VictorJuiz/thesis huggingface dataset:
Essays on Trade Finance in International Transactions

Firms engaged in product transactions are financially linked through various financing arrangements, most notably trade credit, yet many aspects of this linkage remain unclear. This dissertation aims to contribute to the understanding of firms' financing choices and their role in the dynamics of firm-to-firm trade relationships, particularly in an international context. In the first chapter, I thoroughly survey the existing theories and empirical evidence related to the use of trade credit. The literature on financing practices between firms offers numerous theories that attempt to explain why suppliers often finance transactions. Additionally, in the international context, several studies have explored how exporters' and importers' choices of finance arrangements are influenced by cross-country differences in contract enforcement and financial market conditions. By linking these theories to existing empirical works, I provide readers with a comprehensive overview of this extensive literature. The second chapter of this study examines the evolution of trade finance usage within trade relationships as they interact more over time. Using transaction-level customs data with buyer and seller identities, I find that within-relationship evolution contributes only minimally to the previously implicated and observed pattern in the existing literature. Specifically, the observation that transactions conducted by older relationships are associated with a higher likelihood of using trade credit than new relationships is primarily driven by compositional effects. Relationships of longer longevity consistently use more trade credit at every stage. Furthermore, the heterogeneity in trade finance use across relationships is primarily explained by variations across exporters and importers, rather than variations across products. The last chapter investigates whether the use of trade finance in trade relationships shaped their reaction to the recent global financial crisis. Using the same dataset as in the second chapter, I find that trade relationships relying more extensively on trade credit experienced significantly smaller reductions in trade value and a smaller increase in exit rates compared to others during the crisis. Moreover, this divergence persisted even after the crisis, suggesting a lasting impact of the shock. The results hold firm when accounting for various fixed effects and applying Inverse Propensity Score Reweighting to make trade relationships using trade credit to different extents more comparable.

Advisor: Blum, Bernardo S
Characterization of the Early Immune Response to Clozapine: Relevance for Idiosyncratic Drug-Induced Agranulocytosis

Clozapine, a highly efficacious neuroleptic, is seldom prescribed due to the risk of idiosyncratic drug-induced agranulocytosis (IDIAG). Progression to IDIAG is rare and remains poorly defined; however, patients frequently experience transient inflammatory responses early in treatment. Previously, our lab established that 1) a similar immune response occurs in rats and 2) myeloperoxidase (an enzyme present in neutrophils and precursors) bioactivation of clozapine generates neoantigens but the connection between these early mechanistic events remained unclear. Thus, we sought to better understand the induction of this proinflammatory response, focusing on the roles of myeloperoxidase, damage-associated molecular patterns (DAMPs), and inflammasome activation. In THP-1 macrophages, we found that caspase-1 or myeloperoxidase inhibition attenuated clozapine-induced release of inflammatory mediators IL-1β, CXCL1, and C-reactive protein. In Sprague-Dawley rats, clozapine induced dose-related increases in neutrophils, corticosterone, CXCL1, α-1-acid glycoprotein, and calprotectin. Myeloperoxidase inhibition significantly attenuated clozapine-induced increases in neutrophil mobilization from the bone marrow to the blood and spleen. Moreover, the clozapine-triggered release of inflammatory mediators from the liver, spleen, and bone marrow was dampened by myeloperoxidase inhibition. Conversely, caspase-1 inhibition only attenuated clozapine-induced neutrophilia and related cytokine changes. Structural analogues olanzapine and fluperlapine did not induce a proinflammatory response in vitro or in vivo, but did induce similar changes in lymphocytes and corticosterone. In a comparison of clozapine- and olanzapine-exposed extracellular vesicles (EVs), clozapine induced a greater increase in the concentration of EVs enriched from both THP-1 macrophages and rat serum. Moreover, clozapine-exposed EVs induced an inflammasome-dependent response in vitro, supporting a potential role for EVs in immune activation. Proteomic and bioinformatic analyses demonstrated an increased number of differentially expressed proteins with clozapine that were enriched in pathways related to inflammation, myeloid cell chemotaxis, and TGF-β signaling. Together, these novel findings support the hypothesis that myeloperoxidase-mediated clozapine bioactivation leads to neoantigen formation, the release of DAMPs (either as soluble mediators or in EVs), and activation of an innate immune response, propagated in part by inflammasome activation. Overall, a better mechanistic understanding of clozapine-induced inflammation may elucidate ways to predict or prevent IDIAG, enabling more frequent therapeutic use of this and potentially other IDR-associated drugs.

Keywords: agranulocytosis
clozapine
idiosyncratic drug reactions
immunotoxicology
inflammation
innate immune response
Advisor: Uetrecht, Jack
A Disease Management Approach to Health Technology Assessment: A Multi-Methods Analysis for the Prevention and Management of Clostridioides difficile Infection

Health technology assessment (HTA) is a multidisciplinary process with a primary goal to inform health system decision-making. HTA is considered the reference paradigm for the assessment of technology in healthcare with efforts to achieve a high-quality health system. HTA conventionally responds to questions about new market entrants for a single decision-maker. In the context of Canada’s decentralized health system, many decision-makers means many, typically narrow, scopes of analysis. Literature suggests that there are likely implications of this environment which may include overlooking opportunities to identify an optimal mix of interventions that maximizes health outcomes. Our work aimed to draw attention to the conventional scope of the decision problem in HTA, and explore one alternative to this conventional approach, a disease management approach.Study 1 used scoping review methodology to assess how, and to what extent, a systems-level perspective is considered in decision-making for the adoption or de-adoption of a health intervention or technology (e.g., drug, medical device, procedure). Study 2 was a second scoping review to assess how the scope of the decision problem is typically defined within one component of HTA, economic evaluation, and specifically for Clostridioides difficile (C. difficile) infection interventions. Study 3 used economic evaluation methodology, and C. difficile as an exemplar, to identify the optimal implementation strategy for a new vaccine in combination with a new (more effective, more costly) treatment (disease management approach) compared to the conventional approach which typically assesses interventions independently. Study 4 used qualitative methodology to explore opportunities for conceptualizing the decision space in HTA as a disease management approach versus an intervention management approach. Our research confirmed that intervention assessments are typically conducted in isolation to other interventions, assuming that the surrounding intervention environment is static. We highlight that an expanded approach to how we structure the decision problem in HTA, a disease management approach, will not be without its challenges. We provide quantitative and qualitative evidence in support of a step toward a more system-level perspective to HTA and endeavor to showcase a potential opportunity for HTA to contribute to a more proactive, resilient, and sustainable healthcare system in Canada.

Keywords: Clostridioides difficile
economic evaluation
health services research
health technology assessment
systems thinking
Advisor: Sander, Beate
Higher Euler-Kronecker Constants

The coefficients that appear in the Laurent series of Dedekind zeta functions and their logarithmic derivatives are mysterious and seem to contain a lot of arithmetic information. Although the residue and the constant term have been widely studied, not much is known about the higher coefficients. In this thesis, we study these coefficients $\gamma_{K,n}$ that appear in the Laurent series expansion of $\frac{\zeta_K'(s)}{\zeta_K (s)}$ about $s=1$, where $K$ is a global field. For example, when $K$ is a number field, we unconditionally prove certain arithmetic formulas satisfied by these coefficients and we give bounds for them under GRH. Analogous bounds for function fields of curves defined over a finite field are also shown. \vspace{2mm}\\ We also study the distribution of values of higher derivatives of $\mathcal{L}(s,\chi)= L'(s, \chi)/L(s, \chi)$ at $s=1$ where $\chi$ ranges over all non-trivial Dirichlet characters with a given large prime conductor $m$. In particular, we compute moments, i.e. the average of $P^{(a,b)}(\mathcal{L}^{(n)}(1, \chi))$, where $P^{(a,b)}(z) = z^a \overline{z}^b$ and study their asymptotic behaviour as $m \rightarrow \infty$. We then construct a density function $M_{\sigma}(z)$, for $\sigma= $ Re$(s)$ and show that for Re$(s) > 1$ $$\text{Avg}_{\chi} \Phi(\mathcal{L}'(s, \chi)) = \int_{\mathbb{C}} M_{\sigma}(z) \Phi(z) |dz| $$ holds for any continuous function $\Phi$ on $\mathbb{C}$.

Keywords: Dedekind zeta function
Dirichlet L-functions
Distribution
Euler-Kronecker Constant
Moments
Advisor: Murty, Vijaya Kumar
Endocannabinoid Modulation of Amygdala Activity and Circuitry in Post-Traumatic Stress Disorder

Amygdalar dysfunction has been thought to underlie many psychiatric disorders. Most notably, the amygdala is hyperresponsive to threat in Post-Traumatic Stress Disorder (PTSD). PTSD is a distressing, prevalent disorder that is characterized by a cluster of symptoms that can be tied to amygdala dysfunction. Preclinical models suggest that decreased anandamide in the amygdala may drive a loss of top-down inhibition between frontal cortical areas and the amygdala, leading to amygdala hyperresponsivity to threat. Here we used neuroimaging to test the hypothesis that higher fatty acid amide hydrolase (FAAH), the main catabolic enzyme for anandamide, is associated with a decreased fronto-amygdalar functional connectivity and amygdala increased response to threat. 31 healthy control participants and 27 PTSD participants completed a positron emission tomography scan with the radiotracer for FAAH, [11C]CURB, a resting state functional magnetic resonance imaging session, as well as a functional magnetic resonance imaging session during a perceptual face processing task meant to activate the amygdala. [11C]CURB binding in the amygdala correlated negatively with fronto-amygdalar functional connectivity and positively with blood-oxygen-level-dependent (BOLD) signal during processing of angry and fearful faces in both healthy controls and PTSD. Our finding that higher levels of FAAH in the amygdala was associated with an increased amygdala response to a threatening social cues (angry and fearful faces) and decreased fronto-amygdalar functional connectivity is in line with preclinical and neuroimaging studies in humans and suggests the involvement of FAAH in modulating stress and anxiety in humans. The current study also lends support for the potential use of FAAH inhibitors for PTSD.

Advisor: Boileau, Isabelle
Moving Toward Understanding: Negotiating Survival and Wellbeing while Living in Poverty

Poverty in Canada continues to be regarded as an individual problem, rather than a set of complex and institutional systemic failures. Moreover, there remains a longstanding and problematic belief that poverty, homelessness, and disenfranchisement can be ‘solved’ by those living in precarity by merely working harder, and that individuals remain in poverty because of their own independent choices and decisions. This is evidenced through dominant neoliberal discourses surrounding personal responsibilities which will be addressed in this dissertation. What these discourses have failed to address are the frameworks, contexts, and spaces within which poverty is structurally and systemically reproduced. Individuals and communities do not stumble upon poverty. Classism, colonialism, racism, homophobia, ableism, and marginalization, which are visible through poverty, lend themselves to the perpetuation of poverty across generations, as well as purposefully disenfranchising particular intersections of people. What endures then, is a both lack of understanding and wilful neglect about the lived experiences of poverty and homelessness, existing realities of risk, how cycles of poverty become reinforced through relational, institutional, and systemic means, and the role that physical activity and movement has on the lives of the poor. In this dissertation, I interrogate how macro level power structures impact the everyday, micro level lives of people experiencing poverty and homelessness. The data collected in this work comes from a nine-month institutional ethnography at Start Me Up Niagara (SMUN), in St. Catharines, Ontario Canada, where I observed, gathered field notes, and conducted interviews with staff and people who used SMUN. In my findings, I explore how individuals navigate health and wellbeing while experiencing poverty. I address the (in)accessibility to public and private spaces and emphasize the important role of care providers in space of care, like SMUN. I highlight throughout my findings how individuals in Canada experiencing poverty and homelessness, fundamentally, suffer from a lack of health justice, spatial justice, and justice of care. This work addresses the goal of eradicating cycles of poverty and injustice in Canada by highlighting the need for policy implementations at all levels of government. Ethical approval was received by the University of Toronto Research Ethics Board (protocol# 35175).

Keywords: Ethic of Care
Exercise is medicine
Physical Cultural Studies
Poverty
Production of Space
Social Justice
Advisor: Fusco, Caroline
The Postnatal Effects of Prenatal Cannabinoid Exposure

The effect of prenatal cannabis exposure on offspring is an important clinical and societal concern which has limited evidence. Compounds in the cannabis plant, phytocannabinoids, cross the placental barrier and thus may act on the developing embryo. To address the knowledge gap, here I created and characterized a murine exposure model to explore potential postnatal effects of prenatal exposure to cannabinoids. The model involved administering cannabinoids – the synthetic cannabinoid nabilone and principal phytocannabinoids (−)-trans-Δ9-tetrahydrocannabinol (THC) or cannabidiol (CBD) – via subcutaneous injection prior-to and throughout gestation. Herein, I describe effects of these gestational exposures on 1) the behavioural and neuroimaging outcomes in adulthood, and 2) the effects on peripheral immune cell populations. I assessed neuroanatomy in prenatally nabilone, THC, or CBD exposed offspring by magnetic resonance imaging. I found that prenatal nabilone exposure had sex-specific effects on neuroanatomy in juvenile (3-week-old) and adult (9-week-old) offspring. In juvenile mice, the amygdala volume was lower in females and higher in males exposed to nabilone compared to vehicle controls. In adult nabilone-exposed offspring, the basal forebrain was larger in females and smaller in males compared to vehicle controls. In prenatally CBD-exposed offspring, the volume of the arbor vitae of the cerebellum was larger compared to vehicle controls. Prenatal THC did not affect neuroanatomy. I also performed a battery of behaviour tests beginning at the 9-week timepoint in adult THC and CBD-exposed offspring. I found that both compounds produced an anxiolytic phenotype in males in the elevated plus maze. CBD affected novelty exploration in the novel object recognition test in females only. Thus, prenatal THC and CBD exposure produced sex-specific effects on behaviour in adulthood. Using cytometry by time-of-flight, spleen and thymus immune cell populations were quantified at two timepoints in CBD- and THC-exposed offspring. Prenatal THC, but not CBD, affected T cell populations in the neonatal thymus and juvenile spleen. From these results, I conclude that a disturbance in the developmental period caused by exposure to exogenous cannabinoids results in long-term effects to brain and immune systems. These consequences are compound- and sex-specific. Future work should focus on elucidating mechanisms underlying these changes.

Keywords: behaviour
cannabinoids
imaging
preclinical
Advisor: Salter, Michael W
Signaling, Machine Learning, Democracy: A Theory of Misinformation

This dissertation advances a novel theory of misinformation by way of five chapters. Chapter 1 argues that, contrary to mainstream scholarship, misinformation ought not to be conceived of with respect to either truth or accuracy, which we call alethic theories of misinformation. Against both intuitions and mainstream academic opinion, this chapter is oriented towards showing problematic consequences of alethic theories of misinformation that suggest abandoning this methodological paradigm. Chapter 2 argues that an act of communication ought to be considered misinformation if and only if dissemination of that information is conducted in a context that is misleading and non-trivially violates the informational preferences of relevant stakeholders in that context relative to social goals. I show how misinformational discourse ought to be modelled within the context of theories of institutions and signaling theory, employing the resources of game-theory. Chapter 3 applies the theory to four cases studies. The first is a discussion of the history of blood-letting in modern medicine, followed by a second example concerning a prominent conspiracy theory regarding the September 11, 2001 terrorist attacks. A third example concerns several cases of disinformation in the history of espionage, particularly the foreign policies of the United States and the former Soviet Union, with a fourth example discussing the plight of persons with albinism in modern Tanzania. Chapter 4 describes methodological issues of operationalizing concepts of misinformation in the context of contemporary machine learning models of misinformation. The intrinsic value-ladenness of models, pluralistic content of misinformation, and dynamically updating relationship between citizens' and social scientists' concepts of misinformation, jointly suggest that both the construct legitimacy and the construct validity of these models needs to be assessed via more democratic criteria than has previously been recognized. Lastly, chapter 5 argues against the ways in which misinformation has often been described as exhibiting a dynamics analogous to contagious disease epidemics. Prominent epidemiological and inoculation theories of misinformation are discussed illustrating how idiosyncratic features of the social construction of misinformation violate the analogy with contagious diseases resulting in comparative loss of predictive and explanatory power.

Keywords: Disinformation
Machine Learning
Misinformation
Philosophy of Science
Politics
Signaling Theory
Advisor: Baigrie, Brian
Optical Studies of Topological Magnetic Materials

In this thesis, we discuss our optical studies of magnetic materials with known or proposed topological features. The control and detection of spin states is an important area of study within condensed matter physics, with many potential applications in future device design. Materials with both magnetic order and interesting topology present new opportunities for this field via the possibility of hosting topologically non-trivial spin states. The itinerant ferromagnet SrRuO3 has been proposed to host a topological spin texture called a skyrmion due to observations of a bump feature in the Hall resistivity. By carefully studying the magneto-optical Kerr effect (MOKE), supported by measurements of the Hall resistivity and magnetization and theoretical calculations, we show that such bump features could be explained by a complicated dependence of the Kerr angle on the magnetization, and do not require the presence of skyrmions. This indicates that such bump features cannot be relied upon as valid evidence for skyrmion formation. In our final two studies, we investigate the novel magnetic topological insulator MnBi2Te4. At room temperature, we observe large oscillations in the time-resolved reflectivity caused by the excitation of breathing-mode interlayer phonons. Our observations were complemented by polarized Raman measurements, which confirm the interlayer phonon origin and additionally reveal the shear-mode interlayer phonon frequencies. By studying these phonons as a function of sample thickness, we determine the interlayer force constants. At low temperature, we measure static MOKE, time-resolved MOKE, and time-resolved reflectivity at a variety of applied external fields. We observe ultrafast demagnetization signals which can also serve as an effective probe of the magnetic order, revealing discrepancies between the predicted and observed transitions to ferromagnetic order. When applying an in-plane field, we also observe coherent magnon oscillations in the time-resolved MOKE and reflectivity signals which are strongly layer- and field-dependent. As the first comprehensive overview of ultrafast dynamics in MnBi2Te4, these results are a key step towards further explorationof this exciting new material.

Keywords: Magnetism
Magneto-optical effects
Skyrmions
Topological materials
Ultrafast dynamics
Advisor: Yang, Luyi
The Role of Treatment-Seeking Stigma on Treatment Engagement and Outcome

Mental Health treatment-seeking stigma (TSS) is a significant barrier to accessing mental health services prolonging clients’ distress (Breslau et al., 2008; Livingston & Boyd, 2010). Clients continue to express concerns about stigma even after they have entered therapy (Owen et al., 2013), yet little is known about the impact of TSS once clients have begun treatment. Using archival data from a study on the efficacy of cognitive behavioural therapy (CBT) and process experiential-emotion-focused therapy (PE-EFT) for depression, this study sought to elucidate the relationship between TSS, client engagement in therapy and treatment outcome. The findings provided support that TSS remains a barrier during the course of treatment. Higher TSS predicted less change in treatment outcomes from pre- to post-therapy. The relationship between TSS and treatment outcome was not mediated by client engagement as assessed by clients’ depth of experiencing, but it was completely mediated by the working alliance. Additionally, TSS declined over the course of treatment and the decline was predicted by therapists’ empathy. The findings suggested that TSS continues to be an issue even after clients have entered the therapy room highlighting the importance of ongoing research examining TSS and its impact during treatment.

Keywords: Stigma
Advisor: Watson, Jeanne C