VictorJuiz/thesis huggingface dataset:
Decolonizing Indigenous Youth Studies: Photography and Hip Hop as Sites of Resilience

This dissertation examines the role an arts-based educational program played in unleashing youth's creativity as they confront various structures of power that become challenges to social identity, belonging, and self, under different local and national circumstances. My research questions considered how Indigenous youth utilized a photography and hip hop based educational program as a resource to explore social identity and relations, indigeneity, place/space, and the legacy of settler colonialism on education. I also considered how the findings from this study informed and contribute to decolonize Indigenous youth studies and how programs such as mine help Indigenous youth comprehend crisis in the urban environment. This critical ethnography found that in some cases cultural and racial identity existed more internally than externally for youth, with the complexities and contradictions the Indigenous Young Adults (IYAs) face when coming to terms with their social identity. The results showed how much youth grapple with the idea of looking Native and the desire to be more phenotypically Indian as defined by dominant society. The stories of the IYAs became vital to learning about the challenges they faced and obstacles they have overcome, including fighting for recognition under the Indian Act, border politics within Canada and the US, not knowing one's traditional land, and barriers to migrating to the city independently of one's family. Regarding the legacy of settler colonialism on education, of particular interest was how schooling upholds settler colonial ideals and what we can do to dismantle these ideals so that our students are represented in truthful ways. The findings indicated how youth learned about Indigenous cultures in schools and how they were represented in the curriculum. Throughout this project the intent was to propose ways to decolonize education through the arts. It also revealed the positive accomplishments that IYAs worked towards and the ways they show extreme resilience in the light of legacies of settler colonialism on their communities.

Advisor: McCready, Lance T
Therapeutic Effects of Intravenous Immunoglobulin, Platelet Transfusion and B Cell Depletion on Murine Immune Thrombocytopenia (ITP)

Immune thrombocytopenia (ITP) is an autoimmune disease characterized by an isolated thrombocytopenia and increased tendency of bleeding. The pathogenesis of ITP includes both decreased platelet production by megakaryocytes in the bone marrow and increased peripheral platelet destruction in the spleen due to antibody- and T cell-mediated immune responses against self platelet antigens. To better understand the disease and its therapies, I carried out three projects focusing on antibody-mediated ITP, T cell-mediated ITP and the relationship between the two immune pathways. In the first project, I examined the number and morphology of bone marrow megakaryocytes after induction of acute thrombocytopenia by anti-platelet antibodies with different specificities and isotypes. Most of the antibodies did not appear to alter megakaryocyte morphology or maturation within 24 hours. Moreover, although IVIg therapy successfully rescued the thrombocytopenia, it did not exhibit any significant effect on the megakaryocytes. Second, using an active ITP mouse model, I investigated the effect of allogeneic platelet transfusion therapy on T cell-mediated ITP. I found an immunosuppressive effect of the allogeneic transfusions on the T cell-mediated ITP associated with a decrease in the cytotoxic activity of CD8+ T cells in vitro and normalized megakaryocyte number/morphology in the bone marrow. Third, to investigate the relationship between B and T cells in ITP, I depleted B cells in vivo and examined the changes in T cell-mediated ITP. CD8+ T cell-mediated ITP was found ameliorated after B cell depletion therapy and was associated with a decreased proliferation of CD8+ T cells that could be rescued with interleukin (IL)-2 in vitro. This study provided a novel explanation for the therapeutic effect of B cell depletion in ITP and suggests a synergistic role between B cells and T cells in initiating the disease. In summary, this thesis revealed a lack of effect of anti-platelet antibodies on megakaryocytes suggesting that T cells may be involved in mediating bone marrow effects in ITP. Related to the T cells, it further elucidated the therapeutic effects of platelet transfusions and B cell depletion therapy on T cell-mediated ITP. These results may be of importance in decisions regarding the management of ITP.

Keywords: autoimmune disease
B cell depletion
CD20 antibody
immune thrombocytopenia
intravenous immunoglobulin
platelet transfusion
Advisor: Semple, John W.
A Bridging Cell Multiscale Methodology to Model the Structural Behaviour of Polymer Matrix Composites

Composite and nanocomposite materials exhibit behaviour which is inherently multiscale, extending from the atomistic to continuum levels. In composites, damage growth tends to occur at the nano and microstructural scale by means of crack growth and fibre-matrix debonding. Concurrent multiscale modeling provides a means of efficiently solving such localized phenomena, however its use in this application has been limited due to a number of existing issues in the multiscale field. These include the seamless transfer of information between continuum and atomistic domains, the small timesteps required for dynamic simulation, and limited research into concurrent multiscale modeling of amorphous polymeric materials. The objective of this thesis is thus twofold: to formulate a generalized approach to solving a coupled atomistic-to-continuum system that addresses these issues and to extend the application space of concurrent multiscale modeling to damage modeling in composite microstructures. To achieve these objectives, a finite element based multiscale technique termed the Bridging Cell Method (BCM), has been formulated with a focus on crystalline material systems. Case studies are then presented that show the effectiveness of the developed technique with respect to full atomistic simulations. The BCM is also demonstrated for applications of stress around a nanovoid, nanoindentation, and crack growth due to monotonic and cyclic loading. Next, the BCM is extended to modeling amorphous polymeric material systems where an adaptive solver and a two-step iterative solution algorithm are introduced. Finally, the amorphous and crystalline BCM is applied to modeling a polymer-graphite interface. This interface model is used to obtain cohesive zone parameters which are used in a cohesive zone model of fibre-matrix interfacial cracking in a composite microstructure. This allows for an investigation of the temperature dependent damage mechanics from the nano to microscale within polymer matrix composites due to transverse loading. Results from the simulations indicate that the BCM creates a seamless coupling between continuum and atomistic domains for crystalline material systems while substantially reducing force imbalance for amorphous material systems. Multiscale simulation results of the composite microstructure indicated that the model accurately predicted both quantitative (elastic modulus, strength, stress-strain response) and qualitative behaviour when compared to experimental results from the literature.

Keywords: Composites
Computational Mechanics
Damage Machanics
Multiscale Modeling
Advisor: Behdinan, Kamran
Research Ethics in the Ontario College Sector: An Exploratory Descriptive Study of Governance and Administrative Frameworks

The purpose of this study was to explore the existing frameworks for the governance and administration of research ethics policies and practices in place at the Ontario Colleges of Applied Arts and Technology (CAATS), and to identify implications for policy and practice related to the future governance and administration of research ethics at Ontario CAATs. This study examined four key areas associated with the management of compliance with ethics principles related to research conducted at the 22 English language Ontario colleges: the history of the establishment of Research Ethics Boards in the Ontario college sector; what currently exists, in terms of relevant policies, processes, funding and infrastructure at participating colleges; what currently works within the sector, to ascertain areas for improvement; and implications for future policy and practice. Lewin's (1947a) Theory of Planned Change formed the basis of the theoretical framework for this study. College employees responsible for the administration of research ethics and REB Chairs at the participating colleges were the key informants; research ethics administrators from all 22 English language colleges in Ontario were invited to complete an online questionnaire, and interviews were conducted with eight REB Chairs or their designate from a stratified purposeful sample of the English language colleges. The conclusions drawn from this study suggest that numerous driving and restraining forces exist to support and challenge the governance and administration of research ethics at participating colleges, and that these forces can be effectively addressed to improve the governance and administration of research ethics across the Ontario college sector. The study findings may inform policy and practice that could enhance the governance and administration of research ethics for the ultimate benefit of enhancing the culture of applied research and innovation, not just at the colleges that participated in this study, but also at other colleges and institutes across Canada and internationally that may face similar challenges.

Keywords: Administration
Applied research
College
Ethics
Governance
Organizational behaviour
Advisor: Janzen, Katharine
Evolution and Genetics of Plant Sex Chromosomes

Sex chromosomes have evolved multiple times independently in different lineages and the parallel changes that have occurred during their formation suggest that there are general processes driving their evolution. In this thesis I used a variety of approaches, including genetic crossing experiments, mathematical modeling, and statistical analysis of DNA sequence data to study the evolution and genetics of sex chromosomes, focusing on the recently evolved X and Y chromosomes in the plant Rumex hastatulus. I developed methods to identify sex-linked genes using segregation analysis and transcriptome sequencing, and found that both ancestral and neo-Y chromosomes in R. hastatulus have started to genetically degenerate, causing ∼28% and ∼8% hemizygosity of ancestral and derived X chromosomes, respectively. Genes remaining on Y chromosomes also accumulated more amino acid replacements, contained more unpreferred changes in codon use, and exhibited significantly reduced gene expression compared with their X-linked alleles. This genetic degeneration is consistent with theoretical predictions of reduced Y-linked selection efficacy caused by suppressed recombination. My results indicate that the magnitude of genetic degeneration depends on the time since X-Y recombination became suppressed. I also found that diversity on the Y was 40-fold lower than on the X, and nearly 50-fold lower than on autosomes, indicating that selective interference has played a significant role in reducing nucleotide polymorphism during the early stages of X-Y divergence. I also developed a theoretical model to investigate the interactions between sex chromosomes, haploid-phase selection, and selection on the sex ratio. The model's results indicate that biased sex ratios can be evolutionarily stable when there is a trade-off between Fisherian selection on the sex ratio and selection for purging deleterious mutations in the haploid phase. This finding provides a novel evolutionary explanation for biased sex ratios in dioecious plants, where haploid-phase selection is widespread. In conclusion, my analyses indicate that the evolution of sex chromosomes from autosomes can result in significant changes to effective population size, recombination rate, and patterns of gene expression, all of which have important implications for DNA sequence evolution, including the effectiveness of natural selection, rates of molecular evolution, and patterns of genetic diversity.

Keywords: evolutionary biology
molecular evolution
population genetics
sex chromosomes
Advisor: Barrett, Spencer C.H.
Wright, Stephen I.
Experiential Learning in Undergraduate Pharmacy Curriculum: A Case Study of Co-operative Experience of Pharmacy Students

This research study explores the co-operative experience of undergraduate pharmacy students with a focus on its influence on the students’ professional and personal development. The data was collected through semi-structured interviews and focus groups with 19 pharmacy students from the first graduating class in this program, 12 co-op employers, and 12 faculty members. The impact of experiential learning on the professional and personal development of undergraduate pharmacy students during their co-op experiences was multi-dimensional. While students believed that they gained self-confidence and achieved self-discovery and career-related discovery after their co-op placements, their professional and personal development could be driven by their own motivation and personality. Co-op employers and the co-op sites did play a role in influencing students’ individual development. Despite the unstructured and inconsistent nature of co-op, it was evident that co-op offered students the opportunity to explore the diversity of the pharmacy profession. Students should take ownership of their learning and faculty should supplement students’ learning by using teaching moments at school to reinforce and re-align the knowledge and skills acquired in the classroom and those gained during real-world practice. Based on my research, I was able to propose a model of co-op experience integrated in the four stages of Kolb’s experiential learning cycle. I concluded that a hybrid of both structured and unstructured experiential learning for pharmacy students might be an ideal curricular model.

Keywords: Co-operative Experience
Experiential Learning
Health Professions
Personal Development
Pharmacy
Professional Development
Advisor: Austin, Zubin
Fine-grained Adaptivity for Dynamic On-chip Networks

A key challenge of building chip multiprocessors (CMPs) is providing an efficient communication infrastructure for their increasing communication demands. Networks-on-Chip (NoCs) offer a scalable, high-bandwidth, low-latency solution to this problem, but unfortunately incur significant area and power overheads. Current NoCs are mostly agnostic to application requirements and hence are statically provisioned for worst-case traffic scenarios, leading to wasted energy and performance. Based on our observations that a static NoC design cannot optimally support the constantly changing communication requirements of modern, multi-threaded applications, this dissertation proposes fine-grained adaptivity for NoCs. Fine-grained adaptive NoCs provide the ability to adjust NoC resources to the dynamically changing communication requirements during runtime. Specifically, we introduce three novel, adaptive NoC designs that each target a particular area of fine-grained adaptivity. Firstly, we focus on dynamically changing bandwidth requirements and propose fine-grained bandwidth adaptivity. Existing NoCs only use 5% of channel resources on average to avoid performance penalties during phases of high utilization. Our architecture uses fine-grained bandwidth-adaptive bidirectional channels and exploits temporal and spatial variations in bandwidth requirements to improve channel utilization. Our second proposed design focuses on variations in communication locality for hierarchical NoCs. Previous hierarchical NoCs support communication locality only for a fixed cluster of nodes; however, providing a fixed hierarchy is too restrictive in terms of parallelism and data placement. Therefore, we propose a new, more flexible class of hierarchical NoCs: Elastic Hierarchical NoCs. Elastic Hierarchical NoCs dynamically adjust the number and size of clusters during runtime according to the system's communication demands. Our third proposed design targets the prediction of fine-grained variations in communication requirements for dynamic voltage and frequency scaling (DVFS). Efficient DVFS relies on accurate predictions of future network state. While previous approaches are reactive and based on network-centric metrics, we find that these metrics lead to suboptimal DVFS decisions. Instead, we propose to utilize highly predictable properties of cache-coherence communication to derive more specific and reliable NoC traffic predictions. These three innovative designs advance the state-of-the-art by allowing NoCs to adapt to spatially and temporally changing communication requirements during runtime; thereby significantly improving their performance and energy efficiency.

Keywords: chip multiprocessor
computer architecture
many-core
Network-on-Chip
NoC
Advisor: Enright Jerger, Natalie
Weak Value Amplification of a Post-selected Single Photon

Weak value amplification (WVA) is a measurement technique in which the effect of a pre- and post-selected system on a weakly interacting probe is magnified. In this thesis, I present the first experimental observation of WVA of a single photon. We observed that a signal photon - sent through a polarization interferometer and post-selected by photodetection in the almost-dark port - can act like eight photons. The effect of this single photon is measured as a nonlinear phase shift on a separate laser beam. The interaction between the two is mediated by a sample of laser- cooled 85Rb atoms. Electromagnetically induced transparency (EIT) is used to enhance the nonlinearity and overcome resonant absorption. I believe this work to be the first demonstration of WVA where a deterministic interaction is used to entangle two distinct optical systems. In WVA, the amplification is contingent on discarding a large portion of the original data set. While amplification increases measurement sensitivity, discarding data worsens it. Questioning whether these competing effects conspire to improve or diminish measurement accuracy has resulted recently in controversy. I address this question by calculating the maximum amount of information achievable with the WVA technique. By comparing this information to that achievable by the standard technique, where no post-selection is employed, I show that the WVA technique can be advantageous under a certain class of noise models. Finally, I propose a way to optimally apply the WVA technique.

Keywords: Cold Atoms
Nonlinear Optics
Quantum Optics
Weak Measurement
Advisor: Steinberg, Aephraim M
Functional Nanomaterials for Gas-phase Heterogeneous Photocatalysis: Toward Efficient Solar Fuel Production

Harnessing abundant solar energy to facilitate the capture and conversion of greenhouse gas CO2 into carbon-based fuels and chemical feedstocks represents a significant scientific challenge with implications for both climate change and sustainable energy production. Herein, we have demonstrated that highly defected indium oxide, In2O3-x(OH)y, nanoparticles can function as effective gas-phase photocatalysts for CO2 reduction to CO via the reverse water gas shift (RWGS) reaction. Significantly we have found that the presence of both oxygen vacancies and surface hydroxide groups are necessary to facilitate the reaction. Using transient absorption spectroscopy we demonstrated that these defects play a significant role in the excited state charge relaxation pathways, with higher defect concentrations resulting in longer excited state lifetimes, which is attributed to electron and hole trapping in oxygen vacancies and surface hydroxide groups, respectively. This supports the proposed surface Frustrated Lewis Pair (FLP) reaction mechanism, in which a surface active site composed of a Lewis acidic, coordinatively unsaturated indium atom, created by the presence of an oxygen vacancy, adjacent to a Lewis basic hydroxide, assists the adsorption and heterolytic dissociation of H2, which then enables the adsorption and reaction of CO2 to form CO and H2O. Preliminary results indicate that photogenerated electron and hole localization in these defects enhances their Lewis acidity and basicity, lowering the activation energy for the RWGS reaction under illumination. Finally, we demonstrated that by evenly dispersing In2O3-x(OH)y nanoparticles on vertically aligned silicon nanowires (SiNW), we can increase reaction rates by improving reflective losses and facilitating light trapping in the region of the solar spectrum where In2O3-x(OH)y absorbs. Further, by using the photothermal properties of the SiNWs, the light energy not absorbed by In2O3-x(OH)y can be converted into localized heat energy, removing the need for external heating and improving the overall energy efficiency of the process.

Keywords: Artificial photosynthesis
Carbon dioxide
Indium oxide
Metal oxides
Nanoparticles
Solar fuels
Advisor: Ozin, Geoffrey A
A Simple Animal Model for Characterizing Gene Reglatory Control of an Immune Response

A robust but tightly regulated system of innate gut immunity is required for maintaining gut homeostasis. Given the complex nature of the mammalian gut, a simple yet phylogenetically relevant model is useful to decipher the underlying molecular controls that sustain this balance. Here I use the purple sea urchin larva as a morphologically simple model for these studies. I approach this problem with three interrelated strategies: (1) Characterization of larval immunocytes based on morphology, cell behaviour and gene expression, (2) analysis of gene activity in a model of gut-associated immune response to bacteria and (3) regulatory analysis of selected response genes. I characterize five larval cell types that are active in gut immunity and develop a gut associated infection model using the bacterium Vibrio diazotrophicus. RNA-seq analysis of this model is used to identify immune genes that are differentially expressed over the course of infection. Member of the sea urchin IL-17 multigene family are identified as immune response genes. One subfamily, SpIL-17-I, is expressed early upon exposure to V. diazotrophicus in the mid- and hindgut and is then attenuated. BAC-based GFP transgenes and smaller reporter constructs recapitulate endogenous SpIL-17-I expression. Regulatory regions are defined upstream and downstream of the IL-17 coding sequence. Deletions of critical elements results in a decrease or absence of IL-17 expression but never ectopic expression or expression in the absence of immune stimulus. Downstream function of IL-17 was investigated by perturbing its receptors using Morpholino antisense oligonucleotides. In addition to physiological changes in the larva, expression of several immune effector genes are downregulated in IL-17R perturbed embryos. Collectively this work suggests that a core network of regulatory circuitry is shared with the vertebrates in the gut associated immune response even in this simple larval form. This can then form the basis for more elaborate network analysis of gut immunity in future studies using this model.

Keywords: comparative immunity
gut immunity
IL-17
innate immunity
sea urchin
Advisor: Rast, Jonathan P