Search for dissertations about: "Naturvetenskapliga fakulteten"

Showing result 1 - 5 of 689 swedish dissertations containing the words Naturvetenskapliga fakulteten.

2. 1. Future stratospheric ozone depletion will affect a subarctic dwarf shrub ecosystem

   Author : Ulf Johanson; Biologiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Vaccinium; UVB; subarctic; shoot growth; ozone depletion; leaf thickness; irradiation system; heath ecosystem; Empetrum; dwarf shrubs; Calamagrostis; decomposition; Physiological biophysics; Växtfysiologi;

   Abstract : The stratospheric ozone depletion and the concomitant increase in ultraviolet-B (UV-B, 280-320 nm) radiation is of global concern due to the effects of UV-B on living organisms. To investigate the effects of increased levels of UV-B, a field irradiation system was established at a subarctic dwarf shrub heath in Northern Sweden (68 °N). READ MORE

4. 2. Prokaryotic Arsenic Resistance - Studies in Bacillus subtilis

   Author : Emil Aaltonen; Biologiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; ArsB; Bacillus subtilis; arsenic resistance; arsenate reduction; arsenite transport; gene regulation; arsenate; ArsR; arsenite; transmembrane topology; Acr3; ArsK;

   Abstract : Arsenic is a toxic metalloid which is found all over the globe. Due to its toxicity and wide abundance, all living organisms have evolved intrinsic arsenic resistance systems. In this study, three proteins that provide arsenic resistance in the Gram-positive bacterium Bacillus subtilis have been investigated. READ MORE

5. 3. Mating system evolution and self-incompatibility in the wild plant species Brassica cretica

   Author : Kristina Aaltonen; Biologiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; mating system; Brassicaceae; Brassica cretica; recombination; frequency-dependent selection; evolution; population structure; segregation distortion; SCR; self-incompatibility; SRK;

   Abstract : Compared to animals like ourselves, plants have a very flexible sexual life. Most plants are, for example, hermaphrodites with the potential capacity for reproduction by self-fertilization (or selfing). READ MORE

6. 4. Ontogeny and Population Biology of a Sex-Limited Colour Polymorphism

   Author : Jessica Abbott; Biologiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; embryologi; ontogeni; animal morphology; embryology; Utvecklingsbiologi; Damselflies; Colour polymorphism; Development; Frequency-dependence; Morphology; growth animal ; ontogeny; Animal anatomy; Development biology; Djurs anatomi och morfologi; Population divergence; Animal ecology; Djurekologi;

   Abstract : This study has involved investigation of number of populations of the damselfly Ischnura elegans over several years, looking at frequency changes over time, morphological differences between the sexes and the morphs, differences in growth rate and development time, differences in fecundity between the morphs, and genetic differentiation between populations. I. READ MORE

7. 5. Molecular aspects of pheromone evolution in moths

   Author : David Abraham; Biologiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ekologi; 28S genephylogenetic reconstruction pheromone types; ND1 genes; PBP; Pheromone-binding protein genes; Drepanidae; Noctuidae; Geometridae; Lepidoptera; Insect; Evolution; Olfaction; Ecology;

   Abstract : Moths rely on the sense of smell (olfaction) as the main sensory input system in search for potential food sources and in selection of suitable females by males. Specific pheromones are fundamental to the reproductive isolation of species and consequently the olfactory system of moths has evolved to a high level of sensitivity and specificity. READ MORE