Now showing items 2176-2195 of 3493

• #### Paleoethnobotany in Interior Alaska

Vegetation and plant resources can impact forager mobility and subsistence strategies. However, misconceptions about the preservation of organics in subarctic archaeological contexts and underestimations of the importance of plant resources to foraging societies limit paleoethnobotanical research in high-latitude environments. This research draws upon concepts from human behavioral ecology to address questions relating to site seasonality, plant resource use, land use, and deposition and taphonomy. The model developed in this thesis outlines expectations of seasonal archaeobotanical assemblages for Late Pleistocene and Holocene sites in interior Alaska. I consider these expectations in light of plant macroremains found in anthropogenic features from Components 1 and 3 (approximately 13,300 and 11,500 cal yr BP, respectively) at the Upward Sun River site, located in central Alaska. Site-specific methods include bulk sampling of feature matrix in the field and wet-sieving matrix in the laboratory to collect organic remains. Analytical measures of density, diversity, and ubiquity tie together the model expectations and the results from Upward Sun River. The dominance of common bearberry in the Component 1 archaeobotanical assemblage meets the expectations of a late summer or fall occupation. This suggests that site occupants may have focused on mitigating the risk of starvation in winter months by foraging for seasonally predictable and storable resources. The variability in results from the Component 3 features could relate to longer-term occupations that extended from mid-summer to early fall, in which site occupants foraged for locally available and predictable plant resources such as blueberry or low-bush cranberry species. In this thesis, I argue that large mammal resources were a key component in Late Pleistocene and Holocene subsistence strategies. However, foragers were flexible in their behavior and also targeted small mammals, fish, waterfowl, and plant resources in response to environmental conditions and cultural preferences. The results illustrate the long-standing use of culturally and economically important plant resources in interior Alaska and draw attention to aspects of human behavior that are under-conceptualized in northern archaeology, such as the gender division of labor, domestic behavior, and potential impacts of plant resource exploitation on mobility and land use.
• #### Paleohydrology of a catastrophic flood release from Okmok caldera and post-flood eruption history at Okmok Volcano, Umnak Island, Alaska

Okmok caldera, located on the northeastern end of Umnak Island, Alaska, contained a 5.8 x 10⁹m³ lake that catastrophically drained as a result of failure of the 2050 yr. B.P. caldera rim between 1560 and 1010 yr. B.P. Flow competence equations, dam-break models, and the Simplified Dam-Break computer model were used to estimate the paleohydrology of the flood. Models indicate that the peak discharge at the breach in the caldera rim was at least 5.8 x 10⁴ m³/s, and the maximum possible discharge was 1.9 x 10⁶ m³/s. A second smaller flood release occurred 190 yr B.P., coinciding with the 1817 A.D. eruption, and destroyed a small Aleut village at Cape Tanak. Stratigraphic analysis reveals that Okmok Volcano has maintained a high level of volcanic activity following the large flood release. Major eruptive events producing air-fall tephra deposits average 1 every 80 years since 1010 yr. B.P.
• #### Paleomagnetism Of The Wrangellia And Alexander Terranes And The Tectonic History Of Southern Alaska

Wrangellia was the first Alaskan tectonostratigraphic terrane to be widely accepted as allochthonous with respect to North America. There is, however, considerable disagreement as to the age of emplacement of this terrane as well as the hemisphere in which it originated. Some 800 paleomagnetic samples were collected from 24 localities in southern Alaska to elucidate the paleolatitude translation history of Wrangellia and other associated terranes. Data of known polarity from the Skolai Group (Pennsylvanian/Permian) strongly suggest that Wrangellia originated at 10-15 degrees North latitude. The Permian Pybus Dolomite yields a 9 degree S paleolatitude and suggests that the Alexander terrane moved southward in late Paleozoic and Triassic time. Evaluation of geologic data indicates that the Wrangellia and Alexander terranes amalgamated in an oceanic setting in mid to Late Jurassic time. Paleomagnetism of the Brothers Volcanics (Alexander terrane) and MacColl Ridge Formation (Wrangellia) documents a low latitude for both terranes during the Cretaceous, thereby precluding a pre-Tertiary age of emplacement for the amalgamated superterrane. Speculative apparent polar wander paths for Wrangellia and the Alexander terranes, in addition to geologic and biogeographic constraints, allow development of the following hypothetical tectonic model. Both the Alexander and Wrangellia terranes originated in the northern hemisphere adjacent to western North America in mid-paleozoic and late Paleozoic times, respectively. The Alexander terrane moved into the southern hemisphere during the Paleozoic and Wrangellia began moving southward in the Late Triassic or Early Jurassic. These two terranes amalgamated in mid to low southern paleolatitudes in later Jurassic time and formed part of a composite terrane, here termed the Southern Alaska superterrane. This superterrane began northward translation in Late Jurassic time, accreting to North America in Tertiary time.
• #### Paleopedology, palynology, and geochronological interpretation of alluvial paleosols, Cenomanian Dunvegan formation, Alberta, Canada

The Dunvegan Formation is a mid-Cretaceous deltaic deposit exposed in the Rocky Mountain foothills of Alberta and British Columbia along the Peace River Valley. Intrinsic features of Dunvegan Formation paleosols understood through micromorphology, geochemical, and mineralogical analysis provide a paleoclimatic interpretation of warm to cool temperate. Micromorphological and geochemical analysis lead to reconstruction of the depositional and pedogenic histories of the five primary paleosols of this study. Preserved palynomorphs of the paleosols are primarily composed of fern spores with much less abundant conifer and cycad species. The paleoclimate based on the palynomorphs is humid and ranges from cool temperate to subtropical. The overall paleoenvironmental interpretation based on both paleosols and palynology is humid cool to warm temperate. Geochronology using the ⁴⁰Ar/³⁹Ar dating method was implemented in an effort to date pedogenesis. This technique needs further refinement in order to be successful in dating paleosols. The multi-proxy approach of this study lead to a more complete interpretation of the climatic, pedogenic and depositional history and should be used in the future.
• #### Paluwiigum beksdid Sugt'stun aggaggtatuguut Port Graham's Sugt'stun workers plan

This Sustainability Plan was written for the Native Village of Port Graham for their language program, Tamamta Litnaurluta. The Native Village of Port Graham, a federally recognized tribe that serves the Sugpiaq people of Port Graham, Alaska, received a three-year language immersion grant from the Administration for Native Americans (ANA) to provide language instruction for students ranging from Head Start through the 12th grade. The ANA grant will expire at the end of the 2015-2016 school year. This Sustainability Plan provides programmatic recommendations for the Native Village of Port Graham to consider for continuing Tamamta Litnaurluta beyond the life of the grant. The Sustainability Plan includes a funding plan, which contains grants the Tribe can pursue, and a sustainable income plan that address possible scenarios for the operating costs of the language program.
• #### Pandalid shrimps in a tidewater-glacier fjord, Aialik Bay Alaska

Vertical migration and food habits of pandalid shrimps in Aialik Bay, a tidewater-glacier fjord, were related to suspended sediment load and available food resources. Suspended sediments from subglacial streams resulted in Secchi depths of 0.4-1.0 m near the glacier, increasing with distance from the glacier to 1.0-5.0 m near the sill. A large proportion of the Pandalus borealis and P. goniurus populations responded to reduced light in the upper bay by remaining in midwater throughout the day and night. Shrimp food resources, represented by zooplankton and benthos, were reduced in abundance and diversity near the glacier as compared to the region near the sill. Shrimps fed more intensively near or at the bottom than in midwater. The most common items in stomachs of P. borealis were unidentifiable organic matter (84.5%), sediment (83.1%), crustacean fragments (60.9%), identified crustaceans (16.9%), mollusks (16.3%), foraminiferans (15.1%), and plant material (10.0%).
• #### Pandering to glory: Sheldon Jackson's path to Alaska

Presbyterian missionary Sheldon Jackson is a celebrated figure in Alaska history. He is known predominantly for his efforts facilitating the establishment of public schools for Alaska Native people during the late nineteenth century. Jackson's methods have been historically overlooked as being reform-minded initiatives characteristic of Indian assimilation. As a result, historians have concluded that Jackson was a humanitarian with benevolent intentions. Unfortunately, such assessments ignore Jackson's educational platform, which was built upon fictitious slander against indigenous people and the manipulation of Christian women. In addition to speaking tours, Jackson published many editorials, articles, and books alleging that Alaska Native people were barbarous monsters. The propaganda Jackson employed in Alaska was no different from the propaganda he used against Mormons and Native Americans. However, Jackson was maligned for his strategy in the continental United States, whereas in Alaska he was celebrated as a reformer and an authority figure due to ignorance about the northern territory. Alaska captured the public imagination, and Jackson lied about Alaska Native culture for the remainder of his career in order to maintain his Christian enterprise.
• #### Paralytic shellfish poisoning: the relationship between Alexandrium abundance and psp toxins on Kodiak Island, Alaska

Paralytic shellfish poisoning (PSP) events have severe negative impacts on Alaska commercial shellfish fisheries as well as recreational and subsistence harvests. This study, designed to improve existing PSP monitoring programs, involved the use of a rapid sandwich hybridization assay to detect and quantify the relative abundance of Alexandrium catenella based on species-specific LSU rRNA targeted oligonucleotide probes. Blue mussel (Mytilus edulis) toxicity, expressed as saxitoxin equivalents, was determined using the ³H-Saxitoxin receptor binding assay. Shellfish toxicity was relatively low in both 2000 and 2001 compared to historically high values on Kodiak, but exhibited pronounced late spring and late summer peaks, in both years at four to seven sampling sites. Temporal and spatial variability in shellfish toxicity among sites, seasons, and years suggested dynamic, and possibly unpredictable, Alexandrium bloom events. Importantly, DNA probe data revealed a strong association between Alexandrium abundance and shellfish toxicity. The results also demonstrated that increases in Alexandrium abundance preceded elevated toxin levels in shellfish, indicating that this assay may prove useful as a monitoring tool to predict toxic events in shellfish before they are harvested. Water column nutrients and climate data were evaluated to determine if bloom-triggering mechanisms could be identified.
• #### Parasites and skeletal indicators of anemia in the eastern United States

The goal of this research is to examine the influence of parasitic infection and diet in the etiology of anemia in prehistoric human populations of the eastern United States. Prehistorically, anemia is often attributed to a nutrient-deficient diet, while parasite infection is discussed as a secondary cause if at all. However, parasite infection is a leading cause of anemia in the developing world today. Modern epidemiological studies have demonstrated that parasites thrive or perish under particular environmental conditions, and risk for parasite infection can be predicted based on environment using GIS. Here I apply this method to see whether environmental conditions, acting as a proxy for parasite infection risk, can predict prehistoric skeletal lesion rates for porotic hyperostosis and cribra orbitalia, lesions thought to reflect acquired anemia. Rates of porotic hyperostosis and cribra orbitalia in the skeletal remains of children and adults were collected from published data for 22 sites in the eastern United States. GIS was used to gather comparable environmental data. Soil drainage, elevation, precipitation, temperature and the surface area of bodies of water were recorded within a 15 km radius of each site. Carbon isotope data deriving from bone collagen and historic hookworm infection rates were also collected when available. Multiple linear regression was used to test how well environmental variables could predict lesion rates. Statistically significant correlations were found for both adults and children, but the strength and direction of relationships with environmental variables were inconsistent. It is possible that the correlations were related to parasite infection, but it is also possible that the skeletal 'lesions' may result from post-mortem bone degeneration rather than anemia. The correlations for porotic hyperostosis and cribra orbitalia were stronger when examined separately than when examined together, suggesting that the two conditions may have separate etiologies; however, the sample sizes were too small to provide the statistical power required for drawing strong conclusions. Comparison of children and adults showed stronger correlation for children, though when observing the lesions separately this pattern was not consistent. Collagen carbon values and historic hookworm infection rates correlated with lesion rates in children but not adults, perhaps because of differential healing in adults. These results demonstrate that environmental conditions and skeletal lesions are correlated, but the underlying mechanism for this remains unclear. Larger sample sizes would allow for more robust statistical analyses of the trends observed here. Nevertheless, these results do confirm that porotic hyperostosis and cribra orbitalia cannot be assumed to be the result of nutrient-deficient diets. Interpretation of skeletal data for assessing health in the past must also consider the natural and social context in which individuals lived.
• #### Parental perceptions of play: the influences of parent gender, gender role attitudes, and parenting styles on parent attitudes toward child play

The literature overwhelmingly demonstrates that play supports healthy social, emotional, physical, and cognitive development. Efforts to understand parents' support of child play seek to identify parent attitudes toward play, ways in which parents facilitate play for their children, and how they participate in play. Previous findings indicate parent valuation of play is an important factor for childhood play time and finds differences between mothers and fathers in parent-child play. While much research has been done to understand how mothers and fathers play with their sons and daughters, few studies have investigated what factors influence parent valuation of play or facilitate certain types of play. This study used a moderated mediation model to explore how parental attitudes about gender roles influence perceptions of play through parenting style and how this effect may be different for fathers and mothers. Analyses were also performed to understand the relationships between parent attitudes and parent play behaviors. The findings suggested egalitarian gender role attitudes predicted a higher valuation of play and more permissive mindsets toward cross-gender play for both mothers and fathers. Conversely, traditional gender role attitudes were predictive of less permissive mindsets toward cross-gender play for both mothers and fathers. A moderated mediation was found for fathers with traditional gender role attitudes and a permissive or authoritarian parenting style. Fathers with traditional gender role attitudes and a permissive parenting style were less likely to value play for child development. Fathers with traditional attitudes and an authoritarian parenting style had less permissive mindsets toward cross-gender play. Additionally for both mothers and fathers, authoritative parenting was correlated with increased parent play behaviors, while authoritarian parenting was correlated with decreased parent play behaviors. These findings support previous literature in that parent gender and gender role attitudes do appear to influence parent attitudes toward play. They also contribute to our understanding of parent gender differences and the way that parenting style influence this relationship. In addition, parenting style was found to be a facilitator of parent-child play. These findings contribute to an understanding of what kind of parents value play and can be used to inform family psychotherapy and parent education about play.
• #### Particle dynamics in the plasma sheet

Trajectories of charged particles in the tail region of the earth's magnetosphere are studied using a model magnetic field. The particles form a thin sheet-like structure in the magnetotail called the plasma sheet. It is shown that most trajectories are categorized by two dimensionless parameters. One of them is equal to the ratio of the cross-tail electric force to the magnetic force in the midplane and determines the maximum particle energization. The other parameter is the ratio of the plasma sheet thickness to the particle gyroradius in the midplane and determines the degree to which the particle motion is adiabatic. All previous attempts at studying trajectories in the magnetotail are shown to be applicable only over limited ranges of the two parameters. Hence those studies are combined into a common framework, and those trajectories which have not been studied previously are added for completeness.
• #### Particle simulations of magnetic field reconnection and applications to flux transfer events

Basic plasma processes associated with driven collisionless magnetic reconnection at the Earth's dayside magnetopause are studied on the basis of particle simulations. A two-and-one-half-dimensional (2$1\over2$-D) electromagnetic particle simulation model with a driven inflow boundary and an open outflow boundary is developed for the present study. The driven inflow boundary is featured with a driving electric field for the vector potential, while the open outflow boundary is characterized by a vacuum force free condition for the electrostatic potential. The major findings are as follows. (1) The simulations exhibit both quasi-steady single X-line reconnection (SXR) and intermittent multiple X line reconnection (MXR). The MXR process is characterized by repeated formation and convection of magnetic islands (flux tubes or plasmoids). (2) Particle acceleration in the MXR process occurs mainly in O line regions as particles are trapped within magnetic islands, not in X line regions. The MXR process results in a power law particle energy spectrum of $f(E)\sim E\sp{-4}$. (3) Field-aligned particle heat fluxes and intense plasma waves associated with the collisionless magnetic reconnection process are also observed. (4) When applied to the dayside magnetopause, simulation results show that the MXR process tends to generate a simultaneous magnetic field perturbation on both sides of the dayside magnetopause, resembling the observed features of two-regime flux transfer events (FTEs). (5) An intrusion of magnetosheath plasma bulge into the magnetosphere due to the formation of magnetic islands may lead to the layered structures observed in magnetospheric FTEs. (6) In the current sheet, the enhanced tearing mode instability caused by the driving force applied at the driven inflow boundary creates an energy source at a specific wavenumber range with $k\sb{z}L\sim$ 0.3 in the modal spectrum of the magnetic field $B\sb{x}$ component. An inverse cascade of the modal spectrum of $B\sb{x}$ leads to the formation of the large-scale ordered magnetic island structures observed in the simulations. (7) In addition, the results of a theoretical study show that the tearing mode instability, and hence the magnetic reconnection at the dayside magnetopause, do not exhibit strong dependence on the magnetosheath $\beta$ values.
• #### Particles in the Pacific: how productivity and zooplankton relate to particles in the deep sea

The magnitude and spatio-temporal patterns of particulate material flux from the surface ocean through mesopelagic and bathypelagic depths determines sequestration of atmospheric carbon and the food supplied to deep-dwelling ocean life. The factors that influence how and where this organic material is exported from euphotic depths are poorly understood. Zooplankton are thought to play a key role in modulating the transport of surface-produced particles to depths through consumption, fragmentation, active diel vertical migration, and fecal pellet production, thus it is important to study both particulate matter and zooplankton in tandem. In this study, I use an in-situ optical instrument, the Underwater Video Profiler 5 (UVP5), to describe broad scale patterns of large (> 100 μm) particles and zooplankton across a longitudinal transect of the Pacific Ocean during April to June 2015. Satellite-derived surface chlorophyll-a was employed to describe the timescales over which particles arrive in meso- and bathypelagic depths after a productivity peak. High abundances and volumes of particles are noticeable beyond the euphotic zone across the Equator, transition zone, and the sub-arctic Pacific, indicating increased export in these high-nutrient low-chlorophyll (HNLC) areas. In two of these areas, the Equator and transition zone, large abundances and volumes of particles extend into bathypelagic depths. High abundances of zooplankton were seen in all areas where high abundances of particles are seen in bathypelagic waters. Rhizaria were revealed to be pervasive across all biogeographic regions, and appear to play a role in particle attenuation in the sub-arctic Pacific. The insight into patterns between particles, zooplankton, and productivity identify HNLC regions as deserving more detailed examination in future studies of biological pump efficiency.
• #### Passively encouraging offline networking in small, concentrated communities through UI/UX design

The goal of this project is to identify whether it is possible to encourage users to communicate with one an other face-to-face through User Interface (UI) and User Experience (UX) design. It is well known that users can be maliciously manipulated by design elements and that concerns have been raised about the effects o f social media on interpersonal communication. The key is to find non-harmful means of guiding users to the desired action of speaking face-to-face with others. User testing for a custom web app was conducted for the purposes of this project. It is hoped that the results will provide developers with new consideration for UI and UX design.