نتایج جستجو برای: stable oxygen and carbon isotope

تعداد نتایج: 16944832  

2014
Lindsay E. Darjany Christine R. Whitcraft Jesse G. Dillon

Carbon cycling by microbes has been recognized as the main mechanism of organic matter decomposition and export in coastal wetlands, yet very little is known about the functional diversity of specific groups of decomposers (e.g., bacteria) in salt marsh benthic trophic structure. Indeed, salt marsh sediment bacteria remain largely in a black box in terms of their diversity and functional roles ...

Journal: :Journal of Japan Society on Water Environment 2005

Journal: :Journal of pharmaceutical and biomedical analysis 2005
J P Jasper L E Weaner B J Duffy

As a preliminary study of the utility of the natural stable-isotopic differentiation of batch samples produced by different synthetic pathways, multi-stable-isotopic analyses (delta(13)C, delta(15)N, delta(18)O, deltaD) of 53 samples of the antiepileptic drug, Topiramate, produced by three different synthetic pathways (designated "A," "B," "C") were performed. From the outset, we note that ther...

Journal: :Journal of lipid research 2008
Svena M Lüdke Ulrich Flenker Wilhelm Schänzer Dietmar Schomburg

The aim of this study was to investigate the possible existence and magnitude of stable carbon isotope discrimination by human 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR). The catalytic portion of HMGR was expressed and purified. The reaction product mevalonate was lactonized and extracted from the reaction mixture by a solid-phase extraction protocol. Stable carbon isotope ratios of...

Journal: :Ecology 2010
Michael P Lesser Marc Slattery Michael Stat Michiko Ojimi Ruth D Gates Andrea Grottoli

Most studies on coral reefs have focused on shallow reef (< 30 m) systems due to the technical limitations of conducting scientific diving deeper than 30 m. Compared to their shallow-water counterparts, these mesophotic coral reefs (30-150 m) are understudied, which has slowed our broader understanding of the biodiversity, ecology, and connectivity of shallow and deep coral reef communities. We...

Journal: :Journal of hazardous materials 2014
Shannon K Hanna Robert J Miller Hunter S Lenihan

Carbon nanotubes (CNTs) are one of the few truly novel nanomaterials and are being incorporated into a wide range of products, which will lead to environmental release and potential ecological impacts. We examined the toxicity of CNTs to marine mussels and the effect of mussels on CNT fate and transport by exposing mussels to 1, 2, or 3mg CNTsl(-1) for four weeks and measuring mussel clearance ...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2013
James D Wright Morgan F Schaller

The Paleocene/Eocene thermal maximum (PETM) and associated carbon isotope excursion (CIE) are often touted as the best geologic analog for the current anthropogenic rise in pCO2. However, a causal mechanism for the PETM CIE remains unidentified because of large uncertainties in the duration of the CIE's onset. Here, we report on a sequence of rhythmic sedimentary couplets comprising the Paleoce...

2012
Shinsuke Mori Akira Kawasaki Satoru Ishikawa Tomohito Arao

Isotope technique including radioisotopes and stable isotopes is useful and potent tool for various scientific areas. Especially, enriched stable isotopes are indispensable tools for researchers in biological systems (Stürup et al. 2008). Stable isotope ratios are usually used in examining the biogeochemical cycling of light elements such as carbon(C), oxygen (O), nitrogen (N) and sulphur (S) i...

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