Discusses carbon isotope. Medical search. Frequent questions

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)
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)
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)
While traditional stable isotope analyses of tooth enamel (e.g., carbon and oxygen) and trace element ratios (e.g. (blueskytccaalibaba.com)
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)
We show the weathering processes that fractionate dissolved and sedimentary Li isotope ratios, focusing on weathering intensity and clay formation. (nhbs.com)
In recent decades, the natural abundances of stable carbon and nitrogen isotopes (represented as 13 C/ 12 C and 15 N/ 14 N ratios, respectively) have been widely used to probe biogeochemical and ecological processes. (springeropen.com)
Historically, this field started as early as the 1930s, when a custom-made mass spectrometer was constructed to measure subtle differences in the isotopic ratios of natural carbon (Nier and Gulbransen 1939 ). (springeropen.com)
Bogaard A, Hodgson J, Nitsch E et al (2016) Combining functional weed ecology and crop stable isotope ratios to identify cultivation intensity: a comparison of cereal production regimes in Haute Provence, France and Asturias, Spain. (springer.com)
Stable and radiogenic carbon isotopes (δ13C and Δ14C) of organic compounds and phospholipid fatty acids (PLFAs), as well as polycyclic aromatic hydrocarbon (PAH) ratios were used to determine sources and fates of organic contaminants in highly contaminated, and less contaminated sediments of Hamilton Harbour. (mysciencework.com)

discussed how hydrogen and carbon isotope composition analysis can be used to identify different biogenic methane production pathways from its water and CO2 precursors. (wikipedia.org)
Learners examine the method for calculating the atomic weight of copper from the natural percent composition of each of its two isotopes. (bio-alive.com)
The atmospheric carbon dioxide (CO 2 ) mixing ratio and its carbon isotope ( δ 13 C-CO 2 ) composition contain important CO 2 sink and source information spanning from ecosystem to global scales. (copernicus.org)
Stable carbon isotope composition, depth distribution and fate of macroalgae from the Antarctic Peninsula region / G. Fischer, C. Wiencke. (cam.ac.uk)
Stable carbon isotope composition of benthic macroalgae discussed in relation to depth zonation. (cam.ac.uk)
eng#d 035 ## ‡a SPRI-117455 040 ## ‡a UkCU-P ‡b eng ‡e aacr 100 1# ‡a Fischer, G. 245 10 ‡a Stable carbon isotope composition, depth distribution and fate of macroalgae from the Antarctic Peninsula region / ‡c G. Fischer, C. Wiencke. (cam.ac.uk)
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)
of which, the emission factors and stable carbon isotope composition are important basic data. (bvsalud.org)
The carbon isotopic composition of an organism mainly reflects its dietary signature (DeNiro and Epstein 1978 ), and coordinated isotopic measurements of organisms provide a unique approach to describing the dietary habits of animals, a macroscale ecological phenomenon. (springeropen.com)
De Souza CR, Maroco JP, dos Santos TP, Rodrigues ML, Lopes CM, Pereira JS, Chaves MM (2005) Impact of deficit irrigation on water use efficiency and carbon isotope composition (δ 13 C) of field-grown grapevines under Mediterranean climate. (springer.com)
Based on molecular and stable carbon isotope composition of a large collection of gas samples and integrated with the geological context, this article discusses the genesis and migrational characteristics of natural gases from the giant tight sand gas fields of the Upper Paleozoic strata, Ordos Basin (UPOB). (mysciencework.com)
The index decreased along the transect in an off-river direction, correlating strongly with both the branched and isoprenoid tetraether (BIT) index and the stable carbon isotopic composition of the sedimentary organic carbon. (uspermafrost.org)
It is based on canopy conductance inferred from sap flux and intrinsic water-use efficiency estimated from the stable carbon isotope composition of phloem contents. (duke.edu)

In addition to this, while working for Chevron in 1984 Schoell requested funding from Chevron to fund John Hayes of Indiana University to develop continuous-flow compound-specific isotope analysis. (wikipedia.org)
In summary, the session will offer an overview on oxygen and hydrogen applications across different ecosystems in order to facilitate the interpretation of compound-specific isotope patterns. (copernicus.org)

His research focuses on using stable isotopes to characterize the geochemistry of petroleum. (wikipedia.org)
Schoell was mentored by Wolfgang Stahl, who inspired Schoell's interest in hydrogen isotope geochemistry with respect to natural gas research. (wikipedia.org)
Schoell has made many contributions to geochemistry with emphasis on the applications of stable isotope analysis. (wikipedia.org)
3] Degens E T. Biogeochemistry of stable carbon isotopes.In:Eghinton G,Murphy M T,eds.Organic Geochemistry. (adearth.ac.cn)
Although the carbon and nitrogen isotopic compositions of diverse types of organic matter were measured and discussed by the pioneers of isotope geochemistry (e.g. (springeropen.com)
Eby provides students with a solid foundation in basic aqueous geochemistry before discussing the important role carbon compounds, isotopes, and minerals play in environmental issues. (surgerybook.net)

1] Galimov E M. The Biological Fractionation of Isotopes. (adearth.ac.cn)
Metabolic fractionation of carbon isotopes in marine plankton. (adearth.ac.cn)
8] O′Leary M H.Carbon fractionation in plants.Phytochemistry,1981,20:553～567. (adearth.ac.cn)
10] Vogel J C. Fractionation of carbon isotopes during photosynthesis. (adearth.ac.cn)
SUMMARY: A fractionation of sulphur isotopes was found in all metabolic processes investigated except those in which elemental sulphur was the starting substrate for growth of Thiobacillus concretivorus and Chromatium sp. (microbiologyresearch.org)
The data are discussed with reference to the mechanism(s) of fractionation. (microbiologyresearch.org)

This study reports both stable carbon and nitrogen isotope compositions of frugivorous bat guano deposited in a well-preserved stratigraphic succession of Blanchard Cave on Marie-Galante, Guadeloupe. (embrapa.br)

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)
As our knowledge of the distributions of carbon and nitrogen isotopes in organic matter and the factors controlling them has accumulated, the scope of isotopic measurements has greatly expanded. (springeropen.com)

Schoell is known for his work regarding CO2, sedimentary rocks, methane, natural gas, carbon isotopes, and acetate fermentation and how these factors enable identification of the origins of greenhouse gasses. (wikipedia.org)

This session aims to bring together scientists from different fields applying single and dual oxygen and hydrogen isotope approaches on environmental-derived compounds for the reconstruction of climatic and biological processes that go beyond standard isotope analyses of water. (copernicus.org)
We also encourage people working with all techniques (IRMS-, NMR- or spectroscopy-based) to present advances in methods, as well as researchers focusing on improving oxygen and hydrogen isotope-based models to discuss their approaches. (copernicus.org)
These include: field parameters (e.g. electrical conductivity, temperature), major and trace ions (e.g. metals), stable isotopes of oxygen and hydrogen, industrial compounds (CFCs and SF6) and dissolved carbon isotopes (i.e. inorganic and organic forms). (edu.au)
However, it was suggested that a so-called specific difference between the hyperfine splittings in hydrogen-like and lithium-like ions of the same isotope can be used to cancel nuclear structure effects and provide an accurate test of QED [Shabaev et al. (fnal.gov)
The first strategy to be evaluated is the selective fortification of organic compounds with heavier isotopes of carbon (13C) and hydrogen (deuterium). (agingcell.com)

identify that the two primary methods for aquatic and marine methane production are carbon dioxide reduction and acetate fermentation, respectively. (wikipedia.org)
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)
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)
20] KeeLing C D,Mook W G,Tans P P.Recent trends in the 13 C/ 12 C ratio of atmospheric carbon dioxide.Nature,1979, 277: 121～123. (adearth.ac.cn)
Growing food would be a huge challenge for another reason-the depletion of carbon dioxide from the atmosphere. (reasons.org)
The greater the percentage of Earth's surface covered by ice, the less concentration of carbon dioxide in Earth's atmosphere. (reasons.org)
As a carbon isotope study revealed, these altered ocean currents remove carbon dioxide from the atmosphere and transport it to the deep ocean where it remains stored until ice coverage recedes and global mean temperatures rise. (reasons.org)
During the last ice age, the atmospheric carbon dioxide concentration dropped down to 180-190 parts per million. (reasons.org)
3 At levels of 150-500 parts per million of carbon dioxide in the atmosphere, there is a direct correlation between that CO 2 level in the atmosphere and the amount of food plants can produce through photosynthesis. (reasons.org)
If H pylori are present, the bacteria convert the urea into carbon dioxide, which is detected and recorded in your exhaled breath after 10 minutes. (medlineplus.gov)
Detailed knowledge about how climate and human activities influence the sources and sinks of greenhouse gases like carbon dioxide and methane is needed in order to make the informed and effective decisions needed for combating climate change. (lu.se)

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)
In the United Kingdom testing in vitro and after approximately 100 mg to 200 differences in the ratio of carbon isotopes in different compounds. (showyou.com)

INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY ENVIRONMENTAL HEALTH CRITERIA 13 Carbon Monoxide This report contains the collective views of an international group of experts and does not necessarily represent the decisions or the stated policy of either the World Health Organization or the United Nations Environment Programme. (inchem.org)

This method uses isotope dilution with carbon-13 labeled internal standards. (cdc.gov)
Phytoestrogens are then separated from other urine components by reversed phase HPLC, detected by APPI-MS/MS, and quantified by isotope dilution. (cdc.gov)

Stable carbon and oxygen isotope reconstructions based on benthic foraminifera, together with a high-resolution benthic foraminiferal record of Mg/Ca paleothermometry, is presented. (embrapa.br)

We dive deep into this really novel study, touching on stable isotopes, controlled feeding trials, essential and non-essential amino acids, and emerging biomarkers of intake for use in experimental and observational nutrition studies. (nutrition.org)
In our contribution, we discuss the potential, the advances and the limitation of the coupled isotope approach based on leaf wax-derived n -alkane and hemicellulose-derived sugar biomarkers (δ 2 H n -alkanes - δ 18 O sugars ). (copernicus.org)
For this purpose novel isotope tracer approaches were applied, whereby stable isotope (13C) labelled CO2 was fed to plants and the root-released labelled carbon was traced into soil microbial biomarkers. (nerc.ac.uk)

Ions from each analyte and each carbon-13 labeled internal standard are monitored, and the abundances of each ion are measured. (cdc.gov)

Applications like migration studies and dietary reconstructions will also be discussed. (radiocarbon.com)

Isotope-labeling is a useful technique for understanding cellular metabolism. (mdpi.com)
Recent advances in metabolomics have extended the capability of isotope-assisted studies to reveal global metabolism. (mdpi.com)

These findings show that the combination of long-term atmospheric carbon isotope observations and inverse modeling can provide a powerful constraint on the carbon cycle of these complex megacities. (copernicus.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)
In the first section we discuss the molecular classification of sporadic tauopathies, with a focus on describing clinicopathologic relationships. (biomedcentral.com)

A microscopic study of elastic scattering of carbon isotopes from different target nuclei at various incident energies is presented by using density distributions derived for $^{10-14,16}\rm{C}$ nuclei using relativistic mean field (RMF) theory. (ias.ac.in)
This 5-minute video discusses how we know what the Earth's climate was like tens and hundreds of thousands of years ago via climate proxies such as carbon isotopes found in microscopic shells and other sources. (subjecttoclimate.org)

For instance, isotope-assisted metabolomics technology has enabled the mapping of a global metabolic network, estimation of flux at branch points of metabolic pathways, and assignment of elemental formulas to unknown metabolites. (mdpi.com)

It is ubiquitous in nature and, due to its relative persistence, is an important factor in Earth's slow-cycling carbon pool. (mysciencework.com)

We review the biochemical and physiological bases of the use of carbon and nitrogen isotopic compositions as an approach for environmental and ecological studies. (springeropen.com)
An important application of the analysis of carbon and nitrogen isotopic compositions is in ecological studies. (springeropen.com)

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)
This paper tentatively discusses the mechanism, the model of plants carbon isotope discrimination and the progress in environmental change research. (adearth.ac.cn)
14] Farquhar G D, Ehleringer J R, Hubick K T. Carbon isotope discrimination and photosynthesis. (adearth.ac.cn)
18] Francey R J,Gifford R M,sharkey T D,et al.Physiological influences on carbon isotope discrimination in huon pine. (adearth.ac.cn)
19] Kobrner C H, Farquhar G D. R oksandic Z.A global survey of carbon isotope discrimination in plants from high altitude. (adearth.ac.cn)
Araus JL, Febrero A, Buxó R et al (1997) Identification of ancient irrigation practices based on the carbon isotope discrimination of plant seeds: a case study from the south-east Iberian Peninsula. (springer.com)

11] Saurer M,Sigenthaler U.The climate-carbon isotope relationship in tree rings and the signficance of site conditions.Tellus, 1995, (46B): 320～330. (adearth.ac.cn)
The former can demonstrate the rates at which the climate is stabilised from perturbations via weathering, a fundamental piece of the puzzle of the long-term carbon cycle. (nhbs.com)
Dansgaard-Oeschger (D-O) climate instabilities that took place during Marine Isotope Stage 3 are connected to changes in ocean circulation patterns and sea ice cover. (embrapa.br)
For the first time we combine outputs from a climate model with a thermodynamic iceberg model to simulate likely source regions for ice-rafted debris (IRD) found in the Nordic Seas from Marine Isotope Stage M2 to the mid-Piacenzian Warm Period and what this implies about the nature of the Arctic cryosphere at this time. (embrapa.br)
These isotopic data are discussed with regard to climate changes and its specific impact on Eastern Caribbean vegetation during the Late Pleistocene from 40 to 10 ka cal. (embrapa.br)
LUCCI was a research centre at Lund University devoted to studies of the carbon cycle and how it interacts with the climate system. (lu.se)
Working together in a creative cross-disciplinary environment, our goals are to increase the understanding of how the carbon cycle and climate system function and interact, and to disseminate our findings to society. (lu.se)
Although progress has been made in our understanding of the carbon cycle and climate there are several fundamental science questions that remain unanswered and that are pivotal for an increased understanding of the Earth System as well as for our ability to predict future changes through modeling. (lu.se)

The theoretical results are discussed and compared with each other as well as with the experimental data. (ias.ac.in)

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)

This webinar is designed to discuss the role of public health laboratories as part of a larger inter-related system of organizations (including clinical laboratories) that influence the health of populations. (cdc.gov)

We propose using the sap flux/isotope method as an alternative way to estimate canopy GPP, termed GPP iso/SF , at the stand scale and at daily resolution. (duke.edu)

During his time with Chevron, Schoell introduced Mudgas isotope analysis to Chevron and the natural gas industry, and worked in a variety of international locations including locations throughout the Americas, Southeast Asia and Africa as well as parts of Oceania. (wikipedia.org)
The results of Schoell's work have included identifying the pathways of formation that distinguish methane of biogenic origin from that of thermogenic origin using stable isotope analysis. (wikipedia.org)
The Miami-based laboratory also offers stable isotope analysis of bones, carbonates and water samples. (radiocarbon.com)
Here we present the results of stable carbon isotope ( δ 13 C) analysis on charred crop seeds from the Bronze Age site of Kaymakçı in western Anatolia. (springer.com)

This paper will discuss the findings from the studies carried out as part of the soil biodiversity programme (SBP) in examining the diversity and functions of soil microbes. (nerc.ac.uk)
One of the fundamental aims of the SBP was to link the activity and diversity of microbes with functional roles in the cycling of plant derived carbon through the soil food web. (nerc.ac.uk)
Amending soil with black carbon (BC) can change the sorption properties of the soil. (mysciencework.com)

This enables scientists to better track carbon cycle responses to environmental change and tune biochemical processes in vegetation models for an improved simulation of future change. (copernicus.org)
The purpose of this website is to discuss various theories of aging and evaluate several strategies for slowing down the aging processes. (agingcell.com)
Rather than broadly discussing a variety of environmental problems, the author focuses on principles throughout the text, leading students to understand processes and how knowledge of those processes can be applied to environmental problem solving. (surgerybook.net)
How do possible increased extreme events such as devastating storms and flooding affect carbon cycle processes and do we already see such perturbations? (lu.se)

It was found that the periodic puffing regimen yielded 20% less carbon monoxide (CO) than the played-back smoking session, indicating that steady periodic smoking regimens, which are widely used in tobacco smoke research, may not produce realistic smoke aerosols. (who.int)

Given that silicate weathering is the primary long-term method by which CO 2 is removed from the atmosphere, Li isotope research is going through an exciting phase. (nhbs.com)
We present a methodology to detect inconsistencies in perhaps the most important data source for measurements of ecosystem-atmosphere carbon, water, and energy fluxes. (copernicus.org)

7] Keeling C D. A mechanism for cyclic enrichment of carbon-12 by terrestrial plants. (adearth.ac.cn)

Biology and chemistry classes could use this video for lessons about atomic structure, subatomic particles, the uses of stable isotopes in medicine, ecology, biology, and Earth sciences. (subjecttoclimate.org)

Schoell continued his work with methane origin studies expanding his research to consider how stable isotopes can provide insight regarding the temperature of the environment for both thermogenic and biogenic methane production. (wikipedia.org)
Specifically, Schoell collaborated on the paper "Formation temperatures of thermogenic and biogenic methane" authored by D. Stolper, which used "clustered isotope" techniques to determine the temperature at which methane was produced. (wikipedia.org)

The Task Group reviewed and revised the second draft of the criteria document and made an evaluation of the health risks from exposure to carbon monoxide. (inchem.org)
However, several recent publications broadly reviewing health aspects of carbon monoxide have also been used including those of the Commission of the European Communities (1974), NAS/NRC (1977), US Department of Health, Education and Welfare (1970, 1972), and Committee on the Challenges of Modern Society (1972). (inchem.org)
To illustrate its use, dry particulate matter and carbon monoxide yields generated using the playback and equivalent periodic puffing regimens are compared for a single smoking session by a 26-year-old male narghile water-pipe smoker. (who.int)

This presentation will also cover m arine reservoir effects , diagenesis and other common issues as well as isotopic studies involving carbon, nitrogen, oxygen, strontium, and lead isotopes . (radiocarbon.com)

In the paper, "Biogenic methane formation in marine and freshwater environments: CO2 reduction VS. acetate fermentation-Isotope evidence", Schoell et al. (wikipedia.org)

At the same time, research direction of plants carbon isotope in the future is introduced,too. (adearth.ac.cn)
This video from the Paleontological Research Institution describes how scientists can determine ancient climates using isotopes of oxygen in ancient ocean sediments. (subjecttoclimate.org)
assess and critically discuss views and conclusions expressed in primary research publications in the field. (lu.se)

These archives have been used to examine Li isotope changes across both short and long timescales. (nhbs.com)
At the workshop, we would like to examine and discuss a range of relationships between textile production and seals, and sealing practices from a wider geo-chronological perspective. (edu.pl)

The emission factors of organic carbon (OC) of gasoline and natural gas vehicles were much higher than those of elemental carbon (EC) in every test stage. (bvsalud.org)

Students can also explore this lesson about isotopes and getting past temperatures from ice cores. (subjecttoclimate.org)

Anatomy2

Organisms12

Diseases2

Chemicals and Drugs37

Analytical, Diagnostic and Therapeutic Techniques and Equipment9

Phenomena and Processes30

Disciplines and Occupations2

Anthropology, Education, Sociology and Social Phenomena3

Technology, Industry, Agriculture1

Humanities1

Information Science1

Health Care11

Geographicals1

Ratios11

Composition13

Compound-specific isotope2

Geochemistry6

Fractionation6

Stable carbon and nitrogen1

Nitrogen isotopes2

Sedimentary1

Hydrogen5

Dioxide11

Compounds2

United Nations E1

Dilution2

Benthic1

Biomarkers3

Ions1

Reconstructions1

Metabolism2

Atmospheric1

Molecular2

Microscopic2

Metabolic1

Earth's1

Compositions2

Discrimination6

Climate8

Theoretical1

Demonstrates1

Webinar1

Flux1

Analysis4

Soil3

Processes4

Aerosols1

Atmosphere2

Terrestrial1

Ecology1

Temperature2

Monoxide3

Studies1

Methane1

Research3

Examine2

Organic carbon1

Temperatures1