VictorJuiz/thesis huggingface dataset:
Modifiers of the Kidney Response to Activation of the Renin-Angiotensin System: ACE2 and Adiponectin

The renin-angiotensin system (RAS) and the generation of angiotensin II (Ang II) play a central role in promoting kidney disease, but our understanding of the regulation of RAS in the kidney is incomplete. In this context, I examined the interactions between two factors, ACE2 and adiponectin, and the RAS. ACE2 is a recently discovered homologue of ACE. I studied the impact of ACE2 gene deletion on the early phase of inflammation in ischemia-reperfusion (I/R) injury when the RAS is activated. ACE2-/- mice exhibited a marked increase in the inflammatory response, cellular apoptosis and oxidative stress to renal I/R injury. These findings show that ACE2 is an important determinant of I/R injury, a model of acute kidney injury.Adiponectin is produced by adipocytes and its circulating levels decline in obesity. I studied direct interactions between Ang II and adiponectin on cell signaling and activation of NADPH oxidase activity. The rationale for this study is based on the recognition that obesity is an emerging epidemic and it is associated with both increased risk for chronic kidney disease (CKD) and reduced levels of adiponectin. Kidney tubular cells expressed adiponectin receptors and adipoR1-mediated activations of AMPK and cAMP-Epac signaling attenuated Ang II-induced NADPH oxidase activity, NFκB activation, and fibronectin expression. These findings show that adiponectin can protect kidney cells, and that obesity-associated declines in circulating adiponectin may contribute to the link between CKD progression and obesity. Diabetic nephropathy (DN) is also associated with activation of the RAS. I therefore studied the impact of adiponectin gene deletion on the development of DN. Adiponectin-/- mice with diabetes exhibited an exaggerated renal hypertrophic response and more severe albuminuria. Glomerular injury was also greater in the adiponectin-/- mice with diabetes. Deletion of the gene for adiponectin led to increased αSMA expression, collagen IV deposition, and macrophage infiltration in the kidney. In vitro studies showed that adiponectin inhibited high glucose-induced activation of mTOR, TGF-β1, NFκB, and NADPH oxidase in glomerular mesangial cells. These findings show that adiponectin modulates the kidney response to high glucose both in vivo and in vitro.In summary, my studies show that ACE2 and adiponectin are important determinants of kidney injury, at least in part due to their effects on Ang II and high glucose in the kidney.

Keywords: ACE2
adiponectin
diabetes
nephropathy
renin-angiotensin system
Advisor: James, W Scholey
Disclosure of Genetic Information for Personalized Nutrition and Change in Dietary Intake

Background: Personal genetic information has become increasingly accessible as a result of consumer genetic tests. Proponents claim that the information may motivate positive behavioural changes aimed at chronic disease prevention, however, the effects of disclosing genetic information on dietary behaviour have not been well explored.Objectives: To determine the effects of DNA-based dietary advice on intakes of caffeine, vitamin C, added sugar and sodium, as well as to explore individual perceptions of genetic testing and personalized nutrition. Methods: A randomized trial was conducted with men and women aged 20-35 years (n=138). Subjects in the intervention group (I) were given DNA-based dietary advice and those in the control group (C) were given general dietary recommendations. Food frequency questionnaires were collected at baseline, 3- and 12-months and general linear models were used to compare changes in intake between groups. A survey was completed at baseline, the intervention point, and 3- and 12-months to assess perceptions between groups. The chi-square test and Wilcoxon signed-rank test were used to compare responses.Results: Subjects in the intervention group were more likely to agree that the advice would be useful when considering diet (88% [I] vs. 72% [C]; p=0.02). A significant reduction in sodium intake was observed at 12-months among subjects who received DNA-based advice when compared to the control group (mean ± SE: -287.3 ± 114.1 mg/day [I] vs. 129.8 ± 118.2 mg/day [C]; p=0.008). Compared to baseline, subjects rated higher agreement with the statement "I am interested in the relationship between diet and genetics" at 3-months (mean change ± SD: 0.28 ± 0.99, p=0.0002) and 12-months (0.20 ± 1.04, p=0.02). The majority of subjects indicated that a university research lab (47%) or healthcare professional (41%) were the best sources for obtaining accurate personal genetic information, while direct-to-consumer genetic testing company received the fewest selections (12%). Most subjects (56%) considered registered dietitians to be the best source of personalized nutrition.Conclusions: These findings demonstrate that DNA-based dietary advice is more effective than general dietary recommendations at motivating individuals to adopt dietary changes for certain nutrients, and therefore, may be more useful for chronic disease prevention.

Keywords: Genetic testing
Health Behaviour
Nutrigenomics
Nutrition
Advisor: Ahmed, El-Sohemy
Phasgonophora sulcata Westwood (Hymenoptera: Chalcididae): A Potential Augmentative Biological Control Agent For The Invasive Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) in Canada

The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an invasive pest of ash (Fraxinus spp.) in North America. Since its accidental introduction in the early 1990's, A. planipennis has killed millions of ash trees in 22 states and 2 provinces. The widespread establishment of this pest has made eradication impossible. Therefore, long-term management protocols that minimize future populations to non-damaging levels are required. One possible management strategy is biological control using parasitic wasps. In Canada, an endoparasitic chalcidid wasp, Phasgonophora sulcata Westwood, has demonstrated potential as possible augmentative biological control agent of A. planipennis. Unfortunately, very little information exists concerning the interactions of this wasp and its hosts. The goal of my work was to determine the information necessary for both evaluating its effectiveness as an augmentative biological control agent and to provide information that would be useful for parasitoid production and release. I conducted four studies that addressed this problem, specifically (1) determination of the species' basic life history characteristics; (2) analysis of the wasp's courtship behaviours and elucidation of adult-produced pheromones; (3) identification of semiochemicals used in host searching; and (4) observations on the within-tree and temporal distributions of P. sulcata and other parasitoids in A. planipennis-infested sites in Southwestern Ontario. My results indicate that P. sulcata possesses several characteristics associated with effective biological control agents, including synchronization with the preferred host stage, low super-/multiparasitism, and high egg loads at emergence. However, its solitary and delayed development reduces the feasibility of mass rearing. Natural populations may however be effective in areas of high host densities or where augmentation is possible.

Keywords: Biological Control
Chemical Ecology
Emerald Ash Borer
Entomology
Forestry
Phenology
Advisor: Sandy, M. Smith
A Study of the Information Practices of Afghan Newcomer Youth in the Contexts of Leisure and Settlement

AbstractThis exploratory, qualitative study examines the information seeking, sharing and use of young Afghan newcomers to Canada. Through in-depth interviews with seven youth, supplemented by key informant interviews and extensive participant observation, I examined the information practices of youth in the contexts of leisure and settlement. The findings point to the challenges youth faced in meeting their information needs, as well as the complexity, nuance and tension youth found in their leisure pursuits. Leisure was not a single, unified concept for newcomer youth, and the activities youth took part in included a wide range of pleasures, with some constraints and even contradictions as well. By offering a snapshot of the lives and information practices of a group of newcomer youth, this research makes a contribution to information studies research as it adds to the growing body of human information behaviour (HIB) literature regarding the information practices of immigrants and refugees. It documents the information practices and leisure of newcomers, focusing on two understudied groups - refugees and youth - but also uniquely situates these practices within the broader context of settlement. The contextualization of HIB research on immigrants and refugees is vital if we are to better understand newcomers' lives and practices, as well as design and deliver services that meet their needs.

Keywords: Afghan
Canada
Immigration
Information
Leisure
Settlement
Advisor: Nadia, Caidi
The Topology and Geometry of Hyperk채hler Quotients

In this thesis we study the topology and geometry of hyperkähler quotients, as well as some related non-compact Kähler quotients, from the point of view of Hamiltonian group actions. The main technical tool we employ is Morse theory with moment maps. We prove a Lojasiewicz inequality which permits the use of Morse theory in the non-compact setting. We use this to deduce Kirwan surjectivity for an interesting class of non-compact quotients, and obtain a new proof of hyperkähler Kirwan surjectivity for hypertoric varieties. We then turn our attention to quiver varieties, obtaining an explicit inductive procedure to compute the Betti numbers of the fixed-point sets of the natural S^1-action on these varieties. To study the kernel of the Kirwan map, we adapt the Jeffrey-Kirwan residue formula to our setting. The residue formula may be used to compute intersection pairings on certain compact subvarieties, and in good cases these provide a complete description of the kernel of the hyperkähler Kirwan map. We illustrate this technique with several detailed examples. Finally, we investigate the Poisson geometry of a certain family of Nakajima varieties. We construct an explicit Lagrangian fibration on these varieties by embedding them into Hitchin systems. This construction provides an interesting class of toy models of Hitchin systems for which the hyperkähler metric may be computed explicitly.

Keywords: Higgs bundle
hyperkähler quotient
integrable system
Morse theory
quiver variety
symplectic geometry
Advisor: Lisa, C Jeffrey
Kernel Machines are Not Black Boxes - On the Interpretability of Kernel-based Nonparametric Models

Kernel-based nonparametric models are often perceived as uninterpretable black boxes. This notion is however questionable; permutation-based variable importance, for example, is one approach for interpreting various nonparametric models. Unfortunately, besides being computationally intensive, permutation-based variable importance is merely a predictor importance measure for supervised regression analysis, and is inapplicable for unsupervised models. This thesis overcomes these issues by using the gradient of kernel-based nonparametric functions to interpret kernel-based models. In particular, the gradient of a kernel regression function can produce variable importance scores with significant computational advantage over permutation-based variable importance. Gradient information can further reveal predictor-response association structure through dimension reduction and graphical analysis; a property not enjoyed by variable importance scores. Most importantly, kernel methods embody a family of supervised and unsupervised learning techniques, and gradient information can be used to interpret not only supervised kernel models, but also unsupervised ones. This fact is demonstrated by using gradient information to interpret the co-dependence structures, as discovered by kernel canonical correlation analysis, between two variable sets.

Keywords: Canonical Correlation Analysis
Dimension Reduction
Kernel Machines
Nonparametric Regression
Variable Importance
Advisor: Rafal, Kustra
Re-connecting with Nature: Transformative Environmental Education Through the Arts

Environmental educators are seeking ways to make learning relevant in an environment in which students are increasingly disconnected from the natural world and the places where they live, and more connected to digital media and technology. This theoretical study, guided by Thomas Berry's influential cosmological vision and David Orr's environmental education work, examines how the arts may re-direct thinking, awareness, and learning and help learners of all ages to re-imagine our connections to the biotic communities, of which we are a constituent part. It also offers a critical view of modern technologies, and how they may be useful in the environmental learning. By examining different worldviews, educational paradigms, the role of arts in learning, and the use of media and modern technologies, in light of childhood identity development, this study explores how a connection to nature and animal species can develop through experiences with the arts and time outside, help students build ecological identities, and promote sustainability in communities. The argument is made for bringing art into the environmental education curriculum in order to promote collaborative learning, a sense of place and community, 'hybrid thinking,' transdiciplinary learning, and a co-creative dialogue with nature and culture.

Keywords: Art
Creativity
Environmental Education
Nature
Sustainability
Transformative learning
Advisor: Linda, Cameron
A Case Study of the Perceptions of Learning Outcomes of Student Participants in an Undergraduate Research Initiative at City University

Undergraduate research is an area of increasing interest and focus in postsecondary education. Hands-on undergraduate research initiatives are believed to lead to learning outcomes that serve the student in a number of ways, including career choice, employability and tools for lifelong learning. They also advantage employers by facilitating the development of skills that have been identified as desirable for the receptor-community into which they choose to enter, whether that is academia, government, industry, not-for-profits or entrepreneurial activity. There is growing demand from all stakeholders to know what benefits, if any, accrue from participation in undergraduate research programs. The purpose of this mixed methods study was to describe and evaluate the experiences, perceptions and attitudes of participants (n=175) in a case study of the Undergraduate Research Initiative (URI), a full-time, non-curricular, twelve-week summer project, driven by the research interests of students who are mentored by a faculty member, at City University in Ontario. The study aimed to determine the scope of effects on skills and learning outcomes across a diverse range of disciplines (n=40) from the student perspective. Inquiry was based on identifying learning outcomes as reported by participating students; the extent to which perceptions varied by faculty/discipline; the extent to which perceptions aligned with university undergraduate degree level expectations (UUDLEs) as set out in Ontario's Quality Assessment Framework; and the extent to which students' expectations were met by the URI program. An additional area of interest was to examine the synergies and gaps between reported student learning outcomes, university undergraduate degree level expectations, and workplace-identified skills. Findings from this study showed that perceived learning outcomes as a result of participation in the URI program covered a broad spectrum of themes and comprised all three domains (cognitive, affective, and psychomotor) identified by Bloom (Bloom, 1956). The fact that the URI experience led to the development of skills recommended in the UUDLEs guidelines, speaks to the value of the program for accountability purposes. The universality of impact of the URI program across disciplines was somewhat unexpected, but is a strong argument for the importance of program design in meeting objectives.

Keywords: experiential learning
learning assessment
learning outcomes
multidisciplinary
skills gap
undergraduate research
Advisor: Katharine, Janzen
Cultural Considerations in the Delivery of Homecare Services: "Beyond 2 kitchens and a disability/ più di due cucine e disabilità "

This study explored the experiences, interpretations and cultural beliefs of older Italian immigrants who were receiving culturally specific formal homecare services through an assisted living facility in Ontario, to examine how their identity and life history influenced their experiences of receiving care.The current study builds on the existing body of knowledge about Canada's older Italian immigrants, in particular their caregiving traditions and current need for formal care. This research study employed phenomenology to explore the subjective experiences of Canadian Italian older immigrants who were receiving formal homecare services to capture the personal meanings and interpretations of their immigration experiences, as they related to their need for formal homecare services. Interviews were conducted with 25 older Italian immigrants over the age of 75 that were receiving culturally specific homecare services. The participants shared their immigration stories, fears, work history, healthcare challenges and descriptions of arrival, family, losses, and life in Canada. The Life Course Framework was selected to guide this research study, to represent the process of aging and human development that continuously occurs across the life span. The Social Identity Theory was also used to provide additional guidance in understanding the social, cultural and historical influences of their life histories, as they related to their living arrangements in an assisted-living facility in Ontario and need for caregiving services. Three major themes emerged: 1. the importance of communication and relationship building in the provision of care and the barriers in accessing health care services, 2. retaining identity and control, and 3. facing an uncertain future. These themes reveal the importance of language, cultural practices and residential location. At the micro level, these findings demonstrate the importance individuals assign to their immigration history and cultural traditions. At a macro level, the findings reveal the need to provide cost-effective care that enhances the physical and mental well-being of individuals. These findings also reflect the importance assigned to the home environment and the need for workers to develop relationships with clients that are reflective of their cultural needs. Social workers have the ability to appreciate the historical context of Canada's immigrants; to develop policies in support of their cultural practices, traditions and acculturative interests, and the ability to appreciate the aging process and the associated need for formal services. As Canada's multicultural population continues to grow, social workers will be increasingly challenged to deliver culturally competent healthcare services. The findings are intended to offer additional guidance into the meaning of culture and its importance in furtherance of these goals.

Keywords: Aging
Canada
Healthcare
Home care
Immigration
Advisor: Faye, Mishna
Elementary School Office Managers' Positive Extra-role Behaviours

Elementary School Office Managers represent a workforce of over 5000 individuals within the province of Ontario. While their impact on the school is known to the principals, teachers, students, and parents with whom they interact on a regular basis, their contributions have scarcely attracted the attention of educational scholars. Through the lens of Public Service Motivation theory and Extra-Role Behaviour theory, this research sought to identify the personal and work environment influences that impact Elementary Office Managers' Positive Extra-Role Behaviours in Ontario's elementary schools. Through face-to-face interviews with retired elementary office managers, this research found that principal/leader supportiveness, job satisfaction, and individual characteristics were key influences on research participants' positive extra-role behaviour. Possible implications of this research for school districts include: giving consideration to office manger applicants' pre-employment experiences; targeted training for principals on how to nurture office managers' extra-role behavior; the role of the union as detractor to extra-role behaviour, and rethinking the office manager's job description.

Keywords: extra role behaviour
motivation
non-teaching staff
office manager
principal
public service motivation
Advisor: Blair, Mascall
Advancing the COACH Automated Prompting System toward an Unsupervised, Real-world Deployment

The COACH is a prototype automated prompting system designed to encourage independent participation in daily tasks by older adults with dementia. Supervised, clinical trials with the COACH were promising, yet little was known about the capabilities of the system in an unsupervised, real-world environment or the needs of the system's users in such a deployment. To continue development of the COACH toward an unsupervised, real-world in-home deployment I employed an informed approach. First, the needs of the users of the system were identified through a national questionnaire completed by family caregivers of older adults with dementia and validated using a follow-up focus group. Participants indicated that the COACH should provide unobtrusive support of private or personal tasks by leveraging the remaining abilities of the older adults with dementia using the system, promoting independent task completion. Next, the performance of the COACH was evaluated in an unsupervised, real-world clinical deployment. One of the COACH modules responsible for tracking the interactions between the system users and objects in the environment was implicated as the cause of the majority of the failures, successfully identifying only 46.9% of the task steps completed by the trial participants. The technical factors limiting system performance in the real-world clinical deployment were synthesized with the needs of the users to develop technical design criteria which were used to guide the development of an improved COACH prototype. The performance of the new COACH prototype was evaluated in a second supervised deployment, resulting in the successful identification of 93.7% of the task steps completed by trial participants. Encouraged by these results, the COACH system is again ready for evaluation in an unsupervised, real-world environment.

Keywords: Ambient Intelligence
Assistive Technology
Automated task completion
Context-aware sensing
Decision support systems
Smart homes
Advisor: Alex, Mihailidis