Socio-Economic Status and Community Integration: A Study of Formal and Informal Participation of Urban Migrants

The focus of this thesis is twofold, the first being theoretical, the second being methodological. Chapter I consists of a review of the migration literature, specifically that relevant to tie relationship between socio-economic status and the migrant's integration into a new community. From this review, a number of hypotheses are generated and subsequently tested employing data from the Migrant Relocation Study. Socio-economic status is postulated to be related to both formal social participation in voluntary associations and informal social participation--both important aspects of integration. The methodological portion of the thesis consists of the use of a number of methodological techniques, including specifically, index construction, a two wave path analysis and a correction for measurement error, as aids in testing the hypotheses. Factor analysis, one method of index construction is applied to the informal social participation indicators and points out that categories of social relationships are somewhat more complex than a simple kin, non-kin dichotomy which was used previously in the literature. Instead of grouping all kin together, kin can be more accurately represented by considering it to be at least three separate variables and regarding non-kin, there is reason to distinguish between friends, neighbours and co-workers. The hypotheses generated by tho review of the literature are tested using the technique of causal modelling. The particular two wave path model used to test the hypotheses is suggested by Heise (1969). It is for application to survey-type data with measurements made on the same variables and the sample at two times. The lagged paths representing the impact of one variable on another during the period between measurements are the basis for causal inference. This model, thus, allows a test of a causal relationship between socio-economic status and social participation. An important contribution in this thesis is the consideration of measurement error. This thesis attempts to take measurement error into account in solving the path model. Reliability coefficients are calculated for each indicator in the path analysis and the correlation coefficients generated from these are subsequently corrected for attenuation. These corrected coefficients are then used to test the two wave path model. The results of this thesis are not specifically conclusive. Employing the corrected model support is found for a number of the hypotheses. Results generated from the uncorrected model, however, are somewhat more problematic. Support is found for a causal effect of socio-economic status on formal social participation in voluntary associations and a weak effect in a negative direction of socio-economic status on informal social participation with kin. The analysis also suggests that the causal effect of socio-economic status on informal social participation with friends is in a positive direction and with neighbours is in a negative direction.Master of Arts (MA

Intimidation Culture: Free Expression in the Age of Social Media

While social media platforms have dramatically bolstered the ability of ordinary people to broadcast their views to large audiences, the dynamics of online communication have also had a stifling effect on public discourse. Due to social media's tendency to reward content that is extreme and divisive, it is often the case that people with more moderate views engage in self- censorship and preference falsification in order to evade online backlash. This project deploys the philosophy of the seminal liberal thinker John Stuart Mill in order to examine the phenomenon of online intimidation culture and assess its pernicious impact on society. Three social goods are identified that are jeopardized when thought and expression become constrained due to formal or informal censorship. These are critical intellectual faculties, authenticity in discourse, and equity in accountability. It is argued that those who are interested in preserving these social goods have strong grounds for resisting the pressures of intimidation culture and working to establish an atmosphere of free expression wherein people from diverse backgrounds can explore and assess a broad array of competing ideas without fear of punishment. It is likewise argued that despite the persistent toxicity of social media discourse, the societal harms that it produces can be mitigated through the cultivation of institutions that are resilient in the face of pressure campaigns, and firmly committed to intellectual diversity and freedom of expression. Finally, it is posited that social media is not inherently at odds with a Millian atmosphere of free expression. If the incentives that animate online discourse are realigned in order to encourage reasoned discourse rather than performative antagonism, then this technology could be an asset to humans' capacity for compassion by facilitating greater communication and understanding between individuals and groups from different parts of the world.DissertationDoctor of Philosophy (PhD)While social media platforms have dramatically bolstered the ability of ordinary people to broadcast their views to large audiences, the dynamics of online communication have also had a stifling effect on public discourse. Due to social media's tendency to reward content that is extreme and divisive, it is often the case that people with more moderate views engage in self- censorship and preference falsification in order to evade online backlash. This project deploys the philosophy of the seminal liberal thinker John Stuart Mill in order to examine the phenomenon of online intimidation culture and assess its pernicious impact on society. It is argued that despite the persistent toxicity of social media discourse, the societal harms that it produces can be mitigated through the cultivation of institutions that are resilient in the face of pressure campaigns, and firmly committed to intellectual diversity and freedom of expression

Speaking for the Nation: Representation through Indigenous and Minority Language Recognition in Taiwan, New Zealand and Southeast Asia

This “sandwich” dissertation argues that Indigenous and minority language recognition offers a novel way to examine how political representation unfolds in practice. I trace how group claims are articulated and institutionalized by diverse actors working within multiple settings, and how the outcomes of representational work shape perceptions of inclusion and legitimacy. The first chapter finds that Taiwan’s Council of Indigenous Peoples drives Indigenous language policy, demonstrating how representation occurs through executive rather than legislative institutions. The second chapter finds that Māori leaders and policy actors in New Zealand advanced and articulated Māori language priorities across multiple institutions. The third chapter analyzes survey data from Southeast Asia and finds that official language recognition is associated with higher perceptions of democracy and feelings of national pride among minority speakers. Together, the chapters demonstrate that language recognition is negotiated across multiple actors and sites, and can enhance legitimacy and belonging for minority communities

CHEMICAL FUNCTIONALIZATION OF CELLULOSIC MATERIALS VIA AZETIDINIUM CHEMISTRY

This proposed work explores the potential of azetidinium chemistry as a versatile platform for grafting functionalities including alkyl, alkyne, azide, and diallyl, as well as amino silicone — onto a wide range of cellulosic materials within different scales. The developed strategies enable either the functionalization of cellulosic materials to tailor their surface properties or the crosslinking of cellulosic materials to form three-dimensional hydrogels and aerogels. This thesis includes four main research as presented: First, a bifunctional azetidinium coupler was employed to graft functionalities onto carboxylate cellulosic materials. Carboxymethyl cellulose was utilized as a bridge between pulp fibres and functional groups by irreversible adsorption on the surface of pulp fibers and efficient reaction with azetidinium derivatives. Hydrophobicity was introduced through alkyl chains (C12 and C18), while bio-orthogonal reactivity was imparted via alkyne and azide functionalities, enabling further modification of paper sheets. Second, a versatile fluorescent labeling approach was developed using azetidinium–azide linkers, which allowed efficient conjugation with commercially available dyes such as FAM-alkyne and Cy5-alkyne. This method enabled labeling across all scales of cellulosic materials — including CNCs, CNFs, BC, and pulp fibers — without altering their morphology, providing a powerful tool for cellulose imaging and distribution studies. Third, a three-dimensional biomaterials ink was formulated by modifying CMC and CNCs with azetidinium–diallylamine. The resulting inks exhibited excellent shear-thinning and rapid thixotropic recovery, enabling high-fidelity extrusion printing. Incorporation of azetidinium–alkyne-modified CMC further enabled selective functionalization of specific regions within printed hydrogels, opening new possibilities for spatially controlled bioprinting applications. Finally, a water-soluble azetidinium-functionalized amino silicone was synthesized and applied in the fabrication of hydrophobic CNC/silicone aerogels through a water-based process. These aerogels demonstrated tunable mechanical properties, remarkable shape recovery (>90%) under repeated compression, and outstanding performance in solvent absorption, solvent–water separation, and thermal insulation.ThesisDoctor of Philosophy (PhD)Cellulose, the main building block of plant fibers, is one of the most abundant and sustainable materials on Earth. By breaking it down into very small structures such as nanocrystals and nanofibrils, researchers can create lightweight, strong, and biodegradable materials for applications ranging from packaging and water purification to biomedical devices. However, to fulfill more requirements in applications, cellulose often needs to be modified to add new properties. In this work, we developed a simple, water-based chemical tools using azetidinium chemistry to attach useful functions to cellulose. These functions include making cellulose surfaces water-repellent, adding fluorescent tags for imaging, or allowing the material to form three-dimensional structures like hydrogels and aerogels. This research demonstrates environmentally friendly ways to expand how cellulose can be used in new fields

Double Exponential Cubature Kalman Filtering

Gaussian filtering supports many estimation tasks, yet real systems present nonlinearity, outliers, and model mismatch. This thesis advances the methodology and practice of such filters in two parts. First, it develops the Double Exponential Cubature Kalman Filter (DECKF), which evaluates Gaussian-weighted moments using a double exponential cubature rule with positive weights and a scalable point set. The analysis clarifies accuracy and stability as the number of cubature points grows, observes positive-definiteness behavior in the prediction and update steps, and provides tuning guidance that accommodates cubature point count, process and measurement covariances, and numerical conditioning. An additional robust correction strategy, the Double Exponential Sliding Innovation Filter (DE-SIF), constrains the measurement update within a sliding boundary layer to limit the influence of abnormal innovations while preserving the standard Kalman structure and compatibility. Second, the thesis studies performance in a demanding condition monitoring problem. The DECKF is combined with an interacting multiple model framework and is compared against the EKF and UKF on a mode-switching magnetorheological damper governed by Bouc-Wen dynamics. The study quantifies force-estimation accuracy, correlation with reference force, detection performance across operating modes, and statistical consistency via normalized innovations and related tests. Results show that the IMM-DECKF delivers strong force tracking and consistent innovations with competitive detection performance, and that its benefits grow with careful cubature point selection and covariance tuning. Beyond the specific damper experiment, the proposed DE cubature rule and sliding innovation strategy apply to broader estimation tasks where Gaussian filters are standard, including target tracking, navigation, and control, and offer practical guidance on stability, tuning, and diagnostics.The work presented in this thesis was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) through Alliance grant ALLRP 561511-20

Three Essays in Health Economics

This thesis comprises three essays in health economics. Chapter 1, co-authored with Dr. Michel Grignon, examines how minimum wage increases affect access to employer-sponsored prescription drug insurance. Using cross-sectional data linked with provincial minimum wages changes from 2008 to 2019, the study identifies threshold effects: increases of 20–30 cents reduce coverage by about three percent, with the strongest impacts among women, young workers, immigrants, and racial minorities. Chapter 2 evaluates the impact of the Ontario Health Insurance Plan Plus (OHIP+), introduced in 2018 to provide free prescription drug coverage to residents under 25. Applying event study and Difference-in-differences methods with administrative emergency department data, the analysis finds no overall effect on utilization but reveals significant declines among low-income households. This suggests that improved drug access reduced reliance on emergency departments as a substitute source of medication. Chapter 3 investigates how a cancer diagnosis influences household spending patterns by linking the Canadian Cancer Registry with household expenditure survey data. The results show an average decline in total spending of about seven percent following a diagnosis, with the largest reductions in food and income tax expenditures. Although budget shares remain broadly stable, heterogeneity analysis reveals meaningful reallocations across families with and without children, single parents, and younger households. In contrast, subsequent diagnoses generate smaller adjustments.DissertationDoctor of Philosophy (PhD)This thesis examines the effects of Canadian public policies on prescription drug access and healthcare utilization, as well as how health shocks influence household spending decisions. The first chapter asks how raising the minimum wage influences workers' access to drug benefits from their employers. It shows that when the minimum wage rises by a certain amount, some workers—especially women, young people, immigrants, and racial minorities—are less likely to have drug coverage through their jobs. The second chapter examines whether Ontario’s OHIP+ program, launched in 2018 to provide free coverage for prescription drugs to everyone under the age of 25, had any effect on visits to the emergency department. While the program did not change overall emergency department visits among young people, it did reduce visits for those from low-income families. This suggests that before OHIP+, some youth may have gone to the emergency department to get medicines they could not otherwise afford. The third chapter looks at how a cancer diagnosis changes family budgetary decisions. It finds that affected households cut their total spending and shift money around—for example, reducing food spending and increasing spending on housing and healthcare

Modeling and Experimental Characterization of Core Loss of A Switched Reluctance Machine

Core loss significantly impacts the efficiency and thermal performance of Switched Reluctance Machines (SRMs), especially under high speeds. Conventional measurement methods are often inadequate for capturing losses in assembled stator cores, where flux paths are complex, and excitation waveforms are non-sinusoidal. This thesis addresses these limitations by developing and experimentally validating a practical core loss characterization method tailored for SRM stators. The study begins with a comprehensive review of core loss mechanisms and measurement challenges, highlighting the effects of manufacturing processes such as punching and welding on material properties. A core loss measurement method is introduced based on transformer induction theory, enabling time-domain reconstruction of magnetic field quantities from voltage and current waveforms. The method is validated using a ring core and SRM stator geometry with finite element analysis (FEA), replicating practical excitation conditions. An experimental setup is built with a fractional SRM stator core and custom magnetizing yokes. The experimental setup captures induced voltage and current waveforms from the stator. The proposed method is experimentally validated over a wide frequency range from 100 Hz to 10,000 Hz and under varying flux density levels, confirming the applicability for practical core loss characterization of SRM stators

Selenium and Placental Trophoblast Cell Health

Coal mining accelerates the release of selenium (Se) into the environment, where it bioaccumulates through the food chain and increases human exposure. Se is an essential trace element, but Se deficiency and Se excess have been associated with adverse pregnancy outcomes linked to placental dysfunction. Cell culture studies show that Se can increase reactive oxygen species (ROS) in placental trophoblast cells, potentially impairing cell health. This study explored the effects of Se exposure on placental trophoblast cell health and tested the hypothesis that NaSe exposure induces ROS accumulation, leading to reduced placental cell health. This thesis also investigated if ferroptosis, cellular senescence, or apoptosis are induced following exposure to Se and the mechanisms underlying these effects. HTR-8/SVneo cells, a placental trophoblast cell line, were treated with environmentally relevant sodium selenite (NaSe) concentrations (0.1, 0.2, 0.5, 1, 2 µM) for 24 hours. ROS production and mRNA expression of genes related to ferroptosis, senescence, and apoptosis were measured. I evaluated key components of ferroptosis (cellular iron content, the accumulation of malondialdehyde, and LDH release), senescence (ß-galactosidase staining), and apoptosis (TUNEL-based assay) using commercially available kits. To explore mediators underlying apoptosis, I assessed ER stress using an inhibitor experiment, followed by assessing the effect of ER stress on angiogenesis. NaSe treatment at the highest concentration (2 µM) caused a significant increase in ROS production alongside altered mRNA expression of key markers indicative of ferroptosis, senescence, and apoptosis. However, NaSe treatment did not affect functional measures of ferroptosis or cellular senescence. 2 µM of NaSe increased apoptosis, an effect which appeared to be related to increased gene expression of ER stress markers ATF4 and CHOP. To confirm NaSe could directly increase ER stress, cells were co-treated with 4-phenylbutyric acid (4PBA), an ER stress inhibitor. 4PBA blocked the NaSe-induced increase of ATF4 and CHOP. Despite the increase in ER stress, NaSe treatment did not affect angiogenesis. Given the rise in anthropogenic activities is increasing our exposure to Se, further research is needed to understand the mechanisms by which increased Se impacts mammalian reproductive function.ThesisMaster of Science in Medical Sciences (MSMS)Selenium (Se), a naturally occurring trace element, is required for key physiological functions like antioxidant defense, but too much Se can have negative effects on health. Coal mining activities can accelerate the release of Se into the environment; this has been linked adverse reproductive outcomes in fish and wildlife, but the effect of high Se exposure on human reproductive function is unclear. This study explored how Se affects the placenta, a critical organ during pregnancy. Using placental cells, we tested different concentrations of Se and measured its effect on cell health and function. Increased Se exposure generated reactive oxygen species and triggered apoptosis, a form of programmed cell death. Further, it increased gene expression of endoplasmic reticulum (ER) stress markers, which we could inhibit, confirming Se’s ability to promote ER stress. These findings explain how increased Se may harm placental health and contribute to adverse pregnancy outcomes

Towards a neurocomputational and dynamical understanding of rumination

Selena Singh PhD thesis, supervised by Dr. Suzanna Becker.Ruminative brooding, the maladaptive repetitive dwelling on abstract, self-referential thoughts, is a transdiagnostic feature of many psychiatric disorders, yet its neurocognitive mechanisms remain poorly understood. Brooding is both repetitive and perseverative, implicating deficits in cognitive control and maladaptive emotion regulation. We investigated these properties using experimental psychology, computational modeling, network neuroscience, and dynamical systems approaches. First, we reported brooding-associated inhibitory control deficits that were exacerbated by emotional cues, as reflected by performance on Stroop interference tasks. Numerically fitting parallel distributed processing models to participant Stroop data revealed a set of brooding-associated parameters that reflected network sensitivity to changing task demands and activity persistence of emotional processes, but not cognitive control processes. Next, we analyzed relationships between self-regulatory processes and brooding, and their corresponding EEG functional connectivity patterns. We found evidence of internal resistance to emotions and thoughts in brooding. Furthermore, functional connectivity patterns indicated that brooding and emotion dysregulation co-varied with aberrant top-down modulation from prefrontal regions to emotion and interoceptive systems, potentially reflecting compensatory regulation of internal emotional states. Finally, we proposed that brooding is an emergent property of an attractor state within the brain’s default mode network (DMN). Here, we hypothesised that brooding-related attractor dynamics would produce stable, recurrent neural dynamics that resist perturbation. Supporting this, DMN regions demonstrated persistent activity when switching from a cued rumination to a working memory task, consistent with resistance of ruminative thought to perturbation. In addition, nonlinear analyses of the recurrence properties of EEG demonstrated a positive association between brooding and neural recurrence, further supporting this attractor state hypothesis. Together, these studies advance a mechanistic understanding of brooding from neurocomputational, network, and dynamical perspectives