نتایج جستجو برای: δ15n

تعداد نتایج: 888  

2017
Jelmer W Eerkens Bryna Hull Jena Goodman Angela Evoy Joshua D Kapp Sidra Hussain Richard E Green

The chance discovery of a 1.5-3.5 years old mummified girl presents a unique opportunity to further our understanding of health and disease among children in 19th Century San Francisco. This study focuses on carbon and nitrogen stable isotope signatures in serial samples of hair that cover the last 14 months of her life. Results suggest an initial omnivorous diet with little input from marine r...

2016
Isabella C. C. von Holstein Penelope Walton Rogers Oliver E. Craig Kirsty E. H. Penkman Jason Newton Matthew J. Collins

We investigate the origin of archaeological wool textiles preserved by anoxic waterlogging from seven medieval archaeological deposits in north-western Europe (c. 700-1600 AD), using geospatial patterning in carbon (δ13C), nitrogen (δ15N) and non-exchangeable hydrogen (δ2H) composition of modern and ancient sheep proteins. δ13C, δ15N and δ2H values from archaeological wool keratin (n = 83) and ...

2018
Benjamin L. Jones Leanne C. Cullen-Unsworth Richard K. F. Unsworth

Excess nutrients shift the ecological balance of coastal ecosystems, and this eutrophication is an increasing problem across the globe. Nutrient levels may be routinely measured, but monitoring rarely attempts to determine the source of these nutrients, even though bio-indicators are available. Nitrogen stable isotope analysis in biota is one such bio-indicator, but across the British Isles, th...

2014
David D. Gustine Perry S. Barboza Layne G. Adams Nathan B. Wolf

Winter severity can influence large herbivore populations through a reduction in maternal proteins available for reproduction. Nitrogen (N) isotopes in blood fractions can be used to track the use of body proteins in northern and montane ungulates. We studied 113 adult female caribou for 13 years throughout a series of severe winters that reduced population size and offspring mass. After these ...

2016
Jari Syväranta Kristin Scharnweber Mario Brauns Sabine Hilt Thomas Mehner

Hydrogen stable isotopes (δ2H) have recently been used to complement δ13C and δ15N in food web studies due to their potentially greater power to separate sources of organic matter in aquatic food webs. However, uncertainties remain regarding the use of δ2H, since little is known about the potential variation in the amount of exchangeable hydrogen (Hex) among common sample materials or the patte...

2009
Christopher M. sharp Kenneth F. abrahaM Gary burness

Stable isotopes have become an accepted method to track resource acquisition and nutrient utilization by birds. Many studies have used these methods to examine nutrient allocation and utilization during egg formation. None, however, has addressed the potential influence of nutrient utilization and movement during embryo development on the isotopic signature of egg components or its implications...

Journal: :Regional Studies in Marine Science 2021

Evaluating resource use patterns for imperiled species is critical understanding what supports their populations. Here we established stable isotope (δ13C, δ15N) values the endangered green sea turtle (Chelonia mydas) population found within boundaries of Dry Tortugas National Park (DRTO), south Florida, USA. There little gene flow between turtles sampled at DRTO and in other rookeries undersco...

2017
Joan Giménez Ana Cañadas Francisco Ramírez Isabel Afán Susana García-Tiscar Carolina Fernández-Maldonado Juan José Castillo Renaud de Stephanis

Community structure and functioning is shaped by resource partitioning between cooccurring species. Niche differentiation among sympatric species can be reached through trophic, spatial or temporal segregation to avoid competitive exclusion. Intraspecific segregation in the use of habitats and resources might determine, in turn, a population’s niche width and interspecific segregation. The Albo...

2018
Agnes M L Karlson Martin Reutgard Andrius Garbaras Elena Gorokhova

The isotopic niche has become an established concept in trophic ecology. However, the assumptions behind this approach have rarely been evaluated. Evidence is accumulating that physiological stress can affect both magnitude and inter-individual variability of the isotopic signature in consumers via alterations in metabolic pathways. We hypothesized that stress factors (inadequate nutrition, par...

2015
Nina Siebers Christopher Martius Kai-Uwe Eckhardt Marcos V. B. Garcia Peter Leinweber Wulf Amelung

The impact of termites on nutrient cycling and tropical soil formation depends on their feeding habits and related material transformation. The identification of food sources, however, is difficult, because they are variable and changed by termite activity and nest construction. Here, we related the sources and alteration of organic matter in nests from seven different termite genera and feedin...

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