Search for dissertations about: "Radiation sciences"

Showing result 1 - 5 of 1196 swedish dissertations containing the words Radiation sciences.

  1. 1. Effects of solar radiation on the abiotic and bacterially mediated carbon flux in aquatic ecosystems

    Author : Alexandre Magno Anesio; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; bacteria; dissolved inorganic carbon DIC ; bioavailability; aquatic macrophytes; photooxidation; detritus decomposition; Ultraviolet radiation; dissolved organic carbon DOC ; fungi; Hydrobiology; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

    Abstract : In this Thesis, I studied some of the current aspects of organic matter photochemistry. I analyzed abiotic phototransformations of several types of dissolved (DOM) and particulate organic matter (POM). I also evaluated the effects of phototransformation of several types of DOM on bacteria. READ MORE

  2. 2. Waterfowl in temperate eutrophic lakes - Interactions with macroinvertebrates, submerged vegetation and fish

    Author : Ola Marklund; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; Hydrobiology; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi; Chara; Asellus; chironomidae; ultraviolet radiation; epiphytes; predation; herbivory; diel vertical migration; fish; Waterfowl; macroinvertebrates; submerged vegetation;

    Abstract : The aim of this thesis was to explore some of the important links between waterfowl and the biota in shallow eutrophic lakes in temperate areas. Waterfowl depend on macroinvertebrates as sources of protein and calcium, which are essential for egg production and growth. Macroinvertebrates in turn depend on submerged vegetation for food and shelter. READ MORE

  3. 3. Utilization of terrestrially derived dissolved organic nitrogen by aquatic bacteria

    Author : Ramunas Stepanauskas; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; amino acids; spring flood; UV radiation; estuarine mixing; microbial loop; bacterial bioassays; marine eutrophication; bioavailability; Dissolved organic nitrogen; DON; extracellular aminopeptidase; Baltic Sea; Hydrobiology; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

    Abstract : I investigated the bacterial utilization of terrestrially derived dissolved organic nitrogen (DON) in aquatic ecosystems, and assessed the potential role of river-born DON in marine eutrophication. To determine the bioavailability of DON, I developed a bioassay employing N-limited bacterial regrowth cultures, which were calibrated with additions of inorganic nitrogen. READ MORE

  4. 4. Solar radiation effects on decomposition and decomposers of plant litter in lakes

    Author : Måns Denward; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; glucosidase; photo inhibition; photo oxidation; littoral; lakes; ergosterol; fungi; phragmites; bacteria; UV-B; Hydrobiology; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

    Abstract : This thesis summarizes the results of a series of experiments, from test tube up to field study scale, performed to increase the understanding of solar radiation effects on decomposition and microbial decomposers of plant litter in stagnant water of littoral zones. In conclusion, I suggest that fungi play a significant role in the decomposition of plant litter submersed in lakes, and that their distribution is dependent on detritus quality and water chemistry, but also tends to be inversely related to the occurrence of bacteria attached to the litter. READ MORE

  5. 5. Local adaptive pigmentation in Asellus aquaticus -effects of UV-radiation and predation regime

    Author : Jonas Johansson; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; Marinbiologi; limnology; aquatic ecology; marine biology; Hydrobiology; Ekologi; Ecology; damselfly; perch; UV-avoidance; isopod; anti-predator traits; evolution; selective predation; limnologi; akvatisk ekologi; Animal ecology; Djurekologi;

    Abstract : Pigmentation in the freshwater isopod Asellus aquaticus differed between two habitats. Asellus were lighter pigmented in stands of submerged stonewort vegetation, than in nearby reed stands. Moreover, Asellus pigmentation became lighter with time in recently established stonewort stands. READ MORE