Stable nitrogen isotope. Medical search. Frequent questions

Isotopic reference materials are compounds (solids, liquids, gasses) with well-defined isotopic compositions and are the ultimate sources of accuracy in mass spectrometric measurements of isotope ratios. (wikipedia.org)
Due to their critical role in measuring isotope ratios, and in part, due to historical legacy, isotopic reference materials define the scales on which isotope ratios are reported in the peer-reviewed scientific literature. (wikipedia.org)
While the δ values of references are widely available, estimates of the absolute isotope ratios (R) in these materials are seldom reported. (wikipedia.org)
δ X = x / y R s a m p l e x / y R r e f e r e n c e − 1 {\displaystyle \delta ^{X}={\frac {^{x/y}R_{sample}}{^{x/y}R_{reference}}}-1} The δ values and absolute isotope ratios of common reference materials are summarized in Table 1 and described in more detail below. (wikipedia.org)
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)
Analysis of stable isotope ratios from mineralised tissue has been widely used for dietary reconstruction. (springer.com)
Background: The relationship between stable isotope ratios and dietary protein sources has been reported. (ewha.ac.kr)
However, few studies have examined the effect of stable isotope ratios on metabolic risk in humans. (ewha.ac.kr)
We investigated whether the stable isotope ratios of carbon and nitrogen in human hair are associated with blood pressure and hypertension. (ewha.ac.kr)
Hair samples of the subjects were used for the measurement of stable isotope ratios of carbon (δ 13 C) and nitrogen (δ 15 N). Results: The δ 13 C and δ 15 N values showed positive correlations with diastolic blood pressure in the subjects without antihypertensive medication. (ewha.ac.kr)
Hair samples of the subjects were used for the measurement of stable isotope ratios of carbon (δ13C) and nitrogen (δ15N). (ewha.ac.kr)
We quantified the stable isotope ratios of carbon (δ 13 C) and nitrogen (δ 15 N) as well as the total mercury (Hg) concentration in muscle samples from 20 common minke whales ( Balaenoptera acutorostrata ) stranded along the coast of Hokkaido, Japan. (aquaticmammalsjournal.org)
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)
Using the whiskers, researchers could do a stable isotope analysis to examine carbon nitrogen ratios. (nps.gov)
Hansen JH, Hedeholm RB, Sünksen K, Tang Christensen J, Grønkjær P (2012) Spatial variability of carbon (δ 13 C) and nitrogen (δ 15 N) stable isotope ratios in an Arctic marine food web. (int-res.com)
The use of stable carbon and nitrogen isotope ratios will help determine these trophic linkages. (nova.edu)

Relationships between trophic level (estimated using nitrogen stable isotope composition, delta N-15) and body mass (as log(2) size classes) were rarely significant, implying that the larger individuals in this community did not consistently prey on the smaller ones. (researchgate.net)
Internal water temperature, pH and H/D isotope composition. (lu.se)

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)
Within the Environmental Biogeochemistry Section many projects deal with the cycling of bioactive elements (carbon, nitrogen, and phosphorus) as well as trace elements (e.g., lead, copper, mercury, and zinc) and organic contaminants such as per- and polyfluoroalkyl substances (PFAS), polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs). (ansp.org)
Stable isotope biogeochemistry of inorganic carbon and oxygen. (ansp.org)

This document specifies the determination of the ratio of nitrogen isotopes in cotton fibres that are used for textile production. (iso.org)
Conclusions: The stable isotopic ratio of nitrogen in scalp hair is independently associated with hypertension in subjects without antihypertensive medication. (ewha.ac.kr)
ratio of nitrogen 15 to nitrogen 14 relative to atmospheric nitrogen. (noaa.gov)

This fractionation enables the use of stable nitrogen isotopes (δ 15 N) to infer trophic level, and high δ 15 N recorded in bone collagen usually indicates high-protein diets (Sponheimer et al. (springer.com)
In particular, the high δ 15 N of the immature birds in the northeastern area seems to be caused by feeding on 15 N rich diets in the eastern tropical Pacific, off Peru and California, during the northward migration, where occurrence of denitrification with a high nitrogen isotope fractionation factor of up to 1.04 is well known. (int-res.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)

Stable 15 N isotope incubations under dark and anoxic conditions revealed that axenic S. marinoi is able to reduce intracellular nitrate to ammonium that is immediately excreted by the cells. (frontiersin.org)
Using stable isotope incubations ( 15 N-ammonium and 13 C-bicarbonate) and combining transmission electron microscopy (TEM) with quantitative nanoscale secondary ion mass. (lu.se)
Incubations of nitrite and nitric- oxide molecules with bacteria produced nitrogen gas that contained a nitrogen atom from both nitrite and nitric- oxide molecules. (cdc.gov)

Thirty-one percent of the diatom-derived nitrate was converted to nitrogen gas, indicating that a substantial fraction of the intracellular nitrate pool of S. marinoi becomes available to the aggregate-associated bacterial community. (frontiersin.org)
Hence, aggregate-associated diatoms accumulate nitrate from the surrounding water and sustain complex nitrogen transformations, including loss of fixed nitrogen, in anoxic, pelagic microniches. (frontiersin.org)
Additionally, it may be expected that intracellular nitrate not converted before the aggregates have settled onto the seafloor could fuel benthic nitrogen transformations. (frontiersin.org)
The samples were analyzed for nitrate and nitrite ions using ion chromatography (IC) and GC-mass spectrometry (GC-MS). The results indicate a higher stable isotopic ratio of delta 15N/14N in the aerosols collected at the cloud top of one cloud than the aerosols collected from the cloud base of a second cloud at the same altitude (30.48 m) on 18 July 2009. (academicjournals.org)
Most plutonium is found combined with other substances, for example, plutonium dioxide (plutonium with oxygen) or plutonium nitrate (plutonium with nitrogen and oxygen). (cdc.gov)

A method for determining the 18O/16O ratio of organic matter composed of carbon, hydrogen, oxygen, and nitrogen is described. (eurekamag.com)
Each of the major stable isotope systems (hydrogen, carbon, oxygen, nitrogen, and sulfur) has a wide variety of references encompassing distinct molecular structures. (wikipedia.org)
This can mean a material that historically defined an isotopic scale, such as Vienna Standard Mean Ocean Water (VSMOW) for hydrogen isotopes, even if that material is not currently in use. (wikipedia.org)
Earlier studies targeted the isotopes of hydrogen and nitrogen. (naturalnews.com)
However, oxygen isotopes have two advantages over their hydrogen and nitrogen counterparts. (naturalnews.com)
Whereas both hydrogen and nitrogen have two, oxygen has three stable isotopes . (naturalnews.com)

Without isotope references, measurements by mass spectrometry would be much less accurate and could not be used in comparisons across different analytical facilities. (wikipedia.org)
Isotope ration mass spectrometry was used to quantify metabolically produced nitrogen-15. (cdc.gov)

Abstract: The use of carbon and nitrogen stable isotope measurements from TNT was examined as a possible tool for monitoring the natural attenuation of TNT. (dren.mil)
ABSTRACT: Stable isotopes of carbon (δ 13 C) and nitrogen (δ 15 N) were used to examine trophic structures in an arctic marine food web at small and large spatial scales. (int-res.com)

Methods were developed for the on-line analysis of stable isotopes of nitrogen (at natural abundance levels) in NH 3 , NO and NO 2 in order to study the contribution of these trace gases to nitrogen cycling in ecosystems. (uni-bayreuth.de)
Stable isotope analysis (N and C) of fossil cereal grains is regularly explored as a means of obtaining insights to past crop growing conditions and agricultural practices. (lu.se)
Dental calculus is not equivalent to bone collagen for isotope analysis: a comparison between carbon and nitrogen stable isotope analysis of bulk dental calculus, bone and dentine collagen from same individuals from the Medieval site of El Raval (Alicante, Spain). (uv.es)
As a result, we recommend that carbon and nitrogen analysis on bulk dental calculus should only be used as a last resource archaeological dietary marker, if at all. (uv.es)
Salazar García, Domingo Carlos Richards, M.P. Nehlich, O. Henry, A.G. 2014 Dental calculus is not equivalent to bone collagen for isotope analysis: a comparison between carbon and nitrogen stable isotope analysis of bulk dental calculus, bone and dentine collagen from same individuals from the Medieval site of El Raval (Alicante, Spain). (uv.es)
Stable Isotope Lab analysis of fish samples collected at various locations throughout Washington state between 2007 and 2009. (noaa.gov)
Dietary Stable Isotope Analysis (carbon and nitrogen) of bone collagen reveals aspects of past diet. (york.ac.uk)
This culminated in a dissertation project wherein I utilised stable isotope analysis in conjunction with the standard zooarchaeological recording of a 14th Century sub-assemblage of Atlantic Hake (Merluccius merluccius) remains to establish their provenance, and by proxy, the possibility of their trade. (york.ac.uk)
All soil samples are being sent to UW for carbon and nitrogen isotope analysis. (uwyo.edu)
As the recipient of this award, UW's Stable Isotope Facility has been recognized as one of the elite facilities for stable isotope analysis in the United States," Cook says. (uwyo.edu)
The on the quantitative level of NP biodistribution, an analysis aerosol was diluted with nitrogen and--for rat exposures-- is required taking into account NP retention in the entire with oxygen adjusted to obtain 20% oxygen and the synthetic organism as well as the excretion. (cdc.gov)

While it might seem far-fetched to imagine Maasai pastoralists employing nuclear techniques to start agriculture in the arid landscape of East Africa, the Joint Division has supported KARI in developing low-cost, small-scale irrigation technologies based on the use of neutron probes and isotope tracers that are specifically designed to meet the needs of the Maasai. (iaea.org)

Accordingly, the results illustrate the importance of spatial variability when interpreting trophic structure from stable isotopes. (int-res.com)

and (3) traces water, carbon, and nitrogen fluxes using stable isotopes. (wsl.ch)

Additionally, the human samples have higher stable isotope differences, in comparison with faunal samples, than would be expected within the food web, particularly for δ 13 C. This human bone collagen δ 13 C enrichment may reflect a diet rich in aquatic protein intake, which is also supported by δ 34 S archived in human and faunal samples, and the presence of oysters and cockles shells at the excavation. (springer.com)
Palaeodietary reconstruction using the carbon and nitrogen isotope values of bone and dentine collagen is a well-established method and the biochemical processes involved are well known. (uv.es)
Here we report the comparison of carbon and nitrogen stable isotope analyses of bulk calculus to those from bone and dentine collagen. (uv.es)
In our study we examined stable carbon and nitrogen isotopes in polar bear bone collagen. (yahoo.com)

Pollutants of major public health concern include particulate matter, carbon monoxide, ozone, nitrogen dioxide and sulfur dioxide. (who.int)

This study is the first of its kind to analyse carbon, nitrogen and sulphur stable isotope data from skeletons of the eleventh-seventeenth centuries in Portugal. (springer.com)
Stable isotopes : natural and anthropogenic sulphur in the environment / edited by H. R. Krouse and V. A. Grinenko. (who.int)

She completed her PhD at the University of Bristol in 2020, where she focused on using compound-specific 15N-stable isotope probing to elucidate microbial N cycling in grazed ecosystems. (bristol.ac.uk)
Anthropogenic alteration of the form and concentration of nitrogen (N) in aquatic ecosystems is widespread. (usgs.gov)

Isotope reference materials are generated, maintained, and sold by the International Atomic Energy Agency (IAEA), the National Institute of Standards and Technology (NIST), the United States Geologic Survey (USGS), the Institute for Reference Materials and Measurements (IRMM), and a variety of universities and scientific supply companies. (wikipedia.org)
The UoM research team took accurate measurements and interpretations of the oxygen isotopes that made up the organic matter in the space rocks. (naturalnews.com)

Stable isotopes of N ( 14 N, 15 N) are often used to trace the sources of N fueling aquatic primary production, but effective use of this approach requires obtaining a reliable isotopic ratio for phytoplankton. (usgs.gov)

By analyzing them, researchers can determine a compound's isotopic signature, the unique ratio of various isotopes that serve as a fingerprint. (naturalnews.com)

The elemental analyzer produces carbon dioxide and nitrogen gas, which are analyzed for carbon and nitrogen isotopes in an isotope ratio mass spectrometer. (uwyo.edu)

The University of Wyoming Stable Isotope Facility (SIF) is now the go-to laboratory to analyze soil samples from all across the country. (uwyo.edu)

Reconstruction of carbon and nitrogen stable isotope in baleen whale earplugs. (tdl.org)

Approaches for Measuring Stable Carbon and Nitrogen Isotopes in Bacteria. (epa.gov)
Nitrogen availability often limits biological productivity in marine systems, where inorganic nitrogen, such as ammonium is assimilated into the food web by bacteria and photoautotrophic eukaryotes. (lu.se)
Nitrous - oxide also appeared to be an intermediate in the reduction of nitrite to nitrogen by bacteria. (cdc.gov)

The use of stable isotopes of N and O in N 2 O has been proposed as a way to better constrain the global budget of atmospheric N 2 O and to better understand the relative contributions of the main microbial processes (nitrification and denitrification) responsible for N 2 O formation in soil. (nau.edu)
Sinking aggregates also represent pelagic microniches with intensified microbial activity, oxygen depletion in the center, and anaerobic nitrogen cycling. (frontiersin.org)
These observations demonstrate that at least some heterotrophic protists have an innate cellular mechanism for inorganic ammonium assimilation, highlighting a newly discovered pathway for dissolved inorganic nitrogen (DIN) assimilation within the marine microbial loop. (lu.se)
The microbial degradation of native lignin by basidiomyce- citrant and stable in the environment. (lu.se)

Sample weight used for stable isotopes determination. (noaa.gov)

We examined the natural variability of carbon and nitrogen isotopes in the symbiotic sea anemone Anemonia viridis to investigate dietary shifts (autotrophy/heterotrophy) along a natural p CO 2 gradient at the island of Vulcano, Italy. (nature.com)
The use of C. finmarchicus δ 15 N and δ 13 C values as a baseline explained a portion of the spatial variability in isotopes, attributing some of the variation to physical and biological sources. (int-res.com)

Ratio of carbon atoms/nitrogen atoms. (noaa.gov)
Isotopes are atoms of an element that contain different numbers of neutrons compared to the baseline atoms. (naturalnews.com)
he half-life is the time it takes for half of the atoms of a radionuclide to undergo radioactive decay and change it into a different isotope. (cdc.gov)

At the same altitude, the stable nitrogen isotope ratio in the nitrogenous substances found in the aerosol depended on the aerosol position within the clouds. (academicjournals.org)

Several questions remain about the use of bulk calculus as a source of carbon and nitrogen isotope data, however. (uv.es)
Most importantly, there have been no comparative studies of collagen and calculus isotope values, which are necessary to establish the value of bulk calculus as a source of accurate isotope values. (uv.es)
These analyses have been performed on individuals from the El Raval Mudéjar Medieval Cemetery (Eastern Iberia, 15th century A.D.). Although calculus isotope values may be broadly similar to expected values at the population level, we report here no correlation between collagen and bulk dental calculus values at the individual level. (uv.es)

It has only one stable isotope and its valence in all compounds is -1. (cdc.gov)

Using a stable isotope mixing model approach, we estimated that in the presence of effluent between 40 and 90 % of phytoplankton N was derived from NH 4 + after 3 days of downstream transport. (usgs.gov)
In the Arctic, the base of the food web is sourced from two categories: sea ice-associated algae and open-water phytoplankton, which are distinguishable through their carbon isotopes. (yahoo.com)

Second, the annual inundation of the Nile River transports fresh layers of silt-rich fertile soil, which provides stable agriculture and supports cultivating various food crops and raising livestock. (researchgate.net)
UW's Stable Isotope Facility recently received an NSF contract to analyze soil samples for the entire NEON network across the United States. (uwyo.edu)
If too much goes into the soil, nitrogen leaching can occur, which means that the excess drains through the soil and, if it reaches the level of the ground water, it can make the water unsuitable for human consumption. (iaea.org)

A significant variation in the stable carbon and nitrogen isotope compositions between fluvial and marine deposits was recorded. (gov.pl)

This veritable wealth of oxygen isotopes provides more information about the origin of organic material in chondrites. (naturalnews.com)

Investigating biotic uptake of riverine organic nitrogen using a compound-specific stable-isotope probing approach. (bristol.ac.uk)

Fluorine is the most reactive of all the elements, which may be attributed to its large electronegativity (estimated standard potential +2.85 V). It reacts at room temperature or elevated temperatures with all elements other than nitrogen, oxygen, and the lighter noble gases. (cdc.gov)

This article aggregates the δ and R values of common and non-traditional stable isotope reference materials. (wikipedia.org)
It is not yet clear how much of an individual¿s life span dental calculus represents, what portions of the diet it records, and how diagenesis effects the carbon and nitrogen isotope values of this material. (uv.es)

Samples analysed by continuous flow isotope ratio mass spectroscopy. (elementallab.co.uk)
Among samples with the same grow-out period, those that weighed more tended to have higher δ 13 C suggesting a close association between the carbon isotope ratio and growth rate of U. pinnatifida . (e-algae.org)

Studies on the metabolism of nitrous - oxide (10102439) were conducted using nitrous - oxide labeled with the stable isotope nitrogen-15. (cdc.gov)
For the reduction of nitrous - oxide to nitrogen, it may be necessary for a copper containing enzyme to be present. (cdc.gov)

She is a biogeochemist, with expertise in stable isotope probing, and a keen interest in applying analytical chemistry to environmental questions. (bristol.ac.uk)
Environmental change: Habitat changes and nitrogen removal in a tidal freshwater marsh. (ansp.org)

Despite a number of studies indicating increased dietary protein needs in bodybuilders with the use of the nitrogen balance technique, the Institute of Medicine (2005) has concluded, based in part on methodologic concerns, that "no additional dietary protein is suggested for healthy adults undertaking resistance or endurance exercise. (nih.gov)

Richards and Hedges 1999 ), especially when combined with carbon isotope data. (springer.com)

Reconstructed δ13C and δ15N profiles from baleen whale earplugs (N = 17, n = 950 laminae) in this study provide the first recorded birth to death stable isotope profiles for baleen whales. (tdl.org)

Nitrogen cycling in coastal marine environments : proceedings from a SCOPE symposium held at the University of Aarhus, 3-7 June 1985 / edited by T. Henry Blackburn and Jan Sorensen. (who.int)

Anatomy1

Chemicals and Drugs5

Analytical, Diagnostic and Therapeutic Techniques and Equipment2

Phenomena and Processes2

Humanities1

Ratios16

Composition2

Biogeochemistry3

Ratio of nitrogen3

Fractionation3

Incubations3

Nitrate5

Hydrogen6

Mass spectrometry2

Abstract2

Analysis11

Tracers1

Trophic1

Fluxes1

Bone4

Sulfur1

Sulphur2

Ecosystems2

Measurements2

Isotopic ratio1

Fingerprint1

Elemental analyzer1

Laboratory1

Reconstruction1

Bacteria3

Microbial4

Determination1

Variability2

Atoms3

Aerosol1

Bulk3

Compounds1

Phytoplankton2

Soil3

Variation1

Origin of organic1

Uptake1

Reactive1

Values2

Samples2

Nitrous2

Environmental2

Dietary1

Data1

Study1

Marine1