The rural two-lane highway in the southeastern United States is frequently associated with a disproportionate number of serious and fatal crashes. The major research objectives are to investigate the relations between probabilities of fatal crash type occurrence and potential contributing factors from road geometric design characteristics and roadside, environmental features....
The lingcod (Ophiodon elongatus) is an important groundfish species in both recreational and commercial fisheries of the Northeastern Pacific. It is a large, fast-growing, generalist predator of invertebrates and fishes. In response to concerns that lingcod may limit populations of rockfishes (Sebastes spp.), I compared the diets of 375 adult...
The importance of accurately identifying inventories of domestic energy, including forest biomass, has increasingly become a priority of the US government and its citizens as the cost of fossil fuels has risen. It is useful to identify which of these resources can be processed and transported at the lowest cost...
Managing rangelands with livestock grazing is a tool that can be applied to obtain vegetation management objectives. Animals utilize available resources, which vary in quantity and quality, across the landscape. Their movements are adjusted to the spatial and temporal heterogeneity of resource distribution. Controlling livestock distribution is fundamental to economically...
In Zambia, there are approximately 920,000 people living with HIV/AIDS. Children are often referred to as a "window of hope" due to a low HIV/AIDS prevalence rate (UNAIDS/WHO, 2006). With growing numbers of infections and an increased strain on the social and economic structure due to HIV/AIDS there is a...
The marine climate of the Galapagos is spatially and seasonally
heterogeneous. A taxonomically comprehensive study of Galapagos zooplankton has
never been done. This study is an initial effort to establish the distribution and
community structure of zooplankton in the Archipelago. I collected zooplankton
samples by vertical tows over the Galapagos...
Many engineering devices and propulsion systems suffer from undesirable effects of cavitation; such as degradation in the efficiency of pumps and turbines, generation of noise and vibration on ship propeller, increased drag and erosion of propeller blade, etc.
In spite of decades of research on this problem, detailed study of...
Sprawled-posture insects exhibit a remarkable ability to rapidly run in a stable manner
over complex terrain, a feat that has yet to be equaled by man-made legged robots.
Recent experimental results suggest that these insects may employ a hierarchical
control structure, in which locomotion performance emerges from a combination of...
Electronic structure calculations for free and immersed atoms are performed in the context of unrestricted Hartree-Fock Theory. Spherical symmetry is broken, lifting de-generacies in electronic configurations involving the magnetic quantum number m. Basis sets, produced from density functional theory, are then explored for completeness. Com-parison to spectroscopic data is done...
Two essays are focused on semiparametric econometric methods. The first essay investigates applicability of the smooth back tting estimator (SBE) to statistical analysis of residential energy consumption. The second essay attempts to incorporate additivity restrictions into semiparametric stochastic frontier estimation. The procedure described in the first study is used to...
Grapes (e.g. Vitis vinifera L.) are one of the more important fruit crops from an economic standpoint with world market values over 550 million US dollars in 2007 and 2008, second to apples (United States Department of Agriculture). While a satisfactory level of ripeness is of primary concern, the quality...
We propose a new classification method for longitudinal data based on a semiparametric approach. Our approach builds a classifier by taking advantage of modeling information between response and covariates for each class, and assigns a new subject to the class with the smallest quadratic distance. This enables one to overcome...
Pesticides are among the most pervasive environmental contaminants and they are an important potential risk for human health. Agricultural workers are constantly exposed to pesticide spray, drift and residues in the soil and foliage. Many agricultural pesticides are readily absorbed by the body, through contact with the skin, the respiratory...
Endothelial activation with increased expression of cellular adhesion molecules, chemokines and pro-inflammatory cytokines critically contributes to vascular inflammation and the initiation and progression of atherosclerosis. By affecting redox-sensitive cell signaling pathways and transcription factors, redox-active transition metal ions, such as copper and iron, may play an important role in these...
Microbial electrolysis provides a new approach for hydrogen generation from renewable biomass. At current stage, the most likely limiting factors for successful scale up of this technology are the large internal resistance and high fabrication cost. This dissertation presents an attempt to overcome these limitations by investigating novel microbial electrolysis...
There are typically two responses to the complex environmental problems of our time: 1) doom and gloom and 2) optimism. There is a lot of doom and gloom in the environmental literature. This literature warns that the future portends danger for humans and their life support systems. But when one...
My thesis explored the effects of environmental variability on population
dynamics and community composition of aquatic insects. Environmental variability in
the form of flow regime in streams can limit the distribution and life-history traits of
aquatic insects. I used tributaries to the McKenzie River in Oregon with dramatically
different flow...
Non-destructive testing methods and applications have become of increasing interest due to the worldwide aging and deteriorating infrastructure network. In the field of Civil Engineering, bridges and bridge components as well as non-structural elements such as roadway pavements for example, are affected. In particular, the Acoustic Emission (AE) technique offers...
Oxidative stress is recognized as an important underlying factor in the
pathogenesis of many degenerative diseases as well as normal senescence. The
free radicals, reactive oxygen species (ROS) and electrophiles produced during
oxidative stress are capable of modifying nucleic acids, lipids and proteins. There
are a variety of oxidative modifications...
My dissertation concerns two separate issues. The first issue is examined in Essay One, and the second issue is examined in Essays Two and Three.
The first essay develops an economic model of the determination of the rental rate of leased farmland in the United States. Particular attention is placed...