• Decadal scale vegetation maps for the boreal forest surrounding Fairbanks, Alaska

      Huhman, Hannah E.; Prakash, Anupma; Rosselló, Jordi Cristóbal; Dewitz, Jon (2018-08)
      Vegetation maps of a selected area within the boreal forest surrounding Fairbanks, Alaska, have been generated for the nominal years of 1985, 1995, 2005, and 2015 using Landsat 4 and 5 Thematic Mapper and Landsat 8 Operational Land Imager surface reflectance products at 30 meter spatial resolution using a decision tree classification. The maps include 9 U.S. Geological Survey (USGS) vegetation classes, as well as barren land, open water, and ice/snow classes that are consistent with the classes identified in the 2001 National Land Cover Database (NLCD) map of Alaska generated by the USGS. Classification steps are based on USGS methodology, with refinements for the boreal forest, to ensure further comparison to the 2001 USGS NLCD map for Alaska. The overall weighted accuracies of first order estimates of data quality using cross validation are 93.2%, 88.4%, 93.3%, and 86.9% for the nominal years of 1985, 1995, 2005, and 2015 maps, respectively, compared to 81.8% accuracy for the USGS NLCD 2001 product. This study demonstrates that the spatial and spectral resolution of Landsat data is the best available for mapping the vegetation of Alaska's boreal forest at 1:50,000 scale. It also shows that the boreal forests surrounding Fairbanks, Alaska have witnessed a decrease in the growth of evergreen forests, an expansion of shrub and an increase in wetland distribution, all of which have been reported as impacts of a warming climate in the Arctic and Sub-arctic.
    • Decadal Variability In The Arctic Ocean: Greenland-Iceland-Norwegian Seas Ice-Ocean-Atmosphere Climate System

      Dukhovskoy, Dmitry Stanislavovich; Johnson, Mark; Proshutinsky, Andrey (2003)
      This study investigates the decadal variability of the Arctic Ocean---Greenland, Iceland, Norwegian Seas (GIN Sea) system and possible mechanisms driving variability. The theoretical foundation of this work is the theory of Proshutinsky & Johnson [1997] that two major climate states of the Arctic---Anticyclonic Circulation Regime (ACCR) and Cyclonic Circulation Regime (CCR)---are driven by variations in the freshwater contents of the Arctic Ocean and the GIN Sea. It is hypothesized that the Arctic Ocean and the GIN Sea form an auto-oscillatory ice-ocean-atmosphere climate system with a quasi-decadal period of interannual variability. The system is characterized by two stages: (1) cold Arctic (ACCR)---warm GIN Sea with weak interaction between the basins; (2) warm Arctic (CCR)---cold GIN Sea with intense interaction between the basins. Surface air temperature and dynamic height gradients between the basins drive the auto-oscillations. This study investigates interactions between the Arctic Ocean and the GIN Sea. To test the hypothesis, a simple model of the Arctic Ocean and Greenland Sea has been developed. The Arctic shelf processes have been parameterized in a box model coupled with an Arctic Ocean module. Both the Arctic Ocean and Greenland Sea modules are coupled with a thermodynamic ice model and atmospheric models. Several model experiments have been conducted to adjust the model and to reproduce the auto-oscillatory behavior of the climate system. One of the major results of this work is the simulation of auto-oscillatory behavior of the Arctic Ocean---GIN Sea climate system. Periodical solutions obtained with seasonally varying forcing for scenarios with high and low interaction between the regions reproduce major anomalies in the ocean thermohaline structure, sea ice volume, and fresh water fluxes attributed to ACCR and CCR regimes. According to the simulation results, the characteristic time scale of the Arctic Ocean---GIN Sea system variability reproduced in the model is about 10--15 years. This outcome is consistent with theory of Proshutinsky and Johnson [1997] and shows that the Arctic Ocean---GIN Sea can be viewed as a unique auto-oscillating system.
    • Deciphering Okmok Volcano's restless years (2002-2005)

      Reyes, Celso Guillermo; McNutt, Stephen; West, Michael; Freymueller, Jeffrey; Larsen, Jessica (2015-08)
      Okmok Volcano is an active island-arc shield volcano located in the central Aleutian islands of Alaska. It is defined by a 10-km-diameter caldera that formed in two cataclysmic eruptions, the most recent being ~2050 years ago. Subsequent eruptions created several cinder cones within the caldera. The youngest of these, Cone A, was the active vent from 1815 through its 1997 eruption. On July 12 2008 Okmok erupted from new vents located northwest of Cone D. Between 2001 and 2004, geodetic measurements showed caldera inflation. These studies suggested that new magma might be entering the system. In 2002, a newly installed seismic network recorded quasi-periodic ("banded") seismic tremor signals occurring at the rate of two or more episodes per hour. This tremor was a near-continuous signal from the day the seismic network was installed. Although the volcano was not erupting, it was clearly in a state of unrest. This unrest garnered considerable attention because the volcano had erupted just six years prior. The seismic tremor potentially held insight as to whether the unrest was a remnant of the 1997 eruption, or whether it signaled a possible rejuvenation of activity and the potential for eruption. To determine the root cause and implications of this remarkable seismic tremor sequence, I created a catalog of over ~17,000 tremor events recorded between 2003 and mid-2005. Tremor patterns evolved on the scale of days, but remained the dominant seismic signal. In order to facilitate the analysis of several years of data I created a MATLAB toolbox, known as "The Waveform Suite". This toolbox made it feasible for me to work with several years of digital data and forego my introductory analyses that were based on paper "helicorder" records. I first attempted to locate the tremor using the relative amplitudes of the seismograms to determine where the tremor was being created. Candidate tremor locations were constrained to a few locations along a corridor between Cone A and the caldera center. I then determined theoretical ratios between a reference station and stations nearby the candidate sources. Results suggested that the signal originated in the shallow portion of the corridor connecting the surface of Cone A to the top of the central magma chamber. This study also suggested that the source migrated along this corridor. I integrated the tremor patterns with other studies and proposed that heat and pressure from continued injections of magma were responsible for maintaining an open venting system at Cone A. The tremor resulted from the boiling of a shallow hydrothermal system in the vicinity of Cone A and volatiles potentially coming from the magma itself. The tremor catalog demonstrates that the seismic signal waned during the study period suggesting that fewer fresh volatiles entered the system, which may have allowed the pathways connecting the magma and volatiles to the surface to close up. By the time new magma entered the system in 2006, this network of pathways was closed, forcing the volatiles to seek a new exit. In hindsight, the 2003-2005 period of varied and waning seismic tremor, and the inferred end of massive open venting, may have been a pivotal era at Okmok that eventually led to the 2008 eruption.
    • The decision-making process of first year teachers

      Coskey, Isabeau S. (2015-08)
      Attrition rates among beginning teachers have long been a cause for concern. As a profession, teaching is one that is extremely difficult to enter into and find your footing. For most novice teachers the first year of teaching is typically the most difficult due to the challenges faced both in the classroom and personally. During the day a myriad of decisions fall on the shoulders of a teacher and long after students have gone most teachers are continuing to make decisions about the classroom. This project examines the major areas where decisions are being made, charts the decision-making process first year teachers employ, and presents an electronic guidebook that can be used by individuals transitioning from a pre-service program into their first year of teaching.
    • Decline curve analysis and enhanced shale oil recovery based on Eagle Ford Shale data

      Delaihdem, Dieudonne K.; Dandekar, Abhijit; Ahmadi, Mohabbat; Hanks, Catherine (2013-12)
      Transient and fracture dominated flow regimes in tight permeability shale reservoirs with hydraulically fractured horizontal wells impose many unconventional challenges. These include execution of appropriate shale decline curve analysis and the optimization of hydrocarbons recovery. Additionally, short production profiles available are inadequate for accurate production decline analysis. This research assessed the effectiveness of Arps' decline curve analysis and recently established methods--power law exponential analysis, logistic growth analysis, Duong's method and the author's approach--to predict future production of horizontal wells in the Eagle Ford Shale. Simulation models investigated history matching, enhanced shale oil recovery, and drainage area beyond stimulated reservoir volume. Traditional Arps' hyperbolic method sufficiently analyzed past production rates, but inaccurately forecasted cumulative productions. The recent decline models show slight variations in their past performance evaluations and forecasting future production trends. The technique proposed and used in this work enhanced the successful application of Arps' hyperbolic decline from 32.5% to 80%. Simulation results indicate 4.0% primary oil recovery factor and 5.8% enhanced shale oil recovery factor using CO��� miscible injection. Based on pressure observed outside of the stimulated reservoir volume, limited to the range of data used in this study, drainage area outside stimulated reservoir volume is not significant.
    • Decomposition and adsorption of peptides in Alaskan coastal marine sediments

      Luo, Honghong (1994)
      In organic-rich coastal sediments, hydrolyzable amino acids make up a substantial fraction of the sedimentary content of organic nitrogen. How this organic nitrogen resists decomposition and is preserved in sediments is poorly understood. In order to investigate the factors controlling mineralization and preservation of hydrolyzable amino acids, decomposition and adsorption of peptides were studied in suboxic and anoxic pore water and sediments from Resurrection Bay (RB) and Skan Bay (SB), Alaska. Five tritium-labeled peptides, basic di-lysine, acidic di-glutamic acid, and neutral di-alanine, tri-alanine and hexa-alanine, were used as tracers. In filtered pore water, the hydrolysis rates were usually low. The exception was that the initial enzymatic hydrolysis of di-alanine and di-glutamic acid was rapid in SB pore water. The hydrolysis rates of both peptides increased with concentration. In sediments, hydrolysis was found to be the rate-limiting step of peptide decomposition. Alanyl and glutamyl peptides were hydrolyzed faster than lysyl peptide, and the hydrolysis rates among alanyl peptides decreased with increasing molecular weight. Peptide hydrolysis was affected more by molecular structure than by oxic or anoxic conditions. Adsorption of lysyl peptide to sediments was greater than that of other peptides. Basicity enhanced peptide adsorption more than increased molecular weight. Sedimentary organic matter was mainly responsible for peptide adsorption. The different patterns of peptide adsorption in RB and SB sediments were related to the greater total organic carbon concentration in SB sediment. Some of the peptide adsorption was irreversible. Adsorbed peptides were more resistant to biological decomposition than dissolved peptides. Adsorption may be an important step in the process of peptide preservation in sediments, and thus the preservation of sediment organic matter during early diagenesis.
    • Decomposition of dissolved organic matter in Arctic and boreal streams

      Mutschlecner, Audrey; Harms, Tamara; Jones, Jeremy; Guerard, Jennifer (2017-05)
      Arctic and boreal rivers connect terrestrial, oceanic, and atmospheric carbon (C) pools by transporting and processing dissolved organic matter (DOM). DOM composition influences its susceptibility to decomposition (biolability), which in turn determines whether the associated C is respired, stored, or exported. High-latitude ecosystems are changing rapidly due to processes such as permafrost thaw, shifts in vegetative communities, and increasing discharge, and each of these processes can influence the composition of DOM reaching rivers. The eventual fate of riverine DOM, whether it is mineralized or exported, shifts the balance of global C pools. Therefore, to understand how changes to high-latitude ecosystems influence the global C cycle, we must be able to connect patterns in DOM composition to its biolability and subsequent fate within the C cycle. The objectives of this study were to describe spatial and temporal patterns in DOM composition and biolability, and to determine links between the composition and biolability of DOM. I sampled DOM from streams along an Arctic-boreal gradient in interior Alaska throughout the year. I measured DOM biolability and nutrient limitation of decomposition in laboratory incubations and characterized DOM composition using optical properties and chemical analysis. I found that temporal patterns in DOM composition corresponded to seasonal trends in the hydrology of high-latitude catchments, linking DOM source to shallow, organic-rich flowpaths in spring and deeper groundwater flows in winter. Biolability was low, indicating that the majority of riverine DOM is recalcitrant to biological decomposition. I observed increased biolability in response to phosphorus (P) addition, particularly during spring, indicating that phosphorus limits DOM decomposition. To further examine the mechanisms driving C processing in streams, I also conducted a series of whole-stream experiments to compare the relative influence of molecular composition and nutrient content of DOM. I added leaf leachate to boreal streams and measured C retention, which represents both biological uptake and sorption. The leachates varied by molecular composition, due to differences in tissue chemistry of plant species, and in nutrient content, because the leaves were collected from plots with different fertilization regimes. Retention was greatest for leachates derived from trees that had been fertilized with P, indicating P-limitation of biological uptake of C or preferential sorption of P-containing organic molecules. Although leachates varied in molecular composition as determined by optical properties, these differences did not correspond to a difference in uptake rates by species. These patterns in DOM retention indicate that nutrient content is a greater constraint on C uptake than molecular composition. Together, the two studies suggest that export is the primary fate of ambient DOM in high-latitude streams, but that C processing is highly sensitive to inputs of bioavailable DOM. The coupling between the P and C cycles observed in both studies highlights the potential for nutrient availability to constrain or promote CO₂ emissions from C-rich, high-latitude catchments.
    • Decompression induced crystallization of basaltic andesite magma: constraints on the eruption of Arenal volcano, Costa Rica

      Szramek, Lindsay Ann (2004-08)
      Continuously active since 1968, Arenal Volcano in Costa Rica has undergone various eruption styles. The deposited magmas, whereas geochemically similar, show a complex history of magma chamber processes, which are not fully understood. The intricate mixing histories of the phenocrysts and lack of oxide pairs have made determination of the volatile content and oxygen fugacity difficult by conventional methods. Phase equilibria experiments were carried out between 200-50 MPa and 940-1075°C in a TZM furnace at fO₂ of NNO and water saturation. Time in the furnace varied from 7 to 30 hours at constant pressure and temperature. Examination of the natural and experimental phase assemblages constrained the probable pre-eruptive conditions for Arenal magmas to be 50-80 MPa and 950-1040°C. For decompression experiments, the sample was initially held at two conditions 200MPa and 950°C and 60MPa and 1050°C. The samples were then decompressed by 5-30 MPa pressure steps held for 20 seconds to 8 hours until 20 MPa was reached, approximating average decompression rates of 0.25, 0.025, and 0.0013 MPa/s. Textures formed in the experiments and seen in the natural samples constrain the probable ascent rate of the Arenal magma to 0.05 mls. The ascent rate increases as explosivity increases.
    • Deconstructing the western worldview: toward the repatriation and indigenization of wellness

      Rahm, Jacqueline Marie; Koskey, Michael; Lewis, Jordan; John, Theresa; Leonard, Beth (2014-12)
      As Indigenous peoples and scholars advance Native histories, cultures, and languages, there is a critical need to support these efforts by deconstructing the western worldview in a concerted effort to learn from indigenous knowledge and ways of knowing for humanity's future wellbeing. Toward that imperative, this research brings together and examines pieces of the western story as they intersect with Indigenous peoples of the lands that now comprise the United States of America. Through indigenous frameworks and methodologies, it explores a forgotten epistemology of the pre-Socratic and Pythagorean Archaic and Classical Greek eras that is far more similar to indigenous worldviews than it is to the western paradigm today. It traces how the West left behind this timeless wisdom for the "new learning" and the European colonial settlers arrived in the old "New World" with a fragmented, materialistic, and dualistic worldview that was the antithesis to those of Indigenous peoples. An imbalanced and privileged worldview not only justified an unacknowledged genocide in world history, it is characteristic of a psycho-spiritual disease that plays out across our global society. This dissertation suggests that the healing of the western mind rests with shifting the dominant paradigm toward a fundamental axiom of holism found within the life-ways of American Indigenous peoples and also buried within the West's own ancestry, particularly within a misunderstood ancient Greek tradition at the cornerstone of the western world.
    • Deeper than blood

      Brownlee, Yavanna M. (2006-05)
      The poems in 'Deeper than Blood' present a mosaic of geographic location, intensely personal events, friends, family, and observations tied together by a feminine persona who is not afraid to explore her life and the lives of those around her. Section I reaches into the depths of the persona's sexuality and fears of dying, revealing a shadowed and troubled side of the persona. Section II mixes views of the persona from an outside and an inside perspective, looking at how others view her as she stands naked before them and how she observes herself through her past and her memories of people and places. Section III searches through childhood memories, family, and friends for an answer to what comes next in life and after life is over. Throughout the intricate life story presented by these poems, a peaceful mood prevails. By setting the mood as one of calm, the speaker presents the rollercoaster ride of life. Instead of seeming like she is on a wild ride, the persona flows like a boat over the swells of an ocean on a calm day, allowing the reader to take in all the eccentricities of life with the calm that pervades the poetry.
    • Deformation Of Alaskan Volcanoes Measured Using Sar Interferometry And Gps

      Mann, Doerte; Freymueller, Jeffrey (2002)
      Geodetic measurements using the Global Positioning System (GPS) and synthetic aperture radar interferometry (InSAR) show deformation of Okmok, Westdahl, and Fisher volcanoes in the Alaska-Aleutian arc. This thesis shows the variety of deformation signals observed, presents models for the observations, and interprets them in terms of underlying processes. InSAR data show deflation of Okmok caldera during its last eruption in 1997, preceded and followed by inflation of smaller magnitude. Modeling shows that the main deformation source, interpreted as a central magma reservoir, is located at 2.5 to 5.0 km depth beneath the approximate center of the caldera, and 5 km away from the active vent. Mass balance calculations and comparison with the long-term eruptive frequency indicate that Okmok may be supplied with magma continuously from a deep source. GPS measurements between 1998 and 2001 show inflation of Westdahl volcano, with a source located about 7 km beneath the summit. The combined subsurface volume increase measured during the GPS and an earlier InSAR observation period [Lu et al., 2000a] accounts for at least 15% more than the volume erupted from Westdahl in 1991--92, suggesting that an eruption of that size could occur at any time. Neighboring Fisher caldera shows subsidence and contraction across the caldera center that is not related to any eruptive activity. The main mechanisms to explain this deformation are degassing and contractional cooling of a shallow magma body, or depressurization of Fisher's hydrothermal system, possibly triggered by an earthquake in the vicinity of the caldera in 1999. A systematic coherence analysis of SAR interferograms documents the cooling history of the 1997 Okmok lava flow. The flow is incoherent directly after emplacement, but coherence increases as more time has passed since the eruption, and also the shorter the period spanned by the interferogram. Coherence is regained three years after the eruption. This corresponds to the time when the 20 m thick flow has solidified, indicating that flow mobility is the dominant factor degrading coherence on young lava flows. Based on these results, InSAR coherence analysis can be used to derive the minimum thickness of a lava flow.
    • Deg Xinag Oral Traditions: Reconnecting Indigenous Language And Education Through Traditional Narratives

      Leonard, Beth R.; Barnhardt, Raymond J. (2007)
      "Deg Xinag," literally 'local language' is the westernmost of the Athabascan 1 languages. The language area is also referred to as "Deg Hit'an," literally, 'local people'. The Deg Hit'an are often referred to inappropriately in anthropological and linguistic literature as "Ingalik," a Yup'ik word meaning 'lice-infested'. There are currently three villages in western, interior Alaska where this language is spoken and about 20 fluent speakers of this language remaining. As I proceeded through my graduate research I came to understand the significance of indigenous language revitalization in relation to its potential contributions to indigenous and cross-cultural education. These contributions include establishing and enhancing self-identity and self-esteem for indigenous students, as well as contributing in-depth knowledge about local environments thereby enhancing place-based and funds of knowledge educational models (Bamhardt and Kawagley 2005: 15; Moll 1990). This dissertation presents an interdisciplinary analysis of a complex, cosmological Deg Hit'an narrative entitled "Nil oqay Ni'idaxin" or "The Man and Wife" told in the Deg Xinag language by the late Belle Deacon of Grayling Alaska (1987b). Deacon also told her own English version and titled this "The Old Man Who Came Down From Above the Second Layer of the World" (1987c). Underlying structures and meanings used in the contexts of Deg Xinag oral traditions are currently lacking in most published materials for this language, making it difficult to learn and consequently, develop culturally-appropriate language learning programs and curriculum. This analysis encompasses the fields of Alaska Native/indigenous studies, anthropology, and folklore/oral traditions using philosophical and pedagogical frameworks established by indigenous scholars including Gregory Cajete, Oscar Kawagley, and Greg Sarris. 1The term "Athabascan" has varied spellings within the literature, including "Athapaskan" and "Athabaskan." In 1997, Tanana Chiefs Conference (TCC), the interior Alaska tribal consortium adopted a resolution stating their tribes' preference of the spelling using "b" and "c."
    • Delayed effects of oil exposure on fish

      Hicken, Corinne E.; Stekoll, Michael S.; Incardona, John P.; Smoker, William W.; Rice, Stanley D. (2012-05)
      Polycyclic aromatic hydrocarbons (PAHs) are continuously added to aqueous environments through point source and non-point source pollution and can cause deleterious effects on exposed fish populations. Historically, studies have shown that acute PAH exposure causes only short-term effects in adult fish which were resolved when the exposure ended. Chronic exposure to PAHs, however -- even at the less susceptible juvenile and adult stages -- can cause a host of effects including lesions, lower body length and weight, and reduced swimming ability. More recently studies of embryonic fish have demonstrated that much lower PAH concentrations can cause lethal and sub-lethal effects on those embryos and can cause delayed effects on the fish that are not seen until adulthood. This study used zebrafish (Danio rerio) to examine the effects of 48-hour weathered crude oil exposure on both the embryonic fish exposed and the adult fish exposed as embryos but raised in clean water. Oil exposed embryos had increased mortality, pericardial edema, intracranial hemorrhage, and higher cytochrome P4501A (CYP1A) activity. Adult fish exposed as embryos had decreased critical swim speed and rounder hearts than the control fish. These effects may culminate in decreased fitness of the exposed fish population.
    • Delineating drawdown lakes and Salix alaxensis in interior Alaska using Landsat TM and multitemporal SAR imagery

      Fogde, Julieanne L. (2001-08)
      This study evaluates the effectiveness of multitemporal Synthetic Aperture Radar (SAR) data and Landsat ETM+ imagery to delineate: 1) The locations of drawdown lakes within the Iditarod River drainage. 2) The locations of Salix alaxensis along the Innoko River. Both elements are related in that they constitute critical wildlife habitat, and their occurrence is largely due to seasonal flooding. Multitemporal, georeferenced Radarsat SAR imagery was used to classify lakes as either drawdown or non-drawdown. This technique yielded an overall classification accuracy of 78%, proving that multitemporal, georeferenced SAR is a good tool for delineating drawdown lakes. Landsat ETM+ imagery was used to develop three criteria (proximity to turbid water, broadleaf vegetation, and sandbars) to delineate S. alaxensis. Areas that met all three of the criteria had an estimated producer's accuracy of 4% for S. alaxensis, indicating that this technique is ineffective at delineating S. alaxensis.
    • Delineation of Yakutat foreland coho salmon (Oncorhynchus kisutch) stocks using otolith chemistry

      Jones, Matthew A. (2007-08)
      Otolith chemistry was utilized to identify suspected coho salmon sub-stock populations on the Yakutat Foreland of southeast Alaska. In order to demonstrate that otolith chemistry might be successful in sub-stock differentiation, water samples were collected from four adjacent river systems and chemically segregated by collection site. Juvenile coho salmon and adult coho salmon were collected from the same four river systems and were subsequently analyzed for levels of select Ba, Ca, Mg, and Sr isotopes in all otolith edge and core regions using laser ablation-inductively coupled plasma-mass spectrometry. Otolith Sr⁸⁷/Ca⁴⁸ and Mg²⁴/Ca⁴⁸ were used to segregate collection sites, identify sub-stock populations, and infer straying rates for coho salmon on the Yakutat Foreland. Juvenile core and edge otolith chemistry returned moderate to high classification accuracy for three out of four collection' sites (60%-92%) in statistical discriminant analyses. Adult core otolith chemistry could not segregate samples according to collection site in three out of four sites (7%-50%). Yakutat Foreland otolith chemistry analysis results allowed for (1) differentiation of adjacent freshwater systems, (2) a significant amount of coho salmon stock delineation, and (3) a higher suggested rate of straying from natal sites than coho salmon in other locations.
    • Demographic and social consequences of oil and gas development in Siberia, 1960s-early 1990s

      Logunov, Eugene V.; Black, Lydia (1999)
      The main goal of this thesis is to study the demographic and social consequences of rapid oil and gas development in Siberia, to show the experience of solving or failing to solve of wide range of social and cultural issues, and to sum up the results of both the economic impact on the social-cultural processes and the social impact on industrial production. In three decades, the number of new settlers in the Tyumen province was no less than 2,000,000 people. Such a pace of settling previously uninhabited territories with extreme environmental conditions had never occurred before in world practice. This explosive growth of population, dominated by young single males, has resulted in a distorted demographic structure which is hardly capable of reproduction. The birth rate declined sharply, whereas the death rate grew because of accidents, diseases, alcoholism, narcotics addiction, etc. The situation has been aggravated by complete neglect of the development of a social infrastructure. Nearly half of population live in conditions conducive to the degradation of family, morals, health and cultural values. Oil and gas development had numerous negative effects on indigenous peoples of the North. Destruction of the environment has undermined the natural base and functioning of their traditional occupations. They were unable to adapt to the new kinds of economic activity, and social and physical problems have become aggravated. There has been growth of the disease rate and of alcoholism. The descent into poverty has been rapid, and they find themselves under threat of ethnic degeneration and extinction. It was the initial orientation toward creation of a new but permanent population, the politics of "development through settlement," that proved to be one of the main causes of the deep crisis which has affected the region. The formation of a large, heterogeneous, unstable population, taken together with all its problems, accompanied by the inability to create a favorable social environment, mismanagement of manpower resources and an inadequate social infrastructure, have become the leading causes of production failures in the oil and gas industry.
    • Demographic components of philopatry and nest-site fidelity of Pacific black brant

      Lindberg, Mark Steven; Sedinger, James S. (1996)
      I investigated demographic components of nest-site fidelity and philopatry of Pacific black brant (Branta bernicla nigricans). My analyses included data I collected during summer 1990-1993, and also incorporated data obtained between 1986-1989. My studies of nest-site fidelity were limited to the Tutakoke River colony, Yukon-Kuskokwim River Delta, Alaska. Studies of philopatry and dispersal among colonies included observations at 7 breeding colonies of brant marked with tarsal tags (n = 20,147). I observed strong evidence that philopatry of brant was female biased. Probability of breeding philopatry, which was estimated with multi-state modeling techniques, was high (>0.9) and dispersal of adults among breeding colonies was rare. I developed an ad hoc estimator for natal philopatry that was unbiased by a confounding of homing, survival, and detection probabilities. Probability of natal philopatry for females was both age and density dependent. The density-dependent decline in natal philopatry may result from increased rate of permanent nonbreeding or increased probability of dispersal. Observed probability of natal philopatry for males was approximately equivalent to the relative size of their natal colony, suggesting that males pair at random with females from other colonies. Gene flow among populations of brant is largely male mediated, and I predict populations of brant will exhibit distinct mitochondrial DNAs if populations have been reproductively isolated for an adequate period of time. Probability of fidelity to previous nest sites for adults was high (>0.7). Probability of nest-site fidelity was affected by previous nesting success, age, and availability of nest sites. Phenology of nesting, nest-site selection, and clutch size of brant was affected by spring snowmelt. Dispersal of brant from traditional nest sites in years with late springs may represent a tradeoff between site fidelity and timing of nest initiation. Movement of young females from natal nest sites was a mechanism for colony expansion. I observed little evidence that site fidelity was advantageous, and concluded that quality of individual bird, environmental conditions, and demographic status may be more important determinants of breeding performance.
    • Demographics and telomere dynamics of hibernating Arctic ground squirrels (Urocitellus parryii)

      Wilbur, Sara M.; Williams, Cory; Barnes, Brian; Kitaysky, Alexander; Podlutsky, Andrej (2019-08)
      Aging is the complex process by which an organism loses functional integrity over time. Several measurable contributors to or components of the aging process have been identified, one of which is telomere length. Telomeres are the repetitive, nucleoprotein structures located at the ends of linear chromosomes. In general, telomeres shorten over time and when exposed to damaging reactive oxygen species (highly unstable molecules released as a byproduct of cellular respiration). Organisms that have unique physiologies, in addition to those that live longer than otherwise predicted, have recently inspired comparative telomere dynamics studies. Hibernating mammals, which exhibit both heterothermy and long lifespan, have served as models for these new investigations into telomere length dynamics. Several studies over the past decade have measured the effects of torpor (the period of hibernation characterized by extremely low metabolic rates and body temperature) and arousal (from torpor; a brief return to euthermic or high levels of body temperature) on telomere length change in hibernators. This body of work demonstrated that telomere length is preserved across hibernation seasons (likely due to the majority of hibernation spent in torpor), and any telomere shortening that does occur is correlated with arousal frequency. However, all telomere-hibernator studies to date have focused on hibernators from temperate regions and on DNA from a peripheral tissue (either buccal cells or skin tissue). Arctic ground squirrels, the northernmost hibernator and ground squirrel species, are appropriate model candidates to expand the diversity of research in hibernator telomere dynamics, as they remain thermogenic during torpor to defend a viable body temperature against subfreezing ambient temperatures. Maintaining high metabolic rates to support thermogenesis throughout torpor--and over arousals--may lead to increased telomere attrition in this species compared to other hibernators adapted to milder climates. This thesis begins with basic arctic ground squirrel demographics from two well-studied populations in Arctic Alaska. I report that (female) arctic ground squirrels appear to be similarly long-lived as other hibernating species, and that sex-specific differences in lifespan may be driven by behavioral differences between males and females. I also present results from a study comparable to those performed in temperate hibernators: I measured telomere length in freeliving arctic ground squirrels across hibernation and age groups and found that, as in temperate hibernators, telomere length (in ear tissue) is maintained across hibernation. Expanding upon single-tissue telomere studies, I also measured telomere length in brown adipose tissue (the tissue responsible for non-shivering thermogenesis for heat generation during torpor and at arousal initiation), liver, and heart in captive arctic ground squirrels and found that telomeres shortened dramatically in brown adipose tissue only. Overall, this work identifies arctic ground squirrels as capable of maintaining cellular integrity (as measured via telomere length) and of reaching surprising longevity in the face of extreme environmental conditions.