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Risk Factors for Bartonella Seroreactivity Among Veterinary Workers in the Pacific Northwest
No full textThesis (Master's)--University of Washington, 2021Exposure to zoonotic disease is a significant occupational risk in veterinary medicine. In this study, we characterized PPE use, injury frequency, and Bartonella seroreactivity in Washington State veterinary workers. Using a job exposure matrix developed to reflect occupational risk factors for exposure to Bartonella and multiple logistic regression, we explored determinants of risk for Bartonella seroreactivity. Depending on the titer cutoff used, Bartonella seroreactivity was between 24.0% and 55.2%. No significant predictors of seroreactivity were found, though the relationship between high-risk status and increased seroreactivity for some Bartonella species approached significance. The predictive power of the model was likely limited by the small sample size and high level of exposure to risk factors for most participants. Given the high proportion of veterinarians seroreactive to one or more of the three Bartonella spp. known to infect dogs and cats in the United States, and the unclear relationship between occupational risk factors and seroreactivity, more research is needed in this area
The Life Cycle of TTL Cirrus: A Model Evaluation using the DYAMOND Simulations
No full textThesis (Master's)--University of Washington, 2021Thin cirrus in the tropics are important for climate because of their warming effect on the atmosphere and large spatiotemporal extent, coinciding with locations of deep convection. Tropical cirrus are difficult to observe due to their high altitude and thin optical depths. They are also difficult to simulate in conventional global climate models because of the coarse grid spacing and simplified parameterizations of deep convection and cirrus formation in such models.
We investigate the representation of tropical cirrus in global storm-resolving models (GSRMs) because they have higher spatiotemporal resolution and explicit convection, which could provide a more accurate representation of cloud processes. This study uses GSRMs from the DYnamics of the Atmospheric general circulation Modeled On Non-hydrostatic Domains (DYAMOND) project. The aggregate life cycle of topical cirrus are analyzed using joint albedo-OLR histograms to determine the fidelity of models in capturing the observed distribution of cloud populations over representative tropical ocean and land regions. Some models generate more optically thick cirrus or anvils while thin cirrus dominate in other models. Model differences, likely driven by sub-grid processes such as ice microphysics, dominate over the more subtle regional shifts. Understanding the differences in the GSRMs is an important step toward reducing uncertainty
in predictions of future warming that is generated by high cloud feedbacks
The association between hospitalization for a febrile illness and animal exposure at the human-animal interface in Dong Nai, Vietnam, July 2017 – September 2018: a case-control study
No full textThesis (Master's)--University of Washington, 2021Wildlife farms are important interfaces where zoonoses can occur due to frequent and direct contact which farmers have with their animals. We hypothesized that raising wildlife species adversely affected animal farmers’ health because of the increased risk of contracting zoonotic disease, and that wearing PPE would reduce the likelihood of that outcome. To test our hypothesis, we used data collected by the Wildlife Conservation Society in Dong Nai, Vietnam, as part of the PREDICT 2 project, to conduct a case-control study. The outcome we studied was hospitalization for a febrile illness of unknown origin; we hypothesized that this febrile illness could be a zoonotic infection. We investigated the potential exposures related to raising wild taxa as a whole, exposures from individual taxa, and the use of personal protective equipment
Characterizing Grocery Store COVID-19 Controls in the Pacific Northwest
No full textThesis (Master's)--University of Washington, 2021University of WashingtonAbstract
Characterizing Grocery Store COVID-19 Controls in the Pacific Northwest Allen Chan Chair of Supervisory Committee:Marissa Baker
Department of Environmental and Occupational Health Sciences Objectives: To characterize grocery store health and safety controls implemented during the COVID-19 pandemic across stores in different cities, areas of differing levels of income, and types of stores.Methods: This longitudinal, observational study of 16 stores between Seattle, WA (n=9) and Portland, OR (n=7) was conducted from May 2020 to January 2021. Stores were visited monthly and observations of controls were recorded using a standardized checklist in REDCap. Descriptive analyses were conducted to determine the proportion of stores with a certain control.
Results: Controls like mask requirements and plexiglass screens at checkout were most common and consistent across stores and over the study period. There were no clear trends in the implementation of controls among grocery stores of different cities, in areas with differing income levels, and of different chains.
Conclusions: Of the controls observed, mask requirements and plexiglass screens were most common. Specific rules could ensure quick and consistent adoption of controls (e.g., mask mandate). Additionally, low maintenance, less resource intensive controls (e.g., screens) may be easier for stores to implement
Days of Decision: San Francisco’s 1960 House Un-American Activities Committee Protest as a Turning Point of the New Left
No full textAfter the degradation of labor union power throughout the postwar era, a new politics took hold among young Americans, and its academic roots and appeal to student demographics established the university as the new institutional mediator for left-wing activism in the 1960s. The university provided the infrastructure for college students to promote antiwar, civil rights, and civil liberties campaigns both on and off campus. Years before the major events that are tied to the New Left in American collective memory, however, Bay Area college students’ protests against the House Un-American Activities Committee garnered national media attention for their perceived radicalism in the face of repression from the federal government. Student protesters’ altercation with police at San Francisco City Hall in May of 1960 became a turning point at which the Old Left, New Left, and McCarthyism converged, providing valuable insight into the transition of broad left-wing activism from union-based to direct action protest. These student protests prompted outrage from the public and the federal government, and students across the nation soon adopted not only their protest strategy, but also the structure of the student organizations that promoted the demonstration. These protests, the first of their kind and a major precedent for what would become the student New Left movement, complicate the historical understanding of the university as the postwar institutional mediator for left-wing protest, revealing the disparities and power relations between students, professors, and administrators in the pursuit of their respective political agendas
Impact of Urban Residuals-Based Amendments on Soil Health, Crop Yield, and Nutritional Quality
No full textThesis (Master's)--University of Washington, 2021Biosolids and food scraps are highly prevalent in urban waste streams and can be stabilized for beneficial use as soil amendments. The impact of these amendments on soil health and crop response was tested for two urban soils. One soil was collected from the Tacoma Wastewater Treatment plant and was likely a remnant from plant construction. The second soil, a sandy loam, was classified as part of the Woodinville series (Fine-silty, mixed, super active, nonacid, mesic Aeric Fluvaquents) and collected from a farm located at the King County South treatment plant. Kale (Brassica oleracea ‘Winterbor’) and Swiss chard (Beta vulgaris ‘Fordhook Giant’) were grown in succession in a replicated pot trial. Pots were amended with high rates (220 mg ha-1) of two food scrap-based amendments; bokashi and vermicompost, and two biosolids-based materials; a potting soil (Tagro), and a sawdust/biosolids compost (GroCo). A soil-only control and an inorganic N-P-K (24-25-4) fertilizer control (224 kg N ha-1) were included. Soils were analyzed for total C and total N, pH, electrical conductivity (EC), mineralizable (min C), oxidizable carbon (POXC), and Mehlich-III (M-III) extractable nutrients. Plant response was measured via yield and foliar mineral concentrations (Ca, K, Mg, P, Cu, Fe, Mn, and Zn). Across both soils, organic amendments increased total C and total N, and reduced bulk density in comparison to both controls. In general, amendments increased soil available (M-III extractable) K, Mg, and S, and decreased Cu. Changes to soil C:N, pH, and M-III nutrients were mostly consistent with amendment characteristics. Measures of active C demonstrated positive changes to soil biological indicators but were not predictive of differences in plant yield. In the kale and chard, soil and amendment were highly significant factors for plant yield. Of the amendments tested, the Tagro and vermicompost resulted in dramatic improvements in plant yield and measured soil properties. Differences in yield as a result of amendment addition were more pronounced in the Tacoma soil and significantly higher than both controls. GroCo had positive effects on yield in both soils but was similar to the fertilized control in the Renton soil. The only case where bokashi germinated was for chard in the Renton soil. However, after successful germination, the yield was significantly higher than both controls and had the second-highest yield after vermicompost. This suggests further research should investigate the use of bokashi.
Crops grown in the Tacoma soil had select foliar concentrations (P, S, Cu, Mn, and Zn) that were higher than in the Renton soil. Amendment impacts on yield in this soil would improve nutrients provided for an urban gardener relative to crops grown in amended soils in the initially higher-yielding soil (Renton). Overall, vermicompost, GroCo, and Tagro had similar or increased foliar macronutrients relative to the fertilized controls. Vermicompost had particularly large increases in crop K concentrations. Biosolids-based amendments had notably large increases in crop foliar concentrations of Mn and Zn in the chard. The results from this study suggest that food scrap-based residuals have the potential to improve urban soils and increase yields for urban agriculture
Open Data for Public Good: Final Report Narrative
No full textThis report summarizes the five-year trajectory of the Open Data Literacy project (ODL), formerly named Open Data for Public Good (ODPG). The purpose of ODL's work was to 1) Prepare future and current public librarians and information professionals to a) curate collections of open data of value to local communities, and b) build the necessary infrastructure and preservation environments to sustain open data collections for long-term sustainability of these valued assets, and 2) collaborate with public sector agencies and open data providers on advocacy and outreach activities that increase awareness about and use of open data by the public.
ODL had three broad areas of focus: 1) curriculum, 2) fieldwork, and 3) research. This multi-faceted approach formed a strong foundation for educating new professionals but also for supporting and promoting the uptake of open data work by libraries and the broader public sector. Partnerships were fundamental to building capacity and assuring practical applicability of our interdependent education, engagement, and research activities. Library partners included urban, rural, and state libraries; government partners spanned both state and city agencies. The integrated, collaborative approach succeeded at creating vital connections between students and practitioners, and between theory and practice, with tangible outcomes, particularly new curriculum and field experiences for students, but also publications, resources, and job placements for students.ODL was funded by a grant from the Institute of Museum and Library Services (IMLS), Laura Bush 21st Century Librarians Program. Grant number 67-5285
Likelihood Analysis of Causal Models
No full textThesis (Ph.D.)--University of Washington, 2021We analyze several problems in causal inference from the perspective of maximum likelihood. Two archetypal likelihoods are primarily concerned: Gaussian likelihood for continuous data and multinomial likelihood for discrete data. In the first half of this dissertation, Gaussian likelihood is considered for testing and estimation. Motivated by the selection of causal graphs, in Chapter 2, we study testing between marginal and conditional independence in a Gaussian setting with the likelihood ratio test (LRT). We introduce a class of “envelope” distributions by taking pointwise suprema over asymptotic distribution functions of LRT. We show that these envelope distributions are well-behaved and lead to uniformly consistent model selection procedures. In Chapter 3, we consider the estimation of total causal effects under causal sufficiency and linearity. We derive a simple recursive least squares estimator as the MLE under Gaussian errors, which can consistently estimate any identified total effect, under either point or joint intervention. Further, this estimator is shown to be asymptotically efficient even beyond the Gaussian assumption, when compared to a reasonably large class of estimators. In the latter half, we study the inference of instrumental variable (IV) models with discrete data. In Chapter 4, we develop non-asymptotic tail bounds for the likelihood ratio statistic under multinomial sampling. Such bounds are established by bounding the moment generating function of the statistic uniformly over all multinomial parameters, which can be viewed as a finite-sample version of Wilks' theorem. Then, in Chapter 5, such bounds are combined with a convex parametrization of the IV model to streamline statistical inference as convex programming. This approach delivers strong guarantees and circumvents the difficulty in identification and post-selection inference. The approach is illustrated with a case study on the distributional effect of military service on annual earnings, using the Vietnam draft lottery as a monotone instrument. Finally, we study partial identification of the average treatment effect in a latent variable formulation and make connections to the Bell-CHSH inequalities in quantum mechanics
Novel studies of McMurdo Dry Valleys ice-cemented permafrost cores document chemical weathering in permafrost and the timing of Plio-Pleistocene glaciations
No full textThesis (Ph.D.)--University of Washington, 2021The McMurdo Dry Valleys (MDV) are a frigid, hyperarid desert of Antarctica with a landscape dominated by ice-rich permafrost. This research focuses on using two ice-rich permafrost cores collected from the MDV to study chemical processes (Beacon Valley core) and the timing of MDV Plio-Pleistocene glaciations (Victoria Valley core). In the 30-m Beacon Valley core, Mg isotopes and other geochemical data document that active weathering occurs in permafrost at temperatures well below 0°C. The weathering intensity correlates with the modeled unfrozen water content due to freezing point depression as ions are excluded and concentrated. The concept of a eutectic active zone is suggested based on the presence of unfrozen water at subzero temperatures. It is also documented that heavy Mg isotopes are fractionated into precipitating salts, onto the cation exchange complex, and into clay minerals that form in the Beacon Valley core. Using the Mg isotopic composition and a mass balance based on the distribution of Mg in each of these reservoirs, this work reveals that chemical weathering estimations were significantly underestimated when not accounting for secondary mineral formation in the Beacon Valley core. Another noteworthy finding is that the fractionation factor determined for saponite, the dominant secondary clay mineral in the Beacon Valley core, was 0.83‰, and is lower than previously published estimates. Saponite is also the primary Mg-bearing mineral that forms during low-temperature alteration of ocean crust and helps constrain the global Mg budget. The fractionation factor determined in this study suggests that previous calculations overestimated the amount of Mg removed from the ocean during saponite formation. A separate 15-meter ice-cemented permafrost core collected in Victoria Valley provides a novel paleoenvironmental record that is used to interpret the glacial history of the MDV. The core contains three glaciogenic deposits (from bottom to top: Unit 1, 2 and 3) based on the stratigraphic record, oxidized paleosol horizons, carbonate-coated clasts, salt content and composition, and stable isotopes. Cosmogenic nuclides, 26Al and 10Be, were measured in quartz along the depth of the core. Based on forward modeling of the shielding history, the ages of the deposits and the periods of glacial cover are determined. The model suggests that glaciers covered Victoria Upper Valley for at least 3.9 Ma years before depositing Unit 1 approximately 0.7 Ma, suggesting a Plio-Pliestocene glacial event. Unit 2 was deposited ~ 0.66 Ma ago during the retreat of the glacier. During the mid-to-late Pleistocene, Victoria Upper Glacier readvanced into Victoria Upper Valley and covered Unit 2 for ~ 0.23 Ma, and finally deposited Unit 3 approximately 10,000 years ago. The deepest unit in the core, Unit 1, is interpreted as a wet-based glacial till and provides the best age constraint for wet-based glaciation during the late Pliocene to early Pleistocene in the MDV
Pions in Neutron-rich Matter: Implications for Neutron Stars and Supernovae
No full textThesis (Ph.D.)--University of Washington, 2021The effects of pions on astrophysical phenomena have been studied for decades. In the 1970s, Migdal and Sawyer independently proposed that pions could condense in dense matter due to attractive p-wave interactions with nucleons. Many other studies have investigated the possibility of pion condensation in dense neutron-rich matter. However, due to the strong interactions between nucleons and pions, there is a large degree of uncertainty in condensate formation. We have considered the effects of a thermal population of negatively charged pions, where the enhancement from strong interactions with nucleons is taken into account with a virial approximation and find that even without the formation of a condensate, pions are likely to have a large effect on neutron-rich matter at high densities and temperatures, such as the conditions in the proto-neutron star of a core-collapse supernova or inside neutron star mergers. This model is also used for calculations of neutrino mean free path in the processes and as well as calculations of axion emissivity through a pion induced reaction . Due to the pions repulsive s-wave interaction with nucleons and strongly attractive p-wave interactions, the majority of studies have focused on investigations of pion condensation at finite momentum. Early studies concluded that a condensed state at finite momentum was favored, but later more sophisticated analysis found that these results may not be robust at the densities encountered in neutron stars. In this thesis we reevaluate the possibility of s-wave pion condensation through improved calculations of the pion self-energy using Chiral Perturbation Theory