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Visar resultat 1 - 5 av 56 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Parasite on Crayfish : Characterisation of Their Pathogenesis, Host Interactions and Diversity

   Författare :Eakaphun Bangyeekhun; Anders Tunlid; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Zoophysiology; Crayfish; Parasite; Oomycete; Prophenoloxidase; Peroxinectin; Aphanomyces astaci; Psorospermium haecheli; White spot syndrome virus; Zoofysiologi; Animal physiology; Zoofysiologi; biologisk beroendeforskning; Biological Research on Drug Dependence;

   Sammanfattning : The crayfish plague refractory crayfish, Pacifastacus leniusculus, which can harbour the fungal parasite within melanotic sheath, are found to constitutively express the gene encoding for prophenoloxidase (proPO) after mimicking parasite attack. In contrast, the susceptible crayfish, Astacus astacus, responds to the parasite by increased levels of proPO transcript, particularly in the semigranular haemocytes. LÄS MER

3. 2. Causes and consequences of blood parasite infections in birds

   Författare :Martin Stjernman; Biodiversitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Animal physiology; Djurfysiologi; Parasitologi människa och djur ; Parasitology human and animal ; maternal transfer; stabilising selection; parasite resistance; parasites; trade-off; cost of reproduction; Ficedula hypoleuca; pied flycatcher; Haemoproteus; blue tit; Parus caeruleus;

   Sammanfattning : Parasites are ubiquitous and can cause significant fitness reductions to their hosts. Therefore, selection for the evolution of host resistance should be strong. However, resistance may be costly and should be traded-off against other fitness related traits. LÄS MER

4. 3. Speciation - What Can be Learned from a Flycatcher Hybrid Zone?

   Författare :Chris Wiley; Anna Qvarnström; Lars Gustafsson; Roger Butlin; Uppsala universitet; []
   Nyckelord :Biology; speciation; reinforcement; fitness; postzygotic isolation; asymmetrical hybridization; hybrid zone; species recognition; mate choice; sexual selection; direct benefits; parasite resistance; delayed plumage maturation; Ficedula hypoleuca; Ficedula albicollis; flycatcher; Biologi;

   Sammanfattning : Studies of hybrid zones offer important insights into the process of speciation. Much of the knowledge to be gained is dependent on an accurate estimation of the strength of pre- and post-zygotic isolation between hybridizing taxa. My results demonstrate that hybridization can variously affect different components of fitness. LÄS MER

5. 4. Microbial Responses to Antibiotics – Stability of Resistance and Extended Potential of Targeting the Folate Synthesis

   Författare :Maria Jönsson; Göte Swedberg; Steven Meshnick; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Molecular biology; sulfonamide resistance; macrolide; commensal flora; substrate channeling; folate synthesis; Molekylärbiologi; Molecular biology; Molekylärbiologi;

   Sammanfattning : Resistance to antimicrobials is an increasing problem in the world of today, and develops faster than man can counter. It is therefore of importance to study metabolic pathways in order to develop new antibiotics, but also to understand how resistance spreads and stabilizes in microbial populations. LÄS MER

7. 5. Host-Parasite Interactions in Natural Populations

   Författare :Peter Halvarsson; Jacob Höglund; Carles Vilà; Stuart Piertney; Zooekologi Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Arvicola terrestris; avian malaria; balancing selection; Major histocompatibility complex; parasitetranscriptome; Populationsbiologi; Population Biology;

   Sammanfattning : Parasitism is one of the most common ways of living and it has arised in many taxa. Parasites feed and live inside or on their hosts resulting in both long and short term consequences for the host. This thesis is exploring the phenotypic and genotypic effects of animals living with parasitic infections. LÄS MER