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...
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...
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...
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...
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...
Delta-Sigma (ΔΣ) analog-to-digital converters (ADCs) are traditionally used in high quality audio systems, instrumentation and measurement (I&M) and biomedical devices. With the continued downscaling of CMOS technology, they are becoming popular in wideband applications such as wireless and wired communication systems,high-definition television and radar systems. There are two general realizations...
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...
This thesis addresses Micro Aerial Vehicle (MAV) control by leveraging learning based techniques to improve robustness of the control system. Applying classical control methods to MAVs is a difficult process due to the complexity of the control laws with fast and highly non-linear dynamics. These methods are mostly based on...
This thesis presents a progression of novel planning algorithms that culminates in a new family of diverse Monte-Carlo methods for probabilistic planning domains. We provide a proof for performance guarantees and analyze how these algorithms can resolve some of the shortcomings of traditional probabilistic planning methods. The direct policy search...
The immune toxicity of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has been studied for over 35 years, but only recently has the profound immune suppression associated with TCDD exposure been linked to induction of regulatory T cells (Tregs). The effects of TCDD are mediated through binding the aryl hydrocarbon receptor (AhR), a ligand-activated transcription...
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 bi-directional relationships within the personal and contextual environments of adolescents are critical to the development of adolescents and their transition into adulthood. Opportunities for youth to participate in and provide leadership in meaningful programs, gain life skills, and interact with adults in sustained relationships are key features leading to...
Reinforcement learning in real-world domains suffers from three curses of dimensionality: explosions in state and action spaces, and high
stochasticity or "outcome space" explosion. Multiagent domains are particularly susceptible to these problems. This thesis describes ways to mitigate these curses in several different multiagent domains, including real-time delivery of products...
Functional polymers and proteins at interfaces and surfaces are of fundamental importance for biomaterials, biocatalysis and microreactor applications. Candida antarctica lipase B immobilized on poly-DL-tryptophan tethers showed 30x higher
specific activity in aqueous and non-aqueous media than the same enzyme adsorbed or covalently bound directly to the surface. An excess...
X-ray computed tomography is a noninvasive imaging modality capable of reconstructing exact density values of 3D objects. Computed tomography machines are deployed across the world to provide doctors with an image that reveals more detail than a standard x-ray image. We investigate algorithms based on exact computed tomography reconstruction formulas...
The purpose of this exploratory study was to examine scientific arguments constructed by secondary science teachers during instruction. The analysis focused on how arguments constructed by teachers differed based on the mode of inquiry underlying the topic. Specifically, how did the structure and content of arguments differ between experimentally and...
The adduction of proteins and other biomolecules by electrophilic lipid peroxidation products such as 4-hydroxy-2-nonenal (HNE), 4-oxo-2-nonenal (ONE), malondialdehyde (MDA) or acrolein (ACR) is thought to be an initiating and/or propagating factor in the pathophysiology of several diseases such as atherosclerosis, diabetes, Alzheimer's, Parkinson's and other age-related disorders. The identification...
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...
The current appeal of reality television is undeniable, with the specific genre of makeover television having special nationalistic and moral appeal in the United States. Previous analyses of NBC's weight-loss makeover show The Biggest Loser suggest that the program is inherently problematic because of its ingrained fat bias and unethical...
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....
Measurements of social constructs that evaluate natural hazard preparedness are important to decrease natural hazard vulnerability. Preparedness reduces natural hazard impacts and human vulnerability. Investment in education and education research contribute to human sustainable development and natural hazard preparedness. Faced with other needs, people typically do not prepare enough to...
This study examines the U.S. educational experiences of Saudi Arabian students. Using qualitative case study and photo-elicitation research methods, this study conducted multiple interviews with 25 Saudi students and explored their perceptions of their American learning environment, how it differed from Saudi Arabia, and the strategies they developed to successfully...
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...
The purpose of this qualitative case study was to investigate the development of social norms in a fifth-grade reform-based mathematics classroom through a close examination of one teacher's actions during the first three weeks of school. This study offers insights into the following research questions: 1) How does an elementary...
Studies using the pluripotent embryonic carcinoma cell line, P19, as a retinoic acid (RA)-responsive model system have been instrumental towards our understanding of the RA-dependent signaling pathways in development and homeostasis. Grp1-associated scaffold protein (GRASP; also known as Tamalin) was first identified by our group, as a gene robustly induced...
Rubber without reinforcement has limited applications. The strength of reinforced rubber composites can be ten times stronger than that of unreinforced rubbers. Therefore, rubber composites are widely used in various applications ranging from automobile tires to seals, valves, and gaskets because of their excellent mechanical elastic properties. Silica and carbon...
The vegetation in Yosemite National Park changed during the 20th century and may change in the 21st century in response to climate change. Vegetation surveys made during the 1930s and the 1990s provide benchmark records separated by 60 years. This study uses the MC1 dynamic global vegetation model to forecast...
Soil respiration, or the combined CO₂ emissions from roots and soil microorganisms, constitutes one of the largest losses of carbon (C) from terrestrial ecosystems. The major drivers of soil respiration, which include soil moisture, temperature, and substrate quality, have been known for some time. Nevertheless,
correlations between these drivers and...
The long-term evolution of Gaussian eddies is studied in an equivalent barotropic model using both linear and nonlinear quasi-geostrophic theory in an attempt to understand westward propagating satellite altimetry tracked mesoscale eddies. By examining both individual eddies and a large basin seeded with eddies, it is shown that long term...
Creeping bentgrass (Agrostis stolonifera L.) is an outcrossing, small- seeded, perennial grass that can establish outside of cultivation and has several compatible relatives. Glyphosate is a nonselective, broad spectrum, herbicide. Transgenic glyphosate-resistant (GR) creeping bentgrass (GRCB) was developed by The Scotts Company and Monsanto, but is still under USDA-APHIS regulated...
The research‘s purpose was to examine how exemplary community college study abroad programs assisted student participants in acquiring global competence. Three research questions were explored: 1.What issues need to be anticipated when planning a study abroad program for community college students in order to effectively incorporate opportunities for students to...
The purposes of this study were to examine the experiences of African American female students attending urban community colleges, to gain further understanding of how they interpret the meaning of persistence, and to identify the factors that affect their persistence. African American women attending community college in Los Angeles were...
The purpose of this research study was to describe and improve understanding of the meaning of institutionalized sustainability and the role that a college president plays in institutionalizing sustainability on a community college campus. The following questions guided the research: (a) What does it mean to have sustainability “institutionalized” at...
The purpose of this study is to explore the applicability of Collins’ (2001) Good-to-Great theory, as originally introduced for the business sector and as adapted for the social sector, to the ways a community college moved from being “good” to being
“great.” The following questions guided the research: (1) Which...