VictorJuiz/thesis huggingface dataset:
Cognitive and Mental Health in Aging Sexual Minority Populations: Diversifying the Minority Stress Model
Keywords: CLSA
Cognition
Deprivation
Gerontology
Mental Health
Minority Health

The aging population is continuously growing in North America, yet limited efforts have been made to understand the role of aging in the sexual minority research. Guided by the minority stress model (Meyer, 2003), the current study examined cognitive and mental health outcomes of aging sexual minority adults in Canada by using a population data from the Canadian Longitudinal Study on Aging. To understand the role of social factors in sexual minority aging, the study first compared social participation rates between different sexual orientation groups by using the analysis of variance. The second part of the study investigated the relationship between sexual orientation and cognition by conducting multiple regression analyses while considering the role of social participation and social support. The third part of the study explored the relationship between sexual orientation and depression while considering the influence of neighborhood deprivation levels. Findings from the first part of the study indicate that social participation levels differ by sexual orientation in both aging men and women. Results from the second part of the study found that aging gay men perform better in cognitive flexibility and memory related tasks compared to their heterosexual peers even after considering the effects of social support and social participation. Bisexual women also performed significantly better in memory tasks than their lesbian and heterosexual counterparts, while reporting no significant effects of social support or social participation in the model. The third part of the study that investigated the role of neighborhood deprivation levels in the relationship between sexual orientation and depression in aging populations indicated that material deprivation levels contribute to the relationship between lesbian identity and depression in aging women as well as the relationship between bisexual identity and depression in aging men. The results of this study suggest that cognition, social participation, and neighborhood material deprivation are important constructs for studies that explore the aging process of sexual minority populations. In particular, this dissertation’s results related to depression point to the need for further support for aging sexual minority adults through behavioral and policy interventions.
A School-based Cognitive Behavioural Therapy Skills Intervention for Suicide Prevention and Wellbeing in Youth
Keywords: Depression and Anxiety
Population Based
School-Based Intervention
Suicide Prevention
Wellbeing

This dissertation aimed to evaluate the impact of a Cognitive Behavioural Therapy Skills Intervention (CBTSI) on suicidality in middle schoolers. The primary objective was to determine whether the CBTSI produced a meaningful reduction in suicidality (4-item composite) in middle schoolers who endorsed at least one item on the Life Problems Inventory (LPI) questionnaire. Exploratory objectives were to determine if the CBTSI produced a meaningful improvement in depression, anxiety, and wellbeing. Following a feasibility study, I conducted a randomized control trial (RCT) with 430 students (46 classes) in total, to evaluate the causal effect of the CBTSI on outcome measures of interest in a large, urban, diverse school board. In Study 3, I evaluated the potential differences in the impact of the intervention on youth with and without mental health symptoms that may be clinically relevant. A subset of these students participated in Study 4; there were 8 groups of 60 students in total. I utilized qualitative methods to explore students' experiences of the intervention during the RCT and to better understand barriers and facilitators to engagement. Students were 12 to 14 years of age or in grades 7 or 8 for all studies. One of the most reliable risk factors for youth suicide is suicidal ideation and most notably, suicide attempts. Non-suicidal injury’s (NSSI) role in youth suicidality remains debated and is not fully understood. For these reasons, measures of suicidality consisted of a composite score reflective of 1 suicide attempt item, 2 suicidal ideation items and 1 NSSI item. A decision was made to rerun the analyses and introduce the NSSI back into the results of the RCT following a Chronbach’s alpha reliability estimate calculation. Overall results of the quantitative studies indicate inconsistent findings in suicidality, but improved wellbeing. Results across the studies for depression and anxiety outcomes were mixed. When discussing the CBTSI, students expressed that the intervention needs to be adaptable to enhance the personal dignity of youth, respecting their wishes and individual goals. Maximizing the opportunities for involvement and self-determination created an atmosphere for confidence and self-compassion to flourish, the highlighted core themes.
Electrochemical Studies of Molten Salt Corrosion
Keywords: Dealloying
Electrochemistry
Molten salt corrosion
Molten salts
Ni-based alloys
Parting limit

Corrosion mechanisms of Fe-Ni and Fe-22Cr-Ni model alloys with varying Ni contents and Ni-22Cr model alloy were investigated in molten chloride salts at 350-700 °C, simulating the heat transfer circuits of molten salt reactors and thermal solar plants.This study revealed that corrosion properties in molten Cl salts depends on homologous temperatures, metallic solid-solution alloying effects, critical alloy compositions, and impurities. Dealloying of electrochemically reactive element(s) (Fe and/or Fe+Cr) was the dominant form of corrosion; fundamentals and mechanisms of dealloying, and mechanistic connections with aqueous dealloying were determined. It was discovered that at certain conditions, dealloying in molten salts obeys the same rules as the aqueous dealloying. At 350 °C, the dealloying mechanism is mediated by surface diffusion of the more-noble element (Ni) at the alloy/molten salt interface. The microporous dealloying morphology resembled that seen in aqueous systems (but much coarser). The dealloyed layer was a three-dimensional structure with core-shell ligaments; a Ni-rich shell surrounding a core with minor Fe (Fe+Cr), similar to Ag-Au systems in acidic media. At 350 °C, the fundamental parting limit (55-60 at.% of the less-noble element in aqueous solutions) decreased to 44 at.% due to the high surface mobility of elemental Ni. At 350 °C, the parting limit further decreased to a value of approximately 32 at.% Fe when elemental Ni from alloy surface was close to equilibrium with Ni2+ ions that were added to the molten salts, similar to brass in aqueous solutions. Between 500 °C and 700 °C, the dealloying morphology is an interconnected pore/ligament network; however, transitional morphologies evolved, and grain boundary dealloying was common. At 600 °C, bulk diffusion resulted in one-dimensional tunnel-like corrosion morphology ahead of the dealloyed layer. The associated dealloying threshold decreased to values close to 32 at.% and 22 at.% as the temperature rose to 600 °C and 700 °C, respectively. At high homologous temperatures, there is a strong influence of lattice diffusion of alloying elements. However, dealloying of Ni-based alloys in molten salts at up to 700 °C is consistent with percolation dissolution theory; this study revealed that the parting limit remains mostly geometric in nature.
Development and Evaluation of a Wearable Vibrotactile Biofeedback System and a Gait Event Detection Algorithm to Improve Gait Symmetry of Individuals with Lower-limb Amputation
Keywords: Biofeedback
Gait Rehabilitation
Lower-limb Amputation
Prosthetics
Vibrotactile Feedback
Wearable Systems

BACKGROUND: Individuals with lower-limb amputation (LLA) often exhibit gait asymmetry. Biomechanical biofeedback (BFB) systems can improve gait symmetry and overall mobility. However, effective ways of providing vibrotactile feedback, including system functionality and usability have yet to be investigated. Further, effective GED algorithms with low-computational demands are needed to improve performance, wearability, and portability of BFB systems. OBJECTIVE(S): Objective 1 consisted of developing and assessing a wearable BFB system, including multiple vibrotactile feedback strategies, as a clinical tool for improving temporal gait symmetry of LLA. System usability, workload, learning and immediate post-test retention effects were also explored. Objective 2 consisted of developing and evaluating a GED algorithm to accurately detect foot-strike and foot-off events at different walking speeds. METHODS: For objective 1, a systematic literature review investigated BFB systems in gait rehabilitation of LLA. Secondly, a wearable vibrotactile BFB system was developed and evaluated, targeting prosthetic stance/swing time ratio as a percentage of the gait cycle (ST%). Three unique vibrotactile feedback strategies were investigated to induce stance time asymmetries (SR) and changes in walking speed in able-bodied participants. Further, effects on spatiotemporal and kinematics gait parameters were assessed under concurrent, corrective, discrete vibrotactile feedback, targeting stance time symmetry ratio (STSR) of LLA. System usability was assessed with the System Usability Scale and workload with the NASA Task Load Index questionnaire. For objective 2, a GED algorithm (foot-strike and foot-off detection) was developed and assessed via metrics of specificity, sensitivity, and timing error in able-bodied participants walking at slow, self-selected, fast, and random speed. FINDINGS: For objective 1, all participants modulated/improved their gait symmetry (ST%, SR, STSR) using BFB. Gait speed and cadence decreased, and symmetry of kinematic parameters improved with BFB. Learning and immediate post-test retention effects were observed in spatiotemporal and kinematics parameters after BFB was withdrawn. System usability and workload were acceptable. For objective 2, the GED algorithm detected foot-strike and foot-off at various speeds with high sensitivity (94.32%), specificity (94.70%), and low latency (6.52 ± 22.37ms). SIGNIFICANCE: This study provides new insights into the development of gait training BFB systems and low-computational GED algorithms to improve gait symmetry of LLA.
Investigating the Wellbeing of Teachers: A Self Study
Keywords: mindfulness
self-study
social-emotional competencies
teacher wellbeing
teacher wellness

Over the last decades, educational research has given considerable attention to teachers’ burnout. Owing to its negative personal, organizational, and social impacts (e.g., physical and mental ill health, decreased work performance, attrition, turnover), intervention and prevention efforts have consequently been employed to minimize the effects of this syndrome. As teaching-specific stressors are mainly related to the socio-emotional domain, interventions targeting social and emotional learning (SEL) for teachers have been seen to increase in recent years. Mindfulness-based interventions have proven to be successful in reducing teacher stress while improving teachers’ social-emotional competencies. The purpose of this self-study was two-fold. First, the researcher examined the contributing factors leading to her emotional exhaustion and eventual burnout. A typical burnout cycle was evidenced due to both external and internal factors, specifically, the researcher’s perfectionistic tendencies and underdeveloped emotional coping mechanisms. The second part of the research examined the impact of mindfulness practice on the researcher’s wellbeing, including her participation in a mindfulness-based intervention, Teachers on the RISE (TOTR). Findings showed that mindfulness-practices a) promote increased awareness (of self and others) b) improve one’s ability to respond c) improved compassion (for self and others) d) promote responsible decision-making e) improve esteem for the self f) improve self-care, wellbeing, and growth g) impact teacher performance h) impact students i) impact student-teacher relationships j) impact teacher practices k) build connections and community. Discussion included connections to the relevant literature, the researcher’s personal reflections as well as implications for future research.
Re-Drawing Perspectives on and of Contemporary Saudiyyat: Using Suwalif by and for the Saudi Women
Keywords: Contemporary
Discourse
Narrative
Saudi Arabia
Saudi women
Subjectivity

In recent decades, Saudi Arabia has witnessed the implementation of various sociopolitical changes in terms of the direction and management of its society. In this dynamic environment, women in Saudi Arabia are being largely impacted by their navigation within the private and public spaces. This dissertation brings forth the lived experiences of ten, educated, middle-class women in Saudi Arabia to look at how they negotiate their subjectivities; the strategies they use to influence their subject positions within family and society; and how the women reconcile their subjectivities as in-between in an overall process of negotiation. Subjectivity creates a fluidity where there is continuous acting and shifting, and allows for insight into how these women are affected by their interactions. This work is informed by the interpretivist and poststructuralist theoretical frameworks and introduces a narrative methodology of suwalif as a social practice of speaking, retelling and uttering lived experiences of and through these ten saudiyyat. The methodology focuses on bringing their voices away from any overused biases and analyzes the data through narrative research using my expertise as an ‘insider’ to share their suwalif in a culturally sensitive manner. The women bring forth their subjectivities and lived experiences to provoke an uneasiness in conversations around gender that create a space for questioning normative discourses of power.
Optimal Transport, Congested Transport, and Wasserstein Generative Adversarial Networks
Keywords: Congested Transport
Optimal Transport
Variational Image Restoration
Wasserstein Generative Adversarial Networks

Generative Adversarial Networks (GANs) are a method for producing a distribution $\mu$ that one can sample which approximates a distribution $\nu$ of real data. Wasserstein GANs with Gradient Penalty (WGAN-GP) [GAA+17] were designed to update $\mu$ by computing and then minimizing the Wasserstein 1 distance between $\mu$ and $\nu$. In the first part of this thesis we show that in fact, WGAN-GP do not compute this distance. Instead, they compute the minimum of a different optimal transport problem, the so-called congested transport [CJS08]. We then use this result to offer explanations of the observed performance of WGAN-GP. Our discovery also elucidates the role of the gradient penalty sampling strategy in WGAN-GP, and we show that by modifying this distribution one can ameliorate a transient form of mode collapse in the optimal mass flows. The second part of this thesis presents new algorithms for generative modelling based on insights from optimal transport theory. The basic idea is to transform one distribution into another via iterated descent with an adaptive step size on learned Kantorovich potentials computed with WGAN-GP. We provide an initial convergence theory for this technique, as well as guarantees of convergence for an extension of this procedure when the target distribution is supported on a submanifold of Euclidean space with codimension at least two. As a proof of concept, we demonstrate via experiments that this provides a flexible and effective approach for several generative modelling problems, including image generation, translation, and denoising. Further analysis of this algorithm reveals that it is connected to image restoration techniques via learned regularizers, which generalize the classical total variation denoising technique of Rudin-Osher-Fatemi (ROF) [ROF92]. We provide analogues of the results of [Mey01] on ROF to the learned regularizer setting. Leveraging this connection, we provide optimal transport versions of the iterated denoising [AXR+15] and multiscale image decompositions [TNV04] associated with ROF.
Volitional Self-regulation of Individual Neurons in Mnemonic Structures of the Brain
Keywords: Basal Ganglia
Brain Machine Interfaces
Hippocampus
Learning
Memory
Neurofeedback

Brain-machine interfaces allow us to utilize specific neural activity patterns to control a particular behaviour. By establishing a causal link between neural activity and the corresponding behaviour, brain-machine interfaces also serve as a tool for investigating mechanisms of learning and plasticity in the brain. For decades, it has been known that animals, and humans, can be trained to control neural activity in parts of the brain that are involved in producing bodily movements. However, whether this type of self-regulation can be exerted over parts of the brain that are involved in higher cognition, such as memory function, remains an open question. In this thesis, we attempt to answer this question by utilizing brain-machine interfaces to train humans and animals to self-regulate the activity of individual neurons in memory-related brain structures, particularly the hippocampus. Specifically, our objectives are to (1) determine the extent to which animals and humans can learn to self-regulate activity of neurons in memory-related brain structures, and (2) shed light on the neural and behavioural mechanisms that facilitate this type of learning. In humans, we recorded activity of single neurons in individuals with epilepsy to determine whether an arbitrarily selected neuron can be brought under volitional control. Using a visual brain-machine interface, we demonstrated that humans could learn to upregulate the activity of a selected neuron quickly and reliably. Successful learning was correlated with changes in the neural population dynamics, consisting of robust phase-locking of the trained neuron to the local alpha/beta oscillations. We also utilized a similar brain-machine interface to train rats to control the activity of small hippocampal neuronal ensembles. We demonstrated that, like humans, rats could also learn to modulate the activity of individual neurons in the hippocampus. Using video monitoring we identified behavioural correlates of this type of learning which shed light on the behavioural strategies that animals use to learn such an abstract neuroprosthetic skill. Furthermore, by recording simultaneously from multiple electrodes we also demonstrated that learning is associated with increased spike-timing precision between the hippocampus and the closely associated ventral striatum. We further discuss these findings and propose a putative basal ganglia circuit that may play a role in facilitating this type of learning. Our results demonstrate that volitional self-regulation of neural activity is possible in previously uninvestigated memory-related structures, and this type of learning may engage cortico-basal ganglia circuits in a novel manner. These findings open the possibility of utilizing such neuroprosthetic skill learning to further probe learning and plasticity in memory-related structures of the brain and develop novel neuroprosthetics that can probe memory function without any exogenous stimulation.
Civic Participation and Democratic Experience: Civic Tech in Toronto
Keywords: citizenship
civic technology
democratic participation
sidewalk toronto
systems thinking

This thesis examines intersections of civic participation and technology development in Toronto, Canada. In particular, I examine processes that configure civic participation by focussing on the way that people enrol and are enrolled by technology oriented toward the pursuit of public goods, a practice known by those involved as ‘civic tech’. Using ethnographic and action research methods, I examine processes of design and participation at multiple sites, characterised by differing levels of state and civilian involvement. In the first article, I explore the 2018-2020 corporate-run engagementprocess case of the Sidewalk Toronto smart city development, arguing that while certainly robust in scope, the process marginalised participant contributions by maintaining boundaries around key normative dimensions of the proposed smart city, especially around the governance of space, data, and other infrastructures. In the second and third article, I shift focus to Civic Tech Toronto (CTTO), a volunteer-led community group that, since 2015, has gathered civilians and public servants together at weekly hacknights, where they listen to speakers and experiment with technology projects addressing civic issues. The second article examines the governance and production of CTTO, exploring the applicability of commons based peer production language to the community and arguing that its main role as a technology itself is to produce relationships and experiences of community, rather than technological artefacts. Finally, the third article explores how CTTOs activities act as a contact zone that brings civilians and the state closer together in informal relationships. By prioritising social and self-directed cooperation, CTTO moves beyond the typical transactional nature of civic engagement (i.e. one that configures people as ‘users’ of the state or sees them as providers of informational ‘feedback’), and equips both civilians and public servants with the skills they need to interact more productively. Collectively, this research advances our understanding of the value of civic tech not only in terms of the artefacts it produces, but in the infrastructuring work it does: civic tech maintains civic commons that cultivate democratic subjects and creates spaces that ultimately help build trusting relationships between publics and public servants.
The Book of the Judgements of Calatarama: A Case Study of a Medieval Spanish Geomancy
Keywords: Divination
Geomancy
Medieval Spain

Manuscript MS 5-2-27 of the Biblioteca Colombina at the Cathedral of Seville, Spain, contains a single text, the Libro de los juysios de calatarama, the “Book of the judgements of calatarama.” Identified as a translation of a Hebrew translation of an Arabic original, the Libro de los juysios de calatarama is an instructional manual in the Castilian vernacular for a type of divination known as geomancy. Geomancy appears to have originated in the Islamic world and was later adopted in the medieval west via Latin and later vernacular translations. This study of the Libro de los juysios de calatarama contributes to research into this less well-known field of medieval divination through a close analysis of the geomantic practice the text describes. In addition, the incipit of this text identifies it as having been translated by a rabbi at the request of a bishop, and thus the Libro de los juysios de calatarama is not only a reflection of medieval geomancy but also contributes to the understanding of intercultural exchange amongst Muslims, Christians, and Jews in medieval Spain. The majority of the evidence for such intercultural exchange tends to come from the literate, scholarly milieu of medieval Spain. However, given that evidence would suggest that geomancy existed in some form at a popular level, the Libro de los juysios de calatarama provides insight into intercultural exchange at a popular level in medieval Spain. By placing the Libro de los juysios de calatarama within the historical context of both medieval geomancy and medieval Spain, this analysis of the text contributes to the research both on geomancy in particular, and divination in general, as well as to the discussion of multiculturalism in medieval Spain.