Low noise oscillators are universally needed in digital systems for clock generation and synchronization, and in radio-frequency communication front-ends for frequency up- and down-conversion. Noise in oscillators results in timing jitter, and limits the clock frequency of digital systems. In radio-frequency communication systems, phase noise in oscillators lowers the signal-to-noise...
Aquifer recharge is generally driven by fluids that move from the Earth’s surface to groundwater through the unsaturated zone, also known as the vadose zone. When the vadose zone is fractured, fluids, which may include contaminants, can move through the fracture network as well as the porous matrix. Such a...
The problem of locating a signal source, or an emitter, has many civilian and military applications, such as communication regulations enforcement, military reconnaissance, and search-and-rescue operations. Many of the most widely used emitter location methods rely on the accurate and robust estimation of the differential time delay,
or time-difference-of-arrival (TDOA),...
Community colleges in the United States have become an important educational destination for international students. According to the Institute of International Education (IIE, 2006), international students who enrolled for the first time at a U.S. campus increased by 8 per cent, from 131,946 students in 2004/2005 to 142,923 in 2005/2006....
The northwestern corner of the Basin and Range Province (NWBR) lies in southeast Oregon where extensive Late Miocene, mafic to bimodal basalt-rhyolite volcanism and extensional faults dominate a stark and arid landscape. Near Lake Abert, the Late Miocene volcanic section abuts Early Miocene, dominantly intermediate composition volcanoes at the Coleman...
In this dissertation, I present the work of developing more efficient and economical techniques for fragmenting large bio-molecules, and ultimately making mass spectrometry a more powerful tool in proteomics, DNA sequencing, and other areas of biomolecular analysis.
Aiming at lowering the installation and operating cost, and delivering electron capture dissociation...
Dendrimers are nanoscale macromolecules that have highly branched, core-shell structures. Higher generation dendrimers have close-packed peripheral functional groups and a hollow interior. The chemistry of the core and the terminal functionalities can be tailored according to the specific application. These structural characteristics provide room for the design of dendrimers to...
This study has two main objectives. First, we propose an alternative way for treating deposits in modeling a banking firm, which account for both their input and output features. Second, we contribute to modeling failures in the banking sector by distinguishing three groups of factors affecting failures: bank level, industry...
To identify factors limiting 'Candidatus Pelagibacter ubique' maximum cell density and growth rate in pure culture on seawater, the genome sequence of 'Cand. P. ubique' was analyzed, culturing experiments with organic and inorganic nutrient additions were made, and radiotracer uptake experiments were performed. The genome was sequenced, custom data mining...
Inner-shelf circulation and mechanisms of across-shelf transport of water masses were examined using seven years of observations collected by the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO) program, a long-term monitoring effort along the central Oregon coast. Since 1998, moored velocity and hydrographic measurements have been obtained during the...
Oxygen derived radicals are involved in many aspects of life from aging and cell signaling to disease states as diverse as heart disease, diabetes, neurodegeneration and inflammation. Therefore, understanding the function of antioxidant defense proteins and the effects of oxygen derived radicals on protein function is essential to elucidate the...
There has been an increasing realization of the value of innovativeness, the orientation toward innovation, for firms thriving to gain competitive edge. The US forest products industry is no different in this respect and many companies have active initiatives to bring about creativity from their own employees. At the same...
A. W. N. Pugin was a driving force in the Gothic Revival movement in England during the first half of the nineteenth century. He was an architect and a writer who expounded on the virtues of reviving Gothic architecture, not only for its reflection of the sacred mystery of ancient...
The number of women diagnosed with diabetes, including gestational diabetes, will continue to increase in the face of epidemic rates of obesity. The concurrent rise in obesity and diabetes makes it important to determine the risk factors for gestational diabetes mellitus (GDM) and the nature and extent of care offered...
Two experiments were conducted to evaluate the influence of a yeast-derived cell wall preparation (YCW) on forage intake and digestibility, ruminal fermentation characteristics, serum prolactin and prolactin stores, and milk production in beef cattle consuming high-alkaloid tall fescue straw. In Exp. 1, 16 Angus x Hereford ruminally cannulated steers (200...
Human activities are causing profound changes to the global environment, yet the potential consequences of these changes on rising atmospheric carbon dioxide and climate change are not well understood. Improving our understanding of these processes requires an enhanced awareness of how global ecosystems are changing and how these changes affect...
Twenty-six Holstein and 18 Jersey multiparous cows in a randomized block design were assigned by calving date and breed to a non-anionic prepartum diet (CTRL) or a treatment diet containing a commercial anionic salt supplement (Animate®). Control and treatment diets were formulated to a dietary anion-cation difference (DCAD) of 21.3...
Shaped by life course and feminist perspectives, this study investigated the influence of finances, human capital, health, family situations, and work factors on two different retirement transitions among married and partnered men and women. Because women and men arrive at retirement under different life circumstances, logistic regression analyses were conducted...
This dissertation consists of two papers on International Trade topics. The first paper addresses the development of trade patterns between countries in transition and developed economies. The second paper focuses on the nonparametric estimation of the Knowledge-Capital model of multinationals. The first paper provides a framework for understanding patterns of...
Advanced Very-High Resolution Radiometer 4-km data were collected over the northeast Atlantic for May-August, 1995-1999. Aerosol optical depth was retrieved in cloud-free pixels. In pixels containing clouds from only single-layered, low-level systems, a retrieval scheme that accounts for partly-cloudy pixels was used to retrieve: cloud optical depth, droplet effective radius,...
As researchers, policymakers and employers begin focusing
on consumer driven health plan models and medical savings
accounts (MSAs), a better understanding of the political
viability of such reform initiatives is necessary. The
purpose of this study was to survey state legislators'
knowledge and perceptions of medical savings accounts
(MSAs) and...
This study examined a web-based undergraduate course structured around social learning theories through the lens of social construction as a theoretical framework and a case study research method. The purpose of the study was to investigate students' learning experiences from a cognitively guided research framework. Instructional strategies practiced in the...
Mass transfer processes in food systems, such as solute infusion, are poorly understood because of their complex nature. Food systems contain porous matrices and a variety of continuous phases within cellular tissues. Mass transfer processes are generally not pure diffusion: often convection, binding and obstructing diffusion will occur. Monte Carlo...
This dissertation is composed of three essays regarding the finite sample properties of estimators
for nonparametric models.
In the first essay we investigate the finite sample performances of four estimators for additive
nonparametric regression models - the backfitting B-estimator, the marginal integration M-estimator
and two versions of a two stage...
Lichens are an important part of the biota in western Oregon forests, where
they perform valuable ecological roles and contribute significantly to biodiversity.
Lichens in western Oregon are threatened by a number of factors including air
pollution and land use practices. If we wish to maintain the persistence of lichens...
Parasites are unique study organisms for evolutionary ecologists. Yet, molecular ecology studies on parasites have lagged far behind those on free-living organisms. The goal of the review in Chapter 2 was to illustrate areas of research that may be of particular interest in relation to the parasitic life style and...
Jointed goatgrass (Aegilops cylindrica Host; 2n=4x=28; CCDD) is an
agriculturally important species both as a weed and as a genetic resource for
wheat (Triticum aestivum L.; 2n=6x=42; AABBDD) improvement. In order to
better understand the evolution of this species, the diversity of Ae. cylindrica
was evaluated along with its progenitors,...
Tomato [Lycopersicon esculentum Mill.] plants are chilling sensitive and do not
naturally accumulate glycinebetaine (GB), a metabolite that functions as a stress
protectant in plants. While GB can increase tolerance of tomato plants to salt and
drought stresses, its effect on chilling tolerance has not been examined. To evaluate
whether...
The purpose of this study was to describe Iranian immigrant
women's knowledge, beliefs and attitudes towards breast cancer,
and their breast cancer screening behaviors. Specifically, this
research examined the predictors of age-specific breast cancer
screening participation among this population. The participants in
this study consisted (n=34 1) of self-identified first...
Wheat (Triticum aestivum L.) plants exposed to higher than usual temperatures during ripening show altered agronomic and grain quality characteristics. Given that seasonal variation in quality creates difficulties in the marketing and processing of grain, improving the genetic adaptation of wheat cultivars to heat stress is an important objective in...
The purpose of this study was to develop a profile
of Christian College physical education faculty members
regarding their academic preparation, professional
experience, and selected duties, as well as to identify
important components of graduate preparation at the
doctoral level for future faculty at these
institutions.
A survey instrument was...
Enzymes play an important role in the environment, they breakdown natural-occurring and anthropogenic molecules so that they can be transported into cells and utilized. Enzyme assays are routinely used in soil science and oceanography to measure the activities of specific processes and to serve as general indicators of microbial activity....
Habitat fragmentation has been widely studied in the biological literature and
is considered a primary threat to biodiversity. However, there has been little research
on land-use policies to reduce fragmentation. This dissertation focuses on two major
research issues related to fragmentation policies. First, I develop an analytical model
to analyze...
In what is called participatory democracy scholars and practitioners have been calling for the involvement of citizens in decisions that affect their lives. Citizens who emerge to participate in technically complex, decision-making processes find that their involvement is often minimized, disregarded, or neglected due to barriers such as specialized scientific...
According to Block (1999), the greatest problem with inclusion in physical education is the lack of personnel support. Most help comes in the form of teacher assistants such as peer-tutors and paraprofessional who receive very little, if any, direction from the general physical education teacher. However, what remains unknown are...
To increase our understanding of the timber harvesting behavior of family forest owners, I developed theoretical and empirical timber harvesting models for family forest owners in the southeastern United States. An individual-choice model was the basis for the models. Family forest owners were modeled as utility-maximizers who made harvesting decisions...
Small broomrape (Orobanche minor) is a parasitic weed that attaches to the roots of red clover (Trifolium pratense). Small broomrape invasion presents a significant threat to the future of red clover seed production in Oregon. This study was conducted to investigate and develop small broomrape management options for red clover...
A theoretical argument is presented to suggest that engineering curriculum be
designed to develop social capital. Additionally, the value of social capital in the
retention of students in the College of Engineering, and the development, role, and value
of social capital in an electrical engineering laboratory is evaluated. Data collected...
Halogenated monoterpene production by the red macroalga Octhodes secundiramea was studied-under different levels of nutrient, bromide, vanadium and light delivery. The key products formed were identified as myrcene, betaelemene, the Z and E isomers of l0-bromomyrcene, 3-chloro-10E-bromomyrcene, Apakaocthodene A, and isomers of chloromyrcene and dibromomyrcene. The proposed pathway begins with...
In a fluidized bed of magnetically susceptible particles, the presence of
a magnetic field induce the formation of particle chains due to interparticle
magnetic forces. The resulting effect is a change in the overall spatial
distribution of the particles, transitioning from a random, isotropic distribution
to an ordered, anisotropic distribution....
My dissertation focuses on the factors that influence variation in female reproductive success in plethodontid salamanders and in toads. Variation in reproductive success fuels evolutionary change. Although, females often have been overlooked in studies of reproductive success due to perceived lower levels of variation when compared to variation in male...
It is well known that the mitochondrial genome has a much higher spontaneous mutation rate than the nuclear genome. mtDNA mutations have been identified in association with many diseases and aging. mtDNA replication continues throughout the cell cycle, even in post-mitotic cells. Therefore, a constant supply of nucleotides is required...
Questions relating to economic performance, biological conservation and variation in resource abundance and harvest of ocean shrimp have led to increasing pressure for management action. Developing effective management policies for this highly variable resource requires a comprehensive understanding of the fishery and marine processes. Important factors in understanding the fishery...
Volcan Aucanquilcha, a Pleistocene to Recent composite volcano in northern Chile, is the youngest and center-most member of the 11 m.y.-old Aucanquilcha Volcanic Cluster (AVC). The AVC has produced [approximately]350 km³ of lava over its history. Magmatism started slowly and was punctuated by high rates of eruption between 4.5 and...
Forest managers are challenged to provide timber revenues and other resources for society while protecting and enhancing components of biodiversity that are often associated with older forests or older forest structure, such as dead wood. We examined small mammal response to timber harvest in stands 8-10 years following group-selection, two-story,...
Atmospheric boundary layers become stably stratified at night over land when the surface becomes colder than the air layer above. In stable nocturnal boundary layers (SNBL), turbulence becomes weak and intermittent, terrain-induced phenomena such as drainage currents or gravity-waves emerge and the surface heterogeneity is enhanced. Because of their complexity...
With respect to a multienzyme complex of deoxyribonucleoside triphosphate (dNTP) synthesis somehow juxtaposed with DNA replication sites, our laboratory has demonstrated the existence of a multienzyme complex in T4-infected E. coli, named the T4 dNTP synthetase complex, but the idea of direct linkage of dNTP synthesis to DNA replication and...
In this dissertation, I present electronic spectroscopy of a few biologically relevant species and their complexes with solvent molecules in the gas phase using a variety of techniques, including resonantly enhanced multiphoton ionization (REMPI), laser induced fluorescence (LIF), and zero kinetic energy (ZEKE) photoelectron spectroscopy. My work on several methylated...
PCR-based codon-specific random mutagenesis and site-specific mutagenesis were performed to construct a library of 18 amino acid changes at Arg276 in the conserved leucine-loop of the core catalytic domain of human uracil-DNA glycosylase (UNG). Each Arg276 mutant was then overproduced in E. coli cells and purified to apparent homogeneity by...
The neurohypophysial peptide system is involved in modulating a
variety of physiological, neurological, and behavioral responses in
vertebrates. The principal forms of these peptides in non-mammalian
tetrapods are vasotocin (VT) and mesotocin (MT). The studies described
in this thesis used pharmacological, molecular, and biochemical
techniques, along with phylogenetic analyses, to...