Sökning: "environmental isotope"

Visar resultat 1 - 5 av 173 avhandlingar innehållade orden environmental isotope.

  1. 1. Intramolecular isotope analysis reveals plant ecophysiological signals covering multiple timescales

    Författare :Thomas Wieloch; Jürgen Schleucher; Mats Nilsson; Gerd Gleixner; Lisa Wingate; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NMR spectroscopy; tree ring; isotope ratio; isotope effect; intramolecular 13C 12C signal; carbon allocation; acclimation; plant performance; climate reconstruction; plant ecophysiology;

    Sammanfattning : Our societies' wellbeing relies on stable and healthy environments. However, our current lifestyles, growth-oriented economic policies and the population explosion are leading to potentially catastrophic degradation of ecosystems and progressive disruption of food chains. LÄS MER

  2. 2. Identification of brominated organic compounds in aquatic biota and exploration of bromine isotope analysis for source apportionment

    Författare :Maria Unger; Örjan Gustafsson; Lillemor Asplund; Per Andersson; Sheryl Tittlemier; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Polybrominated dibenzo-p-dioxins PBDDs ; NMR spectroscopy; preparative capillary gas chromatography PCGC ; stable bromine isotope ratio; GC-multiple collector- ICP-MS; Environmental chemistry; Miljökemi; miljökemi; Environmental Chemistry;

    Sammanfattning : Brominated organic compounds (BOCs) of both natural and anthropogenic origin are abundant in the environment. Most compounds are either clearly natural or clearly anthropogenic but some are of either mixed or uncertain origin. LÄS MER

  3. 3. Compound-specific stable chlorine isotope analysis : A versatile tool for investigating biochemical and geochemical processes of organochlorine substances

    Författare :Henry Holmstrand; Per Andersson; Örjan Gustafsson; Neil Sturchio; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; compound-specific chlorine isotope analysis; chlorinated organic compounds; Environmental chemistry; Miljökemi;

    Sammanfattning : Chlorinated organic compounds (OCls) from anthropogenic sources are generally considered to be a class of chemicals with high potential for ecotoxicity, including infamous substances such as polychlorinated biphenyls (PCB), dichloro-dibenzo-trichloroethane (DDT) and polychlorinated dibenzo-p-dioxins (PCDD). OCls are also produced naturally, sometimes at the same order of magnitude as anthropogenic compounds. LÄS MER

  4. 4. Coping with environmental change : Lessons from isotope studies in a sentinel species

    Författare :Matias Ledesma; Agnes Karlson; Marleen De Troch; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stable isotope; compound-specific nitrogen stable isotope analysis; trophic niche; harmful algae blooms; contaminants; stress; reproductive success; environmental change; Baltic Sea; marin ekologi; Marine Ecology;

    Sammanfattning : Adaptive evolution and phenotypic plasticity are two key mechanisms by which natural populations avoid extinction in the face of environmental change. Evolutionary young systems, such as the Baltic Sea with low species diversity and steep environmental gradients, are good models for studying how wild populations cope with environmental changes, such as climate-induced alterations in food supply and exposure to environmental contaminants. LÄS MER

  5. 5. Towards understanding stable isotope signatures in stressed systems

    Författare :Caroline Ek; Elena Gorokhova; Katrine Borgå; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Stable isotope analysis; trophic position; chemical exposure; oxidative stress; Daphnia magna; Gammarus spp.; Limecola balthica; Applied Environmental Science; tillämpad miljövetenskap;

    Sammanfattning : Stable isotope analysis (SIA) is a valuable tool in ecotoxicology because δ13C and δ15N may provide insights into the trophic transfer of contaminants in a food web. The relationship between a species’ trophic position (TP, determined from δ15N) and internal concentration of biomagnifying contaminants can be established and used for regulatory purposes. LÄS MER