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Dissertations / Theses on the topic 'Stable isotope tracers'

Author: Grafiati

Published: 4 June 2021

Last updated: 27 January 2023

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1

North, Jessica C., and n/a. "Stable isotope tracers of landfill leachate impacts on aquatic systems." University of Otago. Department of Chemistry, 2006. http://adt.otago.ac.nz./public/adt-NZDU20070504.144317.

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The present study aimed to determine whether stable isotope techniques can be universally applied to detect landfill leachate contamination in aquatic systems. Results of analysis of ��C in dissolved inorganic carbon ([delta]��C-DIC), deuterium and �⁸O in water ([delta]D-H₂O and [delta]�⁸O-H₂O), and �⁵N of dissolved inorganic nitrogen components ([delta]�⁵N-NH₄⁺ and [delta]�⁵N-NO₃⁻) were presented for leachate, surface, and ground water samples collected from seven landfills located throughout New Zealand between 2003 and 2006. The unique conditions within a landfill lead to measurable fractio

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2

Nilsson, Lino. "Nitrogen transformations at the Kiruna mine : The use of stable nitrogen isotopes to trace nitrogen-transforming processes." Thesis, Uppsala universitet, Luft-, vatten och landskapslära, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-209419.

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Release of different nitrogen compounds can cause eutrophication in lakes and rivers whichcan lead to oxygen-free environments in bottom water and in the sediment and can in turnlead to fish-deaths. Ammonium can be toxic to biota and nitrate can in high concentrationeven be toxic to humans. WHO has released a limit for nitrate concentration in drinking waterof 10mg/l. The LKAB mine in Kiruna is the largest underground iron mine in the world and isprospecting, mining and refining iron ore, with an annual production of around 28 milliontons. Release of different nitrogen compounds as a result of

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3

Aravindhan, Karpagam Jucker Beat M. DiNardo N. John. "Assessing the effects of LXR agonists in cholesterol handling: stable isotope tracer studies /." Philadelphia, Pa. : Drexel University, 2005. http://dspace.library.drexel.edu/handle/1860/613.

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4

Benbow, Timothy J., and n/a. "Developing compound-specific stable isotope tools for monitoring landfill leachate." University of Otago. Department of Chemistry, 2008. http://adt.otago.ac.nz./public/adt-NZDU20080314.111826.

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This thesis has developed a suite of compound specific stable isotope tools to monitor landfill leachate and identify the infiltration of leachate to ground water and surface water. These tools have the power to indicate the fractional contribution multiple discrete sources of pollution are making to a single location. This journey began by developing two solid phase extraction (SPE) methods to extract non-polar and polar organic compounds from leachate with minimal fractionation of hydrogen or carbon isotopes. Non-polar compounds were successfully extracted using ENV+ SPE cartridges and polar

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5

Lambertsson, Lars. "Mercury species transformations in marine and biological systems studied by isotope dilution mass spectrometry and stable isotope tracers." Doctoral thesis, Umeå : Univ, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-467.

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6

Husic, Admin. "NUMERICAL MODELING AND ISOTOPE TRACERS TO INVESTIGATE KARST BIOGEOCHEMISTRY AND TRANSPORT PROCESSES." UKnowledge, 2018. https://uknowledge.uky.edu/ce_etds/70.

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This dissertation investigated the physical and biogeochemical processes affecting the source, fate, and transport of sediment, carbon, and nitrogen within a highly-coupled fluviokarst system. Elemental and isotopic datasets were collected at surface and subsurface locations for both dissolved and particulate contaminant phases, new methodology regarding data collection was presented to the karst research community, an in-cave sediment transport model coupling physical transport with elemental and isotopic mass balances of carbon and nitrogen was formulated, pathway and process control on nitr

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7

Crane, Justin D. "The muscle specific protein synthesis response to acute running exercise utilizing multiple stable isotope tracers." Virtual Press, 2008. http://liblink.bsu.edu/uhtbin/catkey/1398709.

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The purpose of this study was to compare the anabolic response to acute running exercise in two different leg muscles in endurance-trained men using two different stable isotope tracers. 6 male subjects (26±2 yr; V02max 63±2 ml•kg-' •min-') performed a 45 min treadmill run at 77±1 % intensity. Infusions of d3-leucine and d5-phenylalanine were used to measure mixed muscle FSR at rest and 24 hr post-exercise. An additional infusion of 10% amino acid solution was added to the post-exercise infusion to maximize the muscle anabolic response. Muscle biopsies were obtained from the vastus lateralis (

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8

Herzka, Sharon Zinah. "Characterization of the recruitment patterns of red drum (Sciaenops ocellatus) larvae to estuarine nursery habitat using stable isotopes as natural tracers of settlement /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.

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9

Buchheister, Andre. "Stable Isotope Dynamics in Summer Flounder Tissues, with Application to Dietary Assessments in Chesapeake Bay." W&M ScholarWorks, 2008. http://www.vims.edu/library/Theses/Buchheister08.pdf.

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10

Turki, Abrar Mohammed. "Application of stable isotope tracers to examine phenylalanine metabolism and protein requirements in children with phenylketonuria (pku)." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/53095.

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Phenylketonuria (PKU) is an inherited inborn error of phenylalanine (PHE) metabolism caused by deficiency of hepatic enzyme phenylalanine hydroxylase (PAH). Therefore, PHE accumulates in plasma leading to mental retardation and developmental delay. Kuvan® (Sapropterin dihydrochloride), a synthetic form of tetrahydrobiopterin (BH₄), has been shown to reduce plasma PHE levels in PKU, but not all patients respond to sapropterin treatment. The major mode of treatment remains nutritional management with dietary restriction of PHE and provision of sufficient protein. The dietary protein requirement

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11

Petermann, Eric. "Submarine and Lacustrine Groundwater Discharge:." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-236816.

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The discharge of groundwater into surface water bodies is a hidden, but significant pathway for the input of water and matter into lakes, rivers, estuaries and the coastal sea. Since groundwater is most often characterized by higher levels of nutrients or heavy metals, its discharge has often a crucial effect on the surface water body´s chemistry and the ecosystem health as well as on the related ecosystem service supply. For instance, groundwater-derived nutrient inputs are essential to fuel primary productivity, but if critical thresholds are exceeded groundwater-derived nutrient inputs can

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12

Freemantle, Erika Brita Leah. "The oxidation of energy substrates during healthy aging." Mémoire, Université de Sherbrooke, 2007. http://savoirs.usherbrooke.ca/handle/11143/3921.

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Glucose and ketones are important energy substrates in the human body and brain. Their use is highly regulated depending on energy status which can vary according to multiple factors such as type of cell, fed or fasted state, type of diet, or health state. Use of either substrate is also subject to multiple homeostatic feedback loops. Energy substrate availability has implications in several disorders including declining cognitive function in the elderly. While glucose availability is known to decrease in elderly with cognitive deficits, it is unclear whether this also occurs in healthy elderl

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13

Wolmarans, Milena Helena Louise. "A flight of fancy in the Chorister Robin-Chat (Cossypha dichroa) : an isotopic standpoint." Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/d1017207.

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Forested areas have been cited for their highly diverse floral and faunal assemblages, which are currently under threat from anthropogenic activities that restrict their range and deplete the resources produced within these naturally fragmented patches. Historically, up to 67 percent of avifaunal species associated with well-treed areas have undergone localised extinctions, consequentially affecting biodiversity as a measure of species richness and ecosystem functionality. To date, more than 900 of the bird species affiliated with forests are under threat and despite the theory surrounding fun

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14

Heikoop, Jeffrey Martin. "Environmental signals in coral tissue and skeleton: examples from the Caribbean and Indo-Pacific /." *McMaster only, 1997.

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15

Wardle, Sophie L. "The impact of N-3 pufa ingestion on metabolic, molecular and epigenetic responses to a short-term high-fat diet." Thesis, University of Stirling, 2015. http://hdl.handle.net/1893/22368.

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Obesity is widely considered a primary risk factor for type 2 diabetes (T2D). However, less is known about the early adaptive responses to short-term periods of high-fat energy excess (HFEE). Previous reports detailing whole-body adaptation to fat and energy oversupply are equivocal, perhaps, in part, owing to use of different experimental protocols, varying durations of dietary manipulation and participant cohorts with individuals of varying characteristics. In addition to use of different dietary protocols between studies, alterations in functional end-point measures due to the type of dieta

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16

Ferreira, Araujo Daniel. "Investigations into isotope biogeochemistry of Zn in coastal areas and mangroves." Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30368/document.

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Les zones côtières du monde entier sont sous fort pression de contamination anthropique comme conséquence de la concentration de la plupart de la population mondiale et des activités économiques le long des côtes et des estuaires. La menace de contaminant sur les écosystèmes rend primordial le développement d'outils capable de détecter les modifications biogéochimiques en vue d'aider dans la prévention, la gestion, et la prédiction de risques dans les études environnementales. Dans ce but, cette thèse étudie la biogéochimie des isotopes du Zinc (Zn) en vue de développer un outil capable de tra

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17

Moore, Mary. "Stable Water Isotopes as Tracers in Global Precipitation." Thesis, Harvard University, 2016. http://nrs.harvard.edu/urn-3:HUL.InstRepos:33493530.

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Stable water isotopes (H2O, H18O, and HDO) are incorporated into the microphysics schemes of two different atmospheric models. This thesis describes the use of these molecules as tracers in precipitation budgets to assess the processes controlling the isotopic signatures of precipitation in the tropics and orographic snow in the mid-latitudes. The idealized simulations of seasonal precipitation budgets in the tropics determine that increased vapor convergence during intense precipitation is most important for setting the isotopic composition of the convective precipitation. The isotopic signa

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18

Colgan, Gary A. "Estimating surface/ground-water mixing using stable environmental isotopes." Thesis, The University of Arizona, 1989. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_etd_hy0042_m_sip1_w.pdf&type=application/pdf.

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19

Campbell, Darcy Jo. "Fractionation of stable chlorine isotopes during transport through semipermeable membranes." Thesis, The University of Arizona, 1985. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_etd_hy0002_m_sip1_w.pdf&type=application/pdf.

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20

Delavau, Carly J. "Development of precipitation δ18O isoscapes for Canada and application within a tracer-aided hydrological model". Taylor and Francis, American Geophysical Union, 2015. http://hdl.handle.net/1993/31946.

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Delineating spatial patterns of precipitation isotopes (“isoscapes”) is important for studies including the hydrology of terrestrial systems, present and past interpretations of climate, and tracer-aided hydrological modelling, among others. However, the extent to which precipitation isoscapes can be predicted across Canada has not been fully articulated. This thesis combines isotopes in precipitation (δ18Oppt) observations from two regional and one global network to create long term and time series precipitation isoscapes for Canada and the northern United States. Multi-linear regressions of

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21

Ulusoy, Ulvi. "Determination of uptake of essential trace elements using stable isotopic tracers and rare earth markers." Thesis, University of Glasgow, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321044.

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22

Featherstone, Amy Marie. "Construction of long annually-resolved shell-based chronologies using Glycymeris glycymeris (Bivalvia ; Glycymerididae) from the Bay of Brest, France." Thesis, Brest, 2017. http://www.theses.fr/2017BRES0052/document.

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Ce doctorat repose sur l'utilisation de Glycymeris glycymeris, un bivalve de la famille des Glycymerididae, pour reconstruire la variabilité environnementale en rade de Brest (France). Il vise à comparer des données géochimiques archivées dans ces coquilles avec diverses variables biologiques et écologiques. Les objectifs sont d'identifier de potentiels proxys et d'étendre notre connaissance de la variabilité environnementale avant les premières mesures instrumentales.Au total, 38 spécimens (vivants ou morts) ont été utilisés pour construire une chronologie s'étendant de 1891 à 2014.Les indice

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23

Cox, Katharine A. "Stable isotopes as tracers for freshwater fluxes into the North Atlantic." Thesis, University of Southampton, 2010. https://eprints.soton.ac.uk/191987/.

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The Arctic acts as both an indicator and a facilitator of global climate change. Many studies have identified the manifold changes in the Arctic hydrological system resulting from global warming. These changes have affected the freshwater balance of the northern North Atlantic and therefore pose a problem to deep water formation in this region, further impacting the global climate. This thesis uses the quasi-conservative properties of oxygen and hydrogen isotopes in watermasses to identify and quantify the freshwater sources to the ocean currents exiting the Arctic into the northern North Atla

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24

Sutton, David G. M. "Stable isotope tracer studies for the measurement of equine gastrointestinal motility." Thesis, University of Glasgow, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.422249.

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25

Lavergne, Aliénor. "Evaluation de l'archive naturelle cernes d'arbre comme traceur du climat passé au nord de la Patagonie." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLV004/document.

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L’Hémisphère Sud, et plus précisément le sud de l’Amérique du Sud, sont très sous-représentés dans les reconstitutions climatiques globales du fait d’un manque de données paléoclimatiques robustes. Mes travaux de thèse ont donc porté sur l’évaluation de l’archive naturelle cernes d’arbre, abondante le long de la Cordillère des Andes, comme traceur paléoclimatique. Je me suis ainsi appliquée à étudier la réponse régionale de deux espèces d’arbre (Fitzroya cupressoides et Nothofagus pumilio) natives du nord de la Patagonie (41°S, Argentine) aux forçages climatiques externes en analysant leurs di

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26

Pérez, Moreno Rodrigo. "Stable isotope and anthropogenic tracer signature of waters in an andean geothermal system." Tesis, Universidad de Chile, 2019. http://repositorio.uchile.cl/handle/2250/170853.

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Tesis para optar al grado de Magíster en Ciencias, Mención Geología<br>El presente trabajo se centra en el uso de isótopos estables y trazadores antropogénicos para investigar el origen, los tiempos de residencia y la evolución de las aguas termales en el Complejo Volcánico Lonquimay-Tolhuaca, ubicado en la parte central de la Zona Volcánica Sur. Veinte muestras de agua subterránea, surgiendo en un amplio rango de temperaturas (8-96°C), son analizadas para determinar su composición química, incluyendo elementos mayores, razones isotópicas (δ2H, δ18O, δ13CTDIC) y la concentración de clorofluoro

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27

Gall, Louise. "Development and application of nickel stable isotopes as a new geochemical tracer." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:ebe3c3e1-0b1b-49ed-b64a-016c8d76f220.

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In this thesis, I have developed a new methodology for the accurate determination of mass-dependent variations in nickel (Ni) isotope compositions. Nickel is initially separated in a three-column ion-exchange procedure, and the purified solutions are analysed by multi-collector inductively coupled plasma mass spectrometry (MCICPMS) using a double-spike technique. Using this methodology, I have measured the first Ni isotope ratios for a wide variety of natural geological samples. Significant Ni isotope variations were observed, with an overall spread in delta 60Ni-values of -0.9 to 2.5 permil.

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28

Boehme-Terrana, Linae Marie. "Trace metals and stable isotopes as tracers of life history and trophic connections in estuarine-dependent fish from Tampa Bay, Florida." [Tampa, Fla.] : University of South Florida, 2007. http://purl.fcla.edu/usf/dc/et/SFE0002241.

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29

Toth, Emoke. "Changements paléoenvironnementaux dans la Parathéthys Centrale pendant le Samartien (Miocène moyen) : étude paléontologique de microfaunes et analyses géochimiques." Phd thesis, Université Claude Bernard - Lyon I, 2009. http://tel.archives-ouvertes.fr/tel-00843092.

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Les changements paléoenvironnementaux se produisant pendant le Sarmatien dans la Paratéthys Centrale ont été reconstitués par l'étude des foraminifères (36 espèces) et des ostracodes (28 espèces) de deux forages, combinée à une analyse géochimique de leurs squelettes calcitiques, des coquilles aragonitiques de gastéropodes et des dents phosphatiques de rongeurs.La composition de la microfaune indique que la connexion entre la Paratéthys et la Méditerranée est interrompue ou réduite à la base du Sarmatien mais qu'un bras de mer persiste entre Paratéthys Centrale et Paratéthys Orientale jusqu'à

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30

Pritchard, Jodie Lee, and jodie_pritchard@hotmail com. "Dynamics of stream and groundwater exchange using environmental tracers." Flinders University. School of Chemistry, Physical & Earth Science, 2006. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20060407.122526.

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Regions of surface water and groundwater exchange are major sites for the transfer and transformation of solutes and nutrients between stream and subsurface environments. Conventional stream and groundwater exchange investigations are limited by methodologies that require intensive field investigations and/or the set-up of expensive infrastructure. These difficulties are exacerbated where hydraulic gradients are very low and stream discharge highly variable. This thesis uses a suite of environmental tracers (Cl-, Rn-222, H-2 & O-18, Sr-87/Sr-86) to characterise the extent of stream and groundw

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31

Einloth, Sharon L. "Intrinsic Isotopic Tracers as Independent Evaluators for China Lake Basin, CA." Thesis, The University of Arizona, 2000. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_etd_hy0204_sip1_w.pdf&type=application/pdf.

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32

Webb, Sarah Christine. "Stable carbon and nitrogen isotopes in insects : the influence of diet." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389063.

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33

Mohammed, Nabaz. "Investigating the behavior of alluvial systems, thanks to the classical, isotopic and emerging tracers : case study of the alluvial aquifer of the Allier River (Auvergne, France)." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0033/document.

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L’objectif de la thèse vise à déterminer les facteurs et processus qui contrôlent l’origine et la qualité des eaux souterraines alluviales et ainsi à mieux comprendre le fonctionnement et la vulnérabilité des aquifères alluviaux qui occupent une place prééminente dans le paysage hydrogéologique mondial tant pour leur rôle économique - production d'eau potable, développement agricole - que pour leur rôle écologique. Des mesures hydrodynamiques, hydrochimiques (ions majeurs, traces, molécules phytosanitaires et pharmaceutiques) combinées à des déterminations isotopiques (oxygène-18, deuterium, c

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Koenig, Karen Marie. "True absorption of selenium in dairy cows : stable isotope tracer methodology and effect of dietary copper." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/27972.

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Gas chromatography mass spectrometry (GCMS) and inductively coupled plasma mass spectrometry (ICPMS) were evaluated for the measurement of selenium (Se) and Se stable isotope ratios. GCMS and ICPMS were found to be accurate for quantitative Se analysis in biological matrices by isotope dilution using Se-78 and Se-76 as internal standards, respectively. A higher precision was obtained for ICPMS than GCMS enabling a smaller quantity of the tracer to be administered to subjects in labelling experiments. The isotopes of choice for metabolic tracers were Se-76 when sample analysis was by GCMS and S

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35

Dessier, Aurélie. "Analyse du compartiment mésozooplanctonique et écologie alimentaire printanière de la sardine, Sardina pilchardus (Walbaum, 1782), et de l’anchois, Engraulis encrasicolus (Linné, 1758) adultes dans le Golfe de Gascogne." Thesis, La Rochelle, 2015. http://www.theses.fr/2015LAROS036/document.

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L’étude de l’écologie alimentaire d’une espèce est une clé de la compréhension de sa biologie et de son fonctionnement dans l’écosystème. Ainsi, les interactions proies-prédateurs sont une des voies qui structurent et déterminent les dynamiques des populations et le réseau trophique à l’échelle d’un écosystème. Parmi les sites d’étude d’intérêt majeur, le milieu marin est un espace soumis à des forçages naturels et anthropiques. A l’échelle de l’Océan Atlantique Nord-Est, le Golfe de Gascogne est une vaste baie bordée par l’Espagne au sud et la France à l’est. Ce Golfe est le siège historique

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Cutajar, Josephine-Anne. "Characterisation of aerosols using carbon and lead stable isotopes and trace elements." Thesis, Open University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339859.

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Mutumi, Gregory Lilgee. "Using stable isotopes to trace the movements of ducks in southern Africa." Master's thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/9801.

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Includes bibliographical references.<br>Despite the importance of movement ecology studies, the field faces a prevailing challenge of methodological limitations in tracking individual organisms. This research investigated the utility of the stable isotope technique to trace movements of ducks in southern Africa. I sampled and analysed feathers of ten duck species for stable isotope proportions of Carbon (δ13C), Nitrogen (δ15N) and Hydrogen (δD), from five wetlands (Strandfontein and Barberspan in South Africa, the Manyame catchment in Zimbabwe, Lake Chuali in Mozambique, and Lake Ngami in Bots

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Mangwende, Tapera Elias. "Quantifying nitrogen leaching in wheat (Triticum aestivum L.) using lysimeter stable isotope conservative tracer and modelling techniques." Diss., University of Pretoria, 2017. http://hdl.handle.net/2263/65909.

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Nitrogen (N) leaching is one of the important pathways that leads to water pollution, and previous studies have highlighted the difficulty in measuring it. The purpose of this study was to evaluate different techniques used to quantify nitrate-N (NO3-N) leaching load and determine fertiliser N use efficiency (FNUE). Lysimeter and field trial sites were planted with wheat (Triticum aestivum) (PAN3400 cultivar) at the University of Pretoria Experimental Farm, Hatfield, Pretoria. Two weighing lysimeters and a drain gauge were installed at the lysimeter trial site. Water content sensors and suctio

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Hean, Jeffrey William. "The trophic ecology of waterbirds in a small temperate estuary: a stable isotope and lipid tracer approach." Thesis, Rhodes University, 2016. http://hdl.handle.net/10962/54356.

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Waterbirds are often overlooked as predators in aquatic ecosystems, despite the fact that waterbirds congregate in great numbers in and around waterways, notably estuaries. To fully appreciate the effect that aquatic feeding waterbird species may have on aquatic prey communities and the role that they play in estuarine food webs, stable isotopes and fatty acid profiles were employed to examine the seasonal diet of selected waterbirds in the Kowie Estuary, Eastern Cape Province, South Africa. Population counts were conducted every month for four seasons to examine the demography of waterbirds i

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40

Chouvelon, Tiphaine. "Structure et fonctionnement des réseaux trophiques par l'utilisation de traceurs écologiques (isotopes stables, métaux) en environnement marin ouvert : le cas du Golfe de Gascogne." Phd thesis, Université de La Rochelle, 2011. http://tel.archives-ouvertes.fr/tel-00718595.

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L'étude de l'écologie alimentaire des organismes ainsi que l'étude de la structure et du fonctionnement des réseaux trophiques, principale caractéristique de l'organisation des écosystèmes, ne sont pas aisées en environnement marin. Des méthodes indirectes d'étude ont donc été développées récemment, telles que l'utilisation de " traceurs écologiques " qui sont des paramètres (bio)chimiques mesurés dans les tissus biologiques des organismes. Sur la base du postulat " je suis ce que je mange ", les traceurs écologiques constituent des indicateurs relativement fiables du niveau trophique des orga

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Arnoux, Marie. "Interactions lacs-eaux souterraines et sensibilité aux changements climatiques et environnementaux." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS581/document.

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Face à l’augmentation actuelle des pressions anthropiques sur les réserves d’eaux douces, leur préservation, et notamment celle des eaux souterraines, est primordiale. Les interactions entre les lacs et les eaux souterraines sont étudiées ici afin d’identifier si certains lacs peuvent être utilisés comme indicateurs de changements qualitatifs et quantitatifs des eaux souterraines, spécialement au Québec où plus de 10% du territoire est recouvert d’eaux douces avec un million de lacs recensés. Une vingtaine de petits lacs de Kettle, situés dans des dépôts fluvioglaciaires, ont été spécifiquemen

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Sivry, Yann. "Utilisation des isotopes stables de Cd, Zn, Cu, Ni et Pb pour quantifier le compartiment échangeable des éléments trace métalliques et de delta66Zn pour tracer les pollutions polymétalliques." Toulouse 3, 2008. http://thesesups.ups-tlse.fr/471/.

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Une technique de " spikage ", ou dilution d'isotopes stables multi-élémentaire, a été est développée afin de quantifier et caractériser simultanément les compartiments échangeables de Cd, Zn, Cu, Ni et Pb dans des sols contaminés. Cette technique a étéest ici validée par comparaison avec les résultats de spikage d'isotopes radioactifs de Cd, ainsi que ceux d'extractions chimiques. Par ailleurs, une étude intégrée des signatures isotopiques du Zn (d66Zn) dans plusieurs compartiments d'écosystèmes contaminés (sites métallurgiques de Viviez-Decazeville, S. -O. France et de Kempen, N. -E. Belgique

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Hall, Grant. "A background investigation into the feasibility of heavy stable isotopes (87Sr/86Sr) as source tracers of early hominids." Master's thesis, University of Cape Town, 1995. http://hdl.handle.net/11427/21404.

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Bibliography: pages 85-96.<br>Heavy stable strontium isotope ratios (⁸⁷Sr/⁸⁶Sr) may be used to characterize the habitat choices of early hominids. The basis for this approach is that different geological substrata may have a characteristic range of ⁸⁷Sr/⁸⁶Sr ratios in the available soil strontium pool. This range may be represented in the plants growing on these various geologies and thus into the bones of animals feeding in these areas. Through an examination of strontium isotope ratios for isotope and soils from 10 different geologies in the Sterkfontein Valley and immediate vicinity, it was

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Gudmundsson, Kjartan. "Alternative methods for analysing moisture transport in buildings : Utilisation of tracer gas and natural stable isotopes." Doctoral thesis, KTH, Byggvetenskap, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3509.

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New methods, based on tracer gas measurements and isotopicanalysis can be used to evaluate the moisture properties ofbuilding materials and provide the means for forensic analysisof the origins and history of excessive water in buildings, theimmediate practical consequences of which will be the abilityto improve the moisture performance of constructions. It is shown, in theory and through measurements how thewater vapour permeability of porous building materials can witha good degree of accuracy be estimated with tracer gasmeasurements that provide an efficient alternative to the cupmethod. Co

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Davies, Ceri. "Developing a stable isotope approach to trace the sources and metabolism of phosphorus in freshwaters." Thesis, Lancaster University, 2016. http://eprints.lancs.ac.uk/86265/.

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The oxygen isotope ratio of dissolved inorganic phosphate (δ18Op) represents a novel and potentially powerful stable isotope tracer for biogeochemical research. Analysis of δ18Op may offer new insights into the relative importance of different sources of phosphorus within natural ecosystems. Due to the isotope fractionations that occur alongside metabolism of phosphorus-containing compounds, δ18Op could also be used to better understand the intracellular and extracellular reaction mechanisms that control phosphorus cycling. In this thesis, new methods were developed and tested for the extracti

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Ourgaud, Mélanie. "Influence des apports anthropiques sur les flux de carbone et de contaminants dans les réseaux trophiques de 'poissons' de l'écosystème à Posidonia oceanica." Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4097/document.

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Les écosystèmes marins côtiers subissent de nombreuses perturbations naturelles et anthropiques. Dans le contexte socio-économique actuel, mieux comprendre le fonctionnement et transfert des contaminants dans ces écosystèmes est primordial. L’étude du transfert de la matière organique et des contaminants aux interfaces, constitue un enjeu crucial. Les principaux objectifs sont de caractériser l’ichtyofaune des herbiers de posidonie et comprendre les relations trophiques ; d’établir les niveaux et variabilité spatiale de la contamination en éléments traces ETs et polluants organiques persistant

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Hernawati, Yulaika. "Meteoric Diagenesis of Plio-Pleistocene Reef Terraces in the Southern Dominican Republic." Scholarly Repository, 2011. http://scholarlyrepository.miami.edu/oa_theses/296.

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Four prograding reef terraces (6, 15, 30, and 50 m) have been repetitively exposed to marine and freshwater alteration during the Pliocene and Pleistocene periods. Prolonged freshwater alterations have resulted in many diagenetic overprints that obscure early diagenetic products. This study investigates the sequence of the diagenetic processes and products in the terrace deposits using five long cores and 14 short cores taken from these different reef terraces. The lithologic changes in the cores were documented for reconstruction of the original depositional frameworks prior to embarking on a

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Briand, Marine. "Place des poissons anguilliformes dans le fonctionnement des écosystèmes récifo- lagonaires de la Nouvelle-Calédonie : rôle trophique et impacts des contaminations." Thesis, Nouvelle Calédonie, 2014. http://www.theses.fr/2014NCAL0055/document.

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Les récifs coralliens de Nouvelle-Calédonie constituent un « hot-spot » de biodiversité marine et sont classés au patrimoine mondial de l’Unesco depuis 2008. Ces récifs sont dans un bon état général, mais ils sont soumis à des pressions anthropiques de plus en plus intenses, engendrées par un développement industriel (mines de nickel) et urbain croissant.Mieux comprendre le fonctionnement des écosystèmes lagonaires calédoniens est donc devenu un enjeu majeur. Ce travail s’inscrit dans cette démarche, avec pour objectifs principaux : (1) de reconstruire l’architecture des réseaux trophiques de

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Gentry, David Keith. "Seasonal isotope and trace-metal profiles of serially-sampled Conus gastropods: proxies for paleoenvironmental change." Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969.1/3871.

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We test the fidelity of shallow-water gastropod skeletons as multi-proxy archives of seasonal paleo-environmental change by performing isotopic and trace-metal analyses on specimens of Conus ermineus from the Gulf of Mexico. Four adult specimens were collected from Stetson Bank in the Flower Garden Banks National Marine Sanctuary during the summer of 2002. Shell samples were milled along axes of growth to produce time-series profiles spanning up to eight years. We corrected the profiles for growth rate effects and compared the tuned results with in situ temperature and salinity records at the

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Gudmundsson, Kjartan. "Alternative approaches to moisture transfer in building materials : the use of natural stable isotopes and tracer gas." Licentiate thesis, KTH, Byggvetenskap, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-34502.

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