نتایج جستجو برای: carbon and sulfur stable isotopes

تعداد نتایج: 16921217  

2012
Luciano O. Valenzuela Lesley A. Chesson Gabriel J. Bowen Thure E. Cerling James R. Ehleringer

Although the globalization of food production is often assumed to result in a homogenization of consumption patterns with a convergence towards a Western style diet, the resources used to make global food products may still be locally produced (glocalization). Stable isotope ratios of human hair can quantify the extent to which residents of industrialized nations have converged on a standardize...

2013
Preetam Choudhary Joyanto Routh Govind J. Chakrapani

Sediment variables total organic carbon (TOC), total nitrogen (TN), total sulfur (TS), as well as their accumulation rates and atomic ratios (C/N and C/S), were studied along with stable isotopes (δ 13 C, δ 15 N, and δ 34 S), and specific biomarkers (n-alkanes and pigments) in a 35-cm-long sediment core from Lake Bhimtal, NW India. The average sedimentation rate is 3.6 mm yr -1 , and the core r...

2014
Alexander V Dubinin Elena O Dubinina Tatyana P Demidova Nataliya M Kokryatskaya Maria N Rimskaya-Korsakova Sofia A Kosova Evgeniy V Yakushev

The Black Sea is the largest euxinic basin on the Earth. The anoxic zone consists of the upper part water mass stratified by density, and the lower water mass homogenized relative to density (depth >1750 m), named the Bottom Convective Layer. To assess homogeneity and possible exchange of matter across the upper and lower boundaries of the Bottom Convective Layer, new data on stable isotope com...

2003
James H. McCutchan William M. Lewis Carol Kendall Claire C. McGrath

Use of stable isotope ratios to trace pathways of organic matter among consumers requires knowledge of the isotopic shift between diet and consumer. Variation in trophic shift among consumers can be substantial. For data from the published literature and supplementary original data (excluding fluid-feeding consumers), the mean isotopic shift for C was +0.5 0.13‰ rather than 0.0‰, as commonly as...

2002
JON E. KEELEY LEONEL O. STERNBERG MICHAEL J. DENIRO

Keeley, J.E., Sternberg, L.O. and DeNiro, M.J., 1986. The use of stable isotopes in the study of photosynthesis in aquatic plants. Aquat. Bot., 26:213--223. The ratio of ~3C/'2C for photosynthetic tissues of 22 aquatic species was unrelated to photosynthetic pathway. In three aquatic environments CAM and non-CAM species were shown to have similar 513C values. Although these CAM species derive u...

2016
Niels J de Winter Christophe Snoeck Philippe Claeys

The study of stable isotopes in fossil bioapatite has yielded useful results and has shown that bioapatites are able to faithfully record paleo-environmental and paleo-climatic parameters from archeological to geological timescales. In an effort to establish new proxies for the study of bioapatites, intra-tooth records of enamel carbonate stable isotope ratios from a modern horse are compared w...

2017
Elizabeth C. Craig Tommy King Jed P. Sparks Paul D. Curtis ELIZABETH C. CRAIG

The double-crested cormorant (Phalacrocorax auritus) has undergone population expansion throughout much of its historical range since the 1970s, resulting in increased pressure on foraging habitats including real and perceived competition with commercial and sport fisheries and impacts on the aquaculture industry. The specific objectives of this study were to determine the stable isotope ratios...

2002
Mark V. Hoyer Binhe Gu Claire L. Schelske

Carbon cycling pathways in lacustrine systems are complex because there are often multiple sources of organic carbon available to the food webs. Among the techniques used to delineate carbon flows from organic matter to consumers, stable isotope analysis may be the most powerful one because isotope compositions of consumers reflect those of the dietary carbon assimilated and incorporated into t...

2016
Naoki Sugiyama

Stable isotope geochemistry is a branch of geology that investigates the age of natural materials, their origin and the processes they have undergone since formation [1]. Stable isotope analysis is also used in biogeochemical studies to monitor element cycling in ecosystems [2] and to identify geographical/regional differences for food provenance and archaeology. Of the elements of interest in ...

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