Food Habits of Arctic Foxes (Alopex Lagopus) on the Western Coast of Svalbard

Food habits of arctic foxes (Alopex lagopus) on the western coast of Svalbard were studied in the years 1986-89. Faeces (n=1018) were collected mostly in summer, and food remains were recorded both at dens and elsewhere in the region. The foxes were opportunistic in their hunting and feeding habits, utilizing a wide variety of available food items. Alcids (mainly little auks and Brunnich's guillemot), gulls (mainly kittiwakes), and fulmars were the major foods in summer. The consumption of alcids by fox families was correlated with availability near the den. In winter, fulmars and, in one region, seals were important foods. Some regional differences in food consumption were found. A change in diet was observed when a litter of pups moved from one den to another (2 of 3 cases). Differences in food habits between years also were found at the same den (4 of 5 cases). Foxes frequently cached food by scatter hoarding, placing only a single item in each cache.Key words: arctic fox, Alopex lugopus, food habits, prey species, food caching, SvalbardOn a étudié les habitudes alimentaires du renard arctique (Alopex lagopus) sur la côte ouest du Svalbard au cours des années allant de 1986 à 1989. On a recueilli les fèces (n = 1018) surtout en été, et on a consigné les débris de nourriture à la fois dans les terriers et ailleurs dans la région. Les renards se montraient opportunistes dans leurs façons de chasser et de se nourrir, et faisaient usage d'une vaste gamme d'aliments à leur portée. Les alcidés (surtout le petit pingouin et la marmette de Brünnich), les mouettes (surtout la mouette à trois doigts) et les fulmars étaient les sources principales de nourriture estivale. La consommation d'alcidés par les familles de renards était corrélée avec leur disponibilité à proximité du terrier. En hiver, les fulmars et, dans un certain endroit, les phoques constituaient une source importante de nourriture. On a trouvé certaines différences régionales dans la consommation alimentaire. On a observé un changement dans le régime lorsqu'une portée de renardeaux se déplaçait d'un terrier à un autre (dans 2 cas sur 3). On a aussi enregistré des différences dans les habitudes alimentaires d'une année à l'autre au même terrier (dans 4 cas sur 5). Les renards cachaient fréquemment la nourriture en l'éparpillant, ne mettant qu'un élément dans chaque cache.Mots clés; renard arctique, Alopex lugopus, habitudes alimentaires, espèces-proies, cache alimentaire, Svalbar

Population dynamics of an island population of water voles Arvicola amphibius (Linnaeus, 1758) with one major predator, the eagle owl Bubo bubo (Linnaeus, 1758), in northern Norway

Predator–prey relationships are of great significance to ecosystems, and their effects on the population dynamics of voles and lemmings (Microtinae) in Boreal and Arctic environments have long been of particular interest. A simple ecosystem with one major prey and one major predator could be an ideal setting for a study of their interactions. This is the situation on several small islands on the coast of northern Norway just below the Arctic Circle, with populations of water voles Arvicola amphibius preyed upon by the eagle owl Bubo bubo. The population dynamics of the water vole was studied by trapping and tagging in 2003–2018, eagle owl pellets were collected for analyses, eagle owl breeding attempts were recorded, and some weather variables collected from official recordings. After having been introduced well into the study period, the number of sheep Ovis aries was also recorded. Water voles were the main prey of the eagle owl, with 89% occurrence in pellets, with an overrepresentation of adults and males. Both predation, sheep grazing and extreme weather events influenced the vole population. Predator exclusion, as happened in three summers due to an intensive radio tracking study, especially increased the number of surviving young (in particular from the early cohorts) and the mass of adults. Extreme weather events, such as flooding in summer and deeply frozen ground in winter, most significantly reduced vole populations. Sheep grazing may exacerbate the effects of predation. A similar multitude of factors may affect populations of other rodent species as well

The influence of night length: Activity of the northern bat Eptesicus nilssonii under conditions of continuous light in midnight sun compared to a southern population

Background - Nearly all insectivorous bats (Chiroptera) are strictly nocturnal, flying and feeding only between sunset and sunrise despite lower insect availability than by day, most likely to avoid predation by diurnal birds. This may represent a great challenge to bats living north of the Arctic Circle, which are exposed to bright nights in the period of the midnight sun. The northern bat Eptesicus nilssonii was studied at different latitudes in Norway (69, 66 and 58°N) by three techniques; visual counts of exits from and returns to roosts, infrared detection with a datalogger and an ultrasound data recorder, to reveal how their activity varied across latitude, season, and night, as well as across light levels. How does a nocturnal bat adjust to perpetual light and what light levels are tolerated? Results -In the north the bats’ active season lasted 2.5 months, 1.5 months shorter than in the south. The bats only flew in 3-4 weeks of midnight sun, and hardly ever left the roost until the sun went behind a hill in the evening. In addition, the timing of their nightly hunting was highly influenced by the darkness of the sky, and they very rarely flew in light levels above 200 foot-candles (FC). As the night became darker than twilight from early August, the bats restricted their activity to between sunset and sunrise. This was the normal situation in southern Norway, where the bats tracked sunset and sunrise throughout the entire season. Those bats appeared to prefer light levels below 100-50 FC and hence, also did fly in twilight conditions. Conclusions - The willingness to fly in twilight by the southern population may be a prerequisite to the northern bat’s survival in the land of the midnight sun. These bats must accept short nights in the first part of their summer season and must be willing to fly in light levels 2-4 times higher than in the south. Most likely, this depends on a reduced predation risk and good abundance of insects at night

Reader to Educator: A Literary Analysis of Power, Literacy and Ideology in Louis Sachar’s Holes

This thesis aims to contribute to the literary discourse surrounding Holes by Louis Sachar through a literary analysis grounded in Foucauldian, neo-Marxist, and Freirean theoretical perspectives, as well as a Critical Literature Pedagogy (CLP) framework. While previous research has examined Holes through lenses such as gender theory, race theory, hauntology, and genre theory, to the author’s knowledge, no study to date has applied these particular frameworks to the analysis of the novel Holes. This thesis seeks to fill this gap by exploring how literature can be used to interrogate power structures and ideological messages embedded within literary texts. The study applies Foucauldian, neo-Marxist, and Freirean theories to examine how power is established, maintained, and resisted at Camp Green Lake, and how literacy functions as both a tool of oppression and empowerment. It further draws on two of the five dimensions of CLP to investigate the implicit ideologies and belief systems in Holes, by reading both with and against the text. This approach models four ways of engaging with literature in the classroom, two of which reflect a critical approach aimed at fostering pupils’ critical thinking, identity formation, and Bildung. By contributing new analytical perspectives to the scholarship on Holes, the thesis also strengthens the researcher’s competence in literary analysis and expands his pedagogical toolkit. As such, the thesis may serve as a resource for other teachers seeking to integrate critical approaches to literature in the Norwegian EFL classroom.This thesis aims to contribute to the literary discourse surrounding Holes by Louis Sachar through a literary analysis grounded in Foucauldian, neo-Marxist, and Freirean theoretical perspectives, as well as a Critical Literature Pedagogy (CLP) framework. While previous research has examined Holes through lenses such as gender theory, race theory, hauntology, and genre theory, to the author’s knowledge, no study to date has applied these particular frameworks to the analysis of the novel Holes. This thesis seeks to fill this gap by exploring how literature can be used to interrogate power structures and ideological messages embedded within literary texts. The study applies Foucauldian, neo-Marxist, and Freirean theories to examine how power is established, maintained, and resisted at Camp Green Lake, and how literacy functions as both a tool of oppression and empowerment. It further draws on two of the five dimensions of CLP to investigate the implicit ideologies and belief systems in Holes, by reading both with and against the text. This approach models four ways of engaging with literature in the classroom, two of which reflect a critical approach aimed at fostering pupils’ critical thinking, identity formation, and Bildung. By contributing new analytical perspectives to the scholarship on Holes, the thesis also strengthens the researcher’s competence in literary analysis and expands his pedagogical toolkit. As such, the thesis may serve as a resource for other teachers seeking to integrate critical approaches to literature in the Norwegian EFL classroom

The Vacuum Polarisation Contribution to the Lamb Shift Using Non-Relativistic Quantum Electrodynamics

In this thesis we calculate the vacuum polarisation contribution to the well-known Lamb shift. The Lamb shift is a correction of order $\alpha^5$ to the non-relativistic energy spectrum of the hydrogen atom. We discuss the gauge symmetry of quantum electrodynamics (QED), and derive the photon propagator in both the Lorenz and Coulomb gauge. We then calculate the vacuum polarisation tensor of the photon in QED. It is calculated using dimensional regularisation and the modified minimal subtraction scheme. We show that the vacuum polarisation results in a finite correction to the photon propagator, and thus changes the two-point function of the photon field. We introduce non-relativistic QED (NRQED), an effective field theory that is popular for QED bound state calculations. Radiative and relativistic corrections are incorporated into NRQED by a matching procedure. The matching procedure enforces that the scattering amplitudes of QED coincide with the scattering amplitudes of NRQED. The vacuum polarisation of the photon is incorporated into NRQED by adding correction terms to the photon Lagrangian. The two-point function of the photon field in NRQED is matched to the two-point function of the photon field in QED at one loop. We use the corrected photon Lagrangian to calculate the vacuum polarisation contribution to the Lamb shift. This contribution is a relatively small fraction of the total Lamb shift, it shifts the level of the 2S$_\frac{1}{2}$-state downward by 27.1 MHz compared to the 2P$_\frac{1}{2}$-state. Lamb shift is an upward shift of around 1000 MHz. We would not have agreement between the theoretical result and experimental observations without the vacuum polarisation contribution. The Lamb shift lifts the degeneracy between the 2S${}_\frac{1}{2}$-state and the 2P$_\frac{1}{2}$-state

Combinatorial Design of Nickel-Chromium Alloys By Physical Vapor Deposition And Electron Beam Welding

Combinatorial methods, which include high efficiency and high throughput methods to create a large compositional range of materials, have proven to be highly effective and efficient in research and development in the chemical and pharmaceutical industries. In this thesis, similar methods for the development and optimization of metals and alloy systems are explored. Combinatorial Ni-Cr alloy samples were developed by physical vapor deposition (PVD) of a wedged film on a bulk material, and then locally melting the two by electron beam welding (EBW). A combinatorial alloy gradient was thus created along the length of the weld. The samples were rapidly characterized for chemical properties by energy dispersive x-ray spectrometry (EDS) and for mechanical properties, namely modulus and hardness, by nanoindentation. All measurements were compared with similar tests on melted and cast Ni-Cr alloy standards, and the microstructures were compared by scanning electron microscopy (SEM). The entire Ni-Cr composition range was established and reproduced with several welded samples of both nickel films on chromium substrates and chromium films on nickel substrates. There were no strong tendencies in the elastic modulus measurements compared to composition, though all values were within reasonable deviation of the modulus of the cast standards. On the other hand, there were strong trends in the hardness measurements that followed similar tendencies of the standard cast Ni-Cr alloys. The hardness values also showed trends that coincided with the composition and phases associated with the Ni-Cr phase diagram. The hardness results obeyed a more definite trend in the nickel rich g-phase, where the hardness increased linearly from 1.2 GPa at pure nickel to about 3.5 GPa at 40 at% Cr. The hardness of the chromium rich a-phase approached nearly 13 GPa when the alloy was between 70 and 85 at% Cr, and then dropped toward the hardness of pure chromium at 3.7 GPa

Ray dynamics in array of disks investigating light management in thin-film solar cells

The use of resonant dielectric structures have shown promising signs as a contributor of light trapping. Nanospheres as a dielectric texture on thin-film solar cells have been demonstrated to increase the overall efficiency significantly compared to flat film cells with reflection coating only. In order to better understand the rationale behind the light trapping of the nanostructure which leads to the increase in efficiency of the solar cell, it is essential to further optimise this efficiency. This thesis introduces a two-dimensional array of disks system representing a simplified model of the nanosphere structures. Simulations of the ray dynamics in the array of disks are done in order to investigate the light trapping properties of the structures. It was found that a broad spectrum of rays form stable islands of different sizes in the phase space of this system. The size of the islands represent the number of rays stabilising in this array of disks over time, and was demonstrated to depend on the refractive index of the disks as well as the distance between them.Bruk av dielektriske nanosfærer som struktur på solceller har vist lovende tegn. Tynnfilm solceller strukturert med nanosfærer har vist signifikant økt effektivitet i forhold til solceller med vanlig antireflekslag. Å forstå de grunnleggende effektene bak lysfangingen som fører til den økte absorpsjonen i solcellene bedre, er av stor betydning for videre optimalisering av effektiviteten til solceller. Denne oppgaven introduserer en streng av to-dimensjonale disker som en forenklet modell av nanostrukturene. I dette systemet ble mengder av forskjellige lysstråler simulert for å undersøke lysfangingsegenskapene i dette systemet. Simuleringene viste at en mengde av lysstrålene lagde stabile øyer i faserommet. Disse øyene var av forskjellig størrelse og avhengig av brytningsindeksen til diskene samt avstanden mellom diskene.M-M

Uncovering the molecular basis for nutritional reprogramming of pancreatic β-cells

Type 2 diabetes er en af de største sundhedsmæssige udfordringer i verden. Diabetes forårsager hvert år millioner af dødsfald. og andelen af type 2 diabetes patienter er stærkt stigende. Diabetes er karakteriseret ved når β-cellerne i bugspytkirtlen ikke længere er i stand til at producere nok insulin til oplagring af næringsstoffer. Den øgede tilgængelighed af næringsstoffer er blevet vist til at spiller en kritisk rolle for β-cellernes evne til at tilpasse sig til det stigende behov for insulin. Imidlertid kan overskydende næringsstoffer også inducere et stressrespons, som i sidste ende kan fører til β-celledysfunktion. For at forstå hvordan type 2 diabetes udvikler sig, er det nødvendigt at forstå og kortlægge de mekanismer der ligger bag β-cellernes evne til at tilpasse sig til næringsstoffer.I denne afhandling har vi brugt forskellige model systemer og metoder til at undersøge β-cellernes evne til at tilpasse sig til øget mængder af næringsstoffer. Det er velkendt, at stimulering med glukose fører til en omprogrammering af β-cellerne, som enten forstærker β-cellernes evne til at dele sig eller nedsætter deres funktion. I det første studie demonstrerer vi, at stimulering med høje koncentrationer af glukose resulterer i en bifasisk omprogrammering af det transskriptionelle netværk i β-celler. Ved at integrere data omkring genekspression med data omkring motiv berigelse, identificerede vi flere nye transkriptionelle regulatorer af glukoseresponset i β-celler. Vi fokuserede på den nukleare receptor RORγ, og demonstrerer at RORγ er en ny regulator af deling af β-cellerne i INS-1E celler og primære β-celler fra rotter. Det første studie lagde grundlaget for det næste studie, hvor vi har anvendt en massespektrometribaseret strategi, RIME, for at identificere andre transkriptionelle regulatorer af glukoseresponset i βcellerne. Vi brugte en underenhed af Mediator komplekset, MED1, til at identificere proteiner forbundet med aktive enhancere i INS-1E celler stimuleret med glukose. Af de identificerede proteiner (kandidatfaktorer) fokuserede vi på cofaktoren Mybbp1a. Vores data viser at Mybbp1a spiller en vigtig rolle for hvordan β-celle responderer på glukose, og deres evne til at dele sig.Mekanismerne der ligger bag omprogrammering som nærringsstoffer forårsager i β-cellerne in vivo mangler at bliver undersøgt. I et tredje studie, anvendte vi en ny musemodel, Ins1CreTRAP-musen, som gjorde det muligt at detektere β-celle-specifikke genomiske ændringer in situ. Vi viste, at kortvarig fodring med en diæt med højt fedtindhold førte til nedsat glukosetolerance og øget deling af β-cellerne. Vi lyktes imidlertid ikke med at effektivt etablere protokollen knyttet til denne musemodel. Af denne grund, anvendes der i øjeblikket andre metoder baseret på enkeltcellesekventering som et alternativ til at undersøge β-celle specifikke genomiske ændringer som respons på næringsstoffer.Type 2 diabetes is one of the leading health concerns in the world. Diabetes causes millions of deaths each year and the number of type 2 diabetes patients is rapidly increasing. Diabetes is characterized by a failure of the pancreatic β-cells to produce enough insulin to meet increased demands for nutrient storage. The increase in nutrient availability is suggested to be an important driver of β-cells adaptation to increased needs for insulin. However, excess nutrients can also induce a stress response, eventually leading to β-cell dysfunction. Thus, expanding our knowledge of the underlying mechanisms regulating β-cell adaptation to nutrients is important for understanding how type 2 diabetes develops.In this Ph.D. project, we have used different approaches to investigate β-cell adaptation to nutrient overload. Glucose stimulation is known to reprogram β-cells eventually leading to both increased proliferation and repression of β-cell function. The first study demonstrate that high glucose stimulation leads to a reprogramming of the β-cell genome, and that the glucose response is biphasic. By integrative genomics, we identified novel transcriptional regulators of the late phase of the glucose response in β-cells. We focused on the nuclear receptor RORγ, and with loss-of-function studies, we demonstrate that RORγ is a novel regulator of β-cell proliferation in the INS-1E cell line and in primary rat β-cells. The second study is a continuation of the first study, where we have applied a mass spectrometrybased strategy, rapid immunoprecipitation mass spectrometry of endogenous proteins (RIME), to identify other regulators of the transcriptional response to glucose response in β-cells. Here we used the Mediator complex subunit MED1, as bait to capture proteins associated with MED1 and thereby activate enhancers in INS-1E cells. Combining loss-of-function studies with genome-wide analysis reveals that knockdown of the top transcriptional MED1-RIME candidate, Mybbp1a, leads to transcriptomic changes in the glucose response, and affect the ability of INS-1E cells to proliferate.The mechanisms underlying nutritional reprogramming in β-cells in vivo remain to be investigated. A third study aimed to investigate nutritional reprogramming in vivo our in-house developed mouse model, the Ins1CreTRAP mouse, which allows for in situ detection of β-cell-specific genomic changes. We performed metabolic phenotyping of the Ins1CreTRAP mice, and we demonstrate that mice have impaired glucose tolerance and increased β-cell proliferation after short-term high fat diet feeding. Unfortunately, we were not able to establish the protocols related to Ins1CreTRAP model. Therefore, other strategies based on single-cell technologies are currently being performed as an alternative for investigating β-cell-specific genomic changes in response to nutrients

Responses to securitizing higher education to counter radicalization and violent extremism: A comparative study of USA and Norway

This thesis aims to explore the responses of university teachers in the USA and Norway to the attempts to make higher education take responsibility for security-related tasks, specifically prevention of radicalization and violent extremism. The two countries have been exposed to terrorist attacks in the past, leading them to face the need to balance freedom and security. Both have adopted a new way to counter terrorism that is a decentralized, whole-of-society approach with a focus on preventing preliminary processes leading to terrorism, namely radicalization and violent extremism. This decentralized responsibility also counts on the higher education sector to partake in the preventive work, as they are considered well-suited to recognize altering behavior with students. Norway has incorporated specified policies into the education sector. The USA has not come this far despite having been more exposed to terrorist attacks in the past and having a significantly different threat picture. The objective is to research what the differences and similarities are in the perceptions of university teachers and explore why they differ in their views and which challenges and dilemmas may arise from the efforts to involve university teachers in the USA and Norway, respectively. A survey was conducted and gathered data from 74 American university teachers and 110 Norwegian university teachers who meet students through lectures. The study’s theoretical framework was based on insights from the securitization theory and previous research on securitizing education. It is suggested that the perceived prevalence of an issue could amplify the receptiveness of the securitizing process for this issue. This study concludes that university teachers in both countries seem to agree that higher education should play a role in preventing radicalization and violent extremism. However, the minor support for repressive measures suggests that most of the university teachers from the American and Norwegian samples oppose a securitization of education. The preferred level of involvement appears to be influenced by how common the problems are perceived to be in the countries. The two countries seem to share similar views on what advantageous opportunities higher education can contribute to in preventive efforts, such as a knowledge-based approach and being a relevant arena to carry out preventive efforts. They also share similar views on some disadvantages of involving universities, such as losing their neutral position and negatively affecting the rights of students to voice opinions. There seems to be a fear of losing the trust of both students and the outside environment, but this worry seems to be more common among American university teachers. Similar challenges between the countries are linked to making university teachers more familiar with the responsibility and better prepared to carry it out. Furthermore, to not risk losing trust, their involvement should not be perceived as them stepping out of their neutral position, nor be perceived as “thought police” preventing students from exploring and developing themselves. The effort should also not be overwhelming for busy teachers to not be able to follow through. However, differences in the perceived prevalence, trust level in authorities and police, as well as the levels of polarization in the two different societies appear to raise more challenges and dilemmas for the USA than for Norway concerning involving universities in preventive efforts

Target Tracking Control for an Unmanned Surface Vessel: Optimal Control vs Reinforcement Learning

This thesis studies the development and performance of Nonlinear Model Predictive Control (NMPC) and Reinforcement Learning (RL) for a target-tracking problem. The methodology involves developing the NMPC and RL approach and comparing their performance through simulated experiments. In the simulations, the controllers steer the Otter unmanned surface vessel (USV) to track a virtual target. The resulting NMPC controller performed with a stable error of approximately 0.7m with a refresh rate of 1.6 Hz. Whereas the best-performing RL Agent demonstrated a twofold performance. In the first part, the Agents managed an error between 0 and approximately 2m. However, when surpassing the experienced observation space from the training session, the Agent generated unfeasible controller signals, resulting in the Otter circling the target while tracking it. The Agent achieved a 1kHz refresh rate. In conclusion, the NMPC may need to be faster for practical implementations, and RL Agents require further development to be reliable. Therefore, for future work, it is suggested to use NMPC as an expert and apply imitation learning when training the Agents to achieve the best of both methods.publishedVersio