• Food, sex, death, and quest: the literary legacy of Sir John Franklin

      Long, Maureen Eleanor (2003-05)
      The story of Sir John Franklin, nineteenth-century British Arctic explorer, has been reinterpreted and reworked by poets, novelists, essayists, and dramatists for more than a century and half. This thesis is an attempt to discover the character and significance of the literary legacy of Sir John Franklin by exploring authors' uses of four common tropes: food, sex, death, and quest. In analyzing these tropes, this thesis focuses primarily on five works of contemporary Canadian literature: Margaret Atwood's short story, "The Age of Lead"; Gwendolyn MacEwen's radio verse play, Terror and Erebus; Geoff Kavanagh's play, Ditch; Mordecai Richler's novel, Solomon Gursky Was Here; and Rudy Wiebe's novel, A Discovery of Strangers. In addition, other works of literature are considered. An appendix lists more than fifty creative works that incorporate Sir John Franklin.
    • Foods and foraging ecology of oldsquaws (Clangula hyemalis L.) on the arctic coastal plain of Alaska

      Taylor, Eric John (1986-09)
      The study was conducted from June to September during 1979 and 1980 in the the West Long Lake area of the National Petroleum Reserve-Alaska. Additional oldsquaws were collected in the inland wetlands near the northwest boundary of the reserve at Ice Cape. West Long Lake and the adjacent Goose Lake are located 15 miles south of the Beaufort Sea and immediately west of Teshekpuk Lake.
    • For generations to come: exploring local fisheries access and community viability in the Kodiak Archipelago

      Ringer, Danielle J.; Carothers, Courtney; Cullenberg, Paula; Davis, Michael; Donkersloot, Rachel (2016-12)
      The sustainability of fisheries and fishing-dependent communities depends upon numerous political, cultural, economic, and ecological factors. My research explores a key threat to this sustainability in Alaska -- the graying of the commercial fishing fleet. As current fishermen approach retirement age and a decreasing number of young people obtain ownership level careers in Alaska's fisheries, succession impacts become an increasingly pressing issue. This research utilized a political ecology framework and mixed methods ethnography, including 70 semi-structured interviews and 609 student surveys, to study local fisheries access and community viability in the Kodiak Archipelago communities of Kodiak City, Old Harbor, and Ouzinkie. This research documents barriers that fishermen face at different stages in their careers and describes related implications. Findings indicate that opportunities for rural youth and fishermen are increasingly constrained by interrelated economic and cultural barriers that have created equity and sustainability concerns. Furthermore, research suggests that the privatization of fisheries access rights is a major catalyst of change that has amplified these barriers, generated social conflict, and resulted in a transformed paradigm of opportunity compared to decades past. Secondly, this research compares fishermen's identities and livelihood motivations to dominant framings in academic literature and policy realms. This comparison reveals that in-depth understandings of fishermen are not well explained by narrow economic assumptions and instead include broader social and cultural dimensions. Lastly, exploration of the entangled relationships between fisheries access and rural youth pathways demonstrates increasing pressures within coastal communities, such as globalization, outmigration, youth ambivalence, substance abuse, and overall constrained opportunities. Nonetheless, coastal communities are working towards increasing local resilience to external pressures through social network support and some youth are bucking demographic trends by moving into fishing livelihoods. Due to the suite of threats facing fishing people and communities, it is increasingly important to have a deeper understanding of natural resource management impacts and local dynamics within fishing communities in order to plan for sustainable coastal futures.
    • Foraging behavior of caribou on a calving ground in northwestern Alaska

      Kuropat, Peggy JoAnn (1984-12)
      Habitat selection, foraging behavior, and forage intake rates by caribou were studied on a calving ground in northwestern Alaska. The pattern of emergence of new plant growth determined habitat use. The grazing pattern reflected a balance between selection for nutrients and plant biomass, and avoidance of plant secondary metabolites. Habitat use was also influenced by predator avoidance. At the time of calving, meteorological conditions provide a snow-free "window" of available Eriophorum vaginatum inflorescences that are of high nutritive value. Subsequently, topographic variation results in a diversity of forbs and shrubs confined in time and space at the time of peak nutritional demands for lactation and growth of calves during June. Intake of deciduous shrub leaves averaged 3.7 g/min and the intake of E. vaginatum inflorescences was 1.1 g/min. Highest observed intake was 5.5 g/min on forbs. Forage selected was of high nutritive value and high digestibility. Thus, caribou selected productive microsites and habitats where intake of preferred forage could be maximized.
    • Foraging ecology and conservation biology of African elephants: Ecological and evolutionary perspectives on elephant-woody plant interactions in African landscapes

      Dudley, Joseph Paine; Bryant, John P. (1999)
      The available scientific evidence indicates that African forest elephants and bush elephants are ecologically and evolutionarily distinct taxa. The current practice of regarding these two taxa as ecotypes of a single species, Loxodonta africana (i.e., L. a. africana Blumenbach 1797, L. a. cyclotis Matschie 1900) appears unwarranted, and obscures issues of major significance to the conservation biology of African elephants. Under a proposed taxonomic revision, the African bush elephant retains the designation Loxodonta africana Blumenbach 1797 while the African forest elephant is recognized as Loxodonta cyclotis Noack 1906. The browsing of woody plants by African bush elephants is a major factor in the structural dynamics of semi-arid woodland and scrubland habitats in Hwange National Park (HNP) and the Sengwa Wildlife Research Area (SWRA), Zimbabwe. Drought, frost and fire also influence the structure and species composition of woody vegetation within HNP. Interactions among these three abiotic factors and elephant browsing may have significant impacts on the dynamics of semi-arid woodland and scrubland habitats of HNP. Mortality attributable to elephant damage was identified as a principal cause of death among large trees (>5.0 in height), and a relatively minor but not insignificant cause of death for shrubs and trees in the 1.0--5.0 in height class. The responses of Colophospermum mopane in SWRA to fertilization treatments corresponded to those predicted by the carbon/nutrient hypothesis of plant anti-herbivore defense. Comparisons of these results with those of previous studies suggest possible changes in the ecology and population biology of elephants in HNP during the past decade. Observed differences in the age-specific mortality of elephant in HNP during die-offs in 1993--1995 and 1980--1984 provide independent evidence of changes in the ecology of elephants in HNP during the period 1983--1993. The population of L. a. africana inhabiting the Matabeleland-Ngamiland-Okavango region of southern central Africa (which includes the HNP population), is the largest extant elephant population on Earth. The magnitude of this population (110,000--120,000), and the high proportion of its range currently under protection as wildlife reserves, indicate that this population may rank as the most viable and potentially sustainable elephant population on Earth.
    • Foraging Ecology And Nutritional Stress Of Tufted Puffins (Fratercula Cirrhata) Inferred From Stable Isotopes, Fatty Acid Signatures, And Field Endocrinology

      Williams, Cory T.; Buck, C. Loren (2008)
      Prey availability has a major impact on the reproductive output of seabirds, yet information on seabird diets throughout the breeding season is often lacking. Although reduced prey availability is known to affect the growth and survival of nestling seabirds, few studies have demonstrated similar effects on indices of adult body condition. I used stable isotopes and fatty acid (FA) signatures to investigate seasonal and age-related variation in the foraging niches of tufted puffins (Fratercula cirrhata). I conducted captive feeding experiments to determine whether inferences based on these techniques are affected by moderate food restriction during growth. I also examined how adult puffins prioritize the competing goals of maximizing the growth rate of their offspring and maintaining their own condition, as measured by body mass and by the stress hormone, corticosterone (CORT). Food restriction during nestling growth affected adipose tissue FA signatures and resulted in blood that was depleted in 15N and 13C relative to well-fed controls. However, effects of nutritional restriction on delta 15N, delta13C, and FA signatures were small compared to variability in prey, indicating physiological effects do not preclude use of these techniques as dietary tracers. Stable isotopes and FA signatures of free-living adults indicated foraging niches changed over the course of the breeding season. Stable isotopes suggest chick-rearing adults and nestlings feed at the same trophic level while FA signatures indicate that parents feed nestlings a diet different from their own. Body mass of adult puffins declined between incubation and chick rearing periods. For females the magnitude of mass decline did not differ between years, whereas for males the decline was greater in the year where young puffins fledged at a lower mass. In a separate analysis, baseline CORT values of adults of both sexes did not differ between years, but were lower than those observed in a separate study area during two consecutive years with low rates of nestling growth and survival. Assuming elevated CORT and reduced body mass impact survival and/or future fecundity, these results suggest the cost of reproduction may be higher for those adults able to fledge young in years characterized by low productivity.
    • Foraging Ecology And Sociality Of Muskoxen In Northwestern Alaska

      Ihl, Claudia; Ruess, Roger; Klein, David (2007)
      I investigated sociality and winter foraging ecology of muskoxen ( Ovibos moschatus) in Cape Krusenstern National Monument, northwestern Alaska. The nutritional value of moss (Hylocomium splendens, Tomenthypnum nitens) for muskoxen was evaluated by incubating moss in rumen-fistulated muskoxen and simulating post-ruminal digestion by incubation in acid-pepsin. Moss was indigestible in muskoxen and gained mass and nitrogen in the rumen. Consequently, high moss consumption during winter may result in net loss of nitrogen from a muskoxen's system. Local and regional differences in moss use by muskoxen and caribou or reindeer (Rangifer tarandus) were investigated in northwestern Alaska in relation to indicators of winter range quality. On muskox winter ranges, increases in fecal moss indicated decreased graminoid cover, harder snow, increased moss cover, and greater animal densities. Higher mobility of caribou than muskoxen during winter limits use of their feces to reflect local forage selection, but fecal moss may indicate caribou winter range quality on a larger, regional scale. Increasing proportions of moss in muskoxen feces may alert wildlife managers to shifts in forage availability due to changing snow conditions. Roles of male and female muskoxen in coordinating group movements were investigated during the snow-free season. Adult females led most activity initiations, foraging-bout movements, and spontaneous group movements. Rutting males actively manipulated female-led movements through herding and blocking. Leaders incurred no costs in terms of lost foraging time. Habitat use by muskoxen shifted from upland habitats in early summer towards lowland sedge meadows during rut. Muskox group sizes decreased from winter to summer to rut. Muskoxen foraging efficiency decreased with group size in spatially unlimited but not in spatially limited habitats. Adult males contributed least to group cohesion, and their presence may contribute to group fission during rut. A conceptual model is presented which discusses how habitat, foraging, social behavior, and predation threat contribute to group sizes, fission and fusion of muskox groups. Results from this study indicate that winter ranges used by muskoxen in Cape Krusenstern may be limiting, which suggests that numbers of muskoxen in this area will likely remain small. Therefore, hunting quotas should be low and limited to males only.
    • Foraging ecology of female Dall's sheep in the Brooks Range, Alaska

      Hansen, Michael Charles (1996)
      Most wild sheep (Ovis) are primarily diurnal. Thus, extreme cold, darkness, and limited quantities of low-quality forage during long winters above the Arctic Circle present a formidable challenge for sheep. Further, summer is particularly short at these high latitudes, providing little time for sheep to accumulate energy reserves for winter. This thesis discusses dietary and behavioral responses of wild sheep to the constraints of Arctic environments. Specifically, I determined diet composition and selection, forage quality, nutrient intake, and activity budgets of adult female Dall's sheep (ewes) (Ovis dalli dalli) near the northern extreme of the range of wild sheep for 2 years and constructed a model of the energy relationships of these animals. Ewes primarily consumed forbs and grasses during summer, and strongly selected forbs over other forages in accordance with the predictions of optimal foraging theory. Diets primarily consisted of grasses in early winter, shifted to sedges in February, and back to grasses in early spring. Shrubs were consistently the least selected class of forage. When the diet was composed of forages with varying digestibility, microhistological analyses not corrected for differential digestibility were biased toward less digestible forage. Winter forage available to Dall's sheep in the northern Brooks Range was low in both digestibility and protein content. In early summer ewes foraged during all hours of the day when sunlight was present for 24 hours. Sheep restricted their foraging almost entirely to daylight hours near the equinoxes, and foraged during all available hours of light, as well as 2.8 hours of the night in December. Daily foraging time varied from 12.9 hours in June to 7.9 hours in December, and, when measured on a daily basis, was positively correlated with average windchill and daylength. Ash-free fecal nitrogen and in vitro digestible dry matter were most highly correlated with activity level on a monthly basis. Energetics modeling indicated that ewes were in a negative energy balance for 6-8 months each winter and lost nearly 30% of their body weight. Duration of the short summer growing period was most important for weight gain, and presence of deep snow determined weight loss in winter.
    • Foraging ecology of yellow-rumped warblers in an Alaskan boreal forest following a spruce beetle outbreak

      Bartecchi Rozell, Kristen (2004-12)
      I examined the foraging ecology of the Yellow-rumped Warbler (Dendroica coronata) several years after an outbreak of spruce beetles (Dendroctonus rufipennis) in the Copper River Basin, Alaska. With increased beetle-induced mortality of white spruce (Picea glauca), a preferred foraging substrate, we predicted warblers would respond through: (1) decreased overall use of white spruce, (2) increased selectivity of live white spruce that remained, and (3) reduced foraging efficiency, reflected by a greater proportion of time spent foraging and lower prey attack rates. We examined warbler foraging behavior and arthropod biomass on commonly used foraging substrates, and in stands with low-moderate (<40%) and heavy (>40%) spruce mortality. Live and dead white spruce, quaking aspen, and willow were the most commonly used foraging substrates, and selection of coniferous versus deciduous tree types varied by breeding stage. Yellow-rumped Warblers foraged extensively on dead spruce in stands with heavy spruce mortality, although they avoided it in stands with low-moderate spruce mortality. Dead spruce supported significantly lower arthropod biomass than any other tree type except black spruce, and warblers that foraged in dead spruce tended to have lower prey attack rates than when they foraged in live white spruce.
    • Foraging patterns of northern fulmars in Alaska inferred from fatty acid signature analysis

      Wang, Shiway W. (2005-12)
      Diets of Northern Fulmars (Fulmarus glacialis) in the North Pacific are poorly known, and thus relationships of fulmars to supporting food webs and their potential sensitivity to ecosystem variability, such as that driven by a changing climate, also are uncertain. I employed a new technique, fatty acid (FA) signature analysis, to examine dietary differences among fulmars at three colonies in Alaska. I predicted that 1) signatures of adipose tissue and stomach oils would differ because the time scale each depot reflects differ and/or because adipose tissue FAs may be influenced by predator metabolism, while stomach oil FAs may be influenced by differential uptake; 2) fulmar diets would differ between colonies located in distinct oceanographic settings, which create unique habitats for prey assemblages; 3) diets would differ temporally within colonies because of inter-annual variability in the physical environment resulting in variation of prey FA signatures; and 4) diets of adult fulmars and their chicks would be similar because they feed by regurgitation. I found that FA signatures of adipose tissue were significantly different than those of stomach oil; there were conspicuous spatial and temporal differences in adipose tissue signatures; but diets of adults may differ from those of chicks.
    • Foraging tactics of humpback whales feeding near salmon hatchery-release sites in Southeast Alaska

      Kosma, Madison M.; McPhee, Megan V.; Straley, Janice M.; Szabo, Andrew R.; Wooller, Matthew J. (2019-12)
      Increases in the humpback whale (Megaptera novaeangliae) population have generated considerable interest in understanding the foraging habits of these large marine predators in the Gulf of Alaska. Globally, humpback whales are classified as generalist predators but are known to exhibit localized differences in diet. Intensified predation pressure is of particular concern to resource managers, who have observed whales feeding at juvenile hatchery salmon release sites in Southeast Alaska. We assessed the diets and behavioral tactics of humpback whales foraging near Hidden Falls Hatchery release sites (in Chatham Strait, 2016 to 2018) to better understand their predatory effects on juvenile hatchery-reared salmon. We used skin biopsies, prey sampling, and stable isotope analysis to estimate whales' diet composition. Aerial footage and photographic sequences were used to assess the foraging tactics used on this prey source. We observed three individual whales repeatedly feeding on juvenile hatchery-reared salmon, and we were able to sample them multiple times over a period spanning shifts in diet. Overall, the diets of these whales were higher trophically than other humpback whales foraging in the area, even before feeding on juvenile hatchery salmon started. These hatchery-feeding whales may be generally more piscivorous than other whales, which focused on planktivorous prey. Our repeat sampling, in conjunction with scheduled introductions of a novel prey source, provided a semi-controlled feeding experiment that allowed for incorporation and turnover rate estimates from humpback whale tissue in a way that was not previously possible for large, free-ranging cetaceans. Finally, during the course of this study we discovered an undescribed feeding tactic employed by hatchery-associated whales. We observed the use of solo bubble-nets to initially corral prey, followed by calculated movements to establish a secondary boundary with the pectoral fins that further condensed prey and increased foraging efficiency. Our study provided the first empirical evidence for what we describe as "pectoral herding". This work deepens our knowledge about humpback whale foraging ecology, how this innovative species is able to exploit newly available prey, and to what extent they feed on commercially valuable hatchery salmon.
    • Forecasting catches of Pacific salmon in commercial fisheries of southeast Alaska

      Marshall, Robert Paul (1992)
      Data collections since 1911 and statistical methods from time series analysis are employed to forecast catches of pink, chum, coho, and sockeye salmon in Southeast Alaska. Knowledge of the spatial and temporal domains favored by Pacific salmon originating in Southeast Alaska is summarized to provide a basis for estimating environmental variation experienced by each species. Catches in northern, southern, and all of Southeast Alaska are forecast with univariate ARIMA, transfer function-noise (TFN), and vector ARMA models. Univariate models for catch in numbers and catch in weight yielded similar results for each species. Air and sea surface temperatures, freshwater discharge, and coastal upwelling enter TFN models for several species and areas. Environmental variables allow TFN models to explain a small amount of variation in the catches (average of 19%) above that explained by univariate models. Forecasts for most, but not all, species and areas are improved (average of 16%) by including environmental data in TFN models. Stock-recruit models with a parameter for density dependent mortality provide the best forecasts of pink salmon catch and are recommended for future forecasts. Winter air and sea surface temperatures enter stock-recruit models for pink salmon, and forecasts of catch and recruitment in northern and southern Southeast Alaska tend to oppose each other and cancel (1981-1985), which suggests that the salmon are caught in areas other than where they originated. Mean absolute percentage error (MAPE) for forecasts of pink salmon catch from stock-recruit models in Southeast Alaska, based on data for 1981-1990, is estimated at 49%, with first, second, and third quartiles of 10%, 23%, and 83%, respectively. Catches of Pacific salmon in Southeast Alaska are significantly correlated and are forecast jointly with good accuracy by vector ARMA models, except when effects believed to result from density dependent mortality are present in the data. Correlations indicate that coho salmon smolts might prey on young pink salmon. Also, recruitment of pink salmon in Southeast Alaska and British Columbia is correlated; regional environmental influences might thus affect catches in both areas. In Southeast Alaska, MAPE for forecasting coho and sockeye salmon catch with time series analysis is about 20%, and about 30% for chum salmon.
    • Forecasting stock-specific upriver migration timing of chinook salmon in the Yukon River

      Mecum, Bryce Douglas; Adkison, Milo D.; Quinn, Terrance J. II; Toshihide, Hamazaki; Mundy, Phillip R. (2016-12)
      Pacific salmon (Oncorhynchus spp.) are an economically and culturally important genus of fishes endemic to the North Pacific. Their sustainable management depends on an understanding of the drivers of their abundance and migration dynamics. In many instances, statistical models are employed to predict abundance and run timing before harvest takes place to more effectively meet management objectives. In this thesis, I created a general-purpose predictive model of run timing that can be applied to many salmon populations. I then applied it to Yukon River Chinook salmon (O. tshawytscha) by generating pre-season predictions of inriver run timing, which I then compared with existing observations of run timing at two upriver locations. Prediction errors were low enough for the model to be useful to management. Models such as the one created in this study represent an objective tool that can be used to reduce subjectivity in fisheries management.
    • Forest biometrics and quantitative analysis of forested ecoystems in coastal Alaska

      Peterson, Randy Louis; Verbyla, David; Liang, Jingjing; Barrett, Tara; Greenberg, Joshua (2014-08)
      Growth and yield models are a mainstay of forestry research and a necessary tool in the forest management decision process. Growth and yield models predict forest population dynamics over time and are an invaluable resource to forest managers making harvest and utilization decisions. At present, there are only a few growth models available for Alaska's coastal forests, all of which are either calibrated with even-aged data or outdated. Yield tables and growth models developed with even-aged data can be useful in even-aged management applications such as clear-cuts; however, these models are not able to predict the outcomes of uneven-aged silvicutural systems. The objective of this thesis is the development of a growth and yield model for coastal Alaska and computer applications to facilitate its use. A density-dependent, distance-independent, size- and species-specific matrix forest growth and yield model is calibrated with data collected on permanent sample plots located throughout coastal Alaska. The resulting growth and yield model enables short- and long-term predictions of stand basal area, volume, and biomass. Model assessment, with a focus on plausibility and accuracy, is evaluated on an independent dataset. Two computer programs (AlaskaPro and fgmod) are developed in conjunction with the new model. These programs can be used by forest researchers and land managers to compare the outcomes of various silvicultural prescriptions.
    • Forest Ecology And Distribution Of Bats In Alaska

      Parker, Doreen Ingrid; Cook, Joseph A.; Klein, David R.; Rexstad, Eric A. (1996)
      This thesis documents distribution of bat species in Alaska and effects of clearcutting on bat activity in temperate rainforests of southeastern Alaska. Occurrence of Myotis lucifugus, M. californicus, M. volans, M. keenii, and Lasionycteris noctivagans is confirmed in southeastern Alaska. I describe new specimens of M. keenii from southeastern Alaska, the first in over 100 years. Myotis lucifugus and Eptesicus fuscus are documented north of 64$\sp\circ$ N latitude. Environmental conditions and geography which influence distribution and latitudinal diversity gradients are discussed. Low bat activity in second-growth forests and clearcuts suggests that these areas provide little summer habitat. Higher activity levels in old-growth and riparian forests suggest these areas are important summer habitat. A change in activity between lactation and post-lactation periods is also noted. Unusual aspects of M. lucifugus ecology in southeastern Alaska are: consumption of spiders; presence of maternity colonies in a temperate rainforest; and intermittent use of hibernacula. <p>
    • Forget Everything

      Richardson, Jean Jolene; Reinhard, John (2003)
      These poems take place in a compromised world. People who have lost their visions of life find themselves on the other side of the crisis, and suddenly the goal is no longer simply to live, but to live authentically. The narrative voice that emerges through this collection is one that struggles to face reality without self-deception, and without comfortable simplifications. The poems themselves are embodiments of faith, because a sincere search for truth implies a belief that whatever the world is, it's worth knowing. <p> Most of these poems are lyrics, struggling to convey one feeling or set of feelings. Other revelations necessary to the narrative and emotional arc of the collection require different forms. A section poem addresses fragmentation; a villanelle embodies obsessive thinking; and prose pieces allow a linking of moments and reasons not possible in other forms, but necessary to the investigation of the material. <p>
    • Formation and optical properties of photochromic silver nanoparticles

      Lee, George Patrick (2005-05)
      Spherical silver nanoparticles may be produced by the reduction of Ag (aq) by borohydride in the presences of citrate. When (phenylphosphinidene) bis-(benzenesulfonic acid) is also present, and the reaction mixture is illuminated, nonspherical Ag nanoparticles are formed. We have discovered that the shape of some Ag nanoparticles can be repeatedly changed by subjecting them to numerous cycles of light and dark. To our knowledge, this has never been reported in the literature. These photo chromic Ag nanoparticles displayed at least two different particle shapes: prismatic and spherical. The difference in morphology could be determined by the color of the solution and by the electronic spectra. The prismatic Ag nanoparticles can be photochemically synthesized in 24hrs and then converted into a spherical form by placing them in the dark for 14hrs. This transformation is accompanied by a blue shift in the visible spectrum. The prismatic particles are reformed by placing them in the light for 4 hrs. This transformation has a red shift in the visible spectrum.
    • The formation of pore ice in coarse grained soils

      Fourie, Walter (2005-12)
      Understanding the formation of pore ice in coarse grained soils is important to geotechnical and geo-environmental projects such as the construction of roads, airstrips and gravel foundations as well as the treatment of contaminated soils in the arctic, sub-arctic, alpine and northern regions. The amount of pore ice present controls the strength characteristics of the soils as well as the flow of fluid through the soil. Tests have been conducted to qualify the impact of gradation, temperature, compaction and initial moisture content on the formation of pore ice in coarse grained soils. The purpose of this study was to prepare a conceptual model of the freezing mechanism in coarse grained soils and to qualify the parameters that influence the ice formation. Results from this study indicate that the presence of fine grained particles in a coarse grained soil greatly impact the depth at which the pore space initially becomes saturated with ice. A conceptual model was developed and its application is shown with regards to the process of thaw weakening in roads and the creation of preferential flow paths in permeable reactive barriers.
    • Formation of solar prominences and eruption of solar magnetic arcade systems

      Choe, Gwang-Son; Lee, Lou-Chuang; Akasofu, Syun-Ichi; Roederer, Juan G.; Swift, Daniel W.; Watkins, Brenton J. (1995)
      Formation and eruption of solar prominences, coronal mass ejections (CMEs) and solar flares are the most magnificent phenomena among solar activities. Observations show that there is an interrelationship among these events and that their manifestation is conditioned by certain common photospheric signatures. One of them is the increase in magnetic shear. In this thesis, the evolution of the solar atmosphere is studied by numerical simulations with photospheric motions as boundary conditions. Firstly, mechanisms of prominence formation are investigated. It is found that prominences can be formed by the development of a thermal instability (1) in a rapidly expanding magnetic arcade, (2) in a magnetic island created by magnetic reconnection or (3) in the current sheet between two bipolar arcades. Secondly, the quasi-static evolution of a magnetic arcade subject to footpoint shearing is studied under the ideal MHD condition. Three distinct evolutionary phases are found, in the last of which a current layer develops and grows indefinitely with the increasing shear. Force-free field solutions are also constructed and compared with dynamic solutions. Finally, resistive evolutions of magnetic arcades are investigated imposing resistivity on the pre-sheared magnetic fields. It is found that there is a critical amount of shear, over which magnetic reconnection can take place to create a magnetic island. The effects of different values and spatial patterns of resistivity are studied. With a localized resistivity, most of principal features in solar eruptive processes are reproduced. A comparative study is made between the numerical results and observations.
    • Forming a therapeutic response to adolescent impulsivity

      Hansen, Kira M.; Gifford, Valerie; McMorrow, Samantha; Daku, Mike (2017-05)
      Utilizing a biopsychosocial perspective, this paper addresses the impact, causes, and treatment of adolescent impulsivity. Specifically, the defining features of impulsivity are identified, and the implications that impulsivity has on adolescent criminal behaviors, treatment participation, and quality of life measures are addressed. As a result of this paper's findings, a therapeutic integration of Dialectical Behavior Therapy and working memory training is proposed in order to meet treatment needs that have gone unaddressed, and this integrated model is presented in the form of a group treatment manual.