• Glacier contribution to lowland streamflow: a multi-year, geochemical hydrograph separation study in sub-Arctic Alaska

      Gatesman, Tiffany A.; Trainor, Thomas P.; Liljedahl, Anna K.; Douglas, Thomas A. (2017-12)
      Glacier melt affects the geochemical composition of rivers; however, quantifying the glacier contribution to subarctic watershed-scale runoff has attracted limited attention. To estimate glacier contribution, we conducted a 6-year geochemical hydrograph separation study in a geologically heterogeneous glacierized watershed in Interior Alaska. Water samples were collected daily from Jarvis Creek during late April through September. Source waters were collected synoptically each year from rain, snow, baseflow (winter discharge), and the glacier terminus discharge. All samples were analyzed for stable water isotopes and dissolved ion concentrations. Stream surface water samples have large seasonal and inter-annual geochemical variation, however, source waters show distinct chemical signatures allowing the application of a geochemical hydrograph separation model to quantify relative source contribution to lowland streamflow. Considerable inter-annual differences within source water signatures emphasize the importance in informing the model with source waters sampled for each season. We estimated a seasonal average of 35% (20 to 44%) glacier terminus discharge contribution with a daily range of 2 (May) to 80% (September). If glacier contribution was to cease completely, stream discharge would be reduced by 48% and 22% in low and high rainfall summers, respectively. Combined with the documented shrinkage of glaciers, our findings emphasizes the need for further research on glacial wastage effect on subarctic watersheds.
    • Global and local contributors to the historical and projected regional climate change on the North Slope of Alaska

      Cai, Lei; Alexeev, Vladimir A.; Arp, Christopher D.; Bhatt, Uma S.; Liljedahl, Anna K. (2018-05)
      This thesis includes four studies that explore and compare the impacts of four contributing factors resulting in regional climate change on the North Slope of Alaska based on a numerical simulation approach. These four contributing factors include global warming due to changes in radiative forcing, sea ice decline, earlier Arctic lake ice-off, and atmospheric circulation change over the Arctic. A set of dynamically downscaled regional climate products has been developed for the North Slope of Alaska over the period from 1950 up to 2100. A fine grid spacing (10 km) is employed to develop products that resolve detailed mesoscale features in the temperature and precipitation fields on the North Slope of Alaska. Processes resolved include the effects of topography on regional climate and extreme precipitation events. The Representative Concentration Pathway (RCP) 4.5 scenario projects lower rates of precipitation and temperature increase than RCP8.5 compared to the historical product. The increases of precipitation and temperature trends in the RCP8.5 projection are higher in fall and winter compared to the historical product and the RCP4.5 projection. The impacts of sea ice decline are addressed by conducting sensitivity experiments employing both an atmospheric model and a permafrost model. The sea ice decline impacts are most pronounced in late fall and early winter. The near surface atmospheric warming in late spring and early summer due to sea ice decline are projected to be stronger in the 21st century. Such a warming effect also reduces the total cloud cover on the North Slope of Alaska in summer by destabilizing the atmospheric boundary layer. The sea ice decline warms the atmosphere and the permafrost on the North Slope of Alaska less strongly than the global warming does, while it primarily results in higher seasonal variability of the positive temperature trend that is bigger in late fall and early winter than in other seasons. The ongoing and projected earlier melt of the Arctic lake ice also contributes to regional climate change on the Northern coast of Alaska, though only on a local and seasonal scale. Heat and moisture released from the opened lake surface primarily propagate downwind of the lakes. The impacts of the earlier lake ice-off on both the atmosphere and the permafrost underneath are comparable to those of the sea ice decline in late spring and early summer, while they are roughly six times weaker than those of sea ice decline in late fall and early winter. The permafrost warming resulted from the earlier lake ice-off is speculated to be stronger with more snowfall expected in the 21st century, while the overall atmospheric warming of global origin is speculated to continue growing. Two major Arctic summer-time climatic variability patterns, the Arctic Oscillation (AO) and the Arctic Dipole (AD), are evaluated in 12 global climate models in Coupled Model Intercomparison Program Phase 5 (CMIP5). A combined metric ranking approach ranks the models by the Pattern Correlation Coefficients (PCCs) and explained variances calculated from the model-produced summer AO and AD over the historical period. Higher-ranked models more consistently project a positive trend of the summer AO index and a negative trend of summer AD index in their RCP8.5 projections. Such long-term trends of large-scale climate patterns will inhibit the increase in air temperature while favoring the increase in precipitation on the North Slope of Alaska. In summary, this thesis bridges the gaps by quantifying the relative importance of multiple contributing factors to the regional climate change on the North Slope of Alaska. Global warming is the leading contributing factor, while other factors primarily contribute to the spatial and temporal asymmetries of the regional climate change. The results of this thesis lead to a better understanding of the physical mechanisms behind the climatic impacts to the hydrological and ecological changes of the North Slope of Alaska that have been become more severe and more frequent. They, together with the developed downscaling data products, serve as the climatic background information in such fields of study.
    • Glucose transporter-4 in mononuclear cells of sled dogs

      Schnurr, Theresia Maria; Dunlap, Kriya; Reynolds, Arleigh; Duffy, Lawrence (2013-12)
      The glucose transporter-4 (GLUT4) is the glucose transporter most responsive to insulin and has been thought to exist predominately in muscle and adipose cells. There have been findings that the glucose transporter-4 isoform is also expressed in subpopulations of white blood cells such as mononuclear cells. This study was designed to validate the presence of GLUT4 in subpopulations of white blood cells of sled dogs and to investigate whether changes in GLUT4 protein levels in white blood cells might be associated with age and stage of conditioning, as it has been reported in muscle. Our initial results have shown the ability to detect GLUT4 in white blood cells of sled dogs with a non-significant trend observed in GLUT4 levels based on age. Subsequent testing showed a statistically significant difference in GLUT4 levels in mononuclear cells based on conditioning in sled dogs. Using sled dogs as a model should enhance our understanding of GLUT4 expression on the surface of subpopulations of white blood cells. The presented projects are groundbreaking for the development of an easy, reliable and minimally invasive diagnostic tool for insulin sensitivity. Our next step in this research is to examine whether the conditioning response of GLUT4 is also observed in human mononuclear cells.
    • Glucose transporter-4 on peripheral blood mononuclear cells in conditioned vs. sedentary college students

      Sticka, Kendra D.; Knall, Cindy M.; Dunlap, Kriya L.; Krebs, Jocelyn E.; Duffy, Lawrence K. (2016-05)
      Glucose transporter 4 (GLUT-4) plays a key role in the pathophysiology of type 2 diabetes. GLUT-4 is upregulated in response to exercise, enhancing cellular glucose transport in skeletal muscle tissue. This mechanism appears to remain intact in individuals with insulin resistance. There is evidence of increased translocation of GLUT-4 and increased transcription of SLC2A, the gene which codes for GLUT-4. Details of the mechanism are poorly understood and are challenging to study due to the invasive nature of muscle biopsy. Peripheral blood mononuclear cells (PBMC) have documented insulin-sensitive GLUT-4 activity and may serve as a proxy tissue for studying skeletal muscle GLUT-4. The purpose of this study was to investigate whether GLUT-4 on PBMC is affected by exercise in a similar fashion to myocytes. Additionally, correlations between PBMC GLUT-4 and common indicators of insulin resistance and dietary patterns were examined. The results show a trend toward higher PBMC GLUT-4 levels in conditioned athletes than in their sedentary counterparts, similar to what has been documented in myocytes. Females were shown to have higher PBMC GLUT-4 levels than males. SLC2A4 mRNA analysis demonstrates a difference in mean gene expression between the conditioned and sedentary participants. Correlations between levels of PBMC GLUT-4 and hemoglobin A1c (HbA1c), glucose, insulin, HOMA-IR, BMI, or body fat were not detected. Relationships between specific nutrients and GLUT-4 were also not detected. This study provides evidence to support exploration of PBMC as a proxy tissue for studying GLUT-4 response to exercise or other non-insulin factors. This could provide important treatment avenues for individuals with insulin resistance and type 2 diabetes.
    • Glycerol Metabolism And Other Biochemical Features Associated With Overwintering In The Adult Insect Pterostichus Brevicornis (Carabidae)

      Arvey, William Dale; Miller, Keith; Irving, Laurence; Behrisch, Hans W.; Smith, Ronald; Williams, Darrell (1974)
    • Go artificial intelligence: a scalable evolutionary approach

      Fraser, Warren Duncan; Hay, Brian; Lawlor, Orion; Genetti, Jon (2016-05)
      This report covers scaling neural networks for training Go artificial intelligence. The Go board is broken up into subsections, allowing for each subsection to be calculated independently, and then factored into an overall board evaluation. This modular approach allows for subsection networks to be translated to larger board evaluations, retaining knowledge gained. The methodology covered shows promise for significant reduction in training times required for unsupervised training of Go AI. A brief history of artificial neural networks and an overview of Go and the specific rules that were used in this project are presented. Experiment design and results are presented, showing a promising proof of concept for reducing training time required for evolutionary Go AI. The codebase for the project is Apache 2.0 licensed and is available on GitHub.
    • Gold and base metal mineralization of the Dolphin intrusion-related gold deposit, Fairbanks Mining District, Alaska

      Raymond, Luke M.; Newberry, Rainer; Larsen, Jessica; Keskinen, Mary (2018-08)
      The Dolphin deposit is an intrusion-related gold deposit (IRGD) located approximately 30 km north of Fairbanks, Alaska. The deposit is in--and adjacent to--a composite mid-Cretaceous pluton intruding amphibolite facies metamorphic rocks. An NI43-101 compliant gold resource estimation for the deposit (utilizing a 0.3 g/t cut-off grade) is 61.5 Million tonnes (Mt) at 0.69 g/t indicated (1.36 million oz = Moz) and 71.5 Mt at 0.69 g/t inferred (1.58 Moz). Due to extensive hydrothermal alteration of the intrusion, identifying rock types in hand sample and thin section, as well as by standard compositional techniques (e.g., SiO₂ vs. Na₂O + K₂O), has proven problematic. By plotting wt % TiO₂ vs. P₂O5 obtained from XRF analyses and four-acid digest ICP-MS data, two distinct population clusters appear. By comparison with least-altered intrusive rock analyses from the Fairbanks district, the igneous units were originally granite and tonalite. Because there is no gradational transition through an intermediate granodiorite unit, they were most likely derived from two separate magmatic bodies rather than in-situ fractionation from a single parent. Tonalite is concentrated along the northern and eastern margins of the stock with granite composing the rest of the body. Tonalite xenoliths in granite and granite dikes intruding tonalite prove that tonalite is the older unit. Investigations of hydrothermal alteration (based on chemical analyses, X-ray diffraction, and thin section examination) show albitic and advanced argillic (kaolinite-quartz) alteration are the dominant styles with sericite common throughout. Advanced argillic is a low temperature (<300°C) low pH alteration style that has not been previously identified in intrusion related gold deposits (IRGDs) in interior Alaska. Albitic alteration probably resulted from higher temperature, more neutral pH fluids. Gold investigations show that gold occurs as coarse-grained Au°, aurostibite, and maldonite in quartz + sulfide veins; fine-grained Au° in the oxide zone; and in many forms in disseminated sulfide. These forms include Au° inclusions in pyrite and arsenopyrite; solid-solution Au within compositionally zoned arsenopyrite; and as Au° nanoparticles in pyrite and probably arsenopyrite. Using UAF's JEOL JXA-8530F microprobe, I found that solid-solution gold occurs only in arsenopyrite with strong compositional zoning. Such grains are always small (< 0.2 mm) and commonly have low As cores; gold- bearing mantles with moderate % As; and higher As rims. In contrast, compositionally homogenous arsenopyrite does not contain detectable solid-solution gold. Pyrite is commonly arsenian and carries dissolved gold (if any) near detection limits. Gold mineralization has not been tied to any one lithology or alteration style; however, gold does seem to correlate with abrupt changes in alteration, especially between sericite + albite and kaolinite + sericite alteration. Gold-bearing, zoned arsenopyrite is predominantly associated with advanced argillic alteration and apparently represents a rapid growth, disequilibrium phenomenon.
    • Gold in sea water

      Wood, Elwyn Devere (1971-05)
    • The governance of wolves in transboundary regions: a triquetrous study of ephemeral agreements transcending sub-national and national boundaries

      Parks, Brett M.; Jolie, Julie Lurman; Kohler, Pia; Juday, Glenn (2013-12)
      Contradictory management objectives in adjacent jurisdictions can affect transboundary wolves and their associated socio-ecological systems. Elite interviews and case study methodology were used in this thesis to explore three transboundary wolf management agreements, their effectiveness, and their impacts on wolves, ecosystems and stakeholders. Separate agreements between the State of Alaska and: Yukon-Charley Rivers National Preserve, and Denali National Park and Preserve, and an agreement between Italy and Switzerland show that despite a diversity of socio-ecological contexts, approaches, and hierarchical level of actors, transboundary wolf agreements are prone to ephemerality. The ephemerality of these agreements appears to be due primarily to institutional path dependency, and to political tension between management entities. The impacts of these agreements and their cessation, on socio-ecological systems are limited by the agreements' limited scopes. The agreements do however figure incrementally into larger trends, especially including changes in rural and urban identities, and in large carnivore management discourse. I argue that a diversity of wolf management approaches across a landscape, and the inherent conflict between management entities preserves adaptive capacity by preventing one size fits all prescriptions based on incomplete knowledge. Assuming no acute state of emergency, incremental rather than transformational change is more equitable to diverse stakeholders; allowing public perception, policy, and scientific knowledge to shift concurrently. The cases also suggest that facilitating trans-entity conversation and coordination at multiple levels would support understanding, and increase the prevalence of creative agreements contributing to amenable, incremental change. Landscape Conservation Cooperatives are put forth as a potential platform or template for this facilitation.
    • GPS based tectonic analysis of the Aleutian arc and Bering plate

      Cross, Ryan S. (2007-05)
      Global Positioning System (GPS) measurements enable a quantitative analysis of tectonic deformation in the Aleutian Islands, Alaska. We construct elastic deformation models to calculate coupling on the subduction interface and the interseismic strain recorded at stations throughout the Aleutian arc. Using a grid-search inversion procedure, we determine an arc translation velocity for each region of the arc, revealing south to southwest motions of 4 to 14 mm/yr. In the central Aleutians, there is good agreement between areas of high coupling and areas of large moment release in major seismogenic events. We have combined modeling results from the Aleutians with direct measurements of station velocities of sites in western Alaska and the Bering Sea islands to test the hypothesis of a clockwise rotating Bering plate. The Bering Sea area including the Aleutian arc and western Alaska is fit by an Euler pole located at 42.5°N, 121.3°E with an angular velocity of 6.0°/my, relative to stable North America. The Bering plate's eastern boundary appears to be related to left lateral faulting in interior Alaska as clockwise rotation of the plate results in south-southwest motion relative to the North American plate. The Bering plate's interaction with a counter-clockwise rotating southcentral Alaska block may be responsible for the decreased slip-rate on the western Denali fault. Thrust earthquake slip azimuths expose a systematic discrepancy with Pacific-Bering plate convergence direction. A simple model of slip partitioning and GPS measurements reveal that slip partitioning is present in the forearc throughout the arc but only develops in the back arc west of Amchitka Pass.
    • Grandparents, great parents: negotiating the role transition to custodial grandparent

      Burnett, Leanne Alaine (2012-05)
      An ever increasing number of grandparents in the United States are taking on the responsibility for providing primary care for their grandchildren. Focus group interviews conducted in two urban communities in Alaska were the basis of this study examining how grandparents negotiate the role transition as they become custodial grandparents. Role theory was used to inform the analysis of the data. The two major themes which emerged suggested these transitions were effected by role conflict and role timing. The grandparents participating in the study indicated that involvement in peer support groups helped them to more successfully negotiate this difficult role transition.
    • Gravity Wave Dynamics Near The Mesospause Over Poker Flat, Alaska (Spectra)

      Smith, Steven Andrews (1985)
      The characteristics of mesospheric gravity waves are studied using racket and radar soundings. The soundings are examined in two different approaches: identification of individual, nearly monochromatic waves, and through the statistical view offered by spectral analysis of wind velocity fluctuations. Simultaneous rocket and radar data has provided a complete overview of the saturation of a large-scale inertio-gravity wave near the summer mesopause. The 3m scale-size turbulence, to which the Poker Flat MST radar responds, was most intense in that phase of the wave that was most nearly unstable. However, the wave amplitude was not sufficient to produce instabilities by itself. Other waves, identified in radar data from the winter mesophere, also lacked sufficient amplitude to become unstable yet were clearly saturated as shown by their lack of growth with height. A comparison of vertical wavenumber spectra, of high spatial resolution (300 m) radar measurements, with a gravity wave model proposed by Van Zandt demonstrates that gravity waves dominate the mesospheric wind spectrum. These spectra also show that the wave amplitudes are approximately 1/2 of the saturation threshold. These observations point towards wave superposition as the cause of the reduced saturation threshold. The mesospheric spectra agree in shape and amplitude with similar spectra obtained in the stratosphere and troposphere. It is concluded that small-scale gravity waves are saturated throughout the lower and middle atmospere. Observations of the growth of wave amplitudes with height as seen in frequency spectral studies are compatible with the conclusion that the small-scale waves are saturated since the vertical wavelength of the largest saturating wave increases with height. Waves with scales greater than the largest saturated wave are at less than saturation amplitudes and do grow with height.
    • Grief counseling for adult pet loss: a primer for mental health professionals

      Sherman, Dawne G.; Gifford, Valerie M.; Hense-Nelson, Brenda J.; McMorrow, Samantha G. (2017-05)
      Grief counseling receives minimal attention in mental health training programs. Many mental health professionals are unprepared to support adult clients with pet loss and the associated bereavement process. Pets fill many vital roles in the lives of adults and the loss of a pet can be a profound experience. Adults sometimes develop intense attachment bonds with pets, and the quality of the human-pet attachment may influence the grief resolution process. Bereaved individuals may experience complicated grief reactions, including co-occurring mental health disorders. Understanding key clinical issues associated with pet loss can both help clinicians provide appropriate client support and facilitate positive treatment outcomes. As an outcome to this research, an educational webinar highlighting key findings gained from the literature review has been developed to assist clinicians with adults whose presenting concerns relate to pet loss.
    • Ground penetrating radar forward and backward modeling for layered snow

      Wang, Wei (2007-08)
      Forward and Backward Ground Penetrating Radar (GPR) modeling can provide the information that is useful for geometric and electromagnetic interpretation of layered materials. Given the depth and dielectric constant of snow, one can simulate the GPR signal. This is called forward modeling. On the other hand, given the GPR signal, the determination of depth and dielectric constant is called backward modeling. In this thesis, we briefly discuss a computational GPR forward modeling approach, based on two pieces of software with different principles. The software GPRMAX is able to model snow layers with the Finite Difference Time Domain method; this method is able to distinguish and resolve two consecutive layers with less thickness ([delta]d = 10cm). The software MATHCAD can be utilized to obtain modeling and imaging result using Transmission Line theory; this method is able to distinguish and resolve two consecutive layers with relative small difference in dielectric constant ([lamda epsilon] = 0.01). Then the comparisons of GPR system outputs and modeling techniques give an evaluation of the working performance of the Ground Penetrating Radar system. Secondly, for backward modeling, we used the layer stripping method on the field data as well as forward modeling results. Furthermore, the relative permittivity can be evaluated by the inverse process of transmission line theory with transmission line forward modeling results.
    • Ground-water capture-zone delineation: method comparison in synthetic case studies and a field example on Fort Wainwright, Alaska

      Ahern, Julie Anne (2005-05)
      Ground-water capture zone delineation is an integral part of the recent Source Water Assessments performed nation-wide. Delineations are used to identify where protection from contamination is critical. The objectives of our study were to compare commonly-used methods by quantifying the differences in capture-zone areas and evaluating whether the differences increase with system complexity. We delineated capture zones of hypothetical case studies. We began with a very simple hydrogeologic system and gradually added complexity. Four methods were applied to each case: Calculated fixed-radius (CFR), two analytical solutions (WHPA and UFE-Thiem), and a numerical model (MODFLOW). Area comparisons revealed that, in comparison to the numerical model, CFR consistently overestimated, WHP A underestimated, and UFE- Thiem was variable and the most similar. We then compared the methods in a field case on Fort Wainwright, Alaska. As our numerical method, we used a sub-regional ground-water flow model. Area comparisons were similar to case-study results. Surface-water features were the most influential complexity in the field case. We concluded that each method is only as accurate as its assumptions. Any added margin of error must be appropriate for both the aquifer complexities and required assumptions specific to a given ground-water system.
    • A grounded theory analysis of conversations with eleven Alaska Native Vietnam veterans

      Beals, Paul Henderson; Mohatt, Gerald; Smith, David; Berman, Gerald (2000-05)
      This thesis studies Alaska Native Vietnam veterans using archival data and grounded theory methods of qualitative analysis. It discusses the impact of cultural and individual beliefs, expectations and experiences on Alaska Native veterans during and since the Vietnam War. Theories developed from and grounded in the narratives of the 11 participants posit that reconciliation with community is a critical factor in healing from the traumas of war.
    • Groundwater dynamics in degrading, discontinuous permafrost

      Barnes, Michelle L.; Barnes, David L.; Shur, Yuri L.; Schnabel, William E.; Leigh, Mary Beth (2014-12)
      In regions impacted by permafrost, discontinuities are areas of possible connection between the supra- and sub-permafrost portions of an aquifer. Permafrost discontinuities influence the transport of contaminants in an aquifer, necessitating delineation of these discontinuities and their influence on groundwater flow. Means of identifying the locations of permafrost discontinuities have previously been limited to geophysical methods and the evaluation of well logs. In this study we use groundwater elevation trends and environmental tracers (e.g., stable isotopes and temperature) to evaluate the dynamics in a sulfolane-contaminated aquifer located in a region of discontinuous permafrost in the Interior of Alaska. Using tracers to identify areas of discontinuities in the permafrost should help us locate thawed through-taliks and may also improve our understanding of the interaction between the supra- and sub-permafrost groundwater in discontinuous permafrost. With this approach we identified at least three discontinuities within the study area. The locations of these discontinuities coincide with transport of the contaminant found in this aquifer. The primary source of recharge for this aquifer is the Tanana River, a major tributary to the Yukon River. The source of water for the Tanana River is glacial melt in the summer and groundwater during the winter. Through the isotopic composition of the supra-permafrost groundwater we show the occurrence of additional recharge to the supra-permafrost groundwater from sub-permafrost groundwater and precipitation. Understanding these dynamics is paramount to characterizing the contaminant transport in permafrost impacted aquifers.
    • Groundwater flow in a vertical plane at the interface of permafrost

      Paturi, Sairavichand; Barnes, David L.; Leigh, Mary Beth; Shur, Yuri (2017-08)
      Groundwater dynamics in discontinuous permafrost aquifers are complex. The topography of permafrost redirects flow in difficult-to-predict directions that can be tens of degrees off from the regional flow direction. Large zones of permafrost vertically separate aquifers into supra and sub-permafrost portions. The flow dynamics in each portion of the aquifer may be dissimilar due to different controlling boundary conditions. In areas of discontinuities in permafrost, known as open taliks, groundwater in the two portions of the aquifer may mix. These areas of mixing are the focus of this study, in particular, the groundwater dynamics in taliks located in the floodplain of lower reaches of rivers. The study hypothesizes that groundwater flow in floodplain taliks of lower reaches of rivers will bifurcate between the supra and sub-permafrost portions of a discontinuous permafrost aquifer. To test this hypothesis gradient, magnitudes and flow directions were determined at several depths ranging from the water table to 150 ft. (45.7 m) below ground surface, using a linear interpolation scheme in various locations in a floodplain talik. Errors in water level measurements due to instrument errors as well as vertically moving wells were propagated into the gradient calculations by Monte Carlo analysis. Results from this research show that a vertical divide in groundwater flow forms a short distance below the top of permafrost. Groundwater flow above the divide routes into the unconfined supra-permafrost portion of the aquifer. Water below the divide flows into the confined portion of the aquifer below permafrost. The position of the vertical groundwater divide may adjust in relation to the water table position. Additionally, a methodology is presented for stochastically propagating measurement errors into gradient analyses by Monte Carlo analysis. Understanding the flow dynamics in discontinuous permafrost aquifers is key to the understanding of contaminant transport, aquifer recharge, and resource development in subarctic environments.