VictorJuiz/thesis huggingface dataset:
Predictors of Hospitalization Among Cystic Fibrosis Patients in Ontario
Keywords: cystic fibrosis
Hospitalization
epidemiology
health services utilization
gender

This dissertation involved linking a clinical cystic fibrosis (CF) data registry with administrative databases to evaluate clinical, demographic, and geographical predictors of hospitalization in CF patients living in Ontario over a 10 year period. In addition, this work assessed the ability of administrative data to identify individuals with CF using the clinical registry as the reference standard. Sex was an independent predictor of hospitalization rates for individuals with CF. Females had a significantly higher hospitalization rate compared to males even after adjusting for important clinical factors suggesting that this finding is not simply due to worse CF disease. In those between 7 and 19 years of age, the adjusted hospitalization rate was 38% higher in females (rate ratio[RR] 1.38, 95% confidence interval [CI] 1.11-1.73). Similarly in those over the age of 19, females had a 30% higher hospitalization rate compared to males (RR 1.30, 95% CI 1.06-1.59). Other significant predictors associated with higher hospitalization rates in both age groups were lower lung function, worse nutritional status, pancreatic insufficiency, and the presence of CF-related diabetes. The presence of Burkholderia cepacia complex in the sputum was a significant predictor in those over the age of 19 years (RR 1.54, 95% CI 1.26-1.89). Distance to CF centre, community size and socioeconomic status were not significant predictors of hospitalization rates in either age group. There was no significant trend in hospitalization rates over time once rates were adjusted for markers of disease severity (p=0.08). Comparing administrative data with the CF registry data, administrative data captured hospitalizations more comprehensively. Despite CF being a specific diagnosis, health administrative databases alone were insufficient to reliably and accurately identify individuals with CF unless they had been hospitalized. The reason for the gender disparity seen within this dissertation is likely multifactorial. There may be differences in outpatient management between the sexes, hormonal influences may modulate disease severity causing higher hospitalization rates, and patient and provider-level influences may affect the decision to hospitalize a patient. Further research is needed in this area to elucidate the factors contributing to this gender gap.
National Fate and Empire: George Grant and Canadian Foreign Policy
Keywords: Canadian Foreign Policy
Political Thought

This study examines the foreign policy views of the Canadian thinker, George Grant. It focuses on the years between Mackenzie King’s re-election in 1935 and the Liberal party’s return to power under Lester Pearson in 1963. During this period, Grant argued, Canada was transformed from a British dependent to a satellite of the United States, a process that he believed had been accelerated by the continentalist economic and security policies of successive Liberal governments. As a young man during World War II, Grant admired the United States of F. D. Roosevelt. But as he began to contemplate the threat that a postwar Pax Americana posed to the societies of the Old World, and, ultimately, to Canada, his misgivings grew. His attempts to understand the emerging order led him to a critical study of modern liberalism, which he believed provided the chief philosophical justification for America’s expansion. Unlike Marxists who saw liberalism as simply an ideology of individual greed, Grant claimed that it succeeded largely by appealing to our hopes for social progress. These hopes found their loftiest expression in the belief that liberalism’s internationalization would produce the conditions for the overcoming of war within and between nations. Grant feared that this ideal could only be achieved through the annihilation of all real cultural diversity—the realization of what he called the universal and homogeneous state. One of his unique claims was that the Liberal policy of rapprochement with the United States after 1935 signaled the growing dominance of this ideal within Canada. This dominance was fed during the Cold War by “realists” like Pearson who decried the utopianism of communism, while failing to reckon with the utopian aspirations of his own society. Fearful of Marxist one-worldism, Pearson committed himself to a single-minded defence of a liberal order that tended to produce even greater homogeneity around the world. Grant’s own practical aim in writing about foreign policy, I argue, was neither to defend liberalism against its “utopian” critics, nor to reject it for an alternative like Marxism, but to highlight the utopian aspirations of liberal society, and thereby subject it to the moderating influence of doubt.
Electromagnetically Induced Exciton Dynamics and Bose-Einstein Condensation near a Photonic Band Gap
Keywords: Quantum Well Exciton
Photonic Band Gap
Bose-Einstein Condensation
Antibunching

We demonstrate electromagnetically-induced anomalous quantum dynamics of an exciton in a photonic band gap (PBG) - quantum well (QW) hetero-structure. Within the engineered electromagnetic vacuum of the PBG material, the exciton can propagate through the QW by the emission and re-absorption of virtual photons in addition to the conventional electronic hopping mechanism. When the exciton wavevector and recombination energy coincide nearly with a photonic band edge, the exciton kinetic energy is lowered by 1-10meV through coherent radiative hopping. This capture of the exciton by the photonic band edge is accompanied by strong electromagnetic dressing in which the exciton's renormalized effective mass is 4-5 orders of magnitude smaller than in the absence of the PBG environment. This dressed exciton exhibits a long radiative lifetime characteristic of a photon-atom bound state and is robust to phonon-assisted, re-combinative decay. By inheriting properties of the PBG electromagnetic vacuum, the bound electron-hole pair becomes a stable, ultra-mobile quantum excitation. Unlike traditional exciton-polariton modes created by placing a QW in a one-dimensional optical cavity, our PBG-QW excitons exhibit strong coupling to optical modes and retain a long lifetime. This is crucial for unambiguous observation of quantum coherence effects such as Bose-Einstein condensation. We present a model for the equilibrium quantum statistics of a condensate of repulsively interacting bosons in a two-dimensional trap. Particle correlations in the ground state are treated exactly, whereas interactions with excited particles are treated in a generalized Bogoliubov mean-field theory. This leads to a fundamental physical picture for condensation of interacting bosons through an anharmonic oscillator ground state coupled to excited Bogoliubov quasiparticles in which the quantum number statistics of condensate particles emerges self-consistently. Our anharmonic oscillator model for the exciton ground state manifold goes beyond the conceptual framework of traditional Bogoliubov theory. Below the Bose-Einstein condensation temperature, our model exhibits a crossover from particle bunching to Poissonian statistics and finally antibunching as temperature is lowered or as the trapping area is decreased. When applied to Bose condensation of long-lived dressed excitons in a photonic band gap material, our model suggests that this system may serve as a novel tunable source for non-classical states of light.
Molecular Evolution of Visual System Genes in Fishes
Keywords: Molecular Evolution
Opsins
Crystallins
Fishes

For many species, vision contributes to a number of fitness-related tasks, including mating and the detection of prey and predators. Selection on the visual system should therefore be strong, especially when ecological or genomic changes open new avenues for evolutionary changes. Visual system proteins are thus attractive systems for molecular evolutionary analyses. This thesis presents a collection of evolutionary studies on two gene families, opsins and crystallins. Opsin proteins determine the wavelengths of light detected by the retina, while crystallin proteins contribute to lens transparency and refractory power. My studies focus on teleost fishes, because teleost visual ecology is exceptionally diverse and because gene duplication is common in this group. In Chapter One, I outline the relevance of protein variation to organismal evolution and describe the analytical methods employed throughout this thesis. Chapter Two considers the long-wavelength sensitive (LWS) opsins of the guppy (Poecilia reticulata). The guppy is shown to possess multiple LWS opsins that have accumulated differences at functionally important amino acid sites since duplicating. Chapter Three focuses on the guppy’s main predator, the pike cichlid Crenicichla frenata, which is shown to have a greater capacity for short-wavelength vision than previously believed. However, this cichlid possesses three fewer opsins than closely-related African cichlids, a difference partly due to duplication of a green-sensitive (RH2) opsin in African cichlids. In Chapter Four, this RH2 duplication event is studied in greater depth; variation in selective constraint is documented following gene duplication and between species from different lakes. Some of the analytical methods employed in Chapter Four were newly developed, as detailed in Chapter Five, where a test for functional divergence among clades is evaluated and then improved upon through the presentation of a new null model that better accommodates among-site variation in selection. In Chapter Six, phylogenetic relationships within the βγ lens crystallin superfamily are clarified, and the functionally distinct γN family is shown to have evolved conservatively compared to other crystallin families. The thesis concludes with suggestions for future directions for evolutionary research on opsins and crystallins, and summarizes recent work that has built on these studies.
Danger Signal in a Rat Model of Nevirapine-induced Skin Rash
Keywords: pharmaceutical science, toxicology
nevirapine, reactive metabolites, skin rash, immune response, danger signals

Nevirapine (NVP) can cause serious skin rashes and hepatotoxicity. It also causes an immune-mediated skin rash in rats but not hepatotoxicity. There is strong evidence that the rash is due to 12-hydroxynevirapine (12-OH-NVP), which is further metabolized to a reactive benzylic sulfate in the skin. This could both act as a hapten and induce a danger signal. In contrast, most of the covalent binding in the liver appears to involve oxidation of the methyl group leading to a reactive quinone methide. In this study we examined the effects of NVP and 12-OH-NVP on gene expression in the liver and skin. Both NVP and 12-OH-NVP induced changes in the liver, but the list of genes was different, presumably reflecting different bioactivation pathways. In contrast, many more genes were up-regulated in the skin by 12-OH-NVP than by NVP, which is consistent with the hypothesis that the 12-hydroxylation pathway is involved in causing the rash. Some genes up-regulated by 12-OH-NVP were Trim63, S100a7a, and IL22ra2, etc. Up-regulation of genes such as S100a7a, which is considered a danger signal, supports the danger hypothesis. Up-regulation of genes such as the ubiquitin ligase and Trim63 are consistent with protein-adduct formation. Up-regulation of IL-22ra2 gene suggests an immune response. These results provide important clues to how NVP causes induction of an immune response, in some cases leading to an idiosyncratic drug reaction.
Leading Diverse Schools: Tempering Accountability Policy with Social Justice
Keywords: leadership
social justice
accountability policy
equity

This qualitative research examines how school principals perceive social justice and accountability, the actions they take, and the reasoning process they use in their attempt to satisfy accountability mandates while simultaneously tackling the various causes of social injustices in their schools. This constructive study aims to gain an in-depth understanding of the world from the subjects’ points of view, to unfold the meaning of their experiences, and to uncover their lived world. It employs semi-structured interviews with open-ended questions guided by the conceptual framework developed from review of literature on social justice, educational leadership, and accountability policy. Twenty-two school principals and vice-principals from the Greater Toronto Area (GTA) were interviewed. The findings show that some participants define social justice as equity, which goes from the economic and political dimensions of resource distribution and equality of opportunity and access, to the cultural aspect of social representation and inclusion. Some view public education as a social justice endeavour with a particular reference to the purpose of public education. Others construe social justice by focusing on its end goal – the academic and social outcomes of students and the impact on their lives. Study participants implement their social justice beliefs and values in praxis by engaging all stakeholders and catalyzing them to be the new force for the social justice movement. Evident in this study is that participants enacted their social justice practices by putting students at the centre, positioning themselves as social justice leaders, developing people for social justice, building school climate through justice, and fostering positive relationship with families and communities. Under current accountability context, principals in this study responded to the current reform by going beyond its narrow focus through instilling a sense of moral responsibility in their perceptions of accountability itself. As social justice activists, they are proactively engaged in expanding its parameters by encompassing the moral, social, and professional aspects of their accountability. Leading for social justice thus becomes a process of constantly confronting and tearing down such obstacles and barriers by leveraging the politics of accountability and social justice to move towards what is best for students.
Talker Discrimination, Emotion Identification, and Melody Recognition by Young Children with Bilateral Cochlear Implants
Keywords: cochlear implants
talker discrimination
emotion identification
music recognition

Users of cochlear implants typically have difficulty differentiating talkers, identifying vocal expressions of emotion, and recognizing familiar melodies because of the degraded spectral cues provided by conventional implants. This thesis examined these abilities in a small, relatively privileged sample of young bilateral implant users. In Study 1 child implant users and a control sample of hearing children were required to judge whether various utterances were produced by a man, woman, or girl (Experiment 1) and to identify the voices of cartoon characters from familiar television programs (Experiment 2). Child implant users’ performance on talker classification was comparable to that of hearing children. Their identification of cartoon characters’ voices was less accurate than that of hearing children but well above chance levels. These findings challenge conventional wisdom about the talker identification difficulties of implant users. In Study 2 the children were required to indicate whether semantically neutral utterances (Experiment 1) or classical piano excerpts (Experiment 2) sounded “happy” or “sad”. In both cases, implant users performed less accurately than hearing children but well above chance levels. Although the findings on emotion recognition in music are in line with those of previous research, the findings on emotion in speech are at odds with claims that young implant users are insensitive to vocal affect. In Study 3 the children were required to identify the theme songs from familiar television programs on the basis of combined timing and pitch cues as well as timing or pitch cues alone. Implant users’ performance was comparable to that of hearing children except when the cues were restricted to pitch relations, which resulted in performance at chance levels. The findings suggest that the musical representations of young implanted listeners include precise information about timing and coarser information about pitch. They also demonstrate, for the first time, that children, both implant users and those with normal hearing, can identify familiar music on the basis of timing cues alone. Overall, the findings highlight the importance of timing cues for implant users, the range of individual differences, and habilitation possibilities for the recognition of talkers, emotion, and music.
Resolution of Singularities of Pairs Preserving Semi-simple Normal Crossings
Keywords: resolution of singularities
simple normal crossings
semi simple normal crossings
desingularization invariant
Hilbert-Samuel function.

Let X denote a reduced algebraic variety and D a Weil divisor on X. The pair (X,D) is said to be semi-simple normal crossings (semi-snc) at a in X if X is simple normal crossings at a (i.e., a simple normal crossings hypersurface, with respect to a local embedding in a smooth ambient variety), and D is induced by the restriction to X of a hypersurface that is simple normal crossings with respect to X. For a pair (X,D), over a field of characteristic zero, we construct a composition of blowings-up f:X'-->X such that the transformed pair (X',D') is everywhere semi-simple normal crossings, and f is an isomorphism over the semi-simple normal crossings locus of (X,D). The result answers a question of Kolla'r.
Automated Quantitative Analysis of Bone Stability and Tumour Burden in the Metastatic Rat Spine
Keywords: Biomedical Engineering

The spine is the most common location of metastatic disease in the skeleton. The occurrence of bone metastasis can lead to severe clinical consequences and a significant decline in quality of life. The evaluation of metastatic disease in the spine has to date been mainly qualitative. More widespread access to multiple imaging modalities has motivated the development of 3D methods to quantitatively evaluate metastatic disease in the spine. Quantitative evaluation is important both in assessing stability of the metastatic spine and the progression/ response of the tumour and bone to treatment over time. Previous studies quantifying stability in the metastatic spine have focused primarily on osteolytic tumours. Local and systemic treatments have impacted the nature of vertebral metastasis, increasing the occurrence of mixed osteolytic and osteoblastic disease. Thus, it is important to focus analyses on models able to accurately represent diverse distribution patterns found in bony metastasis. Preclinical models are widely used in studying the process of metastasis and are able to represent both osteolytic and osteoblastic disease. This proposal aims to establish the biomechanical implications of metastatic disease in the spine through the evaluation of stability and tumour burden in a preclinical model using a multifaceted engineering-based approach. It is hypothesized that the use of automated analysis techniques applied to multimodality imaging will allow quantification of the impact of metastasis on biomechanical stability, tumour burden and bony architecture in the spine, and motivate prediction models that accurately reflect vertebral integrity in both osteolytic and mixed osteolytic/osteoblastic models of spinal metastasis. Specifically, this work aims to: 1) Utilize and compare μMR and μCT based radiologic methods to quantify tumour involvement and vertebral architecture in a rat model of spinal metastasis; and 2) Evaluate the ability of 2D, 3D, and continuum based methods to quantify structural integrity in vertebral metastasis. Overall, this work will focus on developing automated methods to quantify stereologic parameters, and quality in the metastatic spine and the evaluation of stability measures from 2D structural rigidity, Finite Element analysis, image registration and experimental methods. Ultimately this work will yield automated analysis techniques and evaluate the abilities of these methods to predict failure in metastatic vertebrae.
Development of a Comprehensive Ex-vivo Technical Skills Curriculum for an Advanced Minimally Invasive Surgical Procedure
Keywords: curriculum
technical skills
simulation
education

It is well recognized that a certain component of surgical residency training has transitioned from the operating room to the surgical skills lab. Although a significant amount of important work has validated simulators as viable systems for teaching technical skills outside the operating room, the next step is integrating simulators into a comprehensive curriculum. Several frameworks for curricular design have been described in the literature; however, few curricula have been described or validated for minimally invasive surgical procedures. This study describes the design and validation of a comprehensive technical skills curriculum for laparoscopic colorectal surgery, an advanced laparoscopic procedure. The initial step in this project utilized the Delphi consensus methodology to develop a procedure-specific evaluation tool for laparoscopic colorectal surgery. This evaluation tool demonstrated reliability and validity in the context of expert and novice performance in the operating room. The next phase of the project also used the Delphi method to develop international consensus on a proficiency-based virtual reality program designed to teach the technical skills necessary to perform laparoscopic colorectal surgery. This virtual reality training program was then integrated into a comprehensive curriculum consisting of psychomotor training on the virtual reality simulator, as well as cognitive training and a cadaver lab. The final component of this project was a randomized single-blinded controlled trial that demonstrated that surgical residents who participated in the comprehensive curriculum exhibited superior technical skills in the operating room, and superior cognitive knowledge relating to laparoscopic colorectal surgery, compared to residents who received only conventional residency training.