Sökning: "Stable isotope analysis"

Visar resultat 21 - 25 av 79 avhandlingar innehållade orden Stable isotope analysis.

  1. 21. Species interactions and energy transfer in aquatic food webs

    Författare :Jens Munk Nielsen; Monika Winder; Sture Hansson; Michael T. Brett; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Aquatic food webs; zooplankton; stable isotope analysis amino acids; molecular diet analysis; Marine Ecology; marin ekologi;

    Sammanfattning : Food webs are structured by intricate nodes of species interactions which govern the flow of organic matter in natural systems. Despite being long recognized as a key component in ecology, estimation of food web functioning is still challenging due to the difficulty in accurately measuring species interactions within a food web. LÄS MER

  3. 22. Holocene climate and environmental change in high latitudes as recorded by stable isotopes in peat deposits

    Författare :Päivi Kaislahti Tillman; Steffen Holzkämper; Stefan Wastegård; Peter Kuhry; Thomas W. D. Edwards; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stable isotopes; Holocene; subarctic; climate; Sphagnum fuscum; kvartärgeologi; Quarternary Geology;

    Sammanfattning : In this thesis, stable carbon and oxygen isotopes in α-cellulose isolated from Sphagnum fuscum moss remains were used as climate proxies. The main focus was to implement the methods in records from high latitude peatlands in the Northern Hemisphere (west-central Canada and north-eastern European Russia), reconstruct palaeoclimate of the studied regions during the Holocene, and evaluate the compatibility of results with other proxy records, especially tree-ring isotope time-series. LÄS MER

  4. 23. Living in a predation matrix : Studies on fish and their prey in a Baltic Sea coastal area

    Författare :Ida Ahlbeck; Sture Hansson; Hannu Lehtonen; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diet analysis methods; Sander lucioperca; behaviour; rearing environment; diel vertical migration; Acartia spp.; Eurytemora affinis; Perca fluviatilis; stable isotopes; body condition; sedentarity; Marine Ecology; marin ekologi;

    Sammanfattning : This thesis was written within the framework of a biomanipulation project where young-of-the-year (YOY) pikeperch (Sander lucioperca) were stocked to a Baltic Sea bay to improve water quality through a top-down trophic cascade. The aim of my doctorial studies was however focused on a broader ecological question, namely predation (the main driving force in a biomanipulation). LÄS MER

  5. 24. Fractionation of the stable silicon isotopes : analytical method developments and selected applications in geochemistry

    Författare :Emma Engström; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Applied Geology; Tillämpad geologi;

    Sammanfattning : During the last few decades, variations in the 'natural' isotopic abundances of stable elements (termed 'fractionation') have received considerable interest from the scientific community. Though analytical methods and techniques for the measurement of isotopic abundances with adequate figures of merit have been available for light elements (e.g. LÄS MER

  7. 25. Phosphoproteomic analysis of Arabidopsis thaliana ribosomes

    Författare :Hanna Klang Årstrand; Alexander Vener; Cornelia Spetea Wiklund; Ingemar Rundquist; Linköpings universitet; []
    Nyckelord :;

    Sammanfattning : Ribosomes serve as the site of protein synthesis in all living cells. Ribosomes were discovered in 1955 by George E. Palade when he was studying the endoplasmic reticulum which is covered by ribosomes. He received the Nobel Prize in Physiology or Medicine in 1974 for this discovery. LÄS MER