Global ETD Search
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Showing 1 to 11 of 11 for “"Delta 15N"”.
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A Stable Isotopic (Carbon And Nitrogen) Evaluation Of Regional Differences In Herded Animal Diet And Pastoral Risk Management Practices During The Xiongnu Period Of Mongolia.
… relate to Xiongnu statecraft through the use of [delta]13C/[delta]15N bulk sampling of mandibular and maxillary teeth of livestock recovered from mortuary sites in the Egiin Gol Valley of northcentral Mongolia (EG) and Baga Gazaryn Chuluu (BGC), an area located within the Gobi Desert. By comparing …
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Investigating nitrate attenuation in an urban stream using stable isotope geochemistry and continuous monitoring
… were sampled for nitrate concentration and delta-15N at fine spatial intervals to determine the reasons for this decrease. To quantify the effects of dilution, samples were collected from tributaries, groundwater springs, and upstream and downstream of tributaries or groundwater discharge …
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The Effect of Diet on Venom Gene Expression in Tetragnatha versicolor
… eating different prey species by measuring the [delta]15N values of T. versicolor from each site. The results of this analysis were that the [delta]15N values for the two populations of T. versicolor were significantly different. This suggests that the two populations are at different trophic …
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Unifying ecosystem concepts and mercury biomagnification in an estuarine environment using stable isotopes (delta-carbon-13 and delta nitrogen-15).
Isotope ratios of carbon (13C/12C) and nitrogen (15N/14N), on a parts per thousand (‰) basis relative to a standard, were used to trace carbon flows (delta 13C) and trophic positions of organisms (delta15N). Values of delta13C and delta15N were obtained for sediments, suspended particulate …
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Natural abundance of ¹⁵N as a tool for assessing patterns of nitrogen loss from forest ecosystems
… with contrasting nitrate loss patterns, the [delta]15 N of soil and plant material should be higher at sites with higher nitrate losses. An underlying assumption in natural abundance isotope studies is that soil [delta]15 N is at steady-state over time. I found that [delta]15 N was not at …
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Elements and stable isotopes as tracers for sleeper shark biology and the Iceland marine food web
… studies often rely on only two tracers (usually [delta] 13C and [delta]15N) to study marine ecosystems, which are inherently complex. The ability of elements to act as additional tracers of ecological processes in marine organisms and in a marine food web was investigated. The element analysis of …
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Sex-Based Differences in Mortality and Metabolic Disease in Subadult Skeletal Assemblages of Tell Hisban
… diet and weaning patterns using incremental [delta]13C and [delta]15N analysis of dentin. Since metabolic diseases are closely tied to diet and socio-cultural practices, this project was an excellent opportunity to understand this community's biological and social determinants of infant …
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A carbon and nitrogen isotopic analysis of Pleistocene food webs in North America: implications for paleoecology and extinction
… was extracted from specimens and analyzed for delta-13C, delta-15N, % collagen, %C, %N, and C:N. Radiocarbon dating and amino acid analyses were performed on select sample sets. Results indicated that several specimens contained well preserved collagen, the isotopic values of which indicated …
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Spatial habitat variation in a Great Plains river: effects on the fish assemblage and food web structure
… habitat reach had higher variability in [Delta][superscript]13C for fish classified as piscivores/invertivores (P=0.029) and macroinvertebrates (P=0.004) suggesting the complex habitat in the heterogeneous habitat reach provided more variable food sources. The [Delta}15N values also …
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Effects of Low Bioavailable Nitrogen and Phosphorus on Cyanobacteria Dynamics in Eutrophic Lake Erie
The growth and abundance of phytoplankton in freshwater lakes has long been attributed to the concentration of phosphorus (P), and this idea of P-limitation has been a paradigm accepted by limnologists. Hence, lake managers have relied on the strategy of reducing P to restore water quality of …