Potato Virus Y (PVY) is an enduring problem for potato production worldwide. Potato varieties that resist the “ordinary” strain PVYO were developed by breeders, but in recent years, recombinant strains of PVY have been able to circumvent this strain-specific resistance and evade growers and seed certification officials by causing fewer...
Parasites are ubiquitous members of ecological communities, capable of contributing to the decline of vulnerable populations. Therefore, monitoring parasite level is a critical component for host management. Molecular tools, such as quantitative polymerase chain reaction (qPCR), can be valuable additions to monitoring protocols that assess parasitic disease risk to hosts....
Black raspberry (Rubus occidentalis L.) is a US Pacific Northwest specialty crop prized for its unique flavor profile and nutritional attributes. A major obstacle for the raspberry industry is Black raspberry necrosis virus vectored by the large raspberry aphid (Amphorophora agathonica). Market expansion depends on production, which is currently hindered...
Isothiocyanates (ITCs) are produced by roots in a variety of agricultural plants, such as those within the Brassicaceae family. ITCs act as fumigants, and are used to control microbial plant pathogens by adding brassica-origin seed meal to soil prior to replanting. However, there is suggestion that the presence of residual...
Biotic and abiotic processes at continent-ocean interfaces cycle a disproportionate mass of carbon and nutrients relative to their global surface area, and microbial activity is a principal determinant of organic and inorganic matter flux in these transition zones. Most studies using modern high-throughput ‘omics techniques to link microorganisms with costal...
The mountain pine beetle has impacted over 5 million hectares of pine forests in the Rocky Mountains region in the United States. Although some beetle-killed stands are available for salvage harvesting, there are many uncertainties in harvesting beetle-killed stands including safety, costs, recoverable products and their values. These uncertainties impose...
Giant chinquapin (Chrysolepis chrysophylla) is an evergreen hardwood often found as a shrubby understory component of coniferous forests in the Pacific Northwest United States. Due to its ability to sprout quickly after disturbances such as fire and logging it is often viewed as a pest by forest managers. Like its...
The European hazelnut (Corylus avellana L.) is a tree nut crop that is important in Oregon, which produces 99% of the United States’ hazelnuts but only 5% of the world’s supply. In order to maintain this market share, farmers in Oregon need cultivars that produce high quality nuts, mature early,...
Coral reefs form vast ecosystems in tropical oceans that are hotspots for biodiversity and are economically valuable. The ecological success of coral reefs is made possible by the symbiotic relationship between corals and dinoflagellate algae from the family Symbiodiniaceae. In this symbiosis, the algae are found within host gastrodermal cells...
Otoferlin is a C2-domain, transmembrane protein whose mutated form is responsible for the DFNB9 subtype of prelingual hearing impairment. Mutations in otoferlin cause an autosomal recessive, non-syndromic form of deafness that is characterized by auditory neuropathy/ auditory dissynchrony (AN/AD), meaning that the outer hair cells (OHCs) are normal, and the...
On coral reefs, disturbances rarely occur in isolation. Global stressors such as increasing seawater temperature often coincide with local stressors like nutrient pollution. In the face of increasing anthropogenic stress, corals can function as environmental sentinels, although little is known about how multiple stressors interact to disrupt their associated bacterial...
Septoria canker remains the most important disease of poplars in intensively managed forest plantations. Genetic resistance has long been considered the best way to manage for this disease. Transgenic resistance mediated by RNA silencing against pathogens and pests (HIGS: host-induced gene silencing) has shown promise in other pathosystems but has...
Night is an extraordinary resource. Unlike air, water, or soil, nighttime is a spatio-temporal phenomenon, which leads to many crucial roles. It provides refuge to wildlife species, triggers hormonal and behavioral responses among a wide variety of organisms, and serves as an essential migratory backdrop for species that navigate by...
This thesis examines the recent history of the teaching of argument and its implications in the face of new writing standards being implemented in K-12 classrooms under the Common Core State Standards. The new educational policies will shift the focus of writing instruction onto argument writing as part of students'...
The purpose of this study was to determine the possible problem areas in families with a diet-treated phenylketonuric child. Phenylketonuria is an inborn error of metabolism, which in the past caused mental retardation as well as behavioral disturbances. Initially the discovery of diet therapy eliminated the behavioral disturbances, but not...
Specialized or secondary metabolism is a collection of pathways and small molecules that, while beneficial to an organism, are not strictly necessary for survival. Plants use secondary metabolites to, among other things, attract pollinators, defend against biotic and abiotic stressors, and form symbioses. Natural products from plants have seen an...
Sulfur-coated urea (SCU), a slow release nitrogen fertilizer,
may be economically competitive with conventional fertilizers, but
little is known of the mechanism of urea release from SCU and the
environmental factors which affect the urea release rate. Objectives
of this thesis were: (1) to determine factors which affect the rate...
Ethylene was produced by Cylindrocladium floridanum and C. scoparium in culture. Production was methionine dependent and maximal during the active growth phase of the fungus, beginning shortly after spore germination. More ethylene was produced sooner by C. floridanum than C. scoparium. Ethylene was produced by Cylindrocladium both from active mycelium...
Diet, nutrition, and foraging strategies of canvasbacks (Aythya valisineria) and redheads (A. americana) were studied by collecting actively feeding birds throughout the reproductive season in 1980 and 1981; samples of available foods were taken each time a bird was collected. Nutrient composition of the aggregate diet was determined for each...
A parasitic wasp, Trioxys pallidus Haliday
(Hymenoptera: Aphidiidae) was imported from Europe and
initially released against the filbert aphid Mvzocallis
coryli (Goetze) in hazelnut (filbert) orchards of the
Willamette Valley, Oregon beginning in 1984. In the
present study, I investigated the establishment rates of
this parasitoid. A total of 13...
Seventeen populations of Gila Baird and Girard are identified from the Alvord Basin of southeastern Oregon and northwestern Nevada. Gila in the Alvord Basin occupy a wide range of habitats, including warm springs, cool springs, creeks, reservoirs, and a thermal lake. These populations became isolated in remnant habitats when waters...
This collection of poems focuses on a range of content. They pose many questions that consider issues surrounding driving, cars and independence, as well as masculinity, fatherhood, domesticity and parental identity. The collection consists of three parts, Freeway, Menace, and Control. Freeway contains poems on driving and cars, some of...
Forests are some of the most ecologically diverse and dense habitats on the planet. Research shows that the endophyte community, or the fungi, bacteria, and viruses within a forest ecosystem is highly diverse. Fungal endophytes are defined as fungi that live within the tissues of host plants. Relationships between fungal...
This qualitative study explored the experiences of transgender students at a large, public university. The focus of this study was to identify where transgender students found support systems and obstacles at Rivera University. Six students, who self-identified as transgender, participated in one-on-one semi-structured interviews directed by three research questions: (a)...
RNA-Sequencing (RNA-Seq) has rapidly become the de facto technique in transcriptome studies. However, established statistical methods for analyzing experimental and observational microarray studies need to be revised or completely re-invented to accommodate RNA-Seq data's unique characteristics. In this dissertation, we focus on statistical analyses performed at two particular stages in...
More than 2.3 billion pounds of pesticides with a value of $4.1 billions are applied by farmworkers to agricultural crops each year. These chemicals applied to farm lands lead not only to acute and chronic health effects, they also enter the groundwater and food chain of populations. In recent years...
Headwater streams are generally small, first-order streams that can comprise up to 80% (by stream length) of the drainage network in mountainous areas of the Pacific Northwest. These streams are intimately connected with downstream reaches, serving as a source of sediment, woody debris, organic matter and nutrients. The surrounding forests...
The effect of seedbed preparation on the emergence and survival of winterfat (Krascheninnikovia lanata (Gueldenstaedt)) and squirreltail (Elymus elymoides (Raf.) Swezey)) seedlings was determined, while quantifying nutritional changes through the dormant season for four range species. In November of 2004 twenty 9m x 8m plots were randomly prepared with one...
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...
The field of toxicology is challenged with a vast number of environmental chemicals and mixtures to which humans and ecosystems are exposed with limited toxicity data available. Chemical hazard assessment traditionally utilizes mammalian models and can be both cost- and time-limiting and may pose ethical concerns. To rapidly tackle this...
The outbreak of the Coronavirus Disease 2019 (COVID-19) and the restrictions implemented in response to it (e.g., stay-at-home orders, social distancing mandates, business closures) had unprecedented effects on the trucking industry. The pandemic prompted the first significant overhaul of federal hours-of-service (HOS) regulations in over 15 years. Prior to the...
All animals have developed the critical ability to detect, respond to, and detoxify a large array of environmental chemicals and stressors that can cause adverse health effects. Important examples of landmark contaminants around the world are polycyclic aromatic hydrocarbons (PAHs) and dioxins, both of which can act via the aryl...
Pacific Northwest and California freshwater resources are key elements in the life history and ecology of Pacific salmon and steelhead listed as threatened or endangered under the Endangered Species Act. Risk to listed Pacific salmonid species can be assessed by evaluating the spatial and temporal co-occurrence of salmonid species at...
The major purpose of this study was to determine the current status
of family life/sex education programs in the public high schools of
Oregon. A mail questionnaire was submitted to all health teachers in
all the high schools in Oregon. The questionniare was mailed twice to
447 health teachers in...
A pest management program for Tetranychus urticae Koch in Oregon
peppermint was developed based on studies of sampling, plant phenology,
population dynamics and damage thresholds.
A sample size of 45 leaves provided a confidence level of 90%
and a confidence interval of 50%. Estimation of the sample mean was
based...
The genus Deraeocoris Kirschbaum of western America north of
Mexico was revised. Approximately 10,000 specimens from the Nearctic
Region were examined. Taxonomic characters used by previous authors
were reevaluated. In addition to the male parameres, the male vesica
and the female posterior wall of the bursa copulatrix and sclerotized
rings...
Purpose of the Study
The purpose of this thesis is to survey the current practices in
guidance services in the public secondary schools of British Columbia
and on the basis of the survey findings, together with a review of the
literature of guidance, to present recommendations for a feasible
program...
Oomycete and fungal pathogens threaten food, fiber, and forests around the world. With climate change, these pathogens are expected to emerge more frequently. Evolution can facilitate their emergence through mechanisms such as mutations that change or expand host range. Characterizing evolutionary mechanisms in plant pathogens will contribute to our ability...
Coastal Douglas-fir (Pseudotsuga menziesii var menziesii) forests are extensive west of the crest of the Cascade Mountains in Oregon and Washington and are renowned for their productivity, biodiversity, and the ecosystem services they provide. Increasing wildfire activity in recent years including the extensive 2020 Labor Day fires, and a warming...
Eukaryotic small RNA (~20-30 nucleotides) are diverse regulatory molecules that repress gene expression at the transcriptional and post-transcriptional levels, defend hosts against invading viruses and defend genomes against selfish DNA elements. Small RNA populations are studied by high-throughput sequencing of the total small RNA fraction isolated from cells, however, the...
Seasonal abundance and life history traits were compared between populations of the brine fly Ephydra (Hydrokyrus) hians Say (Diptera:Ephydridae), from two western Great Basin alkaline salt lakes. Abert Lake, Oregon, has a relatively low salinity (20-30 g/1 total dissolved solids) and more co-inhabitant benthic species than the higher salinity Mono...
Larval mortality of leafcutting bee, Megachile pacifica (Panzer)
(= rotundata (F.)), is high, usually exceeding 50%. Parasites and
predators are not a limiting factor in the survival of the progeny.
The disease chalk brood has been an important mortality factor since
1974. Inadequate food supply, pollen and nectar, may affect...