Sökning: "trophic effects"

Visar resultat 16 - 20 av 137 avhandlingar innehållade orden trophic effects.

  1. 16. Trophic factors, neuroprotection and spinal cord repair

    Författare :Johan Widenfalk; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; 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

  2. 17. Ecological effects of pesticides in freshwater model ecosystems

    Författare :Lina Wendt-Rasch; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; marine biology; aquatic ecology; limnology; Marinbiologi; Hydrobiology; community; zooplankton; algae; herbicide; insecticide; pesticide mixture; macrophytes; cypermethrin; metsulfuron-methyl; risk assessment; pesticides; microcosms; limnologi; akvatisk ekologi;

    Sammanfattning : In this thesis I have investigated the effects of pesticide exposure on the ecosystem level using various types of experimental ecosystems, i.e. microcosms. The direct effect of exposure to cyperemthrin, a pyretroid insecticide, was a rapid decrease of crustancean zooplankton in enclosures in a lake. LÄS MER

  3. 18. Indirect effects of predation in human-modified landscapes

    Författare :Ellinor Sahlén; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Large carnivores affect prey species, with cascading effects on entire ecosystems. In anthropogenic regions large carnivores come into conflicts with humans, especially in rural areas where farming and hunting traditions are widespread. As a result, large carnivores have been eradicated from many regions across their historical distribution. LÄS MER

  4. 19. The Invasion of the Zebra Mussel - Effects on Phytoplankton Community Structure and Ecosystem Function

    Författare :Rahmat Naddafi; Kurt Pettersson; Peter Eklöv; Willem Goedkoop; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Invasive species; Zebra mussel; Invasion success; Selective feeding; Non-lethal effects of predator; Seston stoichiometry; Delayed fluorescence excitation spectroscopy; Phytoplankton dynamics; Trait-mediated indirect interaction; Ecosystem function;

    Sammanfattning : Biological invasion has become a major threat to economy, ecology, global biodiversity and ecosystem function of aquatic ecosystems. The main aim of the thesis was to study the effects of the zebra mussel (Dreissena polymorpha), a versatile invasive species, on phytoplankton dynamics and ecosystem function of lakes. LÄS MER

  5. 20. Drivers and food web effects of Gonyostomum semen blooms

    Författare :Karin Johansson; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The flagellate Gonyostomum semen forms dense late-summer blooms in humic lakes and is a nuisance to swimmers because it forms a slimy coat on the skin, causing irritation in sensitive individuals. Increasing occurrence and bloom incidence of G. LÄS MER