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HARNESSING TOPIC MODELING AND KNOWLEDGE GRAPHS FOR ENHANCED DISCOVERY IN HEALTH INTEROPERABILITY RESEARCH THROUGH RETRIEVAL-AUGMENTED GENERATION
Get PDFTechnologies today rarely function in isolation. Disparate data repositories and fragmented information systems necessitate seamless interoperability to support both clinical and research applications. This dissertation develops a computational framework for systematically evaluating interoperability standards that facilitate data exchange between research technologies and health systems.Rather than assessing interoperability through a single standard or methodology, this research introduces a structured knowledge model that categorizes interoperability concepts and cross-references them with relevant components, technologies, and terminologies. To achieve this, the study integrates artificial intelligence (AI) techniques, including natural language processing, machine learning, and graph analytics to extract, classify, and visualize interoperability relationships from health informatics literature.The framework applies unsupervised and semi-supervised learning methods, using AI techniques such as Latent Dirichlet Allocation (LDA), Non-Negative Matrix Factorization (NMF), and BERTopic to discover latent topic structures across thousands of biomedical publications. These topic models serve as the foundation for a domain-specific knowledge graph, allowing deeper semantic understanding and organization of interoperability research.To enhance the accuracy of concept extraction and entity recognition, the study creates fine-tunes a biomedical transformer model, Health Interoperability Research Bidirectional Encoder Representation from Transformers (HIResBERT), adapted for health interoperability. This model supports contextualized sentence embeddings and Named Entity Recognition tailored to interoperability use cases.The resulting AI-powered knowledge graph is operationalized through Graph-based Retrieval-Augmented Generation (GraphRAG) application, which facilitates semantic question answering and contextual discovery. Researchers can navigate complex interoperability relationships, uncover gaps, and retrieve literature mapped to relevant standards.Additionally, this research offers a structured mechanism for analyzing interoperability trends and delivers insights. By making complex standards and relationships more navigable, the framework enables researchers to effectively learn about and engage with interoperability concepts and technologies. By leveraging AI to automate the extraction, synthesis, and navigation of domain knowledge, this dissertation presents a scalable and reusable framework for advancing interoperability, clinical decision support, and health data integration within clinical and translational science.Ultimately, this work demonstrates how AI can be harnessed to advance literature discovery, knowledge modeling, and conceptual clarity across key areas of health informatics, laying the foundation for more transparent, data-driven, and integrative approaches to health research.Doctor of Philosoph
Erasing Cultures, Resisting Erasure: A Comparative Analysis of Cultural Genocide Patterns of Persecution and Resistance in the Xinjiang Uyghur Autonomous Region and 20th Century Genocides
Get PDFThis thesis explores the Chinese Communist Party’s (CCP) methods of cultural genocide and corresponding Uyghur resistance in contemporary Xinjiang. Since before the CCP's rise to power in 1949, Uyghurs, a Turkic ethnic minority and the largest non-Han group in Xinjiang, have faced marginalization. The analysis is two-fold. First, I focus on the CCP’s destruction of three primary aspects of Uyghur culture: language, religion, and tangible heritage sites. Here, I compare the CCP’s methods to those occurring in three historical genocides: Native Americans in the United States, the Armenian Genocide, and the Holocaust. Through these comparisons, I highlight parallels of cultural destruction. Second, I compare Uyghur resistance with resistance movements during these three historical genocides. These parallels show universal techniques of survival and defiance under oppressive regimes and place the Uyghur experience within a larger historical and political framework. The comparison of resistances serves as additional evidence for the claim that the CCP’s policies towards Uyghur language, religion, and tangible heritage sites are systematically eliminating Uyghur culture and identity in the region.Master of Art
FROM COURTSIDE TO CASE STUDY: AN ANALYSIS OF ORGANIZATIONAL IDENTITY ON SIGNIFICANT RISES IN WOMEN’S COLLEGE BASKETBALL TEAM RANKINGS
Get PDFThe goal of this study was to understand a team’s culture at the player, coach, and staff level and why it may have influenced their success throughout the course of the season. Participants (7 members of the Iowa State Women’s Basketball Team) were chosen from the team selected for the case study that demonstrated a significant single-season rise in women’s college basketball team rankings for the 2023-2024 season. Participants who agreed to be in the study, completed a semi-structured interview that had ten open-ended questions. Through the themes of leadership, coaching strategies, trust, team identity, and adaptability, it was revealed that these factors of team culture played a role in defining what it means to be a member of Iowa State Women’s Basketball and how their performance might have increased over the course of the season. Results show the importance of team culture and identity in an increase in a team’s performance when preseason expectations were low.Master of Art
BETWEEN FAITH AND EMPIRE: MISSIONARIES AND OPIUM TRADE IN CHINA, 1830–1872
Get PDFThis thesis explores the evolving relationship between Protestant missionaries in China and the opium trade from 1830 to 1872. While missionaries are often depicted as either complicit in imperialist expansion or leading moral crusades, their stance on opium was far more complex and shifted over time. Initially, figures such as Elijah Coleman Bridgman and Samuel Wells Williams condemned the opium trade on moral grounds. However, by the mid-nineteenth century, pragmatic concerns, diplomatic engagements, and the desire to expand missionary influence led many to support its legalization. This study examines missionary writings, diplomatic records, and archival sources to trace these transformations and analyze the broader intersections of religion, commerce, and empire. It argues that missionaries’ shifting attitudes reflected not only theological convictions but also geopolitical and institutional pressures. Ultimately, their involvement laid the groundwork for late-nineteenth-century anti-opium campaigns, illustrating the paradoxes of missionary engagement in China’s colonial and economic history.Master of Art
RIGHT-TO-WORK: HOW WORLD WAR II AGRICULTURAL POLICY SHAPED 20TH CENTURY LABOR HISTORY
Get PDFThis dissertation examines early right-to-work (RTW) legislation in the United States South and, in particular, its origins in the WWII-era Southern agricultural economy. RTW laws, which ban union security agreements requiring all workers covered by a union contract to join or contribute to the cost of that union, have been proven to limit workers’ ability to collectively advocate for better wages, dictate working conditions, and influence electoral politics. While the Taft-Hartley Act of 1947 enshrined states’ ability to pass RTW laws banning union securing agreements, two states, Arkansas and Florida, passed RTW legislation three years prior in 1944. This dissertation argues that, despite the exclusion of agricultural workers from New Deal federal labor law, the first successful RTW campaigns were executed by farm employers (specifically, the American Farm Bureau Federation) in response to farmworker organizing during the Second World War. Specifically, these campaigns responded to farmworkers and farm union leaders using the domestic context of WWII—in particular the high demand for farm labor, the industrialization of farm work, and the federal government’s involvement in the coordination, organization, and compensation of farmworkers through the wartime Farm Labor Program—in order to gain labor organizing protections for farmworkers, including union security. Existing historical literature on RTW has focused on the spread of RTW laws in the industrializing southwest “Sunbelt” region of the country in the post-war period after the passage of the Taft-Hartley Act. This dissertation returns to RTW’s origins, demonstrating how the movement’s early agrarian, Southern orchestrators did not just undercut the possibility that farmworkers would finally join the broader labor movement. They also went on to share their experiences and insights with both federal lawmakers and anti-union actors across the country, in turn shaping and enabling a movement that altered twentieth century labor relations and union organizing for all workers.Doctor of Philosoph
SYNTHESIS AND APPLICATION OF CLEAVABLE SIDE CHAINS IN MODERN ORGANIC SEMICONDUCTORS FOR ACHIEVING THERMAL STABILITY AND HIGH CONDUCTIVITY
Get PDFOrganic semiconductors offer outstanding potential in flexible electronics, such as organic photovoltaics and transparent conductors. However, the general instability of organic semiconductor-based devices to thermal based stressors largely hinders their greater utilization and commercialization. Side chains, while essential for solution processability and morphological tuning of organic semiconductors, contribute significantly to their thermal-based intrinsic and extrinsic degradation by lowering each material’s glass transition temperature and oxidation potential, respectively. To combat these issues while maintaining competitive device performances, this dissertation explores new design rationales for the post processing elimination of side chains from organic semiconductors. First, for organic photovoltaics, we designed a series of PffBT-T4 based statistical co-polymers replacing variable amounts of optimized alkyl side chains with thermocleavable tertiary ester side chains on the polymer backbone. This co-polymer approach revealed a performance-stability tradeoff in solar cells after ester pyrolysis and side chain evaporation at 220 ℃. A co-polymer containing 60 mol% of cleavable side chains demonstrated improved intrinsic thermal stability and maintained significantly higher device efficiency than the homopolymer with 100 mol% cleavable side chains. Next, we reduced the annealing temperature required for tertiary ester pyrolysis by using Brønsted-Lowry acid catalysts which led to a performance enhancement in organic photovoltaics. Organic acids, incorporated as additives in polymer blends, reduced annealing temperatures from above 200 ℃ to as low as room temperature, tunable based on acid strength and concentration. In the final project, we explored the fundamentals of using polythiophenes containing cleavable side chains for molecular doping. By exploring a series of structural isomeric polymers, we discovered the polythiophene, POET-T2-COOH, which achieved a conductivity exceeding 350 S/cm in molecularly doped and side chain cleaved films after a hybrid side chain cleavage with doping condition. Furthermore, these doped conducting films maintained solvent resistance and stable conductivity in an inert atmosphere, opening new applications for cleavable side chain-based materials.Doctor of Philosoph
Teachers’ Self-efficacy and Perspectives in Mandarin Dual Language Programs: An Explanatory Sequential Mixed Methods Study
Get PDFAlong the ethnic-cultural shift and language diversity in the recent decades in American public schools, DL programs are increasing in popularity with their promising effects, among which, Chinese has become the second-most commonly adopted language. Many researchers have noted that a major challenge of DL education is the lack of qualified teachers to meet the demand of flourishing programs across the United States. To address the literature gap regarding the population of MDL teachers, this study draws on theoretical lens from the triadic reciprocal determinism model and sources of influence on self-efficacy with its expansion cognitive mastery experience and imaginal experience, examines MDL teachers’ self-efficacy in the application of the National Dual Language Education Teacher Preparation Standards (NDLETPS) and explores diverse but interrelated factors that affect teachers’ self-efficacy to achieve a more holistic understanding about how past learning experience, professional development activities, and support received at work may predict and explain MDL teachers’ self-efficacy. An explanatory sequential mixed methods design is used to collect and analyze quantitative data through an online survey and qualitative data through follow-up interviews.The quantitative data from the survey presents a general picture of the relationship between MDL teachers’ self-efficacy and their experiences by aggregating survey data from 69 MDL teachers dispersed among 14 states, which are also used to inform the design of the qualitative interview protocol and purposeful sampling of interviewees from the survey participants. The qualitative data from the interviews provides more detailed narratives to understand and explain the quantitative results. Integrated together, findings reveal that experiential learning, integration of subject content and language, and critical consciousness are significant enactive and cognitive mastery experience that should be emphasized in teachers’ learning experience to improve MDL teachers’ self-efficacy; professional interactions and reflective journaling are effective PD activities that can create vicarious and imaginal experience to promote MDL teachers’ self-efficacy; extensive support at work, in particular peer, parental and administrative support as social persuasion and psychophysical wellbeing, plays an important role to improve MDL teachers’ self-efficacy. Practical implications of the findings for researchers, teacher educators and stakeholders are also discussed.Doctor of Philosoph
Photophysical Properties of Molecules and Materials for Solar Energy Conversion
Get PDFA confluence of factors including climate change and national energy security necessitate a shift from fossil fuels to renewable sources. One of the most attractive methods is the conversion of sunlight into chemical fuels, called solar energy conversion. This dissertation advances the fundamental photophysical properties of the molecules and materials involved in two applications of solar energy conversion: dye-sensitized photoelectrochemical cells (DSPECs) and silicon-based hybrid photoelectrodes.Chapter 1 describes the photophysical properties of ruthenium polypyridyl complexes–common chromophores in DSPECs–and the semiconductor photophysics which underpin silicon hybrid photoelectrodes.In Chapter 2, excited-state quenching studies in acetonitrile and acetone is used to study the effect of solvent polarity on the Coulombic attraction between iodide and a ruthenium complex decorated with aldehyde groups. Decreased solvent dielectric in acetone solution was shown to induce stronger association, increasing the equilibrium constant by an order of magnitude compared to acetonitrile, as measured by 1H NMR titration assays. The increased degree of association manifested in an increased contribution of static quenching.Chapter 3 leverages time-resolved infrared spectroscopy to understand the excited state behavior of chloride associated with ruthenium polypyridyl complexes decorated with amide groups in dichloromethane. In such complexes, the ground state equilibrium for chloride association was large ~107 M-1. Following laser excitation, the photoluminescence initially resembles the complex with chloride associated but evolves over time indicating photodissociation (“photo-release”). The time-resolved infrared spectra support an increase in the hydrogen bonding as a function of time. A model is proposed in which chloride migrates orthogonally to the plane of the bipyridine ligand in response to the excited-state dipole.Chapter 4 compares three fabrication methods for a silicon/silicon dioxide (Si/SiOx) passivation layer in silicon hybrid photoelectrodes: native oxide, chemically grown oxide, and thermal oxide, grown by rapid thermal annealing. Through time-resolved infrared spectroscopy, electrochemical impedance spectroscopy, and cyclic voltammetry, the rapid thermal annealing was identified as the optimal interface, possessing good electron transfer to a solution mediator, long lifetimes, and reduced surface trap state densities.Collectively, these findings deepen our understanding of molecular and interfacial photophysics, guiding the design of more efficient systems for solar-to-chemical energy conversion.Doctor of Philosoph
At a Crossroads: German and American Security Policies in Response to China’s Rise
Get PDFThis thesis examines the influence of strategic culture on United States and German security policies towards the People’s Republic of China between 2016 and 2024 by investigating 20th- and 21st- century strategic cultural developments in both countries and observing their influence on contemporary national security decision making. Adopting a constructivist perspective, this study finds that Germany and the United States’ China policies are influenced by fundamentally different perceptions of the way in which the PRC threatens their relative power positions and role perceptions in global affairs, with these perceptions motivated by divergent strategic cultures and further influenced by unique economic considerations. Whereas strategic cultural influences have encouraged American leaders to prioritize preemptive responses to potential threats and seek to maintain a US-dominated international order, they have predisposed German decision makers to favor economic cooperation and place reduced emphasis on security obstacles outside the European continent.Master of Art
Physical Assault During the Perinatal Period by Disability Status and Racial/Ethnic Background.
Get PDFPhysical assault of women at the intersection of race/ethnicity and physical disability is not well studied. This study seeks to assess the prevalence of physical assault-related emergency department or hospital visits among women with physical disabilities during different stages of the perinatal period, stratified by racial/ethnic background. This study used 1998-2020 data from the Massachusetts Pregnancy to Early Life Longitudinal Data System. Unique singleton deliveries were classified into 10 cohorts by combining maternal physical disability status (yes/no) and racial/ethnic background (White, Black, Latinx, Asian/Pacific Islander [API], and American Indian/Alaska Native [AIAN]); nondisabled White mothers served as referent. Outcomes assessed were the presence of assaults up to 1 year before conception, during pregnancy, and up to 1 year postpartum. Compared to nondisabled White mothers, Black, Latinx, and AIAN mothers with physical disabilities were at the highest risk and experienced 16.0, 12.0, and 12.0 times the risk, respectively, of preconception assault; 15.3, 12.7, and 11.6 times the risk of prenatal assault; and 9.0, 8.2, and 9.3 times the risk of postpartum assault (p < .001 for all risk ratios). Adjusting for sociodemographic differences between groups reduced the magnitude of disparities, but Black, Latinx, and AIAN mothers with physical disabilities remained at greatest risk among all cohorts. Women with physical disabilities from minoritized racial/ethnic backgrounds experienced compounded risk of perinatal violence, with risks exceeding those of nondisabled women in the same racial/ethnic groups as well as White women with physical disabilities. Violence against women with physical disabilities, especially during pregnancy, is a major and ongoing public health crisis. Urgent needs include screening and outreach efforts to Black, Latinx, and AIAN mothers with physical disabilities