Sökning: "Myodes"
Visar resultat 1 - 5 av 13 avhandlingar innehållade ordet Myodes.
1. Predator responses to non-stationary rodent cycles
Sammanfattning : Regular fluctuations in population size, cycles, are common in small mammals and have important effects on predator populations and life histories. In this thesis, I identify long-term patterns and processes in two specialist predators, the arctic fox Vulpes lagopus and the rough-legged buzzard Buteo lagopus, in relation to their prey (lemmings and voles) and in the case of the arctic fox also to a dominant competitor, the red fox Vulpes vulpes. LÄS MER
2. MHC polymorphism and host-pathogen interactions: The case of Borrelia in its reservoir host, the bank vole Myodes glareolus
Sammanfattning : The major histocompatibility complex (MHC) class IIB genes exhibit extensive allelic polymorphism, most likely maintained by pathogen-mediated balancing selection (PMBS). PMBS may operate in the form of heterozygote advantage (HA), and/or through the interaction of pathogens and specific MHC alleles via fluctuating selection (FS) or negative frequency-dependent selection (NFDS). LÄS MER
3. Emerging tick-borne pathogens: on the ecology of multiple infections in ticks and reservoir hosts
Sammanfattning : Most animals will encounter several more or less severe infectious diseases during their lifetime, and simultaneous infections with more than one pathogen, or several different strains of the same pathogen, are common in natural populations. Ticks transmit a wide variety of different pathogens and can also be simultaneously infected with more than one pathogen. LÄS MER
4. Pathogen-mediated selection in the immune system of rodents : Exploring selection targets, functional effects and trade-offs
Sammanfattning : Pathogens cause disease and play an important role in shaping evolution of the host immune system. They create pressure on host immunity to evolve in numerous ways, most commonly by increasing divergence between species (positive selection) or increasing polymorphisms within a population (balancing selection). LÄS MER
5. The bank vole (Myodes glareolus) – a novel animal model for the study of diabetes mellitus
Sammanfattning : The bank vole (Microtus arvalis) develops glucose intolerance both when kept in captivity and in the wild state. Glucose intolerant bank voles kept in captivity exhibited polydipsia, polyuria, hyperglycemia, hyperinsulinemia, islet autoantibodies and a markedly changed islet structure resembling so–called hydropic degeneration. LÄS MER