Sökning: "ULTRAVIOLET-B"

Visar resultat 1 - 5 av 16 avhandlingar innehållade ordet ULTRAVIOLET-B.

  1. 1. Skin phototesting using a divergent ultraviolet B beam : development and evaluation on a normal material

    Författare :Michail Ilias; Linköpings universitet; []
    Nyckelord :MEDICINE; MEDICIN;

    Sammanfattning : The phototesting method proposed provokes the skin by means of a divergent UVB beam. The beam divergence is induced by an optical plano-concave !ens placed at the opening of the light guide which directs the light from the UV lamp to the skin. LÄS MER

  3. 2. Effects of enhanced ultraviolet-B radiation on subarctic ecosystems

    Författare :Carola Gehrke; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; pigmentation; photosynthesis; dark respiration; shoot morphology; shoot growth; phanerogams ; species composition cryptogams; productivity; decomposition; dwarf shrubs; bryophytes; peatland ecosystem; heath ecosystem; UV-B; ozone depletion; Plant ecology; Växtekologi;

    Sammanfattning : Biologically harmful ultraviolet-B radiation (UV-B, 280-320 nm) is increasing at the Earth´s surface owing to stratospheric ozone depletion. This is of global concern due to potential impacts of enhanced UV-B radiation on the biosphere. LÄS MER

  4. 3. 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. 4. Modification of flavonoid content and photosynthesis by ultraviolet-B radiation. Atrazine-tolerant and -sensitive ultivars of Brassica napus

    Författare :Louise Olsson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; recovery; quercetin; photosynthesis; photoinhibition; photoacoustics; leaf anatomy; kaempferol; flavonoid; D1 protein; fluorescence; cold stress; carbon dioxide; atrazine tolerance; Brassica napus; UV-B; Physiological biophysics; Växtfysiologi;

    Sammanfattning : Levels of ultraviolet-B (UV-B, 280-320 nm) radiation reaching the Earth´s surface increase due to stratospheric ozone depletion. In this thesis the effect of enhanced UV-B radiation was studied on the atrazine-tolerant mutant Stallion, susceptible to photoinhibition, and the atrazine-sensitive cultivar Paroll of Brassica napus (oilseed rape). LÄS MER

  7. 5. Role of cadmium and ultraviolet-B radiation in plants, Influence on photosynthesis and element content in two species of Brassicaceae

    Författare :Helene Larsson Jönsson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Växtekologi; Plant ecology; UV-B; plant nutrients; photosynthesis; oxygen evolution; chlorophyll fluorescence; Cd uptake; cadmium; Arabidopsis thaliana; Brassica napus; Plant biochemistry; Växtbiokemi; Botany; Botanik;

    Sammanfattning : Plants are exposed to many different stress factors during their lifetime, often more than one factor at a time, which highlights the importance of research regarding interaction among stress factors. Cadmium and ultraviolet-B radiation (UV-B, 280-315 nm) are two potential stress factors in the environment, which have gained increased interest due to atmospheric pollution. LÄS MER