Sökning: "UV-B"

Visar resultat 11 - 15 av 25 avhandlingar innehållade ordet UV-B.

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

   Författare :Måns Denward; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; 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;

   Sammanfattning : 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. LÄS MER

3. 12. Ecophysiological responses of Baltic and Atlantic Fucus vesiculosus to environmental factors

   Författare :Charlotta A Nygård; Nils Ekelund; Mittuniversitetet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; acclimation; Atlantic; Baltic Sea; Bothnian Sea; Cd; Fucus vesiculosus; growth; high PAR; Pb; photosynthesis; salinity; stress; UV-B; Biology; Biologi;

   Sammanfattning : The Baltic Sea is a species-poor ecosystem where marine species coexist with freshwater species. The Baltic Sea offers low salinity, low content of inorganic carbon, long cold winters and no tides. LÄS MER

4. 13. Evolutionary ecology of ultraviolet-B radiation stress tolerance in amphibians

   Författare :Maarit Pahkala; Trevor Beebee; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; amphibians; anomalies; embryonic development; geographic variation; growth; Rana arvalis; Rana temporaria; survival; UV-B radiation; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; populationsbiologi; Population Biology;

   Sammanfattning : During the last decades many amphibian species and populations have experienced declines and extinctions in different parts of the world. Anthropogenic activities are believed to account for these declines, and one of the hypothesized causes has been the increased level of ultraviolet-B (UV-B) radiation due to depletion of the stratospheric ozone layer. LÄS MER

5. 14. The surface complex of Euglena gracilis. Involvement in cellular movements and biochemical and molecular analyses of the components

   Författare :Silja K Petersen-Mahrt; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; UV-B radiation; tubulin; surface complex; plasma membrane; phylogeny; phototaxis; nitrogen deficiency; membrane skeleton; Euglena gracilis; actin; cell shape; Physiological biophysics; Växtfysiologi;

   Sammanfattning : The flagellate Euglena gracilis shows rhythms in phototaxis and cell shape changes between oblong and round. Artificial UV-B radiation of 0.5 W m-2 caused a loss in phototaxis, but the peak of activity occurred at the same time as for control cells. LÄS MER

7. 15. Biological Weighting of UV-B Radiation. The importance of wavelength for the inhibition of microalgae

   Författare :Kristin I. M. Andreasson; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : .... LÄS MER