Eaogorg.files.wordpress.com



GEOCHEMISTRY ARTICLES – October 2017?Analytical ChemistryChahen, L., Quoineaud, A.A., Proriol, D., Artero, S., Vidalie, M., Neyret-Martinez, F., Rivallan, M., 2017. Speciation of basic nitrogen compounds in gas oils and vacuum gas oils by derivatization with BF3 prior to NMR analysis. Energy & Fuels 31, 10752-10759.Ga?uszka, A., Migaszewski, Z.M., Namie?nik, J., 2017. The role of analytical chemistry in the study of the Anthropocene. TrAC Trends in Analytical Chemistry 97, 146-152.Rutkowska, M., Owczarek, K., Guardia, M.d.l., P?otka-Wasylka, J., Namie?nik, J., 2017. Application of additional factors supporting the microextraction process. TrAC Trends in Analytical Chemistry 97, 104-119.Ventura, M., Deus, W.B., Silva, J.R., Andrade, L.H.C., Catunda, T., Lima, S.M., 2018. Determination of the biodiesel content in diesel/biodiesel blends by using the near-near-infrared thermal lens spectroscopy. Fuel 212, 309-314.Gas Chromatography/GC×GC/GC-MSAbou-el-karam, S., Ratel, J., Kondjoyan, N., Truan, C., Engel, E., 2017. Marker discovery in volatolomics based on systematic alignment of GC-MS signals: Application to food authentication. Analytica Chimica Acta 991, 58-67.de Bar, M.W., Hopmans, E.C., Verweij, M., Dorhout, D.J.C., Damsté, J.S.S., Schouten, S., 2017. Development and comparison of chromatographic methods for the analysis of long chain diols and alkenones in biological materials and sediment. Journal of Chromatography A 1521, 150-160.Wang, F., Fan, X., Xia, J.-L., Wei, X.-Y., Yu, Y.-R., Zhao, Y.-P., Cao, J.-P., Zhao, W., Wang, R.-Y., 2018. Insight into the structural features of low-rank coals using comprehensive two dimensional gas chromatography/time-of-flight mass spectrometry. Fuel 212, 293-301.Imagining: AFM, SEM, TEM, HIMChan, P., Halfar, J., Norley, C.J.D., Pollmann, S.I., Adey, W., Holdsworth, D.W., 2017. Micro-computed tomography: Applications for high-resolution skeletal density determinations: An example using annually banded crustose coralline algae. Geochemistry, Geophysics, Geosystems 18, 3542-3553.Falk, N., Chaganti, S.R., Weisener, C.G., 2018. Evaluating the microbial community and gene regulation involved in crystallization kinetics of ZnS formation in reduced environments. Geochimica et Cosmochimica Acta 220, 201-216.Han, J., Chen, B., Zhao, X., Zheng, C., Zhang, J., 2017. Development characteristics and influential factors of organic pores in the Permian shale in the Lower Yangtze Region. Natural Gas Industry 37, 17-26.Li, T., Jiang, Z., Xu, C., Liu, B., Liu, G., Wang, P., Li, X., Chen, W., Ning, C., Wang, Z., 2017. Effect of pore structure on shale oil accumulation in the lower third member of the Shahejie formation, Zhanhua Sag, eastern China: Evidence from gas adsorption and nuclear magnetic resonance. Marine and Petroleum Geology 88, 932-949.Macías-Sánchez, E., Willinger, M.G., Pina, C.M., Checa, A.G., 2017. Transformation of ACC into aragonite and the origin of the nanogranular structure of nacre. Scientific Reports 7, Article 12728.Michelson, K., Sanford, R.A., Valocchi, A.J., Werth, C.J., 2017. Nanowires of Geobacter sulfurreducens require redox cofactors to reduce metals in pore spaces too small for cell passage. Environmental Science & Technology 51, 11660-11668.Neupane, B., Ju, Y., Silwal, B.R., Singh, P.K., Huang, C., 2017. Structural investigations of Eocene coals from foreland basin of central Nepal Himalaya. Energy Exploration & Exploitation 35, 713-733.Pawlak, R., Meier, T., Renaud, N., Kisiel, M., Hinaut, A., Glatzel, T., Sordes, D., Durand, C., Soe, W.-H., Baratoff, A., Joachim, C., Housecroft, C.E., Constable, E.C., Meyer, E., 2017. Design and characterization of an electrically powered single molecule on gold. ACS Nano 11, 9930-9940.Reimers, C.E., Li, C., Graw, M.F., Schrader, P.S., Wolf, M., 2017. The identification of cable bacteria attached to the anode of a benthic microbial fuel cell: Evidence of long distance extracellular electron transport to electrodes. Frontiers in Microbiology 8, 2055. doi: 2010.3389/fmicb.2017.02055.Shao, X., Liu, G., Yang, J., Xu, X., 2017. Research on the synthesis of ionic liquids/layered double hydroxides intercalation composites and their application on the removal of naphthenic acid from oil. Energy & Fuels 31, 10718-10726.Shao, X., Pang, X., Jiang, F., Li, L., Huyan, Y., Zheng, D., 2017. Reservoir characterization of tight sandstones using nuclear magnetic resonance and incremental pressure mercury injection experiments: Implication for tight sand gas reservoir quality. Energy & Fuels 31, 10420-10431.Sinn, C.J.A., Klaver, J., Fink, R., Jiang, M., Schmatz, J., Littke, R., Urai, J.L., 2017. Using BIB-SEM imaging for permeability prediction in heterogeneous shales. Geofluids 2017, Article 4709064.Ta, K., Peng, X., Chen, S., Xu, H., Li, J., Du, M., Hao, J., Lin, Y., 2017. Hydrothermal nontronite formation associated with microbes from low-temperature diffuse hydrothermal vents at the South Mid-Atlantic Ridge. Journal of Geophysical Research: Biogeosciences 122, 2375-2392.Vollnhals, F., Audinot, J.-N., Wirtz, T., Mercier-Bonin, M., Fourquaux, I., Schroeppel, B., Kraushaar, U., Lev-Ram, V., Ellisman, M.H., Eswara, S., 2017. Correlative microscopy combining secondary ion mass spectrometry and electron microscopy: Comparison of intensity–hue–saturation and Laplacian pyramid methods for image fusion. Analytical Chemistry 89, 10702-10710.Wang, L.L., Zhang, G.Q., Hallais, S., Tanguy, A., Yang, D.S., 2017. Swelling of shales: A multiscale experimental investigation. Energy & Fuels 31, 10442-10451.Xu, Q., Jiang, H., Ma, D., Chen, X., Huang, J., Shi, L., 2017. Pyrolysis of a low asphaltene crude oil under idealized in situ combustion conditions. Energy & Fuels 31, 10545-10554.Zhang, J., Li, X., Wei, Q., Sun, K., Zhang, G., Wang, F., 2017. Characterization of full-sized pore structure and fractal characteristics of marine–continental transitional Longtan Formation shale of Sichuan Basin, South China. Energy & Fuels 31, 10490-10504.Zheng, J., Wang, Z., Gong, W., Ju, Y., Wang, M., 2017. Characterization of nanopore morphology of shale and its effects on gas permeability. Journal of Natural Gas Science and Engineering 47, 83-90.Imagining: ?-Xray CTAgematsu, S., Uesugi, K., Sano, H., Sashida, K., 2017. Reconstruction of the multielement apparatus of the earliest Triassic conodont, Hindeodus parvus, using synchrotron radiation X-ray micro-tomography. Journal of Paleontology 91, 1220.Baveye, P.C., Pot, V., Garnier, P., 2017. Accounting for sub-resolution pores in models of water and solute transport in soils based on computed tomography images: Are we there yet? Journal of Hydrology 555, 253-256.Chan, P., Halfar, J., Norley, C.J.D., Pollmann, S.I., Adey, W., Holdsworth, D.W., 2017. Micro-computed tomography: Applications for high-resolution skeletal density determinations: An example using annually banded crustose coralline algae. Geochemistry, Geophysics, Geosystems 18, 3542-3553.de Winter, N.J., Vellekoop, J., Vorsselmans, R., Golreihan, A., Soete, J., Petersen, S.V., Meyer, K.W., Casadio, S., Speijer, R.P., Claeys, P., 2017. An assessment of latest Cretaceous Pycnodonte vesicularis (Lamarck, 1806) shells as records for palaeoseasonality: A multi-proxy investigation. Climate of the Past Discussions 2017, 1-36.Feng, X., Zeng, J., Ma, Y., Jia, K., Qiao, J., Zhang, Y., Feng, S., 2017. Asphaltene deposition preference and permeability reduction mechanisms in oil reservoirs: Evidence from combining X-ray microtomography with fluorescence microscopy. Energy & Fuels 31, 10467-10478.Geng, Y., Liang, W., Liu, J., Cao, M., Kang, Z., 2017. Evolution of pore and fracture structure of oil shale under high temperature and high pressure. Energy & Fuels 31, 10404-10413.Guo, T., Li, Y., Ding, Y., Qu, Z., Gai, N., Rui, Z., 2017. Evaluation of acid fracturing treatments in shale formation. Energy & Fuels 31, 10479-10489.Hosseini-Nasab, S.M., Zitha, P.L.J., 2017. Investigation of chemical-foam design as a novel approach toward immiscible foam flooding for enhanced oil recovery. Energy & Fuels 31, 10525-10534.Huang, X., Zhao, Y.-P., 2017. Characterization of pore structure, gas adsorption, and spontaneous imbibition in shale gas reservoirs. Journal of Petroleum Science and Engineering 159, 197-204.Lebedev, M., Zhang, Y., Sarmadivaleh, M., Barifcani, A., Al-Khdheeawi, E., Iglauer, S., 2017. Carbon geosequestration in limestone: Pore-scale dissolution and geomechanical weakening. International Journal of Greenhouse Gas Control 66, 106-119.Mayo, S., Josh, M., Kasperczyk, D., Kear, J., Zhang, J., Dautriat, J., Pervukhina, M., Clennell, M.B., Sakurovs, R., Sherwood, N., Maksimenko, A., Hall, C., 2018. Dynamic micro-CT study of gas uptake in coal using Xe, Kr and CO2. Fuel 212, 140-150.Saxena, N., Hofmann, R., Alpak, F.O., Berg, S., Dietderich, J., Agarwal, U., Tandon, K., Hunter, S., Freeman, J., Wilson, O.B., 2017. References and benchmarks for pore-scale flow simulated using micro-CT images of porous media and digital rocks. Advances in Water Resources 109, 211-235.Shi, X., Pan, J., Hou, Q., Jin, Y., Wang, Z., Niu, Q., Li, M., 2018. Micrometer-scale fractures in coal related to coal rank based on micro-CT scanning and fractal theory. Fuel 212, 162-172.Voltolini, M., Kwon, T.-H., Ajo-Franklin, J., 2017. Visualization and prediction of supercritical CO2 distribution in sandstones during drainage: An in situ synchrotron X-ray micro-computed tomography study. International Journal of Greenhouse Gas Control 66, 230-245.Xiong, W., Wells, R.K., Menefee, A.H., Skemer, P., Ellis, B.R., Giammar, D.E., 2017. CO2 mineral trapping in fractured basalt. International Journal of Greenhouse Gas Control 66, 204-217.Zhang, Y., Kogure, T., Nishizawa, O., Xue, Z., 2017. Different flow behavior between 1-to-1 displacement and co-injection of CO2 and brine in Berea sandstone: Insights from laboratory experiments with X-ray CT imaging. International Journal of Greenhouse Gas Control 66, 76-84.Liquid Chromatography/LC-MS/SFCAbate-Pella, D., Freund, D.M., Slovin, J.P., Hegeman, A.D., Cohen, J.D., 2017. An improved method for fast and selective separation of carotenoids by LC–MS. Journal of Chromatography B 1067, 34-37.Byrdwell, W.C., 2017. Comprehensive dual liquid chromatography with quadruple mass spectrometry (LC1MS2 × LC1MS2 = LC2MS4) for analysis of Parinari curatellifolia and other seed oil triacylglycerols. Analytical Chemistry 89, 10537-10546.de Bar, M.W., Hopmans, E.C., Verweij, M., Dorhout, D.J.C., Damsté, J.S.S., Schouten, S., 2017. Development and comparison of chromatographic methods for the analysis of long chain diols and alkenones in biological materials and sediment. Journal of Chromatography A 1521, 150-160.Gardner, M.S., McWilliams, L.G., Jones, J.I., Kuklenyik, Z., Pirkle, J.L., Barr, J.R., 2017. Simultaneous quantification of free cholesterol, cholesteryl esters, and triglycerides without ester hydrolysis by UHPLC separation and in-source collision induced dissociation coupled MS/MS. Journal of The American Society for Mass Spectrometry 28, 2319-2329.Venkatramani, C.J., Huang, S.R., Al-Sayah, M., Patel, I., Wigman, L., 2017. High-resolution two-dimensional liquid chromatography analysis of key linker drug intermediate used in antibody drug conjugates. Journal of Chromatography A 1521, 63-72.Wang, R., Ji, H., Ma, P., Zeng, H., Xu, Y., Zhang, Z.-M., Lu, H.-M., 2017. Fast pure ion chromatograms extraction method for LC-MS. Chemometrics and Intelligent Laboratory Systems 170, 68-74.Xu, J., Sun-Waterhouse, D., Qiu, C., Zhao, M., Sun, B., Lin, L., Su, G., 2017. Additional band broadening of peptides in the first size-exclusion chromatographic dimension of an automated stop-flow two-dimensional high performance liquid chromatography. Journal of Chromatography A 1521, 80-89.Zhang, L., Tian, K., Wang, Y., Zou, J., Du, Z., 2017. Characterization of Ancient Chinese textiles by ultra-high performance liquid chromatography/quadrupole-time of flight mass spectrometry. International Journal of Mass Spectrometry 421, 61-70.Mass Spectroscopy/ICR-FTMSFarenc, M., Paupy, B., Marceau, S., Riches, E., Afonso, C., Giusti, P., 2017. Effective ion mobility peak width as a new isomeric descriptor for the untargeted analysis of complex mixtures using ion mobility-mass spectrometry. Journal of The American Society for Mass Spectrometry 28, 2476-2482.Gross, J.H., 2017. Mass Spectrometry, 3rd Edition. Springer. 968 pp.Kang, Y., Schneider, B.B., Covey, T.R., 2017. On the nature of mass spectrometer analyzer contamination. Journal of The American Society for Mass Spectrometry 28, 2384-2392.Krajewski, L.C., Lobodin, V.V., Robbins, W.K., Jin, P., Bota, G., Marshall, A.G., Rodgers, R.P., 2017. Method for isolation and detection of ketones formed from high-temperature naphthenic acid corrosion. Energy & Fuels 31, 10674-10679.Nahan, K.S., Alvarez, N., Shanov, V., Vonderheide, A., 2017. Carbon nanotube fiber ionization mass spectrometry: A fundamental study of a multi-walled carbon nanotube functionalized corona discharge pin for polycyclic aromatic hydrocarbons analysis. Journal of The American Society for Mass Spectrometry 28, 2408-2413.Sta?, M., Chudoba, J., Kubi?ka, D., Bla?ek, J., Pospí?il, M., 2017. Petroleomic characterization of pyrolysis bio-oils: A review. Energy & Fuels 31, 10283-10299.Sultana, C.M., Al-Mashat, H., Prather, K.A., 2017. Expanding single particle mass spectrometer analyses for the identification of microbe signatures in sea spray aerosol. Analytical Chemistry 89, 10162-10170.Tose, L.V., Murgu, M., Vaz, B.G., Rom?o, W., 2017. Application of atmospheric solids analysis probe mass spectrometry (ASAP-MS) in petroleomics: Analysis of condensed aromatics standards, crude oil, and paraffinic fraction. Journal of The American Society for Mass Spectrometry 28, 2401-2407.Trias, R., Ménez, B., le Campion, P., Zivanovic, Y., Lecourt, L., Lecoeuvre, A., Schmitt-Kopplin, P., Uhl, J., Gislason, S.R., Alfre?sson, H.A., Mesfin, K.G., Sn?bj?rnsdóttir, S.?., Aradóttir, E.S., Gunnarsson, I., Matter, J.M., Stute, M., Oelkers, E.H., Gérard, E., 2017. High reactivity of deep biota under anthropogenic CO2 injection into basalt. Nature Communications 8, Article 1063.Vollnhals, F., Audinot, J.-N., Wirtz, T., Mercier-Bonin, M., Fourquaux, I., Schroeppel, B., Kraushaar, U., Lev-Ram, V., Ellisman, M.H., Eswara, S., 2017. Correlative microscopy combining secondary ion mass spectrometry and electron microscopy: Comparison of intensity–hue–saturation and Laplacian pyramid methods for image fusion. Analytical Chemistry 89, 10702-10710.Wu, L., Chládková, B., Lechtenfeld, O.J., Lian, S., Schindelka, J., Herrmann, H., Richnow, H.H., 2018. Characterizing chemical transformation of organophosphorus compounds by 13C and 2H stable isotope analysis. Science of The Total Environment 615, 20-28.Yang, Z., Zhang, G., Hollebone, B.P., Brown, C.E., Yang, C., Lambert, P., Wang, Z., Landriault, M., Shah, K., 2017. Fate of oxygenated intermediates in solar irradiated diluted bitumen mixed with saltwater. Environmental Pollution 231, 622-634.Zorzen?o, P.C.S., Mariath, R.M., Pinto, F.E., Tose, L.V., Rom?o, W., Santos, A.F., Scheer, A.P., Simon, S., Sj?blom, J., Yamamoto, C.I., 2018. Asphaltenes subfractions extracted from Brazilian vacuum residue: Chemical characterization and stabilization of model water-in-oil (W/O) emulsions. Journal of Petroleum Science and Engineering 160, 1-11.Metabolomics/LipidomicsFu, H.-Y., Guo, X.-M., Zhang, Y.-M., Song, J.-J., Zheng, Q.-X., Liu, P.-P., Lu, P., Chen, Q.-S., Yu, Y.-J., She, Y., 2017. AntDAS: Automatic data analysis strategy for UPLC–QTOF-based nontargeted metabolic profiling analysis. Analytical Chemistry 89, 11083-11090.Gold, D.A., O'Reilly, S.S., Watson, J., Degnan, B.M., Degnan, S.M., Kr?mer, J.O., Summons, R.E., 2017. Lipidomics of the sea sponge Amphimedon queenslandica and implication for biomarker geochemistry. Geobiology 15, 836-843.Handley, K.M., Piceno, Y.M., Hu, P., Tom, L.M., Mason, O.U., Andersen, G.L., Jansson, J.K., Gilbert, J.A., 2017. Metabolic and spatio-taxonomic response of uncultivated seafloor bacteria following the Deepwater Horizon oil spill. ISME Journal 11, 2569-2583.Lai, Z., Kind, T., Fiehn, O., 2017. Using accurate mass gas chromatography–mass spectrometry with the mine database for epimetabolite annotation. Analytical Chemistry 89, 10171-10180.Li, L., Ren, W., Kong, H., Zhao, C., Zhao, X., Lin, X., Lu, X., Xu, G., 2017. An alignment algorithm for LC-MS-based metabolomics dataset assisted by MS/MS information. Analytica Chimica Acta 990, 96-102.Mahieu, N.G., Patti, G.J., 2017. Systems-level annotation of a metabolomics data set reduces 25?000 features to fewer than 1000 unique metabolites. Analytical Chemistry 89, 10397-10406.Milman, B.L., Zhurkovich, I.K., 2017. The chemical space for non-target analysis. TrAC Trends in Analytical Chemistry 97, 179-187.Ohemeng-Ntiamoah, J., Datta, T., 2018. Evaluating analytical methods for the characterization of lipids, proteins and carbohydrates in organic substrates for anaerobic co-digestion. Bioresource Technology 247, 697-704.Paliwal, C., Mitra, M., Bhayani, K., Bharadwaj, S.V.V., Ghosh, T., Dubey, S., Mishra, S., 2017. Abiotic stresses as tools for metabolites in microalgae. Bioresource Technology 244, 1216-1226.Wang, M., Wang, C., Han, X., 2017. Selection of internal standards for accurate quantification of complex lipid species in biological extracts by electrospray ionization mass spectrometry—What, how and why? Mass Spectrometry Reviews 36, 693-714.Wang, Y., Feng, R., Wang, R., Yang, F., Li, P., Wan, J.-B., 2017. Enhanced MS/MS coverage for metabolite identification in LC-MS-based untargeted metabolomics by target-directed data dependent acquisition with time-staggered precursor ion list. Analytica Chimica Acta 992, 67-75.Xiang, L., Wei, J., Tian, X.Y., Wang, B., Chan, W., Li, S., Tang, Z., Zhang, H., Cheang, W.S., Zhao, Q., Zhao, H., Yang, Z., Hong, Y., Huang, Y., Cai, Z., 2017. Comprehensive analysis of acylcarnitine species in db/db mouse using a novel method of high-resolution parallel reaction monitoring reveals widespread metabolic dysfunction induced by diabetes. Analytical Chemistry 89, 10368-10375.PuppyomicsKaminski, J., Hynds, J., Morris, P., Waller, B.M., 2017. Human attention affects facial expressions in domestic dogs. Scientific Reports 7, Article 12914.Archaeological/Art Organic ChemistryBüntgen, U., Cosmo, N.D., 2017. Reply to ‘Climate of doubt: a re-evaluation of Büntgen and Di Cosmo’s environmental hypothesis for the Mongol withdrawal from Hungary, 1242 CE’. Scientific Reports 7, Article 12696.Gueriau, P., Rueff, J.-P., Bernard, S., Kaddissy, J.A., Goler, S., Sahle, C.J., Sokaras, D., Wogelius, R.A., Manning, P.L., Bergmann, U., Bertrand, L., 2017. Noninvasive synchrotron-based X-ray Raman scattering discriminates carbonaceous compounds in ancient and historical materials. Analytical Chemistry 89, 10819-10826.Makarewicz, C.A., 2017. Sequential δ13C and δ18O analyses of early Holocene bovid tooth enamel: Resolving vertical transhumance in Neolithic domesticated sheep and goats. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 16-29.Misarti, N., Gier, E., Finney, B., Barnes, K., McCarthy, M., 2017. Compound-specific amino acid δ15N values in archaeological shell: Assessing diagenetic integrity and potential for isotopic baseline reconstruction. Rapid Communications in Mass Spectrometry 31, 1881-1891.Moini, M., Rollman, C.M., 2017. Buyid silk and the tale of Bibi Shahrbanu: Identification of biomarkers of artificial aging (forgery) of silk. Analytical Chemistry 89, 10158-10161.Napolitano, M.P., Kuo, P.-C., Johnson, J.V., Arslanoglu, J., Yost, R.A., 2017. Tandem mass spectrometry of laser-reduced anthraquinones for painted works and dyed cultural artifacts. International Journal of Mass Spectrometry 421, 14-24.Pinke, Z., Ferenczi, L., Romhányi, B.F., Laszlovszky, J., Pow, S., 2017. Climate of doubt: A re-evaluation of Büntgen and Di Cosmo’s environmental hypothesis for the Mongol withdrawal from Hungary, 1242 CE. Scientific Reports 7, Article 12695.Vignola, C., Masi, A., Balossi Restelli, F., Frangipane, M., Marzaioli, F., Passariello, I., Stellato, L., Terrasi, F., Sadori, L., 2017. δ13C and δ15N from 14C-AMS dated cereal grains reveal agricultural practices during 4300–2000BC at Arslantepe (Turkey). Review of Palaeobotany and Palynology 247, 164-174.Zhang, L., Tian, K., Wang, Y., Zou, J., Du, Z., 2017. Characterization of Ancient Chinese textiles by ultra-high performance liquid chromatography/quadrupole-time of flight mass spectrometry. International Journal of Mass Spectrometry 421, 61-70.BiochemistryAn, Y.J., Rowland, S.E., Na, J.-H., Spigolon, D., Hong, S.K., Yoon, Y.J., Lee, J.-H., Robb, F.T., Cha, S.-S., 2017. Structural and mechanistic characterization of an archaeal-like chaperonin from a thermophilic bacterium. Nature Communications 8, Article 827.Baidya, A.K., Bhattacharya, S., Dubey, G.P., Mamou, G., Ben-Yehuda, S., 2018. Bacterial nanotubes: a conduit for intercellular molecular trade. Current Opinion in Microbiology 42, 1-6.Felden, B., Paillard, L., 2017. When eukaryotes and prokaryotes look alike: the case of regulatory RNAs. FEMS Microbiology Reviews 41, 624-639.Gold, D.A., O'Reilly, S.S., Watson, J., Degnan, B.M., Degnan, S.M., Kr?mer, J.O., Summons, R.E., 2017. Lipidomics of the sea sponge Amphimedon queenslandica and implication for biomarker geochemistry. Geobiology 15, 836-843.Hennell James, R., Caceres, E.F., Escasinas, A., Alhasan, H., Howard, J.A., Deery, M.J., Ettema, T.J.G., Robinson, N.P., 2017. Functional reconstruction of a eukaryotic-like E1/E2/(RING) E3 ubiquitylation cascade from an uncultured archaeon. Nature Communications 8, Article 1120.Jones, D.L., Baxter, B.K., 2017. DNA repair and photoprotection: Mechanisms of overcoming environmental ultraviolet radiation exposure in halophilic Archaea. Frontiers in Microbiology 8, 1882. doi: 1810.3389/fmicb.2017.01882 Lee, K.H., Hamashima, K., Kimoto, M., Hirao, I., 2018. Genetic alphabet expansion biotechnology by creating unnatural base pairs. Current Opinion in Biotechnology 51, 8-15.Müller, V., Hess, V., 2017. The minimum biological energy quantum. Frontiers in Microbiology 8, 2019. doi: 2010.3389/fmicb.2017.02019.Osborne, K.A., Gray, N.D., Sherry, A., Leary, P., Mejeha, O., Bischoff, J., Rush, D., Sidgwick, F.R., Birgel, D., Kalyuzhnaya, M.G., Talbot, H.M., 2017. Methanotroph-derived bacteriohopanepolyol signatures as a function of temperature related growth, survival, cell death and preservation in the geological record. Environmental Microbiology Reports 9, 492-500.Ostrovsky, M.A., 2017. Rhodopsin: Evolution and comparative physiology. Paleontological Journal 51, 562-572.Round, J., Roccor, R., Li, S.-N., Eltis, L.D., 2017. A fatty acyl coenzyme A reductase promotes wax ester accumulation in Rhodococcus jostii RHA1. Applied and Environmental Microbiology 83, e00902-00917.Tolar, B.B., Herrmann, J., Bargar, J.R., van den Bedem, H., Wakatsuki, S., Francis, C.A., 2017. Integrated structural biology and molecular ecology of N-cycling enzymes from ammonia-oxidizing archaea. Environmental Microbiology Reports 9, 484-491.Xiong, W., Cano, M., Wang, B., Douchi, D., Yu, J., 2017. The plasticity of cyanobacterial carbon metabolism. Current Opinion in Chemical Biology 41, 12-19.Yu, Z., Chistoserdova, L., 2017. Communal metabolism of methane and the rare earth element switch. Journal of Bacteriology 199, Article e00328-00317.BiodegradationCheng, X., Hou, D., Mao, R., Xu, C., 2018. Severe biodegradation of polycyclic aromatic hydrocarbons in reservoired crude oils from the Miaoxi Depression, Bohai Bay Basin. Fuel 211, 859-867.Gray, D.D., Zonneveld, K.A.F., Versteegh, G.J.M., 2017. Species-specific sensitivity of dinoflagellate cysts to aerobic degradation: A five-year natural exposure experiment. Review of Palaeobotany and Palynology 247, 175-187.Kronenberg, M., Trably, E., Bernet, N., Patureau, D., 2017. Biodegradation of polycyclic aromatic hydrocarbons: Using microbial bioelectrochemical systems to overcome an impasse. Environmental Pollution 231, 509-523.Okere, U.V., Cabrerizo, A., Dachs, J., Ogbonnaya, U.O., Jones, K.C., Semple, K.T., 2017. Effects of pre-exposure on the indigenous biodegradation of 14C-phenanthrene in Antarctic soils. International Biodeterioration & Biodegradation 125, 189-199.Rajamanickam, R., Baskaran, D., 2017. Biodegradation of gaseous toluene with mixed microbial consortium in a biofilter: steady state and transient operation. Bioprocess and Biosystems Engineering 40, 1801-1812.Singh, R., Guzman, M.S., Bose, A., 2017. Anaerobic oxidation of ethane, propane, and butane by marine microbes: A mini review. Frontiers in Microbiology 8, 2056. doi: 2010.3389/fmicb.2017.02056.Xaaldi Kalhor, A., Movafeghi, A., Mohammadi-Nassab, A.D., Abedi, E., Bahrami, A., 2017. Potential of the green alga Chlorella vulgaris for biodegradation of crude oil hydrocarbons. Marine Pollution Bulletin 123, 286-290.Biodegradation pathways/genomicsBiofuels/BiomassChen, B., Wan, C., Mehmood, M.A., Chang, J.-S., Bai, F., Zhao, X., 2017. Manipulating environmental stresses and stress tolerance of microalgae for enhanced production of lipids and value-added products–A review. Bioresource Technology 244, 1198-1206.Duangkaew, P., Inoue, S., Aki, T., Nakashimada, Y., Okamura, Y., Tajima, T., Matsumura, Y., 2017. Quantitative in situ mass spectrometry analysis of mannitol decomposition products under hydrothermal conditions. Energy & Fuels 31, 10866-10873.Hasan, M.F., Vogt, F., 2017. Modeling the transformation of atmospheric CO2 into microalgal biomass. Analyst 142, 4089-4098.Lee, S.Y., Cho, J.M., Chang, Y.K., Oh, Y.-K., 2017. Cell disruption and lipid extraction for microalgal biorefineries: A review. Bioresource Technology 244, 1317-1328.Lovato, G., Alvarado-Morales, M., Kovalovszki, A., Peprah, M., Kougias, P.G., Rodrigues, J.A.D., Angelidaki, I., 2017. In-situ biogas upgrading process: Modeling and simulations aspects. Bioresource Technology 245, 332-341.Martin, B.A., Frymier, P.D., 2017. A review of hydrogen production by photosynthetic organisms using whole-cell and cell-free systems. Applied Biochemistry and Biotechnology 183, 503-519.Ohemeng-Ntiamoah, J., Datta, T., 2018. Evaluating analytical methods for the characterization of lipids, proteins and carbohydrates in organic substrates for anaerobic co-digestion. Bioresource Technology 247, 697-704.Paliwal, C., Mitra, M., Bhayani, K., Bharadwaj, S.V.V., Ghosh, T., Dubey, S., Mishra, S., 2017. Abiotic stresses as tools for metabolites in microalgae. Bioresource Technology 244, 1216-1226.Plegaria, J.S., Kerfeld, C.A., 2018. Engineering nanoreactors using bacterial microcompartment architectures. Current Opinion in Biotechnology 51, 1-7.Round, J., Roccor, R., Li, S.-N., Eltis, L.D., 2017. A fatty acyl coenzyme A reductase promotes wax ester accumulation in Rhodococcus jostii RHA1. Applied and Environmental Microbiology 83, e00902-00917.Ruangsomboon, S., Prachom, N., Sornchai, P., 2017. Enhanced growth and hydrocarbon production of Botryococcus braunii KMITL 2 by optimum carbon dioxide concentration and concentration-dependent effects on its biochemical composition and biodiesel properties. Bioresource Technology 244, 1358-1366.Sengupta, S., Gorain, P.C., Pal, R., 2017. Aspects and prospects of algal carbon capture and sequestration in ecosystems: a review. Chemistry and Ecology 33, 695-707.Singh, A.K., Mallick, N., 2017. Advances in cyanobacterial polyhydroxyalkanoates production. FEMS Microbiology Letters 364, Article fnx189.Sta?, M., Chudoba, J., Kubi?ka, D., Bla?ek, J., Pospí?il, M., 2017. Petroleomic characterization of pyrolysis bio-oils: A review. Energy & Fuels 31, 10283-10299.Ventura, M., Deus, W.B., Silva, J.R., Andrade, L.H.C., Catunda, T., Lima, S.M., 2018. Determination of the biodiesel content in diesel/biodiesel blends by using the near-near-infrared thermal lens spectroscopy. Fuel 212, 309-314.Xie, Y., Sen, B., Wang, G., 2017. Mining terpenoids production and biosynthetic pathway in thraustochytrids. Bioresource Technology 244, 1269-1280.Zhu, B., Chen, G., Cao, X., Wei, D., 2017. Molecular characterization of CO2 sequestration and assimilation in microalgae and its biotechnological applications. Bioresource Technology 244, 1207-1215.BiogeochemistryCuadros, J., 2017. Clay minerals interaction with microorganisms: a review. Clay Minerals 52, 235.Hubas, C., Boeuf, D., Jesus, B., Thiney, N., Bozec, Y., Jeanthon, C., 2017. A nanoscale study of carbon and nitrogen fluxes in mats of purple sulfur bacteria: Implications for carbon cycling at the surface of coastal sediments. Frontiers in Microbiology 8, 1995. doi: 1910.3389/fmicb.2017.01995.Kulkarni, H.V., Mladenov, N., McKnight, D.M., Zheng, Y., Kirk, M.F., Nemergut, D.R., 2018. Dissolved fulvic acids from a high arsenic aquifer shuttle electrons to enhance microbial iron reduction. Science of The Total Environment 615, 1390-1395.Lynch, C., Hartin, C., Chen, M., Bond-Lamberty, B., 2017. Causes of uncertainty in observed and projected heterotrophic respiration from Earth System Models. Biogeosciences Discussions 2017, 1-28.Michelson, K., Sanford, R.A., Valocchi, A.J., Werth, C.J., 2017. Nanowires of Geobacter sulfurreducens require redox cofactors to reduce metals in pore spaces too small for cell passage. Environmental Science & Technology 51, 11660-11668.Sommer, T., Danza, F., Berg, J., Sengupta, A., Constantinescu, G., Tokyay, T., Bürgmann, H., Dressler, Y., Sepúlveda Steiner, O., Schubert, C.J., Tonolla, M., Wüest, A., 2017. Bacteria-induced mixing in natural waters. Geophysical Research Letters 44, 9424-9432.Steiger, M.G., Mattanovich, D., Sauer, M., 2017. Microbial organic acid production as carbon dioxide sink. FEMS Microbiology Letters 364, Article fnx212.Tecon, R., Or, D., 2017. Biophysical processes supporting the diversity of microbial life in soil. FEMS Microbiology Reviews 41, 599-623.Viggi, C.C., Matturro, B., Frascadore, E., Insogna, S., Mezzi, A., Kaciulis, S., Sherry, A., Mejeha, O.K., Head, I.M., Vaiopoulou, E., Rabaey, K., Rossetti, S., Aulenta, F., 2017. Bridging spatially segregated redox zones with a microbial electrochemical snorkel triggers biogeochemical cycles in oil-contaminated River Tyne (UK) sediments. Water Research 127, 11-21.Zafar, R., Watson, J.S., 2017. Adsorption of tetradecanoic acid on kaolinite minerals: Using flash pyrolysis to characterise the catalytic efficiency of clay mineral adsorbed fatty acids. Chemical Geology 471, 111-118.Biofilm/Microcial Induced CorrosionAmano, Y., Iwatsuki, T., Naganuma, T., 2017. Characteristics of naturally grown biofilms in deep groundwaters and their heavy metal sorption property in a deep subsurface environment. Geomicrobiology Journal 34, 769-783.Coutaud, M., Méheut, M., Glatzel, P., Pokrovski, G.S., Viers, J., Rols, J.-L., Pokrovsky, O.S., 2018. Small changes in Cu redox state and speciation generate large isotope fractionation during adsorption and incorporation of Cu by a phototrophic biofilm. Geochimica et Cosmochimica Acta 220, 1-18.Fang, H.W., Lai, H.J., Cheng, W., Huang, L., He, G.J., 2017. Modeling sediment transport with an integrated view of the biofilm effects. Water Resources Research 53, 7536-7557.Guo, X.-p., Niu, Z.-s., Lu, D.-p., Feng, J.-n., Chen, Y.-r., Tou, F.-y., Liu, M., Yang, Y., 2017. Bacterial community structure in the intertidal biofilm along the Yangtze Estuary, China. Marine Pollution Bulletin 124, 314-320.Herren, C.M., McMahon, K.D., 2017. Cohesion: a method for quantifying the connectivity of microbial communities. ISME Journal 11, 2426-2438.Jones, S., 2017. Goo, glue, and grain binding: Importance of biofilms for diagenesis in sandstones. Geology 45, 959-960.Karn, S.K., Fang, G., Duan, J., 2017. Bacillus sp. Acting as dual role for corrosion induction and corrosion inhibition with carbon steel (CS). Frontiers in Microbiology 8, 2038. doi: 2010.3389/fmicb.2017.02038.Okoro, C.C., Samuel, O., Lin, J., 2017. Substrate availability, pH, and temperature influence methanogenesis and mild steel corrosion. Geomicrobiology Journal 34, 729-736.Pfendler, S., Karimi, B., Maron, P.-A., Ciadamidaro, L., Valot, B., Bousta, F., Alaoui-Sosse, L., Alaoui-Sosse, B., Aleya, L., 2018. Biofilm biodiversity in French and Swiss show caves using the metabarcoding approach: First data. Science of The Total Environment 615, 1207-1217.Ren, Z., Gao, H., Elser, J.J., Zhao, Q., 2017. Microbial functional genes elucidate environmental drivers of biofilm metabolism in glacier-fed streams. Scientific Reports 7, Article 12668.Stanton, M.M., Park, B.-W., Vilela, D., Bente, K., Faivre, D., Sitti, M., Sánchez, S., 2017. Magnetotactic bacteria powered biohybrids target E. coli biofilms. ACS Nano 11, 9968-9978.Microbial Mediation of Mineral Formation/DegradationFalk, N., Chaganti, S.R., Weisener, C.G., 2018. Evaluating the microbial community and gene regulation involved in crystallization kinetics of ZnS formation in reduced environments. Geochimica et Cosmochimica Acta 220, 201-216.Huang, W., Cheng, W., Nie, X., Dong, F., Ding, C., Liu, M., Li, Z., Hayat, T., Alharbi, N.S., 2017. Microscopic and spectroscopic insights into uranium phosphate mineral precipitated by Bacillus mucilaginosus. ACS Earth and Space Chemistry 1, 483-492.Joshi, S., Goyal, S., Mukherjee, A., Reddy, M.S., 2017. Microbial healing of cracks in concrete: a review. Journal of Industrial Microbiology & Biotechnology 44, 1511-1525.Orhan, F., Demirci, A., Yanmis, D., 2017. CaCO3 and MgCO3 dissolving halophilic bacteria. Geomicrobiology Journal 34, 804-810.Ta, K., Peng, X., Chen, S., Xu, H., Li, J., Du, M., Hao, J., Lin, Y., 2017. Hydrothermal nontronite formation associated with microbes from low-temperature diffuse hydrothermal vents at the South Mid-Atlantic Ridge. Journal of Geophysical Research: Biogeosciences 122, 2375-2392.Microbial Fuel CellsKhandelwal, A., Vijay, A., Dixit, A., Chhabra, M., 2018. Microbial fuel cell powered by lipid extracted algae: A promising system for algal lipids and power generation. Bioresource Technology 247, 520-527.Reimers, C.E., Li, C., Graw, M.F., Schrader, P.S., Wolf, M., 2017. The identification of cable bacteria attached to the anode of a benthic microbial fuel cell: Evidence of long distance extracellular electron transport to electrodes. Frontiers in Microbiology 8, 2055. doi: 2010.3389/fmicb.2017.02055.Carbon CycleBorges, A.V., Abril, G., Bouillon, S., 2017. Carbon dynamics in the Mekong Delta. Biogeosciences Discussions 2017, 1-41.Clark, D.A., Asao, S., Fisher, R., Reed, S., Reich, P.B., Ryan, M.G., Wood, T.E., Yang, X., 2017. Reviews and syntheses: Field data to benchmark the carbon cycle models for tropical forests. Biogeosciences 14, 4663-4690.Haghnegahdar, M.A., Schauble, E.A., Young, E.D., 2017. A model for 12CH2D2 and 13CH3D as complementary tracers for the budget of atmospheric CH4. Global Biogeochemical Cycles 31, 1387-1407.Horan, K., Hilton, R.G., Selby, D., Ottley, C.J., Gr?cke, D.R., Hicks, M., Burton, K.W., 2017. Mountain glaciation drives rapid oxidation of rock-bound organic carbon. Science Advances 3, Article e1701107.Hubas, C., Boeuf, D., Jesus, B., Thiney, N., Bozec, Y., Jeanthon, C., 2017. A nanoscale study of carbon and nitrogen fluxes in mats of purple sulfur bacteria: Implications for carbon cycling at the surface of coastal sediments. Frontiers in Microbiology 8, 1995. doi: 1910.3389/fmicb.2017.01995.Liang, Y., Zhang, Y., Wang, N., Luo, T., Zhang, Y., Rivkin, R.B., 2017. Estimating primary production of picophytoplankton using the carbon-based ocean productivity model: A preliminary study. Frontiers in Microbiology 8, 1926. doi: 1910.3389/fmicb.2017.01926.Pulliainen, J., Aurela, M., Laurila, T., Aalto, T., Takala, M., Salminen, M., Kulmala, M., Barr, A., Heimann, M., Lindroth, A., Laaksonen, A., Derksen, C., M?kel?, A., Markkanen, T., Lemmetyinen, J., Susiluoto, J., Dengel, S., Mammarella, I., Tuovinen, J.-P., Vesala, T., 2017. Early snowmelt significantly enhances boreal springtime carbon uptake. Proceedings of the National Academy of Sciences 114, 11081-11086.Rosso, I., Mazloff, M.R., Verdy, A., Talley, L.D., 2017. Space and time variability of the Southern Ocean carbon budget. Journal of Geophysical Research: Oceans 122, 7407-7432.Smith, J., 2017. Measuring Earth's carbon cycle. Science 358, 186-187.Stukel, M.R., Ducklow, H.W., 2017. Stirring up the biological pump: Vertical mixing and carbon export in the Southern Ocean. Global Biogeochemical Cycles 31, 1420-1434.Yang, W.H., McNicol, G., Teh, Y.A., Estera-Molina, K., Wood, T.E., Silver, W.L., 2017. Evaluating the classical versus an emerging conceptual model of peatland methane dynamics. Global Biogeochemical Cycles 31, 1435-1453.Carbon SequestrationAl-Anssari, S., Arif, M., Wang, S., Barifcani, A., Lebedev, M., Iglauer, S., 2017. Wettability of nano-treated calcite/CO2/brine systems: Implication for enhanced CO2 storage potential. International Journal of Greenhouse Gas Control 66, 97-105.Bai, B., Hu, Q., Li, Z., Lü, G., Li, X., 2017. Evaluating the sealing effectiveness of a caprock-fault system for CO2-EOR storage: A case study of the Shengli oilfield. Geofluids 2017, Article 8536724.Cudjoe, S., Barati, R., 2017. Lattice Boltzmann simulation of CO2 transport in kerogen nanopores—An evaluation of CO2 sequestration in organic-rich shales. Journal of Earth Science 28, 926-932.Espinoza, D.N., Santamarina, J.C., 2017. CO2 breakthrough—Caprock sealing efficiency and integrity for carbon geological storage. International Journal of Greenhouse Gas Control 66, 218-229.Guida, B.S., Bose, M., Garcia-Pichel, F., 2017. Carbon fixation from mineral carbonates. Nature Communications 8, 1025.Haghi, R.K., Chapoy, A., Peirera, L.M.C., Yang, J., Tohidi, B., 2017. pH of CO2 saturated water and CO2 saturated brines: Experimental measurements and modelling. International Journal of Greenhouse Gas Control 66, 190-203.Hernández-Rodríguez, A., Montegrossi, G., Huet, B., Vaselli, O., Virgili, G., 2017. A study of wellbore cement alteration controlled by CO2 leakage in a natural analogue for geological CO2 storage. Applied Geochemistry 86, 13-25.Lebedev, M., Zhang, Y., Sarmadivaleh, M., Barifcani, A., Al-Khdheeawi, E., Iglauer, S., 2017. Carbon geosequestration in limestone: Pore-scale dissolution and geomechanical weakening. International Journal of Greenhouse Gas Control 66, 106-119.Pan, F., McPherson, B.J., Kaszuba, J., 2017. Evaluation of CO2-fluid-rock interaction in enhanced geothermal systems: Field-scale geochemical simulations. Geofluids 2017, Article 5675370.Perera, M.S.A., 2017. Influences of CO2 injection into deep coal seams: A review. Energy & Fuels 31, 10324-10334.Renforth, P., Henderson, G., 2017. Assessing ocean alkalinity for carbon sequestration. Reviews of Geophysics 55, 636-674.Roberts, J.J., Gilfillan, S.M.V., Stalker, L., Naylor, M., 2017. Geochemical tracers for monitoring offshore CO2 stores. International Journal of Greenhouse Gas Control 65, 218-234.Sengupta, S., Gorain, P.C., Pal, R., 2017. Aspects and prospects of algal carbon capture and sequestration in ecosystems: a review. Chemistry and Ecology 33, 695-707.Taheri, A., Lindeberg, E., Tors?ter, O., Wessel-Berg, D., 2017. Qualitative and quantitative experimental study of convective mixing process during storage of CO2 in homogeneous saline aquifers. International Journal of Greenhouse Gas Control 66, 159-176.Todaka, N., Xu, T., 2017. Reactive transport simulation to assess geochemical impact of impurities on CO2 injection into siliciclastic reservoir at the Otway site, Australia. International Journal of Greenhouse Gas Control 66, 177-189.Trias, R., Ménez, B., le Campion, P., Zivanovic, Y., Lecourt, L., Lecoeuvre, A., Schmitt-Kopplin, P., Uhl, J., Gislason, S.R., Alfre?sson, H.A., Mesfin, K.G., Sn?bj?rnsdóttir, S.?., Aradóttir, E.S., Gunnarsson, I., Matter, J.M., Stute, M., Oelkers, E.H., Gérard, E., 2017. High reactivity of deep biota under anthropogenic CO2 injection into basalt. Nature Communications 8, Article 1063.Voltolini, M., Kwon, T.-H., Ajo-Franklin, J., 2017. Visualization and prediction of supercritical CO2 distribution in sandstones during drainage: An in situ synchrotron X-ray micro-computed tomography study. International Journal of Greenhouse Gas Control 66, 230-245.Xiong, W., Wells, R.K., Menefee, A.H., Skemer, P., Ellis, B.R., Giammar, D.E., 2017. CO2 mineral trapping in fractured basalt. International Journal of Greenhouse Gas Control 66, 204-217.Zhang, Y., Kogure, T., Nishizawa, O., Xue, Z., 2017. Different flow behavior between 1-to-1 displacement and co-injection of CO2 and brine in Berea sandstone: Insights from laboratory experiments with X-ray CT imaging. International Journal of Greenhouse Gas Control 66, 76-84.Zhu, B., Chen, G., Cao, X., Wei, D., 2017. Molecular characterization of CO2 sequestration and assimilation in microalgae and its biotechnological applications. Bioresource Technology 244, 1207-1215.Climate ChangeArias-Ruiz, C., Elliot, M., Bézos, A., Pedoja, K., Husson, L., Cahyarini, S.Y., Cariou, E., Michel, E., La, C., Manssouri, F., 2017. Geochemical fingerprints of climate variation and the extreme La Ni?a 2010–11 as recorded in a Tridacna squamosa shell from Sulawesi, Indonesia. Palaeogeography, Palaeoclimatology, Palaeoecology 487, 216-228.Ga?uszka, A., Migaszewski, Z.M., Namie?nik, J., 2017. The role of analytical chemistry in the study of the Anthropocene. TrAC Trends in Analytical Chemistry 97, 146-152.Khodri, M., Izumo, T., Vialard, J., Janicot, S., Cassou, C., Lengaigne, M., Mignot, J., Gastineau, G., Guilyardi, E., Lebas, N., Robock, A., McPhaden, M.J., 2017. Tropical explosive volcanic eruptions can trigger El Ni?o by cooling tropical Africa. Nature Communications 8, Article 778.Knutti, R., Rugenstein, M.A.A., Hegerl, G.C., 2017. Beyond equilibrium climate sensitivity. Nature Geoscience 10, 727-736.Loiko, S.V., Pokrovsky, O.S., Raudina, T.V., Lim, A., Kolesnichenko, L.G., Shirokova, L.S., Vorobyev, S.N., Kirpotin, S.N., 2017. Abrupt permafrost collapse enhances organic carbon, CO2, nutrient and metal release into surface waters. Chemical Geology 471, 153-165.Melillo, J.M., Frey, S.D., DeAngelis, K.M., Werner, W.J., Bernard, M.J., Bowles, F.P., Pold, G., Knorr, M.A., Grandy, A.S., 2017. Long-term pattern and magnitude of soil carbon feedback to the climate system in a warming world. Science 358, 101-105.Metcalfe, D.B., 2017. Microbial change in warming soils. Science 358, 41-42.Millar, R.J., Fuglestvedt, J.S., Friedlingstein, P., Rogelj, J., Grubb, M.J., Matthews, H.D., Skeie, R.B., Forster, P.M., Frame, D.J., Allen, M.R., 2017. Emission budgets and pathways consistent with limiting warming to 1.5°C. Nature Geoscience 10, 741-747.Myhre, G., Myhre, C.L., Forster, P.M., Shine, K.P., 2017. Halfway to doubling of CO2 radiative forcing. Nature Geoscience 10, 710-711.Vasilevich, R., Lodygin, E., Beznosikov, V., Abakumov, E., 2018. Molecular composition of raw peat and humic substances from permafrost peat soils of European Northeast Russia as climate change markers. Science of The Total Environment 615, 1229-1238.Coal/Lignite/Peat GeochemistryErdenetsogt, B.-O., Lee, I., Ko, Y.-J., 2017. Carbon isotope analysis and a solid state 13C NMR study of Mongolian lignite: Changes in stable carbon isotopic composition during diagenesis. Organic Geochemistry 113, 293-302.Gerami, A., Armstrong, R.T., Johnston, B., Warkiani, M.E., Mosavat, N., Mostaghimi, P., 2017. Coal-on-a-chip: Visualizing flow in coal fractures. Energy & Fuels 31, 10393-10403.Kosateva, A., Stefanova, M., Marinov, S., Czech, J., Carleer, R., Yperman, J., 2017. Characterization of organic components in leachables from Bulgarian lignites by spectroscopy, chromatography and reductive pyrolysis. International Journal of Coal Geology 183, 100-109.Neupane, B., Ju, Y., Silwal, B.R., Singh, P.K., Huang, C., 2017. Structural investigations of Eocene coals from foreland basin of central Nepal Himalaya. Energy Exploration & Exploitation 35, 713-733.Shi, X., Pan, J., Hou, Q., Jin, Y., Wang, Z., Niu, Q., Li, M., 2018. Micrometer-scale fractures in coal related to coal rank based on micro-CT scanning and fractal theory. Fuel 212, 162-172.Singh, A.K., Kumar, A., 2017. Petro-chemical characterisation and depositional paleoenvironment of lignite deposits of Nagaur, Western Rajasthan, India. Environmental Earth Sciences 76, Article 692.Singh, V.P., Singh, B.D., Mathews, R.P., Singh, A., Mendhe, V.A., Singh, P.K., Mishra, S., Dutta, S., Shivanna, M., Singh, M.P., 2017. Investigation on the lignite deposits of Surkha mine (Saurashtra Basin, Gujarat), western India: Their depositional history and hydrocarbon generation potential. International Journal of Coal Geology 183, 78-99.Wang, F., Fan, X., Xia, J.-L., Wei, X.-Y., Yu, Y.-R., Zhao, Y.-P., Cao, J.-P., Zhao, W., Wang, R.-Y., 2018. Insight into the structural features of low-rank coals using comprehensive two dimensional gas chromatography/time-of-flight mass spectrometry. Fuel 212, 293-301.Wang, Y.-C., Xue, Y.-B., Wang, X.-X., 2017. Study on the structure of small molecule compounds and their functional groups in coal. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects 39, 1733-1738.Yang, W.H., McNicol, G., Teh, Y.A., Estera-Molina, K., Wood, T.E., Silver, W.L., 2017. Evaluating the classical versus an emerging conceptual model of peatland methane dynamics. Global Biogeochemical Cycles 31, 1435-1453.Coal Bed MethaneFuertez, J., Boakye, R., McLennan, J., Adams, D.J., Sparks, T.D., Gottschalk, A., 2017. Developing methanogenic microbial consortia from diverse coal sources and environments. Journal of Natural Gas Science and Engineering 46, 637-650.Fuertez, J., Nguyen, V., McLennan, J.D., Adams, D.J., Han, K.-B., Sparks, T.D., 2017. Optimization of biogenic methane production from coal. International Journal of Coal Geology 183, 14-24.Guo, H., Fu, C., Bai, Y., Ma, J., Su, X., 2017. Influence of biogenic gas production on coalbed methane recovery index. Natural Gas Industry B 4, 197-202.Hou, S., Wang, X., Wang, X., Yuan, Y., Pan, S., Wang, X., 2017. Pore structure characterization of low volatile bituminous coals with different particle size and tectonic deformation using low pressure gas adsorption. International Journal of Coal Geology 183, 1-13.Lin, J., Ren, T., Wang, G., Booth, P., Nemcik, J., 2017. Experimental study of the adsorption-induced coal matrix swelling and its impact on ECBM. Journal of Earth Science 28, 917-925.Mayo, S., Josh, M., Kasperczyk, D., Kear, J., Zhang, J., Dautriat, J., Pervukhina, M., Clennell, M.B., Sakurovs, R., Sherwood, N., Maksimenko, A., Hall, C., 2018. Dynamic micro-CT study of gas uptake in coal using Xe, Kr and CO2. Fuel 212, 140-150.Perera, M.S.A., 2017. Influences of CO2 injection into deep coal seams: A review. Energy & Fuels 31, 10324-10334.Sechman, H., Kotarba, M.J., Dzieniewicz, M., Romanowski, T., Fiszer, J., 2017. Evidence of methane and carbon dioxide migration to the near surface zone in the area of the abandoned coal mines in Wa?brzych District (Lower Silesian Coal Basin, SW Poland) based on periodical changes of molecular and isotopic compositions. International Journal of Coal Geology 183, 138-160.Song, J., Su, X., Wang, Q., Chen, P., 2017. A new method for calculating gas content of coal reservoirs with consideration of a micro-pore overpressure environment. Natural Gas Industry B 4, 182-188.Tang, S., Tang, D., Tang, J., Tao, S., Xu, H., Geng, Y., 2017. Controlling factors of coalbed methane well productivity of multiple superposed coalbed methane systems: A case study on the Songhe mine field, Guizhou, China. Energy Exploration & Exploitation 35, 665-684.Tao, S., Chen, S., Tang, D., Zhao, X., Xu, H., Li, S., 2018. Material composition, pore structure and adsorption capacity of low-rank coals around the first coalification jump: A case of eastern Junggar Basin, China. Fuel 211, 804-815.Zeng, Q., Wang, Z., McPherson, B.J., McLennan, J.D., 2017. Modeling competitive adsorption between methane and water on coals. Energy & Fuels 31, 10775-10786.Cosmochemistry/Planetary GeochemistryCouturier-Tamburelli, I., Toumi, A., Piétri, N., Chiavassa, T., 2018. Behaviour of solid phase ethyl cyanide in simulated conditions of Titan. Icarus 300, 477-485.Crandall, P.B., Góbi, S., Gillis-Davis, J., Kaiser, R.I., 2017. Can perchlorates be transformed to hydrogen peroxide (H2O2) products by cosmic rays on the Martian surface? Journal of Geophysical Research: Planets 122, 1880-1892.Fairen, A.G., 2017. Planetary science: Icy Mars lakes warmed by methane. Nature Geoscience 10, 717-718.Kite, E.S., Gao, P., Goldblatt, C., Mischna, M.A., Mayer, D.P., Yung, Y.L., 2017. Methane bursts as a trigger for intermittent lake-forming climates on post-Noachian Mars. Nature Geoscience 10, 737-740.Melwani Daswani, M., Kite, E.S., 2017. Paleohydrology on Mars constrained by mass balance and mineralogy of pre-Amazonian sodium chloride lakes. Journal of Geophysical Research: Planets 122, 1802-1823.Moores, J.E., Smith, C.L., Schuerger, A.C., 2017. UV production of methane from surface and sedimenting IDPs on Mars in light of REMS data and with insights for TGO. Planetary and Space Science 147, 48-60.Niles, P.B., Michalski, J., Ming, D.W., Golden, D.C., 2017. Elevated olivine weathering rates and sulfate formation at cryogenic temperatures on Mars. Nature Communications 8, 998.Pan, L., Ehlmann, B.L., Carter, J., Ernst, C.M., 2017. The stratigraphy and history of Mars' northern lowlands through mineralogy of impact craters: A comprehensive survey. Journal of Geophysical Research: Planets 122, 1824-1854.Potiszil, C., Montgomery, W., Sephton, M.A., 2017. Effects of pressure on model compounds of meteorite organic matter. ACS Earth and Space Chemistry 8, 475-482.Sinclair, J.A., Orton, G.S., Greathouse, T.K., Fletcher, L.N., Moses, J.I., Hue, V., Irwin, P.G.J., 2018. Jupiter’s auroral-related stratospheric heating and chemistry II: Analysis of IRTF-TEXES spectra measured in December 2014. Icarus 300, 305-326.AstrobiologyBlanco, Y., Gallardo-Carre?o, I., Ruiz-Bermejo, M., Puente-Sánchez, F., Cavalcante-Silva, E., Quesada, A., Prieto-Ballesteros, O., Parro, V., 2017. Critical assessment of analytical techniques in the search for biomarkers on Mars: A mummified microbial mat from Antarctica as a best-case scenario. Astrobiology 17, 984-996.Chela-Flores, J., 2017. Instrumentation for testing whether the icy moons of the gas and ice giants are inhabited. Astrobiology 17, 958-961.Domagal-Goldman, S.D., 2017. The power of self-skepticism in astrobiology. Astrobiology 17, 956-957.Fairén, A.G., Parro, V., Schulze-Makuch, D., Whyte, L., 2017. Searching for life on Mars before it is too late. Astrobiology 17, 962-970.Ferreira, R.B., Ferreira, J.B., 2017. The live universe. A biologist's perspective. Frontiers in Astronomy and Space Sciences 4, 4:17. doi: 10.3389/fspas.2017.00017.Gentry, D.M., Amador, E.S., Cable, M.L., Chaudry, N., Cullen, T., Jacobsen, M.B., Murukesan, G., Schwieterman, E.W., Stevens, A.H., Stockton, A., Tan, G., Yin, C., Cullen, D.C., Geppert, W., 2017. Correlations between life-detection techniques and implications for sampling site selection in planetary analog missions. Astrobiology 17, 1009-1021.Kminek, G., Fisk, L.A., 2017. Protecting our investment in the exploration and utilization of space. Astrobiology 17, 955-955.K?lbl, D., Pignitter, M., Somoza, V., Schimak, M.P., Strbak, O., Blazevic, A., Milojevic, T., 2017. Exploring fingerprints of the extreme thermoacidophile Metallosphaera sedula grown on synthetic martian regolith materials as the sole energy sources. Frontiers in Microbiology 8, 1918. doi: 1910.3389/fmicb.2017.01918.Meadows, V.S., 2017. Reflections on O2 as a biosignature in exoplanetary atmospheres. Astrobiology 17, 1022-1052.Nuding, D.L., Gough, R.V., Venkateswaran, K.J., Spry, J.A., Tolbert, M.A., 2017. Laboratory investigations on the survival of Bacillus subtilis spores in deliquescent salt Mars analog environments. Astrobiology 17, 997-1008.Rummel, J.D., Conley, C.A., 2017. Four fallacies and an oversight: Searching for martian life. Astrobiology 17, 971-974.Russell, M.J., Nitschke, W., 2017. Methane: Fuel or exhaust at the emergence of life? Astrobiology 17, 1053-1066.Schulze-Makuch, D., Airo, A., Schirmack, J., 2017. The adaptability of life on earth and the diversity of planetary habitats. Frontiers in Microbiology 8, 2011. doi: 2010.3389/fmicb.2017.02011.Environmental GeochemistryArienzo, M., Donadio, C., Mangoni, O., Bolinesi, F., Stanislao, C., Trifuoggi, M., Toscanesi, M., Di Natale, G., Ferrara, L., 2017. Characterization and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in the sediments of Gulf of Pozzuoli (Campania, Italy). Marine Pollution Bulletin 124, 480-487.Bemanikharanagh, A., Bakhtiari, A.R., Mohammadi, J., Taghizadeh-Mehrjardi, R., 2017. Characterization and ecological risk of polycyclic aromatic hydrocarbons (PAHs) and n-alkanes in sediments of Shadegan international wetland, the Persian Gulf. Marine Pollution Bulletin 124, 155-170.Cao, X., Tarr, M.A., 2017. Aldehyde and ketone photoproducts from solar-irradiated crude oil–seawater systems determined by electrospray ionization–tandem mass spectrometry. Environmental Science & Technology 51, 11858-11866.Dafouz, R., Cáceres, N., Rodríguez-Gil, J.L., Mastroianni, N., López de Alda, M., Barceló, D., de Miguel, ?.G., Valcárcel, Y., 2018. Does the presence of caffeine in the marine environment represent an environmental risk? A regional and global study. Science of The Total Environment 615, 632-642.Kotzakoulakis, K., George, S.C., 2018. Predicting the weathering of fuel and oil spills: A diffusion-limited evaporation model. Chemosphere 190, 442-453.Lyman, S.N., Watkins, C., Jones, C.P., Mansfield, M.L., McKinley, M., Kenney, D., Evans, J., 2017. Hydrocarbon and carbon dioxide fluxes from natural gas well pad soils and surrounding soils in eastern Utah. Environmental Science & Technology 51, 11625-11633.Makatounis, P.E., Skancke, J., Florou, E., Stamou, A., Brandvik, P.J., 2017. Management of oil spill contamination in the Gulf of Patras caused by an accidental subsea blowout. Environmental Pollution 231, 578-588.O'Laughlin, C.M., Law, B.A., Zions, V.S., King, T.L., Robinson, B., Wu, Y., 2017. Settling of dilbit-derived oil-mineral aggregates (OMAs) & transport parameters for oil spill modelling. Marine Pollution Bulletin 124, 292-302.Ramirez, M.I., Arevalo, A.P., Sotomayor, S., Bailon-Moscoso, N., 2017. Contamination by oil crude extraction – Refinement and their effects on human health. Environmental Pollution 231, 415-425.Rushdi, A.I., Al-Shaikh, I., El-Mubarak, A.H., Alnaimi, H.A.J.A., Al-Shamary, N., Hassan, H.M., Assali, M.A., 2017. Characteristics and sources of anthropogenic and biogenic hydrocarbons in sediments from the coast of Qatar. Marine Pollution Bulletin 124, 56-66.Temerdashev, Z.A., Pavlenko, L.F., Korpakova, I.G., Skrypnik, G.V., Klimenko, T.L., Votinova, T.V., Ermakova, Y.S., 2017. On the limitation of the term petroleum products in the determination of the oil pollution of bottom sediments. Journal of Analytical Chemistry 72, 1120-1125.Vaezzadeh, V., Zakaria, M.P., Bong, C.W., 2017. Aliphatic hydrocarbons and triterpane biomarkers in mangrove oyster (Crassostrea belcheri) from the west coast of Peninsular Malaysia. Marine Pollution Bulletin 124, 33-42.Yan, G., Kim, G., 2017. Speciation and sources of brown carbon in precipitation at Seoul, Korea: Insights from excitation–emission matrix spectroscopy and carbon isotopic analysis. Environmental Science & Technology 51, 11580-11587.Yang, Z., Hua, Y., Mirnaghi, F., Hollebone, B.P., Jackman, P., Brown, C.E., Yang, C., Shah, K., Landriault, M., Chan, B., 2018. Effect of evaporative weathering and oil-sediment interaction on the fate and behavior of diluted bitumen in marine environments. Part 2. The water accommodated and particle-laden hydrocarbon species and toxicity of the aqueous phase. Chemosphere 191, 145-155.Yang, Z., Zhang, G., Hollebone, B.P., Brown, C.E., Yang, C., Lambert, P., Wang, Z., Landriault, M., Shah, K., 2017. Fate of oxygenated intermediates in solar irradiated diluted bitumen mixed with saltwater. Environmental Pollution 231, 622-634.BioremediationAhmad, J., 2017. Bioremediation of petroleum sludge using effective microorganism (EM) technology. Petroleum Science and Technology 35, 1515-1522.Alkorta, I., Epelde, L., Garbisu, C., 2017. Environmental parameters altered by climate change affect the activity of soil microorganisms involved in bioremediation. FEMS Microbiology Letters 364, Article fnx200.Dong, X., Jochmann, M.A., Elsner, M., Meyer, A.H., B?cker, L.E., Rahmatullah, M., Schunk, D., Lens, G., Meckenstock, R.U., 2017. Monitoring microbial mineralization using reverse stable isotope labeling analysis by mid-infrared laser spectroscopy. Environmental Science & Technology 51, 11876-11883.Garg, S., Newell, C.J., Kulkarni, P.R., King, D.C., Adamson, D.T., Renno, M.I., Sale, T., 2017. Overview of natural source zone depletion: Processes, controlling factors, and composition change. Groundwater Monitoring & Remediation 37, 62-81.Kronenberg, M., Trably, E., Bernet, N., Patureau, D., 2017. Biodegradation of polycyclic aromatic hydrocarbons: Using microbial bioelectrochemical systems to overcome an impasse. Environmental Pollution 231, 509-523.Li, M., Gao, Y., Qian, W.-J., Shi, L., Liu, Y., Nelson, W.C., Nicora, C.D., Resch, C.T., Thompson, C., Yan, S., Fredrickson, J.K., Zachara, J.M., Liu, C., 2017. Targeted quantification of functional enzyme dynamics in environmental samples for microbially mediated biogeochemical processes. Environmental Microbiology Reports 9, 512-521.Polyak, Y.M., Bakina, L.G., Chugunova, M.V., Mayachkina, N.V., Gerasimov, A.O., Bure, V.M., 2018. Effect of remediation strategies on biological activity of oil-contaminated soil - A field study. International Biodeterioration & Biodegradation 126, 57-68.Sun, J., Pan, L., Tsang, D.C.W., Zhan, Y., Zhu, L., Li, X., 2018. Organic contamination and remediation in the agricultural soils of China: A critical review. Science of The Total Environment 615, 724-740.Xaaldi Kalhor, A., Movafeghi, A., Mohammadi-Nassab, A.D., Abedi, E., Bahrami, A., 2017. Potential of the green alga Chlorella vulgaris for biodegradation of crude oil hydrocarbons. Marine Pollution Bulletin 123, 286-290.Zhang, K., Sun, Y., Cui, Z., Yu, D., Zheng, L., Liu, P., Lv, Z., 2017. Periodically spilled-oil input as a trigger to stimulate the development of hydrocarbon-degrading consortia in a beach ecosystem. Scientific Reports 7, Article 12446.Deep Horizon/MacondoDelmont, T.O., Eren, A.M., 2017. Simulations predict microbial responses in the environment? This environment disagrees retrospectively. Proceedings of the National Academy of Sciences 114, E8947-E8949.Engel, A.S., Liu, C., Paterson, A.T., Anderson, L.C., Turner, R.E., Overton, E.B., 2017. Salt marsh bacterial communities before and after the Deepwater Horizon oil spill. Applied and Environmental Microbiology 83, e00784-00717.Finch, B.E., Marzooghi, S., Di Toro, D.M., Stubblefield, W.A., 2017. Phototoxic potential of undispersed and dispersed fresh and weathered Macondo crude oils to Gulf of Mexico marine organisms. Environmental Toxicology and Chemistry 36, 2640-2650.Handley, K.M., Piceno, Y.M., Hu, P., Tom, L.M., Mason, O.U., Andersen, G.L., Jansson, J.K., Gilbert, J.A., 2017. Metabolic and spatio-taxonomic response of uncultivated seafloor bacteria following the Deepwater Horizon oil spill. ISME Journal 11, 2569-2583.Probst, A.J., Hu, P., Sun, C.L., Dubinsky, E.A., Sieber, C.M.K., Banfield, J.F., Andersen, G.L., 2017. Reply to Delmont and Eren: Strain variants and population structure during the Deepwater Horizon oil spill. Proceedings of the National Academy of Sciences 114 no. 43.Schifter, I., Sánchez-Reyna, G., González-Macías, C., Salazar-Coria, L., González-Lozano, C., 2017. Fluorescence characteristics in the deep waters of South Gulf of México. Marine Pollution Bulletin 123, 165-174.Oil Sand Process Waters/Tailing PondsBarron, M.G., Conmy, R.N., Holder, E.L., Meyer, P., Wilson, G.J., Principe, V.E., Willming, M.M., 2018. Toxicity of Cold Lake Blend and Western Canadian Select dilbits to standard aquatic test species. Chemosphere 191, 1-6.Mohamad Shahimin, M.F., Siddique, T., 2017. Sequential biodegradation of complex naphtha hydrocarbons under methanogenic conditions in two different oil sands tailings. Environmental Pollution 221, 398-406.Thienpont, J.R., Desjardins, C.M., Kimpe, L.E., Korosi, J.B., Kokelj, S.V., Palmer, M.J., Muir, D.C.G., Kirk, J.L., Smol, J.P., Blais, J.M., 2017. Comparative histories of polycyclic aromatic compound accumulation in lake sediments near petroleum operations in western Canada. Environmental Pollution 231, 13-21.UnconventionalShale Gas-CBM ResourcesEvolution/Paleontology/PalynologyAdorno, R.R., do Carmo, D.A., Germs, G., Walde, D.H.G., Denezine, M., Boggiani, P.C., Sousa e Silva, S.C., Vasconcelos, J.R., Tobias, T.C., Guimar?es, E.M., Vieira, L.C., Figueiredo, M.F., Moraes, R., Caminha, S.A., Suarez, P.A.Z., Rodrigues, C.V., Caixeta, G.M., Pinho, D., Schneider, G., Muyamba, R., 2017. Cloudina lucianoi (Beurlen & Sommer, 1957), Tamengo Formation, Ediacaran, Brazil: Taxonomy, analysis of stratigraphic distribution and biostratigraphy. Precambrian Research 301, 19-35.Agematsu, S., Uesugi, K., Sano, H., Sashida, K., 2017. Reconstruction of the multielement apparatus of the earliest Triassic conodont, Hindeodus parvus, using synchrotron radiation X-ray micro-tomography. Journal of Paleontology 91, 1220.Edgar, K.M., Hull, P.M., Ezard, T.H.G., 2017. Evolutionary history biases inferences of ecology and environment from δ13C but not δ18O values. Nature Communications 8, Article 1106.Gray, D.D., Zonneveld, K.A.F., Versteegh, G.J.M., 2017. Species-specific sensitivity of dinoflagellate cysts to aerobic degradation: A five-year natural exposure experiment. Review of Palaeobotany and Palynology 247, 175-187.Havig, J.R., Hamilton, T.L., Bachan, A., Kump, L.R., 2017. Sulfur and carbon isotopic evidence for metabolic pathway evolution and a four-stepped Earth system progression across the Archean and Paleoproterozoic. Earth-Science Reviews 174, 1-21.Lewy, Z., 2017. Dinosaur demise in light of their alleged perennial polar residency. International Journal of Earth Sciences 106, 2609-2616.Norstr?m, E., Katrantsiotis, C., Smittenberg, R.H., Kouli, K., 2017. Chemotaxonomy in some Mediterranean plants and implications for fossil biomarker records. Geochimica et Cosmochimica Acta 219, 96-110.Pennisi, E., 2017. Evolution accelerated when life set foot on land. Science 358, 158.Pereira, J.B.S., Labiak, P.H., Stützel, T., Schulz, C., 2017. Origin and biogeography of the ancient genus Iso?tes with focus on the Neotropics. Botanical Journal of the Linnean Society 185, 253-271.Reilly, S., Summons, R., Mayr, G., Vinther, J., 2017. Preservation of uropygial gland lipids in a 48-million-year-old bird. Proceedings of the Royal Society B: Biological Sciences 284, Article 20171050.Wang, Y., Wang, Y., Du, W., 2017. A rare disc-like holdfast of the Ediacaran macroalga from South China. Journal of Paleontology 91, 1091.Zapalski, M.K., Nowicki, J., Jakubowicz, M., Berkowski, B., 2017. Tabulate corals across the Frasnian/Famennian boundary: architectural turnover and its possible relation to ancient photosymbiosis. Palaeogeography, Palaeoclimatology, Palaeoecology 487, 416-429.Zodrow, E.L., Mastalerz, M., P?eni?ka, J., Cleal, C.J., 2017. Linking Dolerotheca-like prepollen organs with Alethopteris pseudograndinioides foliage and assessing chemical properties of in situ prepollen grains: Implications for reconstructing Pennsylvanian-age alethopterid seed ferns. International Journal of Coal Geology 183, 65-77.Origins of Life/Microbial GenomicsAdam, P.S., Borrel, G., Brochier-Armanet, C., Gribaldo, S., 2017. The growing tree of Archaea: new perspectives on their diversity, evolution and ecology. ISME Journal 11, 2407-2425.Boyle, R., 2017. Eukaryotic origins and the Proterozoic Earth system: A link between global scale glaciations and eukaryogenesis? Earth-Science Reviews 174, 22-38.Fleury, B., Carrasco, N., Millan, M., Vettier, L., Szopa, C., 2017. Organic chemistry in a CO2 rich early Earth atmosphere. Earth and Planetary Science Letters 479, 34-42.Kim, H.-J., Benner, S.A., 2017. Prebiotic stereoselective synthesis of purine and noncanonical pyrimidine nucleotide from nucleobases and phosphorylated carbohydrates. Proceedings of the National Academy of Sciences 114, 11315-11320.Nakayama, T., Inagaki, Y., 2017. Genomic divergence within non-photosynthetic cyanobacterial endosymbionts in rhopalodiacean diatoms. Scientific Reports 7, Article 13075.Parks, D.H., Rinke, C., Chuvochina, M., Chaumeil, P.-A., Woodcroft, B.J., Evans, P.N., Hugenholtz, P., Tyson, G.W., 2017. Recovery of nearly 8,000 metagenome-assembled genomes substantially expands the tree of life. Nature Microbiology 2, 1533-1542.Pearce, B.K.D., Pudritz, R.E., Semenov, D.A., Henning, T.K., 2017. Origin of the RNA world: The fate of nucleobases in warm little ponds. Proceedings of the National Academy of Sciences 114, 11327–11332.Russell, M.J., Nitschke, W., 2017. Methane: Fuel or exhaust at the emergence of life? Astrobiology 17, 1053-1066.Shih, P.M., Ward, L.M., Fischer, W.W., 2017. Evolution of the 3-hydroxypropionate bicycle and recent transfer of anoxygenic photosynthesis into the Chloroflexi. Proceedings of the National Academy of Sciences 114, 10749-10754.Wong, M.L., Charnay, B.D., Gao, P., Yung, Y.L., Russell, M.J., 2017. Nitrogen oxides in early Earth's atmosphere as electron acceptors for life's emergence. Astrobiology 17, 975-983.Hominid EvolutionDannemann, M., Kelso, J., 2017. The contribution of Neanderthals to phenotypic variation in modern humans. The American Journal of Human Genetics 101, 578-589.Devièse, T., Karavani?, I., Comeskey, D., Kubiak, C., Korlevi?, P., Hajdinjak, M., Radovi?, S., Procopio, N., Buckley, M., P??bo, S., Higham, T., 2017. Direct dating of Neanderthal remains from the site of Vindija Cave and implications for the Middle to Upper Paleolithic transition. Proceedings of the National Academy of Sciences 114, 10606-10611.Gibbons, A., 2017. Neandertal genome reveals greater legacy in the living. Science 358, 21.Gibbons, A., 2017. Neandertals gave ‘lost’ African DNA back to moderns. Science 358, 431.Hublin, J.-J., 2017. The last Neanderthal. Proceedings of the National Academy of Sciences 114, 10520-10522.Rivera, T.A., Darata, R., Lippert, P.C., Jicha, B.R., Schmitz, M.D., 2017. The duration of a Yellowstone super-eruption cycle and implications for the age of the Olduvai subchron. Earth and Planetary Science Letters 479, 377-386.Ruiter, D.J.d., Churchill, S.E., Hawks, J., Berger, L.R., 2017. Late Australopiths and the emergence of Homo. Annual Review of Anthropology 46, 99-115.Trinkaus, E., Villotte, S., 2017. External auditory exostoses and hearing loss in the Shanidar 1 Neandertal. PLOS ONE 12, Article e0186684.Fluid InclusionsMangenot, X., Bonifacie, M., Gasparrini, M., G?tz, A., Chaduteau, C., Ader, M., Rouchon, V., 2017. Coupling Δ47 and fluid inclusion thermometry on carbonate cements to precisely reconstruct the temperature, salinity and δ18O of paleo-groundwater in sedimentary basins. Chemical Geology 472, 44-57.Mao, S., Lü, M., Shi, Z., 2017. Prediction of the PVTx and VLE properties of natural gases with a general Helmholtz equation of state. Part I: Application to the CH4–C2H6–C3H8–CO2–N2 system. Geochimica et Cosmochimica Acta 219, 74-95.Raimbourg, H., Thiéry, R., Vacelet, M., Famin, V., Ramboz, C., Boussafir, M., Disnar, J.-R., Yamaguchi, A., 2017. Organic matter cracking: A source of fluid overpressure in subducting sediments. Tectonophysics 721, 254-274.Wang, L.L., Zhang, G.Q., Hallais, S., Tanguy, A., Yang, D.S., 2017. Swelling of shales: A multiscale experimental investigation. Energy & Fuels 31, 10442-10451.General InterestAgarwal, N., Freakley, S.J., McVicker, R.U., Althahban, S.M., Dimitratos, N., He, Q., Morgan, D.J., Jenkins, R.L., Willock, D.J., Taylor, S.H., Kiely, C.J., Hutchings, G.J., 2017. Aqueous Au-Pd colloids catalyze selective CH4 oxidation to CH3OH with O2 under mild conditions. Science, 10.1126/science.aan6515.Dzidek, B., Bochereau, S., Johnson, S.A., Hayward, V., Adams, M.J., 2017. Why pens have rubbery grips. Proceedings of the National Academy of Sciences 114, 10864-10869.Hu, J., Peng, P., 2017. An overview and perspectives on organic geochemistry. Acta Sedimentologica Sinica 35, 968-980.GeologyDenny, A.C., Kozdon, R., Kitajima, K., Valley, J.W., 2017. Isotopically zoned carbonate cements in Early Paleozoic sandstones of the Illinois Basin: δ18O and δ13C records of burial and fluid flow. Sedimentary Geology 361, 93-110.Jones, S., 2017. Goo, glue, and grain binding: Importance of biofilms for diagenesis in sandstones. Geology 45, 959-960.Liu, C., Zhao, H., Zhao, J., Wu, B., Huang, L., Wang, J., Zhang, D., Zhang, S., 2017. Sedimentology of energy basins and the frontier scientific problems. Acta Sedimentologica Sinica 35, 1032-1043.Macías-Sánchez, E., Willinger, M.G., Pina, C.M., Checa, A.G., 2017. Transformation of ACC into aragonite and the origin of the nanogranular structure of nacre. Scientific Reports 7, Article 12728.Marriner, N., Kaniewski, D., Morhange, C., Flaux, C., Giaime, M., Vacchi, M., Goff, J., 2017. Tsunamis in the geological record: Making waves with a cautionary tale from the Mediterranean. Science Advances 3, Article e1700485.Morley, C.K., von Hagke, C., Hansberry, R., Collins, A., Kanitpanyacharoen, W., King, R., 2018. Review of major shale-dominated detachment and thrust characteristics in the diagenetic zone: Part II, rock mechanics and microscopic scale. Earth-Science Reviews 176, 19-50.Wang, Z., Glais, Y., Qiao, L., Huang, A., Liu, J., 2018. Hydro-geochemical analysis of the interplay between the groundwater, host rock and water curtain system for an underground oil storage facility. Tunnelling and Underground Space Technology 71, 466-477.Xu, Y., Huang, Y., Hu, X., Yang, J., 2017. Hot topics in Phanerozoic deep-time climate research: Based on bibliometric analysis. Acta Sedimentologica Sinica 35, 994-1003 Zhao, J., Li, J., Xu, Z., 2017. Advances in the origin of overpressures in sedimentary basins. Acta Petrolei Sinica 38, 973-998.Bolide Impacts/Crater GeochemistryRampino, M.R., Caldeira, K., 2017. Correlation of the largest craters, stratigraphic impact signatures, and extinction events over the past 250?Myr. Geoscience Frontiers 8, 1241-1245.Rodovská, Z., Magna, T., ?ák, K., Kato, C., Savage, P.S., Moynier, F., Skála, R., Je?ek, J., 2017. Implications for behavior of volatile elements during impacts—Zinc and copper systematics in sediments from the Ries impact structure and central European tektites. Meteoritics & Planetary Science 52, 2178-2192.Schmieder, M., Kennedy, T., Jourdan, F., Buchner, E., Reimold, W.U., 2018. A high-precision 40Ar/39Ar age for the N?rdlinger Ries impact crater, Germany, and implications for the accurate dating of terrestrial impact events. Geochimica et Cosmochimica Acta 220, 146-157.Zylberman, W., Quesnel, Y., Rochette, P., Osinski, G.R., Marion, C., Gattacceca, J., 2017. Hydrothermally enhanced magnetization at the center of the Haughton impact structure? Meteoritics & Planetary Science 52, 2147-2165.HydratesHan, D., Wang, Z., Song, Y., Zhao, J., Wang, D., 2017. Numerical analysis of depressurization production of natural gas hydrate from different lithology oceanic reservoirs with isotropic and anisotropic permeability. Journal of Natural Gas Science and Engineering 46, 575-591.Kondori, J., Zendehboudi, S., Hossain, M.E., 2017. A review on simulation of methane production from gas hydrate reservoirs: Molecular dynamics prospective. Journal of Petroleum Science and Engineering 159, 754-772.Li, S., Wang, Z., Xu, X., Zheng, R., Hou, J., 2017. Experimental study on dissociation of hydrate reservoirs with different saturations by hot brine injection. Journal of Natural Gas Science and Engineering 46, 555-562.Nguyen, N.N., Nguyen, A.V., 2017. Hydrophobic effect on gas hydrate formation in the presence of additives. Energy & Fuels 31, 10311-10323.Paganoni, M., Cartwright, J.A., Foschi, M., Shipp, C.R., Van Rensbergen, P., 2018. Relationship between fluid-escape pipes and hydrate distribution in offshore Sabah (NW Borneo). Marine Geology 395, 82-103.Ranieri, U., Koza, M.M., Kuhs, W.F., Klotz, S., Falenty, A., Gillet, P., Bove, L.E., 2017. Fast methane diffusion at the interface of two clathrate structures. Nature Communications 8, Article 1076.Zhang, H., Cheng, Y., Shi, J., Li, L., Li, M., Han, X., Yan, C., 2017. Experimental study of water-based drilling fluid disturbance on natural gas hydrate-bearing sediments. Journal of Natural Gas Science and Engineering 47, 1-10.Zhang, W., Liang, J., Lu, J.a., Wei, J., Su, P., Fang, Y., Guo, Y., Yang, S., Zhang, G., 2017. Accumulation features and mechanisms of high saturation natural gas hydrate in Shenhu Area, northern South China Sea. Petroleum Exploration and Development 44, 708-719.Isotope GeochemistryBrownlow, R., Lowry, D., Fisher, R.E., France, J.L., Lanoisellé, M., White, B., Wooster, M.J., Zhang, T., Nisbet, E.G., 2017. Isotopic ratios of tropical methane emissions by atmospheric measurement. Global Biogeochemical Cycles 31, 1408-1419.Bush, R.T., Wallace, J., Currano, E.D., Jacobs, B.F., McInerney, F.A., Dunn, R.E., Tabor, N.J., 2017. Cell anatomy and leaf δ13C as proxies for shading and canopy structure in a Miocene forest from Ethiopia. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 593-604.Coutaud, M., Méheut, M., Glatzel, P., Pokrovski, G.S., Viers, J., Rols, J.-L., Pokrovsky, O.S., 2018. Small changes in Cu redox state and speciation generate large isotope fractionation during adsorption and incorporation of Cu by a phototrophic biofilm. Geochimica et Cosmochimica Acta 220, 1-18.Edgar, K.M., Hull, P.M., Ezard, T.H.G., 2017. Evolutionary history biases inferences of ecology and environment from δ13C but not δ18O values. Nature Communications 8, Article 1106.Havig, J.R., Hamilton, T.L., Bachan, A., Kump, L.R., 2017. Sulfur and carbon isotopic evidence for metabolic pathway evolution and a four-stepped Earth system progression across the Archean and Paleoproterozoic. Earth-Science Reviews 174, 1-21.Hofmann, L.C., Heesch, S., 2017. Latitudinal trends in stable isotope signatures and carbon concentrating mechanisms of northeast Atlantic rhodoliths. Biogeosciences Discussions 2017, 1-18.Mejía, L.M., Paytan, A., Eisenhauer, A., B?hm, F., Kolevica, A., Bolton, C., Méndez-Vicente, A., Abrevaya, L., Isensee, K., Stoll, H., 2018. Controls over δ44/40Ca and Sr/Ca variations in coccoliths: New perspectives from laboratory cultures and cellular models. Earth and Planetary Science Letters 481, 48-60.Misarti, N., Gier, E., Finney, B., Barnes, K., McCarthy, M., 2017. Compound-specific amino acid δ15N values in archaeological shell: Assessing diagenetic integrity and potential for isotopic baseline reconstruction. Rapid Communications in Mass Spectrometry 31, 1881-1891.Posth, N.R., Bristow, L.A., Cox, R.P., Habicht, K.S., Danza, F., Tonolla, M., Frigaard, N.U., Canfield, D.E., 2017. Carbon isotope fractionation by anoxygenic phototrophic bacteria in euxinic Lake Cadagno. Geobiology 15, 798-816.Tolstikhin, I.N., Ballentine, C.J., Polyak, B.G., Prasolov, E.M., Kikvadze, O.E., 2017. The noble gas isotope record of hydrocarbon field formation time scales. Chemical Geology 471, 141-152.Wu, L., Chládková, B., Lechtenfeld, O.J., Lian, S., Schindelka, J., Herrmann, H., Richnow, H.H., 2018. Characterizing chemical transformation of organophosphorus compounds by 13C and 2H stable isotope analysis. Science of The Total Environment 615, 20-28.Yan, G., Kim, G., 2017. Speciation and sources of brown carbon in precipitation at Seoul, Korea: Insights from excitation–emission matrix spectroscopy and carbon isotopic analysis. Environmental Science & Technology 51, 11580-11587.Zhuang, G.-C., Lin, Y.-S., Bowles, M.W., Heuer, V.B., Lever, M.A., Elvert, M., Hinrichs, K.-U., 2017. Distribution and isotopic composition of trimethylamine, dimethylsulfide and dimethylsulfoniopropionate in marine sediments. Marine Chemistry 196, 35-46.Clumped IsotopesDe Boever, E., Brasier, A.T., Foubert, A., Kele, S., 2017. What do we really know about early diagenesis of non-marine carbonates? Sedimentary Geology 361, 25-51.Haghnegahdar, M.A., Schauble, E.A., Young, E.D., 2017. A model for 12CH2D2 and 13CH3D as complementary tracers for the budget of atmospheric CH4. Global Biogeochemical Cycles 31, 1387-1407.Mangenot, X., Bonifacie, M., Gasparrini, M., G?tz, A., Chaduteau, C., Ader, M., Rouchon, V., 2017. Coupling Δ47 and fluid inclusion thermometry on carbonate cements to precisely reconstruct the temperature, salinity and δ18O of paleo-groundwater in sedimentary basins. Chemical Geology 472, 44-57.Piasecki, A., Sessions, A., Lawson, M., Ferreira, A.A., Santos Neto, E.V., Ellis, G.S., Lewan, M.D., Eiler, J.M., 2018. Position-specific 13C distributions within propane from experiments and natural gas samples. Geochimica et Cosmochimica Acta 220, 110-124.Methods/InstrumentationFleisher, A.J., Long, D.A., Liu, Q., Gameson, L., Hodges, J.T., 2017. Optical measurement of radiocarbon below unity fraction modern by linear absorption spectroscopy. The Journal of Physical Chemistry Letters 8, 4550-4556.Hall, S.J., Huang, W., Hammel, K.E., 2017. An optical method for carbon dioxide isotopes and mole fractions in small gas samples: Tracing microbial respiration from soil, litter, and lignin. Rapid Communications in Mass Spectrometry 31, 1938-1946.Maruccio, L., Quarta, G., Braione, E., Calcagnile, L., 2017. Measuring stable carbon and nitrogen isotopes by IRMS and 14C by AMS on samples with masses in the microgram range: Performances of the system installed at CEDAD-University of Salento. International Journal of Mass Spectrometry 421, 1-7.Yin, L., Li, J., Liu, J., Li, C., Sun, S., Liang, H., Xu, J., 2017. Precise and accurate Re–Os isotope dating of organic-rich sedimentary rocks by thermal ionization mass spectrometry with an improved H2O2-HNO3 digestion procedure. International Journal of Mass Spectrometry 421, 263-270.Mathematical GeochemistryFinsterle, S., Commer, M., Edmiston, J.K., Jung, Y., Kowalsky, M.B., Pau, G.S.H., Wainwright, H.M., Zhang, Y., 2017. iTOUGH2: A multiphysics simulation-optimization framework for analyzing subsurface systems. Computers & Geosciences 108, 8-20.Jung, Y., Pau, G.S.H., Finsterle, S., Pollyea, R.M., 2017. TOUGH3: A new efficient version of the TOUGH suite of multiphase flow and transport simulators. Computers & Geosciences 108, 2-7.Microbiology/ExtremophilesAdam, P.S., Borrel, G., Brochier-Armanet, C., Gribaldo, S., 2017. The growing tree of Archaea: new perspectives on their diversity, evolution and ecology. ISME Journal 11, 2407-2425.Gu, Z., Liu, Y., Xu, B., Wang, N., Jiao, N., Shen, L., Liu, H., Zhou, Y., Liu, X., Li, J., Sun, J., 2017. Hymenobacter frigidus sp. nov., isolated from a glacier ice core. International Journal of Systematic and Evolutionary Microbiology 67, 4121-4125.K?lbl, D., Pignitter, M., Somoza, V., Schimak, M.P., Strbak, O., Blazevic, A., Milojevic, T., 2017. Exploring fingerprints of the extreme thermoacidophile Metallosphaera sedula grown on synthetic martian regolith materials as the sole energy sources. Frontiers in Microbiology 8, 1918. doi: 1910.3389/fmicb.2017.01918.Mori, J.F., Scott, J.J., Hager, K.W., Moyer, C.L., Küsel, K., Emerson, D., 2017. Physiological and ecological implications of an iron- or hydrogen-oxidizing member of the Zetaproteobacteria, Ghiorsea bivora, gen. nov., sp. nov. ISME Journal 11, 2624-2636.Müller, V., Hess, V., 2017. The minimum biological energy quantum. Frontiers in Microbiology 8, 2019. doi: 2010.3389/fmicb.2017.02019.Nguyen, N.-L., Yu, W.-J., Yang, H.-Y., Kim, J.-G., Jung, M.-Y., Park, S.-J., Roh, S.-W., Rhee, S.-K., 2017. A novel methanotroph in the genus Methylomonas that contains a distinct clade of soluble methane monooxygenase. Journal of Microbiology 55, 775-782.Parks, D.H., Rinke, C., Chuvochina, M., Chaumeil, P.-A., Woodcroft, B.J., Evans, P.N., Hugenholtz, P., Tyson, G.W., 2017. Recovery of nearly 8,000 metagenome-assembled genomes substantially expands the tree of life. Nature Microbiology 2, 1533-1542.Xing, T., Liu, Y., Wang, N., Xu, B., Liu, K., Shen, L., Gu, Z., Guo, B., Zhou, Y., Liu, H., 2017. Erythrobacter arachoides sp. nov., isolated from ice core. International Journal of Systematic and Evolutionary Microbiology 67, 4235-4239.Microbial EcosystemsAnderson, R.E., Reveillaud, J., Reddington, E., Delmont, T.O., Eren, A.M., McDermott, J.M., Seewald, J.S., Huber, J.A., 2017. Genomic variation in microbial populations inhabiting the marine subseafloor at deep-sea hydrothermal vents. Nature Communications 8, Article 1114.Aylward, F.O., Boeuf, D., Mende, D.R., Wood-Charlson, E.M., Vislova, A., Eppley, J.M., Romano, A.E., DeLong, E.F., 2017. Diel cycling and long-term persistence of viruses in the ocean’s euphotic zone. Proceedings of the National Academy of Sciences 114, 11446-11451.Carere, C.R., Hards, K., Houghton, K.M., Power, J.F., McDonald, B., Collet, C., Gapes, D.J., Sparling, R., Boyd, E.S., Cook, G.M., Greening, C., Stott, M.B., 2017. Mixotrophy drives niche expansion of verrucomicrobial methanotrophs. ISME Journal 11, 2599-2610.Chiriac, C.M., Szekeres, E., Rudi, K., Baricz, A., Hegedus, A., Drago?, N., Coman, C., 2017. Differences in temperature and water chemistry shape distinct diversity patterns in thermophilic microbial communities. Applied and Environmental Microbiology 83, Article e01363-pte-Port, S., Subirats, J., Fillol, M., Sànchez-Melsió, A., Marcé, R., Rivas-Ruiz, P., Rosell-Melé, A., Borrego, C.M., 2017. Abundance and co-distribution of widespread marine archaeal lineages in surface sediments of freshwater water bodies across the Iberian Peninsula. Microbial Ecology 74, 776-787.Fuertez, J., Boakye, R., McLennan, J., Adams, D.J., Sparks, T.D., Gottschalk, A., 2017. Developing methanogenic microbial consortia from diverse coal sources and environments. Journal of Natural Gas Science and Engineering 46, 637-650.Guo, X.-p., Niu, Z.-s., Lu, D.-p., Feng, J.-n., Chen, Y.-r., Tou, F.-y., Liu, M., Yang, Y., 2017. Bacterial community structure in the intertidal biofilm along the Yangtze Estuary, China. Marine Pollution Bulletin 124, 314-320.Hamilton, T.L., Welander, P.V., Albrecht, H.L., Fulton, J.M., Schaperdoth, I., Bird, L.R., Summons, R.E., Freeman, K.H., Macalady, J.L., 2017. Microbial communities and organic biomarkers in a Proterozoic-analog sinkhole. Geobiology 15, 784-797.He, K., Gilder, S.A., Orsi, W.D., Zhao, X., Petersen, N., 2017. Constant flux of spatial niche partitioning through high-resolution sampling of magnetotactic bacteria. Applied and Environmental Microbiology 83, e01382-01317.Herren, C.M., McMahon, K.D., 2017. Cohesion: a method for quantifying the connectivity of microbial communities. ISME Journal 11, 2426-2438.Liang, Y., Zhang, Y., Wang, N., Luo, T., Zhang, Y., Rivkin, R.B., 2017. Estimating primary production of picophytoplankton using the carbon-based ocean productivity model: A preliminary study. Frontiers in Microbiology 8, 1926. doi: 1910.3389/fmicb.2017.01926.Metcalfe, D.B., 2017. Microbial change in warming soils. Science 358, 41-42.Miao, L., Zhang, Q., Wang, S., Li, B., Wang, Z., Zhang, S., Zhang, M., Peng, Y., 2018. Characterization of EPS compositions and microbial community in an Anammox SBBR system treating landfill leachate. Bioresource Technology 249, 108-116.Mogul, R., Vaishampayan, P., Bashir, M., McKay, C.P., Schubert, K., Bornaccorsi, R., Gomez, E., Tharayil, S., Payton, G., Capra, J., Andaya, J., Bacon, L., Bargoma, E., Black, D., Boos, K., Brant, M., Chabot, M., Chau, D., Cisneros, J., Chu, G., Curnutt, J., DiMizio, J., Engelbrecht, C., Gott, C., Harnoto, R., Hovanesian, R., Johnson, S., Lavergne, B., Martinez, G., Mans, P., Morales, E., Oei, A., Peplow, G., Piaget, R., Ponce, N., Renteria, E., Rodriguez, V., Rodriguez, J., Santander, M., Sarmiento, K., Scheppelmann, A., Schroter, G., Sexton, D., Stephenson, J., Symer, K., Russo-Tait, T., Weigel, B., Wilhelm, M.B., 2017. Microbial community and biochemical dynamics of biological soil crusts across a gradient of surface coverage in the central Mojave Desert. Frontiers in Microbiology 8, 1974. doi: 1910.3389/fmicb.2017.01974.Momper, L., Kiel Reese, B., Zinke, L., Wanger, G., Osburn, M.R., Moser, D., Amend, J.P., 2017. Major phylum-level differences between porefluid and host rock bacterial communities in the terrestrial deep subsurface. Environmental Microbiology Reports 9, 501-511.Niu, M., Fan, X., Zhuang, G., Liang, Q., Wang, F., 2017. Methane-metabolizing microbial communities in sediments of the Haima cold seep area, northwest slope of the South China Sea. FEMS Microbiology Ecology 93, Article fix101.Parada, A.E., Fuhrman, J.A., 2017. Marine archaeal dynamics and interactions with the microbial community over 5 years from surface to seafloor. ISME Journal 11, 2510-2525.Ren, Z., Gao, H., Elser, J.J., Zhao, Q., 2017. Microbial functional genes elucidate environmental drivers of biofilm metabolism in glacier-fed streams. Scientific Reports 7, Article 12668.Ridenhour, B.J., Brooker, S.L., Williams, J.E., Van Leuven, J.T., Miller, A.W., Dearing, M.D., Remien, C.H., 2017. Modeling time-series data from microbial communities. ISME Journal 11, 2526-2537.Silva, B.S.d.O., Coutinho, F.H., Gregoracci, G.B., Leomil, L., de Oliveira, L.S., Fróes, A., Tschoeke, D., Soares, A.C., Cabral, A.S., Ward, N.D., Richey, J.E., Krusche, A.V., Yager, P.L., de Rezende, C.E., Thompson, C.C., Thompson, F.L., 2017. Virioplankton assemblage structure in the lower river and ocean continuum of the Amazon. mSphere 2, DOI: 10.1128/mSphere.00366-00317.Suzuki, S., Ishii, S.i., Hoshino, T., Rietze, A., Tenney, A., Morrill, P.L., Inagaki, F., Kuenen, J.G., Nealson, K.H., 2017. Unusual metabolic diversity of hyperalkaliphilic microbial communities associated with subterranean serpentinization at The Cedars. ISME Journal 11, 2584-2598.Tecon, R., Or, D., 2017. Biophysical processes supporting the diversity of microbial life in soil. FEMS Microbiology Reviews 41, 599-623.Trias, R., Ménez, B., le Campion, P., Zivanovic, Y., Lecourt, L., Lecoeuvre, A., Schmitt-Kopplin, P., Uhl, J., Gislason, S.R., Alfre?sson, H.A., Mesfin, K.G., Sn?bj?rnsdóttir, S.?., Aradóttir, E.S., Gunnarsson, I., Matter, J.M., Stute, M., Oelkers, E.H., Gérard, E., 2017. High reactivity of deep biota under anthropogenic CO2 injection into basalt. Nature Communications 8, Article 1063.Uhlig, C., Kirkpatrick, J.B., D'Hondt, S., Loose, B., 2017. Methane oxidizing seawater microbial communities from an Arctic shelf. Biogeosciences Discussions 2017, 1-37.Ward, L.M., Idei, A., Terajima, S., Kakegawa, T., Fischer, W.W., McGlynn, S.E., 2017. Microbial diversity and iron oxidation at Okuoku-hachikurou Onsen, a Japanese hot spring analog of Precambrian iron formations. Geobiology 15, 817-835.Zinke, L.A., Mullis, M.M., Bird, J.T., Marshall, I.P.G., J?rgensen, B.B., Lloyd, K.G., Amend, J.P., Kiel Reese, B., 2017. Thriving or surviving? Evaluating active microbial guilds in Baltic Sea sediment. Environmental Microbiology Reports 9, 528-536.Petroleum DegradersAl-Mailem, D.M., Kansour, M.K., Radwan, S.S., 2017. Capabilities and limitations of DGGE for the analysis of hydrocarbonoclastic prokaryotic communities directly in environmental samples. MicrobiologyOpen 6, Article e00495.Sampaio, D.S., Almeida, J.R.B., de Jesus, H.E., Rosado, A.S., Seldin, L., Jurelevicius, D., 2017. Distribution of anaerobic hydrocarbon-degrading bacteria in soils from King George Island, Maritime Antarctica. Microbial Ecology 74, 810-820.Singh, R., Guzman, M.S., Bose, A., 2017. Anaerobic oxidation of ethane, propane, and butane by marine microbes: A mini review. Frontiers in Microbiology 8, 2056. doi: 2010.3389/fmicb.2017.02056.Song, Z., Zhao, F., Sun, G., Zhu, W., 2017. Long-term dynamics of microbial communities in a high-permeable petroleum reservoir reveals the spatiotemporal relationship between community and oil recovery. Energy & Fuels 31, 10588-10597.Tamazawa, S., Mayumi, D., Mochimaru, H., Sakata, S., Maeda, H., Wakayama, T., Ikarashi, M., Kamagata, Y., Tamaki, H., 2017. Petrothermobacter organivorans gen. nov., sp. nov., a thermophilic, strictly anaerobic bacterium of the phylum Deferribacteres isolated from a deep subsurface oil reservoir. International Journal of Systematic and Evolutionary Microbiology 67, 3982-3986.Varjani, S.J., Gnansounou, E., 2017. Microbial dynamics in petroleum oilfields and their relationship with physiological properties of petroleum oil reservoirs. Bioresource Technology 245, 1258-1265.Xaaldi Kalhor, A., Movafeghi, A., Mohammadi-Nassab, A.D., Abedi, E., Bahrami, A., 2017. Potential of the green alga Chlorella vulgaris for biodegradation of crude oil hydrocarbons. Marine Pollution Bulletin 123, 286-290.Zhang, K., Sun, Y., Cui, Z., Yu, D., Zheng, L., Liu, P., Lv, Z., 2017. Periodically spilled-oil input as a trigger to stimulate the development of hydrocarbon-degrading consortia in a beach ecosystem. Scientific Reports 7, Article 12446.Oil & Gas ExplorationChen, Y., Shen, A., Pan, L., Zhang, J., Wang, X., 2017. Features, origin and distribution of microbial dolomite reservoirs: A case study of 4th Member of Sinian Dengying Formation in Sichuan Basin, SW China. Petroleum Exploration and Development 44, 745-757.Zhao, W., Wei, G., Yang, W., Mo, W., Xie, W., Su, N., Liu, M., Zeng, F., Wu, S., 2017. Discovery of Wanyuan-Dazhou Intracratonic Rift and its significance for gas exploration in Sichuan Basin, SW China. Petroleum Exploration and Development 44, 697-707.Oil & Gas Generation/ExpulsionMa, Y., Cao, T., Snowdon, L., Qian, M., Jiang, Q., Li, M., Mahlstedt, N., Horsfield, B., 2017. Impact of different experimental heating rates on calculated hydrocarbon generation kinetics. Energy & Fuels 31, 10378-10392.Raimbourg, H., Thiéry, R., Vacelet, M., Famin, V., Ramboz, C., Boussafir, M., Disnar, J.-R., Yamaguchi, A., 2017. Organic matter cracking: A source of fluid overpressure in subducting sediments. Tectonophysics 721, 254-274.Wood, D.A., 2017. Re-establishing the merits of thermal maturity and petroleum generation multi-dimensional modeling with an Arrhenius Equation using a single activation energy. Journal of Earth Science 28, 804-834.Zhang, Z., Wu, Y., Sun, L., Li, Y., Fu, D., Su, L., Zhang, D., Xia, Y., 2017. The changes of hydrocarbon generation and potential in source rocks under semi-closed conditions with 50–840?bar water pressure. Petroleum Science and Technology 35, 1487-1494.Oil & Gas GeochemistryAdebiyi, F.M., Akinola, A.S., Santoro, A., Mastrolitti, S., 2017. Chemical analysis of resin fraction of Nigerian bitumen for organic and trace metal compositions. Petroleum Science and Technology 35, 1370-1380.Chahen, L., Quoineaud, A.A., Proriol, D., Artero, S., Vidalie, M., Neyret-Martinez, F., Rivallan, M., 2017. Speciation of basic nitrogen compounds in gas oils and vacuum gas oils by derivatization with BF3 prior to NMR analysis. Energy & Fuels 31, 10752-10759.Cheng, X., Hou, D., Mao, R., Xu, C., 2018. Severe biodegradation of polycyclic aromatic hydrocarbons in reservoired crude oils from the Miaoxi Depression, Bohai Bay Basin. Fuel 211, 859-867.Fang, R., Li, M., Wang, T.G., Liu, X., Yuan, Y., Jiang, W., Wang, D., Shi, S., 2017. Trimethyldibenzothiophenes: Molecular tracers for filling pathways in oil reservoir. Journal of Petroleum Science and Engineering 159, 451-460.Han, W., Tao, S., Hou, L., Yao, J., 2017. Geochemical characteristics and genesis of oil-derived gas in the Jingbian gas field, Ordos Basin, China. Energy & Fuels 31, 10432-10441.Li, H., Cai, C., Jia, L., Xu, C., Zhang, K., 2017. The effect of water chemistry on thermochemical sulfate reduction: A case study from the ordovician in the Tazhong area, northwest China. Geofluids 2017, 11.Maryutina, T.A., Timerbaev, A.R., 2017. Metal speciation analysis of petroleum: Myth or reality? Analytica Chimica Acta 991, 1-8.?en, ?., 2017. Crude oil and condensate in the Ordovician–Silurian formations of the Eastern European: The Western Black Sea Basin. Petroleum Science and Technology 35, 1437-1444.Tolstikhin, I.N., Ballentine, C.J., Polyak, B.G., Prasolov, E.M., Kikvadze, O.E., 2017. The noble gas isotope record of hydrocarbon field formation time scales. Chemical Geology 471, 141-152.Zhang, H., Chen, S., Lu, J., Huang, H., Li, Y., 2017. Application of 17α(H)-diahopanes in oil-source correlation of Triassic Yanchang Formation in Zhoujiawan area, Ordos Basin, China. Petroleum Science and Technology 35, 1343-1348.Paleoclimatology/PalaeocenographyArabas, A., Schl?gl, J., Meister, C., 2017. Early Jurassic carbon and oxygen isotope records and seawater temperature variations: Insights from marine carbonate and belemnite rostra (Pieniny Klippen Belt, Carpathians). Palaeogeography, Palaeoclimatology, Palaeoecology 485, 119-135.Beddow, H.M., Liebrand, D., Wilson, D.S., Hilgen, F.J., Sluijs, A., Wade, B.S., Lourens, L.J., 2017. A comparison of two astronomical tuning approaches for the Oligocene-Miocene Transition from Pacific Ocean Site U1334 and implications for the carbon cycle. Climate of the Past Discussions 2017, 1-35.Bush, R.T., Wallace, J., Currano, E.D., Jacobs, B.F., McInerney, F.A., Dunn, R.E., Tabor, N.J., 2017. Cell anatomy and leaf δ13C as proxies for shading and canopy structure in a Miocene forest from Ethiopia. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 593-604.Chen, C., Wang, J., Algeo, T.J., Wang, Z., Tu, S., Wang, G., Yang, J., 2017. Negative δ13Ccarb shifts in Upper Ordovician (Hirnantian) Guanyinqiao Bed of South China linked to diagenetic carbon fluxes. Palaeogeography, Palaeoclimatology, Palaeoecology 487, 430-446.Chen, X., Idakieva, V., Stoykova, K., Liang, H., Yao, H., Wang, C., 2017. Ammonite biostratigraphy and organic carbon isotope chemostratigraphy of the early Aptian oceanic anoxic event (OAE 1a) in the Tethyan Himalaya of southern Tibet. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 531-542.Clotten, C., Stein, R., Fahl, K., De Schepper, S., 2018. Seasonal sea ice cover during the warm Pliocene: Evidence from the Iceland Sea (ODP Site 907). Earth and Planetary Science Letters 481, 61-72.Cui, Y., Schubert, B.A., 2017. Atmospheric pCO2 reconstructed across five early Eocene global warming events. Earth and Planetary Science Letters 478, 225-233.Davies-Barnard, T., Ridgwell, A., Singarayer, J., Valdes, P., 2017. Quantifying the influence of the terrestrial biosphere on glacial–interglacial climate dynamics. Climate of the Past 13, 1381-1401.de Winter, N.J., Vellekoop, J., Vorsselmans, R., Golreihan, A., Soete, J., Petersen, S.V., Meyer, K.W., Casadio, S., Speijer, R.P., Claeys, P., 2017. An assessment of latest Cretaceous Pycnodonte vesicularis (Lamarck, 1806) shells as records for palaeoseasonality: A multi-proxy investigation. Climate of the Past Discussions 2017, 1-36.Dickson, A.J., 2017. A molybdenum-isotope perspective on Phanerozoic deoxygenation events. Nature Geoscience 10, 721-726.Dunlea, A.G., Murray, R.W., Santiago Ramos, D.P., Higgins, J.A., 2017. Cenozoic global cooling and increased seawater Mg/Ca via reduced reverse weathering. Nature Communications 8, Article 844.Durham, S.R., Gillikin, D.P., Goodwin, D.H., Dietl, G.P., 2017. Rapid determination of oyster lifespans and growth rates using LA-ICP-MS line scans of shell Mg/Ca ratios. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 201-209.Erhardt, A., 2017. Palaeoceanography: Tropical ties. Nature Geoscience 10, 714-715.Fang, Y., Chen, Z.-Q., Kershaw, S., Li, Y., Luo, M., 2017. An Early Triassic (Smithian) stromatolite associated with giant ooid banks from Lichuan (Hubei Province), South China: Environment and controls on its formation. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 108-122.Feulner, G., 2017. Formation of most of our coal brought Earth close to global glaciation. Proceedings of the National Academy of Sciences 114, 11333-11337.Fu, X., Wang, J., Zeng, S., Feng, X., Wang, D., Song, C., 2017. Continental weathering and palaeoclimatic changes through the onset of the Early Toarcian oceanic anoxic event in the Qiangtang Basin, eastern Tethys. Palaeogeography, Palaeoclimatology, Palaeoecology 487, 241-250.Grillenzoni, C., Monegatti, P., Turco, E., Conti, S., Fioroni, C., Fontana, D., Salocchi, A.C., 2017. Paleoenvironmental evolution in a high-stressed cold-seep system (Vicchio Marls, Miocene, northern Apennines, Italy). Palaeogeography, Palaeoclimatology, Palaeoecology 487, 37-50.Hao, T., Liu, X., Ogg, J., Liang, Z., Xiang, R., Zhang, X., Zhang, D., Zhang, C., Liu, Q., Li, X., 2017. Intensified episodes of East Asian Winter Monsoon during the middle through late Holocene driven by North Atlantic cooling events: High-resolution lignin records from the South Yellow Sea, China. Earth and Planetary Science Letters 479, 144-155.Huyghe, D., Emmanuel, L., Renard, M., Lartaud, F., Génot, P., Riveline, J., Merle, D., 2017. Significance of shallow-marine and non-marine algae stable isotope (δ18O) compositions over long periods: Example from the Palaeogene of the Paris Basin. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 247-259.Intxauspe-Zubiaurre, B., Flores, J.-A., Payros, A., 2017. Variations to calcareous nannofossil CaCO3 content during the middle Eocene C21r-H6 hyperthermal event (~47.4Ma) in the Gorrondatxe section (Bay of Biscay, western Pyrenees). Palaeogeography, Palaeoclimatology, Palaeoecology 487, 296-306.Jenkins, R.G., Hasegawa, T., Haggart, J.W., Goto, A.S., Iwase, Y., Nakase, C., 2017. Cool eastern rim of the North Pacific during Late Cretaceous time: A seep-carbonate paleothermometry from the Nanaimo Group, British Columbia, Canada. Palaeogeography, Palaeoclimatology, Palaeoecology 487, 407-415.Kolling, H.M., Stein, R., Fahl, K., Perner, K., Moros, M., 2017. Short-term variability in late Holocene sea ice cover on the East Greenland Shelf and its driving mechanisms. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 336-350.Komar, N., Zeebe, R.E., 2017. Redox-controlled carbon and phosphorus burial: A mechanism for enhanced organic carbon sequestration during the PETM. Earth and Planetary Science Letters 479, 71-82.Lachniet, M., Asmerom, Y., Polyak, V., Denniston, R., 2017. Arctic cryosphere and Milankovitch forcing of Great Basin paleoclimate. Scientific Reports 7, Article 12955.Li, F., Yan, J., Burne, R.V., Chen, Z.-Q., Algeo, T.J., Zhang, W., Tian, L., Gan, Y., Liu, K., Xie, S., 2017. Paleo-seawater REE compositions and microbial signatures preserved in laminae of Lower Triassic ooids. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 96-107.Li, Y., Schieber, J., Fan, T., Li, Z., Zhang, J., 2017. Regional depositional changes and their controls on carbon and sulfur cycling across the Ordovician-Silurian boundary, northwestern Guizhou, South China. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 816-832.Liao, W., Bond, D.P.G., Wang, Y., He, L., Yang, H., Weng, Z., Li, G., 2017. An extensive anoxic event in the Triassic of the South China Block: A pyrite framboid study from Dajiang and its implications for the cause(s) of oxygen depletion. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 86-95.Loiko, S.V., Pokrovsky, O.S., Raudina, T.V., Lim, A., Kolesnichenko, L.G., Shirokova, L.S., Vorobyev, S.N., Kirpotin, S.N., 2017. Abrupt permafrost collapse enhances organic carbon, CO2, nutrient and metal release into surface waters. Chemical Geology 471, 153-165.Luciani, V., D'Onofrio, R., Dickens, G.R., Wade, B.S., 2017. Planktic foraminiferal response to early Eocene carbon cycle perturbations in the southeast Atlantic Ocean (ODP Site 1263). Global and Planetary Change 158, 119-133.Mejía, L.M., Méndez-Vicente, A., Abrevaya, L., Lawrence, K.T., Ladlow, C., Bolton, C., Cacho, I., Stoll, H., 2017. A diatom record of CO2 decline since the late Miocene. Earth and Planetary Science Letters 479, 18-33.Niezgodzki, I., Knorr, G., Lohmann, G., Tyszka, J., Markwick, P.J., 2017. Late Cretaceous climate simulations with different CO2 levels and subarctic gateway configurations: A model-data comparison. Paleoceanography 32, 980-998.Oksman, M., Weckstr?m, K., Miettinen, A., Juggins, S., Divine, D.V., Jackson, R., Telford, R., Korsgaard, N.J., Kucera, M., 2017. Younger Dryas ice margin retreat triggered by ocean surface warming in central-eastern Baffin Bay. Nature Communications 8, Article 1017.Ren, Y., Zhong, D., Gao, C., Liang, T., Sun, H., Wu, D., Zheng, X., 2017. High-resolution carbon isotope records and correlations of the lower Cambrian Longwangmiao formation (stage 4, Toyonian) in Chongqing, South China. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 572-592.Schobben, M., Stebbins, A., Algeo, T.J., Strauss, H., Leda, L., Haas, J., Struck, U., Korn, D., Korte, C., 2017. Volatile earliest Triassic sulfur cycle: A consequence of persistent low seawater sulfate concentrations and a high sulfur cycle turnover rate? Palaeogeography, Palaeoclimatology, Palaeoecology 486, 74-85.Sternai, P., Caricchi, L., Garcia-Castellanos, D., Jolivet, L., Sheldrake, T.E., Castelltort, S., 2017. Magmatic pulse driven by sea-level changes associated with the Messinian salinity crisis. Nature Geoscience 10, 783-787.Sun, J., Liu, W., Liu, Z., Deng, T., Windley, B.F., Fu, B., 2017. Extreme aridification since the beginning of the Pliocene in the Tarim Basin, western China. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 189-200.Yang, J., Yan, J., Huang, Y., 2017. The Earth's penultimate icehouse-to-greenhouse climate transition and related sedimentary records in low-latitude regions of eastern Tethys. Acta Sedimentologica Sinica 35, 981-993.Zanchetta, G., Bini, M., Giaccio, B., Manganelli, G., Benocci, A., Regattieri, E., Colonese, A.C., Boschi, C., Biagioni, C., 2017. Middle Pleistocene (MIS 14) environmental conditions in the central Mediterranean derived from terrestrial molluscs and carbonate stable isotopes from Sulmona Basin (Italy). Palaeogeography, Palaeoclimatology, Palaeoecology 485, 236-246.Zhang, J., Liu, Z., Brady, E.C., Oppo, D.W., Clark, P.U., Jahn, A., Marcott, S.A., Lindsay, K., 2017. Asynchronous warming and δ18O evolution of deep Atlantic water masses during the last deglaciation. Proceedings of the National Academy of Sciences 114, 11075-11080.Zhang, Z.T., Sun, Y.D., Lai, X.L., Joachimski, M.M., Wignall, P.B., 2017. Early Carnian conodont fauna at Yongyue, Zhenfeng area and its implication for Ladinian-Carnian subdivision in Guizhou, South China. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 142-157.Extinction EventsButton, D.J., Lloyd, G.T., Ezcurra, M.D., Butler, R.J., 2017. Mass extinctions drove increased global faunal cosmopolitanism on the supercontinent Pangaea. Nature Communications 8, Article 733.Chen, Z.-Q., Algeo, T.J., Sun, Y., Schoepfer, S.D., 2017. The Paleozoic-Mesozoic transition in South China: Oceanic environments and life from Late Permian to Late Triassic. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 1-5.Damborenea, S.E., Echevarría, J., Ros-Franch, S., 2017. Biotic recovery after the end-Triassic extinction event: Evidence from marine bivalves of the Neuquén Basin, Argentina. Palaeogeography, Palaeoclimatology, Palaeoecology 487, 93-104.Dameron, S.N., Leckie, R.M., Clark, K., MacLeod, K.G., Thomas, D.J., Lees, J.A., 2017. Extinction, dissolution, and possible ocean acidification prior to the Cretaceous/Paleogene (K/Pg) boundary in the tropical Pacific. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 433-454.Davies, T.W., Bell, M.A., Goswami, A., Halliday, T.J.D., 2017. Completeness of the eutherian mammal fossil record and implications for reconstructing mammal evolution through the Cretaceous/Paleogene mass extinction. Paleobiology 43, 521-536.Emery-Wetherell, M.M., McHorse, B.K., Byrd Davis, E., 2017. Spatially explicit analysis sheds new light on the Pleistocene megafaunal extinction in North America. Paleobiology 43, 642-655.Feng, X., Chen, Z.-Q., Woods, A., Fang, Y., 2017. A Smithian (Early Triassic) ichnoassemblage from Lichuan, Hubei Province, South China: Implications for biotic recovery after the latest Permian mass extinction. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 123-141.He, W., Shi, G.R., Xiao, Y., Zhang, K., Yang, T., Wu, H., Zhang, Y., Chen, B., Yue, M., Shen, J., Wang, Y., Yang, H., Wu, S., 2017. Body-size changes of latest Permian brachiopods in varied palaeogeographic settings in South China and implications for controls on animal miniaturization in a highly stressed marine ecosystem. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 33-45.Hong, H., Fang, Q., Zhao, L., Schoepfer, S., Wang, C., Gong, N., Li, Z., Chen, Z.-Q., 2017. Weathering and alteration of volcanic ashes in various depositional settings during the Permian-Triassic transition in South China: Mineralogical, elemental and isotopic approaches. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 46-57.Lei, L.-D., Shen, J., Li, C., Algeo, T.J., Chen, Z.-Q., Feng, Q.-L., Cheng, M., Jin, C.-S., Huang, J.-H., 2017. Controls on regional marine redox evolution during Permian-Triassic transition in South China. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 17-32.Lewy, Z., 2017. Dinosaur demise in light of their alleged perennial polar residency. International Journal of Earth Sciences 106, 2609-2616.Li, Y., Zhao, L., Chen, Z.-Q., Algeo, T.J., Cao, L., Wang, X., 2017. Oceanic environmental changes on a shallow carbonate platform (Yangou, Jiangxi Province, South China) during the Permian-Triassic transition: Evidence from rare earth elements in conodont bioapatite. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 6-16.Mettam, C., Zerkle, A.L., Claire, M.W., Izon, G., Junium, C.J., Twitchett, R.J., 2017. High-frequency fluctuations in redox conditions during the latest Permian mass extinction. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 210-223.Mouro, L.D., Rakociński, M., Marynowski, L., Pisarzowska, A., Musabelliu, S., Zatoń, M., Carvalho, M.A., Fernandes, A.C.S., Waichel, B.L., 2017. Benthic anoxia, intermittent photic zone euxinia and elevated productivity during deposition of the Lower Permian, post-glacial fossiliferous black shales of the Paraná Basin, Brazil. Global and Planetary Change 158, 155-172.Paul, G., 2017. Polar and K/Pg nonavian dinosaurs were low-metabolic rate reptiles vulnerable to cold-induced extinction, rather than more survivable tachyenergetic bird relatives: comment on an obsolete hypothesis. International Journal of Earth Sciences 106, 2991-2998.Rampino, M.R., Rodriguez, S., Baransky, E., Cai, Y., 2017. Global nickel anomaly links Siberian Traps eruptions and the latest Permian mass extinction. Scientific Reports 7, Article 12416.Reitan, T., Liow, L.H., 2017. An unknown Phanerozoic driver of brachiopod extinction rates unveiled by multivariate linear stochastic differential equations. Paleobiology 43, 537-549.Song, H., Song, H., Algeo, T.J., Tong, J., Romaniello, S.J., Zhu, Y., Chu, D., Gong, Y., Anbar, A.D., 2017. Uranium and carbon isotopes document global-ocean redox-productivity relationships linked to cooling during the Frasnian-Famennian mass extinction. Geology 45, 887-890.van Soelen, E.E., Twitchett, R.J., Kürschner, W.M., 2017. Salinity changes and anoxia resulting from enhanced runoff during the late Permian global warming and mass extinction event. Climate of the Past Discussions 2017, 1-23.Wu, S., Chen, Z.-Q., Fang, Y., Pei, Y., Yang, H., Ogg, J., 2017. A Permian-Triassic boundary microbialite deposit from the eastern Yangtze Platform (Jiangxi Province, South China): Geobiologic features, ecosystem composition and redox conditions. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 58-73.Zaghbib-Turki, D., Beiranvand, B., 2017. Planktonic foraminiferal extinction pattern, evolution, turnover, and geochemical anomalies across the Cretaceous/Paleogene boundary (K/Pg) in Izeh (Zagros Basin, SW Iran). Arabian Journal of Geosciences 10, 443.Zapalski, M.K., Nowicki, J., Jakubowicz, M., Berkowski, B., 2017. Tabulate corals across the Frasnian/Famennian boundary: architectural turnover and its possible relation to ancient photosymbiosis. Palaeogeography, Palaeoclimatology, Palaeoecology 487, 416-429.Zhang, Y., Shi, G.R., Wu, H.-t., Yang, T.-l., He, W.-h., Yuan, A.-h., Lei, Y., 2017. Community replacement, ecological shift and early warning signals prior to the end-Permian mass extinction: A case study from a nearshore clastic-shelf section in South China. Palaeogeography, Palaeoclimatology, Palaeoecology 487, 118-135.Precambrian GeochemistryEroglu, S., van Zuilen, M.A., Taubald, H., Drost, K., Wille, M., Swanner, E.D., Beukes, N.J., Schoenberg, R., 2017. Depth-dependent δ13C trends in platform and slope settings of the Campbellrand-Malmani carbonate platform and possible implications for Early Earth oxygenation. Precambrian Research 302, 122-139.Fleury, B., Carrasco, N., Millan, M., Vettier, L., Szopa, C., 2017. Organic chemistry in a CO2 rich early Earth atmosphere. Earth and Planetary Science Letters 479, 34-42.Hamilton, T.L., Welander, P.V., Albrecht, H.L., Fulton, J.M., Schaperdoth, I., Bird, L.R., Summons, R.E., Freeman, K.H., Macalady, J.L., 2017. Microbial communities and organic biomarkers in a Proterozoic-analog sinkhole. Geobiology 15, 784-797.Hoffmann, J.E., 2017. Geochemistry: Oxygenation by a changing crust. Nature Geoscience 10, 713-714.O'Neill, C., Marchi, S., Zhang, S., Bottke, W., 2017. Impact-driven subduction on the Hadean Earth. Nature Geoscience 10, 793-797.Smit, M.A., Mezger, K., 2017. Earth's early O2 cycle suppressed by primitive continents. Nature Geoscience 10, 788-792.Smith, A.J.B., Beukes, N.J., Gutzmer, J., Czaja, A.D., Johnson, C.M., Nhleko, N., 2017. Oncoidal granular iron formation in the Mesoarchaean Pongola Supergroup, southern Africa: Textural and geochemical evidence for biological activity during iron deposition. Geobiology 15, 731-anics/Microfossils/Microbial EvolutionBoyle, R., 2017. Eukaryotic origins and the Proterozoic Earth system: A link between global scale glaciations and eukaryogenesis? Earth-Science Reviews 174, 22-38.Havig, J.R., Hamilton, T.L., Bachan, A., Kump, L.R., 2017. Sulfur and carbon isotopic evidence for metabolic pathway evolution and a four-stepped Earth system progression across the Archean and Paleoproterozoic. Earth-Science Reviews 174, 1-21.Javaux, E.J., Lepot, K., 2018. The Paleoproterozoic fossil record: Implications for the evolution of the biosphere during Earth's middle-age. Earth-Science Reviews 176, 68-86.Siahi, M., Hofmann, A., Master, S., Mueller, C.W., Gerdes, A., 2017. Carbonate ooids of the Mesoarchaean Pongola Supergroup, South Africa. Geobiology 15, 750-766.Stüeken, E.E., Buick, R., Anderson, R.E., Baross, J.A., Planavsky, N.J., Lyons, T.W., 2017. Environmental niches and metabolic diversity in Neoarchean lakes. Geobiology 15, 767-783.Tang, Q., Hughes, N.C., McKenzie, N.R., Myrow, P.M., Xiao, S., 2017. Late Mesoproterozoic – early Neoproterozoic organic-walled microfossils from the Madhubani Group of the Ganga Valley, northern India. Palaeontology 60, 869-891.Wang, X., Zhang, S., Wang, H., Canfield, D.E., Su, J., Hammarlund, E.U., Bian, L., 2017. Remarkable preservation of microfossils and biofilms in Mesoproterozoic silicified bitumen concretions from northern China. Geofluids 2017, Article 4818207.Ward, L.M., Idei, A., Terajima, S., Kakegawa, T., Fischer, W.W., McGlynn, S.E., 2017. Microbial diversity and iron oxidation at Okuoku-hachikurou Onsen, a Japanese hot spring analog of Precambrian iron formations. Geobiology 15, 817-835.Xiao, S., Bykova, N., Kovalick, A., Gill, B.C., 2017. Stable carbon isotopes of sedimentary kerogens and carbonaceous macrofossils from the Ediacaran Miaohe Member in South China: Implications for stratigraphic correlation and sources of sedimentary organic carbon. Precambrian Research 302, 171-179.Zhu, G.-Y., Ren, R., Chen, F.-R., Li, T.-T., Chen, Y.-Q., 2017. Neoproterozoic rift basins and their control on the development of hydrocarbon source rocks in the Tarim Basin, NW China. Journal of Asian Earth Sciences 150, 63-72.Paleoclimatology/PaleocenographyMills, B.J.W., Scotese, C.R., Walding, N.G., Shields, G.A., Lenton, T.M., 2017. Elevated CO2 degassing rates prevented the return of Snowball Earth during the Phanerozoic. Nature Communications 8, Article 1110.Nutman, A.P., Bennett, V.C., Friend, C.R.L., 2017. Seeing through the magnetite: Reassessing Eoarchean atmosphere composition from Isua (Greenland) ≥3.7?Ga banded iron formations. Geoscience Frontiers 8, 1233-1240.Préat, A., Delpomdor, F., Ackouala Mfere, A.P., Callec, Y., 2018. Paleoenvironments, δ13C and δ18O signatures in the Neoproterozoic carbonates of the Comba Basin, Republic of Congo: Implications for regional correlations and Marinoan event. Journal of African Earth Sciences 137, 69-90.Wang, X., Zhang, S., Wang, H., Bjerrum, C.J., Hammarlund, E.U., Haxen, E.R., Su, J., Wang, Y., Canfield, D.E., 2017. Oxygen, climate and the chemical evolution of a 1400 million year old tropical marine setting. American Journal of Science 317, 861-900.Crustal EvolutionProduction/Engineering GeochemistryFan, Q., Bai, G., Wu, S., Yuan, W., Song, X.-M., 2017. The chemical structure and the kinetics research of oil-wet oil sand from Kazakhstan during pyrolysis process. Petroleum Science and Technology 35, 1495-1501.Kang, J., Myint, A.A., Sim, S., Kim, J., Kong, W.B., Lee, Y.-W., 2018. Kinetics of the upgrading of heavy oil in supercritical methanol. The Journal of Supercritical Fluids 133, 133-138.Krajewski, L.C., Lobodin, V.V., Robbins, W.K., Jin, P., Bota, G., Marshall, A.G., Rodgers, R.P., 2017. Method for isolation and detection of ketones formed from high-temperature naphthenic acid corrosion. Energy & Fuels 31, 10674-10679.Kwek, W., Khan, M.K., Sarkar, B., Kim, J., 2018. Supercritical methanol as an effective medium for producing asphaltenes-free light fraction oil from vacuum residue. The Journal of Supercritical Fluids 133, Part 1, 184-194.Lopes, M.S., da Rocha Watanabe, E.R.L., Savioli Lopes, E., Gomes, V.M., Savioli Lopes, M., Medina, L.C., Maciel Filho, R., Wolf Maciel, M.R., 2017. Extending the true boiling point curve of a heavy crude oil by means of molecular distillation and characterization of the products obtained. Petroleum Science and Technology 35, 1523-1529.Lopes, M.S., da Rocha Watanabe, E.R.L., Tovar, L.P., Lopes, M.S., Darcie, L.d.R., Lopes, E.S., Filho, R.M., Maciel, M.R.W., Medina, L.C., 2017. Development of correlation for extension of the true boiling point (TBP) and molar mass. Petroleum Science and Technology 35, 1530-1536.Peng, B., Gao, W., Motamedi, N., 2017. Kinetic modeling of crude oil gasification for hydrogen production with in situ CO2 capture. Petroleum Science and Technology 35, 1403-1407.Petrov, S.М., Ibragimova, D.A., Safiulina, A.G., Tohidi Kalorazi, B., Vakhin, A.V., Okekwe, R.C., Karalin, E.A., 2017. Conversion of organic matter in the carbonaceous medium in the supercritical water. Journal of Petroleum Science and Engineering 159, 497-505.Shao, X., Liu, G., Yang, J., Xu, X., 2017. Research on the synthesis of ionic liquids/layered double hydroxides intercalation composites and their application on the removal of naphthenic acid from oil. Energy & Fuels 31, 10718-10726.Shi, J., Ma, Y., Li, S., Zhang, L., 2017. Characteristics of thermal bitumen structure as the pyrolysis intermediate of Longkou oil shale. Energy & Fuels 31, 10535-10544.AsphaltenesBoytsova, A., Kondrasheva, N., Ancheyta, J., 2017. Thermogravimetric determination and pyrolysis thermodynamic parameters of heavy oils and asphaltenes. Energy & Fuels 31, 10566-10575.Desgranges, C., Delhommelle, J., 2017. Coarse-grained model and boiling point prediction for asphaltene model compounds via HMC-WL simulations. Energy & Fuels 31, 10699-10705.Díaz-Sánchez, H., Rojas-Trigos, J.B., Leyva, C., Trejo-Zárraga, F., 2017. An approach for determination of asphaltene crystallite by X-ray diffraction analysis: A case of study. Petroleum Science and Technology 35, 1415-1420.Feng, X., Zeng, J., Ma, Y., Jia, K., Qiao, J., Zhang, Y., Feng, S., 2017. Asphaltene deposition preference and permeability reduction mechanisms in oil reservoirs: Evidence from combining X-ray microtomography with fluorescence microscopy. Energy & Fuels 31, 10467-10478.Guzmán, H.J., Isquierdo, F., Carbognani, L., Vitale, G., Scott, C.E., Pereira-Almao, P., 2017. X-ray photoelectron spectroscopy analysis of hydrotreated Athabasca asphaltenes. Energy & Fuels 31, 10706-10717.Morozov, E.V., Martyanov, O.N., 2017. Reversibility of asphaltene aggregation as revealed by magnetic resonance imaging in situ. Energy & Fuels 31, 10639-10647.Ren, T., Wang, Y., Zhang, G., 2017. Influence of the properties of resins on the interactions between asphaltenes and resins. Petroleum Science and Technology 35, 1481-1486.Torkaman, M., Bahrami, M., Dehghani, M., 2017. Influence of temperature on aggregation and stability of asphaltenes. I. Perikinetic aggregation. Energy & Fuels 31, 11169-11180.Tsiamis, A., Taylor, S.E., 2017. Adsorption behavior of asphaltenes and resins on kaolinite. Energy & Fuels 31, 10576-10587.Xu, Q., Jiang, H., Ma, D., Chen, X., Huang, J., Shi, L., 2017. Pyrolysis of a low asphaltene crude oil under idealized in situ combustion conditions. Energy & Fuels 31, 10545-10554.Yakubov, M.R., Milordov, D.V., Yakubova, S.G., Abilova, G.R., Sinyashin, K.O., Tazeeva, E.G., Borisova, U.U., Mironov, N.A., Morozov, V.I., 2017. Vanadium and paramagnetic vanadyl complexes content in asphaltenes of heavy oils of various productive sediments. Petroleum Science and Technology 35, 1468-1472.Zhang, S., Zhang, L., Lu, X., Shi, C., Tang, T., Wang, X., Huang, Q., Zeng, H., 2018. Adsorption kinetics of asphaltenes at oil/water interface: Effects of concentration and temperature. Fuel 212, 387-394.Zorzen?o, P.C.S., Mariath, R.M., Pinto, F.E., Tose, L.V., Rom?o, W., Santos, A.F., Scheer, A.P., Simon, S., Sj?blom, J., Yamamoto, C.I., 2018. Asphaltenes subfractions extracted from Brazilian vacuum residue: Chemical characterization and stabilization of model water-in-oil (W/O) emulsions. Journal of Petroleum Science and Engineering 160, 1-11.Interfaces/EORAhmed, S., Elraies, K.A., Forooozesh, J., Bt Mohd Shafian, S.R., Hashmet, M.R., Hsia, I.C.C., Almansour, A., 2017. Experimental investigation of immiscible supercritical carbon dioxide foam rheology for improved oil recovery. Journal of Earth Science 28, 835-841.Al-Anssari, S., Arif, M., Wang, S., Barifcani, A., Lebedev, M., Iglauer, S., 2017. Wettability of nano-treated calcite/CO2/brine systems: Implication for enhanced CO2 storage potential. International Journal of Greenhouse Gas Control 66, 97-105.Al-Yaseri, A., Zhang, Y., Ghasemiziarani, M., Sarmadivaleh, M., Lebedev, M., Roshan, H., Iglauer, S., 2017. Permeability evolution in sandstone due to CO2 injection. Energy & Fuels.AlYousef, Z., Almobarky, M., Schechter, D., 2017. Enhancing the stability of foam by the use of nanoparticles. Energy & Fuels 31, 10620-10627.Azarshin, S., Moghadasi, J., A Aboosadi, Z., 2017. Surface functionalization of silica nanoparticles to improve the performance of water flooding in oil wet reservoirs. Energy Exploration & Exploitation 35, 685-697.Hosseini-Nasab, S.M., Zitha, P.L.J., 2017. Investigation of chemical-foam design as a novel approach toward immiscible foam flooding for enhanced oil recovery. Energy & Fuels 31, 10525-10534.Li, M., Vashaee, S., Romero-Zerón, L., Marica, F., Balcom, B.J., 2017. A magnetic resonance study of low salinity waterflooding for enhanced oil recovery. Energy & Fuels 31, 10802-10811.Nowbahar, A., Whitaker, K.A., Schmitt, A.K., Kuo, T.-C., 2017. Mechanistic study of water droplet coalescence and flocculation in diluted bitumen emulsions with additives using microfluidics. Energy & Fuels 31, 10555-10565.Razeghi, S.A., Mitrovic, V., Adjei Marfo, S., 2017. The influence of steam injection for Enhanced Oil Recovery (EOR) on the quality of crude oil. Petroleum Science and Technology 35, 1334-1342.Sheng, J.J., 2017. Critical review of field EOR projects in shale and tight reservoirs. Journal of Petroleum Science and Engineering 159, 654-665.Zhang, S., Zhang, L., Lu, X., Shi, C., Tang, T., Wang, X., Huang, Q., Zeng, H., 2018. Adsorption kinetics of asphaltenes at oil/water interface: Effects of concentration and temperature. Fuel 212, 387-394.Heavy Oil ProductionGuo, K., Hansen, V.F., Li, H., Yu, Z., 2018. Monodispersed nickel and cobalt nanoparticles in desulfurization of thiophene for in-situ upgrading of heavy crude oil. Fuel 211, 697-703.Tang, X.-d., Liang, G.-j., Li, J.-j., Wei, Y.-t., Dang, T., 2017. Catalytic effect of in-situ preparation of copper oxide nanoparticles on the heavy oil low-temperature oxidation process in air injection recovery. Petroleum Science and Technology 35, 1321-1326.Recent Sedimentsá Nor?i, G., Glud, R.N., Simonsen, K., Gaard, E., 2018. Deposition and benthic mineralization of organic carbon: A seasonal study from Faroe Islands. Journal of Marine Systems 177, 53-61.Ankit, Y., Mishra, P.K., Kumar, P., Jha, D.K., Kumar, V.V., Ambili, V., Anoop, A., 2017. Molecular distribution and carbon isotope of n-alkanes from Ashtamudi Estuary, South India: Assessment of organic matter sources and paleoclimatic implications. Marine Chemistry 196, 62-70.Ardenghi, N., Mulch, A., Pross, J., Maria Niedermeyer, E., 2017. Leaf wax n-alkane extraction: An optimised procedure. Organic Geochemistry 113, 283-292.Borges, A.V., Abril, G., Bouillon, S., 2017. Carbon dynamics in the Mekong Delta. Biogeosciences Discussions 2017, 1-41.de Bar, M.W., Hopmans, E.C., Verweij, M., Dorhout, D.J.C., Damsté, J.S.S., Schouten, S., 2017. Development and comparison of chromatographic methods for the analysis of long chain diols and alkenones in biological materials and sediment. Journal of Chromatography A 1521, 150-160.Ding, L., Zhao, M., Yu, M., Li, L., Huang, C.-Y., 2017. Biomarker assessments of sources and environmental implications of organic matter in sediments from potential cold seep areas of the northeastern South China Sea. Acta Oceanologica Sinica 36, 8-19.Hamilton, T.L., Welander, P.V., Albrecht, H.L., Fulton, J.M., Schaperdoth, I., Bird, L.R., Summons, R.E., Freeman, K.H., Macalady, J.L., 2017. Microbial communities and organic biomarkers in a Proterozoic-analog sinkhole. Geobiology 15, 784-797.Harouaka, K., Kubicki, J.D., Fantle, M.S., 2017. Effect of amino acids on the precipitation kinetics and Ca isotopic composition of gypsum. Geochimica et Cosmochimica Acta 218, 343-364.Harvey, H.R., Taylor, K.A., 2017. Alkane and polycyclic aromatic hydrocarbons in sediments and benthic invertebrates of the northern Chukchi Sea. Deep Sea Research Part II: Topical Studies in Oceanography 144, 52-62.Hubas, C., Boeuf, D., Jesus, B., Thiney, N., Bozec, Y., Jeanthon, C., 2017. A nanoscale study of carbon and nitrogen fluxes in mats of purple sulfur bacteria: Implications for carbon cycling at the surface of coastal sediments. Frontiers in Microbiology 8, 1995. doi: 1910.3389/fmicb.2017.01995.Mai-Thi, N.-N., St-Onge, G., Tremblay, L., 2017. Contrasting fates of organic matter in locations having different organic matter inputs and bottom water O2 concentrations. Estuarine, Coastal and Shelf Science 198, 63-72.Matys, E.D., Sepúlveda, J., Pantoja, S., Lange, C.B., Caniupán, M., Lamy, F., Summons, R.E., 2017. Bacteriohopanepolyols along redox gradients in the Humboldt Current System off northern Chile. Geobiology 15, 844-857.Nagoji, S.S., Tiwari, M., 2017. Organic carbon preservation in Southeastern Arabian Sea sediments since mid-Holocene: Implications to South Asian Summer Monsoon variability. Geochemistry, Geophysics, Geosystems 18, 3438-3451.Osborne, K.A., Gray, N.D., Sherry, A., Leary, P., Mejeha, O., Bischoff, J., Rush, D., Sidgwick, F.R., Birgel, D., Kalyuzhnaya, M.G., Talbot, H.M., 2017. Methanotroph-derived bacteriohopanepolyol signatures as a function of temperature related growth, survival, cell death and preservation in the geological record. Environmental Microbiology Reports 9, 492-500.Rushdi, A.I., Al-Shaikh, I., El-Mubarak, A.H., Alnaimi, H.A.J.A., Al-Shamary, N., Hassan, H.M., Assali, M.A., 2017. Characteristics and sources of anthropogenic and biogenic hydrocarbons in sediments from the coast of Qatar. Marine Pollution Bulletin 124, 56-66.Sundman, A., Byrne, J.M., Bauer, I., Menguy, N., Kappler, A., 2017. Interactions between magnetite and humic substances: redox reactions and dissolution processes. Geochemical Transactions 18, Article 6 úbia, T., Corella, J.P., Pérez-Zanón, N., Buchaca, T., Trapote, M.C., López, P., Sigró, J., Rull, V., 2018. Historical shifts in oxygenation regime as recorded in the laminated sediments of lake Montcortès (Central Pyrenees) support hypoxia as a continental-scale phenomenon. Science of The Total Environment 612, 1577-1592.Watanabe, Y., Kashiwabara, T., Ishibashi, J.-i., Sekizawa, O., Nitta, K., Uruga, T., Takahashi, Y., 2017. Different partitioning behaviors of molybdenum and tungsten in a sediment–water system under various redox conditions. Chemical Geology 471, 38-51.Zhu, W., Song, Y., Adediran, G.A., Jiang, T., Reis, A.T., Pereira, E., Skyllberg, U., Bj?rn, E., 2018. Mercury transformations in resuspended contaminated sediment controlled by redox conditions, chemical speciation and sources of organic matter. Geochimica et Cosmochimica Acta 220, 158-179.Zhuang, G.-C., Lin, Y.-S., Bowles, M.W., Heuer, V.B., Lever, M.A., Elvert, M., Hinrichs, K.-U., 2017. Distribution and isotopic composition of trimethylamine, dimethylsulfide and dimethylsulfoniopropionate in marine sediments. Marine Chemistry 196, 35-46.Atmospheric GeochemistryAlpert, P.A., Ciuraru, R., Rossignol, S., Passananti, M., Tinel, L., Perrier, S., Dupart, Y., Steimer, S.S., Ammann, M., Donaldson, D.J., George, C., 2017. Fatty acid surfactant photochemistry results in new particle formation. Scientific Reports 7, Article 12693.Brownlow, R., Lowry, D., Fisher, R.E., France, J.L., Lanoisellé, M., White, B., Wooster, M.J., Zhang, T., Nisbet, E.G., 2017. Isotopic ratios of tropical methane emissions by atmospheric measurement. Global Biogeochemical Cycles 31, 1408-1419.Haghnegahdar, M.A., Schauble, E.A., Young, E.D., 2017. A model for 12CH2D2 and 13CH3D as complementary tracers for the budget of atmospheric CH4. Global Biogeochemical Cycles 31, 1387-1407.Wnorowski, A., Charland, J.-P., 2017. Profiling quinones in ambient air samples collected from the Athabasca region (Canada). Chemosphere 189, 55-66.Hydrosphere GeochemistryCao, X., Tarr, M.A., 2017. Aldehyde and ketone photoproducts from solar-irradiated crude oil–seawater systems determined by electrospray ionization–tandem mass spectrometry. Environmental Science & Technology 51, 11858-11866.Daugherty, E.E., Gilbert, B., Nico, P.S., Borch, T., 2017. Complexation and redox buffering of iron(II) by dissolved organic matter. Environmental Science & Technology 51, 11096-11104.Gonsior, M., Luek, J., Schmitt-Kopplin, P., Grebmeier, J.M., Cooper, L.W., 2017. Optical properties and molecular diversity of dissolved organic matter in the Bering Strait and Chukchi Sea. Deep Sea Research Part II: Topical Studies in Oceanography 144, 104-111.Grieman, M.M., Aydin, M., Isaksson, E., Schwikowski, M., Saltzman, E.S., 2017. Methoxy aromatic acids in an Arctic ice core from Svalbard: a proxy record of biomass burning. Climate of the Past Discussions 2017, 1-24.Hernes, P.J., Dyda, R.Y., McDowell, W.H., 2017. Connecting tropical river DOM and POM to the landscape with lignin. Geochimica et Cosmochimica Acta 219, 143-159.Kaiser, K., Canedo-Oropeza, M., McMahon, R., Amon, R.M.W., 2017. Origins and transformations of dissolved organic matter in large Arctic rivers. Scientific Reports 7, Article 13064.Livanou, E., Lagaria, A., Psarra, S., Lika, K., 2017. Dissolved organic matter release by phytoplankton in the context of the Dynamic Energy Budget theory. Biogeosciences Discussions 2017, 1-33.Magnone, D., Richards, L.A., Polya, D.A., Bryant, C., Jones, M., van Dongen, B.E., 2017. Biomarker-indicated extent of oxidation of plant-derived organic carbon (OC) in relation to geomorphology in an arsenic contaminated Holocene aquifer, Cambodia. Scientific Reports 7, Article 13093.Massicotte, P., Stedmon, C., Markager, S., 2017. Spectral signature of suspended fine particulate material on light absorption properties of CDOM. Marine Chemistry 196, 98-106.Mitra, S., Osburn, C.L., Wozniak, A.S., 2017. A preliminary assessment of fossil fuel and terrigenous influences to rainwater organic matter in summertime in the northern Gulf of Mexico. Aquatic Geochemistry 23, 217-231.Patra, S., Ganguly, D., Tiwari, M., Kanuri, V., Muduli, P.R., Robin, R.S., Abhilash, K.R., Charan Kumar, B., Nagoji, S.S., Raman, A.V., Subramanian, B.R., 2017. Isotopic composition (C & N) of the suspended particles and N uptake by phytoplankton in a shallow tropical coastal lagoon. Chemistry and Ecology 33, 708-724.Sabadel, A.J.M., Browning, T.J., Kruimer, D., Airs, R.L., Woodward, E.M.S., Van Hale, R., Frew, R.D., 2017. Determination of picomolar dissolved free amino acids along a South Atlantic transect using reversed-phase high-performance liquid chromatography. Marine Chemistry 196, 173-180.Str??t, K.D., M?rth, C.-M., Undeman, E., 2018. Future export of particulate and dissolved organic carbon from land to coastal zones of the Baltic Sea. Journal of Marine Systems 177, 8-20.Stukel, M.R., Ducklow, H.W., 2017. Stirring up the biological pump: Vertical mixing and carbon export in the Southern Ocean. Global Biogeochemical Cycles 31, 1420-1434.Wünsch, U.J., Murphy, K.R., Stedmon, C.A., 2017. The one-sample PARAFAC approach reveals molecular size distributions of fluorescent components in dissolved organic matter. Environmental Science & Technology 51, 11900-11908.Xu, H., Houghton, E.M., Houghton, C.J., Guo, L., 2018. Variations in size and composition of colloidal organic matter in a negative freshwater estuary. Science of The Total Environment 615, 931-941.Soil GeochemistryBaveye, P.C., Pot, V., Garnier, P., 2017. Accounting for sub-resolution pores in models of water and solute transport in soils based on computed tomography images: Are we there yet? Journal of Hydrology 555, 253-256.Hall, S.J., Huang, W., Hammel, K.E., 2017. An optical method for carbon dioxide isotopes and mole fractions in small gas samples: Tracing microbial respiration from soil, litter, and lignin. Rapid Communications in Mass Spectrometry 31, 1938-1946.Ma, F., Du, C., Zhou, J., Shen, Y., 2017. Optimized self-adaptive model for assessment of soil organic matter using Fourier transform mid-infrared photoacoustic spectroscopy. Chemometrics and Intelligent Laboratory Systems 171, 9-15.Melillo, J.M., Frey, S.D., DeAngelis, K.M., Werner, W.J., Bernard, M.J., Bowles, F.P., Pold, G., Knorr, M.A., Grandy, A.S., 2017. Long-term pattern and magnitude of soil carbon feedback to the climate system in a warming world. Science 358, 101-105.Mogul, R., Vaishampayan, P., Bashir, M., McKay, C.P., Schubert, K., Bornaccorsi, R., Gomez, E., Tharayil, S., Payton, G., Capra, J., Andaya, J., Bacon, L., Bargoma, E., Black, D., Boos, K., Brant, M., Chabot, M., Chau, D., Cisneros, J., Chu, G., Curnutt, J., DiMizio, J., Engelbrecht, C., Gott, C., Harnoto, R., Hovanesian, R., Johnson, S., Lavergne, B., Martinez, G., Mans, P., Morales, E., Oei, A., Peplow, G., Piaget, R., Ponce, N., Renteria, E., Rodriguez, V., Rodriguez, J., Santander, M., Sarmiento, K., Scheppelmann, A., Schroter, G., Sexton, D., Stephenson, J., Symer, K., Russo-Tait, T., Weigel, B., Wilhelm, M.B., 2017. Microbial community and biochemical dynamics of biological soil crusts across a gradient of surface coverage in the central Mojave Desert. Frontiers in Microbiology 8, 1974. doi: 1910.3389/fmicb.2017.01974.Mustasaar, M., Comas, X., 2017. Spatiotemporal variability in biogenic gas dynamics in a subtropical peat soil at the laboratory scale is revealed using high-resolution ground-penetrating radar. Journal of Geophysical Research: Biogeosciences 122, 2219-2232.Santos, F., Wagner, S., Rothstein, D., Jaffe, R., Miesel, J.R., 2017. Impact of a historical fire event on pyrogenic carbon stocks and dissolved pyrogenic carbon in spodosols in northern Michigan. Frontiers in Earth Science 5, 80. doi: 10.3389/feart.2017.00080.Tecon, R., Or, D., 2017. Biophysical processes supporting the diversity of microbial life in soil. FEMS Microbiology Reviews 41, 599-623.Vasilevich, R., Lodygin, E., Beznosikov, V., Abakumov, E., 2018. Molecular composition of raw peat and humic substances from permafrost peat soils of European Northeast Russia as climate change markers. Science of The Total Environment 615, 1229-1238.Wang, C., Wang, Y., Herath, H.M.S.K., 2017. Polycyclic aromatic hydrocarbons (PAHs) in biochar – Their formation, occurrence and analysis: A review. Organic Geochemistry 114, 1-11.Ward, C.P., Nalven, S.G., Crump, B.C., Kling, G.W., Cory, R.M., 2017. Photochemical alteration of organic carbon draining permafrost soils shifts microbial metabolic pathways and stimulates respiration. Nature Communications 8, Article 772.Yeasmin, S., Singh, B., Johnston, C.T., Sparks, D.L., 2017. Organic carbon characteristics in density fractions of soils with contrasting mineralogies. Geochimica et Cosmochimica Acta 218, 215-236.Remote Sensing-Hydrocarbon SeepageBaklouti, S., Ahmadi, R., Bougi, M.S.M., Rasheed, M.A., Rao, P.L.S., Hasan, S.Z., Ksibi, M., 2017. Surface geochemical prospection for hydrocarbons in the oriental platform; the case of Guebiba oilfield, Sfax region, Tunisia. Journal of Petroleum Science and Engineering 159, 830-840.Brownlow, R., Lowry, D., Fisher, R.E., France, J.L., Lanoisellé, M., White, B., Wooster, M.J., Zhang, T., Nisbet, E.G., 2017. Isotopic ratios of tropical methane emissions by atmospheric measurement. Global Biogeochemical Cycles 31, 1408-1419.Ding, L., Zhao, M., Yu, M., Li, L., Huang, C.-Y., 2017. Biomarker assessments of sources and environmental implications of organic matter in sediments from potential cold seep areas of the northeastern South China Sea. Acta Oceanologica Sinica 36, 8-19.Lapham, L., Marshall, K., Magen, C., Lyubchich, V., Cooper, L.W., Grebmeier, J.M., 2017. Dissolved methane concentrations in the water column and surface sediments of Hanna Shoal and Barrow Canyon, Northern Chukchi Sea. Deep Sea Research Part II: Topical Studies in Oceanography 144, 92-103.Mustasaar, M., Comas, X., 2017. Spatiotemporal variability in biogenic gas dynamics in a subtropical peat soil at the laboratory scale is revealed using high-resolution ground-penetrating radar. Journal of Geophysical Research: Biogeosciences 122, 2219-2232.Paganoni, M., Cartwright, J.A., Foschi, M., Shipp, C.R., Van Rensbergen, P., 2018. Relationship between fluid-escape pipes and hydrate distribution in offshore Sabah (NW Borneo). Marine Geology 395, 82-103.Sechman, H., Kotarba, M.J., Dzieniewicz, M., Romanowski, T., Fiszer, J., 2017. Evidence of methane and carbon dioxide migration to the near surface zone in the area of the abandoned coal mines in Wa?brzych District (Lower Silesian Coal Basin, SW Poland) based on periodical changes of molecular and isotopic compositions. International Journal of Coal Geology 183, 138-160.Yan, P., Wang, Y., Liu, J., Zhong, G., Liu, X., 2017. Discovery of the southwest Dongsha Island mud volcanoes amid the northern margin of the South China Sea. Marine and Petroleum Geology 88, 858-870.Source Rocks/Depositional EnvironmentsAbdizadeh, H., Ahmadi, A., Kadkhodaie, A., Heidarifard, M., Shayeste, M., 2017. Estimation of thermal maturity from well logs and seismic data in the Mansuri oilfield, SW Iran. Journal of Petroleum Science and Engineering 159, 461-473.Borrego, A.G., 2017. A dry polishing technique for the petrographic examination of mudrocks: Discussion. International Journal of Coal Geology 183, 136-137.Cánneva, A., Giordana, I.S., Erra, G., Calvo, A., 2017. Organic matter characterization of shale rock by X-ray photoelectron spectroscopy: Adventitious carbon contamination and radiation damage. Energy & Fuels 31, 10414-10419.Ding, X., Gao, C., Zha, M., Chen, H., Su, Y., 2017. Depositional environment and factors controlling β-carotane accumulation: A case study from the Jimsar Sag, Junggar Basin, northwestern China. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 833-842.Emmings, J.F., Davies, S.J., Vane, C.H., Leng, M.J., Moss-Hayes, V., Stephenson, M.H., Jenkin, G.R.T., 2017. Stream and slope weathering effects on organic-rich mudstone geochemistry and implications for hydrocarbon source rock assessment: A Bowland Shale case study. Chemical Geology 471, 74-91.Gajica, G., ?ajnovi?, A., Stojanovi?, K., Kosti?, A., Slipper, I., Antonijevi?, M., Nytoft, H.P., Jovan?i?evi?, B., 2017. Organic geochemical study of the upper layer of Aleksinac oil shale in the Dubrava Block, Serbia. Oil Shale 34, 197–218.Giraldo Gómez, V.M., Beik, I., Podlaha, O.G., Mutterlose, J., 2017. The micropaleontological record of marine early Eocene oil shales from Jordan. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 723-739.Komar, N., Zeebe, R.E., 2017. Redox-controlled carbon and phosphorus burial: A mechanism for enhanced organic carbon sequestration during the PETM. Earth and Planetary Science Letters 479, 71-82.Li, W., Zhang, Z., 2017. Paleoenvironment and its control of the formation of Oligocene marine source rocks in the deep-water area of the northern South China Sea. Energy & Fuels 31, 10598-10611.Luo, Q., Qu, Y., Chen, Q., Xiong, Z., 2017. Organic geochemistry and petrology of mudrocks from the Upper Carboniferous Batamayineishan Formation, Wulungu area, Junggar Basin, China: Implications for petroleum exploration. Energy & Fuels 31, 10628-10638.Lupoi, J.S., Fritz, L.P., Parris, T.M., Hackley, P.C., Solotky, L., Eble, C.F., Schlaegle, S., 2017. Assessment of thermal maturity trends in Devonian–Mmississippian source rocks using Raman spectroscopy: Limitations of peak-fitting method. Frontiers in Energy Research 5, 24. doi: 10.3389/fenrg.2017.00024.Maravelis, A.G., Chamilaki, E., Pasadakis, N., Zelilidis, A., Collins, W.J., 2017. Hydrocarbon generation potential of a Lower Permian sedimentary succession (Mount Agony Formation): Southern Sydney Basin, New South Wales, Southeast Australia. International Journal of Coal Geology 183, 52-64.Mastalerz, M., Schieber, J., 2017. Effect of ion milling on the perceived maturity of shale samples: Implications for organic petrography and SEM analysis. International Journal of Coal Geology 183, 110-119.Yuan, W., Liu, G., Stebbins, A., Xu, L., Niu, X., Luo, W., Li, C., 2017. Reconstruction of redox conditions during deposition of organic-rich shales of the Upper Triassic Yanchang Formation, Ordos Basin, China. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 158-170.Zhang, W., Yang, W., Xie, L., 2017. Controls on organic matter accumulation in the Triassic Chang 7 lacustrine shale of the Ordos Basin, central China. International Journal of Coal Geology 183, 38-51.Zhou, L., Kang, Z., Wang, Z., Peng, Y., Xiao, H., 2017. Sedimentary geochemical investigation for paleoenvironment of the Lower Cambrian Niutitang Formation shales in the Yangtze Platform. Journal of Petroleum Science and Engineering 159, 376-386.Unconventional ResourcesAllen, D.T., Cardoso-Salda?a, F.J., Kimura, Y., 2017. Variability in spatially and temporally resolved emissions and hydrocarbon source fingerprints for oil and gas sources in shale gas production regions. Environmental Science & Technology 51, 12016-12026.Ashley, W.J., Panja, P., Deo, M., 2017. Surrogate models for production performance from heterogeneous shales. Journal of Petroleum Science and Engineering 159, 244-256.Bo-Wei, Z., Ju-He, Z., Guang, F., 2017. Determination of the hydrocarbon content in nanometer size pores adsorbed gas in unconventional reservoir rocks by chemical desorption-gas chromatography. Petroleum Science and Technology 35, 1327-1333.Chen, S., Qin, Y., Zhang, Q., Du, L., Zhao, J., 2017. Numerical description of shale gas desorption stages. Energy Exploration & Exploitation 35, 734-747.Cudjoe, S., Barati, R., 2017. Lattice Boltzmann simulation of CO2 transport in kerogen nanopores—An evaluation of CO2 sequestration in organic-rich shales. Journal of Earth Science 28, 926-932.Du, T., Shan, X., Yi, J., Qu, Y., 2017. Quantitative characteristics of nanoscale pores in gas-bearing volcanic rocks of the Yingcheng Formation in the Songnan gas field. Energy & Fuels 31, 10655-10664.El-Kammar, A., 2017. Oil shale resources in Egypt: the present status and future vision. Arabian Journal of Geosciences 10, Article 439.Geng, Y., Liang, W., Liu, J., Cao, M., Kang, Z., 2017. Evolution of pore and fracture structure of oil shale under high temperature and high pressure. Energy & Fuels 31, 10404-10413.Guo, T., Li, Y., Ding, Y., Qu, Z., Gai, N., Rui, Z., 2017. Evaluation of acid fracturing treatments in shale formation. Energy & Fuels 31, 10479-10489.Han, J., Chen, B., Zhao, X., Zheng, C., Zhang, J., 2017. Development characteristics and influential factors of organic pores in the Permian shale in the Lower Yangtze Region. Natural Gas Industry 37, 17-26.Hou, Y., He, S., Harris, N.B., Yi, J., Wang, Y., Zhang, J., Cheng, C., 2017. The effects of shale composition and pore structure on gas adsorption potential in highly mature marine shales, Lower Paleozoic, central Yangtze, China. Canadian Journal of Earth Sciences 54, 1033-1048.Hu, Q., Zhang, Y., Meng, X., Li, Z., Xie, Z., Li, M., 2017. Characterization of micro-nano pore networks in shale oil reservoirs of Paleogene Shahejie Formation in Dongying Sag of Bohai Bay Basin, East China. Petroleum Exploration and Development 44, 720-730.Huang, X., Zhao, Y.-P., 2017. Characterization of pore structure, gas adsorption, and spontaneous imbibition in shale gas reservoirs. Journal of Petroleum Science and Engineering 159, 197-204.Jiang, S., Chen, L., Wu, Y., Jiang, Z., McKenna, E., 2017. Hybrid plays of Upper Triassic Chang7 lacustrine source rock interval of Yanchang Formation, Ordos Basin, China. Journal of Petroleum Science and Engineering 159, 182-196.Li, J., Ma, Y., Huang, K., Lu, S., Yin, J., Zhang, Y., 2017. Comprehensive polynomial simulation and prediction for Langmuir volume and Langmuir pressure of shale gas adsorption using multiple factors. Marine and Petroleum Geology 88, 1004-1012.Li, T., Jiang, Z., Xu, C., Liu, B., Liu, G., Wang, P., Li, X., Chen, W., Ning, C., Wang, Z., 2017. Effect of pore structure on shale oil accumulation in the lower third member of the Shahejie formation, Zhanhua Sag, eastern China: Evidence from gas adsorption and nuclear magnetic resonance. Marine and Petroleum Geology 88, 932-949.Li, Y., Huang, T., Pang, Z., Jin, C., 2017. Geochemical processes during hydraulic fracturing: a water-rock interaction experiment and field test study. Geosciences Journal 21, 753-763.Liu, Y.C., Chen, D.X., Qiu, N.S., Wang, Y., Fu, J., Huyan, Y., Jia, J.K., Wu, H., 2017. Reservoir characteristics and methane adsorption capacity of the Upper Triassic continental shale in Western Sichuan Depression, China. Australian Journal of Earth Sciences 64, 807-823.Mastalerz, M., Schieber, J., 2017. Effect of ion milling on the perceived maturity of shale samples: Implications for organic petrography and SEM analysis. International Journal of Coal Geology 183, 110-119.Mendhe, V.A., Mishra, S., Khangar, R.G., Kamble, A.D., Kumar, D., Varma, A.K., Singh, H., Kumar, S., Bannerjee, M., 2017. Organo-petrographic and pore facets of Permian shale beds of Jharia Basin with implications to shale gas reservoir. Journal of Earth Science 28, 897-916.Oraki Kohshou, I., Barati, R., Yorro, M.C., Leshchyshyn, T., Adejumo, A.T., Ahmed, U., Kugler, I., Reynolds, M., McAndrew, J., 2017. Economic assessment and review of waterless fracturing technologies in shale resource development: A case study. Journal of Earth Science 28, 933-948.Ortiz Cancino, O.P., Pino Pérez, D., Pozo, M., Bessieres, D., 2017. Adsorption of pure CO2 and a CO2/CH4 mixture on a black shale sample: Manometry and microcalorimetry measurements. Journal of Petroleum Science and Engineering 159, 307-313.Santiago, C.J.S., Kantzas, A., 2017. Chromatographic separation and liquid drop-out in unconventional gas reservoirs. Journal of Petroleum Science and Engineering 159, 553-563.Shao, X., Pang, X., Jiang, F., Li, L., Huyan, Y., Zheng, D., 2017. Reservoir characterization of tight sandstones using nuclear magnetic resonance and incremental pressure mercury injection experiments: Implication for tight sand gas reservoir quality. Energy & Fuels 31, 10420-10431.Sinn, C.J.A., Klaver, J., Fink, R., Jiang, M., Schmatz, J., Littke, R., Urai, J.L., 2017. Using BIB-SEM imaging for permeability prediction in heterogeneous shales. Geofluids 2017, Article 4709064.Striolo, A., Cole, D.R., 2017. Understanding shale gas: Recent progress and remaining challenges. Energy & Fuels 31, 10300-10310.Sun, Z., Wang, Y., Wei, Z., Zhang, M., Wang, G., Wang, Z., 2017. Characteristics and origin of desorption gas of the Permian Shanxi Formation shale in the Ordos Basin, China. Energy Exploration & Exploitation 35, 792-806.Tang, X., Ripepi, N., Luxbacher, K., Pitcher, E., 2017. Adsorption models for methane in shales: Review, comparison, and application. Energy & Fuels 31, 10787-10801.Wang, L.L., Zhang, G.Q., Hallais, S., Tanguy, A., Yang, D.S., 2017. Swelling of shales: A multiscale experimental investigation. Energy & Fuels 31, 10442-10451.Wood, D.A., Hazra, B., 2017. Characterization of organic-rich shales for petroleum exploration & exploitation: A review-Part 1: Bulk properties, multi-scale geometry and gas adsorption. Journal of Earth Science 28, 739-757.Wood, D.A., Hazra, B., 2017. Characterization of organic-rich shales for petroleum exploration & exploitation: A review-Part 2: Geochemistry, thermal maturity, isotopes and biomarkers. Journal of Earth Science 28, 758-778.Wood, D.A., Hazra, B., 2017. Characterization of organic-rich shales for petroleum exploration & exploitation: A review-Part 3: Applied geomechanics, petrophysics and reservoir modeling. Journal of Earth Science 28, 779-803.Yang, Z., Zhu, J., Li, X., Luo, D., Qi, S., Jia, M., 2017. Experimental investigation of the transformation of oil shale with fracturing fluids under microwave heating in the presence of nanoparticles. Energy & Fuels 31, 10348-10357.Yasin, Q., Du, Q., Sohail, G.M., Ismail, A., 2017. Impact of organic contents and brittleness indices to differentiate the brittle-ductile transitional zone in shale gas reservoir. Geosciences Journal 21, 779-789.Zhang, J., Li, X., Wei, Q., Sun, K., Zhang, G., Wang, F., 2017. Characterization of full-sized pore structure and fractal characteristics of marine–continental transitional Longtan Formation shale of Sichuan Basin, South China. Energy & Fuels 31, 10490-10504.Zhang, M., Ayala, L.F., 2018. A semi-analytical solution to compositional flow in liquid-rich gas plays. Fuel 212, 274-292.Zhang, W., Wang, Q., Ye, J., Zhou, J., 2017. Fracture development and fluid pathways in shales during granite intrusion. International Journal of Coal Geology 183, 25-37.Zhang, Y., Liu, J., Xu, H., Niu, X., Qin, G., Cao, D., 2017. Comparison between pore structure and fractal characteristics of continental and transitional coal measures shale:a case study of Yan'an and Taiyuan formations at the northeastern margin of Ordos Basin Acta Petrolei Sinica 38, 1036-1046.Zheng, J., Wang, Z., Gong, W., Ju, Y., Wang, M., 2017. Characterization of nanopore morphology of shale and its effects on gas permeability. Journal of Natural Gas Science and Engineering 47, 83-90.Abstractsá Nor?i, G., Glud, R.N., Simonsen, K., Gaard, E., 2018. Deposition and benthic mineralization of organic carbon: A seasonal study from Faroe Islands. Journal of Marine Systems 177, 53-61. variations in sedimentation and benthic mineralization of organic carbon (OC) were investigated in a Faroese fjord. Deposited particulate organic carbon (POC) was mainly of marine origin, with terrestrial material only accounting for < 1%. On an annual basis the POC export from the euphotic zone amounted to 10.2 mol C m? 2 yr? 1 equating to 37% of the net primary production, and maximum sedimentation rates were associated to the spring bloom. The dynamics in the benthic solute exchange were governed by stratification that isolated the bottom water during summer and intensified sediment resuspension during winter. The POC export from the euphotic zone could not sustain the benthic mineralization rate (10.8 mol C m? 2 yr? 1) and the calculated burial rate (9.8 mol C m? 2 yr? 1) of organic material in the central basin. This indicated considerable focusing of material in the central part of the fjord. This was supported by the fact that the measured benthic mineralization rate – in contrast to most investigations – actually increased with increasing water depth. In August, when mineralization was at its maximum, the dissolved inorganic carbon (DIC) release from the sediment increased by 2.2 mmol m? 2 d? 1 for every m increase in water depth at 30–60 m depth. Due to sediment focusing, the OC burial in the deepest part of the fjord was 9.8 mol C m? 2 yr? 1. This was 2.4 times higher than the average OC burial in the fjord, estimated from the total sedimentation, and benthic mineralization accounting for the water depth related changes in activity. The study in Kaldbaksfj?r?ur underscore that fjords are important sites for long time OC burial, but emphasize the need for accounting for spatial variations when extrapolating results from a single or few stations to the scale of the entire fjord.Abate-Pella, D., Freund, D.M., Slovin, J.P., Hegeman, A.D., Cohen, J.D., 2017. An improved method for fast and selective separation of carotenoids by LC–MS. Journal of Chromatography B 1067, 34-37. are a large class of compounds that are biosynthesized by condensation of isoprene units in plants, fungi, bacteria, and some animals. They are characteristically highly conjugated through double bonds, which lead to many isomers as well susceptibility to oxidation and other chemical modifications. Carotenoids are important because of their potent antioxidant activity and are the pigments responsible for color in a wide variety of foods. Human consumption is correlated to many health benefits including prevention of cancer, cardiovascular disease, and age-related disease. Extreme hydrophobicity, poor stability, and low concentration in biological samples make these compounds difficult to analyze and difficult to develop analytical methods for aimed towards identification and quantification. Examples in the literature frequently report the use of exotic stationary phases, solvents, and additives, such as ethyl acetate, dichloromethane, and methyl tert-butyl ether that are incompatible with liquid chromatography mass spectrometry (LC–MS). In order to address these issues, we implemented the use of LC–MS friendly conditions using a low-hydrophobicity cyano-propyl column (Agilent Zorbax SB-CN). We successfully differentiated between isomeric carotenoids by optimizing two gradient methods and using a mixture of 11 standards and LC–MS in positive ionization mode. Three complex biological samples from strawberry leaf, chicken feed supplement, and the photosynthetic bacterium Chloroflexus aurantiacus were analyzed and several carotenoids were resolved in these diverse backgrounds. Our results show this methodology is a significant improvement over other alternatives for analyzing carotenoids because of its ease of use, rapid analysis time, high selectivity, and, most importantly, its compatibility with typical LC–MS conditions.Abdizadeh, H., Ahmadi, A., Kadkhodaie, A., Heidarifard, M., Shayeste, M., 2017. Estimation of thermal maturity from well logs and seismic data in the Mansuri oilfield, SW Iran. Journal of Petroleum Science and Engineering 159, 461-473. maturity is the primary geological factor in exploration of hydrocarbon resources. Maturity index which is calculated from well-logging information and it is a useful parameter to unravel the burial history and hydrocarbon generation phases of a source rock. This study proposes a new method for estimating maturity index from well logs and seismic data using neural network and ant colony optimization (ACO) approach. The 2D seismic data and petrophysical logs of the Pabdeh Formation from three wells of the Mansuri field are employed to examine the methodology of this study. In the first step, maturity index (MI) was calculated from well logs including neutron, resistivity, sonic and density. The calculated values were used as inputs in a multi-attribute analysis to exploit logical relationships between them and seismic attributes. Seismic inversion was performed and the resulting acoustic impedance was utilized as an external attribute in maturity index estimation. A probabilistic neural network (PNN) was trained by using a set of predictor attributes derived from a multiple regression analysis. Finally, the nonlinear Ant Colony Optimization technique was utilized as an intelligent tool to generate a seismic section of maturity index. Using the Matlab programming environment for math computations and its graphical visualizations the nonlinear ACO section of the maturity index was obtained. The results show that the intelligently derived equation based on the nonlinear ant colony algorithm provides fast and more accurate solutions. The stochastic optimization outperforms the gradient optimization in maturity index estimation from well logs and seismic attributes. The calculated MI values range from 3 to 5 indicating the early stage of the oil window. The simulated MI shows a good agreement with the thermal maturity derived from Rock-Eval pyrolysis.Abou-el-karam, S., Ratel, J., Kondjoyan, N., Truan, C., Engel, E., 2017. Marker discovery in volatolomics based on systematic alignment of GC-MS signals: Application to food authentication. Analytica Chimica Acta 991, 58-67. with an experiment to authenticate walnut oils based on GC-MS analysis of the volatolome, this paper aims to demonstrate the relevance of a two-step alignment-based strategy for the systematic research of VOC markers. The first step of the treatment consists of roughly reducing the time shifts with efficient, known warping techniques like COW (Correlation Optimized Warping). The second step relies on an accurate peak apex alignment in order to refine residual local misalignments and to enable further systematic marker research through univariate or multivariate data treatments. This two-step strategy was implemented on 117 GC-MS analyses of the volatolome of three vegetable oils with very similar composition. During the analysis campaign, the GC-MS system was intentionally subjected to instrumental drifts in order to generate realistic signal shifts. The first part of this study aims to assess the efficiency of the warping-based strategy in terms of signal alignment and sample discrimination. Whereas no distinction between the three oils was possible with unaligned raw GC-MS data, the application of COW enabled a significant but insufficient improvement of both reduction of temporal drifts and between-group separation with 79% of samples being well-classified according to Linear Discriminant Analysis (LDA). Applying the peak apex alignment procedure to COW-treated signals resulted in a suitable correction of the remaining local distortions and improved the proportion of well-classified samples in LDA to 100%. The second part of this study assesses the robustness of the discriminant markers highlighted in this approach by: (i) discussing the relevance of the best markers involved in the LDA model, where a close review of literature confirmed the consistency for two of them, and (ii) validating highlighted makers by retrieving the set of the 23 markers previously determined by manual processing among those automatically found. The third part shows the potential of the systematic approach for untargeted detection of 184 highly significant relevant markers from the oil volatolome. Finally, the fourth part presents a comparison of our hybrid alignment strategy with two reference alignment methods (iCoshift and STW) in order to assess quality alignment of the GC-MS data and to show the three methods' abilities to detect discriminant markers.Adam, P.S., Borrel, G., Brochier-Armanet, C., Gribaldo, S., 2017. The growing tree of Archaea: new perspectives on their diversity, evolution and ecology. ISME Journal 11, 2407-2425. Archaea occupy a key position in the Tree of Life, and are a major fraction of microbial diversity. Abundant in soils, ocean sediments and the water column, they have crucial roles in processes mediating global carbon and nutrient fluxes. Moreover, they represent an important component of the human microbiome, where their role in health and disease is still unclear. The development of culture-independent sequencing techniques has provided unprecedented access to genomic data from a large number of so far inaccessible archaeal lineages. This is revolutionizing our view of the diversity and metabolic potential of the Archaea in a wide variety of environments, an important step toward understanding their ecological role. The archaeal tree is being rapidly filled up with new branches constituting phyla, classes and orders, generating novel challenges for high-rank systematics, and providing key information for dissecting the origin of this domain, the evolutionary trajectories that have shaped its current diversity, and its relationships with Bacteria and Eukarya. The present picture is that of a huge diversity of the Archaea, which we are only starting to explore.Adebiyi, F.M., Akinola, A.S., Santoro, A., Mastrolitti, S., 2017. Chemical analysis of resin fraction of Nigerian bitumen for organic and trace metal compositions. Petroleum Science and Technology 35, 1370-1380. of organics and trace metals of the resin fraction of Nigerian bitumen were carried out with an opinion to establish the environmental consequences of the fossil fuel and as well as characterize them. Bitumen samples were extracted from oil sands via Soxhlet extraction procedure using toluene as the extracting solvent. The bitumen samples were deasphaltened to obtain maltene by dissolving the samples in n-pentane (1:40). Column chromatography was used to fractionate the maltene into its components (saturates, aromatics, and resin) using silica gel as adsorbent and dissimilar solvents of varying polarity (n-hexane for saturates, toluene for aromatics, and methanol for resins). The organic compounds of the resin fraction were examined using Fourier Transform Infrared Spectrophometry (FTIR) and the elemental concentrations were determined using Inductively Coupled Plasma Optical Emission Spectrophotometry (ICP-OES). The infrared spectra of all the resin samples presented distinctive bands including expected polar functional groups which confirmed that the resin was cleanly eluted from the bitumen samples. The concentrations of the analyzed trace metals in the resin fraction were found to be high compared to other fractions and this was confirmed by their T-test values. Fe had the highest average concentration of 34.81 ± 14.37?mg/kg and a range of 19.35?47.48?mg/kg, while Mn had the least mean concentration of 0.94 ± 0.71?mg/kg and a range of 0.35?1.88?mg/kg. The result of cross-plot analysis revealed that resin fraction has strong and positive inter elemental correlation with the NSO and asphaltene fraction of the same bitumen samples. The overall results indicated that processing of the bitumen and/or its resin may cause catalyst poisoning and fouling, corrosion of equipment and pipelines, and particulate emissions into the environment and therefore adequate demetalisation of the fossil fuel must be done before processing.Adorno, R.R., do Carmo, D.A., Germs, G., Walde, D.H.G., Denezine, M., Boggiani, P.C., Sousa e Silva, S.C., Vasconcelos, J.R., Tobias, T.C., Guimar?es, E.M., Vieira, L.C., Figueiredo, M.F., Moraes, R., Caminha, S.A., Suarez, P.A.Z., Rodrigues, C.V., Caixeta, G.M., Pinho, D., Schneider, G., Muyamba, R., 2017. Cloudina lucianoi (Beurlen & Sommer, 1957), Tamengo Formation, Ediacaran, Brazil: Taxonomy, analysis of stratigraphic distribution and biostratigraphy. Precambrian Research 301, 19-35. genus Cloudina Germs, 1972 includes seven species restricted to Ediacaran strata: 1. Cloudina lucianoi (Beurlen and Sommer, 1957) (Tamengo Formation, Brazil); 2. Cloudina hartmanae Germs, 1972 (Nama Group, Namibia); 3. Cloudina riemkeae Germs, 1972 (Nama Group, Namibia; 4. Cloudina waldei Hahn and Pflug, 1985 (Tamengo Formation, Brazil); 5. Cloudina lijiagouensis Zhang et al., 1992 (Yangtze Platform, China), 6. Cloudina sinensis Zhang et al., 1992, (Yangtze Platform, China); and 7. Cloudina carinata Cortijo et al., 2010 (Spain). Cloudina lucianoi was originally attributed to Aulophycus Fenton and Fenton, 1939 and was later suggested to represent a species of Cloudina. Briefly, Cloudina differs from Aulophycus in having a lamellar sessile benthic funnel-within-funnel skeleton instead of a tube-shaped skeleton. Additionally, Aulophycus has been considered restricted to the Cambrian, whereas all Cloudina species have been recorded only in the Ediacaran, with extinction of all species at the end of this period being observed. The results of taxonomic studies of Cloudina lucianoi are presented, as well as a revision of type-section, morphometric analysis, stratigraphic distribution and biostratigraphy. For this focal species, a new description, new diagnosis and morphometric analyses are included. Regarding taxonomy, a brief history is given of the Genus Cloudina, with remarks comparing Cloudina lucianoi with four other species. Additionally, new illustrations of type-material of Cloudina lucianoi, Cloudina hartmanae and Cloudina riemkeae are presented. The aforementioned species are revised in this report; additionally, an up-to-date stratigraphic approach and illustrations of the type-horizon of this species are included. A detailed comparison of the seven species is conducted to present a clearer diagnosis for this species described with material recovered from Brazil.Agarwal, N., Freakley, S.J., McVicker, R.U., Althahban, S.M., Dimitratos, N., He, Q., Morgan, D.J., Jenkins, R.L., Willock, D.J., Taylor, S.H., Kiely, C.J., Hutchings, G.J., 2017. Aqueous Au-Pd colloids catalyze selective CH4 oxidation to CH3OH with O2 under mild conditions. Science, 10.1126/science.aan6515. selective oxidation of methane, the primary component of natural gas, remains an important challenge in catalysis. Using colloidal gold-palladium nanoparticles rather than the same nanoparticles supported on titanium oxide, we oxidized methane to methanol with high selectivity (92%) in aqueous solution at mild temperatures. Using isotopically labeled O2 as an oxidant in the presence of H2O2, we demonstrate that the methanol produced incorporated a substantial fraction (70%) of gas-phase O2. More oxygenated products were formed than H2O2 consumed, suggesting that the controlled breakdown of H2O2 activates methane which subsequently incorporates molecular oxygen through a radical process. If a source of methyl radicals can be established, then the selective oxidation of methane to methanol using molecular oxygen is possible.Agematsu, S., Uesugi, K., Sano, H., Sashida, K., 2017. Reconstruction of the multielement apparatus of the earliest Triassic conodont, Hindeodus parvus, using synchrotron radiation X-ray micro-tomography. Journal of Paleontology 91, 1220. Triassic natural conodont assemblages preserved as impressions on bedding planes occur in a claystone of the Hashikadani Formation, which is part of the Mino Terrane, a Jurassic accretionary complex in Japan. In this study, the apparatus of Hindeodus parvus (Kozur and Pjatakova, 1976) is reconstructed using synchrotron radiation micro-tomography (SR–μCT). This species has six kinds of elements disposed in 15 positions forming the conodont apparatus. Carminiscaphate, angulate, and makellate forms are settled in pairs in the P1, P2, and M positions, respectively. The single alate element is correlated with the S0 position. The S array is a cluster of eight ramiforms, subdivided into two inner pairs of digyrate S1–2 and two outer pairs of bipennate S3–4 elements. The reconstruction is similar to a well-known ozarkodinid apparatus model. In addition, the μCT images show that the ‘anterior’ and ‘posterior’ processes of the S1–2 elements faced the caudal and rostral ends of the living conodont body, respectively.Ahmad, J., 2017. Bioremediation of petroleum sludge using effective microorganism (EM) technology. Petroleum Science and Technology 35, 1515-1522. study was designed for the bioremediation of waste sludge from a petroleum refinery applying effective microorganism (EM) technology. The treated sludge was found rich in organic matter, nitrogen, phosphorus, potassium (N, P, K) and was mixed with clean soil (1:1) to prepare a product named as EM biofertilizer. The EM biofertilizer was compared with FYM. It was shown that the field using EM biofertilizer given 275?kg yield compare to the 230?kg yield obtained with farm yard manure (FYM). The quantity of heavy metals in onion using EM biofertlizer was all within the EU 2006 permissible limits.Ahmed, S., Elraies, K.A., Forooozesh, J., Bt Mohd Shafian, S.R., Hashmet, M.R., Hsia, I.C.C., Almansour, A., 2017. Experimental investigation of immiscible supercritical carbon dioxide foam rheology for improved oil recovery. Journal of Earth Science 28, 835-841. paper presents the rheological behaviour of supercritical CO2 (sCO2) foam at reservoir conditions of 1 500 psi and 80 °C. Different commercial surfactants were screened and utilized in order to generate a fairly stable CO2 foam. Mixed surfactant system was also introduced to generate strong foam. Foam rheology was studied for some specific foam qualities using a high pressure high temperature (HPHT) foam loop rheometer. A typical shear thinning behaviour of the foam was observed and a significant increase in the foam viscosity was noticed with the increase of foam quality until 85%. A desired high apparent viscosity with coarse texture was found at 85% foam quality. Foam visualization above 85% showed an unstable foam due to extremely thin lamella which collapsed and totally disappeared in the loop rheometer. Below 52%, a non-homogenous and unstable foam was found having low viscosity with some liquid accumulation at the bottom of the circulation loop. This research has demonstrated rheology of sCO2 foams at different qualities at HPHT to obtain optimal foam quality region for immiscible CO2 foam co-injection process.Al-Anssari, S., Arif, M., Wang, S., Barifcani, A., Lebedev, M., Iglauer, S., 2017. Wettability of nano-treated calcite/CO2/brine systems: Implication for enhanced CO2 storage potential. International Journal of Greenhouse Gas Control 66, 97-105. are proven to be efficient agents for wettability alteration in subsurface applications including enhanced oil recovery (EOR). Nanofluids can also be used for CO2-storage applications where the CO2-wet rocks can be rendered strongly water-wet, however no attention has been given to this aspect in the past. Thus in this work we presents contact angle (θ) measurements for CO2/brine/calcite system as function of pressure (0.1 MPa, 5 MPa, 10 MPa, 15 MPa, and 20 MPa), temperature (23 °C, 50 °C and 70 °C), and salinity (0, 5, 10, 15, and 20% NaCl) before and after nano-treatment to address the wettability alteration efficiency. Moreover, the effect of treatment pressure and temperature, treatment fluid concentration (SiO2 wt%) and the period of nano-treatment on the wettability of calcite is examined. We find that nano-treatment alters the wettability significantly i.e. intermediate-wet calcite turns strongly water-wet after treatment (e.g. at 20 MPa and 50 °C, θ = 64° for intermediate-wet calcite, and θ = 28° for nano-treated calcite). Consequently, pre-injection of nanofluids will significantly enhanced the storage potential. It was also found that the permanent shift in wettability after nano-treatment is a function of treatment conditions including temperature, pressure, and treatment duration time and that surfaces treated under high pressure and low temperature yield better wettability alteration efficiency. We point out that the change in wettability is attributed to the changes in surface properties of the nano-treated sample. The results of the study thus depict that nanoparticles can significantly enhance storage potential and de-risk storage projects.Al-Mailem, D.M., Kansour, M.K., Radwan, S.S., 2017. Capabilities and limitations of DGGE for the analysis of hydrocarbonoclastic prokaryotic communities directly in environmental samples. MicrobiologyOpen 6, Article e00495. communities in pristine and oil-contaminated desert soil, seawater, and hypersaline coastal soil were analyzed using culture-dependent and culture-independent approaches. The former technique was the dilution-plating method. For the latter, total genomic DNA was extracted and the 16S rRNA genes were amplified using a universal bacterial primer pair and primer pairs specific for Actinobacteria, Gammaproteobacteria, and Archaea. The amplicons were resolved using denaturing gradient gel electrophoresis (DGGE) and sequenced, and the sequences were compared to those in GenBank. The plating method offered the advantages of capturing the targeted hydrocarbonoclastic microorganisms, counting them and providing cultures for further study. However, this technique could not capture more than a total of 15 different prokaryotic taxa. Those taxa belonged predominantly to the genera Alcanivorax, Pseudoxanthomonas, Bosea, Halomonas, and Marinobacter. The individual isolates in culture consumed between 19 and 50% of the available crude oil in 10 days. Although the culture-independent approach revealed much more microbial diversity, it was not problem-free. The subdivision primers exhibited satisfactory specificity, but they failed to capture all the available taxa. The universal bacterial primer pair ignored Actinobacteria altogether, although the primer pair specific for Actinobacteria captured many of them, for example, the genera Geodermatophilus, Streptomyces, Mycobacterium, Pontimonas, Rhodococcus, Blastococcus, Kocuria, and many others. Because most researchers worldwide use universal primers for PCR, this finding should be considered critically to avoid misleading interpretations.Al-Yaseri, A., Zhang, Y., Ghasemiziarani, M., Sarmadivaleh, M., Lebedev, M., Roshan, H., Iglauer, S., 2017. Permeability evolution in sandstone due to CO2 injection. Energy & Fuels. variation is one of the key factors influencing the injectivity of CO2 in CO2 sequestration projects. Despite the research carried out on the subject, the results are highly inconsistent. In this study, the injection of brine (5 wt % NaCl + 1 wt % KCl), CO2-saturated (live) brine, and supercritical CO2 was performed on three homogeneous Berea sandstone plugs with a low clay content and two Bandera Gray sandstone plugs with a high clay content at reservoir conditions (10 MPa and 323 K). Porosity and permeability of the samples were measured using nuclear magnetic resonance (T2 relaxation time), and a dynamic (during flooding) permeability measurement technique, respectively, at different injection rates and injection durations. The mercury intrusion test was also performed on each sample to further evaluate its pore throat size distributions. From the results of this study, it was revealed that the CO2 injection rate is unlikely to affect the permeability significantly. It was also shown that the permeability can be influenced depending upon sandstone pore throat size distribution and the distribution/structure of the clay minerals in the sample.Alkorta, I., Epelde, L., Garbisu, C., 2017. Environmental parameters altered by climate change affect the activity of soil microorganisms involved in bioremediation. FEMS Microbiology Letters 364, Article fnx200., based on the use of microorganisms to break down pollutants, can be very effective at reducing soil pollution. But the climate change we are now experiencing is bound to have an impact on bioremediation performance, since the activity and degrading abilities of soil microorganisms are dependent on a series of environmental parameters that are themselves being altered by climate change, such as soil temperature, moisture, amount of root exudates, etc. Many climate-induced effects on soil microorganisms occur indirectly through changes in plant growth and physiology derived from increased atmospheric CO2 concentrations and temperatures, the alteration of precipitation patterns, etc., with a concomitant effect on rhizoremediation performance (i.e. the plant-assisted microbial degradation of pollutants in the rhizosphere). But these effects are extremely complex and mediated by processes such as acclimation and adaptation. Besides, soil microorganisms form complex networks of interactions with a myriad of organisms from many taxonomic groups that will also be affected by climate change, further complicating data interpretation.Allen, D.T., Cardoso-Salda?a, F.J., Kimura, Y., 2017. Variability in spatially and temporally resolved emissions and hydrocarbon source fingerprints for oil and gas sources in shale gas production regions. Environmental Science & Technology 51, 12016-12026. gridded inventory for emissions of methane, ethane, propane, and butanes from oil and gas sources in the Barnett Shale production region has been developed. This inventory extends previous spatially resolved inventories of emissions by characterizing the overall variability in emission magnitudes and the composition of emissions at an hourly time resolution. The inventory is divided into continuous and intermittent emission sources. Sources are defined as continuous if hourly averaged emissions are greater than zero in every hour; otherwise, they are classified as intermittent. In the Barnett Shale, intermittent sources accounted for 14–30% of the mean emissions for methane and 10–34% for ethane, leading to spatial and temporal variability in the location of hourly emissions. The combined variability due to intermittent sources and variability in emission factors can lead to wide confidence intervals in the magnitude and composition of time and location-specific emission inventories; therefore, including temporal and spatial variability in emission inventories is important when reconciling inventories and observations. Comparisons of individual aircraft measurement flights conducted in the Barnett Shale region versus the estimated emission rates for each flight from the emission inventory indicate agreement within the expected variability of the emission inventory for all flights for methane and for all but one flight for ethane.Alpert, P.A., Ciuraru, R., Rossignol, S., Passananti, M., Tinel, L., Perrier, S., Dupart, Y., Steimer, S.S., Ammann, M., Donaldson, D.J., George, C., 2017. Fatty acid surfactant photochemistry results in new particle formation. Scientific Reports 7, Article 12693. interfaces that exist at the sea surface microlayer or as surfactant coatings on cloud droplets are highly concentrated and chemically distinct from the underlying bulk or overlying gas phase. Therefore, they may be potentially unique locations for chemical or photochemical reactions. Recently, photochemical production of volatile organic compounds (VOCs) was reported at a nonanoic acid interface however, subsequent secondary organic aerosol (SOA) particle production was incapable of being observed. We investigated SOA particle formation due to photochemical reactions occurring at an air-water interface in presence of model saturated long chain fatty acid and alcohol surfactants, nonanoic acid and nonanol, respectively. Ozonolysis of the gas phase photochemical products in the dark or under continued UV irradiation both resulted in nucleation and growth of SOA particles. Irradiation of nonanol did not yield detectable VOC or SOA production. Organic carbon functionalities of the SOA were probed using X-ray microspectroscopy and compared with other laboratory generated and field collected particles. Carbon-carbon double bonds were identified in the condensed phase which survived ozonolysis during new particle formation and growth. The implications of photochemical processes occurring at organic coated surfaces are discussed in the context of marine SOA particle atmospheric fluxes.AlYousef, Z., Almobarky, M., Schechter, D., 2017. Enhancing the stability of foam by the use of nanoparticles. Energy & Fuels 31, 10620-10627. generation is one of the most promising techniques to overcome gas mobility challenges and improve the sweep efficiency of reservoir fluids. The synergistic effect of surfactant and nanoparticles can help produce a stronger and more stable foam in reservoir porous media. The objective of this work is to assess the ability of anionic surfactant and a mixture of the surfactant and nanoparticles to produce foam for gas mobility control and the enhancement of oil recovery. Static, dynamic, and core flood tests were conducted to evaluate foam strength. Static foam tests in the presence of crude oil showed a clear trend on foam behavior when solid nanoparticles were added to surfactant. As the concentration of nanoparticles increases, the foam half-life increases, too. Foamability tests in Bentheimer sandstone showed better foam generation and stabilization when nanoparticles were used. The addition of nanoaprticles to surfactant solutions resulted in higher pressure drop and, therefore, higher reduction of gas mobility compared to surfactant. The rise in temperature from 25 to 50 °C reduces the measured pressure drop across the core samples in the absence and presence of nanoparticles, which can be attributed to the reduction in foam stability and strength. Both surfactant and a mixture of surfactant and nanoparticles were able to enhance oil recovery. The surfactant was able to bring the oil recovery to 41.45% of the original oil in place (OOIP). In contrast, the presence of nanoparticles resulted in higher oil recovery, 49.05%, of the OOIP.Amano, Y., Iwatsuki, T., Naganuma, T., 2017. Characteristics of naturally grown biofilms in deep groundwaters and their heavy metal sorption property in a deep subsurface environment. Geomicrobiology Journal 34, 769-783. biofilm samples were collected from anaerobic groundwater in the depth range of 158.8–199.4 m in a borehole drilled in the Tono area, Japan, to understand their effects on the migration behavior of heavy metals in subsurface environments. The depth range is featured geologically by the lignite formation of sedimentary rocks that bear a uranium ore and the underlying granitic formation. Microbiomes of the derived biofilms, as well as of the ambient bacterioplankton, were characterized based on 16S rRNA gene sequences (clones) or phylotypes, and their heavy metal sorption properties were examined with reference to geochemical features of groundwaters. Phylotypic compositions of the four microbiomes, i.e., of biofilm vs. planktonic bacteria as well as in granitic vs. sedimentary rock groundwaters showed significant differences. In addition, each microbiome was dominated by one or two distinctive phylotypes. In bacterioplankton, the phylotype related to a betaproteobacterial environmental clone dominated 54% of the sequenced clones derived from sedimentary rock groundwater, whereas those related to Denitratisoma oestradiolicum and Clostridium sp. dominated 45% and 37%, respectively, of the clones derived from granitic groundwater. In biofilms, the phylotypes related to Methylobacillus flagellatus and Ignavibacterium album accounted for 77% and 78% of the clones of the biofilms derived from the sedimentary rock and granitic groundwaters, respectively. Chemical and mineralogical analyses demonstrated that high amounts of heavy metals such as Fe, Ni, Cu, Zn, As, Cd, Pb, Th and U accumulated in the biofilms; and their sorption properties varied between biofilms presumably with influences of co-occurring Fe-hydroxides and sulfide minerals under the redox conditions of approximately ?360 to 0 mV in subsurface environments. The biofilm-mineral interaction provides an implication for possible retardation of radionuclide migration in subsurface hydrology, which is of practical interest in geological disposal systems for high-level radioactive waste.An, Y.J., Rowland, S.E., Na, J.-H., Spigolon, D., Hong, S.K., Yoon, Y.J., Lee, J.-H., Robb, F.T., Cha, S.-S., 2017. Structural and mechanistic characterization of an archaeal-like chaperonin from a thermophilic bacterium. Nature Communications 8, Article 827. chaperonins (CPNs) are megadalton sized hollow complexes with two cavities that open and close to encapsulate non-native proteins. CPNs are assigned to two sequence-related groups that have distinct allosteric mechanisms. In Group I CPNs a detachable co-chaperone, GroES, closes the chambers whereas in Group II a built-in lid closes the chambers. Group I CPNs have a bacterial ancestry, whereas Group II CPNs are archaeal in origin. Here we describe open and closed crystal structures representing a new phylogenetic branch of CPNs. These Group III CPNs are divergent in sequence and structure from extant CPNs, but are closed by a built-in lid like Group II CPNs. A nucleotide-sensing loop, present in both Group I and Group II CPNs, is notably absent. We identified inter-ring pivot joints that articulate during ring closure. These Group III CPNs likely represent a relic from the ancestral CPN that formed distinct bacterial and archaeal branches.Anderson, R.E., Reveillaud, J., Reddington, E., Delmont, T.O., Eren, A.M., McDermott, J.M., Seewald, J.S., Huber, J.A., 2017. Genomic variation in microbial populations inhabiting the marine subseafloor at deep-sea hydrothermal vents. Nature Communications 8, Article 1114. is known about evolutionary drivers of microbial populations in the warm subseafloor of deep-sea hydrothermal vents. Here we reconstruct 73 metagenome-assembled genomes (MAGs) from two geochemically distinct vent fields in the Mid-Cayman Rise to investigate patterns of genomic variation within subseafloor populations. Low-abundance populations with high intra-population diversity coexist alongside high-abundance populations with low genomic diversity, with taxonomic differences in patterns of genomic variation between the mafic Piccard and ultramafic Von Damm vent fields. Populations from Piccard are significantly enriched in nonsynonymous mutations, suggesting stronger purifying selection in Von Damm relative to Piccard. Comparison of nine Sulfurovum MAGs reveals two high-coverage, low-diversity MAGs from Piccard enriched in unique genes related to the cellular membrane, suggesting these populations were subject to distinct evolutionary pressures that may correlate with genes related to nutrient uptake, biofilm formation, or viral invasion. These results are consistent with distinct evolutionary histories between geochemically different vent fields, with implications for understanding evolutionary processes in subseafloor microbial populations.Ankit, Y., Mishra, P.K., Kumar, P., Jha, D.K., Kumar, V.V., Ambili, V., Anoop, A., 2017. Molecular distribution and carbon isotope of n-alkanes from Ashtamudi Estuary, South India: Assessment of organic matter sources and paleoclimatic implications. Marine Chemistry 196, 62-70. distribution and δ13C composition of n-alkanes were used to identify organic matter (OM) sources in river dominated Ashtamudi Estuary, Southern India. A number of n-alkane indices have been calculated to illustrate the spatial variability by considering separately river dominated northern reaches and marine influenced southern part of the estuary. The carbon preference index (CPI) and average chain length (ACL) provide evidence for recycled organic inputs in the tidal zone, whereas dominant biogenic contribution has been observed in the riverine zone. The proxy ratio (Paq) and terrigenous/aquatic ratio (TAR) indices demonstrate maximum aquatic productivity in the tidal dominated region of the Ashtamudi Estuary. The quantitative apportion of organic matter sources in Ashtamudi sediments using compound-specific carbon isotope analysis (CSIA) of long-chain n-alkane shows dominance (53–83%) of C3 terrestrial plants derived OM. The results clearly demonstrate the effectiveness of an integrated molecular and stable carbon isotope analysis for quantitatively assessing OM sources in estuarine environments.Arabas, A., Schl?gl, J., Meister, C., 2017. Early Jurassic carbon and oxygen isotope records and seawater temperature variations: Insights from marine carbonate and belemnite rostra (Pieniny Klippen Belt, Carpathians). Palaeogeography, Palaeoclimatology, Palaeoecology 485, 119-135. carbon and oxygen isotope records and discussion of the main variations in seawater temperature through the Sinemurian–Aalenian of the Pieniny Klippen Basin (northern Tethys Ocean) are presented herein. Comparison of the recorded changes in stable-isotope compositions of bulk carbonate and belemnite rostra from an open-marine environment with previously documented, predominantly restricted epicontinental data enables determination of major climatic events that were most likely of worldwide extent. A slight positive δ13C shift is recorded in the lowermost Upper Pliensbachian. A significant positive excursion in carbonate carbon isotope values is documented in the Lower Toarcian Serpentinum Zone. Furthermore, the δ13C values display a falling trend in the Lower–Upper Toarcian and relatively constant values in the Aalenian. Temperatures inferred from the δ18O values of well-preserved belemnite rostra suggest rather cool seawater conditions (10–13 °C) in the Pieniny Klippen Basin during the Late Sinemurian, warming by 4 °C in the Early Pliensbachian and then cooling by 8 °C in the Late Pliensbachian. The seawater temperature rose once more in the Early Toarcian and began to fall again during the Middle Toarcian. In the Middle–?Late Aalenian, seawater temperatures oscillated between 10 and 13 °C.Ardenghi, N., Mulch, A., Pross, J., Maria Niedermeyer, E., 2017. Leaf wax n-alkane extraction: An optimised procedure. Organic Geochemistry 113, 283-292. wax n-alkanes are often extracted from modern plant material to describe their natural occurrence and understand the factors determining their potential as biomarkers for climate reconstruction. Despite several studies on the topic no standardised approach for n-alkane extraction from leaves has been yet devised. A common issue is the necessity to work on leaf subsamples to reduce co-extraction of unwanted polar compounds (e.g. chlorophyll), as they often interfere with individual steps involved in post-extraction, wet-chemical isolation of leaf wax n-alkanes. However, subsampling can generate biases regarding n-alkane distribution, concentration, and isotopic composition due to heterogeneities along the leaf sheath. Therefore, we propose and test an optimised extraction approach. Using leaves of Cladium mariscus and Typha angustifolia, we compared the effect on n-alkane extraction of two solvent mixtures, two extraction techniques and two sample preparation modalities. We found similar results for the two modes of sample preparation (intact vs. shredded leaf), while the use of the two solvent mixes and the two extraction techniques produced significantly different results. n-Hexane/dichloromethane 9:1 was almost twice as efficient (+97%) than the more commonly used dichloromethane/methanol 9:1, producing higher n-alkane yields while reducing co-elution of highly polar compounds. The best results, both for yield, sample processing time and solvent consumption, were achieved in combination with the accelerated solvent extraction technique, averagely +49% more efficient than ultrasound assisted solvent extraction. Alongside, we investigated the distribution of n-alkanes along the leaf sheath of C. mariscus.Arias-Ruiz, C., Elliot, M., Bézos, A., Pedoja, K., Husson, L., Cahyarini, S.Y., Cariou, E., Michel, E., La, C., Manssouri, F., 2017. Geochemical fingerprints of climate variation and the extreme La Ni?a 2010–11 as recorded in a Tridacna squamosa shell from Sulawesi, Indonesia. Palaeogeography, Palaeoclimatology, Palaeoecology 487, 216-228. used a Tridacna squamosa (Tridacnidae, Bivalvia) shell that lived between 2006 and 2012 to reconstruct environmental conditions in South East Sulawesi (Indonesia). We focused mainly on estimating the influence of temperature and rainfall on the shell geochemistry, as well as ENSO anomalies. Comparison of the measured and theoretical δ18O values show clear seasonal variations and confirms that this species secretes its shell at isotopic equilibrium. The δ18O in T. squamosa shows how the increased rainfall associated with monsoon precipitations in this area influences the δ18O shell signal during the rainy season, the correlation between shell δ18O and SST (r2 = 0.62) decrease in warm/wet seasons (SST > 28.5 °C). Shell Mg/Ca profiles presents better correlation with SST (r2 = 0.8) than Sr/Ca profiles (r2 = 0.52). Shell Ba/Ca ratio increases during each dry season when primary productivity is maximum. Secondary Ba/Ca peaks also occur during the certain wet seasons and appear associated with abnormal enhanced runoff. Shell δ13C co-varies with primary productivity and salinity, with highest δ13C values occurring during the dry seasons. During 2010–11, abnormal values were detected in all geochemical proxies as result of the strong La Ni?a event. This calibration study demonstrates the ability of T. squamosa shells to accurately reflect present day environmental processes with seasonal resolutions and to define the local signature of hydrological changes associated with ENSO.Arienzo, M., Donadio, C., Mangoni, O., Bolinesi, F., Stanislao, C., Trifuoggi, M., Toscanesi, M., Di Natale, G., Ferrara, L., 2017. Characterization and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in the sediments of Gulf of Pozzuoli (Campania, Italy). Marine Pollution Bulletin 124, 480-487. of the literature reports on the impact of the former Bagnoli brownfield on the pollution of Bagnoli Bay, embedded in the Gulf of Pozzuoli (GoP). Thus, we studied concentrations, types and sources of sixteen PAHs (EPA) in sediments at 22 sites along 5 transects covering the entire area of GoP. Outstanding levels of PAHs were found, varying from 7.1 μg g? 1 to 2.5 E + 3 μg g? 1. Sediments collected at sites far away from Bagnoli were found to be polluted to a similar extent than those facing the brownfield site, with values > 100 μg g? 1. Total PAHs levels in the sediments of GoP were higher by thirty-eleven thousand fold than those reported by other studies from various marine sites in the world. Transit axes of fine and very fine sands and diagnostic indexes revealed a common pyrolytic PAHs pollution spreading from the Bagnoli plant to all GoP.Ashley, W.J., Panja, P., Deo, M., 2017. Surrogate models for production performance from heterogeneous shales. Journal of Petroleum Science and Engineering 159, 244-256. in geologic parameters such as permeability, porosity and formation compressibility is observed in all reservoirs including the ultra-low permeability reservoirs such as shales. Computing requirements for reservoir simulation of these reservoirs are extensive because of the complexity in geologic model. Surrogate models have been used successfully in conventional reservoirs and homogeneous low-permeability reservoirs. In this study, robust surrogate models are developed to evaluate production performance from heterogeneous low-permeability reservoirs. A workflow is presented to create surrogate models from any or all of the properties which affect production. Methods of representing various degrees of heterogeneities in permeability are considered in this paper. The surrogate models are mathematical functions for important outcomes – recoveries, gas oil ratios (GOR) with respect to the heterogeneous property as input. Representing productions at particular time for different permeability distributions requires a unique function. Logarithmic equation for oil recovery and power law equation for cumulative GOR are found to be the most appropriate functions. The developed surrogate models are then utilized to forecast production for any input distribution of permeability using Monte Carlo simulations. Outputs in the form of probability density functions (PDF) of oil recovery and cumulative GOR are generated after statistical analysis. The probabilistic output is then interpreted as deterministic time series by considering mean values along with their uncertainty bands of standard deviations and 5–95% probability ranges. These models are validated against the results from reservoir simulations with a full heterogeneity distribution. The surrogate models work very well in the middle range of permeability (200-1000nD) to predict oil recovery and cumulative GOR for any given input distribution. These models can be utilized to study production forecast and for performing sensitivity studies while retaining the complexity of the heterogeneous reservoir. These surrogate models are also used to study the effect of variability of permeability in the field on production. In other words, two fields with the same mean permeability but different variability can be compared.Aylward, F.O., Boeuf, D., Mende, D.R., Wood-Charlson, E.M., Vislova, A., Eppley, J.M., Romano, A.E., DeLong, E.F., 2017. Diel cycling and long-term persistence of viruses in the ocean’s euphotic zone. Proceedings of the National Academy of Sciences 114, 11446-11451.: Marine microbial communities exert a large influence on ocean ecosystem processes, and viruses in these communities play key roles in controlling microbial abundances, nutrient cycling, and productivity. We show here that dominant viruses in the open ocean persist for long time periods and that many appear tightly locked in coordinated diel oscillations with their bacterial hosts. The persistent structure of viral assemblages, as well as synchronized daily oscillations of viruses and hosts, are in part the result of the regular diurnal coupling of viral and host replication cycles. Collectively, our results suggest that viruses, as key components of marine ecosystems, are intrinsically synchronized with the daily rhythms of microbial community processes in the ocean’s photic zone. Abstract: Viruses are fundamental components of marine microbial communities that significantly influence oceanic productivity, biogeochemistry, and ecosystem processes. Despite their importance, the temporal activities and dynamics of viral assemblages in natural settings remain largely unexplored. Here we report the transcriptional activities and variability of dominant dsDNA viruses in the open ocean’s euphotic zone over daily and seasonal timescales. While dsDNA viruses exhibited some fluctuation in abundance in both cellular and viral size fractions, the viral assemblage was remarkably stable, with the most abundant viral types persisting over many days. More extended time series indicated that long-term persistence (>1 y) was the rule for most dsDNA viruses observed, suggesting that both core viral genomes as well as viral community structure were conserved over interannual periods. Viral gene transcription in host cell assemblages revealed diel cycling among many different viral types. Most notably, an afternoon peak in cyanophage transcriptional activity coincided with a peak in Prochlorococcus DNA replication, indicating coordinated diurnal coupling of virus and host reproduction. In aggregate, our analyses suggested a tightly synchronized diel coupling of viral and cellular replication cycles in both photoautotrophic and heterotrophic bacterial hosts. A surprising consequence of these findings is that diel cycles in the ocean’s photic zone appear to be universal organizing principles that shape ecosystem dynamics, ecological interactions, and biogeochemical cycling of both cellular and acellular community components. Azarshin, S., Moghadasi, J., A Aboosadi, Z., 2017. Surface functionalization of silica nanoparticles to improve the performance of water flooding in oil wet reservoirs. Energy Exploration & Exploitation 35, 685-697. the past few years, increasing attention has been devoted to the applications of special engineered nanoparticles in enhancing oil recovery. Earlier studies reported the effects of these particles on wettability alteration of reservoir rock. The present study presents a new method for modifying the surface properties of silica nanoparticles to make them more effective for enhancing oil recovery purposes. Contact angle, interfacial tension measurements, and core flood experiments were performed to examine the effects of these surface-modified nanoparticles on the interfacial interactions of injected water and reservoir rock and oil sample. To improve the performance of water flooding, surface-modified nanoparticles were produced in laboratory and it was found that amine-functionalized silica nanoparticles are significantly more effective than typical nanoparticles. Experimental results revealed that both contact angle and interfacial tension decrease more in the presence of functionalized nanoparticles. These results were confirmed by performing core flood tests which showed an 18% increase in total oil recovery compared to typical nanoparticles. Therefore, amine-functionalized silica nanoparticles could be more effective than typical nanoparticles in increasing the sweep efficiency by changing the wettability of reservoir rock and reducing oil/water interfacial tension. Moreover, it was observed that there is an optimum concentration for contact angle and interfacial tension reduced by nanoparticles and in concentration more than this threshold value the interfacial tension starts to increase slightly.Bai, B., Hu, Q., Li, Z., Lü, G., Li, X., 2017. Evaluating the sealing effectiveness of a caprock-fault system for CO2-EOR storage: A case study of the Shengli oilfield. Geofluids 2017, Article 8536724. effective sealing system is crucial for CO2-EOR storage, and these sealing systems are typically composed of the caprocks and faults that surround a reservoir. Therefore, the sealing effectiveness of a caprock-fault system must be evaluated at various stages of CO2-EOR storage projects. This paper presents a new evaluation framework that considers specific site characteristics and a case study on the sealing effectiveness of the caprock-fault system in the Shengli Oilfield. The proposed method is a weighted ranking system where a set of 17 indicators has been developed for the assessment and ranking of the G89 block in terms of their sealing ability for CO2 sequestration. Additional indicators are involved in the method, such as the newly proposed parameter, frontier displacement work which reflects the influence of formation pressure, displacement pressure resistance, and caprock thickness. The new approach considers the sealing mechanisms of caprocks and faults as well as the configuration relationships between them. The method was used to evaluate the sealing effectiveness of the G89 block that has a considerable number of faults and good sealing ability of caprock in the Shengli Oilfield. Baidya, A.K., Bhattacharya, S., Dubey, G.P., Mamou, G., Ben-Yehuda, S., 2018. Bacterial nanotubes: a conduit for intercellular molecular trade. Current Opinion in Microbiology 42, 1-6. use elaborate molecular machines for intercellular contact-dependent interactions. We discuss a relatively less explored type of intercellular connections mediated by tubular membranous bridges, termed nanotubes. Increasing evidence suggests that nanotube structures mediate cytoplasmic molecular trade among neighboring cells of the same and different species. Further, nanotubes were found to facilitate both antagonistic and cooperative interspecies interactions, thereby allowing the emergence of new non-heritable phenotypes in multicellular bacterial communities. We propose that nanotube-mediated cytoplasmic sharing represents a widespread form of bacterial interactions in nature, providing an enormous potential for the emergence of new features. Here we review the current knowledge on bacterial nanotubes, and highlight the gaps in our current understanding of their operation.Baklouti, S., Ahmadi, R., Bougi, M.S.M., Rasheed, M.A., Rao, P.L.S., Hasan, S.Z., Ksibi, M., 2017. Surface geochemical prospection for hydrocarbons in the oriental platform; the case of Guebiba oilfield, Sfax region, Tunisia. Journal of Petroleum Science and Engineering 159, 830-840. and gas exploration were commonly carried out by conventional methods such as geophysical seismic reflection. However, such techniques are costly especially when new discoveries are becoming smaller in surfaces and reserves. The aim of this study consists to improve hydrocarbon exploration techniques by using alternative low cost method based on surface geochemical prospection. We applied an integrated approach using free and adsorbed soil gases to detect potential areas of hydrocarbon micro-seepage. We validated this technique over an already producing oilfield in Sfax region, south-eastern Tunisia. The objective is to assess the use of geochemical indicators as a tool for rapid evaluation of hydrocarbon prospects. A total of 43 free gas samples and 51 soil samples were collected in a grid pattern of 1 × 1 km. Free gas analyses showed concentrations ranging from zero to 30 ppm of hydrocarbon gases. Gas chromatographic analyses of hydrocarbons desorbed gases showed values ranging from zero to 134 ppm. The presence of all hydrocarbon gas components and their relative ratios proves the thermogenic origin of these gases. The interpretation of gas concentration maps demonstrates the presence of active hydrocarbons micro-seepage from petroleum systems. Comparison to geophysical and geological data proved the role of major faults in providing pathways to gas migration to surface. In conclusion, our study confirms that the use of both free gas and adsorbed gas analyses of soil samples is a low cost tool for hydrocarbon exploration. This method allows pointing up hydrocarbon shows zone from large explored surfaces. Then, subsequent seismic and geological investigations can be conducted on smaller areas highlighted by the gas concentration anomalies.Barron, M.G., Conmy, R.N., Holder, E.L., Meyer, P., Wilson, G.J., Principe, V.E., Willming, M.M., 2018. Toxicity of Cold Lake Blend and Western Canadian Select dilbits to standard aquatic test species. Chemosphere 191, 1-6. are blends of bitumen and natural gas condensates or crude oils with only limited toxicity data. Two dilbits, Cold Lake Blend and Western Canadian Select, were tested as either unweathered or weathered oils for acute and chronic toxicity to standard freshwater and estuarine organisms. Water accommodated fractions of the dilbits were characterized for total petroleum hydrocarbons (TPH), polycyclic aromatic hydrocarbons (PAHs), and monoaromatics (BTEX). Acute toxicity of unweathered and weathered dilbits ranged from 4 to 16 mg/L TPH, 8 to 40 μg/L total PAHs, and 0.7 to 16 mg/L BTEX in Ceriodaphnia dubia, Pimephales promelas, Americamysis bahia, and Menidia beryllina. Concentrations of weathered dilbits causing impaired growth (A. bahia) and reproduction (C. dubia) ranged from 0.8 to 3.5 mg/L TPH and 6 to 16 μg/L PAHs. The two dilbits had generally similar acute and short term chronic toxicity expressed as TPH or total PAHs as other crude oils and other petroleum products.Baveye, P.C., Pot, V., Garnier, P., 2017. Accounting for sub-resolution pores in models of water and solute transport in soils based on computed tomography images: Are we there yet? Journal of Hydrology 555, 253-256. the last decade, X-ray computed tomography (CT) has become widely used to characterize the geometry and topology of the pore space of soils and natural porous media. Regardless of the resolution of CT images, a fundamental problem associated with their use, for example as a starting point in simulation efforts, is that sub-resolution pores are not detected. Over the last few years, a particular type of modeling method, known as “Grey” or “Partial Bounce Back” Lattice-Boltzmann (LB), has been adopted by increasing numbers of researchers to try to account for sub-resolution pores in the modeling of water and solute transport in natural porous media. In this short paper, we assess the extent to which Grey LB methods indeed offer a workable solution to the problem at hand. We conclude that, in spite of significant computational advances, a major experimental hurdle related to the evaluation of the penetrability of sub-resolution pores, is blocking the way ahead. This hurdle will need to be cleared before Grey LB can become a credible option in the microscale modeling of soils and sediments. A necessarily interdisciplinary effort, involving both modelers and experimentalists, is needed to clear the path forward.Bemanikharanagh, A., Bakhtiari, A.R., Mohammadi, J., Taghizadeh-Mehrjardi, R., 2017. Characterization and ecological risk of polycyclic aromatic hydrocarbons (PAHs) and n-alkanes in sediments of Shadegan international wetland, the Persian Gulf. Marine Pollution Bulletin 124, 155-170. distribution and sources of PAHs and n-alkanes were determined in the surface sediments from 202 locations in Shadegan international wetland with 537,700 ha. The concentrations of total n-alkanes and PAHs ranged from 395.3 to 14933.46 μg g? 1 dw and 593.74 to 53393.86 ng g? 1 dw, respectively. Compared with other worldwide surveys, the concentration and contamination of sedimentary hydrocarbons were classified very high. A common petrogenic hydrocarbon source was strongly suggested in all sites by n-alkanes' profile with a Cmax at n-C20, Pr/Ph and CPI ratios < 1 in all sites, and high percentage of UCM. Typical profile of petrogenic PAHs with alkyl-substituted naphthalenes and phenanthrenes predominance, various PAH ratios and multivariate analysis indicated that PAHs were mainly derived from petrogenic source. Naphthalene-derived compounds in all sites were significantly above their ERL, and adversely affected benthic biota. 92% of the sites had mean ERM values < 0.1, indicating high ecological risk on the wildlife of the wetland.Blanco, Y., Gallardo-Carre?o, I., Ruiz-Bermejo, M., Puente-Sánchez, F., Cavalcante-Silva, E., Quesada, A., Prieto-Ballesteros, O., Parro, V., 2017. Critical assessment of analytical techniques in the search for biomarkers on Mars: A mummified microbial mat from Antarctica as a best-case scenario. Astrobiology 17, 984-996. search for biomarkers of present or past life is one of the major challenges for in situ planetary exploration. Multiple constraints limit the performance and sensitivity of remote in situ instrumentation. In addition, the structure, chemical, and mineralogical composition of the sample may complicate the analysis and interpretation of the results. The aim of this work is to highlight the main constraints, performance, and complementarity of several techniques that have already been implemented or are planned to be implemented on Mars for detection of organic and molecular biomarkers on a best-case sample scenario. We analyzed a 1000-year-old desiccated and mummified microbial mat from Antarctica by Raman and IR (infrared) spectroscopies (near- and mid-IR), thermogravimetry (TG), differential thermal analysis, mass spectrometry (MS), and immunological detection with a life detector chip. In spite of the high organic content (ca. 20% wt/wt) of the sample, the Raman spectra only showed the characteristic spectral peaks of the remaining beta-carotene biomarker and faint peaks of phyllosilicates over a strong fluorescence background. IR spectra complemented the mineralogical information from Raman spectra and showed the main molecular vibrations of the humic acid functional groups. The TG-MS system showed the release of several volatile compounds attributed to biopolymers. An antibody microarray for detecting cyanobacteria (CYANOCHIP) detected biomarkers from Chroococcales, Nostocales, and Oscillatoriales orders. The results highlight limitations of each technique and suggest the necessity of complementary approaches in the search for biomarkers because some analytical techniques might be impaired by sample composition, presentation, or processing.Bo-Wei, Z., Ju-He, Z., Guang, F., 2017. Determination of the hydrocarbon content in nanometer size pores adsorbed gas in unconventional reservoir rocks by chemical desorption-gas chromatography. Petroleum Science and Technology 35, 1327-1333. method for the hydrocarbon content in nanometer size pores adsorbed gas in unconventional reservoir rocks using gas chromatography (GC-FID) has been established in this paper. The experiment of gas desorption from nanometer size pores using a device for preparing nanometer size rock samples and gas desorption has been carried out to determine the most favorite experiment conditions. The result shows that the best desorption time is about 20?min with the temperature at 80°C and the sample weight of 20?g. The test conditions for gas chromatography are as follows: an OV-101 GC column with carrier gas flow rate at 40?mL/min; the temperature of GC oven began at 50°C for 0.5?min and then increased to 100°C at 10°C/min, with the final temperature being maintained for 5?min. The parallel test shows that the method introduced here is characterized by quickness, accurateness, and high sensibility with relative testing error less than 9.99% (the least is 2.18%). We have tested 19 rock samples from 11 wells of the Songliao Basin, and most desorbed gas contains alkane gases from methane to hexane with total alkane gas content between 233.21 and 49,826.89??L/kg. Desorbed gas content is significantly different among different areas and intervals, based on which gas content of unconventional reservoirs can be estimated.Borges, A.V., Abril, G., Bouillon, S., 2017. Carbon dynamics in the Mekong Delta. Biogeosciences Discussions 2017, 1-41. report a data-set obtained in the three branches (My Tho, Ham Luong, Co Chien) of the Mekong delta (B?n Tre province, Vietnam) in December 2003, April 2004, and October 2004, of biogeochemical variables related to carbon cycling (pH, total alkalinity (TA), O2 saturation level (%O2), calculated partial pressure of CO2 (pCO2), dissolved CH4 concentration, particulate (POC) and dissolved (DOC) organic carbon concentration and stable isotope composition (δ13C-POC, δ13C-DOC), particulate nitrogen (PN), dissolved inorganic carbon (DIC) stable isotope composition (δ13C-DIC), total suspended matter (TSM)). Both the inner estuary (upstream of the mouth) and the outer estuary (river plume) were sampled, as well as side channels. The values of pCO2 ranged between 232 and 4,085 ppm, %O2 between 63 and 114?%, and CH4 between 2 and 2,217?nmol?L?1, within the ranges of values previously reported in temperate and tropical macro-tidal estuaries. Strong seasonal variations were observed. In the upper oligohaline estuary, low pCO2 (479–753?ppm) and high %O2 (98–106?%) values were observed in April 2004 most probably related to freshwater phytoplankton growth owing to low freshwater discharge (1,400?m3?s?1) and increase of water residence time; during the two other sampling periods with a higher freshwater discharge (9,300-17,900?m3?s?1), higher pCO2 (1,895–2,664?ppm) and lower %O2 (69–84?%) values were observed in the oligohaline part of the estuary. During the October 2004 sampling, important phytoplankton growth occurred in the off-shore part of the river plume as attested by changes in the contribution of POC to TSM (%POC), δ13C-POC, POC?:?PN ratios, possibly related to low TSM values (improvement of light conditions for phytoplankton development), leading to low pCO2 (232?ppm) and high %O2 (114?%) values. Water in the side channels in the Mekong delta was strongly impacted by inputs from the extensive shrimp farming ponds. The values of pCO2, CH4, %O2, δ13C-DIC indicated intense organic matter degradation that was partly mediated by sulfate reduction (presumably in sediments), as indicated by the slope of TA and DIC co-variations. The δ13C-POC variations also indicated intense phytoplankton growth in the side channels, presumably due to nutrient enrichment related to the shrimp farming ponds. A dataset in the mangrove creeks of the Ca Mau province (part of the Mekong delta) was also acquired in April 2004 and October 2004. These data extended the range of variability of pCO2 and %O2 with more extreme values than in the Mekong delta (B?n Tre), with maxima and minima of 6,912?ppm and 37?%, respectively. Similarly, the maximum CH4 concentration (686?nmol?L?1) was higher in the Ca Mau province mangrove creeks than in the Mekong delta (B?n Tre, maximum 222?nmol?L?1), during the October 2004 cruise (rainy season and high freshwater discharge period). In April 2004 (dry season and low freshwater discharge period), the CH4 values were much lower than in October 2004 (average 19?±?13 and 210?±?158?nmol?L?1, respectively) in the Ca Mau province mangrove creeks, owing to the higher salinity (average 33.2?±?0.6 and 14.1?±?1.2, respectively) that probably led to higher sediment sulfate reduction, leading to inhibition of sediment methanogenesis and higher anaerobic CH4 oxidation. In the inner estuarine region (three branches of the Mekong delta), CO2 emissions to the atmosphere averaged 121?mmol?m?2?d?1, and the CH4 emissions averaged 118??mol?m?2?d?1. The CO2 emission to the atmosphere from the Mekong inner estuary was higher than reported in the Yangtze and Pearl River inner estuaries. This was probably due to the lower salinity in the Mekong delta branches, possibly due to different morphology; relatively linear channels in the Mekong delta versus funnel-shaped estuaries for the Yangtze and Pearl River inner estuaries.Borrego, A.G., 2017. A dry polishing technique for the petrographic examination of mudrocks: Discussion. International Journal of Coal Geology 183, 136-137. the paper “A dry polishing technique for the petrographic examination of mudrocks” by Gorbanenko (2017), it is important to stress some differences between the proposed polishing procedure and the existing standards for sample preparation for microscopic examination of organic matter, which may lead to less bright surfaces than required for measuring vitrinite reflectance by the most widely used standards (7404-5 ISO, 2009 or ASTM D7708, 2014).Boyle, R., 2017. Eukaryotic origins and the Proterozoic Earth system: A link between global scale glaciations and eukaryogenesis? Earth-Science Reviews 174, 22-38. Proterozoic Earth system is popularly viewed as having comprised prolonged periods of invariant conditions separating intervals of extreme change. Against this backdrop the earliest evidence of eukaryotic organisms is found, raising the (highly uncertain) possibility of an environmental impetus for this fundamental evolutionary transition. Here I review the eukaryotic fossil record and the theoretical issues surrounding eukaryogenesis, with the aim of relating these ideas to the broad context of the Proterozoic Earth system. In terms of fossils, either eukaryotes were present in Proterozoic oceans, (conceivably as early as 2.1Ga, but at the latest by 1.4 Ga), or the macroscopic fossils that are found from this period are prokaryotic colonies that converged on form very close to modern eukaryotes before going extinct (the first possibility is far more parsimonious). In terms of DNA, phylogenetic evidence indicates that eukaryotes derive from a symbiosis between an archaeon host cell and a eubacterial proto-mitochondrion. Bar a tiny number of isolated examples contemporary prokaryotic cells do not simply end up inside the cells of other prokaryotes as a consequence of ecological interactions (however synergistic). Therefore the capacity for phagocytosis in the host cell is by far the most plausible way in which to explain the acquisition of the mitochondrial symbiont. But phagocytosis, and indeed the larger cell size of eukaryotes, is probably incompatible with use of the external cell membrane to sustain a proton gradient for ATP generation (as occurs in prokaryotes). By contrast, the “multi-bacterial power” of ATP generation in numerous mitochondria results in eukaryotes having considerably more free energy available per gene than prokaryotes. Importantly, this can be achieved whilst minimizing the (potentially extreme) free radical damage from “misfiring” electron transport chains, by a “co-location for redox regulation” involving transfer of most mitochondrial genes to the host nucleus, but transcription of key respiratory components near the site of their activity. Thus, debate persists about a “catch-22” situation: Arguably, the host cell requires a cytoskeleton in order to acquire (proto) mitochondria, but cannot energetically sustain a cytoskeleton without ATP generation in multiple mitochondria.Explaining why an initially transient, facultative interaction progressed to full endosymbiosis amounts to aligning the fitness interests of the host and symbiont. I conclude by tentatively speculating that the Paleoproterozoic global-scale glaciations may have provided an impetus for eukaryogenesis by providing some form of extreme bottleneck, in which: (a) Ancestral host and symbiont organisms were physically forced into close proximity for an unprecedented length of evolutionary time, and (b) Restricted dispersal, small populations, and low resource availability rendered survival, rather than fecundity, the dominant component of fitness, permitting sequential fixation of multiple cooperative traits in host and symbiont genomes. Though admittedly speculative, a clear testable prediction is invoked by my suggestion: fossils with unequivocal proto-mitochondria (and perhaps nuclei), after, but not before, the Paleoproterozoic glaciations, should eventually be found.Boytsova, A., Kondrasheva, N., Ancheyta, J., 2017. Thermogravimetric determination and pyrolysis thermodynamic parameters of heavy oils and asphaltenes. Energy & Fuels 31, 10566-10575. analyses of Yarega heavy crude oil, its atmospheric residue, vacuum residue, and asphaltenes were carried out for a better understanding of the pyrolysis of high-molecular-weight hydrocarbons. The degree of influence of asphaltenes on the pyrolysis was determined. Kinetic and thermodynamic parameters of the pyrolysis were also investigated. Activation energy and pre-exponential factor were calculated. It was found that the degree of conversion depends on the average molecular weight of the liquid oil systems. The higher the molecular weight, the lower the final degree of conversion. It was determined that the activation energies of pyrolysis of the liquid oil systems are higher than those of the asphaltenes obtained from these systems. This process occurs due to deasphalting of the leaching of a solvate layer as a result of the existence of two phases (α-phase and β-phase). The β-phase is not soluble in the low-molecular-weight hydrocarbons but partially broken and converted into asphaltenes in the vacuum distillation. Images obtained by scanning electron microscopy showed that the asphaltenes size decreases with increase in density. Asphaltenes from heavy crude oil and atmospheric residue were found to have the highest strength and bond orders, and asphaltenes from vacuum residue have the highest strength of structure.Brownlow, R., Lowry, D., Fisher, R.E., France, J.L., Lanoisellé, M., White, B., Wooster, M.J., Zhang, T., Nisbet, E.G., 2017. Isotopic ratios of tropical methane emissions by atmospheric measurement. Global Biogeochemical Cycles 31, 1408-1419. methane sources are an important part of the global methane budget and include natural wetlands, rice agriculture, biomass burning, ruminants, fossil fuels, and waste. δ13CCH4 can provide strong constraints on methane source apportionment. For example, tropical wetlands in this study give δ13CCH4 values between ?61.5 ± 2.9‰ and ?53.0 ± 0.4‰ and in general are more enriched in 13C than temperate and boreal wetlands. However, thus far, relatively few measurements of δ13CCH4 in methane-enriched air have been made in the tropics. In this study samples have been collected from tropical wetland, rice, ruminant, and biomass burning emissions to the atmosphere. Regional isotopic signatures vary greatly as different processes and source material affect methane signatures. Measurements were made to determine bulk source inputs to the atmosphere, rather than to study individual processes. These measurements provide inputs for regional methane budget models, to constrain emissions with better source apportionment.Büntgen, U., Cosmo, N.D., 2017. Reply to ‘Climate of doubt: a re-evaluation of Büntgen and Di Cosmo’s environmental hypothesis for the Mongol withdrawal from Hungary, 1242 CE’. Scientific Reports 7, Article 12696. our 2016 article in Scientific Reports, we advanced a new hypothesis for the Mongol withdrawal from Hungary in 1242 CE, based on a joint analysis of climatic, environmental, and historical data. The re-evaluation now offered by Pinke et al. casts doubt on this hypothesis. However, their arguments are based on a level of generality that fails to appreciate the specific conditions of the Mongol invasion, do not offer new or different climatic data, and are supported by anachronistic production data and environmental information, which cannot be related to the period in question. While we acknowledge the importance of an open debate, we stand by our conclusions.Bush, R.T., Wallace, J., Currano, E.D., Jacobs, B.F., McInerney, F.A., Dunn, R.E., Tabor, N.J., 2017. Cell anatomy and leaf δ13C as proxies for shading and canopy structure in a Miocene forest from Ethiopia. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 593-604. fossils are most commonly preserved as isolated organs, making it difficult to determine plant life habit or ecosystem structure from fossils. In particular, paleoecologists have struggled to reconstruct forest canopy structure, a character that fundamentally influences hydrology, nutrient cycling, and plant and animal life. Analyses utilizing cellular morphology and leaf carbon isotope composition have been proposed to reconstruct light regime, itself a proxy for canopy structure, and we apply these proxies to exquisitely preserved leaf fossils from the early Miocene Mush Valley site in central Ethiopia. Epidermal cell wall undulation (undulation index, UI) and carbon isotope values (δ13C) were measured for 21 fossil leaves of a legume morphospecies, “Legume 1”. Five leaves of a second legume morphospecies were also analyzed using the same procedures. Carbon isotope ratios and total organic carbon content were measured for 85 additional fossil leaves belonging to at least nine morphospecies. A large range of both leaf δ13C and UI values were obtained for Legume 1, indicating that different leaves were exposed to different amounts of light, as would be expected in a closed-canopy forest. However, Legume 1 leaf UI values do not correlate with leaf δ13C values, implying that one or both of these variables is driven by factors other than light exposure. Additional modern calibrations are needed to determine the key environmental variables for each measure, as well as the influence of forest openings on preserved signatures.Button, D.J., Lloyd, G.T., Ezcurra, M.D., Butler, R.J., 2017. Mass extinctions drove increased global faunal cosmopolitanism on the supercontinent Pangaea. Nature Communications 8, Article 733. extinctions have profoundly impacted the evolution of life through not only reducing taxonomic diversity but also reshaping ecosystems and biogeographic patterns. In particular, they are considered to have driven increased biogeographic cosmopolitanism, but quantitative tests of this hypothesis are rare and have not explicitly incorporated information on evolutionary relationships. Here we quantify faunal cosmopolitanism using a phylogenetic network approach for 891 terrestrial vertebrate species spanning the late Permian through Early Jurassic. This key interval witnessed the Permian–Triassic and Triassic–Jurassic mass extinctions, the onset of fragmentation of the supercontinent Pangaea, and the origins of dinosaurs and many modern vertebrate groups. Our results recover significant increases in global faunal cosmopolitanism following both mass extinctions, driven mainly by new, widespread taxa, leading to homogenous ‘disaster faunas’. Cosmopolitanism subsequently declines in post-recovery communities. These shared patterns in both biotic crises suggest that mass extinctions have predictable influences on animal distribution and may shed light on biodiversity loss in extant ecosystems.Byrdwell, W.C., 2017. Comprehensive dual liquid chromatography with quadruple mass spectrometry (LC1MS2 × LC1MS2 = LC2MS4) for analysis of Parinari curatellifolia and other seed oil triacylglycerols. Analytical Chemistry 89, 10537-10546. two-dimensional (2D) comprehensive liquid chromatography (LC × LC) has become increasingly popular. Most LC × LC separations employ one or more detectors at the outlet of the second dimension, 2D, with very short runs to avoid undersampling. We used six detectors, including dual parallel mass spectrometry (LC1MS2), for detection of the first dimension, 1D. We made an argentation (silver-ion) UHPLC column from a strong cation exchange column for 2D, coupled with UV and LC1MS2 detection. LC1MS2 in 1D combined with LC1MS2 in 2D, plus five other detectors, constituted LC2MS4 in a comprehensive LC1MS2 × LC1MS2 2D-LC separation. Electrospray ionization (ESI) high resolution accurate mass (HRAM) mass spectrometry (MS) and atmospheric pressure chemical ionization (APCI) MS were used in parallel for 1D detection, while atmospheric pressure photoionization (APPI) MS and ESI-MS were used for detection of 2D. The LC1MS2 used for 1D allowed quantification of triacylglycerol (TAG) molecular species of Parinari curatellifolia and other seed oils, while the 2D allowed isomers of TAG containing 18:3 fatty acyl chains as well as TAG regioisomers to be separated and identified. The LC1MS2 in 1D allowed identification of oxo-TAG species by HRAM MS and quantification of 806.3 ± 1.3 and 1101 ± 22 μg/g of α- and γ- tocopherols, respectively, in P. curatellifolia by APCI-MS. It is now feasible to use silver-ion UHPLC as the 2D separation in LC × LC and to use multiple mass spectrometers across both dimensions to perform conventional quantitative analysis and to take advantage of the newest LC × LC separation technology to identify isomers that are otherwise difficult to separate.Cánneva, A., Giordana, I.S., Erra, G., Calvo, A., 2017. Organic matter characterization of shale rock by X-ray photoelectron spectroscopy: Adventitious carbon contamination and radiation damage. Energy & Fuels 31, 10414-10419. detailed characterization of the organic matter in sediments gives a key parameter for the correct evaluation of the petroleum generation potential of a source rock and its modeling in an oil system. To understand the features of the organic matter stored in source rocks, a wide variety of routine techniques are used. Those techniques are mostly destructive, time-consuming, and are not necessarily suitable for all the shale rocks. Thus, new technologies are being explored. XPS is a solid state, nondestructive, and direct method. It can be used to directly probe the speciation of organic carbon in sedimentary materials by C1s spectra measurements. In this work, we demonstrated that a heterogeneous layer of adventitious carbon (AC) is always present on the rock. This layer significantly altered the features of the organic compound fingerprint, which is measured by XPS of C1s. To acquire a reliable organic matter composition of a rock from XPS spectra it is necessary to remove the AC layer by sputtering it with Ar+. Further, the sputtering damage of the organic matter appears after an hour of radiation, and rocks become contaminated again during storage in the UHV chamber. The radiation damage by X-ray is also relevant in the XPS measurement of a rock. This damage is associated with an increment of AC contamination on the rock surface. To minimize this side effect, C1s spectra have to be measured immediately after the sputtering conditioning step. Thus, we developed a method for XPS measurements taking into account the AC contamination and radiation damage. We consider that the proposed method for outcrop shales can be applied to a wide range of rock sampling types, such as cuttings, damaged crowns, and so forth.Cao, X., Tarr, M.A., 2017. Aldehyde and ketone photoproducts from solar-irradiated crude oil–seawater systems determined by electrospray ionization–tandem mass spectrometry. Environmental Science & Technology 51, 11858-11866. and ketone photoproducts were observed in the aqueous phase under oil exposed to simulated sunlight by using 2,4-dinitrophenylhydrazine (DNPH) derivatization and electrospray ionization–tandem mass spectrometry (ESI–MS/MS). Oil samples were spread over seawater in a jacketed beaker held at 27.0 °C and exposed to simulated sunlight. The aqueous phase was collected after irradiation and derivatized with DNPH, which selectively reacts with aldehydes and ketones. The derivatized hydrazones (aldehyde– and ketone–DNPH derivatives) were washed and enriched with a solid-phase extraction cartridge prior to analysis by ESI–MS/MS in negative ion mode. Over 80 aldehyde and ketone photoproducts were observed from scan range 200–1000 atomic mass units (amu) in the aqueous phase after irradiation but were absent in dark controls. Based on the MS/MS fragmentation of the aldehyde– and ketone–DNPH derivatives, most of the aldehyde and ketone photoproduct mass spectra observed from the aqueous phase were determined to be consistent with dicarbonyls, hydroxycarbonyls, and oxo-carboxylic acids. The formation of the photoproducts can be attributed to photoinduced oxidation of oil. The approach in this study allows the easy identification of molar mass and other structural features of aldehyde and ketone photoproducts without interference from the many tens of thousands of parent compounds in the oil. These results will provide insight into the impact of photochemistry on the fate of oil in environmental systems and will have implications for oil-spill response decisions.Carere, C.R., Hards, K., Houghton, K.M., Power, J.F., McDonald, B., Collet, C., Gapes, D.J., Sparling, R., Boyd, E.S., Cook, G.M., Greening, C., Stott, M.B., 2017. Mixotrophy drives niche expansion of verrucomicrobial methanotrophs. ISME Journal 11, 2599-2610. methanotrophic bacteria have evolved a specialist lifestyle dependent on consumption of methane and other short-chain carbon compounds. However, their apparent substrate specialism runs contrary to the high relative abundance of these microorganisms in dynamic environments, where the availability of methane and oxygen fluctuates. In this work, we provide in situ and ex situ evidence that verrucomicrobial methanotrophs are mixotrophs. Verrucomicrobia-dominated soil communities from an acidic geothermal field in Rotokawa, New Zealand rapidly oxidised methane and hydrogen simultaneously. We isolated and characterised a verrucomicrobial strain from these soils, Methylacidiphilum sp. RTK17.1, and showed that it constitutively oxidises molecular hydrogen. Genomic analysis confirmed that this strain encoded two [NiFe]-hydrogenases (group 1d and 3b), and biochemical assays revealed that it used hydrogen as an electron donor for aerobic respiration and carbon fixation. While the strain could grow heterotrophically on methane or autotrophically on hydrogen, it grew optimally by combining these metabolic strategies. Hydrogen oxidation was particularly important for adaptation to methane and oxygen limitation. Complementary to recent findings of hydrogenotrophic growth by Methylacidiphilum fumariolicum SolV, our findings illustrate that verrucomicrobial methanotrophs have evolved to simultaneously utilise hydrogen and methane from geothermal sources to meet energy and carbon demands where nutrient flux is dynamic. This mixotrophic lifestyle is likely to have facilitated expansion of the niche space occupied by these microorganisms, allowing them to become dominant in geothermally influenced surface soils. Genes encoding putative oxygen-tolerant uptake [NiFe]-hydrogenases were identified in all publicly available methanotroph genomes, suggesting hydrogen oxidation is a general metabolic strategy in this guild.Chahen, L., Quoineaud, A.A., Proriol, D., Artero, S., Vidalie, M., Neyret-Martinez, F., Rivallan, M., 2017. Speciation of basic nitrogen compounds in gas oils and vacuum gas oils by derivatization with BF3 prior to NMR analysis. Energy & Fuels 31, 10752-10759. compounds, present in gas oils (GO) or vacuum gas oils (VGO) cuts, affect many of the important petroleum processes such as hydrocracking and hydrotreating due to their nucleophilic character. Basic nitrogen compounds, which can inhibit the acidic sites of the catalysts, are mainly pyridine derivatives (6-membered-ring nitrogen compounds), and despite the use of highly resolutive methods, their characterization, especially in VGO, is still limited. Herein, we propose a new promising methodology, coupling the derivatization with BF3 of nonprotogenic nitrogen species and the use of NMR analysis. By crossing information from 19F, 1H, 1H–19F HMBC and 19F DOSY, it is possible to determine the close environment of the nitrogen atom of the most nucleophilic nitrogen impurities in GO or in VGO cuts, independently of the sizes of the molecules. This approach allows the characterization and comparison of fingerprints of basic nitrogen impurities in charges or effluents.Chan, P., Halfar, J., Norley, C.J.D., Pollmann, S.I., Adey, W., Holdsworth, D.W., 2017. Micro-computed tomography: Applications for high-resolution skeletal density determinations: An example using annually banded crustose coralline algae. Geochemistry, Geophysics, Geosystems 18, 3542-3553. and acidification of the world's oceans are expected to have widespread consequences for marine biodiversity and ecosystem functioning. However, due to the relatively short record of instrumental observations, one has to rely upon geochemical and physical proxy information stored in biomineralized shells and skeletons of calcareous marine organisms as in situ recorders of past environments. Of particular interest is the response of marine calcifiers to ocean acidification through the examination of structural growth characteristics. Here we demonstrate the application of micro-computed tomography (micro-CT) for three-dimensional visualization and analysis of growth, skeletal density, and calcification in a slow-growing, annually banded crustose coralline alga Clathromorphum nereostratum (increment width ～380 ?m). X-ray images and time series of skeletal density were generated at 20 ?m resolution and rebinned to 40, 60, 80, and 100 ?m for comparison in a sensitivity analysis. Calcification rates were subsequently calculated as the product of density and growth (linear extension). While both skeletal density and calcification rates do not significantly differ at varying spatial resolutions (the latter being strongly influenced by growth rates), clear visualization of micron-scale growth features and the quantification of structural changes on subannual time scales requires higher scanning resolutions. In the present study, imaging at 20 ?m resolution reveals seasonal cycles in density that correspond to summer/winter variations in skeletal structure observed using scanning electron microscopy (SEM). Micro-CT is a fast, nondestructive, and high-resolution technique for structural and morphometric analyses of temporally banded paleoclimate archives, particularly those that exhibit slow or compressed growth or micron-scale structures.Chela-Flores, J., 2017. Instrumentation for testing whether the icy moons of the gas and ice giants are inhabited. Astrobiology 17, 958-961. of life beyond Earth may be closer than we think, given that the forthcoming missions to the jovian system will be equipped with instruments capable of probing Europa's icy surface for possible biosignatures, including chemical biomarkers, despite the strong radiation environment. Geochemical biomarkers may also exist beyond Europa on icy moons of the gas giants. Sulfur is proposed as a reliable geochemical biomarker for approved and forthcoming missions to the outer solar system.Chen, B., Wan, C., Mehmood, M.A., Chang, J.-S., Bai, F., Zhao, X., 2017. Manipulating environmental stresses and stress tolerance of microalgae for enhanced production of lipids and value-added products–A review. Bioresource Technology 244, 1198-1206. have promising potential to produce lipids and a variety of high-value chemicals. Suitable stress conditions such as nitrogen starvation and high salinity could stimulate synthesis and accumulation of lipids and high-value products by microalgae, therefore, various stress-modification strategies were developed to manipulate and optimize cultivation processes to enhance bioproduction efficiency. On the other hand, advancements in omics-based technologies have boosted the research to globally understand microalgal gene regulation under stress conditions, which enable further improvement of production efficiency via genetic engineering. Moreover, integration of multi-omics data, synthetic biology design, and genetic engineering manipulations exhibits a tremendous potential in the betterment of microalgal biorefinery. This review discusses the process manipulation strategies and omics studies on understanding the regulation of metabolite biosynthesis under various stressful conditions, and proposes genetic engineering of microalgae to improve bioproduction via manipulating stress tolerance.Chen, C., Wang, J., Algeo, T.J., Wang, Z., Tu, S., Wang, G., Yang, J., 2017. Negative δ13Ccarb shifts in Upper Ordovician (Hirnantian) Guanyinqiao Bed of South China linked to diagenetic carbon fluxes. Palaeogeography, Palaeoclimatology, Palaeoecology 487, 430-446. Late Ordovician Hirnantian glaciation coincided with a major perturbation of the global carbon cycle, characterized by large positive excursions of δ13Ccarb and δ13Corg known as the Hirnantian carbon isotopic excursion (HICE). Previous studies from South China have reported a positive shift in δ13Corg but ambiguous trends in carbonate carbon isotopes. To better define δ13Ccarb variation through the Ordovician-Silurian (O-S) transition in South China, we investigated multiple components (brachiopods, micritic matrix, and microspar cement) in five study sections representing shallow-shelf to deep-basin facies across the Yangtze Block. All sections exhibit negative δ13Ccarb shifts near the base of the Hirnantian stage, with small shifts in two sections (to between ? 2 and ? 1‰) and large shifts in three sections (mostly <? 10‰, minimum ? 13.7‰). Brachiopods commonly exhibit the same δ13C compositions as micrite in a given sample, although some samples contain isotopically heavy brachiopods in a highly 13C-depleted matrix. Because the highly 13C-depleted carbonates are present in two widely separated areas between which only weakly 13C-depleted carbonates are found, there must have been multiple local diagenetic sources of 13C-depleted carbon. We infer that the highly negative δ13Ccarb values were linked to compactional influx of 13C-depleted dissolved inorganic carbon (DIC) into the Guanyinqiao Bed as a result of oxidation of organic matter through microbial sulfate reduction (MSR) or methanogenesis/anaerobic oxidation of methane (AOM) in black shales of the underlying Wufeng and overlying Longmaxi Formations. The results of the present study demonstrate the importance of careful diagenetic screening of C-isotope records in order to fully understand the origin of δ13Ccarb signals and to avoid potential errors in interpreting diagenetically overprinted records as primary marine carbonate events.Chen, S., Qin, Y., Zhang, Q., Du, L., Zhao, J., 2017. Numerical description of shale gas desorption stages. Energy Exploration & Exploitation 35, 734-747. desorption of shale gas is dynamic and multistage processes. Dividing desorption process, describing the desorption stages, and analyzing the main factors in each stage are the research emphasis. The desorption process is described by mathematical models and divided into several stages according to desorption rate and its change rate. The results show that shale gas desorption can be divided into the slow desorption stage, the large desorption stage, and the final desorption stage. The increase of organic matter content not only has a significant effect on extending the production peak but also may lead to arrival of final desorption stage in advance. The increase of clay mineral content can accelerate the arrival of production peak and extend the production peak. It may be possible to analyze the shale gas production process and adjust the production plan on the basis of analyzing the material composition of reservoir.Chen, X., Idakieva, V., Stoykova, K., Liang, H., Yao, H., Wang, C., 2017. Ammonite biostratigraphy and organic carbon isotope chemostratigraphy of the early Aptian oceanic anoxic event (OAE 1a) in the Tethyan Himalaya of southern Tibet. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 531-542. early Aptian oceanic anoxic event (OAE 1a) is well known in the western Tethys, the North Atlantic and the Pacific Ocean, but has not been reported in the eastern Tethys to date. In this paper, we present bulk organic carbon isotope data and ammonite biostratigraphy of a lower Aptian succession from the Gucuo area (southern Tibet). These findings document the occurrence of the OAE 1a for the first time from the eastern Tethys. The studied sequence can be attributed to the D. forbesi and D. deshayesi ammonite zones of the lower Aptian. The δ13Corg data can be correlated with published early Aptian carbon isotope records from the western Tethys and the Pacific. A distinctive negative carbon isotope excursion of 2.4‰ in the upper part of the section corresponds to segment C3 of the OAE 1a, and the following positive excursion correlates to segment C4. The absolute values of the carbon isotope ratio in the Gucuo area are higher than those of known sections in the western Tethys and equatorial Pacific. We suggest that diagenetic alteration is the major cause of the higher absolute values in the Gucuo area.Chen, Y., Shen, A., Pan, L., Zhang, J., Wang, X., 2017. Features, origin and distribution of microbial dolomite reservoirs: A case study of 4th Member of Sinian Dengying Formation in Sichuan Basin, SW China. Petroleum Exploration and Development 44, 745-757. on the drilling cores and slice observations, single well data and geochemical analysis, this paper analyzed features, origin and distribution of the 4th Member reservoirs of Sinian Dengying Formation (Z2dn4) in the Sichuan Basin. It is demonstrated that the main reservoir is a set of microbial dolomites. The discovery of spherical dolomite has revealed that the dolomitization was related to the microbial action, belonging to the early protodolomite of low-temperature precipitation; the primary matrix pores and the penecontemporaneous eroded pores constituted the subject of the reservoir space, which was not due to the interlayer karst process related to the Tongwan Movement and burial-hydrothermal dissolutional process. The microbial mound-shoal complex and penecontemporaneous dissolution mainly control the development and distribution of the scaled reservoirs in Z2dn4. The microbial dolomite reservoir surrounding the intracratonic rift had a large thickness, good continuity and high quality, and was an important target of the survey.Chen, Z.-Q., Algeo, T.J., Sun, Y., Schoepfer, S.D., 2017. The Paleozoic-Mesozoic transition in South China: Oceanic environments and life from Late Permian to Late Triassic. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 1-5. Triassic was a critical period for the evolution of life on Earth. It witnessed the greatest biocrisis of the Phanerozoic (the Permian-Triassic (P-Tr) mass extinction) at its beginning, a limited and fitful recovery from this biocrisis during the Early Triassic, and a more sustained recovery and re-radiation of life during the Middle Triassic. The Middle Triassic recovery featured not only a biotic radiation but also significantly altered ecosystem structures, facilitating the emergence of calcareous nanofossils in the ocean and early dinosaurs on land. During the early Late Triassic, a long-lasting climate extreme (the mid-Carnian Pluvial Event, or CPE) had global effects. South China harbors some of the most accessible and continuous Triassic marine successions in the world, providing opportunities for geologists to probe these biotic and environmental events and their possible causes. The theme of this special issue of Palaeogeography Palaeoclimatology Palaeoecology is the transition from Paleozoic to Mesozoic systems as recorded in latest Permian and Triassic strata of South China. This issue includes biostratigraphic, paleoecologic, sedimentologic, and geochemical studies focused on marine environmental and climatic variation and the biotic and biosedimentary responses to it during the latest Permian and P-Tr transition (4 papers), the Early Triassic (6 papers), and the Late Triassic (2 papers). These contributions advance our understanding of Triassic global events, with a special emphasis on organism-environment interactions during this critical period of Earth history.Cheng, X., Hou, D., Mao, R., Xu, C., 2018. Severe biodegradation of polycyclic aromatic hydrocarbons in reservoired crude oils from the Miaoxi Depression, Bohai Bay Basin. Fuel 211, 859-867. hydrocarbons are major components in crude oil. Biodegradation of polycyclic aromatic hydrocarbons, such as biphenyls, naphthalenes, phenanthrenes and aromatic steroid hydrocarbons have been well studied. However, little is known about the relative susceptibilities to biodegradation of fluorene, dibenzofuran, dibenzothiophene, chrysene and pyrene, and their alkylated homologues. In this study, gas chromatography–mass spectrometry analyses of aromatic fractions of a suite of severely biodegraded crude oils from the Bohai Bay Basin have been performed to investigate the fate and relative susceptibilities of these polycyclic aromatic hydrocarbons during severe biodegradation under geological conditions.Changes in concentrations of varying PAH classes with increasing biodegradation suggest their relative susceptibilities to microbial alteration are in the order biphenyls > naphthalenes > dibenzofurans > phenanthrenes ～ fluorenes > dibenzothiophenes > chrysenes > pyrenes > C26–28 triaromatic steroid hydrocarbons. The relative susceptibilities to biodegradation of individual isomers of chrysenes, dibenzothiophenes, dibenzofurans, fluorenes, pyrenes and triaromatic steroid hydrocarbons were determined based on their compositional changes. The susceptibility to biodegradation of PAHs is not directed related to the number of aromatic rings, but may be controlled by the shapes of the substrate molecules which control the ability to penetrate the cell membrane and to fit the active site of the microbial enzyme. Sulfur-containing compounds, such as dibenzothiphenes, are more resistant to biodegradation than those non-sulfur-containing components with similar molecular structure, which is likely due to their relatively greater biotoxicity. PAHs with more alkyl substituents are generally more resistant to biodegradation, but exceptions were also observed, and this observation may due to demethylation of a substituted compound. Undoubtedly, the positions of alkyl substituents control the susceptibilities to biodegradation of PAH isomers. However, the observation that PAH isomers with β-substituents are more readily biodegraded is not universal, suggesting that the susceptibility of PAH isomers is not controlled by thermodynamic stability, but may be related to their stereochemical structures.Chiriac, C.M., Szekeres, E., Rudi, K., Baricz, A., Hegedus, A., Drago?, N., Coman, C., 2017. Differences in temperature and water chemistry shape distinct diversity patterns in thermophilic microbial communities. Applied and Environmental Microbiology 83, Article e01363-17.: This report describes the biodiversity and ecology of microbial mats developed in thermal gradients (20 to 65°C) in the surroundings of three drillings (Chiraleu [CH], Ciocaia [CI], and Mihai Bravu [MB]) tapping a hyperthermal aquifer in Romania. Using a metabarcoding approach, 16S rRNA genes were sequenced from both DNA and RNA transcripts (cDNA) and compared. The relationships between the microbial diversity and the physicochemical factors were explored. Additionally, the cDNA data were used for in silico functionality predictions, bringing new insights into the functional potential and dynamics of these communities. The results showed that each hot spring determined the formation of distinct microbial communities. In the CH mats (40 to 53°C), the abundance of Cyanobacteria decreased with temperature, opposite to those of Chloroflexi and Proteobacteria. Ectothiorhodospira, Oscillatoria, and methanogenic archaea dominated the CI communities (20 to 65°C), while the MB microbial mats (53 to 65°C) were mainly composed of Chloroflexi, Hydrogenophilus, Thermi, and Aquificae. Alpha-diversity was negatively correlated with the increase in water temperature, while beta-diversity was shaped in each hot spring by the unique combination of physicochemical parameters, regardless of the type of nucleic acid analyzed (DNA versus cDNA). The rank correlation analysis revealed a unique model that associated environmental data with community composition, consisting in the combined effect of Na+, K+, HCO3?, and PO43? concentrations, together with temperature and electrical conductivity. These factors seem to determine the grouping of samples according to location, rather than with the similarities in thermal regimes, showing that other parameters beside temperature are significant drivers of biodiversity. Importance: Hot spring microbial mats represent a remarkable manifestation of life on Earth and have been intensively studied for decades. Moreover, as hot spring areas are isolated and have a limited exchange of organisms, nutrients, and energy with the surrounding environments, hot spring microbial communities can be used in model studies to elucidate the colonizing potential within extreme settings. Thus, they are of great importance in evolutionary biology, microbial ecology, and exobiology. In spite of all the efforts that have been made, the current understanding of the influence of temperature and water chemistry on the microbial community composition, diversity, and abundance in microbial mats is limited. In this study, the composition and diversity of microbial communities developed in thermal gradients in the vicinity of three hot springs from Romania were investigated, each having particular physicochemical characteristics. Our results expose new factors that could determine the formation of these ecosystems, expanding the current knowledge in this regard. Clark, D.A., Asao, S., Fisher, R., Reed, S., Reich, P.B., Ryan, M.G., Wood, T.E., Yang, X., 2017. Reviews and syntheses: Field data to benchmark the carbon cycle models for tropical forests. Biogeosciences 14, 4663-4690. more accurate projections of both the global carbon (C) cycle and the changing climate, a critical current need is to improve the representation of tropical forests in Earth system models. Tropical forests exchange more C, energy, and water with the atmosphere than any other class of land ecosystems. Further, tropical-forest C cycling is likely responding to the rapid global warming, intensifying water stress, and increasing atmospheric CO2 levels. Projections of the future C balance of the tropics vary widely among global models. A current effort of the modeling community, the ILAMB (International Land Model Benchmarking) project, is to compile robust observations that can be used to improve the accuracy and realism of the land models for all major biomes. Our goal with this paper is to identify field observations of tropical-forest ecosystem C stocks and fluxes, and of their long-term trends and climatic and CO2 sensitivities, that can serve this effort. We propose criteria for reference-level field data from this biome and present a set of documented examples from old-growth lowland tropical forests. We offer these as a starting point towards the goal of a regularly updated consensus set of benchmark field observations of C cycling in tropical forests.Clotten, C., Stein, R., Fahl, K., De Schepper, S., 2018. Seasonal sea ice cover during the warm Pliocene: Evidence from the Iceland Sea (ODP Site 907). Earth and Planetary Science Letters 481, 61-72. ice is a critical component in the Arctic and global climate system, yet little is known about its extent and variability during past warm intervals, such as the Pliocene (5.33–2.58 Ma). Here, we present the first multi-proxy (IP25, sterols, alkenones, palynology) sea ice reconstructions for the Late Pliocene Iceland Sea (ODP Site 907). Our interpretation of a seasonal sea ice cover with occasional ice-free intervals between 3.50–3.00 Ma is supported by reconstructed alkenone-based summer sea surface temperatures. As evidenced from brassicasterol and dinosterol, primary productivity was low between 3.50 and 3.00 Ma and the site experienced generally oligotrophic conditions. The East Greenland Current (and East Icelandic Current) may have transported sea ice into the Iceland Sea and/or brought cooler and fresher waters favoring local sea ice formation.Between 3.00 and 2.40 Ma, the Iceland Sea is mainly sea ice-free, but seasonal sea ice occurred between 2.81 and 2.74 Ma. Sea ice extending into the Iceland Sea at this time may have acted as a positive feedback for the build-up of the Greenland Ice Sheet (GIS), which underwent a major expansion ～2.75 Ma. Thereafter, most likely a stable sea ice edge developed close to Greenland, possibly changing together with the expansion and retreat of the GIS and affecting the productivity in the Iceland pte-Port, S., Subirats, J., Fillol, M., Sànchez-Melsió, A., Marcé, R., Rivas-Ruiz, P., Rosell-Melé, A., Borrego, C.M., 2017. Abundance and co-distribution of widespread marine archaeal lineages in surface sediments of freshwater water bodies across the Iberian Peninsula. Microbial Ecology 74, 776-787. inhabiting marine and freshwater sediments have a relevant role in organic carbon mineralization, affecting carbon fluxes at a global scale. Despite current evidences suggesting that freshwater sediments largely contribute to this process, few large-scale surveys have been addressed to uncover archaeal diversity and abundance in freshwater sedimentary habitats. In this work, we quantified and high-throughput sequenced the archaeal 16S rRNA gene from surficial sediments collected in 21 inland waterbodies across the Iberian Peninsula differing in typology and trophic status. Whereas methanogenic groups were dominant in most of the studied systems, especially in organic-rich sediments, archaea affiliated to widespread marine lineages (the Bathyarchaeota and the Thermoplasmata) were also ubiquitous and particularly abundant in euxinic sediments. In these systems, Bathyarchaeota communities were dominated by subgroups Bathyarchaeota-6 (87.95?±?12.71%) and Bathyarchaeota-15 (8.17?±?9.2%) whereas communities of Thermoplasmata were mainly composed of members of the order Thermoplasmatales. Our results also indicate that Archaea accounted for a minor fraction of sedimentary prokaryotes despite remarkable exceptions in reservoirs and some stratified lakes. Copy numbers of archaeal and bathyarchaeotal 16S rRNA genes were significantly different when compared according to system type (i.e., lakes, ponds, and reservoirs), but no differences were obtained when compared according to their trophic status (from oligotrophy to eutrophy). Interestingly, we obtained significant correlations between the abundance of reads (Spearman r?=?0.5, p?=?0.021) and OTU richness (Spearman r?=?0.677, p?<?0.001) of Bathyarchaeota and Thermoplasmata across systems, reinforcing the hypothesis of a potential syntrophic interaction between members of both lineages.Coutaud, M., Méheut, M., Glatzel, P., Pokrovski, G.S., Viers, J., Rols, J.-L., Pokrovsky, O.S., 2018. Small changes in Cu redox state and speciation generate large isotope fractionation during adsorption and incorporation of Cu by a phototrophic biofilm. Geochimica et Cosmochimica Acta 220, 1-18. the importance of phototrophic biofilms in metal cycling in freshwater systems, metal isotope fractionation linked to metal adsorption and uptake by biofilm remains very poorly constrained. Here, copper isotope fractionation by a mature phototrophic biofilm during Cu surface adsorption and incorporation was studied in batch reactor (BR) and open drip flow reactor (DFR) systems at ambient conditions. X-ray Absorption Spectroscopy (both Near Edge Structure, XANES, and Extended Fine Structure, EXAFS) at Cu K-edge of the biofilm after its interaction with Cu in BR experiments allowed characterizing the molecular structure of assimilated Cu and quantifying the degree of CuII to CuI reduction linked to Cu assimilation. For both BR and DFR experiments, Cu adsorption caused enrichment in heavy isotope at the surface of the biofilm relative to the aqueous solution, with an apparent enrichment factor for the adsorption process, ε65Cuads, of +1.1 ± 0.3‰. In contrast, the isotope enrichment factor during copper incorporation into the biofilm (ε65Cuinc) was highly variable, ranging from ?0.6 to +0.8‰. This variability of the ε65Cuinc value was likely controlled by Cu cellular uptake via different transport pathways resulting in contrasting fractionation. Specifically, the CuII storage induced enrichment in heavy isotope, whereas the toxicity response of the biofilm to Cu exposure resulted in reduction of CuII to CuI, thus yielding the biofilm enrichment in light isotope. EXAFS analyses suggested that a major part of the Cu assimilated by the biofilm is bound to 5.1 ± 0.3 oxygen or nitrogen atoms, with a small proportion of Cu linked to sulfur atoms (NS < 0.6) of sulfhydryl groups. XANES analyses showed that the proportion of CuII vs CuI, compared to the initial CuII/CuI ratio, decreased by 14% after the first hour of reaction and by 6% after 96 h of reaction. The value of ε65Cuinc of the biofilm exhibited a similar trend over time of exposure. Our study demonstrates the complexity of biological processes associated with live phototrophic biofilms, which produce large and contrasting isotope fractionations following rather small Cu redox and speciation changes during uptake, storage or release of the metal, i.e., favoring heavy isotopes during complexation with carboxylate ligands and light isotopes during reduction of CuII-O/N to CuI-sulfhydryl moieties.Couturier-Tamburelli, I., Toumi, A., Piétri, N., Chiavassa, T., 2018. Behaviour of solid phase ethyl cyanide in simulated conditions of Titan. Icarus 300, 477-485. order to simulate different altitudes in the atmosphere of Titan, we investigated using infrared spectrometry and mass spectrometry the photochemistry of ethyl cyanide (CH3CH2CN) ices at different temperatures. Heating experiments of the solid phase until complete desorption showed up three phase transitions with a first one appearing to be approximately at the temperature of Titan's surface (94?K), measured by the Huygens probe. Ethyl cyanide, whose presence has been suggested in solid phase in Titan, can be considered as another nitrile for photochemical models of the Titan atmosphere after our first study (Toumi et al., 2016) concerning vinyl cyanide (CH2CHCN). The desorption energy of ethyl cyanide has been calculated to be 36.75 (?±?0.55) kJ mol?1 using IRTF and mass spectroscopical techniques. High energetic photolysis (λ > 120?nm) have been performed and we identified ethyl isocyanide, vinyl cyanide, cyanoacetylene, ethylene, acetylene, cyanhydric acid and a methylketenimine form as photoproducts from ethyl cyanide. The branching ratios of the primary products were determined at characteristic temperatures of Titan thanks to the value of the νCN stretching band strength of ethyl cyanide that has been calculated to be 4.12 × 10?18?cm molecule?1. We also report here for the first time the values of the photodissociation cross sections of C2H5CN for different temperatures.Crandall, P.B., Góbi, S., Gillis-Davis, J., Kaiser, R.I., 2017. Can perchlorates be transformed to hydrogen peroxide (H2O2) products by cosmic rays on the Martian surface? Journal of Geophysical Research: Planets 122, 1880-1892. to their oxidizing properties, perchlorates (ClO4?) are suggested by the planetary science community to play a vital role in the scarcity of organics on the Martian surface. However, alternative oxidation agents such as hydrogen peroxide (H2O2) have received surprisingly little attention. In this study, samples of magnesium perchlorate hexahydrate (Mg(ClO4)2 · 6H2O) were exposed to monoenergetic electrons and D2+ ions separately, sequentially, and simultaneously to probe the effects of galactic cosmic ray exposure of perchlorates and the potential incorporation of hydrogen (deuterium) into these minerals. The experiments were carried out under ultrahigh-vacuum conditions at 50 K, after which the samples were slowly heated to 300 K while the subliming products were monitored by a quadrupole mass spectrometer. In all cases, molecular oxygen (O2) was detected upon the onset of irradiation and also during the warmup phase. In case of a simultaneous D2+-electron exposure, deuterated water (D2O) and deuterium peroxide (D2O2) were also detected in the warmup phase, whereas only small amounts of D2O2 were found after an exclusive D2+ irradiation. These experiments yield the first data identifying hydrogen peroxide as a potential product in the interaction of cosmic rays with perchlorates in the Martian regolith revealing that perchlorates are capable of producing multiple oxidizing agents (O2 and D2O2) that may account for the destruction of organics on the Martian surface.Cuadros, J., 2017. Clay minerals interaction with microorganisms: a review. Clay Minerals 52, 235. in mineral–microbe interaction has grown enormously over recent decades, providing information in a puzzle-like manner which points towards an ever increasingly intimate relationship between the two; a relationship that can be truly termed co-evolution. Clay minerals play a very central role in this co-evolving system. Some 20 years ago, clay scientists looked at clay mineral–microbe studies as a peripheral interest only. Now, can clay scientists think that they understand the formation of clay minerals throughout geological history if they do not include life in their models? The answer is probably no, but we do not yet know the relative weight of biological and inorganic factors involved in driving clay-mineral formation and transformation. Similarly, microbiologists are missing out important information if they do not investigate the influence and modifications that minerals, particularly clay minerals, have on microbial activity and evolution. This review attempts to describe the several points relating clay minerals and microorganisms that have been discovered so far. The information obtained is still very incomplete and many opportunities exist for clay scientists to help to write the real history of the biosphere.Cudjoe, S., Barati, R., 2017. Lattice Boltzmann simulation of CO2 transport in kerogen nanopores—An evaluation of CO2 sequestration in organic-rich shales. Journal of Earth Science 28, 926-932. shale resources remain an important source of hydrocarbons considering their substantial contribution to crude oil and natural gas production around the world. Moreover, as part of mitigating the greenhouse gas effects due to the emissions of carbon dioxide (CO2) gas, organic-rich shales are considered a possible alternate geologic storage. This is due to the adsorptive properties of organic kerogen and clay minerals within the shale matrix. Therefore, this research looks at evaluating the sequestration potential of carbon dioxide (CO2) gas in kerogen nanopores with the use of the lattice Boltzmann method under varying experimental pressures and different pore sizes. Gas flow in micro/nano pores differ in hydrodynamics due to the dominant pore wall effects, as the mean free path (λ) of the gas molecules become comparable to the characteristic length (H) of the pores. In so doing, the traditional computational methods break down beyond the continuum region, and the lattice Boltzmann method (LBM) is employed. The lattice Boltzmann method is a mesoscopic numerical method for fluid system, where a unit of gas particles is assigned a discrete distribution function (f). The particles stream along defined lattice links and collide locally at the lattice sites to conserve mass and momentum. The effects of gas-wall collisions (Knudsen layer effects) is incorporated into the LBM through an effective-relaxation-time model, and the discontinuous velocity at the pore walls is resolved with a slip boundary condition. Above all, the time lag (slip effect) created by CO2 gas molecules due to adsorption and desorption over a time period, and the surface diffusion as a result of the adsorption-gradient are captured by an adsorption isotherm and included in our LBM. Implementing the Langmuir adsorption isotherm at the pore walls for both CO2 gas revealed the underlying flow mechanism for CO2 gas in a typical kerogen nano-pore is dominated by the slip flow regime. Increasing the equilibrium pressure, increases the mass flux due to adsorption. On the other hand, an increase in the nano-pore size caused further increase in the mass flux due to free gas and that due to adsorbed gas. Thus, in the kerogen nano-pores, CO2 gas molecules are more adsorptive indicating a possible multi-layer adsorption. Therefore, this study not only provides a clear understanding of the underlying flow mechanism of CO2 in kerogen nano-pores, but also provides a potential alternative means to mitigate the greenhouse gas effect (GHG) by sequestering CO2 in organic-rich shales.Cui, Y., Schubert, B.A., 2017. Atmospheric pCO2 reconstructed across five early Eocene global warming events. Earth and Planetary Science Letters 478, 225-233. short-lived global warming events, known as hyperthermals, occurred during the early Eocene (56–52 Ma). Five of these events – the Paleocene–Eocene Thermal Maximum (PETM or ETM1), H1 (or ETM2), H2, I1, and I2 – are marked by a carbon isotope excursion (CIE) within both marine and terrestrial sediments. The magnitude of CIE, which is a function of the amount and isotopic composition of carbon added to the ocean–atmosphere system, varies significantly between marine versus terrestrial substrates. Here we use the increase in carbon isotope fractionation by C3 land plants in response to increased pCO2 to reconcile this difference and reconstruct a range of background pCO2 and peak pCO2 for each CIE, provided two potential carbon sources: methane hydrate destabilization and permafrost-thawing/organic matter oxidation. Although the uncertainty on each pCO2 estimate using this approach is low (e.g., median uncertainty = +23%/?18%+23%/?18%), this work highlights the potential for significant systematic bias in the pCO2 estimate resulting from sampling resolution, substrate type, diagenesis, and environmental change. Careful consideration of each of these factors is required especially when applying this approach to a single marine–terrestrial CIE pair. Given these limitations, we provide an upper estimate for background early Eocene pCO2 of 463 +248/?131 ppmv (methane hydrate scenario) to 806 +127/?104 ppmv (permafrost-thawing/organic matter oxidation scenario). These results, which represent the first pCO2 proxy estimates directly tied to the Eocene hyperthermals, demonstrate that early Eocene warmth was supported by background pCO2 less than ～3.5× preindustrial levels and that pCO2>1000 ppmvpCO2>1000 ppmv may have occurred only briefly, during hyperthermal events.Dafouz, R., Cáceres, N., Rodríguez-Gil, J.L., Mastroianni, N., López de Alda, M., Barceló, D., de Miguel, ?.G., Valcárcel, Y., 2018. Does the presence of caffeine in the marine environment represent an environmental risk? A regional and global study. Science of The Total Environment 615, 632-642. is an emerging contaminant considered to be an indicator of human contamination that has been widely detected in various aquatic systems, especially in continental waters. Nevertheless, the extent of its possible environmental impact is yet to be determined. This study determined the presence of caffeine, and evaluated the environmental hazard posed by this substance, in the “Rías Gallegas”, a series of costal inlets in north-west Spain which are of great ecological value and in which fishing and bivalve farming, are a significant source of income. Caffeine was found to be present at concentrations higher than the limit of quantification (LOQ = 3.07 ng L? 1) in 15 of the 23 samples analysed, with the highest seawater concentration being 857 ng L? 1 (the highest measured in seawater in Spain). Six out of 22 seawater samples resulted in a hazard quotient (HQ) from chronic exposure higher than 1 with the highest being 17.14, indicating a high probability of adverse effects in the aquatic environment. Environmental Exposure Distributions (EEDs) generated from a literature review of caffeine levels reported previously in four out of the five continents, showed that 28% of all seawater samples, and 69% of all estuary water samples where caffeine has ever been measured resulted in HQ > 1 for chronic exposure. Further studies into the potential adverse effects that may arise from exposure to caffeine in aquatic systems are still required. Indeed, the need to gain a more in-depth understanding of the long-term ecotoxicological effects of caffeine is essential to ensure the quality of our health and environment.Damborenea, S.E., Echevarría, J., Ros-Franch, S., 2017. Biotic recovery after the end-Triassic extinction event: Evidence from marine bivalves of the Neuquén Basin, Argentina. Palaeogeography, Palaeoclimatology, Palaeoecology 487, 93-104. analyze the Late Triassic extinction and Early Jurassic recovery of bivalve faunas within marine environments in the Atuel River area of the Neuquén Basin, Argentina. Data were collected from a hundred samples with invertebrates in a well-exposed uppermost Triassic to lower Jurassic section in the Neuquén Basin (southern Mendoza Province, Argentina) and allow a high-resolution reconstruction of the local diversity dynamics. The nearly continuous presence of marine stenohaline major taxa such as cnidarians, rhynchonelliform brachiopods, echinoderms and cephalopods indicates normal salinity throughout. All bivalve species were identified, and each occurrence was recorded in meters above the base. To analyze the systematic diversity trends, diversity curves were calculated on the basis of the first and last occurrence data for each bivalve species, and both total diversity and boundary crossers diversity were used. As a result, four main phases were identified: a) Triassic equilibrium phase (Rhaetian), with relatively high origination and extinction rates; b) extinction phase (latest Rhaetian to earliest Hettangian), with high extinction rates and low origination rates; c) recovery phase (late Early to early Late Hettangian), with high origination rates and almost null extinction rates; and d) Jurassic equilibrium phase (Late Hettangian-Sinemurian), again with similar and relatively high origination and extinction rates. The extinction and recovery phases are separated by a gap of about 135 m without identifiable benthonic invertebrates but with early Hettangian ammonites. On the other hand, bivalve palaeoecologic diversity seems to have been more homogeneous along the section, being dominated by attached epifaunal species, though before the extinction epifaunal habits were slightly surpassed by infaunal ones. Slight differences observed include a) shallow burrowers were more diverse during the Rhaetian than during the earliest Jurassic and b) epifaunal free-lying and semi-infaunal attached bivalves were more diverse after the Rhaetian extinction.Dameron, S.N., Leckie, R.M., Clark, K., MacLeod, K.G., Thomas, D.J., Lees, J.A., 2017. Extinction, dissolution, and possible ocean acidification prior to the Cretaceous/Paleogene (K/Pg) boundary in the tropical Pacific. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 433-454. perturbations and changes in ocean circulation during the Maastrichtian stage of the latest Cretaceous raise questions about whether the biosphere was preconditioned for the end-Cretaceous mass extinction of calcareous plankton. A brief acme of inoceramid clams at ~71Ma on Shatsky Rise in the tropical North Pacific was followed by their extinction during the “mid-Maastrichtian event” at 70.1Ma associated with an abrupt warming of deep waters. This was later followed by an interval of intense dissolution beginning ~67.8Ma at ODP Site 1209 (2387m). The late Maastrichtian dissolution interval was initially gradual, and is characterized by a low planktic/benthic (P/B) ratio, highly fragmented planktic foraminifera, mostly an absence of larger taxa, low abundances of smaller taxa, extremely low planktic foraminiferal numbers, and low planktic foraminiferal and nannofossil species richness. A partial recovery in carbonate preservation and calcareous plankton simple diversity began ~250kyr prior to the K/Pg boundary associated with the incursion of a younger (more enriched δ13C) deep water mass, although total abundances of planktic foraminifera in the sediment remained a tiny fraction of their earlier Maastrichtian values. A second, brief dissolution event occurred ~200kyr before the boundary evidenced by renewed increase in planktic fragmentation, but without a decrease in P/B ratio. Our data show that changing deep water masses, coupled with reduced productivity and associated decrease in pelagic carbonate flux was responsible for the first ~1.6-Myr dissolution interval, while Deccan Traps volcanism (?) may have caused surface ocean acidification ~200kyr prior to the K/Pg mass extinction event.Dannemann, M., Kelso, J., 2017. The contribution of Neanderthals to phenotypic variation in modern humans. The American Journal of Human Genetics 101, 578-589. the genetic contribution of Neanderthals to non-disease phenotypes in modern humans has been difficult because of the absence of large cohorts for which common phenotype information is available. Using baseline phenotypes collected for 112,000 individuals by the UK Biobank, we can now elaborate on previous findings that identified associations between signatures of positive selection on Neanderthal DNA and various modern human traits but not any specific phenotypic consequences. Here, we show that Neanderthal DNA affects skin tone and hair color, height, sleeping patterns, mood, and smoking status in present-day Europeans. Interestingly, multiple Neanderthal alleles at different loci contribute to skin and hair color in present-day Europeans, and these Neanderthal alleles contribute to both lighter and darker skin tones and hair color, suggesting that Neanderthals themselves were most likely variable in these traits.Daugherty, E.E., Gilbert, B., Nico, P.S., Borch, T., 2017. Complexation and redox buffering of iron(II) by dissolved organic matter. Environmental Science & Technology 51, 11096-11104. (Fe) bioavailability depends upon its solubility and oxidation state, which are strongly influenced by complexation with natural organic matter (NOM). Despite observations of Fe(II)–NOM associations under conditions favorable for Fe oxidation, the molecular mechanisms by which NOM influences Fe(II) oxidation remain poorly understood. In this study, we used X-ray absorption spectroscopy to determine the coordination environment of Fe(II) associated with NOM (as-received and chemically reduced) at pH 7, and investigated the effect of NOM complexation on Fe(II) redox stability. Linear combination fitting of extended X-ray absorption fine structure (EXAFS) data using reference organic ligands demonstrated that Fe(II) was complexed primarily by carboxyl functional groups in reduced NOM. Functional groups more likely to preserve Fe(II) represent much smaller fractions of NOM-bound Fe(II). Fe(II) added to anoxic solutions of as-received NOM oxidized to Fe(III) and remained organically complexed. Iron oxidation experiments revealed that the presence of reduced NOM limited Fe(II) oxidation, with over 50% of initial Fe(II) remaining after 4 h. These results suggest reduced NOM may preserve Fe(II) by functioning both as redox buffer and complexant, which may help explain the presence of Fe(II) in oxic circumneutral waters.Davies-Barnard, T., Ridgwell, A., Singarayer, J., Valdes, P., 2017. Quantifying the influence of the terrestrial biosphere on glacial–interglacial climate dynamics. Climate of the Past 13, 1381-1401. terrestrial biosphere is thought to be a key component in the climatic variability seen in the palaeo-record. It has a direct impact on surface temperature through changes in surface albedo and evapotranspiration (so-called biogeophysical effects) and, in addition, has an important indirect effect through changes in vegetation and soil carbon storage (biogeochemical effects) and hence modulates the concentrations of greenhouse gases in the atmosphere. The biogeochemical and biogeophysical effects generally have opposite signs, meaning that the terrestrial biosphere could potentially have played only a very minor role in the dynamics of the glacial–interglacial cycles of the late Quaternary. Here we use a fully coupled dynamic atmosphere–ocean–vegetation general circulation model (GCM) to generate a set of 62 equilibrium simulations spanning the last 120?kyr. The analysis of these simulations elucidates the relative importance of the biogeophysical versus biogeochemical terrestrial biosphere interactions with climate. We find that the biogeophysical effects of vegetation account for up to an additional ?0.91?°C global mean cooling, with regional cooling as large as ?5?°C, but with considerable variability across the glacial–interglacial cycle. By comparison, while opposite in sign, our model estimates of the biogeochemical impacts are substantially smaller in magnitude. Offline simulations show a maximum of +0.33?°C warming due to an increase of 25?ppm above our (pre-industrial) baseline atmospheric CO2 mixing ratio. In contrast to shorter (century) timescale projections of future terrestrial biosphere response where direct and indirect responses may at times cancel out, we find that the biogeophysical effects consistently and strongly dominate the biogeochemical effect over the inter-glacial cycle. On average across the period, the terrestrial biosphere has a ?0.26?°C effect on temperature, with ?0.58?°C at the Last Glacial Maximum. Depending on assumptions made about the destination of terrestrial carbon under ice sheets and where sea level has changed, the average terrestrial biosphere contribution over the last 120?kyr could be as much as ?50?°C and ?0.83?°C at the Last Glacial Maximum.Davies, T.W., Bell, M.A., Goswami, A., Halliday, T.J.D., 2017. Completeness of the eutherian mammal fossil record and implications for reconstructing mammal evolution through the Cretaceous/Paleogene mass extinction. Paleobiology 43, 521-536. is a well-established discrepancy between paleontological and molecular data regarding the timing of the origin and diversification of placental mammals. Molecular estimates place interordinal diversification dates in the Cretaceous, while no unambiguous crown placental fossils have been found prior to the end-Cretaceous mass extinction. Here, the completeness of the eutherian fossil record through geological time is evaluated to assess the suggestion that a poor fossil record is largely responsible for the difference in estimates of placental origins. The completeness of fossil specimens was measured using the character completeness metric, which quantifies the completeness of fossil taxa as the percentage of phylogenetic characters available to be scored for any given taxon. Our data set comprised 33 published cladistic matrices representing 445 genera, of which 333 were coded at the species level.There was no significant difference in eutherian completeness across the Cretaceous/Paleogene (K/Pg) boundary. This suggests that the lack of placental mammal fossils in the Cretaceous is not due to a poor fossil record but more likely represents a genuine absence of placental mammals in the Cretaceous. This result supports the “explosive model” of early placental evolution, whereby placental mammals originated around the time of the K/Pg boundary and diversified soon after.No correlation was found between the completeness pattern observed in this study and those of previous completeness studies on birds and sauropodomorph dinosaurs, suggesting that different factors affect the preservation of these groups. No correlations were found with various isotope proxy measures, but Akaike information criterion analysis found that eutherian character completeness metric scores were best explained by models involving the marine-carbonate strontium-isotope ratios (87Sr/86Sr), suggesting that tectonic activity might play a role in controlling the completeness of the eutherian fossil record.de Bar, M.W., Hopmans, E.C., Verweij, M., Dorhout, D.J.C., Damsté, J.S.S., Schouten, S., 2017. Development and comparison of chromatographic methods for the analysis of long chain diols and alkenones in biological materials and sediment. Journal of Chromatography A 1521, 150-160. have compared and assessed the suitability of several chromatographic methods for the analysis of long chain alkenones and long chain diols and the associated paleotemperature proxies (UK’37 and LDI). We evaluated the traditional methods for the analysis of the UK’37 and the LDI, gas chromatography (GC) ? flame ionization detection (FID) and GC mass spectrometry (MS) using selected ion monitoring (SIM), respectively, and developed a new method using GC–MS/MS in multiple reaction monitoring mode (MRM) for the analysis of long chain diols as well as a method for automatic silylation of diols using a robot autosampler. Finally, we evaluated liquid chromatography (LC) methods to simultaneously measure the UK’37 and the LDI, using ultra high performance LC (UHPLC) with low (nominal mass) resolution MS in SIM mode, and UHPLC with high resolution MS (HRMS). Detection and quantification limits and reproducibility were assessed by means of serial dilutions of culture extracts.Automated silylation by a robot autosampler showed similar reproducibility as off-line silylation while substantially decreasing sample preparation time. The novel MRM method had a slightly lower limit of quantification (LOQ; i.e. 0.3 pg C28 1,13-diol injected on-column) than the traditional method (0.5 pg) and improved reproducibility while allowing more unambiguous identification of LCDs in complex matrices. For diols, UHPLC–MS using SIM had the highest LOQ (i.e. 15 pg) and a comparable reproducibility as GC–MS. UHPLC–HRMS had a LOQ of ca. 1.5 pg, and an improved reproducibility for diol analysis. For alkenone analysis, both UHPLC–HRMS and UHPLC–MS using SIM were 2–3 orders of magnitude more sensitive (LOQ ca. 20 and 2 pg C37:2 alkenone injected on-column, respectively) than GC-FID (LOD ca. 3 ng), with a similar reproducibility of the UK’37 index. Hence, UHPLC–HRMS allows simultaneous analysis of the UK’37 and LDI at an increased sensitivity. In addition, it allows simultaneous measurement of TEX86, a temperature proxy based on the isoprenoid glycerol dialkyl glycerol tetraethers. This reduces the preparation time by excluding the need of derivatization and separation of the ketone (containing the long chain alkenones) and polar fractions (containing the long chain diols and GDGTs). However, synthetic standards are required to fully assess the accuracy of the new methods for determination of the LDI and UK’37.De Boever, E., Brasier, A.T., Foubert, A., Kele, S., 2017. What do we really know about early diagenesis of non-marine carbonates? Sedimentary Geology 361, 25-51. carbonate rocks including cave, spring, stream, calcrete and lacustrine-palustrine sediments, are susceptible to early diagenetic processes. These can profoundly alter the carbonate fabric and affect paleoclimatic proxies. This review integrates recent insights into diagenesis of non-marine carbonates and in particular the variety of early diagenetic processes, and presents a conceptual framework to address them. With ability to study at smaller and smaller scales, down to nanometers, one can now observe diagenesis taking place the moment initial precipitates have formed, and continuing thereafter. Diagenesis may affect whole rocks, but it typically starts in nano- and micro-environments. The potential for diagenetic alteration depends on the reactivity of the initial precipitate, commonly being metastable phases like vaterite, Ca-oxalates, hydrous Mg‐carbonates and aragonite with regard to the ambient fluid. Furthermore, organic compounds commonly play a crucial role in hosting these early transformations. Processes like neomorphism (inversion and recrystallization), cementation and replacement generally result in an overall coarsening of the fabric and homogenization of the wide range of complex, primary microtextures. If early diagenetic modifications are completed in a short time span compared to the (annual to millennial) time scale of interest, then recorded paleoenvironmental signals and trends could still acceptably reflect original, depositional conditions. However, even compact, non-marine carbonate deposits may behave locally and temporarily as open systems to crystal-fluid exchange and overprinting of one or more geochemical proxies is not unexpected. Looking to the future, relatively few studies have examined the behaviour of promising geochemical records, such as clumped isotope thermometry and (non-conventional) stable isotopes, in well-constrained diagenetic settings. Ongoing and future in-vitro and in-situ experimental approaches will help to investigate and detangle sequences of intermediate, diagenetic products, processes and controls, and to quantify rates of early diagenesis, bridging a gap between nanoscale, molecular lab studies and the fossil field rock record of non-marine carbonates.de Winter, N.J., Vellekoop, J., Vorsselmans, R., Golreihan, A., Soete, J., Petersen, S.V., Meyer, K.W., Casadio, S., Speijer, R.P., Claeys, P., 2017. An assessment of latest Cretaceous Pycnodonte vesicularis (Lamarck, 1806) shells as records for palaeoseasonality: A multi-proxy investigation. Climate of the Past Discussions 2017, 1-36. order to assess the potential of the honeycomb oyster Pycnodonte vesicularis for the reconstruction of palaeoseasonality, several specimens recovered from the late Maastrichtian Neuquén Basin (Argentina) were subject to a multi-proxy investigation, involving scanning techniques, trace element and isotopic analysis. Combined CT scanning and light microscopy reveals two major calcite micromorphologies in P. vesicularis shells (vesicular and foliated calcite). Micro-XRF analysis and cathodoluminescence microscopy show that reducing pore fluids were able to migrate through the vesicular portions of the shells (aided by bore holes) and cause recrystallization and precipitation of secondary carbonate in the porous micromorphology, thus rendering the vesicular portions not suitable for palaeoenvironmental reconstruction. In contrast, stable isotope and trace element compositions show that the original chemical composition of the shell is well-preserved in the denser, foliated portions, which can therefore be reliably used for the reconstruction of palaeoenvironmental conditions. Stable oxygen and clumped isotope thermometry on carbonate from the dense hinge region yield sea water temperatures of 11?°C, while previous TEX86H palaeothermometry yielded much higher temperatures. The difference is ascribed to seasonal bias in the growth of P. vesicularis, causing warm seasons to be underrepresented from the record, and TEX86H palaeothermometry being potentially biased towards warmer surface water temperatures. Superimposed on this annual mean is a seasonality in δ18O of about 1?‰, which is ascribed to a combination of varying salinity due to fresh water input in the winter and spring season and a moderate temperature seasonality. Attempts to independently verify the seasonality in sea water temperature by Mg?/?Ca ratios of shell calcite are hampered by significant uncertainty due to the lack of proper transfer functions for pycnodontein oysters. The multi-proxy approach employed here enables us to differentiate between well-preserved and diagenetically altered portions of the shells and provides an improved methodology for reconstructing palaeoenvironmental conditions in deep time. While establishing a chronology for these shells was severely complicated by growth cessations and diagenesis, cyclicity in trace elements and stable isotopes allowed a tentative interpretation of the potential annual seasonal cycle in the late Maastrichtian palaeoenvironment of the Neuquén basin. Future studies of fossil ostreid bivalves should target dense foliated calcite rather than sampling bulk or vesicular calcite. Successful application of clumped isotope thermometry on fossil bivalve calcite in this study indicates that temperature seasonality in fossil ostreid bivalves may be constrained by the sequential analysis of well-preserved foliated calcite samples using this method.Delmont, T.O., Eren, A.M., 2017. Simulations predict microbial responses in the environment? This environment disagrees retrospectively. Proceedings of the National Academy of Sciences 114, E8947-E8949. their recent study, Hu et al. (1) simulated in the laboratory the deep-sea oil plume of the Deepwater Horizon (DWH) disaster, and claim successful enrichment of the dominant oil-degrading bacteria found in the environment. Although the simulation offers valuable insights into microbial succession patterns following the addition of oil, our analysis revealed that the dominant hydrocarbon-degrading bacteria in the simulation was not in the environment, and the one in the environment was not in the simulation. The disaster in the Gulf of Mexico led to the formation of a deep-sea oil plume in which the first bacterial responders linked to oil degradation were affiliated with the family Oceanospirillaceae (2?–4). Cultivation efforts failed to isolate members from these early responders; however, a population genome reconstructed from the oil plume is available (5). In their simulation, Hu et al. (1) reconstructed various population genomes, including an abundant Oceanospirillaceae population. The authors named … Comment on: Hu, P., Dubinsky, E.A., Probst, A.J., Wang, J., Sieber, C.M.K., Tom, L.M., Gardinali, P.R., Banfield, J.F., Atlas, R.M., Andersen, G.L., 2017. Simulation of Deepwater Horizon oil plume reveals substrate specialization within a complex community of hydrocarbon degraders. Proceedings of the National Academy of Sciences 114, 7432-7437.Replied to in: Probst, A.J., Hu, P., Sun, C.L., Dubinsky, E.A., Sieber, C.M.K., Banfield, J.F., Andersen, G.L., 2017. Reply to Delmont and Eren: Strain variants and population structure during the Deepwater Horizon oil spill. Proceedings of the National Academy of Sciences. 114, E8950–E8952.Denny, A.C., Kozdon, R., Kitajima, K., Valley, J.W., 2017. Isotopically zoned carbonate cements in Early Paleozoic sandstones of the Illinois Basin: δ18O and δ13C records of burial and fluid flow. Sedimentary Geology 361, 93-110. imaging and analysis of δ18O and δ13C in sandstones from a transect through the Illinois Basin (USA) show systematic μm-scale isotopic zonation of up to 10‰ in both carbonate and quartz cements of the middle-Ordovician St. Peter and Cambrian Mt. Simon formations. Quartz δ18O values are broadly consistent with the model of Hyodo et al. (2014), wherein burial and heating in the Illinois Basin is recorded in systematically zoned quartz overgrowths. Observations of zoned dolomite/ankerite cements indicate that they preserve a more extended record of temperature and fluid compositions than quartz, including early diagenesis before or during shallow burial, and late carbonates formed after quartz overgrowths. Many carbonate cements show innermost dolomite with δ18O values (21–25‰ VSMOW) that are too low to have formed by deposition at low temperatures from ancient seawater (δ18O > ? 3‰) and most likely reflect mixing with meteoric water. A sharp increase in Fe content is commonly observed in zoned carbonate cements to be associated with a drop in δ18O and an abrupt shift in δ13C to higher or lower values. These changes are interpreted to record the passage of hot metal-rich brines through sandstone aquifers, that was associated with Mississippi-Valley Type (MVT) Pb-Zn deposits (ca. 270 Ma) of the Upper Mississippi Valley. Local variability and individual trends in δ13C are likely controlled by the sources of carbon and the degree to which carbon is sourced from adjacent carbonate units or thermal maturation of organic matter. Quartz overgrowths in sandstones provide an excellent record of conditions during burial, heating, and pressure-solution, whereas carbonate cements in sandstones preserve a more-extended record including initial pre-burial conditions and punctuated fluid flow events.Desgranges, C., Delhommelle, J., 2017. Coarse-grained model and boiling point prediction for asphaltene model compounds via HMC-WL simulations. Energy & Fuels 31, 10699-10705. determination of vapor–liquid equilibrium data is a key parameter for the conditions of stability or precipitation of asphaltenes. In this work, using molecular simulation, we parametrize a coarse-grained force field for a series of alkyldipyrene compounds, that are often used as model compounds for asphaltenes, and predict their thermodynamic properties at coexistence. To achieve this, we combine a Wang–Landau approach with hybrid Monte Carlo simulations in the isothermal–isobaric ensemble to sample extensively the configurations of the system over a wide range of densities. This allows us to obtain the conditions of coexistence and to shed light on the impact of the alkyl chain on the thermodynamic properties. Most notably, we identify a quasi-linear relationship between the boiling temperature of these compounds and the length of the alkyl chain.Devièse, T., Karavani?, I., Comeskey, D., Kubiak, C., Korlevi?, P., Hajdinjak, M., Radovi?, S., Procopio, N., Buckley, M., P??bo, S., Higham, T., 2017. Direct dating of Neanderthal remains from the site of Vindija Cave and implications for the Middle to Upper Paleolithic transition. Proceedings of the National Academy of Sciences 114, 10606-10611.: Radiocarbon dating of Neanderthal remains recovered from Vindija Cave (Croatia) initially revealed surprisingly recent results: 28,000–29,000 B.P. This implied the remains could represent a late-surviving, refugial Neanderthal population and suggested they could have been responsible for producing some of the early Upper Paleolithic artefacts more usually produced by anatomically modern humans. This article presents revised radiocarbon dates of the human bones from this site obtained using a more robust purification method targeting the amino acid hydroxyproline. The data show that all the Neanderthal remains are from a much earlier period (>40,000 cal B.P.). These revised dates change our interpretation of this important site and demonstrate that the Vindija Neanderthals probably did not overlap temporally with early modern humans. Abstract: Previous dating of the Vi-207 and Vi-208 Neanderthal remains from Vindija Cave (Croatia) led to the suggestion that Neanderthals survived there as recently as 28,000–29,000 B.P. Subsequent dating yielded older dates, interpreted as ages of at least ～32,500 B.P. We have redated these same specimens using an approach based on the extraction of the amino acid hydroxyproline, using preparative high-performance liquid chromatography (Prep-HPLC). This method is more efficient in eliminating modern contamination in the bone collagen. The revised dates are older than 40,000 B.P., suggesting the Vindija Neanderthals did not live more recently than others across Europe, and probably predate the arrival of anatomically modern humans in Eastern Europe. We applied zooarchaeology by mass spectrometry (ZooMS) to find additional hominin remains. We identified one bone that is Neanderthal, based on its mitochondrial DNA, and dated it directly to 46,200 ± 1,500 B.P. We also attempted to date six early Upper Paleolithic bone points from stratigraphic units G1, Fd/d+G1 and Fd/d, Fd. One bone artifact gave a date of 29,500 ± 400 B.P., while the remainder yielded no collagen. We additionally dated animal bone samples from units G1 and G1–G3. These dates suggest a co-occurrence of early Upper Paleolithic osseous artifacts, particularly split-based points, alongside the remains of Neanderthals is a result of postdepositional mixing, rather than an association between the two groups, although more work is required to show this definitively. Díaz-Sánchez, H., Rojas-Trigos, J.B., Leyva, C., Trejo-Zárraga, F., 2017. An approach for determination of asphaltene crystallite by X-ray diffraction analysis: A case of study. Petroleum Science and Technology 35, 1415-1420. were precipitated from atmospheric residue and divided into two fractions. One of them was left as such and the second one was submitted to washing under reflux. Characterization of both fractions was carried out through elemental analysis and X-ray diffraction. Diffractograms were analyzed in order to obtain crystallite parameters by smoothing processes previous to deconvolution and then local maxima of a polynomial function were detected. Major peaks were found at around 20°, 25°, and 41° corresponding to ?, (002) and (10) bands. Bragg and Scherrer equations were used to determine the aromatic interlayer and aliphatic distances, as well as thickness and diameter of aromatic sheets. The full-width at half-maximum (FWHM) of the main peaks was firstly estimated using the corrector formula, and therefore the corrector procedure was applied to improve the initial guesses of FWHM. Differences in crystallite parameters between both analyzed samples were observed when using this mathematical approach.Dickson, A.J., 2017. A molybdenum-isotope perspective on Phanerozoic deoxygenation events. Nature Geoscience 10, 721-726. expansion and contraction of sulfidic depositional conditions in the oceans can be tracked with the isotopic composition of molybdenum in marine sediments. However, molybdenum-isotope data are often subject to multiple conflicting interpretations. Here I present a compilation of molybdenum-isotope data from three time intervals: the Toarcian Oceanic Anoxic Event about 183 million years ago, Oceanic Anoxic Event 2 about 94 million years ago, and two early Eocene hyperthermal events from 56 to 54 million years ago. A comparison of data from sites located in different hydrographic settings tightly constrains the molybdenum cycle for these intervals, allowing a direct comparison of the expanse of sulfidic conditions in each interval compared to today. Nonetheless, tracing rates of redox change over such rapid climatic events using molybdenum isotopes remains challenging. Future efforts to achieve this goal might be accomplished by analysing specific mineral phases, using complementary redox-sensitive geochemical techniques and by linking isotopic observations with Earth system modelling. Such improvements will make it possible to more fully assess the links between ocean deoxygenation, climatic and oceanographic changes, and biotic turnover.Ding, L., Zhao, M., Yu, M., Li, L., Huang, C.-Y., 2017. Biomarker assessments of sources and environmental implications of organic matter in sediments from potential cold seep areas of the northeastern South China Sea. Acta Oceanologica Sinica 36, 8-19. indexes were analyzed for two piston cores from potential cold seep areas of the South China Sea off southwestern Taiwan. Total organic carbon (TOC) normalized terrestrial (n-alkanes) and marine (brassicasterol, dinosterol, alkenones and iso-GDGTs) biomarker contents and ratios (TMBR, 1/Pmar-aq, BIT) were used to evaluate the contributions of terrestrial and marine organic matter (TOM and MOM respectively) to the sedimentary organic matter, indicating that MOM dominated the organic sources in Core MD052911 and the sedimentary organic matter in Core ORI-860-22 was mainly derived from terrestrial inputs, and different morphologies were the likely reason for TOM percentage differences. BIT results suggested that river-transported terrestrial soil organic matter was not a major source of TOM of sedimentary organic matter around these settings. Diagnostic biomarkers for methane-oxidizing archaea (MOA) were only detected in one sample at 172 cm depth of Core ORI-860-22, with abnormally high iso-GDGTs content and Methane Index (MI) value (0.94). These results indicated high anaerobic oxidation of methane (AOM) activities at or around 172 cm in Core ORI-860-22. However in Core MD052911, MOA biomarkers were not detected and MI values were lower (0.19–0.38), indicated insignificant contributions of iso-GDGTs from methanotrophic archaea and the absence of significant AOM activities. Biomarker results thus indicated that the discontinuous upward methane seepage and insufficient methane flux could not induce high AOM activities in our sampling sites. In addition, the different patterns of TEX86 and Uk′37 temperature in two cores suggested that AOM activities affected TEX86 temperature estimates with lower values in Core ORI-860-22, but not significantly on TEX86 temperature estimates in Core MD052911.Ding, X., Gao, C., Zha, M., Chen, H., Su, Y., 2017. Depositional environment and factors controlling β-carotane accumulation: A case study from the Jimsar Sag, Junggar Basin, northwestern China. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 833-842. combined investigation of bulk geochemistry and molecular geochemistry was carried out on 31 source rock samples from the Lower Permian Lucaogou Formation, in the Jimsar Sag of the Junggar Basin, northwestern China. Geochemical characterization reveals the depositional environments and other factors favorable for the generation and accumulation of β-carotane, an important hydrocarbon precursor. Many core samples have a total organic carbon content > 1%, and Rock-Eval S2 values > 2 mg HC/g rock, suggesting relatively high hydrocarbon generation potential. Biomarkers in the Lucaogou source rock extracts are characterized by short- to long-chain n-alkanes, a wide range of Pr/Ph ratios (0.74–1.42) and β-carotane index values (β-carotane/Cmax, 0.16–1.92), high concentrations of C29 sterane, relatively low tricyclic terpane content, and moderate gammacerane index values (0.14–0.29). This is consistent with a weakly oxidizing to weakly reducing depositional environment, with fresh to brackish water conditions, rapid input of terrigenous organic matter, and a relatively small contribution of aquatic algal-bacterial organic matter. Cross-plots of biomarker parameters and the β-carotane index show that β-carotane in the Lucaogou source rocks is mainly derived from terrigenous organic matter, and is found predominantly in sediments deposited in weakly reducing, brackish environments. It does not appear to have been affected by thermal maturation.Domagal-Goldman, S.D., 2017. The power of self-skepticism in astrobiology. Astrobiology 17, 956-957. abstractDong, X., Jochmann, M.A., Elsner, M., Meyer, A.H., B?cker, L.E., Rahmatullah, M., Schunk, D., Lens, G., Meckenstock, R.U., 2017. Monitoring microbial mineralization using reverse stable isotope labeling analysis by mid-infrared laser spectroscopy. Environmental Science & Technology 51, 11876-11883. the biodegradation of organic compounds is a frequent question in environmental science. Here, we present a sensitive, inexpensive, and simple approach to monitor microbial mineralization using reverse stable isotope labeling analysis (RIL) of dissolved inorganic carbon (DIC). The medium for the biodegradation assay contains regular organic compounds and 13C-labeled DIC with 13C atom fractions (x(13C)DIC) higher than natural abundance (typically 2–50%). The produced CO2 (x(13C) ≈ 1.11%) gradually dilutes the initial x(13C)DIC allowing to quantify microbial mineralization using mass-balance calculations. For 13C-enriched CO2 samples, a newly developed isotope ratio mid-infrared spectrometer was introduced with a precision of x(13C) < 0.006%. As an example for extremely difficult and slowly degradable compounds, CO2 production was close to the theoretical stoichiometry for anaerobic naphthalene degradation by a sulfate-reducing enrichment culture. Furthermore, we could measure the aerobic degradation of dissolved organic carbon (DOC) adsorbed to granular activated carbon in a drinking water production plant, which cannot be labeled with 13C. Thus, the RIL approach can be applied to sensitively monitor biodegradation of various organic compounds under anoxic or oxic conditions.Du, T., Shan, X., Yi, J., Qu, Y., 2017. Quantitative characteristics of nanoscale pores in gas-bearing volcanic rocks of the Yingcheng Formation in the Songnan gas field. Energy & Fuels 31, 10655-10664. detailed study is conducted on the nanoscale pores in the volcanic rocks of the Yingcheng Formation in the Songnan gas field in the Songliao Basin of China. Mercury intrusion porosimetry (MIP) and the nitrogen adsorption method are used to analyze the distribution characteristics of nanoscale pores and their capacity to adsorb methane molecules. Volcanic reservoirs in the Songnan gas field consist of rhyolite, tuff, and volcanic breccia. The results of the MIP method indicate that the microscopic pores in the rhyolite, tuff, and volcanic breccia are mainly >1000 nm, 100–1000 nm, and <100 nm, respectively. The nanoscale pore diameters in the tuff exhibit positive correlations with specific surface area and specific pore volume. The results of the nitrogen adsorption method reveal that the average pore diameter in the volcaniclastic rocks (i.e., the tuff and breccia) is larger than that in the rhyolite. The quantity and geometric shapes of pores are the main factors influencing the ability of the rhyolite and volcanic breccia to contain gas, whereas the pore diameter mainly influences this ability in the tuff. The lower limit of pore diameter that can effectively adsorb methane molecules in the volcanic reservoir of the Songnan gas field is 22 nm. In pores ranging in diameter from 22 nm to 1000 nm, the specific pore volume reaches a maximum of 11 cm3/kg, thus indicating that nanoscale pores can act as good gas reservoirs. This study of nanoscale pores provides a new direction for the exploration of volcanic rock reservoirs. The lower limit of pore diameter for adsorption can be used as an important parameter in gas reservoir research.Duangkaew, P., Inoue, S., Aki, T., Nakashimada, Y., Okamura, Y., Tajima, T., Matsumura, Y., 2017. Quantitative in situ mass spectrometry analysis of mannitol decomposition products under hydrothermal conditions. Energy & Fuels 31, 10866-10873. situ mass spectrometry analysis was conducted for the hydrothermal decomposition of mannitol at different temperatures and residence times in a batch reactor. The temperature was varied in the range of 140–220 °C, and the residence time was varied between 5 and 20 min. The products of mannitol decomposition included furfural, 5-hydroxymethylfurfural, phenol, formic acid, and levulinic acid. At high temperatures, the mass spectrum showed peaks at m/z 46 and 116 that corresponded to formic acid and levulinic acid, respectively. Conventional high-performance liquid chromatography could not detect these acids. Quantification of these products and the rate constants for the mannitol decomposition network were also obtained. The reaction rate coefficients were determined by fitting the experimental results.Dunlea, A.G., Murray, R.W., Santiago Ramos, D.P., Higgins, J.A., 2017. Cenozoic global cooling and increased seawater Mg/Ca via reduced reverse weathering. Nature Communications 8, Article 844. clay minerals formed on or in the seafloor occur in every type of marine sediment. They are recognized to be a major sink of many elements in the ocean but are difficult to study directly due to dilution by detrital clay minerals. The extremely low dust fluxes and marine sedimentation rates in the South Pacific Gyre (SPG) provide a unique opportunity to examine relatively undiluted authigenic clay. Here, using Mg isotopes and element concentrations combined with multivariate statistical modeling, we fingerprint and quantify the abundance of authigenic clay within SPG sediment. Key reactants include volcanic ash (source of reactive aluminium) and reactive biogenic silica on or shallowly buried within the seafloor. Our results, together with previous studies, suggest that global reorganizations of biogenic silica burial over the Cenozoic reduced marine authigenic clay formation, contributing to the rise in seawater Mg/Ca and decline in atmospheric CO2 over the past 50 million years.Durham, S.R., Gillikin, D.P., Goodwin, D.H., Dietl, G.P., 2017. Rapid determination of oyster lifespans and growth rates using LA-ICP-MS line scans of shell Mg/Ca ratios. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 201-209. estimates of life-history traits (e.g., growth rate, lifespan, phenology) of mollusks are valuable data for a number of fields, including paleontology, archaeology, and fisheries science. The best option for obtaining these data for species such as oysters that lack reliable morphological indicators of annual accretionary growth (e.g., growth lines) is to use time consuming and expensive stable isotope analyses. However, laser ablation analyses of Mg/Ca are faster and less expensive than stable isotope analyses, and although several studies have shown Mg/Ca ratios in bivalve shells do not reflect water temperature, there is often a weak correlation that may allow annual cycles to be detected. Here, we explore the utility of line scan analyses of Mg/Ca ratios using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) as a more rapid and less expensive method for obtaining ontogenetic age estimates of mollusk shells than more traditional oxygen stable isotope analyses. We tested this method by measuring Mg/Ca ratios from 21 fossil and modern specimens of two oyster species, Crassostrea virginica and Magallana gigas (formerly Crassostrea gigas), collected across a wide geographic area along the coast of the United States. We compared Mg/Ca growth profiles with either known lifespans or with growth characteristics estimated from δ18O profiles. These analyses showed that Mg/Ca profiles from laser ablation analyses reliably reproduced the annual features of the more widely used δ18O profiles. In total, 97% (n = 102) of all seasonal peaks and troughs, including both those from the δ18O profiles and the expected patterns in the shells of known age, were detectable in the Mg/Ca profiles. We conclude that laser ablation analysis of Mg/Ca ratios is a rapid and cost effective alternative to stable isotope analysis for retrospective estimation of the growth characteristics of oysters and potentially other taxa with shells lacking reliable annual morphological features.Dzidek, B., Bochereau, S., Johnson, S.A., Hayward, V., Adams, M.J., 2017. Why pens have rubbery grips. Proceedings of the National Academy of Sciences 114, 10864-10869.: Why does gripping a pen, tool, or handle feel more secure when it is coated with a rubbery material? The keratin of the skin outer layer is stiff and rough at a small scale. When encountering a smooth, stiff, and impermeable surface, such as polished metal or glass, the actual contact area is initially small as is the friction. Because the keratin softens when it is hydrated by the moisture secreted from the sweat pores, it requires many seconds for the contact area to increase to the value reached almost instantaneously with a soft material, such as a rubber. This mechanism might be used by our tactile sense to identify materials and has implications for the design of tactile displays. Abstract: The process by which human fingers gives rise to stable contacts with smooth, hard objects is surprisingly slow. Using high-resolution imaging, we found that, when pressed against glass, the actual contact made by finger pad ridges evolved over time following a first-order kinetics relationship. This evolution was the result of a two-stage coalescence process of microscopic junctions made between the keratin of the stratum corneum of the skin and the glass surface. This process was driven by the secretion of moisture from the sweat glands, since increased hydration in stratum corneum causes it to become softer. Saturation was typically reached within 20 s of loading the contact, regardless of the initial moisture state of the finger and of the normal force applied. Hence, the gross contact area, frequently used as a benchmark quantity in grip and perceptual studies, is a poor reflection of the actual contact mechanics that take place between human fingers and smooth, impermeable surfaces. In contrast, the formation of a steady-state contact area is almost instantaneous if the counter surface is soft relative to keratin in a dry state. It is for this reason that elastomers are commonly used to coat grip surfaces. Edgar, K.M., Hull, P.M., Ezard, T.H.G., 2017. Evolutionary history biases inferences of ecology and environment from δ13C but not δ18O values. Nature Communications 8, Article 1106. related taxa are, on average, more similar in terms of their physiology, morphology and ecology than distantly related ones. How this biological similarity affects geochemical signals, and their interpretations, has yet to be tested in an explicitly evolutionary framework. Here we compile and analyze planktonic foraminiferal size-specific stable carbon and oxygen isotope values (δ13C and δ18O, respectively) spanning the last 107 million years. After controlling for dominant drivers of size-δ13C and size-δ18O trends, such as geological preservation, presence of algal photosymbionts, and global environmental changes, we identify that shared evolutionary history has shaped the evolution of species-specific vital effects in δ13C, but not in δ18O. Our results lay the groundwork for using a phylogenetic approach to correct species δ13C vital effects through time, thereby reducing systematic biases in interpretations of long-term δ13C records—a key measure of holistic organismal biology and of the global carbon cycle.El-Kammar, A., 2017. Oil shale resources in Egypt: the present status and future vision. Arabian Journal of Geosciences 10, Article 439. Egypt, organic-rich sediments in the Duwi and Dakhla Formations of the Campanian-Danian age are customarily assigned as “oil shale” that occupies the middle latitudes of the country but may extend southward to Kurkur Oases. This oil shale belt has a vast worldwide extension, and it is considered as major oil- and gas-prone source rock in many places, especially in the Middle East. The sedimentation of the oil shale was triggered by the major transgression event that occurred during the Late Cretaceous. The lithology, type of kerogen, organic richness, and thickness of these organic-rich sediments vary markedly both on lateral and vertical scales. In Quseir area, the in-place geological reserves, of oil shale of the 800-kcal/kg quality, is estimated to be more than 9 billion tons that can produce 5.48 bbls equivalent upon retorting. Very optimistic resources are expected in the unexplored Nile Valley region. The factor analysis of data rank representing 1176 core samples and analysis of 58 major and trace elements besides Rock-Eval analyses point to five main controlling factors that control deposition of oil shale. The terrestrial indicators Al2O3, TiO2, Fe2O3, and K2O and the marine indicators Ca and Sr are oppositely loaded in the first factor. The second factor expresses the reducing conditions that prevailed during the deposition of the organic-rich marine environments. The euxinity of the basin is recognized by the third factor where sulfide and vanadium seem to be mutual. The fourth factor expresses the role of dolomitization while the fifth factor points to the humble role of oxidation. Considering the metric core samples, the highest TOC content recorded in the borehole drilled in Abu Tartur plateau is 3.6%, but it is about 14% for Quseir area. Regarding the spot samples in Quseir area, the highest TOC measured about 24%. It is not only the low TOC in Abu Tartur but also the kerogen type that is of type II + III, mostly of terrestrial origin (gas-prone) and lithology dominated by argillites. Organic richness is remarkable in Quseir-Safaga area, where the average TOC of 160-m-thick sequence is about 5%, with kerogen of type I or mixed I + II, mostly of marine origin (oil prone). The Dakhla Formation (Maastrichtian-Danian) is the richest in organic matter while Quseir Formation (Campanian) has the least organic richness and lowest kerogen quality. Detailed investigation on biomarkers confirms the relations among transgression, organic richness, kerogen type, and anoxic conditions. The organic matter is immature as witnessed by the low S1 values (<5%, in average), the low Tmax (<430 °C), the low vitrinite reflectance (<0.4%), and biomarker signature. The variation in the S1 values between 1 and 9% is attributed to the influence of tectonics associating the Red Sea rift. In Quseir-Safaga area, there are particular prolific horizons of oil shale that seem to be visible for utilization by different technologies of combustion and retorting. The content of the heavy metals and uranium, as well as the spent, is a significant benefit. The faulting, dragging, and steep tilting of beds in the Quseir-Safaga area shall remain a serious challenge for extensive utilization of the estimated in-place geological reserves.Emery-Wetherell, M.M., McHorse, B.K., Byrd Davis, E., 2017. Spatially explicit analysis sheds new light on the Pleistocene megafaunal extinction in North America. Paleobiology 43, 642-655. late Pleistocene megafaunal extinctions may have been the first extinctions directly related to human activity, but in North America the close temporal proximity of human arrival and the Younger Dryas climate event has hindered efforts to identify the ultimate extinction cause. Previous work evaluating the roles of climate change and human activity in the North American megafaunal extinction has been stymied by a reliance on geographic binning, yielding contradictory results among researchers. We used a fine-scale geospatial approach in combination with 95 megafaunal last-appearance and 75 human first-appearance radiocarbon dates to evaluate the North American megafaunal extinction. We used kriging to create interpolated first- and last-appearance surfaces from calibrated radiocarbon dates in combination with their geographic autocorrelation. We found substantial evidence for overlap between megafaunal and human populations in many but not all areas, in some cases exceeding 3000 years of predicted overlap. We also found that overlap was highly regional: megafauna had last appearances in Alaska before humans first appeared, but did not have last appearances in the Great Lakes region until several thousand years after the first recorded human appearances. Overlap in the Great Lakes region exceeds uncertainty in radiocarbon measurements or methodological uncertainty and would be even greater with sampling-derived confidence intervals. The kriged maps of last megafaunal occurrence are consistent with climate as a primary driver in some areas, but we cannot eliminate human influence from all regions. The late Pleistocene megafaunal extinction was highly variable in timing and duration of human overlap across the continent, and future analyses should take these regional trends into account.Emmings, J.F., Davies, S.J., Vane, C.H., Leng, M.J., Moss-Hayes, V., Stephenson, M.H., Jenkin, G.R.T., 2017. Stream and slope weathering effects on organic-rich mudstone geochemistry and implications for hydrocarbon source rock assessment: A Bowland Shale case study. Chemical Geology 471, 74-91. study contributes to the exploration and quantification of the weathering of organic-rich mudstones under temperate climatic conditions. Bowland Shales, exposed by a stream and slope, were sampled in order to develop a model for the effects of weathering on the mudstone geochemistry, including major and trace element geochemistry, Rock-Eval pyrolysis and δ13Corg. Four weathering grades (I – IV) are defined using a visual classification scheme; visually fresh and unaltered (I), chemically altered (II, III) and ‘paper shale’ that typifies weathered mudstone on slopes (IV). Bedload abrasion in the stream exposes of visually fresh and geochemically unaltered mudstone. Natural fractures are conduits for oxidising meteoric waters that promote leaching at the millimetre scale and/or precipitation of iron oxide coatings along fracture surfaces. On the slope, bedding-parallel fractures formed (and may continue to form) in response to chemical and/or physical weathering processes. These fractures develop along planes of weakness, typically along laminae comprising detrital grains, and exhibit millimetre- and centimetre-scale leached layers and iron oxide coatings. Fracture surfaces are progressively exposed to physical weathering processes towards the outcrop surface, and results in disintegration of the altered material along fracture surfaces. Grade IV, ‘paper shale’ mudstone is chemically unaltered but represents a biased record driven by initial heterogeneity in the sedimentary fabric. Chemically weathered outcrop samples exhibit lower concentrations of both ‘free’ (S1) (up to 0.6 mgHC/g rock) and ‘bound’ (S2) (up to 3.2 mgHC/g rock) hydrocarbon, reduced total organic carbon content (up to 0.34 wt%), reduced hydrogen index (up to 58 mgHC/gTOC), increased oxygen index (up to 19 mgCO + CO2/gTOC) and increased Tmax (up to 11 °C) compared with unaltered samples. If analysis of chemically weathered samples is unavoidable, back-extrapolation of Rock-Eval parameters can assist in the estimation of pre-weathering organic compositions. Combining Cs/Cu with oxygen index is a proxy for identifying the weathering progression from fresh material (I) to ‘paper shale’ (IV). This study demonstrates that outcrop samples in temperate climates can provide information for assessing hydrocarbon potential of organic-rich mudstones.Engel, A.S., Liu, C., Paterson, A.T., Anderson, L.C., Turner, R.E., Overton, E.B., 2017. Salt marsh bacterial communities before and after the Deepwater Horizon oil spill. Applied and Environmental Microbiology 83, e00784-17.: Coastal salt marshes along the northern Gulf of Mexico shoreline received varied types and amounts of weathered oil residues after the 2010 Deepwater Horizon oil spill. At the time, predicting how marsh bacterial communities would respond and/or recover to oiling and other environmental stressors was difficult because baseline information on community composition and dynamics was generally unavailable. Here, we evaluated marsh vegetation, physicochemistry, flooding frequency, hydrocarbon chemistry, and subtidal sediment bacterial communities from 16S rRNA gene surveys at 11 sites in southern Louisiana before the oil spill and resampled the same marshes three to four times over 38 months after the spill. Calculated hydrocarbon biomarker indices indicated that oil replaced native natural organic matter (NOM) originating from Spartina alterniflora and marine phytoplankton in the marshes between May 2010 and September 2010. At all the studied marshes, the major class- and order-level shifts among the phyla Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria occurred within these first 4 months, but another community shift occurred at the time of peak oiling in 2011. Two years later, hydrocarbon levels decreased and bacterial communities became more diverse, being dominated by Alphaproteobacteria (Rhizobiales), Chloroflexi (Dehalococcoidia), and Planctomycetes. Compositional changes through time could be explained by NOM source differences, perhaps due to vegetation changes, as well as marsh flooding and salinity excursions linked to freshwater diversions. These findings indicate that persistent hydrocarbon exposure alone did not explain long-term community shifts. Importance: Significant deterioration of coastal salt marshes in Louisiana has been linked to natural and anthropogenic stressors that can adversely affect how ecosystems function. Although microorganisms carry out and regulate most biogeochemical reactions, the diversity of bacterial communities in coastal marshes is poorly known, with limited investigation of potential changes in bacterial communities in response to various environmental stressors. The Deepwater Horizon oil spill provided an unprecedented opportunity to study the long-term effects of an oil spill on microbial systems in marshes. Compared to previous studies, the significance of our research stems from (i) a broader geographic range of studied marshes, (ii) an extended time frame of data collection that includes prespill conditions, (iii) a more accurate procedure using biomarker indices to understand oiling, and (iv) an examination of other potential stressors linked to in situ environmental changes, aside from oil exposure. Erdenetsogt, B.-O., Lee, I., Ko, Y.-J., 2017. Carbon isotope analysis and a solid state 13C NMR study of Mongolian lignite: Changes in stable carbon isotopic composition during diagenesis. Organic Geochemistry 113, 293-302. results of a combined carbon isotope analysis and NMR study of a set of lignite samples from Mongolia show that a correlation exists between δ13C value and the ratios of oxygenated carbon (O-aliphatic, carboxyl/carbonyl and O-aromatic carbons) over protonated and carbon substituted aliphatic and aromatic carbons. The results indicate that the δ13C values of the lignite are controlled by two mechanisms: (i) Depletion in 13C as a result of loss of isotopically enriched O-bonded carbons and (ii) enrichment in 13C caused by a loss of isotopically depleted CH4 from aliphatic and aromatic carbons. At the rank of lignite, coal is enriched in 13C because the amount of isotopically enriched CO2 and CO, released from coal as a result of change in chemical structure, is less than that of isotopically depleted CH4.Erhardt, A., 2017. Palaeoceanography: Tropical ties. Nature Geoscience 10, 714-715. in dust flux, export productivity, and bottom-water oxygenation in the equatorial Pacific Ocean have been tightly linked with variations in North Atlantic climate over the past 100,000 years, according to analyses of marine sediments.Local climate anomalies frequently have a global influence. For example, during the last glacial period, influxes of fresh water into the North Atlantic from iceberg discharges resulted in global temperature decreases, stronger winds, higher dust fluxes and the weakening of the Asian summer monsoon1. Writing in Nature Geoscience, Loveley and colleagues2 use a suite of proxies from marine sediments to investigate the influence of these iceberg discharge events, known as Heinrich stadials, on carbon cycling in the eastern equatorial Pacific Ocean. They find that Heinrich stadials are associated with increased dust flux and surface productivity, and hence enhanced carbon burial in the equatorial Pacific.Today, the eastern equatorial Pacific Ocean is a high-nutrient, low-chlorophyll region, with the utilization of available nutrients and phytoplankton growth limited by the supply of iron3. Most of the iron in this region arrives via the deposition and dissolution of dust. In theory, an increase in dust-borne iron should prompt an increase in biological productivity. As this biological carbon is exported to deeper waters, it is consumed along with oxygen and stored in those deep waters as respired carbon. Our confidence in the characterization of these relationships is dependent on the timescale evaluated: a relationship between dust delivery and the export and storage of carbon is established on Milankovitch timescales of tens to hundreds of thousands of years4, but sub-millennial relationships between dust delivery, ocean productivity, and climate are still open to interpretation.To address the interplay of these climate variables at a sub-millennial scale, Loveley and colleagues2 used a multi-proxy geochemical approach. They used three proxies to assess the magnitude of and influences on equatorial carbon burial over the past 100,000 years: dust flux was reconstructed using 232Th fluxes, export production through excess barium, and bottom-water oxygenation through authigenic uranium, all from a sediment core located at about 0°10' S, 85°52' W.According to the reconstructions, dust fluxes during Heinrich stadial events were two times larger than modern fluxes and 50–100% greater than ambient glacial conditions. Most dust flux anomalies corresponded with measurable increases in the export of biological carbon into deeper waters (Fig. 1). While a linear response is not observed between these dust and productivity proxies, a clear qualitative relationship remains. The nature of this relationship becomes clear when these records are assessed alongside a sea surface temperature record from a nearby sediment core5, which indicates that Heinrich stadials were accompanied by enhanced upwelling of deeper water masses. Together, these records indicate that a combination of increased upwelling and dust delivery supplied iron and other nutrients to support enhanced productivity during Heinrich stadials.Loveley et al. propose that the connection between high- and low-latitude climate dynamics lies in substantial changes in atmospheric circulation relative to the present. Their dust flux results would require the Intertropical Convergence Zone (ITCZ) — that is, the zone where the north and south trade winds converge — to shift southwards by at least seven degrees of latitude from the current position. This may be problematic, as current general circulation models suggest that the presence of the Andes mountain belt limits the extent of potential ITCZ migration6. Moreover, existing ITCZ reconstructions using isotope tracers to distinguish between northern and southern dust7 do not have the temporal resolution to fully address the latitudinal ITCZ shifts proposed in this record. Further work evaluating the compositional differences between the dust flux as the ITCZ migrates may help to resolve both the actual location of the ITCZ and the nonlinear response between the excess barium productivity proxy and the 232Th dust proxy, clarifying the effect of iron limitation on high-nutrient, low-chlorophyll regions.Although Loveley and colleagues identify a clear temporal link between enhanced export production, carbon burial, and dust delivery, the links with bottom-water oxygen contents are more complex. Overall, their results show a lack of consistency between bottom-water oxygen content and export production. The inferred bottom-water oxygen contents do not exhibit much millennial-scale variability, instead remaining low throughout much of the glacial period when atmospheric CO2 concentrations are also low, reaching a minimum during the Last Glacial Maximum. This trend in bottom-water oxygen content is consistent with increased respired carbon storage in the deep ocean. During deglaciation, this CO2 was vented to the atmosphere8.An initial rise in atmospheric CO2 concentrations is seen during Heinrich stadial 1, about 17,000 to 15,000 years ago; this rise has been attributed to enhanced upwelling in the Southern Ocean caused by a southward shift in the westerlies. Loveley et al. argue that a corresponding southward shift in the ITCZ also enhanced upwelling in the eastern equatorial Pacific. However, the corresponding increase in productivity due to dust and nutrient delivery caused this region to become a net sink of CO2 during this interval. They end with the provocative thought that even at the onset of atmospheric CO2 rise and deglaciation, negative feedbacks exist to dampen these effects. We clearly should not presume that these CO2 shifts are irreversible.Loveley et al.2 provide strong evidence of an association between North Atlantic ice sheet dynamics and equatorial climate. They have also shown that such relationships are an important component of carbon cycling and exchange in the deep oceanReferences1. Hemming, S. R. Rev. Geophys. 42, RG1005 (2004). 2. Loveley, M. R. et al. Nat. Geosci. 10, 760–764 (2017). 3. Martin, J. H. Paleoceanography 5, 1–13 (1990). 4. Anderson, R. F., Fleisher, M. Q. & Lao, Y. Earth Planet. Sci. Lett. 242, 406–414 (2006). 5. Pena, L. D., Cacho, I., Ferretti, P. & Hall, M. A. Paleoceanography 23, PA3101 (2008). 6. Takahashi, K. & Battisti, D. S. J. Clim. 20, 3434–3451 (2007). 7. Reimi, M. A. & Marcantonio, F. Earth Planet. Sci. Lett. 453, 1–8 (2016) 8. Martínez-Botí, M. A. et al. Nature 518, 219–222 (2015). Eroglu, S., van Zuilen, M.A., Taubald, H., Drost, K., Wille, M., Swanner, E.D., Beukes, N.J., Schoenberg, R., 2017. Depth-dependent δ13C trends in platform and slope settings of the Campbellrand-Malmani carbonate platform and possible implications for Early Earth oxygenation. Precambrian Research 302, 122-139. evolution of oxygenic photosynthesis is widely seen as the major biological factor for the profound shift from reducing to slightly oxidizing conditions in Earth’s atmosphere during the Archean-Proterozoic transition period. The delay from the first biogenic production of oxygen and the permanent oxidation of Earth’s atmosphere during the early Paleoproteorozoic Great Oxidation Event (GOE) indicates that significant environmental modifications were necessary for an effective accumulation of metabolically produced oxygen. Here we report a distinct temporal shift to heavier carbon isotope signatures in lagoonal and intertidal carbonates (δ13Ccarb from ?1.6 to +0.4‰, relative to VPDB) and organic matter (δ13Corg from about ?40 to ?25‰, relative to VPDB) from the 2.58–2.50 Gy old shallow-marine Campbellrand-Malmani carbonate platform (South Africa). This indicates an enhanced primary production and lateral transport of organic material offshore to greater depths as well as a change from an anaerobic to an aerobic ecosystem. Trace element data indicate limited influx of reducing species from deep open ocean water into the platform and an increased supply of nutrients from the continent, both supporting primary production and an increasing oxidation state of the platform interior. These restricted conditions allowed that the dissolved inorganic carbon (DIC) pool in the platform interior developed differently than the open ocean. This is supported by coeval carbonates from the marginal slope setting, which had a higher interaction with open ocean water and do not record a comparable shift in δ13Ccarb throughout the sequence. We propose that the emergence of stable shallow-water carbonate platforms in the Neoarchean provided ideal conditions for the evolution of early aerobic ecosystems, which finally led to the full oxidation of Earth’s atmosphere during the GOE.Espinoza, D.N., Santamarina, J.C., 2017. CO2 breakthrough—Caprock sealing efficiency and integrity for carbon geological storage. International Journal of Greenhouse Gas Control 66, 218-229. pores in high specific surface clay-rich caprocks give rise to high capillary entry pressures and high viscous drag that hinder the migration of buoyant carbon dioxide CO2. We measured the breakthrough pressure and ensuing CO2 permeability through sediment plugs prepared with sand, silt, kaolinite and smectite, and monitored their volumetric deformation using high-pressure oedometer cells. The data show water expulsion and volumetric contraction prior to CO2 breakthrough, followed by preferential CO2 flow thereafter. Our experimental results and data gathered from previous studies highlight the inverse relationship between breakthrough pressure and pore size, as anticipated by Laplace’s equation. In terms of macro-scale parameters, the breakthrough pressure increases as the sediment specific surface increases and the porosity decreases. The breakthrough pressure is usually lower than the values predicted with average pore size estimations; it can reach ～6.2 MPa in argillaceous formations, and 11.2 MPa in evaporites. The CO2 permeability after breakthrough is significantly lower than the absolute permeability, but it may increase in time due to water displacement and desiccation. Leakage will be advection-controlled once percolation takes place at most storage sites currently being considered. Diffusive and advective CO2 leaks through non-fractured caprocks will be minor and will not compromise the storage capacity at CO2 injection sites. The “sealing number” and the “stability number” combine the initial fluid pressure, the buoyant pressure caused by the CO2 plume, the capillary breakthrough pressure of the caprock, and the stress conditions at the reservoir depth; these two numbers provide a rapid assessment of potential storage sites. Unexpected CO2 migration patterns emerge due to the inherent spatial variability and structural discontinuities in geological formations; sites with redundant seal layers should be sought for the safe and long-term storage of CO2.Fairen, A.G., 2017. Planetary science: Icy Mars lakes warmed by methane. Nature Geoscience 10, 717-718. release of methane trapped in Martian subsurface reservoirs following planetary obliquity shifts may have contributed to episodic climate warming between 3.6 and 3 billion years ago, explaining evidence for ancient ice-covered lakes.Decades of spacecraft investigations have confirmed that Mars preserves the geological record of an active and watery past. During the first billion years of the planet's history, known as the Noachian period, Mars probably had a denser atmosphere than today. Although the climate was relatively cold compared to Earth, there is evidence that liquid water flowed in streams and rivers, formed alluvial fans and deltas, and ponded in big lakes and possibly seas1. The next 600 million years of Martian history — the Hesperian period — marked the transition from that early cold and wet Mars to a cold and icy planet via substantial atmospheric loss and decline in planetary heat flow2. The last three billion years on Mars, the Amazonian period, have been dominated by extreme cold and dryness. Although liquid water was scarce during the Hesperian, Kite et al.3 argue in Nature Geoscience that episodic recurrences of cold and wet conditions triggered by bursts of methane stored in the subsurface may have sustained river flow and ice-covered lakes for durations of up to one million years.The mineralogy and geomorphology of the Martian surface suggest largely cold and icy conditions during the Hesperian, when any lakes would have been totally sealed by ice, and therefore isolated from their surrounding environment. However, rare episodes of runoff are recorded by deltas and alluvial fans in certain basins, suggesting occasional warming permitted exterior water to reach the ice-covered lakes (Fig. 1). The geological evidence suggests that each of these rare episodes during which ice-covered lakes formed persisted for up to a million years. Previous hypotheses have struggled to explain lake-forming climates that are both rare and long-lasting. For example, volcanism and impacts can produce episodes of climate warming, but not of sufficiently long duration.Kite et al.3 suggest a warming mechanism for Hesperian climates that is triggered by transitions in the planet's mean obliquity. Such transitions cause latitudinal changes in temperature and thus migration of ground and surface ice. The authors propose that chaotic excursions to high planetary obliquity act to episodically destabilize methane clathrates that are normally trapped beneath ice. The reduced pressure triggers the release of methane — a potent greenhouse gas.How much methane clathrate was stored in the regolith is unknown. Water–rock reactions in the Martian crust due to hydrothermal circulation early in the planet's history would have produced methane, and subsequent cooling locked the methane into pore spaces in the regolith as methane clathrate. For the warming mechanism proposed by Kite et al. to work, the release of methane must be sufficiently high to offset the breakdown of atmospheric methane by photolysis. Kite et al. calculate that there is sufficient subsurface methane for the build-up of millibars of CH4 in the atmosphere. Climate simulations of such a methane pulse produce greenhouse warming that is potentially sufficient to support the formation of long-lived ice-covered lakes on Hesperian Mars. Following the burst of methane into the atmosphere, the concentration of atmospheric methane would gradually decay: Kite et al. find that each episode of atmospheric CH4 enrichment on Mars would last up to a million years.The obliquity-triggered methane burst mechanism explains both the rarity of the warm climates and their persistence, but the magnitude of the warming depends on the total composition of greenhouse gases in the atmosphere. The pulse of methane delivered to the atmosphere can only deliver a modest degree of warming — perhaps between 5 and 10 °C. So, for their mechanism to explain evidence for runoff, the base Mars climate in between periods of methane enrichment needs to already be close to supporting liquid water at the surface. But this is not easy to achieve and climate models have historically struggled to raise the mean surface temperature of early Mars to even a few tens of degrees below zero4.Fortunately, recent climate model simulations5 that incorporate updated estimates of greenhouse warming produce a warmer base climate for Hesperian Mars when background atmospheric levels of methane are included. However, achieving surface temperatures that are near freezing also requires a concentration of CO2 in the atmosphere of over 1 bar, and the only in situ analyses of Mars palaeolake sediments so far — conducted on Gale crater sediments by the Curiosity rover — found low levels of carbonates consistent with just tens of millibars of CO2 in the Hesperian atmosphere6. This concentration would be insufficient for the methane burst mechanism to work.This apparent contradiction could be resolved by considering that the Hesperian lake waters were mostly sealed under ice, which would have hampered chemical exchange with the atmosphere and precipitation of carbonates at the lake bottoms. As a possible analogue to these Hesperian conditions, ice-sealed Antarctic lakes7 have been found to contain negligible carbonate in their sediments, which is attributed to the ice cover not allowing for rejuvenation of CO2 from the atmosphere8. The lakes are fed exclusively by cold-based glaciers that contain minimal amounts of carbon, resulting in carbon-starved lakes. Thus, although carbonates are scarce in the Gale crater sediments, the atmosphere at the time they were deposited could still have had some hundreds of millibars of CO2, plus some H2 and CH4.The resulting scenario for Hesperian Mars may have included a generally very cold and icy climate, similar to the continental Antarctica, with ice-sealed lakes and little or no melting occurring across vast expanses of surface ice over tens of millions of years. At times, however, the changes in atmospheric conditions proposed by Kite et al. may have perturbed the climate for 105 to 106 years, briefly warming the surface to a cold and wet environment similar to that of the Antarctic Dry Valleys, which today host seasonal rivers fed by ice melt that debouch into large ice-covered lakes.Gale crater may preserve the record of Hesperian palaeolakes ponded during the warmer intervals proposed by Kite and co-workers. For example, the layered sediments and deltaic deposits observed in Gale may have formed from individual lakes coming and going within the crater9, over time intervals entirely consistent with the estimated durations for the warmer episodes suggested by Kite and colleagues. Most of the time, however, cold conditions would have restrained weathering and erosion — consistent with the well-preserved rims of secondary craters punctured by the impact that formed Gale. Also, the scarcity of periglacial features (for example, glacial erratics, frost wedges) in Gale is similar to the paucity of such structures in terrestrial ice-sealed lakes. Although sedimentological criteria for the recognition of ice-sealed and ice-covered lakes on Mars are still being developed, there is evidence that glacial and periglacial processes operated in Hesperian lakes at Gale crater10.The methane burst scenario proposed by Kite et al.3 contributes to an emerging view that the existence of liquid water on early Mars arose from a combination of diverse astronomical, geochemical and geological factors. Although it seems unlikely that a single mechanism can explain not only the presence of liquid water, but its recurrence and persistence, the methane burst hypothesis provides a means to episodically tip the Hesperian climate over the edge.References1. Baker, V. et al. Nature 352, 589–594 (1991). 2. Clifford, S. M. & Parker, T. J. Icarus 154, 40–79 (2001). 3. Kite, E. et al. Nat. Geosci. 10, 737–740 (2017). 4. Kasting, J. F. Science 276, 1213–1213 (1997). 5. Wordsworth, R. et al. Geophys. Res. Lett. 44, 665–671 (2017).6. Bristow, T. F. et al. Proc. Natl Acad. Sci. USA 114, 2166–2170 (2017). 7. McKay, C. et al. Nature 313, 561–562 (1985). 8. Neumann, K., Lyons, W. B., Priscu, J. C., Desmarais, D. J. & Welch, K. A. Ann. Glaciol. 39, 518–524 (2004). 9. Grotzinger, J. et al. Science 350, aac7575 (2015).10. Fairén, A. G. et al. Planet. Space Sci. 93–94, 101–118 (2014). Fairén, A.G., Parro, V., Schulze-Makuch, D., Whyte, L., 2017. Searching for life on Mars before it is too late. Astrobiology 17, 962-970. of robotic exploration have confirmed that in the distant past, Mars was warmer and wetter and its surface was habitable. However, none of the spacecraft missions to Mars have included among their scientific objectives the exploration of Special Regions, those places on the planet that could be inhabited by extant martian life or where terrestrial microorganisms might replicate. A major reason for this is because of Planetary Protection constraints, which are implemented to protect Mars from terrestrial biological contamination. At the same time, plans are being drafted to send humans to Mars during the 2030 decade, both from international space agencies and the private sector. We argue here that these two parallel strategies for the exploration of Mars (i.e., delaying any efforts for the biological reconnaissance of Mars during the next two or three decades and then directly sending human missions to the planet) demand reconsideration because once an astronaut sets foot on Mars, Planetary Protection policies as we conceive them today will no longer be valid as human arrival will inevitably increase the introduction of terrestrial and organic contaminants and that could jeopardize the identification of indigenous martian life. In this study, we advocate for reassessment over the relationships between robotic searches, paying increased attention to proactive astrobiological investigation and sampling of areas more likely to host indigenous life, and fundamentally doing this in advance of manned missions.Falk, N., Chaganti, S.R., Weisener, C.G., 2018. Evaluating the microbial community and gene regulation involved in crystallization kinetics of ZnS formation in reduced environments. Geochimica et Cosmochimica Acta 220, 201-216. anoxic environments, sulfate-reducing bacteria (SRB) may precipitate sparingly-soluble, fine-grained sulfides as by-products of dissimilatory sulfate reduction. This bio-mechanism lends importance to acid rock drainage (ARD) remediation efforts for its ability to immobilize harmful metals from contaminant pathways, including Zn. However, SRB often coexist alongside multiple bacterial guilds in these environments, and may be sustained or hindered by the activities and metabolic by-products of their cohorts, driven by the commonly available substrates. Thus, the effectiveness of onset sulfate reduction and resultant metal-sulfide generation in ARD treatment can be enhanced by unravelling the complexities associated with these interactions. This research used material sourced from a passive bioreactor system located at the Stockton Coal Mine, New Zealand to investigate SRB activity and associated community function. RNA sequencing showed spore-forming Desulfitobacterium and Desulfotomaculum as the dominant SRB enriched from the reduced zone of the bioreactor. Metatranscriptomic analysis revealed acetogenic bacteria as syntrophic partners in substrate availability and Pseudomonas as metal-resistant community members. ZnS precipitates were observed by scanning electron microscopy (SEM) in short-term batch enrichments as well as long-term raw bioreactor material, with observed differences in mineral arrangement indicative of different nucleation scenarios. Syntrophy, metal response mechanisms, and the capacity for sporulation were observed as key microbial functions in mine waste reclamation settings. Here, Zn and S mass balance calculations coupled with RNA sequence data and microscopy illuminated favourable physicochemical and biological conditions for early metal sulfide precipitation in passive treatment systems for ARD and highlight the advantages of linking both lab and field-scale studies.Fan, Q., Bai, G., Wu, S., Yuan, W., Song, X.-M., 2017. The chemical structure and the kinetics research of oil-wet oil sand from Kazakhstan during pyrolysis process. Petroleum Science and Technology 35, 1495-1501. pyrolysis experiments on the oil sands from Kazakhstan were carried out in a batch reactor. The FT-IR spectrum and the 1H-NMR spectrum of pyrolysis oil under different temperatures were carried out to investigate the changes of functional group with temperature. The TGA experiments of oil sand were performed at different heating rates of 5, 10, 15, and 20°C/min up to 600°C. The Coats?Redfern method was accepted to calculate the kinetic parameters (apparent activation energy E and frequency factor A) of the desorption stage and the thermal cracking stage, respectively.Fang, H.W., Lai, H.J., Cheng, W., Huang, L., He, G.J., 2017. Modeling sediment transport with an integrated view of the biofilm effects. Water Resources Research 53, 7536-7557. natural sediment is invariably covered by biofilms in reservoirs and lakes, which have significant influence on bed form dynamics and sediment transport, and also play a crucial role in natural river evolution, pollutant transport, and habitat changes. However, most models for sediment transport are based on experiments using clean sediments without biological materials. In this study, a three-dimensional mathematical model of hydrodynamics and sediment transport is presented with a comprehensive consideration of the biofilm effects. The changes of the bed resistance mainly due to the different bed form dynamics of the biofilm-coated sediment (biosediment), which affect the hydrodynamic characteristics, are considered. Moreover, the variations of parameters related to sediment transport after the biofilm growth are integrated, including the significant changes of the incipient velocity, settling velocity, reference concentration, and equilibrium bed load transport rate. The proposed model is applied to evaluate the effects of biofilms on the hydrodynamic characteristics and sediment transport in laboratory experiments. Results indicate that the mean velocity increases after the biofilm growth, and the turbulence intensity near the river bed decreases under the same flow condition. Meanwhile, biofilm inhibits sediment from moving independently. Thus, the moderate erosion is observed for biosediment resulting in smaller suspended sediment concentrations. The proposed model can reasonably reflect these sediment transport characteristics with biofilms, and the approach to integration of the biological impact could also be used in other modeling of sediment transport, which can be further applied to provide references for the integrated management of natural aqueous systems.Fang, R., Li, M., Wang, T.G., Liu, X., Yuan, Y., Jiang, W., Wang, D., Shi, S., 2017. Trimethyldibenzothiophenes: Molecular tracers for filling pathways in oil reservoir. Journal of Petroleum Science and Engineering 159, 451-460. on the thermodynamic stabilities and molecular simulation, two trimethyldibenzothiophene molecular indicators, that is, 2,4,6-/(1,4,6?+?1,4,8?+?3,4,6)-trimethyldibenzothiophene (TMDBT) and (2,4,7?+?2,4,8)-/(1,4,6?+?1,4,8?+?3,4,6)-TMDBT (the numbers indicate the position of methyl-substitute), were proposed to trace subsurface oil migration orientations and reservoir filling pathways. In this paper, we successfully applied the aforesaid parameters both in an Ordovician carbonate reservoir of the Tuoputai region of the Tarim Basin (NW China), and in an Eocene clastic lacustrine reservoir of the Fushan Depression in the Beibuwan Basin, South China Sea. Besides the migration fractionation is proven the main control factor for the relative contents of TMDBT isomers in corresponding oils, which indicates that the trimethyldibenzothiophene molecular parameters can serve as the effective oil migration tracer in an oil reservoir, especially in high to over mature and severely biodegraded oils.Fang, Y., Chen, Z.-Q., Kershaw, S., Li, Y., Luo, M., 2017. An Early Triassic (Smithian) stromatolite associated with giant ooid banks from Lichuan (Hubei Province), South China: Environment and controls on its formation. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 108-122. we report the thickest Early Triassic stromatolite so far recorded, which developed within giant ooid banks in the upper Smithian succession (Lower Triassic) of the Lichuan area, western Hubei Province, South China. Approximately 16 m of stromatolite is embedded within ca. 30-m-thick oolitic limestones that crop out in the upper Daye Formation. The associated conodonts suggest a late Smithian (Early Triassic) age for the stromatolite-ooid complex. Stromatolites exhibit domal, stratified columnar, wavy laminated, cabbage-shaped, roll-up, and conical structures. Stromatolites are overlain by thick oolitic limestone, implying that the demise of the Lichuan stromatolite may be attributed to an environmental change to agitated shallow waters. Four types of microbially-induced microstructures are recognizable in the stromatolites, including diffuse laminated, reticular, intraclastic, and irregular clotted microstructures. Co-occurrence of these microbe-induced microstructures indicates a biogenic origin for the Lichuan stromatolite. The ooids can be categorized into circular, compound, superficial, and irregular types. Some interior layers within ooids exhibit intense fluorescence, indicative of microbial organomineralization, which may have contributed to the formation of the ooids. Moreover, abundant nanometer-scale textures and particles are usually interpreted as microbial involvement during the formation of the dolomite. These nano-textures in both stromatolites and ooids, and authigenic quartz grains commonly preserved in stromatolite can be attributed to abundant organic matter in seawater, resulting from microbial proliferation. The stromatolites described here are evidence of flourishing microbial communities on both eastern and western margins of the Paleo-Tethys Ocean during the middle Early Triassic, suggesting episodic degradation of marine ecosystems after the Permian–Triassic mass extinction.Farenc, M., Paupy, B., Marceau, S., Riches, E., Afonso, C., Giusti, P., 2017. Effective ion mobility peak width as a new isomeric descriptor for the untargeted analysis of complex mixtures using ion mobility-mass spectrometry. Journal of The American Society for Mass Spectrometry 28, 2476-2482. mobility coupled with mass spectrometry was proven to be an efficient way to characterize complex mixtures such as petroleum samples. However, the identification of isomeric species is difficult owing to the molecular complexity of petroleum and no availability of standard molecules. This paper proposes a new simple indicator to estimate the isomeric content of highly complex mixtures. This indicator is based on the full width at half maximum (FWHM) of the extracted ion mobility peak measured in millisecond or square angstrom that is corrected for instrumental factors such as ion diffusion. This value can be easily obtained without precisely identifying the number of isomeric species under the ion mobility peaks. Considering the Boduszynski model, the ion mobility profile for a particular elemental composition is expected to be a continuum of various isomeric species. The drift time-dependent fragmentation profile was studied and confirmed this hypothesis, a continuous evolution of the fragmentation profile showing that the larger alkyl chain species were detected at higher drift time values. This new indicator was proven to be a fast and efficient method to compare vacuum gas oils for which no difference was found using other analytical techniques.Felden, B., Paillard, L., 2017. When eukaryotes and prokaryotes look alike: the case of regulatory RNAs. FEMS Microbiology Reviews 41, 624-639. discovery that all living entities express many RNAs beyond mRNAs, tRNAs and rRNAs has been a surprise in the past two decades. In fact, regulatory RNAs (regRNAs) are plentiful, and we report stunning parallels between their mechanisms and functions in prokaryotes and eukaryotes. For instance, prokaryotic CRISPR (clustered regularly interspaced short palindromic repeats) defense systems are functional analogs to eukaryotic RNA interference processes that preserve the cell against foreign nucleic acid elements. Regulatory RNAs shape the genome in many ways: by controlling mobile element transposition in both domains, via regulation of plasmid counts in prokaryotes, or by directing epigenetic modifications of DNA and associated proteins in eukaryotes. RegRNAs control gene expression extensively at transcriptional and post-transcriptional levels, with crucial roles in fine-tuning cell environmental responses, including intercellular interactions. Although the lengths, structures and outcomes of the regRNAs in all life kingdoms are disparate, they act through similar patterns: by guiding effectors to target molecules or by sequestering macromolecules to hamper their functions. In addition, their biogenesis processes have a lot in common. This unifying vision of regRNAs in all living cells from bacteria to humans points to the possibility of fruitful exchanges between fundamental and applied research in both domains.Feng, X., Chen, Z.-Q., Woods, A., Fang, Y., 2017. A Smithian (Early Triassic) ichnoassemblage from Lichuan, Hubei Province, South China: Implications for biotic recovery after the latest Permian mass extinction. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 123-141. late Smithian ichnoassemblage is reported from the Lower Triassic succession from the Lichuan section, western Hubei Province, South China. This ichnoassemblage comprises 13 ichnogenera, which include simple, horizontal traces (Cochlichnus, Cosmorhaphe, Didymaulichnus, Gordia, Circulichnis, and Planolites), vertical traces (Arenicolites, Laevicyclus), oblique- or horizontal branching traces (Palaeophycus), slightly complex burrow networks (Thalassinoides, and Treptichnus), and grazing traces (Cosmorhaphe and Gyrochorte). These traces are also categorized into fodinichnia, domichnia, pascichnia, and repichnia ethologic types, suggesting a fairly high degree of behavioral complexity. Of these, the fodinichnia traces are most abundant. The ichnoassemblage horizons usually have rather high ichnofabric indices (ii), reaching ii 4–5. Bedding plane coverage is up to 70–90%, resulting in high bedding plane bioturbation index as well (BPBI 4–5). The Lichuan ichnoassemblage traces have mean and maximum diameters of 4.8 mm and 9 mm, respectively (n = 342). The traces penetrate to a depth of up to 30 mm into the sediment, with an average depth of penetration of 15 mm, indicating third to fourth tiering levels (3–4). Overall, the Lichuan ichnofauna shows an abrupt increase in ichnodiversity, burrow width, behavioral complexity, and ecologic tiering level, which are indicative of recovery stages of 2–3 in the late Smithian. When compared to five coeval ichnoassemblages from other sections in South China (Yashan, Susong, Daxiakou, Gaimao, and Tianshengqiao) and coeval ichnoassemblages from elsewhere (northern Italy, Western Australia, western US), the Lichuan trace-fossil assemblage reaches similar level of diversity during this time interval. Paleoenvironmental analysis indicates that the late Smithian recovery pulse is typically confined to the offshore transition setting, whereas more distal zones record much lower levels of recovery. Therefore, time and environmental conditions were the two crucial factors controlling the rate and degree of recovery of trace-making organisms in the aftermath of the latest Permian mass extinction.Feng, X., Zeng, J., Ma, Y., Jia, K., Qiao, J., Zhang, Y., Feng, S., 2017. Asphaltene deposition preference and permeability reduction mechanisms in oil reservoirs: Evidence from combining X-ray microtomography with fluorescence microscopy. Energy & Fuels 31, 10467-10478. deposition in oil reservoirs during acid stimulation, natural depletion, and CO2 injection may cause intense formation damage and reduced productivity. Gaining a better understanding of the asphaltene deposition mechanisms and their influence on the reservoir permeability reduction will contribute to the prevention of reservoir damage and the optimization of development schemes. Although numerous models and experiments have been applied to simulate the asphaltene deposition process and evaluate the reservoir permeability loss, few analyses have been performed on natural samples from oil reservoirs undergoing asphaltene deposition. Moreover, permeability reduction simulation due to asphaltene deposition has not yet been performed in three-dimensional (3D) microscale pore systems. In this work, sandstone samples were collected from natural oil reservoirs with asphaltene deposition and analyzed by both X-ray tomography and fluorescence microscopy to identify the asphaltene. A Navier–Stokes simulator and pore network model are used to study the 3D pore spaces and to calculate the permeabilities and pore radius distributions. Ideal asphaltene deposition models are applied in the 3D pore spaces to simulate the influences of surface adsorption and pore blockage on the permeability reduction. By comparing the calculation results of the ideal models and natural samples, we found that the asphaltene deposition is a coupled effect of the surface adsorption and the pore blockage, which causes a weaker permeability loss than that from the ideal single factor models.\Ferreira, R.B., Ferreira, J.B., 2017. The live universe. A biologist's perspective. Frontiers in Astronomy and Space Sciences 4, 4:17. doi: 10.3389/fspas.2017.00017. looks at all aspects related to life in places other than the Earth, including its biomolecular building blocks and suitable environmental conditions. In the present article, a different approach is followed: a comparative analysis between Astronomy and Biology as discrete domains of science. Remarkable similarities exist between these two apparently widely separated and multidisciplinary fields. Both are driven, from beginning to end, by thermodynamics. Their evolution is studied to a very reasonable degree of accuracy, from beginning to the present day, by analyzing data which were ‘frozen’ in the past. Yet we cannot predict where and how they will go from here. A major difference is that in Biology, unlike Astronomy, we can see and analyse the present (or, more accurately, the immediate past). While the Big Bang is widely accepted as the origin of our universe, the debate about its ultimate fate is far from settled. A plethora of cosmological models has been proposed, many involving the concept of a multiuniverse. The observation that the rate of expansion of the universe is apparently accelerating further boosts the discussion. Entropy may act as a driving force behind the increasing rate of expansion, with nothingness as the maximum possible entropy our universe gets. Using biological systems as an analogy and adopting a broad definition for life, we may speculate the existence of a living multiuniverse, capable of natural evolution, in which each individual universe spontaneously goes through birth, development, reproduction, ageing and death. The possible roles of supermassive black holes (SMBHs) and human-like intelligence on the future evolution of our universe are briefly discussed.Feulner, G., 2017. Formation of most of our coal brought Earth close to global glaciation. Proceedings of the National Academy of Sciences 114, 11333-11337.: The bulk of the coal driving the Industrial Revolution and contributing to global warming today has been deposited during the Carboniferous period (359–299 million years ago), resulting in a significant drawdown of atmospheric carbon dioxide at that time. In this work, a combination of climate model simulations and recent estimates for carbon dioxide levels in the atmosphere is used to demonstrate that the cooling due to the diminished greenhouse effect brought our planet close to the limit of global glaciation ～ ～300 million years ago. These findings highlight the climatic importance of the fossil carbon stored in Earth’s coal deposits and thus have implications for climate policy. Abstract: The bulk of Earth’s coal deposits used as fossil fuel today was formed from plant debris during the late Carboniferous and early Permian periods. The high burial rate of organic carbon correlates with a significant drawdown of atmospheric carbon dioxide (CO2) at that time. A recent analysis of a high-resolution record reveals large orbitally driven variations in atmospheric CO2 concentration between ～ ～150 and 700 ppm for the latest Carboniferous and very low values of 100 ± ± 80 ppm for the earliest Permian. Here, I explore the sensitivity of the climate around the Carboniferous/Permian boundary to changes in Earth’s orbital parameters and in atmospheric CO2 using a coupled climate model. The coldest orbital configurations are characterized by large axial tilt and small eccentricities of Earth’s elliptical orbit, whereas the warmest configuration occurs at minimum tilt, maximum eccentricity, and a perihelion passage during Northern hemisphere spring. Global glaciation occurs at CO2 concentrations <40 ppm, suggesting a rather narrow escape from a fully glaciated Snowball Earth state given the low levels and large fluctuations of atmospheric CO2. These findings highlight the importance of orbital cycles for the climate and carbon cycle during the late Paleozoic ice age and the climatic significance of the fossil carbon stored in Earth’s coal deposits. Finch, B.E., Marzooghi, S., Di Toro, D.M., Stubblefield, W.A., 2017. Phototoxic potential of undispersed and dispersed fresh and weathered Macondo crude oils to Gulf of Mexico marine organisms. Environmental Toxicology and Chemistry 36, 2640-2650. oils contain a mixture of hydrocarbons, including phototoxic polycyclic aromatic hydrocarbons (PAHs) that have the ability to absorb ultraviolet (UV) light. Absorption of UV light by PAHs can substantially increase their toxicity to marine organisms. The objective of the present study was to examine the potential for phototoxicity of fresh and naturally weathered Macondo crude oils alone and in combination with the dispersant Corexit 9500 to mysid shrimp (Americamysis bahia), inland silverside (Menidia beryllina), sheepshead minnow (Cyprinodon variegatus), and Gulf killifish (Fundulus grandis). Acute toxicity tests were conducted using combinations of natural or artificial sunlight and low-energy water-accommodated fractions (WAFs) of fresh and weathered Macondo crude oils collected from the Gulf of Mexico. Studies were also conducted to compare the phototoxicity resulting from natural and artificial sunlight. Fresh Macondo crude oil was more phototoxic than weathered crude oils, both in the presence and in the absence of UV light. Differences in toxicity between fresh and weathered crude oils were likely attributed to lighter-ringed PAHs in fresh crude oils. Phototoxic PAHs were relatively resistant to weathering compared with lighter-ringed PAHs. The addition of Corexit 9500 to crude oil increased toxicity compared with tests with crude oil alone, by increasing phototoxic PAH concentrations in WAFs. Macondo crude oils had the potential to be phototoxic to Gulf of Mexico marine organisms if specific light conditions and PAH concentrations were present during the Deepwater Horizon oil spill.Finsterle, S., Commer, M., Edmiston, J.K., Jung, Y., Kowalsky, M.B., Pau, G.S.H., Wainwright, H.M., Zhang, Y., 2017. iTOUGH2: A multiphysics simulation-optimization framework for analyzing subsurface systems. Computers & Geosciences 108, 8-20. is a simulation-optimization framework for the TOUGH suite of nonisothermal multiphase flow models and related simulators of geophysical, geochemical, and geomechanical processes. After appropriate parameterization of subsurface structures and their properties, iTOUGH2 runs simulations for multiple parameter sets and analyzes the resulting output for parameter estimation through automatic model calibration, local and global sensitivity analyses, data-worth analyses, and uncertainty propagation analyses. Development of iTOUGH2 is driven by scientific challenges and user needs, with new capabilities continually added to both the forward simulator and the optimization framework. This review article provides a summary description of methods and features implemented in iTOUGH2, and discusses the usefulness and limitations of an integrated simulation-optimization workflow in support of the characterization and analysis of complex multiphysics subsurface systems.Fleisher, A.J., Long, D.A., Liu, Q., Gameson, L., Hodges, J.T., 2017. Optical measurement of radiocarbon below unity fraction modern by linear absorption spectroscopy. The Journal of Physical Chemistry Letters 8, 4550-4556. measurements of radiocarbon (14C) near or below a fraction modern 14C of 1 (F14C ≤ 1) are challenging and costly. An accurate, ultrasensitive linear absorption approach to detecting 14C would provide a simple and robust benchtop alternative to off-site accelerator mass spectrometry facilities. Here we report the quantitative measurement of 14C in gas-phase samples of CO2 with F14C < 1 using cavity ring-down spectroscopy in the linear absorption regime. Repeated analysis of CO2 derived from the combustion of either biogenic or petrogenic sources revealed a robust ability to differentiate samples with F14C < 1. With a combined uncertainty of 14C/12C = 130 fmol/mol (F14C = 0.11), initial performance of the calibration-free instrument is sufficient to investigate a variety of applications in radiocarbon measurement science including the study of biofuels and bioplastics, illicitly traded specimens, bomb dating, and atmospheric transport.Fleury, B., Carrasco, N., Millan, M., Vettier, L., Szopa, C., 2017. Organic chemistry in a CO2 rich early Earth atmosphere. Earth and Planetary Science Letters 479, 34-42. emergence of life on the Earth has required a prior organic chemistry leading to the formation of prebiotic molecules. The origin and the evolution of the organic matter on the early Earth is not yet firmly understood. Several hypothesis, possibly complementary, are considered. They can be divided in two categories: endogenous and exogenous sources. In this work we investigate the contribution of a specific endogenous source: the organic chemistry occurring in the ionosphere of the early Earth where the significant VUV contribution of the young Sun involved an efficient formation of reactive species. We address the issue whether this chemistry can lead to the formation of complex organic compounds with CO2 as only source of carbon in an early atmosphere made of N2, CO2 and H2, by mimicking experimentally this type of chemistry using a low pressure plasma reactor. By analyzing the gaseous phase composition, we strictly identified the formation of H2O, NH3, N2O and C2N2. The formation of a solid organic phase is also observed, confirming the possibility to trigger organic chemistry in the upper atmosphere of the early Earth. The identification of Nitrogen-bearing chemical functions in the solid highlights the possibility for an efficient ionospheric chemistry to provide prebiotic material on the early Earth.Fu, H.-Y., Guo, X.-M., Zhang, Y.-M., Song, J.-J., Zheng, Q.-X., Liu, P.-P., Lu, P., Chen, Q.-S., Yu, Y.-J., She, Y., 2017. AntDAS: Automatic data analysis strategy for UPLC–QTOF-based nontargeted metabolic profiling analysis. Analytical Chemistry 89, 11083-11090. data analysis methodology remains a bottleneck for metabolic profiling analysis based on ultraperformance liquid chromatography–quadrupole time-of-flight mass spectrometry. The present work aims to address this problem by proposing a novel data analysis strategy wherein (1) chromatographic peaks in the UPLC–QTOF data set are automatically extracted by using an advanced multiscale Gaussian smoothing-based peak extraction strategy; (2) a peak annotation stage is used to cluster fragment ions that belong to the same compound. With the aid of high-resolution mass spectrometer, (3) a time-shift correction across the samples is efficiently performed by a new peak alignment method; (4) components are registered by using a newly developed adaptive network searching algorithm; (5) statistical methods, such as analysis of variance and hierarchical cluster analysis, are then used to identify the underlying marker compounds; finally, (6) compound identification is performed by matching the extracted peak information, involving high-precision m/z and retention time, against our compound library containing more than 500 plant metabolites. A manually designed mixture of 18 compounds is used to evaluate the performance of the method, and all compounds are detected under various concentration levels. The developed method is comprehensively evaluated by an extremely complex plant data set containing more than 2000 components. Results indicate that the performance of the developed method is comparable with the XCMS. The MATLAB GUI code is available from <, X., Wang, J., Zeng, S., Feng, X., Wang, D., Song, C., 2017. Continental weathering and palaeoclimatic changes through the onset of the Early Toarcian oceanic anoxic event in the Qiangtang Basin, eastern Tethys. Palaeogeography, Palaeoclimatology, Palaeoecology 487, 241-250. Bilong Co North section, located in the South Qiangtang Depression, northern Tibetan Plateau, provides key information on continental weathering and palaeoclimatic changes through the onset of the Early Toarcian oceanic anoxic event (T-OAE) in the eastern Tethys. New mineralogical and geochemical data from the Bilong Co North section suggest that the Lower Unit of the section corresponds to low chemical index of alteration (CIA, 50–57) and ln(Al2O3/Na2O) (0.88–1.16) and high index of compositional variability (ICV, 19–27), indicating a weak weathering and arid climate preceding the onset of the T-OAE. A prominent increase in CIA and ln(Al2O3/Na2O) values is clearly recorded through the onset of the T-OAE, coinciding with a prominent change in Srxs/Ba and clay fractions, suggesting a sharp increase in humidity at the onset of the T-OAE. The palaeoclimatic index of low Srxs/Ba (0.48–4.98) ratios indicates that the climate during the T-OAE interval was most likely semiarid to semimoist. Some redox proxies, including Mo and TOC relationships, Mo-U enrichment factors, and Corg:Ptotal ratios suggest euxinic conditions during the T-OAE interval. The primary productivity parameters show two main fluctuations within the Bilong Co North section, and their patterns are in good agreement with the observation of palaeoclimatic variation patterns, suggesting an influence of palaeoclimate on primary productivity. However, the palaeoproductivity increase during the T-OAE in the Bilong Co North section should mainly be attributed to freshwater inputs rather than solely the result of paleoclimatic change.Fuertez, J., Boakye, R., McLennan, J., Adams, D.J., Sparks, T.D., Gottschalk, A., 2017. Developing methanogenic microbial consortia from diverse coal sources and environments. Journal of Natural Gas Science and Engineering 46, 637-650. gas production is a promising alternative or supplement to conventional methane extraction from coalbeds. Adsorbed and free gas, generated over geologic time, can be supplemented with biogenic gas during short-term engineering operations. There are two generic protocols for doing this. The first is to contact the coal with nutrients to support native bacterial development. The second approach is to inject appropriately cultured ex-situ consortia into subsurface coal accumulations. Research has mainly focused on the former: in-situ stimulation of native microbial communities with added nutrients. Relatively few studies have been conducted on the strategies for enriching ex-situ microbial populations under initial atmospheric exposure for subsequent injection into coal seams to stimulate biodegradation, and methanogenesis. To evaluate the feasibility of ex-situ cultivation, natural microbial populations were collected from various hydrocarbon-rich environments and locations characterized by natural methanogenesis. Different rank coals (i.e., lignite, sub-bituminous, bituminous), complex hydrocarbon sources (i.e., oil shale, waxy crude), hydrocarbon seeps, and natural biogenic environments were incorporated in the sampling. Three levels of screening (down-selection to high grade the most productive consortia) allowed selection of microbial populations, favorable nutrient amendments, sources of the microbial community, and quantification of methane produced from various coal types. Incubation periods of up to twenty-four weeks were evaluated at 23 °C. Headspace concentrations of CH4 and CO2 were analyzed by gas chromatography. After a two-week incubation period of the most promising microbes, generated headspace gas concentrations reached 873,400 ppm (154 sft3/ton or 4.8 scm3/g) for methane and 176,370 ppm (31 sft3/ton or 0.9 scm3/g) for carbon dioxide. Rudimentary statistical assessments – variance analysis (ANOVA) of a single factor - were used to identify trends and levels of significance or impact of the consortia enrichment. It was demonstrated that microbial communities from coal and lake sediments can be enriched and adapted to effectively generate methane under initial atmospheric exposure. The development and enrichment of these methanogenic consortia is described.Fuertez, J., Nguyen, V., McLennan, J.D., Adams, D.J., Han, K.-B., Sparks, T.D., 2017. Optimization of biogenic methane production from coal. International Journal of Coal Geology 183, 14-24. continuously increasing global energy needs, diversified efforts have been made to find and exploit new natural gas resources. These include coalbed methane (CBM), which represents an important global, unconventional source of natural gas. Efforts have been underway for some time to more effectively generate methane in-situ in coal plays by introduction of nutrients and/or microbial consortia. However, much is still to be learned about the limitations and environmental conditions that support microbial growth and are conducive to biogenic methane production from coal. The present investigation evaluated environmental conditions that led to increased methane production from subbituminous coal by introducing a foreign methanogenic consortium that included Methanobacterium sp. A central composite design (CCD) was used to explore a broad range of operational conditions, examine the effects of the important environmental factors, such as temperature, pH and salt concentration, and query a feasible region of operation to maximize methane production from coal. An anticipated detrimental effect of NaCl concentration on methane production was observed for the consortium assessed. The range of feasible operational conditions comprised initial pH values between 4.2 and 6.8, temperatures between 23 °C and 37 °C, and NaCl concentrations between 3.7 mg/cm3 and 9.0 mg/cm3. Coal biogasification was optimal for this consortium at an initial pH value of 5.5, at 30 °C, and at a NaCl concentration 3.7 mg/cm3 (i.e., 145,165 ppm, which is 25.6 sft3/ton).Gajica, G., ?ajnovi?, A., Stojanovi?, K., Kosti?, A., Slipper, I., Antonijevi?, M., Nytoft, H.P., Jovan?i?evi?, B., 2017. Organic geochemical study of the upper layer of Aleksinac oil shale in the Dubrava Block, Serbia. Oil Shale 34, 197–218. detailed evaluation of geochemical properties of oil shale samples from the outcrops of the Lower Miocene upper layer in the Dubrava area, Aleksinac basin, Serbia, was performed. For that purpose X-ray diffraction (XRD) analysis, Rock Eval pyrolysis, gas chromatography-mass spectrometry (GC-MS) analysis of biomarkers and conventional pyrolysis in an autoclave were used.Most of the samples have similar mineral compositions with predominance of clay and feldspar minerals. Three samples are characterised by an elevated content of carbonates, and among them one sample has a notable prevalence of this mineral group. This sample also demonstrated certain differences in biomarker distribution.In most samples organic matter (OM) consists predominantly of type I and II kerogens, showing high oil generative potential, whereas three samples, which contain type II kerogen with a certain input of type III kerogen, demonstrated potential to produce both, oil and gas. The OM of all samples is immature and corresponds to the vitrinite reflectance of ca. 0.40%. Biomarker patterns along with Rock-Eval data indicated a strong contribution of aquatic organisms such as green and brown algae and bacteria with some influence of higher plants OM. The organic matter was deposited in a reducing lacustrine alkaline brackish to freshwater environment under warm climate conditions. Preservation of OM was governed by stratification of the water column rather than its height. Tectonic movements that caused the regional tilting of an investigated area and supported minor marine ingression and influx of fresh water played an important role in formation of the sediments.Conventional pyrolytic experiments confirmed that these sediments at the catagenetic stage could be a significant source of liquid hydrocarbons.Ga?uszka, A., Migaszewski, Z.M., Namie?nik, J., 2017. The role of analytical chemistry in the study of the Anthropocene. TrAC Trends in Analytical Chemistry 97, 146-152. term “Anthropocene” refers to not yet formalized epoch of geologic time during which geologic processes have been dominated by the human impact. This impact takes on many forms. Biological, physical and chemical changes to the Earth System caused by anthropogenic activity are recorded in natural archives either as new fossil assemblages (neobiota), anthropogenic deposits or a wide variety of pollutants emitted to the environment. With the current efforts to formalize the Anthropocene Epoch, a new trend in analytical chemistry has emerged. The use of different dating techniques combined with the study of chemical signals recorded in different natural archives, such as ice cores, marine and freshwater sediments, corals, tree rings, stalactites, allows us to reconstruct historic emission trends. This paper presents characteristics of specific samples to be analyzed and the pertinent analytical techniques to be applied for the purpose of gaining the knowledge required for formalizing the Anthropocene Epoch.Gardner, M.S., McWilliams, L.G., Jones, J.I., Kuklenyik, Z., Pirkle, J.L., Barr, J.R., 2017. Simultaneous quantification of free cholesterol, cholesteryl esters, and triglycerides without ester hydrolysis by UHPLC separation and in-source collision induced dissociation coupled MS/MS. Journal of The American Society for Mass Spectrometry 28, 2319-2329. demonstrate the application of in-source nitrogen collision-induced dissociation (CID) that eliminates the need for ester hydrolysis before simultaneous analysis of esterified cholesterol (EC) and triglycerides (TG) along with free cholesterol (FC) from human serum, using normal phase liquid chromatography (LC) coupled to atmospheric pressure chemical ionization (APCI) tandem mass spectrometry (MS/MS). The analysis requires only 50 μL of 1:100 dilute serum with a high-throughput, precipitation/evaporation/extraction protocol in one pot. Known representative mixtures of EC and TG species were used as calibrators with stable isotope labeled analogs as internal standards. The APCI MS source was operated with nitrogen source gas. Reproducible in-source CID was achieved with the use of optimal cone voltage (declustering potential), generating FC, EC, and TG lipid class-specific precursor fragment ions for multiple reaction monitoring (MRM). Using a representative mixture of purified FC, CE, and TG species as calibrators, the method accuracy was assessed with analysis of five inter-laboratory standardization materials, showing –10% bias for Total-C and –3% for Total-TG. Repeated duplicate analysis of a quality control pool showed intra-day and inter-day variation of 5% and 5.8% for FC, 5.2% and 8.5% for Total-C, and 4.1% and 7.7% for Total-TG. The applicability of the method was demonstrated on 32 serum samples and corresponding lipoprotein sub-fractions collected from normolipidemic, hypercholesterolemic, hypertriglyceridemic, and hyperlipidemic donors. The results show that in-source CID coupled with isotope dilution UHPLC-MS/MS is a viable high precision approach for translational research studies where samples are substantially diluted or the amounts of archived samples are limited.Garg, S., Newell, C.J., Kulkarni, P.R., King, D.C., Adamson, D.T., Renno, M.I., Sale, T., 2017. Overview of natural source zone depletion: Processes, controlling factors, and composition change. Groundwater Monitoring & Remediation 37, 62-81. source zone depletion (NSZD) has emerged as a practical alternative for restoration of light non-aqueous phase liquid (LNAPL) sites that are in the later stages of their remediation lifecycle. Due to significant research, the NSZD conceptual model has evolved dramatically in recent years, and methanogenesis is now accepted as a dominant attenuation process (e.g., Lundegard and Johnson 2006 ; Ng et al. 2015). Most of the methane is generated within the pore space adjacent to LNAPL (Ng et al. 2015) from where it migrates through the unsaturated zone (e.g., Amos and Mayer 2006), where it is oxidized. While great progress has been made, there are still some important gaps in our understanding of NSZD. NSZD measurements provide little insight on which constituents are actually degrading; it is unclear which rate-limiting factors that can be manipulated to increase NSZD rates; and how longevity of the bulk LNAPL and its key constituents can be predicted. Various threads of literature were pursued to shed light on some of the questions listed above. Several processes that may influence NSZD or its measurement were identified: temperature, inhibition from acetate buildup, protozoa predation, presence of electron acceptors, inhibition from volatile hydrocarbons, alkalinity/pH, and the availability of nutrients can all affect methanogenesis rates, while factors such as moisture content and soil type can influence its measurement. The methanogenic process appears to have a sequenced utilization of the constituents or chemical classes present in the LNAPL due to varying thermodynamic feasibility, biodegradability, and effects of inhibition, but the bulk NSZD rate appears to remain quasi-zero order. A simplified version of the reactive transport model presented by Ng et al. has the potential to be a useful tool for predicting the longevity of key LNAPL constituents or chemical fractions, and of bulk LNAPL, but more work is needed to obtain key input parameters such as chemical classes and their biodegradation rates and any potential inhibitions.Geng, Y., Liang, W., Liu, J., Cao, M., Kang, Z., 2017. Evolution of pore and fracture structure of oil shale under high temperature and high pressure. Energy & Fuels 31, 10404-10413. order to study the coupled effect of the temperature and pressure on pyrolysis characteristics and pore and fracture structures of oil shale, a total of 25 groups of pyrolytic reaction experiments have been conducted on 14 mm long and 7 mm in diameter cylindrical oil shale specimens under different temperature and pressure conditions ranging from 20 to 600 °C and 0.1–15 MPa. Further, both X-ray microcomputed tomography (μCT) and mercury intrusion porosimetry (MIP) have been used to comprehensively investigate the network structure, interconnectivity, and evolution of pore and fractures. The results show that the temperature significantly affects the pyrolysis characteristics of oil shale. With rising temperature, both the mass loss and the porosity increase gradually, the number and the maximum aperture of fractures also increase, and the pyrolytic degree intensifies progressively. The increase is most significant from 300 to 500 °C. The maximum mass loss ratio is 20.84%, the largest porosity is 13.52 times larger than that under the room temperature, and the total number and the maximum aperture of the fractures are 813 and 0.383 mm, respectively. Moreover, the pressure has a significant effect on the pore and fracture structures of oil shale. As the pressure increases, both the pore volume and the fracture distributions first decreased and then increased. With the continuous increase of pressure, the porosity and the total number of fractures reach a maximum at the pressure of 15 MPa. Under the coupled effect of temperature and pressure, with both the temperature and pressure increasing, the pores and fractures in the oil shale specimens developed increasingly. Furthermore, using the μCT scan technology, the distribution laws and the connectivity characteristics of the pores and fractures have been investigated. The connected fractures appear when the temperature reaches 300 °C and further extend along the bedding plane or pass through it at 600 °C.Gentry, D.M., Amador, E.S., Cable, M.L., Chaudry, N., Cullen, T., Jacobsen, M.B., Murukesan, G., Schwieterman, E.W., Stevens, A.H., Stockton, A., Tan, G., Yin, C., Cullen, D.C., Geppert, W., 2017. Correlations between life-detection techniques and implications for sampling site selection in planetary analog missions. Astrobiology 17, 1009-1021. conducted an analog sampling expedition under simulated mission constraints to areas dominated by basaltic tephra of the Eldfell and Fimmv?r?uháls lava fields (Iceland). Sites were selected to be “homogeneous” at a coarse remote sensing resolution (10–100?m) in apparent color, morphology, moisture, and grain size, with best-effort realism in numbers of locations and replicates. Three different biomarker assays (counting of nucleic-acid-stained cells via fluorescent microscopy, a luciferin/luciferase assay for adenosine triphosphate, and quantitative polymerase chain reaction (qPCR) to detect DNA associated with bacteria, archaea, and fungi) were characterized at four nested spatial scales (1?m, 10?m, 100?m, and >1?km) by using five common metrics for sample site representativeness (sample mean variance, group F tests, pairwise t tests, and the distribution-free rank sum H and u tests). Correlations between all assays were characterized with Spearman's rank test. The bioluminescence assay showed the most variance across the sites, followed by qPCR for bacterial and archaeal DNA; these results could not be considered representative at the finest resolution tested (1?m). Cell concentration and fungal DNA also had significant local variation, but they were homogeneous over scales of >1?km. These results show that the selection of life detection assays and the number, distribution, and location of sampling sites in a low biomass environment with limited a priori characterization can yield both contrasting and complementary results, and that their interdependence must be given due consideration to maximize science return in future biomarker sampling expeditions.Gerami, A., Armstrong, R.T., Johnston, B., Warkiani, M.E., Mosavat, N., Mostaghimi, P., 2017. Coal-on-a-chip: Visualizing flow in coal fractures. Energy & Fuels 31, 10393-10403. microfluidics are the next generation of tools necessary for studying fluid flows related to subsurface engineering technologies. Traditional microfluidic devices do not capture surface wettability and roughness parameters that can have a significant influence on porous media flows. This is particularly important for coal seam gas reservoirs in which methane gas is transported through a well-developed system of natural fractures that display unique wettability and roughness characteristics. A coal geomaterial microfluidic device can be generated by etching a fracture pattern on a coal surface by using three-dimensional laser micromachining; however, it is unclear if the resulting surface properties are representative of real coal. In an effort to generate a realistic coal microfluidic device, we characterize coal surface roughness properties from real coal cleats. We then compare these results to the roughness of the patterns, generated from laser etching. Roughness measurements in real coal fractures show that cleats and microfractures are mostly oriented parallel to the coal beddings rather than perpendicular to the bedding, which is important when selecting coal for fabrication of a microfluidic device since we find that the natural microfractures influence the resulting roughness of etched fractures. We also compare resulting coal/brine/gas contact angles under static and dynamics conditions. The contact angle for coal is highly heterogeneous. Surface roughness and pore pressure may influence the contact angle. With the aid of the coal geomaterial device, the effect of these parameters on coal wettability can be explored and a range of possible coal contact angles can be visualized and represented. The geomaterial fabrication, as outlined herein, provides a tool to capture more realistic coal surface properties in microfluidics experiments.Gibbons, A., 2017. Neandertal genome reveals greater legacy in the living. Science 358, 21. insult “You're a Neandertal!” has taken on dramatic new meaning in the past few years, as researchers have begun to identify the genes many of us inherited from our long-extinct relatives. By sequencing a remarkably complete genome from a 50,000-year-old bone fragment of a female Neandertal found in Vindija Cave in Croatia, researchers report online in Science this week a new trove of gene variants that living people outside of Africa obtained from Neandertals. Some of this DNA could influence cholesterol levels, the accumulation of belly fat, and the risk of schizophrenia and other diseases.The genome is only the second from a Neandertal sequenced to such high quality that it can reliably reveal when, where, and what DNA was passed from Neandertals to modern humans—and which diseases it may be causing or preventing today. “It's really exciting because it's more than two times better to have two Neandertal genomes,” says evolutionary genomicist Tony Capra of Vanderbilt University in Nashville.The first Neandertal genome was a composite drawn from three individuals from Vindija Cave (Science, 7 May 2010, p. 680). Then, over the past few years, ancient DNA researchers sequenced two more Neandertal genomes, including another high-quality sequence from an individual that lived 122,000 years ago in the Altai Mountains of Siberia. Together, the genomes showed that living Europeans and Asians carry traces of DNA from Neandertals who mated with members of Homo sapiens soon after our species left Africa. (Most Africans lack Neandertal DNA as a result.)A key question has been: What does this archaic DNA do in living humans? Drawing largely on the Altai genome, researchers have published on about two dozen Neandertal gene variants that influence living humans' risk of allergies, depression, blood clots, skin lesions, immunological disorders, and other diseases (Science, 12 February 2016, p. 648).But the Vindija Neandertal lived closer than the Altai one to the time and place where Eurasians' ancestors mated with Neandertals—likely 50,000 to 60,000 years ago, perhaps in the Middle East. So its DNA promised better insight, especially with recently improved methods to extract and sequence ancient DNA (Science, 31 August 2012, p. 1028). Evolutionary geneticist Kay Prüfer of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and colleagues sequenced each base of the female's genome about 30 times on average. The team also used radiocarbon and genetic methods to date the bone.As expected, this Neandertal's genome is more closely related to today's Europeans and Asians than that of the Altai Neandertal. And Prüfer and his colleagues already have discovered 16 new Neandertal gene variants passed on to living humans. These include changes in genes already known to govern levels of cholesterol and vitamin D, and to influence the risk—for better or worse—of developing eating disorders, rheumatoid arthritis, and schizophrenia, as well as the response to antipsychotic drugs. Researchers will now more closely study how each Neandertal version tips the balance in living people.The new Vindija genome also allowed the researchers to better calculate how much Neandertal DNA different groups of humans outside of Africa have inherited. East Asians, with 2.3%–2.6% of Neandertal DNA, topped people from western Asia and Europe, who had 1.8%–2.4%. Prüfer and his colleagues confirmed that the ancestors of the 122,000-year-old Altai Neandertal had also interbred with H. sapiens in a much earlier encounter that took place more than 130,000 years ago.The Altai and Vindija genomes are remarkably similar and that limited genetic diversity suggests that Neandertals lived in small, isolated populations of about 3000 individuals of reproductive age, Prüfer says. “This speaks to debates about why they went extinct,” Capra says. “They probably were less robust in their response to disease, starvation, and changes in climate.”Gibbons, A., 2017. Neandertals gave ‘lost’ African DNA back to moderns. Science 358, 431. Neandertals mated with modern humans, they shared more than an intimate moment and their own DNA. They also gave back thousands of ancient African gene variants that Eurasians had lost when their ancestors swept out of Africa in small bands, perhaps 60,000 to 80,000 years ago. Restored to their lineage, this diversity may have been a genetic gift to Eurasian ancestors as they spread around the world. Today, however, some of these ancient variants are a burden: They seem to boost the risk of becoming addicted to nicotine and having wider waistlines.In talks last week at the annual meeting of The American Society of Human Genetics here, researchers announced that some “Neandertal” genetic variants inherited by modern humans outside of Africa are not peculiarly Neandertal genes, but represent the ancestral human condition. The work highlights just how much diversity was lost when people passed through a genetic bottleneck as they moved out of Africa.“They left many beneficial variants behind in Africa,” says evolutionary genomicist Tony Capra of Vanderbilt University in Nashville, who reported the results. “Interbreeding with Neandertals provided an opportunity to get back some of those variants, albeit with many potentially weakly deleterious Neandertal alleles as well.”His team found the ancient African variants when they scrutinized the genomes of more than 20,000 people in the 1000 Genomes Project and Vanderbilt's BioVU data bank of electronic health records. They soon noticed a strange pattern: Stretches of chromosomes inherited from Neandertals also carried ancient alleles, or mutations, found in all the Africans they studied, including the Yoruba, Esan, and Mende peoples. The researchers found 47,261 of these single-base changes across the genomes of Europeans and 56,497 in Asians, Capra says. In Eurasians these alleles are only found next to Neandertal genes, suggesting all this DNA was acquired at the same time, when the ancestors of today's Eurasians mated with Neandertals roughly 50,000 years ago.The most parsimonious explanation is that these alleles represent the ancestral human condition, inherited by both Neandertals and modern humans in Africa from their common ancestor, Capra says. When people migrated out of Africa, their small numbers resulted in a bottleneck, in which they lost many alleles that remained in larger populations in Africa. Later, the Neandertals reintroduced these alleles—along with distinct Neandertal genes—to the ancestors of Eurasians, Capra says. Some of these ancient alleles were beneficial, such as one that boosted immune responses.But today's humans might prefer to shed others. So far, Capra's team has found three functional variants, which are associated with addiction to nicotine, a wider waistline, and skin pigmentation.The data are “very compelling that Neandertals bring back some of the lost ancestral variance,” of modern humans, said geneticist Mait Metspalu of the Estonian Biocentre in Tartu, who heard the talks.Geneticists at the meeting also zeroed in on archaic DNA “deserts,” where living humans have inherited no DNA from Neandertals or other archaic humans. One of these regions includes the site of the FOXP2 “language” gene. The absence of archaic DNA suggests that in our ancestors, natural selection flushed out the Neandertal version of this gene.Using software that evaluates gene expression, Vanderbilt graduate student Laura Colbran found that Neandertal versions of FOXP2 would have pumped out much less of its protein than is expressed in modern brains. A rare mutation that causes members of a family to produce half the usual amount of FOXP2 protein also triggered severe speech defects, notes Simon Fisher, director of the Max Planck Institute for Psycholinguistics in Nijmegen, the Netherlands, who discovered the gene. Boosting FOXP2 expression may have been key to modern human language, he says.Giraldo Gómez, V.M., Beik, I., Podlaha, O.G., Mutterlose, J., 2017. The micropaleontological record of marine early Eocene oil shales from Jordan. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 723-739. OS-28 located in central Jordan offers an expanded record of calcareous nannofossils and benthic foraminifera for the early Eocene of the southern Tethys. The oil shale succession of the studied interval covers calcareous nannofossil biozones NP10, NP11, NP12 and NP13. Microfossils document the biotic response of calcareous nannofossils and benthic foraminifera to short and long term warming trends of the early Eocene following the Paleocene-Eocene Thermal Maximum (PETM). On a global scale, two early Eocene short term shifts to higher atmospheric CO2 concentration are recorded by negative δ13C excursions. These are known as Eocene Thermal Maximum 2 and 3 (ETM2, ETM3). Stable isotope records (δ13Corg, δ13Ccarb, δ18Ocarb) from the study area do not show these negative excursions, which elsewhere can be correlated with the two hyperthermal events known from early Eocene successions. The absence of negative δ13C signals otherwise typical for ETM2 and ETM3 is explained by a diagenetic alteration of the isotope signal after deposition.High abundances of the nannofossil taxon Sphenolithus spp. in biozone NP10 indicate less fertile conditions for this interval than for the overlying biozone NP11. Throughout biozones NP11 to NP13 Coccolithus pelagicus and Toweius spp. are the dominant taxa of the assemblages, suggesting a mesotrophic environment. Surface waters experienced a temperature change from warm to moderate-warm. The benthic foraminifera in calcareous nannofossils biozone NP10 and in the lower part of NP11 reflect oligo-mesotrophic and moderate to well oxygenated bottom water conditions. Throughout the upper part of biozones NP11, NP12 and NP13, the benthic foraminifera are characterized by an increasing abundance of Anomalinoides zitteli, Lenticulina spp. and Valvulineria scrobiculata. This coincides with enriched total organic matter content (TOC), indicating a shift to mesotrophic conditions and a moderate oxygen supply of the bottom waters. Based on the micropaleontological observations made in core OS-28 the early Eocene is first characterized by an increase and subsequently by a decrease of nutrients and oxygen. The composition of both, benthic and planktic communities was rather controlled by variations of regional environmental parameters than by global ones. These include strong runoff, climatic variability and the architecture of the basin.Gold, D.A., O'Reilly, S.S., Watson, J., Degnan, B.M., Degnan, S.M., Kr?mer, J.O., Summons, R.E., 2017. Lipidomics of the sea sponge Amphimedon queenslandica and implication for biomarker geochemistry. Geobiology 15, 836-843. are a rich natural source of unusual lipids, some of which are of interest as geochemical biomarkers. Although demosponges are animals, they often host dense communities of microbial symbionts, and it is therefore unclear which lipids can be synthesized by the animal de novo, and which require input from the microbial community. To address this uncertainty, we analyzed the lipids of Amphimdeon queenslandica, the only demosponge with a published genome. We correlated the genetic and lipid repertoires of A. queenslandica to identify which biomarkers could potentially be synthesized and/or modified by the sponge. The fatty acid profile of A. queenslandica is dominated by an unusual Δ5,9 fatty acid (cis-5,9-hexacosadienoic acid)—similar to what has been found in other members of the Amphimdeon genus—while the sterol profile is dominated by C27-C29 derivatives of cholesterol. Based on our analysis of the A. queenslandica genome, we predict that this sponge can synthesize sterols de novo, but it lacks critical genes necessary to synthesize basic saturated and unsaturated fatty acids. However, it does appear to have the genes necessary to modify simpler products into a more complex “algal-like” assemblage of unsaturated fatty acids. Ultimately, our results provide additional support for the poriferan affinity of 24-isopropylcholestanes in Neoproterozoic-age rocks (the “sponge biomarker” hypothesis) and suggest that some algal proxies in the geochemical record could also have animal contributions.Gonsior, M., Luek, J., Schmitt-Kopplin, P., Grebmeier, J.M., Cooper, L.W., 2017. Optical properties and molecular diversity of dissolved organic matter in the Bering Strait and Chukchi Sea. Deep Sea Research Part II: Topical Studies in Oceanography 144, 104-111. in the molecular composition of dissolved organic matter (DOM) and its light absorbing chromophoric component (CDOM) are of particular interest in the Arctic region because of climate change effects that lead to warmer sea surface temperatures and longer exposure to sunlight. We used continuous UV-Visible (UV-Vis) spectroscopy, excitation emission matrix fluorescence and ultrahigh resolution mass spectrometry during a transect from the Aleutian Islands in the Bering Sea to the Chukchi Sea ice edge through Bering Strait to determine the variability of DOM and CDOM. These data were combined with discrete sampling for stable oxygen isotopes of seawater, in order to evaluate the contributions of melted sea ice versus runoff to the DOM and CDOM components. This study demonstrated that high geographical resolution of optical properties in conjunction with stable oxygen ratios and non-targeted ultrahigh resolution mass spectrometry was able to distinguish between different DOM sources in the Arctic, including identification of labile DOM sources in Bering Strait associated with high algal blooms and sampling locations influenced by terrestrially-derived DOM, such as the terrestrial DOM signal originating from Arctic rivers and dirty/anchor sea ice. Results of this study also revealed the overall variability and chemodiversity of Arctic DOM present in the Bering and Chukchi Seas.Gray, D.D., Zonneveld, K.A.F., Versteegh, G.J.M., 2017. Species-specific sensitivity of dinoflagellate cysts to aerobic degradation: A five-year natural exposure experiment. Review of Palaeobotany and Palynology 247, 175-187. sedimentary dinoflagellate cyst associations undergo species-selective degradation under oxic conditions. However, there is little known about the temporal relationship between oxygen concentration and bulk dinocyst degradation rate over the time scale of several years, and if this degradation is mainly microbial or chemical. Whilst the overall sensitivity of heterotrophic dinoflagellate cysts is well documented, sensitivity differences within this group have not been studied. Here we examine the rates of cyst degradation of heterotrophic species over short temporal scales across an anoxic–oxic gradient. Sediment with a known dinoflagellate cyst association largely dominated by heterotrophic dinoflagellates, were connected to trap arrays at two different locations, Cap Blanc (NW Africa) and Gotland Basin (central Baltic Sea) and exposed to four different ambient oxygen concentrations representing a complete oxic gradient from 5.1 mL/L to sulphate bearing anoxic waters. Two treatments of either gauze or dialyse membrane in triplicate were established to investigate the effects of chemical or bacterial degradation. Cyst loss was significant at oxic settings, rapidly occurring within the first year of exposure (32%) whereas no significant degradation was observed for suboxic and anoxic exposures. Compiling the degradation rates of individual species under the different exposure settings reveals an overall species sensitivity ranking amongst cysts of heterotrophic species. Species of average resistance: Bitectatodinium spongium, Brigantedinium spp., Echinidinium spp., Echinidinium aculeatum, and Gymnodinium trapeziforme. Species more resistant than average: Stelladinium robustum and Trinovantedinium applanatum. We observe that oxic degradation of cysts of heterotrophic dinoflagellates is fast and selective with maximal cyst association changes during the first year of oxic exposure. These aspects have to be taken into account in palaeoenvironmental and palaeoceanographic reconstructions where bottom/pore water conditions of the upper sediments are oxygenated.Grieman, M.M., Aydin, M., Isaksson, E., Schwikowski, M., Saltzman, E.S., 2017. Methoxy aromatic acids in an Arctic ice core from Svalbard: a proxy record of biomass burning. Climate of the Past Discussions 2017, 1-24. study presents vanillic acid and para-hydroxybenzoic acid levels in an Arctic ice core from Lomonosovfonna, Svalbard covering the past 800 years. These methoxy aromatic acids are likely derived from lignin combustion in wildfires and long-range aerosol transport. Vanillic and para-hydroxybenzoic acid are present throughout the ice core, confirming that these compounds are preserved on millennial time scales. Vanillic and para-hydroxybenzoic acid concentrations in the Lomonosovfonna ice core ranged from below the limits of detection to 0.2 and 0.07?ppb, respectively (1?ppb?=?1000?ng/l). Vanillic acid levels are high (below the limit of detection to 0.1?ppb) from 1200–1400 CE, then gradually decline into the 20th century. The largest peak in the vanillic acid in the record occurs from 2000–2008 CE. In the para-hydrobenzoic acid record, there are three centennial-scale peaks around 1300, 1550, and 1650 CE superimposed on a long-term decline in the baseline levels throughout the record. Air mass back trajectory analysis indicates that Siberia and Europe are the primary source regions for wildfire emissions reaching the Lomonosovfonna site. The Lomonosovfonna data are similar to those from the Eurasian Arctic Akademii Nauk ice core during the early part of the record (1220–1400 CE), but the two ice cores diverge markedly after 1400 CE. This coincides with a shift in North Atlantic climate marked by a change of the North Atlantic Oscillation from a positive to a more negative state.Grillenzoni, C., Monegatti, P., Turco, E., Conti, S., Fioroni, C., Fontana, D., Salocchi, A.C., 2017. Paleoenvironmental evolution in a high-stressed cold-seep system (Vicchio Marls, Miocene, northern Apennines, Italy). Palaeogeography, Palaeoclimatology, Palaeoecology 487, 37-50. exposures of Miocene seep-carbonates enclosed in marine marly sediments (Vicchio outcrops in the northern Apennines, Italy) offer the opportunity to highlight the evolution of a fossil seep ecosystem and the response of benthic communities to high-stressed environmental conditions. For this purpose, seep-related facies and molluscs within carbonate bodies have been studied, coupled with benthic foraminiferal assemblages and carbon and oxygen isotopes in the enclosing marls. The integrated planktonic foraminiferal and calcareous nannofossil biostratigraphy has allowed us to constrain the seepage within well-calibrated bioevents and to stress the relationships with paleoclimatic and paleoceanographic variations during the middle Miocene in the Mediterranean area. Our biostratigraphic data indicate that the onset of the seepage approximates the Mi3b cooling event (13.82 Ma) and the seepage system lasts for 400 kyr. The evolution of the Vicchio cold-seep system passes through four phases: (1) The onset of the seepage, characterized by a pervasive flow of methane-rich fluids, is inferred by δ13C depletion of marly sediments and by prevailing benthic foraminifera indicative of suboxic conditions at the sea-floor. (2) The methane flow becomes focused causing the precipitation of wide pinnacle-like carbonate bodies which contain giants lucinids. Enclosing marls indicate well-oxygenated conditions, possibly enhanced by paleoceanographic variations connected to the Mi3b cooling event. (3) The appearance of the vesicomyid Christineconcha cf. C. regab and the absence of lucinids in seep-carbonates suggest stable methane-rich fluid emissions; higher flow rates locally favoured the flourishment of bacterial mats. Benthic foraminifera show abundance peaks of organic matter depending taxa. (4) The reduced intensity of methane-rich fluid flows favours the precipitation of stratiform carbonate bodies along strike; the macrofauna is characterized by the presence of both Vesicomyidae and giant lucinids. Foraminiferal assemblages in the enclosing marls indicate the restoration of well-oxygenated conditions.Gross, J.H., 2017. Mass Spectrometry, 3rd Edition. Springer. 968 pp. third edition of the highly successful textbook, acclaimed for its comprehensiveness, accuracy, and excellent illustrations and photographs now comes with updated coverage plus numerous didactical improvements:·The number of figures has notably increased, with about one third of them now presented in color. More photographs and schematics make it easier to understand and provide valuable insights into the practical aspects of instrumentation and procedures.·Flow charts describe procedures and approaches to mass spectral interpretation and aid in decision making.·Bulleted enumerations offer a quick overview wherever several features, arguments, assumptions, or properties of a subject call for clear presentation.·Examples and notes now come with a short subheading that immediately conveys what this section is about. More examples, especially of methods and applications are given and some how-to-style paragraphs provide practical guidance.·Each chapter ends with a concise summary that is subdivided into compact sections highlighting the basics of the subject, its figures of merit, typical applications, and its role in current mass spectromety. In the case of instrumentation (chapter 4), there are even summaries covering mass analyzers type by type.·Digital object identifiers (DOIs) are now included to facilitate retrieval of references.·All of this is presented in a new, attractive layout.·The book’s website provides exercises and supplementary material (ms-).Gu, Z., Liu, Y., Xu, B., Wang, N., Jiao, N., Shen, L., Liu, H., Zhou, Y., Liu, X., Li, J., Sun, J., 2017. Hymenobacter frigidus sp. nov., isolated from a glacier ice core. International Journal of Systematic and Evolutionary Microbiology 67, 4121-4125. psychrophilic, Gram-stain-negative, rod-shaped, red-pigmented bacterium, designated strain B1789T, was isolated from an ice core of Muztagh Glacier on the Tibetan Plateau in China. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain B1789T was related to members of the genus Hymenobacter and had highest sequence similarity with Hymenobacter antarcticus JCM 17217T (97.9?%). The major menaquinone was MK-7 and the major polar lipid was phosphatidylethanolamine. The predominant fatty acids were iso-C15?:?0, anteiso-C15?:?0 and summed feature 3 (C16?:?1ω7c and/or C16?:?1ω6c). The DNA G+C content was 59.4?mol%. In DNA–DNA hybridization tests, strain B1789T shared 42?% relatedness with H. antarcticus JCM 17217T. Based on the results of phenotypic and chemotaxonomic tests, strain B1789T was considered as representing a novel species of the genus Hymenobacter , for which the name Hymenobacter frigidus sp. nov. is proposed. The type strain is B1789T (=JCM 30595T=CGMCC 1.14966T). The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain B1789T is KJ755878.Gueriau, P., Rueff, J.-P., Bernard, S., Kaddissy, J.A., Goler, S., Sahle, C.J., Sokaras, D., Wogelius, R.A., Manning, P.L., Bergmann, U., Bertrand, L., 2017. Noninvasive synchrotron-based X-ray Raman scattering discriminates carbonaceous compounds in ancient and historical materials. Analytical Chemistry 89, 10819-10826. compounds are ubiquitous and occur in a diversity of chemical forms in many systems including ancient and historic materials ranging from cultural heritage to paleontology. Determining their speciation cannot only provide unique information on their origin but may also elucidate degradation processes. Synchrotron-based X-ray absorption near-edge structure (XANES) spectroscopy at the carbon K-edge (280–350 eV) is a very powerful method to probe carbon speciation. However, the short penetration depth of soft X-rays imposes stringent constraints on sample type, preparation, and analytical environment. A hard X-ray probe such as X-ray Raman scattering (XRS) can overcome many of these difficulties. Here we report the use of XRS at ～6 keV incident energy to collect carbon K-edge XANES data and probe the speciation of organic carbon in several specimens relevant to cultural heritage and natural history. This methodology enables the measurement to be done in a nondestructive way, in air, and provides information that is not compromised by surface contamination by ensuring that the dominant signal contribution is from the bulk of the probed material. Using the backscattering geometry at large photon momentum transfer maximizes the XRS signal at the given X-ray energy and enhances nondipole contributions compared to conventional XANES, thereby augmenting the speciation sensitivity. The capabilities and limitations of the technique are discussed. We show that despite its small cross section, for a range of systems the XRS method can provide satisfactory signals at realistic experimental conditions. XRS constitutes a powerful complement to FT-IR, Raman, and conventional XANES spectroscopy, overcoming some of the limitations of these techniques.Guida, B.S., Bose, M., Garcia-Pichel, F., 2017. Carbon fixation from mineral carbonates. Nature Communications 8, 1025. assimilate oxidized carbon obtained from one of two sources: dissolved or atmospheric. Despite its size, the pool of lithospheric carbonate is not known to be a direct source for autotrophy. Yet, the mechanism that euendolithic cyanobacteria use to excavate solid carbonates suggests that minerals could directly supply CO2 for autotrophy. Here, we use stable isotopes and NanoSIMS to show that the cyanobacterium Mastigocoleus testarum derives most of its carbon from the mineral it excavates, growing preferentially as an endolith when lacking dissolved CO2. Furthermore, natural endolithic communities from intertidal marine carbonate outcrops present carbon isotopic signatures consistent with mineral-sourced autotrophy. These data demonstrate a direct geomicrobial link between mineral carbonate pools and reduced organic carbon, which, given the geographical extent of carbonate outcrops, is likely of global relevance. The ancient fossil record of euendolithic cyanobacteria suggests that biological fixation of solid carbonate could have been relevant since the mid-Proterozoic.Guo, H., Fu, C., Bai, Y., Ma, J., Su, X., 2017. Influence of biogenic gas production on coalbed methane recovery index. Natural Gas Industry B 4, 197-202. investigating the effect of biogenic gas production on the recovery of coalbed methane (CBM), coal samples spanning different ranks were applied in the microbial-functioned simulation experiments for biogenic methane production. Based on the biogenic methane yield, testing of pore structures, and the isothermal adsorption data of coals used before and after the simulation experiments, several key parameters related to the recovery of CBM, including recovery rate, gas saturation and ratio of critical desorption pressure to reservoir pressure, etc., were calculated and the corresponding variations were further analyzed. The results show that one of the significant functions of microbial communities on coal is possibly to weaken its affinity for methane gas, especially with the advance of coal ranks; and that by enhancing the pore system of coal, which can be evidenced by the increase of porosity and permeability, the samples collected from Qianqiu (Yima in Henan) and Shaqu (Liulin in Shanxi) coal mines all see a notable increase in the critical desorption pressure, gas saturation and recovery rate, as compared to the moderate changes of that of Guandi (Xishan in Shanxi) coal sample. It is concluded that the significance of enhanced biogenic gas is not only in the increase of CBM resources and the improvement of CBM recoverability, but in serving as an engineering reference for domestic coalbed biogenic gas production.Guo, K., Hansen, V.F., Li, H., Yu, Z., 2018. Monodispersed nickel and cobalt nanoparticles in desulfurization of thiophene for in-situ upgrading of heavy crude oil. Fuel 211, 697-703. nickel (Ni) and cobalt (Co) nanoparticles (NPs) with different sizes are synthesized via the thermal decomposition of organometallic precursors by controlling the reaction temperature and surfactant amount. X-ray diffraction analysis of the as-prepared NP samples shows the formation of cubic Ni metal phases with good crystallinity, while the cubic Co metal samples are semi-amorphous. Transmission electron microscopy characterization further confirms that two Ni NP samples with average sizes of 9 and 27 nm, and Co NPs with an average size of 6 nm are successfully prepared with a narrow size distribution. Furthermore, catalytic performance of these monodispersed NPs towards the hydrodesulfurization (HDS) reaction, which plays a pivotal role in the upgrading of heavy crude oil, is evaluated under reservoir-relevant conditions using thiophene as a sulfur-containing model compound. Different parameters including particle size, catalyst dosage, hydrogen donor ratio, temperature, and reaction duration are systematically studied to optimize the catalytic HDS performance. The morphology and size of the spent NP catalysts after the reaction are also analyzed. The results show that the 9 nm Ni NPs exhibit the best HDS activity and stability compared with other catalysts, which suggests that such well-dispersed Ni NPs are promising candidates for the in-situ upgrading and recovery of heavy crude oil from underground reservoirs.Guo, T., Li, Y., Ding, Y., Qu, Z., Gai, N., Rui, Z., 2017. Evaluation of acid fracturing treatments in shale formation. Energy & Fuels 31, 10479-10489. fracturing by stimulated reservoir volume (SRV) is a necessity to realize commercial development of shale gas, and its stimulation mechanism still needs further study, and the effectiveness of supplementary stimulation measures needs further exploration. The shale always contains some carbonate minerals. This paper tests the permeability of acid-etched fracture in shale to explore the influence of carbonate mineral content, acid fluid types and concentration, fracture plane roughness, proppant, and confining pressure on the acid-etched effects in shale, and uses CT scanning to conduct research on variation of microscopic pore-throat texture in shale before and after acid-etching. The test shows that the roughness of the fracture plane perpendicular to the bedding plane is higher than the roughness of that paralleled to the bedding plane, and the roughness in both fracture planes perpendicular to and paralleled to the bedding plane increases as the carbonate minerals content increases. In same group of shale samples, the permeability of self-propped fracture before and after acid-etching respectively is positively correlated with the fractal dimension of the fracture plane before and after acid-etching, and the variation of permeability of self-propped fracture before and after acid-etching is also positively correlated with the variation of fractal dimension of fracture plane before and after acid-etching, which is not shown in different groups of shale samples. When the content of carbonate minerals in shale is between 10% and 30%, the relation between optimum HCL concentration and carbonate mineral content is expressed as Y(OptimumHCLconcentration) = ?0.5X(Carbonatemineralcontent) + 0.15. If the shale has a high carbonate mineral content (>30%), the effect of acid-etching is not easily controlled, so the technique of acid fracturing should be carried out cautiously. The permeability of single-layer proppant and self-propped fracture after acid-etching conforms to Walsh theory within certain pressure, and variation and migration of curve slope reflects unstable arrangement, imbedding, and crush of proppant, and nonreactive filled impurity of clay and quartz desquamated and migrated, which coincides well with constant variation of permeability. Applying proper acid fluids and optimum concentration in shale with varying carbonate contents will increase pore size, fracture width, and fracture number. For the shale with abundant calcite-cemented fractures, the optimum acid fluid concentration should be increased properly. Due to ultralow permeability of the matrix in shale, even high concentration acid fluid could not penetrate the core with barren natural fractures or calcium-filled fractures. The results of research provide valuable information for design of acid fracturing in shale play.Guo, X.-p., Niu, Z.-s., Lu, D.-p., Feng, J.-n., Chen, Y.-r., Tou, F.-y., Liu, M., Yang, Y., 2017. Bacterial community structure in the intertidal biofilm along the Yangtze Estuary, China. Marine Pollution Bulletin 124, 314-320. this study, the 16S rRNA-based Illumina MiSeq sequencing was used to investigate the bacterial community structure and composition of intertidal biofilm taken along the Yangtze Estuary. The results showed that 680,721 valid sequences of seven samples were assigned to 147,239 operational taxonomic units, which belonged to 49 phyla, 246 family and 314 genera. Compared to other studies on water and sediments in the study area, biofilms showed highest index of bacterial diversity and abundances. At different taxonomic levels, both dominant taxa and their abundances varied among the seven samples, with Proteobacteria as the dominant phylum in general. Principal component analysis and cluster analysis revealed that bacterial communities at WSK differed from those at other sampling sites. Salinity, dissolved oxygen, pH and nutrients were the vital environmental factors to influence the bacterial community structure of biofilms. These results may provide a new insight into the microbial ecology in estuarine environments.Guzmán, H.J., Isquierdo, F., Carbognani, L., Vitale, G., Scott, C.E., Pereira-Almao, P., 2017. X-ray photoelectron spectroscopy analysis of hydrotreated Athabasca asphaltenes. Energy & Fuels 31, 10706-10717. asphaltenes from Athabasca crude oil were hydrotreated using a commercial NiW/Al2O3 catalyst and analyzed using X-ray photoelectron spectroscopy. Results showed that the catalyst performed better in the removal of sulfur rather than nitrogen and that sulfur concentration is higher at the surface in comparison to the bulk structure. Moreover, the sample after reaction had a higher oxygen content in comparison to the untreated asphaltene, indicating poor hydrodeoxygenation performance of the catalyst in addition to a higher reactivity toward atmospheric oxygen at the surface of the asphaltene. The latter is proposed to arise once the layer of resin covering the asphaltene is partially converted during the hydrotreating process.Haghi, R.K., Chapoy, A., Peirera, L.M.C., Yang, J., Tohidi, B., 2017. pH of CO2 saturated water and CO2 saturated brines: Experimental measurements and modelling. International Journal of Greenhouse Gas Control 66, 190-203. this work, both spectroscopic and electrometric methods were employed to measure the pH of water saturated with carbon dioxide at pressures up to 6 MPa, temperature ranges from 293.15 to 353.15 K and salinities up to 3 mol kg?1.Furthermore, a model was developed to predict the changes in the pH due to the solubility of CO2 in the aqueous phase at high pressure and high temperature conditions as well as the effect of NaCl. The pH model was developed by coupling the Cubic-Plus-Association Equation of State (CPA EoS) and the Pitzer equations. The former was used to determine the solubility of acid gases in aqueous solutions while the latter was employed to calculate activity coefficients for each ion species. The predictive capability of the pH model was evaluated against the data gathered from the literature and data measured in this work. The model allowed a prediction of the pH with an overall average absolute deviation (AAD) to measured data of 0.03 and 0.06 pH units in the CO2-H2O system using electrometric and spectroscopic techniques, respectively, and between 0.04 and 0.10 pH units in the CO2-H2O-NaCl systems by employing the spectroscopic technique.Haghnegahdar, M.A., Schauble, E.A., Young, E.D., 2017. A model for 12CH2D2 and 13CH3D as complementary tracers for the budget of atmospheric CH4. Global Biogeochemical Cycles 31, 1387-1407. present a theoretical model to investigate the potential of 13CH3D and 12CH2D2, the doubly substituted mass-18 isotopologues of methane, as tools for tracking atmospheric methane sources and sinks. We use electronic structure methods to estimate kinetic isotope fractionations associated with the major sink reactions of methane in air (reactions with OH and Cl radicals) and combine literature data with reconnaissance measurements of the relative abundances of 13CH3D and 12CH2D2 to estimate the compositions of the largest atmospheric sources. This model atmospheric budget is investigated with a simplified box model in which we explore both steady state and dynamical (nonsteady state) conditions triggered by changes in emission or sink fluxes. The steady state model predicts that sink reactions will generate a marked (>100‰) clumped isotope excess in atmospheric Δ12CH2D2 relative to the net source composition. 12CH2D2 measurements may thus be useful for tracing both atmospheric source and sink fluxes. The effect of sinks on Δ13CH3D is much less pronounced, indicating that 13CH3D in air will give a more focused picture of the source composition.Hall, S.J., Huang, W., Hammel, K.E., 2017. An optical method for carbon dioxide isotopes and mole fractions in small gas samples: Tracing microbial respiration from soil, litter, and lignin. Rapid Communications in Mass Spectrometry 31, 1938-1946.: Carbon dioxide isotope (δ13C value) measurements enable quantification of the sources of soil microbial respiration, thus informing ecosystem C dynamics. Tunable diode lasers (TDLs) can precisely measure CO2 isotopes at low cost and high throughput, but are seldom used for small samples (≤5 mL). We developed a TDL method for CO2 mole fraction ([CO2]) and δ13C analysis of soil microcosms.Methods: Peaks in infrared absorbance following constant volume sample injection to a carrier were used to independently measure [12CO2] and [13CO2] for subsequent calculation of δ13C values. Using parallel soil incubations receiving differing C substrates, we partitioned respiration from three sources using mixing models: native soil organic matter (SOM), added litter, and synthetic lignin containing a 13C label at Cβ of the propyl side chain.Results: Once-daily TDL calibration enabled accurate quantification of δ13C values and [CO2] compared with isotope ratio mass spectrometry (IRMS), with long-term external precision of 0.17 and 0.31‰ for 5 and 1 mL samples, respectively, and linear response between 400 and 5000 μmol mol?1 CO2. Production of CO2 from native soil C, added litter, and lignin Cβ varied over four orders of magnitude. Multiple-pool first-order decay models fitted to data (R2 > 0.98) indicated substantially slower turnover for lignin Cβ (17 years) than for the dominant pool of litter (1.3 years) and primed soil C (3.9 years).Conclusions: Our TDL method provides a flexible, precise, and high-throughput (60 samples h?1) alternative to IRMS for small samples. This enables the use of C isotopes in increasingly sophisticated experiments to test biogeochemical controversies, such as the fate of lignins in soil.Hamilton, T.L., Welander, P.V., Albrecht, H.L., Fulton, J.M., Schaperdoth, I., Bird, L.R., Summons, R.E., Freeman, K.H., Macalady, J.L., 2017. Microbial communities and organic biomarkers in a Proterozoic-analog sinkhole. Geobiology 15, 784-797. Salt Spring (Sarasota County, FL, USA) is a sinkhole with groundwater vents at ~77 m depth. The entire water column experiences sulfidic (~50 μM) conditions seasonally, resulting in a system poised between oxic and sulfidic conditions. Red pinnacle mats occupy the sediment–water interface in the sunlit upper basin of the sinkhole, and yielded 16S rRNA gene clones affiliated with Cyanobacteria, Chlorobi, and sulfate-reducing clades of Deltaproteobacteria. Nine bacteriochlorophyll e homologues and isorenieratene indicate contributions from Chlorobi, and abundant chlorophyll a and pheophytin a are consistent with the presence of Cyanobacteria. The red pinnacle mat contains hopanoids, including 2-methyl structures that have been interpreted as biomarkers for Cyanobacteria. A single sequence of hpnP, the gene required for methylation of hopanoids at the C-2 position, was recovered in both DNA and cDNA libraries from the red pinnacle mat. The hpnP sequence was most closely related to cyanobacterial hpnP sequences, implying that Cyanobacteria are a source of 2-methyl hopanoids present in the mat. The mats are capable of light-dependent primary productivity as evidenced by 13C-bicarbonate photoassimilation. We also observed 13C-bicarbonate photoassimilation in the presence of DCMU, an inhibitor of electron transfer to Photosystem II. Our results indicate that the mats carry out light-driven primary production in the absence of oxygen production—a mechanism that may have delayed the oxygenation of the Earth's oceans and atmosphere during the Proterozoic Eon. Furthermore, our observations of the production of 2-methyl hopanoids by Cyanobacteria under conditions of low oxygen and low light are consistent with the recovery of these structures from ancient black shales as well as their paucity in modern marine environments.Han, D., Wang, Z., Song, Y., Zhao, J., Wang, D., 2017. Numerical analysis of depressurization production of natural gas hydrate from different lithology oceanic reservoirs with isotropic and anisotropic permeability. Journal of Natural Gas Science and Engineering 46, 575-591. gas hydrate (NGH) is a promising alternative energy and mainly distributes in deep oceanic sediments. The intrinsic permeability of hydrate-bearing layers can potentially influence heat and pressure transfer during depressurization-induced NGH dissociation. By taking siltstone, sand and clay reservoirs in Shenhu area of South China Sea as examples, this study numerically investigates the effects of the magnitude and anisotropy of reservoir permeability on NGH production process and main physical field evolution. Results reveal that permeability anisotropy could impede advective interaction of fluids in vertical direction, significantly changing temperature and pressure evolution during NGH dissociation. Consequently, NGH dissociation slows down, delaying the coming of peak gas production rate. Some degrees of permeability anisotropy even lead to much earlier termination of NGH dissociation. In this case, the more permeable sand reservoir could possibly have a lower gas production potential than the less permeable siltstone and clay reservoirs. The permeable overburden limits the fluid pressure reduction and weakens the efforts of depressurization production. The re-production by further lowering well pressure only lasts for a short time. Comparatively, the depressurization of constant production mass rate is more effective but only provides a small contribution for the total gas yield.Han, J., Chen, B., Zhao, X., Zheng, C., Zhang, J., 2017. Development characteristics and influential factors of organic pores in the Permian shale in the Lower Yangtze Region. Natural Gas Industry 37, 17-26. of the important subjects for shale reservoir evaluation and research is to describe qualitatively and characterize quantitatively pore structures by using the high-resolution imaging technology. Two shale reservoirs of Permian Dalong and Gufeng Fms in the Lower Yangtze Region were taken in this study. Firstly, the structures of organic pores were systematically observed by using argon-ion polishing SEM technology. Then, a statistical analysis was conducted on the structural parameters of organic pores by using the ImageJ software based on the 3D reconstruction data. And finally, the main factors influencing the development of organic pores were discussed. It is indicated that the organic shale pores in this area can be divided into three types, i.e., organic matter intragranular pores, contraction joints on the edge of organic matter, and micro fissures inside organic matter; different organic matters vary greatly in pore structure parameters, such as pore diameter, pore quantity, plane porosity and organic matter porosity. Besides, different types of organic pores are formed in different stages as the thermal evolution of organic matter advances; in the process of hydrocarbon generation and evaluation of organic matter, organic matter intragranular pores are developed continuously and contraction joints on the edge of organic matter are formed gradually; and in the condition of high evolution, micro fissures are regionally generated inside organic matter (especially vitrinite). Finally, in this area, the development heterogeneity of organic pores in shale is internally controlled by TOC, Ro, organic macerals and clay mineral content, and externally by abnormal pressure.Han, W., Tao, S., Hou, L., Yao, J., 2017. Geochemical characteristics and genesis of oil-derived gas in the Jingbian gas field, Ordos Basin, China. Energy & Fuels 31, 10432-10441. source rocks of natural gas of the Jingbian gas field in Ordos Basin, China, are unclear, and the origin of oil-derived gas is controversial. On the basis of a series of experiments on source rock evaluation, including total organic carbon, Rock-Eval pyrolysis, carbon isotope composition of kerogen, chloroform bitumen A, maceral compositions, and gas chromatograms, we evaluated the hydrocarbon generation potential of the possible source rocks. We also conducted the components and stable carbon isotopes of natural gas and compared geochemical characteristics of natural gas and source rock-adsorbed gas. The results indicate that source rocks from the Lower Permian Taiyuan Formation have some hydrocarbon-generating capability but far less than its proximate Carboniferous and Permian coal measures. Oil-derived gas originated from Lower Permian Taiyuan Formation limestone was expulsed to the Majiagou Formation by coal-derived gas generated from the Carboniferous and Permian coal measures, as indicated by source rock evaluation, adsorbed gas, and geochemical characteristics of gas collected from the limestone-developed area. The former two gases mixed in the Majiagou Formation above the gypsum–salt bed, which corresponds to the geochemical characteristics of gas from the above gypsum–salt bed. Source rocks from the Majiagou Formation above the gypsum–salt bed experienced much more weathering, leaching, and oxidation compared to those under the gypsum–salt bed, suggesting that the latter are comparatively better than the former. As a result of the barrier of the gypsum–salt bed, source rocks of the Majiagou Formation under the gypsum–salt bed can generate a self-stored natural gas reservoir, as indicated by adsorbed gas and geochemical characteristics of gas from under the gypsum–salt bed. Natural gas of the Jingbian gas field is mainly from the Carboniferous and Permian coal measures, with limited oil-derived gas from the Taiyuan Formation.Handley, K.M., Piceno, Y.M., Hu, P., Tom, L.M., Mason, O.U., Andersen, G.L., Jansson, J.K., Gilbert, J.A., 2017. Metabolic and spatio-taxonomic response of uncultivated seafloor bacteria following the Deepwater Horizon oil spill. ISME Journal 11, 2569-2583. release of 700 million liters of oil into the Gulf of Mexico over a few months in 2010 produced dramatic changes in the microbial ecology of the water and sediment. Here, we reconstructed the genomes of 57 widespread uncultivated bacteria from post-spill deep-sea sediments, and recovered their gene expression pattern across the seafloor. These genomes comprised a common collection of bacteria that were enriched in heavily affected sediments around the wellhead. Although rare in distal sediments, some members were still detectable at sites up to 60 km away. Many of these genomes exhibited phylogenetic clustering indicative of common trait selection by the environment, and within half we identified 264 genes associated with hydrocarbon degradation. Alkane degradation ability was near ubiquitous among candidate hydrocarbon degraders, whereas just three harbored elaborate gene inventories for the degradation of alkanes and aromatic and polycyclic aromatic hydrocarbons (PAHs). Differential gene expression profiles revealed a spill-promoted microbial sulfur cycle alongside gene upregulation associated with PAH degradation. Gene expression associated with alkane degradation was widespread, although active alkane degrader identities changed along the pollution gradient. Analyses suggest that a broad metabolic capacity to respond to oil inputs exists across a large array of usually rare indigenous deep-sea bacteria.Hao, T., Liu, X., Ogg, J., Liang, Z., Xiang, R., Zhang, X., Zhang, D., Zhang, C., Liu, Q., Li, X., 2017. Intensified episodes of East Asian Winter Monsoon during the middle through late Holocene driven by North Atlantic cooling events: High-resolution lignin records from the South Yellow Sea, China. Earth and Planetary Science Letters 479, 144-155. varying intensity of the East Asian Winter Monsoon (EAWM) governs the strength of the counter-clockwise surface circulation of the South Yellow Sea and the redistribution of sediment and terrestrial organic material that had accumulated on the shallow shelf during the summer season into the central part of that basin. We compiled a time series spanning about 6.3 ka of terrestrial lignin proxies from sediment core N02 from Central Yellow Sea Mud that has well-preserved high-resolution sedimentary records (24 yr/cm average spacing). The “hydrodynamic sorting effect” driven by century-scale climate variation in the strength of the EAWM exerts the main underlying control on the variation of lignin proxies in marginal sea sediments, rather than paleovegetation variability in provenance region driven by the East Asian Summer Monsoon (EASM). Our lignin proxies data imply that North Atlantic climate forcing recorded by ice-rafted debris (“Bond cycles”) played a critical role in generating EAWM variability on these centennial timescales during the Holocene. These variations of lignin records are superimposed on general multi-thousand-year trends that appear to mirror the relative frequency and intensity of the El Ni?o Southern Oscillation (ENSO). Our results indicate that lignin can be adopted as an additional reliable proxy for paleoclimate evolution, at least in South Yellow Sea area.Harouaka, K., Kubicki, J.D., Fantle, M.S., 2017. Effect of amino acids on the precipitation kinetics and Ca isotopic composition of gypsum. Geochimica et Cosmochimica Acta 218, 343-364. gypsum (CaSO4 · 2H2O) precipitation experiments (initial Ωgypsum = 2.4 ± 0.14, duration ≈ 1.0–1.5 h) were conducted in the presence of the amino acids glycine (190 ?M), l-alanine (190 ?M), d- and l-arginine (45 ?M), and l-tyrosine (200 ?M) to investigate the effect of simple organic compounds on both the precipitation kinetics and Ca isotopic composition of gypsum. Relative to abiotic controls, glycine, tyrosine, and alanine inhibited precipitation rates by ～22%, 27%, and 29%, respectively, while l- and d-arginine accelerated crystal growth by ～8% and 48%, respectively. With the exception of tyrosine, amino acid induced inhibition resulted in fractionation factors (αs-f) associated with precipitation that were no more than 0.3‰ lower than amino acid-free controls. In contrast, the tyrosine and d- and l-arginine experiments had αs-f values associated with precipitation that were similar to the controls.Our experimental results indicate that Ca isotopic fractionation associated with gypsum precipitation is impacted by growth inhibition in the presence of amino acids. Specifically, we propose that the surface-specific binding of amino acids to gypsum can change the equilibrium fractionation factor of the bulk mineral. We investigate the hypothesis that amino acids can influence the growth of gypsum at specific crystal faces via adsorption and that different faces have distinct fractionation factors (αface-fluid). Accordingly, preferential sorption of amino acids at particular faces changes the relative, face-specific mass fluxes of Ca during growth, which influences the bulk isotopic composition of the mineral. Density functional theory (DFT) calculations suggest that the energetic favorability of glycine sorption onto gypsum crystal faces occurs in the order: (1 1 0) > (0 1 0) > (1 2 0) > (0 1 1), while glycine sorption onto the (?1 1 1) face was found to be energetically unfavorable. Face-specific fractionation factors constrained by frequency calculations of clusters derived from DFT structures vary by as much as 1.4‰. This suggests that the equilibrium fractionation factor for the bulk crystal can vary substantially, and that surface sorption can induce changes in αeq associated with gypsum precipitation. While we do not rule out the influence of kinetic isotope effects, our results clearly demonstrate that the mode of crystal growth can have a sizeable effect on the bulk fractionation factor (αs-f).Ultimately, our results suggest that the same mechanism by which organic molecules affect the morphology of a mineral can also impact the isotopic composition of the mineral. The results of our study provide valuable insight into the mechanism of Ca isotopic fractionation during gypsum precipitation. Our results are also important for establishing a framework for accurate interpretations of mineral-hosted Ca isotope records of the past, as we demonstrate a mechanistic pathway by which the biological and chemical environment can impact Ca isotopic fractionation during mineral precipitation.Harvey, H.R., Taylor, K.A., 2017. Alkane and polycyclic aromatic hydrocarbons in sediments and benthic invertebrates of the northern Chukchi Sea. Deep Sea Research Part II: Topical Studies in Oceanography 144, 52-62. Hanna Shoal region represents an important northern gateway for transport and deposition in the Chukchi Sea. This study determined the concentration and distribution of organic contaminants (aliphatic hydrocarbon and polycyclic aromatic hydrocarbons, PAHs) in surface sediments from 34 sites across Hanna Shoal. Up to 31 total PAHs, including parent and alkyl homologues were detected with total concentrations ranging from a low of 168 ng g-1 the western flank of Hanna Shoal (station H34) to 1147 ng g-1 at station in Barrow Canyon (station BarC5). Alkyl PAHs were more abundant than parent structures and accounted for 53–64% of the summed concentrations suggesting overall at background levels (< 1600 ng g-1) in sediments. Alkane (C15-C33) hydrocarbons ranged from 4.3 ?g g-1 on the southern flank of Hanna shoal to 31 ?g g-1 at a northern station. Sediments were often dominated by short chain (C15-C22) alkanes with overall terrestrial aquatic ratios (TAR) for the region averaging 0.20. Based on the ratio of Fl/ (Fl+ Py) and BaF/ (Baf+BeP) verses BA/BA+Ch) in sediments, PAHs are largely derived from petrogenic sources with minor amounts of mixed combustion sources. A diversity of PAHs were detected in the northern whelk Neptunea heros foot muscle with total concentrations ranging from 0.14–1.5 ?g/g dry tissue wt. Larger (and presumably older) animals showed higher levels of PAH per unit muscle tissue, suggesting that animals may bioaccumulate PAH's over time, with low but increasing concentrations also present in internal and external eggs. Alkane hydrocarbons were also higher in whelks with distributions similar to that seen in sediments. The mussel Muscularus discors collected in Barrow Canyon showed constrained distributions and substantially lower concentrations of both PAH's and alkanes than the surrounding surface sediments.Hasan, M.F., Vogt, F., 2017. Modeling the transformation of atmospheric CO2 into microalgal biomass. Analyst 142, 4089-4098. phytoplankton acts as a considerable sink of atmospheric CO2 as it sequesters large quantities of this greenhouse gas for biomass production. To assess microalgae's counterbalancing of global warming, the quantities of CO2 they fix need to be determined. For this task, it is mandatory to understand which environmental and physiological parameters govern this transformation from atmospheric CO2 to microalgal biomass. However, experimental analyses are challenging as it has been found that the chemical environment has a major impact on the physiological properties of the microalgae cells (diameter typ. 5–20 μm). Moreover, the cells can only chemically interact with their immediate vicinity and thus compound sequestration needs to be studied on a microscopic spatial scale. Due to these reasons, computer simulations are a more promising approach than the experimental studies. Modeling software has been developed that describes the dissolution of atmospheric CO2 into oceans followed by the formation of HCO3? which is then transported to individual microalgae cells. The second portion of this model describes the competition of different cell species for this HCO3?, a nutrient, as well as its uptake and utilization for cell production. Two microalgae species, i.e. Dunaliella salina and Nannochloropsis oculata, were cultured individually and in a competition situation under different atmospheric CO2 conditions. It is shown that this novel model's predictions of biomass production are in very good agreement with the experimental flow cytometry results. After model validation, it has been applied to long-term prediction of phytoplankton generation. These investigations were motivated by the question whether or not cell production slows down as cultures grow. This is of relevance as a reduced cell production rate means that the increase in a culture's CO2-sinking capacity slows down as well. One implication resulting from this is that an increase in anthropogenic CO2 may not be counterbalanced by an increase in phytoplankton production. Modeling studies have found that for several different atmospheric CO2 levels provided to single-species cultures as well as to species in competing scenarios the cell production rate does slow down over time.Havig, J.R., Hamilton, T.L., Bachan, A., Kump, L.R., 2017. Sulfur and carbon isotopic evidence for metabolic pathway evolution and a four-stepped Earth system progression across the Archean and Paleoproterozoic. Earth-Science Reviews 174, 1-21. Earth's mantle has provided a ready redox gradient of sulfur compounds (SO2, H2S) since the stabilization of the crust and formation of the ocean over 4 billion years ago, and life has evolved a multitude of metabolic pathways to take advantage of this gradient. These transitions are recorded in the sulfur and carbon isotope signals preserved in the rock record, in the genomic records of extant microorganisms, and in the changing mantle and crust structure, composition and cycling. Here, we have assembled approximately 20,000 sulfur (δ34S, Δ33S, Δ36S) and carbon (δ13C) isotope data points from scientific publications spanning over five decades of geochemical analyses on rocks deposited from 4.0 to 1.5 Ga. We place these data in the context of molecular clock and tectonic and surface redox indicators to identify overarching trends and integrate them into a holistic narrative on the transition of the Earth's surface towards more oxidizing conditions. The greatest extreme in δ34S values of sulfide minerals (? 45.5 to 54.9‰) and sulfate minerals (? 13.6 to 46.6‰) as well as δ13C values in carbonate minerals (? 16.8 to 29.6‰) occurred in the period following the Great Oxidation Event (GOE), while the greatest extremes in organic carbon δ13C values (? 60.9 to 2.4‰) and sulfide and sulfate mineral Δ33S and Δ36S values (? 4.0 to 14.3‰ and ? 12.3 to 3.2‰, respectively) occurred prior to the GOE. From our observations, we divide transitions in Earth's history into four periods: Period 1 (4.00 to 2.80 Ga) during which geochemical cycles were initialized, Period 2 (2.80 to 2.45 Ga) during which S and C isotope systems exhibit changes as conditions build up to the GOE, Period 3 (2.45 to 2.00 Ga) encompassing the GOE, and Period 4 (after 2.00 Ga) after which S and C isotopic systems remained relatively constant marking a time of Earth system geochemical quiescence. Using these periods, we link changes in S and C isotopes to molecular clock work to aid in interpreting emerging metabolic functions throughout Earth's history while underscoring the need for better proxies for robust evolutionary analyses. Specifically, results indicate: 1) an early development of sulfide oxidation and dissimilatory sulfite reduction followed by disproportionation and then sulfate reduction to sulfite resulting in a fully biologically mediated sulfur cycle by ~ 3.25 Ga; 2) support for the acetyl coenzyme-A pathway as the most likely earliest form of biologically mediated carbon fixation following methanogenesis; 3) an increasingly redox-stratified ocean in the Neoarchean with largely oxic surface water and euxinic bottom water during the first half of the Paleoproterozoic; and 4) that secular changes in Earth system crustal cycling dynamics and continent formation likely played a key role in driving the timing of the GOE. Finally, based on geochemical data, we suggest that the Paleoproterozoic be divided into a new Era of the Eoproterozoic (from 2.45 to 2.00 Ga) and the Paleoproterozoic (from 2.00 to 1.60 Ga).He, K., Gilder, S.A., Orsi, W.D., Zhao, X., Petersen, N., 2017. Constant flux of spatial niche partitioning through high-resolution sampling of magnetotactic bacteria. Applied and Environmental Microbiology 83, e01382-17.: Magnetotactic bacteria (MTB) swim along magnetic field lines in water. They are found in aquatic habitats throughout the world, yet knowledge of their spatial and temporal distribution remains limited. To help remedy this, we took MTB-bearing sediment from a natural pond, mixed the thoroughly homogenized sediment into two replicate aquaria, and then counted three dominant MTB morphotypes (coccus, spirillum, and rod-shaped MTB cells) at a high spatiotemporal sampling resolution: 36 discrete points in replicate aquaria were sampled every ～30 days over 198 days. Population centers of the MTB coccus and MTB spirillum morphotypes moved in continual flux, yet they consistently inhabited separate locations, displaying significant anticorrelation. Rod-shaped MTB were initially concentrated toward the northern end of the aquaria, but at the end of the experiment, they were most densely populated toward the south. The finding that the total number of MTB cells increased over time during the experiment argues that population reorganization arose from relative changes in cell division and death and not from migration. The maximum net growth rates were 10, 3, and 1 doublings day?1 and average net growth rates were 0.24, 0.11, and 0.02 doublings day?1 for MTB cocci, MTB spirilla, and rod-shaped MTB, respectively; minimum growth rates for all three morphotypes were ?0.03 doublings day?1. Our results suggest that MTB cocci and MTB spirilla occupy distinctly different niches: their horizontal positioning in sediment is anticorrelated and under constant flux. Importance: Little is known about the horizontal distribution of magnetotactic bacteria in sediment or how the distribution changes over time. We therefore measured three dominant magnetotactic bacterium morphotypes at 36 places in two replicate aquaria each month for 7 months. We found that the spatial positioning of population centers changed over time and that the two most abundant morphotypes (MTB cocci and MTB spirilla) occupied distinctly different niches in the aquaria. Maximum and average growth and death rates were quantified for each of the three morphotypes based on 72 sites that were measured six times. The findings provided novel insight into the differential behavior of noncultured magnetotactic bacteria. He, W., Shi, G.R., Xiao, Y., Zhang, K., Yang, T., Wu, H., Zhang, Y., Chen, B., Yue, M., Shen, J., Wang, Y., Yang, H., Wu, S., 2017. Body-size changes of latest Permian brachiopods in varied palaeogeographic settings in South China and implications for controls on animal miniaturization in a highly stressed marine ecosystem. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 33-45. on the dynamics of body-size changes in varied water depths can provide important insights into the evolution of palaeoenvironments through time. This paper attempts to investigate how the body sizes of two most commonly found chonetid brachiopod species in the uppermost Permian in South China varied with palaeo-bathymetry. The result shows that there is a broadly negative correlation between the latest Permian brachiopod body size and water depth. There is no simple singular variable that could explain this correlation because bathymetry is correlated, either linearly or nonlinearly, to food availability, redox condition and habitat temperature, as well as substrate conditions. Overall, we found that both oxygen and food availability played a more important role in controlling the differences of body sizes, and specifically several depressed factors (low food availability, anoxia, or abnormal temperature) have compounded and caused small body sizes in deeper waters during the latest Permian. We propose that the brachiopod miniaturization during the Permian-Triassic crisis in South China was collectively driven by anoxia, food restriction and high temperature.Hennell James, R., Caceres, E.F., Escasinas, A., Alhasan, H., Howard, J.A., Deery, M.J., Ettema, T.J.G., Robinson, N.P., 2017. Functional reconstruction of a eukaryotic-like E1/E2/(RING) E3 ubiquitylation cascade from an uncultured archaeon. Nature Communications 8, Article 1120. covalent modification of protein substrates by ubiquitin regulates a diverse range of critical biological functions. Although it has been established that ubiquitin-like modifiers evolved from prokaryotic sulphur transfer proteins it is less clear how complex eukaryotic ubiquitylation system arose and diversified from these prokaryotic antecedents. The discovery of ubiquitin, E1-like, E2-like and small-RING finger (srfp) protein components in the Aigarchaeota and the Asgard archaea superphyla has provided a substantive step toward addressing this evolutionary question. Encoded in operons, these components are likely representative of the progenitor apparatus that founded the modern eukaryotic ubiquitin modification systems. Here we report that these proteins from the archaeon Candidatus ‘Caldiarchaeum subterraneum’ operate together as a bona fide ubiquitin modification system, mediating a sequential ubiquitylation cascade reminiscent of the eukaryotic process. Our observations support the hypothesis that complex eukaryotic ubiquitylation signalling pathways have developed from compact systems originally inherited from an archaeal ancestor.Hernández-Rodríguez, A., Montegrossi, G., Huet, B., Vaselli, O., Virgili, G., 2017. A study of wellbore cement alteration controlled by CO2 leakage in a natural analogue for geological CO2 storage. Applied Geochemistry 86, 13-25. study presents the results obtained by studying well integrity in the natural analogue for the geological storage of CO2 of Sant’Albino, Southern Tuscany, which is affected by intense CO2 degassing and where a thermal spa and a CO2 production plant are present. Reaction Path Modeling (RPM) of cement hydration and carbonation as well as Reactive Transport Modeling (RTM) of cement alteration were used to investigate the processes occurring near a hypothetical average production well with a damaged leaking zone, affecting casing and cement, assuming a defined composition of class G Portland cement. It turns out that the advective flow of CO2 from the damaged zone, first, leads to completion of cement carbonation and, second, promotes further cement alteration through considerable dissolution of carbonate minerals. These processes takes place in a relatively short time, in the order of some years. The ultimate consequence of these CO2-promoted comparatively fast chemical reactions is most likely CO2 leakage to the surface.Hernes, P.J., Dyda, R.Y., McDowell, W.H., 2017. Connecting tropical river DOM and POM to the landscape with lignin. Geochimica et Cosmochimica Acta 219, 143-159. rivers account for two thirds of global fluxes of terrigenous organic matter to the oceans, yet because of their remote locations relative to most industrialized countries, they are poorly studied compared to temperate and even Arctic rivers. Further, most tropical river research has focused on large rivers like the Amazon or Congo, yet more than half of organic matter fluxes from tropical rivers comes from much smaller rivers. This study focuses on two such rivers in the Luquillo Experimental Forest of Puerto Rico, namely the Rio Mameyes and Rio Icacos, and uses time-series measurements of lignin biomarkers to put them in context with much bigger tropical rivers in the literature. Although lignin concentrations and carbon-normalized yields offer some distinction between mountainous vs. floodplain tropical river reaches, compositional differences appear to offer greater potential, including S:V vs. C:V plots that may capture the poorly-studied influence of palm trees, and (Ad:Al)s vs. (Ad:Al)v plots that may reflect differences in underlying mineralogy and degradation in soils. Even though dissolved and particulate lignin ultimately come from the same vegetation sources, comparison of dissolved and particulate lignin parameters within the two Puerto Rican rivers indicate that the pathways by which they end up in the same parcel of river water are largely decoupled. Across several particulate lignin studies in tropical rivers, mineral composition and concentration appears to exert a strong control on particulate lignin compositions and concentrations. Finally, the time-series nature of this study allows for new ways of analyzing dissolved lignin endmember compositions and degradation within the catchment. Plots of dissolved lignin parameters vs. lignin concentration reveal both the composition of “fresh” DOM that is likely mobilized from organic-rich soil surface layers along with the extent and trajectory of degradation of that signature that is possible within the lower mineral layers of the soil. Establishing connectivity between river chemistry and catchment sources and processes in this manner is the only way to realize the full potential of river chemistry as a diagnostic tool for changing sources and processes within the catchment.Herren, C.M., McMahon, K.D., 2017. Cohesion: a method for quantifying the connectivity of microbial communities. ISME Journal 11, 2426-2438. ability to predict microbial community dynamics lags behind the quantity of data available in these systems. Most predictive models use only environmental parameters, although a long history of ecological literature suggests that community complexity should also be an informative parameter. Thus, we hypothesize that incorporating information about a community’s complexity might improve predictive power in microbial models. Here, we present a new metric, called community ‘cohesion,’ that quantifies the degree of connectivity of a microbial community. We analyze six long-term (10+ years) microbial data sets using the cohesion metrics and validate our approach using data sets where absolute abundances of taxa are available. As a case study of our metrics’ utility, we show that community cohesion is a strong predictor of Bray–Curtis dissimilarity (R2=0.47) between phytoplankton communities in Lake Mendota, WI, USA. Our cohesion metrics outperform a model built using all available environmental data collected during a long-term sampling program. The result that cohesion corresponds strongly to Bray–Curtis dissimilarity is consistent across the six long-term time series, including five phytoplankton data sets and one bacterial 16S rRNA gene sequencing data set. We explain here the calculation of our cohesion metrics and their potential uses in microbial ecology.Hoffmann, J.E., 2017. Geochemistry: Oxygenation by a changing crust. Nature Geoscience 10, 713-714. minerals in Earth's early upper continental crust suppressed atmospheric oxygen levels until the upper crust became granitic.Atmospheric oxygen is vital for the development and habitability of complex life. Earth's atmosphere lacked oxygen for nearly half of the planet's history. Oxygen levels then rapidly increased about 2.3 to 2.4 billion years ago, during the Great Oxygenation Event (GOE)1, 2, 3, which initiated a stepwise rise in atmospheric oxygen concentrations1. The reason for this increase during the GOE is unclear. Writing in Nature Geoscience Smit and Mezger4 propose that a change in the bulk composition of the upper continental crust about one billion years before the GOE would have caused a decrease in oxygen-consuming reactions at Earth's surface, allowing oxygen to build up in the atmosphere.Most of Earth's atmospheric oxygen is produced via photosynthesis by plants (including phytoplankton) and cyanobacteria. The GOE is thus probably related to an increasing population of cyanobacteria. However, cyanobacteria are likely to have evolved much earlier than the GOE5, when they formed oxygen oases — small-scale oxidized environments. An earlier increase in atmospheric oxygen could have been mitigated by the composition of the oceans and continents1, 6, 7, 8: reducing agents such as reduced iron introduced by hydrothermal fluids into the Archaean oceans, as well as the more iron-rich mafic crust that characterized the younger Earth, may have reacted with any free oxygen, creating oxygen sinks that prevented its accumulation in the atmosphere. Only with a change in crustal composition could oxygen concentrate in the atmosphere. However, the precise nature of the sinks that hampered oxygenation of the atmosphere is ambiguous.Smit and Mezger4 compile a global database of clastic sediment chemical compositions that covers most of Earth's history. Using the ratio of the trace elements Cr and U (normalized to the modern average value for post-Archaean sediment derived from continental crust), they reconstruct changes in crustal mineral composition through time. Specifically, the researchers take advantage of the different partitioning behaviours of Cr and U in refractory detrital minerals — both elements are immobile unless oxidative weathering influences the solubility. During oxidative weathering, Cr combines with minerals such as chromites, while U combines with minerals such as zircon. However, zircon is largely absent in mafic and ultramafic crust, so the Cr/U ratio can be used as a fingerprint of the composition of the source area for the sediments. In line with past work6, 7, 8, the researchers observe a change in crustal composition about 3.3 to 2.4 billion years ago from a dominantly mafic–ultramafic upper continental crust that consisted mainly of minerals such as olivine and pyroxene, to a dominantly felsic upper crustal composition, comprising minerals such as quartz and feldspar.Based on their Cr/U database, Smit and Mezger propose that minerals within the mafic–ultramafic crust were hydrated during hydrothermal alteration, forming serpentine minerals. Serpentines are a class of minerals that incorporate OH groups into their crystal lattice and release H2 in oxygen-scavenging reactions4. These reactions transform the host rock into a serpentinite, which is found exposed in typical Archaean greenstone belts (Fig. 1). Since serpentinization triggers the production of reducing species4, surface waters in the presence of serpentinites would have been highly alkaline and could have influenced cyanobacterial habitats, acting as a sink for the bacteria-produced oxygen.The transition from a dominantly mafic to a more felsic crust was probably related to a changing style of global geodynamics, from a stagnant-lid tectonic regime towards the onset of plate tectonic processes similar to those active today9. With the onset of subduction, the upper mafic crust was eroded and recycled into the mantle, leaving the more evolved felsic crust from mid-crustal levels exposed at the surface of the continents. Removal of the mafic crust would reduce the amount of exposed serpentinites, minimizing serpentinization as an important sink for oxygen thereafter, and allowing oxygenation of the atmosphere.The model of serpentinization as a primary oxygen sink stands independent from previous suggestions that the higher abundance of reduced iron species available for oxygen reduction was responsible for the delay in the rise of atmospheric oxygen following the expansion in cynobacterial populations. Indeed, Smit and Mezger show that the Cr/U ratios are similar in a number of rock types with variable compositions, yet the same iron abundance, implying that iron content was not the primary control on free oxygen availability. The serpentinization model also leaves some freedom for compositional heterogeneities within late Archaean upper continental crust. The dilution of the influence of serpentinites on the chemistry of continental runoff by the end of the Archaean may have led to partial oxidation of the upper ocean water column4, while sub-seafloor serpentinization in the oceanic crust kept the lower water column anoxic beyond the Archaean1.Although serpentinization is certainly an important process in introducing reduced reagents into the environment before the GOE, it is not the only process. Other key sinks for extracting oxygen from the atmosphere include weathering of volcanic glasses8, sulfur-bearing minerals in mafic and ultramafic rocks7, a change in volcanic gas composition10, increased subaerial volcanism11, and hydrothermal Fe precipitation in seawater3. After three billion years, the subduction of more felsic ocean floor sediments may have changed the redox conditions in subduction zones, potentially leading to more oxidized gases being emitted at arc volcanoes, triggering further oxygenation7.Smit and Mezger4 show that serpentinization may have buffered the redox conditions on the Archaean Earth, mitigating the accumulation of atmospheric oxygen. The importance of this process should now be quantified using numerical models and compared with the sulfur isotope record — the only quantitative record of oxygen on Earth across this time period2. If serpentinization was indeed a critical process during the Archaean, the low density of serpentine may also have had a profound impact on geodynamic processes such as crustal recycling and stabilization of continental crust on the early Earth.References1. Lyons, T. et al. Nature 506, 307–315 (2014). 2. Farquhar, J. et al. Science 289, 756–758 (2000). 3. Holland, H. D. Phil. Trans. R. Soc. B 361, 903–915 (2006). 4. Smit, M. & Mezger, K. Nat. Geosci. 10, 788–792 (2017). 5. Brocks, J. J. et al. Science 285, 1033–1036 (1999). 6. Tang, M. et al. Science 351, 372–375 (2016). 7. Lee, C.-T. et al. Nat. Geosci. 9, 417–424 (2016). 8. Kamber, B. S. Chem. Geol. 274, 19–28 (2010)9. Naeraa, T. et al. Nature 485, 627–631 (2012). 10. Holland, H. D. Geochim. Cosmochim. Acta 66, 3811–3826 (2002).11. Kump, L. R. & Barley, M. E. Nature 448, 1033–1036 (2007). Hofmann, L.C., Heesch, S., 2017. Latitudinal trends in stable isotope signatures and carbon concentrating mechanisms of northeast Atlantic rhodoliths. Biogeosciences Discussions 2017, 1-18. are free-living calcifying red algae that form extensive beds in shallow marine benthic environments (<?250?m), which provide important habitats and nurseries for marine organisms and contribute to carbonate sediment accumulation. There is growing concern that these organisms are sensitive to global climate change, yet little is known about their physiology. Considering their broad distribution along most continental coastlines, their potential sensitivity to global change could have important consequences for the productivity and diversity of benthic coastal environments. The goal of this study was to determine the plasticity of dissolved inorganic carbon (DIC) uptake mechanisms of rhodoliths along a latitudinal gradient in the Northeast (NE) Atlantic using natural stable isotope signatures. The δ13C signature of macroalgae can be used to provide an indication of the preferred inorganic carbon source (CO2 vs. HCO3?). Here we present the total (δ13CT) and organic (δ13Corg) δ13C signatures of NE Atlantic rhodoliths with respect to changing environmental conditions along a latitudinal gradient from the Canary Islands to Spitsbergen. The δ13CT signatures (?11.9 to ?0.89) of rhodoliths analysed in this study were generally higher than the δ13Corg signatures, which ranged from ?25.7 to ?2.8. We observed a decreasing trend in δ13CT signatures with increasing latitude and temperature, while δ13Corg signatures were only significantly correlated to DIC. These data suggest that high latitude rhodoliths rely solely on CO2 as an inorganic carbon source, while low latitudes rhodoliths likely take up HCO3? directly. However, depth also has a significant effect on both skeletal and organic δ13C signatures, suggesting that both local and latitudinal trends influence the plasticity of rhodolith inorganic carbon acquisition and assimilation. Our results show that many species, particularly those at lower latitudes, have carbon concentrating mechanisms that facilitate HCO3? use for photosynthesis. This is an important adaptation for marine macroalgae, because HCO3? is available at higher concentrations than CO2 in seawater, and this becomes even more extreme with increasing temperature. The flexibility of CCMs in northeast Atlantic rhodoliths observed in our study may provide a key physiological mechanism for potential adaptation of rhodoliths to future global climate change.Hong, H., Fang, Q., Zhao, L., Schoepfer, S., Wang, C., Gong, N., Li, Z., Chen, Z.-Q., 2017. Weathering and alteration of volcanic ashes in various depositional settings during the Permian-Triassic transition in South China: Mineralogical, elemental and isotopic approaches. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 46-57. better understand the alteration of volcanic ash in different depositional environments, we measured the clay mineralogy, major and trace element geochemistry, and Sr and Nd isotopic composition of altered ashes in two Permian-Triassic boundary (PTB) successions in southern China. The Pengda and Xinmin sections, in Guizhou Province, represent different depositional settings, allowing us to investigate the role of the early burial environment on authigenic clay formation. The PTB ash beds in both sections consist predominantly of mixed-layer illite-smectite clays. Altered ashes in the relatively shallow Pengda section contain predominantly R2 and R3 I/S clays, with 70% to 85% illite layers, whereas their stratigraphic equivalents in the deeper Xinmin section contain only R3 I/S clays, which are of two types, with 88% and 99% illite layers, respectively. The two studied ash beds can be stratigraphically correlated between the Pengda and Xinmin sections, and show similar 143Nd/144Nd ratios (0.511991 for PD-1 and 0.511983 for XM-1; 0.512073 for PD-2 and 0.512074 for XM-2). REE distributions and immobile element cross plots are consistent in suggesting that the altered ashes may have originated via felsic volcanism. Altered ashes in the deep sea Xinmin section have notably high 87Sr/86Sr ratios (0.764209 and 0.795921) relative to those from equivalent horizons in shallower environments (0.728455 and 0.749953). This difference in 87Sr/86Sr ratios is likely attributable to different degrees of chemical weathering. Elemental ratios such as SiO2/Al2O3, K2O/Al2O3, Y/Sr and Zr/Sr all support more intensive chemical leaching in deep-water environments. The altered ashes at Xinmin contain substantially more K2O than those at Pengda, suggesting greater incorporation of K+ into clay minerals due to lower pH during early diagenesis. Clay mineral assemblages and stacking structures of I/S clays in the altered ashes are consistent with a general sequence of smectite illitization during diagenesis and burial metamorphism in both sections.Horan, K., Hilton, R.G., Selby, D., Ottley, C.J., Gr?cke, D.R., Hicks, M., Burton, K.W., 2017. Mountain glaciation drives rapid oxidation of rock-bound organic carbon. Science Advances 3, Article e1701107. millions of years, the oxidation of organic carbon contained within sedimentary rocks is one of the main sources of carbon dioxide to the atmosphere, yet the controls on this emission remain poorly constrained. We use rhenium to track the oxidation of rock-bound organic carbon in the mountain watersheds of New Zealand, where high rates of physical erosion expose rocks to chemical weathering. Oxidative weathering fluxes are two to three times higher in watersheds dominated by valley glaciers and exposed to frost shattering processes, compared to those with less glacial cover; a feature that we also observe in mountain watersheds globally. Consequently, we show that mountain glaciation can result in an atmospheric carbon dioxide source during weathering and erosion, as fresh minerals are exposed for weathering in an environment with high oxygen availability. This provides a counter mechanism against global cooling over geological time scales.Hosseini-Nasab, S.M., Zitha, P.L.J., 2017. Investigation of chemical-foam design as a novel approach toward immiscible foam flooding for enhanced oil recovery. Energy & Fuels 31, 10525-10534. foam can be generated in porous media containing oil, resulting in incremental oil recovery; however, oil recovery factor is restricted. A large fraction of oil recovered by foam flooding forms an oil-in-water emulsion, so that costly methods may need to be used to separate the oil. Moreover, strong foam could create a large pressure gradient, which may cause fractures in the reservoir. This study presents a novel chemical-foam flooding process for enhanced oil recovery (EOR) from water-flooded reservoirs. The presented method involved the use of chemically designed foam to mobilize the remaining oil after water flooding and then to displace the mobilized oil to the production well. A blend of two anionic surfactant formulations was formulated for this method: (a) IOS, for achieving ultralow interfacial tension (IFT), and (b) AOS, for generating a strong foam. Experiments were performed using Bentheimer sandstone cores, where X-ray CT images were taken during foam generation to find the stability of the advancing front of foam propagation and to map the gas saturation for both the transient and the steady-state flow regimes. Then the proposed chemical-foam strategy for incremental oil recovery was tested through the coinjection of immiscible nitrogen gas and surfactant solutions with three different formulation properties in terms of IFT reduction and foaming strength capability. The discovered optimal formulation contains a foaming agent surfactant, a low IFT surfactant, and a cosolvent, which has a high foam stability and a considerably low IFT (1.6 × 10–2 mN/m). Coinjection resulted in higher oil recovery and much less MRF than the same process with only using a foaming agent. The oil displacement experiment revealed that coinjection of gas with a blend of surfactants, containing a cosolvent, can recover a significant amount of oil (33% OIIP) over water flooding with a larger amount of clean oil and less emulsion.Hou, S., Wang, X., Wang, X., Yuan, Y., Pan, S., Wang, X., 2017. Pore structure characterization of low volatile bituminous coals with different particle size and tectonic deformation using low pressure gas adsorption. International Journal of Coal Geology 183, 1-13. pressure N2 and CO2 adsorption experiments were performed on two low volatile bituminous coals to gain insights into mesopore and micropore characteristics and the effects of particle size, composition (mineral matter and maceral) and tectonic deformation on them. Original coal and tectonized coal were sieved into five particle size fractions, i.e., 18–35 mesh (0.50–1.00 mm), 35–60 mesh (0.25–0.50 mm), 60–120 mesh (0.125–0.250 mm), 120–230 mesh (0.063–0.125 mm) and 230–450 mesh (0.032–0.063 mm). Low pressure gas adsorption analysis, proximate analysis and maceral analysis were conducted on each particle size fraction. Specific surface area of mesopore varies from 0.22 m2/g to 3.06 m2/g and from 1.00 m2/g to 2.07 m2/g in original coal and tectonized coal, and that of micropore is from 123.7 m2/g to 164.6 m2/g and from 100.7 m2/g to 106.7 m2/g, respectively. The vast majority of total specific surface area is within micropores. Mesopore specific surface area and volume are dependent on particle size. Decreasing particle size makes some inaccessible mesopores become accessible to N2 molecules, increasing mesopore specific surface area and volume. In contrast to mesopore characteristics, micropore characteristics are independent of particle size. Mineral matter contributes minimally to micropore specific surface area and volume. There is no consistent relationship between mineral matter and mesopore characteristics. Maceral composition, which is represented by the ratio of vitrinite to inertinite, has a uniformly negative correlation with mesopore characteristics, but plays a different role in micropore characteristics. The heterogeneity in composition resulting from sieving is reduced, so the effect of particle size on pore characteristics is weakened in the tectonized coal. Tectonic deformation enhances mesopore specific surface area and volume by removing constricted pore openings and increasing accessible mesopores. Moreover, tectonic deformation is likely to cause micropores collapse, which results in a significant decrease in micropore specific surface area and volume.Hou, Y., He, S., Harris, N.B., Yi, J., Wang, Y., Zhang, J., Cheng, C., 2017. The effects of shale composition and pore structure on gas adsorption potential in highly mature marine shales, Lower Paleozoic, central Yangtze, China. Canadian Journal of Earth Sciences 54, 1033-1048. Ordovician Wufeng Formation and Silurian Longmaxi Formation are two of the most organic-rich and gas-prospective shale formations in the central Yangtze area, China. In this study, we investigate the controls exerted by shale composition and pore structure on methane sorption of these highly matured marine shales (Ro ranges from 2.0% to 4.0%). Samples were analyzed by SEM pore imaging of Ar-ion milled samples, high pressure methane adsorption, and low temperature nitrogen adsorption. In the high TOC Wufeng and lower Longmaxi formations, numerous organic matter pores are present. A positive correlation exists between TOC, BET surface area, and CH4 sorption capacity, indicating that porosity associated with organic matter is the key factor controlling methane sorption capacity of shale samples. In the organic-lean upper Longmaxi Formation, pores within clay particles and carbonate minerals are the major pore types. Organic-lean shale samples from the upper Longmaxi Formation have higher clay content, lower BET surface area, and lower adsorption capacity than organic-rich shales. Within several low TOC samples, a relatively strong correlation exists between illite content and methane sorption capacity, which is interpreted to result from clay mineral-hosted porosity.Hu, J., Peng, P., 2017. An overview and perspectives on organic geochemistry. Acta Sedimentologica Sinica 35, 968-980. significant achievements and potential new research breakthrough in future of organic geochemistry during the last five years are briefly reviewed. Important progress has been achieved on the property and structure of the sedimentary organic matter. The geochemical process involved by the organic matter has been investigated qualitatively due to the technique progress on the molecular and molecular isotopes. The environmental and controlling factors on the formation of hydrocarbon source rocks have been deciphered, however, the sedimentary records to support the deduction of the formation mechanism of hydrocarbon source rocks have not been found. The bio-organic geochemistry contributed to the quantitative reconstruction of environmental and paleoecological issues. New progress will be achieved on the study of the intermediate type of organic matter and quantitative reconstruction of oil and gas reservoir forming process. Introduction of new techniques in new components and isotopes will further improve investigations of organic geochemistry.Hu, Q., Zhang, Y., Meng, X., Li, Z., Xie, Z., Li, M., 2017. Characterization of micro-nano pore networks in shale oil reservoirs of Paleogene Shahejie Formation in Dongying Sag of Bohai Bay Basin, East China. Petroleum Exploration and Development 44, 720-730. typical blocky, laminated and bedded mudrock samples from the Paleogene Shahejie Formation in the Dongying Sag of Bohai Bay Basin, this work systematically focuses on their structure characterization of multiple micro-nano pore networks. A use of mercury injection capillary pressure (MICP) documented the presence of multiple μm-nm pore networks, and obtained their respective porosity, permeability and tortuosity. Different sample sizes (500-841 μm GRI fractions, 1 cm-sized cubes, and 2.54 cm in diameter and 2-3 cm in height core plugs) and approaches (low-pressure N2 gas physisorption, GRI matrix permeability, MICP, helium pycnometry, and pulse decay permeameter) were used to measure pore size distribution, porosity and permeability. The average porosity and matrix permeability determined from MICP are (6.31±1.64)% and (27.4±31.1)×10-9 μm2, the pore throat diameter of pores is mainly around 5 nm, and the median pore throat diameter based on 50% of final cumulative volume is (8.20±3.01) nm in shale. The pore-throat ratios decrease with a decrease of pore size diameter. Moreover, the permeability of shale samples with lamination is nearly 20 times larger than matrix permeability. The geometrical tortuosity of the nano-scale 2.8?10.0 nm pore networks is 8.44 in these shales, which indicates a poor connectivity of matrix pore network and low flow capability. Overall, the variable and limited pore connectivity of shale samples will affect hydrocarbon preservation and recovery.Huang, W., Cheng, W., Nie, X., Dong, F., Ding, C., Liu, M., Li, Z., Hayat, T., Alharbi, N.S., 2017. Microscopic and spectroscopic insights into uranium phosphate mineral precipitated by Bacillus mucilaginosus. ACS Earth and Space Chemistry 1, 483-492. this paper, we used spectroscopic and microscopic techniques to investigate the interaction mechanism between uranium and Bacillus mucilaginosus. According to scanning electron microscope couple with energy dispersive X-ray detector analysis, the lamellar uranium phosphate precipitation was only observed on the living B. mucilaginosus and the resting B. mucilaginosus. The Fourier transform infrared spectroscopy spectrum also indicated the important role of phosphate groups in forming U(VI)-phosphates precipitation. The X-ray diffraction analysis identified the phase of U(VI)-phosphate precipitation as H3OUO2PO4·3H2O. Batch experiment showed that biominerilization amount could be up to 195.84 mg/g when exposing living B. mucilaginosus to U(VI) aqueous solution at pH 5.0 for 1 h. The precipitate was further evidenced by extended X-ray absorption fine structure spectra based on the presence of U–P shell, which demonstrated that hydrogen uranyl phosphate became the main products on the living B. mucilaginosus with prolonged reacting time. After ashing and hydrothermal process, the precipitated U(VI) on B. mucilaginosus could be converted into UO2 and K(UO2)(PO4)·3H2O. Our findings have significant implications in elucidating the potential role of bacteria in the migration of uranium in geological environment.Huang, X., Zhao, Y.-P., 2017. Characterization of pore structure, gas adsorption, and spontaneous imbibition in shale gas reservoirs. Journal of Petroleum Science and Engineering 159, 197-204. multiscale pore structure and its distribution as well as the occurrence state of shale gas and spontaneous imbibition in gas shale are studied experimentally. Most of the pores within organic matters are at nanoscale and are isolated in all directions. They have low porosity and connectivity, which account for the most of pore volume and determine the resource abundance of gas shale reservoirs. The contents of adsorption gas and free gas in the multiscale pore structure of shale rocks increase with the increase of gas pressure, of which the free gas increases faster than that of adsorption gas. The spontaneous imbibition shows the fast shift of T2 peaks to right at early stage of fluid transport through the interconnected network of pore structure in shale rocks. Our results may provide unified methods for clear understanding of the pore structure and fluid transport behavior in shale gas reservoirs and assist the future efficient exploitation of shale gas.Hubas, C., Boeuf, D., Jesus, B., Thiney, N., Bozec, Y., Jeanthon, C., 2017. A nanoscale study of carbon and nitrogen fluxes in mats of purple sulfur bacteria: Implications for carbon cycling at the surface of coastal sediments. Frontiers in Microbiology 8, 1995. doi: 10.3389/fmicb.2017.01995. blooms of purple sulfur bacteria growing seasonally on green stranded macroalgae have a major impact on the microbial composition and functionality of intertidal mats. To explore the active anoxygenic phototrophic community in purple bacterial mats from the Roscoff Aber Bay (Brittany, France), we conducted a combined approach including molecular and high-resolution secondary ion mass spectrometry (NanoSIMS) analyses. To investigate the dynamics of carbon and nitrogen assimilation activities, NanoSIMS was coupled with a stable isotope probing (SIP) experiment and a compound specific isotope analysis (CSIA) of fatty acid methyl ester (FAME). Sediment samples were incubated with 13C- and/or 15N-labeled acetate, pyruvate, bicarbonate and ammonium. NanoSIMS analysis of 13C - and 15N -incubated samples showed elevated incorporations of 13C - and 15N in the light and of 13C -acetate in the dark into dense populations of spherical cells that unambiguously dominated the mats. These results confirmed CSIA data that ranked vaccenic acid, an unambiguous marker of purple sulfur bacteria, as the most strongly enriched in the light after 13C -acetate amendment and indicated that acetate uptake, the most active in the mat, was not light-dependent. Analysis of DNA- and cDNA-derived pufM gene sequences revealed that Thiohalocapsa-related clones dominated both libraries and were the most photosynthetically active members of the mat samples. This study provides novel insights into the contribution of purple sulfur bacteria to the carbon cycle during their seasonal developments at the sediment surface in the intertidal zone.Hublin, J.-J., 2017. The last Neanderthal. Proceedings of the National Academy of Sciences 114, 10520-10522. mechanism of the Neanderthal extinction and their replacement by modern humans of African origin is one of the most discussed issues in paleoanthropology. Central to this discussion are the questions of the chronological overlap between Neanderthal populations and modern humans in Western Eurasia and the precise geographical circumstances of this overlap. For a long time, the Vindija (Croatia) site was considered to provide solid evidence for a long survival of Neanderthals in Central/Southern Europe. Not only did directly dated Neanderthal remains from layer G1 of the site provide radiocarbon ages postdating the most widely accepted transition time of 40–35,000 radiocarbon years ago (1), but the same layer also yielded a type of split-based bone points commonly assigned to the Aurignacian (2), a stone artefact industry of the early Upper Paleolithic that, to date, only yielded human remains of a modern nature (3). For some, this situation implied the possibility of a long and complex interaction between the two groups of hominins in this region and also falsified the notion of a systematic association between defined archaeological assemblages and specific biological populations at the time of the replacement. In PNAS, Devièse et al. (4) provide new radiocarbon dates for the same Vindija Neanderthal samples, dating them to before 40,000 14C B.P., significantly older than previous efforts dating this material to 29–28,000 and 33–32,000 radiocarbon years (1). The bone points of layer G1 could not be dated, but the range of ages obtained from faunal and human samples in this layer suggests taphonomic mixing as a likely mechanism to explain their stratigraphic association in this part of the Vindija stratigraphic sequence. The situation in Vindija is therefore not at all exceptional, and previous results can be explained by the effect of sample contamination and layer admixture. Huyghe, D., Emmanuel, L., Renard, M., Lartaud, F., Génot, P., Riveline, J., Merle, D., 2017. Significance of shallow-marine and non-marine algae stable isotope (δ18O) compositions over long periods: Example from the Palaeogene of the Paris Basin. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 247-259. this study, we test the potentiality of using dasycladales and charophytes, calcareous shallow-marine and non-marine algae respectively as palaeoclimatic recorders. These algae mineralize their carbonate during short periods in summer. Throughout the Palaeogene, we compare the δ18O variation of these two taxa to identify a possible common factor influencing their isotopic composition, i.e. temperatures variations, from a local environmental signal. We sampled and isotopically analyzed eight species of charophytes and seven species of dasycladales from 23 formations ranging from the Palaeocene to the Oligocene series of the Paris Basin. By comparing the δ18O of these two groups living in different environment with that of shallow-marine mollusks from a previous study, we show that temperature variations are the main factor influencing their δ18O compositions and that local environmental effects do not screen the global thermal signal. Maximum annual palaeotemperatures are calculated from the δ18O of the dasycladales and indicate by comparison with the data from mollusks previously analyzed that dasycladales species used probably mineralized their carbonate in equilibrium with sea-water. Dasycladales recorded the global climatic events already known for the Palaeogene, with high temperatures reached during the Early Eocene and Middle Eocene climatic optimums and relative cooling intervals during the Lutetian, the Priabonian and the Rupelian. Charophyte gyrogonites also recorded temperature variations in their δ18O compositions but reconstituting reliable temperature values in non-marine environments is not directly possible and requires constraining δ18O of local continental water using other proxies. These promising results show that carbonates mineralized from algae constitute a reliable support for palaeoclimatic information and should be more widely used in the fossil record.Intxauspe-Zubiaurre, B., Flores, J.-A., Payros, A., 2017. Variations to calcareous nannofossil CaCO3 content during the middle Eocene C21r-H6 hyperthermal event (~47.4Ma) in the Gorrondatxe section (Bay of Biscay, western Pyrenees). Palaeogeography, Palaeoclimatology, Palaeoecology 487, 296-306. carbonate content of calcareous nannofossils is dependent on seawater composition. One of the factors that affect seawater chemistry and consequently the degree of calcification in coccolithophores is temperature, as seen in present day warming oceans. The depth at which carbonates are dissolved (Calcite Compensation depth, CCD) can rise due to an increase in HCO3– and decrease in pH, leading to a major dissolution on the seabed and burndown. Similar processes have also been deduced for Eocene hyperthermal events, such as the PETM and ETM2. This study reports changes in coccolith carbonate mass from a hemipelagic setting (Gorrondatxe, at 1500 m paleodepth) during the core of a minor Eocene hyperthermal event, namely the C21r-H6 event (47.44–47.32 Ma). Image analysis techniques were used to determine differences in the carbonate mass of selected calcareous nannofossil taxa, revealing species-specific patterns. The CaCO3 mass of Chiasmolithus solitus decreased by 50% over the course of the C21r-H6 event, and many specimens also lost their crossed central bars, an additional indication of mass loss; Reticulofenestra sp. (3–5 μm) showed a similar trend, but the percentage of mass lost was lower; Toweius pertusus, interpreted as being reworked, mirrored the behaviour of Chiasmolithus solitus, suggesting that the CaCO3 mass loss may have occurred on the seabed, rather than in the water column. In general, it can be concluded that the lysocline rose to 1500 m paleobathymetry in the Bay of Biscay during the C21r-H6 event. Formation of corrosive bottom water in the North Atlantic Ocean is regarded as being responsible for the rise in the lysocline.Javaux, E.J., Lepot, K., 2018. The Paleoproterozoic fossil record: Implications for the evolution of the biosphere during Earth's middle-age. Earth-Science Reviews 176, 68-86. Paleoproterozoic (2.5–1.6 Ga) Era is a decisive time in Earth and life history. The paleobiological record (microfossils, stromatolites, biomarkers and isotopes) illustrates the biosphere evolution during a time of transitional oceanic and atmosphere chemistries. Benthic microfossil assemblages are recorded in a variety of oxygenated, sulfidic, and ferruginous environments representative of the spatial heterogeneities and temporal variations characteristic of this Era. The microfossil assemblages include iron-metabolizing and/or iron-tolerant prokaryotes, sulfur-metabolizing prokaryotes, cyanobacteria, other undetermined prokaryotes, and eukaryotes. The undetermined microfossils represent a majority of the assemblages and thus raise a challenge to determine the nature and role of microorganisms in these changing environments. Despite the early evolution of the eukaryotic cellular toolkit, early eukaryotic crown group diversification may have been restrained in the Paleoproterozoic by ocean chemistry conditions, but it increased during the late Mesoproterozoic–early Neoproterozoic despite the continuation of similar conditions through the (miscalled) “boring billion”, then amplified significantly (but perhaps within lower taxonomic levels), with the demise of euxinic conditions and increase in ecological complexity.The emerging picture is one of a changing and more complex biosphere in which the three domains of life, Archaea, Bacteria and Eukarya, were diversifying in various ecological niches marked by the diversification of identified microfossils, stromatolites, increasing abundance of preserved biomarkers, and appearance of macroscopic problematic fossils or trace fossils.Jenkins, R.G., Hasegawa, T., Haggart, J.W., Goto, A.S., Iwase, Y., Nakase, C., 2017. Cool eastern rim of the North Pacific during Late Cretaceous time: A seep-carbonate paleothermometry from the Nanaimo Group, British Columbia, Canada. Palaeogeography, Palaeoclimatology, Palaeoecology 487, 407-415. crater-shaped carbonate body newly recognized in the uppermost Northumberland Formation (Nanaimo Group) of the Canadian Pacific coast, is identified as a remnant of methane seepage during latest Campanian time in the northeastern Pacific region. A two meter-long elliptical mound with central concavity is found on a Cretaceous bedding plane observed at Hornby Island, British Columbia, exposed on an expansive intertidal platform. Microstructures characteristic of carbonate associated with methane seepage are readily observed within the rock body and indicate it was formed near the sediment-water interface. Carbon isotope values of the carbonate range between ? 45.5 and + 4.9‰, where the lowermost values characterize anaerobic oxidation of biogenic methane as the primary process that controlled the carbonate precipitation. Oxygen isotope values also exhibit a wide range of values, from ? 9.8 to + 0.6‰. Areas preserving features of earliest precipitation (i.e., radiaxial bladed calcite and micrite with clotted fabric) on cross-sections exhibit the highest δ18O values and indicate a paleotemperature 8.0 ± 0.7 °C for seawater at the seafloor. Development of cool water on uppermost bathyal or outer shelf depths in the northeastern North Pacific is thus implied during the Campanian-Maastrichtian transition. This paleotemperature determination shows a significant variance with those obtained from similar paleo-water depths of the northwestern North Pacific.Jiang, S., Chen, L., Wu, Y., Jiang, Z., McKenna, E., 2017. Hybrid plays of Upper Triassic Chang7 lacustrine source rock interval of Yanchang Formation, Ordos Basin, China. Journal of Petroleum Science and Engineering 159, 182-196. lacustrine Chang7 member of Upper Triassic Yanchang Formation in the Ordos Basin in North China is a source rock interval characterized by organic-rich shale with thin interbeds of stratigraphically associated sandstone and siltstone. The concept of “Hybrid Plays” is put forth after evaluating the facies, geochemistry, porosity, permeability, mineralogy and producibility of different lithofacies in this Chang7 member. The genetically related hydrocarbon bearing hybrid unconventional shale, tight sand and conventional reservoirs within the source rock interval are identified. The interbedded organic-lean reservoirs are efficiently charged with hydrocarbons through short migration from the adjacent organic-rich Chang7 shale that is also a self-sourced shale reservoir. The hydrocarbon accumulation of these hybrid plays has been confirmed by petroleum system modeling and recent exploration and production. “Hybrid Plays” present a unique closed petroleum system hosting continuous hydrocarbons stored in self-sourcing thick shale reservoirs and adjacent thin and relatively coarse-grained siliciclastic interbeds, that together form hybrid unconventional plays in addition to conventional plays throughout the whole source rock interval. “Hybrid Plays” provide the most realistic exploration and production model for targeting the multiple genetically associated stacked plays as one resource play in order to avoid relying solely on clay-rich shale or thin relatively coarse-grained interbed play in source rock intervals of this lacustrine basin.Jones, D.L., Baxter, B.K., 2017. DNA repair and photoprotection: Mechanisms of overcoming environmental ultraviolet radiation exposure in halophilic Archaea. Frontiers in Microbiology 8, 1882. doi: 10.3389/fmicb.2017.01882 archaea push the limits of life at several extremes. In particular, they are noted for their biochemical strategies in dealing with osmotic stress, low water activity and cycles of desiccation in their hypersaline environments. Another feature endemic to their habitats is intense ultraviolet (UV) radiation, which is a challenge that microorganisms must overcome. The consequences of high UV exposure include DNA lesions arising directly from bond rearrangement of adjacent bipyrimidines, or indirectly from oxidative damage, which may ultimately result in mutation and cell death. As such, these microorganisms have evolved a number of strategies to navigate the threat of DNA damage, which we differentiate into two categories, DNA repair and photoprotection. Photoprotection encompasses damage avoidance strategies that serve as a “first line of defense,” and in halophilic archaea include pigmentation by carotenoids, mechanisms of oxidative damage avoidance, polyploidy, and genomic signatures that make DNA less susceptible to photodamage. Photolesions that do arise are addressed by a number of DNA repair mechanisms that halophilic archaea efficiently utilize, which include photoreactivation, nucleotide excision repair, base excision repair, and homologous recombination. This review seeks to place DNA damage, repair, and photoprotection in the context of halophilic archaea and the solar radiation of their hypersaline environments. We also provide new insight into the breadth of strategies and how they may work together to produce remarkable UV-resistance for these microorganisms.Jones, S., 2017. Goo, glue, and grain binding: Importance of biofilms for diagenesis in sandstones. Geology 45, 959-960. you ever heard of biofilms? They are slimy, glue-like membranes that are produced by microbes, like bacteria, fungi, algae and cyanobacteria, forming highly organized communities in order to colonize surfaces. A biofilm consists of the individual cells plus a goo-like extracellular polymeric substance (EPS). Within this framework microbial cells metabolize and reproduce thus extending the goo-like EPS (Decho, 1990, 2000). In marine and non-marine environments, microbial communities interact with the physical sediment dynamics in order to survive. Biostabilization, the trapping or sticking of sediment particles by microorganisms result in the formation of microbially induced sedimentary structures; however, if carbonate precipitation occurs in EPS, and these processes happen in a repetitive manner, a multilayered build-up can form known as stromatolites (Riding, 2000). The oldest known example of stromatolites and microbially induced sedimentary structures are found in microbial metacarbonates that are 3700 m.y. old, recording highly evolved microbial activity early in Earth’s history (Noffke et al., 2013; Nutman et al., 2016). Microbial biofilms have also been attributed to the widespread preservation of the Proterozoic soft-bodied Ediacaran organisms in creating ‘death masks’ allowing enhanced preservation of these delicate organisms (e.g., Gehling, 1999; Laflamme et al., 2011).The occurrence of EPS is of central importance in the formation of microbial carbonates where bacteria, cyanobacteria, and diatoms can all secrete copious amounts of EPS and actively encourage calcium ion precipitation and sediment trapping (see Riding, [2000] and Bosence et al. [2015]for recent reviews). Although important, the literature until recently has neglected the role EPS plays for grain sticking in non-cohesive sandy substrates that dominate the marginal marine sedimentary environment (Gerbersdorf and Wieprecht, 2015).Joshi, S., Goyal, S., Mukherjee, A., Reddy, M.S., 2017. Microbial healing of cracks in concrete: a review. Journal of Industrial Microbiology & Biotechnology 44, 1511-1525. is the most widely used construction material of the world and maintaining concrete structures from premature deterioration is proving to be a great challenge. Early age formation of micro-cracking in concrete structure severely affects the serviceability leading to high cost of maintenance. Apart from conventional methods of repairing cracks with sealants or treating the concrete with adhesive chemicals to prevent the cracks from widening, a microbial crack-healing approach has shown promising results. The unique feature of the microbial system is that it enables self-healing of concrete. The effectiveness of microbially induced calcium carbonate precipitation (MICCP) in improving durability of cementitious building materials, restoration of stone monuments and soil bioclogging is discussed. Main emphasis has been laid on the potential of bacteria-based crack repair in concrete structure and the applications of different bacterial treatments to self-healing cracks. Furthermore, recommendations to employ the MICCP technology at commercial scale and reduction in the cost of application are provided in this review.Jung, Y., Pau, G.S.H., Finsterle, S., Pollyea, R.M., 2017. TOUGH3: A new efficient version of the TOUGH suite of multiphase flow and transport simulators. Computers & Geosciences 108, 2-7. TOUGH suite of nonisothermal multiphase flow and transport simulators has been updated by various developers over many years to address a vast range of challenging subsurface problems. The increasing complexity of the simulated processes as well as the growing size of model domains that need to be handled call for an improvement in the simulator's computational robustness and efficiency. Moreover, modifications have been frequently introduced independently, resulting in multiple versions of TOUGH that (1) led to inconsistencies in feature implementation and usage, (2) made code maintenance and development inefficient, and (3) caused confusion to users and developers. TOUGH3—a new base version of TOUGH—addresses these issues. It consolidates both the serial (TOUGH2 V2.1) and parallel (TOUGH2-MP V2.0) implementations, enabling simulations to be performed on desktop computers and supercomputers using a single code. New PETSc parallel linear solvers are added to the existing serial solvers of TOUGH2 and the Aztec solver used in TOUGH2-MP. The PETSc solvers generally perform better than the Aztec solvers in parallel and the internal TOUGH3 linear solver in serial. TOUGH3 also incorporates many new features, addresses bugs, and improves the flexibility of data handling. Due to the improved capabilities and usability, TOUGH3 is more robust and efficient for solving tough and computationally demanding problems in diverse scientific and practical applications related to subsurface flow modeling.Kaiser, K., Canedo-Oropeza, M., McMahon, R., Amon, R.M.W., 2017. Origins and transformations of dissolved organic matter in large Arctic rivers. Scientific Reports 7, Article 13064. river watersheds are important components of the global climate system and show an amplified response to climate change. Here, we characterize origins and transformations of dissolved organic matter (DOM) in five major Arctic rivers (Kolyma, Lena, Yenisei, Ob, Mackenzie) over 3 years with seasonal sampling periods using measurements of carbohydrates, amino acids, bacterial biomarkers (D-amino acids), and plant protein biomarkers (hydroxyproline). A strong seasonal cycle of bioavailable DOM export was observed that correlated with discharge, vegetation, river morphology and water residence time. The chemical composition of bioavailable DOM was different among rivers reflecting unique characteristics of Arctic river watersheds. Trends in specific bacterial biomarkers were synchronous to changes in bacterial community compositions demonstrating that bacterial communities responded to the seasonal shifts in organic matter quality and chemical composition. Extensive heterotrophic processing of plant and soil-derived DOM resulted in major inputs of bacterial detritus, and bacterial organic matter accounted for 21–42% of DOC in all watersheds. Dissolved organic nitrogen sources were dominated by bacterially-derived nitrogen and important contributions of soluble plant protein during the Spring freshet. Overall, our results demonstrated the importance of watershed characteristics and bacterial metabolism in regulating DOM composition, reactivity and carbon fluxes in Arctic river watersheds.Kaminski, J., Hynds, J., Morris, P., Waller, B.M., 2017. Human attention affects facial expressions in domestic dogs. Scientific Reports 7, Article 12914. mammalian species produce facial expressions. Historically, animal facial expressions have been considered inflexible and involuntary displays of emotional states rather than active attempts to communicate with others. In the current study, we aimed to test whether domestic dog facial expressions are subject to audience effects and/ or changes in response to an arousing stimulus (e.g. food) alone. We presented dogs with an experimental situation in which a human demonstrator was either attending to them or turned away, and varied whether she presented food or not. Dogs produced significantly more facial movements when the human was attentive than when she was not. The food, however, as a non-social but arousing stimulus, did not affect the dogs’ behaviour. The current study is therefore evidence that dogs are sensitive to the human’s attentional state when producing facial expressions, suggesting that facial expressions are not just inflexible and involuntary displays of emotional states, but rather potentially active attempts to communicate with others.Kang, J., Myint, A.A., Sim, S., Kim, J., Kong, W.B., Lee, Y.-W., 2018. Kinetics of the upgrading of heavy oil in supercritical methanol. The Journal of Supercritical Fluids 133, 133-138. crude oil upgrading was conducted in supercritical methanol (scMeOH) using batch reactors. The influence of temperature (653–693 K), reaction time (0–120 min) on product distribution was investigated. The crude oil was upgraded into the light oil with more saturate and less aromatic, resin in scMeOH. The higher the temperature, the faster the asphaltene was converted to coke. In FTIR analysis, scMeOH are presumed to participate in the upgrading of crude oil. To understand the crude oil upgrading process in scMeOH, four lump kinetic model including maltene, asphaltene, coke, and gas was proposed and kinetic parameters were estimated from the experimental data. The calculated rate constants and activation energies showed that the decomposition of asphaltene is the most dominant reaction in the upgrading of crude oil while the generation of coke is suppressed.Kang, Y., Schneider, B.B., Covey, T.R., 2017. On the nature of mass spectrometer analyzer contamination. Journal of The American Society for Mass Spectrometry 28, 2384-2392. throughput in electrospray ionization mass spectrometry (ESI-MS) is limited by the need for frequent ion path cleaning to remove accumulated debris that can lead to charging and general performance degradation. Contamination of ion optics within the vacuum system is particularly problematic as routine cleaning requires additional time for cycling the vacuum pumps. Differential mobility spectrometry (DMS) can select targeted ion species for transmission, thereby reducing the total number of charged particles entering the vacuum system. In this work, we characterize the nature of instrument contamination, describe efforts to improve mass spectrometer robustness by applying DMS prefiltering to reduce contamination of the vacuum ion optics, and demonstrate the capability of DMS to extend the interval between mass spectrometer cleaning. In addition, we introduce a new approach to effectively detect large charged particles formed during the electrospray ionization (ESI) process.Karn, S.K., Fang, G., Duan, J., 2017. Bacillus sp. Acting as dual role for corrosion induction and corrosion inhibition with carbon steel (CS). Frontiers in Microbiology 8, 2038. doi: 10.3389/fmicb.2017.02038. work investigated the role of five different bacteria species as a corrosion inducer as well as corrosion inhibitor with carbon steel (CS). We observed the ability of different bacteria species on the metal surface attachment, biofilm formation, and determined Peroxidase, Catalase enzyme activity in the detached biofilm from the CS surface. We found that each strain has diverse conduct for surface attachment like DS1 3.3, DS2 2.5, DS3 4.3, DS4 4.0, and DS5 4.71 log cfu/cm2 and for biofilm 8.3 log cfu/cm2. The enzyme Peroxidase, Catalase was found in huge concentration inside the biofilm Peroxidase was maximum for DS4 36.0 U/ml and least for DS3 19.54 U/ml. Whereas, Catalase was highest for DS4, DS5 70.14 U/ml and least 57.2 U/ml for DS2. Scanning electron microscopy (SEM) was conducted to examine the biofilm and electrochemical impedance spectroscopy (EIS) were utilized to observe corrosion in the presence of bacteria. The electrochemical results confirmed that DS1, DS3, DS4, and DS5 strains have statistically significant MIC-factors (Microbially Influenced Corrosion) of 5.46, 8.51, 2.36, and 1.04, while DS2 protective effect factor of 0.89. Weight reduction results with carbon steel likewise supports that corrosion was initiated by DS1 and DS3, while DS2 and DS5 have no any impact though with DS4 we watched less weight reduction however assumed no role in the corrosion. We established the relation of Peroxidase enzyme activity of the isolates. DS1, DS3 and having Peroxidase in the range 22.18, 19.54 U/ml which induce the corrosion whereas DS2 and DS5 having 28.57 and 27.0 U/ml has no any effect and DS4 36 U/ml has inhibitory effect, increasing concentration inhibiting the corrosion. For Catalase DS1, DS3 have 67.28, 61.57 U/ml which induce corrosion while DS2 and DS5 57.71 and 59.14 U/ml also has no effect whereas DS4 70.14 U/ml can inhibit corrosion. Results clearly express that in a specific range both enzymes can induce the corrosion. Our goals are to pursuit and locate the potential role of the enzyme in corrosion induction and inhibition. There is still further work is proceeded for the more profound perception.Khandelwal, A., Vijay, A., Dixit, A., Chhabra, M., 2018. Microbial fuel cell powered by lipid extracted algae: A promising system for algal lipids and power generation. Bioresource Technology 247, 520-527. this study, a promising microbial fuel cell (MFC) system has been developed, wherein algae is cultivated in the cathode chamber, algae biomass is harvested and lipids are extracted. The lipid extracted algal (LEA) biomass was then used as an electron donor substrate. The performance of MFCs fed with LEA biomass was compared with that of fruit waste fed MFCs (FP-MFCs), wherein LEA-fed MFC was superior in all aspects. Power density of 2.7 W m?3 was obtained by LEA-fed MFCs which is 145% and 260% higher than FP MFC and control MFC respectively. The volumetric algae productivity of 0.028 kg m?3 day?1 in cathode chamber was achieved. The system was able to generate 0.0136 kWh Kg?1 COD day?1 of electric energy and 0.0782 kWh m?3 day?1 of algal oil energy. The proposed system is a net energy producer which does not rely heavily on the external supply of electron donor substrates.Khodri, M., Izumo, T., Vialard, J., Janicot, S., Cassou, C., Lengaigne, M., Mignot, J., Gastineau, G., Guilyardi, E., Lebas, N., Robock, A., McPhaden, M.J., 2017. Tropical explosive volcanic eruptions can trigger El Ni?o by cooling tropical Africa. Nature Communications 8, Article 778. aerosols from large tropical explosive volcanic eruptions backscatter shortwave radiation and reduce the global mean surface temperature. Observations suggest that they also favour an El Ni?o within 2 years following the eruption. Modelling studies have, however, so far reached no consensus on either the sign or physical mechanism of El Ni?o response to volcanism. Here we show that an El Ni?o tends to peak during the year following large eruptions in simulations of the Fifth Coupled Model Intercomparison Project (CMIP5). Targeted climate model simulations further emphasize that Pinatubo-like eruptions tend to shorten La Ni?as, lengthen El Ni?os and induce anomalous warming when occurring during neutral states. Volcanically induced cooling in tropical Africa weakens the West African monsoon, and the resulting atmospheric Kelvin wave drives equatorial westerly wind anomalies over the western Pacific. This wind anomaly is further amplified by air–sea interactions in the Pacific, favouring an El Ni?o-like response.Kim, H.-J., Benner, S.A., 2017. Prebiotic stereoselective synthesis of purine and noncanonical pyrimidine nucleotide from nucleobases and phosphorylated carbohydrates. Proceedings of the National Academy of Sciences 114, 11315-11320.: Much recent research into the origins of life focuses on the hypothesis that RNA emerged on early Earth by an abiotic process, and gave Earth its first access to Darwinian evolution. This article provides a key step in this process. Here, we show that the phosphorylated ribonucleoside building blocks for RNA can be made stereoselectively under a prebiotic plausible condition with canonical and noncanonical purines, and with one noncanonical pyrimidine. It also shows that threose nucleoside phosphates can be synthesized in a similar way. This result is significant in terms of numbers of steps, high stereo- and regiochemistry, scope, involvement of minerals, and likelihood of the prebiotic availability of its starting materials. Abstract: According to a current “RNA first” model for the origin of life, RNA emerged in some form on early Earth to become the first biopolymer to support Darwinism here. Threose nucleic acid (TNA) and other polyelectrolytes are also considered as the possible first Darwinian biopolymer(s). This model is being developed by research pursuing a “Discontinuous Synthesis Model” (DSM) for the formation of RNA and/or TNA from precursor molecules that might have been available on early Earth from prebiotic reactions, with the goal of making the model less discontinuous. In general, this is done by examining the reactivity of isolated products from proposed steps that generate those products, with increasing complexity of the reaction mixtures in the proposed mineralogical environments. Here, we report that adenine, diaminopurine, and hypoxanthine nucleoside phosphates and a noncanonical pyrimidine nucleoside (zebularine) phosphate can be formed from the direct coupling reaction of cyclic carbohydrate phosphates with the free nucleobases. The reaction is stereoselective, giving only the β-anomer of the nucleotides within detectable limits. For purines, the coupling is also regioselective, giving the N-9 nucleotide for adenine as a major product. In the DSM, phosphorylated carbohydrates are presumed to have been available via reactions explored previously [Krishnamurthy R, Guntha S, Eschenmoser A (2000) Angew Chem Int Ed 39:2281–2285], while nucleobases are presumed to have been available from hydrogen cyanide and other nitrogenous species formed in Earth’s primitive atmosphere. Kite, E.S., Gao, P., Goldblatt, C., Mischna, M.A., Mayer, D.P., Yung, Y.L., 2017. Methane bursts as a trigger for intermittent lake-forming climates on post-Noachian Mars. Nature Geoscience 10, 737-740. existed on Mars later than 3.6 billion years ago, according to sedimentary evidence for deltaic deposition. The observed fluviolacustrine deposits suggest that individual lake-forming climates persisted for at least several thousand years (assuming dilute flow). But the lake watersheds[rsquor] little-weathered soils indicate a largely dry climate history, with intermittent runoff events. Here we show that these observational constraints, although inconsistent with many previously proposed triggers for lake-forming climates, are consistent with a methane burst scenario. In this scenario, chaotic transitions in mean obliquity drive latitudinal shifts in temperature and ice loading that destabilize methane clathrate. Using numerical simulations, we find that outgassed methane can build up to atmospheric levels sufficient for lake-forming climates, if methane clathrate initially occupies more than 4% of the total volume in which it is thermodynamically stable. Such occupancy fractions are consistent with methane production by water-rock reactions due to hydrothermal circulation on early Mars. We further estimate that photochemical destruction of atmospheric methane curtails the duration of individual lake-forming climates to less than a million years, consistent with observations. We conclude that methane bursts represent a potential pathway for intermittent excursions to a warm, wet climate state on early Mars.Kminek, G., Fisk, L.A., 2017. Protecting our investment in the exploration and utilization of space. Astrobiology 17, 955-955. abstractKnutti, R., Rugenstein, M.A.A., Hegerl, G.C., 2017. Beyond equilibrium climate sensitivity. Nature Geoscience 10, 727-736. climate sensitivity characterizes the Earth's long-term global temperature response to increased atmospheric CO2 concentration. It has reached almost iconic status as the single number that describes how severe climate change will be. The consensus on the 'likely' range for climate sensitivity of 1.5 °C to 4.5 °C today is the same as given by Jule Charney in 1979, but now it is based on quantitative evidence from across the climate system and throughout climate history. The quest to constrain climate sensitivity has revealed important insights into the timescales of the climate system response, natural variability and limitations in observations and climate models, but also concerns about the simple concepts underlying climate sensitivity and radiative forcing, which opens avenues to better understand and constrain the climate response to forcing. Estimates of the transient climate response are better constrained by observed warming and are more relevant for predicting warming over the next decades. Newer metrics relating global warming directly to the total emitted CO2 show that in order to keep warming to within 2 °C, future CO2 emissions have to remain strongly limited, irrespective of climate sensitivity being at the high or low end.K?lbl, D., Pignitter, M., Somoza, V., Schimak, M.P., Strbak, O., Blazevic, A., Milojevic, T., 2017. Exploring fingerprints of the extreme thermoacidophile Metallosphaera sedula grown on synthetic martian regolith materials as the sole energy sources. Frontiers in Microbiology 8, 1918. doi: 10.3389/fmicb.2017.01918. biology of metal transforming microorganisms is of a fundamental and applied importance for our understanding of past and present biogeochemical processes on Earth and in the Universe. The extreme thermoacidophile Metallosphaera sedula is a metal mobilizing archaeon, which thrives in hot acid environments (optimal growth at 74°C and pH 2.0) and utilizes energy from the oxidation of reduced metal inorganic sources. These characteristics of M. sedula make it an ideal organism to further our knowledge of the biogeochemical processes of possible life on extraterrestrial planetary bodies. Exploring the viability and metal extraction capacity of M. sedula living on and interacting with synthetic extraterrestrial minerals, we show that M. sedula utilizes metals trapped in the Martian regolith simulants (JSC Mars 1A; P-MRS; S-MRS; MRS07/52) as the sole energy sources. The obtained set of microbiological and mineralogical data suggests that M. sedula actively colonizes synthetic Martian regolith materials and releases free soluble metals. The surface of bioprocessed Martian regolith simulants is analyzed for specific mineralogical fingerprints left upon M. sedula growth. The obtained results provide insights of biomining of extraterrestrial material as well as of the detection of biosignatures implementing in life search missions.Kolling, H.M., Stein, R., Fahl, K., Perner, K., Moros, M., 2017. Short-term variability in late Holocene sea ice cover on the East Greenland Shelf and its driving mechanisms. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 336-350. sea ice is a critical component of the climate system as it influences the albedo, heat, moisture and gas exchange between ocean and atmosphere as well as the ocean's salinity. An ideal location to study natural sea ice variability during pre-industrial times is the East Greenland Shelf that underlies the East Greenland Current (EGC), the main route of Arctic sea ice and freshwaters from the Arctic Ocean into the northern North Atlantic. Here, we present a new high-resolution biomarker record from the East Greenland Shelf (73°N), which provides new insights into the sea ice variability and accompanying phytoplankton productivity over the past 5.2 kyr. Our IP25 based sea ice reconstructions and the inferred PIP25 index do not reflect the wide-spread late Holocene Neoglacial cooling trend that follows the decreasing solar insolation pattern, which we relate to the strong influence of the polar EGC on the East Greenland Shelf and interactions with the adjacent fjord throughout the studied time interval. However, our reconstructions reveal several oscillations with increasing/decreasing sea ice concentrations that are linked to the known late Holocene climate cold/warm phases, i.e. the Roman Warm Period, Dark Ages Cold Period, Medieval Climate Anomaly and Little Ice Age. The observed changes seem to be connected to general ocean atmosphere circulation changes, possibly related to North Atlantic Oscillation and Atlantic Multidecadal Oscillation regimes. Furthermore, we identify a cyclicity of 73–74 years in sea ice algae and phytoplankton productivity over the last 1.2 kyr, which may indicate a connection to Atlantic Multidecadal Oscillation mechanisms.Komar, N., Zeebe, R.E., 2017. Redox-controlled carbon and phosphorus burial: A mechanism for enhanced organic carbon sequestration during the PETM. Earth and Planetary Science Letters 479, 71-82. records reveal a major perturbation in carbon cycling during the Paleocene–Eocene Thermal Maximum (PETM, ～56 Ma), marked by global warming of more than 5?°C and a prominent negative carbon isotope excursion of at least 2.5‰ within the marine realm. The entire event lasted about 200,000 yr and was associated with a massive release of light carbon into the ocean–atmosphere system over several thousands of years. Here we focus on the terminal stage of the PETM, during which the ocean–atmosphere system rapidly recovered from the carbon cycle perturbation. We employ a carbon-cycle box model to examine the feedbacks between surface ocean biological production, carbon, oxygen, phosphorus, and carbonate chemistry during massive CO2 release events, such as the PETM. The model results indicate that the redox-controlled carbon–phosphorus feedback is capable of producing enhanced organic carbon sequestration during large carbon emission events. The locale of carbon oxidation (ocean vs. atmosphere) does not affect the amount of carbon sequestered. However, even though the model produces trends consistent with oxygen, excess accumulation rates of organic carbon (～1700 Pg C during the recovery stage), export production and δ13Cδ13C data, it fails to reproduce the magnitude of change of sediment carbonate content and the CCD over-deepening during the recovery stage. The CCD and sediment carbonate content overshoot during the recovery stage is muted by a predicted increase in CaCO3 rain. Nonetheless, there are indications that the CaCO3 export remained relatively constant during the PETM. If this was indeed true, then an initial pulse of 3,000 Pg C followed by an additional, slow leak of 2,500 Pg C could have triggered an accelerated nutrient supply to the surface ocean instigating enhanced organic carbon export, consequently increasing organic carbon sequestration, resulting in an accelerated restoration of ocean–atmosphere biogeochemistry during the termination phase of the PETM.Kondori, J., Zendehboudi, S., Hossain, M.E., 2017. A review on simulation of methane production from gas hydrate reservoirs: Molecular dynamics prospective. Journal of Petroleum Science and Engineering 159, 754-772. reservoirs have steadily emerged as an important contributor in energy storage. To better understand the role of hydrates in gas production, it is vital to know the challenges related to the hydrate dissociation. To highlight the main technical challenges, further research and engineering investigations are needed for interactions between the molecules, phase behaviours, and detailed mechanisms of hydrate formation and dissociation. This review paper describes the gas hydrate reservoirs, hydrate dissociation, and previous research works related to gas engineering. This study briefly presents the key theoretical concepts and drawbacks of different techniques/kinetics of decomposition; consisting of depressurising, thermal stimulation, chemical injection, and gas swapping. This will be followed by the theory on the molecular dynamics simulation and its application in various decomposition methods. Owing to the limitations of existing experimental and theoretical approaches, development of more accurate theoretical models and equations of state (EOSs) is inevitable. The molecular dynamics simulation strategy has been used as a strong research tool with adequately small scales in both space and time. The practical implication of molecular dynamics (MD) simulation in hydrate dissociation methods is illustrated at the end of this study for further clarification. The complex nature of hydrates clearly implies that new potential functions for current MD tools are required to satisfactorily comprehend the hydrate molecular structure and mechanisms of hydrate decomposition.Kosateva, A., Stefanova, M., Marinov, S., Czech, J., Carleer, R., Yperman, J., 2017. Characterization of organic components in leachables from Bulgarian lignites by spectroscopy, chromatography and reductive pyrolysis. International Journal of Coal Geology 183, 100-109. from Thrace- and Sofia- coal basins, i.e. “Maritsa-East” and “Stanjanci” mines, were subjected to aqueous sequential extraction at 25 °C during 10 weeks. Each 7 days leachates were separated and pH and conductivity were measured. According to the extraction curves μS vs. time two portions were prepared, enriched in salts, extracts from the first two weeks (“front” of the elution) and in organic matter, extracts from the rest of time (“tail” of the elution curve). Combined freeze-dried extracts were characterized by yields, technical and elemental analyses. They were studied by X-ray photoelectron spectroscopy (XPS) and Infrared spectroscopy (IR). According to XPS spectra the main species on the leachate surfaces were carbon atoms in aromatic and aliphatic structures, 48–53 at. % from the total C1s signal. The intensive N1s signal at 400 eV was assigned to pyrroles and amines (1–3 at. %). The most abundant sulphur form was inorganic sulphates while intensities for the other ones were < 1%. Respectively, the sulphatic sulphur content (13.6%) determined for Maritsa leachate was almost seven times higher than the same sulphur for Stanjanci leachate. FTIR spectra gave evidences for oxygen-containing functional groups, i.e. COOH groups in benzene carboxylic acids and their derivatives, in short-chain aliphatic fatty acids and for polyols. The appearance of mineral matter, mainly gypsum and kaolinite, made equivocal the IR spectra interpretation.Acetone soluble portions of “tail” leachates have represented relatively small parts of the organic matter (340 mg/kg Maritsa East and 80 mg/kg Stanjianci lignite) but have assigned reliable evidences for the polar constituents of leachates. Linear fatty acids, nC12–nC32, nC16max, n-alcohols, benzoic acids, i.e. hydroxy-, methoxy-, phthalic acids, were highly abundant. Sterols, stanols, ketosterols were present in both extracts. Phthalates were recognizable as well.AP-TPR-TD-GC/MS technique has proved the presence of phenols, PAHs and heteroatom containing components in leachates flue gases. From an environmental viewpoint it seems that the identified compounds do not represent an acute toxic risk. However, N-containing compounds could raise concerns and further attention is needed to be focused on them.Kotzakoulakis, K., George, S.C., 2018. Predicting the weathering of fuel and oil spills: A diffusion-limited evaporation model. Chemosphere 190, 442-453. majority of the evaporation models currently available in the literature for the prediction of oil spill weathering do not take into account diffusion-limited mass transport and the formation of a concentration gradient in the oil phase. The altered surface concentration of the spill caused by diffusion-limited transport leads to a slower evaporation rate compared to the predictions of diffusion-agnostic evaporation models. The model presented in this study incorporates a diffusive layer in the oil phase and predicts the diffusion-limited evaporation rate. The information required is the composition of the fluid from gas chromatography or alternatively the distillation data. If the density or a single viscosity measurement is available the accuracy of the predictions is higher. Environmental conditions such as water temperature, air pressure and wind velocity are taken into account. The model was tested with synthetic mixtures, petroleum fuels and crude oils with initial viscosities ranging from 2 to 13,000 cSt. The tested temperatures varied from 0 °C to 23.4 °C and wind velocities from 0.3 to 3.8 m/s. The average absolute deviation (AAD) of the diffusion-limited model ranged between 1.62% and 24.87%. In comparison, the AAD of a diffusion-agnostic model ranged between 2.34% and 136.62% against the same tested fluids.Krajewski, L.C., Lobodin, V.V., Robbins, W.K., Jin, P., Bota, G., Marshall, A.G., Rodgers, R.P., 2017. Method for isolation and detection of ketones formed from high-temperature naphthenic acid corrosion. Energy & Fuels 31, 10674-10679. control at refineries remains a challenge because the mechanism of naphthenic acid (NAP) corrosion is still not fully understood. The rate of NAP corrosion does not correlate with acidity (as measured by total acid number); therefore, it has been suggested that a subset of NAP in petroleum fractions may be more corrosive than others. Because the primary corrosion product (iron naphthenates) may thermally decompose to ketones at corrosion temperatures (250–400 °C), ketones in corrosion fluids could potentially be used to implicate specific problematic acids in corrosion tests. To that end, we have developed a method for isolating and characterizing ketones in corrosion test solutions. Ketones from tests on palmitic and 4-cyclohexyl pentanoic acids (C16H32O2 and C11H20O2) have been successfully isolated with a strong anion exchange solid-phase separation. Gas chromatography/mass spectrometry identifies ketones formed as a result of model acid corrosion. Fourier transform ion cyclotron resonance mass spectrometry further confirms the detection of these ketones and structurally confirms ketones by use of a commercially available reagent that targets ketones and aldehydes. Additional oxygen species generated in the corrosion test likely result from reactions between dissolved atmospheric oxygen and the mineral oil matrix. With this method now validated, it can be applied in future studies of more complex acid mixtures to determine any structural specificity in naphthenic acid corrosion.Kronenberg, M., Trably, E., Bernet, N., Patureau, D., 2017. Biodegradation of polycyclic aromatic hydrocarbons: Using microbial bioelectrochemical systems to overcome an impasse. Environmental Pollution 231, 509-523. aromatic hydrocarbons (PAHs) are hardly biodegradable carcinogenic organic compounds. Bioremediation is a commonly used method for treating PAH contaminated environments such as soils, sediment, water bodies and wastewater. However, bioremediation has various drawbacks including the low abundance, diversity and activity of indigenous hydrocarbon degrading bacteria, their slow growth rates and especially a limited bioavailability of PAHs in the aqueous phase. Addition of nutrients, electron acceptors or co-substrates to enhance indigenous microbial activity is costly and added chemicals often diffuse away from the target compound, thus pointing out an impasse for the bioremediation of PAHs. A promising solution is the adoption of bioelectrochemical systems. They guarantee a permanent electron supply and withdrawal for microorganisms, thereby circumventing the traditional shortcomings of bioremediation. These systems combine biological treatment with electrochemical oxidation/reduction by supplying an anode and a cathode that serve as an electron exchange facility for the biocatalyst. Here, recent achievements in polycyclic aromatic hydrocarbon removal using bioelectrochemical systems have been reviewed. This also concerns PAH precursors: total petroleum hydrocarbons and diesel. Removal performances of PAH biodegradation in bioelectrochemical systems are discussed, focussing on configurational parameters such as anode and cathode designs as well as environmental parameters like porosity, salinity, adsorption and conductivity of soil and sediment that affect PAH biodegradation in BESs. The still scarcely available information on microbiological aspects of bioelectrochemical PAH removal is summarised here. This comprehensive review offers a better understanding of the parameters that affect the removal of PAHs within bioelectrochemical systems. In addition, future experimental setups are proposed in order to study syntrophic relationships between PAH degraders and exoelectrogens. This synopsis can help as guide for researchers in their choices for future experimental designs aiming at increasing the power densities and PAH biodegradation rates using microbial bioelectrochemistry.Kulkarni, H.V., Mladenov, N., McKnight, D.M., Zheng, Y., Kirk, M.F., Nemergut, D.R., 2018. Dissolved fulvic acids from a high arsenic aquifer shuttle electrons to enhance microbial iron reduction. Science of The Total Environment 615, 1390-1395. was demonstrated more than two decades ago that microorganisms use humic substances, including fulvic acid (FA), as electron shuttles during iron (Fe) reduction in anaerobic soils and sediments. The relevance of this mechanism for the acceleration of Fe(III) reduction in arsenic-laden groundwater environments is gaining wider attention. Here we provide new evidence that dissolved FAs isolated from sediment-influenced surface water and groundwater in the Bengal Basin were capable of electron shuttling between Geobacter metallireducens and Fe(III). Moreover, all four Bangladesh sediment-derived dissolved FAs investigated in this study had higher electron accepting capacity (176 to 245 μmol/g) compared to aquatic FAs, such as Suwanee River Fulvic Acid (67 μmol/g). Our direct evidence that Bangladesh FAs are capable of intermediate electron transfer to Fe(III) supports other studies that implicate electron shuttling by sediment-derived aqueous humics to enhance Fe reduction and, in turn, As mobility. Overall, the finding of greater electron accepting capacity by dissolved FAs from groundwater and other sediment-influenced environments advances our understanding of mechanisms that control Fe reduction under conditions where electron transfer is the rate limiting step.Kwek, W., Khan, M.K., Sarkar, B., Kim, J., 2018. Supercritical methanol as an effective medium for producing asphaltenes-free light fraction oil from vacuum residue. The Journal of Supercritical Fluids 133, Part 1, 184-194. upgrading of vacuum residue (VR) in supercritical methanol (scMeOH) was investigated without using catalysts. Various process parameters, including temperature (350–425 °C), reaction time (30–90 min), and additives (toluene and hydrogen) were explored to optimize the yield of light fraction oil (LFO) with few impurities. At a 400 °C, 16.7 wt% of VR in methanol for 60 min, the LFO produced in scMeOH contained very low asphaltene content (0.74 wt%) and a very low amount of heteroatom/metallic impurities (S, 3.58 wt%; N, non-detectable; Ni, 10.4 ppm; V, 36.9 ppm, Fe, 7.3 ppm). In addition, the naptha-to-diesel fraction increased from 1 wt% (VR feed) to 15 wt% and the saturate + aromatic content increased from 43.7 area% (VR feed) to 59.6 area% in the LFO. When the reaction time was extended to 90 min at 400 °C, a complete removal of asphaltenes could be achieved.Lachniet, M., Asmerom, Y., Polyak, V., Denniston, R., 2017. Arctic cryosphere and Milankovitch forcing of Great Basin paleoclimate. Scientific Reports 7, Article 12955. Great Basin paleoclimate history has been examined for more than a century, the orbital-scale paleoclimate forcings remain poorly understood. Here we show – by a detailed phasing analysis of a well-dated stalagmite δ18O time series – that Great Basin paleoclimate is linearly related to, but lagged, the 23,000?yr precession cycle in northern hemisphere summer insolation by an average of 3240 years (?900 to 6600?yr range) over the last two glacial cycles. We interpret these lags as indicating that Great Basin climate is sensitive to and indirectly forced by changes in the cryosphere, as evidenced by fast and strong linkages to global ice volume and Arctic paleoclimate indicators. Mid-latitude atmospheric circulation was likely impacted by a northward shifted storm track and higher pressure over the region arising from decreased sea ice and snow cover. Because anthropogenic warming is expected to reduce northern hemisphere snow and ice cover, continued increase in atmospheric greenhouse gases is likely to result in warming and drying over coming centuries that will amplify a warming trend that began ~2400 years ago.Lai, Z., Kind, T., Fiehn, O., 2017. Using accurate mass gas chromatography–mass spectrometry with the mine database for epimetabolite annotation. Analytical Chemistry 89, 10171-10180. spectrometry-based untargeted metabolomics often detects statistically significant metabolites that cannot be readily identified. Without defined chemical structure, interpretation of the biochemical relevance is not feasible. Epimetabolites are produced from canonical metabolites by defined enzymatic reactions and may represent a large fraction of the structurally unidentified metabolome. We here present a systematic workflow for annotating unknown epimetabolites using high resolution gas chromatography–accurate mass spectrometry with multiple ionization techniques and stable isotope labeled derivatization methods. We first determine elemental formulas, which are then used to query the “metabolic in-silico expansion” database (MINE DB) to obtain possible molecular structures that are predicted by enzyme promiscuity from canonical pathways. Accurate mass fragmentation rules are combined with in silico spectra prediction programs CFM-ID and MS-FINDER to derive the best candidates. We validated the workflow by correctly identifying 10 methylated nucleosides and 6 methylated amino acids. We then employed this strategy to annotate eight unknown compounds from cancer studies and other biological systems.Lapham, L., Marshall, K., Magen, C., Lyubchich, V., Cooper, L.W., Grebmeier, J.M., 2017. Dissolved methane concentrations in the water column and surface sediments of Hanna Shoal and Barrow Canyon, Northern Chukchi Sea. Deep Sea Research Part II: Topical Studies in Oceanography 144, 92-103. estimates of methane (CH4) flux suggest that Arctic shelves may be a significant source of atmospheric CH4, a potent greenhouse gas. However, little information is known about the CH4 flux from most Arctic shelves, other than the East Siberian Arctic Shelf. We report here dissolved CH4 concentrations in the water column and within surface sediments of the Northern Chukchi Sea. We hypothesized that this area contains high concentrations of CH4 because it receives nutrient rich waters through the Bering Strait, promoting primary production that enhances an organic-rich material flux to the seafloor and eventual microbial methanogenesis in the sediments. In August 2012, as part of the Chukchi Sea Offshore Monitoring in Drilling Area (COMIDA) project, fourteen stations were sampled on Hanna Shoal, a shallow feature on the shelf, and ten stations across the undersea Barrow Canyon. On Hanna Shoal, water column CH4 concentrations ranged from 14 to 74 nM, and surface concentrations were up to 15 times supersaturated in CH4 compared to equilibrium with the average atmospheric concentrations (3 nM). CH4 concentrations at the sediment-water interface were around 1,500 nM, and typically increased with depth in the sediment. At the head of Barrow Canyon, water column CH4 concentrations ranged from 5 to 46 nM, with the highest concentrations in the deepest waters that were sampled (118 m). Overall, the calculated fluxes to the atmosphere ranged from 1 to 80 ?mol CH4 m?2 d?1 for Hanna Shoal and 4 to 17 ?mol CH4 m?2 d?1 across the Barrow Canyon stations. Although there was a large range in these fluxes, the average atmospheric flux (20 ?mol CH4 m?2 d?1) across Hanna Shoal was 12 times lower than the flux reported from the East Siberian Arctic Shelf in summer. We conclude that while there is a positive flux of CH4 to the atmosphere, this part of the Chukchi Sea is not a significant source of atmospheric CH4 compared to the East Siberian Sea shelf.Lebedev, M., Zhang, Y., Sarmadivaleh, M., Barifcani, A., Al-Khdheeawi, E., Iglauer, S., 2017. Carbon geosequestration in limestone: Pore-scale dissolution and geomechanical weakening. International Journal of Greenhouse Gas Control 66, 106-119. dioxide geosequestration in deep saline aquifers or oil and gas reservoirs is a key technology to mitigate anthropogenic greenhouse gas emissions. Porous carbonate rock is a potential host rock for CO2 storage; however, carbonate rock chemically reacts when exposed to the acidic brine (which is created by the addition of CO2, CO2-saturated brine). These reactive transport processes are only poorly understood, particularly at the micrometre scale, and importantly how this affects the geomechanical rock properties. We thus imaged a heterogeneous oolitic limestone (Savonnières limestone) core before and after flooding with brine and CO2-saturated brine at representative reservoir conditions (323 K temperature, 10 MPa pore pressure, 5 MPa effective stress) in-situ at high resolutions (3.43 μm and 1.25 μm voxel size) in 3D with an x-ray micro-computed tomograph; and measured the changes in nano-scale mechanical properties induced by acid exposure. Indeed the carbonate rock matrix partially dissolved, and absolute and effective porosity and permeability significantly increased. This dissolution was confined to the original flow channels and inlet points. Importantly, the rock matrix weakened significantly (- 47% in indentation modulus) due to the acid exposure.Lee, K.H., Hamashima, K., Kimoto, M., Hirao, I., 2018. Genetic alphabet expansion biotechnology by creating unnatural base pairs. Current Opinion in Biotechnology 51, 8-15. studies have made it possible to expand the genetic alphabet of DNA, which is originally composed of the four-letter alphabet with A–T and G–C pairs, by introducing an unnatural base pair (UBP). Several types of UBPs function as a third base pair in replication, transcription, and/or translation. Through the UBP formation, new components with different physicochemical properties from those of the natural ones can be introduced into nucleic acids and proteins site-specifically, providing their increased functionalities. Here, we describe the genetic alphabet expansion technology by focusing on three types of UBPs, which were recently applied to the creations of DNA aptamers that bind to proteins and cells and semi-synthetic organisms containing DNAs with a six-letter alphabet.Lee, S.Y., Cho, J.M., Chang, Y.K., Oh, Y.-K., 2017. Cell disruption and lipid extraction for microalgal biorefineries: A review. Bioresource Technology 244, 1317-1328. microalgae-based biorefinement process has attracted much attention from academic and industrial researchers attracted to its biofuel, food and nutraceutical applications. In this paper, recent developments in cell-disruption and lipid-extraction methods, focusing on four biotechnologically important microalgal species (namely, Chlamydomonas, Haematococcus, Chlorella, and Nannochloropsis spp.), are reviewed. The structural diversity and rigidity of microalgal cell walls complicate the development of efficient downstream processing methods for cell-disruption and subsequent recovery of intracellular lipid and pigment components. Various mechanical, chemical and biological cell-disruption methods are discussed in detail and compared based on microalgal species and status (wet/dried), scale, energy consumption, efficiency, solvent extraction, and synergistic combinations. The challenges and prospects of the downstream processes for the future development of eco-friendly and economical microalgal biorefineries also are outlined herein.Lei, L.-D., Shen, J., Li, C., Algeo, T.J., Chen, Z.-Q., Feng, Q.-L., Cheng, M., Jin, C.-S., Huang, J.-H., 2017. Controls on regional marine redox evolution during Permian-Triassic transition in South China. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 17-32. oceanic anoxia is regarded as a leading cause of the Permian-Triassic boundary (PTB) mass extinction, its timing, extent, and underlying causes remain unclear. Here, we conducted a high-resolution Fe-S-C-Mo geochemical study of the entire Changhsingian and lowermost Induan succession in a carbonate-ramp setting at Ganxi, western Hubei Province, South China. Six stratigraphic units representing discrete redox intervals were identified based on integrated Fe-S-C-Mo data. Units I–III are of latest Wuchiapingian to early Changhsingian age, with Units I and III characterized by euxinia and Unit II by uncertain redox conditions. Unit IV, of mid-Changhsingian age, records a gradual transition from euxinic to ferruginous conditions. Units V and VI, spanning the latest Permian mass extinction (LPME) to earliest Triassic interval, were deposited under dominantly ferruginous conditions punctuated by both euxinic and oxic episodes. Redox variations at Ganxi were controlled by contemporaneous oceanographic changes in the upper oceanic thermocline region: (i) euxinia in Units I and III may record elevated marine productivity (as suggested by mean organic carbon accumulation rates, or OCAR, of 6.5 and 5.1 mg/cm2/kyr, respectively) that was possibly related to upwelling; (ii) the euxinic-to-ferruginous transition from Unit IV to Units V–VI can be attributed to a combination of reduced sulfate availability and rising terrigenous iron inputs (mean Fe of 1.7% and 3.9%, respectively, for Units V–IV and VI compared to 1.0% for Units I–III); and (iii) transient intervals of euxinia in Units V and VI were facilitated by enhanced sulfate fluxes related to episodic volcanism during this interval. An integration of the redox data from Ganxi with previously published data from the Shangsi and Xiakou sections suggests that enhanced weathering fluxes were most likely the key factor controlling the marine redox transition from euxinic to ferruginous conditions during the latest Permian across the South China region.Lewy, Z., 2017. Dinosaur demise in light of their alleged perennial polar residency. International Journal of Earth Sciences 106, 2609-2616. end-Cretaceous biological crisis is represented by the demise of the non-avian dinosaurs. However, most crucial biologically was the elimination of the photosynthesizing marine phyto- and zooplankton forming the base of the marine food chain. Their abrupt demise attests to sunlight screening darkening the atmosphere for a few years. Alvarez et al. (Science 208:1095–1108, 1980. doi: 10.1126/science.208.44 ) noticed in deep marine end-Cretaceous sediments an anomalous rise in the chemical element iridium (Ir), which is rare on planet Earth and thus suggests an extraterrestrial origin through an impact of a large asteroid. This impact would have ejected enormous quantities of particles and aerosols, shading the solar illumination as attested to by the elimination of the marine photosynthesizing plankton. Such a dark period must have affected life on land. The apparent cold-blooded non-avian dinosaurs, which were used to living in open terrains to absorb the solar illumination, became inactive during the dark period and were incapable of withstanding predators. This was in contrast to cold-blooded crocodilians, turtles and lizards that could hide in refuge sites on land and in the water. Dinosaur relics discovered in Cretaceous Polar Regions were attributed to perennial residents, surviving the nearly half-year-long dark winter despite their ability to leave. The polar concentrations of disarticulated dinosaur bones were suggested as having resulted from a catastrophic burial of a population by floods. However, this should have fossilized complete skeletons. Alternatively, herds of dinosaurs living in high latitudes might have been sexually driven to spend the half year of continuously illuminated polar summer for mating rather than for nourishment, in which the lower latitudes provided as well. The aggressive mating competitions would have left victims among the rivals and of young ones incidentally trampled over, all being consumed and their skeletons disarticulated. Accordingly, the alleged ‘polar dinosaurs’ do not challenge the logical conclusion that the non-avian dinosaurs were cold-blooded, as a result of which they became inactive and subjected to predation during the end-Cretaceous dark period.Li, F., Yan, J., Burne, R.V., Chen, Z.-Q., Algeo, T.J., Zhang, W., Tian, L., Gan, Y., Liu, K., Xie, S., 2017. Paleo-seawater REE compositions and microbial signatures preserved in laminae of Lower Triassic ooids. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 96-107. indicative of paleo-seawater rare earth element (REE) composition and microbial activity were identified in marine ooids from the Lower Triassic of South China using in situ laser ablation–inductively coupled plasma-mass spectroscopy (LA-ICP-MS) together with petrographic and isotope geochemical techniques. Quantitative trace element profiles were generated across successive growth laminae in the cortices of selected ooids. The shale-normalized REE and yttrium (Y) data of these layers show 1) light rare earth element depletion (mean LaSN/YbSN = 0.36 ± 0.14), 2) positive La anomalies (mean (La/La*)SN = 2.02 ± 1.25), and 3) high ratios of Y/Ho (mean 53 ± 12), which are similar to modern seawater compositions and Bahamian ooids. These findings imply that ooids in the study samples faithfully record Early Triassic paleo-seawater chemical signals such as REE + Y distributions. Petrographic observations revealed dark-colored layers with intense fluorescence containing structures that resemble microbial filaments or extracellular polymeric substances. These layers also possess more enriched REE compositions and higher concentrations of nutrient-like elements (e.g., Zn and Ba) than adjacent recrystallized light-colored laminae. Most ooid laminae contain negative Ce anomalies indicative of a well-oxygenated environment of formation, but some laminae have minimal negative anomalies suggesting the influence of suboxic porewater conditions. The present study provides a new perspective on the role of microbes in ooid genesis and on the utility of ooids as proxies for paleo-seawater chemistry.Li, H., Cai, C., Jia, L., Xu, C., Zhang, K., 2017. The effect of water chemistry on thermochemical sulfate reduction: A case study from the ordovician in the Tazhong area, northwest China. Geofluids 2017, 11. water chemistry, sulfate sulfur isotopes, and associated H2S contents and sulfur isotopes were measured from the Ordovician in Tazhong area, Tarim Basin. The aim is to elucidate the effects of geochemical composition of formation water on thermochemical sulfate reduction (TSR) and potential usage of SO4/Cl ratios as a new proxy for TSR extents in areas, where H2S and thiaadamantanes (TAs) data are not available. The formation water has SO4/Cl ratios from 0.0002 to 0.016, significantly lower than 0.04 to 0.05 from 3 to 7 times evapoconcentrated seawater. Thus, the low values are explained to result from TSR. Furthermore, the SO4/Cl ratios show negative correlation relationships to TAs and H2S concentrations, indicating that TSR occurred in a relatively closed system and SO4/Cl ratio can be used to indicate TSR extents in this area. Extensive TSR in the Cambrian in the Tazhong area, represented by low SO4/Cl ratios and high H2S and TAs concentrations, is accompanied by formation water with high TDS and Mg concentrations, indicating the effects of water chemistry on TSR under a realistic geological background. In contrast, the low TSR extent in the Ordovician may have resulted from limited TSR reaction duration and total contribution of aqueous SO4-2.Li, J., Ma, Y., Huang, K., Lu, S., Yin, J., Zhang, Y., 2017. Comprehensive polynomial simulation and prediction for Langmuir volume and Langmuir pressure of shale gas adsorption using multiple factors. Marine and Petroleum Geology 88, 1004-1012. this study, 32 experimental measurements on the isothermal adsorption of methane for 18 shale samples from China's three largest continental oil basins—Songliao, Bohai Bay, and Ordos basins—were used to construct comprehensive polynomial simulation and prediction models for Langmuir volume and Langmuir pressure. The models were based on shale properties (total organic carbon (TOC) content, amount of residual hydrocarbon S1, and mineral composition of rocks) and adsorption condition (temperature) using a weighted sum of multiple variables. The influences of various factors were quantitatively characterized, and the prediction accuracy was verified. Langmuir volume is mainly affected by temperature, shale TOC content, amount of residual hydrocarbon, and clay mineral content; Langmuir pressure is mainly affected by clay, carbonate, feldspar and illite content (because shale pore size can be affected by shale mineral composition). Based on the resource potential and the producibility of shale gas, the area suitable for shale gas exploration and development should have high abundance of organic matter (TOC and residual hydrocarbon S1), low clay mineral content and feldspar content, high conversion rate of montmorillonite to illite (strong diagenesis), and high carbonate content. The comprehensive polynomial prediction model can effectively simulate and predict Langmuir volume and Langmuir pressure, thereby reducing the amount of work necessary for evaluation of shale gas resource potential and economic feasibility.Li, L., Ren, W., Kong, H., Zhao, C., Zhao, X., Lin, X., Lu, X., Xu, G., 2017. An alignment algorithm for LC-MS-based metabolomics dataset assisted by MS/MS information. Analytica Chimica Acta 990, 96-102. chromatography-mass spectrometry (LC-MS) is an important analytical platform for metabolomics study. Peak alignment of metabolomics dataset is one of the keys for a successful metabolomics study. In this work, a MS/MS-based peak alignment method for LC-MS metabolomics data was developed. A rigorous strategy for screening endogenous reference variables was proposed. Firstly, candidate endogenous reference variables were selected based on MS, MS/MS and retention time in all samples. Multiple robust endogenous reference variables were obtained through further evaluation and confirmation. Then retention time of each metabolite feature was corrected by local linear regression using the four nearest neighbor robust reference variables. Finally, peak alignment was carried out based on corrected retention time, MS and MS/MS. Comparing with the other two peak alignment methods, the developed method showed a good performance and was suitable for metabolomics data with larger retention time drift. Our approach provides a simple and robust alignment method which is reliable to align LC-MS metabolomics dataset.Li, M., Gao, Y., Qian, W.-J., Shi, L., Liu, Y., Nelson, W.C., Nicora, C.D., Resch, C.T., Thompson, C., Yan, S., Fredrickson, J.K., Zachara, J.M., Liu, C., 2017. Targeted quantification of functional enzyme dynamics in environmental samples for microbially mediated biogeochemical processes. Environmental Microbiology Reports 9, 512-521. enzymes catalytically drive biogeochemical processes in environments. The dynamic linkage between functional enzymes and biogeochemical species transformation has, however, rarely been investigated for decades because of the challenges to directly quantify enzymes in environmental samples. The diversity of microorganisms, the low amount of available biomass and the complexity of chemical composition in environmental samples represent the main challenges. To address the diversity challenge, we first identify several signature peptides that are conserved in the targeted enzymes with the same functionality across many phylogenetically diverse microorganisms using metagenome-based protein sequence data. Quantification of the signature peptides then allows estimation of the targeted enzyme abundance. To achieve analyses of the requisite sensitivity for complex environmental samples with low available biomass, we adapted a recently developed ultrasensitive targeted quantification technology, termed high-pressure high-resolution separations with intelligent selection and multiplexing (PRISM) by improving peptide separation efficiency and method detection sensitivity. Nitrate reduction dynamics catalyzed by dissimilatory and assimilatory enzymes in a hyporheic zone sediment was used as an example to demonstrate the application of the enzyme quantification approach. Together with the measurements of biogeochemical species, the approach enables investigating the dynamic linkage between functional enzymes and biogeochemical processes.Li, M., Vashaee, S., Romero-Zerón, L., Marica, F., Balcom, B.J., 2017. A magnetic resonance study of low salinity waterflooding for enhanced oil recovery. Energy & Fuels 31, 10802-10811. salinity waterflooding (LSF) has been proposed to improve oil recovery, with major projects in progress worldwide. There is however no consensus on the mechanisms of LSF for enhanced oil recovery (EOR). Wettability change is the most widely accepted mechanism. In this work, magnetic resonance (MR) and magnetic resonance imaging (MRI) were employed to monitor oil displacement processes during model laboratory scale LSF experiments. The MR and MRI measurements permit evaluation of putative LSF mechanisms. Two clay-coated sand packs, one with nonswelling kaolinite, the other with swelling montmorillonite, were prepared as model porous media for LSF. The interactions between pore fluids (oil and water) and the clay-coated pore surfaces were evaluated with relaxation time measurements. A MRI methodology, spin echo single point imaging (SE-SPI), was employed to spatially resolve the T2 distribution along the sand pack. The oil saturation profiles were determined from SE-SPI measurements. A new differential relaxation time distribution method is proposed in this work for oil saturation estimation. The pore fluid self-diffusion coefficients were measured. The mechanism of wettability change for LSF is suggested on the basis of the oil diffusion coefficient variation with LSF. The similarities and differences between the kaolinite and montmorillonite behaviors are discussed. This work demonstrates that MR and MRI are robust tools to monitor oil displacement processes, with the potential to reveal the mechanisms of LSF and other procedures for enhanced oil recovery.Li, S., Wang, Z., Xu, X., Zheng, R., Hou, J., 2017. Experimental study on dissociation of hydrate reservoirs with different saturations by hot brine injection. Journal of Natural Gas Science and Engineering 46, 555-562. brine injection is one of the effective ways to dissociate natural gas hydrate (NGH), and the hydrate saturation is a key parameter which affects the thermal dissociation characteristics of hydrate reservoirs. In this study, experiments of hydrate dissociation by hot brine injection are conducted with a self-designed experimental apparatus. The gas production performance, the variation of pressure and temperature, as well as energy efficiency are investigated with hydrate saturation of 16%, 32%, 48% and 64%.The results show that the average gas production rate will rise with the hydrate saturation increases from 16% to 48%, while when the hydrate saturation increases to 64%, the gas production rate will decrease remarkably due to the high pressure resulting from low permeability and Jamin Effect. The heating range, the temperature increment and the movement rate of thermal front will all decline with the increase of hydrate saturation. The optimal production performance will be achieved when the hydrate saturation is 48% under the experimental conditions, in which case the energy efficiency at the end of hot brine injection is 7.0, and the percentage of cumulative gas production is 65%. Therefore, hot brine injection is not a good choice when the hydrate saturation is equal or greater than 64%.Li, T., Jiang, Z., Xu, C., Liu, B., Liu, G., Wang, P., Li, X., Chen, W., Ning, C., Wang, Z., 2017. Effect of pore structure on shale oil accumulation in the lower third member of the Shahejie formation, Zhanhua Sag, eastern China: Evidence from gas adsorption and nuclear magnetic resonance. Marine and Petroleum Geology 88, 932-949. shale oil occurs primarily in micro–nano pores and fractures, research about the effect of pore structure on shale oil accumulation has great significance for shale oil exploration and development. The effect of pore structure on shale oil accumulation in the lower third member of the Shahejie formation (Es3l), Zhanhua Sag, eastern China was investigated using gas adsorption, soxhlet extraction, nuclear magnetic resonance (NMR) analysis, and field emission scanning electron microscope (FE-SEM) observation. The results indicated that the samples contained a larger amount of ink-bottle-shaped and slit-shaped pores after extraction than before extraction. The pore volume and specific surface area of the samples were approximately 2.5 times larger after extraction than before extraction. Residual hydrocarbon occurred primarily in the free-state form in pores with diameters of 10–1000 nm, which can provide sufficient pore volume for free hydrocarbon accumulation. Therefore, pores with diameters of 10–1000 nm were regarded as “oil-enriched pores”, which are effective pores for shale oil exploration, whereas pores with diameters smaller than 10 nm were regarded as “oil-ineffective pores”. Samples with only well-developed small pores with diameters smaller than 1000 nm showed high oil saturation, whereas samples with both small pores and also relatively large pores and micro-fractures presented low oil saturation. As the minimum pore size allowing fluid expulsion is 1000 nm, pores with diameters greater than 1000 nm were considered as “oil-percolated pores”. Large pores and micro-fractures are generally interconnected and may even form a complex fracture mesh, which greatly improves the permeability of shale reservoirs and is beneficial to fluid discharge.Li, W., Zhang, Z., 2017. Paleoenvironment and its control of the formation of Oligocene marine source rocks in the deep-water area of the northern South China Sea. Energy & Fuels 31, 10598-10611. article discusses the paleoenvironment and its control on Oligocene source rock formation in the deep water area of the northern South China Sea (SCS), including the deep water area of the Qiongdongnan (QDN) Basin and Baiyun Sag of the Pearl River Mouth (PRM) Basin. During E3y and E3l deposition, the terrigenous detrital matter (TDM) inputs were moderate to high and moderate, respectively, as indicated by TiO2 values and SiO2/Al2O3 ratios, which accordingly diluted primary production, causing low to moderate and moderate productivity, respectively. The bottom water was oxic because of abundant TDM input, which was unbeneficial for organic matter accumulation. In this environment, algal organic matter could not be preserved. Terrigenous organic matter (TOM) is the main controlling factor of Oligocene source rock formation in the deep-water area of the QDN basin. Source rocks with high organic matter content in the Yacheng Formation could not be formed, although there was moderate to high TOM input in this period, as suggested by relatively high oleanane/αβ C30hopane (OL/C30H) ratios and low ααα20RC27/ααα20RC29 sterane (C27/C29) ratios. During E3l deposition, the influx of TOM was reduced, making conditions unsuitable for high organic carbon source rock formation. In contrast to the QDN basin, there was an influx of fresh water (the ancient Pearl River) into the PRM basin, which significantly influenced the source rock formation in the Baiyun Sag. Thus, TOM and TDM inputs were abundant during E3z deposition. Increased content of TDM not only reduced primary production, causing moderate and low productivity during E3e and E3z deposition, respectively, but also contributed to oxic conditions. Although most algal organic matter could not be preserved in the oxygenated water column, part of the algal organic matter could have accumulated due to the high sedimentary rate suggested by high content of TDM, which supported Oligocene source rock formation in the Baiyun Sag. TOM mainly controlled the development of source rocks in the Enping Formation, and source rocks with relatively high organic matter abundance could be formed. However, multiple factors (besides the main factors TOM and TDM, paleoproductivity and redox conditions were also included) influenced the source rocks in the Zhuhai Formation. Organic carbon-rich source rocks could have developed in this period.Li, Y., Huang, T., Pang, Z., Jin, C., 2017. Geochemical processes during hydraulic fracturing: a water-rock interaction experiment and field test study. Geosciences Journal 21, 753-763. environmental problems related to flowback fluid have recently become a concern for hydraulic fracturing during shale gas production. Detailed studies on the geochemical reactions during hydraulic fracturing are performed for the Lower Silurian Longmaxi shale formation, Fuling block, Sichuan basin, SW China, through water-rock interaction experiment conducted under reservoir conditions, and comparisons with field test data are made. Results show that the total dissolved solids (TDS) of the flowback fluid increases and Ca2+, Na+, Cl– and SO42– make dominant contributions. The increases of Na+ and Cl– are assumed to be caused by halite dissolution and mixing with in situ formation water in the marine facies reservoir. The main geochemical reactions are inferred to be pyrite oxidation and the dissolution of calcite, dolomite and plagioclase, resulting in increases of major ions in the flowback fluid. Heavy metals, including Mn, Ni, Mo and Zn, exceed the drinking water criteria of China, and the potential threat from leakage should be a concern. Besides of CH4, as the specific pollutant to groundwater system, inorganic geochemical monitoring of shallow groundwater system should track TDS, major ions of Cl–, SO42–, Na+, and Ca2+, trace elements of Li, Ni, Pb, Cu, Zn, Mn, Mo and Rb, and stable isotopes, such as 18OH2O, 2HH2O and 13CDIC.Li, Y., Schieber, J., Fan, T., Li, Z., Zhang, J., 2017. Regional depositional changes and their controls on carbon and sulfur cycling across the Ordovician-Silurian boundary, northwestern Guizhou, South China. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 816-832. controls of regional depositional environment on stable isotope records spanning the Ordovician-Silurian boundary on the Yangtze Platform have seldom been investigated. The objectives of this study include reconstruction of regional depositional settings and assessment of how sedimentary processes may have influenced carbon- and sulfur-isotopic fractionation. Seven shale facies have been recognized in the Wufeng-Longmaxi interval from two locations. Completely bioturbated claystone of the basal Wufeng Formation accumulated on a shallow oxygenated muddy shelf. Overlying faintly banded black siliceous shale suggests deposition under deep anoxic conditions interrupted by episodes of dysoxia. Muddy fossiliferous facies of the Guanyinqiao Formation reflects a glacial sea-level lowstand setting, and the observed proximal to distal heterogeneity of facies matrix supports shallowing in the proximal area. Overlying faintly banded black shale of the Longmaxi Formation tells of a post-glacial transgression. The carbonaceous deposits are overlain by banded gray and dark gray muddy siltstones and suggest a shoaling upward trend. The shallow-water facies display relatively heavier δ13Corg values, whereas deep-water facies are characterized by lower δ13Corg values. Discrepancies between Hirnantian positive δ13Corg excursions in proximal and distal areas probably reflect spatial gradient in seawater δ13CDIC induced by glacioeustasy. Deposits accumulated under oxic and physically dynamic conditions display strong positive δ34Ssulfide excursions, perhaps a consequence of diagenetic sulfate reduction occurred at some depth below the sediment-water interface and removed from the sulfate pool of overlying water column. Negative relationship between δ34Ssulfide and TOC indicates that redox conditions and physical reworking of sediment at the sediment-water interface controlled the rate of microbial sulfate reduction and sulfur isotope fractionation. Overall, co-variation of lithofacies and isotopic records suggests that local heterogeneity of seawater chemistry and sedimentary dynamics may exert partial controls on biogeochemical processes and amplify the magnitude of the Hirnantian isotopic excursions in the proximal area.Li, Y., Zhao, L., Chen, Z.-Q., Algeo, T.J., Cao, L., Wang, X., 2017. Oceanic environmental changes on a shallow carbonate platform (Yangou, Jiangxi Province, South China) during the Permian-Triassic transition: Evidence from rare earth elements in conodont bioapatite. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 6-16. environmental stresses (e.g., expanded anoxia, elevated siliciclastic fluxes) are thought to have been important factors in the latest Permian mass extinction (LPME). Here, we investigate changes in redox conditions and siliciclastic fluxes during the Permian-Triassic transition in South China through in-situ analysis of the rare earth element (REE) composition of albid crowns of single conodont elements measured using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). For comparison, we also analyzed REEs in the sediment matrix enclosing the conodonts (i.e., whole-rock samples). The study locale (Yangou) was located on a shallow carbonate platform on the eastern margin of the Yangtze Platform to minimize the influence of detrital siliciclastics and, thus, enhance the chances of recovering a hydrogenous (seawater-sourced) REE signal.The analyzed conodonts exhibit REE patterns consistent with mixed hydrogenous (seawater) and lithogenous (siliciclastic) sources, with specimens from below the LPME horizon showing dominantly hydrogenous influences (Y/Ho > 50) and those from above the LPME horizon showing dominantly lithogenous influences (Y/Ho < 50). Locally elevated Ce/Ce* ratios and U concentrations in pre-LPME conodonts suggest an episodic shoaling of the oceanic chemocline, causing incursions of suboxic to anoxic seawaters onto the shallow Yangou carbonate platform. Chemical index of alteration (CIA) values increase sharply at the LPME, suggesting increased rates of continental erosion and a relative increase in chemical over physical weathering, possibly as a consequence of globally elevated temperatures. The present case study confirms that conodonts from relatively clean, low-clay (Al < 0.5%) carbonate facies can potentially preserve original seawater REE signatures.Liang, Y., Zhang, Y., Wang, N., Luo, T., Zhang, Y., Rivkin, R.B., 2017. Estimating primary production of picophytoplankton using the carbon-based ocean productivity model: A preliminary study. Frontiers in Microbiology 8, 1926. doi: 10.3389/fmicb.2017.01926. are acknowledged to contribute significantly to primary production (PP) in the ocean while now the method to measure PP of picophytoplankton (PPPico) at large scales is not yet well established. Although the traditional 14C method and new technologies based on the use of stable isotopes (e.g., 13C) can be employed to accurately measure in situ PPPico, the time-consuming and labor-intensive shortage of these methods constrain their application in a survey on large spatiotemporal scales. To overcome this shortage, a modified carbon-based ocean productivity model (CbPM) is proposed for estimating the PPPico whose principle is based on the group-specific abundance, cellular carbon conversion factor (CCF), and temperature-derived growth rate of picophytoplankton. Comparative analysis showed that the estimated PPPico using CbPM method is significantly and positively related (r2 = 0.53, P < 0.001, n = 171) to the measured 14C uptake. This significant relationship suggests that CbPM has the potential to estimate the PPPico over large spatial and temporal scales. Currently this model application may be limited by the use of invariant cellular CCF and the relatively small data sets to validate the model which may introduce some uncertainties and biases. Model performance will be improved by the use of variable conversion factors and the larger data sets representing diverse growth conditions. Finally, we apply the CbPM-based model on the collected data during four cruises in the Bohai Sea in 2005. Model-estimated PPPico ranged from 0.1 to 11.9, 29.9 to 432.8, 5.5 to 214.9, and 2.4 to 65.8 mg C m-2 d-1 during March, June, September, and December, respectively. This study shed light on the estimation of global PPPico using carbon-based production model.Liao, W., Bond, D.P.G., Wang, Y., He, L., Yang, H., Weng, Z., Li, G., 2017. An extensive anoxic event in the Triassic of the South China Block: A pyrite framboid study from Dajiang and its implications for the cause(s) of oxygen depletion. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 86-95. column oxygen deficiency has been considered as a potent driver of the extinction of marine benthos, and is a main feature of marine environments in the aftermath of the end-Permian mass extinction. The record of Permian-Triassic anoxia is more complex than previously thought, and is seen to vary between different palaeogeographic settings, but a full understanding is hindered by a paucity of evidence. During the Permian-Triassic interval the South China Block was located equatorially with Palaeotethys to the north and western Panthalassa to the south. This specific configuration provides a unique opportunity to compare the extent and duration of oxygen deficiency in Palaeotethys and Panthalassa under broadly similar climatic conditions. Sedimentary facies and pyrite framboid size-frequency distributions suggest that the oxygen-poor conditions became widespread across the shallow-marine carbonate platform of the South China Block immediately above the Permian-Triassic boundary and mass extinction level. Oxygen deficiency was most intense at the southern margin of the block where it met Panthalassa. Proposed drivers of the expansion of oxygen minimum zones into platform settings include enhanced terrigenous input and/or ocean stratification, or alternatively the upwelling of nutrient-rich deep ocean water. The former mechanisms are theoretically more likely to have operated in the relatively restricted Palaeotethys which was surrounded by ancient lands. In contrast, Panthalassa would likely have experienced stronger oceanic circulation and therefore be more susceptible to the effects of upwelling. Although variations in the record of the South China Block anoxic event might reflect local factors, the greater intensity of oxygen deficiency and a concomitant larger negative shift in carbonate carbon isotopes on its Panthalassan margin point to a key role for upwelling. This mechanism was likely a major driver of the Permian-Triassic global oceanic anoxic event, which itself was at least partly responsible for the ongoing inhospitable conditions and delayed recovery following the end-Permian extinction.Lin, J., Ren, T., Wang, G., Booth, P., Nemcik, J., 2017. Experimental study of the adsorption-induced coal matrix swelling and its impact on ECBM. Journal of Earth Science 28, 917-925. dioxide (CO2) enhanced coalbed methane (ECBM) is an effective method to improve methane (CH4) production and this technology has already been used to increase gas production in several field trials worldwide. One major problem is the injection drop in the later period due to permeability decrease caused by coal matrix swelling induced by CO2 injection. In order to quantify the swelling effect, in this work, coal samples were collected from the Bulli coal seam, Sydney Basin and adsorption tests with simultaneous matrix swelling measurement were conducted. The adsorption and swelling characteristics were analyzed by measuring the adsorption mass simultaneously with the strain measurement. Then experiments were conducted to replicate the ECBM process using the indirect gravity method to obtain the swelling strain change with CO2 injection. The results show that the coal adsorption capacity in CO2 is almost two times greater than that in CH4, and nitrogen adsorption is the least among these gases. A Langmuir-like model can be used to describe the strain with the gas pressure and the swelling strain induced by gas adsorption has a linear relationship with gas adsorption quantity. Moreover, swelling strain increase was observed when CO2 was injected into the sample cell and the swelling strain was almost the sum of the strains induced by different gases at corresponding partial gas pressure.Liu, C., Zhao, H., Zhao, J., Wu, B., Huang, L., Wang, J., Zhang, D., Zhang, S., 2017. Sedimentology of energy basins and the frontier scientific problems. Acta Sedimentologica Sinica 35, 1032-1043. sedimentary basins refer to the sedimentary basins which can contain energy mineral deposits as oil, gas, coal and/or uranium. Sedimentation and sedimentary formation are the important factors and material basis influencing the occurrence, accumulation and distribution in a certain basin. The sedimentary energy deposits and the formation consist of the key section of sedimentology. It is discussed that the inner relations of the sedimentary formation and the occurrence, accumulation and distribution of the oil, gas, coal and uranium deposits, and proposed that the coal formation is in the transition, cohesion, and the evolutionary stage of past and future during the basin evolution and spatial distribution. It shows that the material source and origin of the initial coal-forming material of the thick coal seam, and indicates that the source area has important influence on sedimentary formation, oil and gas reservoir and uranium mineralization. Two weak points exist in energy basin's sedimentology field. One is the inclination of emphasizing the advanced technology observation test and ignoring detailed analysis of outcrop area. Another is the need to pay attention to and improving the influence degree of later reformation and the restoration level of the paleo sedimentary features of the original basin. Energy basins sedimentology has broadly extensional field and various frontier scientific problems. Therefore, comprehensive, dynamic, integrated research is needed through putting the sedimentology in the space-time evolution of basin formation and reformation together with the evolution of the earth's environment and biological processes. Partial relative frontier scientific problems are focused in this paper, which are dynamics of sedimentary basins, influence of earth's environment and biological processes to sedimentation and mineralization, organic and inorganic effects on the formation of energy minerals, event sedimentology, deep action and mineralization, spatial distribution of energy minerals and sedimentary environment of lack-rich-extreme rich deposit formation, sedimentary formation and geochronology of sedimentary minerals. Liu, Y.C., Chen, D.X., Qiu, N.S., Wang, Y., Fu, J., Huyan, Y., Jia, J.K., Wu, H., 2017. Reservoir characteristics and methane adsorption capacity of the Upper Triassic continental shale in Western Sichuan Depression, China. Australian Journal of Earth Sciences 64, 807-823. well-developed continental shale sequences in the Western Sichuan Depression are characterised by extremely low porosity and permeability, complex lithologies and strong lateral facies changes. The overall lack of proper characterisation of the shale properties has restricted gas exploration and development in the region. In this study, shales from the fifth member of the Xujiahe Formation of the Upper Triassic (T3x5) are comprehensively characterised in terms of their organic geochemistry, mineral composition, microscopic pore structure and gas content. In addition, the influence of various geological factors on the adsorbed gas content is investigated. We proposed a new model for predicting the adsorption gas content of continental shale. The T3x5 shale sequence is found to be rich in organic matter but with variable mineral compositions, pore types and reservoir physical properties. The porosity and permeability of shales are better than those of siltstones and fine sandstones interbedded with the shale under an overall densification background. Mesopores (2–50 nm) are common in the shale sequence, followed by micropores and then macropores. The gas-adsorption capacity of organic-rich shales increases with increasing TOC and clay-mineral contents, maturity and pressure, but decreases with increasing quartz content, carbonate minerals and temperature. The gas-adsorption capacity can thus be expressed as a function of organic matter, clay-mineral content, temperature and pressure. The calculated results are in good agreement with the experiment results and indicate that adsorption gas in the studied shales accounts for 78.9% of the total gas content.Livanou, E., Lagaria, A., Psarra, S., Lika, K., 2017. Dissolved organic matter release by phytoplankton in the context of the Dynamic Energy Budget theory. Biogeosciences Discussions 2017, 1-33. release of dissolved organic matter (DOM) by phytoplankton is a significant process that drives the microbial loop, providing energy and nutrients to bacteria. In this paper, a dynamic energy budget model is proposed for describing DOM release by phytoplankton under nitrogen and phosphorus limiting conditions. The model allows for the distinction of the two major mechanisms of DOM release; passive diffusion related to growth and lysis of the cells and active exudation related to rejection of unprocessed substrates due to stoichiometric constraints. Model results suggest that phosphorus deficiency has less severe effect on phytoplankton growth and primary production (PP) rate than nitrogen deficiency, while co-limitation by both nutrients has the most severe effect. The dependence of dissolved organic carbon (DOC) release rate on the cellular carbohydrates concentration is also highlighted by the model. Furthermore, model predictions resolve the relationship between PP and DOC release under different nutrient availability scenarios, providing a possible explanation for the deviations from 1?:?1 linear relationship between PP and DOC release, often observed in oligotrophic systems. This deviation is a result of the prevalence of the active exudation mechanism and the reduction of the PP rate due to nutrient limitation. Conversely, passive diffusion is more important under nutrient-replete conditions. The different relative contributions of the two mechanisms result in different qualities of DOM produced by phytoplankton in terms of elemental and molecular composition and size fractions, with potential implications for the bioavailability of the produced DOM for bacteria and the coupling of phytoplankton-bacteria dynamics.Loiko, S.V., Pokrovsky, O.S., Raudina, T.V., Lim, A., Kolesnichenko, L.G., Shirokova, L.S., Vorobyev, S.N., Kirpotin, S.N., 2017. Abrupt permafrost collapse enhances organic carbon, CO2, nutrient and metal release into surface waters. Chemical Geology 471, 153-165. of frozen peat in discontinuous permafrost zones may significantly modify the environment at local (slumps and engineering damages) and global (greenhouse gases regime) scales. We studied the aquatic geochemistry of CO2, CH4, dissolved organic carbon (DOC), P, Si, and colloidal trace metal from hollows, depressions, permafrost subsidences and soil waters in the actively thawing discontinuous permafrost zone of Western Siberia Lowland (WSL). This site of abrupt permafrost collapse is dominated by minerotrophic fens located within the flat mound peat bog. The CO2, DOC, major and trace metal concentrations decreased with the increase of the surface area of the water body, along the hydrological continuum (soil water → hollows → depressions and permafrost subsidences → thaw ponds → thermokarst lakes). Aqueous concentrations of CO2, CH4, Ca, Si, P, Al, Fe, Nd, and U were a factor of 4 to 10 higher in the site of catastrophic thaw compared to the steady thawing of a palsa peat bog that was previously studied in the same region. The colloids (1 kDa–0.45 μm) formed in hot spots were strongly enriched in Fe, Al, and trivalent and tetravalent hydrolysates relative to organic carbon.Because the increase in the thickness of the thawing depth intensifies the input of inorganic components from deep mineral horizons, abrupt permafrost thaw enriches the surface waters in Al-rich colloids and low molecular weight organic complexes. As a result, the WSL's surface water colloidal composition may shift from DOM-rich and DOM-Fe-rich to DOM-Al-rich, and the release of low-soluble trivalent and tetravalent hydrolysates from the soil to the river will increase. We hypothesize that in sites of abrupt permafrost thaw, there is direct mobilization of soil waters to a hydrological network (rivers and lakes) and there is minimal transformation by autochthonous processes, which is unlike the case of steady permafrost thawing. Therefore, the change in physical factors, such as water pathways and the water residence time, within a given elementary landscape will likely control the overall impact of on-going permafrost thaw on both the surface water chemistry and dissolved greenhouse gas pattern of the territory. For this, high-resolution (< 2 m) remote sensing analysis of water dynamics in the permafrost landscape is necessary.Lopes, M.S., da Rocha Watanabe, E.R.L., Savioli Lopes, E., Gomes, V.M., Savioli Lopes, M., Medina, L.C., Maciel Filho, R., Wolf Maciel, M.R., 2017. Extending the true boiling point curve of a heavy crude oil by means of molecular distillation and characterization of the products obtained. Petroleum Science and Technology 35, 1523-1529. is evaluated by means of the true boiling point (TBP) curve, making possible to investigate the yields of the products that will be obtained in refineries, as well as establishing operating strategies and process optimization. Refineries determine TBP curves until 838?K. With molecular distillation the TBP can reach values up to 973?K. Molecular distillation shows potential in the separation, purification, and concentration of products. Eta residue is fractioned and the TBP of the whole crude oil is extended. Products of the distillation were characterized by density, SimDis (simulated distillation), and molar mass. Results showed that density and molar mass of the cuts obtained increase as the process temperature increases. These analyses confirm the efficiency of the separation method by molecular distillation.Lopes, M.S., da Rocha Watanabe, E.R.L., Tovar, L.P., Lopes, M.S., Darcie, L.d.R., Lopes, E.S., Filho, R.M., Maciel, M.R.W., Medina, L.C., 2017. Development of correlation for extension of the true boiling point (TBP) and molar mass. Petroleum Science and Technology 35, 1530-1536. true boiling point curve (TBP) is an important tool for the petroleum industry; it is used to obtain the behavior of petroleum during distillation. This work developed a correlation for the extension of the TBP curve by means of molecular distillation. TBP curve is well established for a temperature of 565°C in a conventional distillation. With the correlation developed, it is possible to reach values near 1,000°C. A second correlation was also developed for predicting the values of molar mass of waste petroleum. Both correlations demonstrated to be valid and represent a great advancement for the petroleum industry.Lovato, G., Alvarado-Morales, M., Kovalovszki, A., Peprah, M., Kougias, P.G., Rodrigues, J.A.D., Angelidaki, I., 2017. In-situ biogas upgrading process: Modeling and simulations aspects. Bioresource Technology 245, 332-341. upgrading processes by in-situ hydrogen (H2) injection are still challenging and could benefit from a mathematical model to predict system performance. Therefore, a previous model on anaerobic digestion was updated and expanded to include the effect of H2 injection into the liquid phase of a fermenter with the aim of modeling and simulating these processes. This was done by including hydrogenotrophic methanogen kinetics for H2 consumption and inhibition effect on the acetogenic steps. Special attention was paid to gas to liquid transfer of H2. The final model was successfully validated considering a set of Case Studies. Biogas composition and H2 utilization were correctly predicted, with overall deviation below 10% compared to experimental measurements. Parameter sensitivity analysis revealed that the model is highly sensitive to the H2 injection rate and mass transfer coefficient. The model developed is an effective tool for predicting process performance in scenarios with biogas upgrading.Luciani, V., D'Onofrio, R., Dickens, G.R., Wade, B.S., 2017. Planktic foraminiferal response to early Eocene carbon cycle perturbations in the southeast Atlantic Ocean (ODP Site 1263). Global and Planetary Change 158, 119-133. low latitude locations in the northern hemisphere, striking changes in the relative abundances and diversity of the two dominant planktic foraminifera genera, Morozovella and Acarinina, are known to have occurred close to the Early Eocene Climatic Optimum (EECO; ~ 49–53 Ma). Lower Eocene carbonate-rich sediments at Ocean Drilling Program (ODP) Site 1263 were deposited on a bathymetric high (Walvis Ridge) at ~ 40° S, and afford an opportunity to examine such planktic foraminiferal assemblage changes in a temperate southern hemisphere setting. We present here quantified counts of early Eocene planktic foraminiferal assemblages from Hole 1263B, along with bulk sediment stable isotope analyses and proxy measurements for carbonate dissolution. The bulk sediment δ13C record at Site 1263 resembles similar records generated elsewhere, such that known and inferred hyperthermal events can be readily identified. Although some carbonate dissolution has occurred, the well-preserved planktic foraminiferal assemblages mostly represent primary changes in environmental conditions. Our results document the permanent decrease in Morozovella abundance and increase in Acarinina abundance at the beginning of the EECO, although this switch occurred ~ 165 kyr after that at low-latitude northern hemisphere locations. This suggests that unfavourable environmental conditions for morozovellids at the start of the EECO, such as sustained passage of a temperature threshold or other changes in surface waters, occurred at lower latitudes first. The remarkable turnover from Morozovella to Acarinina was widely geographically widespread, although the causal mechanism remains elusive. In addition, at Site 1263, we document the virtual disappearance within the EECO of the biserial chiloguembelinids, commonly considered as inhabiting intermediate water depths, and a reduction in abundance of the thermocline-dwelling subbotinids. We interpret these changes as signals of subsurface water properties, perhaps warming, and the associated contraction of ecological niches.Luo, Q., Qu, Y., Chen, Q., Xiong, Z., 2017. Organic geochemistry and petrology of mudrocks from the Upper Carboniferous Batamayineishan Formation, Wulungu area, Junggar Basin, China: Implications for petroleum exploration. Energy & Fuels 31, 10628-10638. hydrocarbon generation potential of the Carboniferous Batamayineishan mudrocks has been overlooked for a long time. In this study, organic petrology and geochemistry were used to determine the sedimentary environments, organic matter (OM) type, and organic maturity of the Carboniferous Batamayineishan source rocks, collected from outcrops, Wulungu area, Junggar Basin, China. The maceral composition of the studied samples is dominated by vitrinite and inertinite, ranging from 40 vol % to 100 vol % and from 0 vol % to 60 vol % on a mineral matter free basis, respectively. Liptinite macerals, mainly as lamalginites, are only present in trace amounts in several sediments. Vitrinite reflectance values are 0.67% to 2.78%. TOC values are high in these samples, whereas the S1, S2, and HI are very low. Pr/Ph ratios, the plot of Pr/n-C17 versus Ph/n-C18, DBT/P versus Pr/Ph, and ternary of fluorene, dibenzothiophene, and dibenzofuran indicate that anoxic saline environments prevailed during deposition of the Batamayineishan Formation. This is consistent with the presence of β-carotane and high abundances of gammacerane in the studied samples. The major biological source is from vascular plants, and the kerogen type is humic (type III) as indicated by the maceral composition and rock pyrolysis data. The samples from the No. 4 and No. 6 sections occur in the oil window, whereas the other samples are overmature in terms of hydrocarbon generation. The abundant organic richness, humic kerogen, and high thermal maturity demonstrate that these rocks are effective gas source rocks. The volcanics and mudrocks in the Carboniferous Batamayineishan Formation collectively constitute a self-generation and self-storage petroleum system, and represent a main exploration target for gas discovery for the Carboniferous in the Wulungu area.Lupoi, J.S., Fritz, L.P., Parris, T.M., Hackley, P.C., Solotky, L., Eble, C.F., Schlaegle, S., 2017. Assessment of thermal maturity trends in Devonian–Mmississippian source rocks using Raman spectroscopy: Limitations of peak-fitting method. Frontiers in Energy Research 5, 24. doi: 10.3389/fenrg.2017.00024. thermal maturity of shale is often measured by vitrinite reflectance (VRo). VRo measurements for the Devonian-Mississippian black shale source rocks evaluated herein predicted thermal immaturity in areas where associated reservoir rocks are oil-producing. This limitation of the VRo method led to the current evaluation of Raman spectroscopy as a suitable alternative for developing correlations between thermal maturity and Raman spectra. In this study, Raman spectra of Devonian-Mississippian black shale source rocks were regressed against measured VRo or sample-depth. Attempts were made to develop quantitative correlations of thermal maturity. Using sample-depth as a proxy for thermal maturity is not without limitations either, as thermal maturity as a function of depth depends on thermal gradient, which can vary through time, subsidence rate, uplift, lack of uplift, and faulting. Correlations between Raman data and thermal maturity metrics were quantified by peak-fitting the spectra. Various peak-fitting procedures were evaluated to determine the effects of the number of peaks and maximum peak widths on correlations between spectral metrics and thermal maturity. Correlations between D-frequency, G-band full-width-at-half-maximum (FWHM) and band separation between the G- and D- peaks and thermal maturity provided some degree of linearity throughout most peak-fitting assessments; however, these correlations and those calculated from the G-frequency, D/G FWHM ratio, and D/G peak area ratio also revealed a strong dependence on peak-fitting processes. This dependency on spectral analysis techniques raises questions about the validity of peak-fitting, particularly given the amount of subjective analyst involvement necessary to reconstruct spectra. This research shows how user interpretation and extrapolation affected the comparability of different samples, the accuracy of generated trends, and therefore, the potential of the Raman spectral method to become an industry benchmark as a thermal maturity probe. A Raman method devoid of extensive operator interaction and data manipulation is quintessential for creating a standard method.Lyman, S.N., Watkins, C., Jones, C.P., Mansfield, M.L., McKinley, M., Kenney, D., Evans, J., 2017. Hydrocarbon and carbon dioxide fluxes from natural gas well pad soils and surrounding soils in eastern Utah. Environmental Science & Technology 51, 11625-11633. measured fluxes of methane, nonmethane hydrocarbons, and carbon dioxide from natural gas well pad soils and from nearby undisturbed soils in eastern Utah. Methane fluxes varied from less than zero to more than 38 g m–2 h–1. Fluxes from well pad soils were almost always greater than from undisturbed soils. Fluxes were greater from locations with higher concentrations of total combustible gas in soil and were inversely correlated with distance from well heads. Several lines of evidence show that the majority of emission fluxes (about 70%) were primarily due to subsurface sources of raw gas that migrated to the atmosphere, with the remainder likely caused primarily by re-emission of spilled liquid hydrocarbons. Total hydrocarbon fluxes during summer were only 39 (16, 97)% as high as during winter, likely because soil bacteria consumed the majority of hydrocarbons during summer months. We estimate that natural gas well pad soils account for 4.6 × 10–4 (1.6 × 10–4, 1.6 × 10–3)% of total emissions of hydrocarbons from the oil and gas industry in Utah’s Uinta Basin. Our undisturbed soil flux measurements were not adequate to quantify rates of natural hydrocarbon seepage in the Uinta Basin.Lynch, C., Hartin, C., Chen, M., Bond-Lamberty, B., 2017. Causes of uncertainty in observed and projected heterotrophic respiration from Earth System Models. Biogeosciences Discussions 2017, 1-28. respiration (RH) is a large component of the terrestrial carbon cycle, but one poorly simulated by Earth system models (ESMs), which diverge significantly in their historical and future RH projections. There is little understanding, however, of the causes of this variability and its consequences for future model development and scenario evaluation, and examining the relationships between RH and key climate variables may help to understand where and why models are divergent. We quantified the statistical relationships between RH and other terrestrial/climate variables across a suite of 25 ESMs from the Coupled Model Intercomparison Project phase 5 (CMIP5) for the 20th and 21st centuries, comparing the models both to each other and to an observation-driven global RH dataset. Compared to observations, ESMs consistency overestimate both the magnitude and climate sensitivity of global RH. The relationship between RH and surface air temperature (TAS) is strong, especially at high latitudes, and largely consistent across models. The observed RH and precipitation (PR) relationship is strong and positive (r?≥?0.5, P?<?0.005), but few models consistently show this sensitivity of RH to PR. The RH-TAS relationship explored here, and more pattern scaling methods more generally, can be used to efficiently explore uncertainty and projected changes in RH under a wide range of future emission scenarios, and understand how models' structural and parametric choices produce divergent results. Because uncertainty in RH has large effects on ESM projections of future climate, this may help direct attention to relationships in the carbon cycle that contribute to this uncertainty.Ma, F., Du, C., Zhou, J., Shen, Y., 2017. Optimized self-adaptive model for assessment of soil organic matter using Fourier transform mid-infrared photoacoustic spectroscopy. Chemometrics and Intelligent Laboratory Systems 171, 9-15. technologies, such as infrared spectroscopy, have been applied to develop rapid, cheap but accurate methods for the analysis of soil matter organic (SOM). However, the unsatisfied prediction accuracy resulted from heavy soil heterogeneity limits the practical application. In our previous work, soil identification based self-adaptive partial least squares model (SAM), which was built using identification algorithm and the partial least square regression (PLSR), makes it possible for a wide use. However, soil identification in the SAM needs be further optimized. In this study, we designed an advanced optimal self-adaptive partial least squares model (OPT-SAM), a more general model to predict SOM. 597 soil samples from China with large variances were collected, and the soil spectra were recorded using Fourier transform mid-infrared photoacoustic spectroscopy (FTIR-PAS). Five typical algorithms (Correlation coefficients (CC), Euclidean distance (ED), Mahalanobis distance (MD), Angle cosine (AC), and k-medoids (KM)) were considered for the identification in the SAM model. The results demonstrated that the performances of CC-SAM, ED-SAM, MD-SAM, AC-SAM were significantly improved in comparison with no identification based SAM (NI-SAM), but KI-SAM showed a poor prediction. ED-SAM (R2 = 0.8890, RMSEP = 7.00 g kg?1, RPD = 2.96) indicated the highest accuracy and robustness in all algorithms, which was an optimal model for soil identification and prediction, and CC-SAM (R2 = 0.8572, RMSEP = 7.89 g kg?1, RPD = 2.44) was an alternative choice, especially for prediction with different soil types.Ma, Y., Cao, T., Snowdon, L., Qian, M., Jiang, Q., Li, M., Mahlstedt, N., Horsfield, B., 2017. Impact of different experimental heating rates on calculated hydrocarbon generation kinetics. Energy & Fuels 31, 10378-10392. organic-rich samples from four basins in China have been analyzed, using open-system bulk pyrolysis with heating rates ranging from 0.7 K/min to 40 K/min. The resulting programs have been digitized and first-order Arrhenius kinetics have been optimized using groups of different heating rate ranges. Low heating rate optimization was performed for data generated at 5 K/min, 2 K/min, and either 0.7 or 1 K/min. High heating rate optimization used experimental rates of 15, 25, and 40 K/min. Optimization was also completed for wide heating rate ranges at 40 K/min, 15 K/min, and either 1 or 2 K/min. The kinetics solutions were then used to calculate bulk hydrocarbon generation at a geological heating rate of 3 K/Ma, in order to determine the impact of using different experimental approaches. The results showed that low versus high and narrow versus wide heating rates did not yield systematically different results. The highest predicted geological temperature was observed for the low heating rates (Huadian, Ordos), high heating rates (Maoming), and wide heating rate range (Wang18 and Ordos). The wide heating rate ranges yielded predicted temperatures that were between the high and low heating rates for Huadian and Maoming but higher than or equal to both narrow range rates for Wang18 and Ordos. The results from the Source Rock Analyzer optimized using Kinetics2015 software predicted similar activation energy distributions and frequency factors and, consequently, similar geological temperatures for all samples to the Rock-Eval results optimized using Kinetics2005 software, although the samples run on the two instruments were not homogeneous aliquots but rather separate pieces broken from field or core samples. Predicted temperatures for 50% transformation at a geological heating rate show a variability of less than ±6 °C, which translates to a burial difference of <300 m for a basin with a “normal” geothermal gradient.Macías-Sánchez, E., Willinger, M.G., Pina, C.M., Checa, A.G., 2017. Transformation of ACC into aragonite and the origin of the nanogranular structure of nacre. Scientific Reports 7, Article 12728. a basic tenet in biomineralization is that biominerals grow by accretion of amorphous particles, which are later transformed into the corresponding mineral phase. The globular nanostructure of most biominerals is taken as evidence of this. Nevertheless, little is known as to how the amorphous-to-crystalline transformation takes place. To gain insight into this process, we have made a high-resolution study (by means of transmission electron microscopy and other associated techniques) of immature tablets of nacre of the gastropod Phorcus turbinatus, where the proportion of amorphous calcium carbonate is high. Tablets displayed a characteristic nanoglobular structure, with the nanoglobules consisting of an aragonite core surrounded by amorphous calcium carbonate together with organic macromolecules. The changes in composition from the amorphous to the crystalline phase indicate that there was a higher content of organic molecules within the former phase. Within single tablets, the crystalline cores were largely co-oriented. According to their outlines, the internal transformation front of the tablets took on a complex digitiform shape, with the individual fingers constituting the crystalline cores of nanogranules. We propose that the final nanogranular structure observed is produced during the transformation of ACC into aragonite.Magnone, D., Richards, L.A., Polya, D.A., Bryant, C., Jones, M., van Dongen, B.E., 2017. Biomarker-indicated extent of oxidation of plant-derived organic carbon (OC) in relation to geomorphology in an arsenic contaminated Holocene aquifer, Cambodia. Scientific Reports 7, Article 13093. poisoning of rural populations in South and Southeast?Asia due to high groundwater arsenic concentrations is one of the world’s largest ongoing natural disasters. It is important to consider environmental processes related to the release of geogenic arsenic, including geomorphological and organic geochemical processes. Arsenic is released from sediments when iron-oxide minerals, onto which arsenic is adsorbed or incorporated, react with organic carbon (OC) and the OC is oxidised. In this study we build a new geomorphological framework for Kandal Province, a highly studied arsenic affected region of Cambodia, and tie this into wider regional environmental change throughout the Holocene. Analyses shows that the concentration of OC in the sediments is strongly inversely correlated to grainsize. Furthermore, the type of OC is also related to grain size with the clay containing mostly (immature) plant derived OC and sand containing mostly thermally mature derived OC. Finally, analyses indicate that within the plant derived OC relative oxidation is strongly grouped by stratigraphy with the older bound OC more oxidised than younger OC.Mahieu, N.G., Patti, G.J., 2017. Systems-level annotation of a metabolomics data set reduces 25?000 features to fewer than 1000 unique metabolites. Analytical Chemistry 89, 10397-10406. using liquid chromatography/mass spectrometry (LC/MS) to perform untargeted metabolomics, it is now routine to detect tens of thousands of features from biological samples. Poor understanding of the data, however, has complicated interpretation and masked the number of unique metabolites actually being measured in an experiment. Here we place an upper bound on the number of unique metabolites detected in Escherichia coli samples analyzed with one untargeted metabolomics method. We first group multiple features arising from the same analyte, which we call “degenerate features”, using a context-driven annotation approach. Surprisingly, this analysis revealed thousands of previously unreported degeneracies that reduced the number of unique analytes to ～2961. We then applied an orthogonal approach to remove nonbiological features from the data using the 13C-based credentialing technology. This further reduced the number of unique analytes to less than 1000. Our 90% reduction in data is 5-fold greater than previously published studies. On the basis of the results, we propose an alternative approach to untargeted metabolomics that relies on thoroughly annotated reference data sets. To this end, we introduce the creDBle database (<;), which contains accurate mass, retention time, and MS/MS fragmentation data as well as annotations of all credentialed features.Mai-Thi, N.-N., St-Onge, G., Tremblay, L., 2017. Contrasting fates of organic matter in locations having different organic matter inputs and bottom water O2 concentrations. Estuarine, Coastal and Shelf Science 198, 63-72. goals of this work were to study sedimentary organic matter (OM) composition and transformation since the end of the last deglaciation and to evaluate the influence of contrasting depositional conditions on these parameters. One station was located in the Lower St. Lawrence Estuary (LSLE) where the current bottom waters are hypoxic and receive terrigenous and marine OM. The other station, located in the Gulf of St. Lawrence (GSL), has more oxygenated bottom waters and almost only marine OM inputs. Analyses included enantiomers of amino acids (L and D-AA) and muramic acid that provide different markers of OM alteration state and reactivity and of bacterial contribution to OM composition and diagenesis. The markers clearly indicated the increase in OM alteration state with depth in the sediments of the LSLE and the GSL. The steady decrease in AA yields with depth confirmed the preferential degradation of AA compared to the rest of the OM. The OM in the surface sediment of the LSLE was less altered than that of the GSL and was enriched in bacterial biomass as indicated by much higher muramic acid yields. Results indicated that an important degradation of particulate organic matter occurs in the water column in the GSL, while it takes place mostly in the sediments in the LSLE. The presence of heterogeneous OM and hypoxic conditions in the LSLE likely reduce OM degradation rate in its deep water layer. However, the zone near the water-sediment interface is responsible for large variations in AA composition at both locations. A relatively new redox index, based on AA composition, was tested and appeared robust. This study highlights the importance of ambient conditions in determining the fate of OM and in the biogeochemical cycles of vital elements.Makarewicz, C.A., 2017. Sequential δ13C and δ18O analyses of early Holocene bovid tooth enamel: Resolving vertical transhumance in Neolithic domesticated sheep and goats. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 16-29. transhumance is an important animal husbandry strategy that provides livestock with consistent access to pasture throughout the year and contributed to the intensification of sheep and goat husbandry in the Near East over 10,000 years ago. Sequential carbon (δ13C) and oxygen (δ18O) isotope analyses of teeth from domesticated sheep and goats dating to the early Neolithic (9200 to 8700 cal yr B.P.) from a region of strong local topographic relief in southern Jordan exhibit inverse cyclical isotopic variation characterized by the coincidence of high δ18O values with low δ13C values indicating ingestion of 13C-depleted plants during the summer season. This pattern is consistent with vertical transhumance of caprines moving from low-elevation C3/C4 Irano-Turanian pastures to higher-elevation Mediterranean C3 pastures during the summer, but other seasonally directed animal husbandry strategies involving amendment of livestock diets generate a similar isotopic outcome. Caprine δ18O values referenced against the oxygen isotope ratios of contemporaneous obligate drinking cattle and non-obligate drinking mountain gazelle, bovids with limited home ranges, help distinguish the influence of meteoric water, 18O-enriched leaf water, and movement on the oxygen isotopic composition of sheep and goat tooth enamel. This approach assists in independent validation of vertical transhumance hypothesized for inverse cyclical variation in sequential δ13C and δ18O values and, also, decouples seasonal foddering from mobility in the carbon isotopic dietary record. The isotopic data presented here reveal that complex sheep and goat husbandry systems involving vertical transhumance, stationary flock-keeping, and winter foddering were in place by the late tenth millennium cal y.r. B.P. east of the Jordan Valley.Makatounis, P.E., Skancke, J., Florou, E., Stamou, A., Brandvik, P.J., 2017. Management of oil spill contamination in the Gulf of Patras caused by an accidental subsea blowout. Environmental Pollution 231, 578-588. methodology is presented and applied to assess the oil contamination probability in the Gulf of Patras and the environmental impacts on the environmentally sensitive area of Mesolongi – Aitoliko coastal lagoons, and to examine the effectiveness of response systems. The procedure consists of the following steps: (1) Determination of the computational domain and the main areas of interest, (2) determination of the drilling sites and oil release characteristics, (3) selection of the simulation periods and collection of environmental data, (4) identification of the species of interest and their characteristics, (5) performance of stochastic calculations and oil contamination probability analysis, (6) determination of the worst-cases, (7) determination of the characteristics of response systems, (8) performance of deterministic calculations, and (9) assessment of the impact of oil spill in the areas of interest. Stochastic calculations that were performed for three typical seasonal weather variations of the year 2015, three oil release sites and specific oil characteristics, showed that there is a considerable probability of oil pollution that reaches 30% in the Mesolongi – Aitoliko lagoons. Based on a simplified approach regarding the characteristic of the sensitive birds and fish in the lagoons, deterministic calculations showed that 78–90% of the bird population and 2–4% of the fish population are expected to be contaminated in the case of an oil spill without any intervention. The use of dispersants reduced the amount of stranded oil by approximately 16–21% and the contaminated bird population of the lagoons to approximately 70%; however, the affected fish population increased to 6–8.5% due to the higher oil concentration in the water column. Mechanical recovery with skimmers “cleaned” almost 10% of the released oil quantity, but it did not have any noticeable effect on the stranded oil and the impacted bird and fish populations.Mangenot, X., Bonifacie, M., Gasparrini, M., G?tz, A., Chaduteau, C., Ader, M., Rouchon, V., 2017. Coupling Δ47 and fluid inclusion thermometry on carbonate cements to precisely reconstruct the temperature, salinity and δ18O of paleo-groundwater in sedimentary basins. Chemical Geology 472, 44-57. minerals may provide information about the burial history of geological units and can have practical applications, for instance, for reconstructing the geochemical and thermal histories of sedimentary basins. Clumped isotope, or Δ47, thermometry on carbonates opens a new avenue for interpreting carbonate formation temperature and thermal history of rocks. Yet, most of current knowledge on Δ47 systematics has been acquired via theoretical or experimental studies with only limited validation by the rock-record at geological conditions/timescales. Here, we investigate calcitic and dolomitic cements representative of three genetically different cementation phases from a well-documented mineral paragenesis of a carbonate unit (Middle Jurassic, Paris basin, France). We compare Δ47 with fluid inclusions microthermometry (FIM) data that were independently obtained from the same calcite and dolomite crystal specimens. The range of homogenization temperatures (Th) found for Cal1, Cal2 and Dol1 fluid inclusions fit remarkably well (i.e. within < 5 °C) with the temperatures determined from the Δ47 measurements (TΔ47), for a temperature range between 60 and 100 °C and salinities between 0 and 15 wt% NaCl eq. This provides a consistent rock-based validation of the experimentally determined Δ47 calibration with formation temperature for both calcite and dolomite mineralogy. Such findings also confirm the applicability of Δ47 thermometry in low temperature diagenetic environments (i.e., below circa. 100 °C), which provides higher precision than FIM measurements (i.e., typical uncertainties of ± 6 °C with three Δ47 measurements) though significantly less time-consuming. Importantly, this study underlines how the coupling of both techniques can help to evaluate the degree of preservation of the original temperature information captured by either fluid inclusions or Δ47 compositions, and interpret each proxy as confidently/accurately as possible. Moreover, because both FIM and Δ47 measurements can provide independent constraints on the geochemistry of diagenetic paleofluids (via their salinity and δ18O composition), this study also highlights the benefits of coupling both techniques to further unravel the nature of paleofuids. Finally, we propose a practical guideline as a basis for future applications of combined FIM and Δ47 thermometry.Mao, S., Lü, M., Shi, Z., 2017. Prediction of the PVTx and VLE properties of natural gases with a general Helmholtz equation of state. Part I: Application to the CH4–C2H6–C3H8–CO2–N2 system. Geochimica et Cosmochimica Acta 219, 74-95. general equation of state (EOS) explicit in Helmholtz free energy has been developed to predict the pressure–volume-temperature-composition (PVTx) and vapor-liquid equilibrium (VLE) properties of the CH4–C2H6–C3H8–CO2–N2 fluid mixtures (main components of natural gases). This EOS, which is a function of temperature, density and composition, with four mixing parameters used, is based on the improved EOS of Sun and Ely (2004) for the pure components (CH4, C2H6, C3H8, CO2 and N2) and contains a simple generalized departure function presented by Lemmon and Jacobsen (1999). Comparison with the experimental data available indicates that the EOS can calculate the PVTx and VLE properties of the CH4–C2H6–C3H8–CO2–N2 fluid mixtures within or close to experimental uncertainties up to 623 K and 1000 bar within full range of composition. Isochores of the CH4–C2H6–C3H8–CO2–N2 system can be directly calculated from this EOS to interpret the corresponding microthermometric and Raman analysis data of fluid inclusions. The general EOS can calculate other thermodynamic properties if the ideal Helmholtz free energy of fluids is combined, and can also be extended to the multi-component natural gases including the secondary alkanes (carbon number above three) and none-alkane components such as H2S, SO2, O2, CO, Ar and H2O. This part of work will be finished in the near future.Maravelis, A.G., Chamilaki, E., Pasadakis, N., Zelilidis, A., Collins, W.J., 2017. Hydrocarbon generation potential of a Lower Permian sedimentary succession (Mount Agony Formation): Southern Sydney Basin, New South Wales, Southeast Australia. International Journal of Coal Geology 183, 52-64. research presents a comprehensive approach on the hydrocarbon generation potential applied for the first time on the Lower Permian Mount Agony Formation that is exposed in the southern Sydney Basin, southeast Australia. Thirty mudstone samples were collected and analyzed using different organic geochemical methods such as, Rock-Eval VI-TOC, bitumens extraction, and GC–MS analysis. Attributes such as, quantity, quality and maturity of the organic matter were utilized to estimate the regional source rock potential. The obtained data indicate that the examined samples have poor to good, dominantly gas-prone source-rock potential, and contain a mixed in origin organic matter. The slight predominance of terrestrial organic material is indicated by the low odd to even predominance values, slight predominance of higher n-alkanes over short-chain n-alkanes, OEP25–33, CPI25–33, ACL25–33, and TAR values. Some availability of marine organic material is evidenced by the predominance of intermediate chain n-alkanes and the low n-C19/n-C31 and n-C24 +/n-C24– ratios. The analyzed sediments are thermally mature, as suggested by the Tmax, PI, OEP 25–33 and CPI25–33 values, the Pr/n-C17, Ph/n-C18, C30-moretane/C30-hopane, Ts/(Ts + Tm) and C32S/(S + R) ratios, as well as by the C30-moretane/C30-hopane versus Tm/Ts plot. A mudstone-rich, siliciclastic source rock is implied by the C29/C30 hopane ratios and by the Ts/(Ts + Tm) versus 23tricyclic/hopane cross-plot. This research offers original organic geochemical data of a sedimentary succession that was not so far regarded as source rock. This study adds to the knowledge available for the types of potential reserves in the Southern Sydney Basin, which are mostly focused on coal and coal-seam gas resources.Marriner, N., Kaniewski, D., Morhange, C., Flaux, C., Giaime, M., Vacchi, M., Goff, J., 2017. Tsunamis in the geological record: Making waves with a cautionary tale from the Mediterranean. Science Advances 3, Article e1700485. 2000 to 2015, tsunamis and storms killed more than 430,000 people worldwide and affected a further &amp;gt;530 million, with total damages exceeding US$970 billion. These alarming trends, underscored by the tragic events of the 2004 Indian Ocean catastrophe, have fueled increased worldwide demands for assessments of past, present, and future coastal risks. Nonetheless, despite its importance for hazard mitigation, discriminating between storm and tsunami deposits in the geological record is one of the most challenging and hotly contended topics in coastal geoscience. To probe this knowledge gap, we present a 4500-year reconstruction of “tsunami” variability from the Mediterranean based on stratigraphic but not historical archives and assess it in relation to climate records and reconstructions of storminess. We elucidate evidence for previously unrecognized “tsunami megacycles” with three peaks centered on the Little Ice Age, 1600, and 3100 cal. yr B.P. (calibrated years before present). These ~1500-year cycles, strongly correlated with climate deterioration in the Mediterranean/North Atlantic, challenge up to 90% of the original tsunami attributions and suggest, by contrast, that most events are better ascribed to periods of heightened storminess. This timely and provocative finding is crucial in providing appropriately tailored assessments of coastal hazard risk in the Mediterranean and beyond.Martin, B.A., Frymier, P.D., 2017. A review of hydrogen production by photosynthetic organisms using whole-cell and cell-free systems. Applied Biochemistry and Biotechnology 183, 503-519. hydrogen is a promising currency in the future energy economy due to the uncertain availability of finite fossil fuel resources and environmental effects from their combustion. It also has important uses in the production of fertilizers and platform chemicals as well as in upgrading conventional fuels. Conventional methods for producing molecular hydrogen from natural gas produce carbon dioxide and use a finite resource as feedstock. However, these issues can be overcome by using light energy from the Sun combined with microorganisms and their molecular machinery capable of photosynthesis. In the presence of light, the proteins involved in photosynthesis coupled with appropriate catalysts in higher plants, algae, and cyanobacteria can produce molecular hydrogen, and optimization via genetic modifications and biomolecular engineering further improves production rates. In this review, we will discuss techniques that have been utilized to improve rates of hydrogen production in biological systems based on the protein machinery of photosynthesis coupled with appropriate catalysts. We will also suggest areas for improvement and future directions for work in the field.Maruccio, L., Quarta, G., Braione, E., Calcagnile, L., 2017. Measuring stable carbon and nitrogen isotopes by IRMS and 14C by AMS on samples with masses in the microgram range: Performances of the system installed at CEDAD-University of Salento. International Journal of Mass Spectrometry 421, 1-7. new experimental set-up dedicated to the simultaneous measurements of stable carbon and nitrogen isotopic ratios by IRMS (Isotope Ratio Mass Spectrometry) and 14C by AMS (Accelerator Mass Spectrometry) has been installed at CEDAD (Centre for Dating and Diagnostics)-University of Salento. The new set-up is formed by different functional blocks: an elemental analyzer, an IRMS spectrometer, a gas handling unit and a new hybrid sputtering ion source, connected to the AMS system. The general features of the new system are presented as well as the technical solutions adopted for its integration with the existing AMS system.Different tests were performed by analyzing samples of known isotopic composition and of different masses in order to define optimal operating conditions. In particular it is shown how radiocarbon measurements with precision of 0.6–0.7% and 1% are possible with the new system on samples of mass of the order of ～20 μg and ～10 μg, respectively. Background levels of the order of 10?14 (14C/12C) have been also demonstrated. The new system has then significantly extended the experimental potential of the Centre in several research fields where the possibility to date very low mass samples is either a crucial advantage or mandatory such as in environmental sciences and cultural heritage dating.Maryutina, T.A., Timerbaev, A.R., 2017. Metal speciation analysis of petroleum: Myth or reality? Analytica Chimica Acta 991, 1-8. occurring in crude oil in a great variety of complexed forms are minor but important constituents as they affect the refining and production operations, as well as participate in geochemical processes. These roles of metals are thought to be related to their chemical state the knowledge of which requires performing speciation analysis. While exact metal speciation in crude oil still remains obscure, earnest efforts to decipher it based on using up-to-date hyphenated techniques have been attempted in the past decade. With various levels of fractionation of vanadium and nickel species, liquid chromatography with ICP-MS detection allows for an insight into metal distribution in crude oil or its fractions, according to species molecular weight or polarity. Further speciation information on the metal coordination in a variety of porphyrin compounds can be gained by the use of Fourier transform ion cyclotron resonance mass spectrometry. Individual species of mercury are often available for quantification with gas chromatography-ICP-MS as the method of choice. This mini-review is aimed at revealing and giving rise to the development of those speciation strategies and approaches that can achieve the objectives of identification, characterization and determination of metal species in crude oil and its fractions.Massicotte, P., Stedmon, C., Markager, S., 2017. Spectral signature of suspended fine particulate material on light absorption properties of CDOM. Marine Chemistry 196, 98-106. submicron organic particles can represent an important fraction of the dissolved organic matter (DOM) pool in aquatic ecosystems and their optical properties differ from those normally considered dissolved (< 0.2 μm), which means that the choice of filter type/pore size can influence the light absorption characteristics. In this study, a total of 867 paired CDOM absorption spectra (n = 1734) from different ecosystems (lakes, streams, sewages and estuaries) were measured on 0.2 μm and GF/F (nominal pore size 0.7 μm) filters. The aims were to evaluate how fine organic particles influence the spectral signature of the DOM pool and to quantify the effects of choice of filter type. In aquatic ecosystems influenced by terrestrial DOM (rivers and lakes), the dissolved fraction (here defined as < 0.2 μm) overwhelmed the fine particulate signal (0.2–0.7 μm) which did not contribute significantly to the absorption signal. In contrast, freshly-produced fine particles released by phytoplankton significantly increased measured CDOM absorption in productive environments with low terrestrial background. Our results demonstrate that the choice of filter pore size can have a significant impact on the outcome of spectral metrics often used to characterise CDOM such as the spectral slope (S) or the slope ratio (SR). Hence, this may complicate the combining of CDOM absorption measurements from different studies where different pore sizes were used as fine particulate material may significantly influence the spectral signature, particularly in situations where phytoplankton is the dominating source of DOM.Mastalerz, M., Schieber, J., 2017. Effect of ion milling on the perceived maturity of shale samples: Implications for organic petrography and SEM analysis. International Journal of Coal Geology 183, 110-119. polishing by argon ion beam is a widely used method for examining shale samples for inherent porosity characteristics; the high quality of these surfaces suggests that this technique may also be used for optical reflectance measurements to provide information about the thermal maturity of samples. Yet, the inevitable surface heating that this polishing method engenders has raised concerns that the measured reflectance properties are no longer those of the original sample. To explore the impact of ion milling on the maturity of shale samples as measured by vitrinite and solid bitumen reflectance, five different ion milling configurations were applied to a set of organic-rich New Albany Shale (Late Devonian-Early Mississippian) samples that range in maturity from immature to post-mature. Using two ion mill designs, edge milling vs planar milling, single and dual ion beams, variable acceleration voltages, and milling at room temperature vs samples cooled by liquid nitrogen, provided a wide range of beam heating scenarios. Reflectance of macerals was measured before and after ion milling to investigate whether and to what extent various ion-milling approaches change the reflectance values, and by extension the perceived thermal maturity of organic matter in these samples. Our results demonstrate that more aggressive milling methods, such as the use of multiple beams and higher acceleration voltages elevate reflectance values, and that this effect is most pronounced in immature samples and diminishes for samples of increasing original maturity. Specifically, for the two least mature samples, the most aggressive milling method (configuration D) increased reflectance of vitrinite from 0.48% to 0.58%, and from 0.58% to 0.74%. Increase of reflectance (perceived maturity) can be counteracted by reducing beam intensity (e.g., fewer beams, lower voltage) and cooling of samples with liquid nitrogen. The severity of heating artifacts depends partially on the ion mill design, and non-damaging settings must be determined experimentally for a given ion mill model. Because thermal alteration of organic matter typically involves the expulsion of volatiles, there is also a danger that ion beam heating of immature and oil window samples can skew the porosity characteristics of shale samples. Thus, determining non-damaging ion mill settings has the dual benefit of avoiding measuring false maturity levels and misleading porosity characteristics.Matys, E.D., Sepúlveda, J., Pantoja, S., Lange, C.B., Caniupán, M., Lamy, F., Summons, R.E., 2017. Bacteriohopanepolyols along redox gradients in the Humboldt Current System off northern Chile. Geobiology 15, 844-857. oxygen minimum zones (OMZs) are characterized by the presence of subsurface suboxic or anoxic waters where diverse microbial processes are responsible for the removal of fixed nitrogen. OMZs have expanded over past decades and are expected to continue expanding in response to the changing climate. The implications for marine biogeochemistry, particularly nitrogen cycling, are uncertain. Cell membrane lipids (biomarkers), such as bacterial bacteriohopanepolyols (BHPs) and their degradation products (hopanoids), have distinctive structural attributes that convey information about their biological sources. Since the discovery of fossil hopanoids in ancient sediments, the study of BHPs has been of great biogeochemical interest due to their potential to serve as proxies for bacteria in the geological record. A stereoisomer of bacteriohopanetetrol (BHT), BHT II, has been previously identified in OMZ waters and has as been unequivocally identified in culture enrichments of anammox bacteria, a key group contributing to nitrogen loss in marine OMZs. We tested BHT II as a proxy for suboxia/anoxia and anammox bacteria in suspended organic matter across OMZ waters of the Humboldt Current System off northern Chile, as well as in surface and deeply buried sediments (125–150 ky). The BHT II ratio (BHT II/total BHT) increases as oxygen content decreases through the water column, consistent with previous results from Perú, the Cariaco Basin and the Arabian Sea, and in line with microbiological evidence indicating intense anammox activity in the Chilean OMZ. Notably, BHT II is transported from the water column to surface sediments, and preserved in deeply buried sediments, where the BHT II ratio correlates with changes in δ15N sediment values during glacial–interglacial transitions. This study suggests that BHT II offers a proxy for past changes in the relative importance of anammox, and fluctuations in nitrogen cycling in response to ocean redox changes through the geological record.Mayo, S., Josh, M., Kasperczyk, D., Kear, J., Zhang, J., Dautriat, J., Pervukhina, M., Clennell, M.B., Sakurovs, R., Sherwood, N., Maksimenko, A., Hall, C., 2018. Dynamic micro-CT study of gas uptake in coal using Xe, Kr and CO2. Fuel 212, 140-150. physics of gas uptake in coal constrains the feasibility of coal seam gas extraction and carbon sequestration in coal measures. While X-ray tomography using xenon as an X-ray opaque tracer gas has been used in the past to study gas uptake in coal specimens, synchrotron sources enable high-resolution micro-tomography datasets of high quality to be acquired in minutes adding the ability to quantify the dynamics of gas sorption over time in five coals of similar rank on the microscopic scale. In the present work we describe a synchrotron micro-computed-tomography (micro-CT) study of gas uptake in coal using Xe, Kr and CO2 gases. Measurement of gas uptake over time for Xe and Kr in different specimens and of CO2 induced swelling are reported, together with an analysis of gas diffusion profiles and their correspondence to those expected from diffusion models.The rate of penetration was CO2?>?Kr?>?Xe in all cases, though the rates of penetration varied enormously between different coals. In some cases even 2?months was not enough to allow the Xe to equilibrate fully. The gas distribution was also shown to respond rapidly to flushing with CO2.Meadows, V.S., 2017. Reflections on O2 as a biosignature in exoplanetary atmospheres. Astrobiology 17, 1022-1052. photosynthesis is Earth's dominant metabolism, having evolved to harvest the largest expected energy source at the surface of most terrestrial habitable zone planets. Using CO2 and H2O—molecules that are expected to be abundant and widespread on habitable terrestrial planets—oxygenic photosynthesis is plausible as a significant planetary process with a global impact. Photosynthetic O2 has long been considered particularly robust as a sign of life on a habitable exoplanet, due to the lack of known “false positives”—geological or photochemical processes that could also produce large quantities of stable O2. O2 has other advantages as a biosignature, including its high abundance and uniform distribution throughout the atmospheric column and its distinct, strong absorption in the visible and near-infrared. However, recent modeling work has shown that false positives for abundant oxygen or ozone could be produced by abiotic mechanisms, including photochemistry and atmospheric escape. Environmental factors for abiotic O2 have been identified and will improve our ability to choose optimal targets and measurements to guard against false positives. Most of these false-positive mechanisms are dependent on properties of the host star and are often strongest for planets orbiting M dwarfs. In particular, selecting planets found within the conservative habitable zone and those orbiting host stars more massive than 0.4 M⊙ (M3V and earlier) may help avoid planets with abundant abiotic O2 generated by water loss. Searching for O4 or CO in the planetary spectrum, or the lack of H2O or CH4, could help discriminate between abiotic and biological sources of O2 or O3. In advance of the next generation of telescopes, thorough evaluation of potential biosignatures—including likely environmental context and factors that could produce false positives—ultimately works to increase our confidence in life detection.Mejía, L.M., Méndez-Vicente, A., Abrevaya, L., Lawrence, K.T., Ladlow, C., Bolton, C., Cacho, I., Stoll, H., 2017. A diatom record of CO2 decline since the late Miocene. Earth and Planetary Science Letters 479, 18-33. sea surface temperature records from alkenones record a dramatic cooling of up to 17?°C over the last ～14 Ma, but the relationship between this cooling and greenhouse gas forcing has been elusive due to sparse and contrasting reconstructions of atmospheric CO2 for the time period. Alkenone carbon isotopic fractionation during photosynthesis has previously been used to estimate changes in pCO2 over this interval, but is complicated by significant changes in cell size of the alkenone-producing coccolithophorids over this time period. In this study, we reconstruct carbon isotopic fractionation during photosynthesis (εpεp) using organic compounds trapped within the frustules of pennate diatoms in sediments from the Eastern Equatorial Pacific Ocean at Ocean Drilling Program Site 846 over the last ～13 Ma. Physical separation of pennate diatoms prior to measuring carbon isotopic fractionation enables us to obtain a record with constant cell geometry, eliminating this factor of uncertainty in our pCO2 reconstruction. In the past ～11 Ma, εpεp declines from 15.5 to 10.3‰. Using the classic diffusive model and taking into account variations in opal content, alkenone concentration and coccolith Sr/Ca as indicators of past productivity and growth rate, and sea surface temperature records from the site, we estimate a decline in pCO2 from 454 (+/?41+/?41) to 250 (+/?15+/?15) ppmv between ～11 and 6 Ma. Models accounting for changing the significance of active carbon uptake for photosynthesis, which likely produce more accurate CO2 estimates, suggest a significant larger pCO2 decline of up to twice that shown by the classic diffusive model (in average from 794 (+/?233+/?233) ppmv at ～11 Ma to 288 (+/?25) ppmv at ～6 Ma, considering growth rates varying between 0.5 and 1.7 day?1). Large uncertainties in the pCO2 estimated between ～8 and 11 Ma using the active uptake model are related to the growth rate used for calculations. Together, these results suggest CO2 forcing for this period of steep decline in temperatures.Mejía, L.M., Paytan, A., Eisenhauer, A., B?hm, F., Kolevica, A., Bolton, C., Méndez-Vicente, A., Abrevaya, L., Isensee, K., Stoll, H., 2018. Controls over δ44/40Ca and Sr/Ca variations in coccoliths: New perspectives from laboratory cultures and cellular models. Earth and Planetary Science Letters 481, 48-60. comprise a major fraction of the global carbonate sink. Therefore, changes in coccolithophores' Ca isotopic fractionation could affect seawater Ca isotopic composition, affecting interpretations of the global Ca cycle and related changes in seawater chemistry and climate. Despite this, a quantitative interpretation of coccolith Ca isotopic fractionation and a clear understanding of the mechanisms driving it are not yet available. Here, we address this gap in knowledge by developing a simple model (CaSri–Co) to track coccolith Ca isotopic fractionation during cellular Ca uptake and allocation to calcification. We then apply it to published and new δ44/40Caδ44/40Ca and Sr/Ca data of cultured coccolithophores of the species Emiliania huxleyi and Gephyrocapsa oceanica. We identify changes in calcification rates, Ca retention efficiency and solvation–desolvation rates as major drivers of the Ca isotopic fractionation and Sr/Ca variations observed in cultures. Higher calcification rates, higher Ca retention efficiencies and lower solvation–desolvation rates increase both coccolith Ca isotopic fractionation and Sr/Ca. Coccolith Ca isotopic fractionation is most sensitive to changes in solvation–desolvation rates. Changes in Ca retention efficiency may be a major driver of coccolith Sr/Ca variations in cultures. We suggest that substantial changes in the water structure strength caused by past changes in temperature could have induced significant changes in coccolithophores' Ca isotopic fractionation, potentially having some influence on seawater Ca isotopic composition. We also suggest a potential effect on Ca isotopic fractionation via modification of the solvation environment through cellular exudates, a hypothesis that remains to be tested.Melillo, J.M., Frey, S.D., DeAngelis, K.M., Werner, W.J., Bernard, M.J., Bowles, F.P., Pold, G., Knorr, M.A., Grandy, A.S., 2017. Long-term pattern and magnitude of soil carbon feedback to the climate system in a warming world. Science 358, 101-105.: In a 26-year soil warming experiment in a mid-latitude hardwood forest, we documented changes in soil carbon cycling to investigate the potential consequences for the climate system. We found that soil warming results in a four-phase pattern of soil organic matter decay and carbon dioxide fluxes to the atmosphere, with phases of substantial soil carbon loss alternating with phases of no detectable loss. Several factors combine to affect the timing, magnitude, and thermal acclimation of soil carbon loss. These include depletion of microbially accessible carbon pools, reductions in microbial biomass, a shift in microbial carbon use efficiency, and changes in microbial community composition. Our results support projections of a long-term, self-reinforcing carbon feedback from mid-latitude forests to the climate system as the world warms.Editor's summary. Climate and the carbon cycle. It is still not clear how global warming will affect the global carbon cycle, either in terms of the magnitude of the effect or even its sign. Help in answering that question will come from long-term field-based experiments designed to explore carbon cycle-climate feedbacks in an ecosystem context. Melillo et al. performed a 26-year soil-warming experiment in a mid-latitude hardwood forest (see the Perspective by Metcalfe). Warming has resulted in a complex pattern of net carbon loss from the soil. These results support projections of a long-term, positive carbon feedback from similar ecosystems as the world warms.Melwani Daswani, M., Kite, E.S., 2017. Paleohydrology on Mars constrained by mass balance and mineralogy of pre-Amazonian sodium chloride lakes. Journal of Geophysical Research: Planets 122, 1802-1823. deposits on Mars record high-elevation lakes during the waning stages of Mars' wet era (mid-Noachian to late Hesperian). The water source pathways, seasonality, salinity, depth, lifetime, and paleoclimatic drivers of these widespread lakes are all unknown. Here we combine reaction-transport modeling, orbital spectroscopy, and new volume estimates from high-resolution digital terrain models, in order to constrain the hydrologic boundary conditions for forming the chlorides. Considering a T = 0°C system, we find that (1) individual lakes were >100 m deep and lasted decades or longer; (2) if volcanic degassing was the source of chlorine, then the water-to-rock ratio or the total water volume were probably low, consistent with brief excursions above the melting point and/or arid climate; (3) if the chlorine source was igneous chlorapatite, then Cl-leaching events would require a (cumulative) time of >10 years at the melting point; and (4) Cl masses, divided by catchment area, give column densities 0.1–50 kg Cl/m2, and these column densities bracket the expected chlorapatite-Cl content for a seasonally warm active layer. Deep groundwater was not required. Taken together, our results are consistent with Mars having a usually cold, horizontally segregated hydrosphere by the time chlorides formed.Mendhe, V.A., Mishra, S., Khangar, R.G., Kamble, A.D., Kumar, D., Varma, A.K., Singh, H., Kumar, S., Bannerjee, M., 2017. Organo-petrographic and pore facets of Permian shale beds of Jharia Basin with implications to shale gas reservoir. Journal of Earth Science 28, 897-916. shale deposits of Damodar Valley have received great attention since preliminary studies indicate their potential for shale gas. However, fundamental information allied to shale gas reservoir characteristics are still rare in India, as exploration is in the primary stage. In this study, Barakar shale beds of eastern part of Jharia Basin are evaluated for gas reservoir characteristics. It is evident that Barakar shales are carbonaceous, silty, contains sub-angular flecks of quartz and mica, irregular hair-line fractures and showing lithological variations along the bedding planes, signifying terrestrial-fluviatile deposits under reducing environment. The values of TOC varies from 1.21 wt.% to 17.32 wt.%, indicating good source rock potentiality. The vitrinite, liptinite, inertinite and mineral matter ranging from 0.28 vol.% to 12.98 vol.%, 0.17 vol.% to 3.23 vol.%, 0.23 vol.% to 9.05 vol.%, and 74.74 vol.% to 99.10 vol.%, respectively. The ternary facies plot of maceral composition substantiated that Barakar shales are vitrinite rich and placed in the thermal-dry gas prone region. The low values of the surface area determined following different methods point towards low methane storage capacity, this is because of diagenesis and alterations of potash feldspar responsible for pore blocking effect. The pore size distribution signifying the micro to mesoporous nature, while Type II sorption curve with the H2 type of hysteresis pattern, specifies the heterogeneity in pore structure mainly combined-slit and bottle neck pores.Metcalfe, D.B., 2017. Microbial change in warming soils. Science 358, 41-42. are the largest single terrestrial source of carbon dioxide (CO2), but these emissions are highly sensitive to a range of factors associated with climate change and human land use (1). Researchers have long sought to better understand the underlying drivers of soil CO2 emissions, but the duration of experiments is all too often constrained by project deadlines and personnel contracts, hampering our ability to understand and predict the many gradual but important processes that occur in soils (2). On page 101 of this issue, Melillo et al. (3) report on an intriguing 26-year record of soil respiration responses to warming in a temperate forest. The results from this unusually long time series highlight both the potential pitfalls of drawing hasty conclusions from short-term studies and the importance of long-term experiments in ecosystem and climate science.Shifts in the terrestrial carbon store, of which soils constitute around 70%, are one of the most important but least understood drivers of variation in atmospheric CO2 levels (4, 5). Soil carbon is sensitive to a wide range of factors, of which temperature is one of the most important from a climate change perspective (6). Generally, warm conditions promote microbial activity. Global warming would therefore be expected to increase microbial breakdown of organic carbon and subsequent release as CO2, but demonstrating this conclusively has proved difficult.Several approaches have been used to examine patterns in, and regulators of, soil carbon cycling. Multiple controlled experiments have repeatedly shown increasing soil respiration under warmer conditions (6, 7). A comprehensive global synthesis of soil respiration measurements found an increase associated with rising air temperatures since the 1960s, but the exact mechanisms linking temperature and soil carbon cycling remain unclear (8). Furthermore, it is not well known how much soil carbon is readily available for microbial breakdown versus how much is locked up in recalcitrant material and to what extent this could shift with climate change (6, 9).Melillo et al. make important advances in addressing these gaps with one of the most detailed pictures yet of the responses of soil microbes and carbon cycling over more than two decades of experimental warming. Their results will be invaluable in ongoing efforts to better predict and mitigate carbon losses from soils that face rapid warming associated with climate change.The authors compare soil respiration in forest plots heated with buried cables with soil respiration in untouched plots. The insights derived from these measurements are amplified by repeating these measurements for so long. The authors also draw from a wide range of shorter-term published experiments from the same site to elucidate the mechanisms that control observed shifts in respiration between plots and over time. Over the 26-year period of the experiment, they observed three multiyear phases of soil respiration (see the figure). In the first phase, soil respiration steadily decreased under warmed conditions. This was followed by a second phase where warming induced little change in respiration, and then a third phase of steadily rising respiration. At the time of publication, the experiment is entering a fourth phase where soil respiration is again gradually declining.The authors conclude that decades-long warming stimulates phases of minimal warming-induced respiration, corresponding to widespread soil microbial community reorganization as microbes struggle to adjust to the environmental conditions (see the figure). These phases are followed by surges in breakdown of previously inaccessible soil carbon pools as the reorganized microbial community takes advantage of the warmer conditions. If these findings hold more widely across major terrestrial ecosystems, then a much greater portion of the global soil carbon store could potentially be vulnerable to decomposition and release as CO2 under global warming than previously thought.Melillo et al. make a persuasive argument for the importance of considering the complexity and dynamism of the underground world to understand climate change. Further work would benefit from widening this focus to encompass the complexity above ground and the intricate linkages between above- and belowground domains. Plants regulate the amount and type of carbon inputs to soil over a range of time scales and via various distinct pathways, and these inputs are sensitive to various environmental factors, including temperature (1, 10). These plant-soil interactions represent a key frontier for development in the global vegetation models that are used to predict feedbacks between terrestrial ecosystems and climate change (10, 11).Myriad linkages between plant and soil processes are included in current global vegetation models, but many of these interactions have not been rigorously evaluated against data from field experiments (11). With complementary aboveground data, the warming experiment described by Melillo et al. could add further scientific value as a real-world test bed for the scientific ideas and hypotheses about plant-soil interactions coded in the model algorithms (11). However, perhaps the most critical future activity in the case of this experiment may at first glance seem like the least inspiring: to keep the study going. Experience shows that this kind of tedious repetition and painstaking replication has produced, and will likely continue to produce, some of our most valuable and exciting scientific insights.References1. J. W. Raich, W. H. Schlesinger, Tellus B 44, 81 (1992).2. D. B. Richter et al., Soil Sci. Soc. Am. J. 71, 266 (2007).3. J. M. Melillo et al., Science 358, 101 (2017).4. C. Le Quéré et al., Earth Syst. Sci. Data 8, 605 (2016).5. M. Cao, F. I. Woodward, Glob. Chang. Biol. 4, 185 (1998).6. E. A. Davidson, I. A. Janssens, Nature 440, 165 (2006).7. J. C. Carey et al., Proc. Natl. Acad. Sci. U.S.A. 113, 13797 (2016).8. B. Bond-Lamberty, A. Thomson, Nature 464, 579 (2010).9. R. T. Conant et al., Glob. Chang. Biol. 17, 3392 (2011).10. F. S. Chapin III et al., J. Ecol. 97, 840 (2009).11. N. J. Ostle et al., J. Ecol. 97, 851 (2009).Mettam, C., Zerkle, A.L., Claire, M.W., Izon, G., Junium, C.J., Twitchett, R.J., 2017. High-frequency fluctuations in redox conditions during the latest Permian mass extinction. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 210-223. high-resolution geochemical and sedimentological data from Fiskegrav, East Greenland, reveal fluctuations in marine redox conditions associated with the final disappearance of bioturbating organisms during the latest Permian mass extinction (LPME). Sedimentological observations imply a transgressive episode, and associated geochemical evidence for decreasing oxygen availability and the establishment of persistently ferruginous (Fe2+-rich) conditions implies the shoreward migration of oxygen deficient waters. The long-term decline in dissolved oxygen (DO) availability could have been exacerbated by increasing water temperatures, reducing the solubility of oxygen and promoting thermal stratification. Mixing of the water column could have been further inhibited by freshwater influxes that could have generated salinity contrasts that reinforced thermal stratification. Enhanced runoff could also have increased the delivery of nutrients to the marine shelf, stimulating biological oxygen demand (BOD). During the transition to persistently ferruginous conditions we identify intervals of intermittent benthic meiofaunal recolonization, events that we attribute to small transient increases in DO availability. The mechanism controlling these fluctuations remains speculative, but given the possible centennial- to millennial-scale frequency of these changes, we hypothesise that the mid-latitude setting of Fiskegrav during the Late Permian was sensitive to changes in atmospheric circulation patterns, which may have influenced local precipitation and intermittently modulated some of the processes promoting anoxia.Miao, L., Zhang, Q., Wang, S., Li, B., Wang, Z., Zhang, S., Zhang, M., Peng, Y., 2018. Characterization of EPS compositions and microbial community in an Anammox SBBR system treating landfill leachate. Bioresource Technology 249, 108-116. biofilm system is beneficial for Anammox process designed to treat landfill leachate. In this study, the composition of extracellular polymeric substances (EPS) and the microbial community in an Anammox biofilm system were analyzed to determine the functions driving the biofilm’s ability to treat landfill leachate. The results demonstrated that increasing influent carbon oxygen demand (COD) could stimulate EPS production. EPS helped enrich Anammox bacteria and supplied them with nutrients and enzymes, facilitating effective nitrogen removal (approximately 95%). The variation in Anammox bacteria was similar to the variation in EPS composition. In the tested Anammox Sequencing Biofilm Batch Reactor (SBBR) system, Candidatus Kuenenia was dominant among known Anammox genus, because of its high substrate affinity and because it adapts better to landfill leachate. The relative abundance of Candidatus Kuenenia in the biofilm rose from 3.26% to 12.38%, illustrating the protection and enrichment offered by the biofilm in carrying out Anammox.Michelson, K., Sanford, R.A., Valocchi, A.J., Werth, C.J., 2017. Nanowires of Geobacter sulfurreducens require redox cofactors to reduce metals in pore spaces too small for cell passage. Environmental Science & Technology 51, 11660-11668. of the Geobacteraceae family are ubiquitous metal reducers that utilize conductive “nanowires” to reduce Mn(IV) and Fe(III) oxides in anaerobic sediments. However, it is not currently known if and to what extent the Mn(IV) and Fe(III) oxides in soil grains and low permeability sediments that are sequestered in pore spaces too small for cell passage can be reduced by long-range extracellular electron transport via Geobacter nanowires, and what mechanisms control this reduction. We developed a microfluidic reactor that physically separates Geobacter sulfurreducens from the Mn(IV) mineral birnessite by a 1.4 μm thick wall containing <200 nm pores. Using optical microscopy and Raman spectroscopy, we show that birnessite can be reduced up to 15 μm away from cell bodies, similar to the reported length of Geobacter nanowires. Reduction across the nanoporous wall required reducing conditions, provided by Escherichia coli, and an exogenous supply of riboflavin. Our results discount electron shuttling by dissolved flavins, and instead support their role as bound redox cofactors in electron transport from nanowires to metal oxides. We also show that upon addition of a soluble electron shuttle (i.e., AQDS), reduction extends beyond the reported nanowire length up to 40 μm into a layer of birnessite.Millar, R.J., Fuglestvedt, J.S., Friedlingstein, P., Rogelj, J., Grubb, M.J., Matthews, H.D., Skeie, R.B., Forster, P.M., Frame, D.J., Allen, M.R., 2017. Emission budgets and pathways consistent with limiting warming to 1.5°C. Nature Geoscience 10, 741-747. Paris Agreement has opened debate on whether limiting warming to 1.5?°C is compatible with current emission pledges and warming of about 0.9?°C from the mid-nineteenth century to the present decade. We show that limiting cumulative post-2015 CO2 emissions to about 200?GtC would limit post-2015 warming to less than 0.6?°C in 66% of Earth system model members of the CMIP5 ensemble with no mitigation of other climate drivers, increasing to 240?GtC with ambitious non-CO2 mitigation. We combine a simple climate–carbon-cycle model with estimated ranges for key climate system properties from the IPCC Fifth Assessment Report. Assuming emissions peak and decline to below current levels by 2030, and continue thereafter on a much steeper decline, which would be historically unprecedented but consistent with a standard ambitious mitigation scenario (RCP2.6), results in a likely range of peak warming of 1.2–2.0?°C above the mid-nineteenth century. If CO2 emissions are continuously adjusted over time to limit 2100 warming to 1.5?°C, with ambitious non-CO2 mitigation, net future cumulative CO2 emissions are unlikely to prove less than 250?GtC and unlikely greater than 540?GtC. Hence, limiting warming to 1.5?°C is not yet a geophysical impossibility, but is likely to require delivery on strengthened pledges for 2030 followed by challengingly deep and rapid mitigation. Strengthening near-term emissions reductions would hedge against a high climate response or subsequent reduction rates proving economically, technically or politically unfeasible.Mills, B.J.W., Scotese, C.R., Walding, N.G., Shields, G.A., Lenton, T.M., 2017. Elevated CO2 degassing rates prevented the return of Snowball Earth during the Phanerozoic. Nature Communications 8, Article 1110. Cryogenian period (~720–635?Ma) is marked by extensive Snowball Earth glaciations. These have previously been linked to CO2 draw-down, but the severe cold climates of the Cryogenian have never been replicated during the Phanerozoic despite similar, and sometimes more dramatic changes to carbon sinks. Here we quantify the total CO2 input rate, both by measuring the global length of subduction zones in plate tectonic reconstructions, and by sea-level inversion. Our results indicate that degassing rates were anomalously low during the Late Neoproterozoic, roughly doubled by the Early Phanerozoic, and remained comparatively high until the Cenozoic. Our carbon cycle modelling identifies the Cryogenian as a unique period during which low surface temperature was more easily achieved, and shows that the shift towards greater CO2 input rates after the Cryogenian helped prevent severe glaciation during the Phanerozoic. Such a shift appears essential for the development of complex animal life.Milman, B.L., Zhurkovich, I.K., 2017. The chemical space for non-target analysis. TrAC Trends in Analytical Chemistry 97, 179-187. review describes chemical space, i.e. the set of known and possible compounds, and presents the use of corresponding chemical data in non-target analysis. Its implementation is briefly considered. General and dedicated chemical databases are outlined. Citation and co-citation of chemical compounds in databases are considered. The data transfer from high resolution mass spectrometry to chemical databases is noted to be the key stage of modern non-target analysis. Searched structures are further filtered with the use of reference and computational data. Related issues are also addressed.Misarti, N., Gier, E., Finney, B., Barnes, K., McCarthy, M., 2017. Compound-specific amino acid δ15N values in archaeological shell: Assessing diagenetic integrity and potential for isotopic baseline reconstruction. Rapid Communications in Mass Spectrometry 31, 1881-1891.: Reconstructing stable isotope (SI) ratios at the base of paleo-food webs is often challenging. For coastal systems, the SI ratios of organic matter in archeological shell represents a possible solution, providing a direct record of primary consumer SI ratios in the littoral zone. However, shell is often porous, with organic compounds susceptible to diagenetic alteration or contamination. If molecular isotopic information is well preserved, compound-specific amino acid isotope analysis (CSI-AA) has the potential to provide direct proxies for baseline SI ratios, bypassing many contamination issues, and to allow assessment of the diagenetic state.Methods: We collected shell from both archeological middens and nearby littoral zones in coastal Alaska, and used a simple organic extraction approach based on decalcification with sequential weak HCl additions to liberate organic material. We measured CSI-AA patterns, molar AA distributions, and the CSI-AA degradation parameter (ΣV), in the context of bulk SI ratios in fossil shell, modern shell, and soft tissue from five common taxa (urchin, limpet, mussel, periwinkle, chiton).Results: CSI-AA patterns in both soft tissue and shell were consistent with primary consumers, and were indistinguishable in most modern and fossil shell pairs, showing that amino acid δ15N values can be well preserved in archeological shell. AA molar distributions were also similar, although most fossil shell was enriched in Asx and Gly. Comparison between CSI-AA results from modern specimens confirmed that the source AA group (tracking isotopic baselines) are transferred without substantial modification into the shell record. In contrast, the Trophic AA group had elevated δ15N values in shell versus soft tissue for all taxa examined, suggesting that a correction factor will be required for any CSI-AA proxies using these AAs.Conclusions: Overall, this new data indicates that the CSI-AA analysis of fossil shell represents a promising new approach to determining isotopic baselines in coastal paleo-ecosystems.Mitra, S., Osburn, C.L., Wozniak, A.S., 2017. A preliminary assessment of fossil fuel and terrigenous influences to rainwater organic matter in summertime in the northern Gulf of Mexico. Aquatic Geochemistry 23, 217-231. report here for the first time rainwater organic carbon (OC) concentration and composition collected from open waters over the Gulf of Mexico. Rainwater OC concentrations ranged from 3.7 to 17.3 mg L?1. The δ13C of these rainwater samples ranged from ?26.7 to ?24.2‰ pointing toward terrestrial and/or fossil fuel OC sources (64–100%) combined with marine OC sources. Colored dissolved OM absorbance and EEM fluorescence spectra were indicative of secondary organic aerosol from terrestrial sources as well as aromatic fossil fuel compounds. Air mass back trajectory analyses along with these results indicate that rainwater OC in the Gulf of Mexico may be influenced by oil and gas infrastructure and emissions from known lanes of shipping traffic within the Gulf. These results also suggest that anthropogenic and biogenic emissions from the southeastern continental USA impact rainwater OC in the Gulf of Mexico.Mogul, R., Vaishampayan, P., Bashir, M., McKay, C.P., Schubert, K., Bornaccorsi, R., Gomez, E., Tharayil, S., Payton, G., Capra, J., Andaya, J., Bacon, L., Bargoma, E., Black, D., Boos, K., Brant, M., Chabot, M., Chau, D., Cisneros, J., Chu, G., Curnutt, J., DiMizio, J., Engelbrecht, C., Gott, C., Harnoto, R., Hovanesian, R., Johnson, S., Lavergne, B., Martinez, G., Mans, P., Morales, E., Oei, A., Peplow, G., Piaget, R., Ponce, N., Renteria, E., Rodriguez, V., Rodriguez, J., Santander, M., Sarmiento, K., Scheppelmann, A., Schroter, G., Sexton, D., Stephenson, J., Symer, K., Russo-Tait, T., Weigel, B., Wilhelm, M.B., 2017. Microbial community and biochemical dynamics of biological soil crusts across a gradient of surface coverage in the central Mojave Desert. Frontiers in Microbiology 8, 1974. doi: 10.3389/fmicb.2017.01974. this study, we expand upon the biogeography of biological soil crusts (BSCs) and provide molecular insights into the microbial community and biochemical dynamics along the vertical BSC column structure, and across a transect of increasing BSC surface coverage in the central Mojave Desert, CA, United States. Next generation sequencing reveals a bacterial community profile that is distinct among BSCs in the southwestern United States. Distribution of major phyla in the BSC topsoils included Cyanobacteria (33 ± 8%), Proteobacteria (26 ± 6%), and Chloroflexi (12 ± 4%), with Phormidium being the numerically dominant genus. Furthermore, BSC subsurfaces contained Proteobacteria (23 ± 5%), Actinobacteria (20 ± 5%), and Chloroflexi (18 ± 3%), with an unidentified genus from Chloroflexi (AKIW781, order) being numerically dominant. Across the transect, changes in distribution at the phylum (p < 0.0439) and genus (p < 0.006) levels, including multiple biochemical and geochemical trends (p < 0.05), positively correlated with increasing BSC surface coverage. This included increases in (a) Chloroflexi abundance, (b) abundance and diversity of Cyanobacteria, (b) OTU-level diversity in the topsoil, (c) OTU-level differentiation between the topsoil and subsurface, (d) intracellular ATP abundances and catalase activities, and (e) enrichments in clay, silt, and varying elements, including S, Mn, Co, As, and Pb, in the BSC topsoils. In sum, these studies suggest that BSCs from regions of differing surface coverage represent early successional stages, which exhibit increasing bacterial diversity, metabolic activities, and capacity to restructure the soil. Further, these trends suggest that BSC successional maturation and colonization across the transect are inhibited by metals/metalloids such as B, Ca, Ti, Mn, Co, Ni, Mo, and Pb.Mohamad Shahimin, M.F., Siddique, T., 2017. Sequential biodegradation of complex naphtha hydrocarbons under methanogenic conditions in two different oil sands tailings. Environmental Pollution 221, 398-406. emissions in oil sands tailings ponds are sustained by anaerobic biodegradation of unrecovered hydrocarbons. Naphtha (primarily C6–C10; n- iso- and cycloalkanes) is commonly used as a solvent during bitumen extraction process and its residue escapes to tailings ponds during tailings deposition. To investigate biodegradability of hydrocarbons in naphtha, mature fine tailings (MFT) collected from Albian and CNRL tailings ponds were amended with CNRL naphtha at ～0.2 wt% (～2000 mg L?1) and incubated under methanogenic conditions for ～1600 d. Microbial communities in both MFTs started metabolizing naphtha after a lag phase of ～100 d. Complete biodegradation/biotransformation of all n-alkanes (except partial biodegradation of n-octane in CNRL MFT) followed by major iso-alkanes (2-methylpentane, 3-methylhexane, 2- and 4-methylheptane, iso-nonanes and 2-methylnonane) and a few cycloalkanes (derivatives of cyclopentane and cyclohexane) was observed during the incubation. 16S rRNA gene pyrosequencing showed dominance of Peptococcaceae and Anaerolineaceae in Albian MFT and Anaerolineaceae and Syntrophaceae in CNRL MFT bacterial communities with co-domination of Methanosaetaceae and “Candidatus Methanoregula” in archaeal populations during active biodegradation of hydrocarbons. The findings extend the known range of hydrocarbons susceptible to methanogenic biodegradation in petroleum-impacted anaerobic environments and help refine existing kinetic model to predict greenhouse gas emissions from tailings ponds.Moini, M., Rollman, C.M., 2017. Buyid silk and the tale of Bibi Shahrbanu: Identification of biomarkers of artificial aging (forgery) of silk. Analytical Chemistry 89, 10158-10161. silk forgery is one of the most famous silk forgeries in the world. In 1924–1925, excavation of the Bibi Shahrbanu site in Iran unearthed several silk textiles. The silks were thought to be of the Buyid period (934–1062 BCE) of the Persian Empire and have since been known as the “Buyid silks”. In the 1930s, more silk appeared and was reported as being from the Buyid period as well. Controversy over the authenticity of these silks escalated after the purchase of the silks by museums throughout the world. Extensive investigations of several of these silks have been conducted over the years with respect to iconography, weaving patterns, dyes/mordant, style, and even radiocarbon dating. It was found that most of the silks are not from Buyid period. To test the authenticity of these silk fabrics, the recently developed silk dating technique using amino acid racemization (AAR) in conjunction with capillary electrophoresis mass spectrometry was applied to 13 Buyid silk specimens from the Textile Museum collections. Among these silk specimens, the AAR ratios of only one specimen were consistent with authentic silk fabrics collected from various museums. In addition, the aspartic acid racemization ratio of this specimen was also consistent with its 14C dating. The other “Buyid silks” showed excessive levels of amino acid racemization not only for aspartic acid, but also for phenylalanine and tyrosine, inconsistent with racemization rates of these amino acids in authentic historical silk fabrics. Treatment of modern silk with a base at different pH and temperature reproduced the AAR pattern of the Buyid silks, implying that chemical treatment with a base at relatively high temperatures was perhaps the method used to artificially age these fabrics. The results imply that the racemization ratios of aspartic acid, phenylalanine, and tyrosine can be used as biomarkers for identification of naturally versus artificially aged silk.Momper, L., Kiel Reese, B., Zinke, L., Wanger, G., Osburn, M.R., Moser, D., Amend, J.P., 2017. Major phylum-level differences between porefluid and host rock bacterial communities in the terrestrial deep subsurface. Environmental Microbiology Reports 9, 501-511.'s deep subsurface biosphere (DSB) is home to a vast number and wide variety of microorganisms. Although difficult to access and sample, deep subsurface environments have been probed through drilling programs, exploration of mines and sampling of deeply sourced vents and springs. In an effort to understand the ecology of deep terrestrial habitats, we examined bacterial diversity in the Sanford Underground Research Facility (SURF), the former Homestake gold mine, in South Dakota, USA. Whole genomic DNA was extracted from deeply circulating groundwater and corresponding host rock (at a depth of 1.45 km below ground surface). Pyrotag DNA sequencing of the 16S rRNA gene revealed diverse communities of putative chemolithoautotrophs, aerobic and anaerobic heterotrophs, numerous candidate phyla and unique rock-associated microbial assemblage. There was a clear and near-total separation of communities between SURF deeply circulating fracture fluids and SURF host-rocks. Sequencing data from SURF compared against five similarly sequenced terrestrial subsurface sites in Europe and North America revealed classes Clostridia and Betaproteobacteria were dominant in terrestrial fluids. This study presents a unique analysis showing differences in terrestrial subsurface microbial communities between fracture fluids and host rock through which those fluids permeate.Moores, J.E., Smith, C.L., Schuerger, A.C., 2017. UV production of methane from surface and sedimenting IDPs on Mars in light of REMS data and with insights for TGO. Planetary and Space Science 147, 48-60. paper refines model predictions for the production of methane from UV-irradiated interplanetary dust particles (IDPs) now that the Rover Environmental Monitoring Station (REMS) instrument onboard the Mars Science Laboratory (MSL) Rover has made the first measurements of the UV environment on the surface of Mars, at Gale Crater. Once these measurements are included in a UV radiative transfer model, we find that modelled UV sol-integrated energies across the planet are lower than pre-measurement estimates by 35% on average, considering all latitudes and seasons. This reduction, in turn, reduces the predicted production of methane from individual accreting IDPs, extending their lifetimes and increasing the surface concentration of organics that must accumulate in order to emit sufficient methane to balance the accretion of organic compounds to Mars. Emission from reasonable accumulations of IDPs could range up to ～7.9 × 10?4 ppbv sol?1. Richer deposits of organic carbon at the surface may emit methane at no more than 3.9 ppbv sol?1. An examination of IDP-derived methane production during atmospheric settling indicates that no more than 0.32% of organic carbon from meteor streams may be deposited in the atmosphere. Thus, such a process cannot explain either the spikes observed in methane nor the low equilibrium values observed by MSL. Instead, this discrepancy may be explained if < 80 tons per year of organic carbon survives to the surface, the atmospheric lifetime of methane is < 110 years or the efficiency of the UV-CH4 process is <7%. Under the assumption of reduced carbon input cycling in the Martian system from these processes, both soil concentrations of organic carbon and atmospheric measurements of methane observed by MSL are consistent with the UV-CH4 process. This refinement of methane production from IDPs and its geographical and vertical distribution will be an important input for models attempting to understand the results to be derived from the Trace Gas Orbiter (TGO) mission that will map methane concentrations in the martian atmosphere in 2018 at 0.01 ppbv.Mori, J.F., Scott, J.J., Hager, K.W., Moyer, C.L., Küsel, K., Emerson, D., 2017. Physiological and ecological implications of an iron- or hydrogen-oxidizing member of the Zetaproteobacteria, Ghiorsea bivora, gen. nov., sp. nov. ISME Journal 11, 2624-2636. Fe-oxidizing communities are common at diffuse-flow hydrothermal vents throughout the world’s oceans. The foundational members of these communities are the Zetaproteobacteria, a class of Proteobacteria that is primarily associated with ecosystems fueled by ferrous iron, Fe(II). We report here the discovery of two new isolates of Zetaproteobacteria isolated from the Mid-Atlantic Ridge (TAG-1), and the Mariana back-arc (SV-108), that are unique in that they can utilize either Fe(II) or molecular hydrogen (H2) as sole electron donor and oxygen as terminal electron acceptor for growth. Both strains precipitated Fe-oxyhydroxides as amorphous particulates. The cell doubling time on H2 vs Fe(II) for TAG-1 was 14.1 vs 21.8?h, and for SV-108 it was 16.3 vs 20?h, and it appeared both strains could use either H2 or Fe(II) simultaneously. The strains were close relatives, based on genomic analysis, and both possessed genes for the uptake NiFe-hydrogenase required for growth on H2. These two strains belong to Zetaproteobacteria operational taxonomic unit 9 (ZetaOTU9). A meta-analysis of public databases found ZetaOTU9 was only associated with Fe(II)-rich habitats, and not in other environments where known H2-oxidizers exist. These results expand the metabolic repertoire of the Zetaproteobacteria, yet confirm that Fe(II) metabolism is the primary driver of their physiology and ecology.Morley, C.K., von Hagke, C., Hansberry, R., Collins, A., Kanitpanyacharoen, W., King, R., 2018. Review of major shale-dominated detachment and thrust characteristics in the diagenetic zone: Part II, rock mechanics and microscopic scale. Earth-Science Reviews 176, 19-50. large shale thrust zone behaviour down to the diagenetic-metamorphic boundary is both simple and complex. The task in critical taper, analogue and numerical models has been successfully approximated using simple material parameters. Yet the weakness of shales thrusts on a case-by-case basis show great variability in key factors across a wide range of scales. Understanding of these variables and their relationships to different tectonic settings is patchy due to the different objectives of workers studying the various systems (e.g. seismic hazards, hydrocarbon exploration, structural geology research), and the types of available geological and geophysical data. Early research recognized that megathrusts feature creeping and locked patches, which may be described using the rate and state formalism. In addition to temperature, differential stress and strain rate, key controlling factors on thrust weakness are mineralogy, amount of weak phase present, structure localization mechanisms, grain size and shapes, porosity, permeability and pore fluid pressure. The smectite-illite transition has been a focus of seismic hazard research due to its coincidence with the top of the seismogenic zone. While there may be a relationship, other factors such as pore-fluid pressure variations or structure localization are also important. The critical taper model is a simple means of determining whether basic rock mechanics data (e.g. frictional strength, pore fluid pressure) is appropriate for natural wedges. For example, aseismic basal detachments of gravity driven systems (smaller critical taper wedges) appear to retain higher pore fluid pressures along the basal detachment than seismogenic basal detachments (higher critical taper wedges). In many continental and deltaic fold and thrust belts high organic carbon content is a very important factor in shale weakness due to: 1) the overall more ductile and well-cleaved nature of the shale when organic content is high, 2) the presence of high overpressures due to maturation of organic material, and 3) metamorphism of carbon to low friction graphite. This multifaceted influence of organic carbon content is just one example of the diversity of potential influences on shale thrust zone weakness, which enable shales to be weak despite considerable lateral deposition-related and vertical burial-related changes in composition. Some key variations between different types of fold and thrust belt (gravity driven; accretionary prism; Andean/Himalayan type) lie in systematic variations in clay mineralogy, magnitudes and origins of overpressures, seismic versus aseismic detachments, and different structural localization mechanisms. Further research is required to explore the viability of such distinctions and their impact on structural styles.Morozov, E.V., Martyanov, O.N., 2017. Reversibility of asphaltene aggregation as revealed by magnetic resonance imaging in situ. Energy & Fuels 31, 10639-10647. of asphaltenes followed by precipitation presents severe problems for existing technologies in the production, recovery, and processing of heavy oils. Better understanding of asphaltene behavior behind the processes of their precipitation and dissolution is vital to address this issue. While investigating the inhomogeneity of different oil systems, the reversibility of the asphaltene aggregation process initiated by flocculant in either asphaltene solution in toluene or crude heavy oil was revealed and investigated using magnetic resonance imaging methods. It was found that the inhomogeneous distribution of the flocculant initiates local spatial-selective asphaltene aggregation registered in a thin layer around the flocculant/oil sample interface. The local excess of flocculant concentration over the threshold of asphaltene precipitation onset is a driving force of this process. As the flocculant diffuses into the volume of the sample, a decrease of the asphaltene flocculated area is observed until it disappears when the equilibrium composition throughout the whole volume of the system is achieved. Depending on the overall flocculant concentration, the asphaltene aggregation may not be reversible and could be followed by subsequent precipitation of the asphaltene aggregates. The similarity of the phenomena observed for the model asphaltene solutions and crude heavy oil samples was established. Partial mechanical stirring of the multicomponent system comprising flocculant and oil or asphaltene solution does not prevent the formation of the local zones with increased concentration of asphaltene aggregates; those sizes evolve depending on the flocculant concentration. The results obtained in this work are consistent with the generally accepted concept of asphaltene precipitation reversibility depending on the system composition and are compatible with the observations obtained by other methods. The approach presented can provide deeper insight into the asphaltene precipitation reversibility issue and can facilitate the understanding of asphaltene behavior in heavy oils.Mouro, L.D., Rakociński, M., Marynowski, L., Pisarzowska, A., Musabelliu, S., Zatoń, M., Carvalho, M.A., Fernandes, A.C.S., Waichel, B.L., 2017. Benthic anoxia, intermittent photic zone euxinia and elevated productivity during deposition of the Lower Permian, post-glacial fossiliferous black shales of the Paraná Basin, Brazil. Global and Planetary Change 158, 155-172., the Lower Permian, post-glacial fossiliferous Lontras black shales from the Paraná Basin (southern Brazil) are studied using integrated palynological, geochemical and petrographic methods for the first time in order to decipher the prevalent palaeoenvironmental conditions during their sedimentation. These black shales were deposited in a restricted marine environment. Inorganic geochemical data (U/Th ratios, authigenic uranium, molybdenum), organic geochemical data (total organic carbon, biomarkers) and framboid pyrite size distributions point to predominantly anoxic/euxinic bottom-water conditions. Moreover, the presence of aryl isoprenoids and maleimide biomarkers indicates that euxinia in the water column was intermittently present in the photic zone. The onset of anoxic conditions was caused by elevated productivity in the basin, which was related to deglaciation, marine transgression and the increased delivery of terrestrial nutrients. The presence of a positive organic carbon isotope excursion indicates that the black shale deposition resulted from increased productivity and the expansion of anoxic and nitrogen- and phosphate-enriched waters into the shallow photic zone. The high values of δ15N (exceeding 9‰) may be related to the deglaciation-driven sea-level rise and advection of denitrified water mass from the Panthalassic Ocean to the intracratonic Paraná Basin. Prolonged periods of sea-floor anoxia/euxinia excluded potential scavengers and bioturbators, thus enhancing the preservation of numerous fossil taxa, including fish, sponges, insects and their larval cases, and conodont apparatuses. The intermittent photic zone euxinia may also have contributed to the mass mortality of fish populations, the fossils of which are very well-preserved in these black shales.Müller, V., Hess, V., 2017. The minimum biological energy quantum. Frontiers in Microbiology 8, 2019. doi: 10.3389/fmicb.2017.02019. anaerobic archaea and bacteria live on substrates that do not allow the synthesis of one mol of ATP per mol of substrate via substrate level phosphorylation. Energy conservation in these cases is only possible by a chemiosmotic mechanism that involves the generation of an electrochemical ion gradient across the cytoplasmic membrane that then drives ATP synthesis via an ATP synthase. The minimal amount of energy required for ATP synthesis is thus dependent on the magnitude of the electrochemical ion gradient, the phosphorylation potential in the cell and the ion/ATP ratio of the ATP synthase. It was always thought that the minimum biological energy quantum is defined as the amount of energy required to translocate one ion across the cytoplasmic membrane. We will discuss the thermodynamics of the reactions involved in chemiosmosis and describe the limitations for ion transport and ATP synthesis that led to the proposal that at least -20 kJ/mol are required for ATP synthesis. We will challenge this hypothesis by arguing that the enzyme energizing the membrane may translocate net less than one ion: By using a primary pump connected to an antiporter module a stoichiometry below one can be obtained, implying that the minimum biological energy quantum that sustains life is even lower than assumed to date.Mustasaar, M., Comas, X., 2017. Spatiotemporal variability in biogenic gas dynamics in a subtropical peat soil at the laboratory scale is revealed using high-resolution ground-penetrating radar. Journal of Geophysical Research: Biogeosciences 122, 2219-2232. importance of peatlands as sources of greenhouse gas emissions has been demonstrated in many studies during the last two decades. While most studies have shown the heterogeneous distribution of biogenic gas in peat soils at the field scale (sampling volumes in the order of meters), little information exists for submeter scales, particularly relevant to properly capture the dynamics of hot spots for gas accumulation and release when designing sampling routines with methods that use smaller (i.e., submeter) sampling volumes like flux chambers. In this study, ground-penetrating radar is used at the laboratory scale to evaluate biogenic gas dynamics at high spatial resolution (i.e., cm) in a peat monolith from the Everglades. The results indicate sharp changes (both spatially and temporally) in the dynamics of gas accumulation and release, representing hot spots for production and release of biogenic gases with surface areas ranging between 5 to 10 cm diameter and are associated with increases in porosity. Furthermore, changes in gas composition and inferred methane (CH4) and carbon dioxide (CO2) fluxes also displayed a high spatiotemporal variability associated with hot spots, resulting in CH4 and CO2 flux estimates showing differences up to 1 order of magnitude during the same day for different parts of the sample. This work follows on recent studies in the Everglades and questions the appropriateness of spatial and temporal scales of measurement when defining gas dynamics by showing how flux values may change both spatially and temporarily even when considering submeter spatial scales.Myhre, G., Myhre, C.L., Forster, P.M., Shine, K.P., 2017. Halfway to doubling of CO2 radiative forcing. Nature Geoscience 10, 710-711. doubling of atmospheric CO2 concentrations has become a standard experiment in climate science, and a convenient way of comparing the sensitivity of different climate models. It was introduced by Arrhenius1 in the nineteenth century, and used in the classic paper by Manabe and Wetherald2, which marked the start of the modern era of climate modelling. The doubling of CO2 now has an iconic role in climate research. The equilibrium climate sensitivity (ECS) is defined as the global mean surface temperature change resulting from a doubling of CO23, 4, 5, which is a headline result in Intergovernmental Panel on Climate Change (IPCC) assessments. In its most recent assessment, the IPCC concluded5 that the ECS “is likely in the range 1.5 to 4.5 °C”. We show that we are now halfway to doubling the radiative forcing of CO2 since pre-industrial times, although concentrations are not halfway to doubling.The greenhouse effect due to changes in CO2 — quantified using calculations of radiative forcing —follows, to a good approximation, a logarithmic dependence on the ambient concentration in the atmosphere over the past 1,000 years6. Because of this relationship between radiative forcing and CO2 concentration, the forcing induced by a doubling of CO2 is approximately independent of background levels. A doubling of CO2 is estimated by the IPCC to cause a radiative forcing of 3.7 W m?2. Detailed radiative transfer calculations arrived at a similar estimate7. The uncertainties are small for the radiative forcing due to CO2; uncertainties associated with spectroscopic parameters that underpin forcing calculations are estimated8 to be less than 1%, with overall uncertainties assessed6 to be 10% (with 90% confidence). Forcing estimates of a doubling of CO2 from global climate models have the same best estimate as the IPCC value6, despite these models including rapid atmospheric adjustments that modify the forcing calculated using a radiative transfer model.It is timely to assess where we are now, relative to a doubling. The global mean CO2 abundance in 2016 was 403 ppm according to global observations9, which is less than 50% higher than the pre-industrial CO2 concentration of 278 ppm. However, due to the logarithmic forcing relationship, the halfway point to a doubling of CO2, in terms of radiative forcing, has now been reached. Figure 1a illustrates that this benchmark was met at 393 ppm, in 2012. Halfway to a doubling in the CO2 concentration is 417 ppm, which will be reached before 2025 with current CO2 growth rates. Hence, at CO2 concentrations between 393 ppm and 417 ppm we are more than a halfway to a doubling of CO2 in terms of radiative forcing, but not in concentration (Fig. 1a).Climate change over the industrial era is caused by several anthropogenic climate drivers in addition to CO2, including other atmospheric gases and aerosols, and changes to the land surface6. Increases in concentrations of well-mixed greenhouse gases (WMGHGs) other than CO2 (notably CH4, N2O and halocarbons) contribute to a stronger greenhouse effect. The combined radiative forcing from all WMGHGs was 3.1 W m?2 in 2015 (Fig. 1a) and hence in CO2-equivalent forcing terms, is 84% of the way to a doubling. This value includes an estimate of the radiative forcing caused by CH4, which incorporated its absorption of solar radiation; this update resulted in an increase7 in the CH4 forcing over the period 1750–2011 from 0.48 W m?2 (the value in the Fifth Assessment Report of the IPCC6) to 0.61 W m?2. In radiative forcing terms, this increase is close to the increase in CO2 concentration over the five-year period from 2010 to 2015. Consequently, we estimate that total WMGHG radiative forcing will be equivalent to a doubling of CO2, with present growth rates, by around 2030 (Fig. 1b). This is almost five years earlier than is estimated without the update to the CH4 forcing. Aerosols generally cool the Earth and have historically countered much of this additional WMGHG forcing. Total anthropogenic forcing is expected to be close to the CO2-only forcing, but aerosols add uncertainty6. Nevertheless, in terms of radiative forcing we are still likely to have come more than half way to a doubling of CO2 in the atmosphere.References1. Arrhenius, S. Phil. Mag. J. Sci. 41, 237–276 (1896). 2. Manabe, S. & Wetherald, R. T. J. Atmos. Sci. 24, 241–259 (1967). 3. Forster, P. M. Annu. Rev. Earth Planet. Sci. 44, 85–106 (2016). 4. Roe, G. H. & Baker, M. B. Science 318, 629–632 (2007). 5. Collins, M. et al. in Climate Change 2013: The Physical Science Basis (eds Stocker, T. F. et al.) 1029–1136 (IPCC, Cambridge Univ. Press, 2013). 6. Myhre, G. et al. in Climate Change 2013: The Physical Science Basis (eds Stocker, T. F. et al.) 659–740 (IPCC, Cambridge Univ. Press, 2013). 7. Etminan, M., Myhre, G., Highwood, E. J. & Shine, K. P. Geophys. Res. Lett. 43, 12614–12623 (2016). 8. Mlynczak, M. G. et al. Geophys. Res. Lett. 43, 5318–5325 (2016). 9. Blunden, J. & Arndt, D. S. Bull. Am. Meteorol. Soc. 98, Si–S277 (2017). 10. Prather, M. et al. in Climate Change 2013: The Physical Science Basis (eds Stocker, T. F. et al.) 1395–1445 (IPCC, Cambridge Univ. Press, 2013).Nagoji, S.S., Tiwari, M., 2017. Organic carbon preservation in Southeastern Arabian Sea sediments since mid-Holocene: Implications to South Asian Summer Monsoon variability. Geochemistry, Geophysics, Geosystems 18, 3438-3451. earlier studies show a contrasting long-term trend of the South Asian Summer Monsoon (SASM) after attaining the precessional forcing induced mid-Holocene maximum. The increasing total organic carbon (TOC) concentration of marine sediments in the Southeastern Arabian Sea (SEAS) has been interpreted to imply strengthening SASM since mid-Holocene by a few studies. However, TOC concentration is also influenced by redox conditions, sedimentation rate, and an influx of terrigenous matter depending on the regional settings. So, it needs to be ascertained whether the TOC concentration of the sediments in the SEAS is a signal of productivity related to the SASM strength or preservation. Therefore, we studied multiple proxies (TOC, total nitrogen, atomic C/N, δ13Corg, CaCO3, and major and trace elements concentration) for determining the productivity, redox conditions, detrital supply, and provenance in a sediment core from the upper continental slope of the SEAS spanning the past ～4700 years at centennial scale resolution. The present study shows that the observed increase in the TOC values since the mid-Holocene is a result of better preservation caused by increased sedimentation rate and enhanced reducing conditions. We further show that the SASM has been declining since mid-Holocene after attaining a precession-forced maximum, which corroborates the earlier model ensemble studies.Nahan, K.S., Alvarez, N., Shanov, V., Vonderheide, A., 2017. Carbon nanotube fiber ionization mass spectrometry: A fundamental study of a multi-walled carbon nanotube functionalized corona discharge pin for polycyclic aromatic hydrocarbons analysis. Journal of The American Society for Mass Spectrometry 28, 2408-2413. spectrometry continues to tackle many complicated tasks, and ongoing research seeks to simplify its instrumentation as well as sampling. The desorption electrospray ionization (DESI) source was the first ambient ionization source to function without extensive gas requirements and chromatography. Electrospray techniques generally have low efficiency for ionization of nonpolar analytes and some researchers have resorted to methods such as direct analysis in real time (DART) or desorption atmospheric pressure chemical ionization (DAPCI) for their analysis. In this work, a carbon nanotube fiber ionization (nanoCFI) source was developed and was found to be capable of solid phase microextraction (SPME) of nonpolar analytes as well as ionization and sampling similar to that of direct probe atmospheric pressure chemical ionization (DP-APCI). Conductivity and adsorption were maintained by utilizing a corona pin functionalized with a multi-walled carbon nanotube (MWCNT) thread. Quantitative work with the nanoCFI source with a designed corona discharge pin insert demonstrated linearity up to 0.97 (R2) of three target PAHs with phenanthrene internal standard.Nakayama, T., Inagaki, Y., 2017. Genomic divergence within non-photosynthetic cyanobacterial endosymbionts in rhopalodiacean diatoms. Scientific Reports 7, Article 13075. acquisitions via endosymbioses with prokaryotes were milestones in the evolution of eukaryotes. Still, quite a few uncertainties have remained for the evolution in the early stage of organellogenesis. In this respect, rhopalodiacean diatoms and their obligate cyanobacterial endosymbionts, called spheroid bodies, are emerging as new models for the study of organellogenesis. The genome for the spheroid body of Epithemia turgida, a rhopalodiacean diatom, has unveiled its unique metabolic nature lacking the photosynthetic ability. Nevertheless, the genome sequence of a spheroid body from a single lineage may not be sufficient to depict the evolution of these cyanobacterium-derived intracellular structures as a whole. Here, we report on the complete genome for the spheroid body of Rhopalodia gibberula, a lineage distinct from E. turgida, of?which genome has been fully determined. Overall, features in genome structure and metabolic capacity, including a lack of photosynthetic ability, were highly conserved between the two spheroid bodies. However, our comparative genomic analyses revealed that the genome of the R. gibberula spheroid body exhibits a lower non-synonymous substitution rate and a slower progression of pseudogenisation than those of E. turgida, suggesting that a certain degree of diversity exists amongst the genomes of obligate endosymbionts in unicellular eukaryotes.Napolitano, M.P., Kuo, P.-C., Johnson, J.V., Arslanoglu, J., Yost, R.A., 2017. Tandem mass spectrometry of laser-reduced anthraquinones for painted works and dyed cultural artifacts. International Journal of Mass Spectrometry 421, 14-24. peculiar ionization of anthraquinones, including the artistic dyes alizarin and purpurin, is examined. When alizarin (MW = 240) is ionized by either LDI or MALDI it exhibits a dominant ion of m/z 242 [M + 2H]+ with a far greater abundance than expected from the 13C isotopic contribution from the [M + H]+ ion at m/z 241. For the first time, MS/MS analysis of these anomalous [M + 2H]+ ions is presented, which indicates that they arise from a laser-induced photoreduction of one of the anthraquinone’s carbonyl groups. MS/MS daughter ions produced from neutral losses of either water or ammonia from the [M + 2H]+ ions exhibit different relative abundances, depending upon their respective functional groups’ proximity to the reduced carbonyl. LDI-MS/MS was used for the in situ detection of alizarin in a painting cross section and a swatch of dyed silk.Neupane, B., Ju, Y., Silwal, B.R., Singh, P.K., Huang, C., 2017. Structural investigations of Eocene coals from foreland basin of central Nepal Himalaya. Energy Exploration & Exploitation 35, 713-733. investigations of Eocene coal from foreland basin of central Nepal Himalaya were subjected to attenuated total reflection Fourier transform infrared spectroscopy, X-ray diffraction, high-resolution transmission electron microscopy and scanning electron microscopy to study their chemical and structural characteristics. The attenuated total reflection Fourier transform infrared spectroscopy data show that the less matured coal sample (sub-bituminous) has more aliphatic moieties, whereas the relatively more matured (bituminous) coal samples contain higher fractions of poly-aromatic moieties and saturated long-chain hydrocarbons. Fourier transform infrared spectroscopy spectra reveals the presence of stretching vibrations of aliphatic –CH, –CH2 and –CH3 absorptions, –OH bonds, C=C and –CH of aromatic structures and C=O stretching vibrations of carbonyl groups. X-ray diffraction indicates the presence of crystalline carbon having turbostratic structure along with some highly disordered amorphous carbon while high-resolution transmission electron microscopy study shows the formation of carbon nanostructures of 1.73–8.03?nm size and nominal areas in the range of 11–14?nm2. Single-wall nanotubes of 12.67–36.23?nm diameters were also formed. The nominal size of the single-wall nanotubes is in the range of 16–20?nm. The presence of micro-pores, micro-fissures and micro-cracks were revealed in the scanning electron microscopy study.Nguyen, N.-L., Yu, W.-J., Yang, H.-Y., Kim, J.-G., Jung, M.-Y., Park, S.-J., Roh, S.-W., Rhee, S.-K., 2017. A novel methanotroph in the genus Methylomonas that contains a distinct clade of soluble methane monooxygenase. Journal of Microbiology 55, 775-782. methane oxidation is a key process in the global carbon cycle that acts as a major sink of methane. In this study, we describe a novel methanotroph designated EMGL16-1 that was isolated from a freshwater lake using the floating filter culture technique. Based on a phylogenetic analysis of 16S rRNA gene sequences, the isolate was found to be closely related to the genus Methylomonas in the family Methylococcaceae of the class Gammaproteobacteria with 94.2–97.4% 16S rRNA gene similarity to Methylomonas type strains. Comparison of chemotaxonomic and physiological properties further suggested that strain EMGL16-1 was taxonomically distinct from other species in the genus Methylomonas. The isolate was versatile in utilizing nitrogen sources such as molecular nitrogen, nitrate, nitrite, urea, and ammonium. The genes coding for subunit of the particulate form methane monooxygenase (pmoA), soluble methane monooxygenase (mmoX), and methanol dehydrogenase (mxaF) were detected in strain EMGL16-1. Phylogenetic analysis of mmoX indicated that mmoX of strain EMGL16-1 is distinct from those of other strains in the genus Methylomonas. This isolate probably represents a novel species in the genus. Our study provides new insights into the diversity of species in the genus Methylomonas and their environmental adaptations.Nguyen, N.N., Nguyen, A.V., 2017. Hydrophobic effect on gas hydrate formation in the presence of additives. Energy & Fuels 31, 10311-10323. such as surfactants, polymers, salts, and hydrophobic particles are well-known (and used) to influence gas hydrate formation (GHF). This paper reviews and discusses the mechanisms of their effects. The effects of additives on GHF appear to vary greatly from one additive to another. Even a given additive can change from a promoter to an inhibitor and vice versa when the working conditions are changed. The available literature cannot explain the diverse effects of additives. We argue that the hydrophobic effect plays a critical role in gas hydrate formation. A dissolved hydrophobe organizes the surrounding water into a clathrate-like structure and thereby promotes hydrate formation. A hydrophile, however, disrupts the surrounding water structure and inhibits hydrate formation. Moreover, cooperative hydrophobic interactions create an increased gas concentration around a hydrophobe, which also favors the hydrate formation. In contrast, a hydrophile competes with the gas for water and thereby hinders hydrate formation. In particular, when the additive is an amphiphile, the observed effect is the result of the competition between the hydrophobic moiety (a promoter) and hydrophilic moiety (an inhibitor). This hypothesis provides a universal explanation for the various effects of hydrate additives.Niezgodzki, I., Knorr, G., Lohmann, G., Tyszka, J., Markwick, P.J., 2017. Late Cretaceous climate simulations with different CO2 levels and subarctic gateway configurations: A model-data comparison. Paleoceanography 32, 980-998. investigate the impact of different CO2 levels and different subarctic gateway configurations on the surface temperatures during the latest Cretaceous using the Earth System Model COSMOS. The simulated temperatures are compared with the surface temperature reconstructions based on a recent compilation of the latest Cretaceous proxies. In our numerical experiments, the CO2 level ranges from 1 to 6 times the preindustrial (PI) CO2 level of 280 ppm. On a global scale, the most reasonable match between modeling and proxy data is obtained for the experiments with 3 to 5 × PI CO2 concentrations. However, the simulated low- (high-) latitude temperatures are too high (low) as compared to the proxy data. The moderate CO2 levels scenarios might be more realistic, if we take into account proxy data and the dead zone effect criterion. Furthermore, we test if the model-data discrepancies can be caused by too simplistic proxy-data interpretations. This is distinctly seen at high latitudes, where most proxies are biased toward summer temperatures. Additional sensitivity experiments with different ocean gateway configurations and constant CO2 level indicate only minor surface temperatures changes (<~1°C) on a global scale, with higher values (up to ~8°C) on a regional scale. These findings imply that modeled and reconstructed temperature gradients are to a large degree only qualitatively comparable, providing challenges for the interpretation of proxy data and/or model sensitivity. With respect to the latter, our results suggest that an assessment of greenhouse worlds is best constrained by temperatures in the midlatitudes.Niles, P.B., Michalski, J., Ming, D.W., Golden, D.C., 2017. Elevated olivine weathering rates and sulfate formation at cryogenic temperatures on Mars. Nature Communications 8, 998. Hesperian-aged (~3.7?Ga) layered deposits of sulfate-rich sediments in the equatorial regions of Mars have been suggested to be evidence for ephemeral playa environments. But early Mars may not have been warm enough to support conditions similar to what occurs in arid environments on Earth. Instead cold, icy environments may have been widespread. Under cryogenic conditions sulfate formation might be blocked, since kinetics of silicate weathering are typically strongly retarded at temperatures well below 0?°C. But cryo-concentration of acidic solutions may counteract the slow kinetics. Here we show that cryo-concentrated acidic brines rapidly chemically weather olivine minerals and form sulfate minerals at temperatures as low as ?60?°C. These experimental results demonstrate the viability of sulfate formation under current Martian conditions, even in the polar regions. An ice-hosted sedimentation and weathering model may provide a compelling description of the origin of large Hesperian-aged layered sulfate deposits on Mars.Niu, M., Fan, X., Zhuang, G., Liang, Q., Wang, F., 2017. Methane-metabolizing microbial communities in sediments of the Haima cold seep area, northwest slope of the South China Sea. FEMS Microbiology Ecology 93, Article fix101. seeps are widespread chemosynthetic ecosystems in the deep-sea environment, and cold seep microbial communities of the South China Sea are poorly constrained. Here we report on the archaeal communities, particularly those involved in methane metabolization, in sediments of a newly discovered cold seep (named ‘Haima’) on the northwest slope of the South China Sea. Archaeal diversity, abundance and distribution were investigated in two piston cores collected from a seep area (QDN-14B) and a non-seep control site (QDN-31B). Geochemical investigation of the QDN-14B core identified an estimated sulfate–methane transition zone (Estimated SMTZ) at 300–400 cm below sea floor (cmbsf), where a high abundance of anaerobic methane-oxidizing archaea (ANME) occurred, as revealed by analysis of the 16S rRNA gene and the gene (mcrA) encoding the α-subunit of the key enzyme methyl-coenzyme M reductase. ANME-2a/b was predominant in the upper and middle layers of the estimated SMTZ, whereas ANME-1b outcompeted ANME-2 in the sulfate-depleted bottom layers of the estimated SMTZ and the methanogenic zone. Fine-scale phylogenetic analysis further divided the ANME-1b group into three subgroups with different distribution patterns: ANME-1bI, ANME-1bII and ANME-1bIII. Multivariate analyses indicated that dissolved inorganic carbon and sulfate may be important factors controlling the composition of the methane-metabolizing community. Our study on ANME niche separation and interactions with other archaeal groups improves our understanding of the metabolic diversity and flexibility of ANME, and the findings further suggest that ANME subgroups may have evolved diversified/specified metabolic capabilities other than syntrophic anaerobic oxidation of methane coupled with sulfate reduction in marine sediments.Norstr?m, E., Katrantsiotis, C., Smittenberg, R.H., Kouli, K., 2017. Chemotaxonomy in some Mediterranean plants and implications for fossil biomarker records. Geochimica et Cosmochimica Acta 219, 96-110. increasing utilization of n-alkanes as plant-derived paleo-environmental proxies calls for improved chemotaxonomic control of the modern flora in order to calibrate fossil sediment records to modern analogues. Several recent studies have investigated long-chain n-alkane concentrations and chain-length distributions in species from various vegetation biomes, but up to date, the Mediterranean flora is relatively unexplored in this respect. Here, we analyse the n-alkane concentrations and chain-length distributions in some of the most common species of the modern macchia and phrygana vegetation in south western Peloponnese, Greece. We show that the drought adapted phrygana herbs and shrubs, as well as some of the sclerophyll and gymnosperm macchia components, produce high concentrations of n-alkanes, on average more than double n-alkane production in local wetland reed vegetation. Furthermore, the chain-length distribution in the analysed plants is related to plant functionality, with longer chain lengths associated with higher drought adaptive capacities, probably as a response to long-term evolutionary processes in a moisture limited environment. Furthermore, species with relatively higher average chain lengths (ACL) showed more enriched carbon isotope composition in their tissues (δ13Cplant), suggesting a dual imprint from both physiological and biochemical drought adaptation. The findings have bearings on interpretation of fossil sedimentary biomarker records in the Mediterranean region, which is discussed in relation to a case study from Agios Floros fen, Messenian plain, Peloponnese. The 6000 year long n-alkane record from Agios Floros (ACL, δ13Cwax) is linked to the modern analogue and then evaluated through a comparison with other regional-wide as well as local climate and vegetation proxy-data. The high concentration of long chain n-alkanes in phrygana vegetation suggests a dominating imprint from this vegetation type in sedimentary archives from this ecotone.Nowbahar, A., Whitaker, K.A., Schmitt, A.K., Kuo, T.-C., 2017. Mechanistic study of water droplet coalescence and flocculation in diluted bitumen emulsions with additives using microfluidics. Energy & Fuels 31, 10555-10565. crude oils derived from mined oil sands processed via the Clark hot water extraction process do not meet current specifications for pipeline transport and are corrosive to upgrader equipment by virtue of the high residual water content (2–5%) and salts. Formulated chemical additives used in this process can improve the oil quality by accelerating and enhancing the separation of water from oil. The identification and selection of these formulated additives is typically based on performance data collected in field testing for each component or blend. Herein, two methods are reported to study the effect of chemical additives on the phase separation behavior of water in diluted bitumen emulsions prepared in microfluidic devices. First, water droplets in diluted bitumen were created in the presence of chemical additives and the kinetics of droplet coalescence were compared for various additives and concentrations. Second, using a custom-made device geometry, water droplets in diluted bitumen were formed and aged prior to the addition of chemical additives. The treated droplets were observed to calculate the kinetics of droplet coalescence. The frequency of coalescence events was the same order of magnitude in both studies. The effectiveness of various additives can be determined by measuring the coalescence time, which is dominated by film drainage in the case of the best chemical additives.Nuding, D.L., Gough, R.V., Venkateswaran, K.J., Spry, J.A., Tolbert, M.A., 2017. Laboratory investigations on the survival of Bacillus subtilis spores in deliquescent salt Mars analog environments. Astrobiology 17, 997-1008. features such as recurring slope lineae suggest that liquid water may exist on the surface and near-subsurface of Mars today. The presence of this liquid water, likely in the form of a brine, has important implications for the present-day water cycle, habitability, and planetary protection policies. It is possible that this water is formed, at least partially, by deliquescence of salts, a process during which hygroscopic salts absorb water vapor from the atmosphere and form a saturated liquid brine. We performed laboratory experiments to examine the ability of Bacillus subtilis (B-168) spores, alone or mixed with calcium perchlorate salt (Ca(ClO4)2), to form liquid water via deliquescence under Mars-relevant conditions. Spore survival after exposure to these conditions was examined. An environmental chamber was used to expose the samples to temperature and relative humidity (RH) values similar to those found on Mars, and Raman microscopy was used to identify the phases of water and salt that were present and to confirm the presence of spores. We found that B-168 spores did not condense any detectable water vapor on their own during the diurnal cycle, even at 100% RH. However, when spores were mixed with perchlorate salt, the entire sample deliquesced at low RH values, immersing the spores in a brine solution during the majority of the simulated martian temperature and humidity cycle. After exposure to the simulated diurnal cycles and, in some cases, perchlorate brine, the impact of each environmental scenario on spore survival was estimated by standard plate assay. We found that, if there are deliquescent salts in contact with spores, there is a mechanism for the spores to acquire liquid water starting with only atmospheric water vapor as the H2O source. Also, neither crystalline nor liquid Ca(ClO4)2 is sporicidal despite the low water activity.Nutman, A.P., Bennett, V.C., Friend, C.R.L., 2017. Seeing through the magnetite: Reassessing Eoarchean atmosphere composition from Isua (Greenland) ≥3.7?Ga banded iron formations. Geoscience Frontiers 8, 1233-1240. of early atmosphere compositions from metamorphosed banded iron formations (BIFs) including the well-studied ≥3.7 BIFs of the Isua supracrustal belt (Greenland) are dependent on knowledge of primary versus secondary Fe-mineralogical assemblages. Using new observations from locally well preserved domains, we interpret that a previously assumed primary redox indicator mineral, magnetite, is secondary after sedimentary Fe-clays (probably greenalite) ± carbonates. Within ～3.7 Ga Isua BIF, pre-tectonic nodules of quartz + Fe-rich amphibole ± calcite reside in a fine-grained (≤100 μm) quartz + magnetite matrix. We interpret the Isua nodule amphibole as the metamorphosed equivalent of primary Fe-rich clays, armoured from diagenetic oxidative reactions by early silica concretion. Additionally, in another low strain lacunae, ～3.76 Ga BIF layering is not solid magnetite but instead fine-grained magnetite + quartz aggregates. These magnetite + quartz aggregates are interpreted as the metamorphosed equivalent of Fe-clay-rich layers that were oxidised during diagenesis, because they were not armoured by early silicification. In almost all Isua BIF exposures, this evidence has been destroyed by strong ductile deformation. The Fe-clays likely formed by abiotic reactions between aqueous Fe2+ and silica. These clays along with silica ± carbonate were deposited below an oceanic Fe-chemocline as the sedimentary precursors of BIF. Breakdown of the clays on the sea floor may have been by anaerobic oxidation of Fe2+, a mechanism compatible with iron isotopic data previously published on these rocks. The new determinations of the primary redox-sensitive Fe-mineralogy of BIF significantly revise estimates of early Earth atmospheric oxygen and CO2 content, with formation of protolith Fe-rich clays and carbonates compatible with an anoxic Eoarchean atmosphere with much higher CO2 levels than previously estimated for Isua and in the present-day atmosphere.O'Laughlin, C.M., Law, B.A., Zions, V.S., King, T.L., Robinson, B., Wu, Y., 2017. Settling of dilbit-derived oil-mineral aggregates (OMAs) & transport parameters for oil spill modelling. Marine Pollution Bulletin 124, 292-302. size and settling velocity of oil-mineral aggregates (OMAs) derived from diluted bitumen are primary constituents in predictive models for evaluating the potential fate of oil spilled in the aquatic environment. A series of low sediment concentration (15 mg·L? 1), colder water (< 10 °C) wave tank experiments designed to measure variability in these parameters in naturally-formed OMAs in response the presence or absence of chemical dispersant are discussed. Corresponding lab experiments revealed settling velocities of artificially formed OMAs on the order of 0.1–0.4 mm·s? 1. High-resolution imagery of settling particles were analyzed for particle size, density and settling velocity. In situ formation of OMAs in the wave tank was unsuccessful. Possible effects of chemical dispersant on natural sediment flocculation, the size of suspended oil droplets and clearance rates of suspended particles are discussed.O'Neill, C., Marchi, S., Zhang, S., Bottke, W., 2017. Impact-driven subduction on the Hadean Earth. Nature Geoscience 10, 793-797. cratering was a dominant geologic process in the early Solar System that probably played an active role in the crustal evolution of the young terrestrial planets. The Earth/'s interior during the Hadean, 4.56 to 4 billion years ago, may have been too hot to sustain plate tectonics. However, whether large impacts could have triggered tectonism on the early Earth remains unclear. Here we conduct global-scale tectonic simulations of the evolution of the Earth through the Hadean eon under variable impact fluxes. Our simulations show that the thermal anomalies produced by large impacts induce mantle upwellings that are capable of driving transient subduction events. Furthermore, we find that moderate-sized impacts can act as subduction triggers by causing localized lithospheric thinning and mantle upwelling, and modulate tectonic activity. In contrast to contemporary subduction, the simulated localized subduction events are relatively short-lived (less than 10[thinsp]Myr) with relatively thin, weak plates. We suggest that resurgence in subduction activity induced by an increased impact flux between 4.1 and 4.0 billion years ago may explain the coincident increase in palaeointensity of the magnetic field. We further suggest that transient impact-driven subduction reconciles evidence from Hadean zircons for tectonic activity with other lines of evidence consistent with an Earth that was largely tectonically stagnant from the Hadean into the Archaean.Ohemeng-Ntiamoah, J., Datta, T., 2018. Evaluating analytical methods for the characterization of lipids, proteins and carbohydrates in organic substrates for anaerobic co-digestion. Bioresource Technology 247, 697-704. study provides insights into the characterization of lipids, proteins and carbohydrate content in substrates for codigestion, and evaluates their effects on biogas yield. Among the analytical methods evaluated, the Bligh and Dyer, Hach Total Nitrogen and the Anthrone method were found to be most suitable for lipids, proteins and carbohydrates analysis, respectively. The co-digestibility of ten co-substrate mixes prepared using various volume-to-volume ratios of foodwaste (FW), fats, oils and grease (FOG), and waste activated sludge (WAS) were tested using biomethane potential assays. The three main substrates were mono-digested as well. WAS mono-digestion yielded the lowest methane yield of 118 mL CH4/g VS, while a 50:50 mix of WAS and FOG, containing 85% lipid and 15% protein produced the highest methane yield of 1040 mL CH4/g VS. In general, lipid-rich samples yielded more biogas than samples rich in proteins and carbohydrates. However, samples rich in proteins and carbohydrates had faster biogas production rates.Okere, U.V., Cabrerizo, A., Dachs, J., Ogbonnaya, U.O., Jones, K.C., Semple, K.T., 2017. Effects of pre-exposure on the indigenous biodegradation of 14C-phenanthrene in Antarctic soils. International Biodeterioration & Biodegradation 125, 189-199. aim of this study was to investigate the biodegradation of phenanthrene in five Antarctic soils over 150 days at various temperatures and under slurry conditions. The development of catabolic activity was measured over time (1, 30, 60, 150 days) by the addition of 14C-phenanthrene and measuring changes in the lag phases, rates and extents of 14C-phenanthrene degradation. As the temperature increased (4 °C, 12 °C, 22 °C, 22 °C slurry), the highest extents of 14C-phenanthrene mineralisation increased significantly (0.46%, 12.21%, 24.82%, 60.81%), respectively. This was due to changes in the water availability and 14C-phenanthrene dissolution in aqueous phase, thus enhancing bioaccessibility of the contaminant to indigenous microorganisms within the soil. High catabolic activities can develop in Antarctic soils where appropriate conditions are ensured. However, further studies are however needed to explore the changes in microbial community structure that occur at different incubation temperatures.Okoro, C.C., Samuel, O., Lin, J., 2017. Substrate availability, pH, and temperature influence methanogenesis and mild steel corrosion. Geomicrobiology Journal 34, 729-736. deposits of corroded pipelines in the Niger Delta were analyzed both chemically and microbiologically. The addition of substrate, especially acetate, significantly stimulated the methane production ranging from 0.85 to 1.60?mmole compared with 0.65?mmole of the control. Acetotrophic and hydrogenotrophic methanogens had their optimal methane production and corrosion rate at pH 5.5. All three types of methanogens produced the most methane at 37°C. Methane production by methanogens correlated strongly with corrosion rate. Pyrosequencing surveys show dominance of acetotrophic, hydrogenotrophic, and methylotrophic methanogens in the samples with no significant presence of sulfate-reducing bacteria (SRB), most likely due to the presence of the biocide, tetrakis-hydroxymethyl phosphonium sulfate. Our study shows that methanogens were one possible cause of pipeline failures in samples from the Niger Delta without the syntrophic association with SRB.Oksman, M., Weckstr?m, K., Miettinen, A., Juggins, S., Divine, D.V., Jackson, R., Telford, R., Korsgaard, N.J., Kucera, M., 2017. Younger Dryas ice margin retreat triggered by ocean surface warming in central-eastern Baffin Bay. Nature Communications 8, Article 1017. transition from the last ice age to the present-day interglacial was interrupted by the Younger Dryas (YD) cold period. While many studies exist on this climate event, only few include high-resolution marine records that span the YD. In order to better understand the interactions between ocean, atmosphere and ice sheet stability during the YD, more high-resolution proxy records from the Arctic, located proximal to ice sheet outlet glaciers, are required. Here we present the first diatom-based high-resolution quantitative reconstruction of sea surface conditions from central-eastern Baffin Bay, covering the period 14.0–10.2?kyr BP. Our record reveals warmer sea surface conditions and strong interactions between the ocean and the West Greenland ice margin during the YD. These warmer conditions were caused by increased Atlantic-sourced water inflow combined with amplified seasonality. Our results emphasize the importance of the ocean for ice sheet stability under the current changing climate.Oraki Kohshou, I., Barati, R., Yorro, M.C., Leshchyshyn, T., Adejumo, A.T., Ahmed, U., Kugler, I., Reynolds, M., McAndrew, J., 2017. Economic assessment and review of waterless fracturing technologies in shale resource development: A case study. Journal of Earth Science 28, 933-948. database tracking of USA water usage per well indicates that traditionally shale operators have been using, on average 3 to 6 million gallons of water; even up to 8 million for the entire life cycle of the well based on its suitability for re-fracturing to stimulate their long and lateral horizontal wells. According to our data, sourcing, storage, transportation, treatment, and disposal of this large volume of water could account for up to 10% of overall drilling and completion costs. With increasingly stringent regulations governing the use of fresh water and growing challenges associated with storage and use of produced and flowback water in hydraulic fracturing, finding alternative sources of fracturing fluid is already a hot debate among both the scientific community and industry experts. On the other hand, waterless fracturing technology providers claim their technology can solve the concerns of water availability for shale development. This study reviews high-level technical issues and opportunities in this challenging and growing market and evaluates key economic drivers behind water management practices such as waterless fracturing technologies, based on a given shale gas play in the United States and experience gained in Canada. Water costs are analyzed under a variety of scenarios with and without the use of (fresh) water. The results are complemented by surveys from several oil and gas operators. Our economic analysis shows that fresh water usage offers the greatest economic return. In regions where water sourcing is a challenge, however, the short-term economic advantage of using non-fresh water-based fracturing outweighs the capital costs required by waterless fracturing methods. Until waterless methods are cost competitive, recycled water usage with low treatment offers a similar net present value (NPV) to that of sourcing freshwater via truck, for instance.Orhan, F., Demirci, A., Yanmis, D., 2017. CaCO3 and MgCO3 dissolving halophilic bacteria. Geomicrobiology Journal 34, 804-810. the current study, fifteen halophilic and halotolerant bacteria were isolated from salt-affected soil of ?anl?urfa, Turkey. The isolates were characterized by conventional and molecular techniques (16S rDNA sequence analyses) as belonging to seven different genus including Bacillus (5 isolates), Halobacillus (1 isolate), Oceanobacillus (2 isolates), Halomonas (3 isolate), Nesterenkonia (1 isolate), Chromohalobacter (2 isolates) and Jeotgalibacillus (2 isolates). According to the results obtained, the investigated bacterial strains have high salt tolerance and significant enzyme activities which can improve soil nutrient cycling and fertility. Furthermore, these bacterial strains have been investigated for their ability to dissolve common salts available in salt-affected soils. Salt dissolving experiments showed that two Chromohalobacter isolates were able to dissolve CaCO3 and one of the Halomonas isolate was able to dissolve both CaCO3 and MgCO3. As these bacterial isolates can dissolve CaCO3 and MgCO3, the availability of Ca2+ and Mg2+ ions may increase which can enhance the removal of the excess Na+ in soil profile.Ortiz Cancino, O.P., Pino Pérez, D., Pozo, M., Bessieres, D., 2017. Adsorption of pure CO2 and a CO2/CH4 mixture on a black shale sample: Manometry and microcalorimetry measurements. Journal of Petroleum Science and Engineering 159, 307-313. study of CO2/CH4 adsorption onto kerogen is relevant for shale gas production. Despite much expanded literature, reliable adsorption models still await for a complete description due to the complexity of kerogen. The objective of this study is to provide an original set of experimental data and to use the selectivity as an indicator to test the affinity of the sample for a component over another. The adsorption of pure CO2 and the equimolar mixture CH4/CO2 were explored on a Silurian black shale sample. This outcropping sample was collected in a formation, which is not considered as target for shale gas exploration. However its geochemical profile as well as its thermal maturity suggest this sample is an ideal candidate to study kerogen/carbon dioxide and methane interactions. Both isotherm and enthalpy of adsorption of carbon dioxide were measured up to 3.2 (MPa) by the use of a combined manometric-calorimetric device. The carbon dioxide isotherm was fitted with a modified Langmuir model allowing the determination of the adsorption uptake. The heat of adsorption is an indicator of the affinity of the carbon dioxide with kerogen. Additionally the equimolar mixture methane/carbon dioxide isotherm was performed up to 2 (MPa) by use of a device specially developed and built for gas mixture co-adsorption. The adsorption of each component within the mixture was provided. The estimated selectivity CO2/CH4 highlights a significant affinity of CO2 with the kerogen.Osborne, K.A., Gray, N.D., Sherry, A., Leary, P., Mejeha, O., Bischoff, J., Rush, D., Sidgwick, F.R., Birgel, D., Kalyuzhnaya, M.G., Talbot, H.M., 2017. Methanotroph-derived bacteriohopanepolyol signatures as a function of temperature related growth, survival, cell death and preservation in the geological record. Environmental Microbiology Reports 9, 492-500. of bacteriohopanepolyol (BHP) biomarkers tracing microbiological processes in modern and ancient sediments relies on understanding environmental controls of production and preservation. BHPs from methanotrophs (35-aminoBHPs) were studied in methane-amended aerobic river-sediment incubations at different temperatures. It was found that: (i) With increasing temperature (4°C–40°C) a 10-fold increase in aminopentol (associated with Crenothrix and Methylobacter spp. growth) occurred with only marginal increases in aminotriol and aminotetrol; (ii) A further increase in temperature (50°C) saw selection for the thermophile Methylocaldum and mixtures of aminopentol and C-3 methylated aminopentol, again, with no increase in aminotriol and aminotetrol. (iii) At 30°C, more aminopentol and an aminopentol isomer and unsaturated aminopentol were produced after methanotroph growth and the onset of substrate starvation/oxygen depletion. (iv) At 50°C, aminopentol and C-3 methylated aminopentol, only accumulated during growth but were clearly resistant to remineralization despite cell death. These results have profound implications for the interpretation of aminoBHP distributions and abundances in modern and past environments. For instance, a temperature regulation of aminopentol production but not aminotetrol or aminotriol is consistent with and, corroborative of, observed aminopentol sensitivity to climate warming recorded in a stratigraphic sequence deposited during the Paleocene-Eocene thermal maximum (PETM).Ostrovsky, M.A., 2017. Rhodopsin: Evolution and comparative physiology. Paleontological Journal 51, 562-572. review of physicochemical properties, photochemistry, functions, and evolution of retinal-containing proteins (microbial and of metazoan rhodopsins, mostly visual rhodopsins) is provided. Comparative physiology of visual rhodopsins is considered in detail, mainly the molecular mechanisms of their spectral tuning. Original Russian Text ? M.A. Ostrovsky, 2017, published in Paleontologicheskii Zhurnal, 2017, No. 5, pp. 103–113.Paganoni, M., Cartwright, J.A., Foschi, M., Shipp, C.R., Van Rensbergen, P., 2018. Relationship between fluid-escape pipes and hydrate distribution in offshore Sabah (NW Borneo). Marine Geology 395, 82-103. pipes represent seismic evidence for the focused cross-stratal migration of fluids. In natural gas hydrate systems, these features serve both as conduits for methane-rich fluids and as preferred locations for the formation of gas hydrates. In this study, 3D seismic, well-log and core data from offshore Sabah (NW Borneo) are used to investigate the controls on the occurrence of fluid-escape pipes and their impact on hydrate distribution in a system dominated by the vertical leakage of thermogenic hydrocarbons.The pipes are observed within a gas hydrate stability zone (GHSZ) that extends 100 m below a bottom simulating reflector (BSR), located at 155 m below the seafloor (mbsf). Pipes are restricted to an area with evidence of free gas-bearing sediments, suggesting a causative link where the free gas promotes the build-up of critical fluid pressures. The stacking of the upper terminus of fluid-escape pipes at discrete stratigraphic intervals suggests that fluid flow to the seabed has been episodically enhanced. Possible triggers for cyclical increases of pore fluid pressures are sea-level and temperature fluctuations, tectonic activity and gas leakage from deep reservoirs.This fluid flow system further impacts the gas hydrate distribution. The fluid-escape pipes can be locations where hydrates occur at high concentrations up to the seafloor if the pipe is presently active. Therefore, the observed up-bending of the stratigraphic reflections along the pipes are interpreted as a combination of a net volume increase of the host sediment owing to hydrate formation and seismic velocity pull-up effects. Away from the pipes, hydrates do not occur until 65–152 mbsf and are present only at low to moderate concentrations. At this site of focused fluid flow, fluid-escape pipes constitute, by volume, only 7–11% of the gas hydrate occurrence zone. Nevertheless, we predict that they could host between 20 and 50% of the whole hydrate volume. It is therefore likely that, in similar systems, a volumetrically significant portion of the total hydrate reservoir is hosted within fluid-escape pipes. The distribution of these features should thus be considered as a critical parameter for hydrate volume estimates.Paliwal, C., Mitra, M., Bhayani, K., Bharadwaj, S.V.V., Ghosh, T., Dubey, S., Mishra, S., 2017. Abiotic stresses as tools for metabolites in microalgae. Bioresource Technology 244, 1216-1226., due to various environmental stresses, constantly tune their cellular mechanisms to cope with them. The accumulation of the stress metabolites is closely related to the changes occurring in their metabolic pathways. The biosynthesis of metabolites can be triggered by a number of abiotic stresses like temperature, salinity, UV- radiation and nutrient deprivation. Although, microalgae have been considered as an alternative sustainable source for nutraceutical products like pigments and omega-3 polyunsaturated fatty acids (PUFAs) to cater the requirement of emerging human population but inadequate biomass generation makes the process economically impractical. The stress metabolism for carotenoid regulation in green algae is a 2-step metabolism. There are a few major stresses which can influence the formation of phycobiliprotein in cyanobacteria. This review would primarily focus on the cellular level changes under stress conditions and their corresponding effects on lipids (including omega-3 PUFAs), pigments and polymers.Pan, F., McPherson, B.J., Kaszuba, J., 2017. Evaluation of CO2-fluid-rock interaction in enhanced geothermal systems: Field-scale geochemical simulations. Geofluids 2017, Article 5675370. studies suggest that using supercritical CO2 (scCO2) instead of water as a heat transmission fluid in Enhanced Geothermal Systems (EGS) may improve energy extraction. While CO2-fluid-rock interactions at “typical” temperatures and pressures of subsurface reservoirs are fairly well known, such understanding for the elevated conditions of EGS is relatively unresolved. Geochemical impacts of CO2 as a working fluid (“CO2-EGS”) compared to those for water as a working fluid (H2O-EGS) are needed. The primary objectives of this study are (1) constraining geochemical processes associated with CO2-fluid-rock interactions under the high pressures and temperatures of a typical CO2-EGS site and (2) comparing geochemical impacts of CO2-EGS to geochemical impacts of H2O-EGS. The St. John’s Dome CO2-EGS research site in Arizona was adopted as a case study. A 3D model of the site was developed. Net heat extraction and mass flow production rates for CO2-EGS were larger compared to H2O-EGS, suggesting that using scCO2 as a working fluid may enhance EGS heat extraction. More aqueous CO2 accumulates within upper- and lower-lying layers than in the injection/production layers, reducing pH values and leading to increased dissolution and precipitation of minerals in those upper and lower layers. Dissolution of oligoclase for water as a working fluid shows smaller magnitude in rates and different distributions in profile than those for scCO2 as a working fluid. It indicates that geochemical processes of scCO2-rock interaction have significant effects on mineral dissolution and precipitation in magnitudes and distributions.Pan, L., Ehlmann, B.L., Carter, J., Ernst, C.M., 2017. The stratigraphy and history of Mars' northern lowlands through mineralogy of impact craters: A comprehensive survey. Journal of Geophysical Research: Planets 122, 1824-1854. basin-filling materials of the northern lowlands, which cover approximately one third of Mars' surface, record the long-term evolution of Mars' geology and climate. The buried stratigraphy was inferred through analyses of impact crater mineralogy, detected using data acquired by the Compact Reconnaissance Imaging Spectrometer for Mars. Examining 1045 impact craters across the northern lowlands, we find widespread olivine and pyroxene and diverse hydrated/hydroxylated minerals, including Fe/Mg smectite, chlorite, prehnite, and hydrated silica. The distribution of mafic minerals is consistent with infilling volcanic materials across the entire lowlands (~1–4 × 107 km3), indicating a significant volume of volatile release by volcanic outgassing. Hydrated/hydroxylated minerals are detected more frequently in large craters, consistent with the scenario that the hydrated minerals are being excavated from deep basement rocks, beneath 1–2 km thick mafic lava flows or volcaniclastic materials. The prevalences of different types of hydrated minerals are similar to statistics from the southern highlands. No evidence of concentrated salt deposits has been found, which would indicate a long-lived global ocean. We also find significant geographical variations of local mineralogy and stratigraphy in different basins (geological provinces), independent of dust cover. For example, many hydrated and mafic minerals are newly discovered within the polar Scandia region (>60°N), and Chryse Planitia has more mafic mineral detections than other basins, possibly due to a previously unrecognized volcanic source.Parada, A.E., Fuhrman, J.A., 2017. Marine archaeal dynamics and interactions with the microbial community over 5 years from surface to seafloor. ISME Journal 11, 2510-2525. archaea are critical contributors to global carbon and nitrogen redox cycles, but their temporal variability and microbial associations across the water column are poorly known. We evaluated seasonal variability of free living (0.2–1?μm size fraction) Thaumarchaea Marine Group I (MGI) and Euryarchaea Marine Group II (MGII) communities and their associations with the microbial community from surface to seafloor (890?m) over 5 years by 16S rRNA V4-V5 gene sequencing. MGI and MGII communities demonstrated distinct compositions at different depths, and seasonality at all depths. Microbial association networks at 150?m, 500?m and 890?m, revealed diverse assemblages of MGI (presumed ammonia oxidizers) and Nitrospina taxa (presumed dominant nitrite oxidizers, completing the nitrification process), suggesting distinct MGI-Nitrospina OTUs are responsible for nitrification at different depths and seasons, and depth- related and seasonal variability in nitrification could be affected by alternating MGI-Nitrospina assemblages. MGII taxa also showed distinct correlations to possibly heterotrophic bacteria, most commonly to members of Marine Group A, Chloroflexi, Marine Group B, and SAR86. Thus, both MGI and MGII likely have dynamic associations with bacteria based on similarities in activity or other interactions that select for distinct microbial assemblages over time. The importance of MGII taxa as members of the heterotrophic community previously reported for photic zone appears to apply throughout the water column.Parks, D.H., Rinke, C., Chuvochina, M., Chaumeil, P.-A., Woodcroft, B.J., Evans, P.N., Hugenholtz, P., Tyson, G.W., 2017. Recovery of nearly 8,000 metagenome-assembled genomes substantially expands the tree of life. Nature Microbiology 2, 1533-1542. in cultivating microorganisms have limited the phylogenetic diversity of currently available microbial genomes. This is being addressed by advances in sequencing throughput and computational techniques that allow for the cultivation-independent recovery of genomes from metagenomes. Here, we report the reconstruction of 7,903 bacterial and archaeal genomes from >1,500 public metagenomes. All genomes are estimated to be ≥50% complete and nearly half are ≥90% complete with ≤5% contamination. These genomes increase the phylogenetic diversity of bacterial and archaeal genome trees by >30% and provide the first representatives of 17 bacterial and three archaeal candidate phyla. We also recovered 245 genomes from the Patescibacteria superphylum (also known as the Candidate Phyla Radiation) and find that the relative diversity of this group varies substantially with different protein marker sets. The scale and quality of this data set demonstrate that recovering genomes from metagenomes provides an expedient path forward to exploring microbial dark matter.Sequencing of microbial genomes has accelerated with reductions in sequencing costs, and public repositories now contain nearly 70,000 bacterial and archaeal genomes. The majority of these genomes have been obtained from axenic cultures and disproportionately reflect microorganisms of medical importance. Consequently, current genome repositories are not representative of the microbial diversity known from 16S rRNA gene surveys>. Concerted efforts are being made to address this limitation by targeting phylogenetically distinct microorganisms for cultivation and single-cell sequencing. Although these approaches continue to provide valuable reference genomes, the former is restricted to microorganisms amenable to cultivation and the latter is hampered by technical challenges and the need for specialised equipment>. Obtaining genomes from metagenomes is an emerging approach with the potential for large-scale recovery of near-complete genomes.Until recently, recovering genomes from metagenomic data was restricted to samples with low microbial diversity, but improved sequencing throughput and advances in computational techniques now allow metagenome-assembled genomes (MAGs) to be recovered from high diversity environments. MAGs are obtained by grouping or ‘binning’ together assembled contigs with similar sequence composition, depth of coverage across one or more related samples and taxonomic affiliations. Several tools have been developed that exploit these sources of information to produce genomes from metagenomic data and there are ongoing efforts to evaluate the effectiveness of different approaches. Although closed genomes have been obtained using metagenomic binning methods, MAGs are typically incomplete and may contain contigs from multiple strains or species due to challenges in distinguishing between related community members both in the assembly and binning processes. This has spurred the development of methods for assessing the quality of recovered MAGs in order to allow biological inferences to be made with regards to their estimated completeness and contamination.Significant insights have recently been made based on the MAGs of uncultivated microorganisms. These include elucidation of several phyla previously lacking genomic representatives, including the Patescibacteria superphylum, which has subsequently been referred to as the ‘Candidate Phyla Radiation’ (CPR) as it may consist of upwards of 35 candidate phyla. Notable evolutionary and metabolic insights include the discovery of eukaryotic-like cytoskeleton genes in the archaeon Lokiarchaeota and the identification of putative methane-metabolizing genes in the Bathyarchaeota and Verstraetearchaeota phyla. These initial studies demonstrate the need for additional genomic representatives across the tree of life in order to more fully appreciate microbial evolution and metabolism.Here, we present the first large-scale initiative to recover MAGs from publicly available metagenomes. Nearly 8,000 draft-quality genomes were recovered from over 1,500 metagenomes, more than a threefold increase over large initiatives to genomically populate the tree of life such as the Genomic Encyclopedia of Bacteria and Archaea (~2,000 genomes), the Human Microbiome Project (~2,000) and the largest previous MAG study (~2,500). We refer to our set of MAGs as the Uncultivated Bacteria and Archaea (UBA) data set. Genome-based phylogenetic analysis indicates that the UBA genomes provide the first representatives of several major bacterial and archaeal lineages and substantially expand genomic representation across the tree of life.Patra, S., Ganguly, D., Tiwari, M., Kanuri, V., Muduli, P.R., Robin, R.S., Abhilash, K.R., Charan Kumar, B., Nagoji, S.S., Raman, A.V., Subramanian, B.R., 2017. Isotopic composition (C & N) of the suspended particles and N uptake by phytoplankton in a shallow tropical coastal lagoon. Chemistry and Ecology 33, 708-724. spatial distribution of the C/N ratios and variations in δ13C and δ15N of suspended particulate matter were used to characterise their source in Asia’s largest brackish water lagoon, Chilika, India. In addition, the significance of re-mineralised nutrients in the primary productivity of the shallow lagoon was also determined through quantification of the subsurface nitrogen uptake conditions at two relatively stable locations in the lagoon. The results indicated that the influence of terrestrial organic matter was the maximum in the northern sector and was relatively limited at the central and southern part of the lagoon. In situ 15N uptake experiments (daytime) under biogeochemically stable conditions revealed that the N uptake by phytoplankton ranged between 0.24 and 1.01?mM?m?3?h?1 during pre-monsoon and post-monsoon seasons. New production and regenerated production in the shallow lagoon was also estimated by calculating f-ratios (ratio of nitrate assimilation by phytoplankton to total nitrogenous nutrient assimilation, have been estimated), which varied from 0.52 in the post-monsoon to 0.38 in the pre-monsoon. Lowering of the f-ratio from post- to pre-monsoon indicated a dominance of mineralisation over the new production.Paul, G., 2017. Polar and K/Pg nonavian dinosaurs were low-metabolic rate reptiles vulnerable to cold-induced extinction, rather than more survivable tachyenergetic bird relatives: comment on an obsolete hypothesis. International Journal of Earth Sciences 106, 2991-2998. great majority of researchers concur that the presence of dinosaurs near the poles of their time are part of a large body of evidence that all Cretaceous dinosaurs had elevated metabolic rates more like their avian subbranch and mammals than low-energy reptiles. Yet a few still propose that nonavian dinosaurs were bradyenergetic ectothermic reptiles, and migrated away from the polar winters. The latter is not biologically possible because land animals cannot and never undertake very long seasonal migrations because the cost of ground locomotion is too high even for long limbed, tachyenergetic mammals to do so, much less low-energy reptiles. Nor was it geographically possible because marine barriers barred some polar dinosaurs from moving towards the winter sun. The presence of external insulation on some dinosaurs both strongly supports their being tachyenergetic endotherms and helps explain their ability to survive polar winters that included extended dark, chilling rains, sharp frosts, and blizzards so antagonistic to reptiles that the latter are absent from some locations that preserve dinosaurs including birds and mammals. The hypothesis that nonavian dinosaurs failed to survive the K/Pg crisis because they had reptilian energetics is illogical not only because they did not have such metabolisms, but because many low-energy reptiles did survive the crisis. The global super chill that apparently plagued K/Pg dinosaurs should have seriously impacted dinosaurs at all latitudes, but does not entirely readily explain their loss because some avian dinosaurs and other land tetrapods did survive. High- as well as low-latitude dinosaurs add to the growing evidence that high-energy endothermy has been a common adaptation in a wide variety of vertebrates and flying insects since the late Paleozoic.Pawlak, R., Meier, T., Renaud, N., Kisiel, M., Hinaut, A., Glatzel, T., Sordes, D., Durand, C., Soe, W.-H., Baratoff, A., Joachim, C., Housecroft, C.E., Constable, E.C., Meyer, E., 2017. Design and characterization of an electrically powered single molecule on gold. ACS Nano 11, 9930-9940. surface diffusion of individual molecules is of paramount importance in self-assembly processes and catalytic processes. However, the fundamental understanding of molecule diffusion peculiarities considering conformations and adsorption sites remain poorly known at the atomic scale. Here, we probe the 4′-(4-tolyl)-2,2′:6′,2″-terpyridine adsorbed on the Au(111) herringbone structure combining scanning tunneling microscopy and atomic force microscopy. Molecules are controllably translated by electrons excitations over the reconstruction, except at elbows acting as pinning centers. Experimental data supported by theoretical calculations show the formation of coordination bonds between the molecule and Au atoms of the surface. Using force spectroscopy, we quantify local variation of the surface potential and the lateral force required to move the molecule. We found an elevation of the diffusion barrier at elbows of the reconstruction of ～100 meV compared to the rest of the surface.Pearce, B.K.D., Pudritz, R.E., Semenov, D.A., Henning, T.K., 2017. Origin of the RNA world: The fate of nucleobases in warm little ponds. Proceedings of the National Academy of Sciences 114, 11327–11332.: There are currently two competing hypotheses for the site at which an RNA world emerged: hydrothermal vents in the deep ocean and warm little ponds. Because the former lacks wet and dry cycles, which are well known to promote polymerization (in this case, of nucleotides into RNA), we construct a comprehensive model for the origin of RNA in the latter sites. Our model advances the story and timeline of the RNA world by constraining the source of biomolecules, the environmental conditions, the timescales of reaction, and the emergence of first RNA polymers. Abstract: Before the origin of simple cellular life, the building blocks of RNA (nucleotides) had to form and polymerize in favorable environments on early Earth. At this time, meteorites and interplanetary dust particles delivered organics such as nucleobases (the characteristic molecules of nucleotides) to warm little ponds whose wet–dry cycles promoted rapid polymerization. We build a comprehensive numerical model for the evolution of nucleobases in warm little ponds leading to the emergence of the first nucleotides and RNA. We couple Earth’s early evolution with complex prebiotic chemistry in these environments. We find that RNA polymers must have emerged very quickly after the deposition of meteorites (less than a few years). Their constituent nucleobases were primarily meteoritic in origin and not from interplanetary dust particles. Ponds appeared as continents rose out of the early global ocean, but this increasing availability of “targets” for meteorites was offset by declining meteorite bombardment rates. Moreover, the rapid losses of nucleobases to pond seepage during wet periods, and to UV photodissociation during dry periods, mean that the synthesis of nucleotides and their polymerization into RNA occurred in just one to a few wet–dry cycles. Under these conditions, RNA polymers likely appeared before 4.17 billion years ago. Peng, B., Gao, W., Motamedi, N., 2017. Kinetic modeling of crude oil gasification for hydrogen production with in situ CO2 capture. Petroleum Science and Technology 35, 1403-1407. gasification process in the presence of CaO is an efficient method to convert carbon-based fuels, producing a gas with low concentration of CO2 and high hydrogen yield. In the present work, an unsteady-state, kinetic model of crude oil gasification was developed for prediction of gas composition and performance parameters. The effects of key operating parameters including [H2O]/[C] and [CaO]/[C] on hydrogen yield and CO2 capture ratio (CCR) were studied. The results showed that the CCR increased with increasing [CaO]/[C] from 0.1 to 0.7 (mg/mg) and then decreased, probably due to the reversal of exothermic carbonation reaction by Le Chatelier's principle. In spite of [CaO]/[C], CCR improved continuously with increasing [H2O]/[C] probably due to a significant improvement in the endothermic nature of the process by increasing [H2O]/[C].Pennisi, E., 2017. Evolution accelerated when life set foot on land. Science 358, 158. probably originated in water, but nature did some of its best work once organisms made landfall. That's what Geerat Vermeij has concluded after surveying fossils and family trees to discover where and when some of life's greatest modern advances evolved. Almost all of these seemingly out-of-the-blue innovations, from fungus farming by insects to the water transport systems that made tall trees possible, came about after plants and animals learned how to survive on land some 440 million years ago, Vermeij, an evolutionary biologist at the University of California, Davis, reported last week in Current Biology.“The idea that a dramatic ‘pivot’ in the locus and tempo of biological innovation occurred once complex life colonized the land surface is quite profound,” says Stefan Lalonde, a geobiologist at the European Institute for Marine Studies in Plouzané, France.Many researchers have focused on how newly land-based organisms coped with gravity and the threat of desiccation. But Vermeij wondered instead how the move to land might have changed the pace of evolution. He compiled a list of key innovations that showed up in several groups of organisms and provided a big competitive edge, such as herbivory by vertebrates, flight, echolocation, and warm-bloodedness. Existing fossil evidence enabled him to date the origin of a dozen of these adaptations.Nine appeared first on land and later in the sea, he reported. “Once they evolved on land, they could re-enter the oceans,” where they had a big effect on the ecosystems there, comments Nick Lane, a biochemist at University College London. For example, seagrasses brought land plants' systems for transporting water and acquiring nutrients back to the marine environment. Vermeij found two other traits that are still restricted to land. Another, the tendency of animals to guard their plant or plantlike food sources—appeared about 50 million years ago in both places. Just one, the ability to use electrical currents for communication and hunting—think electric eels—happened first, and only, in water.Lalonde, too, has found evidence of differences in evolution on land and in the sea by studying land-based and sea-going microbes that produced oxygen billions of years ago. But he and some others are not convinced that Vermeij has found a real pattern. “A major difficulty is avoiding bias in the selection of the set of major innovations,” Lalonde says. Many innovations, such as long-distance migration and color vision, don't show up in the fossil record and so were not counted.Still, the work “will encourage us to think about whether there is something special about the terrestrial environment,” says Charles Delwiche, an evolutionary biologist at the University of Maryland in College Park. Vermeij thinks life on land was less constrained because air is easier to move around in than water, but Charles Wellman, a paleontologist at the University of Sheffield in the United Kingdom, wonders whether the terrestrial environment was more stressful, forcing organisms to innovate to survive. And Delwiche suggests that the availability of new places to live was what fueled the surge of innovation following the conquest of the land.“I don't know if I believe” the article, Delwiche says. “But the thing that I love about it is it gets me thinking.”Pereira, J.B.S., Labiak, P.H., Stützel, T., Schulz, C., 2017. Origin and biogeography of the ancient genus Iso?tes with focus on the Neotropics. Botanical Journal of the Linnean Society 185, 253-271. has a worldwide distribution and comprises c. 250 species. With 64 species, South America is its centre of taxonomic diversity. However, South American Iso?tes has been poorly sampled in previous phylogenetic studies, resulting in uncertainties about its phylogenetic relationships and biogeographical history. In this study, we increased the sampling from this region from ten to 26 species and inferred a phylogenetic hypothesis for 75 species worldwide, using one nuclear and three plastid markers. We also used information from four fossils to calibrate the phylogenetic tree. Ancestral range estimates were inferred using BioGeoBEARS. Our phylogenetic tree provides new insights into Neotropical Iso?tes. The earliest diversification of Iso?tes took place after the breakup of Pangaea, and the most species-rich group began to diversify close to the Cretaceous–Palaeogene boundary. Between the South African and core Gondwanan clade and within the core Gondwanan clade, vicariance played an important role in the diversification of Iso?tes. The diversification of the American clade matches the opening of the terrestrial passage between North and South America 13 Mya. We also show that, despite difficulties in the species identification, Iso?tes is a strategic group for testing evolutionary hypotheses and biogeographical patterns across the Neotropics.Perera, M.S.A., 2017. Influences of CO2 injection into deep coal seams: A review. Energy & Fuels 31, 10324-10334. nearly 20 years, CO2 has been injected into coal seams to enhance the recovery of methane in a process known as enhanced coal bed methane (ECBM). However, there is a huge complexity associated with this process, mainly due to the generating complex coal chemicophysical structure rearrangement. This review paper aims to comprehensively discuss two main influencing factors upon CO2 injection in deep coal seams: (1) mobilization of hydrocarbon and (2) coal matrix swelling. CO2 injection into deep coal seams may remove available polycyclic aromatic hydrocarbons (PAHs) from the coal matrix and mobilize them in the coal seam. The amount of hydrocarbon that is mobilized from the coal matrix by the injected CO2 is dependent on coal rank, maceral content, type of available hydrocarbons in the coal mass (both dissolving and nondissolving types), and phase state of the injected CO2 in the seam. Supercritical CO2 has greater solvent ability and, therefore, has the ability to extract a greater percentage of hydrocarbon from the coal matrix. This mobilization of the organic constituents of the coal matrix by the injected CO2 causes many environmental issues. For examples, PAHs that exist in highly volatile bituminous coal are harmful to biota and the environment, even at relatively low concentrations. On the other hand, adsorption of the injected CO2 into the coal mass causes it to be swelled, leading to significant alternations in its internal coal mass structure, resulting in great modifications in its flow and strength properties. This CO2-adsorption-induced coal matrix swelling process is reduced with increasing temperature, exhibits an inverted-U shaped variation with coal rank, and is largely dependent on the pressure and the physical state of the injected CO2, where supercritical CO2 creates a much greater swelling effect, compared to gas/liquid CO2, because of its higher chemical potential. Potential coal seams for CO2 sequestration process are available at extremely deep locations and there is a high possibility of phase change from gas/liquid to supercritical state and, thus, they likely have high swelling rates.Petrov, S.М., Ibragimova, D.A., Safiulina, A.G., Tohidi Kalorazi, B., Vakhin, A.V., Okekwe, R.C., Karalin, E.A., 2017. Conversion of organic matter in the carbonaceous medium in the supercritical water. Journal of Petroleum Science and Engineering 159, 497-505. work is based on the modeling of geothermal transformations of hydrocarbons in oil-bearing formations of deep horizons of the earth's crust - under abnormally high pressure, in the presence of aqueous fluid and carbonaceous substances. The pressure and temperature in the experiments are typical for water in the supercritical state. The regularities of the conversion of heavy oil in supercritical water and in the presence of finely dispersed caustobioliths and metal oxides were shown. Aquathermolysis in the presence of proton provides blockage of free radicals of high-molecular weight hydrocarbons and saturation of unsaturated hydrocarbons, produced by cracking reactions, and inhibiting of condensation reactions of aromatic macromolecules. The hydrogen protons also promote hydrogenation reactions in the crude oil. The regularities of changes of the component, structural-group, fractional and elemental compositions of heavy oil during the conversion under the above conditions were established, rheological characteristics of the initial crude oil and converted oil were studied as well. As a result of carrying out aquathermolysis in the supercritical water environment and in the presence of initiating additives, the high-molecular weight components of the initial crude oil were degraded with the formation of light distillate fractions, which were scarcely present in the initial crude oil. Thus, the conversion rate for various samples amounted to 18–29%. It resulted in the significant reduction in the viscosity of the converted oil, up to 96% compared to the initial crude oil.Pfendler, S., Karimi, B., Maron, P.-A., Ciadamidaro, L., Valot, B., Bousta, F., Alaoui-Sosse, L., Alaoui-Sosse, B., Aleya, L., 2018. Biofilm biodiversity in French and Swiss show caves using the metabarcoding approach: First data. Science of The Total Environment 615, 1207-1217. recent decades, show caves have begun to suffer from microorganism proliferation due to artificial lighting installations for touristic activity. In addition to the aesthetic problem, light encourages microorganisms that are responsible for physical and chemical degradation of limestone walls, speleothems and prehistoric paintings of cultural value. Microorganisms have previously been described by microscopy or culture-dependent methods, but data provided by new generation sequencing are rare. The authors identified, for the first time, microorganisms proliferating in one Swiss and in four French show caves using three different primers. The results showed that both photosynthetic and non-photosynthetic bacteria were the dominant taxa present in biofilms. Microalgae were heavily represented by the Trebouxiophyceae, Eustigmatophyceae and Chlorophyceae groups. Twelve diatoms were also recorded, with dominance of Syntrichia sp. (96.1%). Fungi were predominantly represented by Ascomycota, Zygomycota and Basidiomycota, fully half of the sampled biofilms where Fungi were detected. Comparing microbial communities from bleach-treated caves to those in untreated caves showed no significant difference except for a low-level change in the abundance of certain taxa. These findings provided by Illumina sequencing reveal a complex community structure in the 5 caves based on the assembly of bacteria, cyanobacteria, algae, diatoms, fungi and mosses.Piasecki, A., Sessions, A., Lawson, M., Ferreira, A.A., Santos Neto, E.V., Ellis, G.S., Lewan, M.D., Eiler, J.M., 2018. Position-specific 13C distributions within propane from experiments and natural gas samples. Geochimica et Cosmochimica Acta 220, 110-124. carbon isotope measurements of organic compounds potentially recover information that is lost in a conventional, ‘bulk’ isotopic analysis. Such measurements are useful because isotopically fractionating processes may have distinct effects at different molecular sites, and thermodynamically equilibrated populations of molecules tend to concentrate heavy isotopes in one molecular site versus another. Most recent studies of site-specific 13C in organics use specialized Nuclear Magnetic Resonance (NMR) techniques or complex chemical degradations prior to mass spectrometric measurements. Herein we present the first application of a new mass spectrometric technique that reconstructs the site-specific carbon isotope composition of propane based on measurements of the 13C/12C ratios of two or more fragment ions that sample different proportions of the terminal and central carbon sites. We apply this method to propane from laboratory experiments and natural gas samples to explore the relationships between site-specific carbon isotope composition, full-molecular δ13C, thermal maturity, and variation in organic matter precursors. Our goal is to advance the understanding of the sources and histories of short-chain alkanes within geologic systems. Our findings suggest that propane varies in its site-specific carbon isotope structure, which is correlated with increasing thermal maturity, first increasing in terminal position δ13C and then increasing in both center and terminal position δ13C. This pattern is observed in both experimental and natural samples, and is plausibly explained by a combination of site-specific, temperature-dependent isotope effects associated with conversion of different precursor molecules (kerogen, bitumen, and/or oil) to propane, differences in site-specific isotopic contents of those precursors, and possibly distillation of reactive components of those precursors with increasing maturity. We hypothesize that the largest changes in site-specific isotopic content of propane occur when bitumen and/or oil replace kerogen as the dominant precursors. If correct, this phenomenon could have significant utility for understanding gas generation in thermogenic petroleum systems.Pinke, Z., Ferenczi, L., Romhányi, B.F., Laszlovszky, J., Pow, S., 2017. Climate of doubt: A re-evaluation of Büntgen and Di Cosmo’s environmental hypothesis for the Mongol withdrawal from Hungary, 1242 CE. Scientific Reports 7, Article 12695. their recent article published in the journal Scientific Reports, Büntgen and Di Cosmo have attempted to solve the historical mystery of the sudden Mongol withdrawal from Hungary after a year-long occupation. We cannot share the authors’ viewpoint that environmental circumstances contributed to the decision of the Mongols to abandon Hungary since the hypothesis lacks support from environmental, archaeological and historical evidence. Historical source material in particular suggests that the Mongols were able to settle and sustain their herds in Hungary as is clearly stated in a letter by King Bela IV to the pope. The Mongol army arrived in the kingdom at the end of a severe?drought, and we present empirical evidence that the abundant rain in the spring of 1242 CE did not worsen but rather improved their prospects for sufficient food supplies and pasturage. The marshy terrain of the Hungarian Plain likely did not precipitate the Mongol withdrawal as the Mongol high command ultimately stationed their main forces around the marshy Volga Delta. In contrast to what Büntgen and Di Cosmo have suggested, we argue that the reasons for the sudden withdrawal cannot be explained largely by environmental factors.Plegaria, J.S., Kerfeld, C.A., 2018. Engineering nanoreactors using bacterial microcompartment architectures. Current Opinion in Biotechnology 51, 1-7. microcompartments (BMCs) are organelles that encapsulate enzymes involved in CO2 fixation or carbon catabolism in a selectively permeable protein shell. Here, we highlight recent advances in the bioengineering of these protein-based nanoreactors in heterologous systems, including transfer and expression of BMC gene clusters, the production of template empty shells, and the encapsulation of non-native enzymes.Polyak, Y.M., Bakina, L.G., Chugunova, M.V., Mayachkina, N.V., Gerasimov, A.O., Bure, V.M., 2018. Effect of remediation strategies on biological activity of oil-contaminated soil - A field study. International Biodeterioration & Biodegradation 126, 57-68. effects of oil contamination and different remediation strategies (natural attenuation, biostimulation, and bioaugmentation) on physico-chemical and biological parameters of podzolic soil were studied. The relationships between petroleum hydrocarbons, total organic carbon, nutrients, basal respiration and enzymatic activity (dehydrogenase, catalase and urease) were evaluated in soil over a 9-year period. The principal component analysis indicated that hydrocarbons were mainly responsible for changing metabolic activity for all treatments. Dehydrogenase activity was the most sensitive biological indicator with greater levels in unpolluted soil than those recorded in contaminated soil under all remediation strategies. The activity of urease was not directly correlated with oil degradation, while the relationships of catalase and respiration rate with petroleum hydrocarbons were dependent on method of remediation. Although both biostimulation and bioaugmentation had a positive influence on the biological activity of soil and its physicochemical properties, the considerable part of decontamination could be attributed to degradation activities of indigenous microorganisms. The addition of oil-degrading bacteria (bioaugmentation) enhanced biodegradation rates only temporarily indicating that biostimulation is a better remediation strategy for podzolic soil in the field.Posth, N.R., Bristow, L.A., Cox, R.P., Habicht, K.S., Danza, F., Tonolla, M., Frigaard, N.U., Canfield, D.E., 2017. Carbon isotope fractionation by anoxygenic phototrophic bacteria in euxinic Lake Cadagno. Geobiology 15, 798-816. phototrophic bacteria utilize ancient metabolic pathways to link sulfur and iron metabolism to the reduction of CO2. In meromictic Lake Cadagno, Switzerland, both purple sulfur (PSB) and green sulfur anoxygenic phototrophic bacteria (GSB) dominate the chemocline community and drive the sulfur cycle. PSB and GSB fix carbon utilizing different enzymatic pathways and these fractionate C-isotopes to different extents. Here, these differences in C-isotope fractionation are used to constrain the relative input of various anoxygenic phototrophs to the bulk community C-isotope signal in the chemocline. We sought to determine whether a distinct isotopic signature of GSB and PSB in the chemocline persists in the settling fraction and in the sediment. To answer these questions, we also sought investigated C-isotope fractionation in the water column, settling material, and sediment of Lake Cadagno, compared these values to C-isotope fractionation of isolated anoxygenic phototroph cultures, and took a mass balance approach to investigate relative contributions to the bulk fractionation signature. We found a large C-isotope fractionation between dissolved inorganic carbon (DIC) and particulate organic carbon (POC) in the Lake Cadagno chemocline. This large fractionation between the DIC and POC was also found in culture experiments carried out with anoxygenic phototrophic bacteria isolated from the lake. In the Lake Cadagno chemocline, anoxygenic phototrophic bacteria controlled the bulk C-isotope fractionation, but the influence of GSB and PSB differed with season. Furthermore, the contribution of PSB and GSB to bulk C-isotope fractionation in the chemocline could be traced in the settling fraction and in the sediment. Taken together with other studies, such as lipid biomarker analyzes and investigations of other stratified lakes, these results offer a firmer understanding of diagenetic influences on bacterial biomass.Potiszil, C., Montgomery, W., Sephton, M.A., 2017. Effects of pressure on model compounds of meteorite organic matter. ACS Earth and Space Chemistry 8, 475-482. organic matter has been widely studied; however, its response to pressure has not. Primitive organic matter bearing meteorites, such as CI and CM carbonaceous chondrites, have experienced variable pressures, up to 10 GPa. To appreciate the effects of these pressures on the organic content of these bodies, the model compounds isophthalic acid, vanillin, and vanillic acid were subjected to pressures of up to 11.5 GPa and subsequently decompressed. High-resolution synchrotron source Fourier transform infrared spectroscopy was used to determine the effects of different benzene substituents at high pressure on both the vibrational assignments of the benzene core of the molecules and the ability of the aromatic compounds to form intermolecular hydrogen bonds. The presence of additional peaks at high pressure was found to coincide with molecules that contain carboxyl groups; these features are interpreted as C–H···O intermolecular hydrogen bonds. The formation of these hydrogen bonds has implications for the origination of macromolecular organic matter (MOM), owing to the importance of such attractive forces during episodes of cross-linking, such as esterification. Pressure-induced hydrogen-bond formation is a process by which aromatic MOM precursors could have cross-linked to generate the organic polymers found within extraterrestrial bodies today.Préat, A., Delpomdor, F., Ackouala Mfere, A.P., Callec, Y., 2018. Paleoenvironments, δ13C and δ18O signatures in the Neoproterozoic carbonates of the Comba Basin, Republic of Congo: Implications for regional correlations and Marinoan event. Journal of African Earth Sciences 137, 69-90. Ediacaran Schisto-Calcaire Group is a ～1300 m-thick succession belonging to the West Congo Supergroup in Central Africa. In the Comba Basin, it consists of three carbonate-dominated units defined as formations (SCI to SCIII) that are unconformably overlain by clastic deposits (Mpioka Group) interpreted as a molassic formation associated with the Panafrican Orogen. The underlying Upper Tillite and Cap Carbonate (SCIa) units, considered as markers of the Snowball Earth event were studied in three sections. We investigated the carbonates of the Schisto-Calcaire Group by defining new microfacies (MF1-MF7) and we performed C and O isotopic analyses in order to constraint the depositional and diagenetic events directly after the Marinoan interval. Stratigraphic variations of the stable isotopes are important in the series with lighter δ18O values (>1.5‰) than those of the Neoproterozoic ocean in the SCIc unit. According to regional stratigraphy a temperature effect can be dismissed and a freshwater surface layer is the origin of such negative δ18O values in this unit. The negative δ13C anomaly (?3.5‰ on average) of the Cap Carbonate is similarly to the δ18O values (?6.4‰ on average) in the range of the marine domain during postglacial sea level rise. The sample suite as a whole (SCII and SCIII formations) displays heavier δ18O and δ13C than those of the lower part (SCI unit) of the Schisto-Calcaire Group. The comparison with the Lower Congo (Democratic Republic of Congo) and Nyanga (Gabon) basins shows that the meteoric flushing in SCIc unit of the Schisto-Calcaire Group was regional and not local, and could be derived from a climatic evolution. Although an overall overprint is present, our isotopic relationships argue against overall diagenetic resetting of primary compositions and suggest that with careful examination combined with detailed petrographic analysis general depositional and diagenetic controls can be discerned in oxygen and carbon isotopic data in the Schisto-Calcaire Group.Probst, A.J., Hu, P., Sun, C.L., Dubinsky, E.A., Sieber, C.M.K., Banfield, J.F., Andersen, G.L., 2017. Reply to Delmont and Eren: Strain variants and population structure during the Deepwater Horizon oil spill. Proceedings of the National Academy of Sciences 114 no. 43. laboratory simulation revealed the succession patterns of oil degradation and microbial community changes during the Deepwater Horizon oil spill, one of the largest environmental catastrophes in human history (1). Hu et al. successfully recovered genomes of several oil-degrading bacteria, including one of “Candidatus Bermanella macondoprimitus,” with high identity to the dominant Oceanospirillales 16S rRNA gene sequences recovered from the deep-ocean hydrocarbon plumes (1, 2). Delmont and Eren (3) reanalyzed metagenomic data generated from these plumes (4) to argue that this Bermanella was not present. We find that Delmont and Eren (3) draw their conclusions from methods that are flawed. Importantly, the authors (3) use samples that underwent an emulsion PCR (4) [according to Mason et al. (4) overloaded by ～20 molecules per droplet (5)], which likely resulted in a heavy distortion of the sequenced community and observed abundance patterns (6). Delmont and Eren (3) failed to use any metagenome assembler that attempts to … Original article: Hu, P., Dubinsky, E.A., Probst, A.J., Wang, J., Sieber, C.M.K., Tom, L.M., Gardinali, P.R., Banfield, J.F., Atlas, R.M., Andersen, G.L., 2017. Simulation of Deepwater Horizon oil plume reveals substrate specialization within a complex community of hydrocarbon degraders. Proceedings of the National Academy of Sciences 114, 7432-mented on: Delmont, T.O., Eren, A.M., 2017. Simulations predict microbial responses in the environment? This environment disagrees retrospectively. Proceedings of the National Academy of Sciences. 114, E8947-E8949.Pulliainen, J., Aurela, M., Laurila, T., Aalto, T., Takala, M., Salminen, M., Kulmala, M., Barr, A., Heimann, M., Lindroth, A., Laaksonen, A., Derksen, C., M?kel?, A., Markkanen, T., Lemmetyinen, J., Susiluoto, J., Dengel, S., Mammarella, I., Tuovinen, J.-P., Vesala, T., 2017. Early snowmelt significantly enhances boreal springtime carbon uptake. Proceedings of the National Academy of Sciences 114, 11081-11086.: We quantified a 36-y trend of advanced spring recovery of carbon uptake across the northern hemisphere boreal evergreen forest zone. From this trend, we estimated the corresponding change in global gross primary production (GPP) and further quantified the magnitude and spatiotemporal variability of spring GPP, that is, the cross-photosynthetic carbon uptake by forest. Our main findings are the following: (i) We developed a proxy indicator for spring recovery from in situ flux data on CO2 exchange and recent satellite snowmelt products and (ii) we established a relation between spring recovery and carbon uptake to assess changes in springtime carbon exchange showing a major advance in the CO2 sink. Abstract: We determine the annual timing of spring recovery from space-borne microwave radiometer observations across northern hemisphere boreal evergreen forests for 1979–2014. We find a trend of advanced spring recovery of carbon uptake for this period, with a total average shift of 8.1 d (2.3 d/decade). We use this trend to estimate the corresponding changes in gross primary production (GPP) by applying in situ carbon flux observations. Micrometeorological CO2 measurements at four sites in northern Europe and North America indicate that such an advance in spring recovery would have increased the January–June GPP sum by 29 g?C?m?2 [8.4 g?C?m?2 (3.7%)/decade]. We find this sensitivity of the measured springtime GPP to the spring recovery to be in accordance with the corresponding sensitivity derived from simulations with a land ecosystem model coupled to a global circulation model. The model-predicted increase in springtime cumulative GPP was 0.035 Pg/decade [15.5 g?C?m?2 (6.8%)/decade] for Eurasian forests and 0.017 Pg/decade for forests in North America [9.8 g?C?m?2 (4.4%)/decade]. This change in the springtime sum of GPP related to the timing of spring snowmelt is quantified here for boreal evergreen forests. Raimbourg, H., Thiéry, R., Vacelet, M., Famin, V., Ramboz, C., Boussafir, M., Disnar, J.-R., Yamaguchi, A., 2017. Organic matter cracking: A source of fluid overpressure in subducting sediments. Tectonophysics 721, 254-274. pressure of deep fluids in subduction zones is a major control on plate boundary strength and earthquake genesis. The record, by methane-rich fluid inclusions, of large (~ 50–100 MPa) and instantaneous pressure variations in the Shimanto Belt (Japan) points to the presence of large fluid overpressure at depth (300–500 MPa, ~ 250 °C). To further analyze the connection between methane and fluid overpressure, we determined with Rock-Eval the potential for a worldwide selection of deep seafloor sediments to produce methane as a result of organic matter (OM) cracking due to temperature increase during subduction. The principal factor controlling the methanogenesis potential of sediments is OM proportion, while OM nature is only a subordinate factor. In turn, OM proportion is mainly controlled by the organic terrigenous input. Considering a typical sediment from ocean-continent subduction zones, containing 0.5 wt% of type III OM, cracking of OM has two major consequences: (1) Methane is produced in sufficient concentration as to oversaturate the pore-filling water. The deep fluid in accretionary prisms is therefore a mechanical mixture of water-rich and methane-rich phases; (2) CH4 production can generate large fluid overpressure, of the order of several tens of MPa, The conditions for these large overpressure are a low permeability of the upper plate (< 2.10? 21 m2) and décollement zone (< 10? 18 m2), which may be prevailing in the depth domain (z > 10 km) where OM thermal cracking occurs. At these depths, OM thermal cracking appears as a source of overpressure larger than the last increments of smectite-to-illite reaction. Such large overpressures play potentially a role in facilitating slip along the plate interface. Conversely, the scarcity of earthquakes in ocean-ocean subduction zones such as Marianna or Barbados may be related to the low influx of detrital OM and the limited methane/overpressure generation at depth.Rajamanickam, R., Baskaran, D., 2017. Biodegradation of gaseous toluene with mixed microbial consortium in a biofilter: steady state and transient operation. Bioprocess and Biosystems Engineering 40, 1801-1812. oil refineries are massive emitters of risky volatile organic compounds (VOCs). Among the VOCs, toluene is taken into account as a significant pollutant. In the present study, a compost biofilter is used to treat the toluene vapor. However, an elimination capacity and removal efficiency of the biofilter was investigated for a wide range of toluene concentrations (0.29–3.8 g m?3) and operated for 54 days effectively. Elimination capacity of 93 g m?3 h?1 was recorded as maximum value at a toluene inlet concentration of 114 g m?3 h?1. An elimination capacity was perpetually better at the lower section of the biofilter, and therefore, the value was around 40–60 g m?3 h?1. The high removal efficiency of 97% was obtained at inlet toluene load of 60.55 g m?3 h?1. Hence, the biofilm was quite sensitive to handling transient loading conditions. The pressure drop had no vital impact on the biofilter performance. An Ottengraf model was applied to all phase of biofilter operation in each of the diffusion limiting region and reaction limiting region. The parameters of the model K1 (75.95 g1/2 m?3/2 h?1) and K0 (90.51 g m?3 h?1) were obtained from diffusion and reaction limiting region severally. However, K1 was used to calculate the theoretical elimination capacities, and therefore, K0 was used to discover the biofilm thickness. By the way, the average biofilm thickness was found to be 0.98 mm from reaction limiting region.Ramirez, M.I., Arevalo, A.P., Sotomayor, S., Bailon-Moscoso, N., 2017. Contamination by oil crude extraction – Refinement and their effects on human health. Environmental Pollution 231, 415-425. harmful effects of oil on various species of flora and fauna have been studied extensively; however, few studies have studied the effects of oil exposure on human health. The objective of this research was to collect information on the acute health effects and serious psychological symptoms of the possible consequences of such exposure to crude oil. Some studies focused on the composition of different chemicals used in the extraction process, and wastes generated proved to be highly harmful to human health. Thus, studies have shown that individuals who live near oil fields or wells – or who take part in activities of cleaning oil spills – have presented health conditions, such as irritation to the skin, eyes, mucous membranes, kidney damage, liver, reproductive, among others. In Ecuador, this reality is not different from other countries, and some studies have shown increased diseases related with oil crude and oil spills, like skin irritation, throat, liver, lung, infertility, and abortions, and it has been linked to childhood leukemia. Other studies suggest a direct relationship between DNA damage because of oil resulting in a genetic instability of the main enzymes of cellular metabolism as well as a relationship with some cancers, such as leukemia.Rampino, M.R., Caldeira, K., 2017. Correlation of the largest craters, stratigraphic impact signatures, and extinction events over the past 250?Myr. Geoscience Frontiers 8, 1241-1245. six largest known impact craters of the last 250 Myr (≥70?km in diameter), which are capable of causing significant environmental damage, coincide with four times of recognized extinction events at 36 (with 2 craters), 66, and 145?Myr ago, and possibly with two provisional extinction events at 168 and 215?Myr ago. These impact cratering events are accompanied by layers in the geologic record interpreted as impact ejecta. Chance occurrences of impacts and extinctions can be rejected at confidence levels of 99.96% (for 4 impact/extinctions) to 99.99% (for 6 impact/extinctions). These results argue that several extinction events over the last 250?Myr may be related to the effects of large-body impacts.Rampino, M.R., Rodriguez, S., Baransky, E., Cai, Y., 2017. Global nickel anomaly links Siberian Traps eruptions and the latest Permian mass extinction. Scientific Reports 7, Article 12416. peaks of nickel abundance have been reported in Permian-Triassic boundary sections in China, Israel, Eastern Europe, Spitzbergen, and the Austrian Carnic Alps. New solution ICP-MS results of enhanced nickel from P-T boundary sections in Hungary, Japan, and Spiti, India suggest that the nickel anomalies at the end of the Permian were a worldwide phenomenon. We propose that the source of the nickel anomalies at the P-T boundary were Ni-rich volatiles released by the Siberian volcanism, and by coeval Ni-rich magma intrusions. The peaks in nickel abundance correlate with negative δ13C and δ18O anomalies, suggesting that explosive reactions between magma and coal during the Siberian flood-basalt eruptions released large amounts of CO2 and CH4 into the atmosphere, causing severe global warming and subsequent mass extinction. The nickel anomalies may provide a timeline in P-T boundary sections, and the timing of the peaks supports the Siberian Traps as a contributor to the latest Permian mass extinction.Ranieri, U., Koza, M.M., Kuhs, W.F., Klotz, S., Falenty, A., Gillet, P., Bove, L.E., 2017. Fast methane diffusion at the interface of two clathrate structures. Nature Communications 8, Article 1076. hydrates naturally form on Earth and in the interiors of some icy bodies of the Universe, and are also expected to play a paramount role in future energy and environmental technologies. Here we report experimental observation of an extremely fast methane diffusion at the interface of the two most common clathrate hydrate structures, namely clathrate structures I and II. Methane translational diffusion—measured by quasielastic neutron scattering at 0.8?GPa—is faster than that expected in pure supercritical methane at comparable pressure and temperature. This phenomenon could be an effect of strong confinement or of methane aggregation in the form of micro-nanobubbles at the interface of the two structures. Our results could have implications for understanding the replacement kinetics during sI–sII conversion in gas exchange experiments and for establishing the methane mobility in methane hydrates embedded in the cryosphere of large icy bodies in the Universe.Razeghi, S.A., Mitrovic, V., Adjei Marfo, S., 2017. The influence of steam injection for Enhanced Oil Recovery (EOR) on the quality of crude oil. Petroleum Science and Technology 35, 1334-1342., due to reduction of oil reservoirs and the increasing need for oil as the main source for world energy, the need for production of heavy oil reservoirs is inevitable. The main purpose of this study is to determine the effectiveness of some operational and reservoir parameters and their impact on thermal and productive efficiency of thermal process of steam injection and quality of crude oil. In order to model the process, Eclipse-300 simulator was employed. Detection of these parameters, in addition to determining the best production scenario, can lead to the use of this method with better economic conditions. Hence, the results obtained from this study show that the optimal values obtained for operational parameters of stream injection such as steam quality, steam injection pressure, injection rate and well completion injection depth. The simulation results show that the use of optimal values of steam injection parameters can enhance efficiency of steam injection method and can make this method considered as third EOR method in heavy oil reservoirs than previously known in the petroleum industry.Reilly, S., Summons, R., Mayr, G., Vinther, J., 2017. Preservation of uropygial gland lipids in a 48-million-year-old bird. Proceedings of the Royal Society B: Biological Sciences 284, Article 20171050. various kinds of organic molecules are known to occur in fossils and rocks, most soft tissue preservation in animals is attributed to melanin or porphyrins. Lipids are particularly stable over time—as diagenetically altered ‘geolipids’ or as major molecular constituents of kerogen or fossil ‘geopolymers’—and may be expected to be preserved in certain vertebrate tissues. Here we analysed lipid residues from the uropygial gland of an early Eocene bird using pyrolysis gas chromatography mass spectroscopy. We found a pattern of aliphatic molecules in the fossil gland that was distinct from the host oil shale sediment matrix and from feathers of the same fossil. The fossil gland contained abundant n-alkenes, n-alkanes and alkylbenzenes with chain lengths greater than 20, as well as functionalized long-chain aldehydes, ketones, alkylnitriles and alkylthiophenes that were not detected in host sediment or fossil feathers. By comparison with modern bird uropygial gland wax esters, we show that these molecular fossils are likely derived from endogenous wax ester fatty alcohols and fatty acids that survived initial decay and underwent early diagenetic geopolymerization. These data demonstrate the high fidelity preservation of the uropygial gland waxes and showcase the resilience of lipids over geologic time and their potential role in the exceptional preservation of lipid-rich tissues of macrofossils.Reimers, C.E., Li, C., Graw, M.F., Schrader, P.S., Wolf, M., 2017. The identification of cable bacteria attached to the anode of a benthic microbial fuel cell: Evidence of long distance extracellular electron transport to electrodes. Frontiers in Microbiology 8, 2055. doi: 10.3389/fmicb.2017.02055., filamentous, sulfur-oxidizing bacteria, known as cable bacteria, were discovered attached to fibers of a carbon brush electrode serving as an anode of a benthic microbial fuel cell (BMFC). The BMFC had been operated in a temperate estuarine environment for over a year before collecting anode samples for scanning electron microscopy and phylogenetic analyses. Individual filaments were attached by single terminus cells with networks of pilus-like nano-filaments radiating out from these cells, across the anode fiber surface, and between adjacent attachment locations. Current harvesting by the BMFC poised the anode at potentials of ~170–250 mV vs. SHE, and these surface potentials appear to have allowed the cable bacteria to use the anode as an electron acceptor in a completely anaerobic environment. A combination of catalyzed reporter deposition fluorescent in situ hybridization (CARD-FISH) and 16S rRNA gene sequence analysis confirmed the phylogeny of the cable bacteria and showed that filaments often occurred in bundles and in close association with members of the genera Desulfuromonas. However, the Desulfobulbaceae Operational Taxonomic Units (OTUs) from the 16S sequencing did not cluster closely with other putative cable bacteria sequences suggesting that the taxonomic delineation of cable bacteria is far from complete.Reitan, T., Liow, L.H., 2017. An unknown Phanerozoic driver of brachiopod extinction rates unveiled by multivariate linear stochastic differential equations. Paleobiology 43, 537-549. the evolutionary dynamics of one group of organisms influence that of another group of organisms over the vast timescale of the geological record is a difficult question to tackle. This is not least because multiple factors can influence or mask the effects of potential driving forces on evolutionary dynamics of the focal group. Here, we show how an approach amenable to causality inference for time series, linear stochastic differential equations (SDEs), can be used in a multivariate fashion to shed light on driving forces of diversification dynamics across the Phanerozoic. Using a new, enhanced stepwise search algorithm, we searched through hundreds of models to converge on a model that best describes the dynamic relationships that drove brachiopod and bivalve diversification rates. Using this multivariate framework, we characterized a slow process (half-life of c. 42 Myr) that drove brachiopod extinction. This slow process has yet to be identified from the geological record. Using our new framework for analyzing multiple linear SDEs, we also corroborate our previous findings that bivalve extinction drove brachiopod origination in the sense that brachiopods tended to diversify at a greater rate when bivalves were removed from the system. It is also very likely that bivalves “self-regulate” in the sense that bivalve extinctions also paved the way for higher bivalve origination rates. Multivariate linear SDEs as we presented them here are likely useful for studying other dynamic systems whose signatures are preserved in the paleontological record.Ren, T., Wang, Y., Zhang, G., 2017. Influence of the properties of resins on the interactions between asphaltenes and resins. Petroleum Science and Technology 35, 1481-1486. properties of two resins (Tahe resin and Liaohe resin) and their influences on the dispersion of two asphaltenes (Tahe asphaltene and Liaohe asphaltene) are investigated by laboratory experiments. The results indicate that the adsorption isotherms of two resins are accorded with the Freundlich absorption model. The shape of the curves obtained could be attributed to both multilayer adsorption of resins on asphaltenes surfaces and the penetration of resins into the microporous structure of the asphaltenes. Based on the combined results from the shape of the curves and chemical properties of resins, the relative adsorption quantity of Tahe resin is higher than that of Liaohe resin due to the stronger polarity of Tahe resin, and the effect of Tahe resin on the dispersion of asphaltene is stronger than that of Liaohe rein. The different properties of resin can directly lead to the difference of dispersion performance on asphaltene in crude oil, which is closely related to the chemical structure of resin. The more the number of aromatic structure of the resin, the stronger the effect of resin on the dispersion of asphaltene there is.Ren, Y., Zhong, D., Gao, C., Liang, T., Sun, H., Wu, D., Zheng, X., 2017. High-resolution carbon isotope records and correlations of the lower Cambrian Longwangmiao formation (stage 4, Toyonian) in Chongqing, South China. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 572-592. gain a better understanding of the oceanic environment of the transitional Lower-Middle Cambrian boundary and provide additional data for the global ROECE correlation, we studied the carbon isotope records of shallow-water platform carbonates of the Cambrian Stage 4 Longwangmiao Formation in the Bandenggou section in Chongqing, South China, and correlated with previously reported contemporaneous δ13Ccarb records across a range of depositional environments on the Yangtze Platform and other basins. The δ13Ccarb curve of the Longwangmiao Formation fluctuates frequently approximately 0‰ with multiple excursions at its lower sequence, exhibits a conspicuous negative δ13C excursion with a minimum peak value of ? 4.76‰ at the middle sequence, and then possesses a stable positive distribution upward. The correlation across the platform-to-basin transect on the Yangtze Platform shows that the Toyonian sections, from slope to basin, have similar shapes of δ13C curves, with a depleted trend upward and consistent timings of the largest-amplitude negative δ13C excursion, termed ROECE, while contemporaneous shallow-water platform sections have different δ13C profile shapes and timings of their largest-amplitude negative δ13C excursions, as do sections at a range of depositional environments from a multitude of continents. We infer that the carbon isotopic compositions from the Bandenggou section in the shallow-water environment layer may retain a regional signal. The negative δ13C distribution of the lower sequence is primarily due to a local, long-term riverine influx and low relative sea level at the early stage, which amplified organic matter decay and diminished primary productivity. Eventually, this elevated the oxidation and eutrophication of the shallow water, while the stable positive δ13C distribution upward is attributed to the integrated influence of a long-term scant riverine flux and high relative sea level. Additionally, the location of ROECE in the shallow-water sections still needs substantiation at the global scale.Ren, Z., Gao, H., Elser, J.J., Zhao, Q., 2017. Microbial functional genes elucidate environmental drivers of biofilm metabolism in glacier-fed streams. Scientific Reports 7, Article 12668. biofilms in glacier-fed streams harbor diverse microorganisms driving biogeochemical cycles and, consequently, influencing ecosystem-level processes. Benthic biofilms are vulnerable to glacial retreat induced by climate change. To investigate microbial functions of benthic biofilms in glacier-fed streams, we predicted metagenomes from 16s rRNA gene sequence data using PICRUSt and identified functional genes associated with nitrogen and sulfur metabolisms based on KEGG database and explored the relationships between metabolic pathways and abiotic factors in glacier-fed streams in the Tianshan Mountains in Central Asia. Results showed that the distribution of functional genes was mainly associated with glacier area proportion, glacier source proportion, total nitrogen, dissolved organic carbon, and pH. For nitrogen metabolism, the relative abundance of functional genes associated with dissimilatory pathways was higher than those for assimilatory pathways. The relative abundance of functional genes associated with assimilatory sulfate reduction was higher than those involved with the sulfur oxidation system and dissimilatory sulfate reduction. Hydrological factors had more significant correlations with nitrogen metabolism than physicochemical factors and anammox was the most sensitive nitrogen cycling pathway responding to variation of the abiotic environment in these glacial-fed streams. In contrast, sulfur metabolism pathways were not sensitive to variations of abiotic factors in these systems.Renforth, P., Henderson, G., 2017. Assessing ocean alkalinity for carbon sequestration. Reviews of Geophysics 55, 636-674. the coming century humanity may need to find reservoirs to store several trillions of tons of carbon dioxide (CO2) emitted from fossil fuel combustion, which would otherwise cause dangerous climate change if it were left in the atmosphere. Carbon storage in the ocean as bicarbonate ions (by increasing ocean alkalinity) has received very little attention. Yet recent work suggests sufficient capacity to sequester copious quantities of CO2. It may be possible to sequester hundreds of billions to trillions of tons of C without surpassing postindustrial average carbonate saturation states in the surface ocean. When globally distributed, the impact of elevated alkalinity is potentially small and may help ameliorate the effects of ocean acidification. However, the local impact around addition sites may be more acute but is specific to the mineral and technology. The alkalinity of the ocean increases naturally because of rock weathering in which >1.5 mol of carbon are removed from the atmosphere for every mole of magnesium or calcium dissolved from silicate minerals (e.g., wollastonite, olivine, and anorthite) and 0.5 mol for carbonate minerals (e.g., calcite and dolomite). These processes are responsible for naturally sequestering 0.5 billion tons of CO2 per year. Alkalinity is reduced in the ocean through carbonate mineral precipitation, which is almost exclusively formed from biological activity. Most of the previous work on the biological response to changes in carbonate chemistry have focused on acidifying conditions. More research is required to understand carbonate precipitation at elevated alkalinity to constrain the longevity of carbon storage. A range of technologies have been proposed to increase ocean alkalinity (accelerated weathering of limestone, enhanced weathering, electrochemical promoted weathering, and ocean liming), the cost of which may be comparable to alternative carbon sequestration proposals (e.g., $20–100 tCO2?1). There are still many unanswered technical, environmental, social, and ethical questions, but the scale of the carbon sequestration challenge warrants research to address these.Ridenhour, B.J., Brooker, S.L., Williams, J.E., Van Leuven, J.T., Miller, A.W., Dearing, M.D., Remien, C.H., 2017. Modeling time-series data from microbial communities. ISME Journal 11, 2526-2537. sequencing technologies have advanced, the amount of information regarding the composition of bacterial communities from various environments (for example, skin or soil) has grown exponentially. To date, most work has focused on cataloging taxa present in samples and determining whether the distribution of taxa shifts with exogenous covariates. However, important questions regarding how taxa interact with each other and their environment remain open thus preventing in-depth ecological understanding of microbiomes. Time-series data from 16S rDNA amplicon sequencing are becoming more common within microbial ecology, but methods to infer ecological interactions from these longitudinal data are limited. We address this gap by presenting a method of analysis using Poisson regression fit with an elastic-net penalty that (1) takes advantage of the fact that the data are time series; (2) constrains estimates to allow for the possibility of many more interactions than data; and (3) is scalable enough to handle data consisting of thousands of taxa. We test the method on gut microbiome data from white-throated woodrats (Neotoma albigula) that were fed varying amounts of the plant secondary compound oxalate over a period of 22 days to estimate interactions between OTUs and their environment.Rivera, T.A., Darata, R., Lippert, P.C., Jicha, B.R., Schmitz, M.D., 2017. The duration of a Yellowstone super-eruption cycle and implications for the age of the Olduvai subchron. Earth and Planetary Science Letters 479, 377-386. rhyolitic eruptions preceding and following a caldera-forming eruption can provide insights into the tempo of eruption cycles and timing of magmatic recharge. In this contribution, high-precision 40Ar/39Ar eruption ages were obtained on the three effusive eruptions bracketing the Huckleberry Ridge Tuff, which comprise Yellowstone's first volcanic cycle. These dates are supplemented with detailed paleomagnetic and rock magnetic analyses to resolve discrepancies with previous reported stratigraphy. The Huckleberry Ridge Tuff (2.08 Ma) was preceded by an eruption at 2.14 Ma, and followed by eruptions at 1.98 and 1.95 Ma, all of which occurred during four distinct periods of geomagnetic instability within the Matuyama chron. The first volcanic cycle of Yellowstone has now been constrained to within a 200 kyr timespan, or half of the previously proposed duration, and similar to the duration of volcanic activity for caldera-forming systems in the Jemez Volcanic Field. The maximum duration for magmatic recharge for the first Yellowstone volcanic cycle is no greater than 100 kyr, and likely closer to 40 kyr. Furthermore, the combined 40Ar/39Ar eruption ages and paleomagnetic results provide polarity anchors for the Pre-Olduvai excursion and Olduvai subchron, which are often used as tie-points in studies of early Pleistocene hominin evolution.Roberts, J.J., Gilfillan, S.M.V., Stalker, L., Naylor, M., 2017. Geochemical tracers for monitoring offshore CO2 stores. International Journal of Greenhouse Gas Control 65, 218-234. tracers are proposed as an effective means of detecting, attributing and quantifying any CO2 leaks to surface from geological CO2 storage sites, a key component of Carbon Capture and Storage (CCS) technology. A significant proportion of global CO2 storage capacity is located offshore, with some regions of the world having no onshore stores. To assure regulatory bodies and the public of CO2 storage integrity it is important to demonstrate that robust offshore monitoring systems are in place. A range of chemical tracers for leakage have been tested at onshore pilot CCS projects worldwide, but to date they have not been trialled at injection projects or CO2 release experiments located offshore. Here, for the first time, we critically review the current issues surrounding commercial scale use of tracers for offshore CCS projects, and examine the constraints and cost implications posed by the marine environment. These constraints include the logistics of sampling for tracers offshore, the fate of tracers in marine environments, tracer background levels, marine toxicity and legislative barriers – with particular focus on the Europe and the UK. It is clear that chemicals that form a natural component of the CO2 stream are preferable tracers for ease of permitting and avoiding cost and risks of procuring and artificially adding a tracer. However, added tracers offer more reliability in terms of their unique composition and the ability to control and regulate concentrations. We identify helium and xenon isotopes (particularly 124,129Xe), and artificial tracers such as PFCs and deuterated methane as the most suitable added tracers. This is due to their conservative behaviour, low environmental impact and relative inexpense. Importantly, we also find that SF6 and C14 are not viable tracers for CCS due to environmental concerns, and many other potential tracers can be ruled out on the basis of cost. Further, we identify key challenges that are unique to using tracers for offshore monitoring, and highlight critical uncertainties that future work should address. These include possible adsorption or dispersion of tracer compounds during ascent through the overburden, longevity of tracers over the timeframes relevant for CCS monitoring, the permissible environmental effects of tracer leakage, and tracer behaviour in seabed CO2 bubble streams and in dissolved CO2. These uncertainties directly affect the selection of appropriate tracers, the injection program and concentrations necessary for their reliable detection, and appropriate sampling approaches. Hence offshore tracer selection and associated expense are currently poorly constrained. Further, there is limited experience of sampling for tracers in the marine environment; current approaches are expensive and must be streamlined to enable affordable monitoring strategies. Further work is necessary to address these unknowns so as to evaluate the performance of potential tracers for CO2 leak quantitation and provide more accurate costings for effective offshore tracer monitoring programs.Rodovská, Z., Magna, T., ?ák, K., Kato, C., Savage, P.S., Moynier, F., Skála, R., Je?ek, J., 2017. Implications for behavior of volatile elements during impacts—Zinc and copper systematics in sediments from the Ries impact structure and central European tektites. Meteoritics & Planetary Science 52, 2178-2192. are tektites genetically related to the Ries impact structure, located in Central Europe, but the source materials and the processes related to the chemical fractionation of moldavites are not fully constrained. To further understand moldavite genesis, the Cu and Zn abundances and isotope compositions were measured in a suite of tektites from four different substrewn fields (South Bohemia, Moravia, Cheb Basin, Lusatia) and chemically diverse sediments from the surroundings of the Ries impact structure. Moldavites are slightly depleted in Zn (~10–20%) and distinctly depleted in Cu (>90%) relative to supposed sedimentary precursors. Moreover, the moldavites show a wide range in δ66Zn values between 1.7 and 3.7‰ (relative to JMC 3-0749 Lyon) and δ65Cu values between 1.6 and 12.5‰ (relative to NIST SRM 976) and are thus enriched in heavy isotopes relative to their possible parent sedimentary sources (δ66Zn = ?0.07 to +0.64‰; δ65Cu = ?0.4 to +0.7‰). In particular, the Cheb Basin moldavites show some of the highest δ65Cu values (up to 12.5‰) ever observed in natural samples. The relative magnitude of isotope fractionation for Cu and Zn seen here is opposite to oxygen-poor environments such as the Moon where Zn is significantly more isotopically fractionated than Cu. One possibility is that monovalent Cu diffuses faster than divalent Zn in the reduced melt and diffusion will not affect the extent of Zn isotope fractionation. These observations imply that the capability of forming a redox environment may aid in volatilizing some elements, accompanied by isotope fractionation, during the impact process. The greater extent of elemental depletion, coupled with isotope fractionation of more refractory Cu relative to Zn, may also hinge on the presence of carbonyl species of transition metals and electromagnetic charge, which could exist in the impact-induced high-velocity jet of vapor and melts.Rosso, I., Mazloff, M.R., Verdy, A., Talley, L.D., 2017. Space and time variability of the Southern Ocean carbon budget. Journal of Geophysical Research: Oceans 122, 7407-7432. upper ocean dissolved inorganic carbon (DIC) concentration is regulated by advective and diffusive transport divergence, biological processes, freshwater, and air-sea CO2 fluxes. The relative importance of these mechanisms in the Southern Ocean is uncertain, as year-round observations in this area have been limited. We use a novel physical-biogeochemical state estimate of the Southern Ocean to construct a closed DIC budget of the top 650 m and investigate the spatial and temporal variability of the different components of the carbon system. The dominant mechanisms of variability in upper ocean DIC depend on location and time and space scales considered. Advective transport is the most influential mechanism and governs the local DIC budget across the 10 day–5 year timescales analyzed. Diffusive effects are nearly negligible. The large-scale transport structure is primarily set by upwelling and downwelling, though both the lateral ageostrophic and geostrophic transports are significant. In the Antarctic Circumpolar Current, the carbon budget components are also influenced by the presence of topography and biological hot spots. In the subtropics, evaporation and air-sea CO2 flux primarily balances the sink due to biological production and advective transport. Finally, in the subpolar region sea ice processes, which change the seawater volume and thus the DIC concentration, compensate the large impact of the advective transport and modulate the timing of biological activity and air-sea CO2 flux.Round, J., Roccor, R., Li, S.-N., Eltis, L.D., 2017. A fatty acyl coenzyme A reductase promotes wax ester accumulation in Rhodococcus jostii RHA1. Applied and Environmental Microbiology 83, e00902-17.: Many rhodococci are oleaginous and, as such, have considerable potential for the sustainable production of lipid-based commodity chemicals. Herein, we demonstrated that Rhodococcus jostii RHA1, a soil bacterium that catabolizes a wide range of organic compounds, produced wax esters (WEs) up to 0.0002% of its cellular dry weight during exponential growth on glucose. These WEs were fully saturated and contained primarily 31 to 34 carbon atoms. Moreover, they were present at higher levels during exponential growth than under lipid-accumulating conditions. Bioinformatics analyses revealed that RHA1 contains a gene encoding a putative fatty acyl coenzyme A (acyl-CoA) reductase (FcrA). The purified enzyme catalyzed the NADPH-dependent transformation of stearoyl-CoA to stearyl alcohol with a specific activity of 45 ± 3 nmol/mg · min and dodecanal to dodecanol with a specific activity of 5,300 ± 300 nmol/mg · min. Deletion of fcrA did not affect WE accumulation when grown in either carbon- or nitrogen-limited medium. However, the ΔfcrA mutant accumulated less than 20% of the amount of WEs as the wild-type strain under conditions of nitric oxide stress. A strain of RHA1 overproducing FcrA accumulated WEs to ～13% cellular dry weight under lipid-accumulating conditions, and their acyl moieties had longer average chain lengths than those in wild-type cells (C17 versus C16). The results provide insight into the biosynthesis of WEs in rhodococci and facilitate the development of this genus for the production of high-value neutral lipids. Importance: Among the best-studied oleaginous bacteria, rhodococci have considerable potential for the sustainable production of lipid-based commodity chemicals, such as wax esters. However, many aspects of lipid synthesis in these bacteria are poorly understood. The current study identifies a key enzyme in wax ester synthesis in rhodococci and exploits it to significantly improve the yield of wax esters in bacteria. In so doing, this work contributes to the development of novel bioprocesses for an important class of oleochemicals that may ultimately allow us to phase out their unsustainable production from sources such as petroleum and palm oil. Ruangsomboon, S., Prachom, N., Sornchai, P., 2017. Enhanced growth and hydrocarbon production of Botryococcus braunii KMITL 2 by optimum carbon dioxide concentration and concentration-dependent effects on its biochemical composition and biodiesel properties. Bioresource Technology 244, 1358-1366. purposes of this study were to find the optimum level of supplementing CO2 for increasing the biomass and hydrocarbon production of B. braunii KMITL 2 (A race) and to determine the effects of CO2 level on CO2 fixation and biodiesel properties. The experimental results showed that the alga supplemented with 10% CO2 produced the highest biomass (1.48 ± 0.02 g L?1) and CO2 fixation rate (100.43 ± 1.42 mg L?1 d?1) that were 2.7 and 5.3 times higher than the control (0.04% CO2). The gravimetric hydrocarbon content (36.82 ± 3.39%) and hydrocarbon titer (0.35 ± 0.03 g L?1) of the alga supplemented with 5% CO2 were 1.6 and 2.7 times higher than the control. Cultivation of this strain under 5% CO2 gave the highest hydrocarbon yield and good biodiesel properties with the lowest iodine value and a higher CN value than the ASTM D6751 and EN 14214 fuel standards.Ruiter, D.J.d., Churchill, S.E., Hawks, J., Berger, L.R., 2017. Late Australopiths and the emergence of Homo. Annual Review of Anthropology 46, 99-115. fossil discoveries and new analyses increasingly blur the lines between Australopithecus and Homo, changing scientific ideas about the transition between the two genera. The concept of the genus itself remains an unsettled issue, though recent fossil discoveries and theoretical advances, alongside developments in phylogenetic reconstruction and hypothesis testing, are helping us approach a resolution. A review of the latest discoveries and research reveals that (a) despite the recent recovery of key fossil specimens, the antiquity of the genus Homo remains uncertain; (b) although there exist several australopith candidate ancestors for the genus Homo, there is little consensus about which of these, if any, represents the actual ancestor; and (c) potential convergent evolution (homoplasy) in adaptively significant features in late australopiths and basal members of the Homo clade, combined with probable reticulate evolution, makes it currently impossible to identify the direct ancestor of Homo erectus.Rummel, J.D., Conley, C.A., 2017. Four fallacies and an oversight: Searching for martian life. Astrobiology 17, 971-974. it is anticipated that future human missions to Mars will increase the amount of biological and organic contamination that might be distributed on that planet, robotic missions continue to grow in capability and complexity, requiring precautions to be taken now to protect Mars, and particularly areas of Mars that might be Special Regions. Such precautionary cleanliness requirements for spacecraft have evolved over the course of the space age, as we have learned more about planetary environments, and are the subject of regular deliberations and decisions sponsored by the Committee on Space Research (COSPAR). COSPAR's planetary protection policy is maintained as an international consensus standard for spacecraft cleanliness that is recognized by the United Nations Committee on the Peaceful Uses of Outer Space. In response to the paper presented in this issue by Fairén et al. (2017), we examine both their concept of evidence for possible life on Mars and their logic in recommending that spacecraft cleanliness requirements be relaxed to access Special Regions “before it is too late.” We find that there are shortcomings in their plans to look for evidence of life on Mars, that they do not support their contention that appropriate levels of spacecraft cleanliness are unaffordable, that there are major risks in assuming martian life could be identified by nucleic acid sequence comparison (especially if those sequences are obtained from a Special Region contaminated with Earth life), and that the authors do not justify their contention that exploration with dirty robots, now, is preferable to the possibility that later contamination will be spread by human exploration. We also note that the potential effects of contaminating resources and environments essential to future human occupants of Mars are both significant and not addressed by Fairén et al. (2017). Rushdi, A.I., Al-Shaikh, I., El-Mubarak, A.H., Alnaimi, H.A.J.A., Al-Shamary, N., Hassan, H.M., Assali, M.A., 2017. Characteristics and sources of anthropogenic and biogenic hydrocarbons in sediments from the coast of Qatar. Marine Pollution Bulletin 124, 56-66. sediment samples from the coastal zone of Qatar were collected and analyzed to determine the characteristics, and sources of anthropogenic and biogenic hydrocarbons. The main compounds in these surface sediments included n-alkanes, methyl n-alkanoates, diterpenoids, hopanes, steranes, phthalate esters, polycyclic aromatic hydrocarbons (PAHs) and unresolved complex mixture (UCM). Their total concentrations ranged from 18.7 ± 3.7–81.1 ± 7.5 ng/g (3.7 ± 0.6–10.4 ± 4.8%) for n-alkanes, 8.3 ± 2.3–51 ± 3.4 ng/g (3.0 ± 2.0–5.6 ± 2.0%) for methyl n-alkanoates, 1.8 ± 0.1–10.5 ± 1.0 ng/g (1.0 ± 0.5–0.4 ± 0.1%) for diterpenoids, 0.0–79.3 ± 7.4 ng/g (0.0–7.9 ± 0.6%) for hopanes, 0.0–32.9 ± 7.9 ng/g (0.0–6.5 ± 1.0%) for steranes, 0.7 ± 0.1–36.3 ± 3.4 ng/g (0.1 ± 0.1–1.9 ± 3.4%) for phthalates, 0.30 ± 0.2–7.8 ± 0.7 ng/g (0.02 ± 0.04–0.42 ± 0.72%) for PAHs, and 38 ± 9–609 ± 57 ng/g (38.5 ± 13.4–56.5 ± 13.4%) for UCM. The major sources of these lipids were anthropogenic petroleum residues and plasticizers (80–89%), with lesser amounts from natural higher plants and microbial residues (11–20%). Petroleum residues and plasticizer inputs to the coastal sediments of Qatar likely affect the marine ecosystems and associated species groups as well as shallow coastal nursery and spawning areas.Russell, M.J., Nitschke, W., 2017. Methane: Fuel or exhaust at the emergence of life? Astrobiology 17, 1053-1066. many of the methanogens first encountered at hydrothermal vents were thermophilic to hyperthermophilic and comprised one of the lower roots of the evolutionary tree, it has been assumed that methanogenesis was one of the earliest, if not the earliest, pathway to life. It being well known that hydrothermal springs associated with serpentinization also bore abiotic methane, it had been further assumed that emergent biochemistry merely adopted and quickened this supposed serpentinization reaction. Yet, recent hydrothermal experiments simulating serpentinization have failed to generate methane so far, thus casting doubt on this assumption. The idea that the inverse view is worthy of debate, that is, that methanotrophy was the earlier, is stymied by the “fact” that methanotrophy itself has been termed “reverse methanogenesis,” so allotting the methanogens the founding pedigree. Thus, attempting to suggest instead that methanogenesis might be termed reverse methanotrophy would require “unlearning”—a challenge to the subconscious! Here we re-examine the “impossibility” of methanotrophy predating methanogenesis as in what we have termed the “denitrifying methanotrophic acetogenic pathway.” Advantages offered by such thinking are that methane would not only be a fuel but also a ready source of reduced carbon to combine with formate or carbon monoxide—available in hydrothermal fluids—to generate acetate, a target molecule of the first autotrophs. And the nitrate/nitrite required for the putative oxidation of methane with activated NO would also be a ready source of fixed nitrogen for amination reactions. Theoretical conditions for such a putative pathway would be met in a hydrothermal green rust-bearing exhalative pile and associated chimneys subject to proton and electron counter gradients. This hypothesis could be put to test in a high-pressure hydrothermal reaction chamber in which a cool carbonate/nitrate/nitrite-bearing early acidulous ocean simulant is juxtaposed across a precipitate membrane to an alkaline solution of hydrogen and methane.Rutkowska, M., Owczarek, K., Guardia, M.d.l., P?otka-Wasylka, J., Namie?nik, J., 2017. Application of additional factors supporting the microextraction process. TrAC Trends in Analytical Chemistry 97, 104-119. to the fact that green analytical chemistry is of high importance, the past two decades have witnessed a rapid growth in the sample preparation area with special emphasis on simplification, miniaturization and automation of extraction procedures. In addition, to accelerate the extraction processes and to improve the separation of analytes, several enhanced parameters are applied. These factors include, ultrasounds, microwaves, air, electrical potential and addition of surfactants. Application of these parameters into extraction techniques such like DLLME, EME, LPME bring many advantages including higher extraction efficiency, lower LOD and LOQ parameters, reduced environmental hazards, and consumption of less extracting solvent. Therefore, such techniques like ultrasound-assisted dispersive liquid–liquid microextraction, electro-enhanced hollow fiber membrane liquid phase microextraction, vortex-assisted matrix solid–liquid dispersive microextraction and others are extensively used in analytical practice.Sabadel, A.J.M., Browning, T.J., Kruimer, D., Airs, R.L., Woodward, E.M.S., Van Hale, R., Frew, R.D., 2017. Determination of picomolar dissolved free amino acids along a South Atlantic transect using reversed-phase high-performance liquid chromatography. Marine Chemistry 196, 173-180. free amino acids (DFAA) in seawater are a form of nitrogen (N) available for marine microbes. In oligotrophic environments where N-containing nutrients are the limiting factor for microbial growth, N nutrition from DFAA could be crucial, but as yet it is poorly resolved. Measurements of individual DFAA are challenging as concentrations are typically in the low nmol L? 1 range. Here we report modifications to methodology using o-phthaldialdehyde (OPA) derivatization and reversed phase high performance liquid chromatography (HPLC) that provide a 30-fold improvement in sensitivity enabling the detection of 15 amino acids in seawater with a limit of detection as low as 10 pmol L? 1 with accuracy and precision of better than 10%. This analytical methodology is now suitable for the challenging quantitation of DFAA in oligotrophic seawaters. The method was successfully applied to a suite of seawater samples collected on a cruise crossing the South Atlantic Ocean, where concentrations of DFAAs were generally low (sub nmol L? 1), revealing basin-scale features in the oceanographic distributions of DFAA. This unique dataset implies that DFAAs are an important component of the N cycle in both near-coastal and open oceans. Further calculations suggest that the proportions of organic N originating from DFAA sources were significant, contributing between 0.2 and 200% that of NH4+ and up to 77% that of total inorganic nitrogen in the upper 400 m in some regions of the transect.Sampaio, D.S., Almeida, J.R.B., de Jesus, H.E., Rosado, A.S., Seldin, L., Jurelevicius, D., 2017. Distribution of anaerobic hydrocarbon-degrading bacteria in soils from King George Island, Maritime Antarctica. Microbial Ecology 74, 810-820. diesel fuel Arctic (DFA) degradation has already been demonstrated in Antarctic soils. However, studies comparing the distribution of anaerobic bacterial groups and of anaerobic hydrocarbon-degrading bacteria in Antarctic soils containing different concentrations of DFA are scarce. In this study, functional genes were used to study the diversity and distribution of anaerobic hydrocarbon-degrading bacteria (bamA, assA, and bssA) and of sulfate-reducing bacteria (SRB—apsR) in highly, intermediate, and non-DFA-contaminated soils collected during the summers of 2009, 2010, and 2011 from King George Island, Antarctica. Signatures of bamA genes were detected in all soils analyzed, whereas bssA and assA were found in only 4 of 10 soils. The concentration of DFA was the main factor influencing the distribution of bamA-containing bacteria and of SRB in the analyzed soils, as shown by PCR-DGGE results. bamA sequences related to genes previously described in Desulfuromonas, Lautropia, Magnetospirillum, Sulfuritalea, Rhodovolum, Rhodomicrobium, Azoarcus, Geobacter, Ramlibacter, and Gemmatimonas genera were dominant in King George Island soils. Although DFA modulated the distribution of bamA-hosting bacteria, DFA concentration was not related to bamA abundance in the soils studied here. This result suggests that King George Island soils show functional redundancy for aromatic hydrocarbon degradation. The results obtained in this study support the hypothesis that specialized anaerobic hydrocarbon-degrading bacteria have been selected by hydrocarbon concentrations present in King George Island soils.Santiago, C.J.S., Kantzas, A., 2017. Chromatographic separation and liquid drop-out in unconventional gas reservoirs. Journal of Petroleum Science and Engineering 159, 553-563. study is presented on the impact of heavier components on gas production in unconventional reservoirs. The competing effects of Knudsen and molecular diffusion are incorporated by using Maxwell-Stefan equations and the Dusty-Gas approach. The total flux of gas considers contribution of viscous flow, molecular and Knudsen diffusion, adsorption/desorption and surface diffusion. The model is used to perform numerical experiments demonstrating the effects of transport mechanisms, medium permeability and initial gas composition on production performance. We evaluate pressure decline and chromatographic separation effects in the presence of a wider range of components in flow through both adsorbing and poorly-adsorbing porous media.During gas production, the flow of different chemical species will result in chromatographic separation. Therefore, gas composition will change over time, causing shifts in the phase envelope. Depending on the degree of chromatographic separation, liquid drop-out may occur in the near-wellbore.In this study, we demonstrate that for poorly adsorbing media, the degree of chromatographic separation is small due to the balance between Knudsen and molecular diffusion fluxes. In this case, chromatographic separation is intensified with decreasing permeability, since molecular sieve mechanism becomes dominant with smaller pore sizes at lower pressures. However, when adsorption is present, species separation is more relevant, resulting in significant shifts in the phase envelope. Production behavior is affected by the higher affinity of hydrocarbon molecules with adsorption sites. As a result, condensate formation in the reservoir is likely to occur as production progresses.Many analytical/semi-analytical models available for gas transport in unconventional reservoirs are based on single component or binary mixtures. In this work, we demonstrate the effect of including heavier fractions in modelling gas transport when they are present, which is relevant in prediction of pressure decline, produced gas composition and natural gas liquids (NGLs) yields. Moreover, we demonstrate that gas composition at the wellbore can be significantly influenced by a balance between viscous and diffusion fluxes, and we highlight the relevant transport mechanisms to be considered when modelling multicomponent gas flow in tight reservoirs.Santos, F., Wagner, S., Rothstein, D., Jaffe, R., Miesel, J.R., 2017. Impact of a historical fire event on pyrogenic carbon stocks and dissolved pyrogenic carbon in spodosols in northern Michigan. Frontiers in Earth Science 5, 80. doi: 10.3389/feart.2017.00080. of fire-derived (pyrogenic) C (PyC) stocks in soils remain incomplete for many parts of the world, yet are critical to reduce uncertainties in global PyC estimates. Additionally, PyC dynamics in soils remain poorly understood. For example, dissolved PyC (DPyC) fluxes from soil horizons, as well as the influence of historical fire events on these fluxes and soil PyC stocks remain poorly quantified. In this study, we examined stock and concentration differences in soil PyC and leached DPyC, respectively, between two forest types in the Great Lakes region (USA): (1) a red pine (Pinus resinosa) forest planted after the site had experienced post-logging slash burning in the late nineteenth century (100 year-burned site), and (2) a sugar maple (Acer saccharum) forest that showed no evidence of burning in the past 250 years (unburned site). We hypothesized that the 100 year-burned site would have greater PyC stocks and concentrations of DPyC compared to the unburned site. We measured PyC in soil, as well as DPyC in soil water leaching from O and E horizons following a spring snowmelt event in both 100 year-burned and unburned sites. Additionally, we measured DPyC drained from B horizons in 100 year-burned site. In organic horizons, PyC stocks were 1.8 (Oi) and 2.3 (Oe) times greater in the 100 year-burned site than in the unburned site. Contrary to our initial hypothesis, DPyC concentrations did not differ between sites. On average, DPyC leached from all sites contributed 3.11 ± 0.27% of the total dissolved organic carbon pool. In the 100 year-burned site, a significant decline in concentrations of DPyC leaving the B horizon was attributed to the immobilization of this C pool in the Al and Fe oxides-rich subsoil. Even though PyC stock in O horizons was higher in 100 year-burned than in unburned site, our results did not support our initial hypothesis that the 100 year-burned site would have greater DPyC concentrations than the unburned site, suggesting that any differences in DPyC resulting from a single fire event are either not detectable after >100 years post-burn, and/or that the release of DPyC is a continuous, long-term process resulting from the degradation of historically accumulated PyC.Saxena, N., Hofmann, R., Alpak, F.O., Berg, S., Dietderich, J., Agarwal, U., Tandon, K., Hunter, S., Freeman, J., Wilson, O.B., 2017. References and benchmarks for pore-scale flow simulated using micro-CT images of porous media and digital rocks. Advances in Water Resources 109, 211-235. generate a novel reference dataset to quantify the impact of numerical solvers, boundary conditions, and simulation platforms. We consider a variety of microstructures ranging from idealized pipes to digital rocks. Pore throats of the digital rocks considered are large enough to be well resolved with state-of-the-art micro-computerized tomography technology. Permeability is computed using multiple numerical engines, 12 in total, including, Lattice-Boltzmann, computational fluid dynamics, voxel based, fast semi-analytical, and known empirical models. Thus, we provide a measure of uncertainty associated with flow computations of digital media. Moreover, the reference and standards dataset generated is the first of its kind and can be used to test and improve new fluid flow algorithms. We find that there is an overall good agreement between solvers for idealized cross-section shape pipes. As expected, the disagreement increases with increase in complexity of the pore space. Numerical solutions for pipes with sinusoidal variation of cross section show larger variability compared to pipes of constant cross-section shapes. We notice relatively larger variability in computed permeability of digital rocks with coefficient of variation (of up to 25%) in computed values between various solvers. Still, these differences are small given other subsurface uncertainties. The observed differences between solvers can be attributed to several causes including, differences in boundary conditions, numerical convergence criteria, and parameterization of fundamental physics equations. Solvers that perform additional meshing of irregular pore shapes require an additional step in practical workflows which involves skill and can introduce further uncertainty. Computation times for digital rocks vary from minutes to several days depending on the algorithm and available computational resources. We find that more stringent convergence criteria can improve solver accuracy but at the expense of longer computation time.Schifter, I., Sánchez-Reyna, G., González-Macías, C., Salazar-Coria, L., González-Lozano, C., 2017. Fluorescence characteristics in the deep waters of South Gulf of México. Marine Pollution Bulletin 123, 165-174. profiles of deep-water fluorescence determined by the chlorophyll sensor, polycyclic aromatic hydrocarbons, biomarkers, and other miscellaneous parameters measured in the southern Gulf of Mexico are reported. In the course of the survey, unexpected deep fluorescences were recorded (&gt; 1100 m depth) in half of the 40 stations studied, a novel finding in this area of the Gulf. Currently, the deep-water fluorescence phenomenon is not completely understood, however we observe linear correlation between the fluorescence intensity and chlorophyll-α concentrations and coincidence of higher number of hydrocarbonoclastic bacteria in samples collected precisely in the deep-water fluorescence. This information is particularly interesting in relation to the Deepwater Horizon oil spill in 2010, in view that the aftermaths of the spill can be observed till today as oil plumes trapped in deep water layers that may disturb the natural water ecosystem.Schmieder, M., Kennedy, T., Jourdan, F., Buchner, E., Reimold, W.U., 2018. A high-precision 40Ar/39Ar age for the N?rdlinger Ries impact crater, Germany, and implications for the accurate dating of terrestrial impact events. Geochimica et Cosmochimica Acta 220, 146-157. dating of specimens of moldavite, the formation of which is linked to the Ries impact in southern Germany, with a latest-generation ARGUS VI multi-collector mass spectrometer yielded three fully concordant plateau ages with a weighted mean age of 14.808 ± 0.021 Ma (± 0.038 Ma including all external uncertainties; 2σ; MSWD = 0.40, P = 0.67). This new best-estimate age for the N?rdlinger Ries is in general agreement with previous 40Ar/39Ar results for moldavites, but constitutes a significantly improved precision with respect to the formation age of the distal Ries-produced tektites. Separates of impact glass from proximal Ries ejecta (suevite glass from three different surface outcrops) and partially melted feldspar particles from impact melt rock of the SUBO 18 Enkingen drill core failed to produce meaningful ages. These glasses show evidence for excess 40Ar introduction, which may have been incurred during interaction with hydrothermal fluids. Only partially reset 40Ar/39Ar ages could be determined for the feldspathic melt separates from the Enkingen core. The new 40Ar/39Ar results for the Ries impact structure constrain the duration of crater cooling, during the prevailing hydrothermal activity, to locally at least ～60 kyr. With respect to the dating of terrestrial impact events, this paper briefly discusses a number of potential issues and effects that may be the cause for seemingly precise, but on a kyr-scale inaccurate, impact ages.Schobben, M., Stebbins, A., Algeo, T.J., Strauss, H., Leda, L., Haas, J., Struck, U., Korn, D., Korte, C., 2017. Volatile earliest Triassic sulfur cycle: A consequence of persistent low seawater sulfate concentrations and a high sulfur cycle turnover rate? Palaeogeography, Palaeoclimatology, Palaeoecology 486, 74-85. biodiversity decreases and ecosystem destruction during the end-Permian mass extinction (EPME) have been linked to widespread marine euxinic conditions. Changes in the biogeochemical sulfur cycle, microbial sulfate reduction (MSR), and marine dissolved sulfate concentrations during the Permian-Triassic transition can provide insights into the role of ocean chemistry change in the largest mass extinction in Earth history. In this study, we constrain marine dissolved sulfate concentrations using the MSR-trend method of Algeo et al. [Algeo, T.J., Luo, G.M., Song, H.Y., Lyons, T.W., Canfield, D.E., 2015. Reconstruction of secular variation in seawater sulfate concentrations. Biogeosciences 12, 2131–2151] on sulfur (S) isotope records from Iran (the Kuh-e-Ali Bashi and Zal sections) and Hungary (the Bálvány North and Bálvány East sections). This empirically derived transfer function is based on the S isotope fractionation between sulfate and sulfide associated with MSR in natural aquatic environments. This fractionation is proxied by the difference in S isotope compositions between chromium-reducible sulfur (CRS) and carbonate-associated sulfate (CAS), i.e., Δ34SCAS-CRS. We show that, despite region-specific redox conditions, Δ34SCAS-CRS exhibits a nearly invariant value of 15–16‰ in both study sections. By comparing our record with a Δ34Ssulfate-sulfide density distribution for modern marine sediments, we deduce that porewater Rayleigh distillation, carbonate diagenesis, and other effects are unlikely to have appreciably altered the S isotope offset between CRS and CAS in the study sections. In addition, differences in sedimentary regimes and organic carbon (OC) fluxes between the Iranian and Hungarian sections exclude major influence of the electron donor on MSR-S isotope fractionation and point to a more universal control, i.e., contemporaneous seawater sulfate concentration.The MSR-trend transfer function yielded estimates of seawater sulfate of 0.6–2.8 mM for the latest Permian to earliest Triassic, suggesting a balanced oceanic S-cycle with equal S inputs and outputs and no major changes in sulfate concentrations during this interval. However, a secular trend toward heavier δ34SCAS (by > 5‰) in the earliest Triassic can be explained only by increasing the turnover rate of the S-cycle (by ca. one order of magnitude) and a concomitant change in terrestrial S sources in a box model experiment. Exposure of evaporite deposits having a high δ34S may account for the source change, with a possible role for the Siberian Traps volcanism by magmatic remobilization of Cambrian rock salt. A high sulfur cycle turnover rate would have left the ocean system vulnerable to development of widespread euxinic conditions, posing a sustained threat to marine life during the Early Triassic.Schulze-Makuch, D., Airo, A., Schirmack, J., 2017. The adaptability of life on earth and the diversity of planetary habitats. Frontiers in Microbiology 8, 2011. doi: 10.3389/fmicb.2017.02011. evolutionary adaptability of life to extreme environments is astounding given that all life on Earth is based on the same fundamental biochemistry. The range of some physicochemical parameters on Earth exceeds the ability of life to adapt, but stays within the limits of life for other parameters. Certain environmental conditions such as low water availability in hyperarid deserts on Earth seem to be close to the limit of biological activity. A much wider range of environmental parameters is observed on planetary bodies within our Solar System such as Mars or Titan, and presumably even larger outside of our Solar System. Here we review the adaptability of life as we know it, especially regarding temperature, pressure, and water activity. We use then this knowledge to outline the range of possible habitable environments for alien planets and moons and distinguish between a variety of Planetary Environment Types (PETs). Some of these types are present in our Solar System, others are hypothetical. Our schematic categorization of alien habitats is limited to life as we know it, particularly regarding to the use of solvent (water) and energy source (light and chemical compounds).Sechman, H., Kotarba, M.J., Dzieniewicz, M., Romanowski, T., Fiszer, J., 2017. Evidence of methane and carbon dioxide migration to the near surface zone in the area of the abandoned coal mines in Wa?brzych District (Lower Silesian Coal Basin, SW Poland) based on periodical changes of molecular and isotopic compositions. International Journal of Coal Geology 183, 138-160. objective of this paper is to determine the reasons, origin and character of periodical changes of methane and carbon dioxide concentrations in the near-surface zone as well as emission of these gases to atmosphere after closing bituminous coal and anthracite mines in the former Wa?brzych Coal District (SW Poland). The measurements were performed during the period including the active impact of “water piston effect” on the migration of a coal-bearing gases as well as the period of stabilization of water table of the Pennsylvanian aquifer. In the years 1997–2005, 20 sampling sessions were completed during which 3210 soil gas samples were collected at a depth of about 1.2 m and along 4 measurement lines located in the Gorce and the Sobi?cin depressions. Maximum methane and carbon dioxide concentrations measured in soil gas samples reached 32.4 and 15.7 vol%, respectively. Isotopic study shows that coal-bed gases, recent microbial methane, and multigenetic carbon dioxide from degassing of ground-waters of the Upper Pennsylvanian aquifer occur within the near-surface zone of the Wa?brzych Coal District. Within the Serpukhovian Wa?brzych and Upper Bashkirian-Moscovian ?acle? coal-bearing formations three genetic types of coal-bed gases occur: Variscan thermogenic (methane, higher gaseous hydrocarbons and carbon dioxide), endogenic (abiogenic) carbon dioxide and “late” (Late Cretaceous) and recent microbial methane and carbon dioxide. Changes of mean concentrations of methane and carbon dioxide in the near-surface zone recorded during years of studies demonstrated the influence of “water piston effect”, which drives migration of coalbed gases towards the earth surface. In both the Gorce and the Sobi?cin depressions, gas migrates with various intensity. Generally, the lower methane emission measured in the years 2004–2005, and compared with the period 1999–2000, resulted from the stabilization of groundwater table whereas higher carbon dioxide emission confirms the degassing of shallow groundwaters. Anomalous concentrations of methane and carbon dioxide were related to numerous faults and fracture systems cutting the steeply dipping Upper Mississippian and Pennsylvanian coal-bearing formations, and to the outcrops of these rocks. However, in the near-surface zone, multiproportional mixing of coal-bed gases, recent microbial methane and carbon dioxide is observed. Periodical changes of stable carbon isotope composition of methane and carbon dioxide of near-surface zone in particular sessions are caused by the time-related change of location of water table of Pennsylvanian aquifer in the complicated structure of the Gorce and Sobi?cin depressions. Persistently anomalous concentrations of methane and carbon dioxide in the near surface zone, still observed after several-years-long stabilization of groundwater table, seem to indicate a continuous supply of coalbed gases to the near-surface zone through pervious dislocations. Such an interpretation is confirmed by the extreme value of methane emission detected at a particular sampling site after the cessation of the “water piston” effect. It was presumably caused by the secondary intensification of gas flux from deep sources, triggered by neotectonic movements in the study area.?en, ?., 2017. Crude oil and condensate in the Ordovician–Silurian formations of the Eastern European: The Western Black Sea Basin. Petroleum Science and Technology 35, 1437-1444. Lower Paleozoic sediments of Eastern Europe extend from Poland to the Black Sea Coasts. The Lower Ordovician Bakacak Formation and Middle Ordovician–Silurian Karadere, Ketencikdere, and F?nd?kl? formations of the Western Black Sea Basin contain mudstones and black shales with sandstone and limestone intervals. The mudstones of the Lower Ordovician do not display any potential. But some intervals of the Middle Ordovician–Silurian black shales have potential for unconventional exploration because total organic carbon (TOC) of organic matter contents ranges from 0.11% to 1.94%. Hydrogen index (HI) values of the Karadere, Ketencikdere, and F?nd?kl? formations are ranging 0–139 mg oil/g TOC. Vitrinite reflection equivalent (Roe) estimation from HI shows that the shales locate within the oil, wet gas-condensate, and dry gas zone. In-situ oil and condensate volumes of the black shales have been calculated between 0 and 2812 mg HC/g TOC. These volumes indicate presence of potentially producible hydrocarbon in the some intervals of the Middle Ordovician–Silurian shales. Mineralogical properties of the Karadere, Ketencikdere, and F?nd?kl? formations are suitable for hydraulic fracturing because the shales are dominated by quartz/carbonate. Quartz ratio ranges from 12% to 91% with an average 53%. Total calcite/dolomite content is an average of 13/0.5%. Total clay mineral chance between 0% and 39% with an average of 21%.Sengupta, S., Gorain, P.C., Pal, R., 2017. Aspects and prospects of algal carbon capture and sequestration in ecosystems: a review. Chemistry and Ecology 33, 695-707. storage of carbon dioxide (CO2) and other forms of carbon in non-atmospheric reservoirs is called carbon sequestration. Selective anthropogenic enrichment of the atmospheric carbon pool is causing dire environmental problems, thereby necessitating remediation by mitigation. Algae possess efficient carbon concentrating mechanisms and consequently high photosynthetic rates which make them suitable candidates for biosequestration of CO2. Globally, nearly half of the atmospheric oxygen is generated by algal photosynthesis despite the fact that algae account for less than 1% of photosynthetic biomass. In water bodies, algae are responsible for creating the ‘biological pump’ that transports carbon from the upper sunlit waters to the depth below. A diverse array of photoautotrophs ranging from prokaryotic cyanobacteria to eukaryotic algae such as Chlorophytes, and even protists like euglenoids, contribute to this ‘biological pump’. It operates in a variety of aquatic ecosystems ranging from small freshwater ponds to the oceans where it has been most extensively studied. Two separate but intricately linked processes constitute this ‘biological pump’, viz. the ‘organic carbon pump’ and the ‘calcium carbonate pump’. The present review discusses the natural CO2 sequestration processes carried out by algae and cyanobacteria in their native ecosystems.Shao, X., Liu, G., Yang, J., Xu, X., 2017. Research on the synthesis of ionic liquids/layered double hydroxides intercalation composites and their application on the removal of naphthenic acid from oil. Energy & Fuels 31, 10718-10726. kinds of imidazolium ionic liquids were synthesized, and [Bmim][CH3COO] was selected as a result of its higher deacidification rate at a lower cost. Then, the synthetic ionic liquid was immobilized by layered double hydroxides, and the composites were characterized by Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance (1H NMR), carbon-13 nuclear magnetic resonance (13C NMR), electrospray ionization mass spectrometry (ESI–MS), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and N2 adsorption–desorption isotherms. The results showed that [Bmim][CH3COO] synthesized by the intercalation method exhibited a better deacidification property compared to the dipping method. When [Bmim][CH3COO]/Mg0.5Ca2.5Al1 (I) synthesized by the intercalation method was used as a reagent, the deacidification rate reached 97.61%. The optimum reaction conditions were at the reagent/oil mass ratio of 0.08, the reaction temperature of 313 K, and the reaction time of 1 h. Moreover, the composites still had excellent performance on deacidification after being repeatedly used 6 times.Shao, X., Pang, X., Jiang, F., Li, L., Huyan, Y., Zheng, D., 2017. Reservoir characterization of tight sandstones using nuclear magnetic resonance and incremental pressure mercury injection experiments: Implication for tight sand gas reservoir quality. Energy & Fuels 31, 10420-10431. series of experiments including porosity and permeability measurements, thin section and scanning electron microscopy (SEM) observations, incremental pressure mercury injection (IPMI), and nuclear magnetic resonance (NMR) were conducted to systematically characterize the pore structure of tight sandstone from the Lower Shihezi Formation of Permian (P2x) in the northeastern Ordos Basin, China. The influences of pore types, pore size distribution, and fractal characteristics on reservoir quality of tight sandstones are also investigated. Results show that the studied tight sandstones generally possess poor quality and complex pore structure. The porosity and permeability range from 4.08% to 17.56% (average 9.22%) and from 0.05 to 16.66 mD (average 2.49 mD), respectively. Five pore types were observed in thin section and SEM images: primary intergranular pores, intergranular dissolution pores, intragranular dissolution pores, micropores within clay aggregates, and microfractures. The pore throats are mainly hairy/fibrous, inhibiting the connectivity between pores. Three types of pore structures were identified in the mercury-injection curves and pore size distribution curves from the IPMI experiment and in the T2 relaxation time spectrum obtained by NMR. Both experiments yielded consistent classifications, and their combination was necessary to analyze the pore structure effectively. In general, permeability and porosity are positively related and depend on pore types. Large numbers of small pores confer high storage capacity, whereas small numbers of larger pores improve the flow capability. In the high porosity–permeability zone, larger pores also determine the storage capacity. The P2x tight sandstone is fractal, and macropores are more heterogeneous while micropores are more homogeneous. The fractal dimensions of macropores are good indicators of the reservoir quality of the P2x tight sandstone as larger fractal dimension values of macropores reflect poor reservoir quality.Sheng, J.J., 2017. Critical review of field EOR projects in shale and tight reservoirs. Journal of Petroleum Science and Engineering 159, 654-665. current routine practice to produce oil in shale and tight reservoirs is the primary depletion by combining horizontal well drilling and fracturing. The technology can only produce less than 10% of shale oil, and the oil recovery in tight reservoirs is also low. There is a big prize to be claimed in terms of enhanced oil recovery (EOR) in such reservoirs. To enhance the oil recovery in these reservoirs, a few ideas have been proposed and studied in laboratory (experimental and theoretical or modeling studies). Such ideas include gas injection, water injection, and surfactant injection, especially in huff-n-puff mode. This paper briefly summarizes the research results or conclusions from the laboratory studies first, then focuses on the practices and applications in fields.Field tests of different methods are reviewed and analyzed. It is shown that water injection has been applied in large scale field projects in tight formations and proved successful in China. CO2 injection has been tested many times in small scales in China. Several gas injection and water injection have been tested in US and Canadian shale reservoirs. Detailed results of those projects have not been reported, with test benefits mixed. Although surfactants are added in fracturing fluids to improve oil recovery performance, the mechanisms are not well understood.Shi, J., Ma, Y., Li, S., Zhang, L., 2017. Characteristics of thermal bitumen structure as the pyrolysis intermediate of Longkou oil shale. Energy & Fuels 31, 10535-10544. effects of pyrolysis temperature on the structure of thermal bitumen as the pyrolysis intermediate of Longkou oil shale are investigated through electron paramagnetic resonance spectroscopy, Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, gas chromatography–mass spectrometry (GC-MS), and X-ray photoelectron spectroscopy (XPS). Results indicate that the free radical concentration of thermal bitumen increases at a maximum temperature of 410 °C and then decreases between 410 and 450 °C. Moreover, the g factors of thermal bitumen are slightly higher than 2 and decrease with increasing temperature because of the aromatization of saturates and decarboxylation. FTIR analysis indicates that decarboxylation is completed before the temperature reaches 370 °C. NMR analysis shows that aliphatic and aromatic compounds comprise more than 80% and 15–16% thermal bitumen, respectively. During pyrolysis, the fraction of aliphatic compounds, branched alkane, and the average methylene chain length decrease because of secondary cracking, and the C–C bond at the branch chain is easily cracked into gas and light oil.Shi, X., Pan, J., Hou, Q., Jin, Y., Wang, Z., Niu, Q., Li, M., 2018. Micrometer-scale fractures in coal related to coal rank based on micro-CT scanning and fractal theory. Fuel 212, 162-172. structures of coal seams are the key parameters in the context of enhanced coalbed methane (ECBM) recovery as they determine permeability and productivity. Significant progress has been made in fracture characteristics, however, the detailed structural and fractal characteristics of microfractures of different rank coals (especially high-rank coals in China) are poorly understood. This study aims to analyze the physical characteristics of microfractures with X-ray computed tomography (X-ray CT) and fractal theory, identify the effects of coal rank on the physical properties of microfractures, and discern the relationship between fractal features and permeability. The results show that the experimental coals are dominated by type B microfractures, followed by type A microfractures. Additionally, for the coals investigated in this study, the microfracture network in low-rank coals is usually well-connective, whereas the connectivity and scale of the microfracture network reduces with increasing coal rank. The average microfracture length, width and volume reduces but quantity increases as coal rank increases, and these downward trends can be divided into three stages: rapid decline stage (0.59%?<?Ro, ran?<?1.25%), slow decline stage (1.25%?<?Ro, ran?<?2.25%), and stable stage (Ro, ran?>?2.25%). The average aperture first decreases but then slightly increases with coalification. Furthermore, the fractal dimension (D) of these microfractures increases as coal rank increases in the range of 1.64–1.78, indicating that the microfracture structure gets more complicated with coalification. The CT porosity displays a ‘U-shaped’ trend as the fractal dimension increases: first decreases from 2.12% to 0.94% and then increases from 0.94% to 1.49% (turning point at D?=?1.72). These Chinese coal samples have very low to medium permeability, with highly variable values ranging from 0.004 to 1.465?mD. Coals with higher fractal dimensions are commonly less permeable for gas, and such a relationship is especially apparent for coals with higher ranks. The negative correlation between permeability and fractal dimensions means that coals with higher fractal dimensions are not favorable for CBM exploitation. Our results show that microfracture structures contribute to the permeability of coal reservoirs, and that fractal dimensions plays a significant role in assessing the exploitation potential of a coal seam.Shih, P.M., Ward, L.M., Fischer, W.W., 2017. Evolution of the 3-hydroxypropionate bicycle and recent transfer of anoxygenic photosynthesis into the Chloroflexi. Proceedings of the National Academy of Sciences 114, 10749-10754.: Photosynthesis supports life on our planet; however, we know very little about the origins of this metabolism. Anoxygenic photosynthesis existed prior to the evolution of its more complex counterpart, oxygenic photosynthesis. It is not known which groups of microbes performed anoxygenic photosynthesis on early Earth; one idea has argued that anoxygenic photosynthesis evolved in the bacterial phylum Chloroflexi. We compared the genomes of different members of the Chloroflexi, finding that acquisition of photosynthesis and their unique carbon fixation metabolism evolved remarkably late in Earth history—a time long after the rise of oxygen in the atmosphere. Abstract: Various lines of evidence from both comparative biology and the geologic record make it clear that the biochemical machinery for anoxygenic photosynthesis was present on early Earth and provided the evolutionary stock from which oxygenic photosynthesis evolved ca. 2.3 billion years ago. However, the taxonomic identity of these early anoxygenic phototrophs is uncertain, including whether or not they remain extant. Several phototrophic bacterial clades are thought to have evolved before oxygenic photosynthesis emerged, including the Chloroflexi, a phylum common across a wide range of modern environments. Although Chloroflexi have traditionally been thought to be an ancient phototrophic lineage, genomics has revealed a much greater metabolic diversity than previously appreciated. Here, using a combination of comparative genomics and molecular clock analyses, we show that phototrophic members of the Chloroflexi phylum are not particularly ancient, having evolved well after the rise of oxygen (ca. 867 million years ago), and thus cannot be progenitors of oxygenic photosynthesis. Similarly, results show that the carbon fixation pathway that defines this clade—the 3-hydroxypropionate bicycle—evolved late in Earth history as a result of a series of horizontal gene transfer events, explaining the lack of geological evidence for this pathway based on the carbon isotope record. These results demonstrate the role of horizontal gene transfer in the recent metabolic innovations expressed within this phylum, including its importance in the development of a novel carbon fixation pathway. Siahi, M., Hofmann, A., Master, S., Mueller, C.W., Gerdes, A., 2017. Carbonate ooids of the Mesoarchaean Pongola Supergroup, South Africa. Geobiology 15, 750-766. from the Mesoarchaean Chobeni Formation, Pongola Supergroup, KwaZulu-Natal, South Africa are older than any ooids reported to date. They are made of dolomite and ankerite and show concentric, radial-concentric, micritic, and radial fabrics. Radial ooids are interpreted to have originated from high-Mg-calcite and probably formed by microbial activity in a low-energy regime, while concentric ooids had an aragonite precursor and formed biotically under agitated/high-energy environmental conditions. Micritic ooids formed via the recrystallization of concentric ooids. Ooids and other allochems, such as intraclasts and peloids, contain carbonaceous matter. The close association of carbonaceous matter within ooid cortices with metabolically important elements, such as N, S and P, as identified by nano-scale secondary ion mass spectrometry analysis, allows us to propose a biologically induced origin for some ooids. By analogy with modern examples, a variety of microbial communities probably played a role in carbonate precipitation and ooid formation. Shale-normalized rare earth element (REE) distribution patterns of ooids and other allochems show positive LaSN, GdSN and YSN anomalies, superchondritic Y/Ho ratios and depleted light rare earth elements (LREEs) relative to the heavy rare earth elements (HREEs), which resemble those of seawater. These anomalies are less pronounced than expected for an open marine setting, which is interpreted as evidence for deposition in restricted shallow marine environments. Non-seawater REE patterns in recrystallized matrix and pore- and vein-filling carbonate likely reflect redistribution of rare earth elements during post-depositional alteration and/or reflect differences in the elemental and REE compositions of diagenetic fluids.Silva, B.S.d.O., Coutinho, F.H., Gregoracci, G.B., Leomil, L., de Oliveira, L.S., Fróes, A., Tschoeke, D., Soares, A.C., Cabral, A.S., Ward, N.D., Richey, J.E., Krusche, A.V., Yager, P.L., de Rezende, C.E., Thompson, C.C., Thompson, F.L., 2017. Virioplankton assemblage structure in the lower river and ocean continuum of the Amazon. mSphere 2, DOI: 10.1128/mSphere.00366-17.: The Amazon River watershed and its associated plume comprise a vast continental and oceanic area. The microbial activities along this continuum contribute substantially to global carbon and nutrient cycling, and yet there is a dearth of information on the diversity, abundance, and possible roles of viruses in this globally important river. The aim of this study was to elucidate the diversity and structure of virus assemblages of the Amazon River-ocean continuum. Environmental viral DNA sequences were obtained for 12 locations along the river’s lower reach (n = 5) and plume (n = 7). Sequence assembly yielded 29,358 scaffolds, encoding 82,546 viral proteins, with 15 new complete viral genomes. Despite the spatial connectivity mediated by the river, virome analyses and physical-chemical water parameters clearly distinguished river and plume ecosystems. Bacteriophages were ubiquitous in the continuum and were more abundant in the transition region. Eukaryotic viruses occurred mostly in the river, while the plume had more viruses of autotrophic organisms (Prochlorococcus, Synechococcus) and heterotrophic bacteria (Pelagibacter). The viral families Microviridae and Myoviridae were the most abundant and occurred throughout the continuum. The major functions of the genes in the continuum involved viral structures and life cycles, and viruses from plume locations and Tapajós River showed the highest levels of functional diversity. The distribution patterns of the viral assemblages were defined not only by the occurrence of possible hosts but also by water physical and chemical parameters, especially salinity. The findings presented here help to improve understanding of the possible roles of viruses in the organic matter cycle along the river-ocean continuum.Importance: The Amazon River forms a vast plume in the Atlantic Ocean that can extend for more than 1,000 km. Microbial communities promote a globally relevant carbon sink system in the plume. Despite the importance of viruses for the global carbon cycle, the diversity and the possible roles of viruses in the Amazon are poorly understood. The present work assesses, for the first time, the abundance and diversity of viruses simultaneously in the river and ocean in order to elucidate their possible roles. DNA sequence assembly yielded 29,358 scaffolds, encoding 82,546 viral proteins, with 15 new complete viral genomes from the 12 river and ocean locations. Viral diversity was clearly distinguished by river and ocean. Bacteriophages were the most abundant and occurred throughout the continuum. Viruses that infect eukaryotes were more abundant in the river, whereas phages appeared to have strong control over the host prokaryotic populations in the plume.Sinclair, J.A., Orton, G.S., Greathouse, T.K., Fletcher, L.N., Moses, J.I., Hue, V., Irwin, P.G.J., 2018. Jupiter’s auroral-related stratospheric heating and chemistry II: Analysis of IRTF-TEXES spectra measured in December 2014. Icarus 300, 305-326. present a retrieval analysis of TEXES (Texas Echelon Cross Echelle Spectrograph (Lacy et al., 2002)) spectra of Jupiter’s high latitudes obtained on NASA’s Infrared Telescope Facility on December 10 and 11th 2014. The vertical temperature profile and vertical profiles of C2H2, C2H4 and C2H6 were retrieved at both high-northern and high-southern latitudes and results were compared in ‘quiescent’ regions and regions known to be affected by Jupiter’s aurora in order to highlight how auroral processes modify the thermal structure and hydrocarbon chemistry of the stratosphere. In qualitative agreement with Sinclair et al. (2017a), we find temperatures in auroral regions to be elevated with respect to quiescent regions at two discrete pressures levels at approximately 1 mbar and 0.01 mbar. For example, in comparing retrieved temperatures at 70°N, 60°W (a representative quiescent region) and 70°N, 180°W (centred on the northern auroral oval), temperatures increase by 19.0 ?±? 4.2 K at 0.98 mbar, 20.8 ?±? 3.9 K at 0.01 mbar but only by 8.3 ?±? 4.9 K at the intermediate level of 0.1 mbar. We conclude that elevated temperatures at 0.01 mbar result from heating by joule resistance of the atmosphere and the energy imparted by electron and ion precipitation. However, temperatures at 1 mbar are considered to result either from heating by shortwave radiation of aurorally-produced haze particulates or precipitation of higher energy population of charged particles. Our former conclusion would be consistent with results of auroral-chemistry models, that predict the highest number densities of aurorally-produced haze particles at this pressure level (Wong et al., 2000, 2003). C2H2 and C2H4 exhibit enrichments but C2H6 remains constant within uncertainty when comparing retrieved concentrations in the northern auroral region with quiescent longitudes in the same latitude band. At 1 mbar, C2H2 increases from 278.4 ?±? 40.3 ppbv at 70°N, 60°W to 564.4 ?±? 72.0 ppbv at 70°N, 180°W and at 0.01 mbar, over the same longitude range at 70°N, C2H4 increases from 0.669 ?±? 0.129 ppmv to 6.509 ?±? 0.811 ppmv. However, we note that non-LTE (local thermodynamic equilibrium) emission may affect the cores of the strongest C2H2 and C2H4 lines on the northern auroral region, which may be a possible source of error in our derived concentrations. We retrieved concentrations of C2H6 at 1 mbar of 9.03 ?±? 0.98 ppmv at 70°N, 60°W and 7.66 ?±? 0.70 ppmv at 70°N, 180°W. Thus, C2H6’s concentration appears constant (within uncertainty) as a function of longitude at 70°N.Singh, A.K., Kumar, A., 2017. Petro-chemical characterisation and depositional paleoenvironment of lignite deposits of Nagaur, Western Rajasthan, India. Environmental Earth Sciences 76, Article 692. objective of this study was to know about the depositional environment and petrographic characteristics of lignite deposits of the Nagaur district, Rajasthan, India, and to decipher source rock potential. Lignite samples have been collected from all the working and exposed lignite seams from Matasukh lignite mines of Nagaur following the pillar sampling method. The petrographic study has been done following the International Committee for Coal and Organic Petrology and ISO norms. The study has shown that Nagaur lignites are mostly dominated by the huminite group of macerals followed by liptinite group. The huminite group is mainly represented by attrinite, textinite and ulminite, whereas liptinite is represented mainly by primary liptinites such as resinite, sporinite, suberinite and cutinite. An inertinite group of macerals occurs in the least concentration as compared to the huminite and liptinite group macerals and mainly represented by the semifusinite, funginite and inertodetrinite. In these lignites, carbonate mineral matters are dominating over the pyrite and argillaceous mineral matter. The maceral constituents present in the studied samples indicate a high proportion of type III kerogen and are capable of generating gases only. Based on the reflectance of Eu-ulminite B maceral, Nagaur lignites may be classified as ‘Low-rank B’ (lignite B). The study reveals that lignites originated in the bog forest under ombrotrophic to mesotrophic hydrological conditions. Gelification Index and the Tissue Preservation Index suggest an accumulation of peat in the marshy environment.Singh, A.K., Mallick, N., 2017. Advances in cyanobacterial polyhydroxyalkanoates production. FEMS Microbiology Letters 364, Article fnx189. (PHAs) have received much attention in the current scenario due to their attractive material properties, namely biodegradability, biocompatibility, thermoplasticity, hydrophobicity, piezoelectricity and stereospecificity. All these properties make them highly competitive for various industrial applications similar to non-degradable conventional plastics. In PHA biosynthesis, PHA synthase acts as a natural catalyst for PHA polymerization process using the (R)-hydroxyacyl-CoA as substrate. Cyanobacteria can accumulate PHAs under photoautotrophic and/or mixotrophic growth conditions with organic substrates such as acetate, glucose, propionate, valerate, and so on. The natural incidence of PHA accumulation by the cyanobacteria is known since 1966. Nevertheless, PHA accumulation in cyanobacteria based on the cell biomass and volumetric productivity is critically lower than the heterotrophic bacteria. Consequently, cyanobacteria are nowadays not considered for commercial production of PHAs. Thus, strain improvements by genetic modification, new cultivation and harvesting techniques, advanced photobioreactor development, efficient and sustainable downstream processes, alternate economical carbon sources and usage of various metabolic inhibitors are suggested for enhancing cyanobacterial PHA accumulation. In addition, identification of transcriptional regulators like RNA polymerase sigma factor (SigE) and a response regulator (Rre37) together with the recent major scientific breakthrough on the existence of complete Krebs cycle in cyanobacteria would be helpful in taking PHA production from cyanobacteria to a new-fangled height in near future.Singh, R., Guzman, M.S., Bose, A., 2017. Anaerobic oxidation of ethane, propane, and butane by marine microbes: A mini review. Frontiers in Microbiology 8, 2056. doi: 10.3389/fmicb.2017.02056. deep ocean and its sediments are a continuous source of non-methane short-chain alkanes (SCAs) including ethane, propane, and butane. Their high global warming potential, and contribution to local carbon and sulfur budgets has drawn significant scientific attention. Importantly, microbes can use gaseous alkanes and oxidize them to CO2, thus acting as effective biofilters. A relative decrease of these gases with a concomitant 13C enrichment of propane and n-butane in interstitial waters vs. the source suggests microbial anaerobic oxidation. The reported uncoupling of sulfate-reduction (SR) from anaerobic methane oxidation supports their microbial consumption. To date, strain BuS5 isolated from the sediments of Guaymas Basin, Gulf of California, is the only pure culture that can anaerobically degrade propane and n-butane. This organism belongs to a metabolically diverse cluster within the Deltaproteobacteria called Desulfosarcina/Desulfococcus. Other phylotypes involved in gaseous alkane degradation were identified based on stable-isotope labeling and fluorescence in-situ hybridization. A novel syntrophic association of the archaeal genus, Candidatus Syntrophoarchaeum, and a thermophilic SR bacterium, HotSeep-1 was recently discovered from the Guaymas basin, Gulf of California that can anaerobically oxidize n-butane. Strikingly, metagenomic data and the draft genomes of ca. Syntrophoarchaeum suggest that this organism uses a novel mechanism for n-butane oxidation, distinct from the well-established fumarate addition mechanism. These recent findings indicate that a lot remains to be understood about our understanding of anaerobic SCA degradation. This mini-review summarizes our current understanding of microbial anaerobic SCA degradation, and provides an outlook for future research.Singh, V.P., Singh, B.D., Mathews, R.P., Singh, A., Mendhe, V.A., Singh, P.K., Mishra, S., Dutta, S., Shivanna, M., Singh, M.P., 2017. Investigation on the lignite deposits of Surkha mine (Saurashtra Basin, Gujarat), western India: Their depositional history and hydrocarbon generation potential. International Journal of Coal Geology 183, 78-99. integrated approach is adopted to study the lignite deposits of Surkha mine associated with the Khadsaliya Clays Formation (Eocene) of Saurashtra Basin, western India. The compilation of detailed investigation includes organic petrographical, palynofacies and geochemical analyses. The type and amount of organic matter and its relation to palaeoenvironmental conditions have been determined and discussed along with its significance as hydrocarbon source. The macerals of huminite group show dominance (av. 61%) over the liptinite and inertinite groups. The petrographical indices (GI-TPI, GWI-VI) indicate wood dominated precursors of peat were deposited in limno-telmatic to telmatic regime under mesotrophic hydrological conditions. In palynofacies analysis, it is observed that the particulate organic matter is dominated by the phytoclasts group (av. 69%), followed by the amorphous organic matter (AOM) and palynomorphs. The biomarker signatures show angiosperm and gymnosperm source vegetation. The presence of sesquiterpenoids indicate the occurrence of Dipterocarpaceae flora suggesting the existence of rain-forest vegetation in the vicinity of depositional site. The kaurane-type of diterpenoids suggest the presence of conifers among the source flora. The extrapolation of organic matter data on Tyson's APP diagram along with the Pr/n-C17 vs. Ph/n-C18 plot indicate that the deposition took place in dysoxic-suboxic conditions with intermittent shifting of the environment in proximal settings.The huminite reflectance values (av. 0.31% Rr) show a good correlation with gross calorific values (av. 3917 cal/g) and average Tmax value (416 °C) of the lignites. Furthermore, the abundance of thermally unstable hop-17(21)-ene and ββ-hopane indicate immature stage of lignites. These lignites contain high TOC (av. 35 wt.%) and low ash yields. The volatile matter, carbon and oxygen contents are relatively high, whereas sulphur content is moderate, and hydrogen and nitrogen contents are comparatively low in all the lignite samples. The hydrogen index values vary between 53 and 538 mg HC/g TOC, the atomic values of H/C range from 0.47 to 1.04, and of O/C from 0.20 to 0.29. Overall, the lignite-bearing sequence is characterized by type II–III admixed kerogens (organic matters), and has potential to generate hydrocarbons upon maturation.Sinn, C.J.A., Klaver, J., Fink, R., Jiang, M., Schmatz, J., Littke, R., Urai, J.L., 2017. Using BIB-SEM imaging for permeability prediction in heterogeneous shales. Geofluids 2017, Article 4709064. shale samples from a lacustrine sedimentary sequence of the Newark Basin (New Jersey, USA) are investigated by combining Broad Ion Beam polishing with Scanning Electron Microscopy (BIB-SEM). We model permeability from this 2D data and compare our results with measured petrophysical properties. Three samples with total organic carbon (TOC) contents ranging from 0.7% to 2.9% and permeabilities ranging from 4 to 160?nD are selected. Pore space is imaged at high resolution (at 20,000x magnification) and segmented from representative BIB-SEM maps. Modeled permeabilities, derived using the capillary tube model (CTM) on segmented pores, range from 2.3?nD to 310?nD and are relatively close to measured intrinsic permeabilities. SEM-visible porosities range from 0.1% to 1.8% increasing with TOC, in agreement with our measurements. The CTM predicts permeability correctly within one order of magnitude. The results of this work demonstrate the potential of 2D BIB-SEM for calculating transport properties of heterogeneous shales.Smit, M.A., Mezger, K., 2017. Earth's early O2 cycle suppressed by primitive continents. Nature Geoscience 10, 788-792. oxygen began to accumulate in Earth’s surface environments between 3.0 and 2.4 billion years ago. Links between oxygenation and changes in the composition of continental crust during this time are suspected, but have been difficult to demonstrate. Here we constrain the average composition of the exposed continental crust since 3.7 billion years ago by compiling records of the Cr/U ratio of terrigenous sediments. The resulting record is consistent with a predominantly mafic crust prior to 3.0 billion years ago, followed by a 500- to 700-million-year transition to a crust of modern andesitic composition. Olivine and other Mg-rich minerals in the mafic Archaean crust formed serpentine minerals upon hydration, continuously releasing O2-scavenging agents such as dihydrogen, hydrogen sulfide and methane to the environment. Temporally, the decline in mafic crust capable of such process coincides with the first accumulation of O2 in the oceans, and subsequently the atmosphere. We therefore suggest that Earth’s early O2 cycle was ultimately limited by the composition of the exposed upper crust, and remained underdeveloped until modern andesitic continents emerged.Smith, A.J.B., Beukes, N.J., Gutzmer, J., Czaja, A.D., Johnson, C.M., Nhleko, N., 2017. Oncoidal granular iron formation in the Mesoarchaean Pongola Supergroup, southern Africa: Textural and geochemical evidence for biological activity during iron deposition. Geobiology 15, 731-749. document the discovery of the first granular iron formation (GIF) of Archaean age and present textural and geochemical results that suggest these formed through microbial iron oxidation. The GIF occurs in the Nconga Formation of the ca. 3.0–2.8 Ga Pongola Supergroup in South Africa and Swaziland. It is interbedded with oxide and silicate facies micritic iron formation (MIF). There is a strong textural control on iron mineralization in the GIF not observed in the associated MIF. The GIF is marked by oncoids with chert cores surrounded by magnetite and calcite rims. These rims show laminated domal textures, similar in appearance to microstromatolites. The GIF is enriched in silica and depleted in Fe relative to the interbedded MIF. Very low Al and trace element contents in the GIF indicate that chemically precipitated chert was reworked above wave base into granules in an environment devoid of siliciclastic input. Microbially mediated iron precipitation resulted in the formation of irregular, domal rims around the chert granules. During storm surges, oncoids were transported and deposited in deeper water environments. Textural features, along with positive δ56Fe values in magnetite, suggest that iron precipitation occurred through incomplete oxidation of hydrothermal Fe2+ by iron-oxidizing bacteria. The initial Fe3+-oxyhydroxide precipitates were then post-depositionally transformed to magnetite. Comparison of the Fe isotope compositions of the oncoidal GIF with those reported for the interbedded deeper water iron formation (IF) illustrates that the Fe2+ pathways and sources for these units were distinct. It is suggested that the deeper water IF was deposited from the evolved margin of a buoyant Fe2+aq-rich hydrothermal plume distal to its source. In contrast, oncolitic magnetite rims of chert granules were sourced from ambient Fe2+aq-depleted shallow ocean water beyond the plume.Smith, J., 2017. Measuring Earth's carbon cycle. Science 358, 186-187. of the crowning achievements of modern environmental science is the Keeling curve, the detailed time series of the concentration of atmospheric carbon dioxide (CO2) begun in 1958 that has enabled deep insights into the mechanisms of global climate change. These measurements were difficult to make for most of their 60-year history, involving the physical collection of air samples in flasks at a small number of sites scattered strategically around the globe and the subsequent analysis of their CO2 inventories in a handful of laboratories throughout the world. The Orbiting Carbon Observatory-2 (OCO-2) mission was designed to circumvent those limitations by providing a platform with which atmospheric CO2 can be measured spectrally from space over large geographic areas, thereby offering an unprecedented capability to study, in great detail, the processes that affect the concentration of the gas over a variety of spatial and temporal scales. The satellite can also measure solar-induced fluorescence, a proxy for photosynthesis, which provides valuable information about the biological processes that affect atmospheric CO2.In this issue, a collection of Research Articles presents the initial results from OCO-2, covering the detection of CO2 emissions from specific point sources; measurements of CO2 variations associated with El Ni?o, on land and at sea; and solar-induced fluorescence measurements of photosynthesis for determining gross primary production by plants. With its impressive collection of observational capabilities, OCO-2 will enable measurements of atmospheric CO2 to be made with sufficient precision, resolution, and coverage to faithfully characterize its sources and sinks globally over the seasonal cycle, a long-standing goal in atmospheric and climate science.Sommer, T., Danza, F., Berg, J., Sengupta, A., Constantinescu, G., Tokyay, T., Bürgmann, H., Dressler, Y., Sepúlveda Steiner, O., Schubert, C.J., Tonolla, M., Wüest, A., 2017. Bacteria-induced mixing in natural waters. Geophysical Research Letters 44, 9424-9432. organisms can enhance mixing in their natural environments by creating eddies in their wake and by dragging water along. However, these mixing mechanisms are inefficient for microorganisms, because swimming-induced variations in velocity, temperature, and dissolved substances are evened out before they can be advected. In bioconvection, however, microorganisms induce water movement not by propulsion directly but by locally changing the fluid density, which drives convection. Observations of bioconvection have so far mainly been limited to laboratory settings. We report the first observation and quantification of bioconvection within a stratified natural water body. Using in situ measurements, laboratory experiments, and numerical simulations, we demonstrate that the bacterium Chromatium okenii is capable of mixing 0.3 to 1.2 m thick water layers at around 12 m water depth in the Alpine Lake Cadagno (Switzerland). As many species are capable of driving bioconvection, this phenomenon potentially plays a role in species distributions and influences large-scale phenomena like algal blooms.Song, H., Song, H., Algeo, T.J., Tong, J., Romaniello, S.J., Zhu, Y., Chu, D., Gong, Y., Anbar, A.D., 2017. Uranium and carbon isotopes document global-ocean redox-productivity relationships linked to cooling during the Frasnian-Famennian mass extinction. Geology 45, 887-890. cause of the Frasnian-Famennian boundary (FFB) biotic crisis, one of the “Big Five” Phanerozoic mass extinctions, remains poorly understood. Here, we generated a high-resolution uranium-isotope profile (δ238U) for a marine carbonate section at Baisha, South China, in order to document secular variation in mean global-ocean redox conditions and to compare its relationship to coeval changes in organic carbon burial fluxes (as proxied by δ13Ccarb) and global climate conditions. δ238U varied in a coordinated, mostly positive relationship with δ13Ccarb, indicating that expanded (reduced) oceanic anoxia was linked to lower (higher) productivity. This pattern is inconsistent with productivity control of redox conditions and suggests instead that both proxies responded to a common climatic forcing. We infer that climatic cooling (and glaciation during the Upper Kellwasser Horizon [UKH] event) led to better-ventilated oceanic conditions (higher δ238U) and greater productivity (higher δ13Ccarb) owing to invigoration of global-ocean overturning circulation and enhanced upwelling. Because the UKH event coincided with the FFB mass extinction, cooling rather than oceanic anoxia may have been the main killing mechanism.Song, J., Su, X., Wang, Q., Chen, P., 2017. A new method for calculating gas content of coal reservoirs with consideration of a micro-pore overpressure environment. Natural Gas Industry B 4, 182-188. the gas content of a coal reservoir is calculated, the reservoir pressure measured by well logging and well testing is generally used for inversion calculation instead of gas pressure. However, the calculation result is not accurate because the reservoir pressure is not equal to the gas pressure in overpressure environments. In this paper, coal samples of different ranks in Shanxi and Henan are collected for testing the capillary pressure of coal pores. Based on the formation process of CBM reservoirs and the hydrocarbon generation and expulsion history of coal beds, the forming mechanisms of micro-pore overpressure environments in coal reservoirs were analyzed. Accordingly, a new method for calculating the gas content of coal reservoirs with consideration of a micro-pore overpressure environment was developed. And it was used to calculate the gas content of No. 1 coal bed of the 2nd member of Lower Permian Shanxi Fm in the Zhongmacun Coal Mine in Jiaozuo, Henan. It is indicated that during the formation and evolution of coals, some solid organic matters were converted into gas and water, and gas–water contact is surely formed in pores. In the end, capillary pressure is generated, so the gas pressure in micro-pores is much higher than the hydrostatic column pressure, which results in a micro-pore overpressure environment. Under such an environment, gas pressure is higher than reservoir pressure, so the gas content of coal reservoirs calculated previously based on the conventional reservoir pressure evaluation are usually underestimated. It is also found that the micro-pore overpressure environment exerts a dominating effect on the CBM content calculation of 3–100?nm pores, especially that of 3–10?nm pores, but a little effect on that of pores >100?nm. In conclusion, this new method clarifies the pressure environment of CBM gas reservoirs, thereby ensuring the calculation accuracy of gas content of coal reservoirs.Song, Z., Zhao, F., Sun, G., Zhu, W., 2017. Long-term dynamics of microbial communities in a high-permeable petroleum reservoir reveals the spatiotemporal relationship between community and oil recovery. Energy & Fuels 31, 10588-10597. assess the dynamics of microbial communities in a petroleum reservoir during microbial enhanced oil recovery (MEOR), injected and produced fluids from multiple wells were monitored using molecular microbial methods over 20 months. In this highly permeable (1.5–2.5 μm2) and high-temperature (65 °C) reservoir, communities contain phyla Euryarchaeota, Proteobacteria, Deferribacteres, and Firmicutes, which may be collected by flooding fluids from different habitats through strata. Since the oil-rich areas in the flooded reservoir generally gather around oil wells with high temperatures and strictly anaerobic conditions, the dominance of thermophilic and anaerobic microorganisms, which are capable of inhabiting oil-rich areas, is consistent with positive oil-output responses (temporarily enhanced by 5 × 103 kg per day). During later periods, the communities were dominated by Enterobacter without high-temperature adaptability, which corresponds to a considerable decline in oil-output. Meanwhile, an abnormal increase of community similarity, acetate, and cell concentrations in produced fluids simultaneously indicated a severe enhancement of reservoir permeability along the flooding route, which reveals the direct reason for the community shift and the oil output decline. Therefore, an understanding of the long-term dynamics of reservoir communities is essential for distinguishing functional species and to establish a reservoir-scale connection between microbiology and porous flow.Stanton, M.M., Park, B.-W., Vilela, D., Bente, K., Faivre, D., Sitti, M., Sánchez, S., 2017. Magnetotactic bacteria powered biohybrids target E. coli biofilms. ACS Nano 11, 9968-9978. colonies are typically resistant to general antibiotic treatment and require targeted methods for their removal. One of these methods includes the use of nanoparticles as carriers for antibiotic delivery, where they randomly circulate in fluid until they make contact with the infected areas. However, the required proximity of the particles to the biofilm results in only moderate efficacy. We demonstrate here that the nonpathogenic magnetotactic bacteria Magnetosopirrillum gryphiswalense (MSR-1) can be integrated with drug-loaded mesoporous silica microtubes to build controllable microswimmers (biohybrids) capable of antibiotic delivery to target an infectious biofilm. Applying external magnetic guidance capability and swimming power of the MSR-1 cells, the biohybrids are directed to and forcefully pushed into matured Escherichia coli (E. coli) biofilms. Release of the antibiotic, ciprofloxacin, is triggered by the acidic microenvironment of the biofilm, ensuring an efficient drug delivery system. The results reveal the capabilities of a nonpathogenic bacteria species to target and dismantle harmful biofilms, indicating biohybrid systems have great potential for antibiofilm applications.Sta?, M., Chudoba, J., Kubi?ka, D., Bla?ek, J., Pospí?il, M., 2017. Petroleomic characterization of pyrolysis bio-oils: A review. Energy & Fuels 31, 10283-10299. bio-oils could be used in the future as biofuels or as a source of valuable oxygen-containing chemicals. To facilitate efficient exploitation of bio-oils, a detailed understanding of their structure is necessary. Over the past decade, petroleomic analysis has been widely applied to characterize pyrolysis bio-oils from the lignocellulosic biomass. Typically, a petroleomic analysis has been performed using high-resolution mass spectrometry (HRMS). HRMS has enabled the researchers to determine the molecular weights and molecular formulas of thousands of less volatile and nonvolatile, high-molecular-weight bio-oil compounds to obtain structural information that cannot be obtained using any other method. Here, we discuss the theoretical principles of HRMS and present an overview of the investigations regarding the petroleomic characterization of pyrolysis bio-oils and their key findings. In addition, this review outlines the current knowledge of the structure of bio-oil compounds detectable by HRMS. This could help us to understand the chemical composition of bio-oils in more detail and facilitate the design of processes for bio-oil upgrading and further utilization.Steiger, M.G., Mattanovich, D., Sauer, M., 2017. Microbial organic acid production as carbon dioxide sink. FEMS Microbiology Letters 364, Article fnx212. conversions are an under-regarded option to fix carbon dioxide in significant amounts. In such a conversion, carbon dioxide together with one other carbon source such as glucose is converted to a single carbon product. With mixed-substrate conversions, it is possible to incorporate carbon dioxide into products with higher oxidation states than the co-substrate. Using abundant co-substrates such as glucose, glycerol or methanol, it is possible to produce organic acids anaerobically, using CO2 both as an electron acceptor and as an additional carbon source. Here, we outline the thermodynamic feasibility to produce industrially important organic acids with this approach to provide guidance for future metabolic engineering endeavours.Sternai, P., Caricchi, L., Garcia-Castellanos, D., Jolivet, L., Sheldrake, T.E., Castelltort, S., 2017. Magmatic pulse driven by sea-level changes associated with the Messinian salinity crisis. Nature Geoscience 10, 783-787. 5 and 6 million years ago, during the so-called Messinian salinity crisis, the Mediterranean basin became a giant salt repository. The possibility of abrupt and kilometre-scale sea-level changes during this extreme event is debated. Messinian evaporites could signify either deep- or shallow-marine deposits, and ubiquitous erosional surfaces could indicate either subaerial or submarine features. Significant and fast reductions in sea level unload the lithosphere, which can increase the production and eruption of magma. Here we calculate variations in surface load associated with the Messinian salinity crisis and compile the available time constraints for pan-Mediterranean magmatism. We show that scenarios involving a kilometre-scale drawdown of sea level imply a phase of net overall lithospheric unloading at a time that appears synchronous with a magmatic pulse from the pan-Mediterranean igneous provinces. We verify the viability of a mechanistic link between unloading and magmatism using numerical modelling of decompression partial mantle melting and dyke formation in response to surface load variations. We conclude that the Mediterranean magmatic record provides an independent validation of the controversial kilometre-scale evaporative drawdown and sheds new light on the sensitivity of magmatic systems to the surface forcing.Str??t, K.D., M?rth, C.-M., Undeman, E., 2018. Future export of particulate and dissolved organic carbon from land to coastal zones of the Baltic Sea. Journal of Marine Systems 177, 8-20. Baltic Sea is a semi-enclosed brackish sea in Northern Europe with a drainage basin four times larger than the sea itself. Riverine organic carbon (Particulate Organic Carbon, POC and Dissolved Organic Carbon, DOC) dominates carbon input to the Baltic Sea and influences both land-to-sea transport of nutrients and contaminants, and hence the functioning of the coastal ecosystem. The potential impact of future climate change on loads of POC and DOC in the Baltic Sea drainage basin (BSDB) was assessed using a hydrological-biogeochemical model (CSIM). The changes in annual and seasonal concentrations and loads of both POC and DOC by the end of this century were predicted using three climate change scenarios and compared to the current state. In all scenarios, overall increasing DOC loads, but unchanged POC loads, were projected in the north. In the southern part of the BSDB, predicted DOC loads were not significantly changing over time, although POC loads decreased in all scenarios. The magnitude and significance of the trends varied with scenario but the sign (+ or ?) of the projected trends for the entire simulation period never conflicted. Results were discussed in detail for the “middle” CO2 emission scenario (business as usual, a1b). On an annual and entire drainage basin scale, the total POC load was projected to decrease by ca 7% under this scenario, mainly due to reduced riverine primary production in the southern parts of the BSDB. The average total DOC load was not predicted to change significantly between years 2010 and 2100 due to counteracting decreasing and increasing trends of DOC loads to the six major sub-basins in the Baltic Sea. However, predicted seasonal total loads of POC and DOC increased significantly by ca 46% and 30% in winter and decreased by 8% and 21% in summer over time, respectively. For POC the change in winter loads was a consequence of increasing and a shift in duration of snowfall and onset of the spring flood impacting the input of terrestrial litter, while reduced primary production mainly explained the differences predicted in summer. The simulations also showed that future changes in POC and DOC export can vary significantly across the different sub-basins of the Baltic Sea. These changes in organic carbon input may impact future coastal food web structures e.g. by influencing bacterial and phytoplankton production in coastal zones, which in turn may have consequences at higher trophic levels.Striolo, A., Cole, D.R., 2017. Understanding shale gas: Recent progress and remaining challenges. Energy & Fuels 31, 10300-10310. of a number of technological advancements, unconventional hydrocarbons, and in particular shale gas, have transformed the US economy. Much is being learned, as demonstrated by the reduced cost of extracting shale gas in the US over the past five years. However, a number of challenges still need to be addressed. Many of these challenges represent grand scientific and technological tasks, overcoming which will have a number of positive impacts, ranging from the reduction of the environmental footprint of shale gas production to improvements and leaps forward in diverse sectors, including chemical manufacturing and catalytic transformations. This review addresses recent advancements in computational and experimental approaches, which led to improved understanding of, in particular, structure and transport of fluids, including hydrocarbons, electrolytes, water, and CO2 in heterogeneous subsurface rocks such as those typically found in shale formations. The narrative is concluded with a suggestion of a few research directions that, by synergistically combining computational and experimental advances, could allow us to overcome some of the hurdles that currently hinder the production of hydrocarbons from shale formations.Stüeken, E.E., Buick, R., Anderson, R.E., Baross, J.A., Planavsky, N.J., Lyons, T.W., 2017. Environmental niches and metabolic diversity in Neoarchean lakes. Geobiology 15, 767-783. diversification of macro-organisms over the last 500 million years often coincided with the development of new environmental niches. Microbial diversification over the last 4 billion years likely followed similar patterns. However, linkages between environmental settings and microbial ecology have so far not been described from the ancient rock record. In this study, we investigated carbon, nitrogen, and molybdenum isotopes, and iron speciation in five non-marine stratigraphic units of the Neoarchean Fortescue Group, Western Australia, that are similar in age (2.78–2.72 Ga) but differ in their hydro-geologic setting. Our data suggest that the felsic-dominated and hydrologically open lakes of the Bellary and Hardey formations were probably dominated by methanogenesis (δ13Corg = ?38.7 ± 4.2‰) and biologic N2 fixation (δ15Nbulk =?0.6 ± 1.0‰), whereas the Mt. Roe, Tumbiana and Kylena Formations, with more mafic siliciclastic sediments, preserve evidence of methanotrophy (δ13Corg as low as ?57.4‰, δ13Ccarb as low as ?9.2‰) and NH3 loss under alkaline conditions. Evidence of oxygenic photosynthesis is recorded only in the closed evaporitic Tumbiana lakes marked by abundant stromatolites, limited evidence of Fe and S cycling, fractionated Mo isotopes (δ98/95Mo = +0.4 ± 0.4‰), and the widest range in δ13Corg (?57‰ to ?15‰), suggesting oxidative processes and multiple carbon fixation pathways. Methanotrophy in the three mafic settings was probably coupled to a combination of oxidants, including O2 and SO42-. Overall, our results may indicate that early microbial evolution on the Precambrian Earth was in part influenced by geological parameters. We speculate that expanding habitats, such as those linked to continental growth, may have been an important factor in the evolution of life.Stukel, M.R., Ducklow, H.W., 2017. Stirring up the biological pump: Vertical mixing and carbon export in the Southern Ocean. Global Biogeochemical Cycles 31, 1420-1434. biological carbon pump (BCP) transports organic carbon from the surface to the ocean's interior via sinking particles, vertically migrating organisms, and passive transport of organic matter by advection and diffusion. While many studies have quantified sinking particles, the magnitude of passive transport remains poorly constrained. In the Southern Ocean weak thermal stratification, strong vertical gradients in particulate organic matter, and weak vertical nitrate gradients suggest that passive transport from the euphotic zone may be particularly important. We compile data from seasonal time series at a coastal site near Palmer Station, annual regional cruises in the Western Antarctic Peninsula (WAP), cruises throughout the broader Southern Ocean, and SOCCOM (Southern Ocean Carbon and Climate Observations and Modeling) autonomous profiling floats to estimate spatial and temporal patterns in vertical gradients of nitrate, particulate nitrogen (PN), and dissolved organic carbon. Under a steady state approximation, the ratio of ?PN/?z to ?NO3?/?z suggests that passive transport of PN may be responsible for removing 46% (37%–58%) of the nitrate introduced into the surface ocean of the WAP (with dissolved organic matter contributing an additional 3–6%) and for 23% (19%–28%) of the BCP in the broader Southern Ocean. A simple model parameterized with in situ nitrate, PN, and primary production data suggested that passive transport was responsible for 54% of the magnitude of the BCP in the WAP. Our results highlight the potential importance of passive transport (by advection and diffusion) of organic matter in the Southern Ocean but should only be considered indicative of high passive transport (rather than conclusive evidence) due to our steady state assumptions.Sultana, C.M., Al-Mashat, H., Prather, K.A., 2017. Expanding single particle mass spectrometer analyses for the identification of microbe signatures in sea spray aerosol. Analytical Chemistry 89, 10162-10170. microbes in sea spray aersosol (SSA) have the potential to influence climate and weather by acting as ice nucleating particles in clouds. Single particle mass spectrometers (SPMSs), which generate in situ single particle composition data, are excellent tools for characterizing aerosols under changing environmental conditions as they can provide high temporal resolution and require no sample preparation. While SPMSs have proven capable of detecting microbes, these instruments have never been utilized to definitively identify aerosolized microbes in ambient sea spray aersosol. In this study, an aerosol time-of-flight mass spectrometer was used to analyze laboratory generated SSA produced from natural seawater in a marine aerosol reference tank. We present the first description of a population of biological SSA mass spectra (BioSS), which closely match the ion signatures observed in previous terrestrial microbe studies. The fraction of BioSS dramatically increased in the largest supermicron particles, consistent with field and laboratory measurements of microbes ejected by bubble bursting, further supporting the assignment of BioSS mass spectra as microbes. Finally, as supported by analysis of inorganic ion signals, we propose that dry BioSS particles have heterogeneous structures, with microbes adhered to sodium chloride nodules surrounded by magnesium-enriched coatings. Consistent with this structure, chlorine-containing ion markers were ubiquitous in BioSS spectra and identified as possible tracers for distinguishing recently aerosolized marine from terrestrial microbes.Sun, J., Liu, W., Liu, Z., Deng, T., Windley, B.F., Fu, B., 2017. Extreme aridification since the beginning of the Pliocene in the Tarim Basin, western China. Palaeogeography, Palaeoclimatology, Palaeoecology 485, 189-200. Central Asia is characterized by an extreme arid landscape. Among the Central Asian deserts, the Taklimakan Desert is the largest shifting sand desert which is located in the rain shadow of the Tibetan Plateau and of the other central Asian high mountains. The formation of this desert is important for placing widespread aridification into a regional tectonic context at the western end of the Himalayan-Tibetan orogen. However, there still exists considerable controversy regarding the timing of desert formation, thus impeding our understanding of the climatic effects of the Tibetan uplift and regional environmental changes. Here we report new biostratigraphic age control and multiple high-resolution climatic records from the center of the Taklimakan Desert. Our results reveal dramatic environmental changes at ~5Ma, suggesting that an extremely dry climate has prevailed since the beginning of the Pliocene, which is consistent with findings from a high-resolution borehole record about 670km to the east in the same basin. The two records combined demonstrate that an extremely dry environment prevailed in the entire Tarim Basin from approximately 5Ma. This was related to the reduced transport of water vapor by westerlies in response to the retreat of the Paratethys Ocean driven by global climatic cooling, and the closed oceanic water-vapor pathway between the Pamir and the Tian Shan ranges driven by the ongoing India-Eurasia collision.Sun, J., Pan, L., Tsang, D.C.W., Zhan, Y., Zhu, L., Li, X., 2018. Organic contamination and remediation in the agricultural soils of China: A critical review. Science of The Total Environment 615, 724-740. pollution is a global problem in both developed and developing countries. Countries with rapidly developing economies such as China are faced with significant soil pollution problems due to accelerated industrialization and urbanization over the last decades. This paper provides an overview of published scientific data on soil pollution across China with particular focus on organic contamination in agricultural soils. Based on the related peer-reviewed papers published since 2000 (n = 203), we evaluated the priority organic contaminants across China, revealed their spatial and temporal distributions at the national scale, identified their possible sources and fates in soil, assessed their potential environmental risks, and presented the challenges in current remediation technologies regarding the combined organic pollution of agricultural soils. The primary pollutants in Northeast China were polycyclic aromatic hydrocarbons (PAHs) due to intensive fossil fuel combustion. The concentrations of organochlorine pesticides (OCPs) and phthalic acid esters (PAEs) were higher in North and Central China owing to concentrated agricultural activities. The levels of polychlorinated biphenyls (PCBs) were higher in East and South China primarily because of past industrial operations and improper electronic waste processing. The co-existence of organic contaminants was severe in the Yangtze River Delta, Pearl River Delta, and Beijing-Tianjin-Hebei Region, which are the most populated and industrialized regions in China. Integrated biological-chemical remediation technologies, such as surfactant-enhanced bioremediation, have potential uses in the remediation of soil contaminated by multiple contaminants. This critical review highlighted several future research directions including combined pollution, interfacial interactions, food safety, bioavailability, ecological effects, and integrated remediation methods for combined organic pollution in soil.Sun, Z., Wang, Y., Wei, Z., Zhang, M., Wang, G., Wang, Z., 2017. Characteristics and origin of desorption gas of the Permian Shanxi Formation shale in the Ordos Basin, China. Energy Exploration & Exploitation 35, 792-806. Lower Permian Shanxi Formation marine–continental transitional organic-rich shale is one of the most important potential shale gas plays in the Ordos Basin, China. However, the content and origin of desorbed gas from the Shanxi Formation are poorly documented, limiting the understanding of gas generation and potential play elements. Geochemical characteristics of desorbed gas, including content and origin, are analyzed from 17 core samples of the Shanxi Formation from well SL-1. The results show that the Shanxi Formation shales in the study area are characterized by high total organic carbon content of 1.17–2.63%, type III organic matter, and high Tmax between 493 and 513℃. The desorbed gas content of the shale samples varies from 0.22 to 0.50?m3/t, with an average of 0.37?m3/t, and shows a positive correlation with total organic carbon. The gases are dominated by methane (69.57–89.02%), with small amounts of ethane (0.01–0.09%). The carbon isotopic signature δ13C1 ranges from ?49.5 to ?45.3‰, and the δ13C2 ranges from ?23.3 to ?14.7‰. In addition, gases released from the Shanxi Formation core samples are thermogenic in origin and possibly coal derived, as the Whiticar chart and the diagram of ethane versus δ13C2 suggest.Sundman, A., Byrne, J.M., Bauer, I., Menguy, N., Kappler, A., 2017. Interactions between magnetite and humic substances: redox reactions and dissolution processes. Geochemical Transactions 18, Article 6 substances (HS) are redox-active compounds that are ubiquitous in the environment and can serve as electron shuttles during microbial Fe(III) reduction thus reducing a variety of Fe(III) minerals. However, not much is known about redox reactions between HS and the mixed-valent mineral magnetite (Fe3O4) that can potentially lead to changes in Fe(II)/Fe(III) stoichiometry and even dissolve the magnetite. To address this knowledge gap, we incubated non-reduced (native) and reduced HS with four types of magnetite that varied in particle size and solid-phase Fe(II)/Fe(III) stoichiometry. We followed dissolved and solid-phase Fe(II) and Fe(III) concentrations over time to quantify redox reactions between HS and magnetite. Magnetite redox reactions and dissolution processes with HS varied depending on the initial magnetite and HS properties. The interaction between biogenic magnetite and reduced HS resulted in dissolution of the solid magnetite mineral, as well as an overall reduction of the magnetite. In contrast, a slight oxidation and no dissolution was observed when native and reduced HS interacted with 500 nm magnetite. This variability in the solubility and electron accepting and donating capacity of the different types of magnetite is likely an effect of differences in their reduction potential that is correlated to the magnetite Fe(II)/Fe(III) stoichiometry, particle size, and crystallinity. Our study suggests that redox-active HS play an important role for Fe redox speciation within minerals such as magnetite and thereby influence the reactivity of these Fe minerals and their role in biogeochemical Fe cycling. Furthermore, such processes are also likely to have an effect on the fate of other elements bound to the surface of Fe minerals.Suzuki, S., Ishii, S.i., Hoshino, T., Rietze, A., Tenney, A., Morrill, P.L., Inagaki, F., Kuenen, J.G., Nealson, K.H., 2017. Unusual metabolic diversity of hyperalkaliphilic microbial communities associated with subterranean serpentinization at The Cedars. ISME Journal 11, 2584-2598. from The Cedars springs that discharge from serpentinized ultramafic rocks feature highly basic (pH=~12), highly reducing (Eh<?550?mV) conditions with low ionic concentrations. These conditions make the springs exceptionally challenging for life. Here, we report the metagenomic data and recovered draft genomes from two different springs, GPS1 and BS5. GPS1, which was fed solely by a deep groundwater source within the serpentinizing system, was dominated by several bacterial taxa from the phyla OD1 (‘Parcubacteria’) and Chloroflexi. Members of the GPS1 community had, for the most part, the smallest genomes reported for their respective taxa, and encoded only archaeal (A-type) ATP synthases or no ATP synthases at all. Furthermore, none of the members encoded respiration-related genes and some of the members also did not encode key biosynthesis-related genes. In contrast, BS5, fed by shallow water, appears to have a community driven by hydrogen metabolism and was dominated by a diverse group of Proteobacteria similar to those seen in many terrestrial serpentinization sites. Our findings indicated that the harsh ultrabasic geological setting supported unexpectedly diverse microbial metabolic strategies and that the deep-water-fed springs supported a community that was remarkable in its unusual metagenomic and genomic constitution.Ta, K., Peng, X., Chen, S., Xu, H., Li, J., Du, M., Hao, J., Lin, Y., 2017. Hydrothermal nontronite formation associated with microbes from low-temperature diffuse hydrothermal vents at the South Mid-Atlantic Ridge. Journal of Geophysical Research: Biogeosciences 122, 2375-2392. nontronite deposits have been identified to be closely related to low-temperature hydrothermal activities. However, their formation mechanisms associated with microbes in diffuse hydrothermal vents still remain largely unknown. The friable deposits, collected from the low-temperature diffuse flow at the Southern Atlantic Ridge, display a layered structure. Scanning electron microscope and transmission electron microscope analyses reveal that abundant filamentous, spherical, and rod-shaped mineralized forms are preserved in the yellowish-green layer of the deposits. These mineralized forms primarily consist of Si and Fe. Selected area electron diffraction patterns of the mineralized forms indicate that they are composed of nontronite. High intensities of 12C and 12C14N signals derived from cellular structures determined by nanosecondary ion mass spectrometry suggest the intimate relationship between nontronite and microbes. The results of 454 pyrosequencing analyses provide insights into the microbial communities involved in the biologically induced mineralization in the yellowish-green layer. We propose an evolutionary model for establishing paragenetic sequences among nontronite, Mn oxide, and Fe oxyhydroxide in the deposits. This paragenetic sequence could be widespread in modern and ancient low-temperature hydrothermal fields.Taheri, A., Lindeberg, E., Tors?ter, O., Wessel-Berg, D., 2017. Qualitative and quantitative experimental study of convective mixing process during storage of CO2 in homogeneous saline aquifers. International Journal of Greenhouse Gas Control 66, 159-176. storage of CO2 in deep formations like saline aquifers is being actively considered in order to support the reduction of greenhouse gas emissions. It has been observed that dissolution of CO2 into brine causes an increased density in the mixture and if the corresponding Rayleigh number of the porous medium is high enough to initiate convection flows, then density-driven natural convection occurs and the rate of dissolution increases. As such, an increased contribution by the dissolution mechanism for trapping of CO2 decreases the risk of leakage.However, despite the recognized importance of convective dissolution in geological CO2 storage, there is insufficient experimental data available for studying the accelerated mass transfer rate of CO2 into saline aquifers. In this paper, we focus on performing a series of novel experiments about the density-driven natural convection mechanism in a precise experimental set-up with homogeneous Hele-Shaw cell geometries and by using CO2 and water. Our new approach and procedure for performing the experiments give us an opportunity to have both qualitative (images and video) and quantitative (amount of dissolved CO2 into water) data at the same time. This study examines onset time for convection, critical wavelength of convection fingers and dissolution flux of CO2 into water as objective parameters. The growth and progress of convection fingers after onset time for convection and the effect of model properties on the behavior of the convective mixing process are presented and discussed. Moreover, there are some speeded-up videos from the experiments that are suitable for improving public awareness of the problem facing society. Based on the performed experiments, the calculated dimensionless onset times for convection are 194.90 and 227.80 from quantitative and qualitative measurements respectively and the calculated critical wavelength of convection fingers is 2π/0.0524. Additionally, the dissolution flux of CO2 into water after onset time for convection is related linearly to Δρ·g·cos(θ)·k·C0/μ by a prefactor of 0.021. These results are comparable with the available theoretical and numerical works in the literature. Comparison of the results of the experimental models and their equivalent numerical models shows that while the numerical models are good tools for prediction of growth mechanism, shapes and positions of convection fingers, their effectiveness in the prediction of the onset times for convection and the dissolution fluxes is uncertain.Tamazawa, S., Mayumi, D., Mochimaru, H., Sakata, S., Maeda, H., Wakayama, T., Ikarashi, M., Kamagata, Y., Tamaki, H., 2017. Petrothermobacter organivorans gen. nov., sp. nov., a thermophilic, strictly anaerobic bacterium of the phylum Deferribacteres isolated from a deep subsurface oil reservoir. International Journal of Systematic and Evolutionary Microbiology 67, 3982-3986. novel thermophilic, anaerobic, chemoheterotrophic, acetate-oxidizing and iron(III)-, manganese(IV)-, nitrate- and sulfate-reducing bacterium, designated strain ANAT, was isolated from a deep subsurface oil field in Japan (Yabase oil field, Akita Pref.). Cells of strain ANAT were Gram-stain-negative, non-motile, non-spore forming and slightly curved or twisted rods (1.5–5.0??m long and 0.6–0.7??m wide). The isolate grew at 25–60?°C (optimum 55?°C) and pH 6.0–8.0 (optimum pH 7.0). The isolate was capable of reducing iron(III), manganese(IV), nitrate and sulfate as an electron acceptor. The isolate utilized a limited range of electron donors such as acetate, lactate, pyruvate and yeast extract for iron reduction. Strain ANAT also used pyruvate, fumarate, succinate, malate, yeast extract and peptone for fermentative growth. The major respiratory quinones were menaquinone-7(H8) and menaquinone-8. The strain contained C18?:?0, iso-C18?:?0 and C16?:?0 as the major cellular fatty acids. The G+C?content of the genomic DNA was 34.3?mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain ANAT was closely related to Calditerrivibrio nitroreducens in the phylum Deferribacteres with low sequence similarities (89.5?%), and formed a distinct clade within the family Deferribacteraceae. In addition, the isolate is the first sulfate-reducing member of the phylum Deferribacteres. Based on phenotypic, chemotaxonomic and phylogenetic properties, a novel genus and species, Petrothermobacter organivorans gen. nov., sp. nov., is proposed for the isolate (type strain=ANAT=?NBRC 112621T=DSM 105015T). The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain ANAT is LC155975.Tang, Q., Hughes, N.C., McKenzie, N.R., Myrow, P.M., Xiao, S., 2017. Late Mesoproterozoic – early Neoproterozoic organic-walled microfossils from the Madhubani Group of the Ganga Valley, northern India. Palaeontology 60, 869-891. age of the sedimentary basement of the Ganga Valley in northern India, which is represented by the entirely subsurface Ganga Supergroup, is key for addressing issues related to the tectonic history of the Himalaya. However, the stratigraphic correlations between the Ganga Supergroup in the Ganga Valley, the Vindhyan Supergroup in cratonic India to the south, and Proterozoic successions in the Lesser Himalaya to the north have long been a matter of controversy. This is largely because of the poor age constraint of the Madhubani Group of the upper Ganga Supergroup, which has been variously interpreted as Proterozoic, lower Palaeozoic, or even Mesozoic. To address this issue, we used a low manipulation maceration technique to extract organic-walled microfossils from the Ujhani and Tilhar formations of the lower Madhubani Group. Our study recovered a total of 24 taxa, including Devisphaera corallis gen. et sp. nov. The co-occurrence of Trachyhystrichosphaera aimika, Caudosphaera expansa and Annulusia annulata in the lower Madhubani Group indicates a late Mesoproterozoic to early Neoproterozoic age. Thus, the biostratigraphical data suggest a >300 myr depositional gap between the Madhubani Group and the immediately underlying Bahraich Group, which has been independently constrained to be upper Palaeoproterozoic to lower Mesoproterozoic in age. Therefore, the first-order stratigraphic architecture, with a Palaeoproterozoic–Mesoproterozoic succession unconformably overlain by a Mesoproterozoic–Neoproterozoic succession, is closely similar throughout the Vindhyan Basin, Ganga Valley and Lesser Himalaya, suggesting a shared sedimentary and tectonic history among them.Tang, S., Tang, D., Tang, J., Tao, S., Xu, H., Geng, Y., 2017. Controlling factors of coalbed methane well productivity of multiple superposed coalbed methane systems: A case study on the Songhe mine field, Guizhou, China. Energy Exploration & Exploitation 35, 665-684. Songhe mine field located in western Guizhou Province of China is the most typical region of multiple coal seam development. However, the coalbed methane development practices of commingled drainage in recent years have been proved to be less ideal. In this work, on the basis of dividing gas system, the correlations between geological and engineering factors and gas production data were studied to determine the controlling factors of coalbed methane well productivity. The results indicated that the gas production had a positive correlation with cumulative thickness and gas content of fractured coal seams overall. However, the large cumulative thickness is generally resulted from the increase of coal seam number, and thus increases the reservoir heterogeneity and interlayer difference. The coalbed methane well productivity performance for this type region was a result of the strong interaction of cumulative thickness, burial depth, gas content, permeability, and reservoir pressure of fractured coal seam. However, the interlayer interference was the most direct factors restricting the productivity of commingle drainage by affecting the speed of dewatering and lowering of pressure and gas desorption time of gas-bearing systems. Additionally, the correlations between gas production and interlayer difference and interference were quantitatively analyzed, and the results showed that the wells with large interlayer difference and interference tend to have a poor productivity performance. As a result, the drainage method was particularly an important factor controlling the well productivity for multiple coalbed methane systems, because a proper combination of gas-bearing system and drainage and dewatering sequence are the keys to decrease the interlayer interference. Finally, the commingled drainage in this field was suggested to be conducted in steps according to the reservoir pressure, critical desorption pressure, and gas production pressure of each coalbed methane system.Tang, X.-d., Liang, G.-j., Li, J.-j., Wei, Y.-t., Dang, T., 2017. Catalytic effect of in-situ preparation of copper oxide nanoparticles on the heavy oil low-temperature oxidation process in air injection recovery. Petroleum Science and Technology 35, 1321-1326. situ prepared hydrophobic CuO nanoparticles, about 84.3?nm in mean diameter, was synthesized and used to catalyze heavy oil low-temperature oxidation (LTO) reaction. Experimental results showed the average oxygen consumption rate with CuO nanoparticles addition increased by 1.4?times, and the residue oxygen content in tail gas in autoclave was decreased from 8.76% to 3.9% compared to the blank experiment (without CuO nanoparticles). In addition, the CuO nanoparticles could facilitate the cleavage reaction during LTO. This study can provide guidelines to improve effectively the safety of air flooding technology in the heavy oil.Tang, X., Ripepi, N., Luxbacher, K., Pitcher, E., 2017. Adsorption models for methane in shales: Review, comparison, and application. Energy & Fuels 31, 10787-10801. an optimized adsorption model to estimate the true adsorbed quantity of methane in shale at reservoir conditions is fundamental for estimating the gas-in-place (GIP), and developing an accurate shale gas transport model. However, describing true methane adsorption behavior in shale is challenging because the density or volume of the adsorbed phase cannot be measured directly using current technology. There are several models available to describe the observed adsorption isotherms and extrapolate the true adsorbed quantity of methane, but a consensus model has not been reached by researchers. This work first revisits available absolute and Gibbs excess adsorption models for describing methane in shales. It then compares nine available adsorption models to assess the efficacy of each model in describing both high pressure and low pressure methane adsorption isotherms in shales. Three aspects of the adsorption model are compared: (1) the goodness-of-fit of each adsorption model, (2) interpretation of the observed test phenomena, and (3) predicted isotherms beyond test data. Comparison results show that even though the goodness-of-fit for each model is comparable, the dual-site Langmuir model is still superior to other available models in interpreting observed phenomena and extrapolating adsorption isotherms beyond test data. The successful application of the dual-site Langmuir model therefore lays the foundation for accurately estimating and extrapolating the deep gas resource and differentiating the accurate ratio of the adsorbed phase to bulk gas for use in shale gas transport models. This study also clarifies some inappropriate concepts and methods routinely used by the shale gas community.Tao, S., Chen, S., Tang, D., Zhao, X., Xu, H., Li, S., 2018. Material composition, pore structure and adsorption capacity of low-rank coals around the first coalification jump: A case of eastern Junggar Basin, China. Fuel 211, 804-815. first coalification jump (FCJ) has a significant impact on low-rank coal reservoir heterogeneity, and is of great importance for coalbed methane (CBM) development. Here, a series of experiments were performed for 10 coal samples collected from eastern Junggar Basin, to compare the material composition, pore structure and adsorption capacity of lignite and candle coal. Contrast with the candle coal, the lignite has a higher inertinite content, larger pore volume, better connectivity, and greater specific surface area (SSA). During the process of FCJ, the polycondensation of coal molecules and the compaction of coal matrix occur, leading to a rapid decline of moisture, porosity and permeability, and the cell wall in the candle coal is badly crushed with clay minerals filled from optical microscopy. In general, the larger total pore volume (1.7–300?nm, measured by N2 adsorption) contributes to the larger SSA. The SSA of candle coal mainly comes from the contribution of micropore (&lt;10?nm), especially the 2–3?nm pores, while the micropore and transition pore (10–100?nm) contribute to most of SSA of lignite. However, though the SSA of the candle coal is largely lower than that of the lignite, the CH4 adsorption capacity tends to decrease from the lignite to the candle coal due to material composition difference. Low-field NMR was used to determine the pore and fracture system by analyzing the transverse relaxation time, which showed that only two obvious peaks could be identified in lignite and three peaks at about 0.25?ms, 30?ms and 200?ms are present in the candle coal. The fractal results indicate that the pore surface and complexity inside the coal increase gradually from lignite to candle coal. These observations could deepen awareness and understanding of low-rank coal reservoir heterogeneity and the influence of FCJ on reservoir property.Tecon, R., Or, D., 2017. Biophysical processes supporting the diversity of microbial life in soil. FEMS Microbiology Reviews 41, 599-623., the living terrestrial skin of the Earth, plays a central role in supporting life and is home to an unimaginable diversity of microorganisms. This review explores key drivers for microbial life in soils under different climates and land-use practices at scales ranging from soil pores to landscapes. We delineate special features of soil as a microbial habitat (focusing on bacteria) and the consequences for microbial communities. This review covers recent modeling advances that link soil physical processes with microbial life (termed biophysical processes). Readers are introduced to concepts governing water organization in soil pores and associated transport properties and microbial dispersion ranges often determined by the spatial organization of a highly dynamic soil aqueous phase. The narrow hydrological windows of wetting and aqueous phase connectedness are crucial for resource distribution and longer range transport of microorganisms. Feedbacks between microbial activity and their immediate environment are responsible for emergence and stabilization of soil structure—the scaffolding for soil ecological functioning. We synthesize insights from historical and contemporary studies to provide an outlook for the challenges and opportunities for developing a quantitative ecological framework to delineate and predict the microbial component of soil functioning.Temerdashev, Z.A., Pavlenko, L.F., Korpakova, I.G., Skrypnik, G.V., Klimenko, T.L., Votinova, T.V., Ermakova, Y.S., 2017. On the limitation of the term petroleum products in the determination of the oil pollution of bottom sediments. Journal of Analytical Chemistry 72, 1120-1125. related to the determination of the oil pollution of bottom sediments are discussed. Tarry substances resistant to degradation, whose content can be as high as 50% on a total oil basis, are accumulated in the bottom sediments. The conventional term petroleum products, which implies only a hydrocarbon fraction, does not adequately describe these substances; because of this, the really evaluated level of the oil pollution of bottom sediments becomes underestimated to a considerable degree. We proposed to determine tarry substances in bottom sediments by fluorescence spectrometry at 490–510 nm in combination with a stage of the chromatographic preconcentration and separation of oils and petroleum products into the following main group components: hydrocarbons, tars, and asphaltenes. The substances coextracted with the petroleum products (pesticides, phenols, pigments, etc.) occurred in a chromatographic zone of tars and asphaltenes, but they fluoresce at other wavelengths and do not interfere with the determination. The typical chromatograms of hydrocarbons from the bottom sediments of different water bodies obtained by gas chromatography are given. Original Russian Text ? Z.A. Temerdashev, L.F. Pavlenko, I.G. Korpakova, G.V. Skrypnik, T.L. Klimenko, T.V. Votinova, Ya.S. Ermakova, 2017, published in Zhurnal Analiticheskoi Khimii, 2017, Vol. 72, No. 10, pp. 952–958Thienpont, J.R., Desjardins, C.M., Kimpe, L.E., Korosi, J.B., Kokelj, S.V., Palmer, M.J., Muir, D.C.G., Kirk, J.L., Smol, J.P., Blais, J.M., 2017. Comparative histories of polycyclic aromatic compound accumulation in lake sediments near petroleum operations in western Canada. Environmental Pollution 231, 13-21. examined the historical deposition of polycyclic aromatic compounds (PACs) recorded in radiometrically-dated lake sediment cores from a small, conventional oil and gas operation in the southern Northwest Territories (Cameron Hills), and placed these results in the context of previously published work from three other important regions of western Canada: (1) the Athabasca oil sands region in Alberta; (2) Cold Lake, Alberta; and (3) the Mackenzie Delta, NT. Sediment PAC records from the Cameron Hills showed no clear changes in either source or concentrations coincident with the timing of development in these regions. Changes were small in comparison to the clear increases in both parent and alkyl-substituted PACs in response to industrial development from the Athabasca region surface mining of oil sands, where parent PAC diagnostic ratios indicated a shift from pyrogenic sources (primarily wood and coal burning) in pre-development sediments to more petrogenically-sourced PACs in modern sediments. Cores near in-situ oil sand extraction operations showed only modest increases in PAC deposition. This work directly compares the history and trajectory of contamination in lake ecosystems in areas of western Canada impacted by the most common types of hydrocarbon extraction activities, and provides a context for assessing the environmental impacts of oil and gas development in the future.Todaka, N., Xu, T., 2017. Reactive transport simulation to assess geochemical impact of impurities on CO2 injection into siliciclastic reservoir at the Otway site, Australia. International Journal of Greenhouse Gas Control 66, 177-189. is generally recognized that the removal of impurities from CO2 obtained from coal-fired flue gas carbon capture systems can significantly increase the cost of Carbon Capture and Storage (CCS). During the period from September to December 2014, the CO2CRC in collaboration with Callide Oxyfuel Services Pty Ltd conducted a series of CO2 injection tests into the Paaratte formation (Otway Basin, Victoria, Australia) utilizing product CO2 (near food grade) and product CO2 with added impurities (nominal SO2: 67 ppmv, O2: 6150 ppmv and NOx: 9 ppmv) from the Callide Oxyfuel Project. The purpose of the injection testing was to assess the geochemical effect of the CO2 injected with water on the siliciclastic reservoir. The geochemical test, which was designed and conducted by CO2CRC, consists of water production, Test 1 (injection of CO2-saturated water without impurities), and Test 2 (injection of CO2-saturated water with impurities). In this paper, 2-D radial reactive transport simulations of injection tests were carried out using TOUGHREACT, including: (1) simulation of the pre-injection period from Otway Stage 2B Test in 2011 to the start of the geochemical test; (2) simulations of the pure CO2 and the impure CO2 cases; (3) long-term simulation of the impure CO2 case; and (4) simulations of injection of CO2-saturated water with various impurity concentrations. The numerical model was able to reproduce the observed geochemical changes during the geochemical test. The results indicate that there were negligible differences between the pure CO2 and the impure CO2 cases for both changes in water chemistry and mineralogy, if SO2 or O2 was less than 1000 ppmv. Based on this evaluation of both field test results and simulations, by extrapolation it is concluded that co-injection of impurity gases (up to 1000 ppmv SO2 and 1000 ppmv O2) with CO2 would have insignificant impacts on the reservoir at the Otway site. In the long-term simulation, the distribution area of residual gas in the reservoir was small and the pH of the formation water was near neutral after 1000 years. Moreover, it was predicted that the water disturbed by CO2 impurities would come close to the initial geochemical conditions in the long-term, and that it is highly probable that the long-term impact after 1000 years would become much less compared to the short-term impact in the test period. The method and model presented here was suitable for the Otway site test and would be applicable to other CO2 storage sites with similar conditions.Tolar, B.B., Herrmann, J., Bargar, J.R., van den Bedem, H., Wakatsuki, S., Francis, C.A., 2017. Integrated structural biology and molecular ecology of N-cycling enzymes from ammonia-oxidizing archaea. Environmental Microbiology Reports 9, 484-491. of the molecular ecology and environmental determinants of ammonia-oxidizing organisms is critical to understanding and predicting the global nitrogen (N) and carbon cycles, but an incomplete biochemical picture hinders in vitro studies of N-cycling enzymes. Although an integrative structural and dynamic characterization at the atomic scale would advance our understanding of function tremendously, structural knowledge of key N-cycling enzymes from ecologically relevant ammonia oxidizers is unfortunately extremely limited. Here, we discuss the challenges and opportunities for examining the ecology of ammonia-oxidizing organisms, particularly uncultivated Thaumarchaeota, through (meta)genome-driven structural biology of the enzymes ammonia monooxygenase (AMO) and nitrite reductase (NirK).Tolstikhin, I.N., Ballentine, C.J., Polyak, B.G., Prasolov, E.M., Kikvadze, O.E., 2017. The noble gas isotope record of hydrocarbon field formation time scales. Chemical Geology 471, 141-152. gases may be considered as the most prominent tracers of natural fluids, including hydrocarbons. The atmosphere is the only source of 20Ne, 36Ar, 84Kr, 130Xe in subsurface environments, and their concentrations in pore waters after recharge are known from the solubility data. This allows modelling of noble gas partitioning between coexisting gas, oil and water phases in the course of hydrocarbon formation, migration, and storage. Radiogenic isotopes, 4He*, 21Ne*, 40Ar*, 136Xe*, after being released from source rocks, are mixed with air-derived noble gases already present in the pore space. Concentrations of radiogenic species in the pore space of “typical” hydrocarbon fields are generally so high, that they can hardly be accumulated in situ and thus indicate noble gas transfer from ground waters. The time bearing ratios 4He*/20Ne, 21Ne*/20Ne, 4He*/40ArAIR40Ar*/40ArAIR in hydrocarbon fields are thus proportional to the time interval between the ground water recharge and noble gases partitioning into the hydrocarbon phase(s), the ‘recharge – partition interval’. The largest available data set allows the recharge-partition intervals to be constrained for a large number of hydrocarbon fields, situated in different tectonic settings (ancient plates, young plates, mobile belts). These intervals increase systematically with the ages of hydrocarbon source and trap lithologies and are comparable with these ages. This important feature, valid in general for different hydrocarbon fields, implies: (i) local sources of radiogenic noble gas isotopes in ground waters; (ii) relatively recent formation of hydrocarbon fields and (iii) their short formation time scales.In some cases the duration of formation of a hydrocarbon field can be constrained. For example, nearly constant 21Ne*/20Ne, 40Ar*/40ArAIR ratios, measured in samples from the Magnus oil field (North Sea), give an accumulation time scale ≈ 10 Ma. It should be emphasized that the above noble gas isotope ratios give the time estimates, which are independent of geological reconstructions.Sometimes the noble gas inventory in a hydrocarbon field and ground waters allows characterization of the source rock volume, involved in formation of the field; generally this volume exceeds that of the hydrocarbon field rocks by orders of magnitude.Torkaman, M., Bahrami, M., Dehghani, M., 2017. Influence of temperature on aggregation and stability of asphaltenes. I. Perikinetic aggregation. Energy & Fuels 31, 11169-11180. deposition is one of the most challenging aspects of the petroleum industry that takes place through production, processing, and transportation. In the present study, first, the effect of temperature on the aggregation kinetics of asphaltene in a heptane–toluene mixture is investigated during a set of experiments done at different fixed temperatures. In spite of most previous works in which the collision efficiency is assumed to be constant and equal to one, the obtained experimental data in this study provides deep insights into the mechanism of aggregation of asphaltene particles within an organic medium. A population balance model considering the fractal structure for asphaltene aggregates and variable value for collision efficiency is developed to predict the enlargement of asphaltene floccules with the passage of time. The results show that the assumption of a constant value for collision efficiency is not realistic. The calculated value of collision efficiency decreases with the increase of average particle size during each experiment. Also, the value of collision efficiency decreases with the increase of temperature. In the second part of this work, the zeta potential of asphaltene aggregates in the mixture is measured during the evolution of floccules in separate tests. These results are applied to investigate the asphaltene stability and also to validate the size measurement data obtained in the first part. The measured zeta potentials of evolving particles indicate that the asphaltene aggregates are more stable at high temperatures than at low temperatures. Due to this fact, aggregates reach a significantly smaller mean size at high temperatures in comparison to that at low temperatures.Tose, L.V., Murgu, M., Vaz, B.G., Rom?o, W., 2017. Application of atmospheric solids analysis probe mass spectrometry (ASAP-MS) in petroleomics: Analysis of condensed aromatics standards, crude oil, and paraffinic fraction. Journal of The American Society for Mass Spectrometry 28, 2401-2407. solids analysis probe mass spectrometry (ASAP-MS) is a powerful tool for analysis of solid and liquid samples. It is an excellent alternative for crude oil analysis without any sample preparation step. Here, ASAP-MS in positive ion mode, ASAP(+)-MS, has been optimized for analysis of condensed aromatics (CA) standards, crude oil, and paraffinic fraction samples using a Synapt G2-S HDMS. Initially, two methodologies were used to access the chemical composition of samples: (1) using a temperature gradient varying from 150 to 600 °C at a heating rate of 150 °C?min–1, and (2) with constant temperature of 300 and 400 °C. ASAP(+)-MS ionized many compounds with a typical petroleum profile, showing a greater signals range of m/z 250–1300 and 200–1400 for crude oil and paraffin samples, respectively. Such performance, mainly related to the detection of high molecular weight compounds (>1000?Da), is superior to that of other traditional ionization sources, such as ESI, APCI, DART, and DESI. Additionally, the CA standards were identified in both forms: radicals, [M]+?, and protonated cations, [M + H]+, with minimum fragmentation. Therefore, ASAP was more efficient in accessing the chemical composition of nonpolar and polar compounds. It is promising in its application with ultrahigh resolution MS instruments, such as FT-ICR MS and Orbitrap, since molecular formulas with greater resolution and mass accuracy (<1?ppm) would be assigned.Trias, R., Ménez, B., le Campion, P., Zivanovic, Y., Lecourt, L., Lecoeuvre, A., Schmitt-Kopplin, P., Uhl, J., Gislason, S.R., Alfre?sson, H.A., Mesfin, K.G., Sn?bj?rnsdóttir, S.?., Aradóttir, E.S., Gunnarsson, I., Matter, J.M., Stute, M., Oelkers, E.H., Gérard, E., 2017. High reactivity of deep biota under anthropogenic CO2 injection into basalt. Nature Communications 8, Article 1063. are recognized as one of the major habitats on Earth, harboring diverse and active microbial populations. Inconsistently, this living component is rarely considered in engineering operations carried out in these environments. This includes carbon capture and storage (CCS) technologies that seek to offset anthropogenic CO2 emissions into the atmosphere by burying this greenhouse gas in the subsurface. Here, we show that deep ecosystems respond quickly to field operations associated with CO2 injections based on a microbiological survey of a basaltic CCS site. Acidic CO2-charged groundwater results in a marked decrease (by ~?2.5–4) in microbial richness despite observable blooms of lithoautotrophic iron-oxidizing Betaproteobacteria and degraders of aromatic compounds, which hence impact the aquifer redox state and the carbon fate. Host-basalt dissolution releases nutrients and energy sources, which sustain the growth of autotrophic and heterotrophic species whose activities may have consequences on mineral storage.Trinkaus, E., Villotte, S., 2017. External auditory exostoses and hearing loss in the Shanidar 1 Neandertal. PLOS ONE 12, Article e0186684. Late Pleistocene Shanidar 1 older adult male Neandertal is known for the crushing fracture of his left orbit with a probable reduction in vision, the loss of his right forearm and hand, and evidence of an abnormal gait, as well as probable diffuse idiopathic skeletal hyperostosis. He also exhibits advanced external auditory exostoses in his left auditory meatus and larger ones with complete bridging across the porus in the right meatus (both Grade 3). These growths indicate at least unilateral conductive hearing (CHL) loss, a serious sensory deprivation for a Pleistocene hunter-gatherer. This condition joins the meatal atresia of the Middle Pleistocene Atapuerca-SH Cr.4 in providing evidence of survival with conductive hearing loss (and hence serious sensory deprivation) among these Pleistocene humans. The presence of CHL in these fossils thereby reinforces the paleobiological and archeological evidence for supporting social matrices among these Pleistocene foraging peoples.Tsiamis, A., Taylor, S.E., 2017. Adsorption behavior of asphaltenes and resins on kaolinite. Energy & Fuels 31, 10576-10587. studies have shown that n-C7-precipitated asphaltenes adsorb onto nanoparticles to produce isotherms that are significantly influenced by the dispersed states of both the adsorbate and the adsorbent. In the present work, we investigate this behavior further by determining the adsorption of asphaltene and resin fractions isolated from four different sources onto kaolinite using the depletion method in toluene. Treated conventionally (amount adsorbed, Γ, versus equilibrium bulk concentration, ce), adsorption isotherms for fixed initial concentrations (c0) of C5 and C7 asphaltenes and variable kaolinite mass (ms) are found to be Type I as classified by IUPAC, whereas under the same experimental conditions C5–C7 resins exhibit Type III behavior. By fixing ms and varying c0, however, Type II isotherms are produced by the resins. All of the adsorption results for the same fraction type were found to be very similar, irrespective of the source. The Types I and III isotherms are described very well by the thermodynamic solid–liquid equilibrium (SLE) model of Montoya et al. ( Energy Fuels 2014, 28, 4963?4975) based on the association theory of Talu and Meunier ( AIChE J. 1996, 42, 809?819). Individual isotherms (Γ versus ce) are well-fitted by a shifted Langmuir equation for asphaltenes and by a general Freundlich (power law) relationship for resins. The SLE results verify that in toluene solution the adsorption behavior is complicated by concentration-dependent nanoaggregation of asphaltene species, whereas resin–resin interactions are weaker, but accompanied by adsorbent particle aggregation. On the other hand, when the adsorption data for each fraction type is replotted in terms of the ratio of the experimental parameter c0/ms, as originally done by Wang et al. ( Colloids Surfaces A: Physicochem. Eng. Aspects 2016, 504, 280?286), each set of data merges to a single isotherm which is reasonably well-approximated by a Langmuir-type relationship (we term this a “pseudo-Langmuir equation”), which allows the maximum adsorption to be determined for the different adsorbate/adsorbent systems. The average maximum adsorbed amounts calculated in this way for each of the component types are very similar, being slightly larger for C7A compared with C5A, with the values for the C5–C7R fractions being generally lower and more variable, possibly reflecting some source dependence.\Uhlig, C., Kirkpatrick, J.B., D'Hondt, S., Loose, B., 2017. Methane oxidizing seawater microbial communities from an Arctic shelf. Biogeosciences Discussions 2017, 1-37. communities of the ocean can consume methane dissolved in seawater before it has a chance to escape to the atmosphere and contribute to greenhouse warming. Seawater over the shallow Arctic shelf is characterized by excess methane compared to the atmospheric equilibrium originating in sediments, permafrost and hydrates. Particularly high concentrations are found beneath sea ice. We studied the structure and methane oxidation potential of the microbial communities from seawater collected close to Utqiagvik, Alaska, in April 2016. The in situ methane concentrations were 16.3?±?7.2?nmol?L?1, approximately 4.8 times oversaturated compared to the atmospheric equilibrium. The group of methane oxidizing bacteria (MOB) in the natural seawater and seawater incubations was >?97?% dominated by Methylococcacales (γ-Proteobacteria). Incubations of seawater under a range of methane concentrations led to a loss of diversity in the bacterial community. The abundance of MOB was low with maximal fractions of 2.5?% at 200 times elevated methane concentration, while sequence reads of non-MOB methylotrophs were four times more abundant than MOB in most incubations. The abundances of MOB as well as non-MOB methylotrophs correlated tightly with the rate constant (kox) for methane oxidation, indicating that non-MOB methylotrophs might be coupled to MOB and involved in community methane oxidation. In sea ice, where methane concentrations of 82?±?35.8?nmol?kg?1 were found, Methylobacterium (α-Proteobacteria) was the dominant MOB with a relative abundance of 80?%. MOB abundances were very low in sea ice, with maximal fractions found at the ice-snow interface (0.1?%), while non-MOB-methlylotrophs were present in abundances compared to natural seawater communities. The differences in MOB taxa and an offset in methane concentration and stable isotope ratios between the ice and the water column point toward different methane cycling processes in both habitats.Vaezzadeh, V., Zakaria, M.P., Bong, C.W., 2017. Aliphatic hydrocarbons and triterpane biomarkers in mangrove oyster (Crassostrea belcheri) from the west coast of Peninsular Malaysia. Marine Pollution Bulletin 124, 33-42. Straits of Malacca is one of the world's busiest shipping routes where frequent oil spills occur. Rapid development in the west coast of Peninsular Malaysia is the other major source of petroleum pollution in this narrow waterway. In order to identify occurrence and origin of hydrocarbons in the Straits, mangrove oysters (Crassostrea belcheri) were collected from five sampling locations and analysed for n-alkanes and biomarkers. Soxhlet apparatus and two step column chromatography were used for extraction, purification and fractionation of the oysters. Petroleum origin n-alkanes were detected in majority of the sampling locations which is indicative of anthropogenic activities in this region. Using source and maturity diagnostic ratios for hopanes revealed used crankcase oil as the main source of petroleum hydrocarbons in oysters from all sampling locations except for the Pulau Merambong where signature of South East Asia crude oil (SEACO) was detected.van Soelen, E.E., Twitchett, R.J., Kürschner, W.M., 2017. Salinity changes and anoxia resulting from enhanced runoff during the late Permian global warming and mass extinction event. Climate of the Past Discussions 2017, 1-23. Late Permian biotic crisis had a major impact on marine and terrestrial environments. Rising CO2 levels following Siberian Trap volcanic activity were likely responsible for expanding marine anoxia and elevated water temperatures. This study focusses on one of the stratigraphically most expanded Permian-Triassic records known, from Jameson land, east Greenland. High resolution sampling allows for a detailed reconstruction of the changing environmental conditions during the extinction event and the development of anoxic water conditions. Since very little is known about how salinity was affected during the extinction event, we especially focus on the aquatic palynomorphs and infer changes in salinity from changes in the assemblage and morphology. The extinction event, here defined by a peak in spore/pollen, indicating disturbance and vegetation destruction in the terrestrial environment, postdates a negative excursion in the total organic carbon, but predates the development of anoxia in the basin. Based on the newest estimations for sedimentation rates, the marine and terrestrial ecosystem collapse took between 1.6 to 8?kyrs, a much shorter interval than previously estimated. The palynofacies and palynomorph records show that the environmental changes can be explained by enhanced runoff, increased primary productivity and water column stratification. A lowering in salinity is supported by changes in the acritarch morphology. The length of the processes of the acritarchs becomes shorter during the extinction event and we propose that these changes are evidence for a reduction in salinity in the shallow marine setting of the study site. This inference is supported by changes in acritarch distribution, which suggest a change in palaeoenvironment from open marine conditions before the start of the extinction event to more near-shore conditions during and after the crisis. In a period of sea-level rise, such a reduction in salinity can only be explained by increased runoff. High amounts of both terrestrial and marine organic fragments in the first anoxic layers suggest that high runoff, increased nutrient availability, possibly in combination with soil erosion, are responsible for the development of anoxia in the basin. Enhanced runoff could result from changes in the hydrological cycle during the late Permian extinction event, which is a likely consequence of global warming. In addition, vegetation destruction and soil erosion may also have resulted in enhanced runoff. Salinity stratification could potentially explain the development of anoxia in other shallow marine sites. The input of fresh water and related changes in coastal salinity could also have implications for the interpretation of oxygen isotope records and sea water temperature reconstructions in some sites.Varjani, S.J., Gnansounou, E., 2017. Microbial dynamics in petroleum oilfields and their relationship with physiological properties of petroleum oil reservoirs. Bioresource Technology 245, 1258-1265. is produced by thermal decay of buried organic material over millions of years. Petroleum oilfield ecosystems represent resource of reduced carbon which favours microbial growth. Therefore, it is obvious that many microorganisms have adapted to harsh environmental conditions of these ecosystems specifically temperature, oxygen availability and pressure. Knowledge of microorganisms present in ecosystems of petroleum oil reservoirs; their physiological and biological properties help in successful exploration of petroleum. Understanding microbiology of petroleum oilfield(s) can be used to enhance oil recovery, as microorganisms in oil reservoirs produce various metabolites viz. gases, acids, solvents, biopolymers and biosurfactants. The aim of this review is to discuss characteristics of petroleum oil reservoirs. This review also provides an updated literature on microbial ecology of these extreme ecosystems including microbial origin as well as various types of microorganisms such as methanogens; iron, nitrate and sulphate reducing bacteria, and fermentative microbes present in petroleum oilfield ecosystems.Vasilevich, R., Lodygin, E., Beznosikov, V., Abakumov, E., 2018. Molecular composition of raw peat and humic substances from permafrost peat soils of European Northeast Russia as climate change markers. Science of The Total Environment 615, 1229-1238. substances (HSs) from the mire peat soils of the forest-tundra zone of the European northeast part of Russia have been characterized in terms of molecular composition. This was accomplished using solid-state 13C nuclear magnetic resonance (13C NMR) techniques and electron spin resonance (ESR) spectroscopy. The composition depended on the intensity of cryogenic processes in the active layer, the quality of the humification precursors (the degree of peat material transformation), and the biochemical selection of aromatic fragments during humification. Humic acids (HAs) and fulvic acids (FAs) of the peat soils showed the presence of compounds with a low extent of condensation and a low portion of aromatic fragments, which increased with depth. A higher proportion of aliphatic carbon species was found in the HAs, indicating a low degree of organic matter stabilization. Based on the data from the two types of peat soils, we suggest that particular changes in the proportion of aromatic and unoxidized aliphatic fragments on the border of the bottom of the active layer and permafrost layers can be used as markers of current climatic change.Vegas-Vilarrúbia, T., Corella, J.P., Pérez-Zanón, N., Buchaca, T., Trapote, M.C., López, P., Sigró, J., Rull, V., 2018. Historical shifts in oxygenation regime as recorded in the laminated sediments of lake Montcortès (Central Pyrenees) support hypoxia as a continental-scale phenomenon. Science of The Total Environment 612, 1577-1592. expansion of anoxia has become a global issue and there is potential for worsening under global warming. At the same time, obtaining proper long-term instrumental oxygen records is difficult, thus reducing the possibility of recording long-term changes in oxygen shifts that can be related with climate or human influence.Varved lake sediments provide the better time frame to study this phenomenon at high resolution. We tracked the oxic/anoxic shifts of the varved Lake Montcortès since 1500 CE, and tried to recognise anthropogenic and climatic influences combining biological and geochemical proxies.Four main scenarios emerged: 1) years with abrupt sediment inputs (A); 2) years with outstanding mixing and oxygenation of the water column (B); 3) years with strong stratification, anoxia, intense sulfur bacterial activity and increased biomass production (C); 4) years with stratification and anoxia, but relatively less biomass production (D). In line with current limnologic trends, high supra-annual variability in the occurrence of oxygenation events was observed. Interestingly, at least 45.3% of the years were mixing years and, like the meromictic ones, were mostly clustered into groups of consecutive years, thus alternating years of monomixis with years of meromixis. Most years of D belong to the period 1500–1820 CE, when human activities were the most intense. Most years of A belonged to the climatic unstable period of 1850–1899 CE. Years of B were irregularly distributed but were best represented in the period 1820–1849 CE. Most years of C belonged to the 20th century. More than 90% of the years with climatic instrumental records belonged to B and C. Current climate warming seems to be taking control over the oxygenation capacity of the lake, especially since the second half of the 20th century. Our results support recent findings related to hypoxia spreading at the global scale.Venkatramani, C.J., Huang, S.R., Al-Sayah, M., Patel, I., Wigman, L., 2017. High-resolution two-dimensional liquid chromatography analysis of key linker drug intermediate used in antibody drug conjugates. Journal of Chromatography A 1521, 63-72. this manuscript, the application of high-resolution sampling (HRS) two-dimensional liquid chromatography (2D-LC) in the detailed analysis of key linker drug intermediate is presented. Using HRS, selected regions of the primary column eluent were transferred to a secondary column with fidelity enabling qualitative and quantitative analysis of linker drugs. The primary column purity of linker drug intermediate ranged from 88.9% to 94.5% and the secondary column purity ranged from 99.6% to 99.9%, showing lot-to-lot variability, significant differences between the three lots, and substantiating the synthetic and analytical challenges of ADCs. Over 15 impurities co-eluting with the linker drug intermediate in the primary dimension were resolved in the secondary dimension. The concentrations of most of these impurities were over three orders of magnitude lower than the linker drug. Effective peak focusing and high-speed secondary column analysis resulted in sharp peaks in the secondary dimension, improving the signal-to-noise ratios. The sensitivity of 2D-LC separation was over five fold better than conventional HPLC separation. The limit of quantitation (LOQ) was less than 0.01%. Many peaks originating from primary dimension were resolved into multiple components in the complementary secondary dimension, demonstrating the complexity of these samples. The 2D-LC was highly reproducible, showing good precision between runs with%RSD of peak areas less than 0.1 for the main component. The absolute difference in the peak areas of impurities less than 0.1% were within ±0.01% and for impurities in the range of 0.1%–0.3%, the absolute difference were ±0.02%, which are comparable to 1D-LC. The overall purity of the linker drug intermediate was determined from the product of primary and secondary column purity (HPLC Purity=%peak area of main component in the primary dimension×%peak area of main component in the secondary dimension). Additionally, the 2D-LC separation enables the determination of potential impurities that could impact the downstream process, like ADCs stability, efficacy and patient safety. Peak capacity of this magnitude, sensitivity and reproducibility of 2D-LC for resolving structurally similar impurities co-eluting with the main component has not been demonstrated to date. This application clearly demonstrates the power of 2D-LC in detailed analysis of structurally similar, co-eluting impurities from key linker drug intermediate used in ADCs that is impossible to achieve by conventional 1D-LC.Ventura, M., Deus, W.B., Silva, J.R., Andrade, L.H.C., Catunda, T., Lima, S.M., 2018. Determination of the biodiesel content in diesel/biodiesel blends by using the near-near-infrared thermal lens spectroscopy. Fuel 212, 309-314. dual-beam mode-mismatched configuration of the Thermal Lens (TL) technique was applied to characterize biodiesel, diesel and diesel/biodiesel blends. The excitation was performed using a tunable laser in the near-near infrared region in order to assess overtones and combination bands of the vibration modes. The thermo-optical properties of the fuels were also determined. The results showed that the biodiesel contents in diesel/biodiesel blends can be monitored with this technique, by excitation the third overtone of the C–H (4ν(C–H)) bond stretching vibration at 916?nm. Both the amplitude of the photothermal signal and thermal diffusivity are important parameters to quantify the biodiesel content in diesel/biodiesel blends.Viggi, C.C., Matturro, B., Frascadore, E., Insogna, S., Mezzi, A., Kaciulis, S., Sherry, A., Mejeha, O.K., Head, I.M., Vaiopoulou, E., Rabaey, K., Rossetti, S., Aulenta, F., 2017. Bridging spatially segregated redox zones with a microbial electrochemical snorkel triggers biogeochemical cycles in oil-contaminated River Tyne (UK) sediments. Water Research 127, 11-21. sediments represent an important sink for a number of anthropogenic organic contaminants, including petroleum hydrocarbons following an accidental oil spill. Degradation of these compounds largely depends on the activity of sedimentary microbial communities linked to biogeochemical cycles, in which abundant elements such as iron and sulfur are shuttled between their oxidized and reduced forms. Here we show that introduction of a small electrically conductive graphite rod (“the electrochemical snorkel”) into an oil-contaminated River Tyne (UK) sediment, so as to create an electrochemical connection between the anoxic contaminated sediment and the oxygenated overlying water, has a large impact on the rate of metabolic reactions taking place in the bulk sediment. The electrochemical snorkel accelerated sulfate reduction processes driven by organic contaminant oxidation and suppressed competitive methane-producing reactions. The application of a comprehensive suite of chemical, spectroscopic, biomolecular and thermodynamic analyses suggested that the snorkel served as a scavenger of toxic sulfide via a redox interaction with the iron cycle. Taken as a whole, the results of this work highlight a new strategy for controlling biological processes, such as bioremediation, through the manipulation of the electron flows in contaminated sediments.Vignola, C., Masi, A., Balossi Restelli, F., Frangipane, M., Marzaioli, F., Passariello, I., Stellato, L., Terrasi, F., Sadori, L., 2017. δ13C and δ15N from 14C-AMS dated cereal grains reveal agricultural practices during 4300–2000BC at Arslantepe (Turkey). Review of Palaeobotany and Palynology 247, 164-174. semi-arid environments of the Near East water availability and soil fertility are limiting factors for crop growing and land use is locally adjusted to environmental features. In the last decades stable carbon and nitrogen isotope analyses on archaeobotanical cereal remains have been developed in order to reconstruct water and nutrient sources for grain filling. Diachronic studies on isotope records from single archaeological sites may help distinguish palaeoclimatic changes from human choices in agricultural practices, but they are actually missing.We have analysed 13C isotope discrimination (Δ13C) and N isotope composition (δ15N) on barley, emmer and wheat 14C-AMS dated grains from the archaeological site of Arslantepe, Malatya (South-Eastern Turkey). Our intent is to focus on the exceptionally long-term development of agricultural practices at the site from 4300 to 2000 BC.Stable isotope values of cereals show temporal trends in water supplies and manure application. Irrigation was provided to barley crops from 4300 to 3100 BC during the rise of centralised political organisation at the site. Different locations of barley fields are suggested from 3100 to 2000 BC when domestic economies are attested. In addition, the marked increase of barley δ15N values from 3350 to 3000 BC reveals manuring and/or cultivation in pasturelands due to the deposition of animal urea and dung. Wheat could have been grown close to the site, where irrigation water from natural springs was available. Emmer and wheat seem to have been cultivated in the same areas or directly in the same fields. During 3000–2500 BC intercropping cultivation is inferred by low δ15N values. The evidence of mixture crops confirms the increase of pasturelands during herders' occupations and the concentration of crop fields possibly around the site.Vollnhals, F., Audinot, J.-N., Wirtz, T., Mercier-Bonin, M., Fourquaux, I., Schroeppel, B., Kraushaar, U., Lev-Ram, V., Ellisman, M.H., Eswara, S., 2017. Correlative microscopy combining secondary ion mass spectrometry and electron microscopy: Comparison of intensity–hue–saturation and Laplacian pyramid methods for image fusion. Analytical Chemistry 89, 10702-10710. microscopy combining various imaging modalities offers powerful insights into obtaining a comprehensive understanding of physical, chemical, and biological phenomena. In this article, we investigate two approaches for image fusion in the context of combining the inherently lower-resolution chemical images obtained using secondary ion mass spectrometry (SIMS) with the high-resolution ultrastructural images obtained using electron microscopy (EM). We evaluate the image fusion methods with three different case studies selected to broadly represent the typical samples in life science research: (i) histology (unlabeled tissue), (ii) nanotoxicology, and (iii) metabolism (isotopically labeled tissue). We show that the intensity–hue–saturation fusion method often applied for EM-sharpening can result in serious image artifacts, especially in cases where different contrast mechanisms interplay. Here, we introduce and demonstrate Laplacian pyramid fusion as a powerful and more robust alternative method for image fusion. Both physical and technical aspects of correlative image overlay and image fusion specific to SIMS-based correlative microscopy are discussed in detail alongside the advantages, limitations, and the potential artifacts. Quantitative metrics to evaluate the results of image fusion are also discussed.Voltolini, M., Kwon, T.-H., Ajo-Franklin, J., 2017. Visualization and prediction of supercritical CO2 distribution in sandstones during drainage: An in situ synchrotron X-ray micro-computed tomography study. International Journal of Greenhouse Gas Control 66, 230-245. distribution of supercritical CO2 (scCO2) exerts significant control on a variety of key hydrologic as well as geochemical processes, including residual trapping and dissolution. Despite such importance, only a small number of experiments have directly characterized the three-dimensional distribution of scCO2 in geologic materials during the invasion (drainage) process. We present a study which couples dynamic high-resolution synchrotron X-ray micro-computed tomography imaging of a scCO2/brine system at in situ pressure/temperature conditions with quantitative pore-scale modeling to allow direct validation of a pore-scale description of scCO2 distribution. The experiment combines high-speed synchrotron radiography with tomography to characterize the brine saturated sample, the scCO2 breakthrough process, and the partially saturated state of a sandstone sample from the Domengine Formation, a regionally extensive unit within the Sacramento Basin (California, USA). The availability of a 3D dataset allowed us to examine correlations between grains and pores morphometric parameters and the actual distribution of scCO2 in the sample, including the examination of the role of small-scale sedimentary structure on CO2 distribution. The segmented scCO2/brine volume was also used to validate a simple computational model based on the local thickness concept, able to accurately simulate the distribution of scCO2 after drainage. The same method was also used to simulate Hg capillary pressure curves with satisfactory results when compared to the measured ones. This predictive approach, requiring only a tomographic scan of the dry sample, proved to be an effective route for studying processes related to CO2 invasion structure in geological samples at the pore scale.Wang, C., Wang, Y., Herath, H.M.S.K., 2017. Polycyclic aromatic hydrocarbons (PAHs) in biochar – Their formation, occurrence and analysis: A review. Organic Geochemistry 114, 1-11. of biochar for soil development has been increasingly practiced over the last decade. However, during the pyrolytic production of biochar, polycyclic aromatic hydrocarbons (PAHs) can form and are present on the surface of biochar. Consequently, there may be a potential risk for human health as well as the environment. In the present paper, research progress related to PAHs in biochar with respect to their formation mechanisms, factors that influence their formation, and the methods used to determine the total and bioavailable PAHs are discussed. The pyrolysis process is the key factor responsible for the yield of PAHs in biochar. Slow pyrolysis and longer residence time result in lower PAH yields than the fast pyrolysis and shorter residence time. Temperature is also another significant determinant affecting the formation and yield of PAHs. Low molecular weight PAHs are usually formed at low temperature (< 500 °C) whereas the high molecular weight PAHs commonly appear under high temperature (> 500 °C). Original composition, mineral and moisture content of feedstock, appearance of O2 during pyrolysis or after some treatments also have a considerable effect on the yield of PAHs. Analytical methods for extraction of PAHs from biochar mainly include Soxhlet extraction and accelerated solvent extraction. However, the extraction efficiency depends both on the extractant method and the type of biochar. This review of the literature has noted that future studies should focus on (i) development of a standard protocol for quantifying total and bioavailable PAHs in biochar, (ii) revealing the effect of key chemical components of feedstock and high temperature on the formation of PAHs, and (iii) carrying out eco-toxicological studies at long timescale to evaluate the environmental risk of biochar application.Wang, F., Fan, X., Xia, J.-L., Wei, X.-Y., Yu, Y.-R., Zhao, Y.-P., Cao, J.-P., Zhao, W., Wang, R.-Y., 2018. Insight into the structural features of low-rank coals using comprehensive two dimensional gas chromatography/time-of-flight mass spectrometry. Fuel 212, 293-301. characterization of organic components in low-rank coals is essential for the utilization of coals in clean, effective and value-added ways. Two kinds of low-rank coals were subjected to sequential thermal dissolution in the order of cyclohexane, acetone, and methanol to obtain six soluble portions (SPs) from the coals. Two gas chromatographic systems, gas chromatography/mass spectrometry (GC/MS) and comprehensive two dimensional gas chromatography/time-of-flight mass spectrometry (GC?×?GC/TOF MS), were applied to the characterization of the SPs. Compared to GC/MS, a routine analytical technique for complex mixtures, GC?×?GC/TOF MS improves the separating power, overcomes the co-elution, and reveals more structural details in complex mixtures like coals. Low-polar compounds like aliphatic hydrocarbons and arenes tended to be extracted by cyclohexane. High content of polar alcohols and phenols were identified in the SPs of methanol. Acetone could enrich nitrogen-containing organic compounds (NCOCs) due to hydrogen bond of N–H?O between NCOCs and acetone. Additionally, a series of low-concentration species including some isomers in the SPs were only identified by GC?×?GC/TOF MS. Distributions of various classes of compounds on the two-dimensional total ion chromatograms plot were discussed according to the separation mechanism of the two columns. Detailed analysis of biomarkers was also exhibited and discussed.Wang, L.L., Zhang, G.Q., Hallais, S., Tanguy, A., Yang, D.S., 2017. Swelling of shales: A multiscale experimental investigation. Energy & Fuels 31, 10442-10451. swelling can cause a series of problems during the exploitation of shale gas. However, because of the complex fabric of shale, a thorough understanding of shale swelling has not been gained. In this work, an experimental multiscale approach is employed to characterize the swelling properties of a shale sample from Sichuan basin of China. Wetting/drying tests are performed by environmental scanning electron microscopy (ESEM), and deformation of the material is measured by analyzing the ESEM micrographs using digital image correlation (DIC) techniques. Investigations are conducted at three distinct scales, enabling the macroscopic behavior to be linked to the microscopic mechanisms (e.g., the role of inclusions, the behavior of clay particles). The macroscopic swelling of the tested shale is less than 2%. This limited swelling is mainly due to the presence of nonswelling inclusions as well as the low swelling capacity of the clay inside the shale. Microcracking is evidenced along both the wetting and the drying paths. It is demonstrated that the clay particles swell rather undirectionally perpendicular to their orientation. Moreover, a preferred orientation of the clay particles is found parallel to the bedding plane, which finally leads to a moderate anisotropy of the macroscopic swelling.Wang, M., Wang, C., Han, X., 2017. Selection of internal standards for accurate quantification of complex lipid species in biological extracts by electrospray ionization mass spectrometry—What, how and why? Mass Spectrometry Reviews 36, 693-714. is rapidly expanding because of the great facilitation of recent advances in, and novel applications of, electrospray ionization mass spectrometry techniques. The greatest demands have been for successful quantification of lipid classes, subclasses, and individual molecular species in biological samples at acceptable accuracy. This review addresses the selection of internal standards in different methods for accurate quantification of individual lipid species. The principles of quantification with electrospray ionization mass spectrometry are first discussed to recognize the essentials for quantification. The basics of different lipidomics approaches are overviewed to understand the variables that need to be considered for accurate quantification. The factors that affect accurate quantification are extensively discussed, and the solutions to resolve these factors are proposed-largely through addition of internal standards. Finally, selection of internal standards for different methods is discussed in detail to address the issues of what, how, and why related to internal standards. We believe that thorough discussion of the topics related to internal standards should aid in quantitative analysis of lipid classes, subclasses, and individual molecular species and should have big impacts on advances in lipidomics.Wang, R., Ji, H., Ma, P., Zeng, H., Xu, Y., Zhang, Z.-M., Lu, H.-M., 2017. Fast pure ion chromatograms extraction method for LC-MS. Chemometrics and Intelligent Laboratory Systems 170, 68-74. chromatography coupled with mass spectrometry (LC-MS) has shown great potential in analysis complex samples. However, informative feature extraction is still challenge since the electrospray ionization in LC-MS tends to produce ninety percent or more ions not originated from compounds of interest. The concept of pure ion chromatogram (PIC) is effective to extract informative ions, but tradition PIC methods are time-consuming because of their theories and programming languages. In this study, we present a novel method, called Fast Pure Ions Chromatograms (FPIC), for extracting PICs from raw LC-MS dataset effectively and quickly. This method can search ion of PIC from its maximum bi-directionally and adaptively, which can improve the stability and reduce the computation time drastically. A further speedup has been achieved by exploiting modern software engineering techniques. FPIC was validated by analyzing four LC-MS datasets: MM14 and MM48, simulated MM48 and quantification (MTBLS234) datasets. Results show that FPIC outperformed traditional methods in the recall, precision and F-score, and it has good reliability of quantification. Furthermore, the method is very fast with few adjustable parameters, which leads to an approximately 125-fold speedup over PITracer and 18-fold speedup over XCMS. An open source implementation of the FPIC method is available at <, X., Zhang, S., Wang, H., Bjerrum, C.J., Hammarlund, E.U., Haxen, E.R., Su, J., Wang, Y., Canfield, D.E., 2017. Oxygen, climate and the chemical evolution of a 1400 million year old tropical marine setting. American Journal of Science 317, 861-900. Xiamaling Formation is an exceptionally well-preserved sedimentary succession deposited on a marine passive margin about 1400 million years ago. We used a multi-proxy approach, including iron speciation, trace metal dynamics, and organic geochemistry, to explore the evolution of ocean chemistry through most of the Xiamaling Formation. This evolution is put in the context of the paleogeography and the sedimentological evolution of the Xiamaling depositional system. Overall, the Xiamaling Formation is informally divided into six units based on both sedimentological and geochemical criteria. Of the six units, we fully explored four of them. Unit 4, the lowest unit we studied, is comprised of deep-water red muds, periodically interrupted by green-colored silt and sandy turbidites. Iron extraction results show that the red muds are enriched in highly reactive iron, indicating a water-column source for the iron. However, the low organic carbon contents, low hydrogen index (HI) values, and the oxidized nature of the reactive iron pool indicate deposition in oxygenated bottom waters. We interpret unit 4 to represent a low-productivity ferruginous oxygen-minimum zone (OMZ) environment, underlain by oxygenated bottom waters. The transition to unit 3 reflects an increase in primary productivity, and the development of a more biologically active OMZ, that supported anoxygenic phototrophic bacteria. Still, in this unit, the bottom waters remained oxygenated. The overlying unit 2 represents the transition to deep-water deoxygenation and anoxic waters at the sediment surface. These waters were ferruginous in the bottom part of the unit and sulfidic (euxinic) towards the top. In the uppermost unit 1, euxinic conditions continued, punctuated by more frequent water-column oxygenation towards the upper part of the unit. We place the evolution of these chemical dynamics in the context of climate and climate change, and in particular, the placement of the Xiamaling Formation in relation to the Intertropical Convergence Zone (ITCZ) and the resulting Hadley Cell dynamics. Also, while our results demonstrate the persistence of anoxic water-column conditions high in the water column during the deposition of the Xiamaling Formation, they also demonstrate bottom water oxygenation near the seafloor during the deposition of three of the four units, and over a time interval extending to 10's of millions of years. Wang, X., Zhang, S., Wang, H., Canfield, D.E., Su, J., Hammarlund, E.U., Bian, L., 2017. Remarkable preservation of microfossils and biofilms in Mesoproterozoic silicified bitumen concretions from northern China. Geofluids 2017, Article 4818207., often generally referred to as “bacteria,” are the original and thus oldest life on Earth. They have shaped the chemical environment of the Earth, but they are difficult to find as ancient fossils due to their subtle structure. Here we report well-preserved fossilized microbial communities in silicified bitumen concretions from unit 3 of the Xiamaling Formation (1.39?Ga) in northern China. The numerous silicified bitumen concretions are in a variety of forms including ellipsoidal, spindle, and pancake ones, with diameters of 1~16?cm and thicknesses of 0.5~3?cm. The principal planes of the concretions are at low angle or directly parallel to the depositional plane level, showing obvious depositional characteristics. The concretions are silicified with abundant bitumen inside. Many different kinds of microbial fossils are found in the bitumen, including spherical forms, rods, and filaments, and some of the microbes are aggregated together in the forms of multicellular structures. These concretions preserve a delicate Mesoproterozoic biotic community. Wang, Y.-C., Xue, Y.-B., Wang, X.-X., 2017. Study on the structure of small molecule compounds and their functional groups in coal. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects 39, 1733-1738. molecular compounds from Yanzhou Coal and Shenfu coal were extracted with tetrahydrofuran (THF). The experimental results showed that the end point of the solvent extraction of coal by THF was determined as 12?h. At this point, the extraction rates (ERs) of Yanzhou coal and Shenfu coal were 14 and 10.7%, respectively. The experimental results of the molecular weight and density showed that the extracted materials were the small molecular compounds. The IR characterization indicated that the structure of the small molecular compounds contained mainly the functional groups of aliphatic hydrocarbon, cycloalkane, aromatic hydrocarbons, alcohols, and ethers.Wang, Y., Feng, R., Wang, R., Yang, F., Li, P., Wan, J.-B., 2017. Enhanced MS/MS coverage for metabolite identification in LC-MS-based untargeted metabolomics by target-directed data dependent acquisition with time-staggered precursor ion list. Analytica Chimica Acta 992, 67-75. identification is one of the major bottlenecks in liquid chromatography-mass spectrometry (LC-MS)-based untargeted metabolomics owing to the difficulty of acquiring MS/MS information of most metabolites detected. Data dependent acquisition (DDA) has been currently used to acquire MS/MS data in untargeted metabolomics. When dealing with the complex biological samples, top-n-based DDA method selects only a small fraction of the ions for fragmentation, leading to low MS/MS coverage of metabolites in untargeted metabolomics. In this study, we proposed a novel DDA method to improve the performance of MS/MS acquisition in LC-MS-based untargeted metabolomics using target-directed DDA (t-DDA) with time-staggered precursor ion lists (ts-DDA). Full scan-based untargeted analysis was applied to extract the target ions. After peak alignment, ion filtration, and ion fusion, the target precursor ion list was generated for subsequent t-DDA and ts-DDA. Compared to the conventional DDA, the ts-DDA exhibits the better MS/MS coverage of metabolomes in a plasma sample, especially for the low abundant metabolites. Even in high co-elution zones, the ts-DDA also showed the superiority in acquiring MS/MS information of co-eluting ions, as evidenced by better MS/MS coverage and MS/MS efficiency, which was mainly attributed to the pre-selection of precursor ion and the reduced number of concurrent ions. The newly developed method might provide more informative MS/MS data of metabolites, which will be helpful to increase the confidence of metabolite identification in untargeted metabolomics.Wang, Y., Wang, Y., Du, W., 2017. A rare disc-like holdfast of the Ediacaran macroalga from South China. Journal of Paleontology 91, 1091. fixing organ of the Precambrian macroalga was briefly described by most researchers as a holdfast or rhizoid, suggesting a fixation structure and/or tissue differentiation. An Ediacaran macroscopic alga, Discusphyton whenghuiensis n. gen. n. sp., with a complex disc-like holdfast and an unbranching thallus, has been collected, together with abundant and diverse macrofossils (i.e., the Wenghui biota) in black shales of the upper Doushantuo Formation (~560–551 Ma) in northeastern Guizhou, South China. The Wenghui biota lived in a relatively low-energy marine environment and was preserved in situ or nearby their growth position. Morphologically, the macroalgal thallus, including the compressed lamina and cylindrical stipe, might have been suspended in the water column for photosynthesis. Its holdfast, a rare fixing form, is complex in structure and construction, consisting of a globular rhizome and a discoidal rhizoid. The large-sized discoidal rhizoid is regarded as a flat-bottomed and dome-shaped organ to attach the macroalga on the water-rich muddy seafloor. The globular rhizome, expanded by a thallus on the substrate, was originally harder and spherical nature within the dome-shaped rhizoid. It may have been an important organ as a steering knuckle to connect between the stipe and the rhizoid. The macroscopic metaphyte D. whenghuiensis n. gen. n. sp. shows the appearance of complex holdfast in morphology and bio-functions. However, not enough is known, in the absence of more information, to decipher the phylogenetic affinity of D. whenghuiensis n. gen. n. sp. and the origin of a discoidal rhizoid.Wang, Z., Glais, Y., Qiao, L., Huang, A., Liu, J., 2018. Hydro-geochemical analysis of the interplay between the groundwater, host rock and water curtain system for an underground oil storage facility. Tunnelling and Underground Space Technology 71, 466-477. analysis was performed to investigate the interplay between the groundwater, host rock and water curtain system for the start-up of a pilot underground oil storage facility in China. 54 groundwater samples were collected and analyzed to obtain the characteristics of the hydro-geochemical environment evolution for the start-up period. The groundwater-rock mass interaction was studied with comparing the changes in the ion concentrations, pH values and total dissolved solid concentrations in the groundwater and a mineralogical analysis of the host rock. The groundwater-water curtain system interaction was identified using statistical analysis of the similarity in chemical contents in the groundwater samples. A mixing calculation was performed to evaluate the mixing ratios of the water curtain system, background water and oil/vapor in the seepage water into the storage caverns. It was concluded that calcium carbonate equilibrium is the predominant chemical reaction. The 54 groundwater samples could be classified into 5 clusters. Among the 5 clusters, there is one cluster showing that the tap water injected to the water curtain system is similar in chemical contents to those in the monitoring boreholes around the facility, which confirms the efficiency of the water curtain system for the start-up of the facility. It was found that the two dominant factors influencing the evolution of groundwater chemical content were host rock dissolution and groundwater seepage. Most of seepage water was originated from oil/vapor and water curtain system while the percentage from the background water was almost zero in the start-up period of the facility.Ward, C.P., Nalven, S.G., Crump, B.C., Kling, G.W., Cory, R.M., 2017. Photochemical alteration of organic carbon draining permafrost soils shifts microbial metabolic pathways and stimulates respiration. Nature Communications 8, Article 772. sunlit waters, photochemical alteration of dissolved organic carbon (DOC) impacts the microbial respiration of DOC to CO2. This coupled photochemical and biological degradation of DOC is especially critical for carbon budgets in the Arctic, where thawing permafrost soils increase opportunities for DOC oxidation to CO2 in surface waters, thereby reinforcing global warming. Here we show how and why sunlight exposure impacts microbial respiration of DOC draining permafrost soils. Sunlight significantly increases or decreases microbial respiration of DOC depending on whether photo-alteration produces or removes molecules that native microbial communities used prior to light exposure. Using high-resolution chemical and microbial approaches, we show that rates of DOC processing by microbes are likely governed by a combination of the abundance and lability of DOC exported from land to water and produced by photochemical processes, and the capacity and timescale that microbial communities have to adapt to metabolize photo-altered DOC.Ward, L.M., Idei, A., Terajima, S., Kakegawa, T., Fischer, W.W., McGlynn, S.E., 2017. Microbial diversity and iron oxidation at Okuoku-hachikurou Onsen, a Japanese hot spring analog of Precambrian iron formations. Geobiology 15, 817-835. iron formations (BIFs) are rock deposits common in the Archean and Paleoproterozoic (and regionally Neoproterozoic) sedimentary successions. Multiple hypotheses for their deposition exist, principally invoking the precipitation of iron via the metabolic activities of oxygenic, photoferrotrophic, and/or aerobic iron-oxidizing bacteria. Some isolated environments support chemistry and mineralogy analogous to processes involved in BIF deposition, and their study can aid in untangling the factors that lead to iron precipitation. One such process analog system occurs at Okuoku-hachikurou (OHK) Onsen in Akita Prefecture, Japan. OHK is an iron- and CO2-rich, circumneutral hot spring that produces a range of precipitated mineral textures containing fine laminae of aragonite and iron oxides that resemble BIF fabrics. Here, we have performed 16S rRNA gene amplicon sequencing of microbial communities across the range of microenvironments in OHK to describe the microbial diversity present and to gain insight into the cycling of iron, oxygen, and carbon in this ecosystem. These analyses suggest that productivity at OHK is based on aerobic iron-oxidizing Gallionellaceae. In contrast to other BIF analog sites, Cyanobacteria, anoxygenic phototrophs, and iron-reducing micro-organisms are present at only low abundances. These observations support a hypothesis where low growth yields and the high stoichiometry of iron oxidized per carbon fixed by aerobic iron-oxidizing chemoautotrophs like Gallionellaceae result in accumulation of iron oxide phases without stoichiometric buildup of organic matter. This system supports little dissimilatory iron reduction, further setting OHK apart from other process analog sites where iron oxidation is primarily driven by phototrophic organisms. This positions OHK as a study area where the controls on primary productivity in iron-rich environments can be further elucidated. When compared with geological data, the metabolisms and mineralogy at OHK are most similar to specific BIF occurrences deposited after the Great Oxygenation Event, and generally discordant with those that accumulated before it.Watanabe, Y., Kashiwabara, T., Ishibashi, J.-i., Sekizawa, O., Nitta, K., Uruga, T., Takahashi, Y., 2017. Different partitioning behaviors of molybdenum and tungsten in a sediment–water system under various redox conditions. Chemical Geology 471, 38-51. (Mo) and tungsten (W) are redox-sensitive elements that exhibit contrasting geochemical behaviors under different redox and/or sulfidic conditions despite belonging to the same group in the periodic table. In this study, the geochemistry of Mo and W in a sediment–porewater system was investigated using a core sample collected from sediment containing hydrothermal minerals (Izena Hole, Okinawa, Japan). The Mo contents in the sediment and the porewater were quantified to calculate the partition coefficient Kd (concentration ratio of the solid phase to the aqueous phase) for Mo. However, the W concentration in the porewater was exceedingly low to be detected. Thus, we also conducted laboratory experiments simulating the sediment–porewater system to clarify the partitioning behaviors of Mo and W under redox conditions. X-ray absorption near-edge structure (XANES) spectra were obtained to determine the chemical species of Mo and W in sediment at different depths to understand the chemical processes of Mo and W. In particular, high-sensitivity XANES spectroscopy using wavelength-dispersive fluorescence mode was applied to W L3 edge XANES spectra to reduce the interference signals from coexistent elements (Zn and Ni). This step thereby facilitating the identification of oxygen- and sulfur-coordinated species for W in the sediments.The collected core sample covered a broad range of redox conditions under various hydrogen sulfide (H2S) concentrations depending on the depth. The presence of iron oxides in the upper layer suggested an oxic condition above within 4 cm depth below the seafloor (cmbsf). Iron and Zn sulfide minerals were found in deeper layers (16–24 cmbsf) and indicated the reductive conditions formed in such layer. Hydrogen sulfide was also observed in the porewater of the deeper layer. Analyses for Mo in the natural sediments, as well as XANES analyses, revealed that the Kd was higher in the deeper layer, with high pyrite and H2S contents, than in the upper layer. These results implied that Mo was removed from the porewater under reductive and/or sulfidic conditions. The chemical species of Mo was also an oxygen-coordinated species in the upper layer (0–8 cmbsf). Meanwhile, the detection of sulfide in the deeper layer suggests that Mo sulfidation is an important reaction in Mo enrichment in sediments.On the other hand, at all the depths, W formed oxygen-coordinated species in the sediment. The subtle change of Kd for W with depth suggested that H2S did not affect the W adsorption in our samples. Hence, the Mo/W ratio in the sediments increased with the development of reducing conditions and vice versa in the coexistent porewater. Speciation analysis revealed that the high stability of oxygen-coordinated species of W was responsible for the variations of the Mo/W ratio under various redox conditions.Wnorowski, A., Charland, J.-P., 2017. Profiling quinones in ambient air samples collected from the Athabasca region (Canada). Chemosphere 189, 55-66. paper presents new findings on polycyclic aromatic hydrocarbon oxidation products–quinones that were collected in ambient air samples in the proximity of oil sands exploration. Quinones were characterized for their diurnal concentration variability, phase partitioning, and molecular size distribution. Gas-phase (GP) and particle-phase (PM) ambient air samples were collected separately in the summer; a lower quinone content was observed in the PM samples from continuous 24-h sampling than from combined 12-h sampling (day and night). The daytime/nocturnal samples demonstrated that nighttime conditions led to lower concentrations and some quinones not being detected. The highest quinone levels were associated with wind directions originating from oil sands exploration sites. The statistical correlation with primary pollutants directly emitted from oil sands industrial activities indicated that the bulk of the detected quinones did not originate directly from primary emission sources and that quinone formation paralleled a reduction in primary source NOx levels. This suggests a secondary chemical transformation of primary pollutants as the origin of the determined quinones. Measurements of 19 quinones included five that have not previously been reported in ambient air or in Standard Reference Material 1649a/1649b and seven that have not been previously measured in ambient air in the underivatized form. This is the first paper to report on quinone characterization in secondary organic aerosols originating from oil sands activities, to distinguish chrysenequinone and anthraquinone positional isomers in ambient air, and to report the requirement of daylight conditions for benzo[a]pyrenequinone and naphthacenequinone to be present in ambient air.Wong, M.L., Charnay, B.D., Gao, P., Yung, Y.L., Russell, M.J., 2017. Nitrogen oxides in early Earth's atmosphere as electron acceptors for life's emergence. Astrobiology 17, 975-983. quantify the amount of nitrogen oxides (NOx) produced through lightning and photochemical processes in the Hadean atmosphere to be available in the Hadean ocean for the emergence of life. Atmospherically generated nitrate (NO3?) and nitrite (NO2?) are the most attractive high-potential electron acceptors for pulling and enabling crucial redox reactions of autotrophic metabolic pathways at submarine alkaline hydrothermal vents. The Hadean atmosphere, dominated by CO2 and N2, will produce nitric oxide (NO) when shocked by lightning. Photochemical reactions involving NO and H2O vapor will then produce acids such as HNO, HNO2, HNO3, and HO2NO2 that rain into the ocean. There, they dissociate into or react to form nitrate and nitrite. We present new calculations based on a novel combination of early-Earth global climate model and photochemical modeling, and we predict the flux of NOx to the Hadean ocean. In our 0.1-, 1-, and 10-bar pCO2 models, we calculate the NOx delivery to be 2.4?×?105, 6.5?×?108, and 1.9?×?108 molecules cm?2 s?1. After only tens of thousands to tens of millions of years, these NOx fluxes are expected to produce sufficient (micromolar) ocean concentrations of high-potential electron acceptors for the emergence of life.Wood, D.A., 2017. Re-establishing the merits of thermal maturity and petroleum generation multi-dimensional modeling with an Arrhenius Equation using a single activation energy. Journal of Earth Science 28, 804-834. maturation and petroleum generation modeling of shales is essential for successful exploration and exploitation of conventional and unconventional oil and gas plays. For basin-wide unconventional resource plays such modeling, when well calibrated with direct maturity measurements from wells, can characterize and locate production sweet spots for oil, wet gas and dry gas. The transformation of kerogen to petroleum is associated with many chemical reactions, but models typically focus on first-order reactions with rates determined by the Arrhenius Equation. A misconception has been perpetuated for many years that accurate thermal maturity modeling of vitrinite reflectance using the Arrhenius Equation and a single activation energy, to derive a time-temperature index (ΣTTIARR), as proposed by Wood (1988), is flawed. This claim was initially made by Sweeney and Burnham (1990) in promoting their “EasyRo” method, and repeated by others. This paper demonstrates through detailed multi-dimensional burial and thermal modeling and direct comparison of the ΣTTIARR and “EasyRo” methods that this is not the case. The ΣTTIARR method not only provides a very useful and sensitive maturity index, it can reproduce the calculated vitrinite reflectance values derived from models based on multiple activation energies (e.g., “EasyRo”). Through simple expressions the ΣTTIARR method can also provide oil and gas transformation factors that can be flexibly scaled and calibrated to match the oil, wet gas and dry gas generation windows. This is achieved in a more-computationally-efficient, flexible and transparent way by the ΣTTIARR method than the “EasyRo” method. Analysis indicates that the “EasyRo” method, using twenty activation energies and a constant frequency factor, generates reaction rates and transformation factors that do not realistically model observed kerogen behaviour and transformation factors over geologic time scales.Wood, D.A., Hazra, B., 2017. Characterization of organic-rich shales for petroleum exploration & exploitation: A review-Part 1: Bulk properties, multi-scale geometry and gas adsorption. Journal of Earth Science 28, 739-757., the most abundant of sedimentary rocks, are valued as the source-rocks and seals to porous petroleum reservoirs. Over the past-twenty years, organic-rich shales have also emerged as valuable petroleum systems (reservoir, seal, and source rocks contained in the same formation). As such they have become primary targets for petroleum exploration and exploitation. This Part 1 of a three-part review addresses the bulk properties, multi-scale geometry and gas adsorption characteristics of these diverse and complex rocks. Shales display extremely low permeability, and their porosity is also low, but multi-scale. Characterizing the geometry and interconnectivity of the pore-structure frameworks with the natural-fracture networks within shales is essential for establishing their petroleum exploitation potential. Organic-rich shales typically contain two distinct types of porosity: matrix porosity and fracture porosity. In addition to inter-granular porosity, the matrix porosity includes two types of mineral-hosted porosity: inorganic-mineral-hosted porosity (IP); and, organic-matter-hosted (within the kerogen) porosity (OP). Whereas, the fracture porosity and permeability is crucial for petroleum production from shales, it is within the OP where, typically, much of the in-situ oil and gas resources resides, and from where it needs to be mobilized. OP increases significantly as shales become more thermally mature (i.e., within the gas generation zones), and plays a key role in the ultimate recovery from shale-gas systems. Shales’ methane sorption capacities (MSC) tends to be positively correlated with their total organic carbon content (TOC), thermal maturation, and micropore volume. Clay minerals also significantly influence key physical properties of shale related to fluid flow (permeability) and response to stress (fracability) that determine their prospectivity for petroleum exploitation. Clay minerals can also adsorb gas, some much better than others. The surface area of the pore structure of shales can be positively or negatively correlated with TOC content, depending upon mineralogy and thermal maturity, and can influence its gas adsorption capacity. Part 2 of this three-part review considers, in a separate article, the geochemistry and thermal maturity characteristics of shale; whereas Part 3, addresses the geomechanical attributes of shales, including their complex wettability, adsorption, water imbibition and “fracability” characteristics. The objectives of this Part 1 of the review is to identify important distinguishing characteristics related to the bulk properties of the most-prospective, petroleum-rich shales.Wood, D.A., Hazra, B., 2017. Characterization of organic-rich shales for petroleum exploration & exploitation: A review-Part 2: Geochemistry, thermal maturity, isotopes and biomarkers. Journal of Earth Science 28, 758-778. shale exploitation is still in its infancy outside North America much research effort is being channelled into various aspects of geochemical characterization of shales to identify the most prospective basins, formations and map their petroleum generation capabilities across local, regional and basin-wide scales. The measurement of total organic carbon, distinguishing and categorizing the kerogen types in terms oil-prone versus gas-prone, and using vitrinite reflectance and Rock-Eval data to estimate thermal maturity are standard practice in the industry and applied to samples from most wellbores drilled. It is the trends of stable isotopes ratios, particularly those of carbon, the wetness ratio (C1/Σ(C2+C3)), and certain chemical biomarkers that have proved to be most informative about the status of shales as a petroleum system. These data make it possible to identify production “sweet-spots”, discriminate oil-, gas-liquid- and gas-prone shales from kerogen compositions and thermal maturities. Rollovers and reversals of ethane and propane carbon isotope ratios are particularly indicative of high thermal maturity exposure of an organic-rich shale. Comparisons of hopane, strerane and terpane biomarkers with vitrinite reflectance (Ro) measurements of thermal maturity highlight discrepancies suggesting that Ro is not always a reliable indicator of thermal maturity. Major and trace element inorganic geochemistry data and ratios provides useful information regarding provenance, paleoenvironments, and stratigraphic-layer discrimination. This review considers the data measurement, analysis and interpretation of techniques associated with kerogen typing, thermal maturity, stable and non-stable isotopic ratios for rocks and gases derived from them, production sweet-spot identification, geochemical biomarkers and inorganic chemical indicators. It also highlights uncertainties and discrepancies observed in their practical application, and the numerous outstanding questions associated with them.Wood, D.A., Hazra, B., 2017. Characterization of organic-rich shales for petroleum exploration & exploitation: A review-Part 3: Applied geomechanics, petrophysics and reservoir modeling. Journal of Earth Science 28, 779-803. geomechanical properties of shales to make sense of their complex properties is at the forefront of petroleum exploration and exploitation application and has received much research attention in recent years. A shale’s key geomechanical properties help to identify its “fracibility” its fluid flow patterns and rates, and its in-place petroleum resources and potential commercial reserves. The models and the information they provide, in turn, enable engineers to design drilling patterns, fracture-stimulation programs and materials selection that will avoid formation damage and optimize recovery of petroleum. A wide-range of tools, technologies, experiments and mathematical techniques are deployed to achieve this. Characterizing the interconnected fracture, permeability and porosity network is an essential step in understanding a shales highly-anisotropic features on multiple scales (nano to macro). Well-log data, and its petrophysical interpretation to calibrate many geomechanical metrics to those measured in rock samples by laboratory techniques plays a key role in providing affordable tools that can be deployed cost-effectively in multiple well bores. Likewise, microseismic data helps to match fracture density and propagation observed on a reservoir scale with predictions from simulations and laboratory tests conducted on idealised/simplified discrete fracture network models. Shales complex wettability, adsorption and water imbibition characteristics have a significant influence on potential formation damage during stimulation and the short-term and long-term flow of petroleum achievable. Many gas flow mechanisms and models are proposed taking into account the multiple flow mechanisms involved (e.g., desorption, diffusion, slippage and viscous flow operating at multiple porosity levels from nano- to macro-scales). Fitting historical production data and well decline curves to model predictions helps to verify whether model’s geomechanical assumptions are realistic or not. This review discusses the techniques applied and the models developed that are relevant to applied geomechanics, highlighting examples of their application and the numerous outstanding questions associated with them.Wu, L., Chládková, B., Lechtenfeld, O.J., Lian, S., Schindelka, J., Herrmann, H., Richnow, H.H., 2018. Characterizing chemical transformation of organophosphorus compounds by 13C and 2H stable isotope analysis. Science of The Total Environment 615, 20-28. and excessive use of organophosphorus compounds (OPs) has led to environmental contaminations which raise public concerns. This study investigates the isotope fractionation patterns of OPs in the aquatic environment dependence upon hydrolysis, photolysis and radical oxidation processes. The hydrolysis of parathion (EP) and methyl parathion (MP) resulted in significant carbon fractionation at lower pH (pH 2–7, εC = ? 6.9 ~ ? 6.0‰ for EP, ? 10.5 ~ ? 9.9‰ for MP) but no detectable carbon fractionation at higher pH (pH 12). Hydrogen fractionation was not observed during any of the hydrolysis experiments. These results indicate that compound specific isotope analysis (CSIA) allows distinction of two different pH-dependent pathways of hydrolysis. Carbon and hydrogen isotope fractionation were determined during UV/H2O2 photolysis of EP and tris(2-chloroethyl) phosphate (TCEP). The constant δ2H values determined during the OH radical reaction of EP suggested that the rate-limiting step proceeded through oxidative attack by OH radical on the PS bond. The significant H isotope enrichment suggested that OH radical oxidation of TCEP was caused by an H-abstraction during the UV/H2O2 processes (εH = ? 56 ± 3‰). Fenton reaction was conducted to validate the H isotope enrichment of TCEP associated with radical oxidation, which yielded εH of ? 34 ± 5‰. Transformation products of OPs during photodegradation were identified using Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS). This study highlights that the carbon and hydrogen fractionation patterns have the potential to elucidate the transformation of OPs in the environment.Wu, S., Chen, Z.-Q., Fang, Y., Pei, Y., Yang, H., Ogg, J., 2017. A Permian-Triassic boundary microbialite deposit from the eastern Yangtze Platform (Jiangxi Province, South China): Geobiologic features, ecosystem composition and redox conditions. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 58-73. Permian-Triassic (P-Tr) boundary microbialite (PTB-microbialite) deposit occurs near Xiushui on the southern margin of the eastern Yangtze Platform, South China. This 2-m-thick microbialite overlies uppermost Permian bioclastic limestone with a 5-cm-thick oolite-like grainstone layer at the contact. This PTB-microbialite consists of lower thrombolite (1.5-m thick) and an upper dendrolite (0.5-m thick). The thrombolite interval is characterized by a clotted texture of reddish sparitic patches embedded in a gray micritic matrix, whereas the dendrolite texture consists of brownish sparitic patches embedded within a yellow micritic matrix. Abundant calcified microbes occur in both the thrombolite and the dendrolite, including 1) columnar and clustered fabrics, which are especially rich in the thrombolite, assigned as products of Gakhumella or related microorganisms and 2) microspheroids, 40–60 μm in diameter, with different interior structures. These calcimicrobes are considered to have played an important role in constructing the Xiushui PTB-microbialite. The demise of the microbialite was likely due to a sea-level fall during the early Griesbachian (lowermost Triassic), which resulted in a lowering of the wave base thereby destroying the microbialite frameworks and facilitating the deposition of winnowed skeletal grainstone. Metazoan community structures within the microbialite changed sharply across the end-Permian extinction horizon, which is placed at a sharp negative shift in δ13Ccarb. Quantitative analyses show that the Xiushui microbialite community is similar to that of Chongyang and Cili microbialites. This is probably because all of these microbialites grew along the margins of the Lower Yangtze region during the P-Tr transition. However, unlike other PTB-microbialites, the Xiushui ecosystem contains fairly abundant metazoans, which are dominated by ostracods with minor occurrences of foraminifers, microgastropods and microconchids. Both the ostracod assemblage and the pyrite framboid analyses indicate an upper dysoxic zone to a well-oxygenated condition for the Xiushui microbialite. This implies that some PTB-microbialite ecosystems developed in conditions that were not always harsh; instead, some were hospitable for some metazoans to survive immediately after the end-Permian crisis. Considering that the redox conditions indicated by PTB-microbialites are quite variable, we infer that oxygen levels probably were not the crucial factor affecting the growth of the PTB-microbialites.Wünsch, U.J., Murphy, K.R., Stedmon, C.A., 2017. The one-sample PARAFAC approach reveals molecular size distributions of fluorescent components in dissolved organic matter. Environmental Science & Technology 51, 11900-11908. size plays an important role in dissolved organic matter (DOM) biogeochemistry, but its relationship with the fluorescent fraction of DOM (FDOM) remains poorly resolved. Here high-performance size exclusion chromatography (HPSEC) was coupled to fluorescence emission-excitation (EEM) spectroscopy in full spectral (60 emission and 34 excitation wavelengths) and chromatographic resolution (<1 Hz), to enable the mathematical decomposition of fluorescence on an individual sample basis by parallel factor analysis (PARAFAC). The approach allowed cross-system comparisons of molecular size distributions for individual fluorescence components obtained from independent data sets. Spectra extracted from allochthonous DOM were highly similar. Allochthonous and autochthonous DOM shared some spectra, but included unique components. In agreement with the supramolecular assembly hypothesis, molecular size distributions of the fluorescence fractions were broad and chromatographically unresolved, possibly representing reoccurring fluorophores forming noncovalently bound assemblies of varying molecular size. Samples shared underlying fluorescence components that differed in their size distributions but not their spectral properties. Thus, in contrast to absorption measurements, bulk fluorescence is unlikely to reliably indicate the average molecular size of DOM. The one-sample approach enables robust and independent cross-site comparisons without large-scale sampling efforts and introduces new analytical opportunities for elucidating the origins and biogeochemical properties of FDOM.Xaaldi Kalhor, A., Movafeghi, A., Mohammadi-Nassab, A.D., Abedi, E., Bahrami, A., 2017. Potential of the green alga Chlorella vulgaris for biodegradation of crude oil hydrocarbons. Marine Pollution Bulletin 123, 286-290. production and/or transportation can cause severe environmental pollution and disrupt the populations of living organisms. In the present study, biodegradation of petroleum hydrocarbons is investigated using Chlorella vulgaris as a green algal species. The microalga was treated by 10 and 20 g/l crude oil/water concentrations at two experimental durations (7 and 14 days). Based on the results obtained, C. vulgaris owned not only considerable resistance against the pollutants but also high ability in remediation of crude oil hydrocarbons (~ 94% of the light and ~ 88% of heavy compounds in 14 days). Intriguingly, dry weight of C. vulgaris increased by the rising crude oil concentration indicating the positive effect of crude oil on the growth of the algal species. This biodegradation process is remarkably a continuous progression over a period of time.Xiang, L., Wei, J., Tian, X.Y., Wang, B., Chan, W., Li, S., Tang, Z., Zhang, H., Cheang, W.S., Zhao, Q., Zhao, H., Yang, Z., Hong, Y., Huang, Y., Cai, Z., 2017. Comprehensive analysis of acylcarnitine species in db/db mouse using a novel method of high-resolution parallel reaction monitoring reveals widespread metabolic dysfunction induced by diabetes. Analytical Chemistry 89, 10368-10375. are exerting a variety of biological functions depending on the differences in lengths, saturation levels, and conjugation groups, which to a great extent contribute to the challenges of acylcarnitines quantifications due to various kinds of isomers. Here, we describe a novel method by using high-resolution parallel reaction monitoring (PRM) liquid chromatography-tandem mass spectrometry (LC-MS/MS). Both reversed-phase and normal-phase column were used in order to get accurate, reliable, widespread quantification of acylcarnitines, and without tedious sample preparation procedure. The method provided the most comprehensive acylcarnitine profile with high-resolution MS and MS/MS confirmation to date. A total of 117 acylcarnitines were detected from plasma and urine samples. The application of targeted profiling of acylcarnitines in db/m+ control and db/db diabetic mice indicated incomplete amino acid and fatty acid oxidation on diabetic mice. Interestingly, the reduction of medium odd-numbered chain acylcarnitines in urine samples was first observed between db/m+ and db/db mice. The high-resolution PRM method makes it possible to monitor the widespread metabolic changes of the acylcarnitines in response to stimuli. Besides, the accurate MS and MS/MS spectra data of the 117 acylcarnitines could be used as mass spectrometric resources for the identification of acylcarnitines.Xiao, S., Bykova, N., Kovalick, A., Gill, B.C., 2017. Stable carbon isotopes of sedimentary kerogens and carbonaceous macrofossils from the Ediacaran Miaohe Member in South China: Implications for stratigraphic correlation and sources of sedimentary organic carbon. Precambrian Research 302, 171-179. stratigraphic correlation depends on the integration of paleontological and δ13Ccarb data. However, these data often come from different lithologies (e.g., shales vs. carbonates), making it difficult to directly link biostratigraphic and chemostratigraphic markers. Ediacaran successions in South China consist of mixed carbonates and shales, offering an opportunity for integrated biostratigraphic and chemostratigraphic investigations. Black shales of the Ediacaran Miaohe Member in the Yangtze Gorges area contain macroalgae and Ediacara-type macrofossils, both preserved as carbonaceous compressions. The Miaohe Member has been traditionally regarded as an equivalent to Member IV of the uppermost Doushantuo Formation that records part of the Shuram negative δ13Ccarb excursion in South China. Thus, the Miaohe Member may have the potential to clarify the stratigraphic relationship between Ediacara-type fossils and the Shuram excursion. Recently, however, the Miaohe Member has been partially correlated with the Shibantan Member of the Dengying Formation (the “A” correlation) or partially with Member IV (the “Z” correlation). These correlations have different implications for the relationship between the Miaohe Member and the Shuram excursion. Here we test these two correlations using δ13C data of sedimentary kerogen or total organic carbon (δ13CorgTOC), taking advantage of the distinct δ13CorgTOC values between the Shibantan Member and Member IV. Our data show that δ13CorgTOC of the Miaohe Member is more similar to that of Member IV than to Shibantan Member, providing tentative support for the “Z” correlation. In addition, we also analyzed δ13Corg of individual carbonaceous compression fossils (δ13Corgtaxon), which have lower carbon isotope values than TOC. The data suggest that oxygenic photosynthesizers (e.g., macroalgae, cyanobacteria, and eukaryotic phytoplankton) were not the only contributors to sedimentary TOC. Methylotrophs, photoautotrophs, and chemoautotrophs living in anoxic waters or at the oxycline may have fixed recycled CO2 derived from organic carbon remineralization, thus contributing a significant amount of 13C-depleted organic carbon to sedimentary kerogen in the Miaohe Member.Xie, Y., Sen, B., Wang, G., 2017. Mining terpenoids production and biosynthetic pathway in thraustochytrids. Bioresource Technology 244, 1269-1280. are major bioactive compounds produced by microalgae and other eukaryotic microorganisms. Mining metabolic potential of marine microalgae for commercial production of terpenoids suggest thraustochytrids as one of the promising cell factories. The identification of potential thraustochytrid strains and relevant laboratory scale bioprocesses has been pursued largely. Further investigations in the improvement of terpenoids biosynthesis expect relevant molecular mechanisms to be understood directing metabolic engineering of the pathways. In this review, fermentative and mechanistic studies to identify key enzymes and pathways that are associated to terpenoids biosynthesis in thraustochytrids are discussed. Exploration of biosynthesis mechanisms in other model organisms facilitated identification of potential molecular targets for engineering terpenoids biosynthetic pathway in thraustochytrids. In addition, the preliminary genetic manipulation and in silico analysis in this review provides a platform for system-level metabolic engineering towards thraustochytrid strains improvement. Overall, the review contributes comprehensive information to allow better terpenoids productivity in thraustochytrids.Xing, T., Liu, Y., Wang, N., Xu, B., Liu, K., Shen, L., Gu, Z., Guo, B., Zhou, Y., Liu, H., 2017. Erythrobacter arachoides sp. nov., isolated from ice core. International Journal of Systematic and Evolutionary Microbiology 67, 4235-4239. Gram-stain-negative, rod-shaped bacterial strain, designed RC4-10-4T, belonging to the genus Erythrobacter , was isolated from the East Rongbuk Glacier on the Tibetan Plateau. Strain RC4-10-4T grew optimally at pH 7.0, at 25?°C and in the presence of 2?% (w/v) NaCl. Summed feature 3 (C16?:?1?ω6c and/or iso-C15?:?0 2-OH), summed feature 8 (C18?:?1?ω7c and/or C18?:?1?ω6c) and C16?:?0 were the major fatty acids. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, sphingoglycolipid and phosphatidylcholine. Carotenoid was detected in the cells. The DNA G+C?content of the novel strain was 66.4?mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain RC4-10-4T formed a distinct phylogenetic lineage within the cluster comprising Erythrobacter strains. Similarities between the 16S rRNA gene sequences of strain RC4-10-4T and the closely related strains Erythrobacter luteus KCTC 42179T, Erythrobacter gangjinensis KCTC 22330T, Erythrobacter odishensis KCTC 23981T and Erythrobacter atlanticuls KCTC 42697T were 98.0, 97.6, 97.5 and 97.2?%. The DNA–DNA hybridization values were 37.6, 15.4, 29.8 and 35.8?%, respectively. Based on the phenotypic and phylogenetic characteristics, strain RC4-10-4T represents a novel species of the genus Erythrobacter , for which the name Erythrobacter arachoides sp. nov. is proposed, with the type strain RC4-10-4T (=CGMCC 1.15507T=JCM 31277T). The GenBank accession number for the 16S rRNA gene sequence of strain RC4-10-4T is KU302715.Xiong, W., Cano, M., Wang, B., Douchi, D., Yu, J., 2017. The plasticity of cyanobacterial carbon metabolism. Current Opinion in Chemical Biology 41, 12-19. opinion article aims to raise awareness of a fundamental issue which governs sustainable production of biofuels and bio-chemicals from photosynthetic cyanobacteria. Discussed is the plasticity of carbon metabolism, by which the cyanobacterial cells flexibly distribute intracellular carbon fluxes towards target products and adapt to environmental/genetic alterations. This intrinsic feature in cyanobacterial metabolism is being understood through recent identification of new biochemical reactions and engineering on low-throughput pathways. We focus our discussion on new insights into the nature of metabolic plasticity in cyanobacteria and its impact on hydrocarbons (e.g. ethylene and isoprene) production. We discuss approaches that need to be developed to rationally rewire photosynthetic carbon fluxes throughout primary metabolism. We outline open questions about the regulatory mechanisms of the metabolic network that remain to be answered, which might shed light on photosynthetic carbon metabolism and help optimize design principles in order to improve the production of fuels and chemicals in cyanobacteria.Xiong, W., Wells, R.K., Menefee, A.H., Skemer, P., Ellis, B.R., Giammar, D.E., 2017. CO2 mineral trapping in fractured basalt. International Journal of Greenhouse Gas Control 66, 204-217. in basalt can provide substantial surface area for reactions, and limited mass transfer in fractures can allow accumulation of cations to form carbonate minerals in geologic carbon sequestration. In this study, flood basalt and serpentinized basalt with engineered fractures were reacted in water equilibrated with 10 MPa CO2 at 100 °C or 150 °C for up to 40 weeks. Carbonation in basalt fractures was observed as early as 6 weeks, with Mg- and Ca-bearing siderite formed in both basalts reacted at 100 °C and Mg-Fe-Ca carbonate minerals formed in the flood basalt reacted at 150 °C. X-ray μCT segmentation revealed that precipitates filled 5.4% and 15% (by volume) of the flood basalt fracture after 40 weeks of reaction at 100 °C and 150 °C, respectively. Zones of elevated carbonate abundance did not completely seal the fracture. Limited siderite clusters (<1% volume fraction) were found in localized areas in the serpentinized basalt fracture. A 1-dimensional reactive transport model developed in CrunchTope examined how geochemical gradients drive silicate mineral dissolution and carbonate precipitation in the fracture. The model predicts that siderite will form as early as 1 day after the addition of CO2. The predicted location of maximum siderite abundance is consistent with experimental observations, and the predicted total carbonate volumes are comparable to estimates derived from CT segmentation.Xu, H., Houghton, E.M., Houghton, C.J., Guo, L., 2018. Variations in size and composition of colloidal organic matter in a negative freshwater estuary. Science of The Total Environment 615, 931-941. variations in chemical composition and size distribution of dissolved organic matter (DOM) along the river-lake interface in the Fox River plume were investigated using ultrafiltration, flow field-flow fractionation, UV–Vis and fluorescence spectroscopy and parallel factor analysis. On average, ~ 67% of bulk dissolved organic carbon (DOC) were partitioned in the < 1 kDa (actual cutoff 2.5 kDa) low molecular weight fraction, and the other 33% were in the 1 kDa–0.7 μm colloidal phase. Concentrations of DOC and chromophoric DOM in the bulk and size-fractionated samples decreased monotonously with decreasing conductivity from river to bay waters, demonstrating a dominant terrestrial source and quasi conservative mixing behavior. However, the percentages of colloidal fluorescent-DOM increased while those of carbohydrates decreased from river to bay waters, showing different mixing behavior in the river plume. Colloidal chromophores and humic-like fluorophores were mainly partitioned in the size range of 1–6 nm, but a bimodal distribution (with peaks at 1–6 and 35–45 nm) was observed for colloidal protein-like DOM. Along the river-lake transect, the peak locations of chromophores, humic-like and small-sized protein-like colloids remained almost constant, while the larger-sized protein-like colloids exhibited a slight peak shift from 38.3 to 40.4 nm, showing a molecular size enhancement from high to low conductivity waters, with physical mixing, photochemical/microbial degradation, and disaggregation/repartitioning being the important processes affecting the variations of DOM size and composition. New results herein should enhance our understanding of the heterogeneity of DOM in size and composition and its fate, transport and transformation at the river-lake interface and along the aquatic continuum as a whole.Xu, J., Sun-Waterhouse, D., Qiu, C., Zhao, M., Sun, B., Lin, L., Su, G., 2017. Additional band broadening of peptides in the first size-exclusion chromatographic dimension of an automated stop-flow two-dimensional high performance liquid chromatography. Journal of Chromatography A 1521, 80-89. need to improve the peak capacity of liquid chromatography motivates the development of two-dimensional analysis systems. This paper presented a fully automated stop-flow two-dimensional liquid chromatography system with size exclusion chromatography followed by reversed phase liquid chromatography (SEC × RPLC) to efficiently separate peptides. The effects of different stop-flow operational parameters (stop-flow time, peak parking position, number of stop-flow periods and column temperature) on band broadening in the first dimension (1st D) SEC column were quantitatively evaluated by using commercial small proteins and peptides. Results showed that the effects of peak parking position and the number of stop-flow periods on band broadening were relatively small. Unlike stop-flow analysis of large molecules with a long running time, additional band broadening was evidently observed for small molecule analytes due to the relatively high effective diffusion coefficient (Deff). Therefore, shorter analysis time and lower 1st D column temperature were suggested for analyzing small molecules. The stop-flow two-dimensional liquid chromatography (2D-LC) system was further tested on peanut peptides and an evidently improved resolution was observed for both stop-flow heart-cutting and comprehensive 2D-LC analysis (in spite of additional band broadening in SEC). The stop-flow SEC × RPLC, especially heart-cutting analysis with shorter analysis time and higher 1st D resolution for selected fractions, offers a promising approach for efficient analysis of complex samples.Xu, Q., Jiang, H., Ma, D., Chen, X., Huang, J., Shi, L., 2017. Pyrolysis of a low asphaltene crude oil under idealized in situ combustion conditions. Energy & Fuels 31, 10545-10554. coke formation is crucial to the crude oil in situ combustion (ISC) process. This study provided some insights through analyzing the influences of temperature and reaction atmosphere on the coke chemical–structural property. Thin coke films were produced on the polished single-crystal Si surface from the Xinjiang crude oil. Their functional groups were compared by Fourier transform infrared spectroscopy (FTIR), while the nanostructures were characterized through Raman spectroscopy, X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HRTEM) techniques. In addition, the low-temperature oxidation (LTO) coke and the pyrolytic coke reactivities were investigated by thermogravimetric analyses. The results indicated that the main carbon structures in the pyrolytic coke were amorphous. No crystallization phenomena, such as the aromatic ring condensation and the planar stacking, were observed within the characteristic ISC pyrolytic temperature range. Despite the pyrolytic coke yield increase with the temperature, almost constant chemical–structural properties were conserved. This study compared the chemical–structural properties of the LTO coke and the pyrolytic coke from the ISC process. The greater oxidation rate of the LTO coke was attributed to the considerable O-containing groups.Xu, Y., Huang, Y., Hu, X., Yang, J., 2017. Hot topics in Phanerozoic deep-time climate research: Based on bibliometric analysis. Acta Sedimentologica Sinica 35, 994-1003 on data from ISI Web of Science database, we investigated the research topics in deep-time research since 1900. By analyzing the number of research articles, countries of authors, the themes and authors countries of Top 5% highly cited papers, we try to reveal the research focus and the international influence of Chinese scholars in the deep-time paleoclimate research filed. Our data shows that deep-time research has keep growing rapidly since 1990. The deep-time research mainly focuses on the paleoceanographic events, mass extinctions and their relationship to palaeoclimate, the palaeoclimate change (temperature, pCO2, etc.); Although the sum of research papers is concerned, China has become one of important contributors to deep-time climate research. However, the proportion of Chinese highly influential research is still very low. Yakubov, M.R., Milordov, D.V., Yakubova, S.G., Abilova, G.R., Sinyashin, K.O., Tazeeva, E.G., Borisova, U.U., Mironov, N.A., Morozov, V.I., 2017. Vanadium and paramagnetic vanadyl complexes content in asphaltenes of heavy oils of various productive sediments. Petroleum Science and Technology 35, 1468-1472. the atomic absorption spectrometry and electronic paramagnetic resonance techniques, we have investigated the features of vanadium and vanadyl complexes content in asphaltenes of heavy oils of Permian and Carboniferous productive sediments in the Volga-Ural oil and gas basin deposits. The investigation has been carried out using the heavy oils example, where the asphaltene content ranges from 5.1 to 21.2?wt%, and vanadium content varies in the range of 0.009-0.165?wt%. The specificity of asphaltene?vanadium relationship has been found for heavy oils of various productive sediments. It has been demonstrated that vanadium and vanadyl complexes content in asphaltenes of heavy oils in separate productive sediments varies in the certain range limits.Yan, G., Kim, G., 2017. Speciation and sources of brown carbon in precipitation at Seoul, Korea: Insights from excitation–emission matrix spectroscopy and carbon isotopic analysis. Environmental Science & Technology 51, 11580-11587. carbon (BrC) plays a significant role in the Earth’s radiative balance, yet its sources and chemical composition remain poorly understood. In this work, we investigated BrC in the atmospheric environment of Seoul by characterizing dissolved organic matter in precipitation using excitation–emission matrix (EEM) fluorescence spectroscopy coupled with parallel factor analysis (PARAFAC). The two independent fluorescent components identified by PARAFAC were attributed to humic-like substance (HULIS) and biologically derived material based on their significant correlations with measured HULIS isolated using solid-phase extraction and total hydrolyzable tyrosine. The year-long observation shows that HULIS contributes to 66 ± 13% of total fluorescence intensity of our samples on average. By using dual carbon (13C and 14C) isotopic analysis conducted on isolated HULIS, the HULIS fraction of BrC was found to be primarily derived from biomass burning and emission of terrestrial biogenic gases and particles (>70%), with minor contributions from fossil-fuel combustion. The knowledge derived from this study could contribute to the establishment of a characterizing system of BrC components identified by EEM spectroscopy. Our work demonstrates that, EEM fluorescence spectroscopy is a powerful tool in BrC study, on the basis of its chromophore resolving power, allowing investigation into individual components of BrC by other organic matter characterization techniques.Yan, P., Wang, Y., Liu, J., Zhong, G., Liu, X., 2017. Discovery of the southwest Dongsha Island mud volcanoes amid the northern margin of the South China Sea. Marine and Petroleum Geology 88, 858-870. Dongsha Basin, circling Dongsha Island that is amid the northern margin of the South China Sea, is characterized by thin (～0.5 km) Cenozoic sediments veneering on thick (up to 5 km) Mesozoic strata. Recently, several geophysical and geological surveys, including multiple channel reflection seismic, sub-bottom profiling and benthic dredging, have been conducted on the slope southwest to the Dongsha Island, where the water depth varies from 400 m to 2000 m. A novel discovery is numerous submarine mud volcanoes of various sizes over there, typically 50–200 m high and 0.5–5 km wide. Geophysical profiles document their unusual features, e.g., roughly undulating seafloor, high-amplitude seabed reflectivity, foggy hyperbolic diffractions up to 50 m in water column above seabed, and internal reflection chaos and wipe-out down to 2–3 km level or deeper below the seabed. Benthic dredging from the mud volcanoes gives abundant faunas of high diversity, e.g., scleractinian (stony coral), gorgonian, black coral, thiophil tubeworm, glass sponge, bryozoan etc., indicating booming chemosynthetic community, among which the Lophelia pertusa-like coral and the Euretidae-like glass sponges are the first reports in the South China Sea. Concomitantly with them, there are also abundant authigenic carbonate nodules and slabs, raw, brecciated and breccias with bio-clasts congregation. Besides, there coexist massive mudflows and allogenic coarse-grained quartz, feldspar and tourmaline most likely brought out by mud volcanism. Geochemical analysis of the bottom water samples give dissolved methane concentration up to 4 times higher than the background average. These results lend comprehensive evidences for the ongoing and historical mud volcanism. The escaping methane gas is inferred to source mainly from the Mesozoic strata. Occupying a large province of the deep water slope, ca. 1000 km2 or more, the mud volcanoes is prospective for gas hydrate and natural gas for the Dongsha Basin.Yang, J., Yan, J., Huang, Y., 2017. The Earth's penultimate icehouse-to-greenhouse climate transition and related sedimentary records in low-latitude regions of eastern Tethys. Acta Sedimentologica Sinica 35, 981-993. the Period of Pangea in the Carboniferous-Triassic time, there occurred the Earth's last climate transition from icehouse to greenhouse state, which provides an unique deeptime window to understand the climate impact of deglaciation and global warming in the near future. Studies on the sedimentary records of this period revealed that glaciation, atmosphere CO2 concentration and climate have complicated coupling and feedback mechanisms along with floral replacement on lands and faunal migration in oceans. Low-latitude continents became drying with seasonal precipitation corresponding with Gondwana deglaciation, atmosphere pCO2 rising and temperature increase especially in the west tropical Pangea and monsoon climate came into its acme during the Triassic when the landmass of Pangea symmetrically spreading across the equator. Both North China and South China were island land blocks in the low-latitude eastern Tethys region during the Carboniferous-Triassic era. There developed sedimentary and biological records quite different from the counterparts in the western tropical Pangea, achieving critical information for deeptime climate changes. In this contribution, we briefly review the Carboniferous-Triassic paleoclimate evolution and then discuss the related sedimentary records of North China and South China, pointing out several potential study topics for future deeptime paleoclimate research in China.Yang, W.H., McNicol, G., Teh, Y.A., Estera-Molina, K., Wood, T.E., Silver, W.L., 2017. Evaluating the classical versus an emerging conceptual model of peatland methane dynamics. Global Biogeochemical Cycles 31, 1435-1453. (CH4) is a potent greenhouse gas that is both produced and consumed in soils by microbially mediated processes sensitive to soil redox. We evaluated the classical conceptual model of peatland CH4 dynamics—in which the water table position determines the vertical distribution of methanogenesis and methanotrophy—versus an emerging model in which methanogenesis and methanotrophy can both occur throughout the soil profile due to spatially heterogeneous redox and anaerobic CH4 oxidation. We simultaneously measured gross CH4 production and oxidation in situ across a microtopographical gradient in a drained temperate peatland and ex situ along the soil profile, giving us novel insight into the component fluxes of landscape-level net CH4 fluxes. Net CH4 fluxes varied among landforms (p < 0.001), ranging from 180.3 ± 81.2 mg C m?2 d?1 in drainage ditches to ?0.7 ± 1.2 mg C m?2 d?1 in the highest landform. Contrary to prediction by the classical conceptual model, variability in methanogenesis alone drove the landscape-level net CH4 flux patterns. Consistent with the emerging model, freshly collected soils from above the water table produced CH4 within anaerobic microsites. Even in soil from beneath the water table, gross CH4 production was best predicted by the methanogenic fraction of carbon mineralization, an index of highly reducing microsites. We measured low rates of anaerobic CH4 oxidation, which may have been limited by relatively low in situ CH4 concentrations in the hummock/hollow soil profile. Our study revealed complex CH4 dynamics better represented by the emerging heterogeneous conceptual model than the classical model based on redox strata.Yang, Z., Hua, Y., Mirnaghi, F., Hollebone, B.P., Jackman, P., Brown, C.E., Yang, C., Shah, K., Landriault, M., Chan, B., 2018. Effect of evaporative weathering and oil-sediment interaction on the fate and behavior of diluted bitumen in marine environments. Part 2. The water accommodated and particle-laden hydrocarbon species and toxicity of the aqueous phase. Chemosphere 191, 145-155. this study, the water accommodated and particle-laden hydrocarbon species, and the toxicity of the aqueous phase after oil-sediment interactions by varying the weathering states of diluted bitumen (Cold Lake blend (CLB)), oil type from light to heavy, and sediment type. Compared to the original oils, the sediment-laden total petroleum hydrocarbons (TPH) contained fewer hydrocarbons in the carbon range <C10, comparable contents in C10–C16 range, higher contents in both the C16–C34 and >C34 range. Sediment-laden oil amounts generally decreased with an increased viscosity and asphaltene content of the test oils, as well as with increased sediment particle size. The presence of sediments significantly decreased the oil accommodated in water due to the formation of oil particulate aggregates (OPA) after mixing and settling. Less water accommodated TPH and polycyclic aromatic hydrocarbons (PAHs) were observed for weathered CLB products. However, oil and sediment types did not clearly affect the water accommodated TPH and PAHs. Light molecular PAHs and their alkylated congeners accounted for most of the water accommodated PAH congeners. A microtoxicity test demonstrated that with or without sediment, and regardless of sediment type, the toxicity of the water phase did not change significantly. Light oil of Alberta sweet mixed blend (ASMB) had the highest toxicity, followed by fresh CLB, and then all other oils, suggesting that ASMB and fresh CLB had relatively higher levels of light toxic components dissolved in the water phase compared with the other tested oils.Yang, Z., Zhang, G., Hollebone, B.P., Brown, C.E., Yang, C., Lambert, P., Wang, Z., Landriault, M., Shah, K., 2017. Fate of oxygenated intermediates in solar irradiated diluted bitumen mixed with saltwater. Environmental Pollution 231, 622-634. types of diluted bitumen (dilbit) and a light crude oil spiked onto the surface of saltwater were irradiated with natural solar light in Ottawa to assess the impact of sunlight to the fate of oxygenated intermediates. Oxygenated components, including carbonyl polycyclic aromatic hydrocarbons (PAHs) and acidic polar fractions (naphthenic acid fraction compounds, NAFCs), were identified after periods of solar exposure under both winter and summer conditions. Carbonyl PAHs and NAFCs were formed in both seasons; however, light crude and summer irradiation produced higher abundance of them than dilbits and winter exposure. The formed NAFCs were abundant with the congeners containing a heteroatom of oxygen only (Oo species), accompanied by the minor amounts of sulfur- and nitrogen-containing acids. The produced Oo species were predominant with the congeners with light molecular weight, high degree of saturation and heavy oxygen numbers. For both carbonyl PAHs and NAFCs, their abundance continually increased throughout the period of winter exposure. In the summer, some carbonyl PAHs and all Oo species increased during the early exposure period; then they decreased with continued exposure for most oils, illustrating their transitional nature. Oxygenated intermediates thus appear to have been created through the photo-oxidation of non-to medium-polar petroleum hydrocarbons or the intermediates of aldehydes or ketones (O1). Oil properties, the duration of exposure, exposure season and the chemical structure of these intermediates are critical factors controlling their fate through photo-oxidation. The observed chemical changes highlight the effects of sunlight on the potential behavior, fate and impact of spilled oil, with the creation of new resin group compounds and the reduction of aromatics and saturates. These results also imply that the ecological effects of spilled oil, after ageing in sunlight, depend on the specific oil involved and the environmental conditions.Yang, Z., Zhu, J., Li, X., Luo, D., Qi, S., Jia, M., 2017. Experimental investigation of the transformation of oil shale with fracturing fluids under microwave heating in the presence of nanoparticles. Energy & Fuels 31, 10348-10357. methods of exploiting oil shale such as mining or in situ electric heating cause environmental pollution, and they have huge energy losses and high costs. These problems can be solved by combining microwave heating with hydraulic fracturing for the in situ exploitation of oil shale. In this study, an experimental microwave apparatus was manufactured for laboratory experiments. Different weight proportions of iron oxide nanoparticles (0.1, 0.5, and 1 wt?%), microwave output power (600, 800, and 1000 W), and ultimate reaction temperatures (550, 750, and 950 °C) were taken into account in the design of an orthogonal experiment. Temperature distributions were influenced by microwave power, as well as by the concentration of iron oxide nanoparticles. The iron oxide nanoparticles facilitated a noticeable rise in the temperature of the oil shale in a short time. The experimental results confirmed the advantages of microwave heating, compared to conventional heating, in terms of temperature increases and improved yields of higher quality oil. Specifically, the oil collected under microwave irradiation contained more saturation and aromatics, and less sulfur and nitrogen, than that obtained by conventional heating. The highest oil yield and the best oil quality were obtained with the parameters of output power of 800 W, ultimate reaction temperature of 950 °C, and iron oxide nanoparticles at 0.1 wt?%. Our findings contribute to the application of microwave technology to unconventional resources, and field tests at small scale should be supported.Yasin, Q., Du, Q., Sohail, G.M., Ismail, A., 2017. Impact of organic contents and brittleness indices to differentiate the brittle-ductile transitional zone in shale gas reservoir. Geosciences Journal 21, 779-789. economic success of shale gas plays depends expansively on the brittle-ductile behavior of shale rock for effective hydraulic fracturing. Successful hydraulic fracturing requires targeting the most brittle rocks. Therefore it is worthwhile to classify the shale regarding brittle and ductile zones. To study the impact of brittleness indices in the brittle-ductile transitional zone, we have estimated the mineralogy-based brittleness index, TOC (total organic carbon), pore pressure and geomechanical properties from well logs and core description laboratory measurements. The petrophysical model of Sembar shale from Indus basin Pakistan was compared to brittleness index, organic contents, and pore pressure to differentiate the transitional zones in shale gas reservoirs. The result shows that constant change in rock minerals distribution and brittleness index follow the trend in TOC content, in brittle- ductile and transitional zone. Also, the data was plotted in λρ-μρ lithology templates and plots of Young’s modulus and Poisson’s ratio, shale with high quartz and clay contents trap in less ductile to less brittle zone while shale with abundant quartz and low clay contents give rise in the brittle zone. The observations of this study support the previous research idea by suggesting the zones of brittle and transition controlled by TOC to design the hydraulic fracture more efficient.Yeasmin, S., Singh, B., Johnston, C.T., Sparks, D.L., 2017. Organic carbon characteristics in density fractions of soils with contrasting mineralogies. Geochimica et Cosmochimica Acta 218, 215-236. study was aimed to evaluate the role of minerals in the preservation of organic carbon (OC) in different soil types. Sequential density fractionation was done to isolate particulate organic matter (POM, <1.8 g cm?3) and mineral associated OM (MOM: 1.8–2.2, 2.2–2.6 and >2.6 g cm?3) from four soils, i.e., a Ferralsol, a Luvisol, a Vertisol and a Solonetz. Organic matter (OM) in the density fractions was characterised using diffuse reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and mass spectroscopy in the original states (i.e., without any chemical pre-treatment), and after 6% sodium hypochlorite (NaOCl) and 10% hydrofluoric acid (HF) treatments. The NaOCl oxidation resistant fraction was considered as a relatively stable pool of OC and the HF soluble fraction was presumed as the mineral bound OC. Phyllosilicate-dominated soils, i.e., Vertisol, Luvisol and Solonetz, contained a greater proportion of POM than Fe and Al oxide-dominated Ferralsol. Wider C:N ratio and lower δ13C and δ15N in POM suggest the dominance of labile OC in this fraction and this was also supported by a greater proportion of NaOCl oxidised OC in the same fraction that was enriched with aliphatic C. The sequential density fractionation method effectively isolated OM into three distinct groups in the soils: (i) OM associated with Fe and Al oxides (>1.8 g cm?3 in the Ferralsol); (ii) OM associated with phyllosilicates (1.8–2.6 g cm?3) and (iii) OM associated with quartz and feldspar (>2.6 g cm?3) in the other three soils. Greater oxidation resistance, and more dissolution of OC during the HF treatment in the Fe and Al oxides dominated fractions suggest a greater potential of these minerals to protect OC from oxidative degradation as compared to the phyllosilicates, and quartz and feldspar matrices. OM associated with Fe and Al oxides was predominantly aromatic and carboxylate C. Decreased C:N ratio in the NaOCl oxidation resistant OM and HF soluble OM of phyllosilicates, and quartz and feldspars dominant fractions compared to their untreated fractions indicate a preferred retention of N rich organic compounds by these minerals. OM associated with phyllosilicates was enriched with protonated amide N and aromatic C. Quartz and feldspars associated OM comprised of N containing organic compounds and polysaccharides, although we don’t expect any role of these minerals in their preservation. Our results imply that the abundance and surface properties of minerals in the soil largely control the dynamics of OC and subsequently protect OC from microbial cycling.Yin, L., Li, J., Liu, J., Li, C., Sun, S., Liang, H., Xu, J., 2017. Precise and accurate Re–Os isotope dating of organic-rich sedimentary rocks by thermal ionization mass spectrometry with an improved H2O2-HNO3 digestion procedure. International Journal of Mass Spectrometry 421, 263-270. contribution presents a new method for Re–Os isotope dating organic-rich sedimentary (ORS) rocks by thermal ionization mass spectrometry using an H2O2–HNO3 solution as the digestion medium, rather than CrO3–H2SO4 or inverse aqua regia. The main underlying principle of this method is that H2O2–HNO3 digestion would preferentially liberate hydrogenous Re and Os, and minimize the dissolution of non-hydrogenous detrital Re and Os, thereby providing more accurate and precise ages. A series of tests were performed, and the experimental data demonstrate the fundamental controls on spike–sample equilibrium and that the amount of detrital Re and Os incorporated into the system are subjected to the volumetric ratio of H2O2 to HNO3. The optimum method is a H2O2:HNO3 ratio of 5 to complete spike–sample equilibration, and to minimize the amount of detrital Re and Os in the system. A comparison of our new method with inverse aqua regia and CrO3–H2SO4 showed that the three techniques yield indistinguishable Re–Os results, suggesting complete spike–sample equilibrium was achieved by all of the digestion techniques. Moreover, the data show that our new technique leaches out the least amount of detrital Re and Os isotopes relative to conventional methods Thus, we propose the H2O2–HNO3 method may increase the precision and accuracy of Re–Os depositional ages of organic-rich sedimentary systems.Yu, Z., Chistoserdova, L., 2017. Communal metabolism of methane and the rare earth element switch. Journal of Bacteriology 199, Article e00328-17. metabolism of methane is an important part of the biogeochemical cycling of carbon. Methane is also a major contributor to climate change. A specialized group of microbes that consume methane, the methanotrophs, represent a natural filter preventing even faster accumulation of methane in the atmosphere. Methanotrophy can proceed via both anaerobic and aerobic modes. The anaerobic methanotrophs, represented by both archaea and bacteria, all appear to be engaged in syntrophic interdependencies with other species, to overcome the energetic barriers of methane metabolism in the absence of oxygen. In contrast, aerobic methanotrophy can be carried out by pure cultures of bacteria. However, a concept of communal function in aerobic methane oxidation has been gaining momentum, based on data regarding the natural cooccurrence of specific functional guilds and results from laboratory manipulations. The mechanistic details of how and why the methanotrophs share their carbon with other species, and whether and what they gain in return, are still sparse. In this minireview, we highlight recent studies that led to this new concept of community function in aerobic methane oxidation. We first describe stable isotope probing experiments employing heavy-carbon-labeled methane and tracing methane carbon consumption. We then present an analysis of data on microcosm community dynamics. We further discuss the role of a synthetic community approach in elucidating the principles of carbon flow and species cooperation in methane consumption. Finally, we touch on the role of lanthanides, which are rare Earth elements previously thought to be biologically inert, in bacterial metabolism of methane.Yuan, W., Liu, G., Stebbins, A., Xu, L., Niu, X., Luo, W., Li, C., 2017. Reconstruction of redox conditions during deposition of organic-rich shales of the Upper Triassic Yanchang Formation, Ordos Basin, China. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 158-170. concentration and distribution of organic matter, phosphate nodules, and framboidal pyrite preserved in shales are controlled by organic matter decomposition and the cycles of phosphorus, sulfur, and iron, which, in turn, are controlled by bottom-water redox conditions. The organic-rich shale in the 7th member of the Upper Triassic Yanchang Formation (Ch7) contains high organic carbon concentrations and abundant phosphate nodules and pyrite framboids, providing an opportunity to better understand the redox conditions at the time of deposition. Framboidal pyrite in the Ch7 organic-rich shales are composed of octahedral, pyritohedral, and spherulitic microcrystals with uniform crystal size. SEM photographs and statistical data suggest that pyrite framboids have large mean diameters (10.0 to 18.1 μm) and standard deviations (2.8 to 5.9 μm). This may indicate that the organic-rich shale was deposited under oxic-suboxic bottom-water conditions. The Corg:P ratios of the organic-rich shale exhibit considerable variation, ranging from 7.2 to 216, but the majority of them (83.2%) belong to the lower-intermediate range (< 130), suggesting that the redox conditions were predominantly oxic-suboxic and intermittently anoxic. The Corg:P ratios also show periodic vertical variation, which suggests that redox conditions fluctuated between oxic-suboxic and anoxic. Additional support for the trends based on Corg:P ratios is provided by DOPT values, which show similar vertical variation and redox patterns. All evidence shows that the redox conditions during deposition of the Ch7 organic-rich shale was predominantly oxic-suboxic accompanied by intermittent anoxic environments. The result of this study will be helpful in better understanding the formation mechanism of the Ch7 organic-rich shale.Zafar, R., Watson, J.S., 2017. Adsorption of tetradecanoic acid on kaolinite minerals: Using flash pyrolysis to characterise the catalytic efficiency of clay mineral adsorbed fatty acids. Chemical Geology 471, 111-118. clay mineral kaolinite is one of the major inorganic constituents of sedimentary rocks. Kaolinite-carboxylic acid interactions are of considerable importance from the geochemical perspective. The two-fold aim of this study was to quantify the adsorption of tetradecanoic acid on kaolinite and then the flash pyrolysis of adsorbed fatty acids-kaolinite samples to understand the transformation of adsorbed fatty acids on kaolinite. Adsorption of tetradecanoic acid on kaolinite results in an s-isotherm which reflects the multilayer adsorption. Adsorption of tetradecanoic acid on kaolinite involves its both functionalities i.e. siloxane (tetrahedral face) and hydroxyl surface (octahedral face) as indicated from the pyrolysis results. Flash pyrolysis of tetradecanoic acid adsorbed kaolinite mainly yielded saturated/unsaturated hydrocarbons, aromatic hydrocarbons, and ketones while pure tetradecanoic acid generated saturated/unsaturated hydrocarbons and a series of unsaturated and saturated low molecular weight fatty acids. We have successively tested an empirical approach to identify organic compounds formed from fatty acid adsorbed kaolinite to the organic compounds obtained from fatty acid adsorbed alumina and silica. Kaolinite mainly reflects the transformation of carboxylic acids into hydrocarbons and ketones via hydroxyl surface (octahedral face). Ketonisation is mainly observed at multilayer adsorption of tetradecanoic acid on kaolinite. The major implication of the work is the understanding of fatty acids adsorption on kaolinite via both surfaces of the mineral which is helpful to understand the fate of fatty acids as they pass into the geosphere during diagenesis.Zaghbib-Turki, D., Beiranvand, B., 2017. Planktonic foraminiferal extinction pattern, evolution, turnover, and geochemical anomalies across the Cretaceous/Paleogene boundary (K/Pg) in Izeh (Zagros Basin, SW Iran). Arabian Journal of Geosciences 10, 443. the Izeh section (Zagros Basin, SW Iran), about two third of the planktonic foraminiferal species, representing less than 20% of the individuals, present in the Maastrichtian polytaxic assemblages, became suddenly extinct at the K/Pg boundary. This mass species extinction testifies end-Cretaceous catastrophic bioevent. The Cretaceous species remain became apparently extinct gradually during the earliest Danian. In fact the unkeeled globotruncanids (Globotruncanella and Rugoglobigerina) as well as the small heterohelicids (Heterohelix and Pseudoguembelina) were also affected by extinction and they were reworked in the basal Danian. Except guembelitriids which persisted longer time. The sudden species extinctions were selective, eliminating geographically restricted large, complex, and deeper dwelling forms (i.e., globotruncanids and large heterohelicids). Contrary, few cosmopolitan small, simple surface-subsurface dwellers (i.e., guembelitriids among small heterohelicids and hedbergellids) crossed the K/Pg boundary and survived the catastrophic event. This selective bioevent is related to the end-Cretaceous bolide and produced ejecta impact inducing major environmental changes as decrease in temperature, collapse of nutriment, and flow breakdown in the water mass stratification. Our geochemical results (δ13C negative shift, δ18O positive shift, and trace elements anomalies) are consistent with the cooling due to the collision winter triggering collapse of nutriment. Especially the δ 18O values across the upper Maastrichtian and the K-Pg transition in Izeh section although they are lower; they report similar fluctuations to those in El Kef section. Thus these lower values may be indicative of somewhat warmer water at the sea floor. Besides, like as elsewhere, in Izeh, this Cretaceous end catastrophic bioevent is followed by a delayed gradual recovery. Thus, immediately after the K/Pg boundary was created a nearly empty niche in which persisted few Cretaceous survivors with dwarf individuals. These survivors despite they suffered very stressful environmental conditions, they constituted the root stock of globigerinids from which the Cenozoic planktonic foraminiferal species evolved and developed carnivorous food diet.Zanchetta, G., Bini, M., Giaccio, B., Manganelli, G., Benocci, A., Regattieri, E., Colonese, A.C., Boschi, C., Biagioni, C., 2017. Middle Pleistocene (MIS 14) environmental conditions in the central Mediterranean derived from terrestrial molluscs and carbonate stable isotopes from Sulmona Basin (Italy). Palaeogeography, Palaeoclimatology, Palaeoecology 485, 236-246. paleosol from the Middle Pleistocene lacustrine-fluvial succession of Sulmona Basin, central Italy, was analysed for the land snail shell content, and the stable isotope composition of the shells and associated pedogenic carbonates. The paleosol – known as Fiorata Paleosol – is covered by a thick tephra layer dated to ca. 527 ka allowing the pedogenetic horizons to be correlated to the marine isotope stage (MIS) 14-early MIS 13 interval. The terrestrial mollusc assemblage contained few individuals and was characterized by a low number of species which predominantly indicate open and dry habitats, thus suggesting that Fiorata Paleosol likely developed during glacial conditions of the MIS 14. The δ13C values of pedogenic carbonates and terrestrial shells indicate prevailing C3-type vegetation, probably marked by some degree of water stress. Calculation of the δ18O precipitation values, derived from pedogenic carbonates and shell δ18O values, indicate that the average temperature was 3–5 °C lower than present day. This study highlights how paleosols, despite offering only snapshots of past climate and environments, provide valuable complementary information to paleoclimatic data obtained in the adjacent lacustrine intervals, specifically for the Sulmona successions.Zapalski, M.K., Nowicki, J., Jakubowicz, M., Berkowski, B., 2017. Tabulate corals across the Frasnian/Famennian boundary: architectural turnover and its possible relation to ancient photosymbiosis. Palaeogeography, Palaeoclimatology, Palaeoecology 487, 416-429. Frasnian-Famennian biodiversity crisis has traditionally been considered one of the “Big Five” mass extinctions; among deep changes in the biosphere, it almost completely erased shallow-water marine ecosystems like coral-stromatoporoid reefs, which were widespread on the carbonate platforms in the Devonian. The high biodiversity of bioconstructors during the Givetian-Frasnian acme of Palaeozoic reef development contrasts sharply with very low biodiversity levels during the Famennian. One of major bioconstructing groups in the Palaeozoic was tabulate corals. A statistical analysis of colony architecture of Givetian-Frasnian and Famennian tabulates from the Holy Cross Mountains (Poland) reveals that Givetian and Frasnian tabulate faunas had smaller corallite diameters and higher colony integration, compared to the Famennian faunas. A similar pattern occurs in the Devonian of the Ardennes. In the Holy Cross Mountains the biodiversity drastically decreases in the Late Frasnian. We interpret Givetian-Frasnian tabulate communities as generally photosymbiotic, and their Famennian counterparts as generally aposymbiotic. In Recent corals temperatures above 32 °C are generally considered as a threshold for bleaching (expulsion of photosymbionts), a literature review indicates that in the late Frasnian sea surface temperatures exceeded this threshold. This leads to a discussion of the late Frasnian rise of temperature as a contributing cause of extinction of photosymbiotic bioconstructors, and possibility of a Late Devonian “bleaching event”.Zeng, Q., Wang, Z., McPherson, B.J., McLennan, J.D., 2017. Modeling competitive adsorption between methane and water on coals. Energy & Fuels 31, 10775-10786. gas produced from coals, or coalbed methane (CBM), is a significant component of the energy portfolio for many countries. One challenge associated with CBM production is associated water. Specifically, coalbeds in situ contain significant amounts of water, and ideally this water is removed by pumping prior to the primary recovery of CBM to lower pressure and stimulate methane desorption. Such a prior water production can be challenging because desorption depends on the occurrence state of methane and water in situ, e.g., how much of each fluid is adsorbed or otherwise. Accordingly, primary objectives of this analysis include quantifying both the occurrence state of methane and water of different coals for a range of coalbed properties and conditions, and specifically quantifying the impact of coal moisture on methane desorption. Ultimate and proximate analysis and methane adsorption tests were first conducted on several coal samples from different basins. Simplified local density (SLD) theory was then tailored and applied to describe the adsorption characteristics of specific methane/water mixtures for each coal. Then, a fluid mixing rule was introduced to characterize competitive adsorption processes and a minimum potential energy method was applied to distinguish primary and secondary water adsorptions. Analysis of all resulting data included a regression analysis to obtain best fit parameters. Finally, an analytical reserve estimation method for methane and water was developed to quantify the extent of potential original reserves, and results of the method were compared to forecasts by conventional simulators. Combined results of all analyses suggest that both methane and water adsorptions decrease with temperature. While water adsorption decreases monotonically with pressure, methane adsorption first increases then decreases with pressure. Maximum methane adsorption occurs at approximately 10 MPa pressure. Water will compete with methane for adsorption sites, thus degrading the effective methane adsorption capacity of coal. Both methane and water adsorptions by coal can be effectively described by a competitive adsorption model, but the impact of moisture on methane desorption varies with temperature and pressure. With water divided into adsorbed and free states and with methane occurring in adsorbed, free, and dissolved forms, the proposed reserve estimation method predicted approximately the same original reserves as existing simulators predict, and also quantified how reserves change during CBM recovery.Zhang, H., Chen, S., Lu, J., Huang, H., Li, Y., 2017. Application of 17α(H)-diahopanes in oil-source correlation of Triassic Yanchang Formation in Zhoujiawan area, Ordos Basin, China. Petroleum Science and Technology 35, 1343-1348.α(H)-diahopane are extensively distributed in Yanchang formation source rocks of Ordos Basin, but the content varies greatly. The content of 17α(H)-diahopane is pretty low in Chang 7 oil shale, whereas it is very high in Chang 9 mudstones. Low diahopane abundance of Chang 81 reservoir extracts and similar crossplots of Ts/C29Ts and C30 diahopane/C30 hopane show that Chang 81 oils come from Chang 7 oil shale. However, Chang 82 and Chang 9 reservoir extracts are similar to Chang 9 source rocks in most of geochemical parameters, which indicates that the oil is derived from Chang 9 source rocks.Zhang, H., Cheng, Y., Shi, J., Li, L., Li, M., Han, X., Yan, C., 2017. Experimental study of water-based drilling fluid disturbance on natural gas hydrate-bearing sediments. Journal of Natural Gas Science and Engineering 47, 1-10. gas hydrates (NGH) are widely considered as a promising important substitute energy resource. Some countries are trying to drill and develop NGH; however, the disturbance effect of water-based drilling fluid on the stability of NGH-bearing sediments is unclear, especially the water-based drilling fluid with a thermodynamics hydrate inhibitor. To understand the disturbance effect, this paper studies the affecting patterns of drilling fluid temperatures and thermodynamics hydrate inhibitors on NGH-bearing samples with different hydrate saturations through an experimental study of drilling disturbance induced by water-based drilling fluids and by measuring the acoustic velocity variation of NGH-bearing sediments. The results show that the acoustic velocity of the natural gas hydrate-bearing sediments increases with the growing hydrate saturation. The gas hydrate dissociation is accelerated by the increase in drilling fluid temperatures. However, this acceleration effect declines after hydrate saturation exceeds 50%. The NGH dissociation inside the formation is also affected by the micro distribution of natural gas hydrates. Addition of thermodynamics hydrate inhibitors into the drilling fluid can apparently boost the gas hydrate dissociation, and the greater the concentration of inhibitors, the more obvious the effect. The boost effects of salt-type inhibitors are markedly stronger than the effects of alcohol-type inhibitors. This means that the better inhibition effect of the inhibitors is, the greater the disturbance effect on NGH-bearing sediments. Therefore, the drilling fluid that is suitable for NGH-bearing sediments should not only be capable of suppressing the NGH generation in the wellbore but also should have eased stimulation of the NGH dissociation inside the drilled formation. The findings will provide help with drilling fluid design that is suitable for NGH-bearing sediments and provide a scientific basis for achieving safe drilling through NGH-bearing sediments.Zhang, J., Li, X., Wei, Q., Sun, K., Zhang, G., Wang, F., 2017. Characterization of full-sized pore structure and fractal characteristics of marine–continental transitional Longtan Formation shale of Sichuan Basin, South China. Energy & Fuels 31, 10490-10504. the recent significant progress reviewed in marine and continental shale gas reservoirs, there is no general investigation concerning marine–continental transitional shales, especially in the research of the pore structure and fractal characteristics of marine–continental shale reservoirs. In this study, the pore structure characteristics of 12 typical marine–continental transitional shale samples of the Upper Permian Longtan Formation collected from Southern Sichuan Basin were analyzed, combining techniques of total organic carbon (TOC) content determination, X-ray diffraction, field emission scanning electron microscopy, high-pressure mercury intrusion porosimetry, and low-pressure N2/CO2 adsorption. And the pore fractal characteristics of shales were also analyzed using the Frenkel–Halsey–Hill model with N2 adsorption data. Not only the effects of TOC content and mineralogical compositions for pore structure parameters and fractal dimensions were analyzed but also the relationships between pore structure parameters and fractal dimensions were discussed. The results showed that the macropores (>50 nm) mainly develop within or between clay minerals, while the micropores (<2 nm) and mesopores (2–50 nm) commonly develop within intraparticle pores and organic matter (OM) pores. Marine–continental Longtan shales develop with the characteristic of various pore types, complicated pore structure, and obvious heterogeneity, which mainly consist of silt-shaped pores and ink bottleneck pores. Micropores provide the dominant specific surface area (SSA), whereas meso- and macropores occupy the majority of the pore volume. Both uni- and multimodal pore-size distributions (PSDs) in shales were analyzed; the PSDs of macropores increase rapidly to above 5 μm or below 30 nm, but a flat trend is present within the range of 30 nm to 5 μm; the PSDs of mesopores develop with a peak around 4 nm; and the PSDs of micropores develop with a minor peak around 0.35–0.40 nm and two major peaks around 0.45–0.50 and 0.55–0.60 nm. Micropores and macropores were the most important storage space for shale gas, and the micropores play a pivotal role in shale gas adsorption by providing the dominated SSAs. Two fractal dimensions (D1, 2.523–2.696; D2, 2.754–2.886) are positively associated with the pore volumes and SSAs of shales, and the micropores are the dominant factor for controlling the pore structure heterogeneity. The small pores of marine–continental shales mainly consist of OM pores, which are considerably affected by TOC content; large pores are mainly produced in clay minerals. TOC content has a significant positive relationship not only with the pore volumes and special surface areas of micropores but also with the fractal dimensions; and the enrichment of the clay minerals will contribute to the production of macropores (including fractures) while the brittle ones play the reverse role.Zhang, J., Liu, Z., Brady, E.C., Oppo, D.W., Clark, P.U., Jahn, A., Marcott, S.A., Lindsay, K., 2017. Asynchronous warming and δ18O evolution of deep Atlantic water masses during the last deglaciation. Proceedings of the National Academy of Sciences 114, 11075-11080.: The reorganizations of deep Atlantic water masses are widely thought to regulate glacial–interglacial climate changes. However, the pattern of reorganizations and their impact on ocean tracer transport remain poorly constrained by marine proxies. Our modeling study, which simulates the coevolution of water masses and oxygen isotopes during the last deglaciation, suggests that deglacial meltwater input causes both northern- and southern-sourced deep water transports to decrease. This reorganization pattern leads to asynchronous warming between the deep North and South Atlantic, which might have caused the observed deglacial phasing difference in deep water oxygen isotope records between these ocean basins. We further propose a mechanism to explain the early warming in the northern North Atlantic. Abstract: The large-scale reorganization of deep ocean circulation in the Atlantic involving changes in North Atlantic Deep Water (NADW) and Antarctic Bottom Water (AABW) played a critical role in regulating hemispheric and global climate during the last deglaciation. However, changes in the relative contributions of NADW and AABW and their properties are poorly constrained by marine records, including δ18O of benthic foraminiferal calcite (δ18Oc). Here, we use an isotope-enabled ocean general circulation model with realistic geometry and forcing conditions to simulate the deglacial water mass and δ18O evolution. Model results suggest that, in response to North Atlantic freshwater forcing during the early phase of the last deglaciation, NADW nearly collapses, while AABW mildly weakens. Rather than reflecting changes in NADW or AABW properties caused by freshwater input as suggested previously, the observed phasing difference of deep δ18Oc likely reflects early warming of the deep northern North Atlantic by ～1.4 °C, while deep Southern Ocean temperature remains largely unchanged. We propose a thermodynamic mechanism to explain the early warming in the North Atlantic, featuring a strong middepth warming and enhanced downward heat flux via vertical mixing. Our results emphasize that the way that ocean circulation affects heat, a dynamic tracer, is considerably different from how it affects passive tracers, like δ18O, and call for caution when inferring water mass changes from δ18Oc records while assuming uniform changes in deep temperatures. Zhang, K., Sun, Y., Cui, Z., Yu, D., Zheng, L., Liu, P., Lv, Z., 2017. Periodically spilled-oil input as a trigger to stimulate the development of hydrocarbon-degrading consortia in a beach ecosystem. Scientific Reports 7, Article 12446. this study, time-series samples were taken from a gravel beach to ascertain whether a periodic oil input induced by tidal action at the early stage of an oil spill can be a trigger to stimulate the development of hydrocarbon-degrading bacteria under natural in situ attenuation. High-throughput sequencing shows that the microbial community in beach sediments is characterized by the enrichment of hydrocarbon-degrading bacteria, including Alcanivorax, Dietzia, and Marinobacter. Accompanying the periodic floating-oil input, dynamic successions of microbial communities and corresponding fluctuations in functional genes (alkB and RDH) are clearly indicated in a time sequence, which keeps pace with the ongoing biodegradation of the spilled oil. The microbial succession that accompanies tidal action could benefit from the enhanced exchange of oxygen and nutrients; however, regular inputs of floating oil can be a trigger to stimulate an in situ “seed bank” of hydrocarbon-degrading bacteria. This leads to the continued blooming of hydrocarbon-degrading consortia in beach ecosystems. The results provide new insights into the beach microbial community structure and function in response to oil spills.Zhang, L., Tian, K., Wang, Y., Zou, J., Du, Z., 2017. Characterization of Ancient Chinese textiles by ultra-high performance liquid chromatography/quadrupole-time of flight mass spectrometry. International Journal of Mass Spectrometry 421, 61-70. analytical techniques are playing increasingly important roles in archaeology. In the field of textile archaeology, the characteristics of silk and dyes are important since they may provide essential information on the origin of the material, dyeing techniques, and even historical windows in understanding trading routes of ancient textiles. Here, we first identify the ancient Chinese textiles from Qing Dynasty Royal Palace as silk fibroin by ATR-spectrum, then extraction conditions for dyestuff on textiles were evaluated as it have quite an effect on the analytical results in the chemical analysis, the extract was analyzed by ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-Q-Tof MS) to identify the natural dyes in these ancient textiles. The results showed that a gentle extraction method (MeOH/FA/EDTA) was efficient and berberine, flavonoids and indigo were identified simultaneously in extracts of ancient textiles by high-resolution mass spectrometry. By comparing extraction profiles of pigments in plants as the likely dye sources by UHPLC-Q-TOF MS, we identified Sophora japonica L. and Phellodendron amurense Rupr. as the dye sources in historical silk fibres. The analyses suggest that the bright yellow textiles were likely dyed with a combination of these two plants and aluminium was used as mordant in the dyeing process. The experiment of color restoration confirmed our analysis. This study demonstrated its ability to identify the dyeing technology of ancient China and provide valuable data for the reparation of historical textiles preserved in the Palace Museum, Beijing.Zhang, M., Ayala, L.F., 2018. A semi-analytical solution to compositional flow in liquid-rich gas plays. Fuel 212, 274-292. gas (LRG) reservoirs can exhibit complex phase and flow behavior due to gas condensation and re-vaporization and differences in phase mobilities that results in compositional variations inside the system. To date, the analysis of composition variation in liquid-rich wells has been largely limited to numerical modeling. This work uses a similarity-based analytical approach to study the in situ and flowing fluid composition of gas condensate wells producing under infinite-acting linear and radial flow under constant bottomhole pressure (BHP) condition. We propose a semi-analytical solution to the governing partial differential equations (PDEs) written in terms a compositional fluid formulation for multiphase (gas, oil and water) flow system in liquid rich gas reservoirs. The proposed solution is developed using similarity-theory (i.e. Boltzmann’s transformation) and is validated by both analytical development and numerical simulation data. Using proposed method, pressure and overall composition are solved simultaneously and rigorously without any kind of simplification or approximation, from which producing fluid composition can be fully predicted prior to the availability of field production data. Moreover, results corroborate that when LRG wells are producing under 1 D linear regime – a commonly-observed flow condition for hydraulically-fractured horizontal wells completed in unconventional formations – and against a constant BHP constraint, the producing wellbore fluid composition remains constant as long as the system remains infinite acting, leading to a constant producing gas-oil ratio (GOR). For radial flow, however, producing wells team composition and GOR are shown to be time-dependent before stabilization at a nearly-constant value.Zhang, S., Zhang, L., Lu, X., Shi, C., Tang, T., Wang, X., Huang, Q., Zeng, H., 2018. Adsorption kinetics of asphaltenes at oil/water interface: Effects of concentration and temperature. Fuel 212, 387-394. are the heaviest components in crude oil. It is generally believed that asphaltenes adsorbed at oil/water interface can form a protective layer to stabilize the water-in-oil or oil-in-water emulsions. In this work, the effects of asphaltene concentration and temperature on the dynamic interfacial tension (IFT) of oil (i.e., toluene)/water interface were systematically investigated using a pendent drop shape method. The adsorption process shows three stages as a function of adsorption time. In Regime I, the reduction kinetics of IFT is diffusion-controlled, during which asphaltenes are adsorbed to the oil/water interface spontaneously. The interfacial diffusion coefficient of asphaltenes to the oil/water interface was found to increase with increasing temperature and decreasing asphaltene concentration, which is much lower than the bulk diffusion coefficient predicated by the Stokes–Einstein equation. In Regime II, the steric hindrance arisen from the adsorbed asphaltenes at oil/water interface from Regime I tends to inhibit further adsorption of asphaltenes to the interface. In Regime III, continuous adsorption of asphaltenes to the sublayer of the interface and reconfiguration of adsorbed asphaltenes or asphaltene aggregates occur, contributing to the continuous but very slow reduction of dynamic interfacial tension. Our results provide useful insights into the adsorption kinetics and adsorption mechanism of asphaltenes at oil/water interfaces under different asphaltene concentration and temperature conditions, with implications to many related interfacial phenomena (e.g., emulsion stability) where asphaltenes are present in oil production.Zhang, W., Liang, J., Lu, J.a., Wei, J., Su, P., Fang, Y., Guo, Y., Yang, S., Zhang, G., 2017. Accumulation features and mechanisms of high saturation natural gas hydrate in Shenhu Area, northern South China Sea. Petroleum Exploration and Development 44, 708-719. on the comprehensive interpretation of cores, loggings and 2D/3D seismic data of Shenhu GMGS3 drilling area in the northern South China Sea, the distribution characteristics, differential accumulation mechanism and reservoir forming mechanism of diffusion type natural gas hydrate with high saturation discovered from clayey silt reservoirs were investigated. The following findings are reached through the research: (1) Gas hydrate with high saturation often displays high resistivity, low interval transit time, and strong bottom-simulating reflectors (BSRs), and accompanies with fluid seepage phenomena beneath BSRs, such as mud diapiric structure and gas chimney. (2) The gas hydrate reservoirs are dominated by fine grained clayey silt sediments, and the reservoirs have higher porosity and permeability in local parts. (3) The gas hydrate is largely type I, whereas type II gas hydrate may exist below the type I gas hydrate. (4) The gas sources are mixed microbial and thermogenic gases, and the thermogenic gas originated from the deep formation in the center of Baiyun Sag migrated into shallow strata through faults, mud diapirs and gas chimneys, then was mixed with microbial gas in situ and continued to migrate until they accumulated in the temperature and pressure stability zone and formed diffusion type gas hydrate with high saturation finally. (5) The fluid migration system influenced and controlled the differential distribution of gas hydrate with high saturation.Zhang, W., Wang, Q., Ye, J., Zhou, J., 2017. Fracture development and fluid pathways in shales during granite intrusion. International Journal of Coal Geology 183, 25-37. generally act as barriers to subsurface fluid flow due to their low permeability. Magmatic intrusion can produce fractures in host rocks, but the relationship between fracture development and permeability changes in shales is still not clear. A 48 m-wide granitic dike intruded into the Cambrian black shales at 131.8 ± 1.5 Ma in the Luocun section of the Lower Yangtze region (China). Shale samples from the Luocun section were collected to investigate the influence of granite intrusion on fracture parameters, density, porosity and permeability of shales. Based on the cross-cutting relationship, cements and characteristics of microfractures, three phases of fractures in the Luocun shales were recognized and related with the stress evolution. The widespread, narrow and straight shear fractures (Phase-I) reflect initial fracturing under compression around the intrusion. With continued magma intrusion, thermal reaction of organic matter produced CH4, CO2 and H2O, which joined with siliceous fluids from the granitic dike and increased pore fluid pressure in surrounding shales. High pore fluid pressure and thermal expansion counteracted the regional compression and caused wide, curving extension fractures (Phase-II) in shales near the dike. Meanwhile siliceous fluids transported carboniferous residues through the open pore space and fractures, sealed the fractures and silicified the shales. In the late cooling stage, pore fluid pressure and thermal contraction produced bedding-parallel, narrow extension fractures (Phase-III) in shales near the dike. The small shear displacement along Phase-II and Phase-III fractures implies that they originated as extension fractures and immediately reactivated as shear planes.The effective porosity of shale samples increases from ~ 0.5% at distance ≥ 12.95 m to ~ 2% at 10.05 m and ~ 4% at 0.5 m from the granitic dike. Pressure dependence of plug permeability of shale samples follow an exponential equation. At 6.9 MPa, plug permeability of the shales increases from 1.81 × 10? 19 m2 at 27.45 m to 4.98 × 10? 16 m2 at 0.5 m. Within ~ 37% of the dike width, the fracture density, effective porosity, plug permeability, as well as the equivalent vitrinite reflectance from our previous study, increase sharply with a decreasing distance from the dike, suggesting coincidence of a narrow contact aureole with the “permeability aureole” due to localized hydrofracturing and hydrothermal circulation. Because Phase-II and Phase-III fractures only occur within ~ 37% of the dike width and they were filled by microcrystalline quartz and carboniferous residues, they should be effective fluid pathways and allow fast escape of shale gas during granite intrusion.Zhang, W., Yang, W., Xie, L., 2017. Controls on organic matter accumulation in the Triassic Chang 7 lacustrine shale of the Ordos Basin, central China. International Journal of Coal Geology 183, 38-51. Triassic Chang 7 Formation is a rich lacustrine source rock in the Ordos Basin, central China. Petrographic and geochemical analyses were performed in order to research the mechanism of organic matter (OM) enrichment in the Chang 7 shales. Bulk geochemical data indicate that the OM-rich shales were formed in a fresh and brackish water, which is not usually the case for high TOC (Total Organic Carbon Content) sediments. Therefore, there must be some special conditions favorable for OM enrichment in Chang 7 shales.Petrography and element geochemistry show that the Chang 7 OM-rich shales are abundant in OM-enriched laminae, framboidal pyrites, collophanes, and some elements including iron (Fe), diphosphorus pentoxide (P2O5), copper (Cu), vanadium (V), molybdenum (Mo), and uranium (U). High bio-productivity (algae blooming) and anoxic depositional environments are critical for OM enrichment. As the organic carbon contents increase, the Fe, P2O5, Cu, V, Mo, and U element contents increase as well and the ratios of U/Th and V / (V + Ni) are growing. Many geochemical data demonstrate that the water was oxic, while the environment under the sediment-water interface was anoxic as a result of a high organic supply that sufficiently consumed oxygen.Taking into account the geological settings and our previous studies, we propose that the frequent volcanic events and hydrothermal activity caused by the collision of the North China landmass with the Yangtze landmass and consequential formation of the Qingling Mountains had a significant role in the OM enrichment in the fresh and brackish lacustrine shales. Deposition of volcanic ash into aqueous environments might lead to the increase of some key nutrients, such as Fe and P2O5, which might enhance primary bio-productivity. New evidence for hydrothermal activity, the reddingite, was demonstrated in this study. Not only can the hydrothermal activity provide elements necessary for life, but is also favorable for formation of anoxic settings.The deposition of the Chang 7 lacustrine OM-rich shales can be explained using the High-Bio-Productivity-Driven Model, which is related to volcanic events and hydrothermal activity as a consequence of regional tectonic movements. An anoxic depositional setting is beneficial for OM preservation and slow sedimentation rates in the deep lacustrine environments are favorable for OM enrichment.Zhang, Y., Kogure, T., Nishizawa, O., Xue, Z., 2017. Different flow behavior between 1-to-1 displacement and co-injection of CO2 and brine in Berea sandstone: Insights from laboratory experiments with X-ray CT imaging. International Journal of Greenhouse Gas Control 66, 76-84. this study, we compare the changes in CO2 saturation and pressure drop for two modes of injections: (i) a displacement of brine by supercritical CO2 injection (1-to-1 displacement), and (ii) a forced co-current injection of supercritical CO2 and brine at the same flow ratio (co-injection), respectively, in a laboratory core-flooding experiment using a Berea sandstone sample. The Berea sandstone sample showed a weak bedding structure that consists of high- and low- porosity layers. The main flow direction was set perpendicular to the bedding layers. We utilized the X-ray CT technique to image the rock interior and obtain the information of local porosity and saturation of each voxels in a three dimensional volume. The results show that the co-injection needs a much higher pressure drop to maintain the constant flow rate than the 1-to-1 displacement at similar saturation degrees. Moreover, the co-injection shows significant fluctuations in saturation and pressure drop, whereas the 1-to-1 displacement shows more gradual and monotonous changes. The spontaneous fluctuations in saturation and pressure drop during co-injection are basically coincident in temporal pace, and can be explainable by the intermittent flow of brine and CO2 as shown in differential saturation images. Furthermore, the X-ray images show that the CO2 mainly flows through built flow pathway during the 1-to-1 displacement; whereas the CO2 flows near uniformly and does not strictly rely on pore size and capillarity during the co-injection. CO2 saturation distributes more uniform among image pixels during the co-injection. These dissimilarities between the co-injection and 1-to-1 displacement suggest differences in fluid flow mechanism between them. In the 1-to-1 displacement, the pathway of CO2 flow was created by the forward motion of CO2 over the capillary pressure force. CO2 preferred to first percolating through large-size pores and gradually expanded the percolation region while the CO2 saturation grew. In this process, the displaced brine mainly flowed in its remained phase-pathway–less phase interference occurred. The connection of flow pathway for CO2 naturally satisfied the maintaining of the flow rate. In contrast, during the co-injection, both phases flowed in the pore space. The connection of the phase-pathway was affected by the phase snap-off effect. The transport efficiency of such a partially disconnected flow-pathway was significantly lower than the 1-to-1 displacement case, leading to that much higher drive force of pressure drop was necessary to let the fluids flow at setting rates. Nevertheless, the reachability of CO2 to low-porosity sites during the co-injection was higher than during the 1-to-1 displacement. Our findings are important for understanding of co-injections in applications of relative permeability measurement, and enhanced efficiency in capillary trapping, usage of pore space in CO2 geological storage and in oil recovery.Zhang, Y., Liu, J., Xu, H., Niu, X., Qin, G., Cao, D., 2017. Comparison between pore structure and fractal characteristics of continental and transitional coal measures shale:a case study of Yan'an and Taiyuan formations at the northeastern margin of Ordos Basin Acta Petrolei Sinica 38, 1036-1046. on the fractal geometry method for studying low-temperature nitrogen adsorption, the pore structures and fractal characteristics of organic-rich coal measures shale in continental Yan'an Formation and sea-land transitional Taiyuan Formation at the northeastern margin of Ordos Basin are studied in this study. The fractal FHH model is used to calculate the fractal dimensions D1 and D2 of the large pores (4.34-100 nm) and small pores (less than 4.34 nm), so as to comparatively analyze the relationship between pore structure parameters and fractal dimensions as well as the influences of TOC and mineral compositions on the both. The results are as below:(1) In Yan'an Formation, pore sizes are distributed in the range of 1.8-59 nm, showing a "bimodal" pattern; ink-bottle, slit and plate-like pores are dominantly developed. In Taiyuan Formation, pore sizes are ranged in 3-4.5 nm, showing a "unimodal" pattern; ink-bottle pores are mainly developed. (2) Coal measures shale has double fractal characteristics. D1 and D2 are positively correlated, and D1 is larger than D2, indicating the more complex structures of large pores. Besides, the spatial structures of two types of pores in Yan'an Formation are all complex, while those of large pores in Taiyuan Formation are very complex, but small pores have strong heterogeneity. (3) The smaller the average pore size of coal measures shale is, the more the small pores will be, the larger the specific surface area will be, the bigger the total pore volume will be, and the higher the fractal dimension will be, i.e., the more complex the pore structure is, the more irregular the pore surface will be. The D1 and D2 of Yan'an Formation and D2 of Taiyuan Formation can reflect the corresponding pore structure characteristics, respectively. (4) The pore structure parameters and fractal dimensions of Taiyuan Formation are more significantly affected by TOC and mineral compositions than those of Yan'an Formation. (5) As compared with Taiyuan Formation, Yan'an Formation has better shale reservoir, and is more favorable for the adsorption, occurrence, diffusion and flow of coal measures shale gas.Zhang, Y., Shi, G.R., Wu, H.-t., Yang, T.-l., He, W.-h., Yuan, A.-h., Lei, Y., 2017. Community replacement, ecological shift and early warning signals prior to the end-Permian mass extinction: A case study from a nearshore clastic-shelf section in South China. Palaeogeography, Palaeoclimatology, Palaeoecology 487, 118-135. quantitative investigation of the ecological changes of shallow-marine benthos was undertaken at the Permian–Triassic boundary section at Zhongzhai, South China. The studied fossil material primarily included brachiopods and bivalves owing to their abundance throughout the section, but other subordinate taxonomic groups including ostracods and microgastropods were also integrated for discussion.Overall, a succession of three benthonic paleocommunities was recognized representing three connected ecological evolutionary stages across the Permian–Triassic transition. Both Stage 1 and Stage 2 paleocommunities predated the end-Permian boundary mass extinction, and were characterized by relatively high diversity of brachiopods and bivalves, with no or very rare other taxa. Approaching the end-Permian mass extinction and the PTB itself, the paleocommunity abruptly changed and was replaced by the Stage 2 paleocommunity that was characterized by a relatively low Shannon's diversity (H) coupled with a high Simpson's dominance index (D) and, most notably, a changeover from Neochonetes to Tethyochonetes (both are brachiopod genera) as the most significant ecological dominants. This Simpson's dominance index (D) shift correlates well with food shortage (i.e. much reduced terrestrial influx and acritarch abundance), and is therefore interpreted to signify, possibly, intensified interspecific competitions with Tethyochonetes seemingly outcompeting Neochonetes presumably due to its preadapted smaller body size. The post-extinction (Stage 3) paleocommunity is distinguished by a highly characteristic low-diversity and high-abundance fauna comprised mainly of lingulid brachiopods, Claraia bivalves, microgastropods and ostracods, suggesting a unique and highly stressful ecological regime. In this paleocommunity, Claraia might have acted like a “disaster taxon” and, as such, its ecological functional role in the paleocommunity was activated and elevated because of exceptional ecological conditions (e.g., anoxia, hyperthermal and/or severe food shortage).From the studied section, a number of ecological traits including species abundance distribution, Shannon's diversity (H), community dominance and body-size structure were identified as demonstrating significant changes accompanying community replacement prior to the end-Permian mass extinction. The fact that these changes preceded the mass extinction may suggest that these traits could represent some early warning signals for an impending ecological regime shift. This extended interpretation clearly has significant implications for modern ecological studies to predict future impending ecological regime shifts.Zhang, Z., Wu, Y., Sun, L., Li, Y., Fu, D., Su, L., Zhang, D., Xia, Y., 2017. The changes of hydrocarbon generation and potential in source rocks under semi-closed conditions with 50–840?bar water pressure. Petroleum Science and Technology 35, 1487-1494. order to investigate the effects of water pressure on hydrocarbon yields and potential in source rocks, carbonaceous mudstone from drilling in Liaohe Basin was pyrolyzed in simulation with constant water pressure and high-water-pressure experiments. Results demonstrate that the times of expelling hydrocarbon remarkably promote source rocks yielding liquid hydrocarbons. Increasing water pressure may increase the reaction of generating bitumen and oil, and enhance liquid hydrocarbons generation. Results of TOC, Rock-Eval, and elemental analysis in this study suggest that carbonaceous mudstone dominated by type-III kerogen remains a large number of hydrocarbon-generating potential, which may indicate that carbonaceous mudstone has a good potential to yield deep oil and natural gas. Besides, vitrinite reflectance may be the most suitable parameter to describe the maturity of source rocks.Zhang, Z.T., Sun, Y.D., Lai, X.L., Joachimski, M.M., Wignall, P.B., 2017. Early Carnian conodont fauna at Yongyue, Zhenfeng area and its implication for Ladinian-Carnian subdivision in Guizhou, South China. Palaeogeography, Palaeoclimatology, Palaeoecology 486, 142-157. subdivision of Ladinian and Carnian strata in Guizhou, South China has been a matter of intense debate because of the paucity of age-diagnostic faunas. Here we have carried out a detailed conodont biostratigraphic investigation on the Yangliujing, Zhuganpo and Wayao formations in the Yongyue section of western Guizhou Province. Conodonts are only prolific in the Zhuganpo and Wayao formations. Three genera and twenty species are identified, including two new species Quadralella wanlanensis n. sp. and Quadralella yongyueensis n. sp. They represent a rather endemic fauna of early Carnian age. Four conodont zones are established. They are, in the ascending order, the Paragondolella foliata, Quadralella polygnathiformis, Quadralella tadpole, and Quadralella aff. praelindae zones.Thus in the study area, the Zhuganpo Formation is generally of early Carnian (Julian 1) age whilst the Wayao Formation probably extends from the Julian 2 into the late Carnian (Tuvalian substage). The Ladinian–Carnian boundary (LCB) cannot be precisely defined due to the absence of the ammonoid Daxatina canadensis and the paucity of conodonts. However, the LCB is unlikely lower than the Yangliujing–Zhuganpo formation contact. The Julian 1–Julian 2 (early Carnian) substages boundary is defined in the uppermost Zhuganpo Formation by the occurrence of basal Julian 2 ammonoid Austrotrachyceras ex gr. A. austriacum and is also evidenced by the disappearance of most short-range Julian 1 conodonts in the overlying Wayao Formation.Zhao, J., Li, J., Xu, Z., 2017. Advances in the origin of overpressures in sedimentary basins. Acta Petrolei Sinica 38, 973-998. progress in the studies on the causes of overpressuring has been made during the past decades, which is summarized and discussed in this article. (1) In terms of the causes, overpressuring is categorized into 5 types, i.e., disequilibrium compaction, fluid expansion, diagenesis, tectonic compression, and pressure transfer. The fluid expansion includes hydrocarbon generation, oil cracking to gas, and hydrothermal expansion, while smectite-illite transformation is the most significant overpressuring mechanism in diagenesis. (2) Six methods for identifying overpressuring causes are proposed, namely, the analysis of multi-logging combination, the Bowers method (loading-unloading diagram), velocity-density crossplotting, correlation of porosities, reverse reasoning from pressure calculation and correlation, and comprehensive analyses. (3) With more and more widespread application of the empirical methods in the investigation of overpressuring causes, almost all of the overpressure cases traditionally claimed and widely accepted as the result of disequilibrium compaction have been denied totally or in part, whereas hydrocarbon generation is demonstrated to be the most common cause for overpressuring, and the importance of clay diagenesis especially smectite-illite transformation to overpressuring has been recognized. In addition, the contribution of tectonic compression and pressure transfer to overpressuring is also confirmed. Moreover, overpressures in many basins are believed to be the outcome of combined action of two or more overpressuring mechanisms. (4) The causes of overpressuring differ with the lithology of rocks where overpressure may develop. Generally speaking, the causes of overpressuing are different between source rocks and non-source rocks. In source rocks, overpressures, if any, are frequently related to hydrocarbon generation and sometimes to diagenesis, while in non-source rocks overpressures are commonly caused by disequilibrium compaction, diagenesis and pressure transfer. (5) As far as the analysis of overpressuring causes for source rocks is concerned, we suggest that the content of organic matter should be corrected appropriately because it affects the logging responses including those of density and acoustic velocity. It has been revealed that the cause of overpressuring based on the corrected logging data can be quite different from that without correction.Zhao, W., Wei, G., Yang, W., Mo, W., Xie, W., Su, N., Liu, M., Zeng, F., Wu, S., 2017. Discovery of Wanyuan-Dazhou Intracratonic Rift and its significance for gas exploration in Sichuan Basin, SW China. Petroleum Exploration and Development 44, 697-707. understandings of the geology of Sichuan Basin were achieved in the progress of natural gas exploration in the Sinian-Cambrian strata in Sichuan Basin. An NE trending intracratonic rift was found in the Wanyuan-Dazhou area, northeastern Sichuan Basin. Based on seismic data interpretation, outcrop data and regional tectonic background analysis, we studied the boundary, distribution, formation and evolution history of Wanyuan-Dazhou rift. The following findings were obtained: (1) The seismic section indicates that a steep-slope belt indicating platform margin facies was developed during the deposition of the first and second Member (Z2dn1-Z2dn2) of the Sinian Dengying Formation. The rift generally strikes NE. (2) The thicknesses of the first and second Member of the Dengying Formation are thicker than the third and fourth Member (Z2dn3-Z2dn4) at the periphery of the rift and vice versa inside the rift. (3) The rift formed during the deposition of Z2dn1-Z2dn2 in the Sinian. Filling and subsidence occurred during the deposition of Z2dn3-Z2dn4 in the Sinian. The shrinkage of the rift happened during the deposition of the Lower Cambrian Maidiping Formation – Qiongzhusi Formation. Regional extension and uplift in the Nanhua controlled rift formation. The discovery of the Wanyuan-Dazhou rift changed the traditional understanding of the tectonic and sedimentary framework of Sichuan Basin in the Sinian and Early Cambrian. The periphery of the rift has significant potential for natural gas exploration due to its superior natural gas accumulation conditions in the Sinian.Zheng, J., Wang, Z., Gong, W., Ju, Y., Wang, M., 2017. Characterization of nanopore morphology of shale and its effects on gas permeability. Journal of Natural Gas Science and Engineering 47, 83-90. a microscopic point of view, nano-scale pores are dominant in shale matrix, which provide transport space for natural gas. Accordingly, a pore-scale modeling, which can accurately capture the complex pore morphology and its effects on gas flow behavior, is crucial for understanding the gas transport mechanisms in shale matrix. In this study, the focused ion beam-scanning electron microscope (FIB-SEM) technique was employed to observe and characterize the morphology of the nanopores in shale. Based on the morphology characterizations, three representative porous models (i.e. intergranular pore model, micro-crack model and “honeycomb” pore model) were proposed and generated by numerical methods. The high-Knudsen gas flows in these generated structures were simulated by the lattice Boltzmann method (LBM). A comparison of the simulation results among these three porous models suggests that the nano-scale pore morphology plays an important role in the gas transport properties. Moreover, the high-Knudsen effect leads to a larger apparent permeability for each nano-scale porous model. Our work indicates the importance of the nano-scale pore morphology and the high-Knudsen effect on gas transport properties of shale matrix.Zhou, L., Kang, Z., Wang, Z., Peng, Y., Xiao, H., 2017. Sedimentary geochemical investigation for paleoenvironment of the Lower Cambrian Niutitang Formation shales in the Yangtze Platform. Journal of Petroleum Science and Engineering 159, 376-386. geochemical data and geochemical proxies of the Niutitang Formation shales in the Yangtze Platform were investigated for deciphering paleodepositional environment and elucidating paleoenvironment conditions responsible for organic carbon accumulation. Ce anomalies, Eu anomalies and Y anomalies of the Niutitang Formation shales is between 0.39 and 0.92, between 0.65 and 1.03, between 0.97 and 1.71, respectively. The REE patterns of the Niutitang Formation shales show enrichment in HREE relative to LREE with negative Ce anomalies, positive Y anomalies and negative Eu anomalies, indicating of a greater influence of seawater compared to hydrothermal fluids. U, V and Mo are enriched in the shales, and Mo/Al exhibits strong covariation with TOC contents, whereas U/Al and V/Al show weak covariation with TOC contents, indicating that H2S associated with hydrothermal vents is present. Compare with upper Niutitang Formation shales, higher V/(V + Ni), Ni/Co and V/Cr ratios in lower Niutitang Formation shales imply that the lower Niutitang Formation shales are deposited in anoxic conditions. Higher Mo/Al and Ni/Al ratios exist in the lower Niutitang Formation shales relative to the upper Niutitang Formation shales, indicating higher primary productivity during deposition of the lower Niutitang Formation shales. Thus, the variations of primary productivity and preservation of organic matter associated with redox conditions of bottom water lead to greater TOC contents in lower Niutitang Formation shales relative to upper Niutitang Formation shales.Zhu, B., Chen, G., Cao, X., Wei, D., 2017. Molecular characterization of CO2 sequestration and assimilation in microalgae and its biotechnological applications. Bioresource Technology 244, 1207-1215. are renewable feedstock for sustainable biofuel production, cell factory for valuable chemicals and promising in alleviation of greenhouse gas CO2. However, the carbon assimilation capacity is still the bottleneck for higher productivity. Molecular characterization of CO2 sequestration and assimilation in microalgae has advanced in the past few years and are reviewed here. In some cyanobacteria, genes for 2-oxoglytarate dehydrogenase was replaced by four alternative mechanisms to fulfill TCA cycle. In green algae Coccomyxa subellipsoidea C-169, alternative carbon assimilation pathway was upregulated under high CO2 conditions. These advances thus provide new insights and new targets for accelerating CO2 sequestration rate and enhancing bioproduct synthesis in microalgae. When integrated with conventional parameter optimization, molecular approach for microalgae modification targeting at different levels is promising in generating value-added chemicals from green algae and cyanobacteria efficiently in the near future.Zhu, G.-Y., Ren, R., Chen, F.-R., Li, T.-T., Chen, Y.-Q., 2017. Neoproterozoic rift basins and their control on the development of hydrocarbon source rocks in the Tarim Basin, NW China. Journal of Asian Earth Sciences 150, 63-72. Proterozoic is demonstrated to be an important period for global petroleum systems. Few exploration breakthroughs, however, have been obtained on the system in the Tarim Basin, NW China. Outcrop, drilling, and seismic data are integrated in this paper to focus on the Neoproterozoic rift basins and related hydrocarbon source rocks in the Tarim Basin. The basin consists of Cryogenian to Ediacaran rifts showing a distribution of N-S differentiation. Compared to the Cryogenian basins, those of the Ediacaran are characterized by deposits in small thickness and wide distribution. Thus, the rifts have a typical dual structure, namely the Cryogenian rifting and Ediacaran depression phases that reveal distinct structural and sedimentary characteristics. The Cryogenian rifting basins are dominated by a series of grabens or half grabens, which have a wedge-shaped rapid filling structure. The basins evolved into Ediacaran depression when the rifting and magmatic activities diminished, and extensive overlapping sedimentation occurred. The distributions of the source rocks are controlled by the Neoproterozoic rifts as follows. The present outcrops lie mostly at the margins of the Cryogenian rifting basins where the rapid deposition dominates and the argillaceous rocks have low total organic carbon (TOC) contents; however, the source rocks with high TOC contents should develop in the center of the basins. The Ediacaran source rocks formed in deep water environment of the stable depressions evolving from the previous rifting basins, and are thus more widespread in the Tarim Basin. The confirmation of the Cryogenian to Ediacaran source rocks would open up a new field for the deep hydrocarbon exploration in the Tarim Basin.Zhu, W., Song, Y., Adediran, G.A., Jiang, T., Reis, A.T., Pereira, E., Skyllberg, U., Bj?rn, E., 2018. Mercury transformations in resuspended contaminated sediment controlled by redox conditions, chemical speciation and sources of organic matter. Geochimica et Cosmochimica Acta 220, 158-179. (Hg) contaminated sediments can be significant sources of Hg in aquatic ecosystems and, through re-emission processes, to the atmosphere. Transformation and release of Hg may be enhanced by various sediment perturbation processes, and controlling biogeochemical factors largely remain unclear. We investigated how rates of Hg transformations in pulp-fiber enriched sediment contaminated by Hg from chlor-alkali industry were controlled by (i) transient redox-changes in sulfur and iron chemistry, (ii) the chemical speciation and solubility of Hg, and (iii) the sources and characteristics of organic matter (OM). Sediment-bottom water microcosm systems were exposed to four combinations of air and nitrogen gas for a total time of 24?h. The treatments were: 24?h N2, 0.5?h air?+?23.5?h N2, 4?h air?+?20?h N2 and 24?h of air exposure. As a result of these treatments, microcosms spanned a wide range of redox potential, as reflected by the dissolved sulfide concentration range of ≤0.3–97??M. Four different chemical species of inorganic divalent Hg (HgII) and methyl mercury (MeHg), enriched in different Hg isotope tracers, were added to the microcosms: 201Hg(NO3)2(aq), 202HgII adsorbed to OM (202HgII-OM(ads)), 198HgII as microcrystalline metacinnabar (β-198HgS(s)) and Me204HgCl(aq). Microcosm systems were composed of bottom water mixed with sediment taken at 0–2, 0–5 and 0–10?cm depth intervals. The composition of OM varied with sediment depth such that compared to deeper sediment, the 0–2?cm depth-interval had a 2-fold higher contribution of labile OM originating from algal and terrestrial inputs, serving as metabolic electron-donors for microorganisms. The potential methylation rate constant (kmeth) of Hg tracers and net formation of ambient MeHg (MeHg/THg molar ratio) increased up to 50% and 400%, respectively at intermediate oxidative conditions, likely because of an observed 2-fold increase in sulfate concentration stimulating the activity of sulfate reducing bacteria with a capability of methylating HgII. Due to differences in HgII water-sediment partitioning, kmeth varied by a factor of 11–70 for the different isotope-enriched Hg tracers. The chemical form of HgII was a major controlling factor for kmeth and its response to the resuspension-oxidation of the system. The β-198HgS(s) tracer had the lowest kmeth and it was mainly constrained by redox-driven HgII solubility. The 202HgII-OM(ads) tracer showed an intermediate value on kmeth. It was controlled by both HgII solubility and availability of electron donors and acceptors, regulating bacterial activity. The 201Hg(NO3)2(aq) tracer had the highest value on kmeth which was limited mainly by bacterial activity. The kmeth was up to a factor of 3 higher in the 0–2 cm sediment depth-interval than in 0–5 and 0–10 cm intervals due to a larger contribution of labile OM in the 0–2 cm sediment. Reduction of HgII to Hg0 followed by volatilization exclusively occurred at high sulfidic conditions in the top 0–2 cm sediment. Aromatic moieties of terrestrial OM, present mainly in the top sediment, is suggested to control the reduction of HgII. The Hg0 volatilization rate constant for the 202HgII-OM(ads) tracer exceeded that for β-198HgS(s) by one order of magnitude. Our results suggest that contaminated sediments posing a high risk for reactivation of legacy Hg following transient redox resuspension events are characterized by depletion of sulfate in the sediment porewater prior to resuspension, predominance of HgII species with solubility exceeding that of crystalline β-HgS(s), and conditions promoting in situ formation and/or import of labile OM from algal and terrestrial sources.Zhuang, G.-C., Lin, Y.-S., Bowles, M.W., Heuer, V.B., Lever, M.A., Elvert, M., Hinrichs, K.-U., 2017. Distribution and isotopic composition of trimethylamine, dimethylsulfide and dimethylsulfoniopropionate in marine sediments. Marine Chemistry 196, 35-46. amines and sulfides are ubiquitous organic nitrogen and sulfur compounds in the marine environment and could serve as important energy substrates to methanogens inhabiting anoxic sediments. However, their abundance and isotopic values remain largely unconstrained in marine sediments. In this study, we investigated the distribution of trimethylamine (TMA), dimethylsulfide (DMS) and dimethylsulfoniopropionate (DMSP) in Aarhus Bay, Denmark and provided the first report for their stable carbon isotopic composition. Simultaneous measurement of those two compounds in small volumes of pore waters and sediments was accomplished with gas chromatography in combination with either a purge and trap system for quantification or a headspace method for carbon isotopic analysis. TMA in the solid phase (exchangeable pool, 0.3–6.6 μmol kg?1 wet sediment; base-extractable pool, 2–18 μmol kg?1) was much more abundant than the dissolved pool (< 20 nM), indicating strong adsorption of TMA to sediments. Likewise, total base-hydrolyzable DMS(P)t (including DMS and base-released DMS from DMSP) in sediment was at least three orders of magnitude higher (11–65 μmol kg?1) than the dissolved pool of DMS(P)d in the pore water (including DMS and dissolved DMSP; 1–12 nM). TMA and DMS(P) contents in the solid phase peaked in the surface sediment, consistent with their phytodetrital origin. TMA was more 13C-depleted than DMS(P) (TMA: ?36.4‰ to ?39.2‰; DMS: ?18.6‰ to ?23.4‰), presumably due to different biological or biosynthetic origins of the respective methyl groups. Both compounds showed a downcore decrease in their solid-phase concentration, a feature that was attributed to microbial degradation, but progressive enrichment in 13C (up to 4‰) with depth was observed only for DMS(P). The considerable pool size of TMA and DMS(P) outlined in this study and geochemical evidence of their degradability suggested these two compounds could be potentially important substrates for methane production in sulfate-reducing environments.Zinke, L.A., Mullis, M.M., Bird, J.T., Marshall, I.P.G., J?rgensen, B.B., Lloyd, K.G., Amend, J.P., Kiel Reese, B., 2017. Thriving or surviving? Evaluating active microbial guilds in Baltic Sea sediment. Environmental Microbiology Reports 9, 528-536. life in the deep subsurface biosphere is taxonomically and metabolically diverse, but it is vigorously debated whether the resident organisms are thriving (metabolizing, maintaining cellular integrity and expressing division genes) or just surviving. As part of Integrated Ocean Drilling Program Expedition 347: Baltic Sea Paleoenvironment, we extracted and sequenced RNA from organic carbon-rich, nutrient-replete and permanently anoxic sediment. In stark contrast to the oligotrophic subsurface biosphere, Baltic Sea Basin samples provided a unique opportunity to understand the balance between metabolism and other cellular processes. Targeted sequencing of 16S rRNA transcripts showed Atribacteria (an uncultured phylum) and Chloroflexi to be among the dominant and the active members of the community. Metatranscriptomic analysis identified methane cycling, sulfur cycling and halogenated compound utilization as active in situ respiratory metabolisms. Genes for cellular maintenance, cellular division, motility and antimicrobial production were also transcribed. This indicates that microbial life in deep subsurface Baltic Sea Basin sediments was not only alive, but thriving.Zodrow, E.L., Mastalerz, M., P?eni?ka, J., Cleal, C.J., 2017. Linking Dolerotheca-like prepollen organs with Alethopteris pseudograndinioides foliage and assessing chemical properties of in situ prepollen grains: Implications for reconstructing Pennsylvanian-age alethopterid seed ferns. International Journal of Coal Geology 183, 65-77. and coalified prepollen organs with huge monolete grains are reported for the first time from the Canadian Sydney Coalfield of Pennsylvanian age. Besides regarding these organs as Dolerotheca-like, the putative question is which medullosalean seed fern produced these organs? We investigated for the first time the physicochemistry of the prepollen to determine characteristic behavior under oxidative conditions, reporting results from solid- and liquid states infrared spectroscopy, liquid 1H magnetic resonance, high precision liquid and pyrolytic-gas chromatography, and mass/charge ratios.The organs were tripartite, campanulate (bell-shaped) with lobate margins ca. 20 mm in diameter and ca. 30 mm long, and contained hundreds of elongate sporangia that were up to 8 mm long and filled with huge up to 833 μm long but probably juvenile Monoletes prepollen. These grains were covered by an acellular sporangial layer, which in turn, was covered by a cuticle bearing the imprint of near-isodiametric cells. The principal evidence for linking the Dolerotheca-like structure to foliar Alethopteris pseudograndinioides is shared occurrences of papillate cyclocytic stomata and trichomes, and the physical association of the alethopterid foliage and the prepollen organs. The physicochemical results point to diagenetic influence on the surface morphology and taxonomic parameters, refractory nature of the prepollen (as with extant pollen), and their aliphatic characteristics that are different from the aromatic extant pollen.Zorzen?o, P.C.S., Mariath, R.M., Pinto, F.E., Tose, L.V., Rom?o, W., Santos, A.F., Scheer, A.P., Simon, S., Sj?blom, J., Yamamoto, C.I., 2018. Asphaltenes subfractions extracted from Brazilian vacuum residue: Chemical characterization and stabilization of model water-in-oil (W/O) emulsions. Journal of Petroleum Science and Engineering 160, 1-11. were obtained from a Brazilian vacuum residue (VR) by precipitation with different ratios of n-heptane/VR to give three asphaltene subfractions. The behavior of these different subfractions in relation to the stability of water-in-oil (W/O) emulsions were evaluated. The whole asphaltene subfraction (AH) was obtained with the addition of n-heptane/VR in a 40:1 ratio (v/v) followed by filtration. Two more asphaltene subfractions (A4 and A10) were obtained by precipitation with n-heptane/VR ratios of 4:1 and 10:1, respectively. The properties of the precipitated asphaltene subfractions were analyzed by atmospheric pressure photoionization (APPI) coupled to Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) in positive-ion mode, ultraviolet–visible (UV–Vis) spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. The FT-ICR MS results showed that the A4 subfraction exhibited a profile with a higher amount of heteroatoms, high polarity and broader molecular weight distribution (Mw). An inverse correlation was observed concerning the degree of aromaticity and solubility in heptane/toluene solutions (onset point). The AH and A10 subfractions were more aromatic than A4, as confirmed by 1H NMR analysis. Also, the asphaltene subfractions promoted greater stability of the emulsions produced. The droplet size distribution and bottle test showed similar results for the stability of the emulsions obtained with the three different subfractions. After the application of centrifugal forces, the formation of a densely packed layer emulsion was observed, containing approximately 85% of water. The stabilization was improved when the W/O interface formed a viscous layer and effectively blocked the water coalescence, which remained stable for two weeks.Zylberman, W., Quesnel, Y., Rochette, P., Osinski, G.R., Marion, C., Gattacceca, J., 2017. Hydrothermally enhanced magnetization at the center of the Haughton impact structure? Meteoritics & Planetary Science 52, 2147-2165. is a ~24?Myr old midsize (apparent diameter 23?km) complex impact structure located on Devon Island in Nunavut, Canada. The center of the structure shows a negative gravity anomaly of ?12?mGal coupled to a localized positive magnetic field anomaly of ~900?nT. A field expedition in 2013 led to the acquisition of new ground magnetic field mapping and electrical resistivity data sets, as well as the first subsurface drill cores down to 13?m depth at the top of the magnetic field anomaly. Petrography, rock magnetic, and petrophysical measurements were performed on the cores and revealed two different types of clast-rich polymict impactites: (1) a white hydrothermally altered impact melt rock, not previously observed at Haughton, and (2) a gray impact melt rock with no macroscopic sign of alteration. In the altered core, gypsum is present in macroscopic veins and in the form of intergranular selenite associated with colored and zoned carbonate clasts. This altered core has a natural remanent magnetization (NRM) four to five times higher than materials from the other core but the same magnetic susceptibility. Their magnetization is still higher than the surrounding crater-fill impact melt rocks. X-ray fluorescence data indicate a similar proportion of iron-rich phases in both cores and an enrichment in silicates within the altered core. In addition, alternating-field demagnetization results show that one main process remagnetized the rocks. These results support the hypothesis that intense and possibly localized post-impact hydrothermal alteration enhanced the magnetization of the clast-rich impact melt rocks by crystallization of magnetite within the center of the Haughton impact structure. Subsequent erosion was followed by in situ concentration in the subsurface leading to large magnetic gradient on surface. ................
................

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

Google Online Preview   Download