Sökning: "ultraviolet radiation"

Visar resultat 21 - 25 av 130 avhandlingar innehållade orden ultraviolet radiation.

  1. 21. Zooplankton responses to multiple threats within and across generations

    Författare :Yongcui Sha; Enhet akvatisk ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Predation; Ultraviolet radiation; Daphnia; copepods; plasticity; maternal effects; adaptation; diel vertical migration;

    Sammanfattning : In their natural environments, organisms are unlikely to be distributed randomly but instead they are constantly faced with multiple and variable threats. In order to maximise survival, they need to be able to perceive the present threat level and respond accordingly. LÄS MER

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

    Författare :Ola Marklund; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; 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;

    Sammanfattning : 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. LÄS MER

  4. 23. Prevention of Experimental Cataract Induced by UVR

    Författare :Martin Kronschläger; Per Söderberg; Madeleine Zetterberg; Uppsala universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; cataract; ultraviolet radiation; apoptosis; thioltransferase; caffeine;

    Sammanfattning : Cataract is the leading cause of blindness in the world and is defined by opacification of the normally transparent lens of the eye. The major avoidable cause of cataract is ultraviolet radiation (UVR), but no current strategies have been developed to prevent the onset of cataract. LÄS MER

  5. 24. Temperature effects on UV-B induced DNA damage and repair in plants and a lichen

    Författare :Markus Paulsson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Tobacco Nicotiana tabacum ; Temperature; Subarctic; Plants; Photoreactivation; Photolyase; Lichen; DNA damage; Cyclobutane pyrimidine dimers CPD ; 6-4 Photoproducts; Cladonia arbuscula ssp. mitis; Ultraviolet radiation; UV-B; Vaccinium vitis-idaea; Plant genetics; Växtgenetik;

    Sammanfattning : All living organisms have DNA and since DNA is essential to life it must be repaired when damaged. UV radiation is one of the major DNA damaging agents, which photosynthetic organisms cannot avoid. LÄS MER

  7. 25. Phenotypic responses of zooplankton to variable conditions

    Författare :Marcus Lee; Enhet akvatisk ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Multiple threats; Plasticity; Risk-Spreading; sexual conflict; ultraviolet radiation; Daphnia; Copepods;

    Sammanfattning : Organisms are continually challenged by multiple threats in the environment, and such threats are seldom constant in either time or space. Therefore, organisms must maintain physiological, behavioural, morphological and life- history adaptations across environments to prevent reductions in fitness. LÄS MER