During the first full school year of the Covid-19 pandemic, two central contexts for adolescent development—home and school—changed utterly. In Oregon, most middle- and high schoolers attended school entirely remotely from the beginning of the pandemic, in March, 2020, through the end of April, 2021, removing both the supports available...
Hop (Humulus lupulus L. var. lupulus) is a diploid, dioecious plant with an extensive history of cultivation and use in brewing, as a textile, and for its therapeutic properties. Hop is prized for its ability to produce a variety of aromatic and flavor compounds, as well as compounds with anti-microbial...
The past decade of research has potentiated a revolution in our understanding of mammalian health and evolution by revealing that the gut microbiome plays a central role in mammalian physiology. Our ability to unlock this potential hinges upon the identification of specific groups of gut microbes that elicit effects on...
Increased globalization has greatly increased the ability for species to travel outside of their native range and reach all parts of the world. While most species do not have an impact in new habitats, a small percentage are able to establish a new population and spread, causing ecological damage and...
Dietary nitrate (NO3-), consumed primarily from leafy green and root vegetables, lowers blood pressure, improves vascular function and aerobic exercise performance. This performance-enhancing effect of nitrate supplementation is largely attributed to the increased bioavailability of the signaling molecule, nitric oxide (NO). Nitric oxide is a ubiquitous free radical signaling molecule...
The Champoeg townsite first developed due to its ideal settlement and trade location within the Willamette Valley, becoming the ‘legal birthplace of Oregon’ in 1843. However, by 1860 Champoeg’s significance had begun to decline, and in December of 1861 a devastating flood wiped out the townsite. Archaeological excavations took place...
During the eighteenth century, diagrams increasingly became an important aspect of scientific inquiry. Diagrams employed simplification as a strategy for representing complex information, played a role in standardizing scientific language, and served as instruments of reason to think through and communicate problems and findings in mathematics, physics, chemistry, astronomy, natural...
This dissertation examines the impact of the German naturalist and literary figure Johann Wolfgang von Goethe’s ideas on twentieth century Anglophone plant morphology and biology. Goethe interpreted the organ forms of flowering plants as metamorphoses of each other. His literary, historical, and philosophical writings suggest themes of alienation from and...
Fluorescence has proven to be a robust and powerful method of analysis in numerous fields: forensics, pharmaceutics, geology, food science, and environmental sciences have all developed a large collection of fluorescence instruments and methods to overcome application-specific challenges. Biological applications saw the same development of a fluorescence toolkit with methods...
By means of a case study and historical analysis, this dissertation examines the past and present of avian influenza. By integrating disconnected histories of human and animal influenza, this dissertation links historical insights with the concerns of contemporary avian flu science. It is not only a natural history of avian...
Fungi in the genus Tolypocladium are diverse in their host associations, but the predominant ecologies include parasites of the ectomycorrhizal genus Elaphomyces and pathogens of insects. The aim of this dissertation research is to examine the evolution of these fungi and their host associations. To accomplish this several lines of...
The atomic age was enacted by many scientists as a way to realize health and human rights. Human rights were conceived in this context as rights to economic development, science education, and nuclear medicine. The United States Atomic Energy Commission (AEC) acted hand in hand with UN agencies and educators...
Lichens play many important roles in subarctic terrestrial ecosystems by fixing nitrogen, colonizing rock and gravel, stabilizing otherwise bare soil, adding significantly to vegetation biodiversity and serving as the primary food for caribou in the winter. In these chapters, I analyzed lichen community and ecological trait structure along environmental gradients,...
The aryl hydrocarbon receptor (AhR) has recently been described as a novel therapeutic target, given the potent suppression of multiple immune-mediated diseases following activation by the prototypic ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In the parent-into-F1 graft-versus-host (GVH) model, suppression of the cytotoxic T-lymphocyte (CTL) response is associated with the presence of CD25⁺CTLA-4⁺IL-10⁺Foxp3[superscript...
The materials Fe₂(Si,Ge)(S,Se)₄, Cu₃PS[subscript 4-x]Se[subscript x] (0 ≤ x ≤ 4), and Cu₃PxAs[subscript 1-x]S₄ (0 ≤ x ≤ 1) have been synthesized and studied as new earth-abundant absorbers for single and multijunction photovoltaic cells as well as solar fuel generation. The synthesis, single-crystal growth, and optical and electrical properties of...
Waterborne fecal contamination poses serious risks to human health and can disrupt aquatic ecosystems. Molecular marker methods are widely used to identify and, in some cases, quantify the sources of contamination and guide management decisions regarding water resource protection. However, methods to detect some likely sources of fecal contamination such...
Silicon carbide (SiC) and aluminum nitride (AlN) exhibit a combination of thermal and mechanical properties that are relevant to applications in electronics, aerospace, defense and automotive industries. However, the successful translation of these properties into final applications lies in the net-shaping of these ceramics into fully dense microstructures. Increasing the...
Currently, the technologies used to separate lignocellulosic biomass into its component parts (cellulose, hemicellulose, and lignin) and enzymatically hydrolyze the cellulose to glucose for conversion to ethanol could be improved economically and in terms of efficiency. A major impediment to utilizing the biomass is the presence of residual lignin. The...
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...
This dissertation has two objectives. The first objective is to determine where best to situate the study of mentoring (i.e. the 'making of scientists') on the landscape of the history of science and science studies. This task is accomplished by establishing mentoring studies as a link between the robust body...
In this thesis, I studied the translation of dengue virus RNA using a luciferase reporter gene system in Vero cells. The dengue reporter mRNA construct, which harbors 5´-terminal viral nts and 3´-terminal nts, could be translated efficiently compared to an alpha globin reporter construct. The 5´-cap structure and 3´-untranslated region...
In- stream water temperature is one of the most important environmental
factors associated with the decline in salmonid populations and their habitats in the
Pacific Northwest. Most ecological restoration practices that attempt to reduce instream
temperatures center on replanting or reestablishing riparian vegetation and
increasing flows. However, in a large...
The relative role of cospeciation and host switching in the phylogenetic history of
ascomycete foliar symbionts is addressed in the orders Leotiales and Rhytismatales, fungi
associated predominantly with Pinaceae (Coniferales). Emphasis is placed on comparing
the evolution of the sister genera Pseudotsuga and Larix (Pinaceae) with that of the
pathogenic...
Prolactin (PRL) is a peptide hormone that is involved in a number of diverse physiologic roles, particularly with respect to reproduction, including: influencing sexual and parental behaviors, onset of puberty, regulation of seasonal reproduction, follicular maturation, ovulation, luteinization and corpus luteum (CL) function, steroidogenesis, mammary gland development and lactation, testicular...
High rates and high costs of adolescent pregnancy and school dropout have resulted in the development of many prevention programs; however, little is known about the long-range effectiveness of efforts. Empirical research is needed to document behavioral outcomes over extended periods of time. I interviewed eight young white women who...
The phylogenetic diversity of two continental shelf picoplankton
communities was examined by analyzing SSU (16S) ribosomal RNA (rRNA)
genes amplified from environmental DNA with bacterial-specific primers and
the polymerase chain reaction (PCR). Picoplankton populations collected from
the pycnocline (10 m) over the eastern continental shelf of the United States
near...
In order to understand better the defect structure and dynamics associated
with lower valent dopants complexed with native defects in group IV oxides, In/Cd
perturbed angular correlation spectroscopy was performed in ceria and zirconia. Examining
the orientation symmetry axis of defects in ceria single crystals at low temperature
has allowed...
Many parallel machines, both commercial and experimental, have been/are being designed with toroidal interconnection networks. For a given number of nodes, the torus has a relatively larger diameter, but better cost/performance tradeoffs, such as higher channel bandwidth, and lower node degree, when compared to the hypercube. Thus, the torus is...
Two Oregon reservoirs contaminated by different mercury
sources were compared for mercury distribution in sediment and
bioaccumulation by fish. The average mercury concentration in
the sediment of Cottage Grove reservoir (0.67 ± 0.05 μg/g dry
wt) was higher than for Dorena Reservoir (0.12 ± 0.01 μg/g dry
wt). Sediment mercury...
Unknown questions remain concerning the health of migrant farm workers,
seasonal farm workers, and other rural poor people. The objectives of this study were to
determine the demographic profile of a sample from a Community and Migrant Health
Center; to determine the prevalence of disease in migrant farm workers, seasonal...
The purpose of this study was to determine if certain
identified educational strategies would have an effect on the
success of at-risk students at the secondary level.
Specifically, would school involvement and a mentor program
have an effect on students' attendance, grade point average,
and self-esteem.
An examination of related...
As the volume of genetic sequence data increases due to improved sequencing techniques and increased interest, the computational tools available to analyze the data are becoming inadequate. This thesis seeks to improve a few of the computational methods available to access and analyze data in the genetic sequence databases. The...
The individual through earliest recorded history reveals contradictory views of the
human life-span. "Am I a free and unique individual, able to make choices and decide my
own destiny?, or, "Am I only a victim of circumstance, a speck of dust in the universe's
whirlwind of fate?"
Each view is...
This was an experimental study which compared two different
instructional methods, oral lesson closure versus
written lesson closure, on the achievement of 156 junior
high school students in social studies. This study was
composed of two duplicate experiments. Experiment I was
conducted with 71 seventh grade social studies students at...
Wave dispersion and fracture are phenomena that involve. mechanisms triggered at the scale of a material's internal structure. Experiments were performed with a candidate material to judge the hypothesis that wave dispersion measurements can be used to nondestructively predict fracture strength. Wood-based particleboard was chosen as the candidate material because...
Mounting inflationary economic pressures and the obvious spiralling costs of education, at all levels, has drastically augmented public, administrative, and government concern regarding the effectiveness of many educational training programs. Secretarial Science, which is designed to provide occupational-level training represents such a program. Therefore, this study was conducted in order...