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...
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...
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...
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...
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...
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...
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...
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...
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...
There are seven commercially important species of salmon and trout (genera Oncorhynchus and Salmo) in North America, many of which are closely related but command markedly different prices. The purpose of this research was to provide improved and novel methods for the detection of salmon species substitution on the commercial...
Montane meadows comprise a small area of the predominantly forested landscape
of the Oregon Cascade Range. Tree encroachment in the last century in these areas has
threatened a loss of biodiversity and habitat. Climate change in the coming century may
accelerate tree encroachment into meadows, and exacerbate biodiversity loss. Multiple...
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...
Due to age, original design that is deficient by modern standards, inadequate maintenance, environmental conditions, and increasing loads, large numbers of bridges in United States and elsewhere are classified as deficient and in need of rehabilitation or replacement. According to a national bridge inventory established by the Federal Highway Administration,...
Ecosystems are highly heterogeneous systems subjected to important levels of environmental variability; however, it is common in terrestrial biogeochemical models to assume homogeneous properties of the elements of the system or constant environmental conditions. For some processes, heterogeneity in these models is treated very simplistically, but there is not much...
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...
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...
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...
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...
A duty-cycle controlled switched resistor is a tunable resistive element that uses pulse width modulation as the method of tuning. This thesis will describe the operation of switched resistors and propose several circuit architectures that are well suited to the use of switched resistors. These architectures include filters, mixers, and...
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...