Wave runup is an important physical process that affects nearshore sediment transport, coastal erosion, and flooding. Large and unexpected runup events can also be dangerous to beach goers. Extreme runup statistics are essential parameters used in engineering design of marine structures and in coastal management. Although the study of runup...
Glacial isostatic adjustment (GIA) alters the amplitude and timing of ‘glacioeustatic’ sea level maxima and minima around the globe. No study has examined the intrinsic distance that one can correlate marine stratigraphic records of glacial–interglacial sedimentation across continental shelves subject to varying amounts of GIA. Here, we seek to model...
Coastal flood hazard zones and the design of coastal defenses are often devised using either the maximum recorded total water level (TWL) or a 'design' event such as the 100-year return-level flood, usually projected from observed extreme events. Despite technological advances driving more consistent instrumental records of wave heights and...
The selection process for map projections is a mystery to many mapmakers and GIS users. Map projections ought to be selected based on the map’s geographic extent and the required distortion properties, with the goal of minimizing the distortion of the mapped area. Despite some available selection guidelines, the selection...
A new method is introduced for incorporating bathymetric uncertainty into predictions of nearshore and river flows (i.e., unstratified flows primarily forced by pressure and radiation stress gradients). The method involves the use of the ensemble Kalman filter (EnKF) as a parameter estimation scheme, where the parameter to be estimated is...
The computational identification of gene Transcription Start Sites (TSSs) can provide insights into the regulation and function of genes without performing expensive experiments, particularly in organisms with incomplete annotations. High-resolution general-purpose TSS prediction remains a challenging problem, with little recent progress on the identification and differentiation of TSSs which are...
Successful prediction of nearshore sediment migration is important in determining the vulnerability of a coastline. During energetic wave climates (storm events) sediment rapidly erodes from beaches and is deposited offshore. In subsequent milder wave conditions, the sediment migrates shoreward, accreting on the beach and helping to protect the coastline. It...
The effects of wind forcing on coastal ocean circulation are studied using a
numerical modeling approach. The first region of interest is on the North Carolina
shelf, where the Coastal Ocean Processes (CoOP) Inner Shelf Study (ISS) took place
during August - November 1994. ISS observations are used to initialize,...
Understanding sandbar dynamics and variability is integral to developing a predictive
capacity for nearshore flows, sediment transport, morphological change, and
ultimately for determining coastline exposure to damaging storm waves. Along the
high-energy U.S. Pacific Northwest (PNW) coast, sandbars typically dominate the
bathymetry of the active zone. Here we report on...
Coastal flooding and erosion are major concerns for low lying coastal communities -- particularly in light of accelerated sea level rise and climate change. To improve quantitative understanding of the physical drivers of both flooding and coastal landscape change, this dissertation explores coastal morphodynamics bridging the land-sea interface on modally...
This dissertation has focused on the charateristics of bubbles generated by breaking waves and the feedback of wave-current interaction on the forcing mechanism of low frequency wave especially basin seiching wave. For the first study, Optical image capture observations of breaking waves in a laboratory surf zone are presented. The...
The formation of beach placers primarily involves processes of
waves and currents that selectively sort and concentrate the valuable
minerals according to their densities, sizes and shapes. Black sand
placers are found on the beaches adjacent to the mouth of the Columbia
River. Reviews of historical shoreline changes show that...
Hydrodynamic models are used as a diagnostic tool to understand the temporal variability of shallow-water processes that are difficult to completely resolve with traditional field measurements. For all simulations, modeled quantities are qualitatively or quantitatively compared with available measurements to gain confidence in conclusions derived from the modeled results. In...
Wave breaking in the surf zone is an important forcing
mechanism on the generation of nearshore currents and in the driving
of sediment transport. At the same time, wave breaking can have
significant spatial and temporal variability that needs to be
accounted for in the description of nearshore processes. Remote...
Software maintenance accounts for a large portion of the software development cost, particularly the process of updating programs either to adapt for requirement change or to enhance design or efficiency. Currently, program updates are generally performed manually by programmers using text editors. This is an unreliable
method because syntax and...
The onset of the COVID-19 pandemic led to significant transformations in global mobility patterns, primarily driven by stay-at-home orders and economic shutdowns. These measures resulted in a substantial decline in travel activities worldwide. In the United States, there was a notable reduction in travel demand, with a corresponding decrease in...
Continental margin sediments have been recognized as a major source of dissolved iron to the global ocean. The focus of this study was to build an early diagenetic model that can be used to simulate iron fluxes from continental margins and thereby identify key controlling factors. The model uses the...
Ground-based assessments of foliar diseases including leaf blight are time-consuming and costly. We investigated the potential for using an unmanned aerial system (UAS) in conjunction with a multispectral sensor to determine whether we could more efficiently and reliably detect and quantify leaf blight in Pacific madrones. Our methods included ground-based...
Double-crested cormorants (Phalacrocorax auritus) and Brandt’s cormorants (P. penicillatus) nest sympatrically in a large mixed-species colony on East Sand Island (ESI) in the Columbia River estuary. Ecological theory predicts that such morphologically similar species will partition prey resources when faced with resource limitations. During the summer of 2014, I investigated...
The purpose of this thesis is to represent and calculate unsymmetrical
secondary faults on a grounded wye-to-delta transformer
bank.
This thesis is specifically concerned with the secondary connections
often encountered in industrial installations. Faults on these
systems have not been adequately investigated.
Three types of faults are considered, namely:
1....
Volatile hydrophobic compounds (HOCs) brought into soil and sediment
systems represent a serious threat to the environment. Dissolved
organic carbon (DOC) may exert an important influence over the total
aqueous solubility and mobility of organic pollutants through their
incorporation into micelles or the formation of soluble complexes.
To date, however,...
Great Basin Canada goose (Branta canadensis moffitti) productivity and nesting habitat utilization were studied on the Columbia River within the boundaries of the Umatilla National Wildlife Refuge during the springs of 1974 and 1975.
Five islands, BL-1, BL-2, SD-1, SD-2, and Telegraph Island (TI), contained 88 percent of the nesting...
Small, mountainous river systems have been increasingly studied due to their importance as sources of fluvial sediment and organic matter to the coastal ocean. Thus far, studies of small, mountainous river systems have focused on rivers with very high sediment loads. The well-studied Eel River dispersal system in northern California...
From a landscape ecology perspective, meadows are often seen as landscapes in
transition. Succession and change in meadows may be investigated by considering the
physical and anthropogenic factors that influence the landscape through time. What is
often unknown is how changes occur and how physical and anthropogenic factors
contribute to...
Once considered the largest wetland in Central Asia, the Mesopotamian Marshlands of Southeastern Iraq have nearly disappeared. Various hydrological projects by the Iraqi government and dam construction in the region have nearly destroyed these once rich freshwater wetlands by over 90%. With the launching of Operation Iraqi Freedom recent attempts...
This thesis addresses a common knowledge gap that was identified amongst the Society of Automotive Engineers (SAE) competition design teams at Oregon State University. Students that join the SAE teams at Oregon State University typically do not have experience using physically collected data during a design process. This leads to...
Dramatic declines in several groundfish populations have occurred along
the U.S. West Coast during the last decade (PFMC 1999, Sampson 1997,
Ralston 1998, Bloeser 1999). One problem exacerbating these declines is
insufficient stock assessments, especially for species of west coast rockfish
(Family Scorpaenidae, Genus Sebastes) which comprise the core of...
The Klamath-Siskiyou Ecoregion of southwest Oregon and northern California is greatly departed from its historic, mixed-severity fire regime. This departure manifests in larger wildfires, greater proportions of high burn severity within wildfire perimeters, and decreased diversity of post-fire vegetation successional stages and trajectories across the landscape compared to historical norms....
The 180,000 km² of Arabian lava fields (“harrats” in Arabic) form one of the largest distributed basaltic provinces in the world. Approximately 50% of these are located in Saudi Arabia. The most recent eruption in 1256 AD, as well as seismicity and ground deformation associated with shallow dike emplacement in...
Many geophysical phenomena exhibit complicated dynamics that, due to a variety of factors, diverge quickly from physical models. The arrival of new observations allows researchers to combine the model estimate with measurements in a statistical process called data assimilation to produce a revised estimate of the phenomenon. This assimilation of...
The imposition of sexually objectifying experiences on women socializes women to engage in self-objectification, or the act of placing greater value in physical appearance than internal well-being. These two studies explored the underlying mechanisms linking self-objectification to negative subjective well-being among a group of young adult women (ages 18-26) and...
Arctic-boreal regions are exhibiting the symptoms of profound ecological shifts as they experience pronounced warming. Wildlife in high-latitudes are one such harbinger of change, and their populations are undergoing range-shifts, declines, and extinctions in response to their rapidly altering habitats. As the circumpolar and boreal north is snow-covered for up...
The Cook-Austral island chain has been the center of debate for many years. Contrary to the classical hotspot hypothesis, this volcanic island chain does not exhibit a linear age progression with a single node of active volcanism, but instead shows evidence of young volcanism at several points along the chain....
Increasing numbers of individuals aspire to, seek out, and need a college degree in order to be competitive in the job market (Goyette, 2008; U.S. Department of Education, 2013). College degrees provide access to economic, social, and health benefits (Abel & Deitz, 2014; Autor, 2014). The United States also needs...
In recent years, several interrelated forces—prolonged drought, growing populations, height-ened environmental protections, sustained agricultural use, and hydrologic alterations due to climate change—have increased pressure on water users in the Western United States, where the agricultural sector accounts for up to 90% of total water withdrawals. Technology im-provements developed since the...
Earth’s mantle extends to nearly 3000 km depth, comprises >80 % of Earth’s total volume, and has the largest influence on the primordial and radiogenic heat budget. Despite its importance, the structure and composition of the mantle is still debated. There are three primary models for Earth’s mantle structure that...
Gadoid fish, like Alaska pollock and Pacific whiting, have a high level of trimethylamine-N-oxide demethylase (TMAOase) that catalyzes the breakdown of trimethylamine-N-oxide (TMAO) to formaldehyde (FA) and dimethylamine (DMA) even during frozen storage. FA reacts with amino acid residues to promote covalent cross-links in the formation of inter- and intramolecular...
Wheat is a globally traded staple crop. Wheat is important in human diets because of its agronomic adaptability, physical characteristics, functionality for the production of leavened products and nutritional value. Two significant characteristics make wheat an important staple food-crop. First, the proteins present in wheat endosperm have attributes that enable...
The Eastern California Shear Zone (ECSZ) is a broad zone of dextral shear inboard of the North American - Pacific plate boundary. Despite decades of study, the significance of a mismatch between geodetic velocities and geologic fault slip rates across the ECSZ remains incompletely understood. Geodetically determined interseismic strain across...
By 1900 domestication was a promising, if somewhat vexed, subject in biology. Volumes had been written about domestication, but little serious scientific inquiry was directed toward the phenomenon. Expertise lay with practical men, primarily breeders and fanciers. The bulk of scientific commentary on domestication came from anthropologists who derived theories...
The purpose of the work is to enable students of botany to identify
accurately Oregon ferns, both as living plants and as dried specimens.
Therefore, it provides vegetative keys to the families, genera
and species of the ferns (Class FILICINAE) found in Oregon. Correct
names have been determined using the...
Fidelity to breeding sites in colonial birds is an adaptive trait thought to have evolved to enhance reproductive success by reducing search time for breeding habitat, allowing earlier nest initiation, facilitating mate retention, and reducing uncertainty of predator presence and food availability. Studying a seabird that has evolved relatively low...
Populations of Western Tragopans Tragopan melanocephalus were studied at two areas (Machiara and Salkhala) in the Neelum Valley of northeastern Pakistan. A total of 130 sightings of birds was noted during the breeding seasons in 1982 and 1983, but only 100 were re-located for vegetation analysis. More sightings of birds...
Accurate modeling and simulation of wave propagation in dispersive dielectrics such as water, human tissue and sand, among others, has a variety of applications. For example in medical imaging, electromagnetic waves are used to interrogate human tissue in a non-invasive manner to detect anomalies that could be cancerous. In non-destructive...
The Asphalt Pavement Analyzer (APA) device was used to characterize the impact of various mix factors on the development of permanent deformation in dense-graded mixes given a standard compactive effort. Factors included two aggregate sizes, three VMA levels, two fines contents, three binder contents and four binder types. All specimens...
The cholesterol content (mg/100 g wet tissue) of the
longissimus dorsi muscle and the subcutaneous adipose
tissue of "Country Natural Beef" and regularly produced
beef was determined by a spectrophotometric method.
Proximate analysis (moisture, fat and protein contents) of
both types of beef was also determined.
Country Natural Beef (natural...
The purpose of this study was to investigate the use
of preblended, prerigor beef in reduced salt meat batters.
The functional properties of water-holding capacity, fat
binding and gel strength were evaluated. Proximate
analyses (protein, moisture and fat contents) of all
cooked samples were performed, in duplicate.
The sternomandibularis muscle...
Inheritance from pre-existing mantle domains and fluid and melt contributions from active subduction together produce the geochemical signatures of mantle-derived arc basalts. In this context, this work evaluates the evolution of Cascadia mantle sources by documenting the isotopic and compositional characteristics of primitive basalts along a transect across the Eocene-Oligocene...
Native bees play an important role as pollinators of natural vegetation and agricultural
crops. Yet many pollinators, including some native bees, are declining in numbers.
Some of the potential causes of these declines are habitat destruction and degradation
by various human land uses, including urban development and sprawl, construction of...
The Oregon Mountain area contains an ophiolitic assemblage of rocks which can he divided into two major zones on the basis of lithology: (1) spilite and diabase, with minor chert, and (2) plagiogranite, hornblende gabbro, cumulate gabbro and cumulate ultramafic rocks. The two zones have a total estimated thickness of...
A recent and steady increase in student participation in study-abroad programs
has caused international educators and student affairs professionals to reevaluate the
current study-abroad paradigm and redesign and implement new curricula better suited
to meet the changing needs of international education. Recent emphasis has been
placed on understanding outcomes of...
The current proliferation of portable electronic devices for personal
communication, business and entertainment has created a demand for high energy density
power supplies. A hydrocarbon fuel with a conversion efficiency of over
15% can provide greater energy density than current battery technology for these
applications. Current micro-scale heat engines do...
Northern anchovy (Engraulis mordax) are a dominant forage fish in the California Current large marine ecosystem (CCLME). However, little is known about northern anchovy abundance, distribution, age structure, or population fluctuations relative to ocean conditions in the eastern boundary upwelling system off the U.S. West Coast. This thesis includes three...
Protecting end-users privacy and building trust are the two most important factors needed to support the growth of ecommerce. The increased dependence on the Internet for a wide variety of daily transactions causes a corresponding loss in privacy for many users, as virtually all websites collect data from users directly...
Air travel presents several problems for passengers with disabilities.
One in particular is how they get from their wheelchair and to an aircraft seat.
The commonly used manual transfer method is hazardous to the assistants
and the passenger. There are other alternatives, but they have plenty of room
for improvement....
Forest growth models in the Pacific Northwest are predominantly empirical. Predictions of yield under alternative silvicultural regimes cannot rely completely on field trials; yet empirical growth models are often inadequate for extrapolating untested regimes and genotypes. The limitations of current models include (1) long time-steps (e.g. 5-10 years); (2) insufficient...
The spatial distribution and geologic histories of submarine volcanoes provide insight into submarine eruptive behavior, deep earth processes and plate tectonics. This dissertation examines the evolution of individual submarine volcanic edifices as well as linear trails of seamounts at three spatial and temporal scales.
In order to understand constructive and...
A technique is developed and tested to analyze the interaction of flowing water,
bed topography, and bedload sediment transport in meandering channels where gravel
bars are removed. The method relates the local velocity distribution, bed shear stress and
sediment transport conditions to the local bed configuration in river bends before...
By implementing a series of mass-conserving nested high-resolution models down to approximately 1 km resolution that have realistic bathymetry, coastline, wind forcing and river run-off, the winter 1996-1997 shelf flow near Cape Mendocino, California, is simulated and compared with available observations from the Strata Formation on Margins (STRATAFORM) marine geology...
The early marine phase following freshwater emigration has been identified as a critical period in salmonid (Oncorhynchus spp.) life history, characterized by high but variable mortality. Consistent with the “growth-mortality” and “bigger-is-better” hypotheses, at least some of the mortality during the critical period appears to be size-dependent – with smaller...
Thirteen New World populations of Megachile rotundata and M. apicalis and
two Old World populations of M. rotundata were analyzed at 23 enzyme loci using
cellulose acetate electrophoresis. Conventional and G- or C-banded karyotypes were
also examined in these populations. The principal findings are (1) No differences
were found in...
The feasibility of managing codling moth, Cydia pomonella (L.), with mixtures
of Bacillus thuringiensis-based microbial and selected chemical insecticides was
studied under laboratory and field conditions. Joint actions (synergism, additivity and
antagonism) of these mixtures were determined for both egg and larval stages. Higher
rates of microbial control agents (MCAs),...
There are over 35 known virus and virus-like diseases of sweet cherry (Prunus avium), some with potential to cause severe economic impact by reducing vegetative growth, vigor, and/or quality of fruit. Oregon is the second-ranked state for sweet cherry production in the United States with 13,000 acres and $70.8 million...
Rising global temperatures are having lasting effects on mountain snow environments in the form of diminishing snowpacks, shorter accumulation seasons, and shifts in meltwater timing. Seasonal snowpack is a vital source of water for natural and human systems. In the forested mountain landscapes of the Pacific Northwest seasonal snowmelt feeds...
Continental flood basalts represent short-lived but immense blasts of mafic magma to the continental crust. The youngest and smallest continental flood basalt worldwide, the Columbia River Basalt, initiated with the eruption of the most mafic member, the Steens Basalt (~16.9 Ma). The Steens Basalt is exposed in southeast Oregon, southwest...
Recent reports at the state, national, and international level have called for increased earthquake and tsunami education to increase knowledge of the causes of these hazards, risks from these hazards, and preparedness measures to reduce risk and increase resilience to these hazards. One recommended approach to meet this need is...
The eruptive history of the Quaternary Cascades arc has been relatively well characterized. However, much less is known about the frequency and sizes of explosive eruptions produced by earlier stages of the arc. The Late Neogene Deschutes Formation of Central Oregon preserves a remarkable record of heightened pyroclastic activity during...
Assessing the risk from exposure to a chemical mixture in the environment can seem prohibitively challenging. Most components of the mixture are not readily identifiable, chemicals may interact to cause other-than-additive toxicity, and the number of potential combinations of environmental contaminants is enormous. These challenges can make it seem impossible...
The rapid decline of marine ecosystems worldwide and the failure of traditional single species management pushed for the development of ecosystem-based conservation measures such as marine protected areas (MPA) to slow the loss of marine biodiversity. One approach to MPA creation advocates targeting marine megafauna (e.g., marine mammals, seabirds, sharks,...
Landscape characteristics can strongly influence demographic and genetic processes in wildlife populations. Climate change and human land use are causing many landscapes to change rapidly, and the effects on wildlife populations must be understood to properly manage these threats and design effective conservation strategies. In this dissertation, I explored the...
Landslides are a pervasive hazard that can result in substantial damage to properties and loss of life throughout the world. To understand the nature and scope of the hazard, landslide hazard mapping has been an area of intense research by identifying areas most susceptible to landslides in order to mitigate...
Contracting nucleolar vacuoles are a general and consistent
feature of somatic tobacco cells growing in microcultures. Nucleolar
vacuoles were studied in cells from callus tissues of two
single-cell clones, H-196 and H-239, of hybrid tobacco (Nicotiana
tabacum X N. glutinosa). Vacuoles periodically contracted either
completely or incompletely, apparently releasing a...
An experiment was conducted to determine if selection from
standardized litters would be effective in separating lines of mice
selected for increased and decreased litter weight at 14 days of age,
and if response to selection on this maternally influenced trait could
be accurately predicted.
Data were collected on litter...
Pollution by pesticides is a ubiquitous concern for wildlife. The effects of
pesticides are especially concerning in aquatic environments, which are particularly
vulnerable as they have several exposure routes for the influx of chemicals. These
effects are of particular concern as biodiversity loss reaches unprecedented rates. This
includes recent declines...
This investigation was motivated by the apparent increase in genetic
variability resulting from the systematic combining of gene pools
represented by winter and spring types of wheats.
It was the objective of this study to provide information regarding
the nature of this genetic variability for nine agronomic characters
in populations...
The purpose of this study was to investigate physical education
and sport in Thailand and, based upon expert opinion, to develop a
blueprint of physical education and sport for the nation building of
Thailand. The investigation concentrated on the history, role and
function, purpose of governmental involvement, and future prospects...
In this study, a heterogeneous flow model is proposed based on a non-overlapping domain decomposition method. The model combines potential flow and incompressible viscous flow. Both flow domains contain a free surface boundary.
The heterogeneous domain decomposition method is formulated following the Dirichlet-Neumann method. Both an implicit scheme and an...
Falls are a common problem among older adults, including those who are relatively healthy and living independently. Exercise has been recommended as an intervention to reduce falls by slowing and/or reversing age-related declines in balance, strength, and mobility. However, it remains unclear which types or combinations of programs are most...
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_____________________________________________________________________
Samuel T. Johnson
Falls are a common problem among older adults, including those who are
A study of the phyletic relationships among five species of
tragopans and an outgroup, the Blood Pheasant (Ithaginis cruentus), was
conducted from 1987 to 1991. Biochemical, behavioral, and external
morphologic characteristics were compared. A cladistic approach was
used to compare the behavioral, biochemical, and external morphologic
data collectively, as different...
Reflection of an obliquely incident solitary wave at a vertical wall is studied experimentally in the laboratory wave tank. Precision measurements of water-surface variations are achieved with the aid of laser-induced fluorescent (LIF) technique and detailed temporal and spatial features of the
Mach reflection are captured. During the development stage...
A decision support system (DSS) for nurse scheduling in
hospitals is developed and implemented on microcomputer. The
system includes algorithms and databases for developing weekly
work and shift patterns and combining these into working
schedules for nurses for a specified time horizon, and
interface modules for the user to interact...
It is the responsibility of humans, as environmental stewards, to monitor our impact on the environment so that efforts can be made to remediate the effects of our actions and change behaviors. To better understand our environmental footprint, sensitive and simple analytical methods are needed to quantify the contaminants that...
Chemicals must be bioavailable for there to be a potential for exposure and consequent risk to human or environmental health. Passive sampling devices (PSDs) are used to quantify the time-integrated concentration of bioavailable contaminants. We demonstrate that PSDs can be paired with the zebrafish developmental toxicity bioassay to produce site-specific,...
Toughened ceramics, or bridging ceramics, are being developed in an attempt
to widen the application base of traditional ceramics, which are brittle and have low
resistance to crack extension. The crack growth resistance of these extrinsically
toughened ceramics has been shown to increase with crack length, and unlike
traditional ceramics,...
End users' programs are fraught with errors, costing companies millions of dollars. One reason may be that researchers and tool designers have not yet focused on end-user debugging strategies. To investigate this possibility, this dissertation presents eight empirical studies and a new strategy-based end-user debugging tool for Excel, called StratCel....
The Horsetail Creek (HC) bridge is an example of an Oregon bridge that was classified as structurally deficient and was not designed to withstand earthquake (EQ) excitations. A fiber-reinforced polymer (FRP) rehabilitation was performed on the HC bridge to increase flexural and shear capacities for traffic loads. However, a seismic...
Nine species of ectomycorrhizal fungi were grown in liquid media over a pH range of 2-7. Species fell into five major groups: (1)
growth significantly best only at the optimal pH, (2) growth increased with increase of pH, (3) significantly best growth spans three pH units, (4) spans four pH...
Solid-state esophageal manometry was used to study physiology of the normal llama esophagus. Esophageal baseline pressures, esophageal response to water swallows and to balloon distention, and other motor activity of the esophagus during experiments were measured throughout the entire length of the esophagus. Gross and histologic anatomy, muscle fiber type...
The encroachment of western juniper into mountain big sagebrush plant communities and the subsequent development of juniper stands results in significant changes in vegetation structure and complexity. This study described and compared vegetative structure and bird community measures among four cover types representing a broad range of structural stages among...
How complex traits evolve continues to be a major focus of evolutionary
investigation. A current topic of debate is the hypothesis that the phenotypic
integration of complex traits gives rise to evolutionary constraints. I studied two color
traits in the common garter snake, Thamnophis sirtalis, that show a high level...