Now showing items 3448-3467 of 3493

• #### Why are Lorino and Sireniki so different? Exploring communities through festivals, language use, and subsistence practices in contemporary Chukotka

Based on research in Chukotka, Russian Far East, this thesis focuses on the contemporary predicaments of native sports, public festivals, language practices, and marine mammal subsistence in the communities of Sireniki and Lorino. Through a social-historical contextualization of ethnographic data, it explores possible reasons for the differences found to exist between those villages. In the years of the post-Soviet transition, Lorino emerged as a vivacious community where successful sea-mammal hunters formed the core of its social and cultural hearth. At the time the research was conducted, this characterization appeared in a striking contrast to Sireniki, known to have been a model community in the late Soviet era. This work attempts to explain how Lorino and Sireniki got to where they are today. The insights gained from ethnographic fieldwork and library materials points to the legacy of the Soviet state-induced relocations, post-Soviet reorganization of sea mammal hunting, cultural history, and local leadership patterns. Examined in a comparative light, this constellation of factors helps understand how differently Lorino and Sireniki have developed since the end of the Soviet Union.

• #### Wild-type and mutant 2,2-dialkylglycine decarboxylases: The catalytic role of active site glutamine 52 investigated by site-directed mutagenesis and computer analysis

The ability of pyridoxal 5$\sp\prime$-phosphate (PLP)-dependent 2,2-dialkylglycine decarboxylase (DGD) to catalyze decarboxylation and transamination of amino acids at a single active site depends on the subsite within the active site that cleaves $\alpha$-H and $\alpha$-COO$\sp-$ bonds. As observed in the crystal structure, the strategic position of glutamine 52 at the active site suggests a role in enhancing decarboxylation via formation of a hydrogen bond to the substrate carboxyl group. Supporting evidence for this hypothesis is provided by studies with glutamine 52 active site mutants, computer modeling and protein sequence analyses. Ten mutant DGDs containing alanine, asparagine, aspartate, arginine, glutamate, glycine, histidine, leucine, lysine, and tryptophan at position 52 were produced. All, except the histidine mutant, exhibited decreased rates of decarboxylation compared to wild-type. Histidine and asparagine mutants showed measurable decarboxylation rates. These results and that of wild-type DGD suggest that hydrogen bonding with the substrate is required for decarboxylation. Mutants incapable of hydrogen bonding to the substrate, such as alanine, leucine and tryptophan mutants, showed negligible decarboxylation reactions. Transamination rates increased for some mutants and decreased for others. These data imply that the DGD subsite is influenced by the presence of glutamine 52. Furthermore, there is evidence showing that the subsite environment of wild-type DGD, the histidine and the glutamate mutants are different; the three DGD forms exhibited different chromophores at around $\rm\lambda\sb{max}$ of 500 nm when treated with 2-methylalanine or L-alanine in the presence of 3% glycerol. These results have important implications for other PLP-dependent enzymes, such as ornithine aminotransferase and $\gamma$-aminobutyrate aminotransferase. Since protein sequence alignment indicates DGD is homologous to the two aminotransferases, mutations at amino acid position corresponding to glutamine 52 of DGD at the active sites of these aminotransferases could disrupt the functionality of the enzymes. Protein sequence alignment showed that all but one of the PLP-dependent aminotransferases lack residues at position 52 capable of hydrogen bonding with the substrate carboxyl group, further re-affirming the role of glutamine 52 in decarboxylation.
• #### Wildfire in Alaska: the economic role of fuel treatments and homeowner preferences in the wildland urban interface

The challenges of increased temperatures, drier fuels and more intense wildfires are having a detrimental effect on Alaskans, especially those who live in the wildland urban interface. This area is defined by open wildlands being directly adjacent to homeowners. Human safety and property are exposed to increasing risk from these wildfires as climate-based changes affect the state. The rising costs of suppressing wildfires necessitate exploring potential solutions to minimize the impact on the state population and budget. The purpose of this study is to analyze the feasibility of fuel treatments to reduce suppression costs and provide incentives to private homeowners to create safer property spaces. An electronic survey and choice experiment were administered to 388 Alaskan homeowners to measure willingness-to-pay for different attributes associated with wildfire risk reduction variables, including nearby fuel treatments and overall neighborhood participation. Expenditure data were collected for large Alaskan wildfires between 2007 and 2015. An econometric cost model was developed to estimate the effect of nearby fuel treatments on final wildfire suppression expenditures. In both scenarios, there was a limited effect from public land fuel treatments on homeowner preferences and total suppression costs. Homeowners had a strong preference for thinned fuel treatments but did not prefer clear-cut tracts of land, even when compared to doing nothing at all. The survey provided significant insight into the preferences of Alaskan homeowners, including altruistic behavior, free riding behavior, self-assessment of risk, and the amenity values of surrounding vegetation. The costs of large Alaskan wildfires in the data set was mainly driven by protection level and number of burn days, and not by the presence or potential utilization of fuel treatments.
• #### Wildlife Food Habits And Habitat Use On Revegetated Stripmine Land In Alaska

Food habits and habitat utilization of wildlife species on revegetated stripmine spoils in interior Alaska were studied from 1980 through 1982. Current reclamation techniques were beneficial for tundra voles, short-eared owls and marsh hawks. Caribou, Dall sheep, red fox, coyote, wolf, arctic ground squirrel, waterfowl, and various raptorial birds derived partial benefit from the reclaimed areas. The seeded grasses functioned as minor items in the diets of herbivores while reclaimed sites served as hunting areas for the various carnivores and raptors. Moose, showshoe hare, red-backed voles, willow ptarmigan and most nongame birds were adversely impacted by the reclaimed areas. Woody vegetation and its associated attributes such as cover and food were the essential habitat component missing from the reclaimed areas. Stripmining and reclamation procedures currently practiced in interior Alaska result in the formation of 'islands' of grassland interspersed throughout the natural habitat. The availability of undisturbed habitat adjacent to small sized, seeded areas, has made it possible for wildlife to take advantage of the reclaimed sites and still have sufficient amount of natural food and cover available with which to meet the nutritional and habitat needs of the animal. The detrimental effects of current reclamation procedures increase as the amounts of land disturbed by mining become very large. Present reclamation procedures create grasslands on disturbed sites. As the size of the disturbed area and subsequent areas of revegetation increases, the resulting loss of native forage and habitat will be very detrimental to the local wildlife. This adverse effect could be ameliorated if reseeded areas are interspersed with trees and shrubs. If recreating wildlife habitat is the major goal of reclamation, it is recommended that the creation of a diverse vegetative structure should be considered as important as the establishment of a ground cover.
• #### Willingness to pay for reindeer meat attributes: a niche market study in Interior Alaska

The Alaskan market for reindeer meat is unique. This study's aim is to estimate the average consumer willingness to pay for a range of reindeer meat attributes. These attributes include those that have a direct impact on meat quality such as cut and fat percentage, as well as intangible qualities, such as where the meat is grown and by whom it was raised. The study focuses on the preferences of people in Interior Alaska, specifically the Fairbanks Northstar Borough. The Reindeer Act of 1937 and supply infrastructure limitations have both contributed to a low level of reindeer meat production in Alaska. This study uses an adaptive choice-based conjoint to measure what attributes participants find most important and estimate how much they are willing to pay for those reindeer meat attributes.
• #### Wind energy: is there an economy of scale in Alaska?

The purpose of this project is to show the cost relationship per kilowatt hour (kWh) between small scale (< 25kWh), medium scale (> 25 kWh and < 100 kWh), and large scale (> 100kWh) wind turbines. Our analysis will compare the cost per kWh and identify the economy of scale between our custom small scale models to commercial models. The commercial models used for this project were installed by Golden Valley Electric Association (GVEA) at their Healy, Alaska wind farm. We requested their wind data, capital investment breakdown, and their operations and maintenance costs. This data will be compared to the costs and wind data associated with our custom built wind turbine. Wind energy is dependent on one major variable, the wind. Regardless of the wind turbine size, wind speed, frequency, and duration will affect the efficiency of every wind turbine. Commercial wind farms are new to Alaska. The first major wind power project in Alaska was in 1997 in Kotzebue. This wind farm, of 17 wind turbines, represents the first megawatt of wind power in Alaska. Installation and maintenance of these systems is more expensive in Alaska due to the states' remoteness. Small scale systems used in this study are custom built because small scale commercial systems are not "hardy" enough to withstand Alaska's harsh weather systems. Both medium and large scale systems, for this study, are commercially constructed systems that have been designed to withstand these harsh conditions.
• #### A window to the past: macrofossil remains from an 18,000 year-old buried surface, Seward Peninsula, Alaska

Macrofossil remains and pollen from an 18,000 year old buried surface from the northern Seward Peninsula enable a reconstruction of the full-glacial environment of an upland portion of the Bering Land Bridge. The buried surface represents a dry meadow and herb-rich tundra. Prostrate shrubs were rare on the landscape, but abundant locally. A large and diverse insect fauna populated the surface, preying on the plants and each other. Small mammals and their predators lived on the surface. Large mammals, such as caribou and bison, were present as well. The productivity of the surface was maintained by a continual influx of loess, which replenished the nutrients of the soil. Study of the buried surface provides an important addition to knowledge about the vegetation mosaic of full-glacial Beringia.
• #### Winter feeding ecology and biomagnification of organochlorine contaminants in Alaska polar bears

Dietary pathways expose polar bears to a variety of contaminant profiles and concentrations, ranging from bowhead whale (Balaena mysticetus) as one of the least contaminated marine mammals to the more highly contaminated upper trophic level ringed seal (Phoca hispida) which represent the majority of their annual diet. We used stable isotopes [delta]¹⁵N and [delta]¹³C to estimate trophic status of 139 free-ranging polar bears sampled along Alaska's Beaufort Sea coast in spring 2003 and 2004. The [delta]¹⁵N values of polar bear packed blood cells ranged from 18.2% to 21.4% with a mean of 19.5% (SD=0.7) in 2003 and 19.9% (SD=0.7) in 2004. Two-element three-source mixing models indicated that lower trophic level prey, such as scavenged bowhead whale carcasses, may have composed 11-26% (95% CI) of the diet in 2003, and -2-14% (95% CI) of the diet in 2004. Organochlorine (OC) concentrations in subcutaneous adipose tissue were determined for 47 of the polar bears sampled in 2003 and compared to trophic position ([delta]¹⁵N). Although many OCs appear not to biomagnify in polar bears, we found positive relationships with [delta]¹⁵N in both sexes between concentrations of several highly recalcitrant OCs in models incorporating age, lipid content, and [delta]¹³C. [Delta]¹⁵N was important in explaining variation in OC concentrations, indicating structural differences in food webs and biomagnification of OCs among polar bears related to their sex, age, and the apparent use of lower trophic level prey.
• #### Winter forage selection by barren-ground caribou: effects of fire and snow

Snow depth and hardness were the most influential factors in selection of feeding areas by caribou (Rangifer tarandus) in late winter in northwestern Alaska. Following a 1988 fire, plots were established in late March through April in burned and unbumed tussock tundra in 1990 and 1991. Snow in both burned and unbumed plots was shallower and softer at edges of caribou feeding craters than at adjacent undisturbed points in both years. There was little difference in snow depth or hardness between burned and unbumed plots, although caribou cratered in shallower snow in burned plots than in unbumed plots in 1990. Crater area was greater in unbumed plots in 1990, but there was no difference in crater area between burned and unbumed plots in 1991. Frequencies of particular plant taxa were only significant in determining selection of crater sites in unbumed plots in 1990, when caribou craters had higher relative frequencies of lichens and lower frequencies of bryophytes than unused areas. Fire reduced relative frequency and biomass of most plant taxa, with the exception of post-disturbance species, which occurred primarily in burned plots. Lichens were reduced in burned plots, and lichens composed 59-74% of the late-winter diet of caribou, as determined by microhistological analysis of fecal pellets. Biomass and relative frequency of Eriophorum vaginatum was greater in burned plots than in unbumed plots in 1991, and protein and in vitro digestibility levels were enhanced in samples of this species collected from burned plots in late winter.
• #### Winter foraging ecology of moose in the Tanana Flats and Alaska Range foothills

I studied woody browse distribution, production, removal, species composition, twig size, moose diets, and predicted daily intake of resident and migratory moose in the Tanana Flats and adjacent Alaska Range Foothills, Alaska, 1999-2000. Density of moose in these areas was high (1.1 moose/km²). Moose were experiencing density-dependent effects on reproduction and growth, exhibited by low adult twinning rate (6%) and absence of pregnant yearlings, yet 17.5 kg higher 10-month-old calf body weights in the migratory segment. Of all willow, poplar, and paper birch plants sampled, 74% had a broomed architecture, which I attributed to heavy use by moose. Using a model of daily moose intake based on bite mass and bite density, I estimated that 1) migratory moose met expected intake during winter while intake of resident moose was marginal, 2) moose could not meet their expected daily intake with the mean twig dry mass (0.26 g) remaining unbrowsed at end of winter, and 3) higher predicted intake by migratory moose than resident moose was consistent with their higher 10-month-old calf weights.
• #### Winter habitat of arctic grayling in an interior Alaska stream

Placer mining and the lack of information on winter ecology of Arctic grayling Thymallus arcticus. has raised concern for this popular sportfish. A study was designed to validate aerial radio telemetry data and to locate and describe overwinter areas (OWA) of Arctic grayling in Beaver Creek, Alaska. Reliance on aerial data alone resulted in overestimation of survival and misidentification of 14 of 26 designated OWAs. Twenty-one Arctic grayling were tracked downstream 12-58 km to 12 OWAs spanning a 31-km section of Beaver Creek. Radio-tagged and untagged Arctic grayling occupied areas with ice thickness of 0.4-1.4 m overlying 0.06-0.52 m of water, flowing at 0.03-0.56 m/s. During winter, discharge, cross-sectional area, velocities, and water width in four OWAs decreased until late March; then, cross-sectional area increased due to an increase in discharge that pushed the ice upward. Adult Arctic grayling overwintered downstream of habitat disturbances, and occupied much shallower winter habitats than expected.
• #### Winter movements of Arctic foxes in Northern Alaska measured by satellite telemetry

We studied winter movements of 37 arctic foxes (Alopex lagopus) collared within a petroleum development area at Prudhoe Bay, Alaska (n = 20), and an undeveloped area in the National Petroleum Reserve-Alaska (NPR-A, n = 17) during the winters of 2004, 2005, and 2006 using satellite telemetry. Comparing Prudhoe Bay and NPR-A, differences in mean movement rates of juveniles was 23.9 ± 2.7 km per duty cycle and 10.6 ± 2.8 km per duty cycle for adults, and mean difference in maximum distance from capture site for juveniles was 265.2 ± 63.2 km and 205.5 ± 128.9 km for adults. Juveniles and adults collared in NPR-A were highly mobile and made long distance movements (up to 782 km) while foxes from Prudhoe Bay remained in or near the oil field throughout winter. Extensive use of sea-ice by three juvenile foxes from NPR-A was documented during the winter of 2005-2006. Three juvenile foxes traveled long distances (904, 1096, and 2757 km) during the winter and remained on the sea-ice for extended periods of time (76, 120, and 156 days). These findings verify the use of sea-ice by arctic foxes and raise concerns that the diminishing ice cover may negatively impact populations by limiting access to marine food sources. We conclude that the oilfields are having a strong effect on the winter movements of arctic fox and suggest differences in movements are likely attributable to the availability of anthropogenic foods at Prudhoe Bay.
• #### Winter Precipitation Depths Across The North Slope Of Alaska Simulated From The Weather Research And Forcasting Model And Snowtran-3D

Accurately predicting snow distribution and blowing snow conditions in the Arctic is critical to the design of ice road construction and maintenance as well as for predicting water supplies and runoff during snowmelt, estimating the cost of snow removal, and forecasting tundra travel conditions. A current atmospheric model used by both the operational weather prediction and research communities is the Weather Research and Forecasting model. However, the built-in snow schemes in the model neglect redistribution of snow via wind, one of the key processes in snow pack evolution. This study will involve three parts: (1) diagnostic of the differences in the current snow schemes of the model, (2) evaluation of the model's snow schemes as compared to observational data, and (3) asynchronous coupling of the SnowTran-3D to model predictions using a simple algorithm. The approach provides a simple method for the prediction of snow distribution, improving the realism of current snow distribution models, and will be easily employable for both operational and research applications.
• #### Winter Range Studies Of The Western Arctic Caribou Herd, Northwest Alaska

Climate change is likely to bring a myriad of interrelated changes to the Arctic. One change is warmer and drier conditions that could increase the prevalence of wildfire in northwest Alaska. Wildfires destroy terricolous lichens that Western Arctic Herd caribou (Rangifer tarandus ) rely on during winter; taking decades to recover. My goals were to assess the recent (1950--2007) fire regime within the herd's range, identify characteristics of habitat selected by overwintering caribou, and determine the potential impacts of climate change on the fire regime and caribou winter range. I used a combination of existing data and information collected at vegetation plots to conduct these analyses. I found that wildfires in the tundra were relatively common from 1950--2007, covering approximately 10% of northwest Alaska. Tundra was > 4.5 times more likely to re-burn than boreal forest. This novel, yet intuitive finding could have serious implications if fire starts to become more common in the Arctic. I found that the average annual area burned more than doubled in years where mean August temperatures exceeded 11.7�C (53�F). Caribou use tundra and forested during winter but avoided recently (< 58 years) burned areas in both habitat types likely because they contained < 1/4 of the abundance of forage lichen species than unburned habitats. I found that lichen abundance was 3 times greater in the herd's current winter range versus its historic range -- supporting the theory that caribou shift ranges to compensate for deteriorating grazing conditions. Stand age was the most consistent correlate with lichen abundance. Dwarf birch (Betula spp.) was more abundant in recent burns which may facilitate the intensification of the future fire regime in the region. My modeling efforts revealed that wildfire is likely to become more prevalent, especially on the herd's core winter range, which could have deleterious impacts on caribou winter range and provide quality habitat for moose ( Alces alces). My results should provide a solid foundation to develop a science-based fire management plan for the Western Arctic Herd.
• #### Winter studies of under-ice benthos on the continental shelf of the northeastern Bering Sea

A total of 76 samples from 16 benthic stations over the eastern Bering Sea shelf were taken between 31 January and 17 February, 1970 for purposes of assessing the quantity and distribution of benthic macrofauna. A total of 129 species or taxa were found, with an average density of 1,133 indiv/m^2 and average biomass of 127 g wet/m^2. Species were subjected to elemental analysis for determination of organic carbon and nitrogen content, yielding average values of 5.1% carbon and 1.1% nitrogen expressed as percentage wet weight, which translated into biomass values of 6.5 g C/m^2 and 1.4 g N/m^2 averaged over all stations. Correlation studies yielded 9 species affinity groups, and regression analysis indicated that about 40% of the variability of distribution and density of the major species could be accounted for by salinity, sediment mode particle size, depth, temperature, or dissolved oxygen, with no one factor assuming dominance. Of the 129 species or taxa, 35 account for about 80% of total numbers, wet weight biomass, or carbon biomass, with 8 species making up over 50% of the totals in all categories. Of these 35 major species, 8 are known to be food species of the Pacific walrus. These 8 comprise only 10% of the total number of individual organisms encountered, but make up 60% of the wet weight biomass and 49% of the carbon biomass over the region, sampled.
• #### Winter vertebrate browsing of birch: effects on the use of leaf litter leachates by stream microorganisms

Winter browsing of birch leads to chemical changes in leaves of the following growing season, potentially generating differences in the quality of leachates derived from leaf litter and in leachate use by stream microorganisms. The effects of moose browsing were tested on leachates from leaves collected from browsed and unbrowsed trees and inoculated with microbial communities. Respiration and bacterial abundance were used to assess qualitative differences in leachates. Microbes cultured in leachates derived from leaves of browsed trees had significantly higher rates of oxygen uptake. There were no significant differences in bacterial abundance between treatments. The basis for the qualitative difference in leachates is likely due to an 89% greater concentration of amino acides in leachates derived from leaves of previously browsed trees. This study provides evidence that winter herbivory of birch can influence the use of leaf leachates by stream microbes, demonstrating coupling between riparian zones and stream ecosystems.
• #### "The winter's tale": Leontes' derangement and the chronotope of melancholy

To recent critical formulations regarding melancholy and its role in the Renaissance humoral body, this project contributes the argument that melancholy's trajectory from its natural to its unnatural state carries with it a fundamental shift in temporal-senses. I illustrate this shift through close analysis of Leontes' derangement in Shakespeare's 'The winter's tale.' Based on Renaissance physiological texts, as well as modern psychoanalytic, anthropological, and gender studies, I explore how melancholy's inherent volatility signifies the masculine anxieties of early modern English patriarchy. I argue that melancholy's bifurcated temporal-senses serve to clarify the subjectivity of Renaissancee passions.
• #### Wintering strategies of an Arctic-nesting goose: costs of migration and over-wintering for Pacific black brant

Birds wintering in different climates may have different strategies for storing and using energy. We documented changes in body morphology and composition of Pacific Black Brant (Branta bernicla nigricans) wintering in Alaska and Baja California and modeled the energetic costs of wintering at each location. We compared costs associated with two different wintering strategies: 1) to remain in an unstable and harsh environment but close to breeding grounds, or 2) to migrate long distances to a mild environment, but distant from breeding grounds. Despite dramatic differences in the timing and magnitude of energetic costs between sites, Brant stored similar amounts of lipid and maintained similar body mass throughout winter. Brant operate under similar physiological bounds but changes in organ mass and nutrient storage took place within these bounds. This flexibility allowed Brant to employ two contrasting winter strategies. We suggest that there may be reproductive and energetic advantages associated with shortening migration distance and remaining in Alaska over winter. The number of Brant wintering in Alaska should continue to increase if constraints on food intake do not impede energy storage and survival is similar between sites.