VictorJuiz/thesis huggingface dataset:
Sublethal Effects of Pesticides on Bats: from Cells to Behaviour

Pesticide use associated with agricultural intensification represents a threat for wildlife, particularly for non-target species. Insectivorous bats, for example, regularly forage in agricultural lands, providing valuable pest control services but potentially coming into contact with airborne pesticides and contaminated prey. Commonly used pesticides like organophosphates can impair essential physiological processes, threatening survival and long-term ecological function. Despite growing concern about these impacts, research on bats remains scarce, especially in vulnerable regions like the tropics. I studied the susceptibility of insectivorous bats to pesticide intake and the associated sublethal effects on their physiology and behavior. I used an integrative approach to evaluate risk of exposure, to study sublethal effects, and to test promising non-destructive biomarkers for monitoring pesticide exposure in free-living bats. I used big brown bats (Eptesicus fuscus) as a model for insectivorous species to study the effects of Chlorpyrifos (CPF), a commonly used and highly neurotoxic pesticide. Using a toxicokinetic mathematical model, I found that pesticide intake through skin is particularly important for bats, especially when foraging in arable crops like soybean and corn. Dermal exposure must therefore be included in future risk assessments. Using a set of robust biomarkers, I found neurotoxic effects at molecular (proteomics) and individual levels (behaviour) in bats exposed to an environmentally realistic dose of CPF. Proteins involved in synaptic function, plasticity, oxidative stress, and apoptosis were altered in exposed bats, which also showed reduced exploratory activity and impaired associative memory. These results give insights into the mechanisms of pesticide toxicity and the consequences in bats ecology. Finally, I combined laboratory and field experiments to evaluate the performance of different biomarkers. Micronuclei frequency, a genotoxicity biomarker, and cholinesterase activity, an exposure biomarker, were accurate indicators of toxicant effects in both settings. Leukocyte profiles and hair cortisol, however, were not informative endpoints of pesticide effects. Overall, my results show that combining multiple biomarkers provides stronger, more conclusive evidence of toxic effects of pollutants in wildlife. Understanding the mechanisms and effects at different levels of biological organization can enable researchers to better predict the implications for populations and communities and help to inform mitigation strategies.

Keywords: Behaviour
Biomarkers
Ecotoxicology
Neurotoxicity
Proteomics
Toxicokinetics
Advisor: Welch Jr., Kenneth C
The Cultural “Work” of Baron Gottfried van Swieten: Peering Behind the Printed Score of Joseph Haydn’s Die Jahreszeiten/The Seasons (1802)

This dissertation offers an alternate reading of a troublesome musical work, uncovering disregarded aspects of the genesis and implications of Joseph Haydn’s final oratorio, Die Jahreszeiten/The Seasons (1802). Merging music and book historical methodologies, I revisit the story of Haydn’s final oratorio from the perspective of the librettist: Viennese diplomat, Baron Gottfried van Swieten. By exploring the history of the source material, probing the librettist’s didactic aesthetics, and demonstrating the salience of those aesthetics in his collaboration with Haydn, I offer a revised view of Die Jahreszeiten/The Seasons as the final campaign of Swieten’s illustrious career. First, I explore the history of Swieten’s source material, James Thomson’s The Seasons (1730), as originally adapted for German readers by Barthold Heinrich Brockes (1745). I provide examples of English musical settings that resonate with early theological readings of the poem and show how specific aspects of Brockes’ early translation informed the composition of the libretto. Ultimately, I situate the libretto within a larger history of mediation, translation, and adaptation. My second chapter interrogates the authorship of the oratorio and Swieten’s role as mediator of North German aesthetics—particularly the ideas of Johann Georg Sulzer—into Vienna. Where critics championed the composer as ‘author,’ I explore how discourses of authorship in German print culture obscured the extent of Swieten’s involvement. My final chapters show how Swieten’s aesthetics drew upon the artistic cultures encountered throughout his career via analyses of his annotated libretto. I show how Swieten’s recommended tone paintings and recitatives work in tandem to immerse the characters—and—audience in what I call ‘didactic diegesis,’ negotiating a host of aesthetic perspectives. My concluding coda casts a similar gaze upon Sigismund von Neukomm’s arrangement, which offered a more visceral engagement with the work through bodily engagement. Where music history remembers Die Jahreszeiten/The Seasons as the begrudging capstone of an aged composer’s career, this dissertation champions the work as the final, unsung triumph of an Enlightened reformer obscured by the monuments—both brick and mortar and as constituted through the medium of print—erected in the name of Haydn.

Advisor: Lockhart, Ellen
Naalagiursaniq Tunnganarnirlu (Learning to Listen and be Welcoming): Engaging Inuit Perspectives on Timimut Ikajuqsivik (Rehabilitation Services) for Children in the Qikiqtani Region of Nunavut

Background: Timimut ikajuqsivik (or rehabilitation services in English) for children in the Qikiqtani Region of Nunavut is primarily delivered following mainstream Canadian practices informed by Eurocentric worldviews. Inuit have had little opportunity for their perspectives to inform timimut ikajuqsivik, limiting Inuit access to self-determination and cultural safety in this context. The primary objective of this study was to advance knowledge on how the timimut ikajuqsivik interests of Inuit children in this region can be understood and supported by foregrounding Inuit perspectives, knowledge and worldviews. Methodology: This qualitative study was organized according to the Piliriqatigiinniq Partnership Model for Community Health Research (Healey & Tagak, 2014) and supported by critical theory. The first manuscript (of four presented in this dissertation) describes the accountability framework created to support the bridging of Inuit worldviews and the critical paradigm in the study. Twenty-five participants from two Qikiqtani Region communities shared their knowledge to inform the study. Participatory analysis significantly shaped findings. Findings: Three manuscripts share research findings as follows: (1) proposing five Inuit knowledge concepts that can guide timimut ikajuqsivik; (2) highlighting Inuit knowledge about supporting childhood learning and skill building, and significant tensions between this knowledge and mainstream rehabilitation’s status quo; and (3) describing the importance of relationship-focused and contextually relevant practices to timimut ikajuqsivik moving forward together with Inuit toward reconciliation. The importance of relationships, learning to listen, being welcoming, and offering contextually relevant services, including Inuit providers and language, are highlighted across the findings. Critical analyses in each of the manuscripts describe how systems of inequity privilege Eurocentric perspectives and approaches on Inuit lands, and the negative impacts that can result. In making tensions and power dynamics visible, openings for change can be made. The dissertation concludes with a story of incorporating study learning into personal and professional actions. Conclusion: This thesis shares knowledge about coming together across differences to find ways to support sivumuaqatigiigniq saimmaqatigiinnikkut (moving forward together in reconciliation). With attention to redressing inequitable power dynamics that privilege Eurocentric perspectives over those of Inuit, opportunities abound for timimut ikajuqsivik to collaboratively support the interests of Inuit children and families.

Keywords: Child development
Health equity
Indigenous health
Inuit
Qualitative methodologies
Rehabilitation
Advisor: Nixon, Stephanie
Databound: Histories of Growing Up on the World Wide Web

For the past 30 years, young people have been growing up, existing, and producing data online. Their digital traces are distributed sporadically across the live and dead web, in corporately owned digital spaces, institutional holdings, and web archives. How these traces are theorized, studied, aggregated, deployed, or destroyed deserves increased public and academic attention. In this dissertation I argue that data is inextricably attached to people, both in the ways that it represents them and in the ways that they desire and deserve meaningful control over it. To this end, I propose an ethico-methodological intervention called an “archive promenade,” and developed Care Ethics Scaffolding for research with archived youth data that engages with feminist ethics of care to bring people back in relation with their data when researching the historical web. How an individual’s digital traces came to be, and the ways in which they are connected or distanced from their data, is explored throughout Chapters 3-5 where I demonstrate findings from my qualitative research project, called Early Internet Memories. In this project, I asked millennial participants (b. 1981-1996) who grew up in Canada to describe their memories of growing up online and the digital spaces that they once used to occupy. I also demonstrate how relationships between young people and the internet are not inevitable but rather constructed through government and commercial interests in promoting and creating an ideal child subject to support the growth and development of a new industry. These relationships were also multiple and varied, reflecting intersections of race, gender, class, age, and geographic location, which worked to differentiate many young people’s experiences and memories of the web. I argue that by exploring these histories of growing up online, we can see the processes by which people become databound: attached to the data they have produced throughout their lives in ways that they both can and cannot control through their ability to socially modulate and determine their information privacy. This framing assists in theorizing the long-term implications of online engagement, digital privacy, and the effects of datafication on life and livability on the web.

Keywords: data
digital history
feminist ethics of care
platform studies
web archives
youth
Advisor: Shade, Leslie R
Essays on Firm Choices, Spatial Spillovers, and Neighborhoods

This dissertation is composed of three chapters. Each of these chapters follows an approach that uses economic theory and data to explore different issues within urban and labor economics literature. The first chapter develops an algorithm that uses observed location choices to delineate economic neighborhoods. The second (and main) chapter investigates the role that local agglomeration spillovers play on new firms' outcomes using variation within economic neighborhoods for identification. Finally, the third chapter develops a flexible theoretical framework to empirically study the substitutability of computers and workers across occupations, and how these occupations are organized in the firm's organizational structure.

Advisor: Baum-Snow, Nathaniel
'So what are you going to eat?': Insights from a Simple Foods and Intuitive Eating workshop Series

This qualitative study is situated at the intersection of nutrition education, food literacy (Vidgen & Gallegos, 2014), intuitive eating (Tribole & Resch, 2012), and understandings of the health implications of regularly consuming ultra-processed foods (Monteiro, 2009). In this thesis I explore the perspectives and experiences of seven parents and caregivers from a vulnerable population who participated in a 12-part workshop series (held in a kitchen-equipped community facility in a large Ontarian city). The workshops, which focused on a novel healthy eating framework called ‘Simple Intuitive Eating’ (SIE), revolved around discussing SIE, practicing cooking techniques, tasting resultant foods, and collectively sharing challenges and strategies related to living healthily in a contemporary urban environment. I co-facilitated these workshops alongside a registered dietitian (with whom I also co-created SIE and the workshop curriculum). In this critical case study (Flyvbjerg, 2011), I asked: 1) How do workshop participants make sense of SIE?; and 2) What supports and barriers are operative for participants with regards to eating simply and intuitively? Data sources included pre-, post-, and three-month-post-workshop interviews with participants; video of workshop sessions; participants’ journals; and my field notes and post-workshop audio debriefs. Significant themes were identified in the data using theoretical sampling and constant comparative methods (Lincoln & Guba, 1985). Velardo’s (2015) model of food literacy was useful in interpreting participants’ views on SIE. SIE also interfaced with participants’ preferences for ‘real’ foods, and underscored the roles of trust and ethical sensibility in food literacy. I adapted Castro et al.’s (2016) articulation of patient-centredness, participation and empowerment to a workshop context so as to interpret participants’ experiences with regards to SIE and the workshops themselves. Some participants employed a strategy of ‘muddling through’ (Lindblom, 1959) in navigating complexities of SIE, changing old habits, and home-cooking. Supports and barriers identified in terms of practicing SIE included: economic, temporal, sociocultural-familial and culinary dimensions; awareness, sensation and hunger; habit and addiction; stress, exhaustion and convenience; acquiring food; and exercise, mobility and other coincident health challenges. Findings supported embodied dimensions of food literacy. Implications from this research are provided for food researchers, health practitioners, pedagogues and policymakers.

Keywords: Critical food education
Embodied literacy
Food literacy
Intuitive eating
Nutrition education
Ultra-processed foods
Advisor: Pedretti, Erminia
The Role of Discoidin Domain Receptor 1 (DDR1) in Cardiopulmonary Disease: Characterizing Mouse Models of Pulmonary Hypertension and Impaired Lung Development.

Discoidin domain receptor 1 (DDR1) is a collagen-binding receptor tyrosine kinase that regulates cellular growth, migration, and cell-matrix interactions. However, the roles of DDR1 in the normal or diseased lungs and heart are elusive. Pulmonary hypertension (PH) is a condition that affects the pulmonary vasculature and right side of the heart, and can manifest alongside developmental disorders of the lungs. The pathobiological mechanisms of PH and lung development are not fully understood, partly owing to ineffective mouse models. The work presented in this thesis describes a new mouse model (Ddr1-/- mice) of PH and impaired alveolarization, and outlines a comprehensive methodology for ultrasound imaging of the murine right ventricle (RV). This thesis also explores a potential role for DDR1 in regulating the intercalated disc (ICD), a specialized structure that maintains cell-cell mechanical and electrical coupling in cardiomyocytes. In my first study, I demonstrate that Ddr1-/- mice have a PH-like phenotype involving early mortality, elevated RV systolic pressure, RV hypertrophy and dysfunction, and increased muscularization and reduced density of pre-capillary pulmonary arteries. Ddr1-/- mice also present with enlarged alveolar spaces and reduced secondary septation at 7 days of age. Impaired alveolarization in Ddr1-/- mice results from reduced alveolar epithelial growth, migration, and EMT expression as determined by both in vivo and in vitro experiments. In my second study, I describe a protocol for high frequency ultrasound imaging of mice that have undergone pulmonary arterial constriction to induce RV pressure-overload. The progression of cardiac remodeling was assessed in five acoustic windows and used novel imaging modalities including anatomical M-mode, ECG-based kilohertz visualization, and strain imaging. In my final study, I demonstrate that DDR1 is not required for expression or localization of ICD components in the normal LV, nor the pressure-overloaded myocardium induced by transverse aortic constriction (TAC). However, Ddr1-/- mice had less collagen accumulation in the LV following TAC, compared to WT controls, suggesting a protective phenotype against cardiac fibrosis. In summary, these studies describe a novel phenotype of PH and impaired alveolarization in Ddr1-/- mice, and broaden our understanding of both lung development and RV remodeling.

Advisor: Bendeck, Michelle
Approximations and Scaling Llimits of Markov Chains with Applications to MCMC and Approximate Inference

Markov chains are an essential tool in computational statistics because they form the basis for efficient exact and approximate inference methods, especially in Bayesian statistics. This dissertation offers insight into the viability of approximate inference methods based on both approximations to the transition kernels of a Markov chain for exact methods, and on Markov chains derived from unadjusted stochastic gradient methods. This dissertation also demonstrates how to tune computational methods based upon Markov chains in order to optimize efficiency and accuracy for approximate and exact inference. Results are obtained via two key theoretical methods: (1) an analysis of the perturbation sensitivity of Markov chains using operator theory, and (2) through scaling limits of Markov chains that facilitate a comparison to idealized continuous-time processes. The primary contributions of this dissertation are: (i) a perturbation analysis of reversible geometrically ergodic Markov chains, which characterizes the stability of the stationary distribution and rate of convergence under changes in the transition dynamics; (ii) results on the geometry of probability densities, generalized distributional integration-by-parts, and their consequences; (iii) a joint characterization of the optimal proposal scaling and shaping for the random-walk Metropolis algorithm; and (iv) a complete characterization of the statistical asymptotics of stochastic gradient algorithms as methods for approximate inference, with recommendations on how to tune them for accuracy and efficiency.

Advisor: Roy, Daniel M
Rosenthal, Jeffrey S
Music Performance Anxiety on the Classical Guitar: Expert Strategies from Psychology and Pedagogy

Music performance anxiety (MPA) seriously affects nearly all musicians at some point in their lives and may cause musicians to abandon their careers or develop maladaptive coping mechanisms to manage their symptoms. While peer-reviewed studies have explored a broad array of psychological treatments for MPA, a paucity of research exists regarding expert classical guitarists’ recommendations for MPA symptom management. Since all post-secondary guitar instructors at the expert level interact with MPA in themselves and their students, and each instrumental discipline has idiosyncratic presentations of MPA, this dissertation seeks to understand common approaches and MPA management strategies from the perspective of classical guitar instructors at the post-secondary level—a cohort which includes the researcher. The project compares guitar experts’ recommendations with existing treatment protocols from psychology to understand MPA from a deeper scientific and heuristic perspective while providing pathways for novel research in this topic. This research concluded that guitarists’ approaches prioritized performance excellence and complete mental and physical preparation to manage MPA, while psychological treatments prioritized cognitive components of MPA, musician’s well-being, and symptom reduction. An impressive convergence of approaches appeared in the guitar and psychology literature, particularly regarding the use of mindfulness strategies and strategies from sports psychology.

Keywords: classical guitar
guitar
music performance anxiety
pedagogy
performance
stage fright
Advisor: McFadden, Jeffrey
Testing Immune Mechanisms and Other Hypotheses of Idiosyncratic Drug-Induced Liver Injury (IDILI)

Idiosyncratic drug reactions (IDRs) are adverse drug reactions that do not occur in most patients treated with a drug but remain a major concern in the pharmaceutical industry due to the high risk of uncertainty in its incidence, which may also lead to significant patient morbidity and mortality. As idiosyncratic as they are in humans, IDRs are also as rare in animals, and few valid animal models can simulate the clinical picture seen in humans. The current understanding of how IDRs occur is superficial, but there is compelling evidence that most IDRs are mediated by the immune system. We have developed a valid animal model using a Pd-1-/- mouse with the administration of anti-CTLA-4 to impair immune tolerance in order to unmask the potential of different drugs to cause idiosyncratic drug-induced liver injury (IDILI). As observed with green tea extract, the Pd-1-/- model was able to unmask its ability to cause liver injury similar to the clinical picture in patients. In addition to the modulation of the immune system, other factors such as inhibition of the mitochondrial electron transport chain or the presence of risk factors may contribute to the increased severity of IDILI. The presence of danger-associated molecular patterns (DAMPs) may add to the severity of liver injury; however, complex tolerogenic mechanisms may prevent the progression towards liver failure. Moreover, inhibition of the mitochondrial electron transport chain with rotenone in the Pd-1-/- model did not increase isoniazid-induced liver injury. Although we have developed a validated mouse model, mice are not the best model to study all drugs and IDRs as there are interspecies differences. To address this limitation, we successfully developed a Pd-1 mutant rat using CRISPR/Cas9 technology to study drugs, such as nevirapine, that cannot be studied in mice due to the lack of the required enzyme to create the reactive metabolite. The presence of a drug-mediated skin rash was not observed in the Pd-1 mutant rat, although moderate-to-severe liver injury was observed, which further adds to the complexity of IDILI and IDRs in general.

Keywords: Adverse drug reactions
Animal models
Idiosyncratic drug reactions
Idiosyncratic drug-induced liver injury
Nevirapine
PD-1
Advisor: Uetrecht, Jack