Search Results - "Sessions, Alex"

Prediction of equilibrium distributions of isotopologues for methane, ethane and propane using density functional theory by Piasecki, Alison, Sessions, Alex, Peterson, Brian, Eiler, John

“…Many previous studies have examined abundances of deuterium (D) and 13C within small organic molecules. Recent advances in analytical instrumentation add the…”
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Controls on the D/H ratios of plant leaf waxes in an arid ecosystem by Feakins, Sarah J., Sessions, Alex L.

“…The extent to which leaf water D-enrichment (transpiration) and soil water D-enrichment (evaporation) affect the D/H ratio of plant leaf waxes remains a…”
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Isotope-ratio detection for gas chromatography by Sessions, Alex L.

“…Instrumentation and methods exist for highly precise analyses of the stable‐isotopic composition of organic compounds separated by GC. The general approach…”
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Stratified Redox Model for the Ediacaran Ocean by Li, Chao, Love, Gordon D, Lyons, Timothy W, Fike, David A, Sessions, Alex L, Chu, Xuelei

“…The Ediacaran Period (635 to 542 million years ago) was a time of fundamental environmental and evolutionary change, culminating in the first appearance of…”
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Sulfate was a trace constituent of Archean seawater by Crowe, Sean A., Paris, Guillaume, Katsev, Sergei, Jones, CarriAyne, Kim, Sang-Tae, Zerkle, Aubrey L., Nomosatryo, Sulung, Fowle, David A., Adkins, Jess F., Sessions, Alex L., Farquhar, James, Canfield, Donald E.

“…In the low-oxygen Archean world (>2400 million years ago), seawater sulfate concentrations were much lower than today, yet open questions frustrate the…”
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Clumped isotope effects of thermogenic methane formation: Insights from pyrolysis of hydrocarbons by Dong, Guannan, Xie, Hao, Formolo, Michael, Lawson, Michael, Sessions, Alex, Eiler, John

“…Methane clumped isotope analysis is a tool used to constrain the formation or equilibration temperatures of methane, or to differentiate methane of…”
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Sulfur isotope analysis of cysteine and methionine via preparatory liquid chromatography and elemental analyzer isotope ratio mass spectrometry by Phillips, Alexandra A., Wu, Fenfang, Sessions, Alex L.

“…Rationale Sulfur isotope analysis of organic sulfur‐containing molecules has previously been hindered by challenging preparatory chemistry and analytical…”
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Analysis of the site-specific carbon isotope composition of propane by gas source isotope ratio mass spectrometer by Piasecki, Alison, Sessions, Alex, Lawson, Michael, Ferreira, A.A., Neto, E.V. Santos, Eiler, John M.

“…Site-specific isotope ratio measurements potentially provide valuable information about the formation and degradation of complex molecules—information that is…”
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Route to Renewable PET: Reaction Pathways and Energetics of Diels–Alder and Dehydrative Aromatization Reactions Between Ethylene and Biomass-Derived Furans Catalyzed by Lewis Acid Molecular Sieves by Pacheco, Joshua J, Labinger, Jay A, Sessions, Alex L, Davis, Mark E

“…Silica molecular sieves that have the zeolite beta topology and contain framework Lewis acid centers (e.g., Zr-β, Sn-β) are useful catalysts in the Diels–Alder…”
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Seasonal changes in D/H fractionation accompanying lipid biosynthesis in Spartina alterniflora by Sessions, Alex L.

“…To investigate potential variability in the biosynthetic fractionation of hydrogen isotopes between environmental water and plant lipids, the cord grass…”
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Large D/H variations in bacterial lipids reflect central metabolic pathways by Zhang, Xinning, Gillespie, Aimee L, Sessions, Alex L

“…Large hydrogen-isotopic (D/H) fractionations between lipids and growth water have been observed in most organisms studied to date. These fractionations are…”
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Trace incorporation of heavy water reveals slow and heterogeneous pathogen growth rates in cystic fibrosis sputum by Kopf, Sebastian H., Sessions, Alex L., Cowley, Elise S., Reyes, Carmen, Van Sambeek, Lindsey, Hu, Yang, Orphan, Victoria J., Kato, Roberta, Newman, Dianne K.

“…Effective treatment for chronic infections is undermined by a significant gap in understanding of the physiological state of pathogens at the site of…”
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Biosynthetic and catabolic pathways control amino acid δ2H values in aerobic heterotrophs by Silverman, Shaelyn N., Wijker, Reto S., Sessions, Alex L.

“…The hydrogen isotope ratios (δ 2 H AA values) of amino acids in all organisms are substantially fractionated relative to growth water. In addition, they…”
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Molecular Paleohydrology: Interpreting the Hydrogen-Isotopic Composition of Lipid Biomarkers from Photosynthesizing Organisms by Sachse, Dirk, Billault, Isabelle, Bowen, Gabriel J, Chikaraishi, Yoshito, Dawson, Todd E, Feakins, Sarah J, Freeman, Katherine H, Magill, Clayton R, McInerney, Francesca A, van der Meer, Marcel T.J, Polissar, Pratigya, Robins, Richard J, Sachs, Julian P, Schmidt, Hanns-Ludwig, Sessions, Alex L, White, James W.C, West, Jason B, Kahmen, Ansgar

“…Hydrogen-isotopic abundances of lipid biomarkers are emerging as important proxies in the study of ancient environments and ecosystems. A decade ago,…”
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Organic Reference Materials for Hydrogen, Carbon, and Nitrogen Stable Isotope-Ratio Measurements: Caffeines, n‑Alkanes, Fatty Acid Methyl Esters, Glycines, l‑Valines, Polyethylenes, and Oils by Schimmelmann, Arndt, Qi, Haiping, Coplen, Tyler B, Brand, Willi A, Fong, Jon, Meier-Augenstein, Wolfram, Kemp, Helen F, Toman, Blaza, Ackermann, Annika, Assonov, Sergey, Aerts-Bijma, Anita T, Brejcha, Ramona, Chikaraishi, Yoshito, Darwish, Tamim, Elsner, Martin, Gehre, Matthias, Geilmann, Heike, Gröning, Manfred, Hélie, Jean-François, Herrero-Martín, Sara, Meijer, Harro A. J, Sauer, Peter E, Sessions, Alex L, Werner, Roland A

“…An international project developed, quality-tested, and determined isotope−δ values of 19 new organic reference materials (RMs) for hydrogen, carbon, and…”
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Geochemistry and geobiology of a present-day serpentinization site in California: The Cedars by Morrill, Penny L., Kuenen, J. Gijs, Johnson, Orion J., Suzuki, Shino, Rietze, Amanda, Sessions, Alex L., Fogel, Marilyn L., Nealson, Kenneth H.

“…Ultra-basic (pH 11–12) reducing (−656 to −585mV) groundwater springs discharging from serpentinized peridotite of The Cedars, CA, were investigated for their…”
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Hydroclimate of the western Indo-Pacific Warm Pool during the past 24,000 years by Niedermeyer, Eva M., Sessions, Alex L., Feakins, Sarah J., Mohtadi, Mahyar

“…The Indo-Pacific Warm Pool (IPWP) is a key site for the global hydrologic cycle, and modern observations indicate that both the Indian Ocean Zonal Mode (IOZM)…”
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Identification of Novel Methane-, Ethane-, and Propane-Oxidizing Bacteria at Marine Hydrocarbon Seeps by Stable Isotope Probing by Redmond, Molly C, Valentine, David L, Sessions, Alex L

“…Marine hydrocarbon seeps supply oil and gas to microorganisms in sediments and overlying water. We used stable isotope probing (SIP) to identify aerobic…”
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Biosynthesis of 2-methylbacteriohopanepolyols by an anoxygenic phototroph by Rashby, Sky E, Sessions, Alex L, Summons, Roger E, Newman, Dianne K

“…Sedimentary 2-methyhopanes have been used as biomarker proxies for cyanobacteria, the only known bacterial clade capable of oxygenic photosynthesis and the…”
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Role of APS reductase in biogeochemical sulfur isotope fractionation by Sim, Min Sub, Ogata, Hideaki, Lubitz, Wolfgang, Adkins, Jess F., Sessions, Alex L., Orphan, Victoria J., McGlynn, Shawn E.

“…Sulfur isotope fractionation resulting from microbial sulfate reduction (MSR) provides some of the earliest evidence of life, and secular variations in…”
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