Sökning: "trophic effects"

Visar resultat 6 - 10 av 137 avhandlingar innehållade orden trophic effects.

  1. 6. Ontogenetic bottlenecks : effects on intraguild predation systems and ecosystem efficiency

    Författare :Birte Reichstein; Lennart Persson; André M. De Roos; Priyanga Amarasekare; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; mixed interactions; cannibalism; life-history omnivory; ontogenetic niche shift; biomass overcompensation; biomass production; ontogenetic asymmetry; indirect effects; biology; biologi; zooekologi; Animal Ecology;

    Sammanfattning : Size-dependent differences between individuals in size-structured organisms have fundamental effect on population and community dynamics. Intraguild predation (IGP) is one specifically interesting constellation that often arises when two size-structured populations interact. LÄS MER

  2. 7. Fish on drugs : behaviour modifying contaminants in aquatic ecosystems

    Författare :Annelie Lagesson; Jonatan Klaminder; Tomas Brodin; Kathryn Arnold; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Aquatic ecosystems; Behavioural effects; Ecotoxicology; Endocrine disruptors; Pharmaceuticals; Interaction effects; ekotoxikologi; Ecotoxicology;

    Sammanfattning : Contamination of surface waters is a worldwide problem. One group of emerging contaminants that reach aquatic ecosystems via sewage treatment plant effluents and agricultural run-offs is pharmaceuticals. LÄS MER

  3. 8. Regulation of digestive organ. An experimental study on the role of CCK, Bile and EGF

    Författare :Bodil Ohlsson; Internmedicin - epidemiologi; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Immunology; trophic effects; total parenteral nutrition; salivary glands; pancreaticobiliary diversion; pancreas; liver; intestinal mucosa; epidermal growth factor; cholecystokinin; biliodigestive shunt; Bile; bilary tract; serology; transplantation; Immunologi; serologi; Gastro-enterology; Gastroenterologi;

    Sammanfattning : Cholecystokinin (CCK) is known to exert secretory and trophic effects on the pancreas. Its release from the intestinal mucosa is regulated by pancresic proteases in the small intestine. However, knowledge about the type of responding exocrine cells and the time course of events during stimulation with CCK is lacking. LÄS MER

  4. 9. Role of ecological processes in determining effects of contaminants in aquatic ecosystems

    Författare :Anna-Lea Golz; Clare Bradshaw; Karen Kidd; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; ecosystem approach; ionizing radiation; HBCDD; microcosm; species interactions; indirect effects; Marine Ecotoxicology; marin ekotoxikologi;

    Sammanfattning : Aquatic ecosystems cover approximately 70% of the Earth’s surface and support a wide range of ecosystem services. Despite their importance, aquatic ecosystems are increasingly exposed to anthropogenic stressors, such as contaminants and climate change impacts. LÄS MER

  5. 10. Spinal cord grafts : Interaction with cografts and effects of trophic factors

    Författare :Katarzyna Trok; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; cord injury; spinal cord transplants; regeneration; GDNF; neurotrophins; CNTF; 5HT; immunohistochemistryKatarzyna Trok; 1996ISBN 91-6;

    Sammanfattning : ÑSpinal cord injury is common in the modern society, often afflictsyoung individuals, and often has devastating consequences. The present workstudies possibilities to obtain better conditions for regeneration of the transectedspinal cord in rats, conditions under which spinal cord grafts are able toestablish structural and functional connections with "natural" targets, andeffects of a series of neurotrophic factors on spinal cord graft survival andgrowth. LÄS MER