Sökning: "Asellus"
Visar resultat 6 - 10 av 10 avhandlingar innehållade ordet Asellus.
6. On the Environmental Relevance of Platinum Group Elements
Sammanfattning : It has recently been demonstrated that platinum group elements (PGE) are released from automobile catalysts into the environment, raising concern over ecological and human health risks. However, there is still a lack of knowledge regarding the dispersion and transformation of PGE in the environment and it is therefore difficult to assess potential risks. LÄS MER
7. Mixture toxicity of pesticides and biological effects in agricultural streams : field and laboratory studies
Sammanfattning : The main objective of this thesis was to examine pesticide mixture toxicity and its effects on aquatic biota in agricultural streams. This was accomplished by (1) calculating the ΣTUs for algae and Daphnia magna and a pesticide toxicity index (PTI) based on water quality standards (WQS) for long-term monitoring data (2002-2010), (2) by performing algal inhibition tests with Pseudokirchneriella subcapitata, using both collected in situ water samples and reconstituted water spiked with field-observed pesticide mixtures, and (3) by studying seasonal changes in macroinvertebrate and diatom communities during 2008 in four agricultural streams and determine a set of community-based metrics such as species richness, diversity, ASPT, SPEAR and IPS. LÄS MER
8. Structuring factors for macroinvertebrate communities and the importance for ecosystem processing
Sammanfattning : Aquatic macroinvertebrates play important roles in our ecosystems and are essential for the ecosystem processing. An improved knowledge of structuring factors, such as competition and predation, and the way in which they operates in the macroinvertebrate community is crucial for our understanding of not only the macroinvertebrates but also the ecosystem in general. LÄS MER
9. Coarse detritus in oligotrophic lake littoral zones : utilization by intervertebrates and contribution to carbon flow
Sammanfattning : Syftet med denna avhandling är att öka förståelsen av hur grovt organiskt material, sk grovdetritus, tex löv och makrofytrester, bryts ner i sjöars strandzoner. Motivet bakom intresset för detta är att små näringsfattiga sjöar i skogsrika områden ofta är beroende av tillförsel av energi utifrån och att nedbrytningen av grovdetritus är relativt lite undersökt i sjöar. LÄS MER
10. Uptake and bioaccumulation of ionizable pharmaceuticals in aquatic organisms
Sammanfattning : Pharmaceuticals are found at low concentrations (ng/L) in aquatic environments but bioaccumulation may result in aquatic organisms reaching internal effect levels (µg/L). Environmental hazard assessments include standardized bioaccumulation tests but contrary to the model substances around which the frameworks are built most pharmaceuticals are designed to mimic endogenic chemicals, ionizable, and less lipophilic. LÄS MER
