Sökning: "trophic levels"

Visar resultat 1 - 5 av 146 avhandlingar innehållade orden trophic levels.

  1. 1. Climate change effects on marine species across trophic levels

    Författare :Nan Hu; Enhet akvatisk ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; trophic levels; predation; gastropods; mussels; ocean acidification; ocean warming; interactive effects; interaction types; meta-analysis;

    Sammanfattning : Climate change and anthropogenic activities are producing a range of new selection pressures, both abiotic and biotic, on marine organisms. While there are numerous studies that have investigated the response of individual marine organisms to climate change, few studies have focused on differences in organismal responses across trophic levels. LÄS MER

  3. 2. Brominated natural products at different trophic levels in the Baltic Sea : Identification of polybrominated dioxins, hydroxylated and methoxylated diphenyl ethers

    Författare :Anna Malmvärn; Lillemor Asplund; Åke Bergman; Bert van Bavel; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; polybrominated dibenzo-p-dioxins; hydroxylated polybrominated diphenyl ethers; methoxylated polybrominated diphenyl ethers; Baltic Sea; algae; natural production; Environmental chemistry; Miljökemi; Environmental Chemistry; miljökemi;

    Sammanfattning : Over time, the Baltic Sea has been contaminated by increasing discharges of pollutants from human activities. Persistent organic pollutants (POPs) have caused toxic effects in wildlife and excess of nutrients have led to eutrophication. LÄS MER

  4. 3. Trophic factors, neuroprotection and spinal cord repair

    Författare :Johan Widenfalk; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :spinal cord injury; GDNF; GFRalpha; neurotrophin; VEGF; olfactory ensheathing glia; weight-drop injury; in situ hybridization;

    Sammanfattning : Background: There is no cure for paralysis. The only drug therapy presently in use, acute high-dose methylprednisolone, has only modest effects on outcome. There is therefore a great need for new therapies. LÄS MER

  5. 4. Differential effects of voluntary running on hippocampal plasticity in the adult rat brain

    Författare :Andrew Stuart Naylor; Göteborgs universitet; []
    Nyckelord :exercise; hippocampus; stress; progenitor proliferation; neurogenesis; trophic factors; frontal cortex; spatial memory; rat; pCREB; endogenous opioids;

    Sammanfattning : The continuation of neuronal birth from dividing neural stem cells in the dentate gyrus of the hippocampus throughout adulthood is known to play an important role in maintaining normal hippocampal function, such as memory and learning. Negative alterations in the levels of adult neurogenesis have also been linked to several neurodegenerative diseases, including Alzheimer s disease and mood disorders such as depression. LÄS MER

  7. 5. Food Web Ecology -- individual life-histories and ecological processes shape complex communities

    Författare :Martin Hartvig; Evolutionär ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; food web; community ecology; community assembly; size-structure; life-history omnivory; ontogeny; trophic interactions; trait based model; topology; emergent organisation; size-spectrum;

    Sammanfattning : This thesis sets out a food web framework for size-structured populations. The framework enables an ecological approach to food web modelling as the individual life-history from birth, through maturation, and ultimately death is explicitly resolved with the use of bioenergetics based on individual body size. LÄS MER