Pacific cod (Gadus macrocephalus) is an important species, both economically and ecologically in the Bering Sea and Aleutian Islands (BSAI). However, little is known about its spawning dynamics. To address this knowledge gap, I developed a gross anatomical maturity key for Pacific cod to assess temporal and spatial patterns of reproductive maturity. Gross anatomical maturity keys estimate reproductive maturity by categorizing changes that occur in appearance of ovaries during maturation. Because maturity keys are based on characteristics that change on a continuum, stage assignment can be subjective particularly for ovaries in transition (displaying characteristics of more than one stage). Histological processing is often used to verify maturity key staging by estimating the maturity of individual oocytes from within assessed ovaries. I compared individual oocyte development through histological processing with gross anatomical stage assignments to evaluate the accuracy of Pacific cod maturity key using two approaches. First, assumptions made in delineating advancing characteristics between stages during the development of the key were analyzed by comparing oocyte development from ovaries assigned to key maturity stages by the researchers who designed the key. Secondly, the consistency in the use of the maturity key was addressed by comparing stage assignments to oocyte development for multiple data collectors employing the maturity key in the field. Misclassification rates for the key designers were 22% and field samplers using the key resulted in misclassification rates of 43%. While the misclassification rates are high, the mismatch between histological assessments and gross maturity was very narrow and most often assigned correctly to an adjacent stage. Misclassifications occur most often in the vitellogenin stages where criteria for delineating between stages both histologically and through the use maturity key are based on relative changes in size and color of the ovaries. By using morphological changes to track ovarian maturation, gross anatomical maturity keys provide an easily applied and inexpensive method for the collection of large quantities of data. Maturity data collected by observers aboard commercial fishing vessels in the BSAI were used to construct maps showing spawning sites along the continental shelves of the BSAI between the 100 and 200m isobaths. Spawning stage data for days where a high percentage of spawning was observed ("hot days") were mapped to show areas of high intensity spawning ("hot spots"). Hot spots were identified north of Unimak Island, in the vicinity of the Pribilof Islands, at the shelf break near Zhemchug Canyon, and adjacent to the central and western Aleutian Islands. Further analysis of spawning and spent stage data suggests spawning phenology was consistent during the three study years with varying climate conditions, though variation was seen in the duration of the spawning season among years and regions within years. While the processes determining the timing and location of spawning are poorly understood, knowledge of the above patterns allows further examination of how Pacific cod spawning correspond with environmental conditions throughout the season and between years of varying climate patterns. This work provides an initial description of the distribution and phenology of Pacific cod spawning along with a generalized description of oceanographic features observed at hot spot locations during the spawning season. / Graduation date: 2013

The United States is the third-largest producer of raspberries in the world. Washington State leads the nation in red raspberry (Rubus idaeus L.) production. 'Meeker', the most grown red raspberry cultivar in the Pacific Northwest (Washington, Oregon and British Columbia, Canada) is highly susceptible to Raspberry crumbly fruit, a virusinduced disease that produces drupelet abortion and reduces fruit quality and yield. The disease has long been attributed to Raspberry bushy dwarf virus (RBDV), a pollen-and-seed transmitted virus found in most commercial raspberry fields around the world. In recent years, an increased severity of crumbly fruit was observed in areas where two additional viruses were common. One of these viruses, Raspberry leaf mottle virus (RLMV), was characterized recently and shown to be a novel closterovirus transmitted by the large raspberry aphid Amphorophora agathonica Hottes. The second virus, Raspberry latent virus (RpLV) was a tentative member of the family Reoviridae whose characterization remained to be completed. To investigate the role of these two new viruses in the crumbly fruit disorder, 'Meeker' raspberry infected with single or mixtures of the three viruses, in all possible combinations, were generated by graft inoculation. Eight treatments, including a virus free control, were planted in the field at the Northwestern Research and Extension Center in Mt. Vernon, WA. Plant growth and fruit crumbliness were evaluated during establishment and the second year. Simultaneously, the characterization of RpLV, at the genetic and biological level, was completed. RpLV is a novel member of the plant Reoviridae composed of 26,128 nucleotides divided into 10 genomic dsRNA segments. Analysis of the RNA dependent RNA polymerase (RdRP) indicated that RpLV was related most closely to members of the genus Oryzavirus. However, the genomic terminal regions, conserved at the genus level in reoviruses, did not show homology to those of oryzaviruses, suggesting that RpLV may be a member of a new genus. It was found later, that RpLV was transmitted by A. agathonica. As all other plant reoviruses are transmitted by leaf- and planthoppers, these findings strongly support the creation of a new genus in the plant Reoviridae for the classification of RpLV. Real-time quantification of viral titers in single or mixed infections revealed that the titer of RBDV was enhanced ~400-fold when the virus was found in coinfections with RLMV. Interestingly, plants co-infected with these two viruses showed significant reduction in plant growth during the establishment and second year. Crumbly fruit was more severe in plants infected with the three viruses compared to the virus-free control. Taken together, this work presents valuable information about the interactions between three important raspberry viruses and their effect on plant growth and fruit crumbliness in 'Meeker', the most important red raspberry cultivar in the Pacific Northwest. / Graduation date: 2012

xv, 136 p. : ill. (some col.) / The Pacific Northwest of the United States has been tectonically and magmatically active with the accretion of the Farallon oceanic terrane "Siletzia" ∼50 Ma. The accretion of Siletzia terminated the flat-slab subduction of the Farallon slab and initiated the Cascadia subduction zone. In this dissertation, I focus on both the large-scale tectonic structures preserved seismically in the crust and upper mantle, and the small-scale, short-term aseismic processes on the plate interface. I measure the shear-wave splitting trends around eastern Oregon with a dataset of ∼200 seismometers from 2006-2008 to analyze the upper-mantle anisotropy. The delay times between splitted shear-waves range from 0.8 s to 2.7 s. In the High Lava Plains, the fast polarization direction is approximately E-W with average delay time ∼1.8 s. I infer that there must be significant active flow in a roughly E-W direction in the asthenosphere beneath this area. The splitting pattern is more variable and complicated in NE Oregon, where the crust and mantle lithosphere may be a significant contribution. In terms of the imaged seismic velocity structures, I infer that the Eocene sedimentary basins in south-central Washington lie above a magmatically underplated crust of extended Siletzia lithosphere. Siletzia thrusts under the pre-accretion forearc, and its southeast termination is especially strong and sharp southeast of the Klamath-Blue Mountains gravity lineament. Magmatic intrusion has increased upper crustal velocity as in the less active Washington Cascades, but the higher temperatures beneath the magmatically active Oregon Cascades have a dominating effect. To better understand the physical mechanism of slow slip events on the plate interface, I explore the scaling relationships of various source parameters collected mainly from subduction zones worldwide and also other tectonic environments. The source parameter scaling relationships of slow slip events highlight the similarities and differences between slow slip phenomena and earthquakes. These relationships hold implications for the degree of heterogeneity and fault healing characteristics. The recurrence statistics of northern Cascadia events behave weakly time predictable and moderately anti-slip predictable, which may indicate healing between events. This dissertation includes co-authored materials both previously published and submitted for publication. / Committee in charge: Eugene Humphreys, Chairperson; David Schmidt, Member; Ray Weldon, Member; James Isenberg, Outside Member

Indiana University-Purdue University Indianapolis (IUPUI) / Drivers that influence oceanic productivity are not clearly constrained. However, sea level changes during glacial cycles have been proposed as a potential driver for productivity variations observed over warm and cold climate periods. In order to determine this, additional oceanic paleoproductivity data collection is necessary to estimate the ocean’s feedback in response to a dynamic climate. The eastern equatorial Pacific (EEP) is an ideal site for productivity studies due to its high levels of nutrients and deep upwelling. This research examines the phosphorous and barite geochemisty of four EEP sites while also comparing the sites’ glacial and interglacial productivity variations to the geochemistry and productivity results of an independent central equatorial pacific site. Phosphorus and other elemental data were collected from sites 845, 848, 849, and 853 (ODP Leg 138). Using a Ba/Ti and P/Ti proxy (“excess” proxies), distinct productivity variations during glacial and interglacial periods were observed. While the age model for these sites has been estimated, the observed variations more than likely agree with high productivity during glacial periods and lower productivity during interglacial periods. Central equatorial Pacific cores RR0603-03TC and RR0603-03JC (IODP site survey cruise for Proposal 626) have been used as a reference for geochemical concentration parameters, as well as a comparison tool for productivity variations among the central and eastern sites. The central equatorial geochemistry results provided support for sea level changes driving paleoproductivity variations. The similar variation patterns displayed by the EEP’s geochemical data in this research could provide additional support for this hypothesis.

At a state university in the Pacific Northwest, the authors surveyed 477 matriculating college students about their immunization status, knowledge, self-perceived risk, and health risk behaviors for hepatitis A and B vaccinations. Review of immunization records revealed that 10% of these students were completely immunized for hepatitis A and 58.8% were completely immunized for hepatitis B. Although their knowledge about hepatitis A and B was very good, there were no significant differences in immunization status or health risk behaviors based on their knowledge or their self-perceived risk of hepatitis A and B. About 66% of students perceived they had no risk or low risk for hepatitis A and B and only 5% felt they had a high risk. In spite of the low self-perceived risk, health risk behaviors for hepatitis A and B were common in this population of college students. In the past twelve months, 56.2% of these students reported being sexually active (vaginal, oral, anal sex), including 20.5% who had two or more sexual partners. Students with multiple sexual partners reported having unprotected sex at a high frequency: 61.3% vaginal, 81.1% oral-genital, and 13.2% anal. The non-sexual health risk behaviors were also common in this population: 53.2% had body piercing/tattoos, and 26.5% traveled internationally to regions with intermediate to high rates of hepatitis A (Africa, SE Asia, Central/South America). These students who traveled internationally were more likely to be immunized for hepatitis A, although 70% remained unimmunized. In addition, students with multiple sexual partners or with a body piercing/tattoo were more likely to be immunized for hepatitis B. However, about one-third of these students with multiple sexual partners or body piercing/tattoo have not completed the hepatitis B series. The theory of planned behavior was applied to determine factors that are associated with college students' decision to be vaccinated for hepatitis A and B. For hepatitis A and B vaccinations, important attitude constructs identified were 'vaccine effectiveness, vaccine adverse effects, anticipation anxiety, inconvenience, and vaccine expense.' The subjective norm constructs with the greatest influence for college students were: 'parents, family doctor, and student health services staff'. The significant perceived behavioral constructs were 'parents reminder, student health services (SHS) reminder, and SHS hepatitis vaccine clinic.' In conclusion, there is still a sizable portion of unvaccinated college students who possess health risk behaviors for hepatitis A and B, such as multiple sexual partners, unprotected sexual behaviors, body piercing/tattoos, and international travel. With a greater understanding of college students' attitudes, subjective norms, and perceived behavioral control college health services could develop more effective strategies to educate unvaccinated college students about these risks and motivate them to be immunized. / Graduation date: 2003

The purpose of this phenomenological case study was to understand the experiences of older students' use of web-based student services in a community college setting. For the purpose of this study the term "older student" was defined as people born between the years 1943 and 1960. This group of people, often described as the Baby Boomer generation, would not have had access to computer technologies had they gone to college during their adolescent years. Web-based student services was defined as the range of student services which are placed online, allowing students to access information and services without needing to see someone in-person. There were three major reasons for this study: (a) the increase in the development and use of online student services, (b) the increase of older students in higher education, and (c) further need to understand the unique experiences of older students in higher education. The case study design used an interpretive social science philosophical approach. The study was conducted at a large multi-campus community college in a metropolitan area located in the Northwest. A combination of survey, interviews, institutional data, and student-journals were used to answer the following research questions: (a) What is the experience of older students with web-based technology in a community college setting, (b) How do the older students' overall experiences and use of web-based services affect their community college experience, and (c) How might older students' background and experiences with web-based student services inform community college policy and practice? Close examination of data revealed several major themes of older students' experiences with online student services. These themes are: ��� Student Assumptions ��� Self-Motivation ��� Influence of Prior Work Experiences ��� User Preferences ��� How and What Online Services are Used ��� User Suggestions When these themes are taken into consideration with related literature on the digital divide, technology use in student affairs, older student experiences in the community college, and older students' use of technology, this study offers implications for community college leaders and practitioners in the student affairs and technology development. The implications of this study may impact online service development, assessment of computer literacy, program enhancement or development, and technical changes. / Graduation date: 2013

Jointed goatgrass (Aegilops cylindrica Host) infestations in winter wheat (Triticum aestivum L.) production regions of the central and western USA result in severe economic losses in the wheat market. Field and greenhouse studies were conducted to determine the vernalization requirements of winter wheat, spring wheat, jointed goatgrass, and wheat by jointed goatgrass reciprocal hybrid plants. In field studies, jointed goatgrass plants required more vernalization to produce spikelets and germinable seed than 'Madsen' winter wheat plants. In greenhouse studies, plants of jointed goatgrass populations collected from Oregon and Washington wheat fields required fewer vernalization days to reach the joint stage than Madsen plants. Detailed observations in the greenhouse revealed a longer period between jointing and anthesis for most jointed goatgrass populations that was overlooked in field studies. Vernalization for 6-wk represents the minimum treatment for synchronous reproductive development among jointed goatgrass populations, Madsen winter wheat, and Madsen by jointed goatgrass hybrids, yet the risk of gene transfer might be greater after 7-wk vernalization. In the jointed goatgrass populations tested, there was not selection for a vernalization insensitive growth habit. Because jointed goatgrass spikelets often contain two seed, germination was recorded for primary and secondary positioned seed. Germination of freshly harvested jointed goatgrass seed was promoted by 25/15 C day/night temperatures. However, light and 30/20 C incubation was necessary for maximum germination of non-dormant, primary positioned seed. Both primary and secondary positioned seed within jointed goatgrass spikelets were non-dormant after 16-wk after-ripening at 22 ± 2 C. Under optimum growing conditions, no planting depth selectively allowed wheat germination and emergence while preventing jointed goatgrass germination and emergence. Glume removal did not alleviate dormancy completely in jointed goatgrass seed. Research confirmed jointed goatgrass population polymorphism for vernalization requirements and seed dormancy. Jointed goatgrass reproductive variability might be part of a general purpose genotype strategy to germinate and colonize a wide range of environments. Wheat by jointed goatgrass hybrid plants should be removed from winter and spring wheat fields. Despite a short dormancy period, three or more years of rotation outside of winter annual crops may be necessary to reduce populations of jointed goatgrass. / Graduation date: 2006

Deep-sea bamboo coral (Isidella sp.) SE000901A from the southern Oregon coast (water depth 1048m) provides a high-resolution record of variability of North Pacific Intermediate Water (NPIW) and carbon rain to the sea floor, related to coastal upwelling, from 1808 to 2000AD. Counting of annual layers in magnesium to calcium (Mg/Ca) variations, measured by electron microprobe analysis, yields a detailed age model that is transferred directly to records of carbon and oxygen isotope ratios (δ¹³C and δ¹⁸O) measured by isotope ratio mass spectrometry and trace element ratios measured by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). A significant linear relationship between δ¹³C and δ¹⁸O measured on the carbonate internode of the coral specimen revealed disequilibrium kinetic isotopic variations that depend on calcification rate. The stable isotopic time series are significantly correlated to cadmium to calcium ratios (Cd/Ca) in the carbonate internode, suggesting that cadmium uptake also reflects the rate of calcification. Comparison of phosphorus to calcium ratios (P/Ca) in the carbonate internode to historical records of oxygen concentrations of NPIW suggests that coralline P/Ca is related to the phosphate content of the ambient bottom water, which covaries inversely with oxygen concentration. Stable carbon and nitrogen isotopic ratios (δ¹³C and δ¹⁵N) were measured on two organic gorgonin nodes of our bamboo coral, but incomplete understanding of the gorgonin growth patterns and the difficulty in translating ages between the proteinaceous node and calcareous internode preclude detailed comparison between organic stable isotopes and the trace element and isotopic composition of the well-dated carbonate proxies. Based on correlation of the measured properties to historical variations in coastal upwelling, and high-latitude climate variability, we demonstrate the potential and challenges in using deep-sea bamboo corals to extend records of climate variability into the pre-historical past. / Graduation date: 2012

The invasibility, or susceptibility of an ecosystem to biological invasion is influenced by changes in biotic and abiotic resistance often due to shifts in disturbance regime. The magnitude of invasive propagule pressure interacts with an ecosystem's invasibility to determine the extent of a biological invasion. I examined how propagule pressure, forest community structure and disturbance interact to influence the invasibility of temperate Pacific Northwest forests by the newly-invasive grass, Brachypodium sylvaticum. My goal was to identify which of these factors is most instrumental in enabling the shift from establishment to population growth in B. sylvaticum at the edge of its expanding range. Both observational and experimental studies were employed to identify the many ecological components of this problem. Ecological sampling methods were used to identify trends in B. sylvaticum habitat preference and signs of habitat disturbance. In addition, an experimental study was performed to test the effects of soil and vegetation disturbance on B. sylvaticum seedling propagation. I found that while soil disturbance did not have a significant effect on seedling propagation, vegetation disturbance was implicated in B. sylvaticum spread. Higher propagule pressure and coniferous forest type were also strong predictors of increased B. sylvaticum seedling propagation and survival within established sites. My study demonstrates how propagule pressure and plant community dynamics interact to shift the invasibility of Pacific Northwest forests and facilitate the transition from establishment to spread in the invasion of B. sylvaticum.

Long-term human dietary change is a poorly understood aspect of Columbia Plateau prehistory. Faunal assemblages from thirty-four archaeological sites on the Plateau are organized into fifteen aggregate assemblages that are defined spatially and temporally. These assemblages are examined in terms of a focal-diffuse model using ecological measures of diversity, richness and evenness. Variability and patterning in the prehistoric subsistence record is indicated. Major trends in human diet and shifts in subsistence economies are documented and the relationship between subsistence and some initial semi-sedentary adaptations on the Plateau is clarified.