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

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

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

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

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

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

Subsea inspection and monitoring challenges

Master's thesis in Offshore technology : industrial asset managementThis paper uncovers and suggests solutions for the challenges to control change over time more reliable and cost effective. Front-end concept engineering, design, inspection and monitoring strategies, technologies, systems and methods for Life-of-Field are recommended. Autonomous underwater vehicles (AUV) are identified as a possible cost- efficient opportunity to reduce cost of inspections and monitoring operations while safeguarding asset integrity. A recognized design spiral methodology is used to perform a front-end concept evaluation of an AUV system. Investigation of key technological limitations and new developments within underwater communication, energy storage and wireless power transmission is performed. It further enables opportunities such as AUV recharging station on the seafloor for better utilization. One major learning point is through the use of numerical models and the outcome being a better and more hydro effective hull design. One expectation from this paper may be the aid to collaborating partners in their design work

An Exploratory Study: Out-of-Home Placement Practices in Two Mid-Western Counties

The purpose of this study is to explore the criteria used by social workers in two mid-western counties to place children out of the home. This exploration has been done using a questionnaire that asks questions intended to identify a consensus among workers about the criteria considered to place children. Out-of-home placement for the purpose of this study will include any placement done by a county agency either on an emergency basis or by a plan, started at the beginning of a worker/client relationship. These placements are those in which a child has been removed from the home or from the primary care giver and placed in an alternative living situation. A consensus was established and many opinions regarding county policies were expressed. The opinions followed two themes, internal and external. The external dealt with community resources and the internal dealt with specific county policies and procedures. The concern most often expressed was that the counties tended to focus too heavily on financial matters

Subfossil Records of the Arctic Fox (Alopex Lagopus) Compared to Its Present Distribution in Norway

We studied the prehistoric and historic distribution of arctic foxes in Norway by examining material and reports from archaeological excavations. A total of 44 arctic fox bones were found in 15 excavations, all of which were younger than 5000 years before present (B.P.). The majority of these sites was located within or close to the present distribution of arctic foxes. Additionally, 44 naturally deposited arctic fox bones were found in two excavations dated 36 000-28 000 and 13 000 B.P. respectively, indicating that the arctic fox also lived along the Norwegian coast in the Pleistocene. No arctic fox bone was dated to the period 9000-5000 B.P., and the species may have been rare or absent during this comparatively warm period. Since most bones (61%) were from the distal part of the limbs, the foxes may have been skinned elsewhere and transported to the site of deposition. Bones from red foxes were found in three excavations within the present distribution of arctic foxes, indicating that the arctic fox was relatively more abundant than red foxes during the late prehistoric and the historic periods in south Norway, but less abundant in north Norway.Key words: arctic fox, red fox, prehistoric and historic distributions, archaeological excavations, NorwayOn a étudié les distributions préhistorique et historique du renard arctique en Norvège, en examinant du matériel et des rapports provenant de fouilles archéologiques. Au total, 44 os de renard arctique ont été trouvés dans des fouilles effectuées sur 15 sites, et tous les os dataient de moins de 5000 ans avant le présent. La majorité de ces emplacements était située à l'intérieur ou près de la distribution actuelle du renard arctique. On a en outre trouvé 44 os de renard arctique déposés naturellement dans deux fouilles datées respectivement de 36 000 à 28 000 ans avant le présent et de 13 000 ans avant le présent, ce qui révèle que le renard arctique vivait aussi le long du rivage norvégien au cours du pléistocène. Aucun os de renard arctique n'a été daté de la période allant de 9000 à 5000 avant le présent et il est possible que l'espèce ait été rare ou absente au cours de cette période comparativement tempérée. Étant donné que la plupart des os (61 p. cent) proviennent de la partie distale des membres, il se peut que les renards aient été dépouillés ailleurs et transportés à l'emplacement où ils ont été déposés. On a trouvé des os de renard roux dans trois fouilles à l'intérieur de la distribution actuelle du renard arctique, ce qui révèle que ce dernier était relativement plus abondant que le renard roux en Norvège méridionale, à la fin de la période préhistorique et au cours de la période historique, mais moins abondant en Norvège septentrionale.Mots clés: renard arctique, renard roux, distributions préhistorique et historique, fouilles archéologiques, Norvèg

Interactions between Arctic and Red Foxes in Scandinavia - Predation and Aggression

Arctic fox (Alopex lagopus) populations in Scandinavia are small and restricted to alpine regions, while red foxes (Vulpes vulpes) are common throughout both Norway and Sweden. The two species are similar in behaviour and diet, and thus competition between them is likely. This study provides seven observations of aggressive interactions between the two species. One adult arctic fox and one cub were killed by red foxes, one male arctic fox was chased away from his den, one female arctic fox and a cub fled into the den as a red fox approached, four cubs fled into the den as a red fox walked upon it and once a red fox walked upon the arctic fox den when no arctic foxes could be seen. Only on one occasion did an arctic fox succeed in chasing away a red fox. Red fox predation may prove to be limiting to the small arctic fox population in Scandinavia, and arctic foxes can be displaced from good dens and the most productive regions.Key words: arctic fox (Alopex lagopus), red fox (Vulpes vulpes), interactions, predation, aggression, field observations, ScandinaviaMots clés: renard polaire( Alopex lagopus), renard roux (Vulpes vulpes), interactions, prédation, agression, observations sur le terrain, Scandinavi