VictorJuiz/thesis huggingface dataset:
Resilience and the Relationship between Care Environment and HIV Risk Factors in Orphaned and Separated Children and Adolescents in Western Kenya
Keywords: HIV
Kenya
Orphans
Resilience
Risk
Social Support

Millions of orphaned and separated adolescents and youths (OSAY) in sub-Saharan Africa are at a disproportionately higher risk of many adverse health outcomes, including HIV and associated risk factors, as compared to their non-orphaned peers. This increased vulnerability may be due more to a combination of environmental, social, and psychological factors than orphan-status alone. Care environment has been linked to differences in physical and mental health as well as risk behaviours in this population; however, the mechanisms underlying these relationships are not well understood. This dissertation used rich data on the health and well-being of OSAY in Charitable Children’s Institutions (CCI, i.e. orphanages and rescue centers) and family-based care settings (FBS) to investigate the relationships between care environment, psychological resilience, resilience-building factors, and HIV risk factors in OSAY in western Kenya. The first study examined the psychometric properties of the 14-item Resilience Scale (RS14) tool for measuring psychological resilience in this population. It found a high level of internal consistency reliability, moderate convergent validity, and satisfactory construct validity; supporting the use of the RS14 in OSAY in western Kenya. The second study explored the relationships between care environment, social-psychological factors thought to promote psychological resilience, and psychological resilience. Individuals in CCIs showed greater resilience than those in FBS. Family support, social support, peer support, and volunteering were identified as factors that may facilitate the development of psychological resilience in this population. The third study investigated the causal mechanisms behind the relationships between care environment and HIV risk factors; examining these relationships longitudinally and decomposing the impact of care environment on HIV risk factors into the effects due to mediation, interaction, neither, or both. It found that CCIs provided a strong protective effect against sexual HIV risk factors and that none of resilience, peer support, family support, social support, volunteering, or having one’s material needs met were strong mediators of these effects. Together, these studies make an important contribution to the epidemiological literature on resilience and HIV risk in vulnerable populations in low resource settings, and provide insights to guide future research and support evidence-based policy interventions.
Quantitative Education Researchers’ Conceptualization of Validity in Research Design, and Perceptions of their Work
Keywords: Education Research
Measurement Validity
Quantitative research
Research methodology
Validity in research design
Validity of inferences

The question of whether a study’s findings or conclusions are valid is a universal concern to all researchers, regardless of whether their approach to research is qualitative, quantitative or mixed. The various research traditions adopt differing philosophies about the nature of knowledge and reality. The literature in the quantitative research tradition has already made attempts to include qualitative and mixed methods in the same validity framework. Quantitative researchers usually use some version of the Campbellian validity typology to discuss research validity. Despite this validity typology originating in the fields of experimental and quasi-experimental causal studies, the internal-external validity framework is widely used in many fields including in education. However, differences in conceptualizations and disagreements abound in the use of the terminology associated with that framework. This exploratory study investigates nine quantitative researchers’ conceptualization of validity, their research practices, their research aims, and their decision-making process during research design and implementation. The participants’ contributions suggest that researchers do not limit themselves to one type of study despite using a particular validity framework. Results also indicate that researchers value flexibility in both their validity framework and their research protocols. Participants highlighted that rewards structures in the research community may not always promote good science. These insights are instrumental for understanding the barriers to having a common validity framework, and some of the prevalent issues related to when it comes to current practices of researchers.
Predictors of Self-Injurious Thoughts and Behaviours Among Canadian Post-Secondary Students
Keywords: post-secondary
risk factors
self-injurious behaviour
self-injurious thoughts
suicide

Self-injurious thoughts and behaviours (SITB) represent a collection of life-threatening outcomes ranging from non-suicidal self-injury (NSSI, e.g., self-cutting) to suicidal thoughts (ST) and suicide attempts (SA). Suicide has been identified as a major public health problem and the second leading cause of death among young adults (18 to 24 years), with peak developmental transitions such as attending post-secondary education presenting as a strong catalyst for SITB engagement. Although SITBs have undergone rigorous examination over the years, there remain inconsistencies in the classification of non-suicidal and suicidal SITBs and the prevalence of subsequent risk factors specific to young adults. The purpose of this study was to examine the pre-existing and emerging biopsychosocial risk factors associated with suicidal thoughts and behaviours and non-suicidal self-injury among post-secondary students. While several researchers approach the topic of suicidal thoughts and behaviours separately from non-suicidal self-injury, this study examines the two constructs concurrently and explores risk factors common to both. Using data from the 2013 (n=354) and 2016 (n=270) American College Health Association–National College Health Assessment (ACHA-NCHA), a cross-sectional survey of the health behaviours of Canadian post-secondary students, this study examined the prevalence of 13 biopsychosocial risk factors in a group of students who endorsed engagement in SITB. Of the 13 risk factors examined in the current study, results demonstrate three pre-existing risk factors (interpersonal trauma, substance use and diagnosis of a mental health issue) and three emerging risk factors (disability identification, sleep disturbance and negative affect) converging in the two student samples. Understanding emerging risk factors may help improve suicide risk assessment tools and mitigate suicidal tendencies by providing clinical interventions at earlier stages for post-secondary students. Sleep problems may be a particularly important intervention target because of their non-stigmatizing nature and amenability to mental health treatment.
Unconsummated/Queer Loneliness
Keywords: 1980s
1990s
asexuality
loneliness
media aesthetics
queer theory

This dissertation is organized around a concept called queer loneliness, which I define as a state of unrequited longing, one that contests the borders between the presence and absence of sex. Whereas most queer theory has understandably worked to repair and refigure non-monogamy, this project approaches queer intimacy from the opposite direction, illuminating relations that often occur without sex, without contact, or without a human intermediary. Following from theoretical work on celibacy, autoeroticism, and asexuality, this project examines the criteria through which erotic behaviours become recognizable as sex, rather than as foreplay, fetishism, or masturbation. In this sense, loneliness is not only a paradigm that questions the collapse of sexual evidence and legitimized partnership, but also one that poses consequences for the legibility of erotic life in moving image media. Distance, seclusion, vicariousness, illegibility, and frigidity are all operative figures in this project, and I suggest that these aesthetic paradigms contest an insistence – whether in acts of seeing or interpreting – on union between beholder and object.My methodology combines engagement with queer thinkers, close formal analysis, and attention to sexual historiographies, thereby negotiating culturally specific modes of sexual epistemology through the peripatetic surprise of aesthetic reading. The project is periodized alongside increasing sexual privatization throughout the late 20th century in a variety of national contexts (Belgium, Czechoslovakia, Great Britain, Japan, Taiwan, the United States), focusing particularly on the sacralisation of nuclear family dynamics that proliferated globally during these decades. In this project, I excavate an alternative history of queer cinematic expression in the late 20th century, one that examines how this era simultaneously fortified a conservative, heteronormative pastoralism and permitted a set of stranger erotic relations to seclusion, atomization, and home spaces to take root. Ultimately, this project suggests that unconsummated, celibate, or non-companionate relationalities are not simply a form of negation, but an aesthetic mode, a form of ambient togetherness, a way of doing history, and a component of cinematic grammar.
Co-creating and Implementing a Community-Based Peer-Assisted Physical Activity Program to Promote Exercise and Sport Participation after Moderate-to-Severe Traumatic Brain Injury
Keywords: Community
Exercise
Peer
Physical Activty
Sport
Traumatic Brain Injury

Traumatic brain injury (TBI) is a leading cause of death and disability around the world, and moderate-to-severe TBI may result in long-term or lifelong sequelae that prevent individuals from returning to a pre-injury way of functioning. Physical activity (PA; e.g., exercise and sport) demonstrates the potential to alleviate some of this burden through meaningful health-improving activities that are positive for mood, community participation, and quality of life after moderate-to-severe TBI. However, adults with moderate-to-severe TBI do not participate in recommended amounts of PA. Therefore, establishing best-practice methods to support PA participation in the community after moderate-to-severe TBI is warranted for the purpose of improving long-term outcomes. This doctoral dissertation addresses that gap with (1) a scoping review of the current literature about community-based PA interventions after moderate-to-severe TBI, (2) an exploratory case study of an existing peer-based PA program being piloted in a YMCA fitness centre, (3) an interpretive case study of co-creating a tailored peer-based PA program with key stakeholders, and (4) an interpretative phenomenological analysis of COVID-19’s impact on program participants and their PA. Results showed (1) community-based PA interventions can lead to significant improvements in health-related outcomes after moderate-to-severe TBI, but further research is needed with sex and gender considerations, telehealth applications, and better intervention reporting; (2) the inner mechanisms of a peer-based PA program from the perspective of multiple stakeholders and the autonomy-supportive approaches needed to tailor the intervention for future users; (3) how the participation in and co-creation of a new optimized community-based peer-assisted program can increase PA autonomy, reduce PA barriers, and lead to important biopsychosocial benefits; and (4) the profound impact of COVID-19 and necessary considerations to support PA in a pandemic after moderate-to-severe TBI. Findings of this dissertation include implications for the rehabilitation sciences and literature. Integrated knowledge transfer approaches to co-creating a peer-based PA program in the community can lead to the co-production of knowledge between researchers and users, who benefit from health promotion opportunities that further their participation in society. Peer-based PA programs can transcend rehabilitation to the community context with positive health behaviours that extend beyond a formal intervention.
Contributions to Data-Driven Combinatorial Solvers
Keywords: Combinatorial Optimization
Contrastive Learning
Integer Programming
Machine Learning
Reinforcement Learning

Discrete optimization problems appear in everyday life, with a wide range of applications including airline scheduling, telecommunications network design and healthcare. Modern solvers are intricately crafted to perform well on average across this wide range of applications. This generality is at odds with their emerging applications where the solver is rapidly queried with slightly modified versions of the same problem. Data-driven algorithm design provides a potential solution to this dilemma by tuning various aspects of the solver via machine learning to the desired distribution of a particular domain. Several attempts have been made towards this goal, yet many challenges lie ahead of its adoption in modern solvers. In this dissertation, we identify some of these challenges and propose methods to alleviate or circumvent them. First, we contribute the first ML-based exact model counter by improving the branching heuristic of a conventional solver in a data-driven manner. We show that the resulting solver takes fewer steps in solving unseen similarly distributed instances and can extrapolate to larger instances from the same problem family, sometimes leading to orders of magnitude speedups over the conventional solver. Second, we investigate the potential of contrastive learning in ML-based solvers. Given the NP-hard nature of these problems, the cost of acquiring labels is quite expensive. We show that, by using only 1% of the labelled data, contrastively-trained representations can achieve comparable test accuracy to fully-supervised representations. This positions contrastive learning as a formidable technique for data-driven solver design. Third, we propose a framework based on Monte Carlo tree search for efficient “backdoor” discovery in integer linear programming. The study of backdoors can reveal novel structural properties of these problems and provide insights into their hardness. Lastly, we show how ML can in turn benefit from the discrete mathematics domain. We show how a type of formal logic can be used to express multi-task, temporally extended instructions to reinforcement learning agents. We prove that the resulting agents have theoretical advantages over baseline methods. Particularly, we show that our agent does not suffer from myopia, where the individual subtasks are solved optimally but the combined solution is suboptimal.
Investigating the In vivo Effects of Osteoblast-specific Oerexpression of Gαs and Gαq/11 on Bone Formation and Remodeling during Fracture Repair
Keywords: Biomechanics
Fracture repair
G protein
Osteoblast

G proteins mediate a multitude of physiological processes by transducing extracellular signals from G protein-coupled receptors to various intracellular signaling cascades. Of particular importance in bone are GαS that raises cAMP levels by activating adenylyl cyclase and Gαq/11 that increases intracellular calcium levels via activation of phospholipase C. Using transgenic mice that overexpress either GαS (Gs-Tg) or Gαq/11 (G11-Tg) in osteoblast lineage cells, previous work in our lab has demonstrated that alterations in GαS and Gαq/11 levels in the skeleton can have profound effects on bone mass, microarchitecture, mineral density, and quality. It remains unclear, however, how variation in GαS and Gαq/11 levels affects bone regeneration and repair. To test our hypothesis that increasing Gαs and Gα11 in osteoblasts leads to differential fracture healing responses, we performed stabilized tibial osteotomy in male Gs-Tg and G11-Tg mice at 8 weeks of age and examined the progression of fracture healing by Micro-CT, histomorphometry, and gene expression analysis over a 4-week period. Gs-Tg mouse fractures exhibited diminished cartilage formation, increased callus mineralization, increased bone formation, and improved material stiffness. Histological analyses also revealed excess fibroblasts along the newly formed woven bone surfaces and elevated osteocyte density at the times of increased bone formation and elevated osteoclastic bone resorption in the bone remodeling stage. Coincident with enhanced osteogenesis, elevated osteoblastic Wnt secretion and Wnt/B-catenin signaling was evidenced by quantitative reverse transcription PCR and immunofluorescence staining implicating increased Wnt signaling activation as a mechanism by which increased GαS levels promote osteogenesis and induce fibrosis during bone repair in Gs-Tg mice. In contrast, normal endochondral healing progressed in G11-Tg mice. However, their reduced osteogenic differentiation capacity led to diminished formation of highly mineralized bone and poor structural integrity of healing bone. The lack of changes in osteoclast parameters and osteoclast marker expression suggested that the G11-Tg fracture repair phenotype is driven by osteogenic abnormalities. Overall, our results confirm our hypothesis that GαS and Gαq/11 differentially regulate bone formation and remodeling during fracture repair and highlight that osteoblast GαS and Gαq/11 levels play a significant role in determining the pattern, rate, and extent of fracture healing.
Efficient Algorithms for Smulations of Quantum Chemical Systems
Keywords: Electronic structure
Hamiltonian simulation
Metallic surface
Nonadiabatic dynamics
Quantum computing
Solar light absorption

Even though the physical equations that model chemical systems are known, the complexity of solving, and sometimes even representing such equations, escalates exponentially with the system size for an arbitrary chemical system. However, many different approximations can be made and efficient algorithms found for the accurate description of some chemical systems of interest with reasonable computational effort. In this work, we propose efficient algorithms for the solution of three problems of chemical interest, namely: the electronic structure problem using quantum computers, the simulation of chemical reactions on metallic surfaces, and modelling the absorption of solar radiation by light harvesting molecules. All of the proposed algorithms work within larger frameworks. We start by discussing the importance of each given problem, after which we cover the necessary background for all the used frameworks and show the details on how our proposed algorithms make these frameworks more efficient.
Developing a Diagnostic Approach to Multi-Dimensional Poverty
Keywords: Diagnosis
Health Assessment
Multi-dimensional poverty
Nursing
Person Centered-Care
Triage

Resource accumulation benefiting some people over others has been naturalized throughout human social evolution, even when its acquisition caused widespread suffering, disease, and premature death. The first religious orders, humanitarians, and indeed nurses, all emerged in response to this widespread exploitation and misery. In our globalized and technologically advanced world, there is widening inequality, deepening impoverishment, complex threats to health and security, and increasing uncertainty. As clinicians, we seek to assist people living in multi-dimensional states of suffering, yet our tools and methods are insufficient. Poverty measures often focus on monetary impoverishment alone; most are not meant to be broad or diagnostic in nature; political barriers and other perverse incentives limit the scope of poverty case finding; practice barriers (not least, time) limit case finding in the clinic; and often we focus on symptoms and surface manifestations of poverty – not the root causes. Grounded on an ontological foundation of critical realism and guided by an epistemology of critical theory, this study seeks to address this practice gap by synthesizing existing poverty measures and approaches via a literature scoping review; collecting primary data from health providers and clients through a generic qualitative research study; and constructing a novel diagnostic approach to multi-dimensional poverty with an emphasis on clinical utility. During eight months of data collection in urban Toronto, semi-structured interviews were carried out with 11 healthcare professionals and 6 clients, as well as a multidisciplinary focus group of 5 clinicians. Findings revealed that respondents held diverse perspectives on the definition of “poverty”, what to do about it, and what provider and client roles ought to be. Respondents also helped prioritize life domains, proposed ways to measure complex aspects of life, and suggested settings where a diagnostic approach to poverty would be useful. Based on these findings, I propose the Survival – Orientation – Self-Actualization (S.O.S.) Diagnostic Approach, a novel multi-dimensional measure infusing elements of the nursing process, person-centered care, and ethical triage to better guide poverty case finding and praxis in the clinical setting. The study concludes by offering suggestions on application to practice, informing policy, and suggestions for future research.
Odd Electron Transition Metal Hydride and Amine Complexes and their Associated Proton/Electron/Hydrogen Atom Reactivity
Keywords: Hydride
Inorganic
Paramagnetic
Transition Metals

This thesis is focused on furthering our understanding of the thermodynamics associated with metal hydrides and coordinated amines, namely the acidity, electrochemistry, and M-H and MN-H bond strengths. This understanding will improve catalyst development and should make industrial processes more sustainable and environmentally benign. In chapter 2, literature-reported electrochemistry of metal-hydride complexes is combined with estimated acidities of the oxidized species, in order to examine trends in electrochemical reversibility, acidity, and metal-hydride bond strength. It was found that oxidations to acidic metal hydrides tend to be irreversible due to proton loss. On the other hand, regions of electrochemical reversibility are usually associated with more reducing, less acidic complexes. In addition, the ligand acidity constant (LAC) method of estimating the pKa of metal hydrides and dihydrogen complexes is applied to paramagnetic metals. It was found that the LAC method generally works well for paramagnetic complexes, even though it was empirically derived from pKa of diamagnetic hydrides. Using the work from chapter 2 as a guide, a series of paramagnetic manganese(II) hydride com- plexes were synthesized, as discussed in chapter 3. This series is of the type trans-[MnH(L)(dmpe)2]+ were L is PMe3, C2H4, or CO. All of these complexes were studied by frozen solution EPR spec- troscopy. However, at room temperature, the trans ligand was found to determine the radical stability, and in cases of instability, the decomposition products. trans- PMe3 provides steric bulk and basicity, which stabilizes the radical. The trans-C2H4 complex decomposed by loss of ethylene and ethane, which ultimately yielded the homoleptic tris-dmpe complex and other unidentified side- products. The trans-CO complex provided little steric bulk and was more acidic, such that this complex cleanly lost 1/2 H2 in MeCN to give the MnI product [Mn(CO)(MeCN)(dmpe)2]+. In chapter 4, the focus is on coordinated amines, specifically a secondary amine in a tri-dentate phosphorous-nitrogen-nitrogen (PNN) ligand, which is coordinated to iron and rhodium. This case study used cyclic voltammetry and NMR to measure the acidity, electrochemistry, and MN-H bond dissociation free energies for the complexes.