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Visar resultat 1 - 5 av 227 avhandlingar som matchar ovanstående sökkriterier.
1. Fractionation of Cu and Fe isotopes in metal-rich mine sites : biotic and abiotic processes
Sammanfattning : After mineral exploitation the residual grinded and milled material, rich in sulphide minerals and heavy metals, is often left exposed to the atmospheric variables. This weathered mine waste material can lead to the formation of acid mine drainage (AMD) which has negative effects to the environment. LÄS MER
2. Untangling ambiguities in the microbial fossil record : experimental abiotic and biological approaches
Sammanfattning : Life on early earth has long been the topic of discussion for many researchers: how did it come to be? Which cells came first? Where can we find them? The most ancient rocks on our planet may hold some of the answers to these questions, but many may only be answered in laboratories. Chemical and morphological traces can be found from Archaean deposits, tantalisingly similar to modern day prokaryotes. LÄS MER
3. Abiotic Stress Tolerance. Metabolic and Physiological Effects of Compatible Solutes and Calmodulin on E. coli and Tobacco
Sammanfattning : In their natural habitats, bacteria and plants can be exposed to abiotic stresses such as drought, high salt concentrations and freezing, which are factors limiting their capacity for growth and proliferation. To withstand environmental stresses, they have evolved specific stress responses. LÄS MER
4. Mechanisms and genes controlling the signalling network for biotic and abiotic stress defences in Arabidopsis thaliana (L.) Heyhn : Functional cross-talk between photo-produced reactive oxygen species, photosynthesis and plant disease defence responses
Sammanfattning : Excess excitation energy, mechanical injury and defence against pathogens, each trigger rapid production of reactive oxygen species (ROS) in Arabidopsis thaliana leaves. ROS, such as hydrogen peroxide (H2O2), are required for the induction of systemic acquired acclimation and may lead to redox changes in photosynthetic electron transport (PET). LÄS MER
5. Biotic and abiotic stress in microorganisms and plants: Some Mechanisms of Stress and Programmed Cell Death. Genetic Engineering Approaches Towards Improved Stress Tolerance
Sammanfattning : Various forms of stress, such as biotic and abiotic stress, were studied in microorganisms and plants to learn more about the underlying mechanisms of such stress and potential genetic engineering strategies towards stress tolerance. An antifreeze protein from winter flounder, expressed in E. LÄS MER
