Sökning: "trophic effects"

Visar resultat 16 - 20 av 148 avhandlingar innehållade orden trophic effects.

  1. 16. Predator-prey interactions in freshwater systems: The importance of chemical communication

    Författare :Kajsa Åbjörnsson; Enhet akvatisk ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi; Ecology; Ekologi; Hydrobiology; trophic cascades; non-lethal effects; benefits; costs; heredity; predator experience; alarmsubstances; dietary cues; amphibian larvae; invertebrates; visibility; fish; behaviour; Predator-prey; chemical cues;

    Sammanfattning : Predator released chemical cues provide a valuable source of information to prey organisms that can be used to alter their behaviour in order to reduce predation risk. In this thesis, I have examined under what circumstances chemical cues may be used by prey, and if prey discriminate between different cues. LÄS MER

  3. 17. Transformation/dissolution characteristics of cobalt and welding fume nanoparticles in physiological and environmental media: surface interactions and trophic transfer

    Författare :Nanxuan Mei; Eva Blomberg; Inger Odnevall Wallinder; Jonas Hedberg; Iseult Lynch; KTH; []
    Nyckelord :nanoparticles; cobalt; stainless steel welding fume particles; biomolecules; metal release; trophic transfer; adsorption; agglomeration; algae; nanopartiklar; kobolt; rostfritt stål svetsrök partiklar; biomolekyler; metallfrigöring; trofisk överföring; adsorption; agglomerering; alger; Kemi; Chemistry;

    Sammanfattning : Nanoparticles (NPs) and nanomaterials (NMs) are present everywhere in the environment. They can form both as an act of nature and during human activities. Various kinds of NPs and NMs are engineered for different applications in the ongoing development of nanoscience and technology. LÄS MER

  4. 18. 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. 19. Ecological effects of pesticides in freshwater model ecosystems

    Författare :Lina Wendt-Rasch; Biologiska institutionen; []
    Nyckelord :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

  7. 20. 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