VictorJuiz/thesis huggingface dataset:
Hyperexcitability in Pain Processing Neurons: Pathological and Compensatory Mechanisms
Keywords: Compensation
Computation
Degeneracy
Disinhibition
Hyperexcitability
Pain

Neuropathic pain is associated with hyperexcitability in primary afferent neurons (PANs) and the spinal dorsal horn network. Hyperexcitability develops despite compensatory changes that can offset the effects of pathological changes, implying that compensation ultimately fails. I hypothesized that compensatory changes, despite robustly maintaining certain aspects of excitability, fail to maintain others. To test my hypothesis in PANs, I used an existing computer model to show that distinct ion channel combinations that yield equivalent rheobase fail to yield equivalent outcomes for other factors such as energy used per spike. To test my hypothesis in spinal dorsal horn neurons whose synaptic inhibition can be compromised in distinct ways, I developed a new computer model. Consistent with my hypothesis, simulations revealed that distinct forms of disinhibition differ in their effects on dynamic range and receptive field size. These results demonstrate the limits of compensation and may help explain how hyperexcitability develops despite compensation.
The Impact of the Auditory and Visual Environments on Balance in Children with Bilateral Vestibular Loss and Cochlear Implantation
Keywords: Balance
Children
Cochlear Implant
Compensatory Mechanisms
Sensorineural Hearing Loss
Vestibular

Vestibular impairment is common in congenital sensorineural hearing loss yet children are remarkably able to remain upright. To gain an understanding of how these children compensate for their bilateral cochelovestibular loss (BVL) we investigated the effects visual and auditory virtual environments in children with BVL and bilateral cochlear implantation (CI), ages 8.5-17.9 years, using clinical balance tests and measures of postural control. Children with BVL had significantly impaired balance compared to typically developing children with balance skills approximating those of a 4.5-year-old child. Body movement was significantly greater in children with BVL when performing balance tasks. Children with BVL relied on vision to a greater extent than their typically developing peers. The presence of moving objects in the environment did not significantly alter balance in either group. Balance and postural control improved in children with BVL when CI were on. Children with BVL rely on vision and auditory input through CI in order to balance but this does not restore balance to normal levels. Novel methods are required to reestablish vestibular-type input in this vulnerable population.
Herbal Medicine Use in Adult Dental School Patients at the University of Toronto
Keywords: Dentistry
Herbal medicine

Background: Some herbal medications (HM) may have potential adverse drug interactions and may impact dental treatment. To date, there is a dearth of information on the use of HM among dental patients. Objectives: The primary goal of this study is to determine the prevalence of HM usage among patients in the clinic at the Faculty of Dentistry – University of Toronto. Also, this study will determine the prevalence of recording of HM use in the medical records of the same institution. Materials and Methods: The primary method to assess the prevalence of HM use is by a survey of dental school patients and chart review. Results: 65% of patients currently use one or more HM, while their use is recorded in only 8% of the dental charts. Conclusion: There is a significant difference between the prevalence of HM use and their recording in the dental charts.
Opportunistic Routing in Large-scale Energy Harvesting Wireless Sensor Networks
Keywords: Energy Causality
Energy Harvesting
Multi-hop
Opportunistic Routing
Sensor Network

Energy self-sufficiency is one of the main bottlenecks in the implementation of wireless sensor networks (WSNs). In this regard, energy harvesting (EH), the capture of energy from ambient sources of renewable energies, is a promising solution to the energy problem. However, the resulting randomness in the energy available to nodes forces the redesign of the communications protocols. Of specific interest here is to enable the delivery of sensed data to a fusion center in the EH-WSN. In this thesis, we consider two open problems of practical importance to the implementation of large-scale WSNs. First, we propose the notion of energy outage rate for a single link in WSN as a tool for online consideration of EH in such networks. Second, we propose and mathematically analyze an energy-aware, opportunistic routing protocol for large-scale multi-hop EH-WSNs. Our routing protocol significantly increases the rate of data delivery as compared to the state-of-the-art technologies.
Biocidal and Sporicidal Efficacy of Thermal Spray Copper Alloy Coating with Varying Degrees of Roughness
Keywords: Bacillus
Copper alloy
Endospores
Nanoflowers
Surface roughness
Thermal spray coating

Abstract The biocidal and sporicidal efficacy of copper alloy coating was compared to copper alloy sheet and stainless steel coupons. For surfaces with roughness values of 0.1 and 3.5 Îźm, no significant difference in the killing of Escherischia coli, Staphylococcus epidermidis and Bacillus subtilis was observed between copper alloy sheet and thermal spray copper alloy coupons. Scanning electron microscopic analyses revealed that the degradation of B. subtilis endospores and formation of nanoflowers begin within 2 hours after exposure to the copper surfaces. Flower-like nanostructures appeared in intimate contact with partially degraded endospores. Energy dispersive technology analysis revealed that nanoflowers were composed of carbon-copper-phosphate crystals. Focused ion beam sectioning revealed that the majority of nanoflowers have petal-like structures. This study indicates that thermal spray copper alloy coatings are as effective as copper alloy sheet in the destruction of endospores; thus representing a cost-effective and viable strategy for decreasing the risk of infection within hospital settings.
Platelet-rich Plasma and Cartilage Integration
Keywords: articular cartilage
biologics
cartilage integration
cell migration
platelet-rich plasma
tissue engineering

Biological repair of damaged cartilage is limited by the inability of repair tissue to integrate with host tissue. The study hypothesis is that platelet-rich plasma (PRP) will enhance the integration of bio-engineered cartilage with native cartilage due to increased matrix accumulation, and that chondrocytes migrate out of bio-engineered cartilage, while maintaining their chondrogenic phenotype. Bio-engineered cartilage were either soaked in PRP or Hamâ s F12 (control) and then implanted into the core of a native osteochondral explant and cultured for 2-weeks. Integration was evaluated histologically and biomechanically. The mechanisms of integration were evaluated by biochemistry, RT-PCR, immunohistochemistry and cell migration assays. PRP-soaked constructs integrated with native explants with significantly greater mechanical strength than controls with increased matrix accumulation at the integration zone. Chondrocytes migrated out of PRP-soaked bio-engineered constructs along fibres. The improved integration may be due in part to the increased matrix accumulation and cell migration at the interface.
The Complex Experience of Surgeon Stress in the Operating Room
Keywords: Operating
Operating Room
Stress
Surgery

Surgery is a demanding career; however, research examining acute surgeon stress is lacking. The aim of this study was to capture and explore surgeon stress in the operating room (OR) using a multifaceted methodology. This exploratory pilot study collected surgeonâ s stress data from four facets: physiologic, cognitive, affective and sociocultural. Physiologic data included ECG and cortisol. Affective, cognitive and sociocultural data were captured through inventories, interviews, and observer notes. Data triangulation was used for analysis, focusing on moments of perceived and physiologic stress. A methodology to capture surgeon stress in the OR was refined. Heart rate and heart variability proved the most reliable, sensitive and specific physiologic stress data, but conveyed limited information without perceived stress data. The relationship between perceived and physiologic stress is complex and perceived stress can be present without physiologic stress and vice versa. A multifaceted methodology is necessary to understand the complex surgeon stress experience.
Physiological Detection of Emotional States in Children with Autism Spectrum Disorder (ASD)
Keywords: ASD
Autism spectrum disorder
Emotion detection
Pattern recognition
Physiological signals

Autism spectrum disorder (ASD) is associated with difficulties in emotion processing including attributing emotional states to others and processing of oneâ s own emotional experiences. These difficulties are linked to core social impairments and increased severity of psychiatric co-morbidities such as depression in ASD. The nature of these difficulties has remained largely unknown. This is partially due to limitations in obtaining reliable self report of emotional experiences in this population. Emotion detection using physiological signals is a promising direction in addressing this limitation. Physiological signals can provide an objective language free method for understanding emotional states in ASD. Despite this promise the use of this approach has not been studied in ASD. To this end we develop a physiological approach to detection of emotion in children with ASD. We showed that emotional states can be classified with accuracies>80% in a sample of children with ASD which affirms the feasibility of discriminating affective states in this population.
Ideologies of "Greatness" and the Production of Space and Subjects: A Study of the Goldring Centre for High Performance Sport
Keywords: Higher Education
High Performance Sport
Kinesiology
Landscapes of Sport
Lefebvre
Space

This thesis is a study of a contemporary space at the University of Toronto: The Goldring Centre for High Performance Sport (GCHPS). The motto for the GCHPS was “Pursue (your) Greatness”. I explored the ways in which greatness may be connected to the research and practices of the exercise sciences, sports medicine, and athletics. I drew on the theoretical insights of Lefebvre (1991), and scholars of space and sport (e.g., Pronger, 2001; Atkinson, 2009; van Ingen, 2003; Fusco, 2005). I explain the Centre’s ties to the University’s institutional vision for academic and athletic excellence, as well as the provincial and federal government’s investment in sport. I argue that this production is tied to legacies of classism, whiteness, and scientific knowledge/power, and is neglectful of the interests of the broader university community. I conclude by suggesting that scholars must be critical of the socio-cultural and political aspects of spaces and disciplines.
Autologous Hematopoietic Stem Cell Transplantation for Tolerance Induction in a Mouse Model of Solid Organ Transplantation
Keywords: Cardiac allograft
Hematopoietic Stem Cell Transplantation
MLR
Rapamycin
Regulatory T cell
Transplant Tolerance

The need for long term immunosuppression negatively impacts long term survival and quality of life for solid organ transplant patients. One solution for this would be establishment of immune tolerance. Autologous HSCT has been used clinically for the restoration of self-tolerance in autoimmune disease. We tested whether autologous HSCT and a short treatment with rapamycin could result in tolerance to fully MHC-mismatched allografts. Mice that received HSCT and a short course of the mTORi rapamycin demonstrated significantly prolonged allograft survival compared to untreated and rapamycin-only treated controls. Immunologic studies showed that HSCT-treated mice displayed active immune regulation as demonstrated by a primary MLR response, markedly diminished donor specific antibody levels and significantly higher frequencies of CD4+CD25+FOXP3+ Tregs. These data provide a rationale for human clinical trials to examine the ability of autologous stem cell transplantation to induce tolerance in liver transplant patients (ASCOTT) which are now ongoing.
Defining Novel Molecular Events in Leiomyosarcoma
Keywords: Gene Fusions
Leiomyosarcoma
Molecular Subtypes
Smooth Muscle Differentiation

Leiomyosarcoma (LMS) is a smooth muscle neoplasm and a common histological subtype of soft tissue sarcoma (STS). LMS primarily arises in the retroperitoneum and abdominal cavity, the extremities, and the uterine wall. Current treatment outcomes are poor; consequently, personalized medicine informed by the molecular basis of the disease is needed. Here, YAF2-PRICKLE1 and ESR1-CCDC92, two novel fusion transcripts, were discovered in an LMS cell line and were detected as rare events in the tumor from which that cell line was derived. Furthermore, unbiased cluster analysis indicated that abdominal and extremity LMS transcriptomes group distinctly from uterine LMS transcriptomes, suggesting potential molecular subtypes and supporting the notion that uterine LMS is biologically distinct from abdominal and extremity LMS. Lastly, decreased FOXO4 expression correlated with increased smooth muscle differentiation in LMS. Collectively, these preliminary findings present avenues for future investigations which may facilitate diagnostic and therapeutic innovations for this disease.
Institutional Entrepreneurship, Market-making, and Interaction Dynamics: A Case Study of the Ontario Craft Brewing Market
Keywords: Craft brewing industry
Economic geography
Institutional entrepreneurship
Market-making
Relational economy

This thesis examines institutional entrepreneurship, market-making, and interaction dynamics in the case of Ontarioâ s craft brewing industry. It identifies the presence of institutional entrepreneurship in the industry, and shows that institutional entrepreneurs have mobilized resources to dislodge existing practices, and create new or change existing institutions in their interest - a novel conceptual contribution to the economic geography literature. Moreover, this thesis describes some of the ways that actors in and/or related to the industry have made a market for themselves, despite competition from much larger firms in an established market. The identification of institutional entrepreneurship as a market-making process in the industry presents a more complete explanation of the industryâ s development than previously offered in the craft brewing literature, and the synthesis of these processes, using a relational economic approach, contributes to the economic geography literature.
Mapping Change in Urban Canopy Cover Following an Ice Storm Event: A Case Study of the December 2013 Ice Storm in Toronto and Mississauga
Keywords: Geographic information systems
Ice storm
Object based image analysis
remote sensing
Urban Forestry
Urban trees

Urban forests provide ecosystem services and functions, but are vulnerable to stressful environments and disruptive weather. One type of extreme weather, ice storms, can result in damage to trees. In December 2013, an ice storm hit southern Ontario with significant social and ecological impacts experienced in the Greater Toronto Area; where many cities are initiating management plans to increase canopy coverage. The objective of this project is to explore the changes in urban canopy cover before and after the ice storm through object-based image analysis. The results of this analysis successfully show broad level canopy distributions, patterns of canopy growth and loss, and 3-5% of canopy loss can be attributed to the ice storm on residential land uses. A better understanding of the impacts of the 2013 ice storm addresses a gap in our knowledge of how urban forests respond to extreme weather.
Effects of Bilateral Prelimbic Cortex Inactivation on Contextual Biconditional Discrimination Memory Retrieval in Adult Long-Evans Rats
Keywords: contextual biconditional discrimination
contextual processing
medial prefrontal cortex
prelimbic cortex
reward

The prelimbic (PL) subregion of the medial prefrontal cortex has been widely implicated in the contextual control of appetitive and aversive conditioning through studies of context-induced reinstatement of drug seeking and contextual fear conditioning. However, the role of the PL in mediating contextual processing in appetitively motivated tasks without the involvement of abused substances remains underexplored. Thus, the present study sought to investigate the role of the PL in this process using a previously reported contextual biconditional discrimination (CBD) memory task. We examined the effects of temporary post-acquisition pharmacological inactivation of the PL on CBD memory retrieval and observed robust deficits in contextual memory retrieval following PL inactivation. Our data provide novel insight into the role of the PL in contextual processing in appetitively motivated tasks in the intact brain, indicating a more general role for the PL in appetitive and aversive contextual processing in the drug-free brain.
Trajectory and Breakup of Cryogenic Jets in Crossflow
Keywords: Breakup
Crossflow
Cryogenic
Jet
Trajectory

This study investigated the breakup processes of subcritical cryogenic jets injected in to subsonic crossflows of heated air. The crossflow speed, temperature, and jet velocity were varied to demonstrate the effect of thermal differences on a jet in crossflow. High speed back-lit photography and Mie scattering were used to examine the primary breakup regimes, trajectory, and breakup points. The breakup regimes show little change from jets in crossflow near thermodynamic equilibrium. Penetration of the jet increased with an increase in crossflow temperature. The breakup points in the streamwise direction followed trends previously observed for conventional jets. While the height of column fracture did not increase with momentum flux ratio as much as would be expected, its dependence matched that of the trajectory correlation. It is hypothesized that the observed differences are due to the development of a sheath of evaporated fluid around the main liquid core of the jet.
Frequency-scanned Waveguide-fed Slot Array for Millimetre-wave Radar Applications
Keywords: antenna
frequency-scanning
radar

Millimetre-wave designs have become increasingly common in radar applications due to advantages when compared with traditional microwave designs. The increased operating frequencies offer greater bandwidths and allow for reduced antenna sizes. In radar systems, large bandwidths are used to achieve high range resolutions. At millimetre-wave frequencies, there is sufficient bandwidth for additional uses, most notably, beam steering using a frequency-scanning antenna. Due to their simplicity, these antennas are particularly attractive for commercial radar applications. In this work, a millimetre-wave frequency-scanned slot array was designed based on a serpentine waveguide for a 1.8 GHz bandwidth centred at 34.3 GHz. The antenna was fabricated, and measurements indicated a range resolution better than 1.25 metres over an angular scanning range of 20 degrees. The antenna was incorporated in a simplified radar system, which successfully demonstrated the ability to detect and locate multiple targets simultaneously.
Exploring Interculturality: Dialectical Tensions with Identity and Schooling Systems with First Generation Immigrant Students
Keywords: First Generation Immigrant Students
Interculturality
Relational Dialectics Theory
School Social Structure
Student Experience

First generation immigrant students' experiences, perspectives and histories deeply affect their socio-cultural understanding and connection to their surrounding environments, and can serve as a valuable point of entry into problematizing the concept of static integration. Working from a dialectical perspective, I utilize thirteen first generation immigrant students' accounts to explore their socio-cultural struggles, the two school systems into which they were imbedded and the ways in which these facilitated or impeded immigrant student intercultural experience(s). Results showed that students experienced internal struggles with sociocultural scripts, language and cultural loyalty in confluence with school systems that were in themselves expressing stress vis-Ă -vis socio-cultural facilitation and support.
Health System Performance Measurement in a Circumpolar Context: Selecting Performance Indicators for Maternity Care
Keywords: arctic
circumpolar
indicator
indigenous
maternity care
performance measurement

Performance measurement is a necessary component of a transparent health system. In circumpolar regions, indicators that align with national strategies may fail to address priorities of northern, remote, or Indigenous populations. The objective of this study was to select contextually appropriate performance indicators for maternity care in circumpolar regions. A scoping review of the academic and grey literatures generated a working list of indicators. Fourteen circumpolar maternity care experts then participated in a two-round modified Delphi consensus process. Eleven indicators met criteria for importance, circumpolar relevance, validity, and reliability. Twenty-nine additional indicators were identified for further consideration. This study demonstrated that while most circumpolar maternity care systems engage in performance reporting, current indicators do not always reflect local priorities. This study was effective in identifying contextually appropriate indicators. Future work should ensure that circumpolar performance indicators capture issues related to social determinants of health, travel for care, and cultural competency.
Initial Molecular Characterization of Planarian Pigment Cells, a New Model for Studying Lineage Specification and Gut Excretion
Keywords: Lineage Specification
Photosensitivity
Pigment
Planarian
Regeneration
Stem Cell

ASCs play crucial roles in tissue homeostasis and regeneration. Here, I established pigment cells in Schmidtea mediterranea as a novel model to study ASC lineage specification by identification of hmbs and alas as makers for pigment cells, and ans as a marker for their progenitors. Co-expression analysis between hmbs and tryptophan metabolism enzyme, kmo, suggests ommochrome as one of the responsible pigments for planarian body pigmentation. Initial characterization of this lineage reveals an fst homolog as a negative regulator of pigment cell regeneration and proliferation. Functional studies of light-induced depigmentation also uncover homologs of draper and epimerase as positive regulators of gut excretion mediated pigment cell removal. Together, these findings in pigment cell lineage and gut excretion pave ways to future studies of ASC regulations.
Feasibility of Direct Reprogramming of Myofibroblasts to Lung Epithelial Cells Utilizing PiggyBac Transposon System
Keywords: chronic rejection
direct reprogramming
fibrosis
lung
myofibroblasts
PiggyBac

Organ transplantation is the treatment of choice for management of end-stage organ diseases. Graft failure due to chronic rejection is characterized by fibrosis of structures within the allograft. Immunosuppression has reduced acute rejection but has not had an impact on chronic rejection. In transplanted lungs, epithelial injury predestines small airways to undergo fibrosis and results in activation of myofibroblasts marked by expression of alpha smooth muscle actin (SMA) termed Bronchiolitis Obliterans (BO). In this project we developed an innovative anti-fibrotic strategy using “direct reprogramming” to target this pathogenic response through conversion of myofibroblast to lung epithelial cells. As a proof of concept, we 1) established an in vitro fibrosis model system, 2) tested SMA promoter as a potential driving promoter of the reprogramming cassette, 3) selected and cloned inducing factors in PiggyBac constructs and 4) showed the feasibility of utilizing these tools for the testing of reprogramming strategies targeting fibrosis.