Digital Commons Network^™

Restoring, Protecting, And Expanding Abortion Access In The United States: Seeking Consensus Through The Delphi Method, Sarah Pickering

Dissertations and Theses

Background: The Dobbs v. Jackson Women’s Health Organization Supreme Court decision exacerbated inequitable access to abortion in the US. Agreement is needed on which strategies should be prioritized to restore, protect, and expand abortion access.

Methods: We convened a multidisciplinary, geographically diverse Delphi panel of clinical, research, policy, legal, and advocacy experts to reach consensus (i.e., agreement >67%) on recommended actions. Using feedback from three rounds of surveys, and input from a select expert advisory group (N=10), we iteratively refined the statements and recommendations.

Results: The panel (N=85) developed 25 consensus statements and 32 recommendations for action by advocates, funders, …

Application Of Methods To Population-Based Surveys To Reduce Bias In Estimates Of Sars-Cov-2 Infection Burden In The Population, Saba Qasmieh

Dissertations and Theses

BACKGROUND: Population-based surveys designed to randomly sample the population can be a critical and complementary tool to traditional surveillance approaches. Probability-based surveys enable the measurement of SARS-CoV-2 testing and outcomes that avoid issues around self-selection into testing, making them an effective approach to address ascertainment bias in passive surveillance. For surveys to be a useful and reliable surveillance tool for understanding the burden and distribution of SARS-CoV-2 infection, they need to capture prevalence estimates that are both valid and reliable to be optimally informative for public health measures. The dissertation was undertaken to address three main gaps that have implications …

Tiny Drifters Amidst Global Change: Examining Environmental Drivers, Trophic Impacts, And Management Strategies Of Estuarine Plankton Communities In The Anthropocene, Taylor Nicole Dodrill

Dissertations and Theses

Plankton productivity supports estuarine food webs, and has been tied to the success of fisheries, macroinvertebrates, and cultured shellfish yields. Climate change and alterations to nutrient loads are thought to be influencing plankton assemblages, with toxin-producing harmful algal blooms (HABs) on the rise and nutritional quality of plankton declining globally. These shifts in plankton communities may contribute to low biomass yields and toxin-based closures of important fisheries. The objectives of this dissertation are to identify environmental drivers, trophic impacts, and management strategies to understand and respond to changing estuarine plankton communities. To address these objectives, I used a combination of …

A Mixed Methods Approach To Understanding The Links Between Mining, Climate Change And Selected Health Outcomes In India, Mary J. Cheruvillil

Dissertations and Theses

Despite ample evidence of the significant role that mining activities play in determining health outcomes, in India there is a dearth of comprehensive health studies that draw linkages between mining and health. The purpose of the following study is to investigate the impact of mining activities on population health in India using three different methods: ecological multivariable regression, exploratory spatial data analysis (ESDA) and content analysis of government documents using a phenomenological approach. The first aim uses the ecological multivariable regression to examine associations between mining activities and children’s malnutrition outcomes at the district level. Census data, the Demographic Health …

Drivers And Dynamics Of Phytoplankton Communities And Harmful Algal Blooms In Mountain Lakes, Lara Stephanie Jansen

Dissertations and Theses

Harmful cyanobacterial blooms (cyanoHABs) are a complex and widespread disturbance in freshwater water bodies, impacting water quality for wildlife and human populations. While cyanobacteria often bloom in warm lakes impacted by human development like agriculture, blooms are increasingly reported in cooler waters with limited development in the surrounding watershed. As much of cyanoHAB research has focused on lakes in highly developed watersheds, the understanding of factors leading to cyanobacteria dominance and blooms in the absence of major development remains limited. Mountain lakes can serve as ideal systems to study bloom-forming cyanobacteria in watersheds with minimal development. In addition, mountain lakes …

Spatial Analysis Of Burn Severity And Streamflow Response In The Western Conus, Will Brendan Long

Dissertations and Theses

Wildfire increases the magnitude of runoff in catchments, which can lead to the degradation of ecosystems, risk to infrastructure, and loss of life. The Labor Day Fires of 2020 provided an opportunity to compare multiple large and severe wildfires with the objective of determining potential changes to hydrologic processes in Oregon Cascades watersheds. Geographic information systems (GIS) were implemented to determine the total percentage burned and percentage of high burn severity class of six watersheds on the west-slope of the Oregon Cascade Range. In addition, two control watersheds were included to contrast the influence of climatic effects. Spatial arrangement of …

Efficiency In The Upper Deschutes Basin: Understanding The Hydrosocial Implications Of Irrigation Canal Piping, Rebecca Anderson

Dissertations and Theses

In response to water scarcity, irrigation efficiency projects aim to conserve water for in-stream flow and agricultural use. Piping irrigation canals is a common irrigation efficiency method which reduces the loss of incidental recharge, resulting in trade-offs within a hydrosocial system. Few studies have focused on the consequences of canal piping and none have integrated a critical analysis of the social factors involved in deciding what constitutes 'efficient' water use. This study seeks to fill this gap by combining natural and social science to give attention to the scales and perspectives involved in irrigation efficiency canal piping and the material …

"We've Created Cheap Energy Off The Backs Of Salmon": Dam Removal Politics And Alliances In The Lower Snake River Basin, Krista Harrington

Dissertations and Theses

Dams, once considered by many to be good for water development in the Western U.S., might not be a part of a climate resilient future. Dams have come under increasing scrutiny due to undesirable ecological implications. Although dam removal proposals are growingly popular in recent decades, they are controversial since they impact different stakeholders in different ways. In the Pacific Northwest, the Lower four Snake River dams have long been criticized for their negative impacts on salmon. In February 2021, US Congressman Mike Simpson (R-Idaho) proposed a comprehensive framework to deconstruct the Lower four Snake River dams as an attempt …

Factors Associated With Racial And Ethnic Disparities In Cesarean Delivery Among Women With Low-Risk Pregnancies At New York City Hospitals, 2012-2017, Ellen Brazier

Dissertations and Theses

BACKGROUND: While Cesarean delivery is a life-saving procedure when certain complications arise, it is associated with increased risks of maternal mortality and morbidity, as well as neonatal and childhood morbidities, and increased risks for women during subsequent pregnancies. Stark and persistent racial/ethnic disparities in Cesarean delivery that are not explained by clinical risks raise concerns about overuse of the procedure, as well as the contribution of potentially avoidable Cesareans to disparities in maternal mortality and morbidity. Understanding the extent to which disparities in Cesarean delivery may be attributable to differences in care during labor is critical for addressing these disparities. …

Digging For Information: Investigating The Efficacy Of Tracking And Augmenting Lacunicambarus Nebrascensis For Endangered Dragonfly Conservation, Danielle Elaine Tesar

Dissertations and Theses

Restoration and preservation of habitat for threatened and endangered species can proceed in many ways. Augmentation strategies can be used to supplement threatened and endangered populations or the species and resources on which those imperiled species depend. Comprehensive knowledge of species movement and home range is necessary to formulate effective augmentation plans. For freshwater burrowing crayfish, this type of information is generally lacking. The studies reported here were designed to acquire detailed information that is essential for augmentation of the plains devil crayfish, Lacunicambarus nebrascensis (formerly, Cambarus diogenes). Although L. nebrascensis populations are not considered threatened, this crayfish provides vital …

Poly(Β-Gal-Thr): A New Scalable Synthetic Mucin, Manuel A. Lema

Dissertations and Theses

A method for the preparation of glycosylated polypeptides via the nucleophilic ring-opening polymerization of a glycosylated N-carboxyanhydride (NCA) monomer is reported. The synthesis of 2,3,4,6-tetraacetyl-β-galactose-threonine N-carboxyanhydride (β-AcO-Gal-Thr-NCA) monomer in 5 steps with an 8 % overall yield is described, and the single-crystal X-ray structure is provided. The effect of a series of Ni⁰-based organometallic initiators, nucleophilic amine initiators, co-catalysts, and solvents on the polymerization were explored. The kinetics of the three most promising conditions were studied in greater detail. The conditions that provided the highest yield, low polydispersity (Ð), and …

Modeling Environmental Factors Related To Drought-Induced Tree Mortality Based On Lidar And Hyperspectral Imagery, Lauren Nicole Sharwood

Dissertations and Theses

Climate change is projected to bring more frequent and prolonged droughts, causing widespread forest die-off. Identifying tree mortality over large spatial extents in response to the most recent California drought will help forest managers and conservationists understand where there may be a greater likelihood of future die-offs. In order to find more at-risk areas, this study evaluated how interacting site-specific topographic, climate, substrate, and stand characteristics mediated tree mortality in the Central Sierra Nevada during the 2012-2016 drought. The author used lidar and hyperspectral imagery provided by the National Ecological Observatory Network to identify individual dead trees using the Random …

Exploring Linkages Between Landscape Patterns And Freshwater And Estuarine Bivalves In The Coast Range Of Oregon, Kaegan Michael Scully-Engelmeyer

Dissertations and Theses

Spatial configurations of landscape variables (biotic, abiotic, and socio-ecological) affect and are affected by ecological processes and species in watersheds. This dissertation explores relationships among landscape patterns, ecosystem processes and bivalve species dynamics in coastal watersheds in Oregon, USA. I approached this broad topic through two primary avenues of research: investigating cross-ecosystem threats from pesticide use in forestland management to downstream aquatic environments, and the landscape ecology of an at-risk freshwater mussel species.

Terrestrial land use activities present cross-ecosystem threats to riverine and marine species and processes. Specifically, pesticide runoff can disrupt hormonal, reproductive, and developmental processes in aquatic organisms, …

A Historical Ecology Of Aridland Springs In Desert National Wildlife Refuge, Nuwu/Nuwuvi (Southern Paiute/Chemehuevi) Ancestral Territory, Nevada, Yarrow Sarah Valentine Geggus

Dissertations and Theses

Aridland springs are among the most threatened ecosystems in the world. Vital to desert ecologies and Indigenous cultures, these complex and individualistic ecosystems have layered histories. To inform management in the changing landscape of Desert National Wildlife Refuge, a 1.6 million acre protected area in Southern Nevada, I conducted a historical ecology study of a sample of ten upland springs. Through a six-part interdisciplinary methodology including interviews, archaeological survey, botanical survey, and archival research, I summarize findings into three broad eras: the Nuwu/Nuwuvi pre-Contact Era, the Settler Era, and the U.S. Fish and Wildlife Service Era.

For millennia, Nuwu/Nuwuvi drank …

Wildfire Risk Assessment For A Municipal Watershed In Western Oregon, Usa: Methods For Projecting The Impact Of Mid-21st Century Climate Change On Wildfire Hazard, Andy Mcevoy

Dissertations and Theses

In the western United States, climate change is projected to lead to significant changes in regional wildfire regimes. Historically, forests west of the Cascade crest in Oregon and Washington, USA (westside) have been characterized by low-frequency wildfire events, but climate change projections indicate that wildfire could become a more common disturbance, altering ecological processes and impairing ecosystem services like surface water quality and quantity. Wildfire risk assessments based on simulation models have been used in high frequency fire regimes to evaluate contemporary and future risk, but present unique challenges in westside forests because characteristic low annual burn probabilities result in …

Mathematical Silences, Matthew Nathan Petersen

Dissertations and Theses

Previous studies have shown that mathematicians employ lengthy silences in their collaborations, contrary to the norms that govern every-day collaborations. Such results shows the relevance of an investigation of silence in mathematical collaboration. This dissertation builds off these results in a series of three papers. The first paper describes a methodology that can be employed in the investigation of silence in mathematical collaboration. The second paper analyses silence in the mathematical collaboration of students in junior-level introductory proof classes. It identifies two forms of mathematical activity, reading and ruminating, that students regularly engage in, and which violate the norms of …

The Role Of Strategic Governance In Reducing Infant Mortality Under Crisis Conditions, Lynn Christine Finley

Dissertations and Theses

The infant mortality rate (IMR) in some developing countries has decreased faster than the global average even though these countries lack strong economic growth, good governance, and democracy (often acknowledged precursors to improved health outcomes). What accounts for the improvement of the IMR in the absence of these traditional pathways to health gains? Some scholars suggest that the concept of "strategic governance" might help direct attention to intermediary factors that reduce neonatal deaths in countries that experience crisis conditions. The main objective of this dissertation is to investigate the set of governance practices that have reduced IMR in two such …

More Than Meets The Eye: A Taxonomic Revision Of The Nearctic Species In The Eye-Gnat Genus Amiota Loew (Diptera: Drosophilidae), Lance E. Jones

Dissertations and Theses

Thorough biotic inventories are still needed even in families as seemingly well-studied as fruit flies (Diptera: Drosophilidae). Drosophilidae have had an outsize effect on the history of biology because of their pivotal role in the study of genetics, development, and evolution. Even with more than a century of intensive study, large gaps remain in our understanding of diversity in this fly family, including well-studied areas such as North America. This thesis presents a taxonomic revision of the Nearctic species of the genus Amiota Loew. Twenty-three species are identified as being new to science for publication at a later date. This …

Burdern Of Chronic Health Conditions And Healthcare Utilization Among Mobile Populations In Sub-Saharan Africa, Elizabeth M. Ortiz

Dissertations and Theses

Background: Much of public health research in sub-Saharan Africa on mobile occupations, such as truck drivers and sex workers, has focused on HIV risk. However, evidence is emerging to suggest that the HIV epidemic among these groups is coupled with a high prevalence of chronic health conditions (CHC), specifically hypertension, diabetes, and obesity. For people living with HIV, increased risk of CHC may also be linked to HIV-related chronic inflammatory cascade. In Africa, there has been little research on CHC risk factors or patterns of healthcare utilization among mobile populations. Therefore, the objectives of this study are to examine the …

Do Saproxylic Curculionids Affect The Fitness Of Co-Occurring Cerambycids?, Sheila R. Heath

Dissertations and Theses

Saproxylic insects sometimes coexist in incredibly high numbers under bark and share common resources. Thus, interactions between species are possible and could even explain their coexistence. This study investigates evidence of negative or positive effects of curculionid beetles (Coleoptera: Curculionidae) on cerambycid beetles (Coleoptera: Cerambycidae) that coexisted in dead tree branches in Costa Rica. Co-occurrence analysis and generalized regressions were used to test associations between cerambycid and curculionid species. Three cerambycid species that each co-occurred with a curculionid species were selected to measure fitness. Fitness measures of the cerambycid were compared with abundance of the co-occurring curculionid to assess the …

Fungal Endophytes In A Seed-Free Host: New Species That Demonstrate Unique Community Dynamics, Brett Steven Younginger

Dissertations and Theses

Fungal endophytes are highly diverse, cryptic plant endosymbionts that form asymptomatic infections within host tissue. They represent a large fraction of the millions of undescribed fungal taxa on our planet with some demonstrating mutualistic benefits to their hosts including herbivore and pathogen defense and abiotic stress tolerance. Other endophytes are latent saprotrophs or pathogens, awaiting host plant senescence to begin alternative stages of their life cycles. Most, however, are likely plant commensals with no observable benefits to their hosts while under study. Yet, when considering the context-dependence that may determine plant resistance to pathogen attack, the consortium of endophytes present …

Recovery Of Zooplankton Communities To Whole-Lake Disturbance, Brian Newton Mcgann

Dissertations and Theses

Community assembly following disturbance is a key process in determining the composition and function of the future community. However, replicated studies of community assembly at whole ecosystem scales are rare. Here is described a series of whole-lake experiments in which the recovery of zooplankton communities is tracked following an ecosystem-scale disturbance. Fourteen lakes in eastern Washington were chosen: seven lakes were treated with rotenone, while the remaining seven were reference. Each lake was monitored up to six months before and one to two years after the rotenone treatments. Zooplankton tows were taken monthly, at a shallow, intermediate, and deep site …

Wolbachia-Host Interactions And The Implications To Insect Conservation And Management, Amy Michelle Truitt

Dissertations and Theses

Parasitic reproductive endosymbionts are emerging as formidable threats to insect biodiversity. Wolbachia are prevalent maternally inherited intra-cellular bacteria found in >50% of arthropod species. These symbiotic bacteria interact with their hosts in diverse ways, most often they alter host reproduction causing four conditions that all selectively favor infected females: feminization, male killing, parthenogenesis, and cytoplasmic incompatibility (CI). Furthermore, depending on strain-type and host genetic background, Wolbachia are known to affect insect behavior, expand or shift host thermal tolerance ranges, and confer anti-viral protection to their hosts. Because Wolbachia both reside in and are transmitted with host cell cytoplasm, mitochondria and …

Incorporating Place And Space: A Hierarchical Spatial Approach To Exploring Preventable Congestive Heart Failure Hospitalizations In New York City, Rachael Weiss Riley

Dissertations and Theses

Background: Faced with rising medical care costs, increasing prevalence, and widening health disparities, preventing congestive heart failure (CHF) hospitalizations is a central public health concern. Despite evidence of geographical clustering in preventable CHF admissions, there is a lack of research designed to examine spatial patterning of CHF and the local area neighborhood determinants that contribute to this variability. This study sought to assess and evaluate the importance of both space and place in analyzing preventable CHF hospitalizations and readmissions by applying appropriate statistical techniques, clarifying the assumption inherent in each method, and interpreting the findings within the context of existing …

Are Weevils Picky Eaters? Community Structure And Host Specificity Of Neotropical Saproxylic Beetles (Coleoptera: Curculionidae), Jhunior A. Morillo

Dissertations and Theses

Abstract Primary saproxylic beetles play a major role in forest nutrient cycling and making deadwood accessible to other decomposers. Understanding beetle host preferences and patterns of community assembly is critical for their conservation, and for predicting which species might become invasive. This project aims to investigate the ecological and host specificity, as well as the community composition of curculionids in a mosaic of old-growth (OG) and secondary forest on the Osa Peninsula, Costa Rica. The subfamily Scolytinae was expected to be the most species-rich and abundant. Ambrosia beetles were expected to have more generalist species than other curculionids. Old growth …

Connecting To Nature, Community, And Self: A Conservation Corps Approach To Re-Engaging At-Risk Youth In Science Education, Sara Jo Linden

Dissertations and Theses

The social and environmental challenges of the coming decades will require that individuals possess environmental literacy: the understanding of natural systems combined with a sense of care for the earth, and the confidence and competency to act on its behalf. At the same time, disengaged youth need education environments that foster belonging and promote affective outcomes. The youth conservation corps model provides a natural context for engaging academically at-risk youth in environmental science education, while fostering connection to nature and student self-efficacy in ways that are experiential, relevant, and relationship-based. The focus of this study was a conservation corps program …

Pharmaceutical Contaminants As Stressors On Rocky Intertidal And Estuarine Organisms: A Case Study Of Fluoxetine, Joseph Richard Peters

Dissertations and Theses

Contaminants such as pharmaceuticals are of increasing concern due to their ubiquitous use and persistence in surface waters worldwide. Limited attention has been paid to the effects of pharmaceuticals on marine life, despite widespread detection of these contaminants in the marine environment. Of the existing studies, the majority assess the negative effects of pharmaceuticals over an exposure period of 30 days or less and focus on cellular and subcellular biomarkers. Longer studies are required to determine if chronic contaminant exposure poses risks to marine life at environmentally relevant concentrations. Also scarce in the literature is examination of whole organism effects …

Modern Foraminiferal Assemblages Of The Denmark Strait, Laura Larocca

Dissertations and Theses

Foraminifera occupy a geological range from the early Cambrian to the present day. Their well preserved shells, high relative abundance, and short response time to changing environmental conditions make foraminifera ideal proxies for environmental change. Benthic foraminifera are a valuable but poorly understood paleobiological proxy for the reconstruction of environmental conditions on continental shelves occupied by arctic and subarctic waters. This study identifies, examines, and quantifies calcareous benthic foraminiferal faunas from a sediment core taken from the Denmark Strait. Our analysis of three-thousand individuals from ten discrete samples aim to provide a better understanding of the modern patterns of foraminiferal …

Localized Ecological And Educational Effects Of Environmental Service-Learning In Portland, Oregon, Steven Matthew Braun

Dissertations and Theses

Environmental service-learning is an intentional educational experience(s) wherein learners engage in meaningful activities designed to serve the environment. Environmental service-learning activities vary according to their learning and service goals and include ecomanagement, persuasion, legal action, economic action and political action. The purpose of this mixed methods research was to explore the ecological and educational impacts of grades 6-12 environmental education, with special attention to environmental service-learning throughout Portland, Oregon.

Ecological impacts considered restoration and conservation outcomes of several environmental service-learning programs including plant communities, soils, litter removal and trail maintenance. Educational outcomes considered aspects of environmental literacy including locus of …

Advances In Aquatic Target Localization With Passive Sonar, John Thomas Gebbie

Dissertations and Theses

New underwater passive sonar techniques are developed for enhancing target localization capabilities in shallow ocean environments. The ocean surface and the seabed act as acoustic mirrors that reflect sound created by boats or subsurface vehicles, which gives rise to echoes that can be heard by hydrophone receivers (underwater microphones). The goal of this work is to leverage this "multipath" phenomenon in new ways to determine the origin of the sound, and thus the location of the target. However, this is difficult for propeller driven vehicles because the noise they produce is both random and continuous in time, which complicates its …