Graphium sp., a eukaryotic alkanotroph, is able to oxidize small-molecular weight gaseous n-alkanes, diethyl ether and the branched ether, methyl tert butyl ether
(MTBE). However, information regarding the biochemistry of fungal-mediated alkane and ether metabolism is limited, and questions regarding the identity of alkane oxidation catalysts and the genetic underpinnings...
RNA silencing pathways are required for a wide variety of processes in most
eucaryotes. In plants, small-interfering RNA (siRNA) arising from transposons and other
repetitive sequences is associated with heterochromatin formation and maintenance.
MicroRNAs and trans-acting siRNAs encoded at discrete loci function as negative regulators of
gene expression by triggering...
Rapid change-of-direction tasks have been associated with non-contact anterior cruciate ligament (ACL) injuries and females are more likely to suffer this injury compared to males. The purpose of this investigation was to evaluate the biomechanical behavior of running and three rapid change-of-direction tasks and determine whether sex differences exist across...
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...
There is a wealth of research on issues surrounding teacher burnout and school reform. The literature on burnout, however, does not provide information on system-based burnout prevention models. Comprehensive reform, although intended to improve schools as a whole, does not look at reform models developed as sources of teacher support....
The focus of this study is to develop a general and low-cost solution-based
process to fabricate micro- and nano-structured semiconductors that are suitable
for electronics. This process uses simple metal halide precursors dissolved in a
solvent (organic or aqueous) and is capable of forming uniform and continuous
thin films via...
Environmental stress can negatively affect the ability of organisms to reproduce. Energetic trade-offs exist in all organisms, and under stress, energy may be allocated away from reproduction and towards physiological defense and repair mechanisms. The rocky intertidal environment is ideal for investigating the influence of environmental stress, as organisms are...
Cnidarians, such as anemones and corals, engage in an intracellular symbiosis with
photosynthetic dinoflagellates. Corals form both the trophic and structural foundation of
reef ecosystems. Despite their environmental importance, little is known about the
molecular basis of this symbiosis. In this dissertation we explored the cnidariandinoflagellate symbiosis from two perspectives:...
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...
Many White social scientists and educators are unaware of and/or
detached from the realities of racism and conduct social research that 1.)
perpetuates stereotypes, falsely setting People of Color as inferior and
White people as superior and/or 2.) explains the differences of White
people and People of Color in terms...
The Pacific Northwest has become one of the nation’s premier sweet cherry,
Prunus avium, production areas. As production of sweet cherries has flourished in
Oregon and Washington, so has powdery mildew, caused by the fungus
Podosphaera clandestina, which infects both foliage and fruit causing severe
economic damage to growers. Sweet...
The adsorption and elution of the antimicrobial peptide nisin at hydrophobic,
silanized silica surfaces coated with the poly[ethylene oxide]-poly[propylene oxide]-
poly[ethylene oxide] surfactant Pluronic® F108 was measured in situ, with ellipsometry.
While such layers are known to inhibit protein adsorption, nisin was observed to adsorb in
multilayer quantities, to an...
Accurate chromosome segregation and cell cleavage are critical to maintaining genomic integrity. Both events involve the spindle apparatus, but the exact mechanics is as puzzling as the contradicting models proposed in the last two centuries. In this dissertation, current prevailing models of chromosome segregation and cell cleavage are tested using...
Metal and hydrogen ion acidity and extreme nitrate concentrations typical of
Department of Energy (DOE) legacy waste sites pose formidable challenges to
successful implementation of in situ bio-immobilization. Intermediate-scale (~ 2.5 m),
flow through models of an in situ bio-barrier were constructed to investigate U and Tc
removal from groundwater...
To effectively study dynamic processes like forest succession over long time periods one must effectively integrate data collected at many different times, locations and spatial scales. The purpose of this research is to integrate forest inventory data collected by the USDA Forest Service’s Forest Inventory and Analysis (FIA) Program with...
Piliostigma reticulatum and Guiera senegalensis are two native shrubs that
coexist with row crops in parkland systems of the Sahel of Africa. Although
permanently green all year around in soil depleted in nutrients and dry for a nine-month
period, these shrubs have been largely overlooked. Conventional management of these
shrubs...
There is a strong evidence that human papillomavirus (HPV) is the key causative agent of cervical cancer. However, the majority of women who are exposed to the oncogenic HPV do not develop invasive cervical cancer, suggesting that other factors could play a role in the cause and progression of cervical...
Overtly non-toxic doses of organochlorine (OC) insecticides perturb lipid homeostasis
in mice and rats. To increase understanding of how chlordecone (CD), an OC
insecticide, modulates cholesterol (CH) homeostasis, we determined the effect of CD
pretreatment on the tissue and hepatic subcellular distribution of exogenous [¹⁴C]CH. Corn oil alone or CD...
Many pesticides, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers
(PBDEs), and polycyclic aromatic hydrocarbons are persistent, bio-accumulative, and
toxic. These semi-volatile organic compounds (SOCs) can undergo atmospheric
transport and deposition in cold, remote ecosystems. A better understanding of their
accumulation in the fish of these ecosystems is important to better predict...
Orchard floor management (OFM) practices can improve soil function and alter
the soil biological community. Soil function is dependent on soil forming materials and
on management practices but little is known about how OFM affect orchard soil quality,
fertilizer N uptake, or tree growth and production.
Research plots were located...
More than 4,000 specimens of fruits and seeds were extracted
from the matrix removed from inside the skulls of sabre-tooth cats
excavated from various pits in the Rancho La Brea deposits. Of this
number, spproximately 1,445 specimens are involved in this study.
Many comparisons with modern fruits and seeds made...
Electron-biomolecule interactions are a biologically relevant field of study
because there are several ion fragmentation techniques that have come to the forefront
in mass spectrometric analysis that involve the interaction of charged peptides and
free electrons. By studying the electron energies that cause fragmentation in neutral
amino acids, amino acid...
The main contributions of this thesis are the development and
application of four computationally efficient solutions for
least-squares-based (LS-based) minimum variance spectral estimation
(MVSE). They are: (1) fast computational solution for the 1-D
covariance LS-based MVSE, (2) fast computational solution for the
1-D modified covariance LS-based MVSE, (3) fast computational...
In this thesis, maximum likelihood Doppler frequency estimation and phase noise suppression algorithms for Orthogonal Frequency Division Multiplexing (OFDM) systems are presented. A novel handover decision algorithm for wireless systems, called predictive base station switching (PBSS), is also introduced.
The maximum Doppler Frequency is the ratio of the speed of...
The fungus Cochliobolus victoriae causes Victoria blight of oats and Arabidopsis and is pathogenic due to its production of a compound called victorin, which induces programmed cell death in sensitive plants. Victorin sensitivity in Arabidopsis is conferred by the dominant gene LOCUS ORCHESTRATING VICTORIN EFFECTS1 (LOV1), which encodes a coiled-coil-nucleotide...
Clostridium perfringens type A isolates, an anaerobic enterotoxigenic spore forming bacterium, are the third leading cause of food-borne disease in the United States. Factors that contribute to the virulence of C. perfringens include the ability of the bacterium to form heat resistant spores and to produce an enterotoxin (CPE). Although...
Tetracycline (Tet)-resistant strains of Chlamydia suis were isolated from swine
farms in the Midwest. The isolation of the resistant strains was significant
because Tet is an antibiotic used to treat infections by veterinarians and
doctors. One of the tetracycline (Tet)-resistant strains, R19, was able to
survive in Tet up to...
Human exposure to the carcinogenic polycyclic aromatic hydrocarbons (PAHs) benzo[a]pyrene (B[a]P) and dibenzo[a,l]pyrene (DB[a,l]P) is through environmental complex mixtures, such as urban dust particulate matter (UDPM) and diesel exhaust (DE), however the potency of these PAH within a mixture is not established. To determine the effect of these mixtures on...
In mature Arabidopsis seeds, the testa (seed coat) is no longer a living tissue. Thus,
major sites of gene expression in imbibed seeds are the internal living tissues such
as the embryo and the endosperm. To elucidate the molecular mechanisms of seed
germination, the gene regulation in these two tissues...
A suspected glyphosate-resistant Italian ryegrass (Lolium multiflorum) (OR) population was collected from a filbert (Corylus avellana L.) orchard near Portland, OR. Based on the dose-response experiments conducted in the greenhouse, it was found that the suspected glyphosate-resistant population was approximately fivefold more resistant to glyphosate than the susceptible (S) population....
Many members of the Phylum Cnidaria are mutualistic with unicellular dinoflagellates belonging to the genus Symbiodinium. Corals are the most widely recognized example of these associations due to their key ecological importance in coral reef ecosystems where they serve as the structural and trophic foundation of these rich ecosystems. Coral...
SOCs volatility and persistence properties cause many SOCs to become ubiquitous in the environment as well as accumulate in areas with lower temperatures such as polar or orographic regions. Many anthropogenic SOCs pose a serious risk to human and ecosystem health because of their persistent, bioaccumulative, and toxic properties in...
This dissertation is about the likelihood analysis of ordered categorical responses in a longitudinal/spatial study, meaning regression-like analysis when the response variable is categorical with ordered categories, and is measured repeatedly over time or space on the experimental or sampling units. Particular attention is given to the multivariate ordinal probit...
The biorevolution in the 1970’s greatly stimulated investment in life-science
research. The present dissertation is aimed at evaluating the impact of US public
investment on industrial investment in life-science research. The focus is on three major
life-science fields: biology, medicine, and agriculture. A dynamic model of industrial
R&D investment is...
Chlamydiae are obligate intracellular bacteria that infect a variety of
eukaryotic hosts and affect normal host processes. Within host cells, their
developmental cycle takes place inside non-acidified vacuoles termed inclusions. An
inclusion membrane composed primarily of secreted chlamydial synthesized proteins
called Incs encloses the inclusion. At this location, Incs have...
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...
Delta-Sigma (ΔΣ) analog-to-digital converters (ADCs) are widely used in wireless transceivers. Recently, continuous-time (CT) ΔΣ ADCs gain growing interest in wireless applications for their lower power consumption and wider input bandwidth as compared with the discrete-time (DT) counterparts.
In this thesis, a wideband low-power CT ΔΣ modulator for next generation...
Innovativeness, or the propensity of a firm to create and/or adopt new products, process and business systems, has been measured using several methods in previous research. Examples of theses methods include current technology, self-evaluation, research and development funding, the number of new products, and intellectual property. In addition to the...
The objectives of this thesis were to examine the links between soil microbial community composition and function using the nitrogen (N) cycle as a model for these interactions and to assess the impact of environmental factors such as microclimate, vegetation type, and nutrient availability on microbial diversity and N transformations...
The purpose of this dissertation was to define macrolichen community gradients in relation to succession, grazing and the environment. First, species scores indicating when macrolichen species appeared following disturbance were derived from the literature. Weighted averaging of these data with a community matrix created a successional score for each sample...
Island biogeography has strongly influenced the study of biodiversity because
archipelagos provide natural model systems for investigating patterns of diversity and the
processes that shape ecological communities. I investigated the influence of area and
isolation of islands (n = 32) in the Gulf of California, Mexico on patterns of richness,...
This dissertation focuses on the importance of pelagic subsidies in the Northeast Pacific to rocky shore community regulation. My results document the patterns of pelagic subsidy supply, determine if those subsidies are correlated with community structure, and examine if community regulation differs between areas of high- and low-subsidies. Understanding how...
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...
Research suggests that long-term participation in professional development is critical in helping teachers meet the increasing demands of reform efforts and changing practice (Gallucci, 2003; Darling-Hammond, 1995; Little, 1993). Understanding the influence that participation in a community of teachers as a community of practice may have on teachers’ professional growth...
To increase the knowledge needed to successfully implement the ecosystem-based approach to fishery management, this dissertation investigates important issues within the economics of choice and the economics of displacement. In particular, a discrete choice model of the fishing location decision in the Newport, Oregon bottom trawl groundfish fishery is estimated...
The critical contribution of this dissertation is to provide a better
understanding of the fundamental Chemical Bath Deposition (CBD) growth
kinetic and mechanism for the well known II-VI semiconductor CdS using the
newly developed continuous flow microreactor. This continuous flow microreactor
provides the temporal resolution to control the homogeneous reaction...
With the growing demand for portable/consumer electronics, such as digital
audio/video (AV), the downscaling of device dimensions, which enables the
integration of an increasing number of transistors in a single chip, is mandatory.
This trend also continuously pushes the power supply voltage down to reduce the
power consumption and improve...
Weeping alkaligrass (Puccinellia distans) and Nuttall’s alkaligrass (Puccinellia
nuttalliana) infest Kentucky bluegrass seed fields of eastern Oregon. Weeping
alkaligrass is an introduced species from Eurasia, whereas Nuttall’s alkaligrass is
native to semi arid environments of western North America. These species are often
referred to collectively as ‘alkaligrass’; however, for farmers...
Extending the flight time of an autonomous unmanned air vehicle by soaring is
considered. A suboptimal controller is developed and successful static soaring is
demonstrated with a 6 degree of freedom glider model. Altitude gain rates of between
¼ and ½ m/s are achieved with this simple implementation.
A hybrid...
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...
Pseudomonas butanovora, Mycobacterium vaccae, and Nocardioides sp. CF8 utilize distinctly different butane monooxygenases (BMOs) to initiate degradation of recalcitrant chlorinated ethenes (CEs) that pollute aquifers and soils. BMO-dependent degradation of CEs such as trichloroethylene (TCE) can lead to cellular toxicities. The type and severity of TCE transformation-dependent damage can have...
The central purpose of this dissertation was to explore and expand the use of
an uniform electric field for orientation and for subsequent spectroscopic investigation of asymmetric polar molecules in the gas phase. The systems of study were nitrobenzene (NB) and the nitrotoluene (NT) isomers. We were able to quantitatively...
Studies toward the total syntheses of highly potent cytotoxic alkaloids
including the bromopyrrole alkaloids and indole alkaloids were conducted and are
described. Studies carried out in the course of this dissertation consist of five total syntheses of natural products that include bromopyrrole alkaloids nagelamide A, D and agelastatin D as...
A state-of-the-art radiation detection system for simultaneous spectroscopy
of beta-particles and gamma-rays has been developed. The system utilizes a triplelayer
phoswich detector and a customized Digital Pulse Processor (DPP) built in
our laboratory. The DPP board was designed to digitally capture the analog signal
pulses and, following several digital preprocessing...
The National Assessment of Educational Progress (NAEP) has measured the condition and progress of education since 1969 to provide information on performance of American students in core subjects to policymakers, educators, and the public. Yet, there has been a perception that theses federal resources are under utilized. An analysis of...
The Baculoviridae comprise a diverse group of occluded DNA viruses that contain large double-stranded DNA genomes of 80 - 180 kb and may encode up to 180 gene products. To understand how baculoviruses replicate and process their genomes and the gene products that are involved in these events, a series...
In order to produce infectious virus progeny, vaccinia virus (VV)
undergoes morphogenic proteolysis to regulate the structural rearrangements of
virus particles. Several of the major structural precursor proteins of VV are
cleaved at a conserved Ala-Gly-X (where X is any amino acid) motif by the VV
I7L core protein proteinase...
This qualitative study examined the experiences and perceptions of males aged 16 – 19 who did not complete a traditional high school diploma program because of feeling alienated from the school system. Five participants described their school experiences from elementary school through the point in high school when they decided...
The continued scaling of deep-submicron CMOS technology enables low-voltage high-frequency phase-locked loops (PLLs) to be fully integrated in complex mixed-signal systems. However, fluctuations due to the manufacturing process and variations in
environmental conditions, such as supply voltage and temperature, are also significantly increased. As a result, the performance of PLLs...
CTIP2, a novel C2H2 zinc finger protein, is a transcriptional repressor that functions by at least two mechanisms. CTIP2 interacts with and stimulates transcriptional repression mediated by COUP-TF family members. CTIP2 also represses transcription independently of COUP-TF proteins by direct, sequence-specific DNA binding activity. CTIP2 has been implicated in lymphoid...
In the United States, many of the thorniest natural resource conflicts occur on private lands. This is especially true in the Willamette Valley of Western Oregon where the hallmark habitat type, Oregon white oak woodland and savanna, is imperiled. Almost exclusively found on private land, Oregon white oak is threatened...
This phenomenological inquiry explored dimensions of reflection for older adults in a developmental oriented adventure education experience. Data were gathered from emergent interviews with four individuals while participating in a multi-day, self-contained experiential education program conducted in a rugged environment, and led by a Navajo leader. Two principle research questions...
Floods are the most frequent and damaging of all types of natural disasters and annually affect the lives of millions all over the globe. However, researchers seem to have overlooked the fact that floods do not recognize national boundaries. Therefore, the phenomena of shared, or transboundary floods occurring in international...
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...
Cryptographic devices leak timing and power consumption information that is easily measurable, radiation of various levels, and more. Such devices also have additional inputs, other than plaintext and keys, like voltage, which can be modified to force the device to produce certain faulty outputs that can be used to reveal...
Aquatic fecal contamination from non-point sources impairs environmental health and serves as a vehicle for transmission of waterborne disease, resulting in economic losses worldwide. Accurate methods of diagnosing fecal pollution and its source are needed to prevent human exposure, remediate pollution, and reduce economic impacts. In order to obtain this...
The growth of foster care, particularly kin foster care has greatly outpaced our knowledge. The purpose of this exploratory qualitative study was to develop a more informed understanding of foster family functioning from the perspective of foster parents. This study examined the experiences of 9 kin and 12 nonkin foster...
The impact of recent severe droughts throughout the United States, the potential for climate change to intensify the frequency and severity of drought, and discussion about the future of government assistance in agriculture highlight the need for a transition from drought as ‘disaster’ to drought as ‘managed risk’. However, guidance...
Two native shrub species (Piliostigma reticulatum and Guiera senegalensis) are prominent vegetation components in farmers’ fields in Senegal. However, their role in nutrient cycling and ecosystem function has largely been overlooked. A study including both laboratory and field experiments was conducted to evaluate potential biophysical interactions of the two shrub...
The main objective of this research study is to incorporate construction worker safety and health into sustainable design and construction practices. This can be fulfilled by the development of an innovative construction worker safety and health planning tool, called Sustainable Construction Safety and Health (SCSH) Rating System that will:
•...
A digital implementation of a PLL has several advantages compared to its
analog counterpart. These include easy scalability with process shrink, elimination
of the noise susceptible analog control for a voltage controlled oscillator (VCO) and
the inherent noise immunity of digital circuits. Several recent digital PLL (DPLL)
implementations have achieved...
L. C. Dunn (1893-1974) spent most of his scientific career conducting research in
developmental genetics as a member of the Zoology Department at Columbia
University in the City of New York. He had an accomplished scientific career
researching mutations in mice, which earned him respect from other geneticists and
scientists....
This dissertation uses a new methodological approach for an in-depth analysis of three cartographic works. Studies within the discipline of the history of cartography have followed various methodologies throughout the past century. This dissertation argues that in order to come to a more complete understanding of how maps were produced...
Hot-melt pan-coating, which is a novel coating method and takes 2-3 hours for 300 mg coating weight gain per capsule and tamper-resistant coating, which takes 30 minutes, is much faster than tedious sugar coating and allows greater coating weight gains in shorter times than spray-melt coating. Although hot-melt pan coating...
Nisin, an antibacterial peptide proven to be an effective inhibitor of Gram-positive bacteria, was incorporated into novel block copolymer constructs and tested for retained antibacterial activity. Covalent coupling was achieved by chemical modification of the N-terminal isoleucine to introduce a thiol group. Thiolated nisin derivatives were then linked to poly[ethylene...
This study investigated exemplary middle school mathematics teachers’ knowledge of students’ thinking with algebraic word problem solving and how they used this knowledge and understanding in their planning and teaching of students to solve algebraic word problems.
Initially, a questionnaire was distributed to nine teachers to gather their interpretation of...
Hydrogels have been proposed as candidates for nucleus pulposus replacement due to
their similarity in mechanical behavior to the native tissue when subjected to transient or
static loading; however, given the viscoelastic nature of soft biological tissues, the lack of
dynamic testing is a significant inadequacy in the studies performed...
Vegetation provides food for many insects, and many insects serve as food for bats. We investigated the linkages among these three trophic levels in riparian areas throughout the Oregon Coast Range by examining the influence of vegetation cover, composition, and structure on the activity of nocturnal insects and bats, the...
Normal gait of human is believed to be an adapted motor control result of optimal behavior of individual. Normal gait would be altered by aging or injury without being perceived. Subtle changes in gait which is not easy to detect, can cause many serious problems including joint pains and even...
This dissertation presents a dual-path 2-0 MASH (Multi-stAge-noise -SHaping) ADC with two verified digital corrections of DAC mismatch error and quantization noise leakage. By using these two techniques, the requirements for the analog circuits are greatly relaxed. The dual-path structure generates two outputs, one only composed of conversion errors, the...
Small broomrape (Orobanche minor) is an obligate, chlorophyll-lacking parasite that parasitizes red clover (Trifolium pratense) roots. This study was conducted to develop and implement an integrated, biologically based control program for small broomrape by using wheat as a false host to reduce the soil seed bank. The relationship between temperature...
Solanum species differ in their degree of frost tolerance and cold acclimation capacity. Cultivated potato species of Solanum tuberosum L. are frost-sensitive, incapable of cold acclimation, and have a maximum freezing tolerance of –3°C. Solanum commersonii Dun is frost-tolerant and can survive to –5ºC pre-acclimation and –10ºC post-acclimation. Breeding attempts...
The multistage model of carcinogenesis states that an accumulation of mutations in genes that are important for maintaining cellular homeostasis may lead to cancer. A specific type of mutation observed in particular types of cancer is the CC-->TT mutation found in the TP53 gene of patients with basal or squamous...
Studies towards the total synthesis of (−)-kendomycin (1), a bacterial metabolite with
a unique molecular architecture and pronounced biological activity, are described. These
studies resulted in the synthesis of advanced intermediate 208, containing all of the
carbon atoms of 1.
A Dötz annulation between alkyne 122 and novel chromium carbenoid...
I conducted a multi-scale evaluation of aspen – bird relationships in the northern ungulate winter range of the northern Yellowstone ecosystem during June 2001-03. Questions addressed were: (1) Does bird diversity increase with conifer presence in aspen stands? (2) Given known habitat selection cues, are migrating birds passively intercepted by...
Clostridium perfringens type A isolates producing enterotoxin (CPE) are an
important cause of both food poisoning (FP) and non food borne gastrointestinal
diseases (NFBGID) in both humans and animals. C. perfringens type A food
poisoning is caused by isolates carrying the CPE encoding gene (cpe) on the
chromosome while the...
The purpose of this study was to investigate the stages of exercise change, the levels of physical activity, and barriers to exercise among Kuwaiti individuals with and without disabilities. This study was conducted on 100 participants (50 males and 50 females) aged from 18 to 55 years. Stage of exercise...
Scaling of CMOS technology has progressed relentlessly for the past several
decades. In order for this unprecedented scaling to benefit the performance of
large digital systems, the communication bandwidth between integrated circuits
(ICs) must scale accordingly. However, interconnect technology does not scale as
aggressively, making communication between chips the major...
As the functionality of digital chips continues to increase dramatically, chip- to-chip communication bandwidths must scale accordingly to avoid constraining the overall system performance. Therefore, high speed transceiver design has be- come an important research topic. In particular, the performance of the circuits that are responsible for timing accuracy are...
Digital-to-analog converters (DACs) with wide dynamic range and high
linearity are required for high-end audio applications. A multi-bit delta sigma
audio DAC, using a novel gain-correction technique, is described in this thesis. For
widely varying on-chip RC time constant, the DAC gain can be accurately
controlled by the correction circuitry....
Previous attempts to understand the factors affecting the energetic cost of locomotion have found a direct link between the energetic cost and the mechanical work done during periods when the limb is in contact with the ground. However, when the limb is not in contact with the ground during the...
In this thesis I studied several THz components that can be used for potential THz
technology. THz waves were generated in nonlinear medium via optical rectification
of femtosecond optical pulses. Utilizing the phase matching condition between the
optical and THz waves in a ZnTe crystal, single-cycle broad-band THz pulses were...
Quantitative resistance (QR) to disease is usually more durable than qualitative resistance, but its genetic basis is not well understood. We used the barley/barley stripe rust pathosystem as a model for the characterization of the QR phenotype and associated genomic regions. As an intermediate step in the preparation of near-isogenic...
The biological transformation of dinitrogen gas (N2) into combined forms(termed N2 fixation) by certain genera of oceanic cyanobacteria represents the largest incoming flux of nitrogen to the global ocean. As such, biological nitrogen fixation
plays a significant role in the regulation of oceanic productivity and the export of
carbon and...
Recent science education reforms have placed a large emphasis on inquiry-based teaching strategies as an effective way of improving conceptual understanding of science principles, comprehension of the nature of scientific inquiry, and development of the abilities for inquiry (NRC, 1996). To better understand the relationship between inquiry-based instruction and student...
This thesis examines the mechanisms that couple the monthly-averaged
atmospheric boundary layer (ABL) to open-ocean sea surface temperature (SST)
perturbations on scales of 50-500 km. The observed positive correlation between
surface wind speed anomalies and SST anomalies is successfully simulated using
the Weather Research and Forecasting (WRF) model.
In numerical...
Two-phase flow in helical conduits is important in many industries where reaction between components, heat transfer, and mass transport are utilized as processes. The helical design is chosen for the effects of secondary flow patterns that reduce axial dispersion, increased heat transfer, and also their compact design. The first is...
In 2003 and 2004 vigor zones were delineated in two commercial vineyard
sites based on vine growth variation to assess fruit and wine phenolic chemistry. In
2004, the effects of shading on the accumulation of phenolic compounds were also
investigated. Model extractions were done from the shading experiment and the...
The basaltic landscapes of the Oregon High Cascades form a natural laboratory for examining how geologic setting and history influence groundwater flowpaths, streamflow sensitivity to climate, and landscape evolution. In the High Cascades, highly permeable young basaltic lavas form extensive aquifers. These aquifers are the dominant sources of summer streamflow...
Fuel management has been used as an effective local strategy to reduce the undesirable consequences of wildfires. Many efforts toward scheduling of fuel management activities across a broader landscape have been proposed, with the hope of achieving larger landscape-scale management effects. However, scheduling of fuel management treatments across the broader...