VictorJuiz/thesis huggingface dataset:
Wiring the World: A History of the Earth System Concept in the US Earth Sciences, 1982-1989

Earth scientists today tend to view the planet as an integrated system comprised of interconnected components in the air, land, water, and biota. Earth scientists overwhelmingly use one particular phrase to describe this understanding of the planet: the “Earth system.” How did it become possible to conceive of the Earth as a system? When did “Earth system” become a common phrase? What were the principal factors that led to the concept’s later entrenchment? This dissertation addresses these questions by examining the emergence of the “Earth system” concept among US scientists in the 1980s. While the “global” capacities afforded by post-World War II Earth observing satellites and computer modeling may have been necessary for the conception of the Earth as a system, this dissertation argues that they were not sufficient. There is an important sociological component to the history of the Earth system. The Earth system concept has bureaucratic origins that trace to the mid-1980s and the work of a small group of scientists, the Earth System Sciences Committee. This Committee—formed by NASA’s Advisory Council—developed and promoted a research program called “Earth system science” that would take the whole planet as an object of study. Earth system science failed to gain extensive contemporary support, but the committee’s phrase “Earth system” was widely adopted. I argue that the “Earth system” phrase became entrenched despite the failure of the larger project not because it was well defined but because it was vague. By the 1960s, scientists increasingly perceived satellites and global computer models as supporting the idea that the Earth had interconnected parts that required interdisciplinary study. There was, however, little agreement about how to express this imprecise idea. The phrase “Earth system” was vague enough to adequately fill this semantic void. It served as a boundary object between different scientific disciplines, with enough interpretive flexibility to be narrowly defined by specialists while at the same time being broad enough to facilitate interdisciplinary communication. Vagueness, not analytical precision, thus facilitated the early spread and widespread adoption of the Earth system concept and contributed to its later entrenchment in the Earth sciences.

Keywords: Earth observing satellites
Earth sciences
Earth system
Earth system science (ESS)
Francis Bretherton
NASA
Advisor: Yeang, Chen-Pang
Mental Health Literacies of Secondary School Teachers in Ontario: A Mixed Methods Study

The purpose of this mixed methods study is to investigate the mental health literacies (MHL) of secondary school teachers in Ontario – specifically, how they understand and address the mental health (MH) challenges of students. Over the past decade, the Ontario Ministry of Education (MOE) has encouraged the improvement of teachers’ MHL; this study, therefore, also investigates what opportunities teachers have access to and what barriers they face in supporting students’ MH. A total of 211 secondary school teachers completed an online survey and 21 teachers participated in one-on-one interviews. Approximately three-quarters of the interviewed teachers showed little interest in advancing their knowledge and understanding; the ones who showed interest either had someone in their family, extended family or friends’ circle impacted with MH challenges or their school had a strong focus on MH. Based on the 211 survey respondents, survey results showed that 61.1% of teachers did not support students with MH challenges in the academic session 2017-2018. For the interviewees and survey respondents who participated in the study, the study also showed that teachers from Co-op Education, Special Education, and Guidance Departments were more aware of MH challenges and had more confidence in assisting students with MH challenges. Analyses of the interview data suggest that motivation and exposure to opportunity are the two factors that could drive a teacher’s interest in learning about MH challenges. If a teacher with high intrinsic or extrinsic (administration driven) motivation is provided with many opportunities and/or resources, she or he will take interest and learn about MH of students. However, based on the survey results of survey respondents, only 24.6% of the teachers surveyed in this study worked in schools where principals were attempting to make teachers aware of MH resources. This study has implications for the MOE and the school boards. It is imperative for the MOE to ensure that the school boards provide consistent and continuous professional development to improve educators’ MHL so that they are able to assist students with MH challenges.

Keywords: Barriers
Help-Seeking Efficacy
Mental Health Literacy
Ontario
Secondary School Teachers
Stigma
Advisor: Childs, Ruth
Near-pulse Solutions of the FitzHugh-Nagumo Equations on Cylindrical Surfaces

In 1961, FitzHugh suggested a model to explain the basic properties of excitability, namely the ability to respond to stimuli, as exhibited by the more complex Hodgkin-Huxley equations. The following year Nagumo et al. introduced another version based on FitzHugh's model. This is the model we consider herein. It is called the FitzHugh-Nagumo model and describes the propagation of electrical signals in nerve axons. Many features of the system have been studied in great detail in the case where an axon is modelled as a one-dimensional object. Here we consider a more realistic geometric structure: axons are modelled as warped cylinders and pulses propagate on their surface, closer to the reality of nature. The main results in this thesis are the stability of pulses for standard cylinders of small constant radius, and existence and stability of near-pulse solutions for warped cylinders whose radii are small and vary slowly along their lengths. On the standard cylinder, we write a solution near a pulse as the superposition of a modulated pulse with a fluctuation and prove that the fluctuation decreases exponentially over time as the solution converges to a nearby translation of the pulse. On warped cylinders we write a solution near a pulse in the same way as in standard cylinders and prove bounds on the fluctuation of near-pulse solutions.

Advisor: Sigal, Israel M.
Burchard, Almut
Multi-trophic Metacommunity Responses to Disturbances in a Heterogeneous World

Environmental heterogeneity is a fundamental component of ecological systems, shaping patterns of diversity and stability through dispersal, across space and time. However, intense anthropogenic activities undermine the ecological mechanisms that maintain diversity and the resilience of ecological systems. Although the influence of environmental heterogeneity, dispersal, and species interactions on disturbances have been extensively studied in isolation, a unified approach is needed to understand disturbance and post-disturbance recovery when all these ecological mechanisms vary or are themselves influenced by anthropogenic activity. The objective of my thesis is to evaluate the role of environmental heterogeneity, dispersal and trophic structure in influencing the response of multi-trophic metacommunities to disturbances. In Chapter 1, I offered an introduction to the metacommunity concepts of environmental heterogeneity, dispersal, species interactions, and disturbances, summarizing how metacommunity studies have addressed their relationships. The results of a literature review show that metacommunity studies are greatly skewed to evaluate the various roles of dispersal in homogeneous environments. I explicitly discuss how future metacommunity studies can incorporate further complexity to address the interactive effects of environmental heterogeneity, dispersal, species interactions, and disturbances. In Chapter 2, I evaluated the effects of temporal environmental heterogeneity on metacommunity synchrony, stability and diversity, using a complementary simulation model and microcosm experiment. Environmental fluctuations resulted in greater asynchrony and regional stability, through increased species richness and compositional heterogeneity. For Chapter 3, I investigated the contributions of spatial and temporal environmental heterogeneity to buffer the impacts of a local disturbance of direct mortality, using a model and microcosm experiment. While spatial or temporal environmental heterogeneity allowed for greater metacommunity biomass recovery following disturbance compared to homogeneous environments, spatio-temporal heterogeneity led to the greatest recovery potential. In Chapter 4, I contrasted the contributions of spatio-temporal heterogeneity and dispersal to the simulated impact of different sources of disturbance: connectivity loss, habitat destruction, patch depletion and metacommunity depletion. Results highlighted the importance of maintaining multi-trophic interactions, environmental heterogeneity and species dispersal abilities for heightened resistance to disturbances. Altogether, the findings of my thesis underscore the value and importance of evaluating ecological responses through the interaction of key ecological processes.

Keywords: Competition
Disturbances
Environmental fluctuations
Food-web
Metacommunity
Advisor: Fortin, Marie-Josée
Cadotte, Marc W
From the Theory of Entanglement to the Practice of Optical Quantum Information

This thesis consolidates my research on several topics of quantum information. We start with an analysis of negativity, an entanglement monotone making appearances throughout the thesis. Because negativity is a nonanalytic function of a density matrix, prior methods in the physics literature have been insufficient to compute its derivatives. After developing techniques in complex, patterned matrix calculus, we write down a perturbative expansion of negativity to any order. We continue with another problem in entanglement theory: characterizing the states for which all local actions on one subsystem can be replicated by actions on another. Our results lead to a method for quantifying entanglement based on operational symmetries and tie in to concepts in quantum mechanics, quantum field theory, and classical optics. The study of local operations on entangled states continues with an investigation of the local equivalence of special subsets of graph states, including those that underlie the all-photonic quantum repeater. I show, for certain repeater-like graph states, that equivalence through local unitaries implies equivalence through local Clifford unitaries, investigate certain other properties, and offer alternative proofs and clarifications on existing results. Armed with a better understanding of repeater graph states, I give a blueprint for near-term long-distance all-photonic quantum communication. I make the case that an intercity communication scheme based on a deterministic source of photonic graph states is a good candidate for a proof-of-principle experiment as it is less demanding than an all-photonic repeater but shares its salient features. The design of this experiment is informed by a careful considerations of experimental imperfections. Finally, we transition from discrete-variable quantum communication to continuous-variable quantum computation. Although Gottesman-Kitaev-Preskill (GKP) states are a promising way to encode a qubit into an oscillator, ideal versions of such states have infinite energy. Thus we investigate the impact of finite-energy approximations of GKP states on computational circuits by looking at the behaviour of their physical and logical content through several figures of merit. We complement these results with extensive numerical computations of fidelities, probabilities, and properties of the approximate GKP states produced in photonic circuits.

Keywords: entanglement
graph states
quantum computation
quantum information
quantum optics
quantum repeaters
Advisor: Lo, Hoi-Kwong
Actuarial Bodies: Data, Value, and Fairness in Insurance and Workplace Wellness Programs

This dissertation examines the data practices of personalized interactive insurance (PII) and workplace wellness programs (WWP) in the Canadian and American contexts. Drawing on semi-structured interviews with PII and WWP industry professionals and participants, direct observation at industry events, and analysis of industry documents, I analyze the logics and data practices of PII and WWPs. I argue that the insurance industry’s historical methods of valuing human life, with their raced, gendered, and classed notions of financial value, inform PII’s and WWPs’ data practices. I show how PII and WWPs deploy actuarial data practices to identify ‘burdens’ and ‘crises’ amongst policyholders and employees, frame ‘lifestyle’ and ‘behaviour’ as sites of investment for insurers and employers, and establish rewards as means of activating the future value of health and wellness. I also show how, in the face of uncertainty or doubt around their efficacy, PII and WWPs reorient the way they articulate the value of their services.I analyze the broader power dynamics in these programs, showing how industry actors position themselves as data curators who can facilitate ongoing experimentation on policyholders and employees. I argue that PII and WWPs demand datafied performances of value in the form of ‘healthy behaviour’ and ‘engagement’ from participants. I show how PII and WWPs frame ‘personalized’ data profiles and rewards as a way of increasing actuarial fairness, and argue that ‘fairness’ operates as a strategy of power that plays on an individual desire to control how we are perceived as different than or similar to others in an effort protect social status. Finally, I show how PII and WWPs continue the long-established practice of mobilizing both care and neglect for corporate profit, and argue that the actuarial logic of allocating costs, burdens, and (potential) value creates investable and disposable populations.

Keywords: Data
Insurance
Personalized Interactive Insurance
Self-Tracking
Workplace Wellness
Advisor: Keilty, Patrick
Understanding the Role of Leishmania RNA Virus-1 (LRV-1) in the Pathogenesis of American Tegumentary Leishmaniasis (ATL)

American Tegumentary Leishmaniasis (ATL) comprises a spectrum of cutaneous leishmaniasis (CL) and mucosal or mucocutaneous leishmaniasis (ML/MCL) endemic to Latin America. Leishmania RNA Virus-1 (LRV-1) is a double stranded RNA virus identified in up to 25% of clinical isolates of the Leishmania Viannia subgenus. Approximately 1-15% of patients with healed CL will progress to ML/MCL on average 1-5 years later, the biological underpinnings of which could be related to LRV-1, given its ability to alter expression of certain proinflammatory cytokines and chemokines in both human and murine models. This doctoral thesis sets out to evaluate: 1) the prevalence of LRV-1 in ATL and its potential associations with clinical phenotype; 2) changes in proinflammatory biomarker expression from human macrophages infected with LRV-1 positive and negative strains of Leishmania Viannia braziliensis and L. V. panamensis and 3) virulence factor (VF) RNA transcript expression in previously infected human macrophages. LRV-1 was detected at a rate of 23%-26% and was not directly associated with clinical phenotype. Age was associated with clinical phenotype, whereby patients manifesting ML/MCL were, on average, 10 years older than patients manifesting localized CL (LCL). LRV-1 did not alter pro-inflammatory biomarker expression of TNF-α, IL-1β, IL-6, CXCL10 and SOD at 24- and 48- hours in strains of L. V. panamensis, regardless of isolate source. However, clinical L. V. braziliensis demonstrated significantly lower levels of TNF-α, IL-1β, IL-6 and CXCL10 at 24- and 48- hours compared to the ATCC® L. V. braziliensis strain. A direct comparison of clinical L. V. braziliensis strains, revealed LRV-1 to increase TNF-α and decrease CXCL10 at 48-hours. Analysis of VF RNA transcripts of heat shock protein 23 (HSP23), HSP70, HSP83, HSP100, mannose phosphate isomerase (MPI), cysteine proteinase B (CPB) and zinc metalloproteinase (GP63) revealed no difference in expression by LRV-1 status, however a marked increase at 24- and 48- hours post-macrophage infection was observed. In conclusion, LRV-1 status and causative species potentially represent a combined marker of immune responses as observed by differences in L. V. braziliensis and L. V. panamensis populations, possibly predictive of clinical phenotype.

Keywords: American Tegumentary Leishmaniasis
Cutaneous Leishmaniasis
Leishmania RNA Virus-1 (LRV-1)
Mucocutaneous Leishmaniasis
Mucosal Leishmaniasis
Advisor: Boggild, Andrea K
An Integrated View of Suicidal Ideation: A Look at Individual Difference Vulnerabilities and Day-to-day Risk Factors of Suicidal Thoughts

Prediction of the severity and occurrence of suicidal ideation has been a challenge for decades, possibly due to an almost exclusive focus on predictors months to years prior to suicidal ideation assessment. The primary aim of this dissertation was to provide an integrative view of suicidal ideation by examining vulnerability and risk factors as predictors of suicidal ideation severity (baseline assessment) and occurrence (momentary assessment). Three overarching areas were investigated: (1) emotions as predictors of ideation; (2) beliefs about suicide as an escape or as a solution to a problem; and (3) the intersection between emotions and beliefs about suicide in predicting/maintaining ideation. A relationship between baseline emotion dysregulation and suicidal ideation severity (baseline and 6-months later) was found, along with momentary increases in sadness, hopelessness, and general negative affect as predictors of increased probability of ideation occurrence. Emotional intensity across seven emotional states in day-to-day assessments was found to immediately increase following ideation occurrence, while stress and anxiety reduced in intensity nearly three hours after ideation occurrence. Further, belief in suicide as a solution predicted greater intensity of hopelessness, sadness, stress, and overall negative affect following the occurrence of a thought. Belief in suicide as an escape only predicted greater intensity of anger following occurrence in day-to-day reports. Notably, difficulties generating relevant solutions to a problem predicted greater likelihood of suicidal ideation occurrence in real-time and greater frequency in a two-week period. Regarding the intersection between emotions and beliefs, belief in suicide as an escape moderated the relationship between baseline emotion dysregulation and baseline and 6-month suicidal ideation severity, such that this relationship was stronger for individuals who endorsed this belief. No other significant intersection between emotions and beliefs was found. This dissertation offers a view of the cognitive-emotional aspects of ideation severity and occurrence, with novel results illustrating (a) the importance of beliefs about suicide, (b) the potential maintenance of suicidal ideation through a vicious cycle of increasing negative emotion intensity, and (c) the relationship between difficulties generating relevant solutions to a problem and suicidal ideation. These findings have the potential to inform future assessment and intervention efforts.

Keywords: Ecological Momentary Assessment
Experience Sampling Study
Negative Emotion Intensity
Risk Factors
Suicidal Ideation
Vulnerability Factors
Advisor: Uliaszek, Amanda A
Approaches to Leadership Development and Succession Planning in Canadian Accredited Independent Schools

Despite the significant research on succession and leadership development in the management literature, similar research in K–12 education is limited, including very few studies on Canadian K–12 independent schools. Meanwhile, Canadian Accredited Independent Schools (CAIS) face a significant wave of leadership change, with 6 out of 10 CAIS leaders citing plans to leave or retire from their current school within five years, and board chairs citing leadership succession as a top concern facing their schools. This study examines how CAIS school leaders are approaching leadership development and succession planning in their organization, via qualitative interviews with 20 leaders (heads, HR leaders, board chairs) in seven CAIS schools. An analysis of these interviews reveals significant variation in the sophistication of these schools’ leadership development and succession planning processes. Additionally, from these interviews, six key findings emerged: (1) succession practices across schools are varied, and most of what is being done across schools is replacement rather than succession planning; (2) organizational elements that inhibit or support succession planning and leadership development include: presence of strategic HR, a culture of professional development, access to stretch opportunities for emerging leaders, and the tenure and career stage of current head; (3) succession efforts need to be driven by the head and board chair to be successful; (4) governance succession processes in CAIS schools are strong, if not always well-executed; (5) heads feel that search committees’ reluctance to appoint first-time heads has limited leadership development efforts within CAIS schools, and they raise concern over the rise of international head appointments to CAIS schools; and finally, (6) sponsors who advocate for high-potential leaders are important. The recommendations from this research highlight the desire CAIS school leaders have for more support in structuring succession and leadership development processes in their schools, as well as a call for a national body, like CAIS, to promote the leadership training programs they operate with school boards and executive search firms. This research establishes the groundwork for future, further examination of leadership and succession pathways in Canadian independent schools.

Keywords: Independent school
Leadership
Leadership development
Private School
Succession
Succession planning
Advisor: Flessa, Joseph