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Visar resultat 1 - 5 av 14 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. The role of benthic macrofauna in nitrogen cycling in eutrophic lake sediment

    Författare :Jonas Martin Svensson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; nitrogen retention; nitrous oxide; oligochaetes; chironomids; mineralisation; nitrification; denitrification; eutrophic; sediment; lake; Macrofauna; nitrogen cycling; fish reduction.; Ecology; Ekologi;

    Sammanfattning : This thesis concerns the role of sediment-living macrobenthos in the cycling of nitrogen species and nitrogen transformation in eutrophic freshwater sediments. In my thesis I have, employing 15N-isotope techniques in laboratory experiments, shown the importance of infaunal chironomid larvae and oligochaetes on denitrification in eutrophic lake sediments. LÄS MER

  3. 2. The sensitivity of Swedish alpine lakes to hydro-climatic changes during the Late Holocene

    Författare :Annika Berntsson; Gunhild Rosqvist; Peter G. Langdon; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; alpine lake sediments; temperature reconstruction; precipitation; catchment erosion; chironomids; oxygen isotopes; XRF core scanning; geomorphology; grain size analysis; kvartärgeologi; Quaternary Geology;

    Sammanfattning : The thesis objective is to use lake sediments to investigate the relationships between chironomids, as proxy for temperature, and δ18O and minerogenic in-wash, as precipitation proxies, in northern Sweden during the Late Holocene. Three lakes along a N–S transect in the Scandes were studied using biological, geochemical and physical sediment properties, together with numerical methods. LÄS MER

  4. 3. Sub-lethal Effects of Anthropogenic Contaminants on Aquatic Invertebrates

    Författare :Warren Kunce; Frank Johansson; Jan Örberg; Sarah Josefsson; Jes Rasmussen; Uppsala universitet; []
    Nyckelord :ecotoxicology; sub-lethal; behavior; biomarkers; thermal tolerance; pesticides; pyrethroids; neonicotinoids; pharmaceuticals; antihistamines; microplastics; mixtures; freshwater; invertebrates; chironomids; damselflies; snails; Biology with specialization in Animal Conservation; Biologi med inriktning mot zoologisk bevarandebiologi;

    Sammanfattning : Anthropogenic contaminants are considered to play a substantial role in the decline of freshwater invertebrate diversity. Sub-lethal effects of many of these contaminants on behaviour and life-history traits of aquatic invertebrates may contribute to their decline. LÄS MER

  5. 4. The effects of exposure to microplastics and pollutants on the arthropod microbiome

    Författare :Javier Edo Varg; Richard Svanbäck; Jarone Pinhassi; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; ecotoxicology; host microbiota; freshwater; anthropogenic pollution; microplastics; pesticides; pyrethroids; detergents; toxic metals; daphnids; chironomids; water boatmen; damselflies; dragonflies;

    Sammanfattning : Anthropogenic pollution is widespread across various ecosystems. This disturbance can alter the interaction between a host and its associated microbiome, with repercussions for hosts traits such as health, behavior, and host evolution. LÄS MER

  7. 5. Classes of DNA associated with telomeres in the chironomids C. pallidivittatus and C. tentans

    Författare :Iréne Kamnert; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Genetics; Chironomus; subtelomere; gene conversion; subfamilies; telomere; complex repeats; cytogenetics; Genetik; cytogenetik;

    Sammanfattning : Telomeres in Chironomus consist of long complex tandem DNA repeats, which in C. pallidivittatus have been shown to extend to the extreme end of chromosomes. In C. pallidivittatus the telomeric repeats are present in large blocks, 50-200kb in size, most of them belonging to four major subfamilies. LÄS MER