VictorJuiz/thesis huggingface dataset:
The Unintended Consequences of Policy Changes in Large-Scale Natural Experiments

In the current era of globally dominant technology companies (known colloquially as “big tech”) and expansionist government policies, large scale actions are frequently implemented to solve a wide variety of problems. This thesis examines the unintended consequences of large-scale policy experiments in two distinct domains: public health and media content production. The first chapter focuses on the impact of a $100 incentive policy announced by the Governor of West Virginia to promote COVID-19 vaccination. Using granular data at the county level, a synthetic control approach is employed to evaluate the effects of the policy. The findings indicate a positive effect on partially vaccinated individuals but a negative effect on the unvaccinated population, leading to a decrease in vaccine uptake for the latter group. Moreover, the ideological slant of the county influences the extent of the negative effect, with more Republican-leaning counties exhibiting a stronger decline in vaccination rates. The analysis is reinforced using data from the Household Pulse Survey, which confirms a shift in vaccine hesitancy among unvaccinated individuals in West Virginia after the policy implementation. These results highlight the need for cautious implementation of large-scale monetary incentives, especially in polarized societies like the United States. The second chapter investigates the impact of social media's links to downstream media content on production decisions. Specifically, the effect of an algorithm change by Facebook on the demand for a mainstream media site in Austria is analyzed. The study utilizes internal data from the media firm, which heavily relies on advertising revenue. The algorithm change resulted in a decline of soft content consumption relative to the main website. Specifically, the Leisure category experienced the most substantial negative impact. In response, the media firm adjusted its production by producing 10% less soft content compared to hard content, and it also decreased the total number of articles. These findings indicate that a decrease in advertising revenues led to an increase in content quality, as measured by the ratio of hard to soft content. This contradicts previous research and highlights the potential far-reaching public impact of policy changes by powerful technology companies. The findings presented emphasize the importance of considering contextual factors, such as political ideology and societal polarization, when implementing policies aimed at influencing individual behaviors. Additionally, it sheds light on the complex dynamics between social media and mainstream media, showcasing the influence of algorithm changes on content production decisions. This research provides valuable insights for policymakers, media firms, and scholars studying the intersection of policy, behaviour, algorithms, and media.

Advisor: Soberman, David
Mehta, Nitin
Transport, Fate, and Effects of Microplastics in a Rapidly Changing Arctic

Microplastics (<5 mm) have been deemed a contaminant of emerging Arctic concern. Microplastics are multi-dimensional in that they range in morphology, size, and chemical cocktail (e.g., additives, sorbed contaminants) and are hypothesized to serve as an important transport mechanism for chemical contaminants to and within northern ecosystems. While microplastics and plastic additives have been identified across Arctic ecosystems, there is a need to better understand the transport, fate, and effects of microplastics and their additive chemicals. Here, I explore these three themes through a series of field observations and laboratory experiments. First, in Chapter 2 of this dissertation, I show that while seabirds may be an important transport pathway of microplastics to the Arctic, there are other regional sources that need to be considered. In Chapters 3 and 4, I explored the role of long-range atmospheric transport of microplastics via atmospheric deposition. In Chapter 3, using a high-Arctic ice core, I show an increasing trend of microplastics over time. I also observed a positive relationship between microplastics and organophosphate esters (a plastic additive), suggesting microplastics may act as a long-range transport pathway. In Chapter 4, I sampled snow from five sites at increasing distances from a local community. I observed a change in microplastic and polymer composition in sites closer to the local community suggesting that local sources of microplastics may also be important. In Chapter 5, I investigated the presence of microplastics and additive chemicals in wild-caught Arctic char (Salvelinus alpinus) and their habitat. Here, I show elevated concentrations of microplastics in Arctic char and their summer feeding habitat compared to previously reported observations. I also demonstrate translocation of microplastics to Arctic char. And finally, in Chapter 6, informed by observations in the previous chapters, I exposed larval fish to polyurethane, with and without chemical additives to assess the mechanisms of toxicity. Here, I show that the physical and chemical components of polyurethane affect growth and development, and that the physical particles may facilitate the bioaccumulation of plastic additive chemicals. Throughout my thesis, I highlight the importance of evaluating microplastics as a multi-dimensional contaminant - the physical and chemical properties may influence their fate, transport, and biological effects.

Keywords: Arctic Ecology
Ecotoxicology
Emerging Contaminants
Persistent Organic Chemicals
Plastic Additives
Plastic Pollution
Advisor: Rochman, Chelsea M
MicroRNA Dysregulation in Hereditary Hemorrhagic Telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is a rare, autosomal dominant genetic disease characterized by life threatening vascular malformations. Mutations in endoglin (ENG) and activin receptor-like kinase 1 (ACVRL1) account for ≈90% of HHT cases and disrupt the transforming growth factor β signalling pathway. This predominately results in endothelial cell (EC) and angiogenic dysfunction. HHT mouse models have revealed that the genetic mutations alone are necessary, but not sufficient to generate the observed vascular malformations, suggesting alternative biological factors must be at play. The role of microRNAs (miRNAs), small biomolecules (21-25 nucleotides) that regulate gene expression post-transcriptionally, has yet to be explored in HHT. I hypothesized that miRNA levels are abnormally altered in HHT. To address this gap in knowledge I sought to profile and characterize miRNAs in peripheral blood mononuclear cells (PBMCs) and myeloid angiogenic cells (MACs) derived from HHT patients, as well as in ENG-knockdown human umbilical vein ECs (HUVECs). PBMCs, comprised mostly of lymphocytes and monocytes, are dysfunctional in HHT. MACs, alternatively called early endothelial progenitor cells or circulating angiogenic cells, do not directly incorporate into developing blood vessels but augment angiogenesis in a paracrine manner. MAC dysfunction has been reported in HHT. PBMCs and MACs were isolated from HHT patients and age- and gender-matched healthy controls for comparative miRNA profiling. MiRs-28-5p and -361-3p were found to be significantly decreased in HHT PBMCs, while the mRNA levels of their putative target, insulin-like growth factor 1 (IGF1), were significantly elevated. IGF1 is a potent angiogenic factor and may be contributing to local angiogenic dysfunction. MiR-132-3p was found to be significantly decreased in HHT MACs and enriched in signalling pathways related to HHT pathogenesis that may in part explain HHT MAC dysfunction. ENG, responsible for ≈50% of HHT cases, was knocked down in HUVECs with short interfering RNA technology. MiRNA profiling of ENG-knockdown HUVECs revealed that miRs-139-5p and -454-3p were significantly downregulated. Most notably, inhibition of these miRNAs independently resulted in impaired HUVEC tube formation and their overexpression rescued ENG-knockdown-induced HUVEC dysfunction. These novel findings underscore the critical involvement of miRNA dysregulation in HHT that warrants further research.

Keywords: endothelial cells
epigenetics
hereditary hemorrhagic telangiectasia
microRNAs
rare disease
vascular biology
Advisor: Kutryk, Michael J. B.
Dorian, Paul
Searching for Equity: A Holistic Analysis of East Asian International Student Experiences and Policy Implications – A Case Study of a Canadian University Engineering Program –

This study investigates experiences and perceptions of first year East Asian international students, faculty and staff members in the engineering program in a Canadian university and further identifies and discusses policy gaps affecting first year East Asian international students. This study used a case study approach with a document analysis and fourteen semi-structured qualitative interviews. The document analysis included university and departmental wide documents, such as University of Toronto Internationalization Strategy Document and Academic Planning as well as publicly available policy documents that were identified as gaps by the interview participants, such as Petitions and Mental Health support. The interview data were collected during the COVID-19 pandemic. All three interview groups, East Asian international students in their 1st year, faculty members and student services staff members addressed the need for more mental health support for the East Asian international students, and the faculty and staff group identified lack of culturally responsive interpretation of educational policy major gaps affecting the East Asian international students. This research used a sensemaking framework to analyze the data. In addition, the “Model Minority Myth” was used to interpret the East Asian international student experiences. In conclusion, I characterized the issues of East Asian international students as a “wicked problem” (Rittel & Weber, 1973), as the policy barriers and challenges they face are multifaceted and full of complexities. This study is significant because of the increasing number of East Asian international students in the Canadian higher education landscape. The voices of East Asian international students in scholarship have been limited and lacking, especially related to the policies affecting their experiences. University institutions and policy makers including policy implementers require a more culturally sensitive and nuanced approach in order to address the unique needs of East Asian international students and to ensure their academic and social successes in their institutions.

Keywords: Case study
East Asian international students
Equity policy
model minority myth
Advisor: Bascia, Nina
The Role of Universities in Higher Education Regionalization: Examining Why Universities Are Members of Regional University Associations

This doctoral thesis examines the role of universities in higher education regionalization (HER) through examining why universities are members of regional university associations (RUAs) around the world. I draw on theories of organizations, including economic functionalism, political functionalism, neo-institutionalism, and organizational culture theory to hypothesize why universities are members of RUAs. Using the convergent mixed method research design, I first analyzed RUA documents and websites to understand how RUAs frame their purposes and what activities RUAs carry out. Second, I constructed a novel cross-national dataset to examine institutional and national factors that are associated with university memberships in RUAs. Third, I conducted semi-structured interviews with university leaders in East and Southeast Asia to understand how universities understand their memberships in RUAs and how their memberships in RUAs are related to HER. The findings suggest that RUAs constitute the organizational dimension of HER through functional activities that aim to enhance internationalization opportunities, advocating for universities in regional higher education policies, and cultivating regional identities and values. However, universities being members of RUAs is a global phenomenon but with regional variations. Moreover, universities’ being members of RUAs is associated with universities seeking global status and identity, and the mimetic process in the organizational field, indicating HER as a sociological phenomenon. Interestingly, universities’ understanding of HER is linked to global geopolitics. While HER in East Asia is linked to universities’ criticism of Western dominance and emphasis on the importance of Asia, universities in Southeast Asia tend to favor Western partners, and see HER as an accessible and convenient way to internationalize. Two important insights come out of the findings of the thesis: 1) universities being members of RUAs reflect the organizational dimension of HER, a mechanism that enables the consolidation of the regional higher education field; 2) the regional higher education field is closely linked to global higher education via three ways: HER is often framed as part of internationalization; the differentiated impact of global geopolitics on HER by world region; and there is a link between universities’ regional engagement and their global status and identity.

Advisor: Buckner, Elizabeth
Lattice Point Counts in Teichmuller Space and Negative Curvature

In this thesis we present two different, but related, results; one in the setting of Teichmuller theory, and the other in the setting of negative curvature. For the first result, let $\gamma$ be a pseudo-Anosov homeomorphism of a compact orientable surface $S_g$, and let $L_\gamma$ denote the axis of the action of $\gamma$ on the Teichmuller space of $S_g$, denoted by $\mathcal{T}_g$. In Chapter 3 we obtain asymptotics for the number of translates of $L_\gamma$ that intersect a Teichmuller ball of radius $R$ centered at a fixed $X \in \mathcal{T}_g$, as $R \rightarrow \infty$. For the second result, let $M$ be a compact closed manifold of variable negative curvature. We fix two points $x, y$ in the universal cover $\widetilde{M}$ of $M$, fix an element $\mathrm{id} \neq \gamma$ in the fundamental group $\Gamma$ of $M$, and denote the set of elements in $\Gamma$ that are conjugate to $\gamma$ by $\mathrm{Conj}_\gamma$. In Chapter 4 we obtain asymptotics for the number of $\mathrm{Conj}_\gamma$--orbits of $y$ that lie in a ball of radius $R$ centered at $x$, as $R \rightarrow \infty$. If $M$ is two-dimensional, or of dimension $n \geq 3$ and curvature bounded above by $-1$ and below by $-(\frac{n-1}{n-2})^2$, we find a power saving error term for this count. Since the two results are written in different settings, their similarities might be hidden at first glance. This is why we included Chapter 2, in which we present a unified approach to both results in the setting of constant negative curvature. Writing the arguments in this simple setting helps us emphasize the similarities between the two results.

Keywords: Counting in dynamics
Negative curvature
Teichmuller theory
Advisor: Rafi, Kasra KR
Tissue Mechanics Govern Tumor Quiescence and Chemosensitivity in Medulloblastoma

Medulloblastoma is the most prevalent malignant brain tumor in children (WHO grade 4) that encompasses a heterogeneous group of cerebellar or brainstem embryonal tumors. Current standard-of-care is met with therapy resistance and associated with severe neurocognitive, neuroendocrine, and psychosocial side effects. Intratumoral heterogeneity contributes to treatment resistance and poor prognosis. Loss of mechanical homeostasis is a hallmark of the tumor microenvironment. Mechanosensors, which convert mechanical stimuli into intracellular signals, are key molecules that mediate mechanotransduction mechanisms in malignant diseases. Modulating mechanosensors may offer therapeutic opportunities to reduce disease burden associated with medulloblastoma. My study reveals that Sonic Hedgehog medulloblastoma (which encompasses a third of medulloblastoma patient cases) constructs spatial tissue stiffness niches to dictate region-specific tumor properties. Mechanosensitive ion channel Piezo2 and mechanosensitive G protein-coupled receptor Gpr68 perceive stiffness cues to modulate medulloblastoma growth and chemoresistance. Piezo2 orchestrates an actomyosin-Wnt/β-catenin signaling axis to determine medulloblastoma propagating cell quiescence and blood-tumor barrier permeability. Gpr68 regulates microtubule and primary cilia to promote SHH signaling and reduce tumor quiescence. Loss of Piezo2 improves delivery of therapeutic agents and survival of chemotherapy-treated medulloblastoma-bearing mice. Loss of Gpr68 suppresses medulloblastoma tumor cell proliferation at the expense of reducing tumor chemosensitivity. Collectively, my study reveals spatial tissue mechanics in medulloblastoma, identifies specific mechanosensors that govern tumor quiescence and chemosensitivity, and demonstrates that modulating mechanosensor functions provide a viable approach to treat malignant brain tumor.

Keywords: Blood-tumor barrier
Gpr68
Mechanobiology
Medulloblastoma
Piezo2
Sonic Hedgehog Signaling
Advisor: Huang, Xi
Honouring Grief Experiences in Life, Death, and the Workplace: A Critical Analysis of Bereavement Accommodation for Workers in Precarious Employment in Canada

Bereavement scholarship predominantly explores psychological aspects of grief, which neglects the role of social, economic, and political factors that shape the space allotted to accommodate these experiences. The current Canadian social context offers minimal space to honour bereavement as a part of the human condition. Aiming to respond to calls for enhancing bereavement care, this dissertation explores bereavement accommodation for workers in precarious employment in Ontario, Canada. Drawing on critical qualitative research and feminist ethics, this study employs policy analysis and in-depth interviews to generate multi-scalar knowledge on the everyday experiences of bereaved workers in precarious employment. I argue that there are discrepancies between how bereavement is represented in the social context and the everyday experiences of bereaved workers. The current representation portrays bereavement as a short-term, workplace disruption, neglecting grief and many forms of practical and emotional labour in bereavement. Participants expressed they were uninformed and unprepared for grief and bereavement labour, and that navigating the current context created tension, stress, exhaustion, isolation, and stigma. I argue we need a collective, ontological reckoning with our sense of autonomy, recognizing and honouring our interdependence in life and death. I argue that bereavement is a neglected public health issue driven by socio-political forces that devalue relationality, stigmatize emotions, and render bereavement an individual responsibility. This thesis makes broad recommendations for a public health approach to bereavement care, including enhancing grief literacy, creating more responsive care pathways and strategies for addressing individual and collective grief, and establishing safeguards for precarious workers.

Keywords: Bereavement
Critical
Ethics
Grief
Policy
Precarious employment
Advisor: Kontos, Pia C
Understanding the Connections between Neighborhood Environments and the Burden of Infectious and Non-communicable Diseases in Ghana

Amidst the persistent burden of infectious diseases (i.e., malaria, HIV) across many developing country settings, there is now the added burgeoning burden of non-communicable diseases [NCDs (i.e., cancer, and diabetes)]. This concurrence, described as the double burden of disease (DBD), presents a fundamental public health challenge to governments and relevant stakeholders situated in the global south. The DBD phenomenon has triggered a wave of research interests and policy debates with a focus on behavioral change interventions to the neglect of population-level determinants like the environment. The DBD further appears to have emerged at a time when the healthcare system is not well positioned to effectively respond to population health needs. This dissertation contributes to these gaps by examining the relationship between neighborhood environments and the burden of NCDs and infectious diseases across three cities (Accra, Tamale, and Wa) in Ghana using a sample of 1386 surveys that were collected between September – December 2021. I further examined whether NCD health outcomes differed by gender spatially using multilevel analytic techniques in Stata 14.2 software. Results show that about 1 in 4 people reported at least one NCD health condition and nearly 1 in 5 reported suffering the DBD. The findings further revealed spatial variations of NCD and infectious disease outcomes as respondents from relatively deprived neighborhoods were significantly more likely to report poor health outcomes. Men who spend time outside their residential neighborhood in a typical week were more likely to report being diagnosed with NCDs compared with their counterparts who spend the entire week in their residential neighborhoods. The results demonstrate the need to move beyond individualistic risk factors to discussing important population-level determinants of NCDs like the environment in the fight against NCDs in the developing world. Moreover, the static view of the role of place on health is too reductionist and there is the need to account for other spaces people frequent through a gendered lens. Finally, the emerging epidemiologic transition in Ghana and other developing countries calls for a retooling of the healthcare system to effectively respond to the changing health needs of the population.

Keywords: Behavior
Double burden of disease
Environmental risk
Ghana
Neighborhood environment
Non-communicable disease
Advisor: Kuuire, Vincent
Information-Theoretic Measures of Generalization in Machine Learning

Machine learning (ML) technologies are rapidly being adopted across various industries, scientific fields, and governments. However, despite the widespread use of ML, the research community still lacks a thorough understanding of the principles that explain when and why these technologies work in real-world applications. One of the primary challenges to deploying ML methods is ensuring generalization, or the ability of the model to perform well on unseen data as well as on training data. In this thesis, we explore generalization from an information-theoretic perspective. This perspective allows us to examine the impact of learning algorithms and data distribution on generalization error, a crucial feature that offers an opportunity to address an essential open challenge in generalization theory. Our main goals in this thesis are twofold: (I) to explain the performance of existing learning algorithms used to train modern deep neural networks and (II) to unify and simplify the landscape of generalization frameworks using the language of information theory. For goal (I), we propose a novel approach based on data-dependent estimation to estimate the mutual information terms that appear in generalization bounds. We demonstrate the applicability of this technique in studying the generalization error of Stochastic Gradient Langevin Dynamics (SGLD). Our numerical analyses show that the obtained bounds are the first non-vacuous generalization guarantees for SGLD and its full-batch counterpart for modern deep-learning datasets and architectures. Regarding goal (II), we explore the connections between information-theoretic frameworks for generalization and classical min-max frameworks for generalization. Our results indicate that information-theoretic frameworks are highly expressive in the context of binary classification. However, we also uncover some limitations of information-theoretic techniques when analyzing stochastic gradient descent in the context of stochastic convex optimization.

Keywords: Generalization Theory
Information Theory
Machine Learning
Advisor: Roy, Daniel