VictorJuiz/thesis huggingface dataset:
Elongation Factor P-Dependent Translation and Metabolic Phenotypes of Salmonella
Keywords: Elongation factor
itaconate
ribosome
Salmonella
succinate
Translation

The facultative intracellular pathogen Salmonella has acquired adaptations contributing to virulence, including pathogenicity islands and regulatory alterations. Elongation factor P (EF-P) is a universally conserved translation factor, and deletion of efp in Salmonella results in pleiotropic phenotypes, including hyperactive metabolism, reduced stress resistance, and avirulence. Crystal structures demonstrated that EF-P adopts the shape of a tRNA and binds to the ribosome to stimulate peptide bond synthesis. Preliminary analyses suggested that EF-P is not a general translation factor but rather influences a specific subset of proteins. In this thesis I investigate the mechanism underlying EF-Pâ s impact on translation and how its deletion leads to the observed phenotypes. I present the Salmonella EF-P-dependent proteome, and particular proteins offer explanations for efp mutant phenotypes. Meanwhile, other groups discovered that EF-P rescues ribosomes stalled at polyproline motifs. I expand upon their work and show that polyproline motifs are not strictly necessary or solely sufficient to render a protein dependent on EF-P. I demonstrate that residues upstream of the polyproline motif significantly influence stall strength. Furthermore, translation initiation rate greatly impacts EF-P-dependence. I present a model wherein elongation stalls only reduce protein synthesis if they are more rate-limiting than translation initiation. While examining efp mutants, I discovered a novel phenotype of wild-type Salmonella. When dicarboxylates are the sole carbon source, Salmonella represses its growth using the general stress response sigma factor RpoS, the RpoS-stabilizer IraP, and repression of the dicarboxylate transporter DctA. Moreover, E. coli does not exhibit this phenotype and the E. coli dctA promoter is sufficient to induce Salmonella growth. This divergence suggests a potential role in virulence, and I examine the accumulation of succinate and itaconate in activated macrophage. I demonstrate that the dicarboxylate phenotype does not influence intracellular survival, and I propose novel hypotheses of why Salmonella has evolved this trait.
Problematizing Transition to Adulthood for Young Disabled People
Keywords: critical qualitative inquiry
disability
multimethods approach
parental perspectives
policy analysis
transition to adulthood

The purpose of this critical qualitative study was to understand how transition to adulthood for young people with developmental disabilities (DD) is constituted as a ‘problem’ in policies and practices across sectors in Ontario and the implications for these young people and their parents. This transition to adulthood has been identified as a policy problem in three provincial government sectors in Ontario, Canada—rehabilitation, education, and developmental services. The problem is predominantly framed as a service transition issue, particularly when young people ‘age out’ of pediatric health services by age 19 and public education by age 21, and seek adult-oriented programs and services. Transition policies have been developed in each sector, shaped by both explicit and implicit understandings of key concepts, such as disability and adulthood. These understandings function to constitute transition as a particular kind of problem, and play a key role in what is considered and proposed to address it, but also what is not considered or potentially neglected or even ignored. What is and is not considered has implications for the health and daily lives of young disabled people and their families. Guided by a problem-questioning approach to policy analysis proposed by Carol Bacchi, I used a multimethod design, including analysis of three policy documents and in-depth interviews with 13 parents, to examine how transition to adulthood is constituted as a problem. My analysis revealed that normative assumptions about ways of being, becoming, and acting as an adult shaped an implied problem of disabled children and their inadequate progression to socially valued adult roles and activities. Policies shaped by these assumptions had both positive (e.g., feelings of self-worth for achieving or approximating socially valued roles and activities) and unintended negative effects (e.g., social exclusion, stress or anxiety when adult roles were not achieved) on young disabled people and their parents. These findings highlight opportunities for rethinking the policy problem in ways that can mitigate unintended harmful consequences on young people with DD and their families and for improving their health and daily life circumstances through healthy public policy and cross-sector coordination.
Lexical Knowledge and Bilingual Reading: Within- and Cross-language Associations of Paradigmatic and Syntagmatic Knowledge in English and Mandarin
Keywords: Bilinguals
English and Mandarin
Lexical knowledge

The cross-language relationship of lexical knowledge between typologically dissimilar languages has not received much attention in previous studies. The relationship between lexical depth and reading comprehension in English and Mandarin was thus investigated in two studies. In Study 1, 139 Mandarin-English speaking children (n= 87, aged 8-9 years; n= 52, aged 10-11 years) completed parallel measures of two aspects of lexical depth, paradigmatic and syntagmatic knowledge in both English and Mandarin, along with measures of lexical breadth and non-verbal reasoning. Regression analyses showed a cross-language relationship for paradigmatic but not syntagmatic knowledge for both the younger and older children. In Study 2, the same children were measured for working memory, word reading, morphological awareness and reading comprehension in both languages in addition to the measures used in Study 1. Paradigmatic knowledge was found to be a significant predictor of reading comprehension in both languages but syntagmatic knowledge was a unique predictor only for comprehension in Mandarin for both age cohorts. A cross-language relationship was only observed in the older children between Mandarin paradigmatic knowledge and English reading comprehension. Study 1 results provide evidence of a link between the mental lexicons of both languages in Mandarin-English speaking children at the paradigmatic level. Study 2 findings point to the importance of lexical depth in reading comprehension in both English and Mandarin. The cross-language paradigmatic knowledge-reading comprehension link was found in bilingual children learning contrasting languages but was limited to older children. These findings have implications for instructional practice to facilitate lexical development in bilingual children.
The Role of Uric Acid in Renal and Cardiovascular Function in Patients with Uncomplicated Type 1 Diabetes Mellitus
Keywords: Cardiovascular Function
Renal Function
Type 1 Diabetes
Uric Acid

Patients with type 1 diabetes (T1D) have a 30% lifetime risk of developing diabetic nephropathy (DN) despite the use of current available therapies. It is of paramount importance to identify agents that protect patients with T1D from the initiation and progression of DN. Unfortunately, recent renal protection trials in patients with T1D have either failed, demonstrated harm or reported effects that are far below expectations based on data from experimental models. Accumulating evidence suggests that plasma uric acid (PUA) is associated with multiple key pathways involved in the pathogenesis of diabetic complications, including metabolic, cardiovascular and renal abnormalities. Our work is focused on elucidating the pathophysiologic role of PUA in renal and cardiovascular function in patients with T1D. We showed that PUA levels are surprisingly lower in adolescents and young adults with T1D compared to healthy controls (HC) due to glycosuria, which stimulates increased PUA excretion, likely through the GLUT9 isoform 2 transporter. Despite having lower PUA levels, adolescents and young adults with exhibit a negative correlation between PUA and glomerular filtration rate (GFR), possibly due to increased afferent renal arteriolar resistance and reduced renal perfusion. In the context of previous experimental work, our observation suggests that PUA may mediate afferent renal arteriolar disease, causing ischemia to the renal microcirculation, thereby potentiating renal injury. Although not observed in T1D adolescents, the association of higher PUA levels with higher blood pressure emerged in the young adults with T1D. In our final set of experiments, lowering PUA with febuxostat (FBX) for 8 weeks had a modest blood pressure lowering effect in young adults with T1D. FBX enhanced the renal filtration fraction response to clamped hyperglycemia through an increase in efferent renal arteriolar resistance without impacting the RAAS, suggesting that PUA may augment other vasoconstrictor or vasodilatory mechanisms leading to an augmented renal hemodynamic response to hyperglycemia. Longitudinal outcome trials are required to determine whether our physiologic findings impact renal or cardiovascular outcomes in response to PUA lowering therapies in patients with T1D.
Ancestral and Spiritual Naming of Children among the Jopadhola Lwo of Eastern Uganda
Keywords: Anticolonial Education
Anticolonialism
Decolonization
Indigenous African Knowledge
Indigenous Education
Social Justice

This study brings Indigenous understandings to the anti-colonial resistance by the Jopadhola Lwo people of Eastern Uganda. The Jopadhola Lwo people link with ancestors in the naming ceremonies for their children. For the study, I employed Indigenous methodology to understand how a minority people resist assimilation. I interviewed elders in Dhopadhola Lwo. The Indigenous methodology is the Padhola elders’ agency for educating the researcher. The study objectives investigated: the Indigenous naming practices and how these are understood in contemporary contexts; the Indigenous practices and the possibilities for decolonization; the understanding of the interface of society, culture, and Nature, the nexus of body, mind, and soul, and the spirit from naming ceremonies of Padhola; and the implications for transforming schooling in African and Euro-American contexts. The research findings revealed: 1. Name variations of Padhola with ongoing ceremonies for Apipili and Yao Rut. 2. Resistance to foreign names as Njawala or twigs. 3. Sacred monotheist Indigenous religion thrives with Kuunu shrines. 4. Ancestors reveal children’s names in dreams. 5. Indigenous education resists Christianity. 6. The Jopadhola elders are not worth their salt if they do not resist foreign influence and advocate for a return to traditional education.
Convexity and Cohomology of the Based Loop Group
Keywords: based loop group
convexity
moment map
symplectic geometry

Let K be a compact, connected, simply connected Lie group and define ΩK to be the loops on K. Let ΩalgK be those loops which are the restriction of algebraic maps Cx → Kc. Herein we establish two distinct but related results. In the first, we demonstrate the module structure for various generalized abelian equivariant cohomology theories as applied to equivariantly stratified spaces. This result is applied to the algebraic based loop group for the cases of equivariant singular cohomology, K-theory, and complex cobordism cohomology. Subsequently, we examine the image of the based loop group under the non-abelian moment map. We show that both the Kirwan and Duistermaat convexity theorems hold in this infinite dimensional setting.
A Robust Hierarchical Control Structure for Virtual Power Plants
Keywords: Hierarchical Control Structure
Linear Matrix Inequality
Microgrids
Robust Control
Virtual Power Plants

This dissertation discusses the principles of operation and control requirements of Virtual Power Plants (VPPs). Based on the identied characteristics and performance requirements of VPPs, this dissertation then proposes a robust hierarchical control structure to operate a microgrid in the VPP and islanded modes and to provide a smooth transition between these two modes. Various sources of uncertainties and disturbances aecting dynamics of a microgrid with multiple distributed energy resource (DER) units in both the VPP and islanded modes of operation are identied and classied as local and interconnection uncertainties and exogenous disturbances. An integral quadratic constraint framework is introduced to mathematically represent these perturbations. Based on the obtained uncertain system model, a necessary and sucient condition is proposed to nd robust, decentralized, output-feedback, reference-tracking, local controllers (LCs) for DER units which (i ) guarantee the robust stability of the overall microgrid, and (ii ) ensure disturbance rejection. Rank constrained linear matrix inequalities (LMIs) are further derived to systematically design these LCs. This decentralized structure of LCs constitutes the primary level of the proposed hierarchical control structure. At the secondary level, a robust H1, multivariable, LMI-based, PI control strategy augmented with static, multivariable, LMI-based anti-windup compensator is proposed and designed to operate a microgrid in the VPP mode. The proposed control strategy (i ) guarantees the stability of the overall, closed-loop, unconstrained microgrid while achieving a pre-determined disturbance attenuation level, and (ii ) guarantees the stability of the constrained microgrid while demonstrating graceful performance degradation during controller windup. Furthermore, to operate a microgrid in the islanded mode, a decentralized, droopaugmented, robust voltage control structure is introduced that is composed of: (1) a P- and a Q-V droop-based power sharing controller, (2) the proposed robust LCs, and (3) an open-loop frequency controller. This dissertation adopts frequency-domain and digital time-domain simulation tools, i.e., MATLAB and PSCAD/EMTDC platforms, respectively, to evaluate the attributes and performance of the proposed hierarchical control structure.
From Toronto First Duty Vision to Policy Reality: Scaling Up, Watering Down in the Provincial Implementation of Full-day Kindergarten at the Bruce/WoodGreen Demonstration Site
Keywords: Change
Full-day kindergarten
Integration
Leadership
Quality

Ontario’s Full-day Kindergarten (FDK) evolved in part out of Toronto First Duty (TFD), a demonstration project and feasibility study of integrated early childhood programs delivered through a partnership spanning different auspices. TFD used a model in which kindergarten, child care and other services provided an integrated program. This study tracks the evolution of the FDK program using a case study of Bruce Public School. Through a partnership with WoodGreen Community Services this site became part of TFD and evolved into the internationally known Bruce/WoodGreen Early Learning Centre (BWELC). At full implementation, BWELC provided a full-day, play-based, high quality program for 4-year-old and 5-year-old children, delivered by an integrated staff team, with wrap-around, comprehensive child care. It became the seed for the “scaling up” of Ontario’s FDK program. In more recent years, changes to the staffing and program delivery models with the roll-out of FDK have impacted the early learning experience in a way that might be considered “watering down.” This study aims to tell the story of what occurred at BWELC and why it happened, focusing on the cornerstones of quality and staff integration, moving from initial vision to current reality. Building on the research of the TFD project, the current study continued to employ a case study approach and mixed methods, combining both qualitative and quantitative forms of inquiry. Data were collected using the Early Childhood Environment Rating Scale–Revised, the Toronto Operating Criteria, the Indicators of Change tool, a parent/guardian survey and key informant interviews. The study approach involved three intersecting conceptual frameworks: Theory of change, integration/integrated services, and leadership. A concurrent triangulation approach was used to examine convergence among the data sources. The findings point to reductions in integration and leadership as Bruce Public School adopted the scaled-up system of FDK and to the effects of these key challenges on quality. The study contributes to our understanding of elements that need to be in place to provide high quality early learning environments and provides suggestions for further systems change to address the shortfalls in Ontario’s current FDK program and to continue the transformation into an effective system.
Structural and Vascular Changes Following Laser for Diabetic Macular Edema
Keywords: blood flow
diabetes
diabetic macular edema
laser photocoagulation

Diabetic Retinopathy (DR) and Diabetic Macular Edema (DME) represent ocular complications of diabetes and DME is the leading cause of severe vision loss. This work investigated morphology, function, and circulation in patients with newly diagnosed DME in order to elucidate fundamental steps of the pathogenesis of DME development and resolution following laser treatment. Using the Canon Laser Blood Flowmeter, we investigated parameters of retinal blood flow (RBF) (diameter, velocity, and blood flow) in patients with newly diagnosed DME and compared with a control (non - diabetic) group. We assessed RBF parameters in patients with DME undergoing focal/grid laser photocoagulation. Using Spectral â Domain Optical Coherence Tomography (SD-OCT), we investigated and compared values of choroidal thickness (ChT) using enhanced depth imaging (EDI) and regular imaging (RI) acquisition approaches. Also, using SD-OCT, we examined morphological retinal changes induced by focal / grid laser photocoagulation. The correlation analysis revealed moderate agreement between EDI and RI at the temporal and nasal areas and poor agreement in the central choroidal area. There was a tendency for ChT values to be higher using RI approach than EDI. There was a trend for retinal blood velocity to be higher in patients with DME compared to controls but this difference was not significant. We demonstrated that there was no significant change in RBF parameters following the three, seven and thirty days post focal / grid laser photocoagulation. These results are the first to show simultaneous measurements of RBF parameters in patients with DME following laser and provided initial values for sample size calculation for the future studies. We found a significant reduction of total retinal volume and retinal thickness in the section of most edema between the 3 and 30 days of follow-up. The evaluation of histological retinal details revealed restoration of the external limiting membrane/photoreceptor complex which suggests mechanisms of retinal healing and reorganization. Future studies are needed to further elucidate the evidence in support of these theories on structural and vascular development of DME and post laser treatment.
Balanced Presentations of the Trivial Group and 4-dimensional Geometry
Keywords: balanced presentations
geometry
group theory

We construct a sequence of balanced presentations of the trivial group with two generators and two relators with the following property: The minimal number of relations required to demonstrate that a generator represents the trivial element grows faster than the tower of exponentials of any fixed height of the length of the finite presentation. We prove that 1) There exist infinitely many non-trivial codimension one "thick" knots in R5; 2) For each closed four-dimensional smooth manifold M and for each sufficiently small positive ε the set of isometry classes of Riemannian metrics with volume equal to 1 and injectivity radius greater than ε is disconnected; and 3) For each closed four-dimensional PL-manifold M and any m there exist arbitrarily large values of N such that some two triangulations of M with < N simplices cannot be connected by any sequence of < expm( N) bistellar transformations, where expm( N) = exp(exp(...exp(N))) (m times). We construct families of trivial 2-knots Ki in R4 such that the maximal complexity of 2-knots in any isotopy connecting Ki with the standard unknot grows faster than a tower of exponentials of any fixed height of the complexity of Ki. Here we can either construct Ki as smooth embeddings and measure their complexity as the ropelength (a.k.a the crumpledness) or construct PL-knots Ki, consider isotopies through PL knots, and measure the complexity of a PL-knot as the minimal number of at 2-simplices in its triangulation. For any m we produce an exponential number of balanced presentations of the trivial group with four generators and four relations of length N such that the minimal number of Andrews-Curtis transformations needed to connect any two of the presentations is at least expmi(N).
Width, Ricci Curvature, and Bisecting Surfaces
Keywords: conformal geometry
geometric inqualities
homological filling
quantitative geometry
Ricci curvature

In this thesis we studied width-volume inequalities, bisecting surfaces in three spheres, and the planar case of Larry Guth's sponge problem. Our main result is a width-volume inequality for conformally non-negatively Ricci curved manifolds. We obtain several estimates on the size of minimal hypersurfaces in such manifolds. Concerning geometric subdivision and 3-spheres, we give a positive answer to a question of Papasoglu . Regarding the sponge problem, we show that any open bounded Jordan measurable set in the plane of small area admits an expanding embedding in to a strip of unit height. We also prove that a generalization of the planar sponge problem is NP-complete. This thesis is partially based on joint work with Ye. Liokumovich and Z. Zhu.
Impact of Climate Change on Winter Road Systems in Ontario's Far North: First Nations' and Climatological Perspectives on the Changing Viability and Longevity of Winter Roads
Keywords: Climate Change
Climate modeling
First Nations
Northern Ontario
Winter roads

Climate change is already being experienced in Ontario’s Far North with implications for First Nations communities that are reliant on winter road systems. The first study of this thesis examined how winter road seasons have been affected historically by particular climate conditions by focusing on the timing of opening dates of the James Bay Winter Road (JBWR). This study established a minimum threshold of 380 freezing degree-days (FDDs) below 0°C, a threshold subsequently used to assess the impacts of climate change on winter road systems in the future using climate change projections. The second study explored the current vulnerability of the Fort Albany First Nation community regarding physical, social/cultural, economic impacts associated with changing winter roads and its seasons, as well as river ice regimes. Through the analysis of key informant interviews and winter road user surveys on the changes in winter roads and river ice regimes, the six major themes were identified. As a result, the JBWR has now become a critical seasonal lifeline for not only providing a relatively inexpensive land transport of essential goods and supplies, but also reconnecting coastal remote communities by physical, social, and cultural activities during winter. The third study focused on the viability and longevity of winter road systems in Ontario’s Far North for the next century using recent climate model projections using three Representative Concentration Pathway (RCP) scenarios. Using FDD threshold established in the first study as the main metric, climate conditions are expected to remain favourable in Big Trout Lake and Lansdowne House during winter road construction through the end of 2100. However, climate conditions would possibly be unfavourable for winter road construction at Moosonee, Kapuskasing, and Red Lake by 2041−2070. These studies demonstrate that there is an immediate need to develop adaptation strategies in response to impacts of climate change on winter roads in Ontario’s Far North.