Discrimination nitrogen isotopes. Medical search. Frequent questions

We tested the competing hypotheses that (1) nitrogen discrimination in mammals and birds increases with dietary nitrogen concentration or decreasing C:N ratios and, therefore, discrimination will increase with trophic level as carnivores ingest more protein than herbivores and omnivores or (2) nitrogen discrimination increases as dietary protein quality decreases and, therefore, discrimination will decrease with trophic level as carnivores ingest higher quality protein than do herbivores. (nih.gov)
Relationships between discrimination factors and dietary nitrogen concentration or C:N ratios were either the opposite of what was hypothesized or non-significant. (nih.gov)
During the past four decades, the analysis of stable isotope ratios (e.g., 15 N/ 14 N, 13 C/ 12 C) has been used widely in the study of biogeosciences (e.g. (springeropen.com)
The isotopic δ 13 C%, δ 15 N% values, organic carbon (OC) and total nitrogen contents, and atomic C/N ratios are used as evidence of depositional environment. (gov.pl)
While traditional stable isotope analyses of tooth enamel (e.g., carbon and oxygen) and trace element ratios (e.g. (blueskytccaalibaba.com)
The bidirectional stable nitrogen isotope tracer technique quantified the proportions of assimilated nitrate and ammonium in Brassica napus plantlets grown at different ammonium/nitrate ratios. (biomedcentral.com)
The utilization proportions of sucrose and CO 2 could be quantified by a two end-member isotope mixing model for Bn plantlets grown at different ammonium/nitrate ratios. (biomedcentral.com)
Korean mariculture Undaria pinnatifida was collected during the months of January, February, March, and December of 2010, as well as from January of 2011 to investigate the changes in the carbon and nitrogen stable isotope ratios (δ 13 C and δ 15 N) and heavy metal with respect to it growth and to identify the factors that influence such changes. (e-algae.org)
We found that, after calibration, CLM was able to reasonably simulate the observed fluxes of energy and carbon, carbon stocks, carbon isotope ratios, and ecosystem response to water stress. (copernicus.org)
15] Stuiver M,Braziunas T F.Tree cell ulose 13 C/ 12 C isotope ratios and climatic change.Nature, 1987, (328): 58～60. (adearth.ac.cn)
16] Zimmerman J K,Ehleringer J R. Carbon isotope ratios are correlated with irradiance levels in the Panamanian orchid catasetum viridiflavam. (adearth.ac.cn)

Tree Vitality and Forest Health: Can Tree-Ring Stable Isotopes Be Used as Indicators? (sagepub.com)
Recent Findings In the past two decades, tree-ring stable isotopes have been used not only to reconstruct the impact of past climatic events, such as drought, but also in the study of forest decline induced by air pollution episodes, and other natural disturbances and environmental stress, such as pest outbreaks and wildfires. (sagepub.com)
Summary Tree-ring stable isotopes integrate crown transpiration rates and photosynthesis rates and may enhance our under- standing of tree vitality. (sagepub.com)
We call for the use of tree-ring stable isotopes in future monitoring programmes. (sagepub.com)
Best practices for using tree-ring stable isotopes of Carbon and Oxygen in paleoclimate and ecophysiology. (uqam.ca)

The proposed link between nitrogen and carbon isotopes can refine our knowledge of the potential processes affecting the isotopic fractionation within diet and consumer compartments, as well as environmental samples. (springeropen.com)
Nitrogen isotope ratio tended to be relatively lower when nitrogen content in the blade was higher, probably due to the strengthening of isotope fractionation stemming from plenty of nitrogen in the surrounding environment. (e-algae.org)
1] Galimov E M. The Biological Fractionation of Isotopes. (adearth.ac.cn)
Metabolic fractionation of carbon isotopes in marine plankton. (adearth.ac.cn)
10] Vogel J C. Fractionation of carbon isotopes during photosynthesis. (adearth.ac.cn)
Amino acid δ15N indicates lack of N isotope fractionation during soil organic nitrogen decomposition. (ku.edu)

In this study, we show that the nitrogen isotope composition of organic matter preserved in mammalian tooth enamel (δ 15 N enamel ) records diet and trophic position. (blueskytccaalibaba.com)
The stable isotopic composition of C (δ 13C) and N (δ 15N) of the leaves was used to identify i) the effective drought condition of the treatments and ii) the portion N accrued from the atmosphere by the biological nitrogen fixation. (afrjournal.org)

A significant contribution of g mes to leaf carbon isotope discrimination values was observed. (afs-journal.org)
We investigated long-term effects (8-16 years post-treatment) of thinning and thinning + prescribed burning on ponderosa pine water stress, leaf carbon isotope discrimination and nitrogen concentration, oleoresin exudation flow, phloem thickness, radial growth, and bark beetle abundance relative to unmanaged control stands over 2 years of measurement in 12 stands replicated across the landscape. (usu.edu)
Leaf nitrogen concentration differed between years, but not among treatments. (usu.edu)
The average leaf nitrogen content varied between 2.8% and 3.0% and was not influenced by the drought stress. (afrjournal.org)
A S ), needle carbon isotope discrimination (Δ 13 C) and nitrogen content, and specific leaf area. (lib4ri.ch)
Nitrogen and Photosynthesis in the Flag Leaf of Wheat ( Triticum aestivum L. (google.com.ph)
Correlation between the carbon isotope discrimination in leaf starch and sugars of C 3 plants and the ratio of intercellular and atmospheric partial pressures of carbon dioxide. (adearth.ac.cn)

14] Farquhar G D, Ehleringer J R, Hubick K T. Carbon isotope discrimination and photosynthesis. (adearth.ac.cn)

Stable nitrogen ( 15 N/ 14 N) and carbon ( 13 C/ 12 C) isotopic compositions of amino acids in organisms have widely been employed as a powerful tool to evaluate resource utilization and trophic connection among organisms in diverse ecosystems. (springeropen.com)
However, little is known about the physiological factors or mechanisms responsible for determining the isotopic discrimination (particularly for carbon) within amino acids of organisms. (springeropen.com)
In the present study, we investigated the inter-trophic discrimination of nitrogen and carbon isotopes within amino acids (Δ δ 15 N AA and Δ δ 13 C AA , respectively) using four consumer-diet pairs. (springeropen.com)
Nitrogen isotopes with amino acids undergo varying degrees of isotopic discrimination (Δ δ 15 N AA ) during trophic transfer (e.g. (springeropen.com)
In contrast, the nitrogen (N) isotope ratio of organic material (expressed as δ 15 N vs. AIR in ‰, where δ 15 N = [( 15 N/ 14 N sample / 15 N/ 14 N reference ) − 1] × 1000) derived from bulk tissues or specific compounds (e.g., amino acids) is a widely used proxy for the dietary and trophic behavior of animals in terrestrial and marine food webs. (blueskytccaalibaba.com)
Stable nitrogen isotope analysis of amino acids as a new tool to clarify complex parasite-host interactions within food webs. (nioz.nl)

Hence, excessive nitrate in MS medium is not optimal and causes a waste of inorganic N. Considering the fact that the concentration of nitrate was twice that of ammonium in MS medium (20 mM ammonium, 40 mM nitrate), optimizing the nitrate concentration will effectively improve the nitrogen use efficiency of plantlets. (biomedcentral.com)
Temperature-mediated changes in microbial carbon use efficiency and 13C discrimination. (ku.edu)

Photorespira-tory phenomena in maize: Oxygen uptake, isotope discrimination and carbon dioxide efflux. (ncsu.edu)

Our investigation shows that drought stress increases the nodule biomass of black locust in order to maintain biological nitrogen fixation and to counteract the lower soil nitrogen availability. (afrjournal.org)

These distributions, however, are not intended to reflect the natural variability of the abundances of the different isotopes in the earth's crust or in any other environment. (degruyter.com)

Discrimination factors were summarized for five major diet groupings and 21 different species of birds and mammals. (nih.gov)
This study investigates natural variation in C and N stable isotopes among plant species in two western Amazon flooded forests with contrasting watershed biogeochemistry (white-water várzea-forest and black-water igapó-forest). (scielo.br)
While DNA analysis can visualize the biosphere in terms of species through genetic profiles, isotope analysis can visualize the biosphere in terms of the quantitative flux in physical and/or biochemical processes (e.g. (springeropen.com)
Amino acid (AA) nitrogen stable isotopes (δ 15 N) provide multiple proxies of habitat baseline values and diet that can improve our understanding of species feeding strategies relative to their animal metabolism. (unl.edu)
Murashige and Skoog (MS) [ 4 ] medium, which has a high inorganic nitrogen concentration (60 mM), is widely used for most plant species. (biomedcentral.com)

Despite the potential of nitrogen isotopes for trophic reconstruction, their application in the paleontological record has been limited due to the poor preservation of N-containing organic matter. (blueskytccaalibaba.com)

2013 ). Isotopic discrimination is frequently quantified by the kinetic isotope effect ( α ) and flux ( F ) of the processes (e.g. (springeropen.com)
Isotopic discrimination in helminths infecting coral reef fishes depends on parasite group, habitat within host, and host stable isotope value. (nioz.nl)

With increasing nitrate concentration, the amount of nitrogen in leaves derived from nitrate assimilation increased gradually, while the nitrate utilization coefficient underwent no distinct change for Bn plantlets. (biomedcentral.com)
From the view of the energy cost of nitrogen (N) assimilation, ammonium might be regarded as the preferable N source because the nitrate reduction that reduces nitrate to ammonium consumes large amounts of reducing power [ 1 ]. (biomedcentral.com)
Hence, a combination of an appropriate nitrate concentration and a high concentration of ammonium will contribute to reducing the energy cost used for nitrogen assimilation. (biomedcentral.com)
6 ] found that the nitrogen in the leaves of plantlets was mainly derived from ammonium assimilation even if the concentration of nitrate was twice that of ammonium. (biomedcentral.com)

If this is the case, then stable isotopes, where forests are considered a symbolic part of the cultural which integrate information about stomatal activity and pho- identity [5], citizens were shocked and in some cases there tosynthesis, should be a much better indicator of tree vitality was even panic, incited by environmentalist movements sup- than more commonly used indicators such as tree-ring width ported by poor or nonexistent science. (sagepub.com)

A significant variation in the stable carbon and nitrogen isotope compositions between fluvial and marine deposits was recorded. (gov.pl)
We have developed a rapid method for stable carbon isotopic analyses of total plant-wax n-alkanes using a novel, moving-wire system coupled to an isotope-ratio mass spectrometer (MW-irMS). (mblwhoilibrary.org)
3] Degens E T. Biogeochemistry of stable carbon isotopes.In:Eghinton G,Murphy M T,eds.Organic Geochemistry. (adearth.ac.cn)

Discrimination did not differ between mammals and birds and decreased as protein quality (expressed as biological value) increased with trophic level (i.e., herbivores to carnivores). (nih.gov)

Nitrogen deposition can have severe impacts on forest health and productivity and plays a pivotal role in the global carbon cycle. (mathiasecology.com)
While we know how nitrogen deposition influences many aspects of terrestrial forest ecosystems, it is less clear how deposition impacts rates of soil N transformations and, in particular, how pools of available nitrogen may be altered. (mathiasecology.com)

We concluded that protein quality established the baseline for discrimination between dietary groupings, while other variables, such as dietary protein intake relative to animal requirements, created within-group variation. (nih.gov)

Dietary protein quality accounted for 72% of the variation in discrimination factors across diet groupings. (nih.gov)
We caution about the care needed in developing studies to understand variation in discrimination and subsequently applying those discrimination factors to estimate assimilated diets of wild animals. (nih.gov)

6] Farquhar G D, Oleary M H, Berry J A. On the relationship between carbon isotope discrimination and intercellular carbon dioxide concentration in leaves. (adearth.ac.cn)

Fishes are often utilised in aquatic isotope studies as they structure ecosystems and communities that matter to people, and can cause top-down effects (Kishi et al. (springer.com)
Dr. Sharon Billings' research characterizes the features governing nitrogen, carbon and water fluxes in terrestrial ecosystems, and how these dynamics are influenced by environmental change. (ku.edu)

Tracing nitrogen movement in corn production systems in the North Carolina Piedmont: A nitrogen-15 study. (ncsu.edu)

Plantlets grown in vitro with a mixed nitrogen source utilize sucrose and CO 2 as carbon sources for growth. (biomedcentral.com)

Department of Environmental, Biological and Pharmaceutical Stable isotope analysis of tree rings provides a powerful Sciences and Technologies, University of Campania "L. Vanvitelli", method to assess physiological processes in trees retrospec- Via Vivaldi 43, I-81100 Caserta, Italy tively and to understand the role played by drought in forest Departme nt of Forest Resources Management, Faculty of Forestry, decline episodes. (sagepub.com)
This paper tentatively discusses the mechanism, the model of plants carbon isotope discrimination and the progress in environmental change research. (adearth.ac.cn)
As a forest ecologist, I use stable isotopes in tree rings to study the relationships between plant physiology and environmental changes. (uqam.ca)

The study included seven fertilizer treatments with varying nitrogen rates and sources, as well as two rice cultivars (BRRI dhan67 and BRRI dhan88). (bvsalud.org)
This study demonstrates that carbon isotopes can expose structural weaknesses in CLM and provide a key constraint that may guide future model development. (copernicus.org)
Since plants preserved a lot of information that can reflect the change of natural environment, the study of their carbon isotope discrimination becomes an important field in the research of global change. (adearth.ac.cn)

However, the interaction between soil water availability, carbon allocation and nitrogen fixation is important for a successful establishment of trees on marginal lands and has not yet been investigated for black locust. (afrjournal.org)
Carbon fixation, carbon allocation, and biological nitrogen fixation are to some extent balanced at low irrigation and allow Robinia to cope with long-term water constraints. (afrjournal.org)

In contrast, the trends in the Δ δ 13 C AA value suggest a different metabolic fate for the amino acid carbon isotope. (springeropen.com)

To test this hypothesis, we sampled soils and leaves to measure elevation variations in soil conditions and determined plant responses using discriminations against heavier isotopes, carbon (13C) and nitrogen (15N). (santafe.edu)

Stable isotope (SI) analysis studies rely on knowledge of isotopic turnover rates and trophic-step discrimination factors. (springer.com)
Stable isotope analysis (SIA) provides an alternative dietary analysis tool to SCA, with use of fin tissue, scales and/or epidermal mucus potentially enabling its non-destructive application. (kmae-journal.org)

The biological nitrogen fixation of drought-stressed trees could be maintained at relatively higher values compared to the well-watered trees. (afrjournal.org)
Use of the 15N natural abundance technique to quantify biological nitrogen fixation by woody perennials. (afrjournal.org)

Mucus isotope data differed significantly and predictively from muscle data. (springer.com)

Stable isotope turnover rates represent the change in mass and/or time required for consumer tissues to reflect their new diet, allowing the calculation of an isotopic half-life for the tissue and isotope of interest (Boecklen et al. (springer.com)

Anatomy1

Chemicals and Drugs6

Analytical, Diagnostic and Therapeutic Techniques and Equipment2

Psychiatry and Psychology5

Phenomena and Processes2

Humanities1

Ratios11

Tree-ring stable iso5

Fractionation6

Composition2

Leaf7

Photosynthesis1

Amino acids6

Efficiency2

Oxygen1

Soil nitrogen availability1

Variability1

Species5

Organic matter1

Isotopic discrimination2

Assimilation4

Forests1

Stable carbon3

Trophic level1

Deposition2

Baseline1

Variation2

Concentration1

Ecosystems2

Tracing1

Sucrose1

Environmental3

Study3

Allocation2

Metabolic1

Plant1

Analysis2

Biological2

Significantly1

Tissue1