) on orthogonality evaluation through the use of descriptors from seven different algorithms utilizing mutually different properties of a chromatogram: Pearson correlation, conditional entropy, asterisk equations, convex hull, arithmetic mean (AN) and harmonic mean of the nearest neighbor, and geometric surface coverage (SC). Artificial chromatograms generated in silico and real GC?×?GC separations of diesel, plasma, and urine were used for the evaluation of orthogonality. The sample dimensionality has a deep effect on the orthogonality results of all approaches. The SC algorithm emerged as the best descriptor of local orthogonality samples of both low and high dimensionality, the AN algorithm on the global orthogonality of low-dimensionality samples. However, in the case of samples of high dimensionality, AN consistently indicated just the exploitation of the whole separation space; therefore, only local orthogonality is optimized by means of SC. Since no approach was able to monitor both global and local orthogonality as a single value, a new descriptor, ASCA, was developed. It combines the best global (AN) and local (SC) orthogonality algorithms by averaging, giving the same importance to data spread and crowding. ASCA thus provides the best estimation of orthogonality.Jain, S., Arnepalli, D.N., 2019. Biochemically induced carbonate precipitation in aerobic and anaerobic environments by Sporosarcina pasteurii. Geomicrobiology Journal 36, 443-451. induced calcium carbonate precipitation (MICP) at laboratory scale for modifying the geotechnical properties of soils has been extensively investigated. The successful implementation of MICP in the field encounters many biotic and abiotic challenges. The study aimed to comprehend the role of oxygen availability on the efficacy of MICP catalyzed by S. pasteurii microbe. For this purpose, microbial growth rate, its ureolytic activities and carbonate precipitation by S. pasteurii over aerated, anoxic and anaerobic conditions were studied. The growth rate, ureolytic activity and amount of mineral precipitated were found to be insignificant under anaerobic environment compared to the remaining exposure conditions, which signifies the importance of oxygen for successful implementation of MICP process. The limited ureolytic activities and a minute amount of precipitation observed under anaerobic system were primarily attributed to the enzymes, already produced during the aerobic culture. The rise in the pH during the MICP process was not only because of ureolytic activities but also due to the breakdown of complex proteins in the stationary growth phase. As a whole, the MICP process was significantly inhibited in the absence of oxygen, or without frequent injection of S. pasteurii.Jalilian, M., Tabzar, A., Ghasemi, V., Mohammadzadeh, O., Pourafshary, P., Rezaei, N., Zendehboudi, S., 2019. An experimental investigation of nanoemulsion enhanced oil recovery: Use of unconsolidated porous systems. Fuel 251, 754-762. of nanoparticles in oil and gas industry has attracted considerable attention of engineers and researchers. In this article, the feasibility of nanoemulsion flooding is investigated as a method for Enhanced Oil Recovery (EOR) through coreflooding experiments, using a packed bed and real reservoir fluids. Nine different mixtures of the solvent, surfactant, and nanoparticles in the form of a nanoemulsion phase are generated and used to recover the oil in the context of an EOR process. Various tests are conducted to determine the properties of porous medium and fluids. To study the production performance of this EOR technique, pressure drop across the packed bed are measured, along with the volumetric measurements of the produced fluids. A baseline injection scheme using seawater is also performed. All the nanoemulsion fluids are synthesized using the same base seawater. The Taguchi experimental design approach is employed in this research to design the experiments. The effects of nanoparticles concentration, along with those of surfactant and solvent components of the injection fluid on the oil recovery at the laboratory scale are investigated using the Analysis of Variance (ANOVA) method. Comparing the performance of waterflooding (WF) and nanoemulsion flooding, enhancement in the Recovery Factor (RF) by using emulsions is between 40–107%. Both the pressure and pressure fluctuations are surprisingly higher in the case of WF in comparison to the emulsion flooding. It is also found that under optimal concentration conditions (0.01?g of nanoparticles, 0.015?mL of surfactant, and 1?mL of solvent per one liter of brine), a recovery factor of up to 60% is achieved.Jaramillo, E.A., Royle, S.H., Claire, M.W., Kounaves, S.P., Sephton, M.A., 2019. Indigenous organic-oxidized fluid interactions in the Tissint Mars meteorite. Geophysical Research Letters 46, 3090-3098.: The observed fall and rapid recovery of the Tissint Mars meteorite has provided minimally contaminated samples of the Martian surface. We report analyses of Tissint for organic compounds by pyrolysis‐gas chromatography‐mass spectrometry and for soluble salts by ion chromatography. Pyrolysis‐gas chromatography‐mass spectrometry analysis shows the presence of organic compounds similar to those in the Mars EETA79001 and Nakhla meteorites. The organic profile is dominated by aromatic hydrocarbons, including oxygen and nitrogen‐containing aromatics, and sulfur‐containing species including thiophenes. The soluble salts in Tissint are dominated by sulfate and various oxidation states of chlorine, including perchlorate. The organic compounds and salts in the soils from the Tissint recovery strewn field differ significantly from those found in Tissint suggesting minimal terrestrial contamination. Our results support the hypothesis that the soluble inorganic components of Tissint are most likely a result of indigenous fluid inclusion, thus providing a glimpse into the composition of early Martian fluids.Plain Language Summary: Meteorites that come from Mars usually become contaminated after landing on Earth. One Mars meteorite, named Tissint, was seen falling in the dry Moroccan desert, and many of its pieces were collected within months. We analyzed the meteorite and the local soil for organic compounds and soluble salts. We found differences between the Tissint meteorite and the local soil that suggest that Tissint is uncontaminated. The analyses also showed that the soluble salts in Tissint most likely came from Martian fluids that were similar to terrestrial seawater.Jatiault, R., Loncke, L., Dhont, D., Dubucq, D., Imbert, P., 2019. Geophysical characterisation of active thermogenic oil seeps in the salt province of the lower Congo basin. Part II: A regional validation. Marine and Petroleum Geology 103, 773-791. Lower Congo Basin is known to discharge a substantial volume of oil towards the sea surface, from more than one hundred seafloor seep sites distributed throughout the deep province of the Lower Congo Basin. A large geochemical coring survey confirmed the presence of oil on the seabed. The combination with the seismic data considerably improved the identification of the origin of the oil slicks on the seabed. Multiple specific geophysical characteristics of thermogenic hydrocarbon seep sites were highlighted in a previous detailed analysis of seismic datasets. This study aims to test the characteristics previously identified at regional-scale. The active discharge zone is limited to the distal province of the basin. It is characterised by strong compression/shortening due to the sliding of the post-salt super-sequence, resulting in numerous salt diapirs that control the location of seafloor oil seep sites. The paper describes the bathymetric, reflectivity, amplitude and sub-bottom profiler characteristics of a group of thermogenic seep sites. They correspond essentially to submarine mounds or pockmarks of complex and irregular shape surrounded by hummocky mounds. Active oil pockmarks are systematically associated with positive amplitude anomalies on the seabed and are linked to vertical high-amplitude columns rooted in the seismic reflector and associated with the base of the gas hydrate stability zone. The sub-bottom profiler data shows that the hummocky mounds are connected by a network of faults to high-amplitude bodies buried under a consistent sediment thickness. Based on the definition of specific geophysical features (seafloor mounds, complex shape and irregular pockmarks, positive anomalies of seafloor amplitude, high-amplitude vertical pipes), we identified a series of potential oil seep sites at basin scale. The mounds are particularly recognizable using the seismic curvature attribute; we have identified 2946 individual hummocks that are grouped in 50 zones with a density of 35–240 per km2. They are believed to be associated with asphalt storage on the seafloor and related to the biodegradation of heavy oils during hydrocarbon dysmigration through the sedimentary pile. Unusual double BSRs occur over the study area; these are also a specific feature of thermogenic seep sites. Barely half of the potential sites identified on the seismic datasets are associated with recurrent oil slicks at the sea surface. The proportion of remaining anomalies may be associated with inactive seep sites over the period of satellite-based monitoring or gas-dominated seep sites.Jatiault, R., Loncke, L., Dhont, D., Imbert, P., Dubucq, D., 2019. Geophysical characterisation of active thermogenic oil seeps in the salt province of the lower Congo basin part I: Detailed study of one oil-seeping site. Marine and Petroleum Geology 103, 753-772. report the geophysical characterisation of natural oil seep sites through a combination of sea surface evidence of oil leakage from spatial imagery with a large collection of seafloor and subsurface geophysical data. This paper provides a detailed characterisation of one selected active seep site and identifies possible specific feature of oil seep sites. The oil seep is a complex-shaped feature on the seafloor consisting of a cluster of heterometric pockmarks inside a main depression area and peripheral metre-scale seafloor mounds. A strong deformation related to salt tectonics controls the location of the seafloor source by fracturing the overburden. The associated thermal anomaly induces a vertical modification position of the base of the gas hydrate stability zone (BGHSZ) that is used as a fluid migration route towards the crest of the diapir. The combination of local depressions and seafloor amplitude anomalies linked with vertical high-amplitude pipes rooted on the BGHSZ suggests a focused fluid flow towards the seafloor. In peripheral areas, the seafloor mounds are linked by shallow faults to buried high amplitude patches on sub-bottom profiler sections. The combination of restricted-size seafloor mounds with a progressive deepening of the high amplitude from the seafloor suggests a substantial decrease of the hydrocarbon flow towards peripheral areas. The proximity of actively oil-supplying seafloor depressions and seafloor mounds shows that the hydrocarbon flow rapidly decreases laterally. The thermogenic seep site is affected by two consistent and sub-parallel reflections with negative polarity. The first is interpreted as the methane-related BGHSZ, the second could correspond to the base of a thermogenic BGHSZ produced by a mixture of heavier gas. The seafloor roughness and double BSR appear to be specific features of oil seep sites. The geophysical features revealed at a localised study area will be extrapolated towards a larger province for relevance validation.Jeanne Dit Fouque, K., Ramirez, C.E., Lewis, R.L., Koelmel, J.P., Garrett, T.J., Yost, R.A., Fernandez-Lima, F., 2019. Effective liquid chromatography–trapped ion mobility spectrometry–mass spectrometry separation of isomeric lipid species. Analytical Chemistry 91, 5021-5027. are a major class of molecules that play key roles in different biological processes. Understanding their biological roles and mechanisms remains analytically challenging due to their high isomeric content (e.g., varying acyl chain positions and/or double bond locations/geometries) in eukaryotic cells. In the present work, a combination of liquid chromatography (LC) followed by high resolution trapped ion mobility spectrometry–mass spectrometry (TIMS-MS) was used to investigate common isomeric glycerophosphocholine (PC) and diacylglycerol (DG) lipid species from human plasma. The LC dimension was effective for the separation of isomeric lipid species presenting distinct double bond locations or geometries but was not able to differentiate lipid isomers with distinct acyl chain positions. High resolution TIMS-MS resulted in the identification of lipid isomers that differ in the double bond locations/geometries as well as in the position of the acyl chain with resolving power (R) up to ～410 (R ～ 320 needed on average). Extremely small structural differences exhibiting collision cross sections (CCS) of less than 1% (down to 0.2%) are sufficient for the discrimination of the isomeric lipid species using TIMS-MS. The same level of performance was maintained in the complex biological mixture for the biologically relevant PC 16:0/18:1 lipid isomers. These results suggest several advantages of using complementary LC-TIMS-MS separations for regular lipidomic analysis, with the main emphasis in the elucidation of isomer-specific lipid biological activities.Jeffrey, L.C., Maher, D.T., Johnston, S.G., Maguire, K., Steven, A.D.L., Tait, D.R., 2019. Rhizosphere to the atmosphere: contrasting methane pathways, fluxes, and geochemical drivers across the terrestrial–aquatic wetland boundary. Biogeosciences 16, 1799-1815. wetlands represent the largest natural source of atmospheric CH4, large uncertainties remain regarding the global wetland CH4 flux. Wetland hydrological oscillations contribute to this uncertainty, dramatically altering wetland area, water table height, soil redox potentials, and CH4 emissions. This study compares both terrestrial and aquatic CH4 fluxes in permanent and seasonal remediated freshwater wetlands in subtropical Australia over two field campaigns, representing differing hydrological and climatic conditions. We account for aquatic CH4 diffusion and ebullition rates and plant-mediated CH4 fluxes from three distinct vegetation communities, thereby examining diel and intra-habitat variability. CH4 emission rates were related to underlying sediment geochemistry. For example, distinct negative relationships between CH4 fluxes and both Fe(III) and SO2? were observed. Where sediment Fe(III) and SO2?4 were depleted, distinct positive trends occurred between CH4 emissions and Fe(II)?∕?acid volatile sulfur (AVS). Significantly higher CH4 emissions (p?<?0.01) in the seasonal wetland were measured during flooded conditions and always during daylight hours, which is consistent with soil redox potential and temperature being important co-drivers of CH4 flux. The highest CH4 fluxes were consistently emitted from the permanent wetland (1.5 to 10.5?mmol?m?2?d?1), followed by the Phragmites australis community within the seasonal wetland (0.8 to 2.3?mmol?m?2?d?1), whilst the lowest CH4 fluxes came from a region of forested Juncus spp. (?0.01 to 0.1?mmol?m?2?d?1), which also corresponded to the highest sedimentary Fe(III) and SO2?4. We suggest that wetland remediation strategies should consider geochemical profiles to help to mitigate excessive and unwanted methane emissions, especially during early system remediation periods.Jenniskens, P., Popova, O.P., Glazachev, D.O., Podobnaya, E.D., Kartashova, A.P., 2019. Tunguska eyewitness accounts, injuries, and casualties. Icarus 327, 4-18. airburst events at Chelyabinsk and Tunguska in Russia are the best-documented asteroid impacts of recent times. Models that assess the potential danger from such events rely on an accurate picture of their aftermath. Here, we re-examine the most critical eyewitness accounts of the Tunguska airburst, namely those that describe injuries and casualties, and those that paint a picture of what events were responsible. Not all relevant information has survived in the written record and there are contradictions that create some ambiguity. We find that inside and near the tree-fall area were at least 30 people. Many lost consciousness and at least 3 passed away (immediately or later) as a direct consequence of the Tunguska event. The airburst created a butterfly-shaped pattern of glass damage extending 4–5 times wider than that seen at Chelyabinsk. At these larger distances, any injuries from falls, shattering glass cuts, or from UV radiation exposure were not reported.Jeong, M.S., Noh, D.-H., Hong, E., Lee, K.S., Kwon, T.-H., 2019. Systematic modeling approach to selective plugging using in situ bacterial biopolymer production and its potential for microbial-enhanced oil recovery. Geomicrobiology Journal 36, 468-481. study presents a systematic modeling approach for examining the efficiency of the MEOR process based on in situ selective plugging by bacterial biopolymer production and optimization of the nutrient injection strategy to yield the maximum oil recovery. This study focuses on modeling in situ selective plugging by the bacterial biopolymer dextran that is generated by Leuconostoc mesenteroides. Bacterial growth and dextran generation were described by a stoichiometric equation and kinetic reactions using batch model simulation. Based on the parameters for permeability reduction obtained from the sandpack model, the MEOR process was implemented in a pilot-scale system that included a highly permeable thief zone in a low-permeability reservoir. The base MEOR design yielded a 61.5% improvement of the recovery factor compared to that obtained with waterflooding. The parametric simulations revealed that the recovery efficiency was influenced by the amount of dextran, as well as the distribution of dextran, and thus, the injection strategy is critical for controlling the dextran distribution. By incorporating the results from the sensitivity analysis and optimization to determine the optimal design parameters, a 36.7% improvement of the oil recovery was achieved with the optimized MEOR process in comparison with the base case.Ji, Y., Hou, J., Cui, G., Lu, N., Zhao, E., Liu, Y., Du, Q., 2019. Experimental study on methane hydrate formation in a partially saturated sandstone using low-field NMR technique. Fuel 251, 82-90. of hydrate formation in the porous media is important for carbon storage and the feasibility assessment of developing natural gas hydrates. In this study, we used a novel and real-time monitoring apparatus which combined the hydrate formation system with the low-field nuclear magnetic resonance measurement system to study on the characteristics of methane hydrate formation in a partially saturated sandstone. Results show that hydrate coexists with water and methane in the sandstone at the end of methane hydrate formation by an excess-gas method. Magnetic resonance imaging shows that the spatial distribution of hydrate is affected by the initial distribution of water in the sandstone. Water content plays a role in controlling the termination of hydrate formation. Based on the transverse relaxation time distribution analysis, free gas exists mainly in the large pores, while methane molecules can enter the small pores by dissolution and diffusion, forming methane hydrate with water molecules in the absence of free gas. Methane hydrate is formed in the center of both large and small pores by the excess-gas method. The rate of methane hydrate formation is slower in the small pores than that in the large pores. The range of pore size gradually decreases with the hydrate formation.Jiang, F., Hu, T., Liu, L., Wang, Q., Gao, X., Zhang, P., Li, H., Ning, K., Liu, Y., Zhu, C., 2019. Geochemical and geological characteristics of the Jurassic continental black shale in the Southwestern Depression of Tarim Basin. Geological Journal 54, 1115-1131. Jurassic continental black shale within the Southwestern Depression of Tarim Basin (SDT) have received renewed attention during the past few years due to their potential to be prospected for shale gas, studies on shale characteristics remain rare. In this study, 31 black shale core samples were collected from a well (Buya‐1) drilled recently in the Hetian Sag of the southern SDT, and their geochemical, petrographical, mineralogical, petrophysical, and pore structural characteristics were determined through a series of tests. The results indicate that the black shale has high and variable total organic carbon (TOC) contents ranging between 0.1% and 17.0% (average 3.2%), is dominated by Type III kerogen (gas‐prone), and is in a mature to high‐mature stage. The shale is mainly composed of quartz, clay, and feldspar with mean contents of 40.0% (range = 15.0–72.0%), 51.0% (range = 25–77%), and 5.5% (range = 1–13.0%), respectively. The pore spaces are composed of primary pores, secondary pores, and microfractures. The mean sorbed gas content of the shale is approximately 2.4 m3/t, and the TOC is significantly positively and linearly correlated with the adsorbed gas capacity. The results show that the Jurassic continental shale in the SDT is very favourable for the formation of a large shale gas play, and the middle segment of the Jurassic shale is the most favourable target layer for shale gas exploration due to its greater gas generation capacity, higher mineralogical brittleness, larger gas storage space, and greater gas sorption capacity. This study is significant in guiding subsequent shale gas exploration and development in the Jurassic, SDT, and also is a reference for identifying favourable exploration targets of shale gas resource in other continental basins.Jiang, K., Lin, C., Peng, L., Zhang, X., Cai, C., 2019. Methyltrimethyltridecylchromans (MTTCs) in lacustrine sediments in the northern Bohai Bay Basin, China. Organic Geochemistry 133, 1-9. methyltrimethyltridecylchromans (MTTCs) have been identified and studied for over 30?years in a large number of sediment extracts and crude oils, their origins and significance for palaeosalinity are still debated. Here, the geochemical features of MTTCs in 133 organic-rich lacustrine sediments obtained from the northern Bohai Bay Basin, China, are studied in detail. The sediment samples are in an immature to early mature stage and primarily enriched in Types I and II organic matter, which were deposited in lacustrine environments with relatively weakly stratified water columns and anoxic to suboxic conditions. The development of photic zone euxinia (PZE) in the water column was indicated by the occurrence of aryl isoprenoids. MTTCs were detected in all samples and characterized by low abundances of δ-MTTC and high abundances of α-MTTC. Variations in the relative abundance of MTTCs and calculated MTTCI values, suggest that selected lacustrine sediments were deposited in normal to semi-saline environments. A ternary diagram of mono-, di- and trimethyl-MTTCs was established, and shows potential for application as an indicator of changes in palaeosalinity. Variations in the abundance of MTTCs can effectively indicate palaeosalinity changes in lacustrine environments.Jiménez-Serratos, G., Totton, T.S., Jackson, G., Müller, E.A., 2019. Aggregation behavior of model asphaltenes revealed from large-scale coarse-grained molecular simulations. The Journal of Physical Chemistry B 123, 2380-2396. atomistic simulations of models of asphaltenes in simple solvents have allowed the study of trends in aggregation phenomena to understand the underlying role played by molecular structure. The detail included at this scale of molecular modeling is, however, at odds with the required spatial and temporal resolution needed to fully understand asphaltene aggregation. The computational cost required to explore the relevant scales can be reduced by employing coarse-grained (CG) models, which consist of lumping a few atoms into a single segment that is characterized by effective interactions. In this work, CG force fields developed via the statistical associating fluid theory (SAFT-γ) [Müller, E. A.; Jackson, G. Annu. Rev. Chem. Biomol. Eng. 5, 2014, 405?427] equation of state (EoS) provide a reliable pathway to link the molecular description with macroscopic thermophysical data. A recent modification of the SAFT-VR EoS [Müller, E. A.; Mejía, A. Langmuir 33, 2017, 11518?11529], which allows for the parameterization of homonuclear rings, is selected as the starting point to develop CG models for polycyclic aromatic hydrocarbons. The new aromatic-core models, along with others published for simpler organic molecules, are adopted for the construction of asphaltene models by combining different chemical moieties in a group-contribution fashion. We apply the procedure to two previously reported asphaltene models and perform molecular dynamics simulations to validate the coarse-grained representation against benchmark systems of 27 asphaltenes in a pure solvent (toluene or heptane) described in a fully atomistic fashion. An excellent match between both levels of description is observed for the cluster size, radii of gyration, and relative-shape-anisotropy-factor distributions. We exploit the advantages of the CG representation by simulating systems containing up to 2000 asphaltene molecules in an explicit solvent investigating the effect of asphaltene concentration, solvent composition, and temperature on aggregation. By studying large systems facilitated by the use of CG models, we observe stable continuous distributions of molecular aggregates at conditions away from the two-phase precipitation point. As a further example application, a widely accepted interpretation of cluster-size distributions in asphaltenic systems is challenged by performing system-size tests, reversibility checks, and a time-dependence analysis. The proposed coarse-graining procedure is seen to be general and predictive and, hence, can be applied to other asphaltenic molecular structures.Jimoh, A.A., Lin, J., 2019. Enhancement of Paenibacillus sp. D9 lipopeptide biosurfactant production through the optimization of medium composition and its application for biodegradation of hydrophobic pollutants. Applied Biochemistry and Biotechnology 187, 724-743. in biosurfactant in industrial and environmental applications have increased considerably in recent years, owing to their potential benefits over synthetic counterparts. The present study aimed at analyzing the stability and oil removal efficiency of a new lipopeptide biosurfactant produced by Paenibacillus sp. D9 and its feasibility of its use in biotechnological applications. Paenibacillus sp. D9 was evaluated for optimal growth conditions and improved production yield of lipopeptide biosurfactant with variations in different substrate parameters such as carbon (C), nitrogen (N), C:N: ratio, metal supplements, pH, and temperature. Enhanced biosurfactant production was observed when using diesel fuel and ammonium sulfate as carbon and nitrogen source respectively. The maximum biosurfactant yield of 4.11?g/L by Paenibacillus sp. D9 occurred at a C/N ratio of 3:1, at pH 7.0, 30?°C, 4.0?mM MgSO4, and 1.5% inoculum size. The D9 biosurfactant was found to retain surface-active properties under the extreme conditions such as high thermal, acidic, alkaline, and salt concentration. The ability to emulsify further emphasizes its potential usage in biotechnological application. Additionally, the lipopeptide biosurfactant exhibited good performance in the degradation of highly toxic substances when compared with chemical surfactant, which proposes its probable application in biodegradation, microbial-enhanced oil recovery or bioremediation. Furthermore, the biosurfactants were effective in a test to stimulate the solubilization of hydrophobic pollutants in both liquid environments removing 49.1 to 65.1% diesel fuel including hydrophobic pollutants. The study highlights the usefulness of optimization of culture parameters and their effects on biosurfactant production, high stability, improved desorption, and solubilization of hydrophobic pollutants.Johnson, J.E., Molnar, P.H., 2019. Widespread and persistent deposition of iron formations for two billion years. Geophysical Research Letters 46, 3327-3339.: Composed of chemical precipitates rich in iron and silica, Precambrian iron formations from marine sedimentary records may reveal biogeochemical processes over the first half of Earth history. The limited record of early Archean rock suggests that preservation biases the iron formation record. Like ophiolites, which provide a sparse record of past ocean floor, iron formations deposited on oceanic crust ought to also be rare and preserved only when accreted onto cratons. To correct for potential preservation bias, we scaled masses of iron formations to the areal extent of basement rock of similar age and found that the resultant record is consistent with persistent deposition of iron formations across much of the deep ocean for two billion years. Widespread and long‐term iron formations imply that ferrous iron was available in the deep ocean for billions of years and that the requisite (bio)geochemical mechanisms to produce iron formations were present by 3.8 Ga.Plain Language Summary: Why did the ancient ocean deposit an increasing volume of iron over time, until these “Iron Formations” largely disappeared? Does this pattern reflect a growing titration of oxygen, a surge in iron from mantle superplumes, or the prerequisite of developing continental crust? Or is this distribution simply from the diminishing record of ancient rocks? We normalize the iron formation record over time by scaling it to crustal preservation, and the preservation‐scaled record suggests that there may have been widespread and unchanging deposition of these iron formations across the ancient oceans for two billion years—implying that the (bio)chemical process responsible for making iron formations operated from ~3.8 to ~1.8 billion years ago.Johnson, J.T., Lee, K.W., Bhanot, J.S., McLuckey, S.A., 2019. A miniaturized Fourier transform electrostatic linear ion trap mass spectrometer: Mass range and resolution. Journal of The American Society for Mass Spectrometry 30, 588-594. resolution (M/ΔMFWHM) was increased by reducing the axial length of a Fourier transform electrostatic linear ion trap (FT-ELIT) mass spectrometer. The increase in mass resolution corresponds directly to increased axial ion frequencies in the FT-ELIT. Increased mass resolution was demonstrated for equivalent transient lengths in a 5.25″ versus 2.625″ ELIT using the isotopes of [bradykinin+2H]2+ and [insulin+5H]5+ as test ions. Both bradykinin and insulin show mass resolution increases of ~?90% allowing baseline resolution of the [insulin+5H]5+ isotopes after only 300?ms of data acquisition. Relative changes in mass/charge range were explored using mirror switching to trap ions injected axially into the ELIT. When trapping ions using mirror switching, the mass/charge range in a FT-ELIT mass spectrometer for a given switch time is determined by the time required for fast ions to enter and exit the trap after one reflection versus the time it takes for slow ions to enter the trap. By reducing the length of the FT-ELIT mass spectrometer while maintaining a constant distance from the point from which ions are initially accelerated to the entrance mirror, only the low m/z limit is affected for a given mirror switching time. For the two ELIT lengths examined here, the effective mass/charge range at any given switch time is reduced from m/zlow-8.9*m/zlow for the 5.25″ ELIT to m/zlow-5.2*m/zlow for the 2.625″ ELIT.Johnston, C.O., Stern, E.C., 2019. A model for thermal radiation from the Tunguska airburst. Icarus 327, 48-59. paper develops a model for simulating the radiative flux reaching the ground originating from a meteor shock-layer and wake. The area of radiant burn measured for the Tunguska event provides a test case for the developed model. This model applies recently developed computational fluid dynamic simulations, which include the impact of ablation and radiation on the shock-layer flowfield, and ray-tracing radiation transport with atmospheric absorption. The impact of the meteor view angle is shown to significantly impact the radiative flux. Looking at the meteor along the flight path (head-on) results in lower radiative heating because it reduces the wake field of view, where the large radiating wake is shown to provide a significant contribution to the radiative flux (when viewed from the side). The impact of ablation on the ground radiative flux is negligible because the ablation products are limited to the optically-thick core of the wake. The resulting simulated radiative flux values are correlated as a function of velocity, altitude, view angle, and meteoroid radius. This correlation is then applied to potential Tunguska entry trajectories to provide a simulated ground heating footprint. Comparing this simulated footprint with the measured radiant burn area provides a metric for assessing unknown Tunguska entry parameters. Using this approach, the initial radius resulting in good agreement with the measured radiant burn footprint was found for a range of maximum debris cloud radii, entry angles, and velocities. The resulting optimal initial radii were between 30 and 45?m for the entire range of cases considered. This provides a valuable constraint on initial radius for complementary Tunguska studies, such as blast-wave simulations that aim to reproduce the tree-fall pattern.J?rgensen, B.B., Beulig, F., Egger, M., Petro, C., Scholze, C., R?y, H., 2019. Organoclastic sulfate reduction in the sulfate-methane transition of marine sediments. Geochimica et Cosmochimica Acta 254, 231-245. and methane diffuse vertically along opposed concentration gradients into the sulfate-methane transition in subsurface marine sediments where anaerobic oxidation of methane with sulfate takes place. The stoichiometry of this process is 1:1, yet the calculated sulfate flux often exceeds the calculated methane flux. Our aim was to determine whether organoclastic sulfate reduction, fueled by the oxidation of buried organic matter, explains this excess sulfate flux into the sulfate-methane transition. We analyzed data for sulfate, methane and sulfate reduction from eight sites in Danish coastal waters. Fluxes of sulfate and methane were determined by diffusion-reaction modeling whereas sulfate reduction rates were determined by 35S radiotracer experiments at high depth resolution. The sulfate reduction data showed that the organic carbon mineralization rates followed a log-log linear depth trend throughout the sulfate zone. Extrapolation of this power law trend down into the sulfate-methane transition showed organic carbon oxidation corresponded to 14–59% of the total sulfate flux into the zone and in average explained 82% of the excess sulfate consumption above the 1:1 stoichiometry. A part of the excess sulfate was consumed directly by organoclastic sulfate reduction while a part drove a cryptic methane cycle by which the organic matter was degraded to methane and the methane concurrently oxidized to CO2 with sulfate. We extrapolated the same power law trend down through the methanogenic zone and found that this provided a good estimate of total methanogenesis in the sediment column when compared to the upward flux of methane.Ju, R., Liu, X., Zheng, F., Zhao, X., Lu, X., Zeng, Z., Lin, X., Xu, G., 2019. Removal of false positive features to generate authentic peak table for high-resolution mass spectrometry-based metabolomics study. Analytica Chimica Acta 1067, 79-87. metabolomics research, false positive features from non-sample sources and noises usually exist in the peak table, they will make the results of screening differential metabolites or biomarkers unreliable. In this study, a method to remove false positive features (rFPF) was developed to improve the quality of the peak table. rFPF recognizes real peak profiles based on the information entropy and statistical correlation, and eliminates false positive features from non-sample sources and noises. A standard mixture with 42 standards (14 isotopic labeled internal standards and 28 common standards) and a urine sample were applied to evaluate the effectiveness of the rFPF method. The analysis results of metabolite standards showed that more than 92% false positive features were removed by rFPF, but target standards completely remained. The analysis results of urine sample showed that the number of features was significantly reduced from 7182 to 2522. Interestingly, 98% of the identified metabolites remained after removing false positive features. The proposed rFPF shows great prospects as a new data handling method for metabolomics studies. The MATLAB code and data will be uploaded ().Ju, Y.-w., Huang, C., Sun, Y., Zou, C.-n., He, H.-p., Wan, Q., Wang, X.-q., Lu, X.-c., Lu, S.-f., Wu, J.-g., Chao, H.-t., Liu, H.-l., Qiu, J.-s., Huang, F., Zhu, H.-j., Cai, J.-c., Sun, Y., 2018. Nanogeology in China: A review. China Geology 1, 286-303. is a subject that is a combination of geology and nanoscale science, and it has been a frontier field in recent years. It is also a new subject with the features of intersectionality and multidisciplinary. Digging deeper into geological problems and nanoscale phenomena helps better revealing the more essential mechanisms and processes in geological science, which is also an evitable path in the development of geology. In this paper, we elaborate the concept, feature and main subdisciplines, and summarize three stages of nanogeology development from preliminary research in the 1990s to subject formation in China. After summarizing the researchers’ achievements in this field, we illustrate some primary research progresses of nanogeology in China as eight subdisciplines. On the basis of the above content, we propose the development prospect of nanogeology in China. There are many geologic problems with scientific values and economic benefits, such as research of geologic fundamental problems, resource exploration and development, mechanism study and prediction of geological activities (disasters), mechanism research and management of environmental pollution and others. Nanogeology has a great potential in China to solve all of these problems. As a result, the theories and methods of nanogeology will become enriching and advanced. It offers important theoretical basis and technological methods to deal with major issues concerning the national economy and the people’s livelihoods, such as the prediction of geological activities, as well as resource distribution and its exploration and utilization.Junghare, M., Spiteller, D., Schink, B., 2019. Anaerobic degradation of xenobiotic isophthalate by the fermenting bacterium Syntrophorhabdus aromaticivorans. The ISME Journal 13, 1252-1268. aromaticivorans is a syntrophically fermenting bacterium that can degrade isophthalate (3-carboxybenzoate). It is a xenobiotic compound which has accumulated in the environment for more than 50 years due to its global industrial usage and can cause negative effects on the environment. Isophthalate degradation by the strictly anaerobic S. aromaticivorans was investigated to advance our understanding of the degradation of xenobiotics introduced into nature, and to identify enzymes that might have ecological significance for bioremediation. Differential proteome analysis of isophthalate- vs benzoate-grown cells revealed over 400 differentially expressed proteins of which only four were unique to isophthalate-grown cells. The isophthalate-induced proteins include a phenylacetate:CoA ligase, a UbiD-like decarboxylase, a UbiX-like flavin prenyltransferase, and a hypothetical protein. These proteins are encoded by genes forming a single gene cluster that putatively codes for anaerobic conversion of isophthalate to benzoyl-CoA. Subsequently, benzoyl-CoA is metabolized by the enzymes of?the anaerobic benzoate degradation pathway that were identified in the proteomic analysis. In vitro enzyme assays with cell-free extracts of isophthalate-grown cells indicated that isophthalate is activated to isophthalyl-CoA by an ATP-dependent isophthalate:CoA ligase (IPCL), and subsequently decarboxylated to benzoyl-CoA by a UbiD family isophthalyl-CoA decarboxylase (IPCD) that requires a prenylated flavin mononucleotide (prFMN) cofactor supplied by UbiX to effect decarboxylation. Phylogenetic analysis revealed that IPCD is a novel member of the functionally diverse UbiD family (de)carboxylases. Homologs of the IPCD encoding genes are found in several other bacteria, such as aromatic compound-degrading denitrifiers, marine sulfate-reducers, and methanogenic communities in a terephthalate-degrading reactor. These results suggest that metabolic strategies adapted for degradation of isophthalate and other phthalate are conserved between microorganisms that are involved in the anaerobic degradation of environmentally relevant aromatic compounds.Kadesch, P., Quack, T., Gerbig, S., Grevelding, C.G., Spengler, B., 2019. Lipid topography in Schistosoma mansoni cryosections, revealed by microembedding and high-resolution atmospheric-pressure matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging. Analytical Chemistry 91, 4520-4528. are parasitic platyhelminthes that cause schistosomiasis, which is a life-threatening infectious disease for humans in the tropics and subtropics worldwide. Within the human host, female and male schistosomes develop and pair as a prerequisite for egg production. Part of the eggs get lodged in organs such as the gut, spleen, and liver, where they cause severe inflammatory processes, including liver fibrosis, which is one of the most serious pathological symptoms. High-resolution atmospheric-pressure scanning microprobe matrix-assisted laser desorption/ionization (AP-SMALDI) mass spectrometry imaging (MSI) has been used as a powerful tool to investigate adult schistosomes at the topographic molecular level. An MSI-compatible protocol was developed, covering critical sample preparation steps and focusing on obtaining artifact-free, longitudinal cryosections. Planar, consecutive sections were prepared from ～400 μm thick S. mansoni worm couples, comparing several microembedding approaches. High-resolution MSI at both, 10 and 5 μm lateral resolution unraveled anatomical structures and differential abundances of glycerophospholipids and saccharides in females and males. In addition, glycerophospholipids occurred differentially abundant in worm tissues of the female, such as the gut, which is essential for nutrient uptake and subsequent metabolism. Fragment ions of isobaric phospholipids were investigated by on-tissue MS2 imaging experiments, unambiguously showing isomer-specific ion signals. This study provides a solid basis for investigating schistosome parasites in chemical detail at the whole-worm level by MSI.Kaminski, T., Husein, M.M., 2019. Kinetic modelling of thermal cracking of Arabian atmospheric and vacuum residue. Fuel Processing Technology 189, 89-97. modelling of Arabian atmospheric residue (AR) and vacuum residue (VR) undergoing thermal cracking at 400?°C to 420?°C in an autoclave is detailed in this study. A five-lump model based on the gas, coke, asphaltene, maltene and distillate fractions is developed. Three reaction schemes encompassing 6, 10 or 13 reaction pathways, with the corresponding fitted parameters, are compared. Additionally, coke induction is captured using a step function. Fitting AR experimental results revealed that the root mean squared deviations (RMSE) for the 6-reaction scheme almost equalled the 10- and the 13-reaction schemes and the fit showed the same accuracy. The 6-reaction scheme model was then fitted to slurry catalytic thermal cracking of AR mediated by drill cuttings. A comparison between the kinetic parameters confirmed the catalytic role of the drill cuttings, despite their non-porous morphology, and lower activation energy for distillate formation was observed. Lastly, the 6-reaction, AR-fitted model was employed to predict experimental data from non-catalytic and catalytic thermal cracking of VR. The model could predict the non-catalytic runs to a better extent. Failure to predict the catalytic cracking of VR is attributed to rapid deactivation of the drill cuttings arising from the difference in the nature and concentration of asphaltenes and the hydrogen donors in the VR relative to the AR feedstock.Kang, Y., Rao, Q., Zhao, Q., Wang, H., 2019. Exploration and development potential of the low-maturity continental shale gas in the Fuxin Basin Natural Gas Industry 39, 21-31. order to promote the exploration and development of continental shale gas reservoirs in China further, we systematically summarized the geological features of typical continental shale, such as the Ordos Basin. Then, the shale gas reservoir characteristics, geochemical characteristics and fracturing performance of the Lower Cretaceous Shahai Fm in the Fuxin Basin were analyzed by using the data of TOC contents, rock specific surface, pore size distribution and X-ray diffraction analysis of the whole rock. Based on this, it was compared with the marine/continental shale gas reservoirs from the aspect of geological feature. Finally, the shale gas reservoir and resource potential of the Shahai Fm were evaluated. And the following research results were obtained. First, the formation age of China's continental shale is later, its TOC contents vary in a large range, and its organic matters are mainly of a mixed-humic type. And it is characterized by low thermal evolution degree, low quartz content, high feldspar content, high carbonate content, and comparability of total brittle mineral content to marine shale. Second, shale in the Shahai Fm has shallow burial depth and its mineral composition is dominated by quartz, feldspar and carbonate minerals. Its pores are mainly mesopores with an average porosity of 3.47%. There are diverse reservoir spaces, which is favorable for the accumulation of shale gas. Third, the TOC content of the Shahai Fm shale is mainly above 2%, with a moderate thermal evolution degree of organic matter and high gas content. Fourth, the total brittle mineral content of Shahai Fm shale is up to 60%, indicating a good fracturing performance. Fifth, shale reservoirs in the Shahai Fm can be classified into three categories. Type one is target reservoirs of exploration and development, and Type two is favorable reservoirs. It is estimated that the amount of shale gas resources are in the range of 232.2–286.2 billion m3. It is concluded that the Shahai Fm shale in the Fuxin Basin has both resource potential in geology and fracturing performance in engineering, and its exploration and development prospect is broad. What's more, the potential of commercial shale gas development is great in the sweet-point areas.Kaplan, H.H., Milliken, R.E., Alexander, C.M.O.D., Herd, C.D.K., 2019. Reflectance spectroscopy of insoluble organic matter (IOM) and carbonaceous meteorites. Meteoritics & Planetary Science 54, 1051-1068. organic matter (IOM) is the major organic component of chondritic meteorites and may be akin to organic materials from comets and interplanetary dust particles (IDPs). Reflectance spectra of IOM in the range 0.35–25 μm are presented as a tool for interpreting organic chemistry from remote measurements of asteroids, comets, IDPs, and other planetary bodies. Absorptions in the IOM spectra were strongly related to elemental H/C (atom) ratio. The aliphatic 3.4 μm absorption in IOM spectra increased linearly in strength with increasing H/C for H/C > 0.4, but was absent at lower H/C values. When meteorite spectra from the Reflectance Experiment Laboratory (RELAB) spectral catalog (n = 85) were reanalyzed at 3.4 μm, this detection limit (H/C > 0.4) persisted. Aromatic absorption features seen in IOM spectra were not observed in the meteorite spectra due to overlapping absorptions. However, the 3.4 μm aliphatic absorption strength for the bulk meteorites was correlated with both H/C of the meteorite's IOM and bulk C (wt%). Gaussian modeling of the 3 μm region provided an additional estimate of bulk C for the meteorites, along with bulk H (wt%), which is related to phyllosilicate abundance. These relationships lay the foundation for determining organic and phyllosilicate abundances from reflectance spectra. Both the full IOM spectra and the spectral parameters discussed here will aid in the interpretation of data from asteroid missions (e.g., OSIRIS‐REx, Hayabusa2), and may be able to place unknown spectral samples within the context of the meteorite collection.Karambeigi, M.A., Fallah, N., Nikazar, M., Kharrat, R., 2019. A novel test method for evaluate asphaltene inhibitor efficiency on reservoir rock. Petroleum Science and Technology 37, 1238-1242. deposits can reduce the productivity of the reservoir as well as foul piping and surface equipment. Current chemical and mechanical methods for treating deposition are only partially effective partly because the deposition process is poorly understood. The most commonly way to asphaltene precipitation reduction is applying an asphaltene inhibitor. In order to investigate the extent of formation damage by asphaltenes in crude oil this work has used electro kinetic technique to study the adsorption of asphaltenes in rock pores. Most researchers investigate the kinetics of adsorption by monitoring changes in the concentration of asphaltene or polymer in a dispersion of adsorbent particles or capillaries. This study is a coherent approach to measure amount of asphaltene adsorption on rock surface and survey effect of asphaltene inhibitors on precipitation reduction in porous media.Kast, E.R., Stolper, D.A., Auderset, A., Higgins, J.A., Ren, H., Wang, X.T., Martínez-García, A., Haug, G.H., Sigman, D.M., 2019. Nitrogen isotope evidence for expanded ocean suboxia in the early Cenozoic. Science 364, 386-389.: The million-year variability of the marine nitrogen cycle is poorly understood. Before 57 million years (Ma) ago, the 15N/14N ratio (δ15N) of foraminifera shell-bound organic matter from three sediment cores was high, indicating expanded water column suboxia and denitrification. Between 57 and 50 Ma ago, δ15N declined by 13 to 16 per mil in the North Pacific and by 3 to 8 per mil in the Atlantic. The decline preceded global cooling and appears to have coincided with the early stages of the Asia-India collision. Warm, salty intermediate-depth water forming along the Tethys Sea margins may have caused the expanded suboxia, ending with the collision. From 50 to 35 Ma ago, δ15N was lower than modern values, suggesting widespread sedimentary denitrification on broad continental shelves. δ15N rose at 35 Ma ago, as ice sheets grew, sea level fell, and continental shelves narrowed.Editor's summary: Circulation more than temperature. Changes in continental configuration and sea level affected the ocean's oxygen levels and the rate of denitrification between 70 and 30 million years ago. That finding by Kast et al. shows a fundamental difference from the modern ocean, in which the extent of suboxia is controlled primarily by global temperature. Changes in the nitrogen isotopic composition of marine organic matter correlate with the collision of India and Asia and the circulation changes that occurred as a result. Later, isotopic composition changed further in response to a fall in sea level as global cooling caused ice sheets to grow.Kato, S., Igarashi, K., 2019. Enhancement of methanogenesis by electric syntrophy with biogenic iron-sulfide minerals. MicrobiologyOpen 8, Article e00647. Recent studies have shown that interspecies electron transfer between chemoheterotrophic bacteria and methanogenic archaea can be mediated by electric currents flowing through conductive iron oxides, a process termed electric syntrophy. In this study, we conducted enrichment experiments with methanogenic microbial communities from rice paddy soil in the presence of ferrihydrite and/or sulfate to determine whether electric syntrophy could be enabled by biogenic iron sulfides. Although supplementation with either ferrihydrite or sulfate alone suppressed methanogenesis, supplementation with both ferrihydrite and sulfate enhanced methanogenesis. In the presence of sulfate, ferrihydrite was transformed into black precipitates consisting mainly of poorly crystalline iron sulfides. Microbial community analysis revealed that a methanogenic archaeon and iron- and sulfate-reducing bacteria (Methanosarcina, Geobacter, and Desulfotomaculum, respectively) predominated in the enrichment culture supplemented with both ferrihydrite and sulfate. Addition of an inhibitor specific for methanogenic archaea decreased the abundance of Geobacter, but not Desulfotomaculum, indicating that Geobacter acquired energy via syntrophic interaction with methanogenic archaea. Although electron acceptor compounds such as sulfate and iron oxides have been thought to suppress methanogenesis, this study revealed that coexistence of sulfate and iron oxide can promote methanogenesis by biomineralization of (semi)conductive iron sulfides that enable methanogenesis via electric syntrophy.Kawai, J., McLendon, D.C., Kim, H.J., Benner, S.A., 2019. Hydroxymethanesulfonate from volcanic sulfur dioxide: A “mineral” reservoir for formaldehyde and other simple carbohydrates in prebiotic chemistry. Astrobiology 19, 506-516. formaldehyde (HCHO) was likely generated in Earth's prebiotic atmosphere by ultraviolet light, electrical discharge, and/or volcano-created lightning, HCHO could not have accumulated in substantial amounts in prebiotic environments, including those needed for prebiotic processes that generate nucleosidic carbohydrates. HCHO at high concentrations in alkaline solutions self-reacts in the Cannizzaro reaction to give methanol and formate, neither having prebiotic value. Here, we explore the possibility that volcanic sulfur dioxide (SO2) might have generated a reservoir for Hadean HCHO by a reversible reaction with HCHO to give hydroxymethanesulfonate (HMS). We show that salts of HMS are stable as solids at 90°C and do not react with themselves in solution, even at high (>8 M) concentrations. This makes them effective stores of HCHO, since the reverse reaction slowly delivers HCHO back into an environment where it can participate in prebiotically useful reactions. Specifically, we show that in alkaline borate solutions, HCHO derived from HMS allows formation of borate-stabilized carbohydrates as effectively as free HCHO, without losing material to Cannizzaro products. Further, we show that SO2 can perform similar roles for glycolaldehyde and glyceraldehyde, two intrinsically unstable carbohydrates that are needed by various models as precursors for RNA building blocks. Zircons from the Hadean show that the Hadean mantle likely provided volcanic SO2 at rates at least as great as the rates of atmospheric HCHO generation, making the formation of Hadean HMS essentially unavoidable. Thus, hydroxymethylsulfonate adducts of formaldehyde, glycolaldehyde, and glyceraldehyde, including the less soluble barium, strontium, and calcium salts, are likely candidates for prebiotically useful organic minerals on early Earth.Kayukova, G.P., Mikhailova, A.N., Kosachev, I.P., Eskin, A.A., Morozov, V.I., 2019. Effect of the natural minerals pyrite and hematite on the transformation of Domanik rock organic matter in hydrothermal processes. Petroleum Chemistry 59, 24-33. effect of the natural minerals pyrite and hematite as a catalyst on the efficiency in destruction of the organic matter of Domanik rock, rich in organic matter, at a temperature of 300°C in a steam–carbon dioxide gas environment has been studied. Compared with the original rock and a control experiment, the presence of the natural catalysts in the reaction system leads to an increase in both the amount of mobile hydrocarbons in the rock and the yield of extracts, in which the concentration of saturated hydrocarbons is increased by factors of 12 and 16 in the experiments with pyrite and hematite, respectively, and the asphaltene content is halved. The degradation processes of high-molecular-weight resinous–asphaltenic components and insoluble kerogen lead to the formation of lower n-alkanes and the structuring of asphaltenes to increase the degree of their carbonization, followed by the formation of insoluble substances of the carbene–carboid type appearing as a new dispersed solid phase in the products. The distinctive features of the structural composition of asphaltenes and carbenes–carboids have been revealed. The close composition of the products of hydrothermal–catalytic experiments suggests that pyrite and hematite exhibit similar catalytic properties under hydrothermal conditions.Khishvand, M., Oraki Kohshour, I., Alizadeh, A.H., Piri, M., Prasad, S., 2019. A multi-scale experimental study of crude oil-brine-rock interactions and wettability alteration during low-salinity waterflooding. Fuel 250, 117-131. this study we present the results of a multi-scale experimental investigation of the mechanisms responsible for the increased oil recovery by low-salinity waterflooding (LSWF), i.e., low-salinity effect (LSE). Using core- and substrate-flooding experiments as well as imaging techniques at macro, micro, and nanometer scales, we probe the intricate crude oil-brine-rock interactions and the subtle pore-scale displacement events governing recovery enhancement during LSWF. We performed several LSWF and high-salinity waterflooding (HSWF) experiments on macro-scale (1 inch-diameter) reservoir sandstone core plugs while collecting effluent samples for further analysis.LSWF experiments exhibited a prolonged oil recovery response and notably higher oil recovery compared to HSWF. Imaging effluent samples, at sub-nanometer resolutions using transmission electron microscopy, demonstrated significant fines mobilization during LSWF. The occurrence of electric double layer expansion (DLE) as a source of fines mobilization during LSWF was confirmed by examining scanning electron microscopy images of the reservoir rock substrates before and after contacting the low-salinity brine. Moreover, geochemical analysis of the effluent samples showed evidence of proton excahnge and multi-component ion exchange (MIE) during LSWF. The mobilization of fine particles (due to DLE) and the ion exchange processes are believed to result in removal of oil molecules from the rock surfaces leading to an enhancement in oil recovery as well as alteration of wettability toward increased water-wetness. These observations were then linked to our findings from an earlier study during which LSWF and HSWF experiments were conducted on miniature (5?mm-diameter) core samples while the pore space was being imaged at micrometer resolution. In-situ oil/brine contact angles measured during flow tests conducted on the miniature core samples revealed a significant level of wettability alteration from weakly oil-wet toward increased water-wetness during LSWF. Analysis of fluid occupancy maps showed that this change in wettability lowers the threshold water pressure needed for water-displacing-oil events to take place in the pore elements, which in turn enhances displacement efficiency and oil recovery.Kille, N., Chiu, R., Frey, M., Hase, F., Sha, M.K., Blumenstock, T., Hannigan, J.W., Orphal, J., Bon, D., Volkamer, R., 2019. Separation of methane emissions from agricultural and natural gas sources in the Colorado Front Range. Geophysical Research Letters 46, 3990-3998.: This proof‐of‐concept study demonstrates that methane (CH4) emissions from natural gas (NG) and agriculture can be disentangled using the concept of excess column observations. A network of cost‐effective sensors measured excess column‐averaged dry‐air mole fractions for CH4 (ΔXCH4), ethane (ΔXC2H6 as NG tracer), and ammonia (ΔXNH3 from agriculture) in the Denver‐Julesburg Basin during March 2015. ΔXCH4 varied up to 17 ppb and was >3 times higher with winds from directions where NG is produced. The ΔXCH4 variance is explained by variations in the C2H6‐NH3 tracer pair, attributing 63 ± 17% to NG, 25 ± 10% to agriculture, and 12 ± 12% to other sources. The ratios ΔXC2H6/ΔXCH4 (16 ± 2%; indicates wet NG) and ΔXNH3/ΔXCH4 (43 ± 12%) were compatible with in situ measured ratios. Excess columns are independent of boundary layer height, characterize gases in the open atmosphere, are inherently calibrated, average over extended spatial scales, and provide a complementary perspective to quantify and attribute CH4 emissions on regional scales.Plain Language Summary: Methane is the second most important anthropogenic greenhouse gas. Knowledge about methane sources is increasingly relevant as energy production continues to shift toward natural gas and becomes complicated by collocated emissions from natural gas production and agriculture due to shared land use. There is a need for methods to better decouple emissions from multiple sources that contribute to local enhancements in methane, which are small compared to the regional methane background concentrations, and depend on atmospheric transport and planetary boundary layer height. In this study, we show that the concept of collocated excess column measurements of methane and chemical tracers shows great promise as a viable approach to disentangle methane emissions from multiple sources by means of cost‐effective networks of ground‐based sensors. Excess columns are independent of boundary layer height, which makes quantification and source attribution of methane more straightforward.King, A.C.F., Giorio, C., Wolff, E., Thomas, E., Roverso, M., Schwikowski, M., Tapparo, A., Bogialli, S., Kalberer, M., 2019. Direct injection liquid chromatography high-resolution mass spectrometry for determination of primary and secondary terrestrial and marine biomarkers in ice cores. Analytical Chemistry 91, 5051-5057. atmospheric organic compounds are long-lived enough to be transported from their sources to polar regions and high mountain environments where they can be trapped in ice archives. While inorganic components in ice archives have been studied extensively to identify past climate changes, organic compounds have rarely been used to assess paleo-environmental changes, mainly due to the lack of suitable analytical methods. This study presents a new method of direct injection high performance liquid chromatography-mass spectrometry (HPLC-MS) analysis, without the need of preconcentrating the melted ice, for the determination of a series of novel biomarkers in ice core samples indicative of primary and secondary terrestrial and marine organic aerosol sources. Eliminating a preconcentration step reduces contamination potential and decreases the required sample volume thus allowing a higher time resolution in the archives. The method is characterized by limits of detection (LODs) in the range of 0.01–15 ppb, depending on the analyte, and accuracy evaluated through an interlaboratory comparison. We find that many components in secondary organic aerosols (SOAs) are clearly detectable at concentrations comparable to those previously observed in replicate preconcentrated ice samples from the Belukha glacier, Russian Altai Mountains. Some compounds with low recoveries in the preconcentration steps are now detectable in samples with this new direct injection method significantly increasing the range of environmental processes and sources that become accessible for paleo-climate studies.Kitazato, K., Milliken, R.E., Iwata, T., Abe, M., Ohtake, M., Matsuura, S., Arai, T., Nakauchi, Y., Nakamura, T., Matsuoka, M., Senshu, H., Hirata, N., Hiroi, T., Pilorget, C., Brunetto, R., Poulet, F., Riu, L., Bibring, J.P., Takir, D., Domingue, D.L., Vilas, F., Barucci, M.A., Perna, D., Palomba, E., Galiano, A., Tsumura, K., Osawa, T., Komatsu, M., Nakato, A., Arai, T., Takato, N., Matsunaga, T., Takagi, Y., Matsumoto, K., Kouyama, T., Yokota, Y., Tatsumi, E., Sakatani, N., Yamamoto, Y., Okada, T., Sugita, S., Honda, R., Morota, T., Kameda, S., Sawada, H., Honda, C., Yamada, M., Suzuki, H., Yoshioka, K., Hayakawa, M., Ogawa, K., Cho, Y., Shirai, K., Shimaki, Y., Hirata, N., Yamaguchi, A., Ogawa, N., Terui, F., Yamaguchi, T., Takei, Y., Saiki, T., Nakazawa, S., Tanaka, S., Yoshikawa, M., Watanabe, S., Tsuda, Y., 2019. The surface composition of asteroid 162173 Ryugu from Hayabusa2 near-infrared spectroscopy. Science 364, 272-275.: The near-Earth asteroid 162173 Ryugu, the target of the Hayabusa2 sample-return mission, is thought to be a primitive carbonaceous object. We report reflectance spectra of Ryugu’s surface acquired with the Near-Infrared Spectrometer (NIRS3) on Hayabusa2, to provide direct measurements of the surface composition and geological context for the returned samples. A weak, narrow absorption feature centered at 2.72 micrometers was detected across the entire observed surface, indicating that hydroxyl (OH)–bearing minerals are ubiquitous there. The intensity of the OH feature and low albedo are similar to thermally and/or shock-metamorphosed carbonaceous chondrite meteorites. There are few variations in the OH-band position, which is consistent with Ryugu being a compositionally homogeneous rubble-pile object generated from impact fragments of an undifferentiated aqueously altered parent body.Editor's Summary: Hayabusa2 at the asteroid Ryugu. Asteroids fall to Earth in the form of meteorites, but these provide little information about their origins. The Japanese mission Hayabusa2 is designed to collect samples directly from the surface of an asteroid and return them to Earth for laboratory analysis. Three papers in this issue describe the Hayabusa2 team's study of the near-Earth carbonaceous asteroid 162173 Ryugu, at which the spacecraft arrived in June 2018 (see the Perspective by Wurm). Watanabe et al. measured the asteroid's mass, shape, and density, showing that it is a “rubble pile” of loose rocks, formed into a spinning-top shape during a prior period of rapid spin. They also identified suitable landing sites for sample collection. Kitazato et al. used near-infrared spectroscopy to find ubiquitous hydrated minerals on the surface and compared Ryugu with known types of carbonaceous meteorite. Sugita et al. describe Ryugu's geological features and surface colors and combined results from all three papers to constrain the asteroid's formation process. Ryugu probably formed by reaccumulation of rubble ejected by impact from a larger asteroid. These results provide necessary context to understand the samples collected by Hayabusa2, which are expected to arrive on Earth in December 2020.Klaus, M., Seekell, D.A., Lidberg, W., Karlsson, J., 2019. Evaluations of climate and land management effects on lake carbon cycling need to account for temporal variability in CO2 concentrations. Global Biogeochemical Cycles 33, 243-265.: Carbon dioxide (CO2) concentrations in lakes vary strongly over time. This variability is rarely captured by environmental monitoring but is crucial for accurately assessing the magnitude of lake CO2 emissions. However, it is unknown to what extent temporal variability needs to be captured to understand important drivers of lake carbon cycling such as climate and land management. We used environmental monitoring data of Swedish forest lakes collected in autumn (n = 439) and throughout the whole open water season (n = 22) from a wet and a dry year to assess temporal variability in effects of climate and forestry on CO2 concentrations across lakes. Effects differed depending on the season and year sampled. According to cross‐lake comparisons based on autumn data, CO2 concentrations increased with annual mean air temperature (dry year) or catchment forest productivity (wet year) but were not related to colored dissolved organic matter concentrations. In contrast, open water‐season averaged CO2 concentrations were similar across temperature and productivity gradients but increased with colored dissolved organic matter. These contradictions resulted from scale mismatches in input data, lead to weak explanatory power (R2 = 9–32%), and were consistent across published data from 79 temperate, boreal, and arctic lakes. In a global survey of 144 published studies, we identified a trade‐off between temporal and spatial coverage of CO2 sampling. This trade‐off clearly determines which conclusions are drawn from landscape‐scale CO2 assessments. Accurate evaluations of the effects of climate and land management require spatially and temporally representative data that can be provided by emerging sensor technologies and forms of collaborative sampling.Plain Language Summary: Lakes interact with the atmosphere by exchanging greenhouse gases such as carbon dioxide that have implications for the global climate. In order to predict future carbon dioxide exchanges, the effects of climate and land management need to be determined. Here we show that the apparent effects of climate and forestry on carbon dioxide concentrations in temperate, boreal, and arctic lakes are inconsistent and depend on whether lakes are sampled during autumn or throughout the year and whether it was a wet or dry year. To accurately quantify effects, hundreds of lakes would need to be sampled at least six times per year. Published literature suggests that this is unrealistic. This implies a need for new automated measurement technologies and collaborative teamwork to provide representative data and allow accurate predictions of the effects of climate and land management.Knolhoff, A.M., Kneapler, C.N., Croley, T.R., 2019. Optimized chemical coverage and data quality for non-targeted screening applications using liquid chromatography/high-resolution mass spectrometry. Analytica Chimica Acta 1066, 93-101. small molecule screening methods are used to analyze samples for potential compounds of interest without focusing on specific molecular species. There is great interest in these methods for metabolomic, environmental, forensic, and food safety applications, among others, to determine compounds that are responsible for a particular disease state or the presence of a harmful compound. In order for non-targeted analyses to become standardized and routine, best practices for sample preparation, data collection, and data analysis must be determined. This work focuses on optimizing specific aspects of a non-targeted workflow that utilizes high-resolution mass spectrometry using an Orbitrap instrument coupled to liquid chromatography. Sample preparation, liquid chromatography gradient length, and mass spectrometry resolving power and ionization modes were investigated to determine optimal conditions for detecting and extracting compounds from the data that cover broad molecular and polarity ranges. Infant rice cereal, orange juice, and yogurt with spiked standards were analyzed; food is inherently challenging to analyze due in part to sample complexity and diversity. Of the conditions tested, optimal conditions included a generic sample extraction using acetonitrile, water, and formic acid, a 25 min chromatographic gradient, collecting data in both positive and negative ion modes, and using 70k resolving power. There are of course tradeoffs associated with each of these options that will be described in detail so that the appropriate conditions can be chosen for the desired application.Kondori, J., Zendehboudi, S., James, L., 2019. New insights into methane hydrate dissociation: Utilization of molecular dynamics strategy. Fuel 249, 264-276. reserves play a crucial role in energy storage and resources across the world. Gas hydrate formation may lead to various forms of blockages in oil/gas production and transportation processes, resulting in high capital and operating costs. Hence, it is important to determine the methane hydrate formation conditions and to understand the vital process and thermodynamic parameters. In this study, molecular dynamic (MD) simulations are conducted to investigate the microscopic mechanisms/phenomena and intermolecular forces involved in methane hydrate decomposition, where molecular interactions, structures, and behaviours need to be appropriately determined/selected. Through a systematic parametric sensitivity analysis, the impacts of temperature, pressure, and cage occupancy on hydrate dissociation are studied. Furthermore, the diffusion coefficient, density, and heat capacity of the methane hydrates are determined by employing MD strategy. The stability of water cages is examined at various decomposition times, temperatures, and pressures. According to the radial distribution function and mean square displacement of oxygen-oxygen and carbon-carbon atoms, the stability of hydrate cages decreases with increasing temperature, while it increases with increasing the cage occupancy and pressure. The addition of inhibitors (e.g., methanol) to small cavities in the hydrate structure creates new hydrogen bonds between the water and inhibitor molecules in the cages, accelerating the decomposition of hydrates. A good agreement is noticed between the outcomes of this research work and the results obtained in experimental and theoretical studies available in the literature. Analysing the outcome of the present and previous research works, the current study provides new reliable/logical information on the molecular level of the hydrate dissociation process. It is expected that such a research investigation offers effective tips/guidelines to deal with hydrate formation and dissociation in terms of utilization, prevention, and processing.K?ppel, M., Franzelin, F., Kr?ker, I., Oladyshkin, S., Santin, G., Wittwar, D., Barth, A., Haasdonk, B., Nowak, W., Pflüger, D., Rohde, C., 2019. Comparison of data-driven uncertainty quantification methods for a carbon dioxide storage benchmark scenario. Computational Geosciences 23, 339-354. variety of methods is available to quantify uncertainties arising within the modeling of flow and transport in carbon dioxide storage, but there is a lack of thorough comparisons. Usually, raw data from such storage sites can hardly be described by theoretical statistical distributions since only very limited data is available. Hence, exact information on distribution shapes for all uncertain parameters is very rare in realistic applications. We discuss and compare four different methods tested for data-driven uncertainty quantification based on a benchmark scenario of carbon dioxide storage. In the benchmark, for which we provide data and code, carbon dioxide is injected into a saline aquifer modeled by the nonlinear capillarity-free fractional flow formulation for two incompressible fluid phases, namely carbon dioxide and brine. To cover different aspects of uncertainty quantification, we incorporate various sources of uncertainty such as uncertainty of boundary conditions, of parameters in constitutive relations, and of material properties. We consider recent versions of the following non-intrusive and intrusive uncertainty quantification methods: arbitrary polynomial chaos, spatially adaptive sparse grids, kernel-based greedy interpolation, and hybrid stochastic Galerkin. The performance of each approach is demonstrated assessing expectation value and standard deviation of the carbon dioxide saturation against a reference statistic based on Monte Carlo sampling. We compare the convergence of all methods reporting on accuracy with respect to the number of model runs and resolution. Finally, we offer suggestions about the methods’ advantages and disadvantages that can guide the modeler for uncertainty quantification in carbon dioxide storage and beyond.Korablev, O., Vandaele, A.C., Montmessin, F., Fedorova, A.A., Trokhimovskiy, A., Forget, F., Lefèvre, F., Daerden, F., Thomas, I.R., Trompet, L., Erwin, J.T., Aoki, S., Robert, S., Neary, L., Viscardy, S., Grigoriev, A.V., Ignatiev, N.I., Shakun, A., Patrakeev, A., Belyaev, D.A., Bertaux, J.-L., Olsen, K.S., Baggio, L., Alday, J., Ivanov, Y.S., Ristic, B., Mason, J., Willame, Y., Depiesse, C., Hetey, L., Berkenbosch, S., Clairquin, R., Queirolo, C., Beeckman, B., Neefs, E., Patel, M.R., Bellucci, G., López-Moreno, J.-J., Wilson, C.F., Etiope, G., Zelenyi, L., Svedhem, H., Vago, J.L., Alonso-Rodrigo, G., Altieri, F., Anufreychik, K., Arnold, G., Bauduin, S., Bolsée, D., Carrozzo, G., Clancy, R.T., Cloutis, E., Crismani, M., Da Pieve, F., D’Aversa, E., Duxbury, N., Encrenaz, T., Fouchet, T., Funke, B., Fussen, D., Garcia-Comas, M., Gérard, J.-C., Giuranna, M., Gkouvelis, L., Gonzalez-Galindo, F., Grassi, D., Guerlet, S., Hartogh, P., Holmes, J., Hubert, B., Kaminski, J., Karatekin, O., Kasaba, Y., Kass, D., Khatuntsev, I., Kleinb?hl, A., Kokonkov, N., Krasnopolsky, V., Kuzmin, R., Lacombe, G., Lanciano, O., Lellouch, E., Lewis, S., Luginin, M., Liuzzi, G., López-Puertas, M., López-Valverde, M., M??tt?nen, A., Mahieux, A., Marcq, E., Martin-Torres, J., Maslov, I., Medvedev, A., Millour, E., Moshkin, B., Mumma, Michael?J., Nakagawa, H., Novak, R.E., Oliva, F., Patsaev, D., Piccialli, A., Quantin-Nataf, C., Renotte, E., Ritter, B., Rodin, A., Schmidt, F., Schneider, N., Shematovich, V., Smith, Michael?D., Teanby, N.A., Thiemann, E., Thomas, N., Vander Auwera, J., Vazquez, L., Villanueva, G., Vincendon, M., Whiteway, J., Wilquet, V., Wolff, M.J., Wolkenberg, P., Yelle, R., Young, R., Zasova, L., Zorzano, M.P., the, A.a.N.S.T., 2019. No detection of methane on Mars from early ExoMars Trace Gas Orbiter observations. Nature 568, 517-520. detection of methane on Mars has been interpreted as indicating that geochemical or biotic activities could persist on Mars today. A number of different measurements of methane show evidence of transient, locally elevated methane concentrations and seasonal variations in background methane concentrations. These measurements, however, are difficult to reconcile with our current understanding of the chemistry and physics of the Martian atmosphere, which—given methane’s lifetime of several centuries—predicts an even, well mixed distribution of methane. Here we report highly sensitive measurements of the atmosphere of Mars in an attempt to detect methane, using the ACS and NOMAD instruments onboard the ESA-Roscosmos ExoMars Trace Gas Orbiter from April to August 2018. We did not detect any methane over a range of latitudes in both hemispheres, obtaining an upper limit for methane of about 0.05 parts per billion by volume, which is 10 to 100 times lower than previously reported positive detections. We suggest that reconciliation between the present findings and the background methane concentrations found in the Gale crater would require an unknown process that can rapidly remove or sequester methane from the lower atmosphere before it spreads globally.Korf, A., Jeck, V., Schmid, R., Helmer, P.O., Hayen, H., 2019. Lipid species annotation at double bond position level with custom databases by extension of the MZmine 2 open-source software package. Analytical Chemistry 91, 5098-5105. recent years, proprietary and open-source bioinformatics software tools have been developed for the identification of lipids in complex biological samples based on high-resolution mass spectrometry data. These existent software tools often rely on publicly available lipid databases, such as LIPID MAPS, which, in some cases, only contain a limited number of lipid species for a specific lipid class. Other software solutions implement their own lipid species databases, which are often confined regarding implemented lipid classes, such as phospholipids. To address these drawbacks, we provide an extension of the widely used open-source metabolomics software MZmine 2, which enables the annotation of detected chromatographic features as lipid species. The extension is designed for straightforward generation of a custom database for selected lipid classes. Furthermore, each lipid’s sum formula of the created database can be rapidly modified to search for derivatization products, oxidation products, in-source fragments, or adducts. The versatility will be exemplified by a liquid chromatography–high resolution mass spectrometry data set with postcolumn Paternò–Büchi derivatization. The derivatization reaction was performed to pinpoint the double bond positions in diacylglyceryltrimethylhomoserine lipid species in a lipid extract of a green algae (Chlamydomonas reinhardtii) sample. The developed Lipid Search module extension of MZmine 2 supports the identification of lipids as far as double bond position level.Korolkov, V.V., Summerfield, A., Murphy, A., Amabilino, D.B., Watanabe, K., Taniguchi, T., Beton, P.H., 2019. Ultra-high resolution imaging of thin films and single strands of polythiophene using atomic force microscopy. Nature Communications 10, Article 1537. images of polymers with sub-molecular resolution could provide valuable insights into the relationship between morphology and functionality of polymer optoelectronic devices, but their acquisition is problematic due to perceived limitations in atomic force microscopy (AFM). We show that individual thiophene units and the lattice of semicrystalline spin-coated films of polythiophenes (PTs) may be resolved using AFM under ambient conditions through the low-amplitude (≤?1?nm) excitation of higher eigenmodes of a cantilever. PT strands are adsorbed on hexagonal boron nitride near-parallel to the surface in islands with lateral dimensions ~10?nm. On the surface of a spin-coated PT thin film, in which the thiophene groups are perpendicular to the interface, we resolve terminal CH3-groups in a square arrangement with a lattice constant 0.55?nm from which we can identify abrupt boundaries and also regions with more slowly varying disorder, which allow comparison with proposed models of PT domains.Kosachev, I.P., Kayukova, G.P., Mikhailova, A.N., 2019. Features of composition of oil extracts from the rocks of basement and sedimentary stratums of the Novo-Elkhovskoye field of Tatarstan. Petroleum Science and Technology 37, 1016-1024. comparative analysis of oil extracts from the rocks of the crystalline basement of the ultra-deep well 20009 of the Novo-Elkhovskoye field located within the South-Tatar Arch of the territory of Tatarstan, as well as from the sedimentary strata of the Devonian productive deposits of the Aktashskaya area of this field was carried out. A different yield of extracts from fault rocks (0.018%) and low-permeable (0.007%) basement zones was established and differences in their group and structural-group composition were revealed. In the fault zones of the basement rocks, in comparison with the rocks of low-permeable intervals, resin-asphaltene components predominate, indicating the occurrence of more intense hypergene processes in them. The data of component, structural-group composition and geochemical characteristics of extracts from basement and sedimentary rocks indicates their genetic relationship with sapropel organic matter (OM) of marine genesis. This confirms the fact that the fault and low-permeable zones of the basement rocks served as migration routes for petroleum hydrocarbons during the formation of oil-bearing fields in the South-Tatar Arch.K?ster, D., Sanchez Villalobos, I.M., Jochmann, M.A., Brand, W.A., Schmidt, T.C., 2019. New concepts for the determination of oxidation efficiencies in liquid chromatography–isotope ratio mass spectrometry. Analytical Chemistry 91, 5067-5073. liquid chromatography coupled to isotope ratio mass spectrometry (LC–IRMS), analytes are separated on an LC system and consecutively oxidized to CO2, which is required for the determination of compound-specific carbon isotope ratios. Oxidation is performed in an online reactor by sulfate radicals. Reaction conditions in the interface depend on the flow conditions determined by the LC method and the flow rates and concentrations of oxidation agent and phosphoric acid added in the interface. To determine accurate isotope ratios, a quantitative conversion of the carbon contained in the analyte to the CO2 measurement gas is a prerequisite. Oxidation efficiencies are not commonly evaluated during method development, although certain analytes are known to be difficult to be oxidized by sulfate radicals. For the assessment of the oxidation efficiency of the LC–IRMS system, three different approaches were evaluated. (1) Residual organic carbon in the eluent stream of the interface was determined to calculate oxidation yields depending on the initial analyte concentration. (2) The IRMS response was calibrated to an inorganic carbon reference material to determine oxidation efficiencies with the help of the IRMS as a detector. (3) The oxidation temperature was deliberately reduced while monitoring the δ13C and signal intensity. The common assumption that a linear relation of IRMS signal to analyte concentration is an indicator for complete oxidation in LC–IRMS could be disproved. All three approaches can be applied for future method development in LC–IRMS, monitoring of existing flow injection applications, as well as for verification of complete oxidation in established LC–IRMS methods.Kostyukevich, Y., Vlaskin, M., Zherebker, A., Grigorenko, A., Borisova, L., Nikolaev, E., 2019. High-resolution mass spectrometry study of the bio-oil samples produced by thermal liquefaction of microalgae in different solvents. Journal of The American Society for Mass Spectrometry 30, 605-614. have performed a comparative analysis of the bio-oil produced by thermal liquefaction of microalgae in different solvents using high-resolution Orbitrap mass spectrometry and GC-MS approach. Water, methanol, ethanol, butanol, isopropanol, acetonitrile, toluene, and hexane were used as solvents in which the liquefaction was performed. It was observed that all resulting oils demonstrate a considerable degree of similarity. For all samples, compounds containing 1 and 2 nitrogen atoms dominated in the positive ESI spectra, while a relative contribution of other compounds was small. In negative ESI mode, compounds having 2 to 7 oxygens were observed. Statistical analysis revealed that products can be combined in two groups depending on the solvent used for the liquefaction. To the first group, we can attribute the products obtained by using protic (alcohols) and to the second by using aprotic (acetonitrile, toluene) solvents. Nevertheless, based on our results, we concluded that solvent possesses a minor impact on molecular composition of bio-oil. We suggested that the driving force of the liquefaction reaction is the thermal dehydration of the carbohydrate in algae, resulting in water formation, which could be the trigger of the producing of bio-oil. To prove this hypothesis, we performed the reaction with the dry algae in the absence of the solvent and observed the formation of bio-oil.Kotarba, M.J., Wi?c?aw, D., Bilkiewicz, E., Radkovets, N.Y., Koltun, Y.V., Kmiecik, N., Romanowski, T., Kowalski, A., 2019. Origin and migration of oil and natural gas in the western part of the Ukrainian Outer Carpathians: Geochemical and geological approach. Marine and Petroleum Geology 103, 596-619. established the generation and migration processes as well as the influence of secondary processes of oil and natural gas accumulated in Lower Cretaceous-Oligocene strata of the western part of the Ukrainian Outer Carpathians based on the results of organic geochemical analyses of oil and natural gas related to the geological setting and source organic matter. The Oligocene Menilite beds from the Boryslav-Pokuttya Nappe are the main source rock for oil and natural gas accumulated in the fields of the Boryslav-Pokuttya and Skiba nappes. Co-sourcing of oils and natural gas accumulated in the Skiba Nappe in the study area by both Menilite and Spas beds of this nappe cannot be excluded. In some cases (e.g. Novoshidnytsya field) oil and natural gas originated within the Oligocene Menilite beds of the Boryslav-Pokuttya Nappe, migrated through thrusts and fissure zones and accumulated in the Lower Cretaceous reservoirs of the Skiba Nappe. Oil from small Vovche field and Pohar seep of the Krosno Nappe was generated by Menilite source rocks of this tectonic unit and migrated to the traps. Sporadically oils underwent secondary processes, mainly biodegradation and occasionally water washing. Hydrocarbon gases and carbon dioxide were generated mainly during low-temperature thermogenic processes from Type II kerogen, and partly during the microbial CO2 reduction process. Only natural gas from the Mala Volosyanka oil and gas seep of the Krosno Nappe was documented to have undergone biodegradation.Kotulová, J., Starek, D., Havelcová, M., Pálková, H., 2019. Amber and organic matter from the late Oligocene deep-water deposits of the Central Western Carpathians (Orava–Podhale Basin). International Journal of Coal Geology 207, 96-109. occurrence of amber in the Central Carpathian Paleogene Basin is reported here for the first time. The amber has been analyzed by means of optical microscopic methods, infrared spectroscopy, gas chromatography/mass spectrometry, and pyrolysis-gas chromatography/mass spectrometry to understand the amber composition, origin, taphonomy, alteration, and diagenesis. Organic petrographic and reflectance analyses of organic matter from amber-bearing sediment was carried out to get information about paleoenvironment and maturity of sedimentary rock. Analyses confirmed polylabdane structure associated with Class Ib -type of amber and its possible origin from the conifer family Araucariaceae. It is characterized by a high degree of maturity, where both temperature and exogenic processes have participated in its conversion. Heterogeneity of reflectance values in the resinite suggests that amber was not redeposited from an older and more mature sedimentary unit. The discrepancy between the maturity of the amber and amber-bearing sedimentary rock, along with abundant char and inertinite macerals indicates a probability of thermal alteration of the amber under the influence of heat from a wildfire and increased maturity occurring before its ultimate burial in a deep-sea environment. The assemblage of terrigenous macerals and numerous char and inertinite particles which were found in amber-bearing sediment, as well as in the amber crust, suggest forest-swamp type vegetation affected by wildfires. The presence of amber and predominantly terrigenous organic matter, besides mud rip-up clasts derived from freshwater sediments in deep-marine deposits, indicates a direct connection of terrestrial environments to the deep-water depositional system.Kraiselburd, I., Brüls, T., Heilmann, G., Kaschani, F., Kaiser, M., Meckenstock, R.U., 2019. Metabolic reconstruction of the genome of candidate Desulfatiglans TRIP_1 and identification of key candidate enzymes for anaerobic phenanthrene degradation. Environmental Microbiology 21, 1267-1286. aromatic hydrocarbons (PAHs) are widely distributed pollutants. As oxygen is rapidly depleted in water-saturated PAH-contaminated sites, anaerobic microorganisms are crucial for their consumption. Here, we report the metabolic pathway for anaerobic degradation of phenanthrene by a sulfate-reducing enrichment culture (TRIP) obtained from a natural asphalt lake. The dominant organism of this culture belongs to the Desulfobacteraceae family of Deltaproteobacteria and genome-resolved metagenomics led to the reconstruction of its genome along with a handful of genomes from lower abundance bacteria. Proteogenomic analyses confirmed metabolic capabilities for dissimilatory sulfate reduction and indicated the presence of the Embden-Meyerhof-Parnas pathway, a complete tricarboxylic acid cycle as well as a complete Wood-Ljungdahl pathway. Genes encoding enzymes putatively involved in the degradation of phenanthrene were identified. This includes two gene clusters encoding a multisubunit carboxylase complex likely involved in the activation of phenanthrene, as well as genes encoding reductases potentially involved in subsequent ring dearomatization and reduction steps. The predicted metabolic pathways were corroborated by transcriptome and proteome analyses, and provide the first insights into the metabolic pathway responsible for the anaerobic degradation of three-ringed PAHs.Krentscher, C., Dubois, N., Camperio, G., Prebble, M., Ladd, S.N., 2019. Palmitone as a potential species-specific biomarker for the crop plant taro (Colocasia esculenta Schott) on remote Pacific islands. Organic Geochemistry 132, 1-10. Pacific Island ecosystems of Remote Oceania were dramatically transformed following the arrival of humans within the last ～3000?years, as the new settlers required technological innovations and environmental modifications to maintain their populations. These modifications included the introduction of numerous exotic species, including the important crop Colocasia esculenta Schott (taro) and the development of infrastructure suitable for its cultivation. Archaeological reconstruction of C. esculenta use in the Pacific has been challenging because of the low-specificity of fossil starch granules and its limited pollen production during periods of intense cultivation. Here, we assess a lipid biomarker approach to trace C. esculenta cultivation in the past. We characterized the neutral lipid compositions of leaf samples from common cultivars and widespread indigenous species from the archipelago of Vanuatu by gas chromatography–mass spectrometry (GC–MS). The compound palmitone (hentriacontan-16-one) was a major leaf wax constituent in C. esculenta cultivar samples (mean concentration of 402?±?63??g g–1 dry wt) and was only detected in one other species, the ornamental tree Cananga odorata (175??g g–1 dry wt). The structure of palmitone is favorable for its long-term stability and we demonstrate its preservation potential in a 55?cm sedimentary record from Lake Vesalea on Espiritu Santo, Vanuatu, where C. esculenta is grown today. Palmitone concentrations in this core fluctuated up to 4.1??g g–1 dry wt. Our results indicate that in appropriate environmental contexts, sedimentary palmitone concentrations could be used to reconstruct C. esculenta cultivation and to provide insights about past horticultural innovations in Remote Oceania.Kronen, M., Lee, M., Jones, Z.L., Manefield, M.J., 2019. Reductive metabolism of the important atmospheric gas isoprene by homoacetogens. The ISME Journal 13, 1168-1182. is the most abundant biogenic volatile organic compound (BVOC) in the Earth’s atmosphere and plays important roles in atmospheric chemistry. Despite this, little is known about microbiological processes serving as a terrestrial sink for isoprene. While aerobic isoprene degrading bacteria have been identified, there are no known anaerobic, isoprene-metabolizing organisms. In this study an H2-consuming homoacetogenic enrichment was shown to utilize 1.6?μmoles isoprene h?1 as an electron acceptor in addition to HCO3?. The isoprene-reducing community was dominated by Acetobacterium spp. and isoprene was shown to be stoichiometrically reduced to three methylbutene isomers (2-methyl-1-butene (>97%), 3-methyl-1-butene (≤2%), 2-methyl-2-butene (≤1%). In the presence of isoprene, 40% less acetate was formed suggesting that isoprene reduction is coupled to energy conservation in Acetobacterium spp. This study improves our understanding of linkages and feedbacks between biogeochemistry and terrestrial microbial activity.Kueter, N., Lilley, M.D., Schmidt, M.W., Bernasconi, S.M., 2019. Experimental carbonatite/graphite carbon isotope fractionation and carbonate/graphite geothermometry. Geochimica et Cosmochimica Acta 253, 290-306. isotope exchange between carbon-bearing high temperature phases records the carbon (re-) processing in the Earth's interior, where the vast majority of global carbon is stored. Redox reactions between carbonate phases and elemental carbon govern the mobility of carbon, which then can be traced by its isotopes. We determined the carbon isotope fractionation factor between graphite and a Na2CO3-CaCO3 melt at 900–1500?°C and 1?GPa; The failure to isotopically equilibrate preexisting graphite led us to synthesize graphite anew from organic material during the melting of the carbonate mixture. Graphite growth proceeds by (1) decomposition of organic material into globular amorphous carbon, (2) restructuring into nano-crystalline graphite, and (3) recrystallization into hexagonal graphite flakes. Each transition is accompanied by carbon isotope exchange with the carbonate melt. High-temperature (1200–1500?°C) equilibrium isotope fractionation with type (3) graphite can be described byΔ13Ccarbonate-graphite=3.17(±0.07)·106/T2 (temperature T in K). As the experiments do not yield equilibrated bulk graphite at lower temperatures, we combined the ≥1200?°C experimental data with those derived from upper amphibolite and lower granulite facies carbonate-graphite pairs (Kitchen and Valley, 1995; Valley and O'Neil, 1981). This yields the general fractionation function Δ13Ccarbonate-graphite=3.37±0.04·106/T2 usable as a geothermometer for solid or liquid carbonate at ≥600?°C. Similar to previous observations, lower-temperature experiments (≤1100?°C) deviate from equilibrium. By comparing our results to diffusion and growth rates in graphite, we show that at ≤1100?°C carbon diffusion is slower than graphite growth, hence equilibrium surface isotope effects govern isotope fractionation between graphite and carbonate melt and determine the isotopic composition of newly formed graphite. The competition between diffusive isotope exchange and growth rates requires a more careful interpretation of isotope zoning in graphite and diamond. Based on graphite crystallization rates and bulk isotope equilibration, a minimum diffusivity of Dgraphite?=?2?×?10?17 m2s?1 for T?>?1150?°C is required. This value is significantly higher than calculated from experimental carbon self-diffusion constants (～1.6?×?10?29?m2?s?1) but in good agreement with the value calculated for mono-vacancy migration (～2.8?×?10?16?m2?s?1).Kumar, D.M., Woltering, M., Hopmans, E.C., Sinninghe Damsté, J.S., Schouten, S., Werne, J.P., 2019. The vertical distribution of Thaumarchaeota in the water column of Lake Malawi inferred from core and intact polar tetraether lipids. Organic Geochemistry 132, 37-49. long paleoclimate records generated from Lake Malawi sediments rely on an assumption that the TEX86 paleothermometer reflects annual mean lake surface temperatures. Thaumarchaeota, the producers of the isoprenoid glycerol dialkyl glycerol tetraether (iGDGT) lipids that are the basis of the TEX86 proxy, can occupy a wide range of habitats in the upper water column of lacustrine systems, so it is crucial to specifically constrain the ecology of Thaumarchaeota in Lake Malawi to properly interpret its sedimentary TEX86 record. To investigate the spatial and vertical distribution of Thaumarchaeotal iGDGT production in Lake Malawi, suspended particulate matter (SPM) was collected from the upper water column (>300?m) at three sites spanning the north, central, and south basins of the lake and analyzed for intact polar (IPL) and core (CL) iGDGT lipid abundances. Samples were collected in January during the austral summer when the lake is strongly stratified. Concentrations of the most labile IPL, hexose-phosphohexose (HPH)-crenarchaeol, were greatest just below the deep chlorophyll maximum at ～50?m water depth in the deeper north and central basins and ～30?m in the shallow south basin. Maximum CL concentrations occur below the maximum HPH-crenarchaeol concentrations and therefore possibly reflect the accumulation of recently produced IPL GDGT degradation products. If the export of CLs to the sediments is dominated by this CL pool, sedimentary TEX86 would reflect Thaumarchaeota living within the thermocline during the stratified season and therefore may have a cool bias rather than reflecting true surface water temperatures. An increase in abundances of GDGT-2, crenarchaeol isomer, and monohexose (MH)-crenarchaeol at ～150–200?m suggests that a secondary Thaumarchaeotal population, likely Group I.1b Thaumarchaeota, inhabits the subsurface water column near the anoxic-suboxic boundary. Total production of iGDGTs by this group appears to be much lower than the surface-dwelling clade, but its imprint on sedimentary TEX86 is unknown. An analysis of iGDGT production in the water column throughout the annual cycle is needed to resolve the timing and magnitude of export of CLs to the sediments from these two Thaumarchaeotal populations.Kumar, G., Dharmaraja, J., Arvindnarayan, S., Shoban, S., Bakonyi, P., Saratale, G.D., Nemestóthy, N., Bélafi-Bakó, K., Yoon, J.J., Kim, S.H., 2019. A comprehensive review on thermochemical, biological, biochemical and hybrid conversion methods of bio-derived lignocellulosic molecules into renewable fuels. Fuel 251, 352-367. this review, the conversion (thermochemical, biological and hybrid) of chemical energy chiefly enclosed in biomass structures i.e. as 30–50% cellulose, 15–35% hemicellulose and 10–20% lignin into various forms of fuels/energy products is comparatively analyzed. Cellulose and hemicelluloses formulate almost ～70% of the biomass and are definitely linked to the lignin structural units all the way through covalent and hydrogenic bonds; thereby, the structure formulated is tremendously rigid and resistive against processing. Hence, the vital confront towards the conversion of lignocellulosic biomass into important bio-yields via biorefining is to overcome this obstacle. This article gives an outlook over the major conversion technologies to produce biofuels from lignocellulosic biomass feedstock, by focusing on their typical performances. The core points outlined and argued will be the currently positioned pathways, utilizing the lignocellulosic materials to produce (bio) fuels, prospect on biomass supplies, and discussion on the impact of sustainability criteria, main influencing factors and uncertainties.Kurm, V., van der Putten, W.H., Weidner, S., Geisen, S., Snoek, B.L., Bakx, T., Hol, W.H.G., 2019. Competition and predation as possible causes of bacterial rarity. Environmental Microbiology 21, 1356-1368. assembled communities of bacteria and exposed them to different nutrient concentrations with or without predation by protists. Taxa that were rare in the field were less abundant at low nutrient concentrations than common taxa, independent of predation. However, some taxa that were rare in the field became highly abundant in the assembled communities, especially under ample nutrient availability. This high abundance points at a possible competitive advantage of some rare bacterial taxa under nutrient-rich conditions. In contrast, the abundance of most rare bacterial taxa decreased at low resource availability. Since low resource availability will be the prevailing situation in most soils, our data suggests that under those conditions poor competitiveness for limiting resources may contribute to bacterial rarity. Interestingly, taxa that were rare in the field and most successful under predator-free conditions in the lab also tended to be more reduced by predation than common taxa. This suggests that predation contributes to rarity of bacterial taxa in the field. We further discuss whether there may be a trade-off between competitiveness and predation resistance. The substantial variability among taxa in their responses to competition and predation suggests that other factors, for example abiotic conditions and dispersal ability, also influence the local abundance of soil bacteria.Kuske, S., Horsfield, B., Jweda, J., Michael, G.E., Song, Y., 2019. Geochemical factors controlling the phase behavior of Eagle Ford Shale petroleum fluids. American Association of Petroleum Geologists Bulletin 103, 835-870. types in the Eagle Ford resource play span the range from black oil to dry gas and are produced along regional trends that are largely maturity controlled. A total of 61 shale samples covering all maturity zones were evaluated to document organic richness, organic matter type, and maturation characteristics using established geochemical parameters. Pyrolysis experiments were then performed to simulate the generation of petroleum fluids. Termed the “PhaseSnapShot” approach, one or more target wells with known fluid properties were used as reference; a match with that composition was made using next-formed fluids generated from the shale in a closely located well of slightly lower thermal maturity than the target well(s). Phase behavior predictions from the model were calibrated using a regional pressure–volume–temperature (PVT) database compiled from the public domain. The conceptual model that best matched the PVT data were comprised of two reactive components: (1) a mixture of kerogen and bitumen that generated petroleum within the low permeability shale matrix and (2) bitumen in zones of enhanced porosity within the matrix. The combined generation of gas from both of these components as well as the strong retention of C7+ fluids in the matrix during production were required to match the calibration data. Retention of oil was needed over a broad thermal maturity range (Rock-Eval Tmax release: 440°C –475°C). A key result of this forward model is that phase behavior and bulk compositional properties of hydrocarbons can be quickly and effectively predicted using mature shale samples as long as calibration data from PVT reports are available.Laird, J.D., Belanger, C.L., 2019. Quantifying successional change and ecological similarity among Cretaceous and modern cold-seep faunas. Paleobiology 45, 114-135. recognizing analogues between fossil and modern ecosystems allows paleoecologists to more fully interpret fossil assemblages and modern ecologists to leverage the fossil record to address long-term ecological and environmental changes. However, this becomes increasingly difficult as taxonomic turnover increases the dissimilarity between ecosystems. Here we use a guild-based approach to compare the ecological similarity of Cretaceous cold-seep assemblages preserved in the Pierre Shale surrounding the Black Hills and modern cold-seep assemblages from five previously recognized biofacies. We modify modern assemblage data to include only those taxa with fossilizable hard parts greater than 5 mm in length to make these modern data sets more comparable to potential fossil analogues. We find that while the Black Hills assemblages are more similar in ecological guild composition to the modern thyasirid biofacies, subsets share similarities in ecological structure to the lucinid and mussel-bed biofacies. The fossil seep assemblages are also more similar to one another than are modern assemblages belonging to the same biofacies, despite greater geographic and temporal dissimilarity among the fossil samples. Furthermore, guild-level ordination analyses show a secondary faunal gradient that reflects community succession in the hard substrate–dominated modern assemblages and reveals a parallel faunal gradient in the soft sediment–dominated Cretaceous assemblages, consistent with a gradient in the influence of seep fluids on the faunas. Thus, while the Black Hills assemblages are quite homogeneous in their composition, they capture ecological variation similar to successional patterns in modern seep systems.Large, R.R., Mukherjee, I., Gregory, D., Steadman, J., Corkrey, R., Danyushevsky, L.V., 2019. Atmosphere oxygen cycling through the Proterozoic and Phanerozoic. Mineralium Deposita 54, 485-506. in atmosphere oxygen and ocean sulfate concentrations through time are regarded as important controls on the cycles of sediment-hosted and volcanic-hosted ore deposits. However, estimates of atmosphere oxygen in the Proterozoic have been frustrated by the lack of a direct measurement method and conflicting evidence from various proposed geochemical proxies. Studies in the 1970s to 1990s suggested a relatively oxygenated atmosphere (>?3?wt% O2) in the Proterozoic. However, since the late 1990s, new proxies and modelling have suggested very much lower levels of oxygen (<?0.02?wt% O2). Focusing on redox-sensitive trace elements, here we combine a dataset of over 3000 LA-ICP-MS trace-element analyses on sedimentary pyrite, standardised against Berner’s Phanerozoic O2 modelling and direct measurement of oxygen concentrations in fluid inclusions in sedimentary halite, to develop the first detailed estimate for atmosphere O2 concentration and secular variation from 2200?Ma to the present. The estimates suggest dynamic cycles of atmosphere oxygen that increased in frequency through time. There were possibly three first-order cycles in the Proterozoic varying from 400 to 600 million years in length and a further five first-order cycles in the Phanerozoic from 60 to 120 million years in length. Our estimates of oxygen concentration are at odds with most previous estimates. We suggest, rather than very low atmosphere oxygen in the Proterozoic, the mean concentration was about 7?wt%, rising to a mean of about 10?wt% in the Phanerozoic, but with significant cyclic variation of up to a maximum concentration of possibly over 30?wt%. We observe that the proposed oxygen cycles correlate with biodiversity cycles and to the timing of major stratiform base-metal deposits in sedimentary basins. For example, minima in atmosphere oxygenation correlate with mass extinction events and stratiform Zn–Pb–Ag deposits, whereas maxima in oxygenation correlate with major evolutionary events, global periods of evaporite formation and the timing of stratiform copper deposits.Lash, G.G., 2019. A global biogeochemical perturbation during the Middle Frasnian punctata Event: Evidence from muted carbon isotope signature in the Appalachian Basin, New York State (USA). Global and Planetary Change 177, 239-254. modest positive stable carbon isotope excursion coincident with the Upper Devonian Middlesex Formation of western New York State and beneath the Palmatolepis transitans - Palmatolepis punctata zonal boundary is interpreted to define the beginning of the Middle Frasnian punctata Event. The broad positive excursion that defines this global isotopic event elsewhere, however, appears to have been muted in the northern Appalachian Basin by a tectonically induced regression and associated deposition of the organic-deficient Cashaqua Formation. δ13Corg increases upward through the lower two-thirds of the Cashaqua, peaking approximately 4.5?m below its contact with the overlying Rhinestreet Formation in the mid-punctata Zone. Above this stratigraphic level, δ13Corg diminishes 2.2‰ over a vertical distance of 41?cm that encompasses a newly recognized interval of microtektite-like spherules. Thus, that part of the studied section between the middle of the Middlesex Formation and the peak δ13Corg value in the upper Cashaqua Formation embraces the stratigraphic range of the punctata positive excursion dampened by the regional base level reduction and associated increased flux of 13C-depleted terrestrial weathering runoff, including dissolved inorganic carbon (DIC). δ13Corg values recover to pre-negative excursion levels through the top of the Cashaqua Formation into the lower Rhinestreet Formation. The sharp negative excursion terminating the punctata Event of western New York likely records the sudden introduction of 12C into the ocean - atmosphere system, perhaps related to destabilization of sea-floor methane hydrates. However, hydrate dissociation concurrent with rising global sea level and in the absence of a closely preceding thermal event sufficient to raise bottom-water temperature is problematic. The coincidence of the stratigraphic interval containing the microtektite-like spherules and the onset of the negative carbon isotope excursion suggests that impact-induced mechanical disruption of the ocean floor may have triggered the release of methane.Lattaud, J., Lo, L., Zeeden, C., Liu, Y.-J., Song, S.-R., van der Meer, M.T.J., Sinninghe Damsté, J.S., Schouten, S., 2019. A multiproxy study of past environmental changes in the Sea of Okhotsk during the last 1.5?Ma. Organic Geochemistry 132, 50-61. diols have been detected in a wide range of environments and have been used to reconstruct past environmental changes, however only a few long-term records exist to date. Here we reconstructed past environmental changes in the central Sea of Okhotsk over the last 1.5 million years, covering the Mid-Pleistocene Transition (MPT). Sea surface temperatures (SST) reconstructed using the Long-Chain Diol Index (LDI) reflects glacial/interglacial changes. However, when compared with other organic paleothermometers (Uk′37 and TEXL86) the LDI-SST is lower during interglacials and similar or higher during glacials, possibly suggesting a shift of diol production season during interglacials. The LDI-SST does not change in periodicity around the MPT as observed for the TEXL86, likely due to this seasonal shift. Diatom productivity, as recorded by 1,14-diols and biogenic opal content, increased during the main deglaciations with a succession from Proboscia diatoms to diatoms with a more heavily silicified shell, confirming that primary productivity in the central Sea of Okhotsk is driven by sea-ice progress and retreat. In contrast to the LDI-SST, the 1,14-diols record shows a change in periodicity around the MPT from 41- to 100-kyr cycle, suggesting an influence of orbital parameters on diatom productivity. In the central Sea of Okhotsk, the relative amount of C32 1,15-diol (FC32 1,15), a proxy for riverine input, correlates with sea-level change with more riverine-derived material reaching the core site when the Amur River mouth is closer at lower sea-levels. In agreement, FC32 1,15 shows a change in periodicity during the MPT, with the appearance of a 100-kyr cycle. Our results show that the long chain diols can provide important paleoceanographic information in subpolar environments over long time scales, but that temperature reconstructions can be severely impacted by changes in seasonality.Laurin, J., Barclay, R.S., Sageman, B.B., Dawson, R.R., Pagani, M., Schmitz, M., Eaton, J., McInerney, F.A., McElwain, J.C., 2019. Terrestrial and marginal-marine record of the mid-Cretaceous Oceanic Anoxic Event 2 (OAE 2): High-resolution framework, carbon isotopes, CO2 and sea-level change. Palaeogeography, Palaeoclimatology, Palaeoecology 524, 118-136. Anoxic Event 2 (OAE2; c. 94.5–93.9?Ma) offers insight into the mechanisms of past climate change linked to organic productivity and carbon sequestration. It has been studied extensively, but the vast majority of data come from marine records, thus providing an incomplete view of past climate dynamics. Here we integrate new high-resolution data and published records on depositional environments, the carbon-isotope composition of bulk organic carbon (δ13Corg) and plant cuticles (δ13Ccut), and stomatal-index values, a proxy for pCO2, in well-preserved terrestrial through marginal-marine archives of the initial phase of OAE2. The study area is located on the western margin of the Western Interior Seaway (southwestern Utah). Age constraints are based on a new U-Pb bentonite age and correlation to an orbitally calibrated interval of the Bridge Creek Limestone. n-Alkane abundance suggests predominance of terrestrial contributions to bulk organic carbon for most samples. Despite similarities between carbon-isotope variations and transgressive-regressive shoreline movements, it is argued that δ13Corg and δ13Ccut are not strongly affected by local variables. A series of negative, ~2‰ carbon-isotope excursions is identified and attributed to changes in the size and isotopic value of the atmospheric CO2 reservoir. The temporal spacing of these anomalies (80–120?kyr) is consistent with changes in insolation modulated by orbital eccentricity. A systematic, phase-shifted relationship between the negative carbon-isotope excursions and transgressive increments further suggests a link between carbon-cycle perturbations and meter-scale sea-level change on the 100-kyr time scale. A conceptual model involving insolation-controlled aquifer charge/discharge and biomass burial/degradation in the monsoonal belt is proposed. The framework presented here is available to facilitate further research on the interplay of terrestrial and oceanic carbon reservoirs during OAE2.Le Moine Bauer, S., Sj?berg, A.G., L'Haridon, S., Stokke, R., Roalkvam, I., Steen, I.H., Dahle, H., 2019. Profundibacter amoris gen. nov., sp. nov., a new member of the Roseobacter clade isolated from Loki’s Castle Vent Field on the Arctic Mid-Ocean Ridge. International Journal of Systematic and Evolutionary Microbiology 69, 975-981. bacterial strain, designated BAR1T, was isolated from a microbial mat growing on the surface of a barite chimney at the Loki’s Castle Vent Field, at a depth of 2216?m. Cells of strain BAR1T were rod-shaped, Gram-reaction-negative and grew on marine broth 2216 at 10–37?°C (optimum 27–35?°C), pH 5.5–8.0 (optimum pH 6.5–7.5) and 0.5–5.0?%?NaCl (optimum 2?%). The DNA G+C?content was 57.38?mol%. The membrane-associated major ubiquinone was Q-10, the fatty acid profile was dominated by C18?:?1ω7c (91?%), and the polar lipids detected were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminolipid, one unidentified lipid and one unidentified phospholipid. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain BAR1T clustered together with Rhodobacterales bacterium PRT1, as well as the genera Halocynthiibacter and Pseudohalocynthiibacter in a polyphyletic clade within the Roseobacter clade. Several characteristics differentiate strain BAR1T from the aforementioned genera, including its motility, its piezophilic behaviour and its ability to grow at 35?°C and under anaerobic conditions. Accordingly, strain BAR1T is considered to represent a novel genus and species within the Roseobacter clade, for which the name Profundibacter amoris gen. nov., sp. nov. is proposed. The type strain is Profundibacter amoris BAR1T (=JCM 31874T=DSM 104147T). The GenBank/EMBL/DDB accession number for the 16 rRNA gene sequence of strain BAR1T is MH883801. The genome has been deposited in GenBank under the accession number CP032125.Lee, J., Crampton, K.T., Tallarida, N., Apkarian, V.A., 2019. Visualizing vibrational normal modes of a single molecule with atomically confined light. Nature 568, 78-82. internal vibrations of molecules drive the structural transformations that underpin chemistry and cellular function. While vibrational frequencies are measured by spectroscopy, the normal modes of motion are inferred through theory because their visualization would require microscopy with ?ngstr?m-scale spatial resolution—nearly three orders of magnitude smaller than the diffraction limit in optics. Using a metallic tip to focus light and taking advantage of the surface-enhanced Raman effect to amplify the signal from individual molecules, tip-enhanced Raman spectromicroscopy (TER-SM) reaches the requisite sub-molecular spatial resolution, confirming that light can be confined in picocavities and anticipating the direct visualization of molecular vibrations. Here, by using TER-SM at the precisely controllable junction of a cryogenic ultrahigh-vacuum scanning tunnelling microscope, we show that ?ngstr?m-scale resolution is attained at subatomic separation between the tip atom and a molecule in the quantum tunnelling regime of plasmons7. We record vibrational spectra within a single molecule, obtain images of normal modes and atomically parse the intramolecular charges and currents driven by vibrations. Our analysis provides a paradigm for optics in the atomistic near-field.Lee, J.H., Lee, K.S., 2019. Geochemical evaluation of low salinity hot water injection to enhance heavy oil recovery from carbonate reservoirs. Petroleum Science 16, 366-381. low salinity water injection (LSWI) has recovered residual oil after the conventional waterflood, highly viscous oil has remained in heavy oil reservoirs. Hot water injection is an economic and practical method to improve oil mobility for viscous oil reservoirs. It potentially controls temperature-dependent geochemical reactions underlying the LSWI mechanism and oil viscosity. Therefore, this study has modeled and evaluated a hybrid process of low salinity hot water injection (hot LSWI) to quantify synergistic effects in heavy oil reservoirs. In comparison to seawater injection (SWI) and LSWI, hot LSWI results in more cation ion-exchange (Ca2+ and Mg2+) and more wettability modification. Hot LSWI also reduces oil viscosity. In core-scaled systems, it increases oil recovery by 21% and 6% over SWI and LSWI. In a pilot-scaled reservoir, it produces additional oil by 6% and 3% over SWI and LSWI. Probabilistic forecasting with uncertainty assessment further evaluates the feasibility of hot LSWI to consider uncertainty in the pilot-scaled reservoir and observes enhanced heavy oil production. This study confirms the viability of hot LSWI due to synergistic effects including enhanced wettability modification and oil viscosity reduction effects.Lelieveld, J., Klingmüller, K., Pozzer, A., Burnett, R.T., Haines, A., Ramanathan, V., 2019. Effects of fossil fuel and total anthropogenic emission removal on public health and climate. Proceedings of the National Academy of Sciences 116, 7192.: We assessed the effects of air pollution and greenhouse gases on public health, climate, and the hydrologic cycle. We combined a global atmospheric chemistry–climate model with air pollution exposure functions, based on an unmatched large number of cohort studies in many countries. We find that fossil-fuel-related emissions account for about 65% of the excess mortality rate attributable to air pollution, and 70% of the climate cooling by anthropogenic aerosols. We conclude that to save millions of lives and restore aerosol-perturbed rainfall patterns, while limiting global warming to 2 °C, a rapid phaseout of fossil-fuel-related emissions and major reductions of other anthropogenic sources are needed.Abstract: Anthropogenic greenhouse gases and aerosols are associated with climate change and human health risks. We used a global model to estimate the climate and public health outcomes attributable to fossil fuel use, indicating the potential benefits of a phaseout. We show that it can avoid an excess mortality rate of 3.61 (2.96–4.21) million per year from outdoor air pollution worldwide. This could be up to 5.55 (4.52–6.52) million per year by additionally controlling nonfossil anthropogenic sources. Globally, fossil-fuel-related emissions account for about 65% of the excess mortality, and 70% of the climate cooling by anthropogenic aerosols. The chemical influence of air pollution on aeolian dust contributes to the aerosol cooling. Because aerosols affect the hydrologic cycle, removing the anthropogenic emissions in the model increases rainfall by 10–70% over densely populated regions in India and 10–30% over northern China, and by 10–40% over Central America, West Africa, and the drought-prone Sahel, thus contributing to water and food security. Since aerosols mask the anthropogenic rise in global temperature, removing fossil-fuel-generated particles liberates 0.51(±0.03) °C and all pollution particles 0.73(±0.03) °C warming, reaching around 2 °C over North America and Northeast Asia. The steep temperature increase from removing aerosols can be moderated to about 0.36(±0.06) °C globally by the simultaneous reduction of tropospheric ozone and methane. We conclude that a rapid phaseout of fossil-fuel-related emissions and major reductions of other anthropogenic sources are needed to save millions of lives, restore aerosol-perturbed rainfall patterns, and limit global warming to 2 °C.Lepaulard, C., Gattacceca, J., Swanson-Hysell, N., Quesnel, Y., Demory, F., Osinski, G.R., 2019. A Paleozoic age for the Tunnunik impact structure. Meteoritics & Planetary Science 54, 740-751. report paleomagnetic directions from the target rocks of the Tunnunik impact structure, as well as from lithic impact breccia dikes that formed during the impact event. The target sedimentary rocks have been remagnetized after impact-related tilting during a reverse polarity interval. Their magnetization is unblocked up to 350?°C. The diabase dikes intruding into these sediments retained their original magnetization which unblocks above 400?°C. The impact breccia records a paleomagnetic direction similar to that of the overprints in the target sedimentary rocks. The comparison of the resulting virtual geomagnetic pole for the Tunnunik impact structure with the apparent polar wander path for Laurentia combined with biostratigraphic constraints from the target sedimentary rocks is most consistent with an impact age in the Late Ordovician or Silurian, around 430?450?Ma, soon after the deposition of the youngest impacted sedimentary rocks. Our results from the overprinted sedimentary rocks and diabase dikes imply that the postimpact temperature of the studied rocks was about 350?°C.Li, C., Liu, C., Hu, G., Sun, J., Hao, X., Liu, L., Meng, Q., 2019. Investigation on the multiparameter of hydrate-bearing sands using nano-focus X-ray computed tomography. Journal of Geophysical Research: Solid Earth 124, 2286-2296. this study, a nano‐focus X‐ray computed tomography (X‐CT) is used to observe the formation of methane hydrate in sands on pore scale and to quantify hydrate saturation, pore structure parameters, and permeability of hydrate‐bearing sands. A new analytical technique is developed to improve the identification of water‐hydrate boundary. Three hydrate accumulation habits (i.e., floating, contacting, and cementing) in pore spaces are observed. When there is no methane bubble, hydrate distribution evolves from floating to contacting and then to cementing as hydrate saturation increases. In contrast, only contacting and cementing distribution patterns appear in the pores with methane bubbles. Based on the surface extraction and defect detection from 3‐D images, both the gas/water/hydrate distributions and the pore structure characteristics are investigated. The results show that the porosity, the maximal pore volume, and maximal diameter decrease as hydrates accumulate in the pores. However, the maximal pore surface, the total pore number, and the large pores (>100 voxels) number increase gradually until the hydrate saturation reaches 35%, when they turn to decrease rapidly. The pore structure parameters show detailed changes of hydrate and water on pore scale. The incompressible Navier‐Stokes equations are used to calculate absolute permeability of hydrate‐bearing sands based on X‐ray computed tomography digital images. It indicates that the microdistribution of the hydrate has a significant effect on the permeability calculation. The fluid streamlines obtained through simulation are used to track the water transport paths.Li, C., Zhang, J., Wu, R., Liu, Y., Hu, X., Yan, Y., Ling, X., 2019. A novel strategy for rapidly and accurately screening biomarkers based on ultraperformance liquid chromatography-mass spectrometry metabolomics data. Analytica Chimica Acta 1063, 47-56. reported a novel strategy for rapidly and accurately screening biomarkers based on ultraperformance liquid chromatography-mass spectrometry (UPLC-MS) metabolomics data. First, the preliminary variables were obtained by screening the original variables using method validation. Second, the variables were selected from the preliminary variables and formed the variable sets by testing different thresholds of single factor (variable importance in projection (VIP), fold change (FC), the area under the receiver operating characteristic curve (AUROC), and –ln(p-value)). Then the partial least squares-discriminant analysis (PLS-DA) models were performed. The best threshold of each factor, and the corresponding variable set were found by comparing the models' R2X, R2Y and Q2. Third, the second-step-obtained variable sets were further screened by multi-factors. The best combination of the multi-factors, and the corresponding variable set were found by comparing R2X, R2Y and Q2. The expected biomarkers were thus obtained. The proposed strategy was successfully applied to screen biomarkers in urine, plasma, hippocampus, and cortex samples of Alzheimer's disease (AD) model, and significantly decreased the time of screening and identifying biomarkers, improved the R2X, R2Y and Q2, therefore enhanced the interpreting, grouping, and predicting abilities of the PLS-DA model compared with generally-applied procedure. This work can provide a valuable clue to scientists who search for potential biomarkers. It is expected that the developed strategy can be written as a program and applied to screen biomarkers rapidly, efficiently and accurately.Li, J.-f., Ye, J.-l., Qin, X.-w., Qiu, H.-j., Wu, N.-y., Lu, H.-l., Xie, W.-w., Lu, J.-a., Peng, F., Xu, Z.-q., Lu, C., Kuang, Z.-g., Wei, J.-g., Liang, Q.-y., Lu, H.-f., Kou, B.-b., 2018. The first offshore natural gas hydrate production test in South China Sea. China Geology 1, 5-16. gas hydrates (NGH) is one of key future clean energy resources. Its industrialized development will help remit the huge demand of global natural gas, relieve the increasing pressure of the environment, and play a vital role in the green sustainable growth of human societies. Based on nearly two decades’ studying on the reservoir characteristics in the South China Sea (SCS) and the knowledge of reservoir system, the China Geological Survey (CGS) conducted the first production test on an optimal target selected in Shenhu area SCS in 2017. Guided by the “three-phase control” exploitation theory which focused on formation stabilization, technologies such as formation fluid extraction, well drilling and completing, reservoir stimulating, sand controlling, environmental monitoring, monitoring and preventing of secondary formation of hydrates were applied. The test lasted for 60 days from May 10th when starting to pump, drop pressure and ignite to well killing on July 9th, with gas production of 3.09×105 m3 in total, which is a world record with the longest continuous duration of gas production and maximal gas yield. This successful test brings a significant breakthrough on safety control of NGH production.Li, J.-L., Zhai, X., Ma, Z., Zhang, H.-H., Yang, G.-P., 2019. Spatial distributions and sea-to-air fluxes of non-methane hydrocarbons in the atmosphere and seawater of the Western Pacific Ocean. Science of The Total Environment 672, 491-501. an oceanographic campaign in the western Pacific Ocean from 12 August to 3 October 2014, the concentrations of five non-methane hydrocarbons (NMHCs) were measured in marine atmosphere and seawater. The average mixing ratios of ethane, ethylene, propane, propylene, and isoprene were 1.109?±?0.359, 0.658?±?0.137, 0.711?±?0.377, 0.429?±?0.139, and 0.255?±?0.201?ppbv, respectively. In general, atmospheric concentrations of ethane and propane showed significant decrease from the inshore area to the open ocean, while ethylene and propylene exhibited decreasing trends from low latitudes to high latitudes. The results suggested that atmospheric ethane and propane with long lifetimes were more likely influenced by the air mass transported from continent, while ethylene, propylene and isoprene with short lifetimes were mainly derived from the surface seawater. The average concentrations of ethane, ethylene, propane, propylene, and isoprene in the surface seawater were 6.6?±?5.8, 51.9?±?23.5, 15.4?±?4.3, 17.2?±?3.8, and 23.5?±?8.6?pmol?L?1, respectively. A significant positive correlation was observed between ethane and propane (R2?=?0.45, n?=?39, p?<?0.001), implying that their production and removal pathways in the surface seawater were similar. High concentrations of isoprene were observed in the waters with high Chl-a values, suggesting that the biological process was a controlling factor. The estimated sea-to-air fluxes of ethane, propane, ethylene, propylene, and isoprene were in the range of 0.1–24.9, 4.2–235, 1.0–43.8, 1.5–90.2, and 2.1–149?nmol?m?2?d?1, respectively. This study is of great importance to the contribution to the atmospheric NMHCs from the western Pacific Ocean and provides data supporting for global NMHCs emission estimates.Li, J., Li, L., Bai, S., Ta, K., Xu, H., Chen, S., Pan, J., Li, M., Du, M., Peng, X., 2019. New insight into the biogeochemical cycling of methane, S and Fe above the Sulfate-Methane Transition Zone in methane hydrate-bearing sediments: A case study in the Dongsha area, South China Sea. Deep Sea Research Part I: Oceanographic Research Papers 145, 97-108. methane, S and Fe cycling in the sediments can largely reduce the flux of methane from the ocean to the atmosphere. Compared to a large number of records regarding these processes in the sulfate-methane transition zone (SMTZ), detailed information of these processes in the zone above the SMTZ is still required. In this study, a short sediment core DS16 (330?cm) collected from the methane hydrate-bearing Dongsha area, Northern of the South China Sea, was examined by geochemical and microbial methods. Pore water dissolved inorganic carbon (DIC) had an increasing trend with the increasing depth of the sediment, while the value of δ13C-DIC showed a decreasing pattern. The high concentrations of DIC (up to 32.88?mM) and relatively negative δ13C-DIC (down to ?30.07‰) indicated the occurrence of anaerobic oxidation of methane (AOM) to some extant above the SMTZ in this region. The variation of concentration profiles of H2S (3.69–12.71?mmol/L) and Fe(III) indicated active S and Fe redox reactions occurred in this zone. Notably, both of the decreasing trends of sulfate and Fe(III) correlated well with those of δ13C-DIC, indicating AOM and organic materials coupled with both sulfate and Fe(III) reduction. Moreover, high-throughput sequencing data showed that a number of archaea (ANME-1) and bacteria (Sulfurovum and Shewanella), which are potential methane-, S- and Fe-metabolic related microorganisms, were detected in these sediments. In addition, the functional genes related to sulfate reduction, sulfur oxidation, and Fe uptake were also detected based on metagenomics analysis. Among them, with the depth increase and Fe(III) concentration decrease, the gene related to Fe3+ uptake mechanism decreased, while the gene related to siderophore uptake mechanism remained constant or even slightly increased. Thus, we propose that bacteria acquired Fe(III) via Fe(III) uptake proteins and siderophore uptake proteins in the Fe-deficient environments for reduction, which then might support the occurrence of Fe-AOM. By integrating these data, we suggest the occurrence of active biogeochemical CH4-S-Fe cycling in the zone above the SMTZ under high methane flux.Li, J., Qiao, Y., Zong, P., Wang, C., Tian, Y., Qin, S., 2019. Thermogravimetric analysis and isoconversional kinetic study of biomass pyrolysis derived from land, coastal zone, and marine. Energy & Fuels 33, 3299-3310. types of biofuels derived from land, coastal zone, and marine were pyrolyzed in a thermogravimetric analyzer from room temperature to 1000 °C under different heating rates (50, 80, and 100 °C/min), and three isoconversional mathematical models were established to analyze the kinetic properties of biomass. The results show that the pyrolysis process of biomass derived from different distributions included three main stages: drying and preheating stage, volatile matter evaporation stage, and carbonization stage, whereas the pyrolysis behavior of the marine seawater Spirulina (Sp) biomass is somewhat different from that of land [corn stalks (Cs)] and coastal biomasses [reed (Re)], stemming from the inherent difference in their compositions. Cs and Re species have advantages over microalgae in terms of the difficulty of volatile matters releasing, whereas the pyrolysis process of Re and Sp is faster than Cs because of the catalysis of its high salt tolerance. The heating rate has a significant effect on the performance of devolatilization profiles and maximum weight loss rate, regardless of the biomass type from different regions. The dynamics analysis indicates that Sp species is preferable to Cs and Re in terms of thermochemical conversion because of the lower apparent activation energy for total conversion. From the verification test, we concluded that the simulations for Friedman models presented a good agreement with the experimental conversions calculated at three different heating rates for Cs, Re, and Sp pyrolysis, and that the kinetic simulation of the weight loss curve and kinetic parameters obtained by pyrolysis of three biomasses is reasonable and effective.Li, L., Fang, Z., He, C., Shi, Q., 2019. Separation and characterization of marine dissolved organic matter (DOM) by combination of Fe(OH)3 co-precipitation and solid phase extraction followed by ESI FT-ICR MS. Analytical and Bioanalytical Chemistry 411, 2201-2208. dissolved organic matter (DOM) constitutes a major carbon pool in the global carbon cycle. Characterization of its chemical composition will improve our understanding of its role in global biogeochemical cycles. Currently, solid phase extraction (SPE) followed by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analysis has become a powerful approach to characterize the molecular composition of DOM. However, some components in marine DOM, such as highly oxygenated tannin-like molecules, were lost during the SPE process. In this study, a sequential combination of co-precipitation and SPE procedure was proposed to improve the yield of marine DOM extraction. Ferric hydroxide was used as the co-precipitation agent to separate marine DOM, and SPE was carried out for the extraction of DOM from dissolved and precipitate fractions. The total yield in total organic carbon (TOC) and the number of assigned molecules of SPE-DOM increased by 25% and 51%, respectively, compared with those by direct SPE process. The combined process has good selectivity on tannin-like compounds. The result is instructive for the understanding of DOM molecular composition and potential for a routine method for DOM extraction from environmental water samples, especially for marine DOM containing a small amount of tannin-like compounds.Li, L., Liu, X., Wang, H., Zhao, C., Liu, Q., Shang, X., 2019. Removal of petroleum hydrocarbons and heterocycles by Pseudomonas sp. LKY-5 under aerobic conditions. Petroleum Science and Technology 37, 1298-1305. adaptability and biodegradability of oil pollutants on functional bacteria are two important keys to bioremediation technologies. Pseudomonas sp. LKY-5 revealed strong biological activities in high salinity (3%) and high alkalinity (pH 9.0). n-hexadecane, phenanthrene, pyrene and carbazole could be directly utilized, and inhibited by the presence of DBT. Sulfur compounds and alkanes in No. 0 diesel and FCC diesel were effectively degraded. The concentrations of short chain alkanes were increased significantly after degradation. It can be seen that strain LKY-5 is an excellent bacterial candidate for bioremediation of oil-contaminated sites and sediments.Li, M., Wu, G., Xia, B., Huang, T., Ni, B., Pang, S., Long, X., 2019. Controls on hydrocarbon accumulation in clastic reservoirs of the Tarim Craton, NW China. Marine and Petroleum Geology 104, 423-437. Tarim Craton of NW China hosts abundant hydrocarbon resources within clastic reservoirs characterized by a complex entrapment and fill history. In this paper, we review the processes of hydrocarbon accumulation in typical clastic reservoirs from the literature, and combine this with new research from six hydrocarbon-bearing regions (the Yakela Faulted-Uplift, the southern slope of the Tabei Uplift, the Tazhong Uplift, the northern slope of the Tazhong Uplift, the southern margin of the Bachu Uplift, and volcanic reservoirs) to identify the key controls on hydrocarbon accumulation and distribution in reservoirs of the Tarim Craton. Favorable reservoir–trap configurations exist on structural highs created during the evolution of paleo-uplifts and paleo-slopes in the region, with hydrocarbons accumulating in both structural (fault, salt dome, and thrust-fault anticline) and combined structural-primary stratigraphic traps. Vertical hydrocarbon migration occurred via deep–shallow superposed faults, and (rarely interpreted) fault textures in volcanic conduits. Unconformity surfaces and sand bodies provided pathways for both limited lateral redistribution and significant long-distance (>100?km) migration of hydrocarbons. The prospectivity of upper Paleozoic sandstone facies and paleogeography was controlled by denudation of the paleo-uplifts, and these reservoirs are most likely to host giant oil and gas fields in the region.Li, R., Wu, K., Li, J., Xu, J., Chen, Z., 2019. Shale gas transport in wedged nanopores with water films. Journal of Natural Gas Science and Engineering 66, 217-232. the consideration of a mobile high-viscosity water film and a bulk water layer, an analytical model is proposed to predict gas flow behaviors and gas apparent permeability in nanopores. Physical molecular forces are analyzed to determine the properties and formation of the high-viscosity water film and the bulk water layer. Boundary conditions at a solid-liquid interface and a liquid-gas interface are modified to account for water slippage and gas slip. How mobile bulk water molecules influence gas transport capability in pores of different geometry is investigated with different pore sizes and pressure for the whole range of water saturation, which has been validated with experimental data and simulation results. Besides, the effect of a wedged pore structure on multiphase flow behaviors is also investigated to figure out the influences of pore shape.Li, S., Zhang, D., 2019. How effective is carbon dioxide as an alternative fracturing fluid? SPE Journal 24, 857-876. hydraulic fracturing requires an enormous consumption of water and introduces many potential environmental issues. In addition, water-based fluid tends to be trapped in formations, reducing oil/gas-phase relative permeability, and causes clay-mineral swelling, which lowers absolute permeability. Carbon dioxide (CO2) is seen as a promising alternative working fluid that poses no formation-damage risk, and it can stimulate more-complex and extensive fracture networks. However, very little, if any, extant research has quantitatively analyzed the effectiveness of CO2 fracturing, except for some qualitative fracturing experiments that are based on acoustic emissions. In this study, we systematically examine water and CO2 fracturing, and compare their performance on the basis of a rigorously coupled geomechanics and a fluid-heat-flow model. Parameters investigated include fluid viscosity, compressibility, in-situ stress, and rock permeability, illustrating how they affect breakdown pressure (BP) and leakoff, as well as fracturing effectiveness. It is found that (1) CO2 has the potential to lower BP, benefiting the propagation of fractures; (2) water fracturing tends to create wider and longer tensile fractures compared with CO2 fracturing, thereby facilitating proppant transport and placement; (3) CO2 fracturing could dramatically enhance the complexity of artificial fracture networks even under high-stress-anisotropy conditions; (4) thickened CO2 tends to generate simpler fracture networks than does supercritical CO2 (SC-CO2), but still more-complex fracture networks than fresh water; and (5) the alternative fracturing scheme (i.e., SC-CO2 fracturing followed by thickened-CO2 fracturing) can readily create complex fracture networks and carry proppant to keep hydraulic fractures open. This study reveals that, for intact reservoirs, water-based fracturing can achieve better fracturing performance than CO2 fracturing; however, for naturally fractured reservoirs, CO2 fracturing can constitute an effective way to stimulate tight/shale oil/gas reservoirs, thereby improving oil/gas production.Li, X., Guo, H., Zheng, H., Xiu, W., He, W., Ding, Q., 2019. Roles of different molecular weights of dissolved organic matter in arsenic enrichment in groundwater: Evidences from ultrafiltration and EEM-PARAFAC. Applied Geochemistry 104, 124-134. weight (MW) is a fundamental property of dissolved organic matter (DOM) that may affect the interaction between DOM and metals/metalloids. However, understanding of MW property of groundwater DOM and its roles in arsenic (As) mobilization needs to be improved. In this study, two surface water samples and 12 groundwater samples with different concentrations of As and dissolved organic carbon (DOC) were taken to evaluate the effects of DOM MW on As mobilization by using sequential ultrafiltration technique under a N2 atmosphere. Concentrations of As, Fe, DOC, and spectroscopic properties of OM in each ultrafiltered sample were analyzed. Variations of As, Fe and DOC concentrations in different ultrafiltration fractions show that Fe colloids mainly exist in large size particles (10 kDa-0.45?μm fractions), while organic colloids are mainly present in middle size particles (5–10?kDa fractions). The positive correlations between As and Fe in 10 kDa-0.45?μm fractions (R2?=?0.76, p?<?0.01) and between As and DOC in 5–10?kDa fractions (R2?=?0.61, p?<?0.05) indicate that the complexation of As with large-size Fe colloids and middle-size DOM promotes As mobilization. Parallel factor analysis (PARAFAC) of the three-dimensional fluorescence spectra reveals that DOM in all size fractions comprises three major components, namely C1 (terrestrial humic-like component), C2 (microbial humic-like component), and C3 (protein-like component). The positive correlation between C1 (%) and As concentrations (R2?=?0.73, p?<?0.05) possibly confirms that terrestrial-derived humic-like substance (HS) should be conducive to As enrichment. The spectroscopic indices of various fractions show that low MW DOM is characterized by more microbe-associated OM. Some samples have more than 90% of As in the ‘truly dissolved’ fractions, suggesting that microbial utilization of labile low MW DOM should lead to the enrichment of As, in addition to complexation reactions. Therefore, both As-Fe-HS complexation and microbial degradation of low MW DOM being related to the reductive dissolution of As-bearing Fe oxide minerals enhance As mobilization and enrichment in groundwater.Li, X., Luo, H., Huang, T., Xu, L., Shi, X., Hu, K., 2019. Statistically correlating NMR spectra and LC-MS data to facilitate the identification of individual metabolites in metabolomics mixtures. Analytical and Bioanalytical Chemistry 411, 1301-1309. and LC-MS are two powerful techniques for metabolomics studies. In NMR spectra and LC-MS data collected on a series of metabolite mixtures, signals of the same individual metabolite are quantitatively correlated, based on the fact that NMR and LC-MS signals are derived from the same metabolite covary. Deconvoluting NMR spectra and LC-MS data of the mixtures through this kind of statistical correlation, NMR and LC-MS spectra of individual metabolites can be obtained as if the specific metabolite is virtually isolated from the mixture. Integrating NMR and LC-MS spectra, more abundant and orthogonal information on the same compound can significantly facilitate the identification of individual metabolites in the mixture. This strategy was demonstrated by deconvoluting 1D 13C, DEPT, HSQC, TOCSY, and LC-MS spectra acquired on 10 mixtures consisting of 6 typical metabolites with varying concentration. Based on statistical correlation analysis, NMR and LC-MS signals of individual metabolites in the mixtures can be extracted as if their spectra are acquired on the purified metabolite, which notably facilitates structure identification. Statistically correlating NMR spectra and LC-MS data (CoNaM) may represent a novel approach to identification of individual compounds in a mixture. The success of this strategy on the synthetic metabolite mixtures encourages application of the proposed strategy of CoNaM to biological samples (such as serum and cell extracts) in metabolomics studies to facilitate identification of potential biomarkers.Li, X., Zeng, X., Qiu, D., Zhang, Z., Chen, J., Shao, Z., 2019. Dissimilatory iron [Fe(III)] reduction by a novel fermentative, piezophilic bacterium Anoxybacter fermentans DY22613T isolated from East Pacific Rise hydrothermal sulfides. Geomicrobiology Journal 36, 291-302. iron-reducing microorganisms play an important role in the biogeochemical cycle of iron and influence iron mineral formation and transformation. However, studies on microbial iron-reducing processes in deep-sea hydrothermal fields are limited. A novel piezophilic, thermophilic, anaerobic, fermentative iron-reducing bacteria of class Clostridia, named Anoxybacter fermentans DY22613T, was isolated from East Pacific Rise hydrothermal sulfides. In this report, we examined its cell growth, fermentative metabolites, and biomineralization coupled with dissimilatory iron reduction. Both soluble ferric citrate (FC) and solid amorphous Fe(III) oxyhydroxide (FO) could promote cell growth of this strain, accompanied by increased peptone consumption. More acetate, butyrate, and CO2 were produced than without adding FO or FC in the media. The highest yield of H2 was observed in the Fe(III)-absent control. Coupled to fermentation, magnetite particles, and iron-sulfur complexes were respectively formed by the strain during FO and FC reduction. Under experimental conditions mimicking the pressure prevailing at the deep-sea habitat of DY22613T (20?MPa), Fe(III)-reduction rates were enhanced resulting in relatively larger magnetite nanoparticles with more crystal faces. These results implied that the potential role of A. fermentans DY22613T in situ in deep-sea hydrothermal sediments is coupling iron reduction and mineral transformation to fermentation of biomolecules. This bacterium likely contributes to the complex biogeochemical iron cycling in deep-sea hydrothermal fields.Li, Y.-B., Zhang, Y.-Q., Luo, C., Gao, H., Li, K., Xiao, Z.-R., Wang, Z.-Q., Pu, W.-F., Bai, B., 2019. The experimental and numerical investigation of in situ re-energization mechanism of urea-assisted steam drive in superficial heavy oil reservoir. Fuel 249, 188-197. has been used as an additive for steam drive because its decomposition reaction will increase sweep efficiency and reduce interfacial tension. But its in situ re-energization mechanism has never been discussed in the literature. In this study, the physical experiment and numerical simulation were applied to investigate the in situ energization mechanism of urea in the assistance of steam drive for a superficial heavy oil reservoir. First the PVT experiment showed that the decomposition reaction of urea can increase system pressure by generating carbon dioxide and this phenomenon can become more dramatic with higher temperature. The dissolution of carbon dioxide in crude oil can reduce the re-energization effect. The core flooding experiment results showed that when the steam drive has reached economic limitation, the injected urea solution can flow through the gas breakthrough channel formed by the steam drive and generate carbon dioxide at high temperature. The increased high pressure can push injected steam into the deep area of the core and thus increase the sweep efficiency. Eventually the water cut dropped significantly and the oil displacement efficiency rose by 10%–20%. Finally, a field-scale mechanism model was built using CMG-STARS software to investigate the performance of urea. The results showed that at the reservoir condition, the urea still exhibited excellent re-energization effect for a superficial reservoir. But due to the high density difference, the main contribution to enhanced recovery was that the increased pressure caused higher sweep efficiency of steam–carbon dioxide combination in upper layers. Also with increment of formation pressure, the re-energization effect will become less.Li, Y., Hu, Z., Duan, X., Wang, X., Shi, J., Zhan, H., 2019. The general form of transport diffusivity of shale gas in organic-rich nano-slits—A molecular simulation study using Darken approximation. Fuel 249, 457-471. a potential substitute for the gradually depleted conventional oil and gas resources, shale gas is attracting increasing attention worldwide. Because of the ubiquitous nanopores in shale matrix, studying diffusion behavior of shale gas in nano-scale channels is crucial for its development, which also lays the foundation for the optimization of hydraulic fracturing, horizontal well spacing, etc. This paper focuses on shale gas diffusion behavior in organic-rich nano-slits and establishes a calculation method for generalized transport diffusivity using Darken approximation by molecular simulation (MS). The main conclusions are as follows. (1) For the whole gas, compared to its self-diffusivity which decreases monotonically with pressure, there is a break point for its transport diffusivity in each slit. It’s found that the sequence of magnitudes of transport diffusivities in different pores at low pressures and that at high pressures are contrary. (2) For the bulk district (BD) in 2?nm slit, the self- and transport diffusivities don’t differ much at low pressures and their discrepancy enlarges at high pressures, the deviation of which can be 2.34 times at 41?MPa. (3) The transport diffusivity of the molecules in the Knudsen layer (KL) in 2?nm slit is always larger (1.21–3.76 times) than their self-diffusivity and shows fluctuations at large pressures, other than the self-diffusivity in KL which decreases monotonically with pressure. Furthermore, the deficiencies and directions for improvements of the kinetic self-diffusion model and Knudsen diffusion model are analyzed by the data comparison and the theory background on their derivation and expressions. It is expected that this work will give new insights on the flow capacity of shale gas in nano-scale pores and contribute to a deeper understanding for shale gas evaluation and exploitation.Li, Y., Wang, Z., Gan, Q., Niu, X., Xu, W., 2019. Paleoenvironmental conditions and organic matter accumulation in Upper Paleozoic organic-rich rocks in the east margin of the Ordos Basin, China. Fuel 252, 172-187. transitional shale gas contains significant resources, but scant areas have been developed economically. The evolution of paleoenvironmental and potential of high-quality shales generation from the Carboniferous to Permian (mainly of Benxi, Taiyuan and Shanxi formations) in the east margin of Ordos Basin, China, was systematically studied by integrated analysis including rock-mineral composition, trace elements and organic geochemical testing. The results show that the Benxi Formation consisted principally by marine deposits, while the co-existence of marine and marine-continental transitional deposits are found in the Taiyuan Formation. The Shanxi and its upon Xiashihezi formations are mainly constituted by continental deposits. The Taiyuan Formation has been affected by frequent transgression and regression processes, while the sedimentary environment of the Shanxi Formation was relatively stable. The degree of oxidation gradually increased from the Benxi to the Xiashihezi Formation, and the paleoclimate transformed from humid and warm climate to aridity. The paleosalinity decreased gradually, even though the environment was generally maintained in a salt water environment with considerable rainfall and relatively active hydrodynamic conditions. The paleoproductivity increased gradually, and a generally anoxic environment in the surface water contributed to the enrichment of organic matter. The rock-mineral compositions of the shales are dominated by clay minerals and quartz, and the organic matter content of the shales is relatively high (averaging of 1.28%). The shales primarily contain type III kerogen, and the shales have generally entered a high maturity stage with good gas generation potential. Furthermore, the gas generated from the interbedded coal seams in the Upper Paleozoic is a stable gas supply for interbedded shales. The results provide a geochemical basis for further study of marine-continental transitional shales in the Ordos Basin and supply recommendations for the optimization of high-quality shales production in similar basins around the world.Li, Y., Xu, H., He, C., Shen, Z., Chen, W., Gao, L., Lin, C., Lin, T., Lu, C., Shi, Q., Luo, J., Wang, W., 2019. Transformation and fate of dissolved organic nitrogen in drinking water supply system: A full scale case study from Yixing, China. Science of The Total Environment 673, 435-444. transformation of dissolved organic nitrogen (DON) in the drinking water treatment plants could be closely associated with nitrogenous disinfection by-product (N-DBP) formation. In this study, we have assessed the molecular transformation of DON and its impact on N-DBP formation in a full scale drinking water treatment plant. Based on the result of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analysis, DON compounds with low molecular weight (<1?kDa) were classified as CHON, CHON2 and CHON3 according to the number of nitrogen atoms. Via the analytical window of van Krevelen diagrams, we found that the molecular structural features of CHON, CHON2 and CHON3 were not altered before the chlorination process. In detail, the CHON2 and CHON3 compositions were concentrated on the regions assigned to a lignin-structure while CHON compositions were also distributed in other compounds including proteins, carbohydrates and tannin. Furthermore, CHON formation was more difficult to be removed before the V-filter process. For N-DBP, chlorine-containing DON (Cl-DON) composition was likely to be removed through flocculation and sedimentation processes, whereas N-nitrosamine compounds were removed in V-filter and biological activated carbon filter processes. The health risks of aromatic structure N-nitrosamines due to the pre-chlorination of the raw water should be further studied.Li, Y., Zheng, L., Zhang, Y., Liu, H., Jing, H., 2019. Comparative metagenomics study reveals pollution induced changes of microbial genes in mangrove sediments. Scientific Reports 9, Article 5739. forests are widespread along the subtropical and tropical coasts. They provide a habitat for a wide variety of plants, animals and microorganisms, and act as a buffer zone between the ocean and land. Along with other coastal environments, mangrove ecosystems are under increasing pressure from human activities, such as excessive input of nutrients and toxic pollutants. Despite efforts to understand the diversity of microbes in mangrove sediments, their metabolic capability in pristine and contaminated mangrove sediments remains largely unknown. By using metagenomic approach, we investigated the metabolic capacity of microorganisms in contaminated (CMS) and pristine (PMS) mangrove sediments at subtropical and tropical coastal sites. When comparing the CMS with PMS, we found that the former had a reduced diazotroph abundance and nitrogen fixing capability, but an enhanced metabolism that is related to the generation of microbial greenhouse gases via increased methanogenesis and sulfate reduction. In addition, a high concentration of heavy metals (mainly Zn, Cd, and Pb) and abundance of metal/antibiotic resistance encoding genes were found in CMS. Together, these data provide evidence that contamination in mangrove sediment can markedly change microbial community and metabolism; however, no significant differences in gene distribution were found between the subtropical and tropical mangrove sediments. In summary, contamination in mangrove sediments might weaken the microbial metabolisms that enable the mangrove ecosystems to act as a buffer zone for terrestrial nutrients deposition, and induce bioremediation processes accompanied with an increase in greenhouse gas emission.Liang, S., Hall, W.K., Laaksonen, A., Zhang, Z., Kusalik, G.P., 2019. Characterizing key features in the formation of ice and gas hydrate systems. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 377, Article 20180167. in liquids is critical to a range of important processes occurring in physics, chemistry and life sciences. In this article, we review our efforts towards understanding the crystallization mechanisms, where we focus on theoretical modelling and molecular simulations applied to ice and gas hydrate systems. We discuss the order parameters used to characterize molecular ordering processes and how different order parameters offer different perspectives of the underlying mechanisms of crystallization. With extensive simulations of water and gas hydrate systems, we have revealed unexpected defective structures and demonstrated their important roles in crystallization processes. Nucleation of gas hydrates can in most cases be characterized to take place in a two-step mechanism where the nucleation occurs via intermediate metastable precursors, which gradually reorganizes to a stable crystalline phase. We have examined the potential energy landscapes explored by systems during nucleation, and have shown that these landscapes are rugged and funnel-shaped. These insights provide a new framework for understanding nucleation phenomena that has not been addressed in classical nucleation theory.Liang, X., Liu, S., Wang, S., Deng, B., Zhou, S., Ma, W., 2019. Analysis of the oldest carbonate gas reservoir in China—New geological significance of the Dengying gas reservoir in the Weiyuan structure, Sichuan Basin. Journal of Earth Science 30, 348-366. Weiyuan Structure is the largest surface structure in the Sichuan Basin. However, the abundance of the Dengying Formation gas reservoir in the Weiyuan Structure is low. The height of the gas column is 244 m, but the integrated abundance is only 26.4%. After nearly 40 years of exploration, the Gaoshi1 Well and Moxi8 Well yielded gas flows that marked an important exploration success after the discovery of the Sinian Dengying Formation gas reservoir in the Weiyuan Structure, Sichuan Basin, Lower-Paleozoic in 1964. Combined with research examples of oil and gas migration and gas chimneys around the world, the authors used comprehensive geological-geophysical-geochemical research methods to provide a reasonable explanation of the low abundance of the gas reservoir in the Weiyuan Structure based on the surface and subsurface data. The latest research results show that (1) currently, the Weiyuan Structure is the apex of the Dengying Formation in the Mid-Sichuan Basin. The Guang’an, Longnüsi, Gaoshiti-Moxi, and Weiyuan structures are a series of traps in the Dengying Formation with gradual uplifting spill and closure points during the regional uplift of the Himalayan period. The natural gas of the Dengying Formation accumulated in different ways over a wide range and long distance in the Sichuan Basin. (2) At approximately 40 Ma, the Weiyuan area started to uplift and form the present structure, and it is the only outcropped area with the Triassic Jialingjiang Formation and Leikoupo Formation in the surface of the Sichuan Basin (except the steep structural belt in East Sichuan). Caused by the uplift and denudation, the core of the Weiyuan Structure has formed an escaping “skylight” for natural gas. The evidence of a gas chimney includes (1) the component percentage of non-hydrocarbon gas, which decreased from the bottom to the top, (2) the pressure coefficient is normal because the gas reservoir from the Upper Sinian to the Lower Permian commonly have a normal pressure coefficient (an average of 1.0), and (3) the isotope geochemistry of the argon mostly represents abiogenic characteristics of a deep source, and the 40Ar/36Ar ratio is as high as 2 855–5 222 in the Upper Permian. All of these characteristics provide sufficient evidence for a gas chimney effect. The characteristics of low abundance in the Weiyuan Structure can be a reference example for studying the late reconstruction of deep oil and gas reservoirs in the superimposed basins of western China.Liao, X., Wu, Z., Li, Y., Cao, H., Su, C., 2019. Effect of various chemical oxidation reagents on soil indigenous microbial diversity in remediation of soil contaminated by PAHs. Chemosphere 226, 483-491. oxidation is a promising pretreatment step coupled with bioremediation for removal of polycyclic aromatic hydrocarbons (PAHs). The effectiveness of Fenton, modified Fenton, potassium permanganate and activated persulfate oxidation treatments on the real contaminated soils collected from a coal gas plant (263.6?±?73.3?mg?kg?1 of the Σ16 PAHs) and a coking plant (385.2?±?39.6?mg?kg?1 of the Σ16 PAHs) were evaluated. Microbial analyses showed only a slight impact on indigenous microbial diversity by Fenton treatment, but showed the inhibition of microbial diversity and delayed population recovery by potassium permanganate reagent. After potassium permanganate treatment, the microorganism mainly existed in the soil was Pseudomonas or Pseudomonadaceae. The results showed that total organic carbon (TOC) content in soil was significantly increased by adding modified Fenton reagent (1.4%–2.3%), while decreased by adding potassium permanganate (0.2%–1%), owing to the nonspecific and different oxidative properties of chemical oxidant. The results also demonstrated that the removal efficiency of total PAHs was ordered: permanganate (90.0%–92.4%)?>?activated persulfate (81.5%–86.54%)?>?modified Fenton (81.5%–85.4%)?>?Fenton (54.1%–60.0%). Furthermore, the PAHs removal efficiency was slightly increased on the 7th day after Fenton and modified Fenton treatments, about 14.6%, and 14.4% respectively, and the PAHs removal efficiency only enhanced 4.1% and 1.3% respectively from 1st to 15th day after potassium permanganate and activated persulfate treatments. The oxidants greatly affect the growth of soil indigenous microbes, which cause further influence for PAHs degradation by bioremediation.Liebrand, D., de Bakker, A.T.M., 2019. Bispectra of climate cycles show how ice ages are fuelled. Climate of the Past Discussions 2019, 1-42. increasingly nonlinear response of the climate-cryosphere system to insolation forcing during the Pliocene and Pleistocene, as recorded in benthic foraminiferal stable oxygen isotope ratios (δ18O), is marked by a distinct evolution in ice-age cycle frequency, amplitude, phase, and geometry. To date, very few studies have thoroughly investigated the nonsinusoidal shape of these climate cycles, leaving precious information unused to further unravel the complex dynamics of the Earth's system. Here, we present higher-order spectral analyses of the LR04 δ18O stack that describe coupling and energy exchanges among astronomically-paced climate cycles during the Pliocene and Pleistocene. These advanced bispectral computations show how energy is passed from precession-paced to obliquity-paced climate cycles during the Early Pleistocene (~?2,500–~?750?ka), and ultimately to eccentricity-paced climate cycles during the Middle and Late Pleistocene (from ~?750?ka onward). They also show how energy is transferred among many cycles that have no primary astronomical origin. We hypothesize that the change of obliquity-paced climate cycles during the mid-Pleistocene transition (~?1,200–~?600?ka), from being a net sink into a net source of energy, is indicative of the passing of a land-ice mass-loading threshold in the Northern Hemisphere (NH), after which cycles of crustal depression and rebound started to resonate with the ~?110-kyr eccentricity modulation of precession. However, precession-paced climate cycles remain persistent energy providers throughout the Late Pliocene and entire Pleistocene, which is supportive of a dominant and continuous fuelling of the NH ice ages by insolation in the (sub-) tropical zones, and the control it exerts on meridional heat and moisture transport through atmospheric and oceanic circulation.Liem-Nguyen, V., Huynh, K., Gallampois, C., Bj?rn, E., 2019. Determination of picomolar concentrations of thiol compounds in natural waters and biological samples by tandem mass spectrometry with online preconcentration and isotope-labeling derivatization. Analytica Chimica Acta 1067, 71-78. present a sensitive, selective and robust method for the determination of 14 thiol compounds in aqueous samples. Thiols were derivatized with ω-bromoacetonylquinolinium bromide (BQB) and its deuterium labeled equivalent D7-ω-bromoacetonylquinolinium bromide (D7). Derivatized thiols were preconcentrated by online solid-phase extraction (SPE) followed by liquid chromatography separation and electrospray ionization tandem mass spectrometry determination (SPE/LC-ESI-MS/MS). The robustness of the method was validated for wide ranges in pH, salinity, and concentrations of sulfide and dissolved organic carbon (DOC) to cover contrasting natural water types. The limits of detection (LODs) for the thiols were 3.1–66 pM. Between 6 and 14 of the thiols were detected in different natural sample types at variable concentrations: boreal wetland porewater (0.7–51?nM), estuarine sediment porewater (50 pM–11?nM), coastal sea water (60 pM–16?nM), and sulfate reducing bacterium cultures (80 pM–4?nM). MS/MS fragmentation of the compounds produces two pairs of common product ions, m/z 130.2/137.1 and 218.1/225.1, which enables scanning for unknown thiols in precursor ion scan mode. Using this approach, we identified cysteine, mercaptoacetic acid, N-acetyl-L-cysteine and sulfurothioic S-acid in boreal wetland porewater. The performance of the developed method sets a new state of the art for the determination of thiol compounds in environmental and biological samples.Liggio, J., Li, S.-M., Staebler, R.M., Hayden, K., Darlington, A., Mittermeier, R.L., O’Brien, J., McLaren, R., Wolde, M., Worthy, D., Vogel, F., 2019. Measured Canadian oil sands CO2 emissions are higher than estimates made using internationally recommended methods. Nature Communications 10, Article 1863. oil and gas (O&G) sector represents a large source of greenhouse gas (GHG) emissions globally. However, estimates of O&G emissions rely upon bottom-up approaches, and are rarely evaluated through atmospheric measurements. Here, we use aircraft measurements over the Canadian oil sands (OS) to derive the first top-down, measurement-based determination of the their annual CO2 emissions and intensities. The results indicate that CO2 emission intensities for OS facilities are 13–123% larger than those estimated using publically available data. This leads to 64% higher annual GHG emissions from surface mining operations, and 30% higher overall OS GHG emissions (17 Mt) compared to that reported by industry, despite emissions reporting which uses the most up to date and recommended bottom-up approaches. Given the similarity in bottom-up reporting methods across the entire O&G sector, these results suggest that O&G CO2 emissions inventory data may be more uncertain than previously considered.Lihl, C., Douglas, L.M., Franke, S., Pérez-de-Mora, A., Meyer, A.H., Daubmeier, M., Edwards, E.A., Nijenhuis, I., Sherwood Lollar, B., Elsner, M., 2019. Mechanistic dichotomy in bacterial trichloroethene dechlorination revealed by carbon and chlorine isotope effects. Environmental Science & Technology 53, 4245-4254. (PCE) and trichloroethene (TCE) are significant groundwater contaminants. Microbial reductive dehalogenation at contaminated sites can produce nontoxic ethene but often stops at toxic cis-1,2-dichloroethene (cis-DCE) or vinyl chloride (VC). The magnitude of carbon relative to chlorine isotope effects (as expressed by ΛC/Cl, the slope of δ13C versus δ37Cl regressions) was recently recognized to reveal different reduction mechanisms with vitamin B12 as a model reactant for reductive dehalogenase activity. Large ΛC/Cl values for cis-DCE reflected cob(I)alamin addition followed by protonation, whereas smaller ΛC/Cl values for PCE evidenced cob(I)alamin addition followed by Cl– elimination. This study addressed dehalogenation in actual microorganisms and observed identical large ΛC/Cl values for cis-DCE (ΛC/Cl = 10.0 to 17.8) that contrasted with identical smaller ΛC/Cl for TCE and PCE (ΛC/Cl = 2.3 to 3.8). For TCE, the trend of small ΛC/Cl could even be reversed when mixed cultures were precultivated on VC or DCEs and subsequently confronted with TCE (ΛC/Cl = 9.0 to 18.2). This observation provides explicit evidence that substrate adaptation must have selected for reductive dehalogenases with different mechanistic motifs. The patterns of ΛC/Cl are consistent with practically all studies published to date, while the difference in reaction mechanisms offers a potential answer to the long-standing question of why bioremediation frequently stalls at cis-DCE.Lijith, K.P., Malagar, B.R.C., Singh, D.N., 2019. A comprehensive review on the geomechanical properties of gas hydrate bearing sediments. Marine and Petroleum Geology 104, 270-285. gas hydrates (NGH) that form in sediments beneath the ocean beds are a potential source to meet growing global energy demand. Gas hydrate bearing sediments (GHBS) exhibit improved geomechanical properties (viz., shear strength, stiffness, compressibility, and Poisson's ratio) that are responsible for their greater stability as compared to the native sediments. However, dissociation of gas hydrates during extraction of gas, instability in the GHBS could trigger submarine slope failures, seabed subsidence, and failure of the foundations of seafloor installations. In order to reduce the risk of occurrence of such geohazards, it is imperative to ascertain the stability of GHBS by understanding the variations in their geomechanical properties through field and laboratory investigations, which are time consuming and prohibitively expensive for many researchers. With this in view, the present study attempts to decipher the variation of geomechanical properties with respect to various parameters that affect them (viz., hydrate saturation (SH), hydrate morphology, and confining pressure-temperature conditions), by critically synthesizing the existing data in the literature. It has been noticed that the shear strength and stiffness are the major parameters influencing the stability of GHBS and both share power law relationship with SH. Further, it is noticed that the cohesion is the predominant component of the shear strength of GHBS and shows significant improvement for SH values greater than 15–50%. The variability of cohesion and stiffness with respect to SH have been analysed in tandem with the volumetric deformation, during the shearing process, to propose particle level mechanism hypothesis that provides an insight in to the stress-strain behavior of GHBS. The proposed relationships and mechanisms would aid in understanding the behavior and development of improved modeling of geomechanical properties of GHBS.Linares, V., Adams, M.J., Cradic, M.S., Finkelstein, I., Lipschits, O., Martin, M.A.S., Neumann, R., Stockhammer, P.W., Gadot, Y., 2019. First evidence for vanillin in the old world: Its use as mortuary offering in Middle Bronze Canaan. Journal of Archaeological Science: Reports 25, 77-84. small ceramic juglets that had been used as containers for offerings in an elite Middle Bronze Age III (ca. 1650–1550?BCE) masonry tomb uncovered at Tel Megiddo in the Jezreel Valley, Israel were tested using organic residue analysis. Notably, residues of vanillin, 4-hydroxybenzaldehyde, and acetonvanillone were identified in three of the four juglets examined. These are the major fragrance and flavour components of natural vanilla extract. To date, it has been commonly accepted that vanilla was domesticated in the New World and subsequently spread to other parts of the globe. Our research first ruled out all possibility of sample contamination and then conducted a post-organic residue analysis investigation of various species within the plant kingdom from which these principle compounds could have been exploited. The results shed new light on the first known exploitation of vanilla in an Old World context, including local uses, the significance and employment in mortuary practices, and possible implications for understanding trade networks in the ancient Near East during the second millennium BCE.Lingam, M., Loeb, A., 2019. Subsurface exolife. International Journal of Astrobiology 18, 112-141. study the prospects for life on planets with subsurface oceans, and find that a wide range of planets can exist in diverse habitats with ice envelopes of moderate thickness. We quantify the energy sources available to these worlds, the rate of production of prebiotic compounds, and assess their potential for hosting biospheres. Life on these planets is likely to face challenges, which could be overcome through a combination of different mechanisms. We estimate the number of such worlds, and find that they may outnumber rocky planets in the habitable zone of stars by a few orders of magnitude.Liu, D., Agarwal, R., Li, Y., Yang, S., 2019. Reactive transport modeling of mineral carbonation in unaltered and altered basalts during CO2 sequestration. International Journal of Greenhouse Gas Control 85, 109-120. formation is a new promising CO2 sink for providing secure long-term carbon storage via trapped CO2 in mineral phases. When water enters into the crystal structures of the divalent cation-bearing unaltered basalt, the rock is altered and serpentinized. The serpentinization of the unaltered basalt occurs widely around the world. To evaluate the mineral carbonation efficiency of unaltered and altered basalt over a longer time frame, a predictive modeling frame is established in TOUGHREACT based on data from core-scale static batch experiments and the field-scale Carbfix project. Results indicate that unaltered basalt has higher carbonation efficiency than altered basalt both in the carbonation rate and extent due to serpentine kinetic limitations for aqueous phase CO2 injection, and the carbonates mineralization extent and rate increase with the content of olivine minerals in basalt. Furthermore, under these conditions, the longer CO2 migration distance from the injection site enhances the chance for mineral carbonation in the serpentinized basalt. In addition, rapid aqueous phase CO2 injection may limit mineral carbonation and cause porosity reduction near wellbores in the basaltic reservoir, and this effect is more pronounced in case of unaltered basalt than in the altered basalt. Compared to the injection rate, the impact of reservoir conductivity is found to be significant on mineral carbonation in both the unaltered basalt and altered basalt; higher conductivity is more advantageous for CO2 mineralization under certain circumstances. In combination, the injectivity rate should be carefully assessed at sites based on the reservoir conductivity and whether the basalt is altered or unaltered and the extent of alteration.Liu, F.-J., Zong, Z.-M., Zhu, Y., Wei, X.-Y., Zhu, X.-N., Tang, M.-C., Huang, Z.-X., 2019. Production of benzenecarboxylic acids from two typical Chinese subbituminous coals by oxidation in aqueous sodium hypochlorite solution and insights into structural characteristics. Fuel 247, 386-394. subbituminous coal (ZSBC) and Shenmu-Fugu subbituminous coal (SFSBC) were oxidized in aqueous sodium hypochlorite solution at 30?°C for 10?h to produce valuable benzenecarboxylic acids (BCAs) and to understand structural characteristics of the 2 typical Chinese subbituminous coals. Fourier transform infrared spectrometer, gas chromatograph/mass spectrometer, and direct analysis in real time ionization source coupled to an ion trap mass spectrometer were used to characterize the resulting products from the oxidation. The results show that the distributions of functional groups, molecular masses, and group components of the products from ZSBC and SFSBC oxidation are largely similar. Non-chlorine BCAs are the dominant carboxylic acids (CAs) from the oxidation and the total yields of BCAs from ZSBC and SFSBC oxidation are 15.6?wt% and 16.5?wt% based on organic matter in ZSBC and SFSBC, respectively, suggesting that both coals contain abundant polycyclic or condensed aromatic rings (ARs). Various BCAs, including cata-condensed aromatics, polyaryls, and peri-condensed aromatics, were generated from different aromatic precursors (APs) via the oxidation. According to the distributions of BCAs, ZSBC is rich in polyaryl moieties with Car-Car bridged linkages between the ARs, while SFSBC contains much more highly condensed ARs. O2? dissociated from NaOCl could play a crucial role in producing BCAs from the ARs in ZSBC and SFSBC. In addition, some nitrogen-containing CAs were produced and their possible APs in ZSBC and SFSBC were speculated.Liu, H., Wang, C., Deng, B., Deng, J., Xu, Y., Zhou, W., 2019. Geochemical characteristics and thermal evolution of Paleogene source rocks in Lunpola Basin, Tibet Plateau. Petroleum Science and Technology 37, 950-961. Basin is the first exploration area with industrial oil flow in the hinterland of Tibetan Plateau and the target horizon is the Paleogene Niubao formation and Dingqinghu formation. Based on drilling data from multiple wells, the organic matter abundance, type and maturity of Paleogene source rocks in Lunpola Basin were measured and analyzed using organic geochemistry method. The 67 samples data from middle Niubao formation show that the average of TOC (wt.) is 3.50, S1+S2 is 30.55?mg/g; and the Tmax is 427?～?442?°C, δ13CPDB is -25.6‰ ～ -29.3‰ and Ro is 1.37%～1.84%. The 53 samples data from upper Niubao formation show that the average of TOC (wt.) is 4.16%, S1+S2 is 30.16?mg/g. and the Tmax is 421?～?440?°C, δ13CPDB is -26.9‰ ～ -28.7‰ and Ro is 0.61%～1.35%. The 70 samples data from lower Dingqinghu formation show that the average of TOC (wt.) is 4.16%, S1+S2 is 30.16?mg/g and Ro is 0.58%, and the Tmax is 421?～?440?°C, δ13CPDB is -26.9‰ ～ -28.7‰. These three sets of source rocks have high organic abundance and kerogen type of I- II1. Based on the previous studies of W-1 well in JiangjiaCo depression, XL-3 well in JiangriaCo depression and Z-1 well PaCo depression, a 2D model of north-south tectonic and thermal evolution in Lunpola basin is simulated by Schlumberger's PetroMod method. The results show that the XL-5 well of Niubao formation in Diezong area of Lunpola basin began to generate oil at 41.3Ma and reached the peak of hydrocarbon generation at 36.4Ma; and upper Niubao formation began to generate oil at 38.4Ma and hydrocarbon generation peaked at 31.9Ma. The lower Dingqinghu formation began to generate oil at 24.2Ma. At the end of upper Dingqinghu formation, the basin began the uplift and denudation stage at 23Ma, but the middle and upper Niubao formation and the Lower Dingqinghu formation are still active for hydrocarbon generation. The simulation also shows that the primary deposits in main source rocks are thin in the thrust uplift belt of southern basin and have not entered the stage of oil generation, and that the main oil source area is the Paleogene depression in central basin.Liu, H., Zhang, S., Song, G., Xuejun, W., Teng, J., Wang, M., Bao, Y., Yao, S., Wang, W., Zhang, S., Hu, Q., Fang, Z., 2019. Effect of shale diagenesis on pores and storage capacity in the Paleogene Shahejie Formation, Dongying Depression, Bohai Bay Basin, east China. Marine and Petroleum Geology 103, 738-752. to other marine-shale gas reservoirs in South China, the shale that developed in faulted basins in East China possesses peculiar characteristics regarding the mineral types and their evolution. The diagenesis of inorganic minerals, generation of hydrocarbons, and evolution of organic matter control the final features and quality of these shale reservoirs. Therefore, we must analyze this diagenesis based on the essential characteristics of the representative reservoir and discuss the influence of the diagenesis' evolution stage on the shale reservoir. This topic is also of practical value for contemporary shale-oil exploration and development. In this paper, we observe diagenesis, study its essential characteristics (such as the structure of the reservoir and pores), determine the key factors that control the reservoir's storage capacity, and analyze the role of diagenesis (organic and inorganic) in the evolution of pores and the reservoir's storage capacity. The mineral types are diverse, and the content of calcite and other carbonate minerals is generally very high. Organic matter is abundant, thermal evolution is low, and the hydrocarbon generation capacity is strong. Because of their high variability, some pores are hard to differentiate from microfractures. Dissolved pores, which are generated by intercrystalline pores and the dissolution of calcite, dolomite, and other carbonate mineral grains, are the major component of a macroporous matrix. The large proportion of hydrocarbons that are generated by solid organic matter leads to the accumulation of pressure. The shale generates a high number of microfractures, which form a reservoir space network system that increases the porosity of the reservoir. Dolomite has a unique supporting role for the matrix pores, leading to the development of a matrix pore-seam system. The reservoir's mineral composition, pore diameter, porosity, and organic-matter content determine the reservoir properties and oil saturation. Organic-rich laminated shale has the best physical properties, dominated by macro-pores and easily connected and merged pore seams. The massive shale has the poorest reservoir property. The development and evolution of pores are mainly controlled by the transformation of clay minerals, the content of carbonate minerals, the sedimentary structure and the intensity of diagenesis. Dissolution depends on the intensity of hydrocarbon generation, the expulsion of acid by organic matter, the state of the carbonate minerals and organic matter, and the smooth depression of the fluid environment. Organic diagenesis is closely related to the diagenesis and evolution of inorganic matter and is typically reflected in the recrystallization of calcite, abundance of organic matter, and hydrocarbon generation by organic matter. A local alkaline diagenetic fluid environment and reduction in the degree of hydrocarbon generation transform incremental porosity to pore reduction. Favorable lithofacies and advantageous layer sections should be selected by considering the stage of diagenesis evolution.Liu, J., Xie, H., Wang, Q., Chen, S., Hu, Z., 2019. The effect of pore size on shale gas recovery with CO2 sequestration: Insight into molecular mechanisms. Energy & Fuels 33, 2897-2907. extremely low permeability of the nanopore causes only 5%–15% content of the original shale gas to be extracted, and carbon sequestration with enhanced gas recovery (CS-EGR) has been a potentially feasible win–win solution. In this study, the adsorption isotherms, density distributions, CO2/CH4 adsorption selectivity, adsorption heat, and interaction energies of CH4 and CO2 in the montmorillonite nanopores are calculated and discussed in detail using a series of grand canonical Monte Carlo (GCMC) simulations considering the influence of pore size, temperature, and pressure. The recovery of CH4 in montmorillonite nanopores with various size under different injection pressures is also investigated. The results indicate that pore size has significant influence on the adsorption of CH4 and CO2. Under the same conditions, the adsorption capacity of CO2 is obviously stronger than that of CH4 because the interaction energy and the adsorption heat of CO2 are both relatively larger. CO2 and CH4 have different adsorption sites. CO2 molecules preferentially accumulate near the Na+ cations. In contrast, CH4 molecules are preferentially adsorb in the hollow site of the six-membered oxygen ring in the silicon tetrahedron. Due to the high energy barrier and low diffusion coefficient, CH4 in smaller pores is hard to displace and even cannot be extracted in pores with basal spacing corresponding 12 ? even when the pressure increases to 25 MPa. Supercritical CO2 can displace CH4 more quickly and is preferable for CO2 sequestration. We hope this study will be beneficial for better understanding of the microscopic states of gas molecules in shale and provide guidance for CS-EGR.Liu, J., Zhang, G., Li, Z., Tang, Y., Xiao, H., Lai, H., Yang, C., 2019. Oil charge history of Paleogene–Eocene reservoir in the Termit Basin (Niger). Australian Journal of Earth Sciences 66, 597-606. total of 73 oils from the sandstone reservoir of Paleocene–Eocene Sokor 1 Formation in the Termit Basin (eastern Niger) were analysed to investigate the distribution characteristics of biomarkers. Most of the oil samples are quite similar in their organic geochemical characteristics and should have been derived from the same source bed/source kitchen. The homogenisation temperatures of aqueous inclusions in Paleocene–Eocene reservoir of the Termit Basin vary with a range of 76–125?°C. By combining the homogenisation temperatures with the burial and geothermal histories reconstructed by 1-dimensional basin modelling, the timing and episode of oil charge can be obtained, i.e. 13 to 0?Ma for Paleocene–Eocene reservoirs in the Termit Basin. Two presentative geochemical parameters, i.e. Ts / (Ts?+?Tm) and 2,4-dibenzothiophene/1,4-dibenzothiophene (2,4-DMDBT/1,4-DMDBT) were applied to trace the oil migration direction and filling pathway. The preferred oil-filling points in the northwest section of the Termit Basin were determined, and the promising exploratory targets were proposed for further oil exploration in this region.Liu, K., Ostadhassan, M., 2019. The impact of pore size distribution data presentation format on pore structure interpretation of shales. Advances in Geo-Energy Research 3, 187-197. deeper understanding of pore structures in unconventional shale plays can lead to a better evaluation of storage and transport capacity in these complicated rock types. This task is usually done through pore size distribution (PSD) analysis. In this study, N2 adsorption and high-pressure mercury intrusion porosimetry (MIP) were employed to investigate several shale samples. Three different mathematical forms of PSD data presentation: Incremental pore volume versus diameter (DV), differential pore volume versus diameter (DV/Dd) and the log differential pore volume versus diameter (DV/Dlogd), were used to analyze pore structures from these two different methods. The comparison of the results showed that each form of PSD data presentation could demonstrate various types of important pore information. The DV curve is significantly dependent on the experimental data points’ spacing while the other two are not affected. The DV/Dd curve would incite the existence of smaller pore ranges while the DV/Dlogd would embolden larger pore ranges. Additionally, multifractal analysis from each data presentation style illustrated that the heterogeneity index of PSD calculated from the DV/Dd curve is much significant than the one obtained from the DV/Dlogd curve. DV/Dd is more appropriate to be used for characterizing PSD data from N2 adsorption while DV/Dlogd is preferred when MIP data is collected from larger pores.Liu, K., Yao, T., Liu, Y., Xu, B., Hu, A., Chen, Y., 2019. Elevational patterns of abundant and rare bacterial diversity and composition in mountain streams in the southeast of the Tibetan Plateau. Science China Earth Sciences 62, 853-862. gradients are powerful ‘natural laboratory’ for testing the responses of microbes to geophysical influences. Microbial communities are normally composed of a few abundant and many rare taxa. Abundant and rare taxa play different ecological roles in kinds of environments, but how their diversity and composition patterns response to elevation gradients is still poorly elucidated. In this study, we investigated the elevational patterns of abundant and rare bacterial diversity and composition in a mountain stream from 712 to 3435 m at Gangrigabu Mountain on the Tibetan Plateau, China. Our results revealed abundant and rare bacteria had similar decreasing elevation trend of alpha diversity, and both of them showed a significant elevational distance-decay relationship. However, the turnover rate of the elevational distance-decay of rare bacteria was higher than that of abundant bacteria. The species-abundance distribution patterns of rare taxonomic composition were associated with the elevational gradient, while most of abundant bacterial clades did not display any relationships with elevation. Our results suggested that rare bacteria were more sensitive to changes in elevation gradient.Liu, L., Du, M., Li, G., Fan, J., Schobert, H.H., He, C., 2019. Study on the small molecular composition of cutinite from luquan cutinitic liptobiolith by ultrasonic-assisted sequential extraction. Energy & Fuels 33, 3465-3472. cutinite content in a typical cutinitic liptobiolith from the Luquan area of Yunnan Province, China, of middle Devonian, can be up to 85%. The equal density gradient method was used to separate the cutinite with the density gradient of cutinite being primarily 1.07–1.21 g/cm3. Then, the cutinite was sequentially extracted with methanol, acetone, isometric N-methyl-2-pyrrolidone/carbon disulfide mixture (NMP/CS2), and cyclohexanone with ultrasonic irradiation to afford soluble portions (E1–E4) and residues (R1–R4). In total, about 48.60% of the organic matter in cutinite became soluble. According to the analysis of soluble portions by gas chromatography/mass spectrometry and 1H NMR, E1 was rich in nitrogen-containing organic compounds and esters, amounting to 50.72 and 30.32%. Esters were found in E1, E2, and E4. The content of esters in E2 was 43.54%. In addition, alkanes also were found in E2 and E3, attaining 21.10 and 19.88%, respectively. The main products of cyclohexanone extraction were ketones, about 39.33%. These experimental results indicated that a great deal of oxygen-containing compounds, alkanes, and aromatic species were released during the process of cutinite sequential extraction. The small-molecule component was primarily composed of C12–C18 linear alkane and aromatics of 1–2 rings. Compared with cutin, these findings are reasonably consistent with the results of the small-molecule composition released during coalification.Liu, N.-Z., Zou, Y.-S., Ma, X.-F., Li, N., Wu, S., 2019. Study of hydraulic fracture growth behavior in heterogeneous tight sandstone formations using CT scanning and acoustic emission monitoring. Petroleum Science 16, 396-408. hydraulic fractures (HFs) are likely to be created in heterogeneous formations such as conglomerates, which may cause sand plugging, ultimately resulting in poor stimulation efficiency. This study aims to explore HF growth behavior in conglomerate through laboratory fracturing experiments under true tri-axial stresses combined with computed tomography scanning and acoustic emission (AE) monitoring. The effects of gravel size, horizontal differential stress, and AE focal mechanisms were examined. Especially, the injection pressure and the AE response features during HF initiation and propagation in conglomerate were analyzed. Simple HFs with narrow microfractures are created in conglomerate when the gravels are considerably smaller than the specimen, whereas complex fractures are created when the gravels are similar in size to the specimen, even under high horizontal differential stresses. Breakdown pressure and AE rates are high when a HF is initiated from the high-strength gravel. A large pressure decline after the breakdown may indicate the creation of a planar and wide HF. Analyzing the focal mechanism indicates that the shear mechanism generally dominates with an increase in the HF complexity. Tensile events are likely to occur during HF initiation and are located around the wellbore. Shear events occur mainly around the nonplanar and complex matrix/gravel interfaces.Liu, P., Qian, L., Wang, H., Zhan, X., Lu, K., Gu, C., Gao, S., 2019. New insights into the aging behavior of microplastics accelerated by advanced oxidation processes. Environmental Science & Technology 53, 3579-3588. the environment, microplastics are subjected to multiple aging processes; however, information regarding the impact of aging on the environmental behavior of microplastics is still lacking. This study investigated the alteration properties of polystyrene and high-density polyethylene microplastics by heat-activated K2S2O8 and Fenton treatments to improve the understanding of their long-term natural aging in aquatic environments. Our results indicated that the O/C ratio was an alternative parameter to the carbonyl index (CI) to quantitatively describe the surface alteration properties of microplastics. The correlation model of the O/C ratio or CI versus alteration time was developed and compared by natural alteration of microplastics in freshwater samples. Moreover, the regression equation of the equilibrium adsorption capacity of altered microplastics versus the O/C ratio and average size was proposed. This study is the first effort in differentiating the relationships between the alteration properties and alteration time/adsorption capacity of microplastics, which would be helpful for predicting the weathering degree and accumulation of hydrophilic antibiotics onto aged microplastics in aquatic environments. This research develops promising strategies to accelerate the aging reactions using advanced oxidation processes, which would provide further information to assess the microplastic pollution in actual environments.Liu, R., Heinemann, N., Liu, J., Zhu, W., Wilkinson, M., Xie, Y., Wang, Z., Wen, T., Hao, F., Haszeldine, R.S., 2019. CO2 sequestration by mineral trapping in natural analogues in the Yinggehai Basin, South China Sea. Marine and Petroleum Geology 104, 190-199. trapping of CO2 by precipitation of carbonate minerals is seen as the most permanent and secure mechanism of CO2 storage. We have investigated mineral trapping in CO2-rich siliciclastic reservoirs of the Upper Miocene age in the Yinggehai Basin (South China Sea) and used nearby CO2-poor reservoirs of similar age as benchmarks for the analysis. Within the reservoir, the CO2 has triggered the reaction from calcite plus chlorite to ankerite plus kaolinite, which traps 5?mol of CO2 per mole of chlorite. Geochemical modelling shows that the total amount of permanently trapped CO2 is approximately one half of the CO2 in the newly formed ankerite. Caprock mineralogy shows that CO2 leakage has occurred and CO2 has migrated into the shale-rich caprock, but without loss of caprock integrity.Liu, R., Zhang, G., Sun, M., Pan, X., Yang, Z., 2019. Integrating a generalized data analysis workflow with the Single-probe mass spectrometry experiment for single cell metabolomics. Analytica Chimica Acta 1064, 71-79. conducted single cell metabolomics studies of live cancer cells through online single cell mass spectrometry (SCMS) experiments combined with a generalized comprehensive data analysis workflow. The SCMS experiments were carried out using the Single-probe device coupled with a mass spectrometer to measure molecular profiles of cells in response to two mitotic inhibitors, taxol and vinblastine, under a series of treatment conditions. SCMS metabolomic data were analyzed using a comprehensive approach, including data pre-treatment, visualization, statistical analysis, machine learning, and pathway enrichment analysis. For comparative studies, traditional liquid chromatography-MS (LC-MS) experiments were conducted using lysates prepared from bulk cell samples. Metabolomic profiles of single cells were visualized through Partial Least Square-Discriminant Analysis (PLS-DA), and the phenotypic biomarkers associated with emerging phenotypes induced by drug treatment were discovered and compared through a series of rigorous statistical analysis. Species of interest were further identified at both the single cell and population levels. In addition, four biological pathways potentially involved in the drug treatment were determined through pathway enrichment analysis. Our work demonstrated the capability of comprehensive pipeline studies of single cell metabolomics. This method can be potentially applied to broader types of SCMS datasets for future pharmaceutical and chemotherapeutic research.Liu, X., Liu, M., Chen, X., Yang, Y., Hou, L., Wu, S., Zhu, P., 2019. Indigenous PAH degraders along the gradient of the Yangtze Estuary of China: Relationships with pollutants and their bioremediation implications. Marine Pollution Bulletin 142, 419-427. study investigated the network of polycyclic aromatic hydrocarbon (PAH) degraders in the Yangtze estuarine and coastal areas. Along the estuarine gradients, Proteobacteria and Bacteroidetes were the dominant bacterial phyla, and forty-six potential PAH degraders were identified. The abundance of genes encoding the alpha subunit of the PAH-ring hydroxylating dioxygenases (PAH-RHDα) of gram-negative bacteria ranged from 5.5?×?105 to 5.8?×?107?copies?g?1, while that of gram-positive bacteria ranged from 1.3?×?105 to 2.0?×?107?copies?g?1. The PAH-degraders could represent up to 0.2% of the total bacterial community and mainly respond to PAHs and Cu concentrations, which indicate anthropogenic activities. Salinity and pH showed negative regulating effects on the PAH-degrading potential and the tolerance of bacteria to pollutants. PAH degraders such as Novosphingobium and Mycobacterium exhibit heavy-metal tolerance and core roles in the network of PAH degraders. These outcomes have important implications for bioremediation.Liu, Z., Ajram, G., Rossi, J.-C., Pascal, R., 2019. The chemical likelihood of ribonucleotide-α-amino acid copolymers as players for early stages of evolution. Journal of Molecular Evolution 87, 83-92. ribosomal translation could have evolved remains an open question in most available scenarios for the early developments of life. Rather than considering RNA and peptides as two independent systems, this work is aimed at assessing the possibility of formation and stability of co-polymers or co-oligomers of α-amino acids and nucleotides from which translation might have evolved. Here we show that the linkages required to build such mixed structures have lifetimes of several weeks to months at neutral pH and 20?°C owing to the mutual protecting effect of both neighboring phosphoramidate and ester functional groups increasing their stability by factors of about 1 and 3 orders of magnitude, respectively. This protecting effect is reversible upon hydrolysis allowing the possibility of subsequent reactions. These copolymer models, for which an abiotic synthesis pathway is supported by experiments, form a basis from which both polymerization and translation could have logically evolved. Low temperatures were identified as a critical parameter for the kinetic stability of the aminoacylated nucleotide facilitating the synthesis of the model. This observation independently supports the views that any process involving RNA aminoacyl esters, outstandingly including the emergence of translation, was more probable at 0?°C or below and might be considered a kinetic marker constraining the environment in which translation has evolved.L?ffler, N., Fiebig, J., Mulch, A., Tütken, T., Schmidt, B.C., Bajnai, D., Conrad, A.C., Wacker, U., B?ttcher, M.E., 2019. Refining the temperature dependence of the oxygen and clumped isotopic compositions of structurally bound carbonate in apatite. Geochimica et Cosmochimica Acta 253, 19-38. isotope data from carbonated apatite from in vivo and in vitro samples are presented to refine the relationship between mineral growth temperature and carbonate clumped isotopic composition (Δ47). Δ47, δ18O and δ13C data were obtained from phosphoric acid digestion (T?=?110?°C) of chemically untreated teeth from an African elephant, Greenland sharks, sand tiger sharks and synthetic apatites. These data cover a temperature range between 1?°C and 80?°C and enlarge the calibration dataset presented in Wacker et al. (2016) by a factor of five. Taxon-specific analyses of tooth enamel(oid) and dentine reveal that both tissues show identical Δ47 values even though the content of organic matter differs by an order of magnitude. The following Δ47 temperature calibration for (bio)apatite is derived (R2?=?0.9924, p-value?<?0.0001, n?=?122; 8 samples): Δ47 CDES110 = 0.0325(±0.0012)×106/T2 + 0.2137(±0.0124) (withT in K and Δ47 in ‰)This calibration becomes indistinguishable from a reprocessed empirical calibration of calcite made in the same laboratory if a difference of the acid fractionation factors (AFF) of 0.110‰ between 25?°C and 110?°C is considered. The measured AFF for bioapatite matches the one that is extrapolated from experimental data on calcite and aragonite. The oxygen isotope fractionation between structural carbonate in the synthesized carbonated hydroxylapatites (CHAP) and water between 7?°C and 80?°C closely follows the temperature dependence for the calcite-water system. It is described by the following (CHAP-water) equation (R2?=?0.997, p-value?<?0.04, n?=?17; 3 samples): 1000ln(αCHAP-water) = 17.23±0.59×103×T -1-27.28(±1.73) (with T in K) Both calibrations are applied to shark teeth from a modern Greenland shark and a fossil megatooth shark (Carcharodon megalodon) specimen to reconstruct the apparent Δ47-based habitat temperature of C. megalodon (19?±?4?°C) and the oxygen isotopic compositions of seawater.Logan, B.E., Rossi, R., Ragab, A.a., Saikaly, P.E., 2019. Electroactive microorganisms in bioelectrochemical systems. Nature Reviews Microbiology 17, 307-319. vast array of microorganisms from all three domains of life can produce electrical current and transfer electrons to the anodes of different types of bioelectrochemical systems. These exoelectrogens are typically iron-reducing bacteria, such as Geobacter sulfurreducens, that?produce high power densities at moderate temperatures. With the right media and growth?conditions, many other microorganisms ranging from common yeasts to extremophiles such as?hyperthermophilic archaea can also generate high current densities. Electrotrophic microorganisms that grow by using electrons derived from the cathode are less diverse and have?no common or prototypical traits, and current densities are usually well below those reported for model exoelectrogens. However, electrotrophic microorganisms can use diverse terminal electron acceptors for cell respiration, including carbon dioxide, enabling a variety of novel cathode-driven reactions. The impressive diversity of electroactive microorganisms and the?conditions in which they function provide new opportunities for electrochemical devices, such as microbial fuel cells that generate electricity or microbial electrolysis cells that produce hydrogen or methane.Loison, J.C., Dobrijevic, M., Hickson, K.M., 2019. The photochemical production of aromatics in the atmosphere of Titan. Icarus 329, 55-71. photochemical processes at work in the atmosphere of Titan are very complex and lead to a great variety of compounds with aerosols as an end-product. One of the most complex molecules detected so far is benzene (C6H6). In the present work, we have updated and improved the chemistry of aromatics in order to better understand the main chemical pathways leading to the production of benzene and determine what other aromatics could be produced efficiently in the atmosphere. This new chemical scheme has been incorporated in our 1D photochemical model corresponding to mean conditions. We confirm the importance of ionic chemistry for benzene production in the upper atmosphere and we have found that excited benzene is an important intermediate in benzene production due to the exothermicity of many production reactions. Among the 24 aromatics included in the model, neutral aromatics like toluene (C6H5CH3) and ethylbenzene (C6H5C2H5) are relatively abundant, suggesting in particular that toluene could be detectable in the infrared, and eventually microwave wavelength ranges. However, we obtained large uncertainties on model results highlighting the need for more experiments and theoretical studies to improve the chemistry of aromatics.Long, S., Zhang, Y., Li, J., Sun, Z., Shang, X., Dai, C., 2019. Comprehensive geological modeling technology for shale gas reservoirs Natural Gas Industry 39, 47-55. present, the technical ideas and implementation modes adopted in the geological modeling of shale gas reservoirs are mainly derived from those used in conventional oil and gas reservoirs, so they are not applicable to shale gas reservoirs. Moreover, there are few reports on the results of shale gas geological modeling at home and abroad. In view of this, a technical process of geological modeling for shale gas reservoirs was firstly established according to its particularity. Secondly, a structure and shale sublayer development model for the working area was established based on logging interpretation results, pre-stack and post-stack seismic interpretation data and geological test analysis results of samples. Thirdly, property models of shale gas reservoirs, including thickness, porosity, gas saturation, TOC, silicon content and brittleness index, were established using geostatistic modeling method in the frame model. Fourthly, a natural fracture DFN model was established using the object-based modeling method, based on seismic AFE attribute, structural curvature and strain and dilatation data, combined with geological knowledge and drilling display. Fifthly, a hydraulic fracture model was established based on the estimate of hydraulic fracture distribution pattern and the parameter fitting analysis. Finally, a comprehensive geological model for shale gas reservoirs was established by virtue of step-by-step superposition. What’s more, it was applied to the production history matching and performance prediction of shale gas wells. And the following research results were obtained. First, the geological modeling of shale gas reservoirs is more complex than that of conventional oil and gas reservoirs, and the complexities are presented as difficult classification and correlation of sublayers, multiple matrix parameters restricting each other, diverse geneses and sizes of natural fractures, and complicated distribution of hydraulic fractures under the interference and influence of natural fractures. Second, the natural fracture DFN model is capable of describing the geometrical shape and distribution of fracture system effectively and finely, and the hydraulic fracture model can better embody the distribution of hydraulic fractures and the stimulated reservoir volume (SRV). The establishment of the comprehensive geological model for shale gas reservoirs can be realized by progressively integrating and superposing the structure and sublayer development model, the multi-matrix property parameter model, the multi-scale natural fracture model and the hydraulic fracture model under the constraint of multi-scale natural fracture model. Third, production history matching results of gas wells show that the error of bottomhole pressure is lower than 3.3%, which indicates that the newly established comprehensive geological model of shale gas reservoirs is reliable. In conclusion, the modeling process and method developed in this paper can be used as reference in the establishment of a comprehensive geological model for shale gas reservoirs.Long, Y., Huang, X., Gao, Y., Chen, L., Song, F., Zhang, H., 2019. Swelling mechanism of core–shell polymeric nanoparticles and their application in enhanced oil recovery for low-permeability reservoirs. Energy & Fuels 33, 3077-3088. provides potential benefits for enhanced oil recovery (EOR) in low-permeability reservoirs. In this paper, SiO2/P(MBAAm-co-AM) composite nanoparticles were prepared using the distillation precipitation polymerization method. Scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis were employed to characterize the morphology and microstructure of nanoparticles. The swelling behavior of polymeric nanoparticles in brine was investigated to evaluate the effect of salinity and temperature. Kinetic and thermodynamic analyses were employed to reveal the swelling mechanism. Displacement experiments were performed to investigate their performance in EOR in low-permeability reservoirs. The results show that the swelling ratio of SiO2/P(MBAAm-co-AM) composite nanoparticles is higher at low salinity and high temperature, which can be explained by the Flory theory. The swelling process is spontaneous and endothermic, being controlled by physical adsorption involving the diffusion of water molecules, which complies with the first-order kinetics model. The suspension of SiO2/P(MBAAm-co-AM) composite nanoparticles can improve incremental oil recovery from 10.28 to 21.97% with an increase of the swelled particle size from 580 to 1160 nm. It is feasible that core–shell polymeric nanoparticles can be used for EOR in low-permeability reservoirs.Longman, J., Palmer, M.R., Gernon, T.M., Manners, H.R., 2019. The role of tephra in enhancing organic carbon preservation in marine sediments. Earth-Science Reviews 192, 480-490. of organic carbon (Corg) in marine sediments plays a major role in defining ocean-atmosphere CO2 levels, Earth climate, and the generation of hydrocarbons. Important controls over sedimentary Corg preservation include; biological productivity, Corg isolation from oxidants (mainly dissolved O2) in the overlying water column and sediments, and Corg – mineral association in sediments. Deposition of the products of explosive volcanism (tephra) in the oceans directly enhances Corg burial through all these mechanisms, and indirectly through enhanced formation of authigenic carbonate (Cauth) derived from sedimentary Corg. In the modern oceans, it is suggested that tephra deposition may account for 5–10% of the Corg burial flux and 10–40% of the Cauth burial flux. However, during certain periods in Earth's history, extensive explosive volcanism may have led to enhanced Cauth precipitation on a sufficiently large scale to influence the global ocean-atmosphere carbon cycle. Changes in tephra-related Corg preservation may also have played a role in increasing Corg preservation rates in local marine basins, at the oxic-anoxic boundary and enhanced the generation of hydrocarbon deposits in these settings.Lopes-dos-Santos, R.M.A., De Troch, M., Bossier, P., Van Stappen, G., 2019. Labelling halophilic Archaea using 13C and 15N stable isotopes: a potential tool to investigate haloarchaea consumption by metazoans. Extremophiles 23, 359-365. use of stable isotope (SI) labelling and tracing of live diets is currently considered one of the most comprehensive tools to detect their uptake and assimilation by aquatic organisms. These techniques are indeed widely used in nutritional studies to follow the fate of specific microbial dietary components, unraveling trophic interactions. Nevertheless, to the current date our understanding of aquatic trophic relationships has yet to include a whole domain of life, the Archaea. The aim of the present research was, therefore, to describe a halophilic Archaea (haloarchaea) labelling procedure, using the SI 13C and 15N, to enable the application of SI tracing in future studies of haloarchaea consumption by aquatic metazoans. To this end, three 13C enriched carbon sources and two 15N enriched nitrogen sources were tested as potential labels to enrich cells of three haloarchaea strains when supplemented to the culture medium. Our overall results indicate 13C-glycerol as the most effective carbon source to achieve an efficient 13C enrichment in haloarchaea cells, with Δδ13C values above 5000‰ in all tested haloarchaea strains. As for 15N enriched nitrogen sources, both (15NH4)2SO4 and 15NH4Cl seem to be readily assimilated, also resulting in efficient 15N enrichment in haloarchaea cells, with Δδ15N values higher than 20,000‰. We believe that the proposed methodology will allow for the use of SI labelled haloarchaea biomass in feeding tests, potentially providing unambiguous confirmation of the assimilation of haloarchaea biomass by aquatic metazoans.Lu, Z.-q., Zhai, G.-y., Zhu, Y.-h., Liu, H., Wang, T., Fang, H., Sun, Z.-j., Tang, S.-q., Zhang, Y.-q., 2018. New discovery of the permafrost gas hydrate accumulation in Qilian Mountain, China. China Geology 1, 306-307.. Objectives: As the discovery of gas hydrate in Qilian Mountain permafrost in 2008, the main controlling factors and distribution of gas hydrate are not clear. This restricts the further progress in gas hydrate survey in this area. Hence, China Geological Survey erected the project “Exploration of gas hydrate resources in the Qilian Mountain and its adjacent areas” continuously to better understand the gas hydrate accumulation in terms of greater gas hydrate discovery.2. Methods: Details in the previously discovered gas hydrate were analyzed as a typical example in Qilian Mountain permafrost. The gas source, the formation conditions, the controlling factors and the accumulation distribution of gas hydrate were studied. Combined with geophysical and geochemical survey data, the deployment of gas hydrate drilling was implemented (Fig. 1).3. ResultsThe maximum burial depth of gas hydrate source rock is about 2000–3500 m below the ground surface. Local fractures provide migration paths for the hydrocarbon gases to move upwardly. The mid-upper part of the fault or fracture zone can possibly serve as gas hydrate reservoir. The faults with different properties, the various genetic types of gas source, and the effective supply of gas source are the main factors of the formation and distribution of the gas hydrate.The source rock of the gas hydrate experienced one stage of the gas generation during the Middle Jurassic (Zuo YH et al., 2016). The gas hydrate formation time should be no later than the Early to Middle Pleistocene (Qi BS et al., 2014). The gas hydrate accumulation pattern is summarized in Fig. 1.Gas hydrate layers were newly obtained at the intervals of 188.20 –209.45 m, 259.77 –271.89 m, 300.09 –302.19 m and 357.50–367.59 m below the ground surface in one hole (Fig. 2a). An oil-bearing formation was encountered in one new hole from 362.79 m to 370.58 m below the ground surface in the sandstones (Fig. 2b). A strong gas blowout took place in another new hole at the depth of 52.9 m below the ground surface in sandstone. The flame was as high as 3 –4 m (Fig. 2c), lasting for more than 48 hours. In the field the gas flow was estimated greater than 4800 m3/d.4. Conclusion: The target gas hydrate source rock is defined in this project. The migration of gas hydrate is revealed through fracture analysis. Three main geological controlling factors of the gas hydrate accumulation are found out. A gas hydrate accumulation model is established. Several gas hydrate layers were successfully obtained. A new discovery in oil prospecting was first made in Qilian Mountain permafrost zone.Luis, P., Saint-Genis, G., Vallon, L., Bourgeois, C., Bruto, M., Marchand, C., Record, E., Hugoni, M., 2019. Contrasted ecological niches shape fungal and prokaryotic community structure in mangroves sediments. Environmental Microbiology 21, 1407-1424. are forest ecosystems located at the interface between land and sea where sediments presented a variety of contrasted environmental conditions (i.e. oxic/anoxic, non-sulfidic/sulfidic, organic matter content) providing an ideal ecosystem to study microbial communities with niche differentiation and distinct community structures. In this work, prokaryotic and fungal compositions were investigated during both wet and dry seasons in New Caledonian mangrove sediments, from the surface to deeper horizons under the two most common tree species in this region (Avicennia marina and Rhizophora stylosa), using high-throughput sequencing. Our results showed that Bacteria and Archaea communities were mainly shaped by sediment depth while the fungal community was almost evenly distributed according to sediment depth, vegetation cover and season. A detailed analysis of prokaryotic and fungal phyla showed a dominance of Ascomycota over Basidiomycota whatever the compartment, while there was a clear shift in prokaryotic composition. Some prokaryotic phyla were enriched in surface layers such as Proteobacteria, Euryarchaeota while others were mostly associated with deeper layers as Chloroflexi, Bathyarchaeota, Aminicenantes. Our results highlight the importance of considering fungal and prokaryotic counterparts for a better understanding of the microbial succession involved in plant organic matter decomposition in tropical coastal sediments.Lüning, S., Ga?ka, M., Bamonte, F.P., Rodríguez, F.G., Vahrenholt, F., 2019. The Medieval Climate Anomaly in South America. Quaternary International 508, 70-87. Medieval Climate Anomaly (MCA) is a climatic perturbation with a core period of 1000-1200 AD that is well-recognized in the Northern Hemisphere (NH). Its existence in the Southern Hemisphere (SH) and the level of synchronicity with the NH is still a matter of debate. Here we present a palaeotemperature synthesis for South America encompassing the past 1500 years based on multiproxy data from 76 published land and marine sites. The data sets have been thoroughly graphically correlated and the MCA trends palaeoclimatologically mapped. The vast majority of all South American land sites suggest a warm MCA. Andean vegetation zones moved upslope, glaciers retreated, biological productivity in high altitude lakes increased, the duration of cold season ice cover on Andean lakes shortened, and trees produced thicker annual rings. Similar MCA warming occurred in coastal seas, except in the year-round upwelling zones of Peru, northern Chile and Cabo Frio (Brazil) where upwelling processes intensified during the MCA due to changes in winds and ocean currents. MCA warming in South America and the NH appears to have occurred largely synchronous, probably reaching comparable intensities. Future studies will have to address major MCA data gaps that still exist outside the Andes in the central and eastern parts of the continent. The most likely key drivers for the medieval climate change are multi-centennial Pacific and Atlantic ocean cycles, probably linked to solar forcing.Luo, P., Zhong, N., Khan, I., Wang, X., Wang, H., Luo, Q., Guo, Z., 2019. Effects of pore structure and wettability on methane adsorption capacity of mud rock: Insights from mixture of organic matter and clay minerals. Fuel 251, 551-561. matter content and pore structure are two most important parameters to evaluate methane adsorption capacity of mud rock. However, the applicability of pore structure parameters has not received much attention in previous studies. In this paper, artificial samples consisting of mixture of organic matter (anthracite, type II kerogen) and clay minerals (kaolinite, montmorillonite) are used to investigate the effects of pore structure and wettability on methane adsorption capacity of mud rock.Methane adsorption isotherms from the mixed samples are in accord with Langmuir model and the methane adsorption capacity of organic matter is higher than that of clay minerals. From nitrogen adsorption isotherm analyses, pore structure parameters including specific surface area and pore volume of organic matter are lower than that of clay minerals showing that the methane adsorption capacity of mixed samples is primarily controlled by organic matter content and are inversely related to the specific surface area and pore volume. This makes the organic matter content a more reliable parameter than pore structure to evaluate methane adsorption capacity.The result of wettability for organic matter and clay minerals shows that organic matter is hydrophobic and clay minerals are hydrophilic. Methane as an organic fluid, is more preferentially to be adsorbed on organic matter instead of clay minerals. During methane adsorption, well developed pores in clay minerals are not as effective as those in organic matter, which leads to an inevitable methane adsorption competition between organic matter and clay minerals in mixed samples. From this viewpoint, wettability plays a more important role than pore structure in competitive methane adsorption at subsurface where moisture is always existing.Lusk, B.G., 2019. Thermophiles; or, the modern Prometheus: The importance of extreme microorganisms for understanding and applying extracellular electron transfer. Frontiers in Microbiology 10, 818. doi: 810.3389/fmicb.2019.00818. four billion years ago, the first microorganisms to thrive on earth were anaerobic chemoautotrophic thermophiles, a specific group of extremophiles that survive and operate at temperatures 50 - 125°C and do not use molecular oxygen (O2) for respiration. Instead, these microorganisms performed respiration via dissimilatory metal reduction by transferring their electrons extracellularly to insoluble electron acceptors. Genetic evidence suggests that Gram-positive thermophilic bacteria capable of extracellular electron transfer (EET) are positioned close to the root of the Bacteria kingdom on the tree of life. On the contrary, EET in Gram-negative mesophilic bacteria is a relatively new phenomenon. This suggests that EET evolved separately in Gram-positive thermophiles and Gram-negative mesophiles, and that EET in these distinct bacterial types is a result of a convergent evolutionary process leading to homoplasy. Thus, the study of dissimilatory metal reducing thermophiles provides a glimpse into some of Earth’s earliest forms of respiration. This will provide new insights for understanding biogeochemistry and the development of early Earth in addition to providing unique avenues for exploration and discovery in astrobiology. Lastly, the physiological composition of Gram-positive thermophiles, coupled with the kinetic and thermodynamic consequences of surviving at elevated temperatures, makes them ideal candidates for developing new mathematical models and designing innovative next-generation biotechnologies.Lutfalla, S., Barré, P., Bernard, S., Le Guillou, C., Alléon, J., Chenu, C., 2019. Multidecadal persistence of organic matter in soils: multiscale investigations down to the submicron scale. Biogeosciences 16, 1401-1410., particularly clay-sized minerals, protect soil organic matter (SOM) from decomposition by microorganisms. Here we report the characterization of SOM and the associated minerals over decades of biodegradation, in a French long-term bare fallow (LTBF) experiment started in 1928. The amounts of carbon (C) and nitrogen (N) in the study area declined over time for six fractions (sand, coarse silt, fine silt, coarse clays, intermediate clays, and fine clays). The C:N ratios of SOM associated with silt fractions remained constant, whereas the ratios significantly decreased in clays, reaching very low values in intermediate and fine clays (C:N?<?5) after 8 decades of LTBF conditions. X-ray absorption spectroscopy revealed the following: (i) bulk-scale SOM chemical speciation remained almost constant; (ii) submicron particulate OM was present in coarse clays, even after 79 years of LTBF conditions; and (iii) illite particles became progressively SOM-free with time, whereas mixed-layer illite/smectite and smectites were always associated with OM throughout the bare fallow treatment. In summary, these results suggest that clay-sized minerals preferentially protect N-rich SOM and that smectites and mixed-layer illite/smectite seem to protect associated OM more effectively than pure illites.Ma, H., Pedersen, C.M., Zhao, Q., Lyu, Z., Chang, H., Qiao, Y., Hou, X., Wang, Y., 2019. NMR analysis of the Fischer-Tropsch wastewater: Combination of 1D selective gradient TOCSY, 2D DOSY and qNMR. Analytica Chimica Acta 1066, 21-27. Fischer–Tropsch (FT) process is a practical approach to convert synthesis gas (CO and H2) into hydrocarbons and oxygenates, and these product mixtures are usually well-characterized. However, the analysis of Fischer–Tropsch waste water (FTW) is still somewhat underdeveloped and the exact composition of FTW remains unclear. Herein, various qualitative NMR techniques, especially diffusion-ordered spectroscopy (DOSY) and one dimension (1D) selective gradient total correlation spectroscopy (SelTOCSY) were strategically applied in the analysis of FTW. The NMR results show that the DOSY technique can pseudo-separate most of components in complex mixtures over the diffusion dimension. The SelTOCSY technique is used as a supporting method in the cases where the DOSY technique cannot clearly distinguish overlapped signals. Moreover, the quantitative 1H NMR (qNMR) was further used to quantify the components of the sample. These routine and advanced qualitative and quantitative NMR technique utilized here provide a fast, effective and feasible method for the identification of complex mixtures in FTW, which might be a powerful and fast alternative to gas chromatography or high performance liquid chromatography for FTW research.Ma, Q., Yang, S., Lv, D., Wang, M., Chen, J., Kou, G., Yang, L., 2019. Experimental investigation on the influence factors and oil production distribution in different pore sizes during CO2 huff-n-puff in an ultra-high-pressure tight oil reservoir. Journal of Petroleum Science and Engineering 178, 1155-1163. Xinjiang tight oil reservoir has a low depletion recovery rate and high remaining oil content. The target reservoir has ultra-low permeability and complex pore structure. Therefore, performing water injection is very difficult, resulting in ineffective waterflooding. In this study, a series of experiments were conducted to study the effects of cycle numbers, production pressure, and permeability in CO2 huff-n-puff. The remaining oil production distribution in different pore sizes was also analyzed by the nuclear magnetic resonance (NMR) technique. The results showed that the cumulative oil recovery logarithmically increases with an increase in number of cycles, whereas, the oil recovery cycle decreases. Low production pressure and high permeability result in a higher oil recovery factor (ORF) of CO2 huff-n-puff. In addition, the optimal production pressure is 22?MPa. After the eighth cycle, the cumulative oil recovery can increase by 16.5%–44.5%, approximately 4.7–7.6 times that of the depletion recovery rate, indicating that CO2 huff-n-puff is a feasible way to enhance the ORF of a tight oil reservoir. HPR Chinaowever, the oil production in the first five cycles accounts for 84%–91.7% of the total enhanced recovery. Therefore, CO2 huff-n-puff operations should not have more than five cycles. NMR T2 spectrum analysis shows that in the first cycle, the oil in macro and medium pores (>50?ms) is produced first, followed by small pores (10–50?ms), accounting for 49.5%–79% and 8%–37% of the total ORF, respectively, whereas, oil from the micropores (<10?ms) is rarely produced. However, for the subsequent cycles, the oil production in macro pores and medium pores decreases while that in small pores and micropores increases. Thus, the small pores and micropores become the main oil producing areas.Ma, X., Li, G., Ying, D., Zhagn, B., Li, Y., Dai, X., Fan, Y., Zeng, Y., 2019. Distribution and gas-bearing properties of Permian igneous rocks in Sichuan Basin, SW China. Petroleum Exploration and Development 46, 228-237. on the analysis of outcrop, seismic, logging and drilling data, combined with exploration practice, the characteristics, distribution, reservoir performance and gas-bearing properties of Permian igneous rocks in Sichuan Basin are studied. The study shows that central volcanic eruptive facies are developed in Sichuan Basin, and their lithological assemblages and distribution characteristics show obvious differences. The igneous rocks are mainly distributed in three regions: the southwestern part of the basin has dominantly large- scale overflow facies basalts; the central and western part of the basin, Jianyang-Santai area, develop intrusive rocks, volcanic lavas (basalts) and pyroclastic rocks; and the eastern part of Sichuan, Dazhou-Liangping area, only develop diabase and basalts. Five aspects of understandings are achieved: (1) The Upper Permian igneous rocks can be divided into intrusive rocks and extrusive rocks, with the extrusive rocks as the main body. The chemical compositions of the extrusive rocks are characterized by both alkaline basalt and tholeiitic basalt, and belong to the subalkaline type of transitional basalt magma eruption. (2) There are obvious rhythmic structures vertically among overflow facies basalt, and the single rhythmic layer consists of, from bottom up, pyroclastic rocks (undeveloped), gray and dark gray porphyritic basalts (unstable), dark gray and purple microcrystalline-cryptocrystalline basalts, dark greyish green porous and amygdaloid basalts; the central volcanic eruption shows the rhythm and the vertical sequence of volcanic clastic rocks (agglomerates and breccias), volcanic lava, tuffaceous lava from bottom to top. (3) The pore types of basalt and pyroclastic rocks are diverse, mainly dissolution pore and de-vitrification micropore, but their physical properties are different. Basalt is characterized by ultra-low pore permeability, small reservoir thickness, and reservoirs are distributed in the upper and middle parts of the cycle, with poor lateral comparability. Volcanic clastic rocks are medium to high porous reservoirs (Well YT1: porosity: 8.66%?16.48%, average 13.76%) with large thickness and good reservoir quality. (4) Natural gas in basalts in southwestern basin mainly comes from Middle Permian, and natural gas in volcanic clastic rocks in central and western basin comes from Cambrian Qiongzhusi Formation. (5) Analysis of igneous reservoir-forming conditions in different areas shows that there are relatively insufficient gas sources and great differences in preservation conditions in southwestern basin. Reservoirs are poorly developed and gas-bearing is complex. The Jianyang-Santai area in the central and western part of Sichuan Basin has abundant hydrocarbon sources, developed reservoir, favorable preservation conditions and favorable gas geological conditions, and it is a favorable area for gas exploration.Macdonald, F.A., Swanson-Hysell, N.L., Park, Y., Lisiecki, L., Jagoutz, O., 2019. Arc-continent collisions in the tropics set Earth’s climate state. Science 364, 181-184.: On multimillion-year time scales, Earth has experienced warm ice-free and cold glacial climates, but it is unknown whether transitions between these background climate states were the result of changes in carbon dioxide sources or sinks. Low-latitude arc-continent collisions are hypothesized to drive cooling by exhuming and eroding mafic and ultramafic rocks in the warm, wet tropics, thereby increasing Earth’s potential to sequester carbon through chemical weathering. To better constrain global weatherability through time, the paleogeographic position of all major Phanerozoic arc-continent collisions was reconstructed and compared to the latitudinal distribution of ice sheets. This analysis reveals a strong correlation between the extent of glaciation and arc-continent collisions in the tropics. Earth’s climate state is set primarily by global weatherability, which changes with the latitudinal distribution of arc-continent collisions.Editor's summary: Controlling cooling. On million-year time scales, Earth's climate state is determined by sources and sinks of carbon to the ocean-atmosphere system. But which specific mechanisms are important in controlling the timing of glacial intervals? Macdonald et al. identify arc-continent collisions in the tropics as a primary control (see the Perspective by Hartmann). They compiled a database of Phanerozoic arc-continent collisions and the latitudinal distribution of ice sheets, showing that ice coverage was greatest when those collisions were most widespread, maximizing global weatherability.Magalhaes, V.H., Buffett, B., Archer, D., McGuire, P.C., Pinheiro, L.M., Gardner, J.M., 2019. Effects of oceanographic changes on controlling the stability of gas hydrates and the formation of authigenic carbonates at mud volcanoes and seepage sites on the Iberian margin of the Gulf of Cadiz. Marine Geology 412, 69-80. Gulf of Cadiz is characterized by extensive active and inactive fluid escape structures which manifest as mud volcanoes, diapiric ridges, pockmarks and cold seeps. The high methane content and the presence of gas hydrates in the shallow sediments of the most active fluid escape structures indicate that these are areas of preferential migration and escape of fluids enriched in hydrocarbons and methane. Extensive fields of methane-derived authigenic carbonates are found at fluid escape structures along the upper and mid-continental slope, where the Mediterranean Outflow water is in direct contact with the seafloor, at water depths generally <1400?m. These methane-derived authigenic carbonates occur in much higher abundance at these shallower depths than in the fluid escape structures of the deeper (>1400?m) parts of the basin. The estimated U/Th ages of the authigenic carbonates, suggest that they were probably formed during discrete episodes of gas hydrate activity that may have occurred as a result of rapid climatic changes (such as the termination of the last glacial stage.) Numerical modelling indicates that seafloor temperature variations, associated with glacial/interglacial cycles and the changes of the Mediterranean Outflow pathway, could have restricted or eliminated the gas hydrate stability zone at the mud volcanoes shallower than 1400?m, resulting in intense fluxes of methane-rich fluids to the shallow sediments or even the seafloor. This fluid flux was recorded by the microbially mediated precipitation of authigenic carbonates.Maher, K., Mayer, K.U., 2019. The art of reactive transport model building. Elements 15, 117-118. like artists use their skills of abstraction, simplification, and idealization to capture the essence of a landscape, the articles in this issue of Elements on reactive transport modeling describe how theories and assumptions about the subsurface world can be translated into constructs of a mathematical world. Such theories may encompass the actions of micro- and macroorganisms, solute and gas transport, the speciation of both solid phases and surfaces, and their myriad interactions. The resulting mathematical world, built up over decades, is then distilled and interrogated numerically using computer models made up of advanced algorithms that tenaciously step through time and space. Although the computer world is inherently multilingual, a large fraction of the existing reactive transport models (RTMs) were developed when Fortran was the dominant language for scientific computing. Ultimately, the job of the computers is to mediate between the abstracted conceptual world of the scientists and the striking, but hidden, complexity of the subsurface world. The RTMs are, hence, diplomats in an ever-expanding quest to understand the past, present, and future of the subsurface. How can we apply these algorithms to test and advance our theories about the subsurface world?Maher, K., Mayer, K.U., 2019. Tracking diverse minerals, hungry organisms, and dangerous contaminants using reactive transport models. Elements 15, 81-86. our feet is a fascinating world of flowing water, cosmopolitan microbes, and complex mineral assemblages. Yet we see none of it from above. Our quest to investigate these complex subsurface interactions has led to the development of reactive transport models. These are computer algorithms that allow us to explore, in a virtual way, the natural dynamics of Earth's systems and our anthropogenic impact on those systems. Here, we explain the concepts behind reactive transport models—which include the transport of aqueous species and the descriptions of biogeochemical reactions involving solutes, surfaces and microorganisms—and introduce to reactive transport applications in terrestrial and marine environments.Mairinger, T., Sanderson, J., Hann, S., 2019. GC–QTOFMS with a low-energy electron ionization source for advancing isotopologue analysis in 13C-based metabolic flux analysis. Analytical and Bioanalytical Chemistry 411, 1495-1502. the study of different levels of (intra)cellular regulation and condition-dependent insight into metabolic activities, fluxomics experiments based on stable isotope tracer experiments using 13C have become a well-established approach. The experimentally obtained non-naturally distributed 13C labeling patterns of metabolite pools can be measured by mass spectrometric detection with front-end separation and can be consequently incorporated into biochemical network models. Here, despite a tedious derivatization step, gas chromatographic separation of polar metabolites is favorable because of the wide coverage range and high isomer separation efficiency. However, the typically employed?electron ionization energy of 70 eV leads to significant fragmentation and consequently only low-abundant ions with an intact carbon backbone. Since these ions are considered a prerequisite for the analysis of the non-naturally distributed labeling patterns and further integration into modeling strategies, a softer ionization technique is needed. In the present work, a novel low?energy electron ionization source is optimized for the analysis of primary metabolites and compared with a chemical ionization approach in terms of trueness, precision, and sensitivity.Makeen, Y.M., Abdullah, W.H., Ayinla, H.A., Shan, X., Liang, Y., Su, S., Noor, N.M., Hasnan, H.K., Asiwaju, L., 2019. Organic geochemical characteristics and depositional setting of Paleogene oil shale, mudstone and sandstone from onshore Penyu Basin, Chenor, Pahang, Malaysia. International Journal of Coal Geology 207, 52-72. eastern Chenor Pahang area of the Penyu Basin contains an untapped potential, in part due to poor knowledge of its organic facies characteristics The sedimentary succession of eastern Chenor Pahang area is dominated by fine to coarse grained sandstone occurring in association with oil shale and mudstone in a predominantly fining upward sequence. Detailed geochemical and petrographic characterization was carried out on oil shale and mudstone samples to evaluate the origin and type of organic matter (OM), as well as the paleoenvironmental conditions and organic richness of the Paleogene sedimentary succession. The facies are only enriched in total organic carbon (TOC), potential hydrocarbon yield (S2) and extractible organic matter (EOM) the types of organic matter are important index reflecting the potential of the source rock(s). Based on elemental ratios, the analyzed samples are shown to contain Types I and II kerogens. This finding is supported by the high hydrogen index (HI) of >300?mg HC/g TOC and the presence of abundant liptinitic materials. Biomarker signatures [n-alkanes > n-C25, high C29/C30 17α (H) hopane ratios (0.8–3.3) and high C29 steranes (49–78%)]. Low total sulfur and V/(V?+?Ni) ratio] suggest a predominantly terrestrial source input with some contribution from aquatic microorganisms as indicated by the common occurrence of amorphous organic matter. Combining this results with n-alkane patterns, kerogen types and organic petrography, predominance of C29 sterane probably indicates a contribution of aquatic organisms such as green and brown algae (consistent with Botrycoccus braunii race A and Pediastrum contribution) and some influence of higher plants OM. Integration of biomarker studies with bulk geochemical and petrographic analysis suggests that the analyzed samples were deposited under suboxic conditions in a fresh water lacustrine environment. This finding is corroborated by the ratios of pristane/phytane, V/Ni and Sr/Br. High bioproductivity and a stratified fresh water column with suboxic bottom water condition enhanced OM preservation in the analyzed mudstone and shale facies. The high OM content in these samples maybe related to the fine-grained matrix of the mud rocks and the paleoclimate in the area.Mako?, P., Przyjazny, A., Boczkaj, G., 2019. Methods of assaying volatile oxygenated organic compounds in effluent samples by gas chromatography – a review. Journal of Chromatography A 1592, 143-160. paper is a review of the procedures for the determination of volatile and semivolatile oxygenated organic compounds (O-VOCs) in effluent samples by gas chromatography. Current trends and outlook for individual steps of the procedure for the determination of O-VOCs in effluents are discussed. The available sample preparation techniques and their limitations are described along with GC capillary columns used for O-VOCs separation and selective and universal detectors used for their determination. The results of determination of O-VOC content in various types of real effluents are presented. The lack of legal regulations regarding the presence of the majority of O-VOCs is pointed out as well as the availability of just a few procedures allowing a comprehensive evaluation of the O-VOC content in effluents.Maksimova, Y.G., 2019. Microorganisms and carbon nanotubes: Interaction and applications (review). Applied Biochemistry and Microbiology 55, 1-12. review addresses various aspects of the interaction between carbon nanotubes (CNTs) and microorganisms: the antimicrobial effects of single-walled, multiwalled, functionalized, and nonfunctionalized CNTs; the mechanism of action of these nanomaterials at the single-cell level; and their effects on soil and aquatic microorganisms. Among the mechanisms of action of CNTs on the microbial cell, one should note direct contact, which leads to disruption of the cell wall and cytoplasmic membrane, changes in membrane fluidity, oxidative stress, enzyme inhibition, and reduced transcription of several key genes. It has been shown that the antimicrobial effect of CNTs strongly depends on their diameter, length, aggregation degree, concentration, surface functionalization, degree of purification, and time and intensity of contact. The possibilities of the CNT biodegradation by microorganisms have been studied. It has been shown that the introduction of nanotubes into soils results in changes in the abundances of bacteria of certain taxonomic groups involved in biogeochemical cycles of carbon and nitrogen. This may adversely affect the cycling of these elements in the nature. The review also focuses on recent trends in the development of microbial fuel cells, biosensor technologies, bioremediation, and wastewater treatment in which CNTs display their unique electron-conducting and adsorption properties and serve as a bridge for an understanding of the beneficial aspects of microorganisms.Mancilla-Polanco, A., Johnston, K., Richardson, W.D.L., Schoeggl, F.F., Zhang, Y.G., Yarranton, H.W., Taylor, S.D., 2019. Phase behavior of heavy-oil/propane mixtures. SPE Journal 24, 596-617. phase behavior of heavy-oil/propane mixtures was mapped from temperatures ranging from 20 to 180°C and pressures up to 10 MPa. Both vapor/liquid (VL1) and liquid/liquid (L1L2) regions were observed. Saturation pressures (VL1 boundary) were measured in a Jefri 100-cm3 pressure/volume/temperature (PVT) -cell and blind-cell apparatus. The propane content at which a light propane-rich phase and a heavy bitumen-rich (or pitch) phase formed (L1/L1L2 boundary) was visually determined with a high-pressure microscope (HPM) while titrating propane into the bitumen. High-pressure and high-temperature yield data were measured using a blind-cell apparatus. Here, yield is defined as the mass of the indicated component(s) in the pitch phase divided by the mass of bitumen in the feed. A procedure was developed and used to measure propane-rich-phase and pitch-phase compositions in a PVT cell.Pressure/temperature and pressure/composition phase diagrams were constructed from the saturation-pressure and pitch-phase-onset data. High-pressure micrographs demonstrated that, at lower temperatures and propane contents, the pitch phase appeared as glassy particles, whereas at higher propane contents and temperatures, it appeared as a liquid phase. Ternary diagrams were also constructed to present phase-composition data. The ability of a volume-translated Peng-Robinson cubic equation of state (CEOS) (Peng and Robinson 1976) to match the experimental measurements was explored. Two sets of binary-interaction parameters were tested: temperature-dependent binary-interaction parameters (SvdW) and composition-dependent binary-interaction parameters (CDvdW). Models derived from both types of binary-interaction parameters matched the saturation pressures and the L1L2 boundaries at one pressure but could not match the pressure dependency of the L1L2 boundary or the measured L1L2 phase compositions. The SvdW model could not match the yield data, whereas the CDvdW model matched yields at temperatures up to 90°C.Mandal, A., Deka, B., Mahto, V., Nihalani, M.C., Purohit, S., 2019. Synthesis, characterization and evaluation of a novel asphaltene inhibitor to control organic solid deposition in petroleum formation. Petroleum Science and Technology 37, 780-786. research work deals with synthesis of N-phenylamino hexanol tetramer to be used as an asphaltene inhibitor for crude oil in pores of reservoir. The synthesized additive was characterized using FTIR and Proton NMR spectroscopy, which confirms the formation of tetramer. Asphaltene deposition in the pores of sandstone core is studied by flooding the virgin and additive beneficiated crude oil indicating less deposition in beneficiated crude oil. Wettability alteration studies showed less contact angle hysteresis for virgin crude oil compared to the synthesized inhibitor beneficiated crude oil, which also aids to the lesser deposition of solid in the later one.Mao, F., Fan, H., Wang, J., 2019. Biogenic oxygenates in lignite pyrolysis tars and their thermal cracking revealed by two-dimensional gas chromatography/time-of-flight mass spectrometry (GC×GC-TOFMS). Journal of Analytical and Applied Pyrolysis 139, 213-223.×GC-TOFMS was applied to characterize oxygenates in five lignite tars, which were produced from the pyrolysis of a low-maturity lignite in a two-stage reactor with thermal cracking of volatile matter at a different temperature (500–800?°C) and without thermal cracking. The analysis of the two tars obtained by no cracking and cracking at 500?°C identified 349 and 469 oxygenates with a higher reliability, respectively. Those oxygenates embraced a considerable variety of biomarker species. Many biomarker compounds were the constituents of essential oils or extracts of plants, including long-chain fatty oxygenates (e.g., linolenic acid, erucic acid and 2-hexyldecanol), terpenoids (e.g., cedrenol, caryophyllene oxide and artemisinin) and aromatic compounds (e.g. vanillin, cinnamic acids and flavoniods). Besides, cellulose-degraded primary compounds (e. g., levoglucosenone and furfural) and lignin-derived guaiacols were detected. The results strongly indicated the preservation of various biogenic compositions in the lignite due to the low microbial activity and immature diagenesis. The study also reported the changes of oxygenate classes with cracking temperature by classifying them into chain fatty oxygenates, alicyclic oxygenates and aromatic oxygenates.Marakushev, S.A., Belonogova, O.g.V., 2019. Ideas and perspectives: Development of nascent autotrophic carbon fixation systems in various redox conditions of the fluid degassing on early Earth. Biogeosciences 16, 1817-1828. origin and development of the primary autotrophic metabolism on early Earth were influenced by the two main regimes of degassing of the Earth – reducing (predominance CH4) and oxidative (CO2). Among the existing theories of the autotrophic origin of life in hydrothermal environments, CO2 is usually considered to be the carbon source for nascent autotrophic metabolism. However, the ancestral carbon used in metabolism may have been derived from CH4 if the outflow of magma fluid to the surface of the Earth consisted mainly of methane. In such an environment, the primary autotrophic metabolic systems had to be methanotrophic. Due to the absence of molecular oxygen in the Archean conditions, this metabolism would have been anaerobic; i.e., oxidation of methane must be realized by inorganic high-potential electron acceptors. In light of the primacy and prevalence of CH4-dependent metabolism in hydrothermal systems of the ancient Earth, we propose a model of carbon fixation where the methane is fixed or transformed in a sequence of reactions in an autocatalytic methane–fumarate cycle. Nitrogen oxides are thermodynamically the most favorable among possible oxidants of methane; however, even the activity of oxygen created by mineral buffers of iron in hydrothermal conditions is sufficient for methanotrophic acetogenesis. The hydrothermal system model is considered in the form of a phase diagram, which demonstrates the area of redox and P and T conditions favorable for the development of the primary methanotrophic metabolism.Maraschin, A.J., da Cruz, G.F., Martins, L.L., Severiano Ribeiro, H.J.P., Augustin, A.H., 2019. Relationship between diagenesis and the emplacement of bitumen in the Lower Triassic Piramboia Formation sandstones, Paraná Basin, SW Brazil. Journal of South American Earth Sciences 92, 435-447. of eolian sandstones of the Lower Triassic Piramboia Formation in the eastern margin of the intracratonic Paraná Basin are known as the main occurrence of tar sandstones in Brazil because contain heavy oil (“tar”). In order to investigate the migration of oil into the sandstones petrographic analyses of dune facies were performed. Optical (transmitted, reflected and epifluorescence lights) and Field Emission Scanning Electron (FE-SEM) microscope studies together with X-Ray Diffraction (XRD) analyses showed that the Piramboia Formation sandstones have not been affected by intense diagenesis. Eogenetic features includes mainly thin, continuous inherited ferruginous clay coatings and minor mechanically infiltrated clay coatings around detrital mineral grains. The authigenesis of smectite and K-feldspar overgrowths precipitation begin to develop and during shallow mesodiagenesis, authigenic smectite was gradually transformed into mixed-layer illite-smectite; K-feldspar overgrowths, quartz overgrowths continuous to develop, and pore-filling calcite cement were formed locally. In the late mesodiagenesis the emplacement of oil occurred, filling pores and covering grains, clay coatings and calcite. During later surface exposure, water washing by meteoric fluids and biodegradation transformed the oil into a heavy oil rich in asphaltenes. The influx of acid meteoric waters caused dissolution of detrital K-feldspars as well as meteoric waters generate organic acids which also caused the dissolution of K-feldspars and the consequent generation of secondary porosity with the precipitation of inter- and intragranular vermicular kaolinite. However, kaolinite can be also a product of eodiagenetic process similar to the occur in the telodiagenesis. To evaluate the porosity of the sandstones microtomography analysis were preformed revealing high porosity volume (ca. 26%) and high volume of porous with connectivity (ca. 26%). Although not currently commercially exploited nowadays the knowledge of the Piramboia tar sandstones diagenetic evolution contributes for a better understanding of the Paraná Basin sedimentary fill during the Lower Triassic.Marathe, P.S., Juan, A., Hu, X., Westerhof, R.J.M., Kersten, S.R.A., 2019. Evaluating quantitative determination of levoglucosan and hydroxyacetaldehyde in bio-oils by gas and liquid chromatography. Journal of Analytical and Applied Pyrolysis 139, 233-238. communication evaluates the suitability of gas and liquid chromatography for the quantification of levoglucosan and hydroxyacetaldehyde in bio-oils. It was found that both techniques can principally determine levoglucosan quantitatively in cellulose/biomass derived bio-oils. However, it is also shown that oligo-anhydrosugars present in the bio-oils undergo depolymerisation to levoglucosan during gas chromatography, resulting in an overestimation of the concentration of levoglucosan. Hydroxyacetaldehyde can only be determined quantitatively by liquid chromatography. Presented experimental evidence shows that the high temperature (200–320?°C) of injection in gas chromatography is a key factor causing oligo-anhydrosugars and hydroxyacetaldehyde to react during analysis, which may lead to flawed results.Marconi, D., Weigand, M.A., Sigman, D.M., 2019. Nitrate isotopic gradients in the North Atlantic Ocean and the nitrogen isotopic composition of sinking organic matter. Deep Sea Research Part I: Oceanographic Research Papers 145, 109-124. processes within the Atlantic basin alter the nitrogen (N) and oxygen (O) isotopic compositions (δ15N and δ18O) of nitrate before this nutrient is carried from the upper water column into the deep ocean by the formation of North Atlantic Deep Water (NADW). Here, nitrate δ15N and δ18O measurements along the 2013 CLIVAR/GO-SHIP Atlantic section A16N from 6°S to 61°N are used to calculate the δ15N and δ18O of regenerated nitrate added to the interior at different latitudes and depths along the section. The δ15N of nitrate being regenerated is similar among depths and covaries with δ15N of the nitrate supply to overlying surface waters. These observations are consistent with regenerated nitrate deriving dominantly from sinking N, rather than from dissolved organic or suspended particulate organic N that is circulated through the ocean interior. The δ15N of regenerated nitrate never declines below the δ15N of the nitrate supply, consistent with the dominance of subsurface nitrate over N2 fixation and atmospheric N deposition in fueling net community production. In the low latitudes (<15°N), shallow and mid-depth nitrate δ15N entering from the South in Subantarctic Mode Water (SAMW) is as high as 6.2‰ vs. air due to partial nitrate assimilation in the Southern Ocean surface, while the nitrate δ18O is similar to that measured in deep water. Its low δ18O indicates that nitrate at shallow and mid-depths is mostly regenerated, the low δ18O of which overprints the high δ18O of unused (“preformed”) nitrate from the Southern Ocean. Regenerated nitrate δ18O is calculated to be 1.1–1.2‰ higher than ambient seawater, consistent with previous work. At the southern end of the section, the δ15N of the sinking flux is as high as that of SAMW (~6.2‰) or higher, maintaining the high δ15N of shallow/mid-depth waters and raising the δ15N of nitrate on deeper isopycnals, including those within NADW. SAMW ultimately supplies water for NADW formation, but the high nitrate δ15N of SAMW observed in the southern end of the section does not survive into newly formed NADW, which has a nitrate δ15N of 4.83‰ vs. air. This indicates that the high nitrate δ15N of northward-flowing shallow/mid-depth waters is overprinted by the input of low-δ15N fixed N to the Atlantic, largely by N2 fixation. Our reconstruction of the δ15N of sinking N indicates that most newly fixed N is added south of the North Atlantic subtropical gyre. In the subpolar North Atlantic, the A16N data indicate that the δ15N of the nitrate in NADW does not differ from that of its regional upper ocean sources, for two reasons. First, nitrate is completely consumed in much of the subpolar North Atlantic surface, minimizing the isotopic signal from partial nitrate assimilation. Second, much of the sinking N from the North Atlantic surface is regenerated in newly formed NADW, reuniting the nitrate assimilated in the surface with the preformed nitrate carried down in NADW.Maresca, J.A., Keffer, J.L., Hempel, P.P., Polson, S.W., Shevchenko, O., Bhavsar, J., Powell, D., Miller, K.J., Singh, A., Hahn, M.W., 2019. Light modulates the physiology of nonphototrophic Actinobacteria. Journal of Bacteriology 201, Article e00740-00718.: Light is a source of energy and an environmental cue that is available in excess in most surface environments. In prokaryotic systems, conversion of light to energy by photoautotrophs and photoheterotrophs is well understood, but the conversion of light to information and the cellular response to that information have been characterized in only a few species. Our goal was to explore the response of freshwater Actinobacteria, which are ubiquitous in illuminated aquatic environments, to light. We found that Actinobacteria without functional photosystems grow faster in the light, likely because sugar transport and metabolism are upregulated in the light. Based on the action spectrum of the growth effect and comparisons of the genomes of three Actinobacteria with this growth rate phenotype, we propose that the photosensor in these strains is a putative CryB-type cryptochrome. The ability to sense light and upregulate carbohydrate transport during the day could allow these cells to coordinate their time of maximum organic carbon uptake with the time of maximum organic carbon release by primary producers.Importance: Sunlight provides information about both place and time. In sunlit aquatic environments, primary producers release organic carbon and nitrogen along with other growth factors during the day. The ability of Actinobacteria to coordinate organic carbon uptake and utilization with production of photosynthate enables them to grow more efficiently in the daytime, and it potentially gives them a competitive advantage over heterotrophs that constitutively produce carbohydrate transporters, which is energetically costly, or produce transporters only after detection of the substrate(s), which delays their response. Understanding how light cues the transport of organic carbon and its conversion to biomass is key to understanding biochemical mechanisms within the carbon cycle, the fluxes through it, and the variety of mechanisms by which light enhances growth.Margesin, R., Collins, T., 2019. Microbial ecology of the cryosphere (glacial and permafrost habitats): current knowledge. Applied Microbiology and Biotechnology 103, 2537-2549. in cold ecosystems play a key ecological role in their natural habitats. Since these ecosystems are especially sensitive to climate changes, as indicated by the worldwide retreat of glaciers and ice sheets as well as permafrost thawing, an understanding of the role and potential of microbial life in these habitats has become crucial. Emerging technologies have added significantly to our knowledge of abundance, functional activity, and lifestyles of microbial communities in cold environments. The current knowledge of microbial ecology in glacial habitats and permafrost, the most studied habitats of the cryosphere, is reported in this review.Mariotti, M., Salinas, G., Gabaldón, T., Gladyshev, V.N., 2019. Utilization of selenocysteine in early-branching fungal phyla. Nature Microbiology 4, 759-765. are a diverse group of proteins containing selenocysteine (Sec)—the twenty-first amino acid—incorporated during translation via a unique recoding mechanism. Selenoproteins fulfil essential roles in many organisms, yet are not ubiquitous across the tree of life. In particular, fungi were deemed devoid of selenoproteins. However, we show here that Sec is utilized by nine species belonging to diverse early-branching fungal phyla, as evidenced by the genomic presence of both Sec machinery and selenoproteins. Most fungal selenoproteins lack consensus Sec recoding signals (SECIS elements) but exhibit other RNA structures, suggesting altered mechanisms of Sec insertion in fungi. Phylogenetic analyses support a scenario of vertical inheritance of the Sec trait within eukaryotes and fungi. Sec was then lost in numerous independent events in various fungal lineages. Notably, Sec was lost at the base of Dikarya, resulting in the absence of selenoproteins in Saccharomyces cerevisiae and other well-studied fungi. Our results indicate that, despite scattered occurrence, selenoproteins are found in all kingdoms of life.Marsola, J.C.A., Ferreira, G.S., Langer, M.C., Button, D.J., Butler, R.J., 2019. Increases in sampling support the southern Gondwanan hypothesis for the origin of dinosaurs. Palaeontology 62, 473-482. Dinosaurs were ubiquitous in terrestrial ecosystems through most of the Mesozoic and are still diversely represented in the modern fauna in the form of birds. Recent efforts to better understand the origins of the group have resulted in the discovery of many new species of early dinosaur and their closest relatives (dinosauromorphs). In addition, recent re-examinations of early dinosaur phylogeny have highlighted uncertainties regarding the interrelationships of the main dinosaur lineages (Sauropodomorpha, Theropoda and Ornithischia), and questioned the traditional hypothesis that the group originated in South Gondwana and gradually dispersed over Pangaea. Here, we use an historical approach to examine the impact of new fossil discoveries and changing phylogenetic hypotheses on biogeographical scenarios for dinosaur origins over 20?years of research time, and analyse the results in the light of different fossil record sampling regimes. Our results consistently optimize South Gondwana as the ancestral area for Dinosauria, as well as for more inclusive clades including Dinosauromorpha, and show that this hypothesis is robust to increased taxonomic and geographic sampling and divergent phylogenetic results. Our results do not find any support for the recently proposed Laurasian origin of dinosaurs and suggest that a southern Gondwanan origin is by far the most plausible given our current knowledge of the diversity of early dinosaurs and non-dinosaurian dinosauromorphs.Martínez Narro, G., Pozos Vázquez, C., Mercado González, M.O., 2019. Viscosity reduction of heavy crude oil by dilution with hydrocarbons obtained via chemical recycling of plastic wastes. Petroleum Science and Technology 37, 1347-1354. increasing energy demand is persuading oil companies to exploit unconventional reserves of heavy and extra heavy crude oil, which are characterized for their elevated viscosities and upraised production costs. Expensive flow modifiers are often used to lower the viscosity of heavy crude oils so that pipeline transportation becomes viable. In this study, thermal cracking tests were conducted to obtain hydrocarbons (condensate) of lower molar masses, from common plastic wastes. Physical properties of the products were measured, such as viscosity, density, pour point, cloud point and aniline temperature. Due to their chemical similarity, the hydrocarbon products from the tertiary recycling of postconsumer low density polyethylene (LDPE) plastic bags were used to dilute a heavy crude oil (12°API) and lower its viscosity. Results showed a viscosity reduction of 90% at room temperature of a 5:25 vol:vol blend of hydrocarbons/heavy crude oil. This paper proposes an alternative solution for two alarming global problems: waste plastics recovery and optimal transportation of heavy crude oil; However, an industrial application of this process would have to be combined with municipal solid waste collection and pre-treatment technologies.Martinón-Torres, M., Li, X., Xia, Y., Benzonelli, A., Bevan, A., Ma, S., Huang, J., Wang, L., Lan, D., Liu, J., Liu, S., Zhao, Z., Zhao, K., Rehren, T., 2019. Surface chromium on Terracotta Army bronze weapons is neither an ancient anti-rust treatment nor the reason for their good preservation. Scientific Reports 9, Article 5289. forty years, there has been a widely held belief that over 2,000 years ago the Chinese Qin developed an advanced chromate conversion coating technology (CCC) to prevent metal corrosion. This belief was based on the detection of chromium traces on the surface of bronze weapons buried with the Chinese Terracotta Army, and the same weapons’ very good preservation. We analysed weapons, lacquer and soils from the site, and conducted experimental replications of CCC and accelerated ageing. Our results show that surface chromium presence is correlated with artefact typology and uncorrelated with bronze preservation. Furthermore we show that the lacquer used to cover warriors and certain parts of weapons is rich in chromium, and we demonstrate that chromium on the metals is contamination from nearby lacquer after burial. The chromium?anti-rust treatment?theory should therefore be abandoned. The good metal preservation probably results from the moderately alkaline pH and very small particle size of the burial soil, in addition to bronze composition.Matsubayashi, J., Tayasu, I., 2019. Collagen turnover and isotopic records in cortical bone. Journal of Archaeological Science 106, 37-44. collagen of modern and ancient animals is a useful tissue for isotope analyses because it is stable over time. However, uncertainty regarding metabolic turnover processes of bone collagen can make isotope analysis difficult to correlate with relevant life history information. We used radiocarbon (14C) dating to examine turnover within cortical bone and to investigate retrospective isotope ratios along the growth direction of mid-shaft femurs of several large mammals with long life-span, including brown bear (Ursus arctos), sika deer (Cervus nippon), Japanese serow (Capricornis crispus), and Japanese macaque (Macaca fuscata). The individuals examined died between 1971 and 1986, and their bones were thus expected to contain radiocarbon generated by nuclear bomb testing, which led to an atmospheric 14C spike around 1964. Therefore, 14C dating could be used to date sections of cortical bone at fine scale. The 14C ages in the bone sections of all specimens except the Japanese serow specimen showed similar trends; perimedullary bone sections contained younger carbon, which has depleted 14C after the peak of the 14C spike, whereas 14C ages became rapidly older in midcortical sections before gradually becoming younger towards the bone surface. We observed metabolic turnover of collagen driven by bone remodelling in perimedullary bone sections, but we observed no evidence of remodelling in midcortical and pericortical sections. Thus, our results confirm that bone collagen in femoral cortical bone records retrospective isotopic information during skeletal growth of mammals and suggest that entire femoral cortical bone of aged terrestrial mammals represents isotopic values during adolescence rather than an average value from several years prior to death.Matys, E.D., Mackey, T., Grettenberger, C., Mueller, E., Sumner, D.Y., Hawes, I., Summons, R.E., 2019. Bacteriohopanepolyols across environmental gradients in Lake Vanda, Antarctica. Geobiology 17, 308-319. (BHPs) are bacterial membrane lipids that may be used as biological or environmental biomarkers. Previous studies have described the diversity, distribution, and abundance of BHPs in a variety of modern environments. However, the regulation of BHP production in polar settings is not well understood. Benthic microbial mats from ice‐covered lakes of the McMurdo Dry Valleys, Antarctica provide an opportunity to investigate the sources, physiological roles, and preservation of BHPs in high‐latitude environments. Lake Vanda is one of the most stable lakes on Earth, with microbial communities occupying specific niches along environmental gradients. We describe the influence of mat morphology and local environmental conditions on the diversity and distribution of BHPs and their biological sources in benthic microbial mats from Lake Vanda. The abundance and diversity of C‐2 methylated hopanoids (2‐MeBHP) are of particular interest, given that their stable degradation products, 2‐methylhopanes, are among the oldest and most prevalent taxonomically informative biomarkers preserved in sedimentary rocks. Furthermore, the interpretation of sedimentary 2‐methylhopanes is of great interest to the geobiology community. We identify cyanobacteria as the sole source of 2‐MeBHP in benthic microbial mats from Lake Vanda and assess the hypothesis that 2‐MeBHP are regulated in response to a particular environmental variable, namely solar irradiance.Mawalkar, S., Brock, D., Burchwell, A., Kelley, M., Mishra, S., Gupta, N., Pardini, R., Shroyer, B., 2019. Where is that CO2 flowing? Using Distributed Temperature Sensing (DTS) technology for monitoring injection of CO2 into a depleted oil reservoir. International Journal of Greenhouse Gas Control 85, 132-142. Distributed Temperature Sensing (DTS) system, along with a five-level, behind-casing pressure sensing array was installed as part of the Midwest Regional Carbon Sequestration Partnership (MRCSP) large-scale carbon dioxide (CO2) storage test in a depleted Niagaran pinnacle reef oil reservoir in Northern Michigan. The reef is being monitored during its initial reservoir fill-up period as CO2 is being injected to raise the reservoir pressure for enhanced oil recovery (EOR). DTS data are analyzed with results from the initial injection of ?101,000?metric tons of CO2 , injected between January 2017 and December 2018. This paper discusses the results of real-time DTS combined with multi-level pressure monitoring. The collection, processing, and interpretation of large amounts of data from fiber-optic-based DTS provides an opportunity to obtain high-resolution information on migration of CO2 in the reservoir.Mayayo, M.J., Yuste, A., Luzón, A., Corzo, A., Mu?oz, A., Pérez, A., Soriano, A., 2019. Fe-rich microspheres pseudomorphs after pyrite framboids in Holocene fluvial deposits from NE Spain: Relationship with environmental conditions and bacterial activity. Sedimentary Geology 386, 103-117. iron oxides-rich microsphere types (Type I to III) were detected in an Holocene 17?m-thick stratigraphic succession located in the Iberian Range (NE Spain). Lithofacies features indicate that the studied materials were generated in an alluvial-dominated setting, with a channeled area fringed by floodplain zones. During high water levels and high-energy floods, gravels and sands deposited in the active area and in lateral overbank areas. In these lateral areas, mud settling took place when flood decreased and then anoxic conditions could be reached due to microbial oxidation of organic matter and the low permeability of the marly sediment. X-ray diffraction (XRD) analysis of 32 samples and microtextural observation of 10 samples by Field Emission Scanning Electron Microscopy (FESEM) revealed the occurrence of Fe oxi-hydroxides microspheres showing different surficial structure. These microspheres are pseudomorphs after pyrite framboids although the formation of some primary Fe oxy-hydroxides aggregates cannot be rejected. Pyrite framboids genesis in sediments underlying oxic-dysoxic water column would have been favored by anoxic conditions reached in lateral overbank areas after main flooding, involving the activity of Fe reducing bacteria and sulfate-reducing bacteria (SRB), given the high SO4= availability provided by the highly mineralized groundwater from the upstream Ba?os de Ari?o spring. Subsequent change to oxic conditions during the exposition of the floodplain enhanced the transformation of pyrite into Fe oxy-hydroxides, as well as in microenvironments around cracks and roots. Pyrite oxidation likely took place with the implication of neutrophilic iron oxidizing Bacteria and Archaea living in microaerophilic conditions, as well as cyanobacteria, given the close association of Fe oxides framboids with microbial features. In addition, pyrite and/or Fe oxi-hydroxides framboids from marl levels could have been incorporated to sand sediments during further overbank flooding episodes. Under these new oxic conditions pyrite oxidation would have been favored and even the formation of primary Fe oxy-hydroxides.McInnes, A.S., Laczka, O.F., Baker, K.G., Larsson, M.E., Robinson, C.M., Clark, J.S., Laiolo, L., Alvarez, M., Laverock, B., Kremer, C.T., van Sebille, E., Doblin, M.A., 2019. Live cell analysis at sea reveals divergent thermal performance between photosynthetic ocean microbial eukaryote populations. The ISME Journal 13, 1374-1378. at sea provides insight into which traits of ocean microbes are linked to performance in situ. Here we show distinct patterns in thermal tolerance of microbial phototrophs from adjacent water masses sampled in the south-west Pacific Ocean, determined using a fluorescent marker for reactive oxygen species (ROS). ROS content of pico-eukaryotes was assessed after 1, 5 and 25?h of incubation along a temperature gradient (15.6–32.1?°C). Pico-eukaryotes from the East Australian Current (EAC) had relatively constant ROS and showed greatest mortality after 25?h at 7?°C below ambient, whereas those from the Tasman Sea had elevated ROS in both warm and cool temperature extremes and greatest mortality at temperatures 6–10?°C above ambient, interpreted as the outcome of thermal stress. Tracking of water masses within an oceanographic circulation model showed populations had distinct thermal histories, with EAC pico-eukaryotes experiencing higher average temperatures for at least 1 week prior to sampling. While acclimatization and community assembly could both influence biological responses, this study clearly demonstrates that phenotypic divergence occurs along planktonic drift trajectories.McMullan, S., Collins, G.S., 2019. Uncertainty quantification in continuous fragmentation airburst models. Icarus 327, 19-35. evidenced by the Chelyabinsk and Tunguska airburst events in Russia, decameter-scale Near-Earth Objects (NEOs) can pose a hazard to human life and infrastructure from the energy they deposit in the atmosphere as they break up. To understand the potential damage these small NEOs can cause on Earth's surface, it is imperative to be able to model their atmospheric entry quickly and accurately. Here we compare three semi-analytical models of asteroid airbursts that differ in their descriptions of fragment separation and spreading. Each model can be calibrated to produce a good fit to the energy deposition curve inferred from Chelyabinsk observations, but in each case the implied initial meteoroid strength is different and when the calibrated models are upscaled to Tunguska, the results diverge. This introduces an inter-model uncertainty that compounds the large range of uncertain physical and model parameters that influence probabilistic hazard assessment. Uncertainty quantification of airburst energy deposition was performed for a theoretical impacting object with H-magnitude 27, assuming no prior knowledge of any other impactor or model parameter. Each of the three models produces a different distribution of airburst outcomes, however, the variation attributable to physical parameter uncertainty is far larger than the inter-model differences. To constrain the initial conditions of the Tunguska event, the same uncertainty quantification was performed for an H-magnitude 24 event. Among the scenarios consistent with Tunguska observations (5–10?km burst altitude, 10–60° trajectory angle, 3–50?MT TNT total energy release) the most likely range of impact conditions was: radius of 25–75?m, mass of 1× 108– 2.5× 109 kg, initial velocity of 11.5–33?km/s, and angle of 25–60°.Mechelke, J., Longrée, P., Singer, H., Hollender, J., 2019. Vacuum-assisted evaporative concentration combined with LC-HRMS/MS for ultra-trace-level screening of organic micropollutants in environmental water samples. Analytical and Bioanalytical Chemistry 411, 2555-2567. evaporative concentration (VEC) was successfully applied and validated for the enrichment of 590 organic substances from river water and wastewater. Different volumes of water samples (6?mL wastewater influent, 15?mL wastewater effluent, and 60?mL river water) were evaporated to 0.3?mL and finally adjusted to 0.4?mL. 0.1?mL of the concentrate were injected into a polar reversed-phase C18 liquid chromatography column coupled with electrospray ionization to high-resolution tandem mass spectrometry. Analyte recoveries were determined for VEC and compared against a mixed-bed multilayer solid-phase extraction (SPE). Both approaches performed equally well (≥?70% recovery) for a vast number of analytes (n?=?327), whereas certain substances were especially amenable to enrichment by either SPE (e.g., 4-chlorobenzophenone, logDow,pH7 4) or VEC (e.g., TRIS, logDow,pH7 ??4.6). Overall, VEC was more suitable for the enrichment of polar analytes, albeit considerable signal suppression (up to 74% in river water) was observed for the VEC-enriched sample matrix. Nevertheless, VEC allowed for accurate and precise quantification down to the sub-nanogram per liter level and required no more than 60?mL of the sample, as demonstrated by its application to several environmental water matrices. By contrast, SPE is typically constrained by high sample volumes ranging from 100?mL (wastewater influent) to 1000?mL (river water). The developed VEC workflow not only requires low labor cost and minimum supervision but is also a rapid, convenient, and environmentally safe alternative to SPE and highly suitable for target and non-target analysis.Mehrotra, N., Shah, S.K., Basavaiah, N., Laskar, A.H., Yadava, M.G., 2019. Resonance of the ‘4.2ka event’ and terminations of global civilizations during the Holocene, in the palaeoclimate records around PT Tso Lake, Eastern Himalaya. Quaternary International 507, 206-216. driven changes have impacted various civilizations and have major influence on human population globally. Remote regions such as the Himalaya also archived these climatic events in various proxies. The Eastern Himalaya region has recorded the Holocene climate change events in numerous proxy records. A multi–proxy record of the early to late–mid Holocene climate change from the catchment of PankangTeng Tso (PT Tso) Lake at an altitude of 3935?m asl in the Tawang district of Arunachal Pradesh was studied. A 90?cm sediment profile showed a synchronous pattern of Holocene climate changes in the palynological, environmental magnetic and carbon isotope data recorded. Dominant cold-humid conditions at 4625?cal?yr BP followed by a cold-dry period was documented in the proxy data. The vegetation vis–à–vis climate varied throughout the Holocene and cold–dry conditions along with sub-alpine vegetation prevailed in the region around the “4.2ka event”. Human activities and environmental changes in the Tawang district during the Holocene probably impacted the vegetation during this significant period of the development and demise of major global civilizations.Mehta-Kolte, M.G., Stoeva, M.K., Mehra, A., Redford, S.A., Youngblut, M.D., Zane, G., Grégoire, P., Carlson, H.K., Wall, J., Coates, J.D., 2019. Adaptation of Desulfovibrio alaskensis G20 to perchlorate, a specific inhibitor of sulfate reduction. Environmental Microbiology 21, 1395-1406. sulfide produced by sulfate-reducing microorganisms (SRM) poses significant health and economic risks, particularly during oil recovery. Previous studies identified perchlorate as a specific inhibitor of SRM. However, constant inhibitor addition to natural systems results in new selective pressures. Consequently, we investigated the ability of Desulfovibrio alaskensis G20 to evolve perchlorate resistance. Serial transfers in increasing concentrations of perchlorate led to robust growth in the presence of 100 mM inhibitor. Isolated adapted strains demonstrated a threefold increase in perchlorate resistance compared to the wild-type ancestor. Whole genome sequencing revealed a single base substitution in Dde_2265, the sulfate adenylyltransferase (sat). We purified and biochemically characterized the Sat from both wild-type and adapted strains, and showed that the adapted Sat was approximately threefold more resistant to perchlorate inhibition, mirroring whole cell results. The ability of this mutation to confer resistance across other inhibitors of sulfidogenesis was also assayed. The generalizability of this mutation was confirmed in multiple evolving G20 cultures and in another SRM, D. vulgaris Hildenborough. This work demonstrates that a single nucleotide polymorphism in Sat can have a significant impact on developing perchlorate resistance and emphasizes the value of adaptive laboratory evolution for understanding microbial responses to environmental perturbations.Meile, C., Scheibe, T.D., 2019. Reactive transport modeling of microbial dynamics. Elements 15, 111-116. transport modeling of microbially mediated processes has contributed significantly to an improved understanding of elemental cycling in Earth's near-surface environments. We describe key characteristics of microbial reactive transport models, recent advances in modeling approaches, and the application of such models to terrestrial and marine environmental problems. We introduce relevant case studies and discuss ways to integrate omics data (e.g., genomics, proteomics, metabolomics) that can inform and validate microbial reactive transport models, thereby improving our ability to address some of the grand challenges in a changing world.Melenevskii, V.N., Klimin, M.A., Tolstokorov, S.V., 2019. Diagenesis of organic matter in peat: Rock–Eval pyrolysis data. Geochemistry International 57, 227-231.–Eval pyrolysis data were obtained on a collection of peat samples at various diagenesis stages (from depths of 0–350 cm) from the Gurskoe deposit, lower Amur area, and on producers of organic matter (OM). The pyrograms of the peat OM are superpositions of three peaks: (1) a low-temperature one, with temperatures of hydrocarbon release lower than 300°C, (2) an intermediate-temperature peak, with hydrocarbons released at 300–400°C, and (3) a high-temperature one, corresponding to hydrocarbon release at temperatures above 400°C. The peaks correspond to the lipid, labile, and kerogen OM components, respectively. The diagenetic transformation of OM is associated with a gradual decrease in the contents of the lipid and labile components and an increase in the content of the kerogen component. The process is the most intense in the upper part of the vertical section.Menlyadiev, M., Henderson, B.L., Zhong, F., Lin, Y., Kanik, I., 2019. Extraction of amino acids using supercritical carbon dioxide for in situ astrobiological applications. International Journal of Astrobiology 18, 102-111. detection of organic molecules that are indicative of past or present biological activity within the Solar System bodies and beyond is a key research area in astrobiology. Mars is of particular interest in this regard because of evidence of a (perhaps transient) warm and wet climate in its past. To date, space missions to Mars have primarily used pyrolysis technique to extract organic compounds from the Martian regolith, but it has not enabled a clear detection of unaltered native Martian organics. The elevated temperatures required for pyrolysis extraction can cause native Martian organics to react with perchlorate salts in the regolith, possibly resulting in the chlorohydrocarbons that have been detected by mass spectrometry, a commonly used in situ technique for space applications. Supercritical carbon dioxide (SCCO2) extraction technique is a powerful alternative to pyrolysis that may be capable of extracting and delivering unaltered native organic species to an analyser. In this study, we report the SCCO2 extraction of unaltered amino acids (AAs) with simple laboratory analyses of extracts by capillary electrophoresis laser-induced fluorescence (CE/LIF) and liquid chromatography with mass spectrometry (LC/MS) techniques. The extraction efficiencies of several representative AAs using SCCO2 with small amounts of pure water (~1–5%) as a co-solvent were determined. Glass beads were used as a model substrate to examine the effects of several experimental parameters and Johnson Space Center (JSC) Mars-1A Martian regolith simulant was used to study the effect of complex matrix on extraction efficiencies. With optimized experimental conditions (75C and 5% of water), extraction efficiencies from doped JSC Mars-1A were found to be ~40% for glycine, alanine and serine and ~10% for lysine. Extraction of native organics from undoped JSC Mars-1A suggests that SCCO2/water solvent system can extract both organics extractable with pure SCCO2 and those extractable with pure water. Additionally, species not extracted by either pure SCCO2 or pure water were extracted with SCCO2/water solvent. Despite the preliminary nature of this work, it paves the path for more comprehensive extraction studies of astrobiologically relevant samples with thorough analyses of resulting extracts.Merey, S., 2019. Well completion operations in gas hydrate reservoirs. International Journal of Oil, Gas and Coal Technology 20, 373-396. the consumption of conventional oil and gas resources, gas hydrate reservoirs have become very popular recently. Due to the sensitive nature of gas hydrate reservoirs, special cares and equipment designs are necessary during drilling and well completion of gas hydrate wells. Therefore, in this study, it was aimed to describe special well completions operations such as cementing, perforations, sand screen or gravel packing, and well completion strings during completing gas hydrate wells. Merey, ?., 2019. Analysis of the effect of experimental adsorption uncertainty on CH4 production and CO2 sequestration in Dadas shale gas reservoir by numerical simulations. Journal of Petroleum Science and Engineering 178, 1051-1066. importance of unconventional gas reservoirs such as shale gas reservoirs has increased with the decline of conventional gas reservoirs and advancement in horizontal drilling and hydraulic fracturing in the world. Recently, there have been many exploration activities in Dadas shales, Turkey. Previously, the adsorption capacities of CH4 and CO2 on Dadas shale samples were measured by using volumetric adsorption experimental set-up. Although adsorption uncertainties of these experiments were calculated, their effects on CH4 production or CO2 sequestration in Dadas shales were not evaluated in field scale. In this study, the numerical simulations for CH4 gas production via 500?m long horizontal well from Dadas shale gas reservoir with different adsorption cases due to experimental adsorption uncertainties were conducted by using TOUGH?+?RealGasBrine. It was observed that initial CH4 adsorption capacity of Dadas shales varies from 2.1% to 20.9% because of experimental adsorption uncertainty and absorbed gas volume corrections. Numerical simulations showed initial adsorbed gas % and final adsorbed gas % vary significantly. Similarly, the injection of CO2 into the depleted Dadas shale gas reservoir was analyzed by numerical simulations at different adsorption cases due to experimental adsorption uncertainty and adsorbed gas volume correction. Final adsorbed CO2% varies from 18.1% to 27.5%. Furthermore, there are important differences in the amount of CO2 injected, final adsorbed CH4% and final adsorbed CO2% during CO2 injection simulations. The main reasons of these differences are experimental adsorption uncertainty and adsorbed gas volume correction. This study showed that the volumetric adsorption experimental method is not reliable in low adsorption values as in Dadas shales. It only gives adsorption ranges. The implication of this study is that the effect of experimental adsorption uncertainty obtained with the volumetric adsorption method on CH4 production or CO2 sequestration in Dadas shale gas reservoir is significant in field scale.Milligan, J.N., Royer, D.L., Franks, P.J., Upchurch, G.R., McKee, M.L., 2019. No evidence for a large atmospheric CO2 spike across the Cretaceous-Paleogene boundary. Geophysical Research Letters 46, 3462-3472.: Currently, there is only one paleo‐CO2 record from plant macrofossils that has sufficient stratigraphic resolution to potentially capture a transient spike related to rapid carbon release at the Cretaceous‐Paleogene (K‐Pg) boundary. Unfortunately, the associated measurements of stomatal index are off‐calibration, leading to a qualitative interpretation of >2,300‐ppm CO2. Here we reevaluate this record with a paleo‐CO2 proxy based on leaf gas exchange principles. We also test the proxy with three living species grown at 500‐ and 1,000‐ppm CO2, including the nearest living relative of the K‐Pg fern, and find a mean error rate of ~22%, which is comparable to other leading paleo‐CO2 proxies. Our fossils record a ~250‐ppm increase in CO2 across the K‐Pg boundary from ~625 to ~875 ppm. A small CO2 spike associated with the end‐Cretaceous mass extinction is consistent with many temperature records and with carbon cycle modeling of Deccan volcanism and the meteorite impact.Plain Language Summary: Currently, there is only one paleo‐CO2 record close enough to the Cretaceous‐Paleogene (K‐Pg) boundary to record a rapid release in atmospheric CO2, a greenhouse gas. This record is based on the stomatal frequencies of fern fossils at the K‐Pg boundary and Ginkgo fossils before and after the boundary. Unfortunately, due to deficiencies with the method, the CO2 inferences are only qualitative. Here we look at the same fossils with a proxy based on leaf gas exchange principles (i.e., photosynthesis). We first test the proxy with three living species grown at 500‐ and 1,000‐ppm CO2, including the nearest living relative of the K‐Pg fern, and find a comparable accuracy to other quantitative paleo‐CO2 proxies. The fossils record a modest ~250‐ppm increase in CO2 across the K‐Pg boundary. These estimates are consistent with most temperature records and with carbon cycle modeling of Deccan volcanism and the meteorite impact.Misios, S., Gray, L.J., Knudsen, M.F., Karoff, C., Schmidt, H., Haigh, J.D., 2019. Slowdown of the Walker circulation at solar cycle maximum. Proceedings of the National Academy of Sciences 116, 7186.: Influences of the 11-y solar cycle (SC) on climate have been speculated, but here we provide robust evidence that the SC affects decadal variability in the tropical Pacific. By analyzing independent observations, we demonstrate a slowdown of the Pacific Walker Circulation (PWC) at SC maximum. We find a muted hydrological cycle at solar maximum that weakens the PWC and this is amplified by a Bjerknes feedback. Given that a similar muted hydrological cycle has been simulated under increased greenhouse gas forcing, our results strengthen confidence in model predictions of a weakened PWC in a warmer climate. The results also suggest that SC forcing is a source of skill for decadal predictions in the Indo-Pacific region.Abstract: The Pacific Walker Circulation (PWC) fluctuates on interannual and multidecadal timescales under the influence of internal variability and external forcings. Here, we provide observational evidence that the 11-y solar cycle (SC) affects the PWC on decadal timescales. We observe a robust reduction of east–west sea-level pressure gradients over the Indo-Pacific Ocean during solar maxima and the following 1–2 y. This reduction is associated with westerly wind anomalies at the surface and throughout the equatorial troposphere in the western/central Pacific paired with an eastward shift of convective precipitation that brings more rainfall to the central Pacific. We show that this is initiated by a thermodynamical response of the global hydrological cycle to surface warming, further amplified by atmosphere–ocean coupling, leading to larger positive ocean temperature anomalies in the equatorial Pacific than expected from simple radiative forcing considerations. The observed solar modulation of the PWC is supported by a set of coupled ocean–atmosphere climate model simulations forced only by SC irradiance variations. We highlight the importance of a muted hydrology mechanism that acts to weaken the PWC. Demonstration of this mechanism acting on the 11-y SC timescale adds confidence in model predictions that the same mechanism also weakens the PWC under increasing greenhouse gas forcing.Misra, S., Varma, A.K., Hazra, B., Biswas, S., Samad, S.K., 2019. The influence of the thermal aureole asymmetry on hydrocarbon generative potential of coal beds: Insights from Raniganj Basin, West Bengal, India. International Journal of Coal Geology 206, 91-105. aim of the present study is to uncover hydrocarbon generation potential of an area intruded by lamprophyre dyke. Lamprophyre dyke induced a short-distance asymmetric thermal aureole in coal beds with more intense impact along the dip direction. Large ash yield, carbon content, lower volatile matter content, hydrogen indices, presence of natural coke, disordered kaolinite peaks, less pronounced aliphatic peaks, higher aromaticity under Fourier Transform Infra-Red spectroscopy (FTIR); highly rugged surface and large pores with the aid of Atomic force microscopy (AFM); abundant calcium carbonate mineral phases (calcite, dolomite, ankerite) and high-temperature silica phases (tridymite, sanidine) under X-ray diffraction (XRD) are the consequences of pronounced thermal effect and expulsion of hydrocarbons. Furthermore, the estimated vitrinite reflectance (EVRo) calculated through maximum pyrolysis temperature (Tmax) and measured mean random vitrinite reflectance (VRo) show the maximum difference in the heat-affected coal samples. In addition, parameters for source rock reconstruction and indices for quantification of FTIR spectra i.e. index of aliphaticity (IAL), index of aromaticity (IAR) and index for hydrocarbon generation (IHG) are introduced for coals. The distant (i.e. least-heat-affected) coals collected opposite to the dip direction of the coal bed have a higher potential for hydrocarbon generation. The igneous intrusion thus played a significant role in enhancing the maturity of the organic material, in turn, augmenting the hydrocarbon generation potential for targeting hydrocarbon plays of the area although at the expense of proximal samples.Mohamed, N.S., El Nady, M.M., 2019. Potentiality and timing of generation of Kareem and Rudeis formations, Central Gulf of Suez. Petroleum Science and Technology 37, 925-933. study aims to evaluate source rock formations (Kareem and Rudeis) through quantitative and qualitative analysis of pyrolysis data from 44 ditch samples from three wells (Elkhaligue-1, Kareem-1, and El Ayune-1) at different depths in the central Gulf of Suez. From these data we concluded that Kareem and Rudeis formations are fair to good source rocks and have a generating potential fair to good to generate both oil and gas generated from mixed type II kerogene deposited under anoxic conditions, also they considered as fair to good oil sources. Both formations are mature and this conclusion is confirms by the burial histories of the three wells where Kareem Formation reached the early stage of generation at time ranges from 6 to 1.5?m.y while Rudeis Formation reached the oil window at time ranges from 18 to 6.6?m.y which considered a very good timing for excellent preservation efficiency of the hydrocarbons generated.Mokhtari, R., Ayatollahi, S., 2019. Dissociation of polar oil components in low salinity water and its impact on crude oil–brine interfacial interactions and physical properties. Petroleum Science 16, 328-343. many efforts into the study of fluids interaction in low salinity water flooding, they are not probing the basics of transport phenomena between the involved phases. This work is aimed to bring new understanding of fluid–fluid interaction during low salinity water flooding through a series of organized experiments in which a crude oil sample with known properties was kept in contact with different brine solutions of various ionic strengths. Measuring brine pH, conductivity and crude oil viscosity and density for a period of 45?days illustrates the strong effect of the contact time and ionic strength on the dissociation of polar components and physical properties of the crude oil and brine. Besides, the interfacial tension (IFT) measurements show that the interfacial interactions are affected by several competitive interfacial processes. By decreasing the ionic strength of the brine, the solubility of naphthenic acids in the aqueous solution increases, and hence, the conductivity and the pH of the aqueous phase decrease. To verify this important finding, UV–Vis spectroscopy and 1H NMR analysis were also performed on aged brine samples. Notably, there is an ionic strength of brine in which the lowest IFT is observed, while the other physical properties are remained relatively unchanged.Mora, A., García-Bautista, D.F., Reyes-Harker, A., Parra, M., Blanco, V., Sánchez, N., de la Parra, F., Caballero, V., Rodriguez, G., Ruiz, C., Naranjo, J., Tesón, E., Ni?o, F., Quintero, I., Moreno, N., Cardozo, E., Gamba, N., Horton, B.K., Arias-Martinez, J.P., 2019. Tectonic evolution of petroleum systems within the onshore Llanos Basin: Insights on the presence of Orinoco heavy oil analogs in Colombia and a comparison with other heavy oil provinces worldwide. American Association of Petroleum Geologists Bulletin 103, 1179-1224. accumulations of hydrocarbons in the onshore Llanos Basin of Colombia are characterized by a central zone (Casanare province) with greater than 20° API gravity oils and a southern province with biodegraded, less than 15° API gravity oils. To date, no conceptual model successfully explains this spatial zonation. In this paper, we employ multiple one-dimensional time–temperature models to map the kitchens for three different source rocks and compare maturity levels through the Cenozoic with the presence or absence of reservoir, seal, overburden, and traps in paleogeographic maps of the Llanos Basin. We find that the Llanos Basin Cenozoic petroleum migration and charge may have been governed by a sedimentary–structural evolution tied to the adjacent orogenic belt in which (1) Paleogene stratigraphic traps developed in the south, as favored by a more segmented basement and potentially transpressional stresses; (2) a subsequent Neogene phase with more pervasive east-dipping low-displacement normal fault traps was discovered; and (3) a final Pliocene–present day phase of contractional traps was found in the easternmost foothill areas. When compared with the evolution of several potential kitchens, we suggest that Upper Cretaceous rocks from the Eastern Cordillera are the primary hydrocarbon source in the zone of heavy biodegraded oils to the south, whereas Lower Cretaceous and selected terrigenous Upper Cretaceous source rocks are largely responsible for the younger Neogene contractional traps of the foothills. This evolutionary pattern for the Llanos Basin favors the presence of smaller but numerous hydrocarbon accumulations rather than the broader zones of heavy oils, as found in the Orinoco belt of Venezuela.Mora, A., Gomez, R.A., Diaz, C., Caballero, V., Parra, M., Villamizar, C., Lasso, A., Ketcham, R.A., Gonzalez-Penagos, F., Rico, J., Arias-Martinez, J.P., 2019. Water flow, oil biodegradation, and hydrodynamic traps in the Llanos Basin, Colombia. American Association of Petroleum Geologists Bulletin 103, 1225-1264. this study, we provide new data to understand the groundwater flow patterns in the Llanos Basin and their impact on oil biodegradation and the geothermal regimes as well as how the structural styles and anthropogenic activities impact these patterns. Previous studies suggest an active flow of groundwater and variable salinities whose spatial pattern is apparently unrelated to topographically driven groundwater flow. These observations have led to different hypotheses regarding the influence of groundwater flow on Llanos Basin geothermal gradients and oil biodegradation.In this contribution, we present data regarding the hydraulic heads, salinities, geothermal gradients, and structural styles of the Llanos Basin to propose hypotheses explaining these observations. Structural cross sections and subsurface stratigraphic correlations allow us to suggest that the pattern of flow is best explained by a correlation between groundwater flow and structural styles. A basement map of the Llanos Basin confirms that the most important factor controlling geothermal gradients is the type of basement, whereas the factor of groundwater flow appears to be of secondary importance. The evolution of the basin and the frequent absence of correlation between fresh water and the more biodegraded oils support the interpretation that biodegradation is controlled by an older flow of water that started as early as the Oligocene. Finally, mass balances suggest that the temporal scales and volumes of groundwater flow are much larger than the scales observed during the development of the oil fields.Moridis, G.J., Reagan, M.T., Queiruga, A.F., Kim, S.-J., 2019. System response to gas production from a heterogeneous hydrate accumulation at the UBGH2-6 site of the Ulleung basin in the Korean East Sea. Journal of Petroleum Science and Engineering 178, 655-665. investigate the feasibility of production from a layered marine gas hydrate reservoir using the properties and conditions corresponding to the UBGH2-6 site of the Ulleung Basin in the Korean East Sea. The work expands and furthers previous investigations in support of a proposed field test. The target system is location in deep water and consists of 13?m of alternating hydrate-bearing sand and soft mud layers and will be produced using a vertical well. We assess production potential during a 14-day field test, examine sensitivity to heterogeneity in permeability, porosity, and initial hydrate saturation, and assess the geomechanical response of the system to short-term production. Producing gas from the system appears to be technically feasible, however, low production rates and relatively large water production rates are expected during the field test. Expected subsidence and reservoir compaction is limited given the current data and the short timeframes of the production test.Morin, T.H., 2019. Advances in the eddy covariance approach to CH4 monitoring over two and a half decades. Journal of Geophysical Research: Biogeosciences 124, 453-460. Receding permafrost may expose the largest store of sequestered carbon to microbes ready to convert it to greenhouse gases. The fluxes of biogenic gases associated with boreal wetlands have historically been difficult to measure, limiting our understanding of what may happen as permafrost thaws. The many difficulties in working in high-latitude climates have dramatically limited our understanding on the spatial and temporal distribution of fluxes and what is likely to change with a warming climate. The use of the eddy covariance approach to measure methane emissions has been developing steadily over the past 26?years. Taylor et al. (2018, ) is an excellent example of the advancements made in the field. Here I summarize the history of the eddy covariance methane literature, describe advancements in spatial and temporal coverage, and look at important drivers of methane emissions.Morrison, D., Robertson, D.K., 2019. Introduction to Icarus special papers on Tunguska. Icarus 327, 1-3.. The Tunguska Impact EventThe 1908 cosmic impact near the Stony Tunguska River in Siberia has intrigued the public and puzzled scientists for more than a century. This is the largest impact on the Earth in historic times, and the first such event to be attributed to the collision of a small comet or asteroid. The event was an airburst, with no known impact crater. Unfortunately, no fragments of the exploding body have been recovered, perhaps because it fell in a boggy area, and the first scientific survey was not carried out until two decades after the event. The data from which to reconstruct the event consist primarily of the distribution of fallen and burned trees, a handful of eyewitness accounts mostly from tens of kilometers distance, seismic records primarily from Irkutsk 1000 km distant, atmospheric pressure waves (infrasound) recorded at several stations, and an upper atmospheric phenomenon called white nights that persisted for several nights in northern Europe.In addition to its interest as a rare scientific phenomenon, Tunguska is important for understanding the hazard of cosmic impacts and planning possible mitigation strategies. The multimegaton explosion damaged more than a thousand hectares of forest and would have been sufficient, had it been differently targeted, to destroy a moderate sized city. The object was not detected before it hit, so we know little about its size or composition. Indeed, there has been a long-standing dispute whether it was a stony asteroid or an ice-rich comet. We know it struck with a speed of at least the Earth’s escape velocity of 11 km/sec. Together with estimates of the explosion energy (calibrated by comparison with nuclear bomb tests), this implies a diameter of as large as a hundred meters, with average intervals for such impacts of several centuries, but with large uncertainties. The smaller 2013 airburst of an asteroid over Chelyabinsk, Russia, has stimulated interest in better understanding both the Chelyabinsk and Tunguska impact events.2. The 2018 Tunguska WorkshopIn January 2018, a workshop at NASA Ames Research Center brought together approximately 50 experts on impact airbursts to re-examine the Tunguska event in the light of recent work on Chelyabinsk. Approximately half of the attendance, and three of the presentations, were virtual. Co-Chairs were Donovan Mathias and David Morrison of Ames Research Center. The papers in this issue of Icarus are derived in part from presentations at this workshop.The questions posed at the workshop included comparison between the Tunguska and Chelyabinsk airbursts, critical summaries of the limited data on the Tunguska event, and efforts to determine the nature of the impactor. In addition to weak seismic and infrasound signatures, the primary data are the tree-fall pattern and the topography of the site. A major source of uncertainty is the condition of the forest, and hence the wind-speeds necessary to topple trees. Several hydrocode computer models were discussed in detail, but without fully resolving differences. Interpretations should include thermal effects, which have not generally been used to constrain the airburst.The Workshop clarified the current status of airburst modeling. The results from four different computer codes were in general agreement, and they converged on a most likely (or least unlikely) energy for Tunguska in the range of 10-20 Mt, corresponding to a diameter of 50-70 m if a composition similar to Chelyabinsk is assumed, or a wider range if different compositions and entry velocities are considered. Interpretation in terms of the frequency of such strikes depends on the unknown properties (size and albedo) of the impactor, but suggests likely intervals between such impacts closer to a millennium rather than a century.The workshop was supported by the NASA Planetary Defense Coordination Office (PDCO) and Ames Research Center.3. Papers in this issueSeven papers in this issue, derived from presentations at the Tunguska Workshop, provide an overview of current work to understand the Tunguska event and its implications.Jenniskens et al. summarize the information from eyewitness accounts, injuries, and casualties, much of it collected 19 years or more after the Tunguska event. They identify at least 3 casualties and document strong shocks and broken glass out to 400 km from the impact.McMullan & Collins compare three semi-analytic atmospheric entry models of the Tunguska event. They find good agreement among the models, noting that the main uncertainties are in the assumed input parameters. They suggest the Tunguska airburst was at 5-10 km with a total energy release of 3-50 Mt, corresponding to a diameter for a stony impactor of 50-150 m.Robertson and Mathias use hydrocode models, concluding that the blast energy (most likely near 10 Mt) is constrained primarily by the tree-fall pattern, but with uncertainties introduced by assumptions about the tree wind resistance. They explore a wide range of impactor size, density, strength, and entry conditions, including both asteroids and comets.Johnston and Stern use thermal models of the radiative heating to the ground, including the roles of ablation and radiation on the shock-layer flowfield, to interpret the observed burn pattern as indicating (for nominal entry conditions) a probable impactor diameter of 60-90m.Artemieva et al. model possible dust trains (from ablation and fragmentation), plumes (condensed vapor), and atmospheric disturbances for the Chelyabinsk and Tunguska events. They conclude that the Tunguska plume could have lofted particles to altitude >100km, providing an explanation for the ‘white nights’ seen over northern Europe.In two papers, Wheeler and Mathias use hydrocode models to explore a wide range of impactor properties and assess the impact risks. In the case of Tunguska, we can determine (with uncertainties) the impactor mass and energy, but not pre-impact brightness, which is the reverse of the situation for asteroids observed astronomically. For Tunguska they suggest a stony impactor with nominal energy of 10-20 Mt, diameter 50-90 m, and burst altitude of 12-17 km. Considering a full range of possible parameters together with probabilities derived from asteroid statistics, they conclude that larger asteroids are more likely to cause Tunguska-scale damage, despite their lower impact frequencies.The convergence of a variety of models for the Tunguska event is encouraging (although the 2008 work by Boslough and Crawford remains at the low end of estimates.). What the models yield is basically the energy of the explosion, which can only be translated into impactor size with assumptions about the density and trajectory of the object. Estimating average recurrence intervals for such impacts is harder yet, since the astronomical surveys do not directly measure asteroid size or mass, and the population data for Tunguska-size impactors from these surveys is limited. While it is possible to estimate probable values, the uncertainties in impactor sizes and impact frequencies that match the Tunguska data are quite large. The addition of better knowledge of the health of the forest, and the use of burn data, should improve the Tunguska models in future, but are unlikely to greatly improve estimates of impact frequency for Tunguska-class events.TUNGUSKA BIBLIOGRAPHY of recent (post 1995) papers in EnglishMraz, E., Wolfgramm, M., Moeck, I., Thuro, K., 2019. Detailed fluid inclusion and stable isotope analysis on deep carbonates from the North Alpine Foreland Basin to constrain paleofluid evolution. Geofluids 2019, Article 8980794. recent interest on environmentally friendly energy resources has increased the economic interest on the Upper Jurassic carbonate rocks in the North Alpine Foreland Basin, which serves as a hydrogeothermal reservoir. An economic reservoir use by geothermal fluid extraction and injection requires a decent understanding of porosity–permeability evolution of the deep laying Upper Jurassic strata at depths greater than 2000?m. The analysis of paleofluids caught in cements of the rock mass helps to determine the postdepositional reservoir evolution and fluid migration. Therefore, the high- and low-permeability areas of the Upper Jurassic in the North Alpine Foreland Basin referred to as Molasse Basin were analyzed by means of encountered postdepositional cements to determine the reservoir evolution. The cements were sampled at different hydrocarbon and geothermal wells, as well as at outcrops in the Franconian and Swabian Alb. To determine the composition and temperature of the paleofluids, fluid inclusions and cements of the Upper Jurassic carbonate rocks were analyzed by microthermometry and stable isotope measurements. Since drill cuttings are a rather available sample material compared to drill cores, a new microthermometry measurement method was achieved for the around 1?mm drill cuttings. Salinity and formation temperature of paleofluids in fluid inclusions and isotope data are consistent with previous studies and reveal a 5-stage evolution: the main cementation phases are composed of (I) the early diagenesis in limestones (200-400?m, 40-50°C), (II) early diagenetic dolomitization, and (III) burial dolomitization (1-2?km, II: 40-90°C; III: 70-100°C; 40?g/L NaCl equiv.), and (IV) late burial calcification (IIIa: 110-140°C, IIIb: 140-200°C) linked to tectonic features in the Molasse Basin. In the outcrop samples, a subsequent (V) cementation phase was determined controlled by karstification. In the southwest, an increase in salinity of the fluid inclusions in vein calcites, above the salinity of the Jurassic seawater, highlights the influence of basin fluids (diagenetic, evaporitic). In the other eastern wells, vein calcites have precipitated from a low saline fluid of around 10-20?g/L NaCl equiv. The low salinity and the isotope values support the theory of a continuous influence of descending meteoric fluids. Consequently, the Upper Jurassic seawater has been diluted by a meteoric fluid to a low saline fluid (<1?g/L), especially in areas with high permeability. Here, we show how a better understanding of cementation trajectory at depth can help to generate a better understanding of geothermal usability in deep carbonate reservoirs.Mu?oz-Velasco, I., García-Ferris, C., Hernandez-Morales, R., Lazcano, A., Peretó, J., Becerra, A., 2018. Methanogenesis on early stages of life: Ancient but not primordial. Origins of Life and Evolution of Biospheres 48, 407-420. the six known autotrophic pathways, the Wood-Ljungdahl pathway (WL) is the only one present in both the acetate producing Bacteria (homoacetogens) and the methane producing Archaea (hydrogenotrophic methanogens), and it has been suggested that WL is one of the oldest metabolic pathways. However, only the so-called carbonyl branch is shared by Archaea and Bacteria, while the methyl branch is different, both in the number of reactions and enzymes, which are not homologous among them. In this work we show that some parts of the methyl branch of archaeal Wood-Ljungdahl pathway (MBWL) are present in bacteria as well as in non-methanogen archaea, although the tangled evolutionary history of MBWL cannot be traced back to the Last Common Ancestor. We have also analyzed the different variants of methanogenesis (hydrogenotrophic, acetoclastic and methylotrophic pathways), and concluded that each of these pathways, and every different enzyme or subunit (in the case of multimeric enzymes), has their own intricate evolutionary history. Our study supports the scenario of hydrogenotrophic methanogenesis being older than the other variants, albeit not old enough to be present in the last archaeal common ancestor.Murase, J., Sugimoto, A., Shingubara, R., Morozumi, T., Takano, S., Maximov, T.C., 2019. Methane oxidation potential of the arctic wetland soils of a taiga-tundra ecotone in northeastern Siberia. Biogeosciences Discussions 2019, 1-28. wetlands are significant sources of atmospheric methane and the observed accelerated climate changes in the arctic could cause the change in methane dynamics, where methane oxidation would be the key process to control methane emission from wetlands. In this study we determined the potential methane oxidation rate of the wetland soils of a taiga-tundra transition zone in northeastern Siberia. Peat soil samples were collected in summer from depressions covered with tussocks of sedges and Sphagnum spp. and from mounds vegetated with moss and larch trees. A bottle incubation experiment demonstrated that the soil samples collected from depressions in the moss- and sedge-dominated zones exhibited active methane oxidation with no time lag. The potential methane oxidation rates at 15?°C ranged from 94 to 496?nmol?h?1?g?1?dw. Methane oxidation was observed over the depths studied (0–40?cm) including the water-saturated anoxic layers. The maximum methane oxidation rate was recorded in the layer above the water-saturated layer: the surface (0–2?cm) layer in the sedge-dominated zone and in the middle (4–6?cm) layer in the moss-dominated zone. The methane oxidation rate was temperature-dependent, and the threshold temperature of methane oxidation was estimated to be ?4 to ?11?°C, which suggested methane oxidation at subzero temperatures. Soil samples collected from the frozen layer of Sphagnum peat also showed immediate methane consumption when incubated at 15?°C. The present results suggest that the methane oxidizing bacteria in the wetland soils keep their potential activities even under anoxic and frozen conditions and immediately utilize methane when the conditions become favorable. On the other hand, the inhibitor of methane oxidation did not affect the methane flux from the sedge and moss zones in situ, which indicated the minor role of plant-associated methane oxidation.Murray, J., Prouty, N.G., Peek, S., Paytan, A., 2019. Coral skeleton δ15N as a tracer of historic nutrient loading to a coral reef in Maui, Hawaii. Scientific Reports 9, Article 5579. nutrient loading to nearshore environments has been linked to declining water quality and ecosystem health. Macro-algal blooms, eutrophication, and reduction in coral cover have been observed in West Maui, Hawaii, and linked to nutrient inputs from coastal submarine groundwater seeps. Here, we present a forty-year record of nitrogen isotopes (δ15N) of intra-crystalline coral skeletal organic matter in three coral cores collected at this site and evaluate the record in terms of changes in nitrogen sources. Our results show a dramatic increase in coral δ15N values after 1995, corresponding with the implementation of biological nutrient removal at the nearby Lahaina Wastewater Reclamation Facility (LWRF). High δ15N values are known to be strongly indicative of denitrification and sewage effluent, corroborating a previously suggested link between local wastewater injection and degradation of the reef environment. This record demonstrates the power of coral skeletal δ15N as a tool for evaluating nutrient dynamics within coral reef environments.Mustafin, R.N., 2019. The relationship between transposons and transcription factors in the evolution of eukaryotes. Journal of Evolutionary Biochemistry and Physiology 55, 14-23. are important sources of binding sites for transcription factors whose specific activation characterizes the embryonic development of animals. In the evolution of eukaryotes, molecular domestication of the mobile genetic elements led to the emergence of multiple novel proteins, including the transcription factors involved in the control over cell differentiation. Transposons are presented abundantly in intergenic DNA, introns and 3’-untranslated regions, specifically, near the genes of the transcription factors which they regulate. This promotes gene interregulation via transposon activation by the products of their expression in consecutive divisions of stem cells, thus representing a dynamic biological encoding of the species-specific ontogenetic regulation. This program can be implemented due to tissue- and stage-specific regulation mediated by the presence of transposons at certain genomic sites. The crucial role of domesticated transposon genes in controlling genome operation and key developmental stages provides a sound argument in favor of this assumption. Russian Text ? R.N. Mustafin, 2019, published in Zhurnal Evolyutsionnoi Biokhimii i Fiziologii, 2019, Vol. 55, No. 1, pp. 14–22.Naik, R., Araujo, J., Pratihary, A., Kurian, S., Naqvi, S.W.A., 2019. Sedimentary sulphate reduction and organic matter mineralization across salinity gradient of the Mandovi Estuary, West coast of India. Estuarine, Coastal and Shelf Science 221, 21-29. Mandovi Estuary, located along the tropical west coast of India, transforms from being a freshwater-dominated body during the monsoon season to a tide-dominated system during post-monsoon season, with a salinity gradient developing from the freshwater end to the estuarine mouth (～0–33). The sulphate reduction (SR) rates were measured by the 35SO42? radiotracer method in the estuarine sediments at three different sites. The porewater H2S concentrations were negligible at all the sites and SR rates did not exhibit any clear trend along the salinity gradient. Pyrite content (3.45–12.9?mg?g?1) was the highest at the marine end and decreased towards the freshwater end. The SR rate (15.71?mmol?m?2 d?1) and total Fe content (14–20%) were highest in sediments of mid-estuary with intermediate salinity and variable porosity. Organic carbon (OC) mineralization rate through SR also did not show any trend along the salinity gradient with intermediate salinity site having higher values (31.83?mmol?C m2 d?1) compared to other sites (3.12–8.62?mmol?C m2 d?1). SR was responsible for ～8–50% of sedimentary OC mineralization implying that OC mineralization through Fe (III) and Mn (IV) reduction possibly played major role owing to their high concentrations in the estuarine sediments.Nakagawa, R., Nakai, S.i., Miyakoshi, T., Honda, T., 2019. Materials and provenance determination of lacquerware from the Ryukyu Kingdom period by pyrolysis-gas chromatography/mass spectrometry and 87Sr/86Sr isotope ratio. Journal of Archaeological Science: Reports 25, 72-76. wood chips found in a wooden coffin discovered in the Mumujyana graves of the Ryukyu Kingdom period were analyzed by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), and the 87Sr/86Sr isotope ratio of one piece was measured by multi-collector inductively coupled plasma mass spectrometry to determine the materials used to produce the lacquerware and their provenance. Results from the derivative Py-GC/MS indicate that the lacquer was produced from sap of both Toxicodendron vernicifluum, which grows in eastern Asia, and Toxicodendron succedaneum, which grows in southeastern Asia. The 87Sr/86Sr isotope ratios of the film layer and wooden base of one large chip, which is considered to be a stripped piece of the wooden coffin, were <0.710. The Sr concentration of the film layer, however, was 35.0?ppm, significantly higher than that of raw lacquer sap. It is possible that the Sr isotope ratios of the film layer reflect that of a black pigment observed by cross-section analysis. From the 87Sr/86Sr ratios of two parts of the chip, it is likely that the lacquer painting was done where the black pigment and wood were available. It is likely that the wooden coffin was constructed on the main islands of Japan. Meanwhile, the presence of a chip lacquered with Toxicodendron succedaneum demonstrates that the Ryukyu Kingdom had diverse trade relationships with surrounding countries.Nemirovskaya, I.A., Onegina, V.D., Lisitzin, A.P., Konovalov, B.V., 2019. Origin of hydrocarbons in suspended matter and bottom sediments near the Crimean Peninsula. Doklady Earth Sciences 484, 189-193. study of hydrocarbons has shown that their content in the surface water of Feodosiya Gulf varies greatly (from 11 to 179 ?g/L) and sometimes exceeds the maximal permissible concentration (MPC) for oil hydrocarbons. Their greatest concentrations were revealed in 2016. Alkanes were of mixed autochthonous and allochthonous origin. Weathered oil hydrocarbons were revealed only in some samples. The content of hydrocarbons in bottom sediments depended on their granulometric composition, and they were dominated by terrigenous alkanes. Oil and pyrogenic hydrocarbons were revealed as components of polycyclic aromatic hydrocarbons. In an open part of the Black Sea to the south of the Crimean Peninsula, the content of hydrocarbons in the surface water and bottom sediments was at the level of background concentration, and they were dominated by terrigenous homologues.Nesheim, T.O., 2019. Examination of downward hydrocarbon charge within the Bakken-Three Forks petroleum system – Williston Basin, North America. Marine and Petroleum Geology 104, 346-360. Bakken and Three Forks Formations of the Williston Basin have been targeted by over 10,000 unconventional style wells (horizontal drilling coupled with hydraulic fracturing). Exploration and developmental drilling initially focused on the Middle Bakken but later expanded into the underlying upper Three Forks (located directly below the Bakken) and eventually the middle and lower Three Forks, which are positioned 10s to 100 + feet below the Bakken. Hydrocarbons (oil and associated gas) within both formations are believed to be sourced from the upper and lower Bakken shale members, which are both highly organic-rich (>10% TOC), thermally mature petroleum source beds. However, minimal literature exists examining the relationship between hydrocarbons generated by the lower Bakken shale and expelled downward into the various reservoirs of the Three Forks.Core-plug oil and water saturation data from 65 partial to complete Three Forks cores were utilized to map out fluid saturation trends within the upper, middle, and lower Three Forks. Over 500 core chip analyses from 52 cores were used to spatially delineate the present day average hydrogen index (thermal maturity) of the lower Bakken shale while a lower shale isopach map was created from wireline logs of 240 wells. Lastly, the geochemical and standard core-plug data from four complete Bakken-Three Forks cores were used to calculate and compare the volumetric amount of oil generated and expelled from the lower Bakken shale with the original oil in place (OOIP) of the entire Three Forks section.The results show a strong spatial relationship between increased thickness-thermally maturity of the lower Bakken shale and increased core-plug oil saturations across the upper to middle Three Forks members, and a similar, but less pronounced relationship with the lower Three Forks. The calculated lower Bakken shale expelled oil volumes ranged from 13 to 51 million barrels of oil (MMBO) per section (640 acres) which overall equaled to exceeded the OOIP of the entire Three Forks section (9–25 MMBO/section). These spatial and volumetric relationships indicate that local hydrocarbon generation and expulsion from the lower Bakken shale is the primary control for hydrocarbon charge within the underlying Three Forks Formation, where in some locations hydrocarbons have been pushed downwards 200 + ft. Understanding downward hydrocarbon charge has implications in exploring for and developing hydrocarbon resources within the Bakken-Three Forks as well as numerous other unconventional petroleum tersheim, B.J., Brocks, J.J., Schwelm, A., Hope, J.M., Not, F., Lomas, M., Schmidt, C., Schiebel, R., Nowack, E.C.M., De Deckker, P., Pawlowski, J., Bowser, S.S., Bobrovskiy, I., Zonneveld, K., Kucera, M., Stuhr, M., Hallmann, C., 2019. Putative sponge biomarkers in unicellular Rhizaria question an early rise of animals. Nature Ecology & Evolution 3, 577-581. dawn of animals remains one of the most mysterious milestones in the evolution of life. The fossil lipids 24-isopropylcholestane and 26-methylstigmastane are considered diagnostic for demosponges—arguably the oldest group of living animals. The widespread occurrence and high relative abundance of these biomarkers in Ediacaran sediments from 635–541 million years (Myr) ago have been viewed as evidence for the rise of animals to ecological importance approximately 100?Myr before their rapid Cambrian radiation. Here we show that the biosynthesis of 24-isopropylcholestane and 26-methylstigmastane precursors is common among early-branching unicellular Rhizaria—heterotrophic protists that play an important role in trophic cycling and carbon export in the modern ocean. Negating these hydrocarbons as sponge biomarkers, our study places the oldest evidence for animals closer to the Cambrian Explosion. Cambrian silica hexactine spicules that are approximately 535?Myr old now represent the oldest diagnostic sponge remains, whereas approximately 558-Myr-old Dickinsonia and Kimberella (Ediacara biota) provide the most reliable evidence for the emergence of animals. The proliferation of predatory protists may have been responsible for much of the ecological changes during the late Neoproterozoic, including the rise of algae, the establishment of complex trophic relationships and the oxygenation of shallow-water habitats required for the subsequent ascent of macroscopic animals.Nguyen, D.T., Fujihara, A., 2018. Chiral recognition in cold gas-phase cluster ions of carbohydrates and tryptophan probed by photodissociation. Origins of Life and Evolution of Biospheres 48, 395-406. recognition between tryptophan (Trp) and carbohydrates such as D-glucose (D-Glc), methyl-α-D-glucoside (D-glucoside), D-maltose, and D-cellobiose in cold gas-phase cluster ions was investigated as a model for chemical evolution in interstellar molecular clouds using a tandem mass spectrometer containing a cold ion trap. The photodissociation mass spectra of cold gas-phase clusters that contained Na+, Trp enantiomers, and d-maltose showed that Na+(D-Glc) was formed via the glycosidic bond cleavage of D-maltose from photoexcited homochiral Na+(D-Trp)(D-maltose), while the dissociation did not occur in heterochiral Na+(L-Trp)(D-maltose). The enantiomer-selective dissociation was also observed in the case of D-cellobiose. The enantiomer-selective glycosidic bond cleavage of disaccharides suggested that photoexcited D-Trp could prevent chemical evolution of sugar chains from D-enantiomer of carbohydrates in molecular clouds. The spectra of gas-phase clusters that contained Na+, Trp enantiomers, and D-Glc indicated that enantiomer-selective protonation of L-Trp from D-Glc could induce enantiomeric excess via collision-activated dissociation of the protonated L-Trp. In the case of protonated clusters, photoexcited H+(L-Trp) dissociated via Cα–Cβ bond cleavage in the presence of D-Glc or D-glucoside, where the excited states of H+(L-Trp) contributed to the enantiomer-selective reaction in the clusters. These enantiomer selectivities in cold gas-phase clusters indicated that chirality of a molecule induced enantiomeric excess of other molecules via enantiomer-selective reactions in molecular clouds.Nguyen, K., Love, G.D., Zumberge, J.A., Kelly, A.E., Owens, J.D., Rohrssen, M.K., Bates, S.M., Cai, C., Lyons, T.W., 2019. Absence of biomarker evidence for early eukaryotic life from the Mesoproterozoic Roper Group: Searching across a marine redox gradient in mid-Proterozoic habitability. Geobiology 17, 247-260. about 2.0 billion years ago (Ga), there is evidence for a period best known for its extended, apparent geochemical stability expressed famously in the carbonate–carbon isotope data. Despite the first appearance and early innovation among eukaryotic organisms, this period is also known for a rarity of eukaryotic fossils and an absence of organic biomarker fingerprints for those organisms, suggesting low diversity and relatively small populations compared to the Neoproterozoic era. Nevertheless, the search for diagnostic biomarkers has not been performed with guidance from paleoenvironmental redox constrains from inorganic geochemistry that should reveal the facies that were most likely hospitable to these organisms. Siltstones and shales obtained from drill core of the ca. 1.3–1.4 Ga Roper Group from the McArthur Basin of northern Australia provide one of our best windows into the mid‐Proterozoic redox landscape. The group is well dated and minimally metamorphosed (of oil window maturity), and previous geochemical data suggest a relatively strong connection to the open ocean compared to other mid‐Proterozoic records. Here, we present one of the first integrated investigations of Mesoproterozoic biomarker records performed in parallel with established inorganic redox proxy indicators. Results reveal a temporally variable paleoredox structure through the Velkerri Formation as gauged from iron mineral speciation and trace‐metal geochemistry, vacillating between oxic and anoxic. Our combined lipid biomarker and inorganic geochemical records indicate at least episodic euxinic conditions sustained predominantly below the photic zone during the deposition of organic‐rich shales found in the middle Velkerri Formation. The most striking result is an absence of eukaryotic steranes (4‐desmethylsteranes) and only traces of gammacerane in some samples—despite our search across oxic, as well as anoxic, facies that should favor eukaryotic habitability and in low maturity rocks that allow the preservation of biomarker alkanes. The dearth of Mesoproterozoic eukaryotic sterane biomarkers, even within the more oxic facies, is somewhat surprising but suggests that controls such as the long‐term nutrient balance and other environmental factors may have throttled the abundances and diversity of early eukaryotic life relative to bacteria within marine microbial communities. Given that molecular clocks predict that sterol synthesis evolved early in eukaryotic history, and (bacterial) fossil steroids have been found previously in 1.64 Ga rocks, then a very low environmental abundance of eukaryotes relative to bacteria is our preferred explanation for the lack of regular steranes and only traces of gammacerane in a few samples. It is also possible that early eukaryotes adapted to Mesoproterozoic marine environments did not make abundant steroid lipids or tetrahymanol in their cell membranes.Nguyen, M.-T., Pirngruber, G.D., Chainet, F., Albrieux, F., Tayakout-Fayolle, M., Geantet, C., 2019. Molecular-level insights into coker/straight-run gas oil hydrodenitrogenation by Fourier transform ion cyclotron resonance mass spectrometry. Energy & Fuels 33, 3034-3046. paper aims to understand the reactivity of different nitrogen species during the catalytic hydrodenitrogenation (HDN) of a mixture of straight-run gas oil and coker gas oil. Effluents at different HDN conversions were analyzed by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR/MS), with electrospray ionization (ESI). Positive ESI (ESI(+)) allows a selective ionization of basic nitrogen compounds, whereas negative ESI (ESI(?)) leads to selective ionization of neutral nitrogen compounds. FT-ICR/MS in ESI(+) or (?) mode generates distributions of the nitrogen compounds in the basic and neutral class, respectively, according to their carbon number and double bond equivalent (DBE), which is related to the degree of aromaticity and the number of rings. The evolution of the DBE distribution and the carbon number distribution as a function of HDN conversion gives rich information concerning the main reaction pathways and the reactivity of different nitrogen species. For the basic compounds, a shift to a lower DBE was observed, which was interpreted as the formation of partially hydrogenated or ring-opened intermediates. These intermediates were then slowly converted to the final HDN products. At intermediate conversion levels, especially light compounds were accumulated as intermediates whereas the heavy compounds were directly converted to HDN products, probably due to preferential adsorption. The neutral compounds showed a very different behavior. At the early reaction stages, they were quickly converted to HDN products, but at high conversion, the conversion of residual carbazole and tetrahydrobenzocarbazole compounds was completely inhibited. The inhibition was probably provoked by the formation of partially hydrogenated basic intermediates, which were stronger inhibitors than the aromatic pyridine rings in the feed. The contribution of cracking reactions was weak, since the overall carbon number distribution of the nitrogen compounds did not change much during hydrotreatment.Niederberger, T.D., Bottos, E.M., Sohm, J.A., Gunderson, T., Parker, A., Coyne, K.J., Capone, D.G., Carpenter, E.J., Cary, S.C., 2019. Rapid microbial dynamics in response to an induced wetting event in Antarctic dry valley soils. Frontiers in Microbiology 10, 621. doi: 610.3389/fmicb.2019.00621. cold deserts of the McMurdo Dry Valleys (MDV), Antarctica, host a high level of microbial diversity. Microbial composition and biomass in arid vs. ephemerally wetted regions are distinctly different, with wetted communities representing hot spots of microbial activity that are important zones for biogeochemical cycling. While climatic change is likely to cause wetting in areas not historically subject to wetting events, the responses of microorganisms inhabiting arid soils to water addition is unknown. The purpose of this study was to observe how an associated, yet non-wetted microbial community responds to an extended addition of water. Water from a stream was diverted to an adjacent area of arid soil with changes in microbial composition and activities monitored via molecular and biochemical methods over seven weeks. The frequency of genetic signatures related to both prokaryotic and eukaryotic organisms adapted to MDV aquatic conditions increased during the limited seven week period, indicating that the soil community was transitioning into a typical “high-productivity” MDV community. This work is consistent with current predictions that MDV microbial communities in arid regions are highly sensitive to climate change, and further supports the notion that changes in community structure and associated biochemical cycling may occur much more rapidly than predicted.Niezgodzki, I., Tyszka, J., Knorr, G., Lohmann, G., 2019. Was the Arctic Ocean ice free during the latest Cretaceous? The role of CO2 and gateway configurations. Global and Planetary Change 177, 201-212. Arctic region is thought to play a key role in unraveling Mesozoic climate evolution. However, Late Cretaceous climate reconstructions in the high latitudes suffer from contradicting paleoclimatic interpretations. Toward the end of the Cretaceous hot-house, atmospheric CO2 concentration declined potentially enabling the formation of sea-ice in the Arctic Ocean. We use a coupled atmosphere-ocean climate model to investigate possible effects of different atmospheric CO2 levels and gateway configurations between the North proto-Atlantic Basin and the Arctic Ocean on the formation of Arctic sea-ice in the latest Cretaceous. Sensitivity tests were run with two atmospheric CO2 levels (840 and 1120?ppm, representing 3× and 4× pre-industrial concentrations, respectively) with six paleogeographic configurations. In the experiment with 840?ppm CO2, seasonal Arctic sea-ice is observed in each gateway configuration in December–June, while for 1120?ppm sea-ice in the central Arctic is either limited or absent, depending on gateway configuration. This suggests the existence of a CO2 threshold, estimated between 3× and 4× pre-industrial (PI) CO2 levels. For higher atmospheric CO2 levels sea-ice formation can only occur by the combined effect of cold winds blowing over the Arctic from continental North America during boreal winter and seawater freshening. The latter can be caused by either very limited or an absence of gateway connections between the Arctic and the open ocean. Such a configuration likely developed in the latest Cretaceous, i.e. close to the Cretaceous/Paleogene boundary interval.Nisbet, E.G., Manning, M.R., Dlugokencky, E.J., Fisher, R.E., Lowry, D., Michel, S.E., Myhre, C.L., Platt, S.M., Allen, G., Bousquet, P., Brownlow, R., Cain, M., France, J.L., Hermansen, O., Hossaini, R., Jones, A.E., Levin, I., Manning, A.C., Myhre, G., Pyle, J.A., Vaughn, B.H., Warwick, N.J., White, J.W.C., 2019. Very strong atmospheric methane growth in the 4?years 2014–2017: Implications for the Paris Agreement. Global Biogeochemical Cycles 33, 318-342.: Atmospheric methane grew very rapidly in 2014 (12.7 ± 0.5 ppb/year), 2015 (10.1 ± 0.7 ppb/year), 2016 (7.0 ± 0.7 ppb/year), and 2017 (7.7 ± 0.7 ppb/year), at rates not observed since the 1980s. The increase in the methane burden began in 2007, with the mean global mole fraction in remote surface background air rising from about 1,775 ppb in 2006 to 1,850 ppb in 2017. Simultaneously the 13C/12C isotopic ratio (expressed as δ13CCH4) has shifted, has shifted, now trending negative for more than a decade. The causes of methane's recent mole fraction increase are therefore either a change in the relative proportions (and totals) of emissions from biogenic and thermogenic and pyrogenic sources, especially in the tropics and subtropics, or a decline in the atmospheric sink of methane, or both. Unfortunately, with limited measurement data sets, it is not currently possible to be more definitive. The climate warming impact of the observed methane increase over the past decade, if continued at >5 ppb/year in the coming decades, is sufficient to challenge the Paris Agreement, which requires sharp cuts in the atmospheric methane burden. However, anthropogenic methane emissions are relatively very large and thus offer attractive targets for rapid reduction, which are essential if the Paris Agreement aims are to be attained.Plain Language Summary: The rise in atmospheric methane (CH4), which began in 2007, accelerated in the past 4 years. The growth has been worldwide, especially in the tropics and northern midlatitudes. With the rise has come a shift in the carbon isotope ratio of the methane. The causes of the rise are not fully understood, and may include increased emissions and perhaps a decline in the destruction of methane in the air. Methane's increase since 2007 was not expected in future greenhouse gas scenarios compliant with the targets of the Paris Agreement, and if the increase continues at the same rates it may become very difficult to meet the Paris goals. There is now urgent need to reduce methane emissions, especially from the fossil fuel industry.Nouara, A., Panagiotopoulos, C., Balesdent, J., Violaki, K., Bard, E., Fagault, Y., Repeta, D.J., Sempéré, R., 2019. Liquid chromatographic isolation of individual carbohydrates from environmental matrices for stable carbon analysis and radiocarbon dating. Analytica Chimica Acta 1067, 137-146. are among the most abundant organic molecules in both aquatic and terrestrial ecosystems; however, very few studies have addressed their isotopic signature using compound-specific isotope analysis, which provides additional information on their origin (δ13C) and fate (Δ14C). In this study, semi-preparative liquid chromatography with refractive index detection (HPLC-RI) was employed to produce pure carbohydrate targets for subsequent offline δ13C and Δ14C isotopic analysis. δ13C analysis was performed by elemental analyzer-isotope ratio mass spectrometer (EA-IRMS) whereas Δ14C analysis was performed by an innovative measurement procedure based on the direct combustion of the isolated fractions using an elemental analyzer coupled to the gas source of a mini carbon dating system (AixMICADAS). In general, four successive purifications with Na+, Ca2+, Pb2+, and Ca2+ cation-exchange columns were sufficient to produce pure carbohydrates. These carbohydrates were subsequently identified using mass spectrometry by comparing their mass spectra with those of authentic standards. The applicability of the proposed method was tested on two different environmental samples comprising marine particulate organic matter (POM) and total suspended atmospheric particles (TSP). The obtained results revealed that for the marine POM sample, the δ13C values of the individual carbohydrates ranged from??18.5 to??16.8‰, except for levoglucosan and mannosan, which presented values of??27.2 and??26.2‰, respectively. For the TSP sample, the δ13C values ranged from??26.4 to??25.0‰. The galactose and glucose Δ14C values were 19 and 43‰, respectively, for the POM sample. On the other hand, the levoglucosan radiocarbon value was 33‰ for the TSP sample. These results suggest that these carbohydrates exhibit a modern age in both of these samples. Radiocarbon HPLC collection window blanks, measured after the addition of phthalic acid (14C free blank), ranged from??988 to??986‰ for the abovementioned compounds, indicating a very small background isotopic influence from the whole purification procedure. Overall, the proposed method does not require derivatization steps, produces extremely low blanks, and may be applied to different types of environmental samples.Noutahi, E., El-Mabrouk, N., Calderon, V., Blanchette, M., Lang, B.F., 2019. Rapid genetic code evolution in green algal mitochondrial genomes. Molecular Biology and Evolution 36, 766-783. code deviations involving stop codons have been previously reported in mitochondrial genomes of several green plants (Viridiplantae), most notably chlorophyte algae (Chlorophyta). However, as changes in codon recognition from one amino acid to another are more difficult to infer, such changes might have gone unnoticed in particular lineages with high evolutionary rates that are otherwise prone to codon reassignments. To gain further insight into the evolution of the mitochondrial genetic code in green plants, we have conducted an in-depth study across mtDNAs from 51 green plants (32 chlorophytes and 19 streptophytes). Besides confirming known stop-to-sense reassignments, our study documents the first cases of sense-to-sense codon reassignments in Chlorophyta mtDNAs. In several Sphaeropleales, we report the decoding of AGG codons (normally arginine) as alanine, by tRNA(CCU) of various origins that carry the recognition signature for alanine tRNA synthetase. In Chromochloris, we identify tRNA variants decoding AGG as methionine and the synonymous codon CGG as leucine. Finally, we find strong evidence supporting the decoding of AUA codons (normally isoleucine) as methionine in Pycnococcus. Our results rely on a recently developed conceptual framework (CoreTracker) that predicts codon reassignments based on the disparity between DNA sequence (codons) and the derived protein sequence. These predictions are then validated by an evaluation of tRNA phylogeny, to identify the evolution of new tRNAs via gene duplication and loss, and structural modifications that lead to the assignment of new tRNA identities and a change in the genetic code.Novikov, E.A., Sergeev, Y.A., Sanzharov, V.V., Safieva, R.Z., Vinokurov, V.A., 2019. Application of multidimensional analysis methods to dead oil characterization on the basis of data on thermal field-flow fractionation of native asphaltene nanoparticles. Petroleum Chemistry 59, 34-47. distribution curves of native nanoasphaltenes in the form of fractograms for a significant sample of crude oils have been obtained using the thermal field-flow fractionation of asphaltenes, and a multidimensional analysis of the fractionation data has been carried out in order to construct calibration models for predicting the physicochemical properties of the studied oils.Nsibande, S.A., Montaseri, H., Forbes, P.B.C., 2019. Advances in the application of nanomaterial-based sensors for detection of polycyclic aromatic hydrocarbons in aquatic systems. TrAC Trends in Analytical Chemistry 115, 52-69. aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants which are of health concern. It is therefore not surprising that there has been significant research interest in developing sensitive and cost effective strategies for monitoring these compounds. Here we provide an update on applications of various nanomaterials and nanocomposites in the detection and quantification of PAHs in water. Advances in synthesis and tailoring of functional nanomaterials has allowed for their use in fluorescence spectrophotometry, surface-enhanced Raman spectrometry (SERS), and in electrochemical based sensor systems for different analytical applications. This can be attributed to their extensive tunability. Finally, we discuss future prospects on the role of nanoscience in PAH analysis and highlight the need to move towards the development of portable devices based on these nanomaterials for field analysis. This review thus gives an overview of a number of alternative methods to chromatography based analysis of PAHs.Nyberg, B., Helland-Hansen, W., Klausen, T.G., 2019. The largest delta plain in Earth’s history. Geology 47, 470-474. plains host heavily populated and extensive agricultural areas with strong anthropogenic overprints on the natural evolution of these important landforms. Furthermore, modern delta plains have formed over a short geological time frame, representing immature end members to ancient counterparts in Earth’s history—it could thus be argued that these are poor analogues for deciphering the sedimentary rock record. Our present study offers unique insight into the controls and potential extent of ancient deltas by investigation of the Triassic Boreal Ocean, where a large delta plain has been traced across >1.65 × 106 km2. We show by comparison that the Triassic Boreal Ocean delta plain is larger than all modern and known ancient counterparts. Supply-driven progradation of this delta system proceeded uninterrupted on a 106 yr scale, indicating relative sea-level stability during this period—in support of a Triassic Greenhouse without pronounced glaciations. Reconstructed paleo-bathymetric relief shows the Triassic Boreal Ocean to have been one order of magnitude smaller than modern equivalents, explaining its vast extent. Despite its extent, the delta plain shows similar geomorphological characteristics to many modern delta plains, supporting their validity as analogues to the ancient, although scales might vary significantly.Oliveros, C.H., Field, D.J., Ksepka, D.T., Barker, F.K., Aleixo, A., Andersen, M.J., Alstr?m, P., Benz, B.W., Braun, E.L., Braun, M.J., Bravo, G.A., Brumfield, R.T., Chesser, R.T., Claramunt, S., Cracraft, J., Cuervo, A.M., Derryberry, E.P., Glenn, T.C., Harvey, M.G., Hosner, P.A., Joseph, L., Kimball, R.T., Mack, A.L., Miskelly, C.M., Peterson, A.T., Robbins, M.B., Sheldon, F.H., Silveira, L.F., Smith, B.T., White, N.D., Moyle, R.G., Faircloth, B.C., 2019. Earth history and the passerine superradiation. Proceedings of the National Academy of Sciences 116, 7916-7925.: Our understanding of the factors that affected the diversification of passerines, the most diverse and widespread bird order (Passeriformes), is limited. Here, we reconstruct passerine evolutionary history and produce the most comprehensive time-calibrated phylogenetic hypothesis of the group using extensive sampling of the genome, complete sampling of all passerine families, and a number of vetted fossil calibration points. Our phylogenetic results refine our knowledge of passerine diversity and yield divergence dates that are consistent with the fossil record, and our macroevolutionary analyses suggest that singular events in Earth history, such as increases in Cenozoic global temperature or the colonization of new continents, were not the primary forces driving passerine diversification.Abstract: Avian diversification has been influenced by global climate change, plate tectonic movements, and mass extinction events. However, the impact of these factors on the diversification of the hyperdiverse perching birds (passerines) is unclear because family level relationships are unresolved and the timing of splitting events among lineages is uncertain. We analyzed DNA data from 4,060 nuclear loci and 137 passerine families using concatenation and coalescent approaches to infer a comprehensive phylogenetic hypothesis that clarifies relationships among all passerine families. Then, we calibrated this phylogeny using 13 fossils to examine the effects of different events in Earth history on the timing and rate of passerine diversification. Our analyses reconcile passerine diversification with the fossil and geological records; suggest that passerines originated on the Australian landmass ～47 Ma; and show that subsequent dispersal and diversification of passerines was affected by a number of climatological and geological events, such as Oligocene glaciation and inundation of the New Zealand landmass. Although passerine diversification rates fluctuated throughout the Cenozoic, we find no link between the rate of passerine diversification and Cenozoic global temperature, and our analyses show that the increases in passerine diversification rate we observe are disconnected from the colonization of new continents. Taken together, these results suggest more complex mechanisms than temperature change or ecological opportunity have controlled macroscale patterns of passerine speciation.Olsen, J.E., Krause, D.F., Davies, E.J., Skjetne, P., 2019. Observations of rising methane bubbles in Trondheimsfjord and its implications to gas dissolution. Journal of Geophysical Research: Oceans 124, 1399-1409.: Gas dissolution reduces the release of methane to the atmosphere from subsea sources. Being able to predict and assess the methane flux to the atmosphere requires knowledge on gas dissolution and mass transfer. This can be obtained by studying the size evolution of bubbles rising in water. New data of bubble size evolution have been obtained by releasing, tracking, and filming methane bubbles with an ROV in the Trondheimsfjord from depths varying between 100 and 300 m. Released bubbles had an initial diameter between 5 and 7 mm and were tracked until they reached a diameter of roughly 2 mm. The new data were compared against theory, applying established correlations for the mass transfer coefficient. There was an inconsistency between experiment and theory. Thus, new correlations for the mass transfer are proposed. The new correlations are consistent with both the new experiments and previously published experiments. They indicate that the conditions in the ocean can be labeled as partly contaminated with respect to mass transfer.Plain Language Summary: Methane bubbles released from the ocean can reach the atmosphere and affect the methane concentration in the atmosphere. Methane is a potent greenhouse gas and highly combustible. How much gas enters the atmosphere depends on how much gas is dissolved in the ocean. The shrinking of bubbles and the development of bubble size are signatures of the gas dissolution. There is a lack of knowledge on methane dissolution in seawater. An experiment outside Trondheim, Norway, has been conducted where an ROV released methane bubbles and recorded images of the bubbles as they rose upward. These images have been analyzed to shed light on gas dissolution.Onishchenko, Y.V., Vakhin, A.V., Gareev, B.I., Batalin, G.A., Morozov, V.P., Eskin, A.A., 2019. The material balance of organic matter of Domanic shale formation after thermal treatment. Petroleum Science and Technology 37, 756-762. this paper, we discuss the amount of generated gaseous and liquid hydrocarbons as a product of artificial maturation of organic matters of Domanic black shale. The material balance of organic matter for initial rock sample and after thermal treatment at 300 and 500?°С were estimated. The amount of generated liquid hydrocarbon was minimum at 500?°С. As a result of kerogen destruction, no asphaltenes were observed during generation of liquid hydrocarbons. Based on the results of elemental analysis, Van Krevelen diagram was plotted.Oren, A., Meng, F.-W., 2019. ‘Red – the magic color for solar salt production’ – but since when? FEMS Microbiology Letters 366, Article fnz050. communities of carotenoid-rich members of the Halobacteria (Euryarchaeota), the bacterium Salinibacter (Bacteroidetes) and the eukaryotic alga Dunaliella color the brines of most saltern crystallizer ponds red. The first report we found from the western world mentioning these red brines dates from 1765: the Encyclopédie of Diderot and coworkers. Earlier descriptions of solar salterns since Roman times do not mention red ponds. These include the Astronomica of Manilius, Pliny's Naturalis Historia (1st century), the description of Italian salterns in De Reditu Suo by Namatianus (5th century), Agricola's De Re Metallica (1556) and an anonymous description of French salterns (1669). This suggests that in earlier times, saltern brines may not have been red. In salterns which are operated today in the traditional way as practiced in the Middle Ages, no red brines are observed. Prokaryotic densities in the salterns of Se?ovlje (Slovenia) and Ston (Croatia) are an order of magnitude lower than in modern saltern crystallizers. This is probably due to the much shorter residence time of the brine in the traditionally operated salterns. In China, red saltern brines were documented earlier: in Li Shizhen's compendium of Materia Medica Ben Cao Kang Mu, completed in 1578 and based on older sources.Orrego-Ruiz, J.A., Medina-Sandoval, C.F., Hinds, C.C., ?lvaro, V.-G., Rojas-Ruiz, F.A., 2019. FT-ICR MS determination of the role of naphthenic acids on the stabilization of alkali/surfactant/polymer emulsified effluents: A field study. Journal of Petroleum Science and Engineering 179, 192-198. Alkali/Surfactant/Polymer flooding (ASP) projects have been developed worldwide. Nevertheless, some disadvantages have limited the success of ASP during the execution in field, such as injection lines scaling and strong emulsification of the produced fluids. Commonly, appropriate formulations for particular reservoir conditions are selected after a series of evaluation steps. These includes tests of surfactants, polymers and commercially available alkali, based on the reservoir temperature, reservoir salinity, reservoir water pH, rock permeability, formation type and adsorption of the surfactant on the matrix rock, to obtain the highest oil recovery at the lowest cost. As part of the different strategies adopted for increasing the oil recovery factor, San Francisco oil field, Huila Colombia, was selected in 2012 for ASP flooding application at pilot scale. After two years of injection, ASP effluents affected considerably the quality of water and its treatment for reinjection. The present work focuses on the compositional study of the production effluents obtained after ASP flooding. A detailed analysis using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) allowed disclosing the role of natural organic acids on reducing the interfacial tension which in turn entailed highly stable microemulsions. Together with the added surfactant, naphthenic acids (because of the alkaline pH) prompts the formation of these thermodynamically stable oil in water systems. A test using an acid free oil proved that the formation of microemulsions strongly depends on naphthenic acids presence. Additional tests using oils with different acidity showed the dependence on the naphthenics acids structure over the emulsion stability. The results obtained in this study stands out FT-ICR MS as a prominent tool on understanding breaking and/or clarifying treatment processes from a molecular level point of view and thus, could help on proposing a correct and cost effective water treatment.Ossa Ossa, F., Hofmann, A., Spangenberg, J.E., Poulton, S.W., Stüeken, E.E., Schoenberg, R., Eickmann, B., Wille, M., Butler, M., Bekker, A., 2019. Limited oxygen production in the Mesoarchean ocean. Proceedings of the National Academy of Sciences 116, 6647-6652.: Episodic development of “oxygen oases” during the Archean Eon characterizes the hundreds of millions of years transition to permanent oxygenation in the atmosphere–hydrosphere system at the Great Oxidation Event (～2.4–2.3 Ga). One of these well-characterized oxygen oases is recorded in Mesoarchean sediments of the Pongola Supergroup. We show that in contrast to the Neoarchean, biological oxygen production in a shallow ocean having Mo-based nitrogen fixation was not sufficient to result in a dissolved nitrogen reservoir that would carry the isotopic effects of an aerobic nitrogen cycle. Nevertheless, it appears that low concentrations of bioavailable phosphorus, rather than nitrogen, suppressed the growth and expansion of oxygenic photosynthesizers and may explain why pervasive and permanent oxygenation was delayed during the Archean Eon.Abstract: The Archean Eon was a time of predominantly anoxic Earth surface conditions, where anaerobic processes controlled bioessential element cycles. In contrast to “oxygen oases” well documented for the Neoarchean [2.8 to 2.5 billion years ago (Ga)], the magnitude, spatial extent, and underlying causes of possible Mesoarchean (3.2 to 2.8 Ga) surface-ocean oxygenation remain controversial. Here, we report δ15N and δ13C values coupled with local seawater redox data for Mesoarchean shales of the Mozaan Group (Pongola Supergroup, South Africa) that were deposited during an episode of enhanced Mn (oxyhydr)oxide precipitation between ～2.95 and 2.85 Ga. Iron and Mn redox systematics are consistent with an oxygen oasis in the Mesoarchean anoxic ocean, but δ15N data indicate a Mo-based diazotrophic biosphere with no compelling evidence for a significant aerobic nitrogen cycle. We propose that in contrast to the Neoarchean, dissolved O2 levels were either too low or too limited in extent to develop a large and stable nitrate reservoir in the Mesoarchean ocean. Since biological N2 fixation was evidently active in this environment, the growth and proliferation of O2-producing organisms were likely suppressed by nutrients other than nitrogen (e.g., phosphorus), which would have limited the expansion of oxygenated conditions during the Mesoarchean.Ostle, C., Thompson, R.C., Broughton, D., Gregory, L., Wootton, M., Johns, D.G., 2019. The rise in ocean plastics evidenced from a 60-year time series. Nature Communications 10, Article 1622. production has increased exponentially since its use became widespread in the 1950s. This has led to increased concern as plastics have become prevalent in the oceanic environment, and evidence of their impacts on marine organisms and human health has been highlighted. Despite their prevalence, very few long-term (>40 years) records of the distribution and temporal trends of plastics in the world’s oceans exist. Here we present a new time series, from 1957 to 2016 and covering over 6.5 million nautical miles, based on records of when plastics have become entangled on a towed marine sampler. This consistent time series provides some of the earliest records of plastic entanglement, and is the first to confirm a significant increase in open ocean plastics in recent decades.Othman, F., Naufaliansyah, M.A., Hussain, F., 2019. Effect of water salinity on permeability alteration during CO2 sequestration. Advances in Water Resources 127, 237-251. migration during CO2 injection into water-saturated rocks causes mineral dissolution and precipitation. We present a careful experimental study to investigate the effect of water salinity on permeability damage during CO2 sequestration. Core samples were cut from two Berea sandstone blocks for coreflooding images. The core samples were characterized using X-Ray Powder Diffraction (XRD), X-Ray Fluorescence (XRF), and Scanning Electron Microscopy (SEM) analyses. The coreflooding began by injecting a core sample with water having salinity values of 0, 10, 30, or 60?g/L NaCl. Then, CO2-saturated water was injected to displace the previously injected water. The resulting fluid was then displaced by the injection of water-saturated supercritical (sc) CO2. Throughout coreflooding, the pressure difference across the core sample was monitored, and produced water samples were collected. After the coreflooding, SEM and energy dispersive X-ray spectroscopy (EDS) analysis was run to generate images that were then registered with the pre-injection images to reveal fines migration. The produced water samples were subjected to measurement of fines concentration and ionic chromatography analysis. During CO2-saturated water injection, permeability increased for low-salinity water coreflooding (0 and 10?g/L NaCl) and decreased for high-salinity water coreflooding (30 and 60?g/L NaCl). After water-saturated scCO2 injection, Permeability decrease ranged from 85% for freshwater (0?g/L NaCl) to 20% for high-salinity water (60?g/L NaCl). Fines migration and its consequent mineral dissolution and precipitation determine the core samples' permeability.Paleos, C.M., 2019. Organization and compartmentalization by lipid membranes promote reactions related to the origin of cellular life. Astrobiology 19, 547-552. crystals have certain physical properties that promote chemical reactions which cannot occur in bulk phase media. These properties are displayed, among other molecules, by amphiphilic compounds which assemble into membrane structures then concentrate and organize biologically relevant monomers within their confined spaces. When mixtures of lipids and nucleotides are cycled multiple times between hydrated and anhydrous conditions, the monomers polymerize in the dry phase into oligonucleotides. Upon rehydration, mixtures of the polymers are encapsulated in lipid-bounded compartments called protocells. Reactions in liquid crystalline organizing matrices represent a promising approach for future research on how primitive cells could emerge on the early Earth and other habitable planets.Paramasivan, K., Rajagopal, K., Mutturi, S., 2019. Studies on squalene biosynthesis and the standardization of its extraction methodology from Saccharomyces cerevisiae. Applied Biochemistry and Biotechnology 187, 691-707. this study, a homogenization-based extraction method was developed and was compared to five conventional methods of squalene extraction. Squalene recovered from this novel procedure gave 3.5-fold, 10-fold, 16-fold, and 8.1-fold higher yield than standard procedures, viz., saponification with 60% KOH, acidic saponification, saponification with 18% KOH, and glass beads method, respectively. Furthermore, this procedure has been evaluated on laboratory Saccharomyces cerevisiae strains such as BY4742 and CEN.PK2-1C (native), deletion strains (ERG6 and ERG11), and tHMG1 overexpressed S. cerevisiae strains. When sonication method of cell lysis was replaced with homogenization, it was found that the yields were significantly higher and reached a value of 9?mg/g DCW in case of BY4742. In addition, squalene yield in ergosterol mutant strains has been analyzed and was found to be 1.8-fold and 3.4-fold higher in ERG6 and ERG11 deletion strains, respectively, than in BY4742. Squalene was also found to be higher at the optimized temperature of 30?°C and pH?6.0. Furthermore, tolerance of S. cerevisiae to external squalene at various concentrations has been carried and found that the organism was tolerant up to 25?g/L of squalene.Park, J.W., Ladd, S.N., Sachs, J.P., 2019. Hydrogen and carbon isotope responses to salinity in greenhouse-cultivated mangroves. Organic Geochemistry 132, 23-36. hydrogen and carbon isotope ratios (2H/1H and 13C/12C) of mangrove lipids can be used to quantitatively reconstruct past salinity and 2H/1H ratios of environmental water, and in some cases precipitation rate. This approach is based on the observation that net 2H- and 13C-fractionation increases and decreases, respectively, with the salinity of environmental water. In order to better understand the mechanisms underlying these empirical observations and ultimately improve estimates of paleoprecipitation from the paired H and C isotope approach, we analyzed the isotopic composition of fatty acids from five species of mangroves cultivated in salinity treatments of 5–30?ppt (g/kg) for 3.5?years in a greenhouse. Decreased net 13C-fractionation with salinity in three mangrove species was attributed to increased water use efficiency and thus a 13C-enriched internal CO2 pool. Net 2H-fractionation decreased with salinity in three mangrove species, opposite to previous observations of mangroves growing along salinity gradients in lakes and estuaries. The difference between uncultivated and greenhouse-cultivated mangroves may result from variability of 2H/1H of environmental water in natural environments. In addition, decreased net 2H-fractionation with salinity could be due to temporal variability in 2H/1H of leaf water and timing of lipid production, and the use of stored carbohydrates in seeds. Due to the sensitivity of the salinity and 13C-fractionation relationship for calculating both salinity and water isotopes, optimization of mangrove lipid H and C isotopes as a paleohydrologic tracer may be best achieved through laboratory-based calibrations of the relationship between 13C-fractionation and salinity.Patel, A.B., Singh, S., Patel, A., Jain, K., Amin, S., Madamwar, D., 2019. Synergistic biodegradation of phenanthrene and fluoranthene by mixed bacterial cultures. Bioresource Technology 284, 115-120. aromatic hydrocarbons (PAHs) are highly recalcitrant compounds and difficult to degrade. Therefore in this work, using a bioremediation approach, mixed bacterial cultures (ASPF) was developed and enriched from polluted marine sediments capable of degrading 400?mg/L of phenanthrene and fluoranthene in Bushnell Hass medium. ASPF consists of 22 bacterial genera dominated by Azoarcus and Chelativorans. The biostimulation effect of three water soluble fertilizers (NPK, urea, and ammonium sulfate) showed that NPK and ammonium sulfate have enhanced the degradation, whereas urea has decreased their degradation. ASPF was also able to degrade phenanthrene and fluoranthene in the presence of petroleum hydrocarbons. But degradation was found to decrease in the presence of pathway intermediates (phthalic acid and catechol) due to enzymatic feedback inhibition. Optimum degradation of both PAHs was observed under room temperature, suggesting the practical applicability of ASPF.Patel, M.K., Pandey, S., Brahmbhatt, H.R., Mishra, A., Jha, B., 2019. Lipid content and fatty acid profile of selected halophytic plants reveal a promising source of renewable energy. Biomass and Bioenergy 124, 25-32. research has focused on the production of biofuel from different bio-resources, especially non-edible and underutilized plants. In this study, total lipid contents and fatty acids composition were evaluated both qualitatively and quantitatively for twelve abundant halophytes to ascertain their potential as feedstock for renewable energy. Non-succulent halophytes contained the highest total lipid content (about 5–7%, except Porteresia coarctata), followed by shrubby (about 2.6%) and succulent halophytes (1–1.8%). The FA profile shows that halophytes are a rich source of alpha-linolenic, linolenic and palmitic acids. Oleic and stearic acids were also detected in some halophytes. A low content of MUFA (except P. coarctata) was detected in all the halophytes, but the maximum content of SFA was estimated in Salicornia brachiata, Suaeda fruticosa, and P. coarctata. Halophyte Sporobolus virginicus contained more than 80% PUFA, followed by Heleochloa setulosa, Sesuvium portulacastrum, Atriplex griffithii and Salvadora persica. An important qualitative indicator density was found to be at par with recommended standards, but the cetane number of S. fruticosa and S. brachiata also matched the standards. The overall fatty acid profile of the selected halophytes makes them suitable for biofuel, and their potential could be enriched by improving agronomical practices and downstream processing.Paton, T.R., Brett, C.E., Kampouris, G.E., 2019. Genesis, modification, and preservation of complex Upper Ordovician hardgrounds: Implications for sequence stratigraphy and the Great Ordovician Biodiversification Event. Palaeogeography, Palaeoclimatology, Palaeoecology 526, 53-71. from the Upper Ordovician strata of eastern Laurentia exhibit a wide range of morphologies, though the development of their complex surface topographies remains poorly understood. These early lithified seafloors, which can be laterally very extensive, may provide key information about basin dynamics and global ocean fluctuations. Based on spectacular exposures and newly-excavated material, we examined a suite of hardgrounds from the Upper Ordovician (Katian) of southern Ontario and the Cincinnati Arch region and documented the processes of genesis, development, and modification of simple, complex, and block hardgrounds. In this study, we used extensive field work, petrology, and cathodoluminescence to determine the evolution and shaping of hardgrounds as a result of intense submarine erosion and prolonged exposure of these surfaces and reveal a progression from simple to complex hardgrounds and ultimately to isolated cobble- to boulder-sized block hardgrounds. We survey the distribution of hardgrounds in a sequence stratigraphic framework to determine allocyclic controls on hardground development, highlight the important role that mixed siliciclastic-carbonate environments play in promoting the development of heterogeneous hardground topographies, and analyze the effects of high surface reliefs on local depositional and erosional regimes. In addition, we interpret the impact of increasingly abundant complex hardgrounds throughout the Ordovician on hard-substrate community diversification and their contribution to the Great Ordovician Biodiversification Event. We also discuss time-specific aspects of the Late Ordovician that made it a peak interval of hardground proliferation.Pellis, A., Comerford, J.W., Weinberger, S., Guebitz, G.M., Clark, J.H., Farmer, T.J., 2019. Enzymatic synthesis of lignin derivable pyridine based polyesters for the substitution of petroleum derived plastics. Nature Communications 10, Article 17622. concerns over increasing global plastic pollution, interest in the production and characterization of bio-based and biodegradable alternatives is rising. In the present work, the synthesis of a series of fully bio-based alternatives based on 2,4-, 2,5-, and 2,6-pyridinedicarboxylic acid-derived polymers produced via enzymatic catalysis are reported. A similar series of aromatic-aliphatic polyesters based on diethyl-2,5-furandicarboxylate and of the petroleum-based diethyl terephthalate and diethyl isophthalate were also synthesized. Here we show that the enzymatic synthesis starting from 2,4-diethyl pyridinedicarboxylate leads to the best polymers in terms of molecular weights (Mn?=?14.3 and Mw of 32.1?kDa when combined with 1,8-octanediol) when polymerized in diphenyl ether. Polymerization in solventless conditions were also successful leading to the synthesis of bio-based oligoesters that can be further functionalized. DSC analysis show a clear similarity in the thermal behavior between 2,4-diethyl pyridinedicarboxylate and diethyl isophthalate (amorphous polymers) and between 2,5-diethyl pyridinedicarboxylate and diethyl terephthalate (crystalline polymers).Peng, C., Bryce, C., Sundman, A., Borch, T., Kappler, A., 2019. Organic matter complexation promotes Fe(II) oxidation by the photoautotrophic Fe(II)-oxidizer Rhodopseudomonas palustris TIE-1. ACS Earth and Space Chemistry 3, 531-536.(II)–organic matter (Fe(II)–OM) complexes are present in the photic zone of aquatic environments and due to their reactivity may play an important role in biogeochemical cycling. Complexation of Fe has been shown to influence the rates and extent of many chemical and microbial redox reactions. However, it is currently unknown whether, how fast, and to which extent Fe(II)–OM complexes can be oxidized by anoxygenic photoautotrophic Fe(II)-oxidizing microorganisms which are widespread in photic habitats and use electrons from Fe(II) to fix CO2. Here, we used the photoautotrophic Fe(II)-oxidizer Rhodopseudomonas palustris TIE-1 to demonstrate that Fe(II) complexation by OM significantly accelerated the rates of Fe(II) oxidation by strain TIE-1 compared to the oxidation of nonorganically bound, free Fe(II), although a fraction of the Fe(II) present as Fe(II)–OM complexes seemed to resist microbial oxidation. Analysis of Fe–OM aggregate sizes showed that the remaining, nonoxidized Fe(II) and almost all of the Fe(III) in the Fe(II)–humic and Fe(II)–fulvic acid oxidation products were in the form of colloids (3–200 nm). In summary, this study shows that Fe(II)–OM complexes can be oxidized microbially in the photic zone, and the complexation of Fe(II) by OM controls the kinetics and extent of Fe(II) oxidation.Peng, C., Bryce, C., Sundman, A., Kappler, A., 2019. Cryptic cycling of complexes containing Fe(III) and organic matter by phototrophic Fe(II)-oxidizing bacteria. Applied and Environmental Microbiology 85, Article e02826-02818.: Fe-organic matter (Fe-OM) complexes are abundant in the environment and, due to their mobility, reactivity, and bioavailability, play a significant role in the biogeochemical Fe cycle. In photic zones of aquatic environments, Fe-OM complexes can potentially be reduced and oxidized, and thus cycled, by light-dependent processes, including abiotic photoreduction of Fe(III)-OM complexes and microbial oxidation of Fe(II)-OM complexes, by anoxygenic phototrophic bacteria. This could lead to a cryptic iron cycle in which continuous oxidation and rereduction of Fe could result in a low and steady-state Fe(II) concentration despite rapid Fe turnover. However, the coupling of these processes has never been demonstrated experimentally. In this study, we grew a model anoxygenic phototrophic Fe(II) oxidizer, Rhodobacter ferrooxidans SW2, with either citrate, Fe(II)-citrate, or Fe(III)-citrate. We found that strain SW2 was capable of reoxidizing Fe(II)-citrate produced by photochemical reduction of Fe(III)-citrate, which kept the dissolved Fe(II)-citrate concentration at low (<10?μM) and stable concentrations, with a concomitant increase in cell numbers. Cell suspension incubations with strain SW2 showed that it can also oxidize Fe(II)-EDTA, Fe(II)-humic acid, and Fe(II)-fulvic acid complexes. This work demonstrates the potential for active cryptic Fe cycling in the photic zone of anoxic aquatic environments, despite low measurable Fe(II) concentrations which are controlled by the rate of microbial Fe(II) oxidation and the identity of the Fe-OM complexes.Importance: Iron cycling, including reduction of Fe(III) and oxidation of Fe(II), involves the formation, transformation, and dissolution of minerals and dissolved iron-organic matter compounds. It has been shown previously that Fe can be cycled so rapidly that no measurable changes in Fe(II) and Fe(III) concentrations occur, leading to a so-called cryptic cycle. Cryptic Fe cycles have been shown to be driven either abiotically by a combination of photochemical reduction of Fe(III)-OM complexes and reoxidation of Fe(II) by O2, or microbially by a combination of Fe(III)-reducing and Fe(II)-oxidizing bacteria. Our study demonstrates a new type of light-driven cryptic Fe cycle that is relevant for the photic zone of aquatic habitats involving abiotic photochemical reduction of Fe(III)-OM complexes and microbial phototrophic Fe(II) oxidation. This new type of cryptic Fe cycle has important implications for biogeochemical cycling of iron, carbon, nutrients, and heavy metals and can also influence the composition and activity of microbial communities.Penn, J.L., Weber, T., Chang, B.X., Deutsch, C., 2019. Microbial ecosystem dynamics drive fluctuating nitrogen loss in marine anoxic zones. Proceedings of the National Academy of Sciences 116, 7220-7225.: The removal of bioavailable nitrogen (N), a critical nutrient that limits marine primary production, is thought to vary due to climate forcing of the ocean’s low oxygen zones. Here we demonstrate that competition between aerobic and anaerobic microbes for scarce resources drives fluctuations in the rate of marine N loss over time, even in a stable environment. Biological oscillations have been theorized for nearly a century in idealized models, but are shown here for the first time in a three-dimensional and data-constrained model of ocean circulation. A predicted geochemical signature of the oscillations is detected in environmental samples. This previously overlooked source of natural variability reconciles conflicting empirical evidence for the dominance of heterotrophic versus autotrophic pathways of N removal.Abstract: The dynamics of nitrogen (N) loss in the ocean’s oxygen-deficient zones (ODZs) are thought to be driven by climate impacts on ocean circulation and biological productivity. Here we analyze a data-constrained model of the microbial ecosystem in an ODZ and find that species interactions drive fluctuations in local- and regional-scale rates of N loss, even in the absence of climate variability. By consuming O2 to nanomolar levels, aerobic nitrifying microbes cede their competitive advantage for scarce forms of N to anaerobic denitrifying bacteria. Because anaerobes cannot sustain their own low-O2 niche, the physical O2 supply restores competitive advantage to aerobic populations, resetting the cycle. The resulting ecosystem oscillations induce a unique geochemical signature within the ODZ—short-lived spikes of ammonium that are found in measured profiles. The microbial ecosystem dynamics also give rise to variable ratios of anammox to heterotrophic denitrification, providing a mechanism for the unexplained variability of these pathways observed in the ocean.Percival, L.M.E., Selby, D., Bond, D.P.G., Rakociński, M., Racki, G., Marynowski, L., Adatte, T., Spangenberg, J.E., F?llmi, K.B., 2019. Pulses of enhanced continental weathering associated with multiple Late Devonian climate perturbations: Evidence from osmium-isotope compositions. Palaeogeography, Palaeoclimatology, Palaeoecology 524, 240-249. high rates of continental weathering have frequently been proposed as a key stimulus for the development of widespread marine anoxia during a number of Late Devonian environmental and biospheric crises, which included a major mass extinction during the Frasnian–Famennian transition (marked by the Upper and Lower Kellwasser horizons). Here, this model is investigated by presenting the first stratigraphic record of osmium-isotope trends (187Os/188Os) in upper Devonian strata from the Kowala Quarry (Holy Cross Mountains, Poland). Changes in reconstructed 187Os/188Os seawater values to more radiogenic compositions are documented at the base of both the Lower (~0.42 to ~0.83) and Upper (~0.31 to ~0.81) Kellwasser horizons characteristic of the Frasnian–Famennian transition, and additionally within upper Famennian shales that record a more minor environmental perturbation known as the Annulata Event (~0.20 to ~0.53). These shifts indicate the occurrence of extremely enhanced continental weathering rates at the onsets of the Kellwasser crises and during the later Annulata Event. The similarity of 187Os/188Os values in this study from Frasnian–Famennian boundary and lower Famennian strata (between 0.4 and 0.5) to those from North American stratigraphic equivalents suggests that the 187Os/188Os values record global trends. These findings support a causal relationship between increased continental weathering (and thus, nutrient supply to the marine shelf) and the environmental perturbations that occurred during numerous Late Devonian events, including both of the biospherically catastrophic Kellwasser crises as well as other, less severe, oceanic anoxic events.Pesesse, R., Stefanuto, P.H., Schleich, F., Louis, R., Focant, J.F., 2019. Multimodal chemometric approach for the analysis of human exhaled breath in lung cancer patients by TD-GC?×?GC-TOFMS. Journal of Chromatography B 1114-1115, 146-153. cancer is the deadliest cancer in developed countries. To reduce its mortality rate, it is important to enhance our capability to detect it at earlier stages by developing early diagnostic methods. In that context, the analysis of exhaled breath is an interesting approach because of the simplicity of the medical act and its non-invasiveness. Thermal desorption comprehensive two-dimensional gas chromatography time of flight mass spectrometry (TD-GC?×?GC-TOFMS) has been used to characterize and compare the volatile content of human breath of lung cancer patients and healthy volunteers. On the sampling side, the contaminations induced by the bags membrane and further environmental migration of VOCs during and after the sampling have also been investigated. Over a realistic period of 6?h, the concentration of contaminants inside the bag can increase from 2 to 3 folds based on simulated breath samples. On the data processing side, Fisher ratio (FR) and random forest (RF) approaches were applied and compared in regards to their ability to reduce the data dimensionality and to extract the significant information. Both approaches allow to efficiently smooth the background signal and extract significant features (27 for FR and 17 for RF). Principal component analysis (PCA) was used to evaluate the clustering capacity of the different models. For both approaches, a separation along PC-1 was obtained with a variance score around 35%. The combined model provides a partial separation with a PC-1 score of 52%. This proof-of-concept study further confirms the potential of breath analysis for cancer detection but also underlines the importance of quality control over the full analytical procedure, including the processing of the data.Petkowski, J.J., Bains, W., Seager, S., 2019. An apparent binary choice in biochemistry: Mutual reactivity implies life chooses thiols or nitrogen-sulfur bonds, but not both. Astrobiology 19, 579-613. fundamental goal of biology is to understand the rules behind life's use of chemical space. Established work focuses on why life uses the chemistry that it does. Given the enormous scope of possible chemical space, we postulate that it is equally important to ask why life largely avoids certain areas of chemical space. The nitrogen-sulfur bond is a prime example, as it rarely appears in natural molecules, despite the very rich N-S bond chemistry applied in various branches of industry (e.g., industrial materials, agrochemicals, pharmaceuticals). We find that, out of more than 200,000 known, unique compounds made by life, only about 100 contain N-S bonds. Furthermore, the limited number of N-S bond-containing molecules that life produces appears to fall into a few very distinctive structural groups. One may think that industrial processes are unrelated to biochemistry because of a greater possibility of solvents, catalysts, and temperatures available to industry than to the cellular environment. However, the fact that life does rarely make N-S bonds, from the plentiful precursors available, and has evolved the ability to do so independently several times, suggests that the restriction on life's use of N-S chemistry is not in its synthesis.We present a hypothesis to explain life's extremely limited usage of the N-S bond: that the N-S bond chemistry is incompatible with essential segments of biochemistry, specifically with thiols. We support our hypothesis by (1) a quantitative analysis of the occurrence of N-S bond-containing natural products and (2) reactivity experiments between selected N-S compounds and key biological molecules. This work provides an example of a reason why life nearly excludes a distinct region of chemical space. Combined with future examples, this potentially new field of research may provide fresh insight into life's evolution through chemical space and its origin and early evolution.Pezzatti, J., González-Ruiz, V., Sanchez, S.C., Gagnebin, Y., Joshi, A., Guillarme, D., Schappler, J., Picard, D., Boccard, J., Rudaz, S., 2019. A scoring approach for multi-platform acquisition in metabolomics. Journal of Chromatography A 1592, 47-54. the ultimate goal of untargeted metabolomics is the analysis of the broadest possible range of metabolites, some new metrics have to be used by the researchers to evaluate and select different analytical strategies when multi-platform analyses are considered. In this context, we aimed at developing a scoring approach allowing to compare the performance of different LC-MS conditions for metabolomics studies. By taking into account both chromatographic and MS attributes of the analytes’ peaks (i.e. retention, signal to noise ratio, peak intensity and shape), the newly proposed score reflects the potential of a set of LC-MS operating conditions to provide useful analytical information for a given compound. A chemical library containing 597 metabolites was used as a benchmark to apply this approach on two RPLC and three HILIC methods hyphenated to high resolution mass spectrometry (HRMS) in positive and negative ionization modes. The scores not only allowed to evaluate each analytical platform, but also to optimize the number of analytical methods needed for the analysis of metabolomics samples. As a result, the most informative combination of three LC methods and ionization modes was found, leading to a coverage of nearly 95% of the detected compounds. It was therefore demonstrated that the overall performance reached with three selected methods was almost equivalent to the performance reached when five LC-MS conditions were used.Pires, A.E., Detry, C., Chikhi, L., Rasteiro, R., Amorim, I.R., Sim?es, F., Matos, J., Petrucci-Fonseca, F., Ollivier, M., H?nni, C., Cardoso, J.L., Arias, P., Diniz, M., Araújo, A.C., Bicho, N., Sousa, A.C., Moreno-García, M., Arruda, A.M., Fernández-Rodríguez, C., Porfírio, E., Arnaud, J.M., Valente, A., Gon?alves, D., Alves, L., G?therstr?m, A., Davis, S.J.M., Ginja, C., 2019. The curious case of the Mesolithic Iberian dogs: An archaeogenetic study. Journal of Archaeological Science 105, 116-129. investigated the genetic composition of six Canis remains from western Iberia, directly radiocarbon dated to 7,903–7,570 years (cal BP). They were identified as dogs via their archaeological and depositional context, osteometry, and a high percentage of aquatic diet shared with humans. For comparison, genetic data were obtained from an additional 37 Iberian dog remains from the Neolithic to Late Antiquity, as well as two Palaeolithic and a Chalcolithic Canis identified as wolves. Previous data indicated that dog mtDNA haplogroup A (HgA) is prevalent in extant European dogs (>50%), in the Near East and Asia, but rare or absent (<10%) in European Canis older than 3,000 years (cal BP). We found a high frequency (83%) of dog HgA in Mesolithic Iberian dog remains. This is the first report of a high frequency of dog HgA in pre-Neolithic Europe. We show that, contrary to the current view, Canis with HgA did not necessarily arrive in Europe from East-Asia. This phylogeographical difference in HgA frequency demonstrates that genetic differentiation was high prior to, or as a consequence of, domestication which may be linked with pre-Neolithic local processes for Iberian wolf domestication. Our results emphasize that knowledge of both ancient wolves' and early dogs’ genetic profiles from the European periphery should improve our understanding of the evolution of the European dog.Pleyer, H.L., Strasdeit, H., Fox, S., 2018. A possible prebiotic ancestry of porphyrin-type protein cofactors. Origins of Life and Evolution of Biospheres 48, 347-371. previous experiments that simulated conditions on primordial volcanic islands, we demonstrated the abiotic formation of hydrophobic porphyrins. The present study focused on the question whether such porphyrins can be metalated by prebiotically plausible metal ion sources. We used water-insoluble octaethylporphyrin (H2oep) as a model compound. Experiments were conducted in a nitrogen atmosphere under cyclic wet–dry conditions in order to simulate the fluctuating environment in prebiotic rock pools. Wetting–drying proved to be a crucial factor. Significant yields of the metalloporphyrins (20–78% with respect to H2oep) were obtained from the soluble salts MCl2 (M?=?Mg, Fe, Co, Ni and Cu) in freshwater. Even almost insoluble minerals and rocks metalated the porphyrin. Basalt (an iron source, 11% yield), synthetic jaipurite (CoS, 33%) and synthetic covellite (CuS, 57%) were most efficient. Basalt, magnetite and FeCl2 gave considerably higher yields in artificial seawater than in freshwater. From iron sources, the highest yields, however, were obtained in an acidic medium (hydrochloric acid with an initial pH of 2.1). Under these conditions, iron meteorites also metalated the porphyrin. Acidic conditions were considered because they are known to occur during eruptions on volcanic islands. Octaethylporphyrinatomagnesium(II) did not form in acidic medium and was unstable towards dissolved Fe2+. It is therefore questionable whether magnesium porphyrins, i.e. possible ancestors of chlorophyll, could have accumulated in primordial rock pools. However, abiotically formed ancestors of the modern cofactors heme (Fe), B12 (Co), and F430 (Ni) may have been available to hypothetical protometabolisms and early organisms.Pohlner, M., Dlugosch, L., Wemheuer, B., Mills, H., Engelen, B., Reese, B.K., 2019. The majority of active Rhodobacteraceae in marine sediments belong to uncultured genera: A molecular approach to link their distribution to environmental conditions. Frontiers in Microbiology 10, 659. doi: 610.3389/fmicb.2019.00659. studies on benthic microbial communities focus on fundamental biogeochemical processes or the most abundant constituents. Thereby, minor fractions such as the Rhodobacteraceae are frequently neglected. Even though this family belongs to the most widely distributed bacteria in the marine environment, their proportion on benthic microbial communities is usually within or below the single digit range. Thus, knowledge on these community members is limited, even though their absolute numbers might exceed those from the pelagic zone by orders of magnitudes. To unravel the distribution and diversity of benthic, metabolically active Rhodobacteraceae, we have now analyzed an already existing library of bacterial 16S rRNA transcripts. The dataset originated from 154 individual sediment samples comprising seven oceanic regions and a broad variety of environmental conditions. Across all samples, a total of 0.7% of all 16S rRNA transcripts was annotated as Rhodobacteraceae. Among those, Sulfitobacter, Paracoccus and Phaeomarinomonas were the most abundant cultured representatives, but the majority (78%) was affiliated to uncultured family members. To define them, the 45 most abundant Rhodobacteraceae-OTUs assigned as “uncultured” were phylogenetically assembled in new clusters. Their next relatives particularly belonged to different subgroups other than the Roseobacter group, reflecting a large part of the hidden diversity within the benthic Rhodobacteraceae with unknown functions. The general composition of active Rhodobacteraceae communities was found to be specific for the geographical location, exhibiting a decreasing richness with sediment depth. One third of the Rhodobacteraceae-OTUs significantly responded to the prevailing redox regime, suggesting an adaption to anoxic conditions. A possible approach to predict their physiological properties is to identify the metabolic capabilities of their nearest relatives. Those need to be proven by physiological experiments, as soon an isolate is available. Because many uncultured members of these subgroups likely thrive under anoxic conditions, in future research, a molecular-guided cultivation strategy can be pursued to isolate novel Rhodobacteraceae from sediments.Porter, T.J., Schoenemann, S.W., Davies, L.J., Steig, E.J., Bandara, S., Froese, D.G., 2019. Recent summer warming in northwestern Canada exceeds the Holocene thermal maximum. Nature Communications 10, Article 1631. Beringia is one of the few Western Arctic regions where full Holocene climate reconstructions are possible. However, most full Holocene reconstructions in Eastern Beringia are based either on pollen or midges, which show conflicting early Holocene summer temperature histories. This discrepancy precludes understanding the factors that drove past (and potentially future) climate change and calls for independent proxies to advance the debate. We present a ~13.6 ka summer temperature reconstruction in central Yukon, part of Eastern Beringia, using precipitation isotopes in syngenetic permafrost. The reconstruction shows that early Holocene summers were consistently warmer than the Holocene mean, as supported by midges, and a thermal maximum at ~7.6–6.6 ka BP. This maximum was followed by a ~6 ka cooling, and later abruptly reversed by industrial-era warming leading to a modern climate that is unprecedented in the Holocene context and exceeds the Holocene thermal maximum by +1.7?±?0.7?°C.Postma, T.J.W., Bandilla, K.W., Celia, M.A., 2019. Estimates of CO2 leakage along abandoned wells constrained by new data. International Journal of Greenhouse Gas Control 84, 164-179. viability of carbon capture and geological storage (CCS) projects depends in part on the risk that injected CO2 or displaced pore fluid will leak out of the target formation into surrounding formations or to the surface. Abandoned oil and gas wells, of which millions exist both throughout the United States and globally, form a potential conduit for this leakage. Recently, specific field measurements have been made to quantify the range of effective permeabilities that can be expected in abandoned wells, enabling us to, for the first time, combine field-scale numerical simulations of CO2 sequestration in deep saline aquifers with real data on effective permeabilities of leaky wells. Using a previously developed semi-analytical reservoir simulator that can accommodate an arbitrary sequence of alternating aquifers and aquicludes, as well as an arbitrary number of leaky wells, we investigated how the amount of CO2 that leaks out of the target formation depends on the spatial density of nearby abandoned wells and their effective permeability. Furthermore, we assess the influence that variations in pressure and temperature found between geological targets have on this dependency. We find that the observed differences in leakage between geological targets are controlled almost exclusively by differences in density of CO2 at the local subsurface conditions, causing the CO2 plume to contact a different number of wells when injecting at the same constant mass rate. We quantitatively assess the results obtained from our numerical experiments by combining them with the permeability data that have recently become available, typical spatial densities of abandoned wells, and performance requirements put forward in the literature. Our results indicate that leakage of CO2 through abandoned wells is unlikely to be a major limitation in storage security of CCS projects.Poturay, V.A., Kompanichenko, V.N., 2019. Composition and distribution of saturated hydrocarbons in the thermal waters and vapor–water mixture of the Mutnovskii geothermal field and Uzon caldera, Kamchatka. Geochemistry International 57, 74-82. paper presents data on the composition and molecular-mass distribution of saturated hydrocarbons in sterile vapor–water mixture from wells and in high-temperature springs in the Mutnovskii hydrothermal area and Uzon caldera. The condensate of the vapor–water mixture and thermal waters from the Mutnovskii area contain low-molecule n-alkanes, which were generated by thermogenic processes. The boiling mud pot of the Donnoe fumarole field typically contains hydrocarbons whose origin is likely related to thermocatalytic transformations of the biomass of thermophilic microorganisms. A separate type of the molecular-mass distribution is typical of the geyser in the caldera of Uzon volcano: this material contains n?alkanes, which were generated by two processes: chemical re-synthesis of floral organic remnants and biogenic synthesis with the probable involvement of bacteria and algae.Prasad, P.S.R., Kiran, B.S., 2019. Self-preservation and stability of methane hydrates in the presence of NaCl. Scientific Reports 9, Article 5860. hydrate, a solid transformed from an ensemble of water and gaseous molecules under suitable thermodynamic conditions, is present in marine and permafrost strata. The ability of methane hydrates to exist outside of its standard stability zone is vital in many aspects, such as its utility in gas storage and transportation, hydrate-related climate changes and gas reservoirs on the planet. A systematic study on the stability of methane hydrates divulges that the gas uptake decreased by about 10% by increasing the NaCl content to 5.0?wt%. The hydrate formation kinetic is relatively slower in a system with higher NaCl. The self-preservation temperature window for hydrate systems with NaCl 1.5, 3.0 and 5.0?wt% dramatically shifted to a lower temperature (252?K), while it remained around 270?K for NaCl 0.0 and 0.5?wt%. Based on powder x-ray diffraction and micro-Raman spectroscopic studies, the presence of hydrohalite (NaCl·2H2O) phase was identified along with the usual hydrate and ice phases. The eutectic melting of this mixture is responsible for shifting the hydrate stability to 252?K. A systematic lattice expansion of cubic phase infers the interaction between NaCl and water molecules of hydrate cages.Price, T.D., Spicuzza, M.J., Orland, I.J., Valley, J.W., 2019. Instrumental investigation of oxygen isotopes in human dental enamel from the Bronze Age battlefield site at Tollense, Germany. Journal of Archaeological Science 105, 70-80. isotopes were analyzed in human teeth dating to approximately 1250 BC from a Bronze Age battlefield along the Tollense River in northwestern Germany. Tooth enamel was sectioned, prepared, and analyzed using Secondary Ion Mass Spectrometry (SIMS) and Confocal Laser Fluorescence Microscopy (CLFM). The results of the study indicate that diagenesis has locally altered the tooth enamel. Brightly luminescing domains seen by confocal laser fluorescent microscopy are chemically changed in oxygen isotope ratios and elemental [Cl] concentrations. Values of δ18O are up to 2.7‰ lower in altered domains. Thus, diagenetic changes are observed in enamel that is 3250 years old and has been waterlogged for most of its depositional history. We recommend that studies of enamel in human teeth routinely evaluate the possibility of diagenesis.Priyadarshini, E., Priyadarshini, S.S., Pradhan, N., 2019. Heavy metal resistance in algae and its application for metal nanoparticle synthesis. Applied Microbiology and Biotechnology 103, 3297-3316. ungenerous release of metals from different industrial, agricultural, and anthropogenic sources has resulted in heavy metal pollution. Metals with a density larger than 5?g?cm?3 have been termed as heavy metals and have been stated to be potentially toxic to human and animals. Algae are known to be pioneer organisms with the potential to grow under extreme conditions including heavy metal-polluted sites. They have evolved efficient defense strategies to combat the toxic effects exerted by heavy metal ions. Most of the algal strains are reported to accumulate elevated metal ion concentration in cellular organelles. With respect to that, this review focuses on understanding the various strategies used by algal system for heavy metal resistance. Additionally, the application of this metal resistance in biosynthesis of metal nanoparticles and metal oxide nanoparticles has been investigated in details. We thereby conclude that algae serve as an excellent system for understanding metal uptake and accumulation. This thereby assists in the design and development of low-cost approaches for large-scale synthesis of nanoparticles and bioremediation approach, providing ample opportunities for future work.Pruss, S.B., Jones, D.S., Fike, D.A., Tosca, N.J., Wignall, P.B., 2019. Marine anoxia and sedimentary mercury enrichments during the Late Cambrian SPICE event in northern Scotland. Geology 47, 475-478. mercury concentrations in ancient sedimentary rocks are used as a fingerprint for large igneous province (LIP) volcanism because there is a tight association between known LIPs and coeval sedimentary Hg anomalies. While nonvolcanic processes of sedimentary Hg enrichment, including redox variations, have been demonstrated in modern settings, interpretations of ancient sedimentary Hg records have focused on LIP volcanism. Here, we document a link between sedimentary Hg enrichment and marine redox changes during the late Cambrian Steptoean positive isotopic carbon excursion (SPICE) event, a time with no known LIP. We report a new occurrence of the SPICE event from the Eilean Dubh Formation of northern Scotland, which preserves a series of coeval Hg enrichments. Abundant glauconite, a redox-sensitive iron-bearing mineral, co-occurs stratigraphically with the SPICE and Hg enrichments but is rare to absent from the rest of the section, and bioturbation is low in strata spanning the SPICE. We suggest that local Hg enrichments were driven by changing marine redox conditions during the SPICE event, rather than emplacement of a LIP. Redox oscillations should be considered as an additional control on Hg enrichments in the geologic record.Purvis, G., van der Land, C., Sano, N., Cockell, C., Barlow, A., Cumpson, P., Lopez-Capel, E., Gray, N., 2019. The organic stratigraphy of Ontong Java Plateau tuff correlated with the depth-related presence and absence of putative microbial alteration structures. Geobiology 17, 281-293. in geological samples are often interpreted as fossilised life; however, such interpretations are equivocal, as abiotic processes can be invoked to explain their presence. Thus, additional lines of chemical evidence are invaluable in confirming or refuting such morphological evidence. Glass shards in tuff from the Ontong Java Plateau (OJP) contain microtubular structures that are in close proximity to functionalised nitrogen substituted aromatic compounds that may be indicative of the chemical remnants of biological activity. The organic composition of the OJP tuff containing microtubular alteration structures was compared with tuff without such features. In addition, organic matter associated with horizons with compacted remnants of woody material buried in the OJP tuff and overlying pelagic calcareous foraminifer sediment were also characterised, to ascertain the provenance of the organic matter found in the OJP tuff. As a further control, the organic material in submarine and terrestrial basalts from other locations were also characterised providing further evidence to support the view that the organic matter in the OJP tuff is authigenic. Carbon–nitrogen chemistry was detected across all OJP tuff samples irrespective of the presence or absence of microtubular features, but was not detected in either the wood material, the overlying pelagic sediments or in the basalts from other locations. The results indicate no direct link between the OJP nitrogenous organic compounds and the presence or absence of microtubular features.Purvis, R.M., Lewis, A.C., Hopkins, J.R., Wilde, S.E., Dunmore, R.E., Allen, G., Pitt, J., Ward, R.S., 2019. Effects of ‘pre-fracking’ operations on ambient air quality at a shale gas exploration site in rural North Yorkshire, England. Science of The Total Environment 673, 445-454. observations of air quality and meteorological parameters (NOx, O3, NMHCs, SO2, PM) were made over a 2.5-year period (2016–2018) before, during and after preparations for hydraulic fracturing (fracking) at a shale gas exploration site near Kirby Misperton, North Yorkshire, England. As one of the first sites to apply for permits to carry out hydraulic fracturing, it has been subject to extensive regulatory and public scrutiny, as well as the focus for a major programme of long-term environmental monitoring. A baseline period of air quality monitoring (starting 2016) established the annual climatology of atmospheric composition against which a 20-week period of intensive activity on the site in preparation for hydraulic fracturing could be compared. During this ‘pre-operational phase’ of work in late 2017, the most significant effect was an increase in ambient NO (3-fold) and NOx (2-fold), arising from a combination of increased vehicle activity and operation of equipment on site. Although ambient NOx increased, air quality limit values for NO2 were not exceeded, even close to the well-site. Local ozone concentrations during the pre-operational period were slightly lower than the baseline phase due to titration with primary emitted NO. The activity on site did not lead to significant changes in airborne particulate matter or non-methane hydrocarbons. Hydraulic fracturing of the well did not subsequently take place and the on-site equipment was decommissioned and removed. Air quality parameters then returned to the original (baseline) climatological conditions. This work highlights the need to characterise the full annual climatology of air quality parameters against which short-term local activity changes can be compared. Based on this study, changes to ambient NOx appear to be the most significant air quality ahead of hydraulic fracturing. However, in rural locations, concentrations at individual sites are expected to be below ambient air quality limit thresholds.Qian, H., Ju, P., Zhang, D., Ma, L., Hu, Y., Li, Z., Huang, L., Lou, Y., Du, C., 2019. Effect of dissolved oxygen concentration on the microbiologically influenced corrosion of Q235 carbon steel by halophilic archaeon Natronorubrum tibetense. Frontiers in Microbiology 10, 844. doi: 810.3389/fmicb.2019.00844. influence of dissolved oxygen concentration (DOC) on the microbiologically influenced corrosion (MIC) of Q235 carbon steel in the culture medium of halophilic archaea Natronorubrum tibetense was investigated. The increase of DOC from 0.0 ppm to 3.0 ppm was found to strengthen the oxygen concentration cell by promoting cathodic reaction. Meanwhile, the increased DOC also promoted archaea cell growth, which could consume more metallic iron as energy source and aggravated the localized corrosion. When the DOC further increased to 5.0 ppm, the uniform corrosion was dominant as the biofilms became uniformly presented on the steel surface. Combined with the stronger inhibition effect of oxygen diffusion by the increased biofilm coverage, the MIC of carbon steel in the 5.0 ppm medium was weaker than that in the 3.0 ppm medium. From weight loss and electrochemical tests, the results all demonstrated that the carbon steel in the 3.0 ppm medium had the largest corrosion rate.Qiu, H., Zou, L., Zhang, M., Zhu, C., Jia, Y., 2019. Compositions of lipid compounds in the oil and gas releasing sediments in the northern South China Sea. Acta Sedimentologica Sinica 37, 416-423. and composition of organic carbon is the key to demonstrating the early diagenesis of organic carbon in the formation of oil and gas. Surface sediments were collected and analyzed to determine the content and form composition of lipid biomarkers in the estuary of the Pearl River Basin and adjacent areas in the South China Sea. The sources and occurrence of lipid compounds are also discussed. Results show that the organic carbon content range was 0.22%-0.66% in the sediment samples. The δ13C was -20.88‰ to -22.93‰, which implies a marine source of organic carbon. In total, 21 fatty acids, 6 fatty alcohols, 8 sterols and phytol were detected in the sediments. The content of total fatty acids, fatty alcohols, sterols and phytol ranged from 12.57 to 40.27 μg/g, 5.35-8.98 μg/g, 0.15-3.75 μg/g and 0.01-3.99 μg/g dry weight, respectively. The higher contents were located at the stations closest to the Pearl River estuary and Taiwan Strait. Lipid compounds mainly existed as free (FR) and base hydrolytic (BH) forms, with very little in acidic hydrolytic (AH) form. Phytol and sterols dominated BH components, but AH phytol was not detected. Lipid compounds primarily originate from marine microalgae and bacteria, with a small contribution from higher plants. The specific fatty acids produced by marine microalgae and bacteria contributed 21.18%-33.78% and 11.02%-15.64% to total fatty acids, respectively. The content of branched chain fatty acids (possibly derived from sulfate-reducing bacteria) was higher, at 1.79-2.62 μg/g dry weight, and accounted for 5.14%-6.50% of total fatty acids in sediments closest to the Pearl River estuary. These consisted of archaea microbes, implying sulfate reduction.Qiu, Z., Song, H., Hu, C., Wignall, P.B., Song, H., 2019. Carbonate thermoluminescence and its implication for marine productivity change during the Permian-Triassic transition. Palaeogeography, Palaeoclimatology, Palaeoecology 526, 72-79. Permian-Triassic (P-Tr) crisis was the largest mass extinction of the Phanerozoic and eliminated over 90% of marine species. However, the nature of marine productivity changes during the crisis is a matter of on-going debate. Here, thermoluminescence (TL) measurements from 144 bulk carbonate samples from Meishan (South China) show two levels of variation in TL peak intensities at ~270?°C. The first-order variation is characterized by a rapid, nearly three-fold increase. A secondary variation is interpreted to record periodic fluctuations on a Milankovitch scale (~20-kyr rhythm). The periodic variations of TL are negatively correlated with Mn concentrations, suggesting primary productivity is a key factor controlling the TL peak intensity by photo-reduction of particulate Mn in the presence of organic matter. Therefore, the periodic fluctuations of TL were likely controlled by primary productivity changes on orbital timescales. A significant rise of TL peak intensities across the P-Tr boundary represents the rapid increase of dissolved Mn associated with enhanced marine productivity and/or oceanic anoxia.Rafels-Ybern, ?., Torres, A.G., Camacho, N., Herencia-Ropero, A., Roura Frigolé, H., Wulff, T.F., Raboteg, M., Bordons, A., Grau-Bove, X., Ruiz-Trillo, I., Ribas de Pouplana, L., 2018. The expansion of inosine at the wobble position of tRNAs, and its role in the evolution of proteomes. Molecular Biology and Evolution 36, 650-662. modification of adenosine to inosine at the first position of transfer RNA (tRNA) anticodons (I34) is widespread among bacteria and eukaryotes. In bacteria, the modification is found in tRNAArg and is catalyzed by tRNA adenosine deaminase A, a homodimeric enzyme. In eukaryotes, I34 is introduced in up to eight different tRNAs by the heterodimeric adenosine deaminase acting on tRNA. This substrate expansion significantly influenced the evolution of eukaryotic genomes in terms of codon usage and tRNA gene composition. However, the selective advantages driving this process remain unclear. Here, we have studied the evolution of I34, tRNA adenosine deaminase A, adenosine deaminase acting on tRNA, and their relevant codons in a large set of bacterial and eukaryotic species. We show that a functional expansion of I34 to tRNAs other than tRNAArg also occurred within bacteria, in a process likely initiated by the emergence of unmodified A34-containing tRNAs. In eukaryotes, we report on a large variability in the use of I34 in protists, in contrast to a more uniform presence in fungi, plans, and animals. Our data support that the eukaryotic expansion of I34-tRNAs was driven by the improvement brought by these tRNAs to the synthesis of proteins highly enriched in certain amino acids.Rageot, M., Théry-Parisot, I., Beyries, S., Lepère, C., Carré, A., Mazuy, A., Filippi, J.-J., Fernandez, X., Binder, D., Regert, M., 2019. Birch bark tar production: Experimental and biomolecular approaches to the study of a common and widely used prehistoric adhesive. Journal of Archaeological Method and Theory 26, 276-312. bark tar, the oldest adhesive known in Europe, was widely used during Prehistory. This material, produced by the dry distillation of birch bark, has been identified in various spheres of activities and provides valuable information on the know-how and technical and territorial systems of past societies. This biomaterial can also provide evidence on socio-economic networks and mobility. However, very little is known about the production systems of birch bark tar during Prehistory, including the Neolithic period. The lack of findings in the archaeological record necessitates the development of an approach that combines experimental archaeology and biomolecular chemistry. We present here (1) the results of experiments in which different birch bark tar production systems were tested and (2) the molecular signatures of the birch bark tars produced according to different processes based on the use of ceramic vessels. The key role of bark quality is highlighted for the first time. This study also details direct archaeological inference of the experimental results obtained: a total of 23 samples from the site of Nice-Giribaldi (France, second part of the fifth century BCE) was investigated. Different categories of birch bark tars were identified during Neolithic in the south of France, providing evidence for the existence of complex manufacturing systems and procurement networks.Ragsdale, S.W., 2019. Elusive microbe that consumes ethane found under the sea. Nature 568, 40-41. microorganism that consumes ethane in the absence of environmental oxygen has been discovered. In the depths of the sea, this microbe, which oxidizes ethane, partners with another that reduces sulfate to sulfide. Plumes of natural gas emanate from the bottom of the ocean. These hydrocarbon emissions comprise around 90% methane, with ethane making up most of the rest. Such deep-sea sources are responsible for 5% of the methane, a greenhouse gas, present in Earth’s atmosphere1. The amount of hydrocarbon released from the deep sea into the atmosphere is substantially reduced by microorganisms that capture and use these gases as their sole source of cellular carbon and energy. Writing in Nature, Chen et al.2 describe the culmination of a ten-year scientific mission to identify and characterize the microorganisms and reactions that are responsible for ethane consumption at hydrocarbon seeps in the deep sea.The microbes that metabolize the small alkane molecules methane, propane and butane to carbon dioxide in the absence of environmental oxygen (a process called anaerobic oxidation) have been identified, but those that use ethane have been elusive. Although the oxidation of alkanes by enzymes known as oxygenases in the presence of environmental oxygen (aerobic oxidation) is a thermodynamically favourable reaction, and thus likely to happen, the anaerobic process is thermodynamically unfavourable. Therefore, anaerobic alkane oxidation can occur only if it is coupled to an extremely thermodynamically favourable reduction reaction.Chen et al. show that the anaerobic oxidation of ethane involves a mutually beneficial relationship, called syntrophy, between two microorganisms (Fig. 1). A newly identified microbe, the archaeon ‘Candidatus Argoarchaeum ethanivorans’, oxidizes ethane to CO2. Like all known anaerobic microbes that oxidize methane, propane and butane, Ca. A. ethanivorans is classified as an anaerobic methanotrophic (ANME) archaeon. Chen et al. show that the oxidation of ethane to CO2 requires another biochemical reaction, the reduction of sulfate to sulfide. The genome of Ca. A. ethanivorans lacks sulfate-reducing enzymes, but an analysis of the microorganisms that live in the same microbial culture as Ca. A. ethanivorans revealed the presence of two bacterial strains from the genus Desulfosarcina that reduce sulfate to sulfide.There is active debate concerning the nature of the syntrophic relationship between alkane-oxidizing archaea and sulfate-reducing bacteria. Does it involve the exchange of metabolites such as hydrogen molecules, small organic molecules or sulfur-containing molecules between the partner species? Or does it involve the direct interspecies transfer of electrons? Evidence for the direct transfer of electrons is supported by the observation that alkane-oxidizing microbes contain genes that encode cytochrome enzymes with multiple haem groups, which catalyse reduction and oxidation reactions3–5; such reactions involve the transfer of electrons between molecules. Furthermore, transmission electron microscopy has revealed the presence of filament-like nanowire connections between methane- or butane-oxidizing microbes and sulfate-reducing microbes. These filaments are thought to be needed for interspecies electron transfer3,4. Nevertheless, contrasting evidence also shows that ANME archaea involved in marine methane oxidation produce a sulfur-containing molecule that is transferred to a sulfate-reducing partner microorganism6.Chen et al. think that, for ethane oxidation, the transfer of a sulfur-containing metabolite is the process most likely to underlie the interaction between these two types of microorganism. This is because Ca. A. ethanivorans produces a lot of sulfur during growth, lacks the nanowire structures that have been observed in methane-oxidizing microbes, and grows as single cells rather than as a biofilm (a structure in which microbial cells stick to each other). All of these features could facilitate interspecies electron transfer. But Chen et al. also observed that the genomes of the sulfate-reducing bacteria they studied encode multi-haem cytochromes and the components of nanowire connections similar to those that are found in cultures of alkane-oxidizing and sulfate-reducing microbes grown together3. So, the jury is still out on how this interspecies coupling occurs.What is the biochemical pathway for transforming ethane into CO2? Chen and colleagues demonstrate unambiguously that the genome of Ca. A. ethanivorans contains three genes that encode the subunits of a previously unknown enzyme, which we call here ethyl-coenzyme M reductase (ECR). They then identify the protein sequence of ECR using mass spectrometry. ECR is closely related to an enzyme called methyl-coenzyme M reductase (MCR), which is present in microorganisms that oxidize or generate methane. Chen et al. also identify the final product of the reaction catalysed by ECR, ethyl-coenzyme M. Chen et al. modelled the 3D structures of the Ca. A. ethanivorans ECR and the butane-metabolizing enzyme (butyl-coenzyme M reductase) of ‘Candidatus Syntrophoarchaeum’4, and compared them with the known structure of the MCR of Methanothermobacter marburgensis7. On the basis of this structure comparison, as well as an alignment of the sequences of all known MCR-related proteins, they conclude that ECR and the other enzymes that metabolize non-methane hydrocarbon gases form a distinct cluster within an overarching group of enzymes called the alkyl-coenzyme M reductase (ACR) family, which catalyse the anaerobic oxidation of alkanes.By analogy with the well-studied enzymatic mechanism of MCR8, it is likely that ECR initiates anaerobic ethane oxidation by transforming ethane into an ethyl radical molecule, which is very reactive. It will be exciting when researchers are able to generate sufficient amounts of ECR to determine its enzymatic and biophysical properties. For example, how does it selectively catalyse the oxidation of ethane when the natural gas plumes where Ca. A. ethanivorans grows are so rich in methane? The authors’ analysis did not reveal any obvious distinguishing features of the binding pockets of ACR enzymes, including ECR, that could explain their preference for metabolizing specific alkanes. However, the structures that the authors compared represent the inactive states of ACRs. It is to be hoped that the crystal structures of the active states of this enzyme family will soon be determined to help clarify this and other questions about their mechanism.Chen et al. propose a plausible route from ECR-generated ethyl-coenzyme M to CO2. In this model, ethyl-coenzyme M is transformed into acetyl-coenzyme A, a molecule involved in many other metabolic processes, which is then oxidized through a mechanism called the reverse Wood–Ljungdahl pathway9. The authors identified proteins that are involved in this pathway using genomic and proteomic methods. However, the conversion of ethyl-coenzyme M to acetyl-coenzyme A still requires experimental validation. A similar gap in knowledge also exists for other non-methane oxidation pathways, including anaerobic butane oxidation by Ca. Syntrophoarchaeum4.The next logical steps are to resolve the controversy regarding the nature of the communication between the newly identified ethane-oxidizing microorganism and its sulfate-reducing partner, and to build the metabolic bridge between ethyl-coenzyme M and acetyl-coenzyme A.Figure 1 | The fate of deep-sea hydrocarbons.?The plumes of gas that are produced at the ocean bottom are composed mainly of methane, the smallest alkane molecule, but also contain smaller amounts of other alkanes, including ethane, propane and butane (quantities shown in teragrams per year; 1 Tg?=?1012 grams)1,10–13. Deep-sea microorganisms consume a large proportion of these gases, and only a small proportion ends up in the atmosphere, where it contributes to the greenhouse effect. The microbial oxidation of alkanes into carbon dioxide in the absence of oxygen (anaerobic oxidation) requires a complementary reaction comprising the reduction of sulfate to sulfide. These two reactions are carried out by distinct alkane-oxidizing (deep-colour symbols) and sulfate-reducing (pale symbols) microorganisms. Other microorganisms perform aerobic oxidation nearer the sea’s surface (not shown). Chen et al.2 identified the archaeon ‘Candidatus Argoarchaeum ethanivorans’ as the first known microbe to oxidize ethane anaerobically. They also identified two strains of bacterium from the genus Desulfosarcina that reduce sulfate to sulfide and enable ethane oxidation to occur. References1. Judd, A. G. Environ. Geol. 46, 988–996 (2004).2. Chen, S.-C. et al. Nature 568, 108–111 (2019).3. Krukenberg, V. et al. Environ. Microbiol. 20, 1651–1666 (2018).4. Laso-Pérez, R. et al. Nature 539, 396–401 (2016).5. McGlynn, S. E., Chadwick, G. L., Kempes, C. P. & Orphan, V. J. Nature 526, 531–535 (2015).6. Milucka, J. et al. Nature 491, 541–546 (2012).7. Ermler, U., Grabarse, W., Shima, S., Goubeaud, M. & Thauer, R. K. Science 278, 1457–1462 (1997).8. Wongnate, T. et al. Science 352, 953–958 (2016).9. Ragsdale, S. W. & Pierce, E. Biochim. Biophys. Acta 1784, 1873–1898 (2008).10. Plass-Dülmer, C., Koppmann, R., Ratte, M. & Rudolph, J. Glob. Biogeochem. Cycles 9, 79–100 (1995).11. Etiope, G. & Ciccioli, P. Science 323, 478 (2009)12. Bousquet, P. et al. Nature 443, 439–443 (2006).13. Dals?ren, S. B. et al. Nature Geosci. 11, 178–184 (2018).Rahman, S., Rahman, L., Khalil, A.T., Ali, N., Zia, D., Ali, M., Shinwari, Z.K., 2019. Endophyte-mediated synthesis of silver nanoparticles and their biological applications. Applied Microbiology and Biotechnology 103, 2551-2569. has emerged as a frontier technology for fabrication of functionally diverse nanoparticles that possess tremendous therapeutic implications. Various biological resources have already demonstrated their potential to produce nanoparticles with interesting features. Endophytic microbes live in a symbiotic relationship with plants possessing a unique and versatile reservoir of potentially therapeutic secondary metabolites having the tendency to reduce metallic ions into nanoparticles. Successful biosynthesis of AgNPs using endophytic organisms has already been reported; however, the overall picture about its synthesis and applications is still not clear. In the current article, a comprehensive review of literature was performed for comparing different physical and biological properties of endophytic microbe-derived AgNPs. In addition, the present paper mechanistically explains the synthesis of AgNPs and their diverse pharmacognostic properties. Further studies are encouraged to understand the mechanism of biopharmaceutical effects of these endophyte-mediated NPs.Raina, J.-B., Fernandez, V., Lambert, B., Stocker, R., Seymour, J.R., 2019. The role of microbial motility and chemotaxis in symbiosis. Nature Reviews Microbiology 17, 284-294. symbiotic relationships rely on the acquisition of microbial partners from the environment. However, the mechanisms by which microbial symbionts find and colonize their hosts are often unknown. We propose that the acquisition of environmental symbionts often necessitates active migration and colonization by the symbionts through motility and chemotaxis. The pivotal role of these behaviours in the onset and maintenance of symbiotic interactions is well established in a small number of model systems but remains largely overlooked for the many symbioses that involve the recruitment of microbial partners from the environment. In this Review, we highlight when, where and how chemotaxis and motility can enable symbiont recruitment and propose that these symbiont behaviours are important across a?wide range of hosts and environments.Raj, I., Qu, M., Xiao, L., Hou, J., Li, Y., Liang, T., Yang, T., Zhao, M., 2019. Ultralow concentration of molybdenum disulfide nanosheets for enhanced oil recovery. Fuel 251, 514-522. enhanced oil recovery (C-EOR) agents, such as polymer and surfactants, have been used to recover residual oil from reservoirs. The investigation for finding more efficient and more economic agents has never been stopped. Here, we demonstrate the potential of two-dimensional MoS2 nanosheets as a C-EOR agent. The synthesized amphiphilic MoS2 nanosheets function as a surfactant by altering the wettability of the core even at very low concentrations. The laboratory core flooding experiments were performed in the man-made core samples with various permeabilities in range of 2.5–2500?mD saturated with crude oil (100 cP) and model oil (25 cP). The brine with the salinity of 98,171?mg/L is used for secondary flooding and nanofluid containing 0.005?wt% of nanosheets is used for tertiary flooding. We observe 21.18% and 18.25% of residual oil is recovered during tertiary flooding in 25?mD core samples saturated with model and crude oil respectively. This work reveals the new possibilities for economical production of oil using nanosheet based materials.Rasmussen, C.M.?., Kr?ger, B., Nielsen, M.L., Colmenar, J., 2019. Cascading trend of Early Paleozoic marine radiations paused by Late Ordovician extinctions. Proceedings of the National Academy of Sciences 116, 7207-7213;.: The first 120 million years of Phanerozoic life witnessed significant changes in biodiversity levels. Attempts to correlate these changes to potential short-term environmental drivers have been hampered by the crude temporal resolution of current biodiversity estimates. We present a biodiversity curve for the Early Paleozoic with high temporal precision. It shows that once equatorial sea-surface temperatures fell to present-day levels during the early Mid Ordovician, marine biodiversity accumulation accelerated dramatically. However, this acceleration ceased as increased volcanism commenced during the mid-Late Ordovician. Since biodiversity levels were not restored for at least ～35 million years, this finding redefines the nature of the end Ordovician mass extinctions and further reframes the Silurian as a prolonged recovery interval.Abstract: The greatest relative changes in marine biodiversity accumulation occurred during the Early Paleozoic. The precision of temporal constraints on these changes is crude, hampering our understanding of their timing, duration, and links to causal mechanisms. We match fossil occurrence data to their lithostratigraphical ranges in the Paleobiology Database and correlate this inferred taxon range to a constructed set of biostratigraphically defined high-resolution time slices. In addition, we apply capture–recapture modeling approaches to calculate a biodiversity curve that also considers taphonomy and sampling biases with four times better resolution of previous estimates. Our method reveals a stepwise biodiversity increase with distinct Cambrian and Ordovician radiation events that are clearly separated by a 50-million-year-long period of slow biodiversity accumulation. The Ordovician Radiation is confined to a 15-million-year phase after which the Late Ordovician extinctions lowered generic richness and further delayed a biodiversity rebound by at least 35 million years. Based on a first-differences approach on potential abiotic drivers controlling richness, we find an overall correlation with oxygen levels, with temperature also exhibiting a coordinated trend once equatorial sea surface temperatures fell to present-day levels during the Middle Ordovician Darriwilian Age. Contrary to the traditional view of the Late Ordovician extinctions, our study suggests a protracted crisis interval linked to intense volcanism during the middle Late Ordovician Katian Age. As richness levels did not return to prior levels during the Silurian—a time of continental amalgamation—we further argue that plate tectonics exerted an overarching control on biodiversity accumulation.Rathi, R., Lavania, M., Singh, N., Sarma, P.M., Kishore, P., Hajra, P., Lal, B., 2019. Evaluating indigenous diversity and its potential for microbial methane generation from thermogenic coal bed methane reservoir. Fuel 250, 362-372. enhanced coal bed methane process has emerged as cheaper, feasible and environment friendly approach for enhancing coal bed methane (CBM) generation worldwide. Despite the fact that India has tremendous potential for CBM, there are many challenges towards microbial translation of CBM. Therefore, to explore the possibility of microbial enhanced CBM generation from the deep thermogenic CBM reservoir, diversity of the microbial community was investigated using the 16S rRNA gene amplification methods. Additionally, a culture dependent analysis from the formation water of the reservoir was performed to access the ability of the indigenous microbes to produce methane from coal when enriched with suitable nutrient supplements. Culture independent data revealed the nature of communities i.e. bacterial and archaeal domain, majorly from thermophilic profile. The bacterial community was dominated by proteobacterial and Firmicutes taxa, while archaeal community was dominated by Euryarchaeota taxa (acetoclastic methanogens). The enrichment cultures derived from the formation water were able to produce methane (1002??mol/g coal) at 45?°C. The 16S rRNA gene analysis depicted that the enriched microbial culture was dominated with anaerobic thermophilic fermentative bacteria of Clostridiales family and acetoclastic Methanosarcinales methanogens. The present study depicts the biogenic methane generation in the thermogenic-gas containing CBM reservoir could be enhanced by stimulating the indigenous microorganisms through providing suitable nutrient supplements. Present investigation is likewise the prime response to deliberate about the capability of thermogenic CBM reservoir (temperature?>?40?°C) in India for biogenic methane generation through culture independent and culture dependent examination.Ratnayake, A.S., Sampei, Y., 2019. Organic geochemical evaluation of contamination tracers in deepwater well rock cuttings from the Mannar Basin, Sri Lanka. Journal of Petroleum Exploration and Production Technology 9, 989-996. data from rock-cutting samples can give rise to faulty interpretations due to contamination from drilling fluids used in modern deepwater petroleum exploration. In this study, oil-based drilling contaminants were removed by solvent extraction with dichloromethane and methanol (9:1) solution. Bulk and molecular organic geochemical characteristics were examined for both oil-based drilling mud and cleaned rock-cutting samples. Total organic carbon (TOC) values are notably high in heavy liquid oil-based drilling mud mixtures (TOC?=?21.4–63.3%, average?=?34.6% ± 8.6) compared to cleaned rock cuttings (TOC?=?0.4–1.5%, average?=?0.8% ± 0.3). In addition, drilling mud mixtures contain higher concentrations of unresolved complex mixtures (UCM) in the n-alkanes fraction. Therefore, it is difficult to distinguish individual homologues in the n-alkanes fraction. The triterpanes also have relatively high UCM contents compared to steranes fractions. However, hydrocarbon homologues can be identified in both the triterpanes and steranes fractions of oil-based drilling mud mixtures. Gas chromatograms indicate that the n-alkanes fractions of rock cuttings initially cleaned with solvent still show considerable contamination from drilling fluids. This remaining contamination was removed by an additional cleaning step using the soxhlet extraction technique. The triterpanes fraction in solvent-cleaned rock cuttings does not contain an overprint of heavy liquid oil-based drilling mud contamination. However, solvent-cleaned rock cuttings may still retain contamination signatures at the sterane C28-20R homologue due to coelution. The geochemical overprint of contaminants in the cleaned rock cuttings can be interpreted as infiltration of lower molecular weight compounds into micro-cracks of the cuttings. The distribution of these molecules varies in each hydrocarbon fraction. Therefore, close inspection of contamination effects is required before interpretation of traditional organic geochemical proxies such as source rock characteristics and maturity.Reddin, C.J., Kocsis, ?.T., Kiessling, W., 2019. Climate change and the latitudinal selectivity of ancient marine extinctions. Paleobiology 45, 70-84. rapid climate change is anticipated to increase extinction risk nonuniformly across the Earth's surface. Tropical species may be more vulnerable than temperate species to current climate warming because of high tropical climate velocities and reduced seawater oxygen levels. To test whether rapid warming indeed preferentially increased the extinction risk of tropical fossil taxa, we combine a robust statistical assessment of latitudinal extinction selectivity (LES) with the dominant views on climate change occurring at ancient extinction crises. Using a global data set of marine fossil occurrences, we assess extinction rates for tropical and temperate genera, applying log ratios to assess effect size and Akaike weights for model support. Among the classical “big five” mass extinction episodes, the end-Permian mass extinction exhibits temperate preference of extinctions, whereas the Late Devonian and end-Triassic selectively hit tropical genera. Simple links between the inferred direction of climate change and LES are idiosyncratic, both during crisis and background intervals. More complex models, including sampling patterns and changes in the latitudinal distribution of continental shelf area, show tropical LES to be generally associated with raised tropical heat and temperate LES with global cold temperatures. With implications for the future, our paper demonstrates the consistency of high tropical temperatures, habitat loss, and the capacity of both to interact in generating geographic patterns in extinctions.Reintjes, G., Arnosti, C., Fuchs, B., Amann, R., 2019. Selfish, sharing and scavenging bacteria in the Atlantic Ocean: a biogeographical study of bacterial substrate utilisation. The ISME Journal 13, 1119-1132. the roles played by individual heterotrophic bacteria in the degradation of high molecular weight (HMW) substrates is critical to understanding the constraints on carbon cycling in the ocean. At five sites in the Atlantic Ocean, we investigated the processing of organic matter by tracking changes in microbial community composition as HMW polysaccharides were enzymatically hydrolysed over time. During this investigation, we discovered that a considerable fraction of heterotrophic bacteria uses a newly-identified ‘selfish’ mode of substrate processing. We therefore additionally examined the balance of individual substrate utilisation mechanisms at different locations by linking individual microorganisms to distinct substrate utilisation mechanisms. Through FISH and uptake of fluorescently-labelled polysaccharides, ‘selfish’ organisms were identified as belonging to the Bacteroidetes, Planctomycetes and Gammaproteobacteria. ‘Sharing’ (extracellular enzyme producing) and ‘scavenging’ (non-enzyme producing) organisms predominantly belonged to the Alteromonadaceae and SAR11 clades, respectively. The extent to which individual mechanisms prevail depended on the initial population structure of the bacterial community at a given location and time, as well as the growth rate of specific bacteria. Furthermore, the same substrate was processed in different ways by different members of a pelagic microbial community, pointing to significant follow-on effects for carbon cycling.Reji, L., Tolar, B.B., Smith, J.M., Chavez, F.P., Francis, C.A., 2019. Differential co-occurrence relationships shaping ecotype diversification within Thaumarchaeota populations in the coastal ocean water column. The ISME Journal 13, 1144-1158. factors contributing to depth-related diversification of marine Thaumarchaeota populations remain largely unresolved. To investigate the role of potential microbial associations in shaping thaumarchaeal ecotype diversification, we examined co-occurrence relationships in a community composition dataset (16S rRNA V4-V5 region) collected as part of a 2-year time series in coastal Monterey Bay. Ecotype groups previously defined based on functional gene diversity—water column A (WCA), water column B (WCB) and Nitrosopumilus-like clusters—were recovered in the thaumarchaeal 16S rRNA gene phylogeny. Networks systematically reflected depth-related patterns in the abundances of ecotype populations, suggesting thaumarchaeal ecotypes as keystone members of the microbial community below the euphotic zone. Differential environmental controls on the ecotype populations were further evident in subnetwork modules showing preferential co-occurrence of OTUs belonging to the same ecotype cluster. Correlated abundances of Thaumarchaeota and heterotrophic bacteria (e.g., Bacteroidetes, Marinimicrobia and Gammaproteobacteria) indicated potential reciprocal interactions via dissolved organic matter transformations. Notably, the networks recovered ecotype-specific associations between thaumarchaeal and Nitrospina OTUs. Even at depths where WCB-like Thaumarchaeota dominated, Nitrospina OTUs were found to preferentially co-occur with WCA-like and Nitrosopumilus-like thaumarchaeal OTUs, highlighting the need to investigate the ecological implications of the composition of nitrifier assemblages in marine waters.Ren, B., Bryant, S.L., Lake, L.W., 2019. Estimating local capillary trap volume capacities using a geologic criterion. International Journal of Greenhouse Gas Control 85, 46-57. pressure heterogeneity causes local capillary trapping of CO2 in saline aquifers. However, quantifying local capillary trapping using conventional reservoir simulation is computationally intensive. This work employs a geologic criterion (GC) to rapidly estimate the volume capacity of local capillary traps in static geologic models. The criterion refers to the ‘critical capillary entry pressure’ that is used to indicate flow barriers and flow paths during buoyant flow. A previous study (Saadatpoor, 2012) found that issues exist in the criterion method: unknown physical critical capillary entry pressures and boundary barriers. This work addresses the two issues. It is shown that the criterion method gives a close upper bound estimation of local capillary trap volume capacities. Several fine-scale geostatistical realizations of capillary entry pressure fields are considered, and the effects of reservoir heterogeneity, system sizes, aspect ratios, and boundary types are examined. The results from the GC are also strictly interpreted through invoking a simple counting argument. The overall work enhances our mechanistic understanding of the geological controls of local capillary traps.Ren, S., Yao, G., Zhang, Y., 2019. High-resolution geostatistical modeling of an intensively drilled heavy oil reservoir, the BQ 10 block, Biyang Sag, Nanxiang Basin, China. Marine and Petroleum Geology 104, 404-422. a high-resolution subsurface model is the ultimate goal of reservoir characterization. The “BQ 10 Block”, in Biyang Sag of Nanxiang Basin in China, is a data-rich mature field with heavy oil deposits penetrated by over two hundred wells with an average well spacing of 75m. The aim of this study is to establish a three-dimensional high-resolution model of the BQ 10 reservoir and to accurately and efficiently derive its geological and geometrical properties. A geostatistical modeling study was carried out in combination with stratigraphic correlation, core observations, log interpretation, lithology estimation, and sedimentary facies analysis. Based on core and wireline log data, lithology and conventional well logs (i.e. resistivity, gamma ray, and spontaneous potential) were correlated first. Lithofacies data at cored well locations were grouped into petrofacies units based on reservoir quality data. Using a neural network method, petrofacies at uncored wells was predicted based on correlation with conventional well logs. For different petrofacies, statistical analyses revealed correlation between laboratory porosity and permeability with acoustic well logs. A petrofacies model was built alternatively with indicator kriging, truncated Gaussian simulation (TGS), and sequential indicator simulation (SIS). SIS with a 3D trend model was identified to give the most reasonable petrofacies distribution. Using this model, facies-controlled petrophysical property modeling was performed using sequential Gaussian simulation (SGS). A validation procedure based on “minimum acceptance criteria” was employed to ensure that the SIS/SGS realizations are consistent. For this data-rich reservoir, this study demonstrates an effective application of the standard geostatistical modeling techniques on constructing high-resolution reservoir models of a heavy oil reservoir. The final suite of models reveal a likely range of reservoir facies and petrophysical property distributions for BQ 10, which can be useful for designing heavy oil recovery operations.Retelletti Brogi, S., Kim, J.-H., Ryu, J.-S., Jin, Y.K., Lee, Y.K., Hur, J., 2019. Exploring sediment porewater dissolved organic matter (DOM) in a mud volcano: Clues of a thermogenic DOM source from fluorescence spectroscopy. Marine Chemistry 211, 15-24. volcanoes (MVs) are potential conduit migration pathways for deep thermogenic DOM. In this study, we investigated the dissolved organic matter (DOM) of porewater in a MV in the Canadian Beaufort Sea and compared dissolved organic carbon (DOC) and fluorescent DOM (FDOM) between the MV and a reference site (RS). The chemical and isotopic compositions (Cl?, δ18O and δD) of porewater from the MVs indicated that these fluids are derived from a mixture of seawater, meteoric water, and clay dehydration, causing a freshening of the porewaters. Interestingly, the porewaters in the MV exhibited DOC concentrations up to 14 times higher than those in the RS. This high DOC concentration was attributed to a higher concentration in the deep fluid moving upwards through the MV, and in minor part to processes such as particulate organic matter sulfate reduction, anaerobic oxidation of methane and higher biological activity in the MV sediments. The fluorescence results showed the presence of four components in both MV and RS sites, which included two humic-like, one microbial humic-like, and a protein-like component. All the four fluorescent components increased with depth, showing a good linear relationship with DOC. However, the DOC-normalized fluorescence in the porewater DOM was on average 3 to 7 times lower in the MV, suggesting that the DOM molecules have undergone thermogenic processes in the deep sediments, and that shallow processes do not affect significantly the FDOM composition. Our results highlight that fluids migrating from the deep sediment through the MV can be an important source of thermogenically altered DOM to the shallow sediments and overlaying water column.Revel’skii, I.A., Yashin, Y.S., Revel’skii, A.I., 2019. Atmospheric pressure photoionization mass spectrometry: New capabilities for the determination of the numbers of components in complex mixtures and their identification. Journal of Analytical Chemistry 74, 192-197. atmospheric pressure photoionization and photochemical ionization mass spectrometry (APPI/APPCI?MS) makes it possible to compare the number of peaks in a mass spectrum with the number of components in the test mixture because of the measurements of the mass spectra of individual compounds, which mainly consist of the peaks of a molecular ion (M+) or a protonated molecule (MH+). The capabilities of gas chromatography–electron ionization (EI) and atmospheric pressure ionization mass spectrometry for the identification of trace components of complex mixtures are considered. The advantages of APPI/APPCI?MS, which makes it possible to increase the reliability of the detection of components in the complex mixtures of organic compounds, over EI mass spectrometry are shown. Rey-Sanchez, C., Bohrer, G., Slater, J., Li, Y.-F., Grau-Andrés, R., Hao, Y., Rich, V.I., Davies, G.M., 2019. The ratio of methanogens to methanotrophs and water-level dynamics drive methane exchange velocity in a temperate kettle-hole peat bog. Biogeosciences Discussions 2019, 1-48. are a large source of methane (CH4) to the atmosphere, yet the uncertainty around the estimates of CH4 flux from peatlands is large. To better understand the spatial heterogeneity in temperate peatland CH4 emissions and their response to physical and biological drivers, we studied CH4 dynamics throughout the growing seasons of 2017 and 2018 in Flatiron Lake Bog, a kettle-hole peat bog in Ohio. The site is composed of six different hydro-biological zones: an open water zone, four concentric vegetation zones surrounding the open water, and a restored zone connected to the main bog by a narrow channel. At each of these locations, we monitored water level (WL), CH4 pore-water concentration at different peat depths, CH4 fluxes from the ground and from representative plant species using chambers, and microbial community composition with focus here on known methanogens and methanotrophs. Integrated CH4 emissions for the growing season were estimated as 315.4?±?166?mg?CH4 ?m?2?d?1 in 2017, and 362.3?±?687?mg?CH4 ?m?2?d?1 in 2018. Median CH4 emission was highest in the open water, then decreased and became more variable through the concentric vegetation zones as the WL dropped, with extreme emission hotspots observed in the Tamarack mixed woodlands (TMW), and low emissions in the restored zone (18.8–30.3?mg?CH4 ?m?2?d?1). Generally, CH4 flux from above-ground vegetation was negligible compared to ground flux (<?0.4?%), although blueberry plants were a small CH4 sink. Pore-water CH4 concentrations varied significantly among zones, with the highest values in the TMW, close to saturation, and the lowest values in the restored zone. While the CH4 fluxes and pore-water concentrations were not correlated with methanogen relative abundance, the ratio of methanogens to methanotrophs in the upper portion of the peat was significantly correlated to CH4 exchange velocity (here defined as the ratio between pore-water concentration of CH4 in the top of the peat profile and CH4 flux). This study illustrates the importance of the interactions between water level and microbial composition to better understand CH4 fluxes from bogs, and wetlands in general.Rezaei, M., Gieleciak, R., Michaelian, K.H., 2019. Determination of olefin contents in liquid hydrocarbons using a quantum cascade laser and a photoacoustic detector. Energy & Fuels 33, 2859-2866. determination of olefin contents in liquid hydrocarbons by means of laser-based infrared spectroscopy was demonstrated for the first time in this work. This new technique utilizes a commercial mid-infrared external-cavity quantum cascade laser and a photoacoustic detector to monitor characteristic olefin C═C absorption bands in the ～1640–1680 cm–1 (5.95–6.1 μm) region. It is suitable for measurements of olefin concentrations in a variety of samples, including those derived from partially upgraded bitumen. To confirm this capability, olefin concentrations in the solutions of model compounds, thermally cracked and hydrotreated naphthas, and actual olefin-rich distillate samples were measured. This investigation showed that infrared lasers create a viable alternative to the conventional NMR and chemical methods widely used to determine the olefin contents in hydrocarbon feedstocks and products.Rezk, M.G., Foroozesh, J., Zivar, D., Mumtaz, M., 2019. CO2 storage potential during CO2 enhanced oil recovery in sandstone reservoirs. Journal of Natural Gas Science and Engineering 66, 233-243. can be sequestered in hydrocarbon reservoirs when it is injected for enhanced oil recovery (EOR) purpose. This study aims to experimentally evaluate the CO2 sequestration potential in sandstone reservoirs during CO2-EOR projects with a focus on the effect of active forces in the reservoir. To do so, a series of core flooding experiments at reservoir conditions were conducted using horizontal and vertical systems. A real light crude oil sample together with two native sandstone cores used here that were taken from a Malaysian oil field. The experiments were performed at near-miscible condition. Four secondary CO2 flooding tests were conducted through a composite core arrangement at various flow rates in a horizontal system to investigate the effect of viscous forces on the oil recovery and also the CO2 storage. Additionally, the gravity force effect was studied by conducting a gas (CO2) assisted gravity drainage (GAGD) test in a vertical system. The results showed that the highest oil recovery at all stages of CO2 flooding was obtained during the GAGD test. Considering flooding in the horizontal system, the ultimate recovery factor (RF) was significantly improved by increasing the CO2 injection rate. Furthermore, by investigating the interplay between the governing forces during CO2 injection, it was found that a higher oil RF was obtained at a lower capillary number at early stages of the test, while the CO2 injection rate (viscous forces) should be increased after breakthrough to overcome the capillary forces and recover more oil. In terms of CO2 storage, it was useful to quantify CO2 storage efficiency and CO2 trapping mechanisms which was mainly solubility trapping. Therefore, CO2 solubility in crude oil was also measured at various pressures. The gravitational effect in the GAGD test resulted in the highest CO2 storage percentage. While in the horizontal system, the storage efficiency of CO2 decreased with increasing the injection rate. Furthermore, a dimensionless number was proposed to investigate the combined effect of active forces in addition to CO2 diffusion during CO2 flooding operations. Finally, two correlations based on the combined dimensionless number were introduced to predict oil RF and CO2 storage efficiency for near-miscible CO2 flooding processes.Richter, N., Longo, W.M., George, S., Shipunova, A., Huang, Y., Amaral-Zettler, L., 2019. Phylogenetic diversity in freshwater-dwelling Isochrysidales haptophytes with implications for alkenone production. Geobiology 17, 272-280. of the order Isochrysidales are unique among haptophyte lineages in being the exclusive producers of alkenones, long‐chain ketones that are commonly used for paleotemperature reconstructions. Alkenone‐producing haptophytes are divided into three major groups based largely on molecular ecological data: Group I is found in freshwater lakes, Group II commonly occurs in brackish and coastal marine environments, and Group III consists of open ocean species. Each group has distinct alkenone distributions; however, only Groups II and III Isochrysidales currently have cultured representatives. The uncultured Group I Isochrysidales are distinguished geochemically by the presence of tri‐unsaturated alkenone isomers (C37:3b Me, C38:3b Et, C38:3b Me, C39:3b Et) present in water column and sediment samples, yet their genetic diversity, morphology, and environmental controls are largely unknown. Using small‐subunit (SSU) ribosomal RNA (rRNA) marker gene amplicon high‐throughput sequencing of environmental water column and sediment samples, we show that Group I is monophyletic with high phylogenetic diversity and contains a well‐supported clade separating the previously described “EV” clade from the “Greenland” clade. We infer the first partial large‐subunit (LSU) rRNA gene Group I sequence phylogeny, which uncovered additional well‐supported clades embedded within Group I. Relative to Group II, Group I revealed higher levels of genetic diversity despite conservation of alkenone signatures and a closer evolutionary relationship with Group III. In Group I, the presence of the tri‐unsaturated alkenone isomers appears to be conserved, which is not the case for Group II. This suggests differing environmental influences on Group I and II and perhaps uncovers evolutionary constraints on alkenone biosynthesis.Rimmer, P.B., Rugheimer, S., 2019. Hydrogen cyanide in nitrogen-rich atmospheres of rocky exoplanets. Icarus 329, 124-131. cyanide (HCN) is a key feedstock molecule for the production of life's building blocks. The formation of HCN in an N2-rich atmospheres requires first that the triple bond between N≡N be severed, and then that the atomic nitrogen find a carbon atom. These two tasks can be accomplished via photochemistry, lightning, impacts, or volcanism. The key requirements for producing appreciable amounts of HCN are the free availability of N2 and a local carbon to oxygen ratio of C/O?≥ 1. We discuss the chemical mechanisms by which HCN can be formed and destroyed on rocky exoplanets with Earth-like N2 content and surface water inventories, varying the oxidation state of the dominant carbon-containing atmospheric species. HCN is most readily produced in an atmosphere rich in methane (CH4) or acetylene (C2H2), but can also be produced in significant amounts (>1?ppm) within CO-dominated atmospheres. Methane is not necessary for the production of HCN. We show how destruction of HCN in a CO2-rich atmosphere depends critically on the poorly-constrained energetic barrier for the reaction of HCN with atomic oxygen. We discuss the implications of our results for detecting photochemically produced HCN, for concentrating HCN on the planet's surface, and its importance for prebiotic chemistry.Rincón-Tomás, B., Duda, J.-P., Somoza, L., González, F.J., Schneider, D., Medialdea, T., Santofimia, E., López-Pamo, E., Madureira, P., Hoppert, M., Reitner, J., 2019. Cold-water corals and hydrocarbon-rich seepage in Pompeia Province (Gulf of Cádiz) – living on the edge. Biogeosciences 16, 1607-1627. cold-water corals (CWCs) have a global distribution and have commonly been found in areas of active fluid seepage. The relationship between the CWCs and these fluids, however, is not well understood. This study aims to unravel the relationship between CWC development and hydrocarbon-rich seepage in Pompeia Province (Gulf of Cádiz, Atlantic Ocean). This region is comprised of mud volcanoes (MVs), coral ridges and fields of coral mounds, which are all affected by the tectonically driven seepage of hydrocarbon-rich fluids. These types of seepage, for example, focused, scattered, diffused or eruptive, is tightly controlled by a complex system of faults and diapirs. Early diagenetic carbonates from the currently active Al Gacel MV exhibit δ13C signatures down to ?28.77?‰ Vienna Pee Dee Belemnite (VPDB), which indicate biologically derived methane as the main carbon source. The same samples contain 13C-depleted lipid biomarkers diagnostic for archaea such as crocetane (δ13C down to ?101.2?‰ VPDB) and pentamethylicosane (PMI) (δ13C down to ?102.9?‰ VPDB), which is evidence of microbially mediated anaerobic oxidation of methane (AOM). This is further supported by next generation DNA sequencing data, demonstrating the presence of AOM-related microorganisms (ANMEs, archaea, sulfate-reducing bacteria) in the carbonate. Embedded corals in some of the carbonates and CWC fragments exhibit less negative δ13C values (?8.08?‰ to ?1.39?‰ VPDB), pointing against the use of methane as the carbon source. Likewise, the absence of DNA from methane- and sulfide-oxidizing microbes in sampled coral does not support the idea of these organisms having a chemosynthetic lifestyle. In light of these findings, it appears that the CWCs benefit rather indirectly from hydrocarbon-rich seepage by using methane-derived authigenic carbonates as a substratum for colonization. At the same time, chemosynthetic organisms at active sites prevent coral dissolution and necrosis by feeding on the seeping fluids (i.e., methane, sulfate, hydrogen sulfide), allowing cold-water corals to colonize carbonates currently affected by hydrocarbon-rich seepage.Rissanen, A.J., M?ki, A., Tiirola, M., Mpamah, P.A., Taipale, S., Peura, S., Biasi, C., Nyk?nen, H., 2019. Vertical stratification of bacteria and archaea in sediments of a small boreal humic lake. FEMS Microbiology Letters 366, Article fnz044. sediments of small boreal humic lakes are important carbon stores and greenhouse gas sources, the composition and structuring mechanisms of their microbial communities have remained understudied. We analyzed the vertical profiles of microbial biomass indicators (PLFAs, DNA and RNA) and the bacterial and archaeal community composition (sequencing of 16S rRNA gene amplicons and qPCR of mcrA) in sediment cores collected from a typical small boreal lake. While microbial biomass decreased with sediment depth, viable microbes (RNA and PLFA) were present all through the profiles. The vertical stratification patterns of the bacterial and archaeal communities resembled those in marine sediments with well-characterized groups (e.g. Methanomicrobia, Proteobacteria, Cyanobacteria, Bacteroidetes) dominating in the surface sediment and being replaced by poorly-known groups (e.g. Bathyarchaeota, Aminicenantes and Caldiserica) in the deeper layers. The results also suggested that, similar to marine systems, the deep bacterial and archaeal communities were predominantly assembled by selective survival of taxa able to persist in the low energy conditions. Methanotrophs were rare, further corroborating the role of these methanogen-rich sediments as important methane emitters. Based on their taxonomy, the deep-dwelling groups were putatively organo-heterotrophic, organo-autotrophic and/or acetogenic and thus may contribute to changes in the lake sediment carbon storage.Robertson, D.K., Mathias, D.L., 2019. Hydrocode simulations of asteroid airbursts and constraints for Tunguska. Icarus 327, 36-47. wide range of meteors were simulated impacting Earth's atmosphere using the ALE3D hydrocode. The size, density, strength curve, entry angle, and velocity of the meteors were varied to cover the parameter space of airbursts of interest to planetary defense in general which encompasses the Tunguska event in particular. The hydrocode simulations were used to calibrate a simple analytical model that can be used to quickly estimate the burst height of an incoming asteroid or comet.The hydrocode simulations show both rocky asteroids and icy comets are plausible Tunguska meteors, over a wide range of sizes, speeds, entry angles, at least in terms of the energy delivered and height of burst required to produce the tree-fall, and the lack of an obvious impact crater on the ground. This agrees with previous analytical estimates and hydrocode simulations of hypothetical Tunguska meteors, and provides a complete range of possibilities.Modelling of the tree wind resistance predicts windspeeds of 40–50?m/s are required to fell most of the trees. This is slower than previous estimates from nuclear test data, but faster than lower bound estimates from a 3?Mt blast. It suggests an energy of 10?Mt is most likely for Tunguska, but requires missing tree size distribution and wind response data to better narrow the probability distribution of potential Tunguska impactors.Rochette, P., Ala?, R., Beck, P., Brocard, G., Cavosie, A.J., Debaille, V., Devouard, B., Jourdan, F., Mougel, B., Moustard, F., Moynier, F., Nomade, S., Osinski, G.R., Reynard, B., Cornec, J., 2019. Pantasma: Evidence for a Pleistocene circa 14?km diameter impact crater in Nicaragua. Meteoritics & Planetary Science 54, 880-901. circa 14?km diameter Pantasma circular structure in Oligocene volcanic rocks in Nicaragua is here studied for the first time to understand its origin. Geomorphology, field mapping, and petrographic and geochemical investigations all are consistent with an impact origin for the Pantasma structure. Observations supporting an impact origin include outward-dipping volcanic flows, the presence of former melt-bearing polymict breccia, impact glass (with lechatelierite and low H2O, <300?ppm), and also a possible ejecta layer containing Paleozoic rocks which originated from hundreds of meters below the surface. Diagnostic evidence for impact is provided by detection in impact glass of the former presence of reidite in granular zircon as well as coesite, and extraterrestrial ε54Cr value in polymict breccia. Two 40Ar/39Ar plateau ages with a combined weighted mean age of 815?±?11 ka (2 σ; P?=?0.17) were obtained on impact glass. This age is consistent with geomorphological data and erosion modeling, which all suggest a rather young crater. Pantasma is only the fourth exposed crater >10?km found in the Americas south of N30 latitude, and provides further evidence that a significant number of impact craters may remain to be discovered in Central and South America.Rogers, K., Saintilan, N., Mazumder, D., Kelleway, J.J., 2019. Mangrove dynamics and blue carbon sequestration. Biology Letters 15, 20180471. monitored coastal wetland vertical accretion, elevation gain and surface carbon (C) at Homebush Bay, Australia over 18 years (2000–2017) in three settings initially characterized by saltmarsh, mixed saltmarsh–mangrove ecotone and mangrove-dominated zones. During this time, the saltmarsh transitioned to mixed saltmarsh–mangrove ecotone, and the mixed saltmarsh–mangrove ecotone transitioned to mangrove, consistent with vegetation transitions observed across the east Australian continent in recent decades. In spite of mangrove recruitment and thickening in the former saltmarsh zone, and the dominance of mangrove root material as a contributing C source, the rate of C accumulation in the former saltmarsh zone did not change over the study period, and there was no significant increase in surface elevation. This contrasted with the response of sites with a longer history of mangrove colonization, which showed strong accretion and C accumulation over the period. The result suggests that the C accumulation and surface elevation gains made as a result of mangrove colonization may not be observable over initial decades, but will be significant in the longer term as forests reach maturity.Romagnoli, P., Balducci, C., Perilli, M., Esposito, G., Cecinato, A., 2019. Organic molecular markers in marine aerosols over the Western Mediterranean Sea. Environmental Pollution 248, 145-158. scientific campaign was undertaken along the Western sector of the Mediterranean Sea in the summer 2015 (26th Jun to 13th Jul), with the goal of gathering information about organic contaminants affecting marine aerosol over the Italian seas and with a special focus on changes in composition due to sources. 24 PM10 atmospheric samples in total were chemically characterized, including polycyclic aromatic hydrocarbons (PAHs), aliphatic hydrocarbons (n-alkanes) and phthalate esters. Contemporarily, regulated gaseous toxicants (i.e. ozone, nitrogen oxides and sulfur dioxide) and meteorological parameters were recorded. Samplings were carried out inshore in front of harbors (N?=?7) and along the cruise, both during the vessel shipping (N?=?11, transects) and at its stops offshore (N?=?6). Total PAH concentrations ranged from 0.03 to 1.94?ng/m3 and raised close to harbors and coastal sites, confirming that continental sources were responsible for the strong increase of pollution levels there compared to offshore. The percent composition and diagnostic ratio rates of PAHs were different for harbors, while transects were in agreement with offshore stops, possibly due to the different impact of pollution sources. n-Alkanes (C21-C38) and the corresponding carbon preference index rates (CPI) were assessed; their values ranged 8.7–90?ng/m3 and 1.1–2.9 respectively, which suggested that fossil fuel combustion was the dominant source, though biogenic emission could contribute. Alkyl phthalates revealed wide variability in concentrations among aerosol samples. Moreover, long-range atmospheric transport and particle ageing effect induced by photo-oxidants were important factors controlling the composition of organic aerosols in the Mediterranean Sea air.Ross, D., Deamer, D., 2019. Prebiotic oligomer assembly: What was the energy source? Astrobiology 19, 517-521. of nucleotides and amino acids to form large, complex, and potentially functional products was an early and essential event on the paths leading to life's origin. The standard Gibbs energies of the condensation reactions are uphill, however, and at equilibrium will yield only declining sequences of small, nonfunctional oligomers. Geochemically produced condensing agents such as carbonyl sulfide, cyanamide, and polyphosphates have been proposed to invert the unfavorable condensation Gibbs energies and thereby activate exergonic condensation. We argue, however, that although activators may provide modest yields of oligomers, the inherently episodic nature of their sources throttles their effectiveness, and the fundamental hydrolytic instabilities of oligonucleotides and peptides ultimately prevail to yield decreasing product sequences. Notably, the Gibbs energy governing oligomer formation is antientropic. Accordingly, we propose that declining progression can be surmounted in evaporating pools in which a favorable entropy change is produced when high surface/volume ratios concentrate reactants at the air/water interface in continuous cycles of wetting and drying. The severely reduced configurational freedom of the solutes then inverts the antientropic nature of the condensation reactions, pivoting them to exergonic states and thus to the production of ascending sequences of complex polymeric products.Rubin-Blum, M., Antony, C.P., Sayavedra, L., Martínez-Pérez, C., Birgel, D., Peckmann, J., Wu, Y.-C., Cardenas, P., MacDonald, I., Marcon, Y., Sahling, H., Hentschel, U., Dubilier, N., 2019. Fueled by methane: deep-sea sponges from asphalt seeps gain their nutrition from methane-oxidizing symbionts. The ISME Journal 13, 1209-1225. host a remarkable diversity of microbial symbionts, however, the benefit their microbes provide is rarely understood. Here, we describe two new sponge species from deep-sea asphalt seeps and show that they live in a nutritional symbiosis with methane-oxidizing (MOX) bacteria. Metagenomics and imaging analyses revealed unusually high amounts of MOX symbionts in hosts from a group previously assumed to have low microbial abundances. These symbionts belonged to the Marine Methylotrophic Group 2 clade. They are host-specific and likely vertically transmitted, based on their presence in sponge embryos and streamlined genomes, which lacked genes typical of related free-living MOX. Moreover, genes known to play a role in host–symbiont interactions, such as those that encode eukaryote-like proteins, were abundant and expressed. Methane assimilation by the symbionts was one of the most highly expressed metabolic pathways in the sponges. Molecular and stable carbon isotope patterns of lipids confirmed that methane-derived carbon was incorporated into the hosts. Our results revealed that two species of sponges, although distantly related, independently established highly specific, nutritional symbioses with two closely related methanotrophs. This convergence in symbiont acquisition underscores the strong selective advantage for these sponges in harboring MOX bacteria in the food-limited deep sea.Rummel, J.D., 2019. From planetary quarantine to planetary protection: A NASA and international story. Astrobiology 19, 624-627. paper treats the very specific history of one aspect of space policy and how it, or more specifically its name, developed in the first two decades of the Space Age. The concepts of preventing the biological and organic contamination of other planetary bodies, which also protect the biosphere from the consequences of finding extraterrestrial life and returning it to Earth, were established in the late 1950s with the beginning of the Space Age. Within their first decade, those concepts were labeled “planetary quarantine,” a name that suggested the concepts but unfortunately came with latent baggage of its own. Over time, that sobriquet was replaced by the more prosaic “planetary protection,” which has less of a baggage problem and has come to be used in common parlance to describe this contamination avoidance within the spaceflight community. This paper does not duplicate material found in the “official” NASA history of planetary protection (Meltzer, 2011), which covered this specific subject only broadly, nor was the same material presented by Meltzer's predecessor (Phillips, 1974), who could not cover it because it had not happened yet.Sáenz, J.S., Roldan, F., Junca, H., Arbeli, Z., 2019. Effect of the extraction and purification of soil DNA and pooling of PCR amplification products on the description of bacterial and archaeal communities. Journal of Applied Microbiology 126, 1454-1467.: This study evaluated the effects of DNA extraction method, DNA purification and pooling of PCR amplification products on the description of bacterial and archaeal diversity.Methods and Results: Soil DNA was extracted by the Power Soil DNA extraction kit and a customized Griffiths’ protocol. Both methods are based on cell disruption by bead beating. In total, we used three soils and six independent extractions from each soil obtained by each of the two methods. Then, three of the six extracts of each treatment were further purified by spin columns filled with Sepharose 2B and polyvinylpolypyrrolidone (PVPP). The V4 hypervariable region of the 16S rRNA gene was amplified from each extract using the 515F/806R primer pair in four independent reactions. Three amplification products were combined and sequenced as a pooled sample, while the additional amplification product was sequenced individually. The resulting 72 amplification products were sequenced by Illumina MiSeq platform. DNA extraction method had a statistically significant effect on the estimation of the composition of microbial communities that might overwhelm differences in microbial communities from distinct soils. On the other hand, a further DNA purification step or pooling of PCR amplification products had a minor effect on the description of bacterial and archaeal communities.Conclusions: DNA extraction had the strongest effect on the description of bacterial and archaeal communities; low concentration of impurities, which allow PCR amplification, can still generate a minor additional bias, while PCR stochastic variability had the lowest effect.Significance and Impact of the Study: Although it is well known that methodological factors affect the description of microbial communities, the relative importance of each step is still unknown. The present study determined that of the factors tested, the DNA extraction method had the strongest effects on the description of bacterial and archaeal communities.Sagidullin, A.K., Stoporev, A.S., Manakov, A.Y., 2019. Effect of temperature on the rate of methane hydrate nucleation in water-in-crude oil emulsion. Energy & Fuels 33, 3155-3161. nucleation of methane hydrate in the emulsions of water in oil has been studied experimentally at a pressure of 12.5 MPa within the temperature range of ?3.0 to ?4.9 °C (supercooling 17.8–19.7 °C). It was demonstrated that the experimental survival curves are composed of two regions with different slopes to the time axis. Nucleation rates calculated for initial and final (in parentheses) regions of survival curves turned out to be equal to 0.00065 (0.00055), 0.00036 (0.00017), and 0.00018 (0.00010) s–1 m–2 for temperatures ?4.9, ?4.0, and ?3.0 °C, respectively. The experimental data were extrapolated to the regions of higher and lower supercooling values using a known expression describing the dependence of the nucleation rate on temperature. It may be expected that the information concerning the temperature dependence of hydrate nucleation rates in water–oil systems will be useful to optimize the consumption of kinetic hydrate inhibitors during the development of oil and gas deposits.Saidoun, M., Palermo, T., Passade-Boupat, N., Gingras, J.-P., Carrier, H., Daridon, J.-L., 2019. Revisiting asphaltenes instability predictions by probing destabiliztion using a fully immersed quartz crystal resonator. Fuel 251, 523-533. method of Asphaltene Instability Trend (ASIST) was derived from London dispersions first principles and Flory-Huggins theory to model the microscopical appearance of unstable flocs using limited number of refractive index (nD) measures on stock-tank oils (STO), series of liquid precipitants (n-alkanes) and routine PVT data (Buckley et al., 2007). In order to eliminate the tuning of the aging time of solutions in the method, the experimental protocol was modified by monitoring the signal of a fully immersed Quartz Crystal Resonator (QCR) to detect the instantaneous destabilization of asphaltenes in the surrounding media. Isothermal titrations were performed under atmospheric pressure while mixing. The test matrix was designed to vary the chain length of the n-alkanes titrant and the temperature. Subsequent refractive indices at detected conditions were used to calculate solubility parameters (δ) and to predict the instantaneous detection of unstable asphaltenes during the expansion of gas dissolved systems using the exact same immersed apparatus. Predictions were then challenged against experimental observations of artificial live oil systems created by recombining dead oils with gas mixtures at pressures up to 1000?bar. Isothermal Constant Mass Expansion (CME) experiments provided measured volumes as a function of pressure which served for modeling, along with the QCR sensor signal to probe the first agregation and deposition of unstable asphaltenes for each system at various conditions. Prediction results were compared to experimental detections for 2 different crude oils, temperatures ranging from 45°C to 120°C and gas dissolved concentrations ranging from 0 to 60 %mol.Sakai, M., Hayakawa, Y., Funada, Y., Ando, T., Fukusaki, E., Bamba, T., 2019. Development of a practical online supercritical fluid extraction–supercritical fluid chromatography/mass spectrometry system with an integrated split-flow method. Journal of Chromatography A 1592, 161-172., we describe a practical online supercritical fluid extraction-supercritical fluid chromatography/mass spectrometry (SFE-SFC/MS) system with an integrated split-flow method and a pre-column trap method that is well suited for the continuous extraction and separation of a wide range of compounds, including hydrophilic ones. Although an SFE-SFC system with a splitting method is already commercially available, in this study, we added some new features to this system: 1) a splitting method that further reduces the amount of extractant introduced into SFC, 2) a trap column, connected before the analytical column, with a different separation mechanism than the analytical column in the system with the splitting method, and 3) a system for calculating the recovery rate of SFE during online SFE-SFC/MS. In the above setup, part of the analyzed extract is introduced into the separation section at a higher split ratio owing to the make-up pump flow rate, thus reducing the distortion of the target analyte peak shape caused by the use of a strong extractant. Furthermore, the separation efficiency is improved by the use of an additional pre-column capable of interacting with compounds weakly retained on the analytical column. Finally, we show that equalization of the SFE and autosampler injection conditions allows evaluation of the recovery rate of SFE during online SFE-SFC/MS.Sakai, S., Takaki, Y., Miyazaki, M., Ogawara, M., Yanagawa, K., Miyazaki, J., Takai, K., 2019. Methanofervidicoccus abyssi gen. nov., sp. nov., a hydrogenotrophic methanogen, isolated from a hydrothermal vent chimney in the Mid-Cayman Spreading Center, the Caribbean Sea. International Journal of Systematic and Evolutionary Microbiology 69, 1225-1230. novel hydrogenotrophic methanogen, strain HHBT, was isolated from a deep-sea hydrothermal vent chimney sample collected from Beebe Vent Field at the Mid-Cayman Spreading Center, Caribbean Sea. The cells were non-motile regular to irregular cocci possessing several flagella. The novel isolate grew at 60–80?°C, pH 5.0–7.4 and with 1–4?% of NaCl (w/v). The isolate utilized H2/CO2 as the only substrates for growth and methane production. The results of phylogenetic analyses of both 16S rRNA and mcrA gene sequences and comparative genome analysis indicated that HHBT represented a member of the order Methanococcales , and was closely related to the members of the genera Methanothermococcus and Methanotorris . The most closely related species were Methanothermococcus okinawensis IH1T and Methanotorris igneus Kol 5T in comparison of 16S rRNA gene sequences (each with 93?% identity), and Methanotorris formicicus Mc-S-70T in the case of deduced amino acid sequence similarity of mcrA genes (92?% similarity). The ANI and AAI values between HHBT and the members of the genera Methanothermococcus and Methanotorris were 69–72?%?and 66–70?%, respectively. Although many of the morphological and physiological characteristics were quite similar between HHBT and the species of the genera Methanothermococcus and Methanotorris , they were distinguishable by the differences in susceptibility to antibiotics, formate utilization, growth temperature and NaCl ranges. On the basis of these phenotypic, phylogenetic and genomic properties, we propose that strain HHBT represents a novel species, of a novel genus, Methanofervidicoccus abyssi gen. nov., sp. nov. The type strain is HHBT (=JCM 32161T=DSM 105918T). The GenBank/EMBL/DDBJ accession numbers for the draft genome sequence of Methanofervidicocus abyssi HHBT are BFAX01000001–BFAX01000005.Sakaizawa, R., Sato, T., Mori, C., Oyama, H., Tsumune, D., Tsubono, T., Kano, Y., 2019. Position and flux estimation of the unexpected seepage of CO2 purposefully stored in a subseabed geological formation. International Journal of Greenhouse Gas Control 84, 131-146. mitigate global warming, the large volume of CO2 released into the atmosphere must be reduced. CO2 capture and storage (CCS) are promising means for this. In addition, CCS operators who inject and store CO2 into subseabed geological formations may be legally required to monitor CO2 leakage into seawater, even though such events are very unlikely; after detecting unusually high CO2 concentrations, their social responsibility implies specifying the position and flux of the associated CO2 seepage in the sea site. In this study, we adopted the adjoint marginal sensitivity method to predict such parameters based on the information recorded by a limited number of CO2 sensors located on the seafloor. In particular, we newly derived the adjoint marginal sensitivity from the relationship between a source term and the measured concentrations. We successfully conducted two-dimensional tests and three-dimensional simulations with a realistic topography; tidal and ocean currents with CO2 dispersion were time-forwardly simulated and the seepage information was efficiently evaluated via time-backward numerical tests. However, the limitation of this method also emerged. We accumulated knowledge on its practical utility and proposed some ways to reduce the estimation errors. It is also inferred that this method can be applied for the source detection of various marine pollutants and resources.Salmo, S.G., Malapit, V., Garcia, M.C.A., Pagkalinawan, H.M., 2019. Establishing rates of carbon sequestration in mangroves from an earthquake uplift event. Biology Letters 15, 20180799. assessed the carbon stocks (CS) in mangroves that developed after a magnitude 7.1 earthquake in Silonay, Oriental Mindoro, south Luzon, The Philippines in November 1994. The earthquake resulted in a 50 cm uplift of sediment that provided new habitat within the upper intertidal zone which mangroves colonized (from less than 2 ha pre-earthquake to the current 45 ha, 23 years post-earthquake). The site provided an opportunity for a novel assessment of the rate of carbon sequestration in recently established mangroves. The carbon stock was measured in above-ground, below-ground and sediment compartments over a seaward to landward transect. Results showed a mean carbon stock of 549 ± 30 Mg C ha?1 (of which 13% was from the above-ground biomass, 5% from the below-ground biomass and 82% from the sediments). There was high carbon sequestration at a 40 cm depth that can be inferred attributable to the developed mangroves. The calculated rate of C sequestration (over 23 years post-earthquake) was 10.2 ± 0.7 Mg C ha?1 yr?1 and is comparable to rates reported from mangroves recovering from forest clearing. The rates we present here from newly developed mangroves contributes to calibrating estimates of total CS from restored mangroves (of different developmental stages) and in mangroves that are affected by disturbances.Santos, D., Amaral, M., Filho, E.B.M., Dourado, R.S., Coutinho, J.A.P., Borges, G.R., Franceschi, E., Dariva, C., 2019. Revisiting the methodology for asphaltenes precipitation. Journal of Petroleum Science and Engineering 178, 778-786. world increase in energy demand has directed the petroleum industry to exploit unconventional oil reserves such as the Brazilian Pre-Salt reservoirs. Production conditions verified in those reservoirs enhance the occurrence of asphaltene precipitation as well as the correlated problems. Asphaltenes are well known as a solubility class. Such classification makes tough the determination of consistent chemical properties for these compounds. In this scenario, this study aims to analyze the influence of the standard precipitation methodologies upon the asphaltene characteristics. Three oils were selected, which are hereinafter called BR1, BR2, and BR3. Oil BR1 was produced from a Post-Salt reservoir while oils BR2 and BR3 are originated from a Post-Salt one. The asphaltenes were extracted through precipitation by n-heptane according to the ASTM 2007, ASTM 6560 (IP-143), the so-called ASTM 6560 SOHXLET, and the NUESC methodology. Asphaltene fractions were characterized regarding their chemical composition (FTIR) and thermal stability (DSC). The results showed that endothermic events typically registered for compounds which are strange to the commonly accepted asphaltene composition were verified. Also, the degradation temperature varied according to the precipitation method. In turn, the FTIR spectra detected a peak which is usually associated with naphthenic acids (3500?cm?1). Therefore, the FTIR analysis confirmed what was indicated by the thermograms. In summary, it was concluded that the asphaltene fractions that were extracted through the commonly used ASTM 2007 methodology from the Pre-Salt oils were a precipitated complex composed by asphaltenes and wax of naphthenic acids. Thus, the present work results are suggested as a starting point for the analyses of asphaltene properties and their implications on the crude oil behavior.Sanz Rodriguez, E., Plummer, C., Nation, M., Moy, A., Curran, M., Haddad, P.R., Paull, B., 2019. Sub-1 mL sample requirement for simultaneous determination of 17 organic and inorganic anions and cations in Antarctic ice core samples by dual capillary ion chromatography. Analytica Chimica Acta 1063, 167-177. significant advance of delivering high value multi-species data from sub-1 mL ice core sample volumes allows higher temporal resolution in deposition records of inorganic and low molecular weight organic anions and cations. The determination of these species is a fundamental strategic requirement in modern paleoclimate studies. Herein, for the first time, a dual capillary ion chromatography (Cap-IC) based method for the simultaneous separation of 17 organic and inorganic anions and cations in low volume Antarctic ice core samples is presented. The total amount of sample required for direct injection has been reduced to 190?μL, which is 35 times lower than the amount of sample required by standard ion chromatography methods. A dual Cap-IC system configured for the simultaneous determination of cations and anions was used throughout. A range of chromatographic parameters was optimised for both anion and cation systems to obtain baseline separations of all target analytes in a suitable run time and to minimise the amount of sample required. Baseline separation of matrix and trace ‘marker’ ions were achieved in less than 35?min, after injecting only 40?μL of sample in each IC system. Limits of detection (LODs) for all analytes determined were within a range similar to that achieved by previously published standard bore IC-based methods. Intra- and inter-day repeatability were evaluated, with both parameters being typically below 3% for peak area. In further validation of the method, a comparative analysis of a set of 420 ice core samples from Aurora Basin North site, Antarctica, previously analysed by standard IC, established that the proposed low sample volume technique was applicable as a routine measurement approach in ice core analysis projects.Scalice, D., Dolci, W., Brochu, L., Merriman, T., Davis, H., Billings, L., Voytek, M.A., 2019. FameLab USA: Improving science communication skills for early career scientists. Astrobiology 19, 614-623. International is a science communication competition for early career scientists pioneered by the Cheltenham Science Festival in the United Kingdom in 2005. At its heart is training in the best practices and techniques of good communication. NASA's Astrobiology Program and its partners implemented FameLab USA, one of over 30 implementations around the globe, from 2012 to 2016. FameLab USA's focus was on providing high-quality training for participants and equipping and empowering early career scientists to become skilled, confident communicators of science. The impacts of FameLab USA on participants have been studied, and results from these analyses are presented here.Significant gains in skills for all participants were documented, especially their ability to make better connections with audiences and use thematic structural elements to organize a presentation. Participants reported gaining confidence in their ability to communicate and expanding their self-identity to include “science communicator” in addition to “scientist.” They also reported that the FameLab experience increased the likelihood that they would look for communications opportunities and meet challenges presented by their institutional environment to engaging in communication. The overall conclusion is that improving and expanding communication skills and attitudes have changed how participants value communicating about their work and how competent they feel in doing so, which leads to their communicating more often.Schaper, J.L., Posselt, M., Bouchez, C., Jaeger, A., Nuetzmann, G., Putschew, A., Singer, G., Lewandowski, J., 2019. Fate of trace organic compounds in the hyporheic zone: Influence of retardation, the benthic biolayer, and organic carbon. Environmental Science & Technology 53, 4224-4234. fate of 28 trace organic compounds (TrOCs) was investigated in the hyporheic zone (HZ) of an urban lowland river in Berlin, Germany. Water samples were collected hourly over 17 h in the river and in three depths in the HZ using minipoint samplers. The four relatively variable time series were subsequently used to calculate first-order removal rates and retardation coefficients via a one-dimensional reactive transport model. Reversible sorption processes led to substantial retardation of many TrOCs along the investigated hyporheic flow path. Some TrOCs, such as dihydroxy-carbamazepine, O-desmethylvenlafaxine, and venlafaxine, were found to be stable in the HZ. Others were readily removed with half-lives in the first 10 cm of the HZ ranging from 0.1 ± 0.01 h for iopromide to 3.3 ± 0.3 h for tramadol. Removal rate constants of the majority of reactive TrOCs were highest in the first 10 cm of the HZ, where removal of biodegradable dissolved organic matter was also the highest. Because conditions were oxic along the top 30 cm of the investigated flow path, we attribute this finding to the high microbial activity typically associated with the shallow HZ. Frequent and short vertical hyporheic exchange flows could therefore be more important for reach-scale TrOC removal than long, lateral hyporheic flow paths.Schito, A., Spina, A., Corrado, S., Cirilli, S., Romano, C., 2019. Comparing optical and Raman spectroscopic investigations of phytoclasts and sporomorphs for thermal maturity assessment: the case study of Hettangian continental facies in the Holy cross Mts. (central Poland). Marine and Petroleum Geology 104, 331-345. maturity of six organic rich samples from Jurassic continental successions cropping out in the Holy Cross Mountains in Central Poland, has been characterized by classic thermal maturity indicators, micro-Raman spectroscopy and Palynomorph Darkness Index, in order to create a multi-method workflow for complex palynofacies thermal maturity assessment. Transmitted light observations on dispersed organic matter define a Hettangian lacustrine depositional environment, characterized by periods of reducing/oxidizing conditions and variable sedimentation rates. Thermal maturity detected by classical maturity indicators and PDI indicates an early maturation stage of hydrocarbon generation and is in agreement with spectroscopic analyses performed on phytoclast groups. Moreover, Raman parameters in the sporomorph group indicate a systematic shift toward a lower degree of aromatization compared to the phytoclast group. Finally, the multivariate statistical analysis performed on Raman spectra is found to be a promising tool to define and predict the heterogeneity of dispersed organic matter in sediments.Schmidt, G.A., Frank, A., 2019. The Silurian hypothesis: would it be possible to detect an industrial civilization in the geological record? International Journal of Astrobiology 18, 142-150. an industrial civilization had existed on Earth many millions of years prior to our own era, what traces would it have left and would they be detectable today? We summarize the likely geological fingerprint of the Anthropocene, and demonstrate that while clear, it will not differ greatly in many respects from other known events in the geological record. We then propose tests that could plausibly distinguish an industrial cause from an otherwise naturally occurring climate event.Schneider, B., Otto, S., 2019. Organic matter mineralization in the deep water of the Gotland Basin (Baltic Sea): Rates and oxidant demand. Journal of Marine Systems 195, 20-29. observations of total CO2 (CT) accumulation in the deep water of the Gotland Basin were initiated in 2003. The measurements were performed four to five times per year and were complemented by the determination of nutrient and O2/H2S concentrations. The major objective of those measurements was to study organic matter (OM) mineralization. This was facilitated during two periods of stagnation, from 2004 to 2006 and from 2007 to 2014, identified on the basis of temperature-salinity diagrams. In a follow-up to our assessment of the data from the first period, we present here an overall picture of CT accumulation in the deep water of the Gotland Basin. CT measurements were performed at five different depths between 150?m and the sediment surface at 235?m. Mineralization rates for three individual sub-layers were obtained from CT mass balances that took into account vertical mixing across the boundaries of the sub-layers. Mixing coefficients were calculated from the mass balances for salinity. The mass balance calculations yielded the source/sink strength of CT, O2, H2S, NO3? and NH4+ for each time interval between measurements. The accumulated release of CT was shown to increase linearly with time and to reflect consistent mean annual mineralization rates of ~2?mol?m?2 for both stagnation periods, which indicated the absence of significant decadal variability. A dependency of the mineralization rate on the redox conditions in the overlying water column was not detected. For the first stagnation period, the sequential use of different oxidants, including O2, NO3? and SO42?, was identified. A determination of oxidant consumption with respect to OM mineralization yielded a mean molar ratio of 1.2 oxygen equivalents per carbon atom of OM, a distinct deviation of the OM composition described by classical Redfield stoichiometry.Schulz-Vogt, H.N., Pollehne, F., Jürgens, K., Arz, H.W., Beier, S., Bahlo, R., Dellwig, O., Henkel, J.V., Herlemann, D.P.R., Krüger, S., Leipe, T., Schott, T., 2019. Effect of large magnetotactic bacteria with polyphosphate inclusions on the phosphate profile of the suboxic zone in the Black Sea. The ISME Journal 13, 1198-1208. Black Sea is the world’s largest anoxic basin and a model system for studying processes across redox gradients. In between the oxic surface and the deeper sulfidic waters there is an unusually broad layer of 10–40?m, where neither oxygen nor sulfide are detectable. In this suboxic zone, dissolved phosphate profiles display a pronounced minimum at the upper and a maximum at the lower boundary, with a peak of particulate phosphorus in between, which was suggested to be caused by the sorption of phosphate on sinking particles of metal oxides. Here we show that bacterial polyphosphate inclusions within large magnetotactic bacteria related to the genus Magnetococcus contribute substantially to the observed phosphorus peak, as they contain 26–34% phosphorus compared to only 1–5% in metal-rich particles. Furthermore, we found increased gene expression for polyphosphate kinases by several groups of bacteria including Magnetococcaceae at the phosphate maximum, indicating active bacterial polyphosphate degradation. We propose that large magnetotactic bacteria shuttle up and down within the suboxic zone, scavenging phosphate at the upper and releasing it at the lower boundary. In contrast to a passive transport via metal oxides, this bacterial transport can quantitatively explain the observed phosphate profiles.Schwab, V.F., Nowak, M.E., Elder, C.D., Trumbore, S.E., Xu, X., Gleixner, G., Lehmann, R., Pohnert, G., Muhr, J., Küsel, K., Totsche, K.U., 2019. 14C-free carbon is a major contributor to cellular biomass in geochemically distinct groundwater of shallow sedimentary bedrock aquifers. Water Resources Research 55, 2104-2121. the global significance of the subsurface biosphere, the degree to which it depends on surface organic carbon (OC) is still poorly understood. Here, we compare stable and radiogenic carbon isotope compositions of microbial phospholipid fatty acids (PLFAs) with those of in situ potential microbial C sources to assess the major C sources for subsurface microorganisms in biogeochemical distinct shallow aquifers (Critical Zone Exploratory, Thuringia Germany). Despite the presence of younger OC, the microbes assimilated 14C-free OC to varying degrees; ~31% in groundwater within the oxic zone, ~47% in an iron reduction zone, and ~70% in a sulfate reduction/anammox zone. The persistence of trace amounts of mature and partially biodegraded hydrocarbons suggested that autochthonous petroleum-derived hydrocarbons were a potential 14C-free C source for heterotrophs in the oxic zone. In this zone, Δ14C values of dissolved inorganic carbon (?366 ± 18‰) and 11MeC16:0 (?283 ± 32‰), an important component in autotrophic nitrite oxidizers, were similar enough to indicate that autotrophy is an important additional C fixation pathway. In anoxic zones, methane as an important C source was unlikely since the 13C‐fractionations between the PLFAs and CH4 were inconsistent with kinetic isotope effects associated with methanotrophy. In the sulfate reduction/anammox zone, the strong 14C‐depletion of 10MeC16:0 (?942 ± 22‰), a PLFA common in sulfate reducers, indicated that those bacteria were likely to play a critical part in 14C‐free sedimentary OC cycling. Results indicated that the 14C‐content of microbial biomass in shallow sedimentary aquifers results from complex interactions between abundance and bioavailability of naturally occurring OC, hydrogeology, and specific microbial metabolisms.Schwab, V.F., Nowak, M.E., Trumbore, S.E., Xu, X., Gleixner, G., Muhr, J., Küsel, K., Totsche, K.U., 2019. Isolation of individual saturated fatty acid methyl esters derived from groundwater phospholipids by preparative high-pressure liquid chromatography for compound-specific radiocarbon analyses. Water Resources Research 55, 2521-2531. the biogeochemical pathways utilized by microbes living in groundwater is essential for understanding the subsurface C cycle and the fate of organic compounds, including pollutants. The radiocarbon signature (Δ14C) of fatty acid methyl esters derived from microbial phospholipids (PLFA) provides useful information for differentiating microbial C sources and infering microbial metabolism. However, in subsurface environments, those analyses remain challenging. Here we present a method combining large volume groundwater filtration (up to 10,000 L) and PLFA purification for subsequent compound‐specific radiocarbon analyses. The analytical method involves conventional chemical extraction of PLFA followed by purification of individual compounds by semipreparative high‐performance liquid chromatography. Different saturated PLFA in amounts of up to 10 μg each can be simultaneously separated on a C18 high‐load column using a mixture of MeOH/water and acetonitrile as the mobile phase. Our procedure introduced dead‐Cext contaminations of 0.57 ± 0.29 and 0.35 ± 0.18 μg for the high‐performance liquid chromatography and combustion/graphitization steps of the sample preparation, respectively. However, tests on different high‐performance liquid chromatography C18 columns revealed a large difference in dead Cext associated with column bleed. Modern Cext in the amount of 0.40 ± 0.20 μg was introduced by the combustion/graphitization step of the sample preparation, but other steps did not add modern Cext. The entire method recovered ～50% of the purified compounds on average, but this did not affect their 14C content. This method will allow routine analysis of the Δ14C of PLFA isolated from groundwaters or other sample types, revealing the relationships between microbial and soil‐derived C, sedimentary or dissolved C sources.Seitz, K.W., Dombrowski, N., Eme, L., Spang, A., Lombard, J., Sieber, J.R., Teske, A.P., Ettema, T.J.G., Baker, B.J., 2019. Asgard archaea capable of anaerobic hydrocarbon cycling. Nature Communications 10, Article 1822. reservoirs of natural gas in the oceanic subsurface sustain complex communities of anaerobic microbes, including archaeal lineages with potential to mediate oxidation of hydrocarbons such as methane and butane. Here we describe a previously unknown archaeal phylum, Helarchaeota, belonging to the Asgard superphylum and with the potential for hydrocarbon oxidation. We reconstruct Helarchaeota genomes from metagenomic data derived from hydrothermal deep-sea sediments in the hydrocarbon-rich Guaymas Basin. The genomes encode methyl-CoM reductase-like enzymes that are similar to those found in butane-oxidizing archaea, as well as several enzymes potentially involved in alkyl-CoA oxidation and the Wood-Ljungdahl pathway. We suggest that members of the Helarchaeota have the potential to activate and subsequently anaerobically oxidize hydrothermally generated short-chain hydrocarbons.Selliez, L., Briois, C., Carrasco, N., Thirkell, L., Thissen, R., Ito, M., Orthous-Daunay, F.R., Chalumeau, G., Colin, F., Cottin, H., Engrand, C., Flandinet, L., Fray, N., Gaubicher, B., Grand, N., Lebreton, J.P., Makarov, A., Ruocco, S., Szopa, C., Vuitton, V., Zapf, P., 2019. Identification of organic molecules with a laboratory prototype based on the Laser Ablation-CosmOrbitrap. Planetary and Space Science 170, 42-51. the Solar System, extra-terrestrial organic molecules have been found on cometary primitive objects, on Titan and Enceladus icy moons and on Mars. Identification could be achieved for simple organic species by remote sensing based on spectroscopic methods. However in situ mass spectrometry is a key technology to determine the nature of more complex organic matter. A large panel of mass spectrometers has already been developed for space exploration combining different types of analysers and ion sources. Up to now the highest mass resolution reached with a space instrument is 9000?at?m/z 28 and corresponds to the DFMS-ROSINA instrument (Balsiger et?al., 2007) dedicated to the study of the comet 67P/Churyumov-Gerasimenko's atmosphere and ionosphere, in a low pressure environment. A new concept of mass analyser offering ultra-high mass resolving power of more than 50,000?at?m/z 56 (under high vacuum condition about 10?9?mbar) is currently being developed for space applications: the CosmOrbitrap (Briois et?al., 2016), based on the Orbitrap? technology. This work challenges the use of LAb-CosmOrbitrap, a space instrument prototype combining Laser Ablation ionisation and the CosmOrbitrap mass analyser, to identify solid organic molecules of relevance to the future space exploration. For this purpose a blind test was jointly organised by the JAXA-HRMS team (Japan Aerospace Exploration Agency-High Resolution Mass Spectrometry) and the CosmOrbitrap consortium. The JAXA team provided two organic samples, whereas the CosmOrbitrap consortium analysed them without prior information. Thanks to the high analytical performances of the prototype and our HRMS data post-processing, we successfully identified the two molecules as HOBt, hydroxybenzotriazole (C6H5N3O) and BBOT, 2,5-Bis(5-tert-butyl-benzoxazol-2-yl)thiophene (C26H26N2O2S), with a mass resolving power of, respectively, 123 540 and 69 219. The success of this blind test on complex organic molecules shows the strong potential of LAb-CosmOrbitrap for future space applications.Serikova, S., Pokrovsky, O.S., Laudon, H., Krickov, I.V., Lim, A.G., Manasypov, R.M., Karlsson, J., 2019. High carbon emissions from thermokarst lakes of Western Siberia. Nature Communications 10, Article 1552. Western Siberia Lowland (WSL), the world’s largest permafrost peatland, is of importance for understanding the high-latitude carbon (C) cycle and its response to climate change. Warming temperatures increase permafrost thaw and production of greenhouse gases. Also, permafrost thaw leads to the formation of lakes which are hotspots for atmospheric C emissions. Although lakes occupy ~6% of WSL, lake C emissions from WSL remain poorly quantified. Here we show high C emissions from lakes across all permafrost zones of WSL. The C emissions were especially high in shoulder seasons and in colder permafrost-rich regions. The total C emission from permafrost-affected lakes of WSL equals ~12?±?2.6?Tg?C?yr?1 and is 2-times greater than region’s C export to the Arctic coast. The results show that C emission from WSL lakes is a significant component in the high-latitude C cycle, but also suggest that C emission may decrease with warming.Shan, C., Ye, J., Scarlett, A., Grice, K., 2019. Molecular and isotopic characteristics of mature condensates from the East China Sea Shelf Basin using GC×GC-TOFMS and GC-IRMS. Journal of Earth Science 30, 376-386. this study, biomarkers, together with stable carbon (δ13C) and hydrogen (δD) isotopic compositions of n-alkanes have been examined in a suite of condensates collected from the East China Sea Shelf Basin (ECSSB) in order to delineate their source organic matter input, depositional conditions and evaluate their thermal maturity. Previously, GC-MS analyses have shown that all the condensates are formed in oxidizing environment with terrestrial plants as their main source input. No significant differences were apparent for biomarker parameters, likely due to the low biomarker content and high maturity of these condensates. Conventional GC-MS analysis however, may provides limited information on the sources and thermal maturity of complex mixtures due to insufficient component resolution. In the current study, we used comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS) to increase the chromatographic resolution. Compounds such as alkyl cyclohexanes, alkyl cyclopentanes and diamondoids, which can be difficult to identify using conventional GC-MS analysis, were successfully identified using GC×GC-TOFMS. From our analyses we propose two possibly unreported indicators, including one maturity indicator (C5?-cyclohexane/5+-cyclohexane) and one oxidation-reduction environment indicator (alkyl-cyclohexane/alkyl-cyclopentane). Multiple petroleum charging events were proposed as an explanation for the maturity indicators indexes discrepancy between methyl-phenanthrene index (MPI) and methyl-adamantane index (MDI). In addition, the stable isotopic results show that condensates from the Paleogene have significantly higher positive δ13C values of individual n-alkanes than the Neogene samples. Based on δD values, the samples can be divided into two groups, the differences between which are likely to be attributed to different biosynthetic precursors. Variation within each group can likely be attributed to vaporization.Shang, F., Xie, X., Li, S., 2019. Enrichment conditions of Hetaoyuan Formation shale oil in Biyang Depression, China. Journal of Petroleum Exploration and Production Technology 9, 927-936. this paper, the data of thin section, organic petrology, geochemistry, lithology and porosity were used to investigate enrichment conditions of Hetaoyuan Formation shale oil in the Biyang Depression. The results show the shale oil is a kind of low-maturity oil with medium density and low viscosity, and main factors controlling shale oil enrichment include total organic content (TOC), formation pressure, lithofacies and effective reservoirs. Shales in the fifth organic-rich interval are developed widely with large thickness (reach up to 150?m), high TOC content (2.0–4.68%), better organic matter types (type I and II1) and appropriate thermal maturity (usually larger than 0.5%), which are beneficial to generate much hydrocarbon, and volume expansion causes overpressure in source rock, especially in sections with low hydrocarbon expulsion efficiency due to less fractures. Free hydrocarbons S1 values increase with TOC contents, and significant overpressure correlates with the larger OSI (S1/TOC × 100) values and porosity. Well-developed calcareous shales and argillaceous shales with silty shale interlayers have better porosity, and effective pores (throat diameters greater than 10?nm) contribute to 47.5% of the total volume.Sharma, P., Marinov, I., Cabre, A., Kostadinov, T., Singh, A., 2019. Increasing biomass in the warm oceans: Unexpected new insights from SeaWiFS. Geophysical Research Letters 46, 3900-3910. phytoplankton biomass and community structure are expected to change under global warming, with potentially significant impacts on ocean carbon, nutrient cycling, and marine food webs. Previous studies have indicated decreases of primary production and chlorophyll a concentrations and oligotrophic gyre expansions from satellite ocean‐color measurements, purportedly due to global warming. We review this topic via a reanalysis of a novel backscattering‐based phytoplankton functional type and phytoplankton biomass time series over the 1997–2010 period. Unlike previous work, we find that globally the biomass and the percent of large (small) phytoplankton increase (decrease). The oligotrophic gyres contract or expand depending on the chlorophyll a threshold definition employed. In the subtropical gyres, chlorophyll a trends are likely due to physiological changes, while the increasing biomass trends are due to winds and relevant mixing length scale increases.She, H., Kong, D., Li, Y., Hu, Z., Guo, H., 2019. Recent advance of microbial enhanced oil recovery (MEOR) in China. Geofluids 2019, Article 1871392. with other enhanced oil recovery (EOR) techniques like gas flooding, chemical flooding, and thermal production, the prominent advantages of microbial enhanced oil recovery (MEOR) include environment-friendliness and lowest cost. Recent progress of MEOR in laboratory studies and microbial flooding recovery (MFR) field tests in China are reviewed. High biotechnology is being used to investigate MFR mechanisms on the molecular level. Emulsification and wettability alternation due to microbial effects are the main interests at present. Application of a high-resolution mass spectrum (HRMS) on MEOR mechanism has revealed the change of polar compound structures before and after oil degradation by the microbial on the molecular level. MEOR could be divided into indigenous microorganism and exogenous microorganism flooding. The key of exogenous microorganism flooding was to develop effective production strains, and difficulty lies in the compatibility of the microorganism, performance degradation, and high cost. Indigenous microorganism flooding has good adaptation but no follow-up process on production strain development; thus, it represents the main development direction of MEOR in China. More than 4600 wells have been conducted for MEOR field tests in China, and about 500 wells are involved in MFR. 47 MFR field tests have been carried out in China, and 12 field tests are conducted in Daqing Oilfield. MFR field test’s incremental oil recovery is as high as 4.95% OOIP, with a typical slug size less than 0.1?PV. The input-output ratio can be 1?:?6. All field tests have shown positive results in oil production increase and water cut reduction. MEOR screening criteria for reservoirs in China need to be improved. Reservoir fluid, temperature, and salinity were the most important three parameters. Microbial flooding technology is mature in reservoirs with temperature lower than 80°C, salinity less than 100,000?ppm, and permeability above 5?mD. MFR in China is very close to commercial application, while MFR as quaternary recovery like those in post-polymer flooding reservoirs needs further study.Shemin, G., Deev, E., Vernikovsky, V.A., Drachev, S.S., Moskvin, V., Vakulenko, L., Pervukhina, N., Sapyanik, V., 2019. Jurassic paleogeography and sedimentation in the northern West Siberia and South Kara Sea, Russian Arctic and Subarctic. Marine and Petroleum Geology 104, 286-312. study is focused on the depositional history of Jurassic oil- and gas-bearing sedimentary rocks, which currently occur at 3–6?km depth below the surface in the northern West Siberian Basin, the South Kara Basin and the western Yenisei-Khatanga Basin. Using data from deep wells, such as paleontological data and bedding geometries, lithology of rocks derived from cores and well log data, sediment thicknesses, results of detailed correlation of sedimentary cyclic units, and regional multichannel seismic reflection profiles, the authors produced 13 litho-paleogeographic maps of the studied region accompanied by W-E cross-sections.The maps present paleogeographic environments that existed during the deposition of each of 12 regional stratigraphic stages, namely: Lower Jurassic Zimniy (Hettangian – lowermost Upper Pliensbachian), Levinskiy (middle Upper Pliensbachian), Sharapov (uppermost Pliensbachian), Kiterbyut (lowermost Toarcian), Lower-Middle Jurassic Nadoyakh (uppermost Lower Toarcian – lowermost Aalenian), Middle Jurassic Laida (uppermost Lower Aalenian – lowermost Upper Aalenian), Vym (uppermost Aalenian – lowermost Bajocian), Leont'evskiy (uppermost Lower Bajocian – lowermost Upper Bajocian), Malyshev (uppermost Bajocian – lowermost Upper Bathonian), Middle-Upper Jurassic Vasyugan (uppermost Bathonian – lowermost Oxfordian), Upper Jurassic Georgiev (uppermost Oxfordian – lowermost Tithonian) and Bazhenov (uppermost Lower Tithonian – earliest Berriasian). The maps show the extent of exposed land, continental (alluvial plains), transitional (nearshore and coastal flood plains) and marine (water depth <25?m, 25–100?m, 100–200?m and 200–600?m) sedimentation areas. In addition to paleogeography, we identified, characterized and mapped 14 lithologic areas, which provide more specific information about Jurassic rocks and sedimentation regimes of the studied region. The litho-paleogeographic maps show rock types, the distribution of sediment thicknesses, deep-water sediment-starved areas and clinoform-dominated areas.The presented results provide a more reliable framework for the re-evaluation of existing Jurassic hydrocarbon plays and identification of new plays in the West Siberian province.Shen, J., Chen, J., Algeo, T.J., Yuan, S., Feng, Q., Yu, J., Zhou, L., O’Connell, B., Planavsky, N.J., 2019. Evidence for a prolonged Permian–Triassic extinction interval from global marine mercury records. Nature Communications 10, Article 1563. latest Permian mass extinction, the most devastating biocrisis of the Phanerozoic, has been widely attributed to eruptions of the Siberian Traps Large Igneous Province, although evidence of a direct link has been scant to date. Here, we measure mercury (Hg), assumed to reflect shifts in volcanic activity, across the Permian-Triassic boundary in ten marine sections across the Northern Hemisphere. Hg concentration peaks close to the Permian-Triassic boundary suggest coupling of biotic extinction and increased volcanic activity. Additionally, Hg isotopic data for a subset of these sections provide evidence for largely atmospheric rather than terrestrial Hg sources, further linking Hg enrichment to increased volcanic activity. Hg peaks in shallow-water sections were nearly synchronous with the end-Permian extinction horizon, while those in deep-water sections occurred tens of thousands of years before the main extinction, possibly supporting a globally diachronous biotic turnover and protracted mass extinction event.Shen, X., Wang, R., Xiong, X., Yin, Y., Cai, Y., Ma, Z., Liu, N., Zhu, Z.-J., 2019. Metabolic reaction network-based recursive metabolite annotation for untargeted metabolomics. Nature Communications 10, Article 1516. metabolite annotation is a challenge in liquid chromatogram-mass spectrometry (LC-MS)-based untargeted metabolomics. Here, we develop a metabolic reaction network (MRN)-based recursive algorithm (MetDNA) that expands metabolite annotations without the need for a comprehensive standard spectral library. MetDNA is based on the rationale that seed metabolites and their reaction-paired neighbors tend to share structural similarities resulting in similar MS2 spectra. MetDNA characterizes initial seed metabolites using a small library of MS2 spectra, and utilizes their experimental MS2 spectra as surrogate spectra to annotate their reaction-paired neighbor metabolites, which subsequently serve as the basis for recursive analysis. Using different LC-MS platforms, data acquisition methods, and biological samples, we showcase the utility and versatility of MetDNA and demonstrate that about 2000 metabolites can cumulatively be annotated from one experiment. Our results demonstrate that MetDNA substantially expands metabolite annotation, enabling quantitative assessment of metabolic pathways and facilitating integrative multi-omics analysis.Sheng, G., Javadpour, F., Su, Y., 2019. Dynamic porosity and apparent permeability in porous organic matter of shale gas reservoirs. Fuel 251, 341-351. effect, adsorbed-layer thinning, and desorption-induced shrinkage processes in porous organic matter (OM) change pore sizes during depressurization of shale reservoirs. While the first two processes have been studied in the past, desorption-induced shrinkage has not been studied in detail. We develop a model that includes all of these processes to study the dynamics of pore size change with pore pressure. We further relate change in OM pore sizes to the change in dynamic porosity and apparent permeability (AP) of OM. The ability of a poromechanical process to contract pores diminishes as pore pressure decreases. On the contrary, the ability of adsorbed-layer thinning and desorption-induced shrinkage to enlarge pores increases as pore pressure is reduced. Pore size change in smaller pores is more sensitive to poromechanical and adsorbed-layer thinning processes. Dynamic porosity and AP can change as much as 10% and 15%, respectively, by reducing pore pressure from 50?MPa (e.g., initial reservoir pressure) to 4?MPa (e.g., economic limit). The contribution of each process depends on the initial pore size distribution (PSD) of the system and pore pressure. At pore pressures greater than 20?MPa, the poromechanical process dominates and decreases porosity and AP; in other words, porosity and AP decrease as initial reservoir pressure reduces to 20?MPa. Below 20?MPa, desorption-induced shrinkage and adsorbed-layer thinning processes shift the balance to increase porosity and AP.Shimizu, N., 2019. Big picture geochemistry from microanalyses – My four-decade odyssey in SIMS. Geochemical Perspectives 8, 1-104. Ion Mass Spectrometry (SIMS) is now a well established analytical technique in geochemistry. Its developmental history goes back to the 1970s. Here, I tell the story of how I got involved in its applications to geochemistry in 1974 at the Institut de Physique du Globe in Paris (IPGP) with the Cameca IMS 300 instrument and my ensuing struggles with theories of secondary ion formation processes and the eventual development of the energy filtering approach as an effective method for suppressing molecular ion interferences in silicate minerals and glasses.The geochemical applications of the techniques that I developed with my colleagues at IPGP, Massachusetts Institute of Technology (MIT), and Woods Hole Oceanographic Institution (WHOI) are summarised in four different categories: (1) trace element zoning of phenocrysts and the kinetics of magmatic crystallisation processes, (2) trace element abundance patterns and geochemical processes in the mantle, (3) use of trace element abundances in magmatic processes in the mid-ocean ridge system, and (4) use of Sr/Ca ratios in biogenic carbonates in palaeoceanographic studies.Trace element zoning patterns observed in phenocrysts reveal that crystal growth in magmas can occur with non-equilibrium partitioning of trace elements at the crystal-melt interface. Trace element zoning patterns in augite phenocrysts from Gough Island also indicate repeated drastic changes in magma composition, suggesting a turbulent dynamic state of magma bodies beneath eruptive centres.Chondrite normalised rare earth element (REE) patterns measured in clinopyroxenes from mantle rocks (peridotites from the Horoman massif and xenoliths in basalts from both oceanic and continental localities) show strong evidence for melt-rock reactions, indicating that lithospheric peridotites depleted in incompatible elements by melt extraction often show evidence of having been subsequently enriched in these elements through melt-rock reaction. The distribution of Sr in garnet inclusions in peridotitic diamonds from South Africa and Siberia is highly heterogeneous over wide concentration ranges, suggesting growth of inclusion garnets as well as formation of these diamonds, occurred shortly before the diamonds were carried to the surface by kimberlite eruptions.Rare earth element and other trace element abundance patterns measured in clinopyroxenes in abyssal peridotites clearly indicate that melting and melt extraction processes beneath mid-ocean ridges is akin to fractional melting by which small degree melt fractions are progressively extracted from residues as the mantle decompresses and only later mixed, sometimes incompletely, to form mid-ocean ridge basalt lavas erupted on the ocean floor. However, meltrock reactions between residual peridotites and upwelling melt fractions could significantly alter trace element abundance patterns of originally residual clinopyroxenes. In situ analyses reveal very large trace element variations occurring on intra-mineral scales, suggesting that precipitation of clinopyroxene also occurred during melt-rock reactions. It is evident that abyssal peridotites contain complex geochemical histories beyond melt extraction via fractional melting.Sr/Ca variations in coral skeletons (aragonite) reveal strong effects of photosynthesis of symbiont algae in day time growth zones, while those in night time growth zones near centres of calcification record variations of sea surface temperatures (SST) in Porites lutea. In Astrangia poculata, which experience a large temperature range (-2 – 23 °C), non-symbiotic skeletons faithfully record temperature variations, while symbiotic skeletons display ontogenic effects of algal symbionts. Sr/Ca variations in coccolithophores across the Paleocene-Eocene Thermal Maximum (PETM) display different responses of individual species to the sudden greenhouse environment, and the severity of the response also is dependent on the oceanographic conditions of their habitats.Shoukry, A.E., El-Banbi, A.H., Sayyouh, H., 2019. Modelling asphaltene precipitation with solvent injection using cubic-PR solid model. Petroleum Science and Technology 37, 889-898. equation-of-state solid models are commonly-used to predict asphaltene precipitation behavior. Thermodynamic parameters are needed to model this behavior under different pressures and temperatures, and are usually obtained through fitting the model to multi asphaltene onset experiments. This paper introduces an empirical linear relation (tested on six oil samples) relating Asphaltene Onset Pressure (AOP) with injected solvent amount. In addition, waxes and aromatics correlations are utilized to obtain the thermodynamic parameters within the model. The two modifications decrease the number of tuning parameters of the model, as well as reduce the number of lab measurements needed to apply it. The model is tested on two oil samples, with previously published data, to predict AOPs. Using aromatics correlations provided more rational trends for AOP than waxes correlations. Besides, both correlations create a practical domain inside which the laboratory AOP values lie. The new additions enhance the prediction capabilities of the model in the lack of asphaltene experiments.Sinclair, J.A., Moses, J.I., Hue, V., Greathouse, T.K., Orton, G.S., Fletcher, L.N., Irwin, P.G.J., 2019. Jupiter's auroral-related stratospheric heating and chemistry III: Abundances of C2H4, CH3C2H, C4H2 and C6H6 from Voyager-IRIS and Cassini-CIRS. Icarus 328, 176-193. present an analysis of Voyager-1-IRIS and Cassini-CIRS spectra of Jupiter's high latitudes acquired during the spacecrafts' respective flybys in November 1979 and January 2001. We performed a forward-model analysis in order to derive the abundances of ethylene (C2H4), methylacetylene (CH3C2H), diacetylene (C4H2) and benzene (C6H6) in Jupiter's northern and southern auroral regions. We also compared these abundances to: 1) lower-latitude abundances predicted by the Moses et al. (2005) ‘Model A’ photochemical model, henceforth ‘Moses 2005A’, and 2) abundances derived at non-auroral longitudes in the same latitude band. This paper serves as an extension of Sinclair et al. (2017b), where we retrieved the vertical profiles of temperature, C2H2 and C2H6 from similar datasets. We find that an enrichment of C2H4, CH3C2H and C6H6 with respect to lower-latitude abundances is required to fit the spectra of Jupiter's northern and southern auroral regions. For example, for CIRS 0.5?cm?1 spectra of Jupiter's southern auroral region, scale factor enrichments of 6.40?1.15+1.30 and 9.60?3.67+3.98 are required with respect to the Moses 2005A vertical profiles of C2H4 and C6H6, respectively, in order to fit the spectral emission features of these species at ～950 and ～674?cm?1. Similarly, in order to fit the CIRS 2.5?cm?1 spectra of Jupiter's northern auroral region, scale factor enrichments of 1.60?0.21+0.37, 3.40?1.69+1.89 and 15.00?4.02+4.01 with respect to the Moses 2005A vertical profiles of C2H4, CH3C2H and C6H6 were required, respectively. Outside of Jupiter's auroral region in the same latitude bands, only upper-limit abundances of C2H4, CH3C2H and C6H6 could be determined due to the limited sensitivity of the measurements, the weaker emission features combined with cooler stratospheric temperatures (and therefore decreased thermal emission) of these regions. Nevertheless, for a subset of the observations, derived abundances of C2H4 and C6H6 in Jupiter's auroral regions were higher (by 1?σ) with respect to upper-limit abundances derived outside the auroral region in the same latitude band. This is suggestive that the influx of energetic ions and electrons from the Jovian magnetosphere and external solar-wind environment into the neutral atmosphere in Jupiter's auroral regions drives enhanced ion-related chemistry, as has also been inferred from Cassini observations of Saturn's high latitudes (Fletcher et al., 2018; Guerlet et al., 2015; Koskinen et al., 2016). We were not able to constrain the abundance of C4H2 in either Jupiter's auroral regions or non-auroral regions due to its lower (predicted) abundance and weaker emission feature. Thus, only upper-limit abundances were derived in both locations. From CIRS 2.5?cm?1 spectra, the upper limit abundance of C4H2 corresponds to a scale factor enhancement of 45.6 and 23.8 with respect to the Moses 2005A vertical profile in Jupiter's non-auroral and auroral regions.Sinha, H.N., Patel, R.C., Kumar, B.A., 2019. Characteristics of the palynomorphs and hydrocarbon potential in the continental Permian Raniganj Formation, Banespetali Nala, West Bengal. Journal of the Geological Society of India 93, 431-436. youngest coal seam of the Raniganj Formation of upper Permian age has been critically examined for microfloral assemblages near to the continental P/T boundary of India. The study reveals a rich and diversified microfloral assemblages and it tentatively corresponds with long distances homotaxial beds of SE Turkey, Australia and Antarctica. Based on the microfloral assemblages, the dark shale occurring at the youngest coal seam of the Raniganj Formation tentatively assigns a Wordian to Capitanian (260–265Ma) age. Some of the forms such as Striatoabieites multistriatus, Protohaploxipinus sp., Striatopodocarpites fusus, Striatopodocorpites cancellatus, Praecolpatites sinuosus, Plicatipollenites gondwanensis have a wide range of distributions from low to high palaeo-latitudinal Gondwanan provinces. This attributes that these forms probably were not climate dependent, but other might vaguely be ascribed to be climatic sensitive. Apatite Fission Track (AFT) and maturation study based on spore/pollen coloration attributes to the possibility of small amount of liquid hydrocarbon and large commercial gas accumulations in the Raniganj Formation.Sippo, J.Z., Maher, D.T., Schulz, K.G., Sanders, C.J., McMahon, A., Tucker, J., Santos, I.R., 2019. Carbon outwelling across the shelf following a massive mangrove dieback in Australia: Insights from radium isotopes. Geochimica et Cosmochimica Acta 253, 142-158. soil carbon stocks are known to decrease following forest loss due to respiration and enhanced soil CO2 emissions. However, changes in carbon outwelling to the coastal ocean due to mangrove forest disturbance have not been considered. In December 2015, an extremely large mangrove dieback event (～7000 hectares, spanning 1000?km of coastline) occurred in the Gulf of Carpentaria, Australia. To assess the effect this dieback event had on carbon outwelling, we used radium isotopes and dissolved carbon measurements (dissolved organic carbon, DOC, dissolved inorganic carbon, DIC, and total alkalinity, TAlk) to estimate cross-shelf carbon transport from living and dead mangrove areas and to calculate the carbon losses from living and dead forest soils via SGD. Radium distributions imply cross shelf eddy diffusivity of 107.5?±?26.9 and 104.6?±?23.9?m?2?s?1 from dead and living areas and radium water ages reveal that mangrove carbon reaches 10?km offshore within 7?days. Outwelling rates from living and dead areas were explained by soil carbon losses via SGD. This study suggests a decrease in carbon outwelling to the ocean from dead forest areas compares to living areas by 0–12% for DOC, 50–52% for DIC and by 37–51% for TAlk ～8?months after the dieback event occurred. Changes to oceanic carbon outwelling rates following mangrove loss are likely driven by a gradual depletion of carbon stocks from the sediment profile.Slack, J.F., Shanks, W.C., Ridley, W.I., Dusel-Bacon, C., DesOrmeau, J.W., Ramezani, J., Fayek, M., 2019. Extreme sulfur isotope fractionation in the Late Devonian Dry Creek volcanogenic massive sulfide deposit, central Alaska. Chemical Geology 513, 226-238. Dry Creek Zn-Pb-Cu-Ag-Au volcanogenic massive sulfide (VMS) deposit, in east-central Alaska, occurs in a Late Devonian sequence of peralkaline rhyolite tuff, minor graphitic argillite, and local peralkaline quartz-porphyry rhyolite intrusions. Principal mineralized facies are semi-massive and massive sulfide in variably silicified and graphitic rhyolite tuff, massive sulfide in graphitic argillite, disseminated sulfides in graphitic and non-graphitic rhyolite tuff, and vein-hosted sulfides in a subvolcanic, peralkaline quartz-porphyry intrusion. In situ analysis of the sulfur isotope composition of sulfide minerals from all facies of the deposit shows a total range in δ34S values from ?48.0 to 23.1‰. This remarkable 71.1‰ variation is more than twice the largest range known for sulfides in nearly all individual VMS deposits, both modern and ancient, which typically is <25‰. Based on results of geochemical reaction modeling presented here, extreme sulfur isotope systematics in the Dry Creek deposit is attributed to two main processes: low-temperature (<100?°C) kinetically controlled bacterial sulfate reduction (BSR) in anoxic to locally sulfidic bottom waters and pore fluids, and higher temperature (100–300?°C) hydrothermal sulfate reduction (HSR) of seawater sulfate during water-rock reactions. Deposition of organic-rich sediments prior to and during mineralization provided the key environment that promoted microbially mediated fractionations with Δ34Ssulfate-sulfide of up to 70‰. During BSR reaction progress modeling, residual sulfate evolved by Rayleigh distillation in pore water, producing δ34SSO4 values up to 58‰; normal Late Devonian seawater sulfate had δ34SSO4?=?22‰. BSR produced FeS precipitates with δ34S values from ?50 to ?15‰. Integrated textural and δ34S data also suggest that isotopically light H2S produced in pore fluids by BSR was incorporated into hydrothermal fluids and early disseminated sulfide minerals during the emplacement of peralkaline quartz-porphyry rhyolite intrusions in the shallow subsurface, broadly coeval with VMS mineralization. Modeling of moderate- to high-temperature (100–300?°C) hydrothermal sulfate reduction (HSR) of seawater-rock interaction predicts sulfide minerals with δ34S values from ?8 to 19‰.High-precision CA-ID-TIMS U-Pb geochronology of zircons from a synvolcanic peralkaline quartz porphyry intrusion yields a weighted mean 206Pb/238U date of 363.02?±?0.43?Ma (2σ total uncertainty). This date indicates that the formation of graphitic and sulfidic sediments at Dry Creek, and contemporaneous VMS mineralization, occurred at least 3.6?m.y. before, and hence are unrelated to, widespread black shale deposition during the Hangenberg Event at ca. 359?Ma.Slotznick, S.P., Webb, S.M., Kirschvink, J.L., Fischer, W.W., 2019. Mid-Proterozoic ferruginous conditions reflect postdepositional processes. Geophysical Research Letters 46, 3114-3123.: To evaluate the mechanics of mid‐Proterozoic environmental iron transport and deposition, we coupled microscale textural and bulk rock magnetic techniques to study the ~1.4‐Ga lower Belt group, Belt Supergroup, Montana and Idaho. We identified a pyrrhotite‐siderite isograd that marks metamorphic iron‐bearing mineral reactions beginning in subgreenschist facies samples. Even in the best‐preserved parts of the basin, secondary overprints were common including recrystallization of iron‐bearing sulfides, base metal sulfides, and nanophase pyrrhotite. Despite these overprints, a record of redox chemistry was preserved in the early diagenetic framboidal pyrite and detrital iron oxides including trace nanoscale magnetite that remained after sulfidization in anoxic and sulfidic sedimentary pore fluids. Based on these results, we interpret the Belt Basin as having oxic waters, at least in shallow‐water environments, with no indication of abundant ferrous iron in the water column; this is consistent with the cooccurrence of early eukaryotic fossils within the same strata.Plain Language Summary: Observing iron chemistry and mineralogy in sedimentary rocks is one of the primary methods for understanding ancient redox environments; today, iron is poorly soluble in seawater due its high dioxygen levels, but some iron‐based metrics suggest that ocean and lakes were rich in soluble iron for a billion years after the rise in atmospheric oxygen 2.3 Ga. Using a novel approach for evaluating iron environmental processes, we analyzed the iron‐bearing minerals within 1.4‐Ga rocks and were able to untangle which minerals were primary, containing information about the ancient environment, and which minerals were secondary, telling the story of later alteration through fluids carrying new elements into the rock or higher temperatures/pressures from burying the sediments. Primary detrital iron minerals implied that the Belt Basin waters were oxygenated, at least in shallow‐water environments, contrary to prior work but consistent with the rich fossil record of eukaryotes in the same strata.Smit, K.V., Shirey, S.B., Hauri, E.H., Stern, R.A., 2019. Sulfur isotopes in diamonds reveal differences in continent construction. Science 364, 383-385.: Neoproterozoic West African diamonds contain sulfide inclusions with mass-independently fractionated (MIF) sulfur isotopes that trace Archean surficial signatures into the mantle. Two episodes of subduction are recorded in these West African sulfide inclusions: thickening of the continental lithosphere through horizontal processes around 3 billion years ago and reworking and diamond growth around 650 million years ago. We find that the sulfur isotope record in worldwide diamond inclusions is consistent with changes in tectonic processes that formed the continental lithosphere in the Archean. Slave craton diamonds that formed 3.5 billion years ago do not contain any MIF sulfur. Younger diamonds from the Kaapvaal, Zimbabwe, and West African cratons do contain MIF sulfur, which suggests craton construction by advective thickening of mantle lithosphere through conventional subduction-style horizontal tectonics.Editor's summary: Sulfur tells tectonic secrets. Plate tectonics dominates how the surface of Earth is shaped over geologic time; however, we do not know when this important process started on Earth. Smit et al. used sulfur isotopes in diamonds to show that atmospheric sulfur was entering the mantle 3 billion years ago through plate subduction. Older diamonds do not have this signature, constraining when plate tectonics started on Earth to around 3 billion years ago.Soleymanzadeh, A., Yousefi, M., Kord, S., Mohammadzadeh, O., 2019. A review on methods of determining onset of asphaltene precipitation. Journal of Petroleum Exploration and Production Technology 9, 1375-1396. industry suffers from flow assurance problems that occur both in upstream and downstream operations. One of the common flow assurance issues arises from precipitation and deposition of asphaltenes in various locations along the oil production path including near wellbore region in the reservoir, production tubing, flowlines and separation unit at the surface. Asphaltene particles precipitate out of oil continuum due to changes in temperature, pressure or composition. Such changes in operating conditions occur during different recovery processes (natural depletion, gas injection, chemical injection, etc.) as well as production and blending of different oils during transportation. There are different experimental methodologies documented in the literature that describe how to determine onset of asphaltene precipitation. In this paper, a comprehensive review is performed on all the available procedures to measure onset of asphaltene precipitation. The advantages and limitations associated with all these methods are also documented.Sollai, M., Villanueva, L., Hopmans, E.C., Keil, R.G., Sinninghe Damsté, J.S., 2019. Archaeal sources of intact membrane lipid biomarkers in the oxygen deficient zone of the eastern tropical South Pacific. Frontiers in Microbiology 10, 765. doi: 710.3389/fmicb.2019.00765. are ubiquitous in the modern ocean where they are involved in the carbon and nitrogen biogeochemical cycles. However, the majority of Archaea remain uncultured. Archaeal specific membrane intact polar lipids (IPLs) are biomarkers of the presence and abundance of living cells. They comprise archaeol and glycerol dibiphytanyl glycerol tetraethers (GDGTs) attached to various polar headgroups. However, little is known of the IPLs of uncultured marine Archaea, complicating their use as biomarkers. Here, we analyzed suspended particulate matter (SPM) obtained in high depth resolution from a coastal and open ocean site in the eastern tropical South Pacific (ETSP) oxygen deficient zone (ODZ) with the aim of determining possible biological sources of archaeal IPL by comparing their composition by Ultra High Pressure Liquid Chromatography coupled to high resolution mass spectrometry with the archaeal diversity by 16S rRNA gene amplicon sequencing and their abundance by quantitative PCR. Thaumarchaeotal Marine Group I (MGI) closely related to Ca. Nitrosopelagicus and Nitrosopumilus dominated the oxic surface and upper ODZ water together with Marine Euryarchaeota Group II (MGII). High relative abundance of hexose phosphohexose- (HPH) crenarchaeol, the specific biomarker for living Thaumarchaeota, and HPH-GDGT-0, dihexose- (DH) GDGT-3 and -4 were detected in these water masses. Within the ODZ, DPANN (Diapherotrites, Parvarchaeota, Aenigmarchaeota, Nanoarchaeota, Nanohaloarchaea) of the Woesearchaeota DHVE-6 group and Marine euryarchaeota Group III (MGIII) were present together with a higher proportion of archaeol-based IPLs, which were likely made by MGIII, since DPANN archaea are supposedly unable to synthesize their own IPLs and possibly have a symbiotic or parasitic partnership with MGIII. Finally, in deep suboxic/oxic waters a different MGI population occurred with HPH-GDGT-1, -2 and DH-GDGT-0 and -crenarchaeol, indicating that here MGI synthesize membranes with IPLs in a different relative abundance which could be attributed to the different detected population or to an environmental adaptation. Our study sheds light on the complex archaeal community of one of the most prominent ODZs and on the IPL biomarkers they potentially synthesize.Solyanikova, I.P., Golovleva, L.A., 2019. Hexadecane and hexadecane-degrading bacteria: Mechanisms of interaction. Microbiology 88, 15-26. review presents the results of investigation of the interaction between the hydrophobic substrate hexadecane and microbial cells. Three aspects of this process are discussed in more detail: (1) interaction of bacterial cells with the hydrophobic substrate, including characteristics of the cell surface and the conformational changes occurring at contact between the cell and the insoluble substrate; (2) molecular basics of the degradation of hydrophobic compounds at each stage of the cell–substrate interaction, such as synthesis of dispersing components, dispersion of the water-insoluble substrate, sorption of the hydrophobic compound by the cell and its storage, as well as transcription regulation of the genes involved either directly in biodegradation or in the processes associated with growth on hydrophobic substrates; and (3) bacterial synthesis of surfactants in the course of the degradation of hydrophobic compounds, diversity of their structure and conditions for their enhance release, as well as their biotechnological application.Song, H., Wignall, P.B., Song, H., Dai, X., Chu, D., 2019. Seawater temperature and dissolved oxygen over the past 500 million years. Journal of Earth Science 30, 236-243. temperature and dissolved oxygen concentrations are critical factors that control ocean productivity, carbon and nutrient cycles, and marine habitat. However, the evolution of these two factors in the geologic past are still unclear. Here, we use a new oxygen isotope database to establish the sea surface temperature (SST) curve in the past 500 million years. The database is composed of 22 796 oxygen isotope values of phosphatic and calcareous fossils. The result shows two prolonged cooling events happened in the Late Paleozoic and Late Cenozoic, coinciding with two major ice ages indicated by continental glaciation data, and seven global warming events that happened in the Late Cambrian, Silurian-Devonian transition, Late Devonian, Early Triassic, Toarcian, Late Cretaceous, and Paleocene-Eocene transition. The SSTs during these warming periods are about 5–30 °C higher than the present-day level. Oxygen contents of shallow seawater are calculated from temperature, salinity, and atmospheric oxygen. The results show that major dissolved oxygen valleys of surface seawater coincide with global warming events and ocean anoxic events. We propose that the combined effect of temperature and dissolved oxygen account for the long-term evolution of global oceanic redox state during the Phanerozoic.So?nicka, M., Lüders, V., 2019. Super-deep, TSR-controlled Phanerozoic MVT type Zn-Pb deposits hosted by Zechstein-2 gas reservoir carbonate (Ca2), Lower Saxony Basin, Germany. Chemical Geology 508, 62-77. Earth's crust is endowed with outstanding mineral wealth, however, in the future near-surface ore deposits will become exhausted and mineral potential of deeper crustal levels will become a target for exploration. Knowledge of the fluid dynamics of deep-seated ore-forming systems in e.g. sedimentary basins is therefore crucial for developing genetic models, which would facilitate effective exploration of hidden orebodies. Here we utilized fluid inclusion and stable isotope analyses in order to decipher the ore-forming processes, which were responsible for deposition of considerable deep-seated (2.7–3.6?km) Zn-Pb mineralization in the Lower Saxony Basin (LSB). Massive sphalerite-rich stratiform/stratabound and vein-type mineralization in the LSB is hosted by Ca2 carbonate. Our data show that ore deposition was controlled by mixing of reservoir H2S with hot (T?=?125–208?°C), highly-saline (21–32?wt% NaCl equiv.) metalliferous fluids ascending from greater depth along fault zones. Sulfur isotope ratios of sulfides (δ34S?=??12.5 to +8.5‰) and carbon isotope ratios of fluid inclusion gases (δ13CCH4?=??6.2 to ?22.7‰; δ13CCO2?=??0.8 to ?6.2‰) reveal compelling evidence for TSR (thermochemical sulfate reduction)-derived origin of H2S. The ore-forming fluids were expelled from an over-pressurized system during Late Cretaceous basin inversion. Depth estimates show that the Zn-Pb mineralization in the LSB formed considerably deeper (3.3–4.4?km) than any other Phanerozoic MVT Zn-Pb deposit and therefore they can be classified as a super-deep, TSR-controlled MVT end-member.Sousa, E.d.S., Júnior, G.R.S., Silva, A.F., Reis, F.d.A.M., de Sousa, A.A.C., Cioccari, G.M., Capilla, R., de Souza, I.V.A.F., Imamura, P.M., Rodrigues, R., Lopes, J.A.D., de Lima, S.G., 2019. Biomarkers in Cretaceous sedimentary rocks from the Codó Formation - Parnaíba Basin: Paleoenvironmental assessment. Journal of South American Earth Sciences 92, 265-281. geological works showed that Codó Formation - CF (Parnaíba Basin, Brazil) has been deposited in the Aptian, and suffered the influence of various transgressive-regressive marine cycles, thus suggesting various depositional environment possibilities from saline lacustrine deltaic to shallow marine during sedimentation. Cretaceous potential source rock samples from the CF were investigated to identify diagnostic biomarkers in order to ascertain paleoenvironmental conditions of deposition and thermal evolution of organic matter. The TOC results showed low organic matter (OM) contents and Rock-Eval analysis implying low thermal evolution of organic matter. GC-MS analysis showed a great diversity of biomarkers within the five studied samples. The main features of organic matter composition were: low content of n-alkanes, Ph???Pr, presence of i-25, i-30 (squalane) and gammacerane thus suggesting saline to hypersaline depositional environment. The biomarkers fingerprint showed a full series of ββ hopanes and Δ13(18) hopenes, αααR and βααR steranes, and Δ5 and Δ8(14) sterenes, pointing out immature OM. Several C30 steranes have been detected, among them 4α(methyl)- and 4β(methyl)-24-ethylcholestane, 24-n-propylcholestane and 24-isopropylcholestane (all identified by co-injection) and dinosteranes, which some of them are indicative of a marine depositional system.Souza, I.D., Nan, H., Queiroz, M.E.C., Anderson, J.L., 2019. Tunable silver-containing stationary phases for multidimensional gas chromatography. Analytical Chemistry 91, 4969-4974. achieve high separation power of complex samples using multidimensional gas chromatography (MDGC), the selectivity of the employed stationary phases is crucial. The nonpolar × polar column combination remains the most popular column set used in MDGC. However, resolution of mixtures containing light analytes possessing very similar properties remains a formidable challenge. The development of stationary phases that offer unique separation mechanisms have the potential to significantly improve MDGC separations, particularly in resolving coeluting peaks in complex samples. For the first time, a stationary phase containing silver(I) ions was successfully designed and employed as a second-dimension column using comprehensive two-dimensional gas chromatography (GC × GC) for the separation of mixtures containing alkynes, dienes, terpenes, esters, aldehydes, and ketones. Compared with a widely used nonpolar and polar column set, the silver-based column exhibited superior performance by providing better chromatographic resolution of coeluting compounds. A mixture of unsaturated fatty acids was successfully separated using a GC × GC method in which the elution order in the second dimension was highly dependent on the number of double bonds within the analytes.Sowers, T.D., Holden, K.L., Coward, E.K., Sparks, D.L., 2019. Dissolved organic matter sorption and molecular fractionation by naturally occurring bacteriogenic iron (oxyhydr)oxides. Environmental Science & Technology 53, 4295-4304. (oxyhydr)oxides are highly reactive, environmentally ubiquitous organic matter (OM) sorbents that act as mediators of terrestrial and aqueous OM cycling. However, current understanding of environmental iron (oxyhydr)oxide affinity for OM is limited primarily to abiogenic oxides. Bacteriogenic iron (oxyhydr)oxides (BIOs), common to quiescent waterways and soil redox transitions, possess a high affinity for oxyanions (i.e., arsenate and chromate) and suggests that BIOs may be similarly reactive for OM. Using adsorption and desorption batch reactions, paired with Fourier transform infrared spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry, this work demonstrates that BIOs are capable of sorbing leaf litter-extracted DOM and Suwannee River Humic/Fulvic Acid (SRHA/SRFA) and have sorptive preference for distinct organic carbon compound classes at the biomineral interface. BIOs were found to sorb DOM and SRFA to half the extent of 2-line ferrihydrite per mass of sorbent and was resilient to desorption at high ionic strength and in the presence of a competitive ligand. We observed the preferential sorption of aromatic and carboxylic-containing species and concurrent solution enrichment of aliphatic groups unassociated with carboxylic acids. These findings suggest that DOM cycling may be significantly affected by BIOs, which may impact nutrient and contaminant transport in circumneutral environments.Spring, S., Sorokin, D.Y., Verbarg, S., Rohde, M., Woyke, T., Kyrpides, N.C., 2019. Sulfate-reducing bacteria that produce exopolymers thrive in the calcifying zone of a hypersaline cyanobacterial mat. Frontiers in Microbiology 10, 862. doi: 810.3389/fmicb.2019.00862. microbial mats in hypersaline environments are important model systems for the study of the earliest ecosystems on Earth that started to appear more than three billion years ago and have been preserved in the fossil record as laminated lithified structures known as stromatolites. It is believed that sulfate-reducing bacteria play a pivotal role in the lithification process by increasing the saturation index of calcium minerals within the mat. Strain L21-Syr-ABT was isolated from anoxic samples of a several centimeters thick microbialite-forming cyanobacterial mat of a hypersaline lake on the Kiritimati Atoll (Kiribati, Central Pacific). The novel isolate was assigned to the family Desulfovibrionaceae within the Deltaproteobacteria. Available 16S rRNA-based population surveys obtained from discrete layers of the mat indicate that the occurrence of a species-level clade represented by strain L21-Syr-ABT is restricted to a specific layer of the suboxic zone, which is characterized by the presence of aragonitic spherulites. To elucidate a possible function of this sulfate-reducing bacterium in the mineral formation within the mat a comprehensive phenotypic characterization was combined with the results of a comparative genome analysis. Among the determined traits of strain L21-Syr-ABT several features were identified that could play a role in the precipitation of calcium carbonate: (i) the potential deacetylation of polysaccharides and consumption of substrates such as lactate and sulfate could mobilize free calcium; (ii) under conditions that favor the utilization of formate and hydrogen, the alkalinity engine within the mat is stimulated, thereby increasing the availability of carbonate; (iii) the production of extracellular polysaccharides could provide nucleation sites for calcium mineralization. In addition, our data suggest the proposal of the novel species and genus Desulfohalovibrio reitneri represented by the type strain L21-Syr-ABT (= DSM 26903T = JCM 18662T).Stauffer, P.H., Rahn, T., Ortiz, J.P., Salazar, L.J., Boukhalfa, H., Behar, H.R., Snyder, E.E., 2019. Evidence for high rates of gas transport in the deep subsurface. Geophysical Research Letters 46, 3773-3780.: Barometric pumping caused by atmospheric pressure fluctuations contributes to the motion of gases in the vadose zone. While the resulting gas transport is often negligible in unfractured porous rocks, rates of transport in fractured media can be significant. Deep atmospheric pumping has implications for nuclear gas detection, water balance, and contaminant transport. We present results from a tracer test conducted to characterize deep subsurface fractured basalt and investigate the effects of barometric pumping on gaseous contaminant mobility. The tracer test provides data to constrain permeability, porosity, and diffusivity in a numerical representation of the experiment. A numerical model is used to simulate gas flow and dispersive transport under fluctuating pressure conditions. Tracer test and simulation results suggest that barometric pumping induces 10 to 100 times more mixing in the basalt than predicted by gas diffusion alone. Within the basalt fractures, estimates of gas velocity reach maximums of nearly 1,000 m/day.Plain Language Summary: Weather systems have associated changes in atmospheric pressure. Storm systems bring low pressure and blue skies bring high pressure. These changes in pressure are also imposed on the soils and rocks beneath our feet. If the soils and rocks have sufficient open pore space or well‐connected fractures, atmospheric pressure changes can drive air into or pull air out of these geologic materials. This phenomenon is known as barometric pumping. Barometric pumping can accelerate the migration of natural or man‐made gases. In this study, we have investigated the effects of barometric pumping on a highly fractured geologic formation that underlies the Los Alamos National Laboratory. To do so, we injected a nonreactive tracer gas called sulfur hexafluoride and monitored its concentration over time for several days. These measurements are used to constrain simulations that take into account the fractured nature of the geologic formation. We have determined that barometric pumping has a significant influence on this particular geologic formation and discovered that gases may travel at rates of up to a kilometer per day for brief periods, much higher than the tens of centimeters per day possible if the gases were dispersed by simple molecular diffusion.Stopka, S.A., Samarah, L.Z., Shaw, J.B., Liyu, A.V., Veli?kovi?, D., Agtuca, B.J., Kukolj, C., Koppenaal, D.W., Stacey, G., Pa?a-Toli?, L., Anderton, C.R., Vertes, A., 2019. Ambient metabolic profiling and imaging of biological samples with ultrahigh molecular resolution using laser ablation electrospray ionization 21 Tesla FTICR mass spectrometry. Analytical Chemistry 91, 5028-5035. spectrometry (MS) is an indispensable analytical tool to capture the array of metabolites within complex biological systems. However, conventional MS-based metabolomic workflows require extensive sample processing and separation resulting in limited throughput and potential alteration of the native molecular states in these systems. Ambient ionization methods, capable of sampling directly from tissues, circumvent some of these issues but require high-performance MS to resolve the molecular complexity within these samples. Here, we demonstrate a unique combination of laser ablation electrospray ionization (LAESI) coupled with a 21 tesla Fourier transform ion cyclotron resonance (21T-FTICR) for direct MS analysis and imaging applications. This analytical platform provides isotopic fine structure information directly from biological tissues, enabling the rapid assignment of molecular formulas and delivering a higher degree of confidence for molecular identification.Strangl, M., Ortner, E., Buettner, A., 2019. Evaluation of the efficiency of odor removal from recycled HDPE using a modified recycling process. Resources, Conservation and Recycling 146, 89-97. series of recent global and local policymaking processes is promoting or demanding developments in the recycling of post-consumer plastic packaging waste. After successfully clearing most hurdles in the PET bottle sector to promote a successful market launch of the recycled PET products, it is now important to take measures to meet the challenges associated with the recycling of polyolefins such as HDPE. In this respect, the need to further improve recycling technologies is currently prevalent because the quality parameters of the recycled materials do not yet meet the strict industrial requirements. In this context, apart from optical or mechanical properties, there is increasing awareness of odorous contaminants in the recycled products. Therefore, in this study, a modified HDPE recycling method was evaluated for its ability to reduce odors. For the aim of mapping and understanding the odor of recycled HDPE pellets with different residence times in a special decontamination reactor a combinatory sensory and instrumental-olfactometric approach was applied. Furthermore, based on the characterization of the causative odorants by gas chromatography-olfactometry and two-dimensional gas chromatography-mass spectrometry/olfactometry, quantitative determination of selected odorants was carried out over time using stable isotope dilution analysis. With regard to the decontamination efficacy of the evaluated decontamination process, we observed that the decrease in the concentration profiles of the monitored odorants went along with a sensorially relevant overall odor minimization of the recycled HDPE. The results of the study are aiding the adaptation of technological procedures for smell reduction or complete decontamination.Strassert, J.F.H., Jamy, M., Mylnikov, A.P., Tikhonenkov, D.V., Burki, F., 2019. New phylogenomic analysis of the enigmatic phylum Telonemia further resolves the eukaryote tree of life. Molecular Biology and Evolution 36, 757-765. resolution of the broad-scale tree of eukaryotes is constantly improving, but the evolutionary origin of several major groups remains unknown. Resolving the phylogenetic position of these “orphan” groups is important, especially those that originated early in evolution, because they represent missing evolutionary links between established groups. Telonemia is one such orphan taxon for which little is known. The group is composed of molecularly diverse biflagellated protists, often prevalent although not abundant in aquatic environments. Telonemia has been hypothesized to represent a deeply diverging eukaryotic phylum but no consensus exists as to where it is placed in the tree. Here, we established cultures and report the phylogenomic analyses of three new transcriptome data sets for divergent telonemid lineages. All our phylogenetic reconstructions, based on 248 genes and using site-heterogeneous mixture models, robustly resolve the evolutionary origin of Telonemia as sister to the Sar supergroup. This grouping remains well supported when as few as 60% of the genes are randomly subsampled, thus is not sensitive to the sets of genes used but requires a minimal alignment length to recover enough phylogenetic signal. Telonemia occupies a crucial position in the tree to examine the origin of Sar, one of the most lineage-rich eukaryote supergroups. We propose the moniker “TSAR” to accommodate this new mega-assemblage in the phylogeny of eukaryotes.Stravs, M.A., Pomati, F., Hollender, J., 2019. Biodiversity drives micropollutant biotransformation in freshwater phytoplankton assemblages. Environmental Science & Technology 53, 4265-4273. of chemical pollutants is an ecological process requiring multifunctionality (multiple metabolic pathways) and, potentially, high biodiversity. Phytoplankton communities are highly diverse functionally and taxonomically and co-occur with complex mixtures of organic pollutants in aquatic environments. Here, we investigated how phytoplankton species richness (SR) and class richness (CR) determine the biotransformation of a mixture of 37 structurally diverse pollutants using laboratory experiments and analysis of high-resolution mass spectrometry data. Laboratory phytoplankton communities were assembled from pure cultures by creating a gradient from one to five taxonomic groups, and 5 to 11 total species, in defined medium. The biotransformation of pollutants over 6 days and the total number of transformed chemicals increased with CR for 13 considerably transformed compounds. The total number of transformation products (TPs, up to 42) was positively affected by both CR and SR: CR had a positive effect on stable TPs found, and SR led to more transient TPs. Our data indicate that both taxonomic and functional diversity are important for biotransformation of anthropogenic chemicals in phytoplankton and suggest that plankton biodiversity could play a role in the remediation of pollutant loads in aquatic ecosystems.Struchkov, I.A., Rogachev, M.K., Kalinin, E.S., Roschin, P.V., 2019. Laboratory investigation of asphaltene-induced formation damage. Journal of Petroleum Exploration and Production Technology 9, 1443-1455. purpose of this study is to evaluate the degree of formation damage caused by asphaltene deposition in the pore throats in case of oilfield operation. Many wells in the Samara region oilfields are operated under high reservoir drawdown, with downhole pressure lower than the bubble point. Such wells’ operating conditions lead to a change in oil composition (light components are extracted from oil while asphaltenes are precipitated and deposited) in the near wellbore, and the productivity of the wells declines due to asphaltene deposition. The study procedure presented in the paper included the following methods: high-pressure microscopy with grain size analysis (the visual method), the near infrared light scattering method and the gravimetric method to measure asphaltenes onset pressure in oil. Formation damage was measured by the filtration method. Asphaltene concentration in oil after filtration was measured by the photocolorimetric analysis. Microcomputed tomography of the core sample was provided to visualize formation damage. In addition, fluid flow in the pore space was simulated before and after asphaltene deposition using a dynamic simulator. In the paper, reservoir oil of one of the Russian oilfields was investigated. The main results of this paper are the following: asphaltene onset pressure in oil at the reservoir temperature (48?°C) was measured as equal to 6.8?MPa which is slightly higher than the bubble-point (6.5?MPa). Oil was flowed through the core sample of the field at three different specific backpressures (at constant flow rate) and formation damage was estimated. The studies have shown that decrease in permeability of the core is caused by asphaltene deposition in the pore space. In this case, a decrease in the amount of asphaltenes in oil emerging from the core sample is observed which was proved by the spectrophotometric analysis. Via microcomputed tomography, a 3D model of the rock matrix and the pore space of the initial and damaged core sample was constructed and a decrease in porosity after formation damage was estimated. Based on the obtained 3D model of the core, computer simulation of fluid flow (in a dynamic simulator) in the initial and damaged core was performed, and the flow parameters (velocity and streamlines) were calculated. The proposed methodology including a set of physical methods to study a core before and after formation damage combined with fluid flow simulation enables predicting potential complications under the field operation.Sturm, A., Fowle, D.A., Jones, C., Leslie, K., Nomosatryo, S., Henny, C., Canfield, D.E., Crowe, S.A., 2019. Rates and pathways of CH4 oxidation in ferruginous Lake Matano, Indonesia. Geobiology 17, 294-307. study evaluates rates and pathways of methane (CH4) oxidation and uptake using 14C‐based tracer experiments throughout the oxic and anoxic waters of ferruginous Lake Matano. Methane oxidation rates in Lake Matano are moderate (0.36 nmol L?1 day?1 to 117 μmol L?1 day?1) compared to other lakes, but are sufficiently high to preclude strong CH4 fluxes to the atmosphere. In addition to aerobic CH4 oxidation, which takes place in Lake Matano's oxic mixolimnion, we also detected CH4 oxidation in Lake Matano's anoxic ferruginous waters. Here, CH4 oxidation proceeds in the apparent absence of oxygen (O2) and instead appears to be coupled to some as yet uncertain combination of nitrate (NO3-), nitrite (NO2-), iron (Fe) or manganese (Mn), or sulfate (SO4-2) reduction. Throughout the lake, the fraction of CH4 carbon that is assimilated vs. oxidized to carbon dioxide (CO2) is high (up to 93%), indicating extensive CH4 conversion to biomass and underscoring the importance of CH4 as a carbon and energy source in Lake Matano and potentially other ferruginous or low productivity environments.Sugita, S., Honda, R., Morota, T., Kameda, S., Sawada, H., Tatsumi, E., Yamada, M., Honda, C., Yokota, Y., Kouyama, T., Sakatani, N., Ogawa, K., Suzuki, H., Okada, T., Namiki, N., Tanaka, S., Iijima, Y., Yoshioka, K., Hayakawa, M., Cho, Y., Matsuoka, M., Hirata, N., Hirata, N., Miyamoto, H., Domingue, D., Hirabayashi, M., Nakamura, T., Hiroi, T., Michikami, T., Michel, P., Ballouz, R.L., Barnouin, O.S., Ernst, C.M., Schr?der, S.E., Kikuchi, H., Hemmi, R., Komatsu, G., Fukuhara, T., Taguchi, M., Arai, T., Senshu, H., Demura, H., Ogawa, Y., Shimaki, Y., Sekiguchi, T., Müller, T.G., Hagermann, A., Mizuno, T., Noda, H., Matsumoto, K., Yamada, R., Ishihara, Y., Ikeda, H., Araki, H., Yamamoto, K., Abe, S., Yoshida, F., Higuchi, A., Sasaki, S., Oshigami, S., Tsuruta, S., Asari, K., Tazawa, S., Shizugami, M., Kimura, J., Otsubo, T., Yabuta, H., Hasegawa, S., Ishiguro, M., Tachibana, S., Palmer, E., Gaskell, R., Le Corre, L., Jaumann, R., Otto, K., Schmitz, N., Abell, P.A., Barucci, M.A., Zolensky, M.E., Vilas, F., Thuillet, F., Sugimoto, C., Takaki, N., Suzuki, Y., Kamiyoshihara, H., Okada, M., Nagata, K., Fujimoto, M., Yoshikawa, M., Yamamoto, Y., Shirai, K., Noguchi, R., Ogawa, N., Terui, F., Kikuchi, S., Yamaguchi, T., Oki, Y., Takao, Y., Takeuchi, H., Ono, G., Mimasu, Y., Yoshikawa, K., Takahashi, T., Takei, Y., Fujii, A., Hirose, C., Nakazawa, S., Hosoda, S., Mori, O., Shimada, T., Soldini, S., Iwata, T., Abe, M., Yano, H., Tsukizaki, R., Ozaki, M., Nishiyama, K., Saiki, T., Watanabe, S., Tsuda, Y., 2019. The geomorphology, color, and thermal properties of Ryugu: Implications for parent-body processes. Science 364, 252.'s Summary: Hayabusa2 at the asteroid Ryugu. Asteroids fall to Earth in the form of meteorites, but these provide little information about their origins. The Japanese mission Hayabusa2 is designed to collect samples directly from the surface of an asteroid and return them to Earth for laboratory analysis. Three papers in this issue describe the Hayabusa2 team's study of the near-Earth carbonaceous asteroid 162173 Ryugu, at which the spacecraft arrived in June 2018 (see the Perspective by Wurm). Watanabe et al. measured the asteroid's mass, shape, and density, showing that it is a “rubble pile” of loose rocks, formed into a spinning-top shape during a prior period of rapid spin. They also identified suitable landing sites for sample collection. Kitazato et al. used near-infrared spectroscopy to find ubiquitous hydrated minerals on the surface and compared Ryugu with known types of carbonaceous meteorite. Sugita et al. describe Ryugu's geological features and surface colors and combined results from all three papers to constrain the asteroid's formation process. Ryugu probably formed by reaccumulation of rubble ejected by impact from a larger asteroid. These results provide necessary context to understand the samples collected by Hayabusa2, which are expected to arrive on Earth in December 2020.Structured AbstractIntroduction: The asteroid 162173 Ryugu is the target of the Japanese Hayabusa2 mission, which is designed to collect samples from Ryugu’s surface and return them to Earth. We seek to understand Ryugu’s formation from a parent body, both to better explain the origin of near-Earth asteroids and to provide context for analyzing the samples. Theoretical calculations indicate that Ryugu-size asteroids are likely produced through catastrophic disruption of a parent body, formed in the early Solar System, whose fragments then reaccumulated. Ryugu later migrated from the main asteroid belt to its current near-Earth orbit.Rationale: Hayabusa2 rendezvoused with the asteroid in June 2018. Detailed global observations of Ryugu were conducted with Hayabusa2’s remote-sensing instruments, including the optical navigation cameras (ONCs), laser altimeter [light detection and ranging (LIDAR) altimeter], and a thermal infrared camera (TIR). We examined the asteroid’s surface colors, geomorphological features, and thermal properties to constrain models of its formation.Results: Geologic features on Ryugu include a circum-equatorial ridge, an underlying east-west dichotomy, high boulder abundance, impact craters, and large-scale color uniformity.We estimate that the impact craters penetrating the top 10 meters of Ryugu’s surface have existed for 107 to 108 years, indicating that the last major resurfacing likely occurred while Ryugu was still located in the main asteroid belt. In contrast, the low number density of small craters (~10 m in diameter) suggests a very young resurfacing age (? 106 years) for the top 1-meter layer.Multicolor optical observations revealed that Ryugu possesses the average spectrum of a Cb-type asteroid and lacks a ubiquitous 0.7-?m absorption band. These spectral observations and a principal components analysis suggest that Ryugu originates from the Eulalia or Polana asteroid family in the inner main belt, possibly via more than one generation of parent bodies.Ryugu’s geometric albedo at 0.55 ?m is 4.5 ± 0.2%, among the lowest in the Solar System. Moderately dehydrated carbonaceous chondrites and interplanetary dust particles (IDPs) are the only meteoritic samples with similarly low albedos. The high boulder abundance and the spectral properties of the boulders are consistent with dehydrated surface materials, which might be analogous to thermally metamorphosed meteorites.The spectra of Ryugu’s surfaces occupy a small area in the dehydration track of our principal component space, suggesting that a large volume of Ryugu’s original parent body experienced similar degrees of partial dehydration. Such uniformity is more consistent with internal heating on the parent body than heating due to multiple impacts. Nevertheless, it is possible that global partial dehydration could result from impacts if the parent body sustained many impacts before its catastrophic disruption. Geochemical analyses of thermally metamorphosed meteorites are consistent with short-term heating; thus, this scenario cannot be readily discarded.A third possibility is that Ryugu is covered with materials that experienced only incipient aqueous alteration, possibly similar to some IDPs. If so, the spectral trend observed in Ryugu’s boulders may be a progression of aqueous alteration.Conclusion: Multiple scenarios remain viable, but the Hayabusa2 remote-sensing data are most consistent with parent-body partial dehydration due to internal heating. This scenario suggests that asteroids formed from materials that condensed at ≤150 K (the H2O condensation temperature under typical solar nebula conditions) must have either formed sufficiently early to contain high concentrations of radiogenic species, such as 26Al, or formed near the Sun, where they experienced other heating mechanisms. The degree of internal heating would constrain the location and/or timing of the snow line (the dividing line between H2O condensation and evaporation) in the early Solar System.Abstract: The near-Earth carbonaceous asteroid 162173 Ryugu is thought to have been produced from a parent body that contained water ice and organic molecules. The Hayabusa2 spacecraft has obtained global multicolor images of Ryugu. Geomorphological features present include a circum-equatorial ridge, east-west dichotomy, high boulder abundances across the entire surface, and impact craters. Age estimates from the craters indicate a resurfacing age of ? 106 years for the top 1-meter layer. Ryugu is among the darkest known bodies in the Solar System. The high abundance and spectral properties of boulders are consistent with moderately dehydrated materials, analogous to thermally metamorphosed meteorites found on Earth. The general uniformity in color across Ryugu’s surface supports partial dehydration due to internal heating of the asteroid’s parent body.Sun, F., Yao, Y., Li, G., Dong, M., 2019. Transport behaviors of real gas mixture through nanopores of shale reservoir. Journal of Petroleum Science and Engineering 177, 1134-1141. modeling of shale gas transport through nanopores is the basis for shale gas production simulation. The real shale gas always consists of a series of gases, including ethane, propane and hydrogen sulfide etc. Previous models neglected the multi-component effect on the shale gas transport mechanisms. In this paper, a novel model is presented for simulating the real gas mixture transport through nanopores of shale formation. Firstly, a model is presented for ideal shale gas transport through nanopores considering the multi-component effect, then, the real gas effect is coupled into the model. Simulation results show that: (a) When it is under low pressure level condition, the conductivities of slippage flow and Knudsen diffusion increase with decreasing methane fraction. (b) When it is under medium pressure level condition, the conductivities of slippage flow and Knudsen diffusion increase with decreasing methane fraction. (c) Under high pressure condition, the conductivities of different flow patterns increase with decreasing methane fraction.Sun, L., Xu, C.-p., Xiao, K.-y., Zhu, Y.-s., Yan, L.-y., 2018. Geological characteristics, metallogenic regularities and the exploration of graphite deposits in China. China Geology 1, 425-434. demand for graphite resources has been increasing due to its extensive use. Graphite deposits in China are mainly distributed in Heilongjiang, Innner Mogolia, Sichuan, Shanxi and Shandong, characterized by “one old & one new” and “many in east & few in west”. There are mainly three genetic types, including regional metamorphic type, contact metamorphic type and hydrothermal type. Here we provide a summary of the metallogenic regularity and 15 metallogenic belts in China based on the study of the geology of national graphite deposits. In recent years, great progress has been made in the research of genesis, mineral exploration and evaluation on graphite deposits, which indicate great potential for graphite resource in China. The authors suggest that the research on geochronology, ore sources, the genesis of crystalline graphite and exploration for hydrothermal graphite in China should be heightened.Sun, S., Liu, Q., Chen, S., Yu, W., Zhao, C., Chen, H., 2019. Optimization for microbial degradation of petroleum hydrocarbon (TPH) by Enterobacter sp. S-1 using response surface methodology. Petroleum Science and Technology 37, 821-828. this research, the response surface method designed by Box-Behnken was used to study the effect of temperature, pH value and TPH concentration on the biodegradation of Enterobacter sp. S-1contaminated soil. The value of determination coefficient (R2=0.9565) by analysis of variance (ANOVA) indicated a satisfactory agreement between the quadratic model and the experimental data. It was found that TPH degradation rate was more significantly affected (p <0.0006) by temperature compared with other two parameters. In the temperature of 30 °C, pH value of 7.14 and TPH concentration was 4.83?g/L, the best degradation rate was 81.63%.Sun, Z.-l., Cao, H., Geng, W., Zhang, L., Zhang, X.-r., Xu, C.-l., Li, X., Guo, J.-w., 2018. A three-dimensional environmental monitoring system for the production of marine gas hydrates. China Geology 1, 570-571.. Objectives: As about 99% of the natural gas hydrate (NGH) resources are stored on the seafloor, it is inevitable that in its process of exploration and production, there will be geohazards such as methane leakage, seabed subsidence, ecosystem damage and even landslide. Therefore, a set of integrated systems for environmental monitoring in the process of NGH production has been proposed in the consideration of environmental disasters that may arise in the process of hydrate production. We set up monitoring units from the seabed, water column to wellbore, in order to obtain integrated data concerning environmental effects during the hydrate production, with the aim of an early warning in the event of potential environmental geohazards.2. Methods: Guided by the actual needs of environmental monitoring during the production and development of marine NGH in China, the design concept of “systematization, dynamization, modularization and multi-function” is adopted, and the design schemes of foreign countries in this regard (Lee JY et al., 2013; Chee S et al., 2014) are also consulted, as well as the environmental monitoring schemes for a trial production in the South China Sea in 2017 (Ye JY et al., 2018). In our design, the monitoring module for topographic deformation and seabed subsidence is also added according to the actual need, as well as the unified power supply design.3. Results: This system (Invention patent license number: ZL201710-181354.4) can monitor the environmental impact of hydrate development in real time in three dimensions. There are two monitoring circles inside and outside the well site. The main functions of the inner circle are to monitor seabed gas leakage, drilling mud pollution, turbidity anomaly, seabed deformation and subsidence related to the hydrate production. In addition, parameters like ocean current and dissolved oxygen are also monitored inside of the inner circle. In contrast, anchor systems are mainly located in the outer circle. Additionally, the cross-shaped topographic deformation monitor extends between the inner and outer circles to better monitor the seabed deformation in a wider range. Anchor systems are set up according to the depth of water in the production area. Usually, pressure chambers with sensors are set up at 50 m and 200 m vertically away from the seabed, integrating methane sensor, nephelometer, ADCP and CTD to monitor environmental parameters, such as methane, concentration turbidity, current velocity etc.Outside the monitoring circle, a device for uniform power supply and data acquisition and storage for various monitoring instruments is laid out. Moreover, patrol AUV and ROV can be used to monitor the methane leakage and other environmental parameters in a wider range periodically based on the engineering platform. The biological ecology and topography outside the core circles can also be dynamically monitored to increase the monitoring scope of this system.Vertically, this system consists of environmental monitoring wells, seabed-based workstations, and an anchor system with a depth of more than 300 m from the bottom, AUV and ROV with an infinite water depth. Furthermore, atmospheric sampling and monitoring instruments are also installed on the engineering platform, thus establishing a whole set of environmental monitoring systems which can provide real-time and long-term monitoring of reservoirs, sea beds, water bodies and atmosphere to ensure the environmental safety of hydrate production.4. Conclusions: Our system reserves enough comprehensive capability for the monitoring of marine NGH production. It not only pays attention to the conventional parameters, such as water chemistry, gas leakage, seabed deformation and subsidence within hundreds of meters of the production well, but also takes into account the dynamic changes of micro-topography, geomorphology and biological ecosystems. During the production process, an integrated, dynamic and three-dimensional monitor can be achieved, thus ensue the environmental friendliness of utilization of NGH resources.Takagi, H., Kimoto, K., Fujiki, T., Saito, H., Schmidt, C., Kucera, M., Moriya, K., 2019. Characterizing photosymbiosis in modern planktonic foraminifera. Biogeosciences Discussions 2019, 1-32. has played a key role in the diversification of foraminifera and their carbonate production through geologic history. However, identification of photosymbiosis in extinct taxa remains challenging and even among the extant species the occurrence and functional relevance of photosymbiosis remains poorly constrained. Here, we investigate photosymbiosis in living planktonic foraminifera by measuring active chlorophyll fluorescence with fast repetition rate fluorometry. This method provides unequivocal evidence for the presence of photosynthetic capacity in individual foraminifera and it allows us to characterize multiple features of symbiont photosynthesis including chlorophyll a (Chl a) content, potential photosynthetic activity (Fv?/?Fm), and light absorption efficiency (σPSII). To obtain robust evidence for the occurrence and importance of photosymbiosis in modern planktonic foraminifera, we conducted measurements on 1266 individuals from 30 species of the families Globigerinidae, Hastigerinidae, Globorotaliidae, and Candeinidae. Among the studied species, 19 were recognized as symbiotic and 11 as non-symbiotic. Of these, six species were newly confirmed as symbiotic and five as non-symbiotic. Photosymbiotic species have been identified in all families except the Hastigerinidae. A significant positive correlation between test size and Chl a content, found in 16 species, is interpreted as symbiont growth scaled to the growth of the host, consistent with persistent possession of symbionts through the lifetime of the foraminifera. The remaining three symbiont-bearing species did not show such a relationship, and their Fv?/?Fm values were comparatively low, indicating that their symbionts do not grow once acquired from the environment. The objectively quantified photosymbiotic characteristics have been used to design a metric of photosymbiosis, which allows the studied species to be classified along a gradient of photosynthetic activity, providing a framework for future ecological and physiological investigations of planktonic foraminifera.Talbi, R., Lakhdar, R., Smati, A., Spiller, R., Levey, R., 2019. Aptian–Albian shale oil unconventional system as registration of Cretaceous oceanic anoxic sub-events in the southern Tethys (Bir M’Cherga basin, Tunisia). Journal of Petroleum Exploration and Production Technology 9, 1007-1022. Bir M’Cherga basin (North-east Tunisia), with about 600?km2 area, had recorded four Middle Cretaceous source rocks well stratigraphically correlated with the four known oceanic anoxic sub-events: OAE1a, OAE1b, OAE1c, and OAE1d. Variety of lithology, thickness and organic richness had characterized these source rocks. The sedimentary tectonic analysis, the petrology and geochemistry study established the petroleum system of these source rocks. Basin formation began early in the Barremian–Aptian interval by synsedimentary tectonics reactivating old basement faults. During the Aptian–Albian, the formed basin had a depocenter that recorded thicker black shales while its NW and SE edges remained raised under the Triassic halokinetic activities. The evolution of the sedimentary filling during this period generated two sedimentary cycles corresponding to two filling second-order fining and thickening upwards sequences. The black shales that constitute these source rocks are formed between subtidal and external platform environment and are interbedded with juxtaposed high organic rich layers and poor ones. The rich organic facies consists of dark shale that constitutes the source rock. The poor organic beds formed by light grey and nodular limestones constitute an intra host reservoir. Thereby, petroleum system consists in an “unconventional oil shale hybrid systems with a combination of juxtaposed organic-rich and organic-lean intervals associated to open fractures”. The kerogen is essentially amorphous, with marine planktonic origin and low ligneous organic matter contribution. This organic material of dark facies had been well preserved in an anoxic environment with little or no energy. Light grey limestones were of oxic-to-sub-oxic environment. The stage of the thermal evolution for these source rocks provided by IH/Tmax diagram is of the “oil window”. The average transformation ratio (TR) is estimated as 45% suggesting thus black shales are oil shale resources which still close about untransformed 55% of its hydrocarbon generating potential. The expulsion and release of oil into these source rocks are proven by the observation of hydrocarbons filling micro-cracks and by the variable values of the oil saturation index OSI ranging from 0 to 138%. The latter exceeds 100% near the paleo-high reliefs indicating two “oil crossover” areas attributed to the high degree of oil source rock saturation and accumulation of hydrocarbons considered ideal for hydraulic fracturing. This oil crossover is a consequence of secondary migration into black shale source rock, achieved by various faults created during the distensive phase that were reactivated again several times.Taylor, H.L., Duivestein, I.J.K., Farkas, J., Dietzel, M., Dosseto, A., 2019. Technical note: Lithium isotopes in dolostone as a palaeo-environmental proxy – an experimental approach. Climate of the Past 15, 635-646. (Li) isotopes in marine carbonates have considerable potential as a proxy to constrain past changes in silicate weathering fluxes and improve our understanding of Earth's climate. To date the majority of Li isotope studies on marine carbonates have focussed on calcium carbonates. The determination of the Li isotope fractionation between dolomite and a dolomitizing fluid would allow us to extend investigations to deep times (i.e. Precambrian) when dolostones were the most abundant marine carbonate archives. Dolostones often contain a significant proportion of detrital silicate material, which dominates the Li budget; thus, pretreatment needs to be designed so that only the isotope composition of the carbonate-associated Li is measured. This study aims to serve two main goals: (1) to determine the Li isotope fractionation between Ca–Mg carbonates and solution, and (2) to develop a method for leaching the carbonate-associated Li out of dolostone while not affecting the Li contained within the detrital portion of the rock. We synthesized Ca–Mg carbonates at high temperatures (150 to 220?°C) and measured the Li isotope composition (δ7Li) of the precipitated solids and their respective reactive solutions. The relationship of the Li isotope fractionation factor with temperature was obtained: 103lnαprec-sol = ?((2.56±0.27)106)/T2+(5.8±1.3)Competitive nucleation and growth between dolomite and magnesite were observed during the experiments; however, there was no notable effect of their relative proportion on the apparent Li isotope fractionation. We found that Li isotope fractionation between the precipitated solid and solution is higher for Ca–Mg carbonates than for Ca carbonates. If the temperature of a precipitating solution is known or can be estimated independently, the above equation could be used in conjunction with the Li isotope composition of dolostones to derive the composition of the solution and hence make inferences about the past Li cycle. In addition, we also conducted leaching experiments on a Neoproterozoic dolostone and a Holocene coral. Results show that leaching with 0.05?M hydrochloric acid (HCl) or 0.5?% acetic acid (HAc) at room temperature for 60?min releases Li from the carbonate fraction without a significant contribution of Li from the siliciclastic detrital component. These experimental and analytical developments provide a basis for the use of Li isotopes in dolostones as a palaeo-environmental proxy, which will contribute to further advance our understanding of the evolution of Earth's surface environments.Taylor, L.D., O’Dea, A., Bralower, T.J., Finnegan, S., 2019. Isotopes from fossil coronulid barnacle shells record evidence of migration in multiple Pleistocene whale populations. Proceedings of the National Academy of Sciences 116, 7377.: Migration has long been hypothesized to have played a critical role in baleen whale evolution, but fossil constraints on the history of migration are sparse. Here we provide evidence that the oxygen isotope composition of modern whale barnacle shells reliably records migration pathways. We also analyze fossil whale barnacle shells from three Pleistocene localities and show that they display isotope profiles similar to those of modern specimens. Our results indicate the presence of migration among all three ancient whale populations studied and point to the possibility of reconstructing changes in migratory behaviors from the Pliocene to the present.Abstract: Migration is an integral feature of modern mysticete whale ecology, and the demands of migration may have played a key role in shaping mysticete evolutionary history. Constraining when migration became established and assessing how it has changed through time may yield valuable insight into the evolution of mysticete whales and the oceans in which they lived. However, there are currently few data which directly assess prehistoric mysticete migrations. Here we show that calcite δ18O profiles of two species of modern whale barnacles (coronulids) accurately reflect the known migration routes of their host whales. We then analyze well-preserved fossil coronulids from three different locations along the eastern Pacific coast, finding that δ18O profiles from these fossils exhibit trends and ranges similar to modern specimens. Our results demonstrate that migration is an ancient behavior within the humpback and gray whale lineages and that multiple Pleistocene populations were undertaking migrations of an extent similar to those of the present day.Teixeira Parente, M., Mattis, S., Gupta, S., Deusner, C., Wohlmuth, B., 2019. Efficient parameter estimation for a methane hydrate model with active subspaces. Computational Geosciences 23, 355-372. gas hydrates have increasingly become a topic of interest because of their potential as a future energy resource. There are significant economical and environmental risks associated with extraction from hydrate reservoirs, so a variety of multiphysics models have been developed to analyze prospective risks and benefits. These models generally have a large number of empirical parameters which are not known a priori. Traditional optimization-based parameter estimation frameworks may be ill-posed or computationally prohibitive. Bayesian inference methods have increasingly been found effective for estimating parameters in complex geophysical systems. These methods often are not viable in cases of computationally expensive models and high-dimensional parameter spaces. Recently, methods have been developed to effectively reduce the dimension of Bayesian inverse problems by identifying low-dimensional structures that are most informed by data. Active subspaces is one of the most generally applicable methods of performing this dimension reduction. In this paper, Bayesian inference of the parameters of a state-of-the-art mathematical model for methane hydrates based on experimental data from a triaxial compression test with gas hydrate-bearing sand is performed in an efficient way by utilizing active subspaces. Active subspaces are used to identify low-dimensional structure in the parameter space which is exploited by generating a cheap regression-based surrogate model and implementing a modified Markov chain Monte Carlo algorithm. Posterior densities having means that match the experimental data are approximated in a computationally efficient way.Thiel, J., Byrne, J.M., Kappler, A., Schink, B., Pester, M., 2019. Pyrite formation from FeS and H2S is mediated through microbial redox activity. Proceedings of the National Academy of Sciences 116, 6897-6902.: Pyrite is the most abundant iron?sulfur mineral in sediments. Over geological times, its burial controlled oxygen levels in the atmosphere and sulfate concentrations in seawater. However, the mechanism of pyrite formation in sediments is still being debated. We show that lithotrophic microorganisms can mediate the transformation of FeS and H2S to FeS2 at ambient temperature if metabolically coupled to methane-producing archaea. Our results provide insights into a metabolic relationship that could sustain part of the deep biosphere and lend support to the iron?sulfur-world theory that postulated FeS transformation to FeS2 as a key energy-delivering reaction for life to emerge.Abstract: The exergonic reaction of FeS with H2S to form FeS2 (pyrite) and H2 was postulated to have operated as an early form of energy metabolism on primordial Earth. Since the Archean, sedimentary pyrite formation has played a major role in the global iron and sulfur cycles, with direct impact on the redox chemistry of the atmosphere. However, the mechanism of sedimentary pyrite formation is still being debated. We present microbial enrichment cultures which grew with FeS, H2S, and CO2 as their sole substrates to produce FeS2 and CH4. Cultures grew over periods of 3 to 8 mo to cell densities of up to 2 to 9 × 106 cells per mL?1. Transformation of FeS with H2S to FeS2 was followed by 57Fe M?ssbauer spectroscopy and showed a clear biological temperature profile with maximum activity at 28 °C and decreasing activities toward 4 °C and 60 °C. CH4 was formed concomitantly with FeS2 and exhibited the same temperature dependence. Addition of either penicillin or 2-bromoethanesulfonate inhibited both FeS2 and CH4 production, indicating a coupling of overall pyrite formation to methanogenesis. This hypothesis was supported by a 16S rRNA gene-based phylogenetic analysis, which identified at least one archaeal and five bacterial species. The archaeon was closely related to the hydrogenotrophic methanogen Methanospirillum stamsii, while the bacteria were most closely related to sulfate-reducing Deltaproteobacteria, as well as uncultured Firmicutes and Actinobacteria. Our results show that pyrite formation can be mediated at ambient temperature through a microbially catalyzed redox process, which may serve as a model for a postulated primordial iron?sulfur world.Thieme, L., Graeber, D., Hofmann, D., Bischoff, S., Schwarz, M.T., Steffen, B., Meyer, U.-N., Kaupenjohann, M., Wilcke, W., Michalzik, B., Siemens, J., 2019. Dissolved organic matter characteristics of deciduous and coniferous forests with variable management: different at the source, aligned in the soil. Biogeosciences 16, 1411-1432. organic matter (DOM) is part of the biogeochemical cycles of carbon and nutrients, carries pollutants and drives soil formation. The DOM concentration and properties along the water flow path through forest ecosystems depend on its sampling location and transformation processes. To improve our understanding of the effects of forest management, especially tree species selection and management intensity, on DOM concentrations and properties of samples from different ecosystem fluxes, we studied throughfall, stemflow, litter leachate and mineral soil solution at 26 forest sites in the three regions of the German Biodiversity Exploratories. We covered forest stands with three management categories (coniferous, deciduous age class and unmanaged beech forests). In water samples from these forests, we monitored DOC concentrations over 4 years and characterized the quality of DOM with UV-vis absorption, fluorescence spectroscopy combined with parallel factor analysis (PARAFAC) and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Additionally, we performed incubation-based biodegradation assays. Multivariate statistics revealed strong significant effects of ecosystem fluxes and smaller effects of main tree species on DOM quality. Coniferous forests differed from deciduous forests by showing larger DOC concentrations, more lignin- and protein-like molecules, and fewer tannin-like molecules in throughfall, stemflow, and litter leachate. Cluster analysis of FT-ICR-MS data indicated that DOM compositions, which varied in aboveground samples depending on tree species, become aligned in mineral soil. This alignment of DOM composition along the water flow path in mineral soil is likely caused by microbial production and consumption of DOM in combination with its interaction with the solid phase, producing a characteristic pattern of organic compounds in forest mineral soils. We found similarly pronounced effects of ecosystem fluxes on the biodegradability of DOM, but surprisingly no differences between deciduous and coniferous forests. Forest management intensity, mainly determined by biomass extraction, contribution of species, which are not site-adapted, and deadwood mass, did not influence DOC concentrations, DOM composition and properties significantly.Thomas, C., Ariztegui, D., 2019. Fluid inclusions from the deep Dead Sea sediment provide new insights on Holocene extreme microbial life. Quaternary Science Reviews 212, 18-27. Dead Sea Deep Drilling Project allowed us to retrieve a continuous sedimentary record spanning the two last glacial cycles. This unique archive, in such an extreme environment, has permitted the development of new proxies and the refinement of already available paleoenvironmental studies. Although life is pushed to its extremes in the Dead Sea environment, several studies have highlighted the impact of microbial activity on this harsh milieu. The identity and means of adaptation of these organisms are however partly ignored. We also know relatively little on the way this extreme ecosystem has evolved with time, and how it will react to growing pressure. In this study, we have used the fluid inclusions trapped in halite, the main evaporitic phase during arid periods in the Dead Sea, to investigate the way the Dead Sea ecosystem has evolved. By extracting ancient DNA from Holocene halite fluid inclusions, we have obtained fossil bacterial and archaeal 16S rRNA gene sequences that suggest that the main microbial actors of the present Dead Sea have been present in the lake for a relatively long period, emphasizing the stability of this extreme environment. This is the case of extreme halophilic archaea of the Salinarchaeum genera. Additionally, we show that current phylotypes of the deep biosphere, such as Acetothermia bacteria are present within the obtained fluid inclusions sequences, which would support seeding of the deep biosphere from the water column. Finally, through the retrieval of sequences assigned to Halodesulfurarchaeum and Desulfovermiculus genera, we shed light on putative new actors of the sulfur cycle involving respectively archaea and bacteria, which could play an unexpected role in the reduction of sulfur species. Together, these data provide new research avenues for both geologists and biologists working in this extreme environment, and help to increase understanding of the evolution of the Dead Sea ecosystem with time.Thomas, C., Ariztegui, D., Antheaume, I., Grossi, V., 2019. Recycling of archaeal biomass as a new strategy for extreme life in Dead Sea deep sediments. Geology 47, 479-482. and Bacteria that inhabit the deep subsurface (known as the deep biosphere) play a prevalent role in the recycling of sedimentary organic carbon. In such environments, this process can occur over millions of years and requires microbial communities to cope with extremely limited sources of energy. Because of this scarcity, metabolic processes come at a high energetic cost, but the ways heterotrophic microbial communities develop to minimize energy expenses for a maximized yield remain unclear. Here, we report molecular biomarker evidence for the recycling of archaeal cell wall constituents in extreme evaporitic facies of Dead Sea deep sediments. Wax esters derived from the recombination of hydrolyzed products of archaeal membrane lipids were observed in gypsum and/or halite sedimentary deposits down to 243 m below the lake floor, implying the reutilization of archaeal necromass possibly by deep subsurface bacteria. By recycling the building blocks of putatively better-adapted archaea, heterotrophic bacteria may build up intracellular carbon stocks and mitigate osmotic stress in this energy-deprived environment. This mechanism illustrates a new pathway of carbon transformation in the subsurface and demonstrates how life can be maintained in extreme environments characterized by long-term isolation and minimal energetic resources.Tian, L., Wang, M., Zhang, X., Yang, X., Zong, Y., Jia, G., Zheng, Z., Man, M., 2019. Synchronous change of temperature and moisture over the past 50 ka in subtropical southwest China as indicated by biomarker records in a crater lake. Quaternary Science Reviews 212, 121-134. the past few decades, studies on the Indian Summer Monsoon (ISM) have been mainly based on paleo-marine records whilst the sparsity of land records limits our understanding of the ISM evolutionary process over continental landscapes. Here, we provide paleoclimate reconstructions based on n-alkanes and branched glycerol dialkyl glycerol tetraethers (brGDGTs) from a 50-ka lacustrine sediment core collected from Lake Tengchong Qinghai in southwestern subtropical China. Our results reveal that the botanical sources of sedimentary n-alkanes in this lake are mainly from aquatic macrophytes and terrestrial plants. The lake level evolution from the MIS 3 to the Holocene can be divided into four stages: high in the MIS 3, low in the LGM, high in last deglacial and low in mid and late Holocene. Our brGDGTs-based climate reconstructions indicate that the mean air temperature differences between the present-day and the LGM were up to about 3–4?°C. From MIS 3 to Holocene, there was a broadly and consistently synchronous trend between precipitation and air temperature in this ISM region. This is different from the asynchronous temperature and precipitation variations in the East Asian Summer Monsoon (EASM) regions in the period of last glacial termination. Our study shows that the climate in ISM regions was primarily driven by changes in June summer solar insolation at 30°N, and those glacial boundary conditions such as ice volume and sea surface temperature might also have affected the ISM.Tian, T., Zhou, S., Fu, D., Yang, F., Li, J., 2019. Characterization and controlling factors of pores in the Lower Cambrian Niutitang shale of the Micangshan Tectonic Zone, SW China. Arabian Journal of Geosciences 12, 251. Cambrian marine shale has become a new target of shale gas resource evaluations in the complex geological region of southern China, where the Niutitang Formation is among the most important shale gas reservoirs. Recently, the micropore structural characterization and main controlling factors of the ancient shale have become popular research topics. The micropore structures of certain shale samples from the Niutitang Formation in the Micangshan tectonic zone were investigated at the microscale and nanoscale using low-temperature nitrogen gas adsorption (GA) and a combination of broad ion beam (BIB) milling and field-emission scanning electron microscopy (FE-SEM). Then, we analyzed how the mineral composition and thermal evolution affect the pore development in the Niutitang shale through the results of X-ray diffraction (XRD) and vitrinite equivalent reflectance (VRoequiv) calculated by bitumen reflectance (Rb). The BSE images by the BIB/FE-SEM system show that multiple pore types are present in the ancient Niutitang shale and form a complex pore network under the influences of mineral contents and thermal maturation.Tocheri, M.W., 2019. Previously unknown human species found in Asia raises questions about early hominin dispersals from Africa. Nature 568, 176-178. in southeast Asia have unearthed a previously unreported hominin species named Homo luzonensis. The discovery has implications for ideas about early hominin evolution and dispersal from Africa. Homo sapiens is the only living species of a diverse group called hominins (members of the human family tree who are more closely related to each other than they are to chimpanzees and bonobos). Most extinct hominin species are not our direct ancestors, but instead are close relatives with evolutionary histories that took a slightly different path from ours. Writing in Nature, Détroit et al.1 report the remarkable discovery of one such human relative that will no doubt ignite plenty of scientific debate over the coming weeks, months and years. This newly identified species was found in the Philippines and named Homo luzonensis after Luzon, the island where bones and teeth from individuals of this species were excavated from Callao Cave. Specimens of H. luzonensis were dated to minimum ages of 50,000 and 67,000 years old, which suggests that the species was alive at the same time as several other hominins belonging to the genus Homo, including Homo sapiens, Neanderthals, Denisovans and Homo floresiensis.Rapidly changing knowledge about hominin evolution in Asia is forcing the re-examination of ideas about early hominin dispersals from Africa to Eurasia. Hominins appear in the fossil record about 6 million to 7 million years ago in Africa, and the earliest hominin fossils in Eurasia are about 1.8 million years old2. Explanations for the earliest hominin dispersals from Africa fall under what is known as the Out of Africa I paradigm3. Modern humans only come into focus in the Out of Africa II paradigm, which refers to the early dispersals of H. sapiens from Africa to Eurasia that first occurred in the past 200,000 years4.Ever since Homo erectus was discovered in the early 1890s in Indonesia on the island of Java, this species has essentially been the only character of interest in the Out of Africa I dispersal events. The conventional viewpoint is that this intrepid hominin began to stride gallantly towards far-off places around 1.5 million to 2 million years ago (a dispersal that enabled it to ultimately occupy territory across Africa and Eurasia)3. Meanwhile, the other hominin species around at that time stayed in Africa, living on borrowed time and facing imminent extinction. Compared with H. erectus, these species — for example, other early Homo species such as Homo habilis, as well as the australopiths (hominins not in the genus Homo), which include Paranthropus and Australopithecus — had smaller brains and an anatomy that is less similar to that of modern humans. Indeed, as this simplified old story goes, how could such species possibly compete given the anatomical and probable behavioural advantages that H. erectus possessed?Certain discoveries have challenged these entrenched ideas by raising the possibility that other hominins besides H. erectus dispersed from Africa to Eurasia during the Early Pleistocene (a period that occurred 2.58 million to 0.78 million years ago)5. Stone tools found in China are 2.1 million years old6, but no fossils as old as that have been attributed to H. erectus. It is also under debate whether H. erectus is the ancestor of H. floresiensis7, a species that lived on the Indonesian island of Flores. H. luzonensis provides yet more evidence that hints that H. erectus might not have been the only globe-trotting early hominin.Détroit and colleagues have assigned seven teeth, two hand bones, three foot bones and one thigh bone to H. luzonensis. These remains, including one bone that was found previously8, came from at least two adults and one child. The teeth include two premolars and three molars from an individual’s upper jaw (Fig. 1). Overall, these teeth and bones have a striking combination of characteristics never before reported together in a hominin species.When compared with the molars of other hominin species, H. luzonensis molars are astonishingly small, and the simplified surfaces of their crowns and their low number of cusps are features that look similar to the molar crowns and cusps of H. sapiens. Yet the shapes of H. luzonensis teeth share similarities with the teeth of H. erectus from Asia, and the size ratio of H. luzonensis premolars to molars is similar to that of Paranthropus, species of which are known for their massive jaws and teeth. The authors also used 3D imaging to examine the enamel–dentine junction (EDJ), which is an internal region of the tooth where dentine material meets the enamel layer. H. luzonensis premolar EDJs have a form that is distinct from that of hominins other than H. floresiensis. However, depending on the specific H. luzonensis molar that was analysed, the EDJs either look like those of H. erectus from Asia or like those of H. sapiens. This strange juxtaposition of features in a single individual’s jaw is completely unexpected and clouds our ability to reasonably assess, at least for now, the exact evolutionary relationships between H. luzonensis and other hominin species.Although attempts to extract DNA from H. luzonensis specimens have so far been unsuccessful, the anatomy of the foot and hand bones of H. luzonensis strengthens the case that these remains represent a previously unknown hominin species. A foot bone called the third metatarsal has an anatomy in H. luzonensis that is distinct from that of other hominin species, including H. sapiens8. The authors’ 3D shape analyses of a H. luzonensis toe bone show that its shape is essentially indistinguishable from the toe bones of Australopithecus afarensis and Australopithecus africanus (Fig. 1), despite the separation of these australopiths from H. luzonensis by at least 2 million to 3 million years of evolution. Similar analyses found that a H. luzonensis finger bone most resembles the finger bones of australopiths and species of early Homo. Finally, the H. luzonensis finger and toe bones are curved, which suggests that climbing was an important part of this species’ behavioural repertoire, as was also the case for many species of early hominin9.The discovery of H. floresiensis raised the question of whether it evolved from a species of early Homo7,10, for which evidence of its existence outside Africa has yet to be documented. Scientists are still struggling to answer this definitively11,12. The question is more pressing with the discovery of H. luzonensis, given the need to explain yet another hominin species that, like H. floresiensis, was around during part of the Late Pleistocene (defined as a period of time 126,000 to 11,700 years ago), had Homo-like teeth but australopith-like hands and feet, and that lived on an island only reachable after a major sea crossing. Perhaps H. floresiensis and H. luzonensis are both descendants of H. erectus populations that evolved separately on their respective islands for hundreds of thousands of years, if not more13,14. However, explaining the many similarities that H. floresiensis and H. luzonensis share with early Homo species and australopiths as independently acquired reversals to a more ancestral-like hominin anatomy, owing to evolution in isolated island settings, seems like a stretch of coincidence too far15.Given the rich history of the Out of Africa I paradigm, unsurprisingly, H. erectus has been the centre of attention in ideas about early hominin evolution and dispersals in Asia. Nevertheless, it is worth considering how different these ideas might be if, in the 1890s, H. floresiensis or H. luzonensis had been discovered rather than H. erectus. Because H. luzonensis provides the first glimpse of a second hominin species living on a distant island at a time when H. sapiens populations from Africa were beginning to spread across the world, one thing can be said for certain — our picture of hominin evolution in Asia during the Pleistocene just got even messier, more complicated and a whole lot more interesting.References1. Détroit, F. et al. Nature 568, 181–186 (2019).2. Ferring, R. et al. Proc. Natl Acad. Sci. USA 108, 10432–10436 (2011).3. Fleagle, J. G. et al. (eds) Out of Africa I: the First Hominin Colonization of Eurasia (Springer, 2010).4. Hershkovitz, I. et al. Science 359, 456–459 (2018).5. Dennell, R. & Roebroeks, W. Nature 438, 1099–1104 (2005).6. Zhu, Z. et al. Nature 559, 608–612 (2018).7. Brown, P. et al. Nature 431, 1055–1061 (2004).8. Mijares, A. S. et al. J. Hum. Evol. 59, 123–132 (2010).9. Kivell, T. L. et al. Nature Commun. 6, 8431 (2015).10. Morwood, M. J. et al. Nature 437, 1012–1017 (2005).11. van den Bergh, G. D. et al. Nature 534, 245–248 (2016).12. Argue, D., Groves, C. P., Lee, M. S. Y. & Jungers, W. L. J. Hum. Evol. 107, 107–133 (2017).13. Brumm, A. et al. Nature 441, 624–628 (2006).14. Ingicco, T. et al. Nature 557, 233–237 (2018).15. Morwood, M. J. & Jungers, W. L. J. Hum. Evol. 57, 640–648 (2009).Top?uo?lu, B.D., Meydan, C., Nguyen, T.B., Lang, S.Q., Holden, J.F., 2019. Growth kinetics, carbon isotope fractionation, and gene expression in the hyperthermophile Methanocaldococcus jannaschii during hydrogen-limited growth and interspecies hydrogen transfer. Applied and Environmental Microbiology 85, Article e00180-00119.: Hyperthermophilic methanogens are often H2 limited in hot subseafloor environments, and their survival may be due in part to physiological adaptations to low H2 conditions and interspecies H2 transfer. The hyperthermophilic methanogen Methanocaldococcus jannaschii was grown in monoculture at high (80 to 83?μM) and low (15 to 27?μM) aqueous H2 concentrations and in coculture with the hyperthermophilic H2 producer Thermococcus paralvinellae. The purpose was to measure changes in growth and CH4 production kinetics, CH4 fractionation, and gene expression in M. jannaschii with changes in H2 flux. Growth and cell-specific CH4 production rates of M. jannaschii decreased with decreasing H2 availability and decreased further in coculture. However, cell yield (cells produced per mole of CH4 produced) increased 6-fold when M. jannaschii was grown in coculture rather than monoculture. Relative to high H2 concentrations, isotopic fractionation of CO2 to CH4 (εCO2-CH4) was 16‰ larger for cultures grown at low H2 concentrations and 45‰ and 56‰ larger for M. jannaschii growth in coculture on maltose and formate, respectively. Gene expression analyses showed H2-dependent methylene-tetrahydromethanopterin (H4MPT) dehydrogenase expression decreased and coenzyme F420-dependent methylene-H4MPT dehydrogenase expression increased with decreasing H2 availability and in coculture growth. In coculture, gene expression decreased for membrane-bound ATP synthase and hydrogenase. The results suggest that H2 availability significantly affects the CH4 and biomass production and CH4 fractionation by hyperthermophilic methanogens in their native habitats.Importance: Hyperthermophilic methanogens and H2-producing heterotrophs are collocated in high-temperature subseafloor environments, such as petroleum reservoirs, mid-ocean ridge flanks, and hydrothermal vents. Abiotic flux of H2 can be very low in these environments, and there is a gap in our knowledge about the origin of CH4 in these habitats. In the hyperthermophile Methanocaldococcus jannaschii, growth yields increased as H2 flux, growth rates, and CH4 production rates decreased. The same trend was observed increasingly with interspecies H2 transfer between M. jannaschii and the hyperthermophilic H2 producer Thermococcus paralvinellae. With decreasing H2 availability, isotopic fractionation of carbon during methanogenesis increased, resulting in isotopically more negative CH4 with a concomitant decrease in H2-dependent methylene-tetrahydromethanopterin dehydrogenase gene expression and increase in F420-dependent methylene-tetrahydromethanopterin dehydrogenase gene expression. The significance of our research is in understanding the nature of hyperthermophilic interspecies H2 transfer and identifying biogeochemical and molecular markers for assessing the physiological state of methanogens and possible source of CH4 in natural environments.Torghabeh, A.K., Rezaee, R., Pimentel, N., Johnson, L., Alshakhs, M., 2019. Petroleum geochemistry, burial history and shale gas potential of the Goldwyer Formation - Canning Basin, Western Australia. International Journal of Oil, Gas and Coal Technology 20, 420-440. organic-rich shale horizons in the Canning Basin, Western Australia, acted as source rocks for conventional oil and gas fields. The aim of this study is to investigate one of its units, the Goldwyer Formation (Ordovician in age, as the Utica Shale in USA) as a potential shale gas play. Geochemical analysis such as Rock-Eval pyrolysis and total organic carbon (TOC) estimation, as well as thermal and burial history modelling were used. The organic matter is mixed type II/III kerogen and the total organic carbon (TOC) values range between 0.16 and 4.8 wt%. Tmax values between 335°C and 471°C and vitrinite reflectance values between 0.71 and 1.3 Ro% point to the main oil to wet and dry thermogenic gas zones, with a trend of increasing maturity in the west-central part of the basin. The results of this study show that the Goldwyer shale may be considered as potential shale-gas play.Torres Manno, M.A., Pizarro, M.D., Prunello, M., Magni, C., Daurelio, L.D., Espariz, M., 2019. GeM-Pro: a tool for genome functional mining and microbial profiling. Applied Microbiology and Biotechnology 103, 3123-3134. is a new tool for gene mining and functional profiling of bacteria. It initially identifies homologous genes using BLAST and then applies three filtering steps to select orthologous gene pairs. The first one uses BLAST score values to identify trivial paralogs. The second filter uses the shared identity percentages of found trivial paralogs as internal witnesses of non-orthology to set orthology cutoff values. The third filtering step uses conditional probabilities of orthology and non-orthology to define new cutoffs and generate supportive information of orthology assignations. Additionally, a subsidiary tool, called q-GeM, was also developed to mine traits of interest using logistic regression (LR) or linear discriminant analysis (LDA) classifiers. q-GeM is more efficient in the use of computing resources than Gem-Pro but needs an initial classified set of homologous genes in order to train LR and LDA classifiers. Hence, q-GeM could be used to analyze new set of strains with available genome sequences, without the need to rerun a complete Gem-Pro analysis. Finally, Gem-Pro and q-GeM perform a synteny analysis to evaluate the integrity and genomic arrangement of specific pathways of interest to infer their presence. The tools were applied to more than 2 million homologous pairs encoded by Bacillus strains generating statistical supported predictions of trait contents. The different patterns of encoded traits of interest were successfully used to perform a descriptive bacterial profiling.Touret, J.L.R., Huizenga, J.M., Kehelpannala, K.V.W., Piccoli, F., 2019. Vein-type graphite deposits in Sri Lanka: The ultimate fate of granulite fluids. Chemical Geology 508, 167-181. graphite vein deposits hosted in granulite facies metamorphic rocks in Sri Lanka are unique because of their large size and high crystallinity. In this paper, we present a review of the structural-metamorphic setting of the graphite veins and of the graphite stable carbon isotope data, and we present fluid inclusion data from quartz in the graphite veins and in the host rocks from several graphite deposits in Sri Lanka. The studied host rocks show decompression rims of plagioclase and orthopyroxene after garnet. The quartz in these decompression rim textures comprise, in order of abundance, high-salinity brine, H2O-CO2, and low-salinity aqueous fluid inclusions. The brine fluid is responsible for metasomatic features observed in garnet decompression rims, including feldspar leaching and re-precipitation. Quartz cogenetic with vein graphite comprises, in order of abundance, low-salinity aqueous, CO2, high-salinity brine, and H2O-CO2 fluid inclusions. Published graphite carbon isotope data indicates a dominant mantle source, mixed with small amounts of carbon-bearing fluids of supracrustal origin. We propose that large quantities of mantle-derived CO2 fluid are temporarily stored in the lower crust during the final stage of Gondwana supercontinent amalgamation. The CO2 is subsequently released from the lower crustal rocks during decompression associated with fast uplift. The graphite veins in Sri Lanka were formed during this uplift stage and represent as such paleofluid channels. In this respect, they are comparable to the quartz?carbonates mega-shear zones found in other granulite terranes. Depending on the redox conditions, mantle CO2 and brines may either result in the formation of graphite or quartz?carbonate veins.Truong, N., Monroe, A.A., Glein, C.R., Anbar, A.D., Lunine, J.I., 2019. Decomposition of amino acids in water with application to in-situ measurements of Enceladus, Europa and other hydrothermally active icy ocean worlds. Icarus 329, 140-147. test the potential of using amino acid abundances as a biosignature at icy ocean worlds, we investigate whether primordial amino acids (accreted or formed by early aqueous processes) could persist until the present time. By examining the decomposition kinetics of amino acids in aqueous solution based on existing laboratory rate data, we find that all fourteen proteinogenic amino acids considered in this study decompose to a very large extent (>99.9%) over relatively short lengths of time in hydrothermally active oceans. Therefore, as a rule of thumb, we suggest that if amino acids are detected at Enceladus, Europa, or other hydrothermally active ocean worlds above a concentration of 1?nM, they should have been formed recently and not be relicts of early processes. In particular, the detection of aspartic acid (Asp) and threonine (Thr) would strongly suggest active production within the ocean, as these amino acids cannot persist beyond 1 billion years even at the freezing point temperature of 273?K. Identifying amino acids from the oceans of icy worlds can provide key insight into their history of organic chemistry.Tsch?rtner, J., Lai, B., Kr?mer, J.O., 2019. Biophotovoltaics: Green power generation from sunlight and water. Frontiers in Microbiology 10, 866. doi: 810.3389/fmicb.2019.00866. is a relatively new discipline in microbial fuel cell research. The basic idea is the conversion of light energy into electrical energy using photosynthetic microorganisms. The microbes will use their photosynthetic apparatus and the incoming light to split the water molecule. The generated protons and electrons are harvested using a bioelectrochemical system. The key challenge is the extraction of electrons from the microbial electron transport chain into a solid state anode. On the cathode a corresponding electrochemical counter reaction will consume the protons and electrons, e.g. through the oxygen reduction to water, or hydrogen formation. In this review, we are aiming to summarize the current state of the art and point out some limitation. We put a specific emphasis on Cyanobacteria, as these microbes are considered future workhorses for photobiotechnology and are currently the most widely applied microbes in biophotovoltaics research. Current progress in biophotovoltaics is limited by very low current outputs of the devices while a lack of comparability and standardization of the experimental set-up hinders a systematic optimization of the systems. Nevertheless, the fundamental questions of redox homeostasis in phototrophs and the potential to directly harvest light energy from a highly efficient photosystem, rather than through oxidation of inefficiently produced biomass are highly relevant aspects of biophotovoltaics.Turbet, M., Forget, F., 2019. The paradoxes of the Late Hesperian Mars ocean. Scientific Reports 9, Article 5717. long-standing debate on the existence of ancient oceans on Mars has been recently revived by evidence for tsunami resurfacing events that date from the Late Hesperian geological era. It has been argued that these tsunami events originated from the impact of large meteorites on a deglaciated or nearly deglaciated ocean present in the northern hemisphere of Mars. Here we show that the presence of such a late ocean faces a paradox. If cold, the ocean should have been entirely frozen shortly after its formation, thus preventing the formation of tsunami events. If warm, the ice-free ocean should have produced fluvial erosion of Hesperian Mars terrains much more extensively than previously reported. To solve this apparent paradox, we suggest a list of possible tests and scenarios that could help to reconcile constraints from climate models with tsunami hypothesis. These scenarios could be tested in future dedicated studies.Tuttle, R.N., Demko, A.M., Patin, N.V., Kapono, C.A., Donia, M.S., Dorrestein, P., Jensen, P.R., 2019. Detection of natural products and their producers in ocean sediments. Applied and Environmental Microbiology 85, Article e02830-02818.: Thousands of natural products have been identified from cultured microorganisms, yet evidence of their production in the environment has proven elusive. Technological advances in mass spectrometry, combined with public databases, now make it possible to address this disparity by detecting compounds directly from environmental samples. Here, we used adsorbent resins, tandem mass spectrometry, and next-generation sequencing to assess the metabolome of marine sediments and its relationship to bacterial community structure. We identified natural products previously reported from cultured bacteria, providing evidence they are produced in situ, and compounds of anthropogenic origin, suggesting this approach can be used as an indicator of environmental impact. The bacterial metabolite staurosporine was quantified and shown to reach physiologically relevant concentrations, indicating that it may influence sediment community structure. Staurosporine concentrations were correlated with the relative abundance of the staurosporine-producing bacterial genus Salinispora and production confirmed in strains cultured from the same location, providing a link between compound and candidate producer. Metagenomic analyses revealed numerous biosynthetic gene clusters related to indolocarbazole biosynthesis, providing evidence for noncanonical sources of staurosporine and a path forward to assess the relationships between natural products and the organisms that produce them. Untargeted environmental metabolomics circumvents the need for laboratory cultivation and represents a promising approach to understanding the functional roles of natural products in shaping microbial community structure in marine sediments.Importance: Natural products are readily isolated from cultured bacteria and exploited for useful purposes, including drug discovery. However, these compounds are rarely detected in the environments from which the bacteria are obtained, thus limiting our understanding of their ecological significance. Here, we used environmental metabolomics to directly assess chemical diversity in marine sediments. We identified numerous metabolites and, in one case, isolated strains of bacteria capable of producing one of the compounds detected. Coupling environmental metabolomics with community and metagenomic analyses provides opportunities to link compounds and producers and begin to assess the complex interactions mediated by specialized metabolites in marine eit, A.T., Hestnes, A.G., Robinson, S.L., Schintlmeister, A., Dedysh, S.N., Jehmlich, N., von Bergen, M., Herbold, C., Wagner, M., Richter, A., Svenning, M.M., 2019. Widespread soil bacterium that oxidizes atmospheric methane. Proceedings of the National Academy of Sciences 116, 8515-8524. Significance: Increasing atmospheric methane concentrations contribute significantly to global warming. The only known biological sink for atmospheric methane is oxidation by methane oxidizing bacteria (MOB). Due to the lack of pure cultures, the physiology and metabolic potential of MOB that oxidize atmospheric methane remains a mystery. Here, we report on isolation and characterization of a MOB that can grow on air and utilizes methane at its atmospheric trace concentration as a carbon and energy source. Furthermore, this strain has the potential to utilize five additional atmospheric gases, carbon dioxide, carbon monoxide, hydrogen, nitrogen, and oxygen to supply its metabolism. This metabolic versatility might be the key to life on air and this discovery is essential for studying the biological methane sink.Abstract: The global atmospheric level of methane (CH4), the second most important greenhouse gas, is currently increasing by ～10 million tons per year. Microbial oxidation in unsaturated soils is the only known biological process that removes CH4 from the atmosphere, but so far, bacteria that can grow on atmospheric CH4 have eluded all cultivation efforts. In this study, we have isolated a pure culture of a bacterium, strain MG08 that grows on air at atmospheric concentrations of CH4 [1.86 parts per million volume (p.p.m.v.)]. This organism, named Methylocapsa gorgona, is globally distributed in soils and closely related to uncultured members of the upland soil cluster α. CH4 oxidation experiments and 13C-single cell isotope analyses demonstrated that it oxidizes atmospheric CH4 aerobically and assimilates carbon from both CH4 and CO2. Its estimated specific affinity for CH4 (a0s) is the highest for any cultivated methanotroph. However, growth on ambient air was also confirmed for Methylocapsa acidiphila and Methylocapsa aurea, close relatives with a lower specific affinity for CH4, suggesting that the ability to utilize atmospheric CH4 for growth is more widespread than previously believed. The closed genome of M. gorgona MG08 encodes a single particulate methane monooxygenase, the serine cycle for assimilation of carbon from CH4 and CO2, and CO2 fixation via the recently postulated reductive glycine pathway. It also fixes dinitrogen and expresses the genes for a high-affinity hydrogenase and carbon monoxide dehydrogenase, suggesting that atmospheric CH4 oxidizers harvest additional energy from oxidation of the atmospheric trace gases carbon monoxide (0.2 p.p.m.v.) and hydrogen (0.5 p.p.m.v.).Tyurina, Y.Y., Tyurin, V.A., Anthonymuthu, T., Amoscato, A.A., Sparvero, L.J., Nesterova, A.M., Baynard, M.L., Sun, W., He, R., Khaitovich, P., Vladimirov, Y.A., Gabrilovich, D.I., Bayir, H., Kagan, V.E., 2019. “Redox lipidomics technology: Looking for a needle in a haystack". Chemistry and Physics of Lipids 221, 93-107. life is based on numerous metabolic oxidation reactions as well as biosynthesis of oxygenated signaling compounds. Among the latter are the myriads of oxygenated lipids including a well-studied group of polyunsaturated fatty acids (PUFA) - octadecanoids, eicosanoids, and docosanoids. During the last two decades, remarkable progress in liquid-chromatography-mass spectrometry has led to significant progress in the characterization of oxygenated PUFA-containing phospholipids, thus designating the emergence of a new field of lipidomics, redox lipidomics. Although non-enzymatic free radical reactions of lipid peroxidation have been mostly associated with the aberrant metabolism typical of acute injury or chronic degenerative processes, newly accumulated evidence suggests that enzymatically catalyzed (phospho)lipid oxygenation reactions are essential mechanisms of many physiological pathways. In this review, we discuss a variety of contemporary protocols applicable for identification and quantitative characterization of different classes of peroxidized (phospho)lipids. We describe applications of different types of LC-MS for analysis of peroxidized (phospho)lipids, particularly cardiolipins and phosphatidylethanolalmines, in two important types of programmed cell death - apoptosis and ferroptosis. We discuss the role of peroxidized phosphatidylserines in phagocytotic signaling. We exemplify the participation of peroxidized neutral lipids, particularly tri-acylglycerides, in immuno-suppressive signaling in cancer. We also consider new approaches to exploring the spatial distribution of phospholipids in the context of their oxidizability by MS imaging, including the latest achievements in high resolution imaging techniques. We present innovative approaches to interpretation of LC-MS data, including their audio-representation analysis. Overall, we emphasize the role of redox lipidomics as a communication language, unprecedented in diversity and richness, through the analysis of peroxidized (phospho)lipids.Ungerer, P., Yiannourakou, M., Mavromaras, A., Collell, J., 2019. Compositional modeling of crude oils using C10–C36 properties generated by molecular simulation. Energy & Fuels 33, 2967-2980. to the lack of detailed analysis in the C10+ fraction and scarcity of reliable thermodynamic properties on polycyclic compounds, it is usually not feasible to relate crude oil properties with the chemical structure of heavy fractions. Over the last decades, the description of C10–C36 fractions has mostly relied on average Cn properties determined from observations. We propose an alternative approach in two major steps. In the first step, we use Monte Carlo simulation methods to generate vapor–liquid equilibrium (VLE) data on representative hydrocarbons between C10 and C30, from ambient to near-critical temperature. Based on these results, standard liquid density and saturation pressure are correlated for naphthenic hydrocarbons (mono- and polycyclic), aromatic hydrocarbons (monocyclic, polycyclic, and naphthenoaromatic), and thiophenic compounds up to C36. In the second step, we apply the predicted properties on C10–C36 families to model nine real crude oils. The Cn fractions (n = 10–36) are described with an exponential distribution, and the concentrations of n-iso/naphthenes/aromatics/NSO compounds are modeled explicitly. Using crude-specific information (e.g., C1–C10 analysis) and general statistics about reservoir fluids (e.g., target region in ternary diagrams), we obtain an excellent agreement of crude oil density, average molecular weights of Cn+ fractions, and SARA analysis (when available). The predicted standard liquid density of Cn fractions increases with the carbon number, as observed on real fluids. The higher Cn density observed in aromatic crudes is also well predicted. These results suggest that additional properties (e.g., VLE of live oils) may be predicted with more insight by applying the proposed simulation-based approach in future studies.van Dijk, J., Fernandez, A., Storck, J.C., White, T.S., Lever, M., Müller, I.A., Bishop, S., Seifert, R.F., Driese, S.G., Krylov, A., Ludvigson, G.A., Turchyn, A.V., Lin, C.Y., Wittkop, C., Bernasconi, S.M., 2019. Experimental calibration of clumped isotopes in siderite between 8.5 and 62?°C and its application as paleo-thermometer in paleosols. Geochimica et Cosmochimica Acta 254, 1-20. clumped isotope composition of carbonates can be directly related to their formation temperature in the environment, but a robust temperature calibration for siderite is still lacking, and thus limits the applicability of this tool. Here, we present a new calibration for the clumped isotope composition of siderites precipitated with two different techniques between 8.5 and 62?°C:Δ47=0.0428±0.002?106/T2+0.0683±0.022 [±95%CL,T in Kelvin] R2=0.92 The slope of our calibration obtained at an acid digestion temperature of 115?°C is statistically indistinguishable from recently published calcite and dolomite clumped isotope calibrations. The intercept differs from calcite at phosphoric acid digestion temperatures of 70 and 115?°C due to a difference in phosphoric acid fractionation, highlighting the necessity of a siderite specific calibration. We performed the first survey of the clumped isotope compositions of siderites from different environmental settings at ambient temperatures including two permanently waterlogged swamp sites as modern analogues for pedogenic siderite formation in the geologic record. We conclude that pedogenic siderites form at temperatures between the Mean Annual Air Temperature (MAAT) and the summer air temperature highlighting the strong potential of siderites for paleoclimate reconstructions in continental environments.van Wijnen, J., Ragas, A.M.J., Kroeze, C., 2019. Modelling global river export of microplastics to the marine environment: Sources and future trends. Science of The Total Environment 673, 392-401., transported by rivers to oceans, are triggering environmental concern. This study aims to better understand river export of microplastics from land to sea. We developed the Global Riverine Export of Microplastics into Seas (GREMiS) model, a global, spatially explicit model for analysing the annual microplastics export to coastal seas. Our results indicate that riverine microplastics export varies among world regions, with several hotspots, e.g., South East Asia, and, depending on the 2050 scenario, may be doubled (‘Business as usual’) or halved due to improved waste management (‘Environment profits’). Globally, our model simulations indicated fragmentation of macroplastics as the main source of microplastics, but this result heavily depends on the assumed fragmentation rate. Sewerage discharges contributed only 20%, ranging from 1% (Africa) to 60% (OECD countries) and decreasing by 2050 as a result of improved sanitation. We conclude that, combating microplastics in the aquatic environment requires more region-specific analyses.Vandeginste, V., Snell, O., Hall, M.R., Steer, E., Vandeginste, A., 2019. Acceleration of dolomitization by zinc in saline waters. Nature Communications 10, Article 1851. (CaMg(CO3)2) plays a key role in the global carbon cycle. Yet, the chemical mechanisms that catalyze its formation remain an enigma. Here, using batch reactor experiments, we demonstrate an unexpected acceleration of dolomite formation by zinc in saline fluids, reflecting a not uncommon spatial association of dolomite with Mississippi Valley-type ores. The acceleration correlates with dissolved zinc concentration, irrespective of the zinc source tested (ZnCl2 and ZnO). Moreover, the addition of dissolved zinc counteracts the inhibiting effect of dissolved sulfate on dolomite formation. Integration with previous studies enables us to develop an understanding of the dolomitization pathway. Our findings suggest that the fluids’ high ionic strength and zinc complexation facilitate magnesium ion dehydration, resulting in a dramatic decrease in induction time. This study establishes a previously unrecognized role of zinc in dolomite formation, and may help explain the changes in dolomite abundance through geological time.Vanryckeghem, F., Huysman, S., Van Langenhove, H., Vanhaecke, L., Demeestere, K., 2019. Multi-residue quantification and screening of emerging organic micropollutants in the Belgian part of the North Sea by use of Speedisk extraction and Q-Orbitrap HRMS. Marine Pollution Bulletin 142, 350-360. about the occurrence of emerging organic micropollutants in the marine environment is still very limited, especially when focusing on the Belgian Part of the North Sea (BPNS). This study therefore optimized and validated a Speedisk? based SPE and LC-Q-Orbitrap HRMS method to tackle the challenge of measuring the expected ultra-trace concentrations in seawater. This method was applied to 18 samples collected at different locations in the open sea and harbor of the BPNS. Forty-eight compounds, among which several pharmaceuticals, personal care products or pesticides described in the EU Watchlist, were detected – some for the first time in seawater – at concentrations ranging up to 156?ng?L?1. Moreover, the untargeted screening potential of the newly developed HRMS method was highlighted by revealing the presence of up to 1300 unknown components in a single sample and by assigning molecular formulae to those components demonstrating high discriminative potential between samples.Varliero, G., Bienhold, C., Schmid, F., Boetius, A., Molari, M., 2019. Microbial diversity and connectivity in deep-sea sediments of the South Atlantic polar front. Frontiers in Microbiology 10, 665. doi: 610.3389/fmicb.2019.00665. spreading ridges account for one-third of the global mid-ocean ridges. Their impact on the diversity and connectivity of benthic deep-sea microbial assemblages is poorly understood, especially for hydrothermally inactive, magma-starved ridges. We investigated bacterial and archaeal diversity in sediments collected from an amagmatic segment (10°?17°E) of the Southwest Indian Ridge (SWIR) and in the adjacent northern and southern abyssal zones of similar water depths within one biogeochemical province of the Indian Ocean. Microbial diversity was determined by 16S ribosomal RNA (rRNA) gene sequencing. Our results show significant differences in microbial communities between stations outside and inside the SWIR, which were mostly explained by environmental selection. Community similarity correlated significantly with differences in chlorophyll a content and with the presence of upward porewater fluxes carrying reduced compounds (e.g. ammonia, sulfide), suggesting that trophic resource availability is a main driver for changes in microbial community composition. At the stations in the SWIR axial valley (3655?4448 m water depth), microbial communities were enriched in bacterial and archaeal taxa common in organic matter-rich subsurface sediments (e.g. SEEP-SRB1, Dehalococcoida, Atribacteria, and Woesearchaeota) and chemosynthetic environments (mainly Helicobacteracaea). The abyssal stations outside the SWIR communities (3760?4869 m water depth) were dominated by OM1 clade, JTB255, Planctomycetaceae, and Rhodospirillaceae. We conclude that ultraslow spreading ridges create a unique environmental setting in sedimented segments without distinct hydrothermal activity, and play an important role in shaping microbial communities and promoting diversity, but also in connectivity among deep-sea habitats.Vasconcelos, B., Teixeira, J.C., Dragone, G., Teixeira, J.A., 2019. Oleaginous yeasts for sustainable lipid production—from biodiesel to surf boards, a wide range of “green” applications. Applied Microbiology and Biotechnology 103, 3651-3667. growing world population and a growing number of applications for vegetable oils are generating an increasing demand for these oils, causing serious environmental problems. A sustainable lipid production is then fundamental to address these problems. Oleaginous yeasts are a promising solution for sustainable lipid production, but, with the current knowledge and technology, they are still not a serious alternative in the market. In this review, the potential of these yeasts is highlighted and a discussion is made mainly focused on the economics of the oleaginous yeast oil production and identification of the key points to be improved to achieve lower production costs and higher income. Three main stages of the production process, where costs are higher, were identified. To render economically feasible the production of oils using oleaginous yeasts, a reduction in production costs must occur in all stages, lipid yields and productivities must be improved, and production must be targeted to high-value product applications.Venetz, J.E., Del Medico, L., W?lfle, A., Sch?chle, P., Bucher, Y., Appert, D., Tschan, F., Flores-Tinoco, C.E., van Kooten, M., Guennoun, R., Deutsch, S., Christen, M., Christen, B., 2019. Chemical synthesis rewriting of a bacterial genome to achieve design flexibility and biological functionality. Proceedings of the National Academy of Sciences 116, 8070-8079.: The fundamental biological functions of a living cell are stored within the DNA sequence of its genome. Classical genetic approaches dissect the functioning of biological systems by analyzing individual genes, yet uncovering the essential gene set of an organism has remained very challenging. It is argued that the rewriting of entire genomes through the process of chemical synthesis provides a powerful and complementary research concept to understand how essential functions are programed into genomes.Abstract: Understanding how to program biological functions into artificial DNA sequences remains a key challenge in synthetic genomics. Here, we report the chemical synthesis and testing of Caulobacter ethensis-2.0 (C. eth-2.0), a rewritten bacterial genome composed of the most fundamental functions of a bacterial cell. We rebuilt the essential genome of Caulobacter crescentus through the process of chemical synthesis rewriting and studied the genetic information content at the level of its essential genes. Within the 785,701-bp genome, we used sequence rewriting to reduce the number of encoded genetic features from 6,290 to 799. Overall, we introduced 133,313 base substitutions, resulting in the rewriting of 123,562 codons. We tested the biological functionality of the genome design in C. crescentus by transposon mutagenesis. Our analysis revealed that 432 essential genes of C. eth-2.0, corresponding to 81.5% of the design, are equal in functionality to natural genes. These findings suggest that neither changing mRNA structure nor changing the codon context have significant influence on biological functionality of synthetic genomes. Discovery of 98 genes that lost their function identified essential genes with incorrect annotation, including a limited set of 27 genes where we uncovered noncoding control features embedded within protein-coding sequences. In sum, our results highlight the promise of chemical synthesis rewriting to decode fundamental genome functions and its utility toward the design of improved organisms for industrial purposes and health benefits.Ver?an K?k, M., Varfolomeev, M.A., Nurgaliev, D.K., 2019. Determination of SARA fractions of crude oils by NMR technique. Journal of Petroleum Science and Engineering 179, 1-6. this research, four different crude oils from Tatarstan oil fields with wide range of API gravities (from 16.6 to 32.5 °API) were used for hydrogen and carbon nuclear magnetic resonance spectroscopy (H NMR and C NMR) determinations. The hydrogen and carbon aromaticity factors were calculated by using the results of H NMR and C NMR spectroscopy results. The results show that the aromaticity factors were high for heavy crude oils. For predicting SARA fractions, the correlations were developed as a function of aromaticity factors. The developed correlations showed high accuracy for predicting SARA fractions for four crude oils.Vielst?dte, L., Linke, P., Schmidt, M., Sommer, S., Haeckel, M., Braack, M., Wallmann, K., 2019. Footprint and detectability of a well leaking CO2 in the Central North Sea: Implications from a field experiment and numerical modelling. International Journal of Greenhouse Gas Control 84, 190-203. wells pose a risk for the loss of carbon dioxide (CO2) from storage sites, which might compromise the suitability of carbon dioxide removal (CDR) and carbon capture and storage (CCS) technologies as climate change mitigation options. Here, we show results of a controlled CO2 release experiment at the Sleipner CO2 storage site and numerical simulations that evaluate the detectability and environmental consequences of a well leaking CO2 into the Central North Sea (CNS). Our field measurements and numerical results demonstrate that the detectability and impact of a leakage of <55?t yr?1 of CO2 would be limited to bottom waters and a small area around the leak, due to rapid CO2 bubble dissolution in seawater within the lower 2?m of the water column and quick dispersion of the dissolved CO2 plume by strong tidal currents. As such, the consequences of a single well leaking CO2 are found to be insignificant in terms of storage performance. Only prolonged leakage along numerous wells might compromise long-term CO2 storage and may adversely affect the local marine ecosystem. Since many abandoned wells leak natural gas into the marine environment, hydrocarbon provinces with a high density of wells may not always be the most suitable areas for CO2 storage.Vikman, M., Marjamaa, K., Nykyri, M., Small, J.S., Miettinen, H., Heikinheimo, L., Haavisto, T., It?vaara, M., 2019. The biogeochemistry of gas generation from low-level nuclear waste: Microbiological characterization during 18 years study under in situ conditions. Applied Geochemistry 105, 55-67. Finland low level radioactive waste (LLW) contains considerable amounts of cellulose and hemicellulose-based material. Metals are also present in LLW and steel containers are used to store and dispose waste. The microbial degradation of cellulose and hemicellulose, together with the utilization of hydrogen generated by metal corrosion, will result in gas generation under final repository conditions. Microbially mediated LLW degradation and gas generation processes can influence the performance of multi-barrier systems, such as by accelerating corrosion and can affect the mobility of radionuclides from the repository. A large-scale in situ Gas Generation Experiment (GGE) was established in 1997 in Olkiluoto, Finland, to simulate the gas generation from LLW under geological repository conditions. A significant observation from the GGE was that the pH conditions were heterogeneous (pH 11 to 6), providing optimal neutral pH niches for microbial activity from the outset of the experiment. Over the extended time scale of the experiment, chemical conditions were stabilized and differences in the microbial abundances and community structure in various GGE compartments became less significant. The results demonstrate that LLW is converted to methane and carbon dioxide by a succession of anaerobic processes within a complex microbial consortium. Several genes related to cellulose and hemicellulose hydrolysis were detected using bacterial 16S rRNA gene sequencing and PICRUSt bioinformatics software. In addition, microbial groups with potential to metabolise formed saccharides to acetate, hydrogen and volatile fatty acids were detected. Hydrogenotrophic methanogens dominated after one year of operation, which was related to the utilization of hydrogen generated by anaerobic corrosion of steel and metallic waste. Acetoclastic methanogens were detected for the first time in 2005, coinciding with an increase in gas generation rate. Sulphate reducers were the most significant microbial group competing with methanogens for electron donors and their relative ratio compared to methanogens decreased considerably during the operation of the GGE. From the microbiological point of view, the results are consistent with the sequence of microbial processes simulated by previous biogeochemical modelling studies of the experiment.Wade, L., 2019. New species of ancient human unearthed. Science 364, 108. strange new species may have joined the human family. Fossils found in a cave on Luzon, the largest island in the Philippines, include tiny molars suggesting their owners were small; curved finger and toe bones hint they climbed trees. Homo luzonensis, as the species has been christened, lived some 50,000 to 80,000 years ago, when the world hosted multiple archaic humans, including Neanderthals and Denisovans, and when H. sapiens may have been making its first forays into Southeast Asia. The discovery echoes that of another unusual ancient hominin discovered in the region—the diminutive H. floresiensis, or "hobbit," found on the island of Flores in Indonesia. Paleoanthropologists suspect the islands of Southeast Asia may have been a cradle of diversity for ancient humans, and that H. luzonensis, like H. floresiensis, may have evolved a small body size in isolation on an island.Waltham, D., 2019. Is Earth special? Earth-Science Reviews 192, 445-470. conditions may be required for the origin of life and/or the evolution of complex organisms. Hence, Earth attributes—such as plate-tectonics, oceans, magnetism and a large moon—may be necessary preconditions, for our own existence, that are rare in the general population of planets. The unknown magnitude of this observational bias undermines understanding of our planet. However the discovery and characterization of exoplanets, along with advances in mathematical modelling of Earth systems, now allow this “anthropic selection” effect to be more thoroughly evaluated than before. This paper looks at a number of properties of our Solar System and our planet. It examines their possible benefits for life, whether these properties might be rare, whether they required fine-tuning and whether they have an associated habitability-lifetime. It also discusses additional data likely to become available in the near future.None of the individual properties considered show convincing evidence for anthropic bias. However, the time-scales associated with habitability— in particular, those associated with solar-warming, with axial stability and with planetary-cooling—are surprisingly similar and this provides tentative support for the view that Earth may be special.Walton, E.L., Timms, N.E., Hauck, T.E., MacLagan, E.A., Herd, C.D.K., 2019. Evidence of impact melting and post-impact decomposition of sedimentary target rocks from the Steen River impact structure, Alberta, Canada. Earth and Planetary Science Letters 515, 173-186. bolide impacts deliver vast amounts of energy to the Earth's near surface. This crustal process almost universally includes sedimentary target rocks; however, their response to impact is poorly understood, in part because of complexities due to layering, pore space and the presence of volatiles that are difficult to model. The response of carbonates to bolide impact remains contentious, yet whether they melt or decompose and liberate gases by the reaction CaCO3(s) → CaO(s) + CO2(g)↑, has significant implications for post-impact climatic effects. We report on previously unknown carbonate impact melts at the Steen River impact structure, Canada, and the first description of naturally shocked barite, BaSO4. Carbonate melts are preserved as groundmass-supported calcite-rich clasts, sampled from an up to 164 m thick, continuous sequence of crater-fill polymict breccias. Electron microscopy reveals fluidal- and ocellar-textured calcite and barite, intimately associated with silicate melt, consistent with these phases being in the liquid state at the same time. Raman spectroscopy and electron backscatter diffraction (EBSD) mapping confirm the presence of high-pressure phases – reidite and coesite – within some Steen River carbonate melt-bearing breccias. These minerals attest to the strong shock provenance of the breccia and provide constraints on their shock history. Preservation of reidite lamellae in zircon indicates a shock pressure >30 GPa <60 GPa and temperatures <1473 K. In addition to melting, we present compelling evidence for widespread (70–100%) decomposition of carbonate target rocks, mixed as lithic clasts into hot impact breccias. In this context, decomposition occurs strictly post-impact due to thermal equilibration-related heating. We demonstrate that this mechanism for CO2 outgassing is likely more widespread than previously recognized. The presence of andradite-grossular garnet serve as mineralogical markers of decomposition, analogous to limestone-replacing skarn deposits. Ca-rich garnet may therefore prove an important indicator mineral for post-shock decomposition of carbonate-bearing target rocks at other craters. These findings significantly advance our understanding of how sedimentary rocks respond to hypervelocity impact, and have wide-reaching implications for estimating the amount and timing of climatically-active volatile release due to impact events.Wang, J.-q., Gong, J.-m., Zhang, L., Cheng, H.-y., Liao, J., Chen, J.-w., Su, J., Yang, C.-s., 2018. Discussion on “sandwich” structures and preservation conditions of shale gas in the South Yellow Sea Basin. China Geology 1, 485-492. In order to make a breakthrough in Mesozoic-Paleozoic shale gas exploration in the South Yellow Sea Basin, a comparison of the preservation conditions was made within the Barnett shale gas reservoirs in the Fortworth Basin, the Jiaoshiba shale gas reservoirs in Sichuan Basin and potential shale gas reservoirs in Guizhou Province. The results show that the “Sandwich” structure is of great importance for shale gas accumulation. Therein to, the “Sandwich” structure is a kind of special reservoir-cap rock assemblage which consist of limestone or dolomite on the top, mudstone or shale layer in the middle and limestone or dolomite at the bottom. In consideration of the Mesozoic-Paleozoic in the Lower Yangtze, and Laoshan Uplift with weak Paleozoic deformation and thrust fault sealing on both flanks of the Laoshan Uplift, a conclusion can be drawn that the preservation conditions of shale gas probably developed “Sandwich” structures in the Lower Cambrian and Permian, which are key layers for the breakthrough of shale gas in the South Yellow Sea. Moreover, the preferred targets for shale gas drilling probably locate at both flanks of the Laoshan Uplift.Wang, L., Li, J., Chen, Y., Yang, H., Shao, J., Zhang, X., Yu, H., Chen, H., 2019. Investigation of the pyrolysis characteristics of guaiacol lignin using combined Py-GC?×?GC/TOF-MS and in-situ FTIR. Fuel 251, 496-505. investigate the pyrolysis behavior of guaiacol lignin (G-lignin) at 400–750?°C and its major decomposition mechanisms, ginkgo MWL as a typical G-lignin was decomposed in a micro-pyrolyzer, coupling two-dimensional gas chromatography with time-of-flight mass spectrometric detection (Py-GC?×?GC/TOF-MS) and an in-situ infrared pyrolysis reactor (in-situ FTIR). The pyrolysis products showed that a large amounts of guaiacol phenols were produced at low temperature, which indicated that guaiacol phenols were an important intermediate product, and other lignin-derived aromatic chemicals formed from guaiacol phenols by de-methyl, de-methoxyl reactions, and broken off branch structures. Relatively high contents of 2-methoxyphenol and l-(2-hydroxy-5-methylphenyl) ethanone were obtained at 450?°C, up to 19.46% and 16.35%, respectively. However, when temperature increased, 2-methoxyphenol and l-(2-hydroxy-5-methylphenyl) ethanone should be transformed to catechol and p-cresol by the removal of the carbonyl group from the branch and methyl from the methoxyl group, respectively. The methyl breakage of 4-ethyl-2-methoxyphenol and de-methoxyl of mequinol caused the formation of creosol and phenol, respectively, when temperatures increased. Two-dimensional perturbation correlation infrared spectroscopy (2D-PCIS) was introduced to analyze the in-situ FTIR spectra, and it was found that the cleavage of alcoholic or phenolic C-O bond was the major reaction in G-lignin decomposition, and the methyl in methoxyl groups could be easily removed from methoxyl to form CH4. Based on 2D-PCIS, reaction pathways involving the change sequence of several functional groups from G-lignin were proposed. Three reaction paths were provided from a model lignin with β-O-4, α-O-4 and 5-5′ connection to 1-(2-hydroxy-5-methylphenyl) ethanone, 2-methoxyphenol, catechol, trans-isoeugenol, p-cresol, phenol and benzene.Wang, M., Guo, Z., Jiao, C., Lu, S., Li, J., Xue, H., Li, J., Li, J., Chen, G., 2019. Exploration progress and geochemical features of lacustrine shale oils in China. Journal of Petroleum Science and Engineering 178, 975-986. the consumption of conventional petroleum resources, the exploration and development (E&P) of unconventional hydrocarbons in recent years have supplemented the shortage of petroleum resources to some extent. Shale gas has been successfully exploited from marine strata in southern China; however, E&P of lacustrine shale oil resources with large resource potentials have not reached expectations. This paper reviews the progress of exploration for lacustrine shale oil in China and discusses the geochemical features of shale and shale oil from a key shale oil exploration area in the Jiyang Depression to accelerate lacustrine shale oil exploration and to provide an improved understanding of prospective shale oil locations.For the first time, shale oil exploration, shale geochemistry, and geological features for nine major lacustrine sedimentary basins in China are summarized explicitly, and a detailed comparison analysis with Bakken, Eagle Ford, and Permian shales is conducted. The geochemical data (more than 600 analytical data points) and shale oil geochemical characteristics from four key shale oil exploration wells in the Jiyang Depression were analyzed in detail and were also used to analyze the prospect of shale oil exploration in this area. Finally, the research status of shale oil “sweet spot” evaluation is summarized, and key research directions needing further work are presented.In China, many wells have accidently produced certain amounts of shale oil from mudstone/shale fractures. The exploration and geochemical characteristics of lacustrine shales indicate not only that shale oil is a rich resource but also that it shows good exploration breakthrough potential, such as intersalt shale oil with an OSI (oil saturation index) generally higher than 300 and located in the Jianghan Basin. Samples from four key wells reveal geochemical features of lacustrine shale in ES3 (the third member of the Paleogene Shahejie Formation) and ES4 (the fourth member of the Paleogene Shahejie Formation) that demonstrate a high richness of organic matter in the ES3 and ES4 shales from the Jiyang Depression. Kerogen types are mainly I-II1, in a low maturity-mature stage, and OSI values are higher than 100; shale oil flows are also being produced from shale fractures. In general, the progress of exploration for lacustrine shale oil in China has been unsatisfactory in recent years. We believe that shale oil mobility and shale fracability are vital factors for shale oil exploitation, which should be strengthened and further studied.Wang, T., Philp, R.P., 2019. Oil families and inferred source rocks of the Woodford–Mississippian tight oil play in northcentral Oklahoma. American Association of Petroleum Geologists Bulletin 103, 871-903. oils produced from the Woodford Shale and overlying Mississippian strata in central Oklahoma were characterized geochemically to determine their possible source(s). The 168 core samples from the Woodford and Mississippian sections of 14 wells in central Oklahoma were initially characterized by total organic carbon (TOC), Rock-Eval, and vitrinite reflectance, and select samples (TOC > 1.0 wt. %) were subjected to biomarker analyses to characterize source input, depositional environment, maturity, and oil-to-source rock correlations. Thermal maturity parameters indicate the Woodford Shale is immature to marginally mature in Payne County, Oklahoma, and shows a progressive increase in maturity toward the southwest. Close to the Nemaha uplift, the Woodford is in the main stage of oil generation. It is proposed that the oils in this area have three possible origins: (1) Oils produced from the Woodford and overlying Mississippian strata have similar fingerprints, suggesting the Woodford Shale and overlying Mississippian strata are in communication; (2) oils produced near the Nemaha uplift (Logan and western Payne Counties) were sourced from the Woodford but had a significant Mississippian source contribution based on source-specific biomarkers; (3) oils east of the Cherokee platform (eastcentral Payne County) share strong Woodford source characteristics, and they were not generated in situ from the immature Woodford Shale but probably migrated from the Woodford Shale in the deeper part of the Anadarko Basin in southern Oklahoma. These results are consistent with the findings that indicate abundant marine coarse-grained biogenic silica (radiolarian-rich) chert facies found in eastcentral Payne County may contribute to good reservoir petrophysical properties, suggesting the Woodford Shale may not be a source in this area but simply a tight reservoir.Wang, X.-N., Yin, Y.-H., Cheng, X., Chen, L., Chen, M.-L., Zheng, J.-Y., Jin, Y.-Y., Liu, J.-Q., Liu, L.-F., Xin, G.-Z., 2019. Development and validation of a systematic platform for broad-scale profiling of microbial metabolites. Talanta 200, 537-546. chromatography-mass spectrometry based profiling of microbial metabolites has been a challenging task due to their diverse physicochemical properties and wide concentration ranges. This study is aimed to develop a systematic platform for the broad-scale profiling of microbial metabolites by integrating aqueous-lipophilic biphasic extractions and chemical derivatizations with a data-dependent automatable metabolite annotation algorithm. This complementary strategy of detection will not only largely expand the metabolite coverage, but also facilitate the drawing out of interested submetabolome using designed chemical derivatizations. Then, the data-dependent metabolite annotation algorithm is able to automatically match the raw MS/MS data with those of compounds in the self-collected databases. The performance of this platform is illustrated through the analysis of two representative bacteria (Escherichia coli and Pseudomonas aeruginosa) and intestinal contents samples from experimental colitis mice. As a result, 292 metabolites corresponding to 875 annotated features distributing over 25 chemical families were putatively annotated in a short time. Of these metabolites, 197 and 218 are respectively from the bacteria and intestinal contents, and 107 are identified in all three biological samples. This systematic platform could be used to accomplete high-coverage detection and high-quality data processing of microbial metabolites. At the same time, chemical derivatization design and the establishment of self-collected databases will facilitate self-driven untargeted analysis.Wang, X., Wang, C., Zhu, T., Gong, P., Fu, J., Cong, Z., 2019. Persistent organic pollutants in the polar regions and the Tibetan Plateau: A review of current knowledge and future prospects. Environmental Pollution 248, 191-208. to their low temperatures, the Arctic, Antarctic and Tibetan Plateau are known as the three polar regions of the Earth. As the most remote regions of the globe, the occurrence of persistent organic pollutants (POPs) in these polar regions arouses global concern. In this paper, we review the literatures on POPs involving these three polar regions. Overall, concentrations of POPs in the environment (air, water, soil and biota) have been extensively reported, with higher levels of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) detected on the Tibetan Plateau. The spatial distribution of POPs in air, water and soil in the three polar regions broadly reflects their distances away from source regions. Based on long-term data, decreasing trends have been observed for most “legacy POPs”. Observations of transport processes of POPs among multiple media have also been carried out, including air–water gas exchange, air–soil gas exchange, emissions from melting glaciers, bioaccumulations along food chains, and exposure risks. The impact of climate change on these processes possibly enhances the re-emission processes of POPs out of water, soil and glaciers, and reduces the bioaccumulation of POPs in food chains. Global POPs transport model have shown the Arctic receives a relatively small fraction of POPs, but that climate change will likely increase the total mass of all compounds in this polar region. Considering the impact of climate change on POPs is still unclear, long-term monitoring data and global/regional models are required, especially in the Antarctic and on the Tibetan Plateau, and the fate of POPs in all three polar regions needs to be comprehensively studied and compared to yield a better understanding of the mechanisms involved in the global cycling of POPs.Wang, Y., Feng, X., Natarajan, V.P., Xiao, X., Wang, F., 2019. Diverse anaerobic methane- and multi-carbon alkane-metabolizing archaea coexist and show activity in Guaymas Basin hydrothermal sediment. Environmental Microbiology 21, 1344-1355. Anaerobic oxidation of methane greatly contributes to global carbon cycling, yet the anaerobic oxidation of non-methane alkanes by archaea was only recently detected in lab enrichments. The distribution and activity of these archaea in natural environments are not yet reported and understood. Here, a combination of metagenomic and metatranscriptomic approaches was utilized to understand the ecological roles and metabolic potentials of methyl-coenzyme M reductase (MCR)-based alkane oxidizing (MAO) archaea in Guaymas Basin sediments. Diverse MAO archaea, including multi-carbon alkane oxidizer Ca. Syntrophoarchaeum spp., anaerobic methane oxidizing archaea ANME-1 and ANME-2c as well as sulfate-reducing bacteria HotSeep-1 and Seep-SRB2 that potentially involved in MAO processes, coexisted and showed activity in Guaymas Basin sediments. High-quality genomic bins of Ca. Syntrophoarchaeum spp., ANME-1 and ANME-2c were retrieved. They all contain and expressed mcr genes and genes in Wood-Ljungdahl pathway for the complete oxidation from alkane to CO2 in local environment, while Ca. Syntrophoarchaeum spp. also possess beta-oxidation genes for multi-carbon alkane degradation. A global survey of potential multi-carbon alkane metabolism archaea shows that they are usually present in organic rich environments but are not limit to hydrothermal or marine ecosystems. Our study provided new insights into ecological and metabolic potentials of MAO archaea in natural environments. This article is protected by copyright. All rights reserved.Wang, Y., Wang, L., Wang, J., Jiang, Z., Wang, C.-C., Fu, Y., Song, Y.-F., Wang, Y., Liu, D., Jin, C., 2019. Multiscale characterization of three-dimensional pore structures in a shale gas reservoir: A case study of the Longmaxi shale in Sichuan basin, China. Journal of Natural Gas Science and Engineering 66, 207-216. typical Longmaxi (LMX) shale sample from Sichuan basin, China, is investigated in three dimensional through multiscale tomography methods spanning pixel sizes from 3.25?μm to 10?nm, combining X-ray computed tomography and focused ion beam-scanning electron microscopy imaging techniques. Pores, organic matter (OM) and pyrite were segmented and reconstructed at multiple scales and the representative elementary volume (REV) of each phase at different scales based on the convergence of error bars in the volume fraction are determined. Results show that REVs at each scale varied between different phases. The determination of REV defined the applicable scale of different methods as well as the appropriate scales of specific structures. Porosity of LMX shale determined at different scales shows significant difference at two orders of magnitude. This difference likely was caused by structural heterogeneity together with the limitations of methods. This study confirms that REV is a feasible and powerful approach in modeling shale using multiscale 3D imaging. The application of multiscale 3D imaging techniques to worldwide shale gas reservoirs could allow for significant insights into the assessment of migration mechanisms within low-permeability systems.Watanabe, S., Hirabayashi, M., Hirata, N., Hirata, N.A., Noguchi, R., Shimaki, Y., Ikeda, H., Tatsumi, E., Yoshikawa, M., Kikuchi, S., Yabuta, H., Nakamura, T., Tachibana, S., Ishihara, Y., Morota, T., Kitazato, K., Sakatani, N., Matsumoto, K., Wada, K., Senshu, H., Honda, C., Michikami, T., Takeuchi, H., Kouyama, T., Honda, R., Kameda, S., Fuse, T., Miyamoto, H., Komatsu, G., Sugita, S., Okada, T., Namiki, N., Arakawa, M., Ishiguro, M., Abe, M., Gaskell, R., Palmer, E., Barnouin, O.S., Michel, P., French, A.S., Mcmahon, J.W., Scheeres, D.J., Abell, P.A., Yamamoto, Y., Tanaka, S., Shirai, K., Matsuoka, M., Yamada, M., Yokota, Y., Suzuki, H., Yoshioka, K., Cho, Y., Tanaka, S., Nishikawa, N., Sugiyama, T., Kikuchi, H., Hemmi, R., Yamaguchi, T., Ogawa, N., Ono, G., Mimasu, Y., Yoshikawa, K., Takahashi, T., Takei, Y., Fujii, A., Hirose, C., Iwata, T., Hayakawa, M., Hosoda, S., Mori, O., Sawada, H., Shimada, T., Soldini, S., Yano, H., Tsukizaki, R., Ozaki, M., Iijima, Y., Ogawa, K., Fujimoto, M., Ho, T.-M., Moussi, A., Jaumann, R., Bibring, J.-P., Krause, C., Terui, F., Saiki, T., Nakazawa, S., Tsuda, Y., 2019. Hayabusa2 arrives at the carbonaceous asteroid 162173 Ryugu—A spinning top–shaped rubble pile. Science 364, 268-272.: The Hayabusa2 spacecraft arrived at the near-Earth carbonaceous asteroid 162173 Ryugu in 2018. We present Hayabusa2 observations of Ryugu’s shape, mass, and geomorphology. Ryugu has an oblate “spinning top” shape, with a prominent circular equatorial ridge. Its bulk density, 1.19 ± 0.02 grams per cubic centimeter, indicates a high-porosity (>50%) interior. Large surface boulders suggest a rubble-pile structure. Surface slope analysis shows Ryugu’s shape may have been produced from having once spun at twice the current rate. Coupled with the observed global material homogeneity, this suggests that Ryugu was reshaped by centrifugally induced deformation during a period of rapid rotation. From these remote-sensing investigations, we identified a suitable sample collection site on the equatorial ridge.Editor's Summary: Hayabusa2 at the asteroid Ryugu. Asteroids fall to Earth in the form of meteorites, but these provide little information about their origins. The Japanese mission Hayabusa2 is designed to collect samples directly from the surface of an asteroid and return them to Earth for laboratory analysis. Three papers in this issue describe the Hayabusa2 team's study of the near-Earth carbonaceous asteroid 162173 Ryugu, at which the spacecraft arrived in June 2018 (see the Perspective by Wurm). Watanabe et al. measured the asteroid's mass, shape, and density, showing that it is a “rubble pile” of loose rocks, formed into a spinning-top shape during a prior period of rapid spin. They also identified suitable landing sites for sample collection. Kitazato et al. used near-infrared spectroscopy to find ubiquitous hydrated minerals on the surface and compared Ryugu with known types of carbonaceous meteorite. Sugita et al. describe Ryugu's geological features and surface colors and combined results from all three papers to constrain the asteroid's formation process. Ryugu probably formed by reaccumulation of rubble ejected by impact from a larger asteroid. These results provide necessary context to understand the samples collected by Hayabusa2, which are expected to arrive on Earth in December 2020.Wei, J.N., Belanger, D., Adams, R.P., Sculley, D., 2019. Rapid prediction of electron–ionization mass spectrometry using neural networks. ACS Central Science 5, 700-708. confronted with a substance of unknown identity, researchers often perform mass spectrometry on the sample and compare the observed spectrum to a library of previously collected spectra to identify the molecule. While popular, this approach will fail to identify molecules that are not in the existing library. In response, we propose to improve the library’s coverage by augmenting it with synthetic spectra that are predicted from candidate molecules using machine learning. We contribute a lightweight neural network model that quickly predicts mass spectra for small molecules, averaging 5 ms per molecule with a recall-at-10 accuracy of 91.8%. Achieving high-accuracy predictions requires a novel neural network architecture that is designed to capture typical fragmentation patterns from electron ionization. We analyze the effects of our modeling innovations on library matching performance and compare our models to prior machine-learning-based work on spectrum prediction.Weihe, S.H.C., Mangayayam, M., Sand, K.K., Tobler, D.J., 2019. Hematite crystallization in the presence of organic matter: Impact on crystal properties and bacterial dissolution. ACS Earth and Space Chemistry 3, 510-518. dissimilatory iron reduction (DIR) is a widespread process in oxygen-poor sediments and waters, where it regulates Fe and C cycling and contributes to nutrient and trace metal distribution. This process is fairly well-studied in terms of iron substrate, microbial DIR strain, and water chemistry. However, far less is known about DIR rates and yields of iron substrates that are tightly associated with organic matter, even though most iron substrates that form in nature are partially or completely covered by organic matter. Here, we assessed the impact of alginate on hematite crystallization and subsequently assessed the stability of thus formed alginate–hematite precipitates in DIR experiments with Shewanella oneidensis MR-1. We found that during hematite synthesis via forced hydrolysis, the presence of alginate reduces hematite crystal and particle sizes and induces the formation of closely associated alginate–hematite composites. This is explained by alginate molecules acting as nucleation sites. Upon exposure of these composites to S. oneidensis MR-1, a ～30–50% decrease (dependent upon the alginate content of composites) in the initial hematite reduction rate is observed in comparison to alginate-free, pure hematite. However, while DIR rates ceased after 48 h in the pure hematite system, reduction steadily progressed in the presence of the alginate–hematite composites, overall leading to a slightly higher DIR yield after 8 days. These trends are explained by alginate physically hindering direct contact between bacterial cells and hematite surfaces, thus lowering initial DIR rates. In turn, this lower rate potentially reduces quick passivation of cell and/or mineral surfaces by Fe(II) adsorption and/or surface precipitates as observed in the pure hematite system, thus enabling prolonged DIR reaction in the presence of alginate. Overall, this study highlights that a common natural organic molecule, such as alginate, can largely impact hematite formation in natural settings, leading to composites that show very different stabilities toward DIR compared to pure hematite. These are important considerations for predicting DIR processes and any associated element cycles in natural settings as well as for potential use of DIR for biotechnical applications.Weiss, G.M., Chivall, D., Kasper, S., Nakamura, H., da Costa, F., Soudant, P., Sinninghe Damsté, J.S., Schouten, S., van der Meer, M.T.J., 2019. Impact of metabolic pathways and salinity on the hydrogen isotope ratios of haptophyte lipids. Biogeosciences Discussions 2019, 1-28. isotope ratios of biomarkers have been shown to reflect water isotope ratios, and in some cases correlate significantly with salinity. The δ2H-salinity relationship is best studied for long-chain alkenones, biomarkers for haptophyte algae, and is known to be influenced by a number of different environmental parameters. It is not fully known why δ2H ratios of lipids retain a correlation to salinity, and whether this is a general feature for other lipids produced by haptophyte algae. Here, we analyzed δ2H ratios of three fatty acids, brassicasterol, long-chain C37 alkenones and phytol from three different haptophyte species grown over a range of salinities. Lipids synthesized in the cytosol, or relying on precursors of cytosolic origin, show a correlation between their δ2H ratios and salinity. In contrast, biosynthesis in the chloroplast, or utilizing precursors created in the chloroplast, yields lipids that do not show a correlation δ2H ratios and salinity. This leads to the conclusion that location of metabolism is the first-order control on the salinity signal retained in δ2H ratios of certain lipids. Additionally, we found that δ2H ratios of alkenones from batch cultures of the Group II haptophyte species Tisochrysis lutea correlate positively with temperature, contrary to findings from cultures of Group III haptophytes, but retain a similar response to nutrient availability in line with other Group III haptophytes.Wells, M.J.M., Stretz, H.A., 2019. Supramolecular architectures of natural organic matter. Science of The Total Environment 671, 1125-1133. new conceptual model for supramolecular aggregation of natural organic matter (OM) is proposed. Scientific awareness of OM as natural hydrogels is slowly increasing although in the literature they are primarily categorized as physical hydrogels stabilized only by weak interactions. The supramolecular view of OM is here expanded, based on insight from comprehensive hydrogen bond theory, to include three-center–four-electron near-covalent linkages and introduce a new category of metachemical hydrogels that are neither chemical nor physical hydrogels. Hydrogels are typically classified into chemical (permanent, covalently bonded) or physical (reversible, ionic, hydrophobic, or hydrogen bonded) classes based on crosslinking. However, augmented by contemporary advances in hydrogen bonding theory purporting that not all hydrogen bonds are weak and that some hydrogen bonding motifs result in moderate and strong interactions, the popular supramolecular view of OM is extended to include all types of hydrogen bonds. We propose a new category of hydrogels exists—metachemical hydrogels—as a fundamental component of OM. Strong, near covalent, equally shared hydrogel cross-linkages in the metachemical hydrogel can outcompete water. Here, metachemical (≤1?μm diameter) and physical (>1?μm diameter) hydrogels are described as two primary forms of aggregates observed for OM in a hierarchical ‘supramolecular within supramolecular’ self-assembling architecture with new information about shear. The metachemical hydrogels are postulated to be encapsulated within a dispersible physical hydrogel scaffold which can form, dissipate, and spontaneously re-form over turbulent/quiescent cycles indicating reversible abiotic self-assembly. The significance of this investigation is to understand the form OM evolved in nature to provide essential functions. The potential for strong intermolecular forces to form a metachemical hydrogel in OM and the concept of a dynamic dual metachemical/physical hydrogel structure was not previously introduced. The metachemical hydrogel construct should inform hydrogen bonded systems in other chemical and biochemical disciplines.Wenqi, Z., Guiyang, M., Zhiyong, H., 2019. Effect of organic alkali, n-alkanol, and nonionic surfactant ternary compound system on viscosity reduction of viscous crude oil. Petroleum Science and Technology 37, 989-996. reduce the viscosity of viscous crude oil and flow resistance, the effect of a ternary compound system including organic alkali, n-alkanol, and nonionic surfactants on viscous crude oil viscosity reduction was studied. The results showed that n-alkanol effectively reduced the droplet size of an emulsion and the viscosity of viscous crude oil and improved the fluidity of viscous crude oil. Of the low-carbon n-alkanols, n-pentanol has the best viscosity-reducing effect. The organic alkali avoids the phenomenon of fouling and corrosion caused by inorganic alkali and reacts with the acidic macromolecular components in viscous crude oil to generate alkanolamides, which produce synergistic effects with nonionic surfactants and reduce the interfacial tension between oil and water. In the ternary compound of organic alkali, n-alkanol, and nonionic surfactant, the viscosity reduction effect of viscous crude oil is significantly enhanced compared with that of a single reagent. The viscosity reduction rate of viscous crude oil of the diethanolamine ternary compound system reached 98.1% and was the best choice by experimental validation. It is shown that a reasonable formula of compound system and dosage can significantly reduce the viscosity of viscous crude oil.West, C., Lemasson, E., 2019. Unravelling the effects of mobile phase additives in supercritical fluid chromatography—Part II: Adsorption on the stationary phase. Journal of Chromatography A 1593, 135-146. mobile phases employed in current practice of supercritical fluid chromatography (SFC) are usually composed of a mixture of pressurized carbon dioxide and a co-solvent. The co-solvent is most often an alcohol and may contain a third component in small proportions, called an additive (acid, base or salt). In the first part of this series, the effects of mobile phase additives on the polarity and apparent pH of the mobile phase were explored. In the present paper, we examine the effects pertaining to adsorption of additives on the stationary phase. Ammonium acetate was selected as a representative case, because it is often employed in current practice. To favour its solubility and further improve chromatographic quality, a small portion of water is also advocated. First, the equilibration time is observed to be largely increased in the presence of an additive, especially when mobile phase compositions containing only low proportions of methanol co-solvent are employed. Secondly, the effects of ammonium acetate are more thoroughly assessed with a modified version of the solvation parameter model (five Abraham descriptors and two descriptors to take account of positive and negative charges on ionizable species). On a hybrid silica stationary phase (ACQUITY UPC2 BEH), the effects of increasing concentration of ammonium acetate (0–25?mM in the methanol co-solvent) are investigated. The retention of acidic species is the most strongly affected, with a continuous retention increase when additive concentration increases. The retention of basic and neutral species is also moderately affected. Then thirty-two stationary phases based on sub-2?μm totally porous particles or sub-3?μm superficially porous particles are characterized with and without 20?mM ammonium acetate and 2% water in the methanol co-solvent. The effects of adsorbed additive on the interaction capabilities are discussed. Finally, the interest of introducing the additive in the dilution solvent, a method that was sometimes recommended to simplify the workflow, is also discussed with a model basic compound.Wetterich, S., Davidson, T.A., Bobrov, A., Opel, T., Windirsch, T., Johansen, K.L., González-Bergonzoni, I., Mosbech, A., Jeppesen, E., 2019. Stable isotope signatures of Holocene syngenetic permafrost trace seabird presence in the Thule District (NW Greenland). Biogeosciences Discussions 2019, 1-25. permafrost from ice wedge polygons in the vicinity of large seabird breeding colonies in the Thule District, NW Greenland, was drilled to explore the relation between permafrost aggradation and seabird presence. The latter is reliant on the presence of the North Water (NOW) polynya in the northern Baffin Bay. The onset of peat accumulation associated with the arrival of little auks (Alle alle) in a breeding colony at Annikitisoq north of Cape York is radiocarbon-dated to 4400?cal?yr?BP. A thick-billed murre (Uria lomvia) colony on Appat (Saunders ?) in the mouth of the Wolstenholme Fjord started 5650?cal?yr?BP. Both species provide marine-derived nutrients (MDNs) that fertilise vegetation and promote peat growth. The geochemical signature of organic matter left by the birds is traceable in the frozen Holocene peat. The peat accumulation rates at both sites are highest after the onset and decrease over time and were about two-times faster at the little auk site than at the thick-billed murre site. High accumulation rates induce shorter periods of organic matter (OM) decomposition before it enters the perennially frozen state. This is seen in comparably high C?/?N and less depleted δ13C, pointing to a lower degree of OM decomposition at the little auk site, while the opposite pattern can be discerned at the thick-billed murre site. Peat accumulation rates correspond to δ15N trends, where decreasing accumulation led to increasing depletion in δ15N as seen in the little-auk related data. In contrast, the more decomposed OM of the thick-billed murre site shows almost stable δ15N. Late Holocene wedge ice fed by cold season precipitation was studied at the little auk site and provides the first such stable-water isotopic records from Greenland with mean δ18O of ?18.0?±?0.8?‰, mean δD of ?136.2?±?5.7?‰, mean d excess of 7.7?±?0.7?‰, and a δ18O-δD slope of 7.27, which is close to those of the modern Thule Meteoric Water Line. The syngenetic ice wedge polygon development is mirrored in testacean records of the little auk site and delineates polygon low-centre, dry-out and polygon-high-centre stages. The syngenetic permafrost formation directly depending on peat growth (controlled by bird activity) falls within the period of Neoglacial cooling and the establishment of the NOW polynya, thus indirectly follows the Holocene climate trends.Wheatley, D.F., Chan, M.A., Okubo, C.H., 2019. Clastic pipes and mud volcanism across Mars: Terrestrial analog evidence of past Martian groundwater and subsurface fluid mobilization. Icarus 328, 141-151. pipes are cylindrical injection features that vertically crosscut bedding with sharp contacts. Terrestrial pipes have cylindrical morphologies, massive or radially graded interiors, and raised outer rims. Increased grain size and subsequent cementation along the more porous edges makes the rims more resistant to weathering. Pipes have crosscutting relationships with other pipes due to multiple formation events or migrating eruption centers, and are associated with other soft-sediment deformation features. Terrestrial clastic pipes form via liquefaction and fluidization, which require a near-surface groundwater system to initiate (i.e., sand-sized sediments must be saturated for pipes to form).Clastic pipes (cm to 1000+?m diameters) occur on Mars across multiple time periods and terrains and are recognized in both rover and orbital imagery. A conical or cylindrical geometry and massive interior/core characterize these features. The pipes on Mars show various geomorphic expressions and are classified into five types by the presence or absence of a raised outer rim, or a central pit. These types are interpreted to represent the erosional evolution of pipes at different stages from their initial surface eruptive structures to their weathered remnants (eroded conical hills). Martian pipes formed via fluidization as evidenced by: 1) raised outer rims possibly indicating textural differences along the pipe edges from traction interactions of fluid-suspended sediment; 2) crosscutting relationships with other pipes suggesting reactivated fluidization pathways or migrating eruptive vents; and 3) close spatial association between pipes and other features thought to form by soft-sediment deformation (e.g., contorted bedding). Integration of terrestrial analog data with the Mars observations provides evidence for past Martian groundwater and subsurface fluid mobilization.Wheeler, L.F., Mathias, D.L., 2019. Probabilistic assessment of Tunguska-scale asteroid impacts. Icarus 327, 83-96. Tunguska meteor airburst has been extensively studied and modeled in attempts to deduce its size, properties, and impact characteristics. However, most of the existing modeling and simulation studies have investigated a small subset of cases based on assumptions of representative densities, velocities, or other properties. In this study, we use a probabilistic asteroid impact risk model to assess the entry, burst, and ground damage from 50 million Tunguska-scale asteroid impacts, covering a full range of potential impactor properties. The impact cases are sampled from probabilistic distributions representing our current knowledge of asteroid properties, entry trajectories, and size frequencies. The results provide a broader characterization of the range and relative likelihood of asteroid properties that could yield Tunguska-scale impacts. Results show that Tunguska-like events can be produced by a broad range of impact scenarios, and prevailing size and energy estimates of 50–80?m or 10–20?Mt remain within the relatively likely property ranges. However, our results suggest that objects with slightly larger initial energies of 20–30?Mt and diameters 70–80?m are more likely to cause Tunguska-scale damage areas than objects on the smaller end of the potential size range. Even when relative size frequencies are accounted for, the greater damage potential of larger objects outweighs their rarity, while the low damage potential of small objects counteracts their frequency.Wheeler, L.F., Mathias, D.L., 2019. Reprint of “Effects of asteroid property distributions on expected impact rates”. Icarus 327, 72-82. of the risk posed by asteroid impacts depend implicitly upon estimates of how frequently asteroids of different sizes and properties are expected to strike Earth. These impact rates are generally based upon populations of near-Earth objects as a function of absolute magnitude, which are then translated to equivalent size frequencies by assuming an average albedo. However, this simplified approach neglects the broad distribution of sizes and properties among objects of a given absolute magnitude. In this study, we use a probabilistic asteroid impact risk model to more rigorously investigate the effects of asteroid property distributions on estimated impact rates as a function of diameter, energy, mass, and blast damage radius. We also use impact damage modeling results to compare the effects of the new distribution-based results on expected casualty rates for two sample risk assessment cases. The current study focuses on mid-sized objects with diameters of 20–300m, which could cause substantial local ground damage but are unlikely to produce larger-scale regional or global effects. Particular emphasis is placed on sizes similar to the 1908 Tunguska event, which provides a unique source of evidence for such impacts and is often used as a reference point for damage potential and impact rates in the literature. Results demonstrate that accounting for realistic distributions of asteroid properties can significantly reduce expected impact intervals for these size ranges compared to estimates based on mean albedo, density, and velocity assumptions. These lower impact intervals, in turn, result in higher expected casualty estimates in impact risk assessment applications.Whitmire, D.P., 2019. Implication of our technological species being first and early. International Journal of Astrobiology 18, 183-188. to the Principle of Mediocrity, a cornerstone of modern cosmology, in the absence of any evidence to the contrary, we should believe that we are a typical member of an appropriately chosen reference class. If we assume that this principle applies to the reference class of all extant technological species, then it follows that other technological species will, like us, typically find that they are both the first such species to evolve on their planet and also that they are early in their potential technological evolution. Here we argue that this suggests that the typical technological species becomes extinct soon after attaining a modern technology and that this event results in the extinction of the planet's global biosphere.Whitney, N.M., Johnson, B.J., Dostie, P.T., Luzier, K., Wanamaker, A.D., 2019. Paired bulk organic and individual amino acid δ15N analyses of bivalve shell periostracum: A paleoceanographic proxy for water source variability and nitrogen cycling processes. Geochimica et Cosmochimica Acta 254, 67-85. high-resolution, well-dated, marine proxies of environmental, climatic, and oceanographic conditions is critical in order to advance our understanding of the ocean’s role in the global climate system. While some work has investigated bulk and compound specific stable nitrogen isotope (δ15N) values in bivalve shells as proxies for environmental variability, the small concentrations of nitrogen found in the organic matrix of the shell calcium carbonate (hereafter carbonate) makes developing high resolution records challenging. This study investigates the potential of using the bulk and amino acid δ15N values of bivalve periostracum, the protein layer on the outside of the shell, as a proxy archive of nitrogen cycling processes and water source variability. Bulk δ15N values were measured on the periostracum, carbonate, and adductor muscle of Arctica islandica shells collected in the Gulf of Maine. Increased variability of isotopic values across growth lines compared to along growth lines support mechanistic reasoning based on growth processes that periostracum is recording changes in δ15N values over the course of the clam’s lifetime (up to 500?years). In addition, the statistically significant relationship between periostracum δ15N values and contemporaneous carbonate δ15N values of the same shell (r?=?0.82, p?<?0.0001, n?=?40) suggests that periostracum preserves a similar δ15N signal to that preserved in the carbonate. This finding, coupled with the fact that source amino acid δ15N values of periostracum are similar to that of the adductor muscle and the particulate organic matter (POM) consumed by the clam, suggests that periostracum bulk δ15N values reflect the δ15N values of the clam’s food source. The isotopic offsets between periostracum, carbonate, and adductor muscle δ15N values are primarily caused by differences in amino acid composition of the different tissue types, as evidenced by isotope mass balance calculations, although may also be related to differences in δ15N values of the individual amino acids of the different tissue types, especially for the trophic amino acids. Compound specific δ15N analyses of the periostracum of A. islandica shells were used to determine that the calculated trophic position of the clams in this study (1.4?±?0.4) did not change significantly between 1783 and 1997. Phenylalanine δ15N values over the last 70?years show similar trends to that of the bulk record, suggesting that changes in bulk δ15N values over that time period are related to changes in baseline δ15N values. Periostracum δ15N values from shells collected in the western Gulf of Maine have decreased by ～1‰ since the mid-1920s. This trend (?0.008‰/year) is not statistically different from the trend of previously published δ15N values of deep-sea corals from the entrance to the Gulf of Maine over the same time period. This coral record has been shown to indicate a shift in water source in the region and therefore the similarity between the two records suggest that changes in periostracum δ15N values are reflecting broader North Atlantic hydrographic changes. Our study introduces a new, high-resolution, and absolutely dated paleoceanographic proxy of baseline δ15N values, presenting the opportunity for future reconstructions of aspects of nitrogen cycling and water source changes in the global oceans.Wilde, M.J., Cordell, R.L., Salman, D., Zhao, B., Ibrahim, W., Bryant, L., Ruszkiewicz, D., Singapuri, A., Free, R.C., Gaillard, E.A., Beardsmore, C., Thomas, C.L.P., Brightling, C.E., Siddiqui, S., Monks, P.S., 2019. Breath analysis by two-dimensional gas chromatography with dual flame ionisation and mass spectrometric detection – Method optimisation and integration within a large-scale clinical study. Journal of Chromatography A 1594, 160-172. medicine has spurred new innovations in molecular pathology leading to recent advances in the analysis of exhaled breath as a non-invasive diagnostic tool. Volatile organic compounds (VOCs) detected in exhaled breath have the potential to reveal a wealth of chemical and metabolomic information. This study describes the development of a method for the analysis of breath, based on automated thermal desorption (TD) combined with flow modulated comprehensive two-dimensional gas chromatography (GC×GC) with dual flame ionisation and quadrupole mass spectrometric detection (FID and qMS). The constrained optimisation and analytical protocol was designed to meet the practical demands of a large-scale multi-site clinical study, while maintaining analytical rigour to produce high fidelity data. The results demonstrate a comprehensive method optimisation for the collection and analysis of breath VOCs by GC×GC, integral to the standardisation and integration of breath analysis within large clinical studies.Williams, A.J., Eigenbrode, J., Floyd, M., Wilhelm, M.B., O'Reilly, S., Johnson, S.S., Craft, K.L., Knudson, C.A., Andrejkovi?ová, S., Lewis, J.M.T., Buch, A., Glavin, D.P., Freissinet, C., Williams, R.H., Szopa, C., Millan, M., Summons, R.E., McAdam, A., Benison, K., Navarro-González, R., Malespin, C., Mahaffy, P.R., 2019. Recovery of fatty acids from mineralogic Mars analogs by TMAH thermochemolysis for the sample analysis at Mars Wet Chemistry Experiment on the Curiosity Rover. Astrobiology 19, 522-546. Mars Curiosity rover carries a diverse instrument payload to characterize habitable environments in the sedimentary layers of Aeolis Mons. One of these instruments is Sample Analysis at Mars (SAM), which contains a mass spectrometer that is capable of detecting organic compounds via pyrolysis gas chromatography mass spectrometry (py-GC-MS). To identify polar organic molecules, the SAM instrument carries the thermochemolysis reagent tetramethylammonium hydroxide (TMAH) in methanol (hereafter referred to as TMAH). TMAH can liberate fatty acids bound in macromolecules or chemically bound monomers associated with mineral phases and make these organics detectable via gas chromatography mass spectrometry (GC-MS) by methylation. Fatty acids, a type of carboxylic acid that contains a carboxyl functional group, are of particular interest given their presence in both biotic and abiotic materials. This work represents the first analyses of a suite of Mars-analog samples using the TMAH experiment under select SAM-like conditions. Samples analyzed include iron oxyhydroxides and iron oxyhydroxysulfates, a mixture of iron oxides/oxyhydroxides and clays, iron sulfide, siliceous sinter, carbonates, and shale. The TMAH experiments produced detectable signals under SAM-like pyrolysis conditions when organics were present either at high concentrations or in geologically modern systems. Although only a few analog samples exhibited a high abundance and variety of fatty acid methyl esters (FAMEs), FAMEs were detected in the majority of analog samples tested. When utilized, the TMAH thermochemolysis experiment on SAM could be an opportunity to detect organic molecules bound in macromolecules on Mars. The detection of a FAME profile is of great astrobiological interest, as it could provide information regarding the source of martian organic material detected by SAM.Williamson, C.J., Cameron, K.A., Cook, J.M., Zarsky, J.D., Stibal, M., Edwards, A., 2019. Glacier algae: A dark past and a darker future. Frontiers in Microbiology 10, 524. doi: 510.3389/fmicb.2019.00524.‘Glacier algae’ grow on melting glacier and ice sheet surfaces across the cryosphere, causing the ice to absorb more solar energy and consequently melt faster, while also turning over carbon and nutrients. This makes glacier algal assemblages, which are typically dominated by just three main species, a potentially important yet under-researched component of the global biosphere, carbon and water cycles. This review synthesises current knowledge on glacier algae phylogenetics, physiology and ecology. We discuss their significance for the evolution of early land plants and highlight their impacts on the physical and chemical supraglacial environment including their role as drivers of positive feedbacks to climate warming, thereby demonstrating their influence on Earth’s past and future. Four complementary research priorities are identified that will facilitate broad advances in glacier algae research, including: establishment of reliable culture collections, sequencing of glacier algae genomes, development of diagnostic biosignatures for remote sensing, and improved predictive modelling of glacier algae biological-albedo effects.Wilson, R.M., Neumann, R.B., Crossen, K.B., Raab, N.M., Hodgkins, S.B., Saleska, S.R., Bolduc, B., Woodcroft, B.J., Tyson, G.W., Chanton, J.P., Rich, V.I., 2019. Microbial community analyses inform geochemical reaction network models for predicting pathways of greenhouse gas production. Frontiers in Earth Science 7, 59. doi: 10.3389/feart.2019.00059. mechanisms, pathways, and rates of CO2 and CH4 production are central to understanding carbon cycling and greenhouse gas flux in wetlands. Thawing permafrost regions are of particular interest because they are disproportionally affected by climate warming and store large reservoirs of organic C that may be readily converted to CO2 and CH4 upon thaw. This conversion is accomplished by a community of microorganisms interacting in complex ways to transform large organic compounds into fatty acids and ultimately CO2 and CH4. While the central role of microbes in this process is well-known, geochemical rate models rarely integrate microbiological information. Herein, we expanded the geochemical rate model of Neumann et al., (2016, Biogeochemistry 127: 57–87) to incorporate a Bayesian probability analysis and applied the result to quantifying rates of CO2, CH4, and acetate production in closed-system incubations of peat collected from three habitats along a permafrost thaw gradient. The goals of this analysis were twofold. First, we integrated microbial community analyses with geochemical rate modeling by using microbial data to inform the best model choice among equally mathematically feasible model variants. Second, based on model results, we described changes in organic carbon transformation among habitats to understand the changing pathways of greenhouse gas production along the permafrost thaw gradient. We found that acetoclasty, hydrogenotrophy, CO2 production, and homoacetogenesis were the important reactions in this system, with little evidence for anaerobic CH4 oxidation. There was a distinct transition in the reactions across the thaw gradient. The collapsed palsa stage presents an initial disequilibrium where the abrupt (physically and temporally) change in elevation introduces freshly fixed carbon into anoxic conditions and the fermentation products build up over time as the system transitions through the acid phase and electron acceptors are depleted. In the bog, fermentation slows, while methanogenesis increases. In the fully-thawed fen, most of the terminal electron acceptors are depleted and the system becomes increasingly methanogenic. This suggests that as permafrost regions thaw and dry palsas transition into wet fens, CH4 emissions will rise, increasing the warming potential of these systems and accelerating climate warming feedbacks.Witze, A., 2019. Mars methane hunt comes up empty, flummoxing scientists. Nature 568, 153-154. Gas Orbiter spacecraft did not find the gas in red planet’s atmosphere during its first months of operation.A spacecraft that was supposed to solve the mystery of methane on Mars has instead compounded scientists’ confusion. The European–Russian Trace Gas Orbiter (TGO), which began looking for the gas last year, has yet to find any whiffs of it in Mars’s atmosphere, says a study published on 10 Ap?ril in Nature1.“It’s a huge surprise,” says Dorothy Oehler, a planetary geologist at the Planetary Science Institute in Houston, Texas.Earlier Mars missions have detected hints of methane wafting through the atmosphere. The TGO’s failure so far to find the gas suggests that an unknown process is scrubbing much of it from the atmosphere soon after it appears, says Oleg Korablev, a physicist at the Space Research Institute in Moscow and lead author of the study.Planetary scientists are keen to understand where Martian methane comes from because most methane in Earth’s atmosphere is produced by living organisms. Pinning down how much methane is in Mars’s atmosphere, and where, would help researchers to determine whether the gas comes from geological sources, such as chemical reactions in rocks, or has a more exciting origin — potentially, Martian life2.Scientists have repeatedly spotted methane on Mars over the past 15 years. The reports include telescopic views of a plume of methane3 in 2003 and occasional detections by NASA’s Curiosity rover since it landed at Gale crater4 in 2012. The European Space Agency’s Mars Express spacecraft has spotted the gas at multiple sites5 — including a plume near Gale6 in 2013.Sniffing the skies: Aiming to answer the question more definitively, the TGO arrived at Mars in 2016 and began collecting atmospheric data in April 2018. Between April and August 2018, it found no signs of methane, even though its instruments can detect the gas at concentrations below 50 parts per trillion.Curiosity sniffed about 500 parts per trillion of methane in mid-June 2018 — at the same time that the TGO flew overhead without seeing any, says Christopher Webster of the Jet Propulsion Laboratory in Pasadena, California, who runs the rover’s methane-measuring instrument. Models suggest that any methane plumes should drift upward and mix well into the planet’s atmosphere within a few months.“Why do they disappear so quickly?” asks John Moores, a planetary scientist at York University in Toronto, Canada. “There’s some piece of the puzzle we are missing.”Researchers are looking for answers in the gap between Curiosity, which hunts for methane 1 metre above Mars’s surface, and the TGO, which takes its best measurements at least 5 kilometres above the planet. The scientists are trying to determine how methane could be destroyed relatively close to Mars’s surface. One possibility is that methane seeping out of the ground is removed by some kind of low-altitude chemical reaction — perhaps involving dust — before it can drift higher into the air, says Michael Mumma, a planetary scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. A team based at Aarhus University in Denmark, which has studied how dust particles could deplete Martian methane7, will describe its ideas on 11 April at the European Geosciences Union meeting in Vienna.In June 2018, just a few months after the TGO began monitoring Mars's atmosphere, a giant dust storm spread across the planet. It obscured Mars's atmosphere and temporarily forced the spacecraft to focus its search for methane on high elevations and latitudes.Outlook hazy: Still, some researchers are sceptical that the TGO will ever find the gas. “I’ve never seen a convincing detection of indigenous methane on Mars, and I don’t believe I ever will,” says Kevin Zahnle, a planetary scientist at NASA's Ames Research Center in Moffett Field, California, who has long argued that the reports of Martian methane are observational errors.But Oehler says that methane probably wafts erratically out of geologically active regions on Mars, such as those riddled with faults. With the only on-ground measurements of the gas coming from Curiosity, scientists simply haven’t had the chance to observe how it might be seeping from different parts of the planet’s surface, or how methane might be destroyed as it drifts upward8. Sushil Atreya, a planetary scientist at the University of Michigan in Ann Arbor, would like to see a series of methane-measuring drones, dirigibles or balloons float over many areas of the Martian surface. In the meantime, the TGO will continue to monitor Mars’s atmosphere through at least 2022. So far, it has observed only a fraction of a Martian year, which lasts nearly two Earth years. Hints of methane might yet emerge as the seasons pass.“One thing about Mars is it’s never boring,” says Oehler.References1. Korablev, O. et al. Nature (2019).2. Yung, Y. L. et al. Astrobiology (2018).3. Mumma, M. J. et al. Science 323, 1041–1045 (2009).4. Webster, C. R. et al. Science 360, 1093–1096 (2018).5. Formisano, V., Atreya, S., Encrenaz, T., Ignatiev, N., & Giuranna, M. Science 306, 1758–1761 (2004).6. Giuranna, M. et al. Nature Geosci. (2019).7. Knak Jensen, S. J. et al. Icarus 236, 24–27 (2014).8. Etiope, G. & Oehler, D. Z. Planet. Space Sci. 168, 52–61 (2019).Wood, R., Liu, A.G., Bowyer, F., Wilby, P.R., Dunn, F.S., Kenchington, C.G., Cuthill, J.F.H., Mitchell, E.G., Penny, A., 2019. Integrated records of environmental change and evolution challenge the Cambrian Explosion. Nature Ecology & Evolution 3, 528-538. ‘Cambrian Explosion’ describes the rapid increase in animal diversity and abundance, as manifest in the fossil record, between ~540 and 520 million years ago (Ma). This event, however, is nested within a far more ancient record of macrofossils extending at least into the late Ediacaran at ~571 Ma. The evolutionary events documented during the Ediacaran–Cambrian interval coincide with geochemical evidence for the modernisation of Earth’s biogeochemical cycles. Holistic integration of fossil and geochemical records leads us to challenge the notion that the Ediacaran and Cambrian worlds were markedly distinct, and places biotic and environmental change within a longer-term narrative. We propose that the evolution of metazoans may have been facilitated by a series of dynamic and global changes in redox conditions and nutrient supply, which, potentially together with biotic feedbacks, enabled turnover events that sustained multiple phases of radiation. We argue that early metazoan diversification should be recast as a series of successive, transitional radiations that extended from the late Ediacaran and continued through the early Palaeozoic. We conclude that while the Cambrian Explosion represents a radiation of crown-group bilaterians, it was simply one phase amongst several metazoan radiations, some older and some younger.Wotte, T., Skovsted, C.B., Whitehouse, M.J., Kouchinsky, A., 2019. Isotopic evidence for temperate oceans during the Cambrian Explosion. Scientific Reports 9, 6330. Cambrian Explosion was a key event in the evolution of life on Earth. This event took place at a time when sea surface temperatures have been proposed to reach about 60?°C. Such high temperatures are clearly above the upper thermal limit of 38?°C for modern marine invertebrates and preclude a major biological revolution. To address this dichotomy, we performed in situ δ18O analyses of Cambrian phosphatic brachiopods via secondary ion mass spectrometry (SIMS). The δ18Ophosphate data, which are considered to represent the most primary δ18Oseawater signature, were identified by evaluating the diagenetic alteration of the analyzed shells. Assuming ice-free conditions for the Cambrian ocean and no change in δ18Oseawater (-1.4‰ to -1‰; V-SMOW) through time, our temperatures vary between 35?°C?±?12?°C and 41?°C?±?12?°C. They are thus clearly above (1) recent subequatorial sea surface temperatures of 27?°C–35?°C and (2) the upper lethal limit of 38?°C of marine organisms. Our new data can therefore be used to infer a minimal depletion in early Cambrian δ18Oseawater relative to today of about -3‰. With this presumption, our most pristine δ18Ophosphate values translate into sea surface temperatures of about 30?°C indicating habitable temperatures for subequatorial oceans during the Cambrian Explosion.Wo?niak-Karczewska, M., Lisiecki, P., Bia?as, W., Owsianiak, M., Piotrowska-Cyplik, A., Wolko, ?., ?awniczak, ?., Heipieper, H.J., Gutierrez, T., Chrzanowski, ?., 2019. Effect of bioaugmentation on long-term biodegradation of diesel/biodiesel blends in soil microcosms. Science of The Total Environment 671, 948-958. studied long-term (64.5?weeks) biodegradation of diesel fuel, diesel/biodiesel blends (B10-B90) and biodiesel fuels in urban soil microcosms containing indigenous microorganisms, or indigenous microorganisms augmented with a hydrocarbon-degrading bacterial community. Mineralization extent (mmol of CO2 per day) of B10-B30 blends was smaller compared with diesel fuel at both short- (28?days) and long-term (109?days), and increased with biodiesel content. Priming with hydrocarbon degraders accelerated mineralization in the short-term (by up to 140%), with highest influence using blends with lower biodiesel content, but did not significantly influence kinetics and mineralization extent in the long-term. Although the biodiesel fraction was degraded completely within 64.5?weeks, 3–12% of the total aromatic and aliphatic hydrocarbons remained in the microcosms. Barcoded 16S rRNA gene MiSeq sequencing analysis revealed a significant effect of blend type on the community structure, with a marked enrichment of Sphingobacteriia and Actinobacteria classes. However, no significant influence was determined in the long-term, suggesting that the inoculated bacterial community may not have survived. Our findings show that biodiesel is preferentially degraded in urban soil and suggest that the value of bioaugmentation for bioremediating biodiesel fuels with hydrocarbon-degrading bacteria is limited to short-term exposures to lower (B10-B30) blends.Wozniak, A.S., Prem, P.M., Obeid, W., Waggoner, D.C., Quigg, A., Xu, C., Santschi, P.H., Schwehr, K.A., Hatcher, P.G., 2019. Rapid degradation of oil in mesocosm simulations of marine oil snow events. Environmental Science & Technology 53, 3441-3450. the Deepwater Horizon oil spill in the Gulf of Mexico, natural marine snow interacted with oil and dispersants forming marine oil snow (MOS) that sank from the water column to sediments. Mesocosm simulations demonstrate that Macondo surrogate oil incorporates into MOS and can be isolated, extracted, and analyzed via Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). Up to 47% of the FTICR-MS signal from MOS extracts can be attributed to formulas also found in Macondo surrogate oil demonstrating extensive oil incorporation. Additionally, oxygenation patterns for MOS extracts provide evidence for degraded oil compounds. Formulas having similar double bond equivalents but higher oxygen content (MOS CHO: CHO2–9, DBE2–16, MOS CHON: CHO0–7N1, DBE9–18; Macondo CHO: CHO1–4, DBE2–15, CHON: CHO0–3N1, DBE9–21) were found in MOS extracts generating isoabundance distributions similar to those of environmentally aged oil. Such shifts in molecular composition are consistent with the transformation of high DBE oil components, unobservable by FTICR-MS until oxygenation in the mesocosms. Low light conditions and the rapid proliferation of hydrocarbon-degraders observed in parallel studies suggest biological activity as the primary cause of oil degradation. MOS may thus represent an important microenvironment for oil degradation especially during its long transit below the euphotic zone to sediments.Wright, J.T., 2018. Milan M. ?irkovi?: The Great Silence: The Science and Philosophy of Fermi’s Paradox (Review). Origins of Life and Evolution of Biospheres 48, 423-425. ?irkovi? wants you to take the Fermi Paradox more seriously. In his latest book, The Great Silence: The Science and Philosophy of Fermi’s Paradox, he argues it is in fact “one of the deepest, subtlest, and most persistent challenges in the history of science” (to quote just one superlative-filled passage).?irkovi? brings an encyclopedic familiarity of the professional and popular literature and history of the Fermi Paradox, including important contributions from science fiction. This makes for an undoubtedly scholarly work: its final quarter (over 100 pages!) is entirely devoted to extensive endnotes, impressively up-to-date references, and a (disappointingly incomplete) index.?irkovi? also brings a wide background to the discussion, using a broad range of artistic and popular references to illustrate points (reaching from Lovecraft to Dilbert, from Resnais to xkcd). The prose is alternatingly dense (befitting a thorough philosophical critique of the work to date), and...Wu, H., Wang, M., Zhu, S., Xie, J., Preis, S., Li, F., Wei, C., 2019. Structure and function of microbial community associated with phenol co-substrate in degradation of benzo[a]pyrene in coking wastewater. Chemosphere 228, 128-138. wastewater (CWW) contains high contents of phenols and other toxic and refractory compounds including polycyclic aromatic hydrocarbons (PAHs) with the most carcinogenic benzo[a]pyrene (BaP) among them. The mechanism of PAHs/BaP degradation in activated sludge of CWW treatment with phenol as co-substrate was studied. For characterizing the structure and functions of microbial community associated with BaP degradation with phenol as co-substrate, high-throughput MiSeq sequencing was used to examine the 16S rRNA genes of microbiology, revealing noticeable shifts in CWW activated sludge bacterial populations. Major genera involved in anaerobic degradation were Tissierella_Soehngenia, Diaphorobacter and Geobacter, whereas in aerobic degradation Rhodanobacter, Dyella and Thauera prevailed. BaP degradation with phenol as co-substrate induced bacterial diversification in CWW activated sludge in opposite trends when anaerobic and aerobic conditions were applied. In order to predict the microbial community functional profiling, a bioinformatics software package of phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) was run to find that some dominant genera enriched in the BaP pathway may own the ability to degrade PAHs/BaP. Further experiments should focus on testing the dominant genera in BaP degradation at different oxygen levels.Wu, H., Xiong, L., Ge, Z., Shi, H., Wang, T., Fan, L., 2019. Fine characterization and target window optimization of high-quality shale gas reservoirs in the Weiyuan area, Sichuan Basin Natural Gas Industry 39, 11-20.'s Weiyuan Shale Gas Block is structurally located at the Baimazhen syncline held by the Weiyuan paleo-uplift and Ziliujing anticline in the Sichuan Basin. In this block, the Wufeng Fm of Upper Ordovician–Longmaxi Fm of Lower Silurian is an organic-rich dark shale deposit of deep-water shelf facies, whose litho-electric characteristics of geophysical logging are obviously different vertically and reservoir heterogeneity is strong. For providing a guidance for target window optimization and drilling trajectory tracking and adjustment of horizontal wells in the Weiyuan Shale Gas Block, parameter indexes were evaluated by refining the reservoir classification based on well logging subdivision, fine characterization of core laminae, high-precision geophysical prediction and genetic analysis of sedimentary microfacies. Furthermore, the "sweet spots" of shale gas reservoirs were predicted. Then, the target window was optimized and the trajectory of a horizontal well was designed. Finally, the effects of the target window of a horizontal well on shale gas productivity were evaluated. And the following research results were obtained. First, three types of laminae are developed in the high-quality shale reservoir at the bottom of Wufeng Fm–Long 1 Member, and they are vertically staggered and overlapped, which reflects the microscopic difference of sedimentary environment and reservoir quality. Second, shale gas reservoirs in this block can be divided into high-quality reservoirs, better reservoirs, general reservoirs and poor reservoirs. Third, the sublayer 2–31 at the bottom of Longmaxi Fm is biogenic sedimentary microfacies and it has the characteristics of "geological + engineering" sweet spot, e.g. high TOC contents, high porosity, high brittleness, high gas content and low in-situ stress difference, so it is classified as a high-quality reservoir. Fourth, actual drilling results show that the location selection of the target window of a horizontal well has a significant impact on single-well shale gas productivity, and the penetration rate of a high-quality reservoir is the key geological factor to achieve high-yield shale gas. The research results provide support for the evaluation of shale gas productivity and lay a foundation for the commercial development of shale gas in the Weiyuan Shale Gas Block.Wu, J., Liang, C., Jiang, Z., Zhang, C., 2019. Shale reservoir characterization and control factors on gas accumulation of the Lower Cambrian Niutitang shale, Sichuan Basin, South China. Geological Journal 54, 1604-1616. Lower Cambrian Niutitang shale is reported to be the oldest strata for large-scale shale gas reserves. Based on outcrop observations and laboratory analyses, this study used a comprehensive approach that integrated sedimentology, mineralogy, petrology, organic geochemistry, and reservoir geology to estimate the prospects for exploring for shale gas in the Lower Cambrian Niutitang Formation, southern China. Whole rock and clay mineral X-ray diffraction, scanning electron microscope (SEM) observations, and petro-physical property measurements indicate that the Niutitang shale is dominated by quartz and clay minerals with minor amounts of plagioclase, potassium feldspar, calcite, dolomite, and pyrite. The organic matter in the Niutitang shale is dominated by type-1 kerogen, with TOC levels ranging from 1.35% to 14.3% (average 4.46%) and Ro values ranging from 1.86% to 4.18% (average 2.79%). The three primary types of pores in the shale are organic pores, microfractures, and micropores. The micropores are primarily found in the clay mineral crystals and pyrite, and the microfractures are found along the boundaries of quartz grains. Most of the pore diameters are less than 20?nm, mainly concentrate at about 10?nm, which is consistent with that the organic pores act as the main storage space. The pore volume and gas content are strongly controlled by the mineral composition and lithofacies, and TOC content. The factors favouring shale gas accumulation of the Niutitang shale in the study area include (1) an effective thickness and widespread distribution, (2) a high organic carbon content and appropriate organic matter maturity, and (3) a favourable depositional environment.Wu, L., Ma, J., 2019. The Global Catalogue of Microorganisms (GCM) 10K type strain sequencing project: providing services to taxonomists for standard genome sequencing and annotation. International Journal of Systematic and Evolutionary Microbiology 69, 895-898. World Federation of Culture Collections and the World Data Center for Microorganisms (wdcm) initiated an international community-led project to sequence and annotate newly described prokaryotic taxa. This sequencing project aims to cooperate with international culture collections and the International Journal of Systematic and Evolutionary Microbiology and contribute to the expansion of whole genome sequencing databases for type strains. It will provide global microbial taxonomists with free standard genome sequencing and annotation services. Taxonomists are encouraged to contact the wdcm and participant culture collections to submit a type strain sequencing proposal.Wu, M., Ding, M., Yao, J., Li, C., Li, X., Zhu, J., 2019. Development of a multi-continuum quadruple porosity model to estimate CO2 storage capacity and CO2 enhanced shale gas recovery. Journal of Petroleum Science and Engineering 178, 964-974. storage of CO2 in shale formation not only enhances natural gas recovery, but also sequestrates CO2 effectively. According to this technology, a multi-continuum quadruple porosity binary component gas model is developed to investigate carbon dioxide storage capacity and CO2 enhanced shale gas recovery, which is based on multiple flow mechanisms, including dissolution, adsorption/desorption, viscous flow, diffusion, slip flow and stress sensitivity of hydraulic fractures. This fully coupled model is divided into quadruple media, including organic matters, organic pore system, matrix system and natural fracture system. The matrix-fracture transfer flow is simulated by modified multiple interacting continua (MINC) method. Embedded discreate fracture model (EDFM) is introduced to describe the gas flow in hydraulic fractures and the transfer flow between hydraulic fractures and natural fractures. Finite difference method (FDM) and quasi-Newton iterative method are applied to solve this model. The reliability and practicability of this model is validated by matching the production history of a fractured horizontal well in shale gas reservoir. The effects of relevant parameters on production curves are analyzed, including adsorption parameters, dissolution parameters, well production pressure, injection pressure, volumetric fraction of kerogen and injection opportunity. The result shows that the model in this work is reliable and practicable, and the model presented here can be used to investigate the injectivity of CO2 and CO2 enhanced shale gas recovery.Wu, N.-y., Liu, C.-l., Hao, X.-l., 2018. Experimental simulations and methods for natural gas hydrate analysis in China. China Geology 1, 61-71. paper provides an overview of the developments in analytical and testing methods and experimental simulations on gas hydrate in China. In the laboratory, the analyses and experiments of gas hydrate can provide useful parameters for hydrate exploration and exploitation. In recent years, modern analytical instruments and techniques, including Laser Raman spectroscopy (Raman), X-ray diffraction (XRD), X-ray computed tomography (X-CT), scanning electron microscope (SEM), nuclear magnetic resonance (NMR) and high pressure differential scanning calorimetry (DSC), were applied in the study of structure, formation mechanisms, phase equilibrium, thermal physical properties and so forth of gas hydrates. The detection technology and time-domain reflectometry (TDR) technique are integrated to the experimental devices to study the physical parameters of gas hydrates, such as the acoustics, resistivity, thermal and mechanical properties. It is believed that the various analytical techniques together with the experimental simulations from large-scale to micro-scale on gas hydrate will play a significant role and provide a powerful support for future gas hydrate researches.Wu, Y., Gao, S., Liu, Z., Zhao, J., Ji, B., Zeng, X., Yu, Z., 2019. The quantification of chlorinated paraffins in environmental samples by ultra-high-performance liquid chromatography coupled with Orbitrap Fusion Tribrid mass spectrometry. Journal of Chromatography A 1593, 102-109. high-production-volume chemicals, chlorinated paraffins (CPs) have raised an increasing environmental concern in recent years. However, their accurate analysis and quantification is still a huge challenge due to the high complexity of their technical formulations and the interference from CPs congeners and other polychlorinated products. In this study, a novel method for the simultaneous analysis of short-chain (SC) and medium-chain (MC) CPs in a single injection has been developed using ultra-high-performance liquid chromatography coupled with Orbitrap Fusion Tribrid mass spectrometry (UHPLC-Orbitrap Fusion TMS). Compared with other analytical methods for CPs, this novel method can greatly shorten the measurement time and provides a lower limit of detection. A high resolution of 120,000 FWHM was set to avoid the self-interference of CPs congeners and to eliminate interferences from chlorinated olefins (COs). Accuracies for SCCPs and MCCPs standards were evaluated at 75–103% and 83–118%, respectively. The developed method was further validated by determining CPs in sediment, soil, and indoor dust samples. This novel method gives higher CPs concentrations than those achieved by gas chromatography-electron capture negative ionization low-resolution mass spectrometry (GC-ECNI-LRMS), with factors of 1.1–12.5 for SCCPs and 0.7–2.7 for MCCPs, respectively. Some new CPs, such as C8Cl7-8 and C9Cl5-8, have been determined in soil samples for the first time, indicating great potential of this novel method for routine CP analysis in various environmental samples.Wu, Y., Zhu, K., Zhang, J., Müller, M., Jiang, S., Mujahid, A., Muhamad, M.F., Sia, E.S.A., 2019. Distribution and degradation of terrestrial organic matter in the sediments of peat-draining rivers, Sarawak, Malaysian Borneo. Biogeosciences Discussions 2019, 1-37. peatlands are one of the largest pools of terrestrial organic carbon (OCterr); however, our understanding of the dynamics of OCterr in peat-draining rivers remains limited, especially in Southeast Asia. This study used bulk parameters and lignin phenols concentrations to investigate the characteristics of OCterr in a tropical peat-draining river system (the main channel of the Rajang and three smaller rivers) in the western part of Sarawak, Malaysian Borneo. The depleted δ13C levels and lignin composition of the organic matter indicates that the most important plant source of the organic matter in these rivers is woody angiosperm C3 plants, especially in the three small rivers sampled. The diagenetic indicator ratio (i.e., the ratio of acid to aldehyde of vanillyl phenols (Ad?/?Al)v) increased with decreasing mean grain size of sediment from the small rivers. The selective sorption of acid relative to aldehyde might explain the variations in the (Ad?/?Al)v ratio. The (Ad?/?Al)v ratio appears to be related to the C?/?N ratio (the ratio of total organic carbon to total nitrogen) in the Rajang and small rivers, where slower degradation of OCterr and a higher total nitrogen percentage (TN%) were observed, compared to other river systems. Most of the OCterr discharged from the Rajang and small river systems was material derived from woody angiosperm plants with limited diagenetic alteration before deposition, and so could potentially provide significant carbon to the atmosphere after degradation.Wu, Z., Liu, H., 2019. Investigation of hot-water flooding after steam injection to improve oil recovery in thin heavy-oil reservoir. Journal of Petroleum Exploration and Production Technology 9, 1547-1554. steam stimulation (CSS) is one of the popular methods to recovery heavy oil reserves that play an important role in supplying the energy consumption over the world. To solve the problems during the late CSS, we perform the feasibility study of hot-water flooding (HWF) after CSS with laboratory experiments and numerical simulation. The experimental results revealed the optimized water temperature to conduct HWF is 120?°C and the correct moment to convert is when the oil recovery of steam injection reaches 20%. Based on the geological properties of Jinlou oilfield in China, a series of numerical simulations were run to analyze the influence of several sensitive factors. It is necessary to transform development method because there are large quantities of remaining oil assembling at the inter-well region during the late stage of CSS and this after analyzing the oil saturation, reservoir temperature and oil viscosity distribution. The effect of HWF in reverse-rhythm and compound-rhythm reservoir is satisfactory, but is poor in positive-rhythm reservoir. It is suitable to reservoirs with thickness lower than 5?m and permeability variation coefficient less than 0.3. This study can provide a reference for enhanced oil recovery for thin heavy oil reservoirs after steam injection.Wurm, G., 2019. Traveling to the origins of the Solar System. Science 364, 230-231. December 2014, the Japanese spacecraft Hayabusa2 began its more than 2 billion miles journey to rendezvous and land on a rocky body with a diameter of no more than a kilometer. It arrived in June 2018, and on pages 272, 268, and 252 of this issue, the first observations of Hayabusa2's remote sensing instruments are reported by Kitazato et al. (1), Watanabe et al. (2), and Sugita et al. (3), respectively. Designed to probe the geology, morphology, and composition of the asteroid, this mission will help clarify the formation of the solar system 4.5 billion years ago.Xia, L., Cao, J., Hu, S., Li, S., 2019. How marine incursion influences the quality of lacustrine source rocks: The Paleogene Nanxiang Basin, eastern China. American Association of Petroleum Geologists Bulletin 103, 1071-1096. impact of marine incursions during transgression (i.e., sea level rises and the shoreline moves landward) on the formation and quality of lacustrine source rocks is an important and contentious issue. In this study, we present a case study of the Paleogene Hetaoyuan Formation in the Biyang sag, Nanxiang Basin, eastern China. Paleontological, trace-element, and biomarker data indicate that the Hetaoyuan source rocks in this region were influenced by a marine incursion. The paleontological evidence indicates that the marine incursion resulted in the introduction of red and brown algae, which commonly inhabit marine environments. Trace-element analyses yielded representative evidence of marine incursion (e.g., equivalent boron content >300 ppm and B/Ga ratio >4.2). Biomarker evidence for marine incursion includes C26/C25 tricyclic terpanes ratios of 1:3, which is the threshold for distinguishing marine organic matter from lacustrine. Using the B/Ga ratio as a typical paleosalinity indicator, it was determined that the influence of marine incursion decreased from the Biye 1 to Cheng 2 to An 3006 wells, with the B/Ga ratio average decreasing from 7.51 to 6.81 to 3.73, respectively. With an increasing extent of marine incursion (e.g., distance landward, overall water depth, and marine–freshwater mixing), the primary productivity of organic matter increased, and the preservational environment became more reducing. These changes resulted in higher contents of organic matter (total organic carbon = 2–8 wt. %) and a more favorable type of organic matter for oil generation (kerogen type I–II), indicating that the marine incursion had a positive effect on the formation of source rocks. Therefore, the formation mechanism of high-quality source rocks in coastal lacustrine basins during high sea-level periods and associated resource potential might need to be reevaluated (e.g., the Campanian lower Neslen Formation along the margins of the Western Interior Seaway of North America and the terminal Oligocene–early Miocene in the fluvial Saldanha Bay at the southwestern tip of Africa). The results also provide useful data for regional oil and gas exploration.Xie, L.-F., Wang, F., Zhai, L.-L., Xu, Y.-P., Duan, P.-G., 2019. A sequenced batch process for integrated hydropyrolysis and hydrotreatment of a microalgae and used engine oil blend. Fuel Processing Technology 190, 47-54. sequenced batch process for integrated hydropyrolysis and hydrotreatment (IHP-T) of microalgae and used engine oil (UEO) was examined to produce sulfur-free diesel-like fuel. Four sequenced runs were performed. In the first run, the microalgae and UEO blend was processed at 673?K for 4?h with 6?MPa H2 and 5?wt% kgPt/C/kgfeed to obtain the first-run light oil (FR-LO) and first-run heavy oil (FR-HO) by centrifugation. Next, the same procedure as that employed in the first run was used to treat the LO recovered from a previous run in a new run until the fourth run. The oils obtained in the second, third, and fourth run were named the second-run light oil (SR-LO), second-run heavy oil (SR-HO), third-run light oil (ThR-LO), third-run heavy oil (ThR-HO), fourth-run light oil (FR-LO), and fourth-run heavy oil (FR-HO). LO was always the dominant product fraction in the four runs, and the yields of FR-LO, SR-LO, ThR-LO, and FoR-LO were 83.33, 89.24, 89.29, and 88.34?wt%, respectively. The N, O, and S contents of the LOs always decreased during the sequenced IHP-T process. Zero S content was observed for both the ThR-LO and FoR-LO. The N content of the FoR-LO decreased to 2?ppm (w/v), which is below the requirement for China V gasoline (10?ppm). The total acid number of the LOs decreased from 21.62 for the FR-LO to 1.89 for the FoR-LO. The FoR-LO mainly consisted of saturated hydrocarbons (~47%), unsaturated hydrocarbons (37%), and aromatic compounds (36%) and had a higher heating value (HHV) of 46.37 MJ/kg, a density of 0.80?kg/m3, and a kinematic viscosity of 1.89?×?10?3?m2/s. The properties of the FoR-LO are very similar to those of market gasoline. Thus, sequenced IHP-T is a very promising process for producing S-free diesel-like fuel from microalgae and UEO.Xie, X., Amann-Hildenbrand, A., Littke, R., Krooss, B.M., Li, M., Li, Z., Huang, Z., 2019. The influence of partial hydrocarbon saturation on porosity and permeability in a palaeogene lacustrine shale-hosted oil system of the Bohai Bay Basin, Eastern China. International Journal of Coal Geology 207, 26-38. calcareous (>40% carbonate) mudstones (Ro from 0.56 to 0.88%) from the Bohai Bay Basin were studied by combined petrographical, geochemical and petrophysical analysis in order to assess and quantify the pore space, pore filling and its influence on gas transport capacity. TOC contents ranged from 1.44% to 5.12% and porosities (ΦHe) determined by helium pycnometry, from 1.3% to 6.4%. Bitumen-filled porosity (ΦS1) was estimated to range between 0.3 and 2.0% based on Rock-Eval S1 values and an assumed bitumen density of 0.90?g/cm3. The “true” total porosity (Φtotal?=?ΦHe?+?ΦS1) amounts to 1.9–8.5%. The in-situ oil saturation (So) was estimated to range between 25% and 52%, with two samples (L69-1B and L69-2) having relatively high oil saturation (71% and 91%). The conductivity of the remaining “open” pore space was measured on three samples with different orientations and oil saturations from 17 to 24%. The effective Klinkenberg-corrected gas permeability coefficients range between 63 and 2000 nDarcy, and permeability is highest parallel to bedding. Upon loading from 10 to 40?MPa confining pressure the intrinsic permeability coefficients decreased by one order of magnitude, revealing a relatively high exponential stress sensitivity coefficient (0.069?MPa?1) and much lower zero stress permeability (1.416?×?10?6?mD) than most gas shales. This could be due to pore plugging by ductile bitumen.Xiong, H., Devegowda, D., Huang, L., 2019. EOR solvent-oil interaction in clay-hosted pores: Insights from molecular dynamics simulations. Fuel 249, 233-251. understanding of EOR processes in shales, especially in organic or kerogen pore systems, has grown rapidly over the last few years. While clays are ubiquitous in shales and may make-up over 50% by volume of the shale matrix, there has been little to no focus on solvent-oil interactions in these pore systems. While hydrocarbon storage is likely to happen predominantly in the organics, the inorganic material might serve as conduits for fluid transfer from the organics to the fracture systems. This work uses molecular dynamics and numerical simulations to investigate the mechanisms governing EOR in clay-hosted pores to address this knowledge gap. Because illite is the most common clay mineral in shales, we use a slit-pore model of illite to simulate oil and oil-solvent mixtures in clay pores to quantify the extent of miscibility, diffusion, viscosity reduction and oil swelling of the oil under illite confinement. Temperature and the presence of water is expected to also control the rate of diffusion, viscosity, oil swelling and the degree of confinement. To account for these effects, our simulations span a wide range of temperatures and concentrations of water. Finally, the findings from molecular dynamics simulations are utilized in reservoir-scale EOR models to demonstrate their impact. Our results confirm that oil swelling, diffusion and viscosity reduction are a few of the dominant pore-scale mechanisms governing EOR. However, our findings also demonstrate that bulk fluid properties can cause overly optimistic predictions of the efficacy of EOR. Confinement in illite is shown to negatively impact miscibility for methane-rich solvents. Secondly the self-diffusion of fluids under illite confinement are only 30% of their values in the bulk. Most significantly, oil-solvent mixture viscosities under illite confinement are about two orders of magnitude higher compared to their bulk values. The presence of water exacerbates all of these effects and in fact compromises the solubility of the injected solvent. Commercially available reservoir simulators accommodate a whole host of reservoir and well architectures, but the transport equations are derived using bulk fluid properties. However, our work underscores the need for rigorous small-scale experiments and modeling studies to properly account for the effects of confinement that can have significantly compromise EOR efficacy in plays where a high percentage of the pore volume is contained in sub-20?nm pores. A model that does not take in to account nonporous confinement can be overly optimistic and compromise project economics, especially if connectivity is driven by the smaller pore throats.Xu, C.-l., Sun, Z.-l., Geng, W., Zhang, X.-r., Cao, H., Liu, L.-p., Zhang, X.-l., Zhai, B., 2018. Thermal recovery method of submarine gas hydrate based on a thermoelectric generator. China Geology 1, 568-569.. Objective: Natural gas hydrates are considered as a potential alternative fuel resource to petroleum and gas (Chong ZR et al., 2016), which can be exploited by means of depressurization, thermal method, inhibitor injection, etc. For the thermal method, gas hydrates are decomposed into water and methane when the reservoir is heated to above the equilibrium temperature of gas hydrate (Li X et al., 2016). However, the thermal recovery method needs a great deal of heat, and thus the feasibility of economic exploitation is reduced. In this paper, we report a set of equipment that can be used to exploit submarine gas hydrates economically, basing on a thermoelectric generator which uses the temperature difference between gas hydrate reservoirs (temperature is blow 0°C) and dry hot rock or hot brine bearing layers (temperature is above 200°C).2. Methods: Due to the geothermal gradient or magmatic activities in deeply buried stratum, dry hot rock, high temperature and high-pressure brine bearing layers, or other high temperature reservoirs are commonly developed under gas hydrate reservoirs (Yamano M et al., 1986). As a result, a set of equipment based on a thermoelectric generator could use the natural high temperature fluids or dry hot rocks as heat sources for gas hydrate exploitation. With the design concept of “systematization, dynamization, safety and economy” this approach adds a thermoelectric generator and current control function to previous equipment, which is of great significance to reduce the exploitation cost and decrease the difficulties of technology development.3. Results: The gas hydrate exploitation system has recently been granted a national patent for invention (ZL201710181351.0). Specifically, the system contains three parts, i.e. energy feeding well, producing well and current controller settled between the energy feeding well and the producing well (Fig. 1). An energy feeding well is equipped with a casing penetrating through both the gas hydrate reservoir and the high temperature layers, and the casing is connected with the hydrate reservoir (cold end) and the high temperature layers through perforation completion. A thermoelectric generator connecting the cold end and the hot end is used to generate electric power, and then the power is delivered to the input of current controller. The producing well is equipped with a casing penetrating through the gas hydrate reservoir, and the casing is connected with the hydrate reservoir through perforation completion as well; inside the perforated zone, a hot electrode connecting to the output of the current controller, is used to heat the gas hydrate reservoir; the current generated by the energy feeding well is regulated by the current regulator, and then transmitted to the hot electrode that heats the gas hydrate reservoir. Finally, thermal recovery of natural gas in the gas hydrate reservoir is pared with the existing technology, the thermal recovery method has some advantages. This method utilizes the natural temperature gradient between a gas hydrate reservoir and dry hot rock or hot brine bearing layers to exploit submarine gas hydrates, which increases the efficiency of energy development and utilization, reduces the difficulties of technology development, eliminates the external pollution risk and improves the overall exploitation efficiency. In addition, the current controllers, settling between the energy feeding well and the producing well, could regulate the electric energy accurately to meet the needs of gas hydrate decomposition. Pressure-reducing gas outlet valves are installed at the wellhead of each energy feeding well and producing well, to ensure gas recovery is successful and safe.4. Conclusions: Based on the thermoelectric generator, a thermal recovery system of submarine gas hydrate is reported, which includes the energy feeding well, the producing well and the current controller. This set of equipment is suitable for exploiting gas hydrate reservoirs which are buried shallow and also coexist with high geothermal gradients. This method addresses the low energy utilization efficiency problems of the thermal recovery method which needs lot of extra heat, and thus increases the feasibility of economic exploitation.Xu, F., Xu, G., Yuan, H., Liang, H., 2019. Fluid system and pressure evolution study based on isotope and fluid inclusion geochemistry: a case study on the Sinian Dengying and the Cambrian Longwangmiao Formation in the Gaoshiti-Moxi structure, Central Sichuan Basin. Arabian Journal of Geosciences 12, 260. microscopic observation and analysis reveal multi-stage mineral fillings and fluid charging in the Sinian (Ediacaran) Dengying and the Cambrian Longwangmiao Formation in the Gaoshiti-Moxi structure, Central Sichuan Basin. Reservoir pore space is filled with five different stages of minerals from the edge to the center: fine crystalline dolomite, rimmed bitumen, coarse crystalline dolomite, stripped or oil droplet-like bitumen, and calcite or quartz, respectively. Sr, C, and O isotopic analysis for fine crystalline dolomite and the late stage calcite and quartz filled in reservoir pore space indicate that, prior to oil-generating window of the Cambrian Qiongzhusi Formation, the Sinian Dengying and the Cambrian Longwangmiao Formation were within the same connected and open fluid system. But after the gas-generating window, the Cambrian Longwangmiao Formation evolves gradually into a relatively independent and closed fluid system. By restoring the paleo fluid pressure, it is found that the paleo fluid pressure coefficient of the Sinian Dengying Formation has gone from 1.0, 1.1 to 1.2, 1.2, 1.2 to 1.3, and 1.0 to 1.1 at different evolution stages of source rock (at corresponding Ro value of 0.5, 1.3, 1.7, 2.0, and over 2.8, respectively), and the paleo fluid pressure coefficient of the Cambrian Longwangmiao Formation has varied from 1.0, 2.1 to 2.2, 1.8 to 1.9, 1.6 to 1.8, and 1.55 to 1.75. The pressure restoration result reveals that overpressure has never occurred in the Sinian Dengying Formation during the geological history, but overpressure commonly occurred in the Cambrian Longwangmiao Formation, and the values varied at different evolution stages of source rock. This pressure evolution process also demonstrates that the Sinian Dengying and the Cambrian Longwangmiao Formation, prior to the oil-generating window, were within an identical normal pressure fluid system. Meanwhile, it also matches well with the present exploration discoveries: the overpressured gas pools of the Cambrian Longwangmiao Formation are preserved up to now and hold hundreds of billions cubic meters of gas reserves, while the Sinian Dengying Formation contains residual normal pressure gas pools that formed after the adjustment of natural gas over a large area.Xu, J., Green, N.J., Gibard, C., Krishnamurthy, R., Sutherland, J.D., 2019. Prebiotic phosphorylation of 2-thiouridine provides either nucleotides or DNA building blocks via photoreduction. Nature Chemistry 11, 457-462. in the study of the origin of life have demonstrated how some of the building blocks essential to biology could have been formed under various primordial scenarios, and could therefore have contributed to the chemical evolution of life. Missing building blocks are then sometimes inferred to be products of primitive biosynthesis, which can stretch the limits of plausibility. Here, we demonstrate the synthesis of 2′-deoxy-2-thiouridine, and subsequently 2′-deoxyadenosine and 2-deoxyribose, under prebiotic conditions. 2′-Deoxy-2-thiouridine is produced by photoreduction of 2,2′-anhydro-2-thiouridine, which is in turn formed by phosphorylation of 2-thiouridine—an intermediate of prebiotic RNA synthesis. 2′-Deoxy-2-thiouridine is an effective deoxyribosylating agent and may have functioned as such in either abiotic or proto-enzyme-catalysed pathways to DNA, as demonstrated by its conversion to 2′-deoxyadenosine by reaction with adenine, and 2-deoxyribose by hydrolysis. An alternative prebiotic phosphorylation of 2-thiouridine leads to the formation of its 5′-phosphate, showing that hypotheses in which 2-thiouridine was a key component of early RNA sequences are within the bounds of synthetic credibility.Xu, L., Xu, S., Zhang, Q., Zhang, S., Tian, Y., Zhao, Z., Cai, Y., 2019. Chlorinated-methylsiloxanes in Shengli oilfield: Their generation in oil-production wastewater treatment plant and presence in the surrounding soils. Environmental Science & Technology 53, 3558-3567. two oil–wastewater treatment stations of Shengli Oilfield, cyclic volatile methylsiloxanes (cVMS, D4–D6) in the wastewater stream were found to undergo chlorination during electro-oxidation process for wastewater containing chlorine ions (16.1–42.0 g/L). Their converted fractions were 4.71–28.0% for monochlorinated D4–D6 and 0.22–7.96% for dichlorinated D4, which were ～2 orders of magnitude higher than those for hydroxylated products. Furthermore, portions of chlorinated methylsiloxanes retained in excess sludge were released to the surrounding soils. In soil samples (n = 500), chlorinated methylsiloxanes concentrations (<LOD-586 ng/g dw (dry weight), detection frequency (df) = 6.60–45.6%) decreased roughly exponentially with respect to the distance away from these two stations. During 2008–2017, the measured total chlorinated cVMS kept increasing in the dewatered-sludge (from 58.5 to 120 μg/g dw), while their concentrations in the surrounding soils doubled (from 93.4 to 184 ng/g dw) in first 6 years, but decreased since then (48.0 ng/g at 2017). Simulating experiments showed that monochlorinated D4–D6 in soil had 1.1–2.4 times longer hydrolysis (6.92–234 days) and volatilization (4.62–325 days) half-lives than their paired nonchlorinated cVMS. Among isomers of dichlorinated D4, D3D(CHCl2) had greatest hydrolysis (7.75–33.8 days) and volatilization (135–271 days) rates, followed by D3D(CH2Cl)2, D2(D(CH2Cl))2 and DD(CH2Cl)DD(CH2Cl).Xu, M., Yi, J., Qi, P., Wang, H., Marasteanu, M., Feng, D., 2019. Improved chemical system for molecular simulations of asphalt. Energy & Fuels 33, 3187-3198. simulation methods have become popular to explore the micromechanical and thermodynamic properties of asphalt. The chemical components of the system are the key to accurate and reliable results. In this research, molecules to simulate fresh asphalt are collected from existing research, and molecules to simulate aged asphalt binders are generated according to the widely accepted aging chemistry of asphalt. Using these molecules, a new asphalt chemical system is proposed, in which three typical asphalt models and the corresponding aging models are established. The mass fractions of saturate, aromatic, resin, and asphaltene and of elements found with the model are very close to test results. The density of the stable model is calculated and compared to that of the real materials. The simulated atomic force microscopy force curve is used to calculate the maximum adhesion force, nanohardness, and modulus of the asphalt surface. The model characterizes the aging characteristics of asphalt binders well.Xu, W., Gao, Y.-h., Gong, L.-f., Li, M., Pang, K.-L., Luo, Z.-H., 2019. Fungal diversity in the deep-sea hadal sediments of the Yap Trench by cultivation and high throughput sequencing methods based on ITS rRNA gene. Deep Sea Research Part I: Oceanographic Research Papers 145, 125-136. hadal zone is among the least studied habitats on the planet, and the composition, distribution and variations of the biological communities in the hadal zone are poorly understood. Recent explorations of the ocean trenches have revealed distinctive metabolic and functional microbial communities in the hadal biosphere. Compared to bacteria and archaea, fungal community in hadal trenches is poorly documented. In this study, we present, for the first time, results of a comparative survey of the sediment-associated fungal communities at the Yap Trench by using high-throughput sequencing and culture-based techniques. The fungal diversity obtained from these techniques were different, with 11.1% of the fungal genera shared between both techniques. Through ITS2 (internal transcribed spacer 2 of the rDNA) metabarcode sequencing from 42 sediment samples, 890 fungal operational taxonomic units (OTUs) were found based on clustering at a 97% sequence similarity cutoff level. Of these OTUs, 98 OTUs belonged to Ascomycota, 52 OTUs to Basidiomycota, 1 OTU to Chytridiomycota, 4 OTUs to Mortierellomycota, 19 OTUs to Mucoromycota and 2 OTUs to Rozellomycota, whereas 714 OTUs could not be assigned to any fungal phylum. The Ascomycota and the Basidiomycota comprised 49.74% and 5.84% of the total sequences, respectively t. Eurotiomycetes was identified as the most dominant fungal class. The culture-based technique also revealed Eurotiomycetes as the most abundant class, but some classes, such as Endogonomycetes and Umbelopsidomycetes, were not detected by the culture-based technique. Altogether, our findings provide valuable information for the understanding of fungal distribution and potential ecological roles of fungi in deep-sea hadal trenches.Yan, Z., Shao, L., Glasspool, I.J., Wang, J., Wang, X., Wang, H., 2019. Frequent and intense fires in the final coals of the Paleozoic indicate elevated atmospheric oxygen levels at the onset of the End-Permian Mass Extinction Event. International Journal of Coal Geology 207, 75-83. the End-Permian mass extinction event (EPME) there is extensive evidence for depletion of oxygen in the marine realm. Atmospheric models based upon biogeochemical cycling predict a comparable decline leading up to this event and have been postulated as a possible driver for marine depletion. However, these models contrast with broadly contemporaneous empirical evidence from charcoal in coals. New charcoal data from the temporally well-constrained late Permian Xuanwei Formation coals of eastern Yunnan Province, China, deposited just prior to the onset of the Permian-Triassic Transitional Beds, supports the coarser analysis and further challenges these biogeochemical models. Inertinite group macerals, comprising fusinite, semifusinite, macrinite, inertodetrinite, secretinite, all funginite with elevated reflectance, and some micrinite, are proxies for wildfire activity, and indicate abundant evidence for this phenomenon in the latest Permian and preclude low levels of atmospheric oxygen concentration coevally. Henceforward, we will employ the term ‘inertinite group macerals sensu amplo’ to refer to just these precise macerals, though these encompass what are the overwhelming preponderance of inertinites in most coals. Both inertinite abundance and reflectance indicate an increase in fire activity and intensity towards the End-Permian faunal crisis. Quantitatively, these inertinite data indicate atmospheric oxygen concentration was high and at the close of the Paleozoic was probably elevated to levels well above those of the present-day. The elevated fire activity at this time may have functioned as a causal link to explain some localized oxygen depletion in the marine realm as a result of post-fire increased run-off and erosion. However, globally depressed atmospheric oxygen concentration at the End-Permian was not a driver of extensive marine anoxia at that time.Yang, F., Xue, L., Yang, S., Chen, G., Bi, G., Lv, C., Ma, M., Su, L., Zhang, D., Zhou, Q., 2019. Characteristics of organic acids in lacustrine organic-rich shale, Ordos Basin, China. Petroleum Science and Technology 37, 876-881. acids are critical to studying the formation of secondary porosity in tight lacustrine reservoirs, Ordos Basin. The expelled fluids produced through hydrocarbon evolution in a semi-closed system under different pressure and temperature settings (16.9?MPa, 250?°C; 22.1?MPa, 300?°C; 32.5?MPa, 350?°C; 37.7?MPa, 370?°C; 42.9?MPa, 400?°C; and 52.2?MPa, 450?°C) were collected. In this study, 12 different organic acids were identified using ion chromatography, and both the concentration and species of organic acids indicate a two-step process.Yang, N., Guo, H., Lei, Y., Zhang, Y., Wang, M., Liu, F., Hu, R., Hu, Y., 2019. XAS combined with Py-GC study on the effects of temperatures and atmospheres on sulfur release and its transformation behavior during coal pyrolysis. Fuel 250, 373-380. (YZ) coal with comparably high organic sulfur and high pyrite content was selected to investigate the effects of temperatures on sulfur release and its transformation during pyrolysis under Ar and CO2 atmospheres. Pyrolysis connected with gas chromatography (Py-GC) was used to analyze the sulfur containing gases of H2S, COS and SO2, and the sulfur transformation during pyrolysis was measured by Sulfur K-edge X-ray absorption spectroscopy (S-XAS). For YZ raw, deashed and depyrited coals, desulfurization ratios gradually increase with the increasing temperatures, while their char yields gradually decrease under both atmospheres. Under Ar atmosphere, minerals in YZ coal have catalytic effect on the decomposition of sulfurs. However, the effect of minerals on sulfur decomposition is different under CO2 atmosphere. Under CO2 atmosphere, the release amounts of H2S, COS and SO2 for each sample are higher than that under the Ar atmosphere and the difference becomes more significant after 600?°C. This suggests that CO2 atmosphere is more helpful for the decomposition of stable sulfur at comparatively higher temperatures. Based on the analysis of Sulfur K-edge XAS, CO2 atmosphere can promote the decomposition of stable FeS and thiophenes during pyrolysis. Thus, based on the analysis of Py-GC and Sulfur K-edge XAS, CO2 atmosphere is more beneficial for the release of sulfur containing gases and for the decomposition of stable sulfur than Ar atmosphere. This provides detailed information about the effects of temperatures on sulfur release and transformation behavior during pyrolysis under CO2 atmosphere.Yang, Y.-M., Dilmore, R.M., Mansoor, K., Buscheck, T.A., Bromhal, G.S., 2019. Integration of wellbore pressure measurement and groundwater quality monitoring to enhance detectability of brine and CO2 leakage. International Journal of Greenhouse Gas Control 85, 143-155. detectability is a key consideration in evaluating the effectiveness of a measurement, monitoring and verification (MMV) plan for a geologic carbon storage (GCS) project. While studies have shown that surface-based, geophysical monitoring methods may be sensitive enough to detect CO2 leakage, these methods are an indirect indicator of leakage. A drawback to relying on direct geochemical monitoring is that by the time a significant leak is confirmed, it may be too late to mitigate or remediate the environmental impacts. In this study, we combine information from geophysical and geochemical monitoring methods to provide an integrated diagnosis of leakage events. The detectability for various monitoring parameters (pH, TDS, alkalinity, Ca, Cl, Na, and pressure) collected from monitoring wells are evaluated by leakage detection probability, using simulated wellbore-leakage/plume-migration events and monitoring scenarios for a hypothetical GCS operation at the Kimberlina site in California, USA. The NUFT code is used to model these events, by coupling wellbore-leakage simulations to 3-dimensional reactive, multi-phase, flow and transport simulations of brine and CO2 leakage-plume migration in aquifers overlying the GCS reservoir. Wellbore leakage in legacy wells located 1.4, 3.4 and 6.8?km from the CO2 injector is evaluated for a range of (1) wellbore bottom-hole pressure and CO2 saturation determined by GCS simulations, (2) regional groundwater gradient in the aquifers, and (3) wellbore permeability. Simulated leakage-induced changes in seven monitoring parameters at different depths are used to calculate the corresponding detection probabilities, based on the background distribution data and selected monitoring-technology detection thresholds. The responses for these monitoring parameters are tested and combined to enhance the overall detectability. The results indicate the leakage signals are more easily detected at shallower depths where buoyant CO2 has migrated and flashed from supercritical to gas phase, causing a large increase in CO2 volume. While the results suggest pH monitoring is more responsive to the simulated leakage events than TDS monitoring at shallower depths, TDS changes may be more readily observed at greater depths. The addition of carbonate alkalinity can confirm CO2 leakage detection and help distinguish CO2 leakage from other contamination sources. Direct pressure change measurements are very sensitive to leakage, but the rapid and broad propagation of the pressure response hinders using such measurements to easily locate the origin of leakage. Combining measurements could greatly improve the confidence of leakage diagnosis. High bottom-hole CO2 saturation, such as that for a leaky well close to the injector (?1.4?km), high regional groundwater gradient, and high wellbore permeabilities all increase the leakage plume size, and thus the leakage detectability. Our analysis suggests pressure monitoring is a valuable indicator of leakage events at early stages, while pH, TDS and carbonate alkalinity monitoring can directly diagnose leakage impacts by providing more detailed information in the groundwater receptor. Finally, an example Bayesian belief network model is presented for evaluating the effect of risk reduction options in terms of joint monitoring detection probability using the associated simulation scenarios. This framework is demonstrated to inform how pressure and groundwater quality information can be integrated into site MMV and risk management plans.Yang, Y., Wang, K., Zhang, L., Sun, H., Zhang, K., Ma, J., 2019. Pore-scale simulation of shale oil flow based on pore network model. Fuel 251, 683-692. pore-grain characteristics of shale oil reservoir rocks are complex: nano-size pore throats, multi-scale of pore size and topology, and rich in organic matter. Generally, shale oil flow in nanoporous media is significantly affected by microscopic fluid slippage and adsorption on the pore surfaces, which give rise to variable slip length, viscosity ratio of adsorbed phase to bulk phase, and thickness of adsorption layer in organic & inorganic pore throats. In this study, a new pore network model is developed based on a modified shale oil flow equation to consider those combinational effects on shale oil permeability under different organic matter contents, and then is applied to provide an order analysis of those effects on the permeability of a representative shale model. Different flow patterns characterizing fluid-solid interaction are also discussed. Analysis results show that shale oil permeability is strongly influenced by the slip length. The effect of adsorption on permeability is negligible for cases considered. Shale oil flow is mainly controlled by inorganic pores when volumetric TOC is low. The influence of TOC on permeability depends on slippage and adsorption conditions in organic and inorganic matters, referred in this paper to as flow patterns. As the organic matter content increases, the connectivity of organic pores and throats improves, which further affects network permeability.Yao, Q., Sun, M., Gao, J., Wang, R., Zhang, Y., Xu, L., Ma, X., 2019. Organic sulfur compositions and distributions of tars from the pyrolysis of solvent pretreatment vitrinite of high sulfur coal. Journal of Analytical and Applied Pyrolysis 139, 291-300. low temperature solvent pretreated experiments of vitrinite sorted out from Permo-carboniferous high organic sulfur fine coal were performed to research the effects of solvent pretreatment on the characteristics of pyrolysis products and the composition and distribution of sulfur in the produced coal tar. Six solvents containing hot water, ethanol solution, 1, 2-propanediol solution, KOH solution, KOH-ethanol solution and KOH-1, 2-propanediol solution were employed. The results show that the solvent pretreatment method has little influence on the organic sulfur content of coal, but it results in the increase of coal tar yield and a great variation of volatiles during the pyrolysis of pretreated coals. Six types of thiophenes, containing benzothiophene, dibenzothiophene, naphthothiophene, benzo[b]naphthothiophene, dinaphthothiophene and phenanthro[9,10-b]thiophene, were detected in coal tars. The pretreatments of hot water, ethanol solution and alkaline ethanol solution show the ring opening to large aromatic structures in coal. The generation of benzothiophene, dinaphthothiophene and phenanthro[9,10-b]thiophene may be due to the ring opening effect.Ye, J.-l., Qin, X.-w., Qiu, H.-j., Liang, Q.-y., Dong, Y.-f., Wei, J.-g., Lu, H.-l., Lu, J.-a., Shi, Y.-h., Zhong, C., Xia, Z., 2018. Preliminary results of environmental monitoring of the natural gas hydrate production test in the South China Sea. China Geology 1, 202-209. gas hydrate (NGH) is considered as one of the new clean energy sources of the 21st century with the highest potential. The environmental issues of NGH production have attracted the close attention of scientists in various countries. From May 10 to July 9, 2017, the first offshore NGH production test in the South China Sea (SCS) was conducted by the China Geological Survey. In addition, environmental security has also been effectively guaranteed via a comprehensive environmental monitoring system built during the NGH production test. The monitoring system considered sea-surface atmosphere methane and carbon dioxide concentrations, dissolved methane in the sea water column, and the seafloor physical oceanography and marine chemistry environment. The whole process was monitored via multiple means, in multiple layers, in all domains, and in real time. After the production test, an environmental investigation was promptly conducted to evaluate the environmental impact of the NGH production test. The monitoring results showed that the dissolved methane concentration in seawater and the near-seabed environment characteristics after the test were consistent with the background values, indicating that the NGH production test did not cause environmental problems such as methane leakage.Yoneda, J., Takiguchi, A., Ishibashi, T., Yasui, A., Mori, J., Kakumoto, M., Aoki, K., Tenma, N., 2019. Mechanical response of reservoir and well completion of the first offshore methane-hydrate production test at the eastern Nankai Trough: A coupled thermo-hydromechanical analysis. SPE Journal 24, 531-546. gas production from offshore gas-HBS, there are concerns regarding the settlement of the seabed and the possibility that frictional stress will develop along the production casing. This frictional stress is caused by a change in the effective stress induced by water movement caused by depressurization and dissociation of hydrate as well as gas generation and thermal changes, all of which are interconnected. The authors have developed a multiphase-coupled simulator by use of a finite-element method named COTHMA. Stresses and deformation caused by gas-hydrate production near the production well and deep seabed were predicted using a multiphase simulator coupled with geomechanics for the offshore gas-hydrate-production test in the eastern Nankai Trough. Distributions of hydrate saturation, gas saturation, water pressure, gas pressure, temperature, and stresses were predicted by the simulator. As a result, the dissociation of gas hydrate was predicted within a range of approximately 10 m, but mechanical deformation occurred in a much wider area. The stress localization initially occurred in a sand layer with low hydrate saturation, and compression behavior appeared. Tensile stress was generated in and around the casing shoe as it was pulled vertically downward caused by compaction of the formation. As a result, the possibility of extensive failure of the gravel pack of the well completion was demonstrated. In addition, in a specific layer, where a pressure reduction progressed in the production interval, the compressive force related to frictional stress from the formation increased, and the gravel layer became thin. Settlement of the seafloor caused by depressurization for 6 days was within a few centimeters and an approximate 30 cm for 1 year of continued production.Yoshikawa, G., Blanc-Mathieu, R., Song, C., Kayama, Y., Mochizuki, T., Murata, K., Ogata, H., Takemura, M., 2019. Medusavirus, a novel large DNA virus discovered from hot spring water. Journal of Virology 93, Article e02130-02118.: Recent discoveries of new large DNA viruses reveal high diversity in their morphologies, genetic repertoires, and replication strategies. Here, we report the novel features of Medusavirus, a large DNA virus newly isolated from hot spring water in Japan. Medusavirus with a diameter of 260 nm shows a T=277 icosahedral capsid with unique spherical-headed spikes on its surface. It has a 381 kb genome encoding 461 putative proteins, 86 of which have their closest homologs in Acanthamoeba castellanii, whereas 279 (61%) are ORFans. The virus lacking the genes of DNA topoisomerase II and RNA polymerase showed that the DNA replication takes place in the host nucleus while the progeny virions are assembled in the cytoplasm. Furthermore, Medusavirus encoded all of five types of histones (H1, H2A, H2B, H3, and H4) and one DNA polymerase, which are phylogenetically placed at the root of the eukaryotic clades. By contrast, the host amoeba encoded many Medusavirus homologs including the major capsid protein. These facts strongly suggested that amoeba is indeed the most promising natural host of Medusavirus, and lateral gene transfers have taken place repeatedly and bidirectionally between the virus and its host since the early stage of their co-evolution. Medusavirus reflects the traces of direct evolutionary interactions between the virus and eukaryotic hosts, which may be caused by sharing the DNA replication compartment and evolutionarily long lasting viral-host relationships. Based on its unique morphological characteristics and phylogenomic relationships with other known large DNA viruses, we propose that Medusavirus forms a new family Medusaviridae.Importance: We have isolated a new NCLDV virus from hot spring water in Japan, named Medusavirus. This new NCLDV is phylogenetically placed at the root of the eukaryotic clades based on the phylogenies of several key genes including DNA polymerase, and surprisingly encodes the full set of histone homologs. Furthermore, its laboratory host, Acanthamoeba castellanii, encodes many Medusavirus homologs in its genome including the major capsid protein, suggesting that the amoeba is the genuine natural host of this new virus from ancient times, and lateral gene transfers have occurred between the virus and amoeba repeatedly. These results suggest that Medusavirus is a unique NCLDV preserving ancient footprints of evolutionary interactions with its hosts, thus providing clues to elucidate the evolution of NCLDVs, eukaryotes, and viral-host interaction. Based on the dissimilarities with other known NCLDVs, we propose that Medusavirus forms a new viral family Medusaviridae.Yoshiya, K., Sato, T., Omori, S., Maruyama, S., 2018. The birthplace of proto-life: Role of secondary minerals in forming metallo-proteins through water-rock interaction of Hadean rocks. Origins of Life and Evolution of Biospheres 48, 373-393. surface of Hadean Earth was mainly covered with three types of rocks—komatiite, KREEP basalt and anorthosite—which were remarkably different from those on the modern Earth. The water-rock interaction between these rocks and water provided a highly reducing environment and formed secondary minerals on the surface of the rocks that are important for producing metallo-enzymes for the emergence of primordial life. Previous studies suggested a correlation between the active site of metallo-enzymes and sulfide minerals based on the affinity of their structures, but they did not discuss the origin of metallic elements contained in these minerals which is critical to understanding where life began. We investigated secondary minerals formed through water-rock interactions of komatiite in a subaerial geyser system, then discussed the relationship between the active site of metallo-enzymes and secondary minerals. Instead of komatiite, we used serpentinite collected from the Hakuba Happo area, Nagano Prefecture in central-north Japan, which is thought to be a modern analog for the Hadean environment. We found several minor minerals, such as magnetite, chromite, pyrite and pentlandite in addition to serpentine minerals. Pentlandite has not been mentioned in previous studies as one of the candidates that could supply important metallic elements to build metallo-enzymes. It has been shown to be a catalyst for hydrogen generation possibly, because of structural similarity to the active site of hydrogenases. We consider the possibility that nickel-iron sulfide, pentlandite, could be important minerals for the origin of life. In addition, we estimated what kinds of minor minerals would be obtained from the water-rock interaction of these rocks using thermodynamic calculations. KREEP basalt contains a large amount of iron and it could be useful for producing metallo-enzymes, especially ferredoxins—electron transfer enzymes, which may have assisted in the emergence of life.You, J., Li, C., Liu, D., Yang, F., Sun, G., 2019. Influence of the aggregation state of asphaltenes on structural properties of the model oil/brine interface. Energy & Fuels 33, 2994-3002. the continuous exploitation of heavy oil resources, the stability of heavy oil emulsions and further its demulsification technology are receiving more and more attention. One of the most important elements that affect the stability of heavy oil emulsion is asphaltenes. Under this background, the effect of the aggregation state of asphaltenes on the structure-related properties of the model oil/brine water interface is investigated in this study, and further the relation between the structural properties of the interface and the macroscopic stability of the emulsion is studied. It is observed through the dynamic light scattering experiment that there is an abrupt increase in the particle size of the asphaltene aggregates at the concentration of 100 ppm, indicating the enhancement of the aggregation degree above this concentration. The higher level of aggregation changes the adsorption kinetics of the asphaltenes at the interface, causing a slower descending rate of the diffusion coefficient. Meanwhile, although the interfacial viscoelastic experiment demonstrates that the interfacial dilational modulus is increased with the addition of asphaltenes, the rising trend becomes gentle and the loss angle hardly changes at the concentrations above 100 ppm, indicating that the cross-linked structure in the interfacial film changes slightly with the addition of asphaltenes. In addition, it is found through the interface contraction experiment that no crumpling appears at the interfacial film at concentrations below 100 ppm. At the concentrations above 100 ppm, the crumpling of the interfacial film is observed. However, the contraction and expansion processes are reversible. Finally, it is proven with a bottle test method that there is a positive correlation between the macroscopic stability of the emulsion and the interfacial dilational modulus.Yu, W., Song, J., Chen, C., Song, Q., Zhao, C., Li, X., Chen, H., 2019. Phragmites stimulation and natural attenuation of indigenous microbial community accelerated bioremediation of oil contaminated soil. Petroleum Science and Technology 37, 882-888. high-throughput sequencing method was used to reflect fluctuation of indigenous microbial community during phragmites stimulation process in this study. Results showed Proteobacteria, Fimicutes, and Actinobacteria were most influential in process, Firmicutes and Deinococcus-Thermus were positively affected by nutrient amendment. Firmicutes can be seen as indicator of degradation rate. Dietzia, Salinimicrobium, and Halomonas were the most dominant genus in both Phragmites and Blank setups. These results indicated phragmites addition improved the efficiency of biodegradation and significantly regulated the microbial community structure and functions during remediation process.Yuan, Y., Rezaee, R., 2019. Impact of paramagnetic minerals on NMR-converted pore size distributions in Permian Carynginia shales. Energy & Fuels 33, 2880-2887. size distribution (PSD) is a fundamental petrophysical parameter for shale formation evaluation. Nuclear magnetic resonance (NMR), performing as a widely acknowledged technique, directly measures transverse relaxation time (T2), which can be converted into PSD via surface relaxivity (SR). Technically, SR is utilized as a constant value in the entire formation, nevertheless, the laboratory calculated SRs revealed that they are likely to vary with mineralogy and can be influenced by Fe-bearing paramagnetic minerals, which could further affect NMR-converted pore structure properties. This study was performed on Permian Carynginia shale samples to compare the NMR-converted PSD with that measured by mercury injection capillary pressure (MICP). The surface relaxivity was calculated from the logarithmic mean T2 value (T2,lm) based on NMR measurement and the surface to volume ratio (SVR) based on low-pressure nitrogen gas adsorption (LP-N2-GA). The results show that Fe-bearing paramagnetic mineral contents are linear positively correlated with SR values, which were calculated to range between 0.08 and 0.32 μm/s in our tested samples. The paramagnetic mineral of higher content expedites the NMR T2 surface relaxation rate, leading to the divergent shifts in NMR- converted PSD curves.Yuan, Y., Xu, T., Xia, Y., Xin, X., 2019. Comparison of simplistic and geologically descriptive production modeling for natural-gas hydrate by depressurization. SPE Journal 24, 563-578. exploration at the Eastern Nankai Trough of Japan revealed the variable distribution of hydrate accumulations, which are composed of alternating beds of sand, silt, and clay in sediments, with vertically varying porosity, permeability, and hydrate saturation. The main purposes of this work are to evaluate gas productivity and identify the multiphase-flow behavior from the sedimentary-complex hydrate reservoir by depressurization through a conventional vertical well. We first established a history-matching model by incorporating the available geological data at the offshore-production test site in the Eastern Nankai Trough. The reservoir model was validated by matching the fluid-flow rates at a production well and temperature changes at a monitoring well during a field test. The modeling results indicate that the hydrate-dissociation zone is strongly affected by the reservoir heterogeneity and shows a unique dissociation front. The gas-production rate is expected to increase with time and reach the considerable value of 3.6×104 std m3/d as a result of the significant expansion of the dissociation zone. The numerical model, using a simplified description of porosity, permeability, and hydrate saturation, leads to significant underestimation of gas productivity from the sedimentary-complex hydrate reservoir. The results also suggest that the interbedded-hydrate-occurrence systems might be a better candidate for methane (CH4) gas extraction than the massive hydrate reservoirs.Yusupova, I.F., 2019. The role of organic matter in formation of the properties of a shale deposit. Doklady Earth Sciences 484, 89-91. oil shales–kukersites were studied as an example of rocks with rock-forming organic matter (OM). The volumetric significance of their OM is shown (due to the low density) in the volume and thickness of the shale layers. A higher OM content is responsible for a lower strength of the shales relative to the carbonate rocks of the deposit. The variable OM contents and other heterogeneities of the shale layers (structure, nodules, etc.) are factors of the mosaic distribution of areas with different density–strength properties and, as a result, of uneven reduction of layers and their deformation in the case of OM loss (full or partial). It is concluded that the intercalation of kukersite and limestone layers leads to density and strength anisotropy of the shale deposit. Episodic loss of OM and carbonates by the shales is considered for the local areas of the deposit: here, kukersites contain only a terrigenous component with clasts of limestones, shales, and epigenetic sulfides. The loss of OM is explained by sulfate-reduction processes in the underground hydrosphere.Zaeri, M.R., Shahverdi, H., Hashemi, R., Mohammadi, M., 2019. Impact of water saturation and cation concentrations on wettability alteration and oil recovery of carbonate rocks using low-salinity water. Journal of Petroleum Exploration and Production Technology 9, 1185-1196. this study, the effect of initial water saturation on the oil recovery for carbonate rocks is investigated using spontaneous imbibition experiments. The experiments are performed using 20 times diluted sea water as imbibing fluid and the sea water as initial water. In addition, the impact of pH and Ca2+, Mg2+, Na+, and K+ cations concentration change of imbibing fluid are investigated during tests. These results help to identify the active cations in the wettability alteration process of carbonate rocks during the low-salinity water injection. A mechanism is proposed to describe the effect of initial water saturation on the oil recovery by low-salinity water injection. The impact of initial water saturation on the wettability alteration might be positive or negative depending on its value and the rock permeability. The comparison of divalent cations concentrations shows that the minimum adsorption of Ca2+ and maximum desorption of Mg2+ lead to maximum oil recovery of spontaneous imbibition. The results confirm that three cations of Ca2+, Mg2+, and Na+ are active for wettability alteration of carbonate rocks in the presence of sea water as initial water and diluted sea as imbibing fluid, whilst the amounts of potassium remain constant.Zaimes, G.G., Littlefield, J.A., Augustine, D.J., Cooney, G., Schwietzke, S., George, F.C., Lauderdale, T., Skone, T.J., 2019. Characterizing regional methane emissions from natural gas liquid unloading. Environmental Science & Technology 53, 4619-4629. “bottom-up” probabilistic model was developed using engineering first-principles to quantify annualized throughput normalized methane emissions (TNME) from natural gas liquid unloading activities for 18 basins in the United States in 2016. For each basin, six discrete liquid-unloading scenarios are considered, consisting of combinations of well types (conventional and unconventional) and liquid-unloading systems (nonplunger, manual plunger lift, and automatic plunger lift). Analysis reveals that methane emissions from liquids unloading are highly variable, with mean TNMEs ranging from 0.0093% to 0.38% across basins. Automatic plunger-lift systems are found to have significantly higher per-well methane emissions rates relative to manual plunger-lift or non-plunger systems and on average constitute 28% of annual methane emissions from liquids unloading over all basins despite representing only ～0.43% of total natural gas well count. While previous work has advocated that operational malfunctions and abnormal process conditions explain the existence of super-emitters in the natural gas supply chain, this work finds that super-emitters can arise naturally due to variability in underlying component processes. Additionally, average cumulative methane emissions from liquids unloading, attributed to the natural gas supply chain, across all basins are ～4.8 times higher than those inferred from the 2016 Greenhouse Gas Reporting Program (GHGRP). Our new model highlights the importance of technological disaggregation, uncertainty quantification, and regionalization in estimating episodic methane emissions from liquids unloading. These insights can help reconcile discrepancies between “top-down” (regional or atmospheric studies) and “bottom-up” (component or facility-level) studies.Zakharov, Y.D., Biakov, A.S., Horacek, M., Goryachev, N.A., Vedernikov, I.L., 2019. The first data on the N isotopic composition of the Permian and Triassic of northeastern Russia and their significance for paleotemperature reconstructions. Doklady Earth Sciences 484, 21-24. is proposed that unstable temperature conditions in the Late Wuchiapingian and Early Changhsingian (Late Permian) changed in the Boreal Superrealm to less contrasting climatic conditions in the Late Changhsingian and Early Induan (the formation time of trap formation of the Siberian Platform), with a stable trend of increasing temperature in the Early Triassic. The problem of the absence of signs of mass extinction of marine organisms at the Permian–Triassic boundary in the Boreal Superrealm is discussed.Zanolli, C., Kullmer, O., Kelley, J., Bacon, A.-M., Demeter, F., Dumoncel, J., Fiorenza, L., Grine, F.E., Hublin, J.-J., Nguyen, A.T., Nguyen, T.M.H., Pan, L., Schillinger, B., Schrenk, F., Skinner, M.M., Ji, X., Macchiarelli, R., 2019. Evidence for increased hominid diversity in the Early to Middle Pleistocene of Indonesia. Nature Ecology & Evolution 3, 755-764. the first discovery of Pithecanthropus (Homo) erectus by E. Dubois at Trinil in 1891, over 200 hominid dentognathic remains have been collected from the Early to Middle Pleistocene deposits of Java, Indonesia, forming the largest palaeoanthropological collection in South East Asia. Most of these fossils are currently attributed to H. erectus. However, because of the substantial morphological and metric variation in the Indonesian assemblage, some robust specimens, such as the partial mandibles Sangiran 5 and Sangiran 6a, were formerly variably allocated to other taxa (Meganthropus palaeojavanicus, Pithecanthropus dubius, Pongo sp.). To resolve the taxonomic uncertainty surrounding these and other contentious Indonesian hominid specimens, we used occlusal fingerprint analysis (OFA) to reconstruct their chewing kinematics; we also used various morphometric approaches based on microtomography to examine the internal dental structures. Our results confirm the presence of Meganthropus as a Pleistocene Indonesian hominid distinct from Pongo, Gigantopithecus and Homo, and further reveal that Dubois’s H. erectus paratype molars from 1891 are not hominin (human lineage), but instead are more likely to belong to Meganthropus.Zatirakha, A.V., Uzhel, A.S., Loshin, A.A., Chernobrovkina, A.V., Smolenkov, A.D., Shpigun, O.A., 2019. Novel stationary phases for ion chromatography and hydrophilic interaction liquid chromatography. Journal of Analytical Chemistry 74, 12-20. review covers the research of the Laboratory of Chromatography of the Division of Analytical Chemistry of the Department of Chemistry of Moscow State University in the development of new stationary phases for hydrophilic interaction liquid chromatography and ion chromatography performed in 2007–2017. The principles that guided the team in selecting matrices for each type of adsorbents, approaches to the modification of surface, and the methods of forming functional layers are discussed. The revealed regularities of changes in the chromatographic properties of materials on varying the structural fragments of the functional layers are described in detail, which enabled the authors to develop approaches to obtaining stationary phases that are not inferior to commercial analogs in efficiency and selectivity.Zeinali, S., Khalilzadeh, M., Bagheri, H., 2019. Generic extraction medium: From highly polar to non-polar simultaneous determination. Analytica Chimica Acta 1066, 1-12. preparation for non-target analysis is challenging due to the difficulty in the extraction of polar and non-polar analytes simultaneously. Most commercial solid sorbents lack the proper comprehensiveness for extraction of analytes with different physiochemical properties. A possible key is the combination of hydrophobic polymer and hydrophilic surface functional groups in solid based extraction methods in order to generate the susceptibility for retaining both polar and non-polar analytes. To pursue this goal, in this study, four polar groups including NH2, NO2, COOH, and COCH3 were chemically bound to Amberlite XAD-4 substrate in order to prepare a generic extraction platform. To validate the applicability of extractive phases, 22 analytes possessing wide range of polarities (LogP range between??2 and?+7) were chosen for extraction using the synthesized polymers by online micro solid phase extraction (μ-SPE) and further analyzed with high-performance liquid chromatography and UV–Vis detection (HPLC-UV). The recovery data were compared with commercial sorbents by t-test, principal component analysis (PCA) and hierarchical cluster analysis (HCA). Amberlite XAD-4 modified with COOH group (XAD-COOH) revealed extraction efficiencies statistically better than commercially available sorbents including LiChrolut? EN, Oasis? HLB and Amberlite? XAD-4?. The reproducibility and repeatability of XAD-COOH were also studied and acceptable results were obtained. Furthermore, the swellability of polymers was also measured and the results were comparable with commercial ones. To evaluate the extraction ability of XAD-COOH in real sample matrix, water sample near a heavy crude oil spill, urine and hospital wastewater were analyzed. Comparison of the data with LiChrolut? EN corroborates the dominance of XAD-COOH for screening analysis.Zeinalzadeh, A., Moussavi-Harami, R., Mahboubi, A., Kassaie-Najafi, M., Rezaee, R., 2019. Thermal modelling of gas generation and retention in the Jurassic organic-rich intervals in the Darquain field, Abadan Plain, SW Iran. Journal of Petroleum Exploration and Production Technology 9, 971-987. petroleum system with Jurassic source rocks is an important part of the hydrocarbons discovered in the Middle East. Limited studies have been done on the Jurassic intervals in the 26,500?km2 Abadan Plain in south-west Iran, mainly due to the deep burial and a limited number of wells that reach the basal Jurassic successions. The goal of this study was to evaluate the Jurassic organic-rich intervals and shale gas play in the Darquain field using organic geochemistry, organic petrography, biomarker analysis, and basin modelling methods. This study showed that organic-rich zones present in the Jurassic intervals of Darquain field could be sources of conventional and unconventional gas reserves. The organic matter content of samples from the organic-rich zones corresponds to medium-to-high-sulphur kerogen Type II-S marine origin. The biomarker characteristics of organic-rich zones indicate carbonate source rocks that contain marine organic matter. The biomarker results also suggest a marine environment with reducing conditions for the source rocks. The constructed thermal model for four pseudo-wells indicates that, in the kitchen area of the Jurassic gas reserve, methane has been generated in the Sargelu and Neyriz source rocks from Early Cretaceous to recent times and the transformation ratio of organic matter is more than 97%. These organic-rich zones with high initial total organic carbon (TOC) are in the gas maturity stage [1.5–2.2% vitrinite reflectance in oil (Ro)] and could be good unconventional gas reserves and gas source rocks. The model also indicates that there is a huge quantity of retained gas within the Jurassic organic-rich intervals.Zeyen, N., Benzerara, K., Menguy, N., Brest, J., Templeton, A.S., Webb, S.M., Gérard, E., Moreira, D., López-García, P., Tavera, R., Morin, G., 2019. Fe-bearing phases in modern lacustrine microbialites from Mexico. Geochimica et Cosmochimica Acta 253, 201-230. metal ions impurities in microbialites have been previously suggested as paleoenvironmental and/or paleobiological proxies. However, how metals are incorporated into microbialites remains poorly known. Here, in order to assess the distribution and speciation of Fe in modern microbialites, we conducted bulk X-ray diffraction, infrared spectroscopy, X-ray absorption near-edge structure (XANES) spectroscopy, electron microscopy and X-ray microscopy analyses on samples collected from shallow depths in five alkaline lakes in Mexico: Lake Alchichica, Lake La Preciosa, Lake Atexcac, Lake La Alberca de Los Espinos and Lake Pátzcuaro. A range of Fe contents were measured in these microbialites, from low (～0.12?wt.%) to relatively high (～2.2?wt.%). Fe was distributed heterogeneously in microbialites, mostly localized as hotspots or sometimes arranged as discrete laminae. Fe was mostly trivalent in all microbialites and was incorporated into diverse authigenic phases, the proportion of which varied among microbialites. Authigenic phases included Fe-bearing Mg-phyllosilicates such as kerolite and/or stevensite, i.e. (Mg,Fe(II),Fe(III))3Si4O10(OH)2·nH2O and Fe-Mg layered double hydroxides (LDH), i.e. pyroaurite [Mg(II)6Fe(III)2(CO3)(OH)16·4H2O] and/or iowaite [Mg(II)6Fe(III)2Cl2(OH)16·4H2O], together with Fe-(oxyhydr)oxides. Carbonate phases were negligible carriers of Fe in all lakes. Iowaite/pyroaurite phases, which have often been found as low temperature alteration products in serpentinites, were surprisingly observed in Lake Alchichica, whereas Fe-bearing kerolite/stevensite was present in Lake La Preciosa, Lake Atexcac, Lake La Alberca de Los Espinos and Lake Pátzcuaro. Fe present in these shallow water microbialites may be originated from groundwater seepage derived from adjacent Fe-rich volcanic rocks. We suggest that the occurence of iowaite/pyroaurite vs authigenic Fe-bearing kerolite/stevensite depends on the orthosilicic acid concentration in the lakes. Pyroaurite/iowaite may form and stay preserved in Lake Alchichica because of the low [H4SiO4] as well as high alkalinity, [Mg2+], [CO32?], [Cl?] and pH (～9) prevailing in this lake, while in other lakes, where [H4SiO4] is higher (above ～0.4?mM), Fe-bearing kerolite or smectite phases are formed. Overall, the message carried by the Fe-bearing mineral phases in these modern microbialites is multifold: Fe-bearing phases within microbialites may contain some information on environmental conditions (e.g., [H4SiO4]) as well as on geochemical processes implicated during their formation (e.g., seepage of anoxic Fe-bearing groundwater). Considering the reactivity of pyroaurite/iowaite and kerolite/stevensite and their possible transformation into diverse mineral phases upon microbial activity, burial and diagenesis, a careful appraisal of Fe speciation using a similar combination of bulk and microscopy analyses is required in order to better assess the origin of Fe in ancient microbialites.Zhai, G.-y., Wang, Y.-f., Zhou, Z., Liu, G.-h., Yang, Y.-r., Li, J., 2018. “Source-Diagenesis-Accumulation” enrichment and accumulation regularity of marine shale gas in southern China. China Geology 1, 319-330. the breakthrough of shale gas exploration and development in the Ordovician Wufeng Formation (Fm.) and Silurian Longmaxi Fm. of Chongqing Jiaoshiba area, Changning-Weiyuan area, etc. in Sichuan basin, a series of discovery and breakthrough were obtained by China Geological Survey in the Cambrian Niutitang Fm. and Sinian Doushantuo Fm. shale of the areas with complicated structure outside Sichuan basin. Based on the understanding of the law of shale gas enrichment in Longmaxi Fm. in the basin, this paper puts forward three elements of the formation and enrichment of shale gas, which are the “Source”, the “Diagenesis” and the “Accumulation”, after deeply studying the law shale gas enrichment and accumulation in Sinian-Cambrian reservoir of the complex structure area outside the basin. The “Source” means the sedimentary environment and petrological characteristics of organic shale. The “Diagenesis” means the basin tectonic subsidence and hydrocarbon generation and expulsion process of organic matter. The “Accumulation” means the tectonic uplift and shale gas preservation. It is proposed that the Sinian-Cambrian and Ordovician-Silurian black shale series in the middle and upper Yangtze region of southern China were both formed in the deep-water shelf environment of rift trough and foreland basin respectively. The dessert intervals were formed in the strong reduction environment under transgressive system tract. The shale lithology belongs to calcium-siliceous and charcoal-siliceous respectively. Based on the summary of structural evolution in Yangtze area, the correlation of structural burial depth with shale diagenesis and the coupling evolution of organic matter with pore structure are discussed. Combining with structural styles, the preservation conditions of shale gas are discussed. Five types of shale gas reservoir control models are further described. Two types of future exploration directions, which are reverse fault syncline and paleo-uplift margin in complex structural area outside the basin, are proposed.Zhai, G.-y., Wang, Y.-f., Zhou, Z., Yu, S.-f., Chen, X.-l., Zhang, Y.-x., 2018. Exploration and research progress of shale gas in China. China Geology 1, 257-272. are three types of shale gas resources in China. The resources are present in large amounts and are widely distributed. Marine facies, transitional facies and continental facies resources each account for a third. Based on resource distributions, there are many wells penetrated into the Sinian, Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian strata of the Yangtze plate and its periphery, the North China Craton and the Tarim Basin. Many years of exploration have indicated that the marine Silurian Longmaxi shale gas is widely distributed in south China and has been industrialized in its production in the Sichuan basin. The shale gas from the Cambrian Niutitang Formation and the Sinian Doushantuo Formation are important discoveries in Yichang, Hubei and Zhenba, Shanxi. There are also shale gas resources found within transitional facies and continental facies in different areas in China. The “two element enrichment theory” has been summarized during the exploration process of Silurian marine shale gas in the Sichuan Basin. In addition, horizontal drilling and fracturing technologies up to 3500 m in depth have been developed. Based on the understanding of shale gas accumulation in a complex tectonic zone outside the Sichuan basin, a preliminary summary of the formation of the “converse fault syncline control reservoir” and “paleo uplift control reservoir” model has been constructed. The dominant theory of “Trinity” shale gas enrichment and the high yield of the “deep water Lu Pengxiang sedimentary facies belt, structural preservation conditions and overpressure” is summarized. Guided by the above theories. Anye1 well in Guizhou and Eyangye1 well in Hubei were drilled. “Four storey” oil and shale gas is found in the Permian Qixia group, the Silurian Shiniulan Formation, the Longmaxi Formation and the Ordovician Baota Formation in Anye1 well. Good shale gas has been gound in the Cambrian Niutitang formation inian Doushantuo formation in Eyangye 1well. This paper aims to summarize and review the main progress, theoretical technology and problems of shale gas exploration and development in recent years in China, and predicts the future exploration and development direction for shale gas and possible exploration areas.Zhang, B., Shan, C., Hao, Z., Liu, J., Wu, B., Pan, B., 2019. Transformation of dissolved organic matter during full-scale treatment of integrated chemical wastewater: Molecular composition correlated with spectral indexes and acute toxicity. Water Research 157, 472-482. one of the key economic modes in China, chemical industry park (CIP) has made great contribution to the Chinese rapid economic growth. Concomitantly, how to effectively and safely dispose of the CIP wastewater (CIPWW) has been an unavoidable issue. Molecular transformation of dissolved organic matter (DOM) in CIPWW treatment is essential to optimize the employed process and to provide solid basis for risk evaluation of the discharged effluent as well. In this study, electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR-MS) was used to characterize the molecular transformation of DOM during full-scale treatment of integrated chemical wastewater in a centralized wastewater treatment plant (CWWTP), where the combined process follows hydrolysis/acidification (HA)-flocculation/precipitation (FP)-A2/O-membrane bioreactor (MBR)-ultrafiltration (UF)-reverse osmosis (RO). Compared to municipal wastewater, DOM in CIPWW exhibited higher unsaturation degree, lower molecular weight, and higher toxicity. In FP unit, DOM of C<24 and higher nominal oxidation state of carbon (NOSC) values was preferentially removed. The HA and anaerobic units are capable of significantly degrading DOM, resulting in great changes in molecular composition of DOM. However, the anoxic, oxic, and MBR units only lead to a slight change of the molecular formulae. The terminal units of UF and RO can remove most DOM, with the concentration of dissolved organic carbon (DOC) declining by 19.2% and 94.6% respectively. The correlation between spectral indexes and acute toxicity with the molecular formulae of DOM suggested that polyphenols and highly unsaturated phenols were positively correlated with the specific UV absorbance at 254 nm (SUVA254). In addition, both compounds (0.32?<?O/C?<?0.63) as well as the aliphatic ones (0.22?<?O/C?<?0.56) presented positive correlation with acute toxicity. Further, the pairwise correlation analysis illustrated that SUVA254, O/Cwa, double bond equivalence (DBEwa), and NOSCwa were positively correlated with each other, whereas the acute toxicity was positively correlated with humification index (HIX), O/Cwa, and DBEwa.Zhang, B., Wang, S., Diao, M., Fu, J., Xie, M., Shi, J., Liu, Z., Jiang, Y., Cao, X., Borthwick, A.G.L., 2019. Microbial community responses to vanadium distributions in mining geological environments and bioremediation assessment. Journal of Geophysical Research: Biogeosciences 124, 601-615. Vanadium mining activities can cause contamination of the surrounding geological environment. Vanadium may exist in multiple matrices due to its migration and transformation, forming interactive relationships; however, the connection between vanadium distributions in multiple matrices and microbial community responses remains largely unknown. Vanadium is a redox-sensitive metal that can be microbiologically reduced and immobilized. To date, bioremediation of vanadium-contaminated environments by indigenous microorganisms has rarely been evaluated. This paper reports a systematic investigation into vanadium distributions and microbial communities in soils, water, and sediment from Panzhihua, China. Large vanadium contents of 1130.1?±?9.8?mg/kg and 0.13?±?0.02?mg/L were found in surface soil and groundwater. Vanadium in surface water tended to precipitate. Microbial communities isolated from similar environments were alike due to similarity in matrix chemistry whereas communities were distinct when compared to different matrices, with lower richness and diversity in groundwater. Proteobacteria was distributed widely and dominated microbial communities within groundwater. Redundancy analysis shows that vanadium and nutrients significantly affected metal-tolerant bacteria. Long-term cultivation (240?days) suggests the possibility of vanadium bioremediation by indigenous microorganisms, within acid-soluble fraction. This active fraction can potentially release mobile vanadium with shifted redox conditions. Vanadium (V) was bio-reduced to less toxic, mobile vanadium (IV) primarily by enriched Bacillus and Thauera. This study reveals the biogeochemical fate of vanadium in regional geological environments and suggests a bioremediation pathway via native vanadium-reducing microbes.Zhang, D., Lin, Q., Xue, N., Zhu, P., Wang, Z., Wang, W., Ji, Q., Dong, L., Yan, K., Wu, J., Pan, X., 2019. The kinetics, thermodynamics and mineral crystallography of CaCO3 precipitation by dissolved organic matter and salinity. Science of The Total Environment 673, 546-552. carbonate (CaCO3) precipitation is an important geochemical process. In the estuary zone and some arid shallow lakes, DOM (dissolved organic matter) and salinity are two frequent changing factors that may affect CaCO3 precipitation. The joint effect of DOM and salinity on CaCO3 precipitation kinetics and thermodynamics are still unclear. In this study, effects of DOM on CaCO3 precipitation process at 0.5‰ and 70‰ salinity were investigated by QCM (Quartz Crystal Microbalance) technique, real-time pH measurement and single-injection nanoliter ITC (isothermal titration calorimetry). The mineral crystallography was analyzed by SEM-EDS. Both DOM and salinity had inhibitory effect on CaCO3 precipitation. DOM had more pronounced inhibitory effect on CaCO3 precipitation at lower salinity. Regardless of DOM, 70‰ salinity inhibited CaCO3 precipitation >0.5‰ salinity. The CaCO3 precipitation kinetics followed the first-order kinetic model and the adhesion kinetics of the instantaneous nucleation and crystal growth stage could be well described by the exponential function. CaCO3 precipitation was an endothermic process and high salinity strongly hindered CaCO3 precipitation. The effect of DOM on the absorbed heat was significant at 0.5‰ salinity. At 70‰ salinity, regardless of the effect of DOM, CaCO3 precipitation rate was greatly slowed down because it needed much more heat. CaCO3 minerals were dominated by rhombohedral calcite while CaCO3 minerals were mainly shaped as spherical vaterite at 0.5‰ salinity and rhombohedral calcite at 70‰ salinity. The crystal phase changed during CaCO3 precipitation at 0.5‰ salinity. In conclusion, the presence of DOM had substantial impact on the micrograph of the CaCO3 minerals. The percentage of flawed crystals with rough surface increased significantly with increased DOM concentration.Zhang, K., Sang, S., Liu, C., Ma, M., Zhou, X., 2019. Experimental study the influences of geochemical reaction on coal structure during the CO2 geological storage in deep coal seam. Journal of Petroleum Science and Engineering 178, 1006-1017. unminable coal seams are suitable geological bodies for carbon dioxide capture and storage (CCS). In order to discuss the geochemical reaction between the injected carbon dioxide (CO2) and deep coal seam, and study its influence on the structure of reservoir, the high-ash anthracite, high-volatile anthracite, low-volatile bituminous coal obtained from Qinshui basin, China, and high-volatile bituminous coal obtained from Bohaiwan basin, China, were processed to 4–8?mm. Then the simulation experiments for the CO2 injection were conducted for 10 days at the burial depth of 1500?m under in-situ reservoir conditions. The conclusions were obtained based on the changes of minerals, elemental concentrations and pore structure parameters of coal before and after the reaction. Different minerals underwent various geochemical reactions and mechanisms after CO2 injection. These geochemical reactions can transform the reservoir structure, which was mainly reflected in the connection of pores and fissures, and the blockage on the pore throat. The reactions between carbonate minerals and the CO2 acid fluid were violent and quick, which can increase the volume of macropores and fractures. While the weak reactions of silicate minerals may affects the micropores in coal. The chlorite and feldspar could continuously react with the CO2 acid fluid, with the slow dissolution of potassium, sodium and silicon, which makes it possible to use these characteristics to monitor the geochemical reaction. Besides, the volumes of the micropores (1–2?nm) in the anthracite were significantly increased, making it a potential geological body for CCS.Zhang, K., Tontiwachwuthikul, P., Jia, N., Li, S., 2019. Four nanoscale-extended equations of state: Phase behaviour of confined fluids in shale reservoirs. Fuel 250, 88-97. this paper, the thermodynamic phase behaviour of pure and mixing nanoconfined fluids in shale reservoirs are studied. First, an analytical generalized equation of state (EOS) is developed by including the effects of pore radius and intermolecular interactions. Based on the generalized EOS, four extended cubic EOS are proposed and used to calculate the thermodynamic phase behaviour. The four extended cubic EOSs, the extended van der Waals (vdW), Redlich?Kwong (RK), Soave?Redlich?Kwong (SRK), and Peng?Robinson (PR) EOSs, are found to accurately predict the pressure–volume (P–V) diagrams of different systems in nanopores. More specifically, the extended RK (E-RK) EOS may fail to accurately calculate the phase behaviour at high temperatures and the extended PR (E-PR) EOS is more accurate for liquid phase pressure calculations. The overall calculated P–V diagrams for the pure components in nanopores from the extended EOS shift up and right relative to those of the bulk-phase case and the EOS only including the intermolecular interactions. Furthermore, as a physical meaningless phenomenon, the negative pressure state is completely avoided in the calculated P-V diagrams from the extended EOSs. Compared to the measured bubble-point pressure (Pb) for the four different confined mixing fluids, the E-vdW, E-RK, and E-SRK EOS provide accurate estimates of Pb with overall percentage average absolute deviations (AAD%) of 10.95%, 12.07%, and 9.37%, respectively. The proposed extended EOSs are capable to accurately predict the critical properties and their shifts in nanopores. A bottom limit for the continuous reduction of the critical properties by decreasing the pore radius is obtained from the proposed extended EOSs, which is, for example, 5?nm for C8H18.Zhang, R.-w., Lu, J.-a., Wen, P.-f., Kuang, Z.-g., Zhang, B.-j., Xue, H., Xu, Y.-x., Chen, X., 2018. Distribution of gas hydrate reservoir in the first production test region of the Shenhu area, South China Sea. China Geology 1, 493-504. May and July of 2017, China Geological Survey (CGS), and Guangzhou Marine Geological Survey (GMGS) carried out a production test of gas hydrate in the Shenhu area of the South China Sea and acquired a breakthrough of two months continuous gas production and nearly 3.1 × 105 m3 of production. The gas hydrate reservoir in the Shenhu area of China, is mainly composed of fine-grained clay silt with low permeability, and very difficult for exploitation, which is very different from those discovered in the USA, and Canada (both are conglomerate), Japan (generally coarse sand) and India (fracture-filled gas hydrate). Based on 3D seismic data preserved-amplitude processing and fine imaging, combined with logging-while-drilling (LWD) and core analysis data, this paper discusses the identification and reservoir characterization of gas hydrate orebodies in the Shenhu production test area. We also describe the distribution characteristics of the gas hydrate deposits and provided reliable data support for the optimization of the production well location. Through BSR feature recognition, seismic attribute analysis, model based seismic inversion and gas hydrate reservoir characterization, this paper describes two relatively independent gas hydrate orebodies in the Shenhu area, which are distributed in the north-south strip and tend to be thicker in the middle and thinner at the edge. The effective thickness of one orebody is bigger but the distribution area is relatively small. The model calculation results show that the distribution area of the gas hydrate orebody controlled by W18/W19 is about 11.24 km2, with an average thickness of 19 m and a maximum thickness of 39 m, and the distribution area of the gas hydrate orebody controlled by W11/W17 is about 6.42 km2, with an average thickness of 26 m and a maximum thickness of 90 m.Zhang, S., Wang, P.-k., Zhu, Y.-h., Xiao, R., Pang, S.-j., 2018. New delineation of two favorable zones for gas hydrate in southern Qinghai and northern Tibet, China. China Geology 1, 304-305.. Objectives: Southern Qinghai-northern Tibet permafrost region is a place having the most widespread and most developed permafrost in China with good mineralization conditions and prospecting potentials for gas hydrate (Zhu YH et al., 2011). In 2011, China Geological Survey initiated a special national program entitled “Gas hydrate resource exploration and trial mining”, which signaled a prelude to a comprehensive gas hydrate survey in southern Qinghai-northern Tibet permafrost region. So far, appreciable progress has been made in the geological, geophysical, geochemical and drilling survey across a number of key blocks. This paper is intended to examine the fundamental conditions for gas hydrate mineralization based on previous findings, delineate favorable zones for gas hydrate mineralization, and to make contributions to the onshore gas hydrate resource exploration in China.2. Methods: After many years of practice, China has formed its own onshore gas hydrate survey methods characterized by a plane-line-point combination. The survey is based on hydrate accumulation system theory, focused on the main controlling factors of the accumulation, and supported by geological, geochemical, geophysical and drilling survey.3. Results: 1:50000 gas hydrate geological survey was conducted in key blocks across Shenglihe, Biluocuo, Yahu, Suonahu, Tumen and Tucuo, which are shown the stratigraphic sequences, established the preliminary stratigraphic frameworks and identified the structural features and styles. Regional geological surveys are able to shortlist favorable zones for gas hydrate, after block survey and integrated geochemical-geophysical survey to delineate favorable zones for gas hydrate.Ten gas hydrate test drilling wells were drilled in southern Qinghai-northern Tibet, which identified the strata lithology, permafrost thickness, geothermal gradient, source rocks and reservoir properties in the drill holes. In Yahu, QK-6 and QK-7 revealed the first high-pressure shallow gas. In Quemocuo, QK-8 was discovered good hydrocarbon gas signatures in the Upper Triassic Bagong, and Bolila Formations were detected with maximum total hydrocarbon (TG) of 5.349%. In Wuli, TK-2 and TK-3 were detected suspected CO2 type hydrate (Liu SQ et al., 2017). After preliminarily identifying the main controlling factors for the gas hydrate in southern Qinghai-northern Tibet on basis of “point” breakthroughs, two gas hydrate mineralization models were established for the “Qilianshan style” fault system and mud volcano system. On the basis of the two gas hydrate mineralization models, two main favorable zones were delineated in the Qiangtang Basin (Fig. 1): One is a favorable zone for gas hydrate enrichment in eastern Qiangtang, for example, the Yahu–Quemocuo–Maqu–Tuotuohe gas hydrate mineralization zone. The other is a favorable zone for mud volcano escape and accumulation in western Qiangtang.4. Conclusions: The southern Qinghai-northern Tibetan region is a place having the best onshore gas hydrate mineralization conditions and prospecting potentials in China. Establishment of the gas hydrate mineralization models and delineation of the favorable zones provide basis for subsequent work deployment and will definitely contribute to the onshore gas hydrate resource survey and evaluation in China.Zhang, S., Wang, X., Wang, H., Bjerrum, C.J., Hammarlund, E.U., Haxen, E.R., Wen, H., Ye, Y., Canfield, D.E., 2019. Paleoenvironmental proxies and what the Xiamaling Formation tells us about the mid-Proterozoic ocean. Geobiology 17, 225-246. Mesoproterozoic Era (1,600–1,000 million years ago, Ma) geochemical record is sparse, but, nevertheless, critical in untangling relationships between the evolution of eukaryotic ecosystems and the evolution of Earth‐surface chemistry. The ca. 1,400 Ma Xiamaling Formation has experienced only very low‐grade thermal maturity and has emerged as a promising geochemical archive informing on the interplay between climate, ecosystem organization, and the chemistry of the atmosphere and oceans. Indeed, the geochemical record of portions of the Xiamaling Formation has been used to place minimum constraints on concentrations of atmospheric oxygen as well as possible influences of climate and climate change on water chemistry and sedimentation dynamics. A recent study has argued, however, that some portions of the Xiamaling Formation deposited in a highly restricted environment with only limited value as a geochemical archive. In this contribution, we fully explore these arguments as well as the underlying assumptions surrounding the use of many proxies used for paleo‐environmental reconstructions. In doing so, we pay particular attention to deep‐water oxygen‐minimum zone environments and show that these generate unique geochemical signals that have been underappreciated. These signals, however, are compatible with the geochemical record of those parts of the Xiamaling Formation interpreted as most restricted. Overall, we conclude that the Xiamaling Formation was most likely open to the global ocean throughout its depositional history. More broadly, we show that proper paleo‐environmental reconstructions require an understanding of the biogeochemical signals generated in all relevant modern analogue depositional environments. We also evaluate new data on the δ98Mo of Xiamaling Formation shales, revealing possible unknown pathways of molybdenum sequestration into sediments and concluding, finally, that seawater at that time likely had a δ98Mo value of about 1.1‰.Zhang, W., Gu, J., Li, Y., Lin, L., Wang, P., Wang, C., Qian, B., Wang, H., Niu, L., Wang, L., Zhang, H., Gao, Y., Zhu, M., Fang, S., 2019. New insights into sediment transport in interconnected river–lake systems through tracing microorganisms. Environmental Science & Technology 53, 4099-4108. growing awareness of the wider environmental significance of diffuse sediment pollution in interconnected river–lake systems has generated the need for reliable provenance information. Owing to their insufficient ability to distinguish between multiple sources, common sediment source apportionment methods would rarely be a practical solution. On the basis of the inseparable relationships between sediment and adsorbed microorganisms, community-based microbial source tracking may be a novel method of identifying dominant sediment sources in the era of high-throughput sequencing. Dongting Lake was selected as a study area as it receives considerable sediment import from its inflowing rivers during the flood season. This study was conducted to characterize the bacterial community composition of sediment samples from the inflow-river estuaries and quantify their sediment microbe contributions to the central lake. Metagenomic analysis revealed that the community compositions of source sediment samples were significantly different, allowing specific sources to be identified with the machine learning classification program SourceTracker. A modified analysis using SourceTracker found that the major contributors to three major lake districts were the Songzi, Zishui, and Xinqiang Rivers. The impacts of hydrodynamic conditions on source apportionment were further verified and suggested the practicability of this method to offer a systematic and comprehensive understanding of sediment sources, pathways, and transport dynamics. Finally, a novel framework for sediment source-tracking was established to develop effective sediment management and control strategies in river–lake systems.Zhang, W., Que, Z., Gao, M., Lü, C., Huang, C., Huang, D., Xie, Z., 2019. Geochemical characteristics and sedimentary environment evolution of the carbonaceous-siliceous mudstone of the Guanyintang Formation of the Lower Cambrian, northwestern Jiangxi Province. Acta Sedimentologica Sinica 37, 278-291. black rock series of the Lower Cambrian in northwestern Jiangxi is an important source of uranium and other metals. The carbonaceous-siliceous mudstone of the Guanyintang Formation is a typical black rock type. This study of the element geochemistry and paleoenvironmental evolution characteristics of the carbonaceous-siliceous mudstone shows that the clay mineral content of the rock is 55%-59%, with average contents of SiO2 69.47%; Al2O3 11.39%; Fe2O3 3.32%; K2O 2.76%; MgO 1.57%; and TOC 5.82%. The chemical composition is characterized by high silicon, low aluminum, low potassium and low magnesium. It is rich in carbon. Comparison with the argillaceous rocks in eastern China shows that this carbonaceous-siliceous mudstone is relatively enriched in Ni, V, U, Ba, Cd, In, Tl, Se, W, Mo, Cu, Zn, Au, Ag, As, Sb and so on. From the upper to lower levels, SiO2, Na2O, Ni and Mo content increases gradually, and Al2O3, K2O, TiO2, H2O, LOI, Cr, Th, Ba, Ga, Li, Be, Rb, Sc, Sn, Bi, Cu, Pb, Zn, Ag and REE decrease gradually. The discriminant parameters or diagrams of the major or trace elements show that the source of the sedimentary material was terrigenous clastic rocks in a stable deep-water reducing environment and a low deposition rate. From early to late, the weathering effect of the source area has gradually been enhanced, the climate is becoming wetter, and the water in the basin is becoming increasingly desalinized.Zhang, X., Lin, B., Zhu, C., Yan, F., Liu, T., Liu, T., Li, Y., 2019. Petrophysical variation of coal treated by cyclic high-voltage electrical pulse for coalbed methane recovery. Journal of Petroleum Science and Engineering 178, 795-804. experiments and field application of high-voltage electrical pulse (HVEP) technology, a good method for coalbed methane (CBM) enhancement, have achieved great progress. However, previous studies mainly concentrated on the crushing effect of a single pulse on coal, ignoring the influence of multiple cyclic electrical pulses on the pore structure. Besides, the current in electrical breakdown was rarely studied. In this study, the effect of cyclic number on pore variation was investigated, and the mechanism of electrical breakdown was discussed by measuring the current waveform. Moreover, the micro fissure and pore variations of coal before and after electrical breakdown were measured by adopting scanning electron microscopy (SEM) and low temperature liquid nitrogen adsorption (LT-N2A). Under the action of cyclic HVEP, both Linhua (LH) anthracite coal and Hongliu (HL) bituminous coal can be crushed into small pieces. SEM results indicate that the number of cracks increase with the number of cycle. LT-N2A analyses show that the cumulative pore volumes and surface areas of LH and HL coals both increase after electrical breakdown, so does the pore structure fractal dimension, which provides a smoother channel for CBM desorption. Additionally, the great energy instantly injected into the coal could produce huge expansion stress and immediately break the coal from inside. Current waveforms during the breakdown demonstrate that the peak current increase with the number of cycle, whereas the breakdown time decrease with it. This indicates the alteration of electrical properties of coal during the breakdown, which affects the next discharge.Zhang, Y.-g., Chen, J.-w., Liang, J., Ou, G., Wu, D., 2018. Evidence of the existence of paleo reservoirs in Laoshan Uplift of the South Yellow Sea Basin. China Geology 1, 566-567.. Objectives: The study of the paleo-reservoir is of great significance for oil and gas exploration. Firstly, the existence of paleo-reservoirs can reflect there has been hydrocarbon accumulation process in this area, where there once was the advantageous condition with source-reservoir-cap combination; secondly, it can indicate that this area has certain resource potential. The purpose of this research is: through the study of the paleo-reservoir of CSDP-2 well in the Laoshan uplift of the South Yellow Sea Basin, which is a scientific investigation well, it can provide geological basis for marine oil and gas exploration of the Mesozoic and Paleozoic in the Laoshan uplift of the South Yellow Sea Basin, and at the same time can provide important information for future exploration target selection.2. Methods: In this study, CSDP-2 well in the Laoshan uplift of the South Yellow Sea Basin was taken as the research object. On the basis of detailed core observation and comprehensive analysis of logging data, a series of analyses of rock fluorescence slice identification, fluid inclusion observation and identification and inclusion composition were carried out for the core samples in key strata, and the evidence of paleo-reservoir existence for CSDP-2 well was clarified.3. Results: At present, there is only one well (CSDP-2, the scientific investigation well) in the Laoshan uplift, which is located in the west of the Laoshan uplift where faults are relatively developed. From Silurian to Lower Triassic, there has been an oil and gas show of the CSDP-2 well with different degrees, which reflect the hydrocarbon accumulation process in this area. Studies have indicated that there is evidence for the Paleo-reservoir existence of a CSDP-2 well in a different formation (Silurian, Carboniferous and Permian) and different lithologies (sandstone, limestone and dolomite), including good oil and gas shows from logging and a lot of asphalt and inclusions in the reservoir.3.1. Good oil and gas show from loggingFrom the logging data of the CSDP-2 well, fluorescence can be observed in sandstone, limestone and dolomite of Silurian, Carboniferous and Permian, oil spot regional, especially the crude oil seepage along the calcite vein of sandstone was observed in the Dalong Formation (Fm.) of Permian in depth of 885 m, and the brownish yellow oil spot and immersion in the Longtan Fm. of in depth of 1294–1296 m. There have been the obvious anomalies from gas logging in four reservoir sections of the CSDP-2 well, which are upper dolomite segments of the Lower Silurian (2666.61 –2674.12 m), the central sandstone segment of the Fentou-Maoshan Fm. of the Upper and Middle Silurian (2612–2622 m), limestone segment of the Chuanshan Fm. of the Upper Carboniferous and lower sandstone segment of the Longtan Fm. of the Upper Permian (1533 –1563 m). The gas of logging was mainly methane, with a gas logging value of 0.6%–6%, and a background value of gas logging of 0.3% –0.5%. The gas logging value of dolomite and limestone reservoir is obviously higher than that in the sandstone reservoir, the main reason is that pore, vug and fracture are relatively developed in dolomite and limestone reservoir, especially for the upper dolomite reservoir of the Lower Silurian.3.2. Large amount of asphalt existing in the reservoirMicroscopic identification showed that a large number of black and dark brown solid asphalts were filled in different formations of the CSDP-2 well (Silurian, Carboniferous and Permian) and different lithologies (sandstone, limestone and dolomite), no fluorescence showing, which state there has been a process of hydrocarbon filling and reservoir forming on a relatively large scale in this region. The occurrence of asphalt is characterized with filling in the sandstone intergranular pore in the Fentou-Maoshan Fm. of Silurian and the Longtan-Dalong Fm. of Permian, secondly filling in the micro-fracture, while in the upper dolomite reservoir of the Lower Silurian and limestone reservoir of the Chuanshan Fm. of the Upper Carboniferous, with filling in dolomite and limestone fracture, calcite vein intergranular fracture and solution pores.3.3. A large number of oil and gas inclusions in the reservoirThrough the observation and identification of fluid inclusions in the reservoirs of Silurian, Carboniferous and Permian, it is found that there are a large number of oil and gas inclusions in the sandstone, limestone and dolomite reservoirs (Fig. 1). Comparative analysis indicated that the abundance of oil and gas inclusions is too high in general, which is extremely high in the sandstone reservoir of the Upper-Middle Silurian, and GOI is 45%–85%, secondly in sandstone of the Longtan-Dalong Fm. of Permian, and GOI is 10%–50%. While the abundance of oil and gas inclusions in dolomite of the Lower Silurian and limestone of the Upper Carboniferous is relatively lower than that in the sandstone reservoir, and their GOI are 3%–20% and 1%–5% respectively. The liquid hydrocarbons in the inclusions are mainly transparent and colorless, and some are light brown-yellow, light gray-yellow, light-yellow, showing light blue-blue fluorescence, or no fluorescence (Fig. 1). which is a light oil containing inclusion. The gaseous hydrocarbons in the inclusions are mainly gray, showing no fluorescence (Fig. 1). The result of micro-Raman testing shows that the main components of gas inclusions in diagenetic minerals is methane, which can reflect the existence of the enrichment and reservoir forming with large scale for CH4 hydrocarbon gas in this region.4. Conclusions: (i) The existence of multi-set paleo-reservoirs in the marine of the Middle-Paleozoic of the Laoshan uplift of the South Yellow Sea Basin which reflects the hydrocarbon accumulation process in large-scale, which can prove sufficiently there is a good prospect for petroleum exploration in the marine Mesozoic-Paleozoic in the Laoshan uplift of the South Yellow Sea Basin.(ii) The stable construction zone is a favorable target for exploration in the Laoshan uplift of the South Yellow Sea Basin in the marine Mesozoic-Paleozoic, where it is possible to obtain oil and gas breakthroughs.Zhang, Y., Goll, D., Bastos, A., Balkanski, Y., Boucher, O., Cescatti, A., Collier, M., Gasser, T., Ghattas, J., Li, L., Piao, S., Viovy, N., Zhu, D., Ciais, P., 2019. Increased global land carbon sink due to aerosol-induced cooling. Global Biogeochemical Cycles 33, 439-457. aerosols have contributed to historical climate change through their interactions with radiation and clouds. In turn, climate change due to aerosols has impacted the C cycle. Here we use a set of offline simulations made with the Organising Carbon and Hydrology In Dynamic Ecosystems (ORCHIDEE) land surface model driven by bias‐corrected climate fields from simulations of three Coupled Model Intercomparison Project Phase 5 (CMIP5) Earth system models (ESMs; IPSL‐CM5A‐LR, CSIRO‐Mk3.6.0, and GISS‐E2‐R) to quantify the climate‐related impacts of aerosols on land carbon fluxes during 1860–2005. We found that climate change from anthropogenic aerosols (CCAA) globally cooled the climate, and increased land carbon storage, or cumulative net biome production (NBP), by 11.6–41.8 PgC between 1860 and 2005. The increase in NBP from CCAA mainly occurs in the tropics and northern midlatitudes, primarily due to aerosol‐induced cooling. At high latitudes, cooling caused stronger decrease in gross primary production (GPP) than in total ecosystem respiration (TER), leading to lower NBP. At midlatitudes, cooling‐induced decrease in TER is stronger than that of GPP, resulting in NBP increase. At low latitudes, NBP was also enhanced due to the cooling‐induced GPP increase, but precipitation decline from CCAA may negate the effect of temperature. The three ESMs show large divergence in low‐latitude CCAA precipitation response to aerosols, which results in considerable uncertainties in regional estimations of CCAA effects on carbon fluxes. Our results suggest that better understanding and simulation of how anthropogenic aerosols affect precipitation in ESMs is required for a more accurate attribution of aerosol effects on the terrestrial carbon cycle.Zhao, J.-Z., Li, J., Wu, W.-T., Cao, Q., Bai, Y.-B., Er, C., 2019. The petroleum system: a new classification scheme based on reservoir qualities. Petroleum Science 16, 229-251. new classification of petroleum systems (PSs) based on reservoir qualities is proposed. We classify PSs into the following three basic types: (1) source-rock petroleum system (SPS); (2) tight-reservoir or tight petroleum system (TPS); and (3) conventional-reservoir or conventional petroleum system (CPS). The CPS is a PS in which hydrocarbons accumulate in conventional reservoirs, and all the essential elements and processes are significant and indispensable. Oil and gas accumulations are geographically discrete and therefore exist as discontinuous accumulations. The TPS is a PS where hydrocarbons accumulate in tight reservoirs and the source rock, reservoir, seal, migration, and trap are also indispensable, but the traps are mostly non-anticlinal and the accumulations are primarily quasi-continuous and secondarily discontinuous. The SPS is a PS where both hydrocarbon generation and accumulation occurred in source rocks and traps and migration are unnecessary or inconsequential; the hydrocarbon distribution is extensive and continuous and has no distinct boundaries. The aforementioned three PSs can be derived from a common hydrocarbon source kitchen and are closely linked in terms of their formation and distribution. Therefore, to maximize the exploration efficiency, a comprehensive study and different strategies are needed by considering the SPS, TPS, and CPS as parts of a greater whole.Zhao, S., Li, Y., Min, H., Yu, Q., Wang, Z., Deng, T., Liu, H., Chen, J., 2019. Mechanisms controlling organic matter enrichment in the Lower Silurian Longmaxi Formation black shale unit, southwestern margin of the Yangtze Platform, China. Arabian Journal of Geosciences 12, 252. Lower Silurian Longmaxi Formation black shale unit at the southwestern margin of the Yangtze Platform has a great potential to contain shale gas. Based on the geochemical and microscopic characteristics of the Longmaxi Formation black shale unit, the depositional environment and the characteristics of the silica in the black shale were analyzed. The mechanism whereby the Longmaxi Formation black shale unit in the study area was enriched in organic matter is discussed from the perspective of upwelling and sea-level change. The conclusions of the research are as follows: (1) The shale in the Gesala section with a total organic carbon (TOC) content greater than 2% is approximately 55?m thick, which is favorable for shale gas accumulation in the study area. (2) The Longmaxi Formation black shale unit was deposited in an anoxic marine environment. Marine primary productivity was high during the deposition of the Longmaxi Formation black shale unit. (3) The Longmaxi Formation black shale unit is rich in biogenic silica due to the development of ocean upwelling. (4) Upwelling and sea-level rise jointly controlled the enrichment of organic matter in the Longmaxi Formation black shale unit. The upwelling supplied nutrients and promoted biological reproduction, which promoted marine primary productivity. The higher productivity also contributed to the formation of an anoxic environment in the bottom seawater. The sea-level rise was favorable for the formation of a reducing deep-water environment and deposition of fine-grained sediments, which was beneficial to the preservation of organic matter.Zhao, X.-m., Song, F.-y., Deng, J., Rao, Z., Wen, Z.-g., Hu, D.-g., Yi, L., Liu, C., 2018. New indications of gas hydrate in the northeastern China permafrost zone. China Geology 1, 308-309.. Objectives: The Mohe Basin in Heilongjiang, China has a NEE thrust nappe belt, which was assembled by the root zone, middle thrust zone and thrust front, north-south and north-east normal faults with three tectonic activities of the Middle Jurassic to Eocene, the Miocene, and the Early to Middle Pleistocene. The middle thrust zone and thrust front has a large number of folds, thrust faults, fractures and glutenites, which are the major structures of gas hydrate accumulation in the Mohe Basin.A survey of gas hydrates in the northeastern permafrost areas is mainly focused on the Mohe Basin, which covers approximately 2.13×104 km. The survey area is located at the northern end of the Greater Khingan Mountains in China with well developed permafrost. The majority of the Mohe Basin was filled with roughly 6 km thickness of the Middle Jurassic clastic formations with river-lake facies, from the bottom to the top including Xiufeng Formation, Ershierzhan Formation, Mohe Formation, and Kaikukang Formation, respectively. All the formations are the target zone of gas hydrate survey in the Mohe Basin.In this research, a comprehensive analysis of the surveying data of gas hydrate in the Mohe permafrost are carried out to examine the details of gas hydrate accumulation in this area, such as the permafrost thickness, gas source rocks, hydrocarbons, and the gas hydrate controlling structures and so on.2. Methods: Methods for natural gas hydrate surveys in the Mohe basin are used as following: surface geology surveys; audio magnetotelluric methods (AMT); direct current sounding; reflection seismic methods; surface geochemical surveys; drilling; and gas logging, and so on. With these methods, five shallow geological wells of gas hydrate were implemented. Except Well MK-2, with a well depth of approximately 2300 m, and Well MK-1, with a well depth of approximately 500 m, the other three wells were mainly in the 1000 m depth range (Table 1).3. ResultsDark mudstone is highly developed in the Ershierzhan and Mohe Formations, in which the Mohe Formation contains more than 300 m of dark mudstones and the Ershierzhan Formation includes almost 100 m of dark mudstones (Table 1). This presents very rich gas source rock, and a major potential for the generation of the hydrocarbon gas.The drilling results in recent years indicated that the mudstone, sandstone, and fracture zones in the Mohe basin contain considerable amounts of gases. This basin has approximately 0.14 –307.55 mL/L, with an average of 36.62 mL/L of gases, in which methane are commonly 93.2% to 100%, ethane and other heavy hydrocarbon are about 0 to 6%. These hydrocarbon gases can be used for the potential gas hydrate formation in the Mohe permafrost.The Mohe Basin has been determined to be located in a consecutive permafrost zone. As indicated in the latest survey results, the permafrost in the Mohe Basin is generally 60 m to 80 m thick (Zhao XM et al., 2011), with a maximum thickness of 100 m (Fig. 1). It is not only fairly equal to the Qilian Mountains, where gas hydrates have been found, but also similar to the Yamal Peninsula in Siberia, which is speculated to have a large distribution of potential gas hydrates (Chuvilin EM et al., 1998; Yakushev VS et al., 2000), which can satisfy the basic requirement of gas hydrate formation in the Mohe permafrost.4. Conclusion: Although gas hydrate has not been discovered in the Mohe permafrost so far, it is certain that there were the conditions for gas hydrate formation and accumulation potentials. Further, the Ershibazhan and the Longhe Forest Farms, Wusuli Ford, and their surrounding areas in the middle Mohe Basin are the better target plays for the explorations of gas hydrate in the Mohe Permafrost.Zhao, Z., Cao, Y., Fan, Y., Yang, H., Feng, X., Li, L., Zhang, H., Xing, L., Zhao, M., 2019. Ladderane records over the last century in the East China sea: Proxies for anammox and eutrophication changes. Water Research 156, 297-304. ammonium oxidation (anammox), an important process for converting fixed nitrogen to N2, plays an important role in the present-day marine nitrogen cycle. However, little is known about anammox activities in the past, especially in regions that were strongly affected by human activities, evidenced by eutrophication and hypoxia, which promote anammox bacteria growth. In this study, ladderanes have been measured in a sediment core and suspended particulate matter (SPM) in the East China Sea (ECS), to reconstruct the anammox record and to evaluate its responses to eutrophication and hypoxia. The detection and distribution of different ladderane lipids in SPM provide additional evidence that ladderanes were mostly produced in the water column and could reflect anammox activities. Summed ladderane content from the core varied between 11 and 300?ng/g dry weight (dw) sediment, with C20-[5]-ladderane fatty acid methyl esters (FAME) as the predominant compound (5–150?ng/g dw), followed by C20-[3]-ladderane FAME (1–110?ng/g dw), C18-[3]-ladderane FAME (1–32?ng/g dw) and C18 -[5]-ladderane FAME (3–11?ng/g dw). The detection of ladderanes over the last century indicate the existence of anammox in the past. The rapidly increasing trend of ladderanes since the 1960s correlates with an increase in phytoplankton biomarkers (Σ(B?+?D?+?A), brassicasterol (B), dinosterol (D) and C37 alkenones (A)), indicating that eutrophication exacerbated anammox growth. The co-variation between our ladderane record and published records of low-oxygen tolerant foraminiferal microfossils and hypoxia events over the past 60 years suggested that sediment ladderanes are a useful indicator for past changes of oxygen depletion or hypoxia in the ECS.Zheng, D., Wang, W., Reza, Z., 2019. Integrated pore-scale characterization of mercury injection/imbibition and isothermal adsorption/desorption experiments using dendroidal model for shales. Journal of Petroleum Science and Engineering 178, 751-765. from conventional reservoirs, shale formations have limited pore connectivity and unique pore spatial-distributions. Consequently, theoretical pore-network models developed for conventional formations are not representative of the pore topology within unconventional rocks. This paper presents a theoretical pore-network model, dendroidal model, based on the analysis of reconstructed pore-scale model extracted from Scanning Electron Microscope images. Dendroidal model is a semi-acyclic model, which characterizes the poor connectivity of void space without sacrificing the interaction between main flow paths. Dendroidal model infers pore-body distribution based on the hysteresis effect of isothermal adsorption/desorption measurements and characterizes pore-throat distribution using mercury injection capillary pressure data. The use of dual-compressibility model in pore-network model construction eliminates the effect of compressibility of both void space and matrix. Total organic carbon (TOC) content and minerology determine the composition of pore bodies and pore throats. The difference in mercury intrusion and extraction caused by trapping hysteresis and contact-angle hysteresis affects the stochastically distributed parameters, including pore-throat length, pore-throat cross-sectional morphology, coordination number and pore-body spatial distribution. We used shale core samples from Marcellus and Wolfcamp formations to validate the dendroidal models by calculating the absolute permeability without slippage effect. This newly developed pore-network model integrates aforementioned seven distinct types of experimental data to capture the realistic pore structures within shales.Zheng, M., Liu, T., Gao, Z., Wu, J., Jiang, G., Li, Q., Li, Z., Xie, L., 2019. Simulation of natural gas hydrate formation skeleton with the mathematical model for the calculation of macro-micro parameters. Journal of Petroleum Science and Engineering 178, 429-438. quantitative relationship among the four process parameters (bentonite, binders, pressure, and time) of artificial core preparation, two macroscopic physical parameters (permeability and porosity), and three microscopic pore parameters (average pore and throat diameters and pore throat ratio) are investigated through multiple sets of experiments. Further, this research considers the natural gas hydrate formation skeleton in the Mount Elbert Well on Alaska North Slope as the simulated object. The optimal artificial core formula with permeability and porosity similar to the in situ hydrate formation skeleton was optimized by an orthogonal test, the fitting function relationships among these three aspects were obtained, and a relationship model was established.The results demonstrated that the permeability and porosity of the optimal formula are extremely close to the natural formation skeleton, and the microscopic pore morphology is similar to that of the natural cores. The established relationship model can be used to accurately estimate the permeability, porosity, and pore and throat diameters using the four process parameters; in turn, the process parameters also can be estimated. The digital simulation preparation technology of the natural gas hydrate formation skeleton developed in this work can accurately and quickly estimate the macro-micro physical parameters of the artificial hydrate formation skeleton. Further, it can also prepare 60-cm-long cores that can be used in the subsequent experimental study of the physical property response in hydrate formation drilling, playing an important role for the simulation of natural formation skeletons.Zheng, Y., Harwood, C.S., 2019. Influence of energy and electron availability on in vivo methane and hydrogen production by a variant molybdenum nitrogenase. Applied and Environmental Microbiology 85, Article e02671-02618.: The anoxygenic phototrophic bacterium Rhodopseudomonas palustris produces methane (CH4) from carbon dioxide (CO2) and hydrogen (H2) from protons (H+) when it expresses a variant form of molybdenum (Mo) nitrogenase that has two amino acid substitutions near its active site. We examined the influence of light energy and electron availability on in vivo production of these biofuels. Nitrogenase activity requires large amounts of ATP, and cells exposed to increasing light intensities produced increasing amounts of CH4 and H2. As expected for a phototroph, intracellular ATP increased with increasing light intensity, but there was only a loose correlation between ATP content and CH4 and H2 production. There was a much stronger correlation between decreased intracellular ADP and increased gas production with increased light intensity, suggesting that the rate-limiting step for CH4 and H2 production by R. palustris is inhibition of nitrogenase by ADP. Increasing the amounts of electrons available to nitrogenase by providing cells with organic alcohols, using nongrowing cells, blocking electrons from entering the Calvin cycle, or blocking H2 uptake resulted in higher yields of H2 and, in some cases, CH4. Our results provide a more complete understanding of the constraints on nitrogenase-based production of biofuels.Importance: A variant form of Mo nitrogenase catalyzes the conversion of CO2 and protons to the biofuels CH4 and H2. A constant supply of electrons and ATP is needed to drive these reduction reactions. The bacterium R. palustris generates ATP from light and has a versatile metabolism that makes it ideal for manipulating electron availability intracellularly. We therefore explored its potential as a biocatalyst for CH4 and H2 production. We found that intracellular ADP had a major effect on biofuel production, more pronounced than the effect caused by ATP. This is probably due to inhibition of nitrogenase activity by ADP. In general, the amount of CH4 produced by the variant nitrogenase in vivo was affected by electron availability much less than was the amount of H2 produced. This study shows the nature of constraints on in vivo biofuel production by variant Mo nitrogenase.Zhong, C., Qin, Q., Fan, C., Hu, D., 2019. Effect of nanometer pore structure on methane adsorption capacity in organic-rich shale. Petroleum Science and Technology 37, 1243-1250. marine organic-rich shale of the Longmaxi Formation in the Dingshan area, southeast Sichuan, was studied using scanning electron microscopy (SEM), nitrogen adsorption/desorption and methane isothermal adsorption, mainly emphasizing the nanometer pore structure of organic matter (OM) and its effect on methane adsorption. The results show that the organic-rich shale with high total organic carbon (TOC) content in the high mature stage mainly develops a large number of inkbottle-shaped pores with sizes of 3-50?nm, which provide more effective adsorption sites and storage space for methane adsorption and enhance the adsorption ability of methane.Zhong, C., Qin, Q., Fan, C., Hu, D., 2019. Geochemical characteristics of shale gas and its response to thermal maturity (Ro) in the Longmaxi formation, Dingshan area, Southeast Sichuan. Petroleum Science and Technology 37, 1270-1278. composition and carbon isotope distribution of shale gas from the Longmaxi Formation in the Dingshan area were measured, and their responses to thermal maturity (Ro) were analyzed. The results show that the shale gas is mainly composed of methane (97.98–98.99%), ethane, propane and nonhydrocarbon gases (N2 and CO2) and is an organic high temperature oil-type cracked gas. The wetness value [(C2+C3)/(C1+C2+C3) × 100%] ranges from 0.39% to 0.74%. The early (Ro > 1.3%) residual kerogen and crude oil cracking gas was mixed with the late (Ro > 2.0%) secondary cracking gas, resulting in the full inversion of the carbon isotope sequence (δ13C1?>?δ13C2?>?δ13C3).Zhong, S., Wan, Z., Duan, B., Liu, D., Luo, B., 2019. Do earthquakes trigger mud volcanoes? A case study from the southern margin of the Junggar Basin, NW China. Geological Journal 54, 1223-1237. volcanoes are significant indicators of neotectonic activity and have important research significance. Mud volcanoes can not only be used as an important index for the long-term evaluation of oil and gas fields but are also an important symbol for locating gas hydrates in the seabed. Additionally, the eruption of mud volcanoes will affect drilling, pipe laying, and other projects, and the eruption of large amounts of methane gas can also cause greenhouse effects and climate change. The trigger mechanisms of mud volcanoes have always been a focus of debate among geologists. In recent years, many scholars have argued that mud volcanoes are triggered by earthquake activity. However, the stress and strain caused by earthquakes and their control mechanisms on the eruption of mud volcanoes still require further study. This paper is based on the calculated results of static stresses caused by the M5.5 Wusu earthquake of May 2, 1995, the M5.4 Shawan earthquake of January 9, 1996, the M5.3 Shihezi earthquake of February 14, 2003, and the M6.3 Xinyuan-Hejing earthquake of June 30, 2012, on the Horgos, Dushanzi, Aiqigou, and Baiyanggou mud volcanoes distributed in the southern margin of the Junggar Basin, NW China. The calculated static stresses, the earthquake response characteristics of these four groups of mud volcanoes, and the continuous observational data of the Horgos mud volcanoes showed that static stresses from these earthquakes did not reach the triggering threshold, though the mud volcanoes exhibited a good relationship with earthquakes. We speculate that static stress may not be the main triggering mechanism for the mud volcanoes and that the mechanisms of earthquake triggering may be divided into two types: (a) For a mud volcano in a critical state before an earthquake, dynamic stress changes may trigger eruption of the mud volcano by increasing permeability and mobilizing magma; (b) for mud volcanoes that have not yet reached the critical eruption state before an earthquake, both static and dynamic stresses play roles in their activities.Zhou, G., Wei, G., Hu, G., 2019. The catalytic effect of manganese carbonate on kerogen pyrolysis in the absence and presence of water. Petroleum Science and Technology 37, 1115-1122. investigate the effect of Mn ore on the chemical components and isotopic compositions of gas products during kerogen pyrolysis in the absence or presence of water, a series of pyrolysis experiments on Type-I kerogen with manganese carbonate and/or water were conducted in closed gold capsules at 325–600?°C for 72?h with 300?bar. The heavy hydrocarbon gas yields increased significantly over 450?°C due to the participation of manganese. As for isotopic compositions, the manganese catalysis caused a decrease in the 13CCH4 and an increase in the 13CC2H6 over 475?°C; the δD values of methane generated during anhydrous pyrolysis with manganese carbonate are much lower than those produced by the pyrolysis of kerogen alone. Furthermore, the δD values are the most negative during hydrous pyrolysis with manganese ore. In addition to the thermal decomposition of manganese carbonate to form carbon dioxide, water provides sources of hydrogen and oxygen to form H2 and CO2. Manganese carbonate inhibits the association of sulfur-free radicals to hydrogen to form H2S. The i-C4/n-C4 ratio for gas products was evidently higher due to the existence of manganese and water, they can enhance the carbocation mechanism.Zhou, J., Liu, M., Xian, X., Jiang, Y., Liu, Q., Wang, X., 2019. Measurements and modelling of CH4 and CO2 adsorption behaviors on shales: Implication for CO2 enhanced shale gas recovery. Fuel 251, 293-306. thorough study of the adsorption behavior of shales to methane (CH4) and carbon dioxide (CO2) is critical for carbon dioxide sequestration in shale gas reservoirs and enhanced shale gas recovery. This paper discusses the results of an adsorption study of CH4 and CO2, in single gas environment, on a set of shale samples taken from the Sichuan and Ordos Basins. The results indicated that shale exhibit higher affinity to CO2 as compared to CH4 under similar pressure and temperature conditions, and the preferential adsorption ratio of CO2 over CH4 varies between 1.66 and 8.32. Furthermore, the experimental data were modeled using Langmuir, Dubibin-Astakhov (D-A), Dubinin-Redushckevich (D-R) and Ono-Kondo models. The accuracy of the models in quantifying CH4 and CO2 adsorption on shale was compared using an error analysis technique. For CH4, both of Langmuir and D-A models performed satisfactorily with comparable accuracy. For subcritical CO2, the performance of the D-A model is the best. However, for supercritical CO2, Ono-Kondo model fitted the experimental data the best, which is the proposed model to use. The results of this study can provide the basis for the estimation of the CO2 sequestration capacity in shale formations.Zhou, Z., Bao, S.-j., Chen, X.-l., Yu, S.-f., Chen, K., Guo, T.-x., Xu, Q.-f., 2018. A discovery of Silurian tight shale gas in Jianshi, Hubei, China. China Geology 1, 160-161.. Objective: The study area is located in the north of Jianshi area, Hubei province. According to the geologic survey, the Silurian black shale in the area is characterized by high abundance of organic matter and high hydrocarbon potential. From 1980s, Jianghan Oilfield has drilled 7 wells in Jiannan gas field located in the south of study area, which showed different degree of oil and gas and revealed a good exploration prospect for the Silurian strata.The purpose of this study is to find out the stratigraphic prospecting of Silurian strata in northern Jianshi area, the characteristics of organic rich shale within Longmaxi Formation (S1l) obtain reservoir physical parameter of the Xintan Formation (S1x) tight sandstone, learn oil-gas reservoir-forming assemblages of this area, and provide data for evaluating potentials of shale gas and tight sandstone gas.2. Methods: Through geological field survey, sample collection and test analysis to the Silurian strata in northern Jianshi and its surrounding areas, and combined with regional tectonics and lithofacies palaeogeography, CGS oil & gas survey drilled geological survey well JD-1 in northern Jianshi area. The drilling depth of JD-1 is 1810 m, core length is 1784 m, and the whole well section is performed the logging.In order to obtain the abundance and type of shale organic matter, thermal maturity, gas bearing, reservoir porosity and permeability, core samples collected from the Longmaxi Formation, the Xintan Formation and the Luoreping Formation are analyzed on organic geochemistry and Reservoir physical property. The data mentioned above can combined with gas logging data to evaluate the potential of oil and gas resources in the study area.3. Results: JD-1 shows that the Silurian strata consists of the Shamao Formation, the Luoreping Formation, Xintan Formation and Longmaxi Formation. The Longmaxi Formation and overlying the Upper Ordovician Wufeng Formation (O3w) is composed of graptolite rich black shale, whose thickness is 43.7 m. The TOC content of shale is 0.2% to 11.24%, with the average value is 4.39%, in which the thickness of shale of TOC >2% is 25 m, mainly in the bottom of the Langmaxi formation and the Wufeng Formation (Fig. 1). The type of organic matter is I-II1 type, and the thermal maturity (Ro) is 2.5% to 2.9%, which means that it is in the early stage of over maturity, showing good hydrocarbon generation ability. The Xintan Formation is composed of deep gray argillaceous siltstone with porosity ranging from 5.6% to 11.24% and air permeability ranging from 0.0455 mD to 1.6712 mD, with an average value of 0.777 mD, which is a typical tight sandstone reservoir. The Luoreping formation and Shamao group is composed of thick layer of green-gray green mudstone with permeability generally lower than 10-6 mD. Based on the above, the Silurian strata in JD-1 wells drilling area developed the tight sandstone gas source reservoir caprock combinations, which is consist of Wufeng-Longmaxi Formation (source rock) - Xintan Formation (reservoir)-Luoreping Formation (caprock), with the Wufeng-Longmaxi Formation shale gas and Xintan Formation tight sandstone gas reservoir-forming assemblages.The gas logging abnormal is shown in the Silurian strata during JD-1 well drilling. The total gas logging hydrocarbon in 1190-1738 m well section of the Xintan Formation is more than 1% of thickness of 193 m, and more than 2% of thickness of 93 m (Fig. 1), which is interpreted as gas bearing reservoir. Gas logging total hydrocarbon and methane is increased from 0.09% to 21.5% and 0.087% to 19.89% with gas out of mud ignition success respectively when drilling to 1345 m deep gray argillaceous siltstone. This is the first acquisition of tight sandstone gas in the Silurian strata in the complex tectonic area of west Hubei to northeast Chongqing, which is expected to open a new area of oil and gas exploration and development in this area. Gas logging total hydrocarbon in 1738.55-1782.25 m well section of the Wufeng-Longmaxi Formation is 0.93% to 11.07%. The black shale is graptolite-bearing and the bubble is obvious when the core of the rock inundated. The field desorption gas content of 21 core samples is increased to 0.92 m3/t on average (without loss gas and residual gas). Drilling shows that the Silurian strata in north Jianshi area has the prospect of exploration and development for tight sandstone gas and shale gas.4. Conclusions: JD-1 well drilling in North Jianshi area shows that the Upper Ordovician Wufeng Formation organic-rich shale is characteristed by large thickness, high abundance of organic matter, moderate thermal maturity and good hydrocarbon generation ability, and the Xintan Formation is a typical tight sandstone reservoir. The source-reservoir-cap assemblages for Wufeng-Longmaxi Formation shale gas and Xintan Formation tight sandstone gas are existed in the Silurian strata.The Xintan Formation tight sandstone gas reservoir and the Wufeng-Longmaxi Formation shale gas reservoir in JD-1 well encountered good oil and gas shows, showing that the Silurian strata in North Jianshi area has the prospect of exploration and development for tight sandstone gas and shale gas.Zhu, X., Mao, S., Sun, Y., Jia, G., Wu, N., Yan, W., 2019. Long chain diol index (LDI) as a potential measure to estimate annual mean sea surface temperature in the northern South China Sea. Estuarine, Coastal and Shelf Science 221, 1-7. chain alkyl diols (LCDs) were studied to probe the ability of long chain diol index (LDI) as a sea surface temperature (SST) or temperature record at depth in the open northern South China Sea (SCS). The results showed that riverine LCDs, which may affect LDI-derived SSTs, was less significant due to the substantially low fractional abundance (generally?<?20% and averaged 10%) of 1,15-C32 diol in core sediments. The LDI-derived SSTs demonstrated a generally similar trend as SST records calculated from other proxies in nearby cores, suggesting that the LDI proxy can be a potential index to estimate ancient annual mean SST in the open northern SCS. The integration of novel data from the open sea with already published data in the coastal area would provide comprehensive information on the paleo-temperature evolution of the northern SCS.Zhu, Z., Tan, P., Yang, J., Ge, H., Liu, L., 2019. Mass spectrometric identification of adhesive utilized in a tian-tsui tiara of the mid-Qing Dynasty (1776–1839 CE) in the collection of the Tang Clan Folk Museum. Studies in Conservation 64, 187-192. study identified and interpreted an adhesive used in the making of a tiara of the mid-Qing Dynasty (1776-1839 CE), in the collection of the Tang Clan Folk Museum. By performance of mass spectrometry-based proteomics, a sample of adhesive residue was identified as bovine collagen proteins at the molecular level with high confidence. The result highlights the first example of accurate determination of the origin of the adhesive adopted in the tian-tsui craft, providing novel information and contributing to study of the significance, development, and exchange of tian-tsui craftsmanship.Zú?iga, D., Kaal, J., Villacieros-Robineau, N., Froján, M., Alonso-Pérez, F., De la Granda, F., Castro, C.G., 2019. Tracing sinking organic matter sources in the NW Iberian upwelling system (NE Atlantic Ocean): Comparison between elemental, isotopic and molecular indicators. Journal of Analytical and Applied Pyrolysis 139, 114-122. studied the seasonal fluctuations in the composition of sinking particulate organic matter (POM) in the only upwelling-affected continental margin of Europe, to improve our understanding of the carbon (C) cycle of such systems. The methods employed targeted the elemental, stable isotope (δ13Coc and δ15N) and molecular (Py-GC-MS) composition. The results showed that the sinking POM in this margin is predominantly of marine origin, with δ15N (5.2?±?0.3‰) and C/N (9.7?±?1.0) values similar to those of marine plankton, and high abundances of pyrolysis products with isoprenoid structures, N-containing products from proteins (indoles, cyanobenzenes, etc.), and N-acetylated polysaccharides (acetamide, acetamidofurans) from chitin and peptidoglycan. Furthermore, the dataset demonstrates seasonal differences in POM composition under different oceanographic scenarios: i) dominance of most N-compounds, fatty acids and isoprenoid products during highly productive upwelling seasons, and ii) an increase in the relative abundance of linear alkanes/alkenes, phenols, lignin and PAH reflecting terrestrial influence during downwelling periods. In addition, the detection of isoprenoid alkylthiophenes traces (compounds formed under reducing conditions in the sediment) point to resuspended sediment in the trap material due to hydrodynamic effects of currents and waves on the seafloor. The results show that analytical pyrolysis is a useful tool for identifying different types of autochthonous and terrestrial POM, and therefore identification of the sources of sinking POM. ................
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