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...
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...
Understanding seasonal changes in growth, survival, and movement rates is
crucial to salmonid management. These life history characteristics provide a context for
evaluation of management actions. We evaluated the life history of individually
marked Oncorhynchus mykiss gairdneri in the South Fork John Day River basin in
Northeastern Oregon. This thesis...
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 thermal denaturation of proteins has been extensively studied using several methods including differential scanning calorimetry (DSC). A custom-built optical system was used to study thermal effects on protein as an alternative method to DSC measurements. It was used to investigate the thermal stability of bovine serum albumin (BSA) with...
Vaccinia virus is the prototypic member of the Orthopoxvirus genus. It undergoes a complex replication process where a key step in the transition from immature virion to intracellular mature virion is the cleavage of the major core protein precursors. The product of the I7L open reading frame (ORF) is a...
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...
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...
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...
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....
Over-winter growth of juvenile salmonids may be linked to ocean survival and thus species persistence. Diet, growth, and prey available to juvenile coho, Oncorhynchus kisutch, were examined from December 2004 to April 2005 in four tributaries of the West Fork Smith River (WFSR), Oregon. Juvenile coho growth rate and condition...
First introduced to the USA in 1958, Myxobolus cerebralis, the parasite responsible for whirling disease in salmonids, has since spread across the country causing severe declines in wild trout populations in the intermountain west. Recent development of risk assessment models used to assess the likelihood and consequences of exotic parasite...
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...
Recent studies suggest that competition from brook trout (Salvelinus fontinalis; EBT) may have negative effects (e.g. displacement) on Lahontan cutthroat trout (Oncorhynchus clarki henshawi; LCT). Results from these studies have failed to elucidate the responsible mechanisms and have not examined if changing environmental conditions result in competitive/subordinate role reversals. The...
Molecular genetic and enzymological techniques have been employed to study antibiotic biosynthesis. The nonproteinogenic amino acid capreomycidine is the signature residue found in the tuberactinomycin family of antitubercular peptide antibiotics and an important element of the pharmacophore. Recombinant VioG, a single module peptide synthetase from the viomycin gene cluster cloned...
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...
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...
Giant otters (Pteronura brasiliensis) and humans in the Lower Yasuní Basin (Ecuador) have similar food and space requirements: they consume comparable arrays of fish species, and they use similar aquatic and terrestrial habitats. Resource partitioning could facilitate coexistence by allowing each species exclusive access to some resources.
My research examines...
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...
The droplet formation process in the vicinity of the nozzle exit and the behavior of a spreading droplet during impingement on a smooth glass surface were studied. Two nozzle geometries were tested. The first case was a stiff stainless steel nozzle plate 0.787 mm thick. The second case was a...
Biocompatible hydrogels composed of covalently crosslinked, chemically modified hyaluronan (HA), gelatin (Gtn), and heparin (Hp) were synthesized for controlled release of human vascular endothelial growth factor (VEGF) or basic fibroblast growth factor (bFGF). We hypothesized that inclusion of small quantities of heparin in these gels would result in regulated growth...
The image of Native Americans in the United States has changed through
the passage of time. Part of this change is directly related to the representation of
their cultures in a museum setting and the inception of cultural resource laws that
govern them. This research looks at four museums, two...
Invasion by exotic species can pose a major challenge for developing native
plant communities in wetland restoration projects. Often native plant communities
do not develop as anticipated in restored wetlands due to colonization by exotic
species that dominate the native plant community. Despite the time and expense to
restore wetlands,...
The continuation of geoarchaeological investigations at Tseriadun (35CU7) contributes to the understanding of the site's depositional history and the associated environments, thereby identifying the long term geomorphic change in the area and providing the environmental context for local human activity as it is reflected in the archaeological record. Meeting this...
Few parenting curricula exist that are culturally-appropriate to the Mexican-immigrant population served by many programs. The Even Start family literacy program has four integrated components, making it more difficult to find appropriate curricula for the families they serve. During Winter 2006, discussion groups were conducted with participants in two Even...
An autonomous, in-situ instrument was developed to detect dissolved copper in seawater, suitable for deployment on time scales from weeks to months. A commercially available in-situ nitrate analyzer (YSI 9600) was adapted to measure copper (II) in seawater by chemiluminescence. Modifications included construction of a photomultiplier (PMT) based detector and...
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...
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...
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...
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:
•...
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...
Several different petrological techniques have been applied to lava flows between
200 to 475,000 years old from Mount Hood, Oregon. Mount Hood is unusual, in comparison to nearby Mount St. Helens and Mount Jefferson, in that it has produced relatively homogeneous lava compositions over 475,000 years. Erupted lavas are mostly...
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...
Educators and other individuals within the long term care continuum along
with current gerontological researchers call for consideration of quality of life
factors related to aging. Optimal aging applies to physical health, as well as
cognitive and socio-emotional health. Each is imperative to a quality of life,
specifically in long...
Over 150 years ago, C. Bergmann observed a within-species pattern of increasing body size as elevation and latitude increased. Bergmann’s data came from numerous endothermic taxa, but the pattern has since been documented among numerous poikilotherms and invertebrates. The ferocious waterbug Abedus herberti Hidalgo (Hemiptera: Belostomatidae) lives in isolated populations...
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...
Clostridium perfringens type A isolates produce the spore-specific enterotoxin, CPE, upon sporulation in the gastrointestinal tract of humans and animals. Spo0A is a response regulator representing the major transcription factor for sporulation initiation in C. perfringens. In Bacillus subtilis, a multicomponent phosphorelay involving five histidine kinases (KinA-KinE), the intermediate response...
The highly conserved multi-protein mismatch repair (MMR) system is known for its ability to correct post replication errors in genomic DNA. A hallmark of MMR deficiency in all organisms is microsatellite instability. The initiating proteins in the eukaryotic MMR system are hetrodimers formed with an integral MSH2 subunit and one...
Warming of the terrestrial biosphere due to the anthropogenic addition of carbon dioxide to the earth’s atmosphere is becoming a major focus of scientific inquiry. Predictions of the extent of this warming are hampered by uncertainty in the ability of the earth’s ecosystems to counteract this effect by sequestering carbon...
Once considered the largest wetland in Central Asia, the Mesopotamian Marshlands of Southeastern Iraq have nearly disappeared. Various hydrological projects by the Iraqi government and dam construction in the region have nearly destroyed these once rich freshwater wetlands by over 90%. With the launching of Operation Iraqi Freedom recent attempts...
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...
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...
Vegetation change is an important factor affecting the global carbon cycle, land-atmosphere interaction, and terrestrial ecology. The study of vegetation change on a global scale can be used to evaluate the impact of global climate change on terrestrial ecosystems. Satellite remote sensing can monitor vegetation change at the global scale,...
There is growing interest in using nutrient manipulations to control invasive
plants such as Brornus lectorurn L. (cheatgrass). Both labile (sucrose) and recalcitrant
(straw and sawdust) carbon sources are added to the soil surface to reduce plant
available soil N via soil microbial immobilization. However, the application rates
used in...
The Steller Sea Lion Research Initiative was passed in 2001 to provide funding to help scientists determine causes and solutions for the population crash of Steller sea lions (Eumetopias jubatus). In response to need to understand population dynamics of Steller sea lions, NOAA Fisheries has spearheaded a large-scale, range-wide research...
Nares Strait is one of three main passages of the Canadian Archipelago that
channels freshwater from the Arctic Ocean to the North Atlantic. There are very few
observations regarding the role of this region on the present day Arctic freshwater budget,
and even less regarding the changes in freshwater fluxes...
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...
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...
This work describes the fabrication of a high uranium density fuel for the
Reduced Enrichment of Research and Test Reactors Program. In an effort to decrease
the use of high enriched uranium in research and test reactors around the world, new
fuels with high uranium densities must be developed such...
High performance multi-cell delta-sigma modulators are a preferred choice in applications which require programmability. Multi-cell delta-sigma modulators with M unit cells provide 10log10(M) SQNR improvement for the same thermal noise and bias power due to the uncorrelated quantization noises of the M unit ADCs. This concept is used in this...