Salmonid run sizes are strongly affected by their early marine stage. Fully understanding the life history of salmonids means understanding how they interact with their marine environment and with other fishes. Changes in the biological and physical environment off the Columbia River region affects the distribution and abundance of predatory...
The objective of this research is to determine the correlation of lacustrine micro-fossils in Lake Tanganyika to changes in climate and lake levels during the Late Pleistocene and Early Holocene.
Lake Tanganyika is the second deepest and one of the oldest lakes in the world. The horst and graben geometry...
Seabirds are an integral component of marine ecosystems, however, because humans typically observe only snapshots of their lives at sea, our understanding of seabird foraging ecology is often limited. A more complete understanding of the ecological roles of seabirds and identification of critical foraging habitats requires the ability to follow...
Thermohaline interleaving is an important mechanism for laterally fluxing salt, heat, and nutrients between oceanic water masses. Interleaving is driven by a release of potential energy resulting from the vastly differing diffusivities of heat and salt in seawater. The flows are composed of stacked intrusions that flux more buoyant and...
The Tobin Range of central Nevada lies in the Basin and Range extensional province near the transition between more extended terrane (>50%) to the south and east, and generally less extended terrane to the north and west. Geologic mapping, 40Ar/39Ar dating and whole-rock geochemical analysis were employed to establish the...
Pacific rockfishes (genus Sebastes) have attracted wide scientific and public interest from an evolutionary, fishery and conservation standpoints. This dissertation addresses several hypotheses involving spatial and temporal scales of genetic change in two overfished rockfishes, darkblotched (S. crameri) and canary rockfish (S. pinniger), using statistical analyses of genetic variation within...
Structure-forming invertebrates belong to a polyphyletic group of primarily sessile and sedentary megafauna that can significantly enhance the complexity of physical habitats. A number of these organisms, including cold-water corals and sponges, are known to be slow growing and vulnerable to physical disturbance. In addition, as filter feeders, these invertebrates...
Growing societal demand for forest products is pressuring managers to increase productivity from a finite land area, and it is expected that increased supply will come mostly from expansion of intensively managed stands. The USDA Forest Service and numerous collaborators created the Long-Term Soil Productivity (LTSP) network of research sites...
This research addressed the complexities of identity development in the lives of seven elementary and middle school preservice literacy teachers during their graduate teacher education program at a private western university using a poststructural feminism theoretical lens. This research investigated two questions: 1) How do preservice teachers develop their identity...
Ceratomyxa shasta is a myxozoan parasite of salmonids and requires the freshwater polychaete, Manayunkia speciosa to complete its life cycle. The parasite’s distribution is currently limited to the Pacific Northwest region of North America and has been reported to cause substantial losses of both wild and hatchery salmonids. The spatial...
Despite the importance of tropical forest ecosystems in the global carbon cycle, there have been few studies of carbon dynamics in this biome. The magnitude of carbon stocks in the tropics and their changes over time are poorly known since ground-based observations are lacking. In this study, total carbon stocks...
To date, the use of oceanographic data in fisheries management has been limited by the scarcity and the difficulty of accessing complete oceanographic datasets. Consequently, fish stocks are managed with limited knowledge about the habitat where fish live and incomplete understanding of what oceanographic conditions affect their populations. With the...
The primary responsibility of electric utilities is to supply consistent, dependable, and affordable energy to private customers, businesses, and industries. As with many businesses, electric utilities are experiencing the effects of an aging workforce and expending considerable resources to train their current and replacement workers. Community colleges can partner with...
Molecular genetic and enzymological techniques have been employed to study antibiotic biosynthesis. In this thesis, we studied the formation and modification of the nonproteinogenic amino acid enduracididine (End), which exists in two important antibiotics, mannopeptimycins (MPPs) and enduracidin.
Sequence analysis of the MPP gene cluster revealed that the product of...
An acceptable microparticulate diet for marine fish larvae may be defined as an artificial diet that contains, retains, and delivers the required nutrients to support survival and growth. Factors affecting ingestion rate of prey items by fish larvae include environmental factors such as light intensity, prey/background contrast, possible chemical cues,...
Two of the most powerful ways in which humans have altered ecosystems are by increasing productivity and changing the densities of important consumers. The bottom-up effects of productivity and the top-down effects of consumers have been identified as primary determinants of biological diversity, though the links between them remain unclear....
This thesis presents a channelized digital receiver design for UWB sytems in a multipath indoor environment. The UWB technology has been used for commercial and military purposes due to a number of advantages such as low-power consumption, noise-like and carrier free. The energy of UWB signal is spread over a...
Rotifers and brine shrimp (Artemia) are important prey items for rearing marine fish larvae. Their availability in the water column may be reduced when they are transferred to larval rearing tanks at lower temperature. In this study, Brachionus rotundiformis (SS-type) and Brachionus plicatilis (L-type) were semi-continuously cultured and fed on...
I measured responses of free-ranging Rocky Mountain elk (Cervus elaphus) to recreational disturbance at Starkey Experimental Forest and Range, Oregon from April to October, 2003 and 2004. Resting, feeding, and travel activities of 13 cow elk were recorded at 5-minute intervals using Actiwatch™ motion sensors. Elk were subjected to four...
There are a number of wood properties which affect the quality of forest products such as lumber and pulp. Of these, wood density is considered by some to be the single most important physical characteristic because it is an excellent predictor of strength, stiffness, hardness, and paper-making capacities. Accurately assessing...
Elevated groundwater nitrate (NO3
-) concentrations in the Southern Willamette
Valley (SWV) caused the Oregon Department of Environmental Quality (ODEQ) to
declare a Groundwater Management Area (GWMA) in Spring, 2004. To better
understand direction of groundwater flow, groundwater age, and nitrate transport
pathways of the SWV we developed a steady-state...
Streptococcus gordonii is a bacterial species that naturally colonizes the oral cavity of most healthy humans. It resides in the mouth as an adherent to dental surfaces and, with few exceptions, does not cause disease in individuals it inhabits. It possesses qualities that encourage its use as a vector to...
The extended-Lifshitz-Kosevitch formalism (ELK) unifies the treatment of
the de Haas-van Alphen (dHvA) effect, allowing it to transcend its traditional roles
of mapping Fermi surfaces and measuring effective masses. Here we exploit the
capabilities of dHvA as a probe of many-body effects to examine heavy-fermion su-
perconductivity. ELK successfully describes...
The impact of forest roads on the hydrology of forested watersheds has long been studied. While forest roads have been reported to alter storm runoff at the road segment scale, the potential for changes to be detectable at the small watershed scale has been debated. The purpose of this study...
The purpose of this dissertation was to explore the experience of gifted girls transitioning from elementary school to sixth and seventh grade. The current counseling literature in this area found that gifted girls often struggle emotionally when transitioning to sixth and seventh grade. The bulk of this literature was based...
This thesis focuses on two aspects of transparent electronics, SnO₂ transparent thin-film transistors (TTFTs) and transparent circuits. Both depletion- and enhancement-mode SnO₂ TTFTs are realized. The maximum effective mobility for the depletion- and enhancement-mode devices are 2 cm²V⁻¹s⁻¹ and 0.8 cm²V⁻¹s⁻¹, respectively. A variety of techniques to decrease the carrier...
The objectives of this project were to determine the effects of harvest maturity, packaging, and storage conditions on subsequent fruit quality of Actinidia arguta ‘Ananasnaya’ and to investigate the use of edible coatings to improve fruit quality and storage life. The influences of harvest maturity (6.0, 8.7, 9.1, and 15.1%...
In recent years, there has been growing interest in both industry and academia to use continuous-time (CT) Δ-Σ A/D converters for wideband wireless and wireline communication applications.
So far no reported CT Δ-Σ A/D modulator achieves 14-bit or higher dynamic range (DR) with more than 2MHz signal bandwidth (equivalently 4MS/s)....
This dissertation concentrates on the controlling factors on the instability of the Laurentide Ice Sheet (LIS) and their effects on abrupt climate change. Northern Hemisphere climate fluctuated abruptly during the last deglaciation possibly related to variability in Atlantic meridional overturning circulation (AMOC) and reduced aerial extent of the LIS. Reductions...
This research addresses sample process variance estimation on continuous domains and for non-probability samples in particular. The motivation for the research is a scenario in which a program has collected non-probability samples for which there is interest in characterizing how much an extrapolation to the domain would vary given similarly...
Riparian zone vegetation can influence terrestrial and aquatic food webs through variations in the amounts, timing, and nutritional content of leaf and other litter inputs. Differences in vegetation composition and density, as well as riparian topography, may modulate the strength and quality of these inputs. Changes in inputs to small...
We isolated and characterized the expression of two genes from Populus
trichocarpa that are homologous to the TERMINAL FLOWER 1 (TFL1) gene from
the model annual plant Arabidopsis. In Arabidopsis, overexpression of the TFL1
gene extends the vegetative growth phase, and the homozygous mutant tfl1 allele
causes early flowering and...