Stable Isotope

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Angus I. Lamond - One of the best experts on this subject based on the ideXlab platform.

  • Stable Isotope labeling with amino acids in nematodes
    Nature Methods, 2011
    Co-Authors: Mark Larance, Aymeric P Bailly, Ehsan Pourkarimi, Sarah Coulthurst, Grant Buchanan, Anton Gartner, Dimitris P. Xirodimas, Angus I. Lamond
    Abstract:

    A method for performing quantitative proteomics experiments in Caenorhabditis elegans using Stable-Isotope labeling with amino acids in cell culture (SILAC) is described. The authors used the method to identify heat shock–responsive proteins in worms. Also online, Fredens et al. describe a very similar method.

  • Stable-Isotope labeling with amino acids in nematodes.
    Nature Methods, 2011
    Co-Authors: Mark Larance, Aymeric P Bailly, Ehsan Pourkarimi, Ronald T Hay, Sarah Coulthurst, Grant Buchanan, Anton Gartner, Dimitris P. Xirodimas, Angus I. Lamond
    Abstract:

    We describe an approach for accurate quantitation of global protein dynamics in Caenorhabditis elegans. We adapted Stable-Isotope labeling with amino acids in cell culture (SILAC) for nematodes by feeding worms a heavy lysine- and heavy arginine-labeled Escherichia coli strain and report a genetic solution to elminate the problem of arginine-to-proline conversion. Combining our approach with quantitative proteomics methods, we characterized the heat-shock response in worms.

Stuart Bearhop - One of the best experts on this subject based on the ideXlab platform.

  • bayesian Stable Isotope mixing models
    Environmetrics, 2013
    Co-Authors: Andrew C Parnell, Stuart Bearhop, Donald L Phillips, Brice X Semmens, Eric J Ward, Jonathan W Moore, Andrew L Jackson, Jonathan Grey, David J Kelly, Richard Inger
    Abstract:

    In this paper, we review recent advances in Stable Isotope mixing models (SIMMs) and place them into an overarching Bayesian statistical framework, which allows for several useful extensions. SIMMs are used to quantify the proportional contributions of various sources to a mixture. The most widely used application is quantifying the diet of organisms based on the food sources they have been observed to consume. At the centre of the multivariate statistical model we propose is a compositional mixture of the food sources corrected for various metabolic factors. The compositional component of our model is based on the isometric log-ratio transform. Through this transform, we can apply a range of time series and non-parametric smoothing relationships. We illustrate our models with three case studies based on real animal dietary behaviour.

  • applications of Stable Isotope analyses to avian ecology
    Ibis, 2008
    Co-Authors: Richard Inger, Stuart Bearhop
    Abstract:

    In the past 20 years the use of Stable Isotope analysis has become increasingly common in ecological studies. In fact, in some instances these techniques have yielded remarkable insights into the foraging preferences and migrations of birds. Despite these advances and the potential of the approach, it is possibly still not as widely used as might be expected. In this paper we aim to illustrate the potential of the approach in the hope of encouraging more avian ecologists to think again about how these techniques might provide insights in the systems on which they work. We discuss some of the principles behind the approach, and review some of the more recent ornithological studies that have used Stable Isotope techniques to trace trophic pathways or infer migratory origins. We follow this by discussing some of the latest ideas on how Stable Isotopes may be used to generate community metrics and close by detailing the important assumptions and caveats that should be considered before undertaking any studies using this technique.

Hans Demmelmair - One of the best experts on this subject based on the ideXlab platform.

  • Safety of Stable Isotope use.
    European Journal of Pediatrics, 1997
    Co-Authors: Berthold Koletzko, Thorsten Sauerwald, Hans Demmelmair
    Abstract:

    The increased employment of Stable Isotope tracers for diagnostic and research purposes frequently raises questions on potential risks associated with their use, which is of particular importance in the paediatric age group. Biological effects and the potential of adverse events has been evaluated in a large number of animal and, in part, also human studies. Possible differences in physical, chemical and biochemical behaviour resulting in kinetic and thermodynamic Isotope effects between Stable Isotopes of the same element are related to the relative differences in atomic weight. Deuterium (2H), which differs markedly in mass form the predominant hydrogen Isotope 1H, may induce serious side-effects at high concentrations in body fluids. The threshold dose for the occurrence of side-effects lies well above the usual tracer dosages for clinical use. In contrast to deuterium, heavier Stable Isotopes such as 13C, 15N or 18O that differ relatively little in mass from the predominant Isotopes such as 12C, does not show any adverse biological effects even at highest enrichments. Conclusion The doses of Stable Isotope tracer substances that are used for clinical diagnostic and research purposes appear safe and without any adverse effects. Stable Isotope tracers should only be used in children if the tracee is safe at the doses applied, and tracer is chemically pure and Stable. In the case of intravenous application, the tracer preparation must also be sterile and pyrogen free.

  • Safety of Stable Isotope use.
    European journal of pediatrics, 1997
    Co-Authors: Berthold Koletzko, Thorsten Sauerwald, Hans Demmelmair
    Abstract:

    The increased employment of Stable Isotope tracers for diagnostic and research purposes frequently raises questions on potential risks associated with their use, which is of particular importance in the paediatric age group. Biological effects and the potential of adverse events has been evaluated in a large number of animal and, in part, also human studies. Possible differences in physical, chemical and biochemical behaviour resulting in kinetic and thermodynamic Isotope effects between Stable Isotopes of the same element are related to the relative differences in atomic weight. Deuterium (2H), which differs markedly in mass from the predominant hydrogen Isotope 1H, may induce serious side-effects at high concentrations in body fluids. The threshold dose for the occurrence of side-effects lies well above the usual tracer dosages for clinical use. In contrast to deuterium, heavier Stable Isotopes such as 13C, 15N or 18O that differ relatively little in mass from the predominant Isotopes such as 12C, does not show any adverse biological effects even at highest enrichments. The doses of Stable Isotope tracer substances that are used for clinical diagnostic and research purposes appear safe and without any adverse effects. Stable Isotope tracers should only be used in children if the trace is safe at the doses applied, and tracer is chemically pure and Stable. In the case of intravenous application, the tracer preparation must also be sterile and pyrogen free.

Craig A. Johnson - One of the best experts on this subject based on the ideXlab platform.

  • Stable Isotope GEOCHEMISTRY
    American Mineralogist, 2003
    Co-Authors: Craig A. Johnson
    Abstract:

    This volume was prepared for a like-titled short course that took place at the 2001 Geological Society of America annual meeting in Boston. The objective of the course was to review select topics within the field of Stable Isotope geochemistry that the organizers felt had emerged or greatly advanced since 1986, the year of publication of an earlier volume in the Reviews series that focussed on Stable Isotopes ( Stable Isotopes in High Temperature Geological Processes . J.W. Valley, H.P. Taylor Jr., and J.R. O’Neil, Editors, Reviews in Mineralogy, vol. 16). Stable Isotope Geochemistry consists of 13 separate chapters authored or coauthored by 17 leading researchers. The chapter titles are: (1) Equilibrium Oxygen, Hydrogen and Carbon Isotope Fractionation Factors Applicable to Geologic Systems , (2) Rates and Mechanisms of Isotopic Exchange , (3) Fractionation of Carbon and Hydrogen Isotopes in Biosynthetic Processes , (4 ) Stable Isotope Variations in Extraterrestrial Materials , (5 ) Oxygen Isotope Variations of Basaltic …

Ulrich Flenker - One of the best experts on this subject based on the ideXlab platform.

  • Conference report. Recent developments in Stable Isotope research: joint European Stable Isotope User Meeting 2008.
    Bioanalysis, 2009
    Co-Authors: Ulrich Flenker
    Abstract:

    A rapidly increasing number of applications are currently emerging from Stable Isotope research whilst, at the same time, significant evolution of the instrumentation may also be observed. The European Stable Isotope community gathered in Giens, France, to exchange views and discuss recent developments.

  • Stable Isotope analysis of the bioelements: an introduction.
    Bioanalysis, 2009
    Co-Authors: Ulrich Flenker
    Abstract:

    The abundances of the Stable Isotopes of the bioelements are not constant. Subtle, but significant, variations may be induced by physical, physiological and biochemical processes. These variations may be detected and quantified. Often, Isotope fingerprints are characteristic of certain processes and may reveal information concerning the sources and origins of compounds of interest. Moreover, natural variabilities of Stable Isotopes may be exploited in order to perform tracer experiments. The most accurate technology to perform Stable Isotope analysis is (gas) Isotope ratio MS (IRMS). Compound-specific approaches employ hyphenation of GC and LC to IRMS. In these approaches, complete conversion to simple gases prior to MS is required. Analysis by Stable Isotope ratio spectroscopy currently approaches the accuracy of IRMS. However, for bioanalytical projects, it is still predominantly confined to material synthetically enriched with Stable Isotopes.