English
norskDoktorgradsavhandlinger (BFE-fak): Recent submissions
Now showing items 221-240 of 300
-
Pseudocalanus (Copepoda: Calanoida) of the North Atlantic Ocean : species composition, environmental preferences and phylogeography
(Doctoral thesis; Doktorgradsavhandling, 2013-06-25)The seven species of the genus Pseudocalanus (Copepoda: Calanoida) are difficult to identify because of very small interspecific, and comparatively large intraspecific, divergence of morphologic and morphometric traits. Thus, despite the fact that Pseudocalanus spp. are among the most abundant metazoans in the world, our knowledge of them at the species level is limited. The main objective of this ... -
Modelling tourism demand, travel mode choice and destination loyalty
(Doctoral thesis; Doktorgradsavhandling, 2013-05-24)This dissertation has three simultaneous purposes: (1) to investigate the effects of both economic and non-economic factors on the domestic tourist flow to Khanh Hoa province in the long term and the short term; (2) to examine how the characteristics of domestic tourists and the attributes of travel modes influence tourists’ choice of travel mode to Nha Trang, Khanh Hoa; and (3) to investigate how ... -
Rent creation and distribution-Theory and the Vietnamese small scale purse seine fishery
(Doctoral thesis; Doktorgradsavhandling, 2013-06-14)In Vietnam, as in many other countries, the fisheries sector plays an important role in securing food, providing livelihood, and promoting economic development. Vietnamese fisheries are characterized by open access, and the number of fishing vessels has increased tremendously over the past years while the harvest growth has slowed down. This seems to indicate that the fisheries have reached the limit ... -
Investigating coastal ecosystem structure and dynamics using Ecopath mass-balance modelling and stable isotope data
(Doctoral thesis; Doktorgradsavhandling, 2013-06-13)Marine økosystemer er svært komplekse, og derfor bruker vi modeller for å kunne forenkle og systematisere kompliserte sammenhenger. Slike økologiske modeller brukes i utstrakt grad innen forskning og forvalting. Hva de ulike artene av fisk og krepsdyr spiser er svært viktig å vite for å kunne forstå hvordan artene påvirker hverandre, og dette kan vi finne ut med en liten vevsprøve for å måle stabile ... -
Oil and gas activity in the high north: Economic opportunities and political dependencies
(Doctoral thesis; Doktorgradsavhandling, 2013-06-07)The aim of this thesis is to analyze what drives Arctic oil and gas activity, and the political effects of the oil and gas industry in the high north. Based on existing political economy theories, four different articles explore these questions by using different methodological approaches. The main findings are that while the potential for a large increase in Arctic oil and gas output is significant, ... -
Determinants and effects of moth population dynamics in altitudinal gradients in northern Fennoscandia
(Doctoral thesis; Doktorgradsavhandling, 2013-05-21)The aim of this PhD-project has been to increase our knowledge of trophic interactions along altitudinal gradients in a system of sympatric, cyclically outbreaking geometrid moth species in sub-arctic, coastal birch forest in northern Norway. The project resulted in four scientific publications; two sub-studies focused on the causal effect of natural enemies on the observed complex spatio-temporal ... -
Seabirds, climate and prey. A population study of two seabird species.
(Doctoral thesis; Doktorgradsavhandling, 2013-05-30)Many seabird populations have declined dramatically over recent decades, and studying the demography and population dynamic in seabird populations is important to gaining a better understanding of causes and mechanisms lying behind such changes and to identify targets for conservation and management. Climate and prey availability are known to affect demography and population dynamics of seabirds. ... -
PLGA (poly(D,L-lactic-co-glycolic)acid) particles as DNA carriers in Atlantic salmon (Salmo salar L.)
(Doctoral thesis; Doktorgradsavhandling, 2013-04-25)Adjuvanter benyttes for å styrke/bedre immunresponsen ved vaksinering. PLGA (poly(lactic-co-glycolic)acid) er en biologisk nedbrytbar polymer som innehar adjuvantegenskaper når den benyttes i form av partikler. Som vaksinebærere kan partikler beskytte mot nedbryting, stimulere inflammatoriske immunresponser og initiere adaptive immunresponser. Partikler er også vist å gi økt opptak i ulike celletyper. ... -
Bureaucrats and Boundaries. The changing intersection between experts, local communities and environmental administration in nature protection
(Doctoral thesis; Doktorgradsavhandling, 2013-03-08)Loss of biodiversity and fragmentation of habitats are two of the world’s persistent environmental problems. This is due to the emerging complexities, uncertainties and questions of societal scale in both defining and resolving the problems. One of the challenges connected to resolving these problems pertains to the divide between the local level, which carries the costs of restrictions and regulations ... -
Anglerfish Lophius piscatorius L. in Faroese waters. Life history, ecological importance and stock status
(Doctoral thesis; Doktorgradsavhandling, 2013-04-16)Anglerfish Lophius piscatorius has during the last two decades become a highly exploited resource and is now one of the five most economically important demersal fish species in the Faroese fishery. Despite this, there is at present little information available on the population status of anglerfish in Faroese waters. The main aim of this study is to increase the biological knowledge of anglerfish ... -
Polar bears (Ursus maritimus) in the Barents Sea area : population biology and linkages to sea ice change, human disturbance and pollution
(Doctoral thesis; Doktorgradsavhandling, 2013-03-16)Polar bears in the Barents Sea population have been protected from hunting in Russia since 1956 and following the signing of the international Polar Bear Agreement in 1973 in Norway. This thesis seeks to summarise current knowledge on key population biology issues four decades after the Norwegian protection and almost six after the Russian. Further, it discusses threats that have developed in the ... -
Stoichiometry of lipid synthesizing calanoid copepods in Arctic and sub-Arctic marine regions Insights into limitation and elemental cycling from characterization of C:N:P ratios
(Doctoral thesis; Doktorgradsavhandling, 2012-12-12)Calanoid copepods, Calanus finmarchicus, C. glacialis and C. hyperboreus, are key species in Arctic and sub-Arctic marine ecosystems. They represent important prey for a number of species such as juvenile herring and cod because of their high but seasonally variable calorific value: they synthesize and store lipids as part of their survival strategy. Limitations in food quantity and quality can have ... -
Hunter's behavioural responses to changes in bag size and willow grouse density : implications for management and interpretation of harvest data
(Doctoral thesis; Doktorgradsavhandling, 2012-12-19)An important aspect of ecological research is to provide guidelines and tools to wildlife managers. The ecological feature of density dependence which shapes population responses to harvest are important for wildlife management, but monitoring practices and exploiter dynamics to the changing resources and management regimes should also be included. Bag records are often collected by wildlife managers ... -
Spectral changes in fillet of Atlantic salmon as affected by freshness loss and spoilage during cold storage.
(Doctoral thesis; Doktorgradsavhandling, 2012-12-03)Spectral effects of microbial growth, packaging atmosphere and heme oxidation were investigated with fresh salmon. The presence of microorganisms and their growth have little effect on the development of spectral features in fresh salmon during storage prior to extensive spoilage. Important spectral changes occur at 606 and 636 nm in the spectra of fresh salmon during storage. Heme oxidation is the ... -
Vole population cycles and the role of colonisation
(Doctoral thesis; Doktorgradsavhandling, 2012-12-06)The multiannual population cycles in small rodents have triggered an intense debate between proponents of population-intrinsic and community-extrinsic factors as the cycle generating mechanisms. A well-known challenge is the apparent absence of vole individuals during the low phase of the population cycle and the fact that most studies addressing vole and lemming behaviour and demography are conducted ... -
Trophic relationships and the role of Calanus in the oceanic ecosystems south and north of Iceland
(Doctoral thesis; Doktorgradsavhandling, 2012-12-03)The waters south and north of Iceland vary greatly both oceanographically and biologically with the rather stable and warm Atlantic waters south and west of Iceland and the more variable and cold Arctic and sub-Arctic waters, north and east of Iceland. The aim of this study was to increase the knowledge on the role of Calanus copepods and trophic relations of the key components of the oceanic ... -
Characterization of a Cytokinin Response Factor in Arabidopsis thaliana
(Doctoral thesis; Doktorgradsavhandling, 2012-05-15)Acclimation responses to environmental growth conditions in plants involve complex and fine-tuned signalling networks. Environmental signals, biotic and abiotic, are received and mediated, and lead eventually to transcriptional regulation. The plant hormones are vastly involved in these processes as intercellular mediators whereas the reception of such a hormone at the site of action involves ... -
Interactions between small rodents and their food plants in tundra habitats
(Doctoral thesis; Doktorgradsavhandling, 2012-10-19)Small rodents are key herbivores of arctic ecosystems, where their cyclic population dynamics have important implications for vegetation dynamics. The role of vegetation for shaping small rodent population dynamics remains, however, unclear. Evaluation of this interaction has been greatly hampered by the rather fragmentary knowledge of small rodents feeding ecology, which in turn is due to methodological ... -
Diversity along a speciation continuum : ecology and morphology of northern European whitefish (Coregonus lavaretus)
(Doctoral thesis; Doktorgradsavhandling, 2012-08-24)How new species are formed is still a major question in evolutionary biology. In ecological speciation, natural selection drives the evolution of slight distinctions between individuals into extensive differences between species. In this thesis, early stages of an ecologically driven speciation process are addressed using ecological and morphological data from a large number of European whitefish ... -
Late Weichselian to early Holocene vegetation and bird activity on Andøya, Nordland County : as evidenced primarily by macrofossils
(Doctoral thesis; Doktorgradsavhandling, 2012-10-26)This thesis shows that Late Weichselian vegetation on Andøya may have been more diverse than previous studies have revealed. The thorough investigation of macrofossils in four parallel cores provides more reliable evidence for interpreting changes in vegetation cover than reconstructions based on a single core. The botanical macrofossils retrieved in this study largely support previous studies ...
