Isotope ratio carbon isotopes. Medical search. Frequent questions

Light isotopes tend to decay into isotopes of boron and heavy ones tend to decay into isotopes of nitrogen. (wikipedia.org)
11 C → 11 B + e+ + ν e + 0.96 MeV 11 C + e− → 11 B + ν e + 1.98 MeV It is produced from nitrogen in a cyclotron by the reaction 14 N + p → 11 C + 4 He Carbon-11 is commonly used as a radioisotope for the radioactive labeling of molecules in positron emission tomography. (wikipedia.org)
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)
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)
Conclusions: The stable isotopic ratio of nitrogen in scalp hair is independently associated with hypertension in 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)
Stable isotopes of carbon (δ13C), sulfur (δ34S), oxygen (δ18O), hydrogen (δ2H), nitrogen (δ15N), and radioactive isotope of hydrogen (tritium) have been applied in combination with conventional techniques (chemical) to investigate Karachi coastal water pollution due to Layari and Malir rivers, which mainly carry the domestic and industrial wastewater of Karachi Metropolitan. (intechopen.com)
collected from nonpolluted northwest coast was higher as compared to the average δ15N contents (8.0‰ air) of Ulva from the Manora Channel, suggesting that nitrogen isotopic ratios of Ulva spp. (intechopen.com)
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)
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)
All soil samples are being sent to UW for carbon and nitrogen isotope analysis. (uwyo.edu)
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)
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)
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)
Of particular interest is the unambiguous detection and measurement of the nitrogen-15 isotope. (eso.org)
Measurements of isotopic ratios is an especially daunting undertaking, mainly because of the extreme weakness of the spectral signatures (emissions) of the less abundant species like carbon-13, nitrogen-15, etc. (eso.org)

Further data for radioisotopes (radioactive isotopes) of carbon are listed (including any which occur naturally) below. (webelements.com)
Has 2 halo neutrons Carbon-11 or 11 C is a radioactive isotope of carbon that decays to boron-11. (wikipedia.org)
A dating method that uses measurements of certain radioactive isotopes to calculate the ages in years (absolute age) of rocks and minerals. (theodora.com)

Plants find it easier to use the lighter isotopes (12 C ) when they convert sunlight and carbon dioxide into food. (wikipedia.org)
Similarly, lighter isotopes have an easier time getting about in the push-and-pull of biological matter at Lilliputian scales, driven by energy and molecular interactions. (livescience.com)

Stable carbon (δ¹³C) and hydrogen (δ²H) isotopes have been used to characterize hydrocarbons for exploration, development and production since the 1960s, and have re-emerged as predictive tools with the development of unconventional "tight" oil and gas plays. (onepetro.org)
Maturities derived from carbon and hydrogen isotopes can serve as controls in regional maturity maps, which are used to help define areas of oil, wet gas and dry gas production. (onepetro.org)
Stable carbon and hydrogen isotope values show a strong correlation to both initial and cumulative GOR for the unconventional Niobrara and Codell intervals of Wattenberg Field. (onepetro.org)
These are long chain organic molecules made from carbon, hydrogen and oxygen. (schoolscience.co.uk)

Stable isotope ratio analysis provides valuable information across a wide variety of fields, including environmental studies, food analysis, forensics, carbon-dating and geochemistry. (lgcgroup.com)
Validation of the correlation between Niobrara and Codell production GOR and stable isotope composition was provided by an independent geochemistry dataset from the USGS. (onepetro.org)

It begins with isotope ratio measurements. (icr.org)
Use the 13C -resonance at 2.75 MeV for precision measurements of the 13C/12C-ratio. (lu.se)

The isotopic composition - the ratios of the stable isotopes of elements such as 2H/1H or 13C/12C - provides an isotopic fingerprint of a material, which can reveal information about its geographical origin, how it has been processed or manufactured or when it was produced. (lgcgroup.com)

Table 2a) Stable isotope ratios of planktonic foraminifera from sediment core EN066-38PG in the equatorial Atlantic. (pangaea.de)
12 C and 13 C are measured as the isotope ratio δ13C in benthic foraminifera and used as a proxy for nutrient cycling and the temperature dependent air-sea exchange of CO2 (ventilation). (wikipedia.org)

Increasing carbon dioxide (CO 2 ) emissions drive ongoing ocean acidification (OA) and place marine ecosystems in a vulnerable state 1 . (nature.com)
Ocean acidification occurs when seawater takes up increasing amounts of atmospheric carbon dioxide. (earthmagazine.org)
CHAMPAIGN, Ill. - According to a popular hypothesis, grasses such as maize, sugar cane, millet and sorghum got their evolutionary start as a result of a steep drop in atmospheric carbon dioxide levels during the Oligocene epoch, more than 23 million years ago. (scienceblog.com)
C4 plants are more efficient than C3 plants at taking up atmospheric carbon dioxide and converting it into the starches and sugars vital to plant growth. (scienceblog.com)
This means these grasses were present 32 to 34 million years ago, well before studies indicate atmospheric carbon dioxide levels made their precipitous decline. (scienceblog.com)
With atmospheric carbon dioxide levels now on the increase, he said, "there are also implications about how C3 and C4 plants will fare in the future. (scienceblog.com)

It is known that stable carbon isotope fractionation is associated with the fixation of CO in autotrophic organisms [2]. (lu.se)

Carbon is the most common proxy, but in a new study published in Paleoceanography , researchers have turned to boron. (earthmagazine.org)
To verify the pattern observed in the isotopes, the team also measured boron-to-carbon ratios. (earthmagazine.org)
The boron isotope shift provides robust evidence for a change in ocean pH, and the boron-to-carbon record provides additional, intriguing clues to carbon cycle changes occurring at one of the most dramatic climate events of the Cenozoic," says Katherine Allen, a paleoceanographer at Columbia University's Lamont-Doherty Earth Observatory who was not involved with the study. (earthmagazine.org)

Specifically, as Feehan had done, Stoddard looked at the ratios of two carbon isotopes, or versions of an element containing different numbers of neutrons. (livescience.com)

The unified atomic mass unit is defined as 1/12 of the mass of an unbound atom of carbon-12 in its ground state. (wikipedia.org)
Although α cluster structures have been widely discussed in the light N ≈ Z mass region, the neutron-to-proton ratio deviates from unity in the nuclei near β-stability line and in neutron-rich nuclei. (osti.gov)
It can now automatically send them to a mass spectrometer or an isotope ratio mass spectrometer. (schoolscience.co.uk)
In the isotope ratio mass spectrometer the samples are burnt in a micro furnace to make CO 2 . (schoolscience.co.uk)
The difference in the mass, m, shows up when the ratio m/q is measured to an accuracy of better than 0.5 parts per million. (schoolscience.co.uk)
Lower-numbered isotopes, possessing less mass, are lighter than higher-numbered isotopes. (livescience.com)
Using a spooling-wire micro-combustion device to combust the grains, and an isotope mass spectrometer to determine the relative ratio of C-12 and C-13 in the sample, Nelson and Illinois graduate student Michael Urban analyzed hundreds of individual grains of grass pollen collected from study sites in Spain and France. (scienceblog.com)

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

Ms. Johnson is a member of the Diane M. O'Brien Laboratory and focuses her research on how we can utilize naturally occurring stable isotope ratios in circulating metabolites as biomarkers of dietary intake. (nutrition.org)
This table shows information about naturally occuring isotopes , their atomic masses , their natural abundances , their nuclear spins , and their magnetic moments . (webelements.com)
This is not to be confused with the relative percentage isotope abundances which totals 100% for all the naturally occurring isotopes. (webelements.com)
Further data for naturally occuring isotopes of carbon are listed above. (webelements.com)
There are three naturally occurring isotopes of carbon: 12, 13, and 14. (wikipedia.org)

Fewer carbon-14 atoms in plant and animal specimens (a lower carbon-14 ratio) would give them far more carbon years than they deserve. (icr.org)
Fatty acids are named according to the number of carbon atoms they have. (schoolscience.co.uk)
So C16 (n-hexadecanoic acid) has 16 carbon atoms and C18 (n-octadecanoic acid) has 18 carbon atoms. (schoolscience.co.uk)
These are the numbers of carbon atoms in the fatty acid molecule. (schoolscience.co.uk)
This can be confusing because we will be talking about analyzing the ratio of 13 C and 12 C in these carbon atoms. (schoolscience.co.uk)
That means how much of the carbon isotope 13 C is in the fatty acid molecules with 16 carbon atoms each. (schoolscience.co.uk)
Fig. 7.6 Gas chromatograph showing two main fatty acids, C16 (16 carbon atoms) and C18 (18 carbon atoms) and smaller peaks for C14, 15 and 17. (schoolscience.co.uk)
16 and 18 are the numbers of carbon atoms in the fatty acids. (schoolscience.co.uk)
C3 and C4 refer to the number of carbon atoms in the first molecular product of photosynthesis. (scienceblog.com)

The purpose of this paper is to investigate dietary changes of A. viridis using isotopic compositions, particularly carbon source shifts in the anemone metabolism, in response to high p CO 2 /low pH conditions in situ . (nature.com)
Background: The relationship between stable isotope ratios and dietary protein sources has been reported. (ewha.ac.kr)
Analysis of stable isotope ratios from mineralised tissue has been widely used for dietary reconstruction. (springer.com)

Table 5) Stacked records of stable carbon and oxygen isotopes for Equatorial Atlantic Globigerinoides sacculifer. (pangaea.de)
A sensitive instrument measures the ratio of carbon-14 in organic remains to the more common and stable carbon-13 and carbon-12 isotopes. (icr.org)
Energy difference between recoils from 13C and 12C in the In this context, stable carbon isotopes play a certain role in the interpretation of biological activity, particularly when the fossil record is angular interval 150-180 degrees is about 85 keV. (lu.se)

Since carbon 14 decays relatively rapidly, the method is only reliable for the last 40,000 years. (theodora.com)

Freshwater fish exhibit variation in δ 13 C depending on the ecosystem as freshwater plants have numerous sources of carbon, unlike terrestrial plants (Zohary et al. (springer.com)
C3 and C4 plants differ in their proportions of two carbon isotopes, C-12 and C-13. (scienceblog.com)

This table gives information about some radiosotopes of carbon, their masses , their half-lives , their modes of decay , their nuclear spins , and their nuclear magnetic moments . (webelements.com)
Those who treat very old carbon years as if they were actual years must assume that the Flood and its drop in magnetic field strength never happened. (icr.org)

For many phototrophic communities, cyanobacteria are the primary producers, capturing solar energy and providing fixed carbon and molecular oxygen to heterotrophic populations. (frontiersin.org)

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)
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)
Because we analyze carbon isotopes in a material unique to grasses (pollen) we were able to detect C4 grasses at lower abundances than previous studies," Nelson said. (scienceblog.com)

Carbon-14 is an isotope of the element carbon. (icr.org)
An outcrop there containing veins of the mineral aragonite, dredged up to the surface scores of millions of years ago by geological processes, was found to contain weirdly high levels of a lightweight version of the element carbon . (livescience.com)

Scientists must use math formulas to convert isotope ratios into age estimates. (icr.org)

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)
There is a complex biological reason for the milk fats having less carbon 13 in the fatty acid 18. (schoolscience.co.uk)

Other studies analyzed the ratios of carbon isotopes in bulk soil samples to determine the ratio of C3 to C4 plant remains at different soil horizons, which correspond to different geological time periods. (scienceblog.com)
Rather than analyzing plant matter in bulk sediment samples, David Nelson, a postdoctoral researcher in Hu's lab at the time of the study (now a professor at the University of Maryland), analyzed the carbon isotope ratios of individual grains of grass pollen, a technique he pioneered while working with Hu in the lab of biogeochemistry professor Ann Pearson at Harvard University. (scienceblog.com)

LGC, in its role as the UK's National Measurement Laboratory (NML) and designated institute for chemical and bio-measurement, has expanded its portfolio of certified reference materials to include a new set of glycine materials in solution certified for absolute carbon isotope ratio, traceable to the SI (International System of Units). (lgcgroup.com)

These results demonstrate the potential of natural gas stable isotope signatures as a useful and reliable fluid quality prediction tool. (onepetro.org)
Fieldwork by J.G. Feehan for his 1997 doctoral dissertation with Yale professor Mark T. Brandon, who now is Stoddard's academic advisor, had identified the aragonite's very light carbon signatures. (livescience.com)

These anomalies precede a decline in coprophilous spores and correlate with an abrupt peak in soot and C/OC ratios, indicative of large-scale regional biomass burning. (nature.com)

Stable isotope ratio variation in natural systems reflects the dynamics of Earth systems processes and imparts isotope labels to Earth materials. (springer.com)

The kit can also be used for the validation of new methods, the monitoring of the performance of methods used for the determination of carbon isotope ratios, and for the training and evaluation of staff. (lgcgroup.com)
The high quality of the data obtained of this moving 9th-magnitude object has permitted a determination of the cometary abundance of various elements and their isotopes [2] . (eso.org)

Stable isotope analysis can be executed pre-completion on samples obtained from mud gas and/or gas desorbing from cuttings and core. (onepetro.org)
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 C-12 atom has been given the atomic weight of exactly 12.000000000 and is used as the basis upon which the atomic weight of other isotopes is determined. (webelements.com)

Overall, our findings show that A. viridis is characterized by a higher autotrophic/heterotrophic ratio as p CO 2 increases. (nature.com)

2 of biomass from inorganic carbon [2]. (lu.se)

These data can help predict fluid type, API gravity, and gas-oil ratio (GOR), all of which can help guide land acquisition and development decisions. (onepetro.org)
Richards and Hedges 1999 ), especially when combined with carbon isotope data. (springer.com)

The age of organic material determined by the amounts of carbon isotopes 12, 13 and 14. (theodora.com)

Life alters the typical ratio of C-12 to C-13 because most biochemical processes -eating, growth, and so on - divide isotopes into lighter and heavier camps. (livescience.com)

Our study shows that the rate of carbon emissions and resulting acidification [during the PETM were] an order of magnitude slower than what's going on right now," Penman says. (earthmagazine.org)

Carbon 12 and 13 are stable isotopes and the amounts remain the same even in dead material. (theodora.com)

Previous related work from the O'Brien Laboratory published in AJCN may be of interest to readers, as well as a related commentary on the use of stable isotope ratios in nutritional epidemiology . (nutrition.org)
Even when a radiocarbon laboratory measures very precise isotope ratios in a sample, any age estimate from the formula will only be as good as the four assumptions that went into it. (icr.org)

Extrinsic sources of carbon for the host include zooplankton and particulate organic carbon (POC) 17 . (nature.com)

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)
If Noah's Flood actually happened about 4,500 years ago, as the Scriptures record, then it would have affected, and possibly steamrolled, carbon-14 ratios in very old samples. (icr.org)

1. Carbon-14 has been decaying at basically the same rate throughout Earth's history. (icr.org)
The likeliest explanation is that lifeforms, once buried deep in the Earth's crust, altered the ancient aragonite's carbon signature. (livescience.com)

δ 15 N values and C/N ratios did not change in Symbiodinium and host tissue along the p CO 2 gradient. (nature.com)
Absorption Ratio, Differential-- Ratio of concentration of a nuclide in a given organ or tissue to the concentration that would be obtained if the same administered quantity of this nuclide were uniformly distributed throughout the body. (cdc.gov)

There is a need for a series of materials certified for absolute values, to ensure that small variations in how replacement materials behave, or how they are measured, do not impact the comparability of isotope ratio results across time and space. (lgcgroup.com)
Together with a decrease in the difference between δ 13 C values of both fractions at the higher p CO 2 sites, these results indicate there is a greater net autotrophic input to the A. viridis carbon budget under high p CO 2 conditions. (nature.com)

2. In Fig. 7.7 the carbon 13 isotope levels form a 45 degree line. (schoolscience.co.uk)

Knowledge of the abundance of the stable isotopes [2] of the light elements in different solar system objects provides critical clues to the origin and early evolution of these objects and of the system as a whole. (eso.org)

A beach outcrop at Davis Head on Lopez Island in Washington State, where researchers at Yale discovered veins of aragonite containing oddly light carbon isotopes suggestive of life's imprint. (livescience.com)

The former makes up the vast majority of carbon on the Earth. (livescience.com)

This carbon signature is usually produced by microbes that excrete the carbon-containing compound methane. (livescience.com)

C-13 can also be used for the production of the radioisotope N-13 which is a PET isotope. (webelements.com)
This is also the only carbon radioisotope found in nature, as trace quantities are formed cosmogenically by the reaction 14 N + n → 14 C + 1 H . The most stable artificial radioisotope is 11 C , which has a half-life of 20.3402(53) min. (wikipedia.org)

In order to gain the best possible insight into the origins and formation of the niche in which we live, it is therefore important to determine such isotopic abundance ratios in as many members of the solar family as possible. (eso.org)

By looking at the carbon isotopes of animals, it can even be determined whether an animal feeds in its own environment or comes into town and finds food in garbage cans. (uwyo.edu)

Carbon isotopic records of nutrient-depleted surface water place constraints on the past fertility of the oceans and on past atmospheric pCO2 levels. (pangaea.de)

However, the relative scale that is used for carbon isotope ratios is defined by reference standards that have changed over time and one of which has recently been shown to be unstable. (lgcgroup.com)

Adsorption Coefficient (Koc)-- The ratio of the amount of a chemical adsorbed per unit surface area or per unit weight of organic carbon of a specific particle size in the soil or sediment to the concentration of the chemical in solution at equilibrium. (cdc.gov)

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