VictorJuiz/thesis huggingface dataset:
Community Engagement Practices at MLSE Launchpad
Keywords: community engagement
corporate social responsibility
development
sociology
sport
sport-for-development

Sport-for-development (SFD) organizations increasingly deliver programs in marginalized communities within the Global North. Despite this growth in programming, and significant academic attention towards this trend, studies of the methods through which SFD organizations receive input from and engage with communities have been largely absent. The purpose of this study was to explore how Maple Leafs Sports and Entertainment Launchpad, an SFD centre in downtown Toronto recruits in and relates to the surrounding Moss Park community. Data collection consisted of semi-structured interviews with nine staff, and observations over four months at Launchpad and its external community events. The main results were as follows: a significant group of participants were attracted to the space through non-sport activities, despite previous focuses on sport recruitment; Launchpad provided a number of “extras” that filled in fundamental gaps in public services; and important distinctions between the language of “engagement” and “recruitment” among staff emerged.
Kinetics of Neutrophil Recruitment and their NF-κB Response to Neisseria gonorrhoeae Uterine Infection
Keywords: female reproductive tract
Neisseria gonorrhoeae
neutrophils
NF-κB
pelvic inflammatory disease

Neisseria gonorrhoeae (Ngo) is the bacterial pathogen responsible for the sexually transmitted infection gonorrhea. Aside from the cervicitis typical of gonococcal infection in women, untreated infections may ascend into the upper genital tract, leading to a devastating inflammatory response that can result in pelvic inflammatory disease. In this thesis, I reveal the first leukocyte responders to Ngo uterine infection using a transgenic mouse model that expresses green fluorescence protein (GFP) when the immediate-early transcription factor NF- κB is activated. Using flow cytometry, my results demonstrate recruitment of neutrophils into the infected uterus, where only a subset of these neutrophils displays activated NF-κB, and most of which are not associated with gonococci, suggesting that these populations may represent different neutrophil phenotypes. These findings make it enticing to consider that the responding neutrophils are of a phenotype incapable of clearing infection, and may help explain persistent colonization observed in untreated individuals.
Extract and Component-Specific Allergen Recognition Patterns in Canadian Children: Insights into Preschool Asthma and Nut Allergy
Keywords: allergic sensitization
allergy
asthma
component resolved diagnosis
IgE

The early presence and diversity of allergic sensitization is a risk factor for the development of asthma and a diagnostic marker for allergy. Assessing IgE sensitization at the allergen extract and protein component level may increase specificity by providing insights into allergen protein families involved and thereby improve predictions of clinical relevance of sensitization. Using a comprehensive multiplex IgE test, we characterized sensitization profiles in a cohort of preschool asthmatics and identified potential allergen biomarkers (Ara h 1, 2, 3, 6, Fel d 1, and Can f 1) that were associated with more severe asthma. We also identified allergen components that may be able to improve specificity of peanut and tree nut allergy diagnosis in this pediatric population (Ara h 1, 2, 6, Cor a 14, Jug r 1, Ana o 3). Lastly, we generated models that allow the comparison and conversion of specific IgE-levels measured using different testing platforms.
Optimization of Murine Pancreas Decellularization to Obtain ECM for a Co-Culture System Capable of Producing Mature Pancreas Cell Types
Keywords: decellularization
extracellular matrix
pancreas
recellularization
stem cells
tissue engineering

Maturation and cell organization have remained issues for in vitro pancreatic tissue engineering. However, many culture conditions do not incorporate the extracellular matrix (ECM), an element crucial to organogenesis. This project aimed to create a 3D co-culture system with murine ECM. To obtain ECM, optimization of decellularization was explored using perfusion of whole pancreas or lobe as well as by using soak-agitation for slices. The detergents Triton X-100, CHAPS and SDS were tested. ECMs were analyzed for DNA content and retention of critical ECM proteins. CHAPS was chosen for further optimization with benzonase and resulted in decellularized ECM that retained key proteins. This ECM was tested as both a 2D coating and a 3D intact tissue slice matrix for survival and maturation of embryonic stem cells. Only the 3D slices suggested maturation toward a pancreatic lineage. Therefore, this study created a 3D co-culture system to help further tissue engineering efforts.
Three-dimensional Assembly and Characterization of Protein-based Tubular Constructs for Tissue Engineering
Keywords: Bile duct
Microfluidics
Tissue Engineering
Tubular constructs

In this thesis I present a strategy for rolling highly aligned collagen sheets into tubular constructs which have applications as implantable bile duct grafts or in organ-on-a-chip systems. Aligned collagen sheets were extruded through a microfluidic device following a previously described protocol, and vertically stacked to achieve suitable mechanical properties for rolling. A rolling process was developed, characterized, and optimized for rolling tubular structures with a 700 μm inner diameter and 50 μm wall thickness, mimicking the dimensions of rat bile ducts. Rolled tubes were mechanically characterized for suture retention strength and burst pressure. The mechanism of failure in these tests was also investigated, providing insights for methods to further increase mechanical properties. Cholangiocyte precursors and cholangiocyte cysts were loaded into tubes in a custom-made tube hosting device and appeared to attach, spread, and remain viable up to 9 days in culture.
Cyclical Variation in Predation Risk: Impacts on Snowshoe Hare (Lepus americanus) Offspring through Maternal Programming
Keywords: Maternal effects
Non-consumptive effects
Population cycles
Predation
Snowshoe hare
Stress physiology

Snowshoe hare (Lepus americanus) populations cycle over 10-year periods, primarily driven by predation. High predation risk triggers the decline phase of the cycle through both direct mortality and non-consumptive stress effects that curtail reproduction and survival. The decline phase is followed by an enigma, the prolonged low phase, where the population fails to recover. This suggests maternal stress effects may act to program offspring across generations in this population. Through a natural monitoring study spanning the hare cycle, we investigated the impact of changing predation risk and maternal stress on offspring. Offspring in the decline phase showed a suite of changes to their behaviour, condition, physiology and gene expression compared to offspring from the increase and peak phases, suggesting maternal programming is occurring. This study was novel in documenting changes in gene expression of hippocampal glucocorticoid receptors in response to a natural increase in predation risk in a wild mammal.
Three-phase Wireless Power Transfer for Electric Vehicle Charging with Improved Receiver Misalignment Tolerance
Keywords: electric vehicle charging
receiver misalignment
wireless power transfer

Charging of electric vehicles through inductive wireless power transfer (WPT) provides an attractive alternative to traditional wired charging. However, existing WPT systems display high degradation in efficiency and throughput power when transmitter and receiver become misaligned. A three-phase WPT system with magnetically decoupled transmitter windings is proposed to address this degradation. By optimal selection of the transmitter phase current distribution, a region of maximal flux density can be centred at the receiver location, achieving nearly constant efficiency and throughput power for receiver misalignment up to ±20cm. Excitation of the three-phase transmitter coil is provided by a conventional three-phase inverter, halving the number of semiconductors and gate drivers used with previous technologies. Experimental results demonstrate 92.97% coil efficiency and 88.45% system efficiency at perfect alignment at 3.3kW power transfer. Performance is shown to hardly degrade with misalignments up to 20cm, where coil efficiency remains at 90.52% and system efficiency at 86.66%.
Characterizing the HLA Restriction and Functional Avidity of a HERV-specific T cell Receptor
Keywords: Adoptive cell therapy
Human Endogenous Retroviruses (HERV)
Human immunodeficiency virus (HIV)
Major histocompatibility complex (MHC)
S-glutathionylation
T cell receptor (TCR)

Given that the rapid mutation of HIV mediates its immune escape, methods to enhance recognition of infected cells are urgently needed. Typically-dormant endogenous retrovirus (HERV) proteins are upregulated upon HIV infection and may thus serve as immutable surrogate markers of infected cells. In HIV patients, T cell responses to HERV epitopes correlate with an innate ability to control virus without therapy, raising the question of whether HERV-reactivity can enhance clearance of HIV-infected cells in an adoptive cell therapy approach. It remains to be seen whether de novo HERV-specificity can be conferred to allogeneic T cells by exogenous expression of HERV specific TCRs. Herein, we have expressed one-such TCR in a T cell line, showing that it successfully confers recognition of an epitope from HERV-K(HML-2)-Env. This in vitro system enabled an in-depth analysis of the TCR-peptide-MHC interaction, revealing that recognition is restricted to presentation by HLA B*07:02, and is enhanced by S-glutathionylation of the antigenic peptide.
Hydrophilic Cargo-Loaded Microbubbles for Ultrasound-Triggered Local Delivery
Keywords: Drug Carrier
Localized Delivery
Ultrasound

Microbubbles are intravenous ultrasound-responsive agents that can cavitate upon insonation. There is ongoing interest in incorporating hydrophilic therapeutic and imaging agents into microbubbles for local, ultrasound-triggered delivery. A proof-of-concept microbubble capable of carrying hydrophilic molecules, providing ultrasound contrast, and cavitating was designed. Calcein was selected as a model cargo for optical verification of co-localization. First, 75% v/v Span 80 and 25% v/v Tween 80 surfactants were selected to solubilize calcein in cyclooctane. Second, calcein-loaded oil was emulsified as microdroplets stabilized with 2-dipalmitoyl-sn-glycero-3-phosphocholine and 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethyleneglycol)-5000] phospholipids. Microdroplets were lyophilized, decafluorobutane gas-filled, and saline reconstituted to form calcein-loaded microbubbles. These were characterized for size distribution, calcein loading, contrast enhancement and cavitation. Calcein-loaded microbubbles (peak: 4.3 μm) demonstrated cargo co-localization and a concentration per microbubble volume of 0.077±0.038 mg/mL. Microbubbles provided ultrasound contrast and underwent inertial cavitation at MI≥0.77. This synthesis method may be extended to encapsulate other hydrophilic cargo in acoustically-active carriers.
Synthesis of a GlmU Bisubstrate Inhibitor
Keywords: Bisubstrate
GlmU
Glucosamine-1-phosphate
Inhibitor
Synthesis

In an attempt to combat antibiotic resistance, new drugs are constantly being developed. One method of killing bacteria is to inhibit the formation of the cell wall, which is vital to the survival of the cell. This project involves the chemoenzymatic synthesis of a bisubstrate inhibitor of M. tuberculosis GlmU, as well as the synthesis of glucosamine-1-phosphate (GlcN-1-P), a commercially expensive substrate of GlmU. These two compounds were synthesized by making acetamides followed by phosphorylation using the enzyme NahK. Acetyltransferase kinetics and inhibition were assessed by using a continuous ultraviolet absorbance assay involving an Ellman’s reagent derivative and Michaelis-Menten kinetics. The bisubstrate inhibitor (EL44) inhibits GlmU competitively with respect to acetyl-CoA (AcCoA) with a Ki of 9 ± 2 μM, which makes it the strongest inhibitor among published M. tuberculosis GlmU inhibitors. It also noncompetitively inhibits GlmU with respect to GlcN-1-P with a Ki of 51 ± 6 μM. Overall, the two target compounds were successfully synthesized and the inhibitor exhibited inhibitory activity against the formation of N-acetylglucosamine-1-phosphate.
Development, Characterization and Field Testing of a Passive Air Sampler for Monitoring Occupational Exposure to Mercury Vapors
Keywords: Exposure estimates
Exposure monitoring
Gaseous elemental mercury
Passive sampling
Risk assessment

An activated carbon-based passive air sampler for gaseous elemental mercury (GEM) was modified for personal exposure monitoring. Calibration yielded a sampling rate of 0.070 m3/day. Deployments lasting 8 hours result in method detection limits below the ASTDR and WHO minimum risk level of 200 ng/m3. The sampler has a measurement range of at least four orders of magnitude. Passive sampler derived air concentrations were not statistically significantly different from active air samplers, but passive sampling was more precise than personal pump sampling. Stationary and personal passive air samplers were used to characterize inhalation exposure to GEM of individuals (1) crushing mercury-containing compact fluorescent lights, (2) living and working in two Ghanaian artisanal and small-scale gold mining communities and (3) working at a Norwegian electronics recycling facility. Exposure concentrations ranging from
Exploration of p-Block Adamantyl Chemistry
Keywords: Adamantane
Bismuth
Main Group
Organometalic
Reaction
Sodium

Adamantane, which is the simplest of the diamondoid molecules, shows great applicability in drug design, materials chemistry and as ligands for directed catalysts. Despite this, it has long been underrepresented in the field of organometallic chemistry. This underrepresentation can be traced back to the fact that stable, isolable, and anionic adamantyl sources have been difficult to synthesize. In 2017, the Fekl group developed diadamantyl zinc, which sought to address these problems with traditional anionic sources and has allowed for the synthesis of new metal adamantyl complexes. Building on this work, this project attempts to expand the adamantyl chemistry that can be accessed using diadamantyl zinc. The synthesis and partial characterization of 6 novel adamantyl compounds: tris-2-adamantyl bismuth (III), di-2-adamantyl Indium chloride, tri-2-adamantyl indium, di-2-adamantyl boron (III) bromide, di-2-adamantyl phosphorous bromide and tri-2-adamantyl are disclosed. Additionally, attempted synthesis of di-2-adamantyl ytterbium is discussed.
Investigating Pathways of Energy Transfer in Freshwater Food Webs
Keywords: Biotracer
Fatty acids
Fish
Food web
Highly Branched Isoprenoids

In complex ecological systems it is difficult to classify all interacting species, especially when the number of interacting organisms can be high, and species can respond differently to the same environment. Biochemical biotracers are useful tools to tease apart trends in food web structure through changing seasons. I used a novel biotracer and determined the presence of two highly branched isoprenoid (HBI) isomers in freshwater food webs of two temperate lakes. For the first time, my study demonstrated HBI trophic transfer from lower producers up to higher consumers. I then broadened these results by determining how fatty acid biotracers representative of three different energetic pathways change seasonally in top trophic position fish. Using and combining biotracer tools is important since lake ecosystems are facing multiple interacting stressors (e.g. eutrophication, climate change). The biotracers applied in my thesis helped provide a better understanding of the processes that shape food web structure.
Detection and Occurrence of Microplastics through Municipal and Pilot-scale Drinking Water Treatment Plants
Keywords: Biofiltration
Drinking Water Treatment
Microplastic removal
Microplastics
Particle enumeration
QA/QC

Concern regarding microplastic contamination in the environment by water providers and consumers has led to the investigation of microplastics in drinking water. Here, the development of a new method is described for microplastic analysis in drinking water samples, minimizing contamination and applying relevant QA/QC guidelines. The described method achieved an overall recovery of >80% for microplastics of various sizes, shapes, and composition, in drinking water matrices. Additionally, a full-scale conventional drinking water treatment plant employing coagulation, flocculation, filtration, and chlorination was sampled for microplastics, alongside a pilot-scale plant with eight parallel filters, receiving different treatment. Full-scale treatment removed 52% of microplastics from raw (42 ± 18 particles/L) to tap water (20 ± 8 particles/L). Ozonation, media type, biological contact, and flow rate through the filters contributed no additional removal. Coagulation, flocculation, and sedimentation accounted for 70% of particle removal, the highest removal of unit processes examined.
Autonomous Mobile Robot Navigation in 3D Rough Terrain using Deep Reinforcement Learning
Keywords: Deep Reinforcement Learning
Mobile Robotics
Rough Terrain Navigatin

Autonomous 3D rough terrain navigation requires a mobile robot to maneuver cluttered environments that have abrupt changes in terrain elevation and surface normal. Thus a navigation framework is required to determine the traversability of robot surrounding terrain using onboard sensory inputs, and overcome disturbances from 3D terrain interactions and sensor noises. This thesis presents a rough terrain navigation framework developed in simulation using deep reinforcement learning and a novel sim-to-real pipeline to overcome the gap between simulation and the real world. The pipeline was incorporated into a mobile robot architecture and the real-world experiments showed that the robot was able to successfully navigate from any arbitrary starting location to arbitrary goal location in the real-world 3D terrain.
Low-power Edge-combining Ring-oscillator-based RF Transmitters for Flexible-electrode Neural Microimplants
Keywords: Biomedical
Edge-combining
Integrated Circuits
Low Power
Neural Implants
RF Transmitters

The vision of distributed microimplants for neuromodulation at the spatial scale of a single neuron calls for closed-loop wireless transmitters (TX) with ultra-small area and power. Gold-standard LC-oscillators are power-efficient but their dimensions scale down poorly at sub-GHz frequencies preferable for low tissue attenuation. Ring-oscillators (ROs) are compact but are too power-hungry for microimplant power budgets. This thesis proposes the use of frequency-multiplying edge-combining (EC) techniques for synthesizing a high-frequency RF TX carrier from a slower and lower-power RO core. It presents two alternative methods of voltage-mode and current-mode EC by exploiting inherent properties of ROs with minimal or no circuit overhead. The two techniques are validated in the design of two ISM-915MHz direct modulation transmitters fabricated in a 65nm CMOS process. Both designs achieve sub-50x50μm dimensions and sub-100μW power consumption at 20Mbps output data rate while meeting the sub-50nS wakeup requirement for event-based wireless communication in neural microimplants.
Dreissenid Mussel Control in Drinking Water Treatment Plants: Temperature Effects and a Copper-based Alternative
Keywords: Conventional Water Treatment Processes
Copper-Based Product
Dreissenid Mussels
Drinking Water Treatment
Prechlorination

The validity of a temperature-based threshold for starting prechlorination for dreissenid mussel control in water treatment plants was evaluated by monitoring larval settlement onto surfaces for two years at three utilities in Lake Ontario. Temperature was a poor predictor of mussel settlement, but settlement was consistently observed between July and November. Therefore, a calendar-based approach for prechlorination was proposed. Chlorine is effective against dreissenids, but it enhances the formation of disinfection by-products. A copper-based product was analyzed as an alternative to chlorine. Doses as low as 30 µg/L of copper were observed to produce increased larval mortality compared to controls. The impacts of copper on coagulation/flocculation and dual media, GAC, and biologically active filtration were studied. Copper was removed to different extents by the different treatment processes. No significant adverse impacts on the performance of these processes were noted. However, studies of longer duration are required to support these findings.
Design and Evaluation of Orthopedic Alignment Tools for Guidewire and Screw Insertion
Keywords: Clinical Study
Design
Orthopedics
Product Development
Surgical Tools

The Femoral Antegrade Starting Tool (FAST) was invented to facilitate guidewire alignment in femoral intramedullary nailing procedures. Previous cadaver studies demonstrated FAST’s potential to reduce surgical time and radiation exposure. This thesis continued the development of FAST through a first in human trial and expanded the guidewire insertion technology to be applicable to pelvic reconstruction procedures. The FAST design was enhanced for usability, manufacturability, assembly, sterilization and cleaning. A clinical pilot study to evaluate the tool’s safety and surgical workflow was planned and successfully executed (n=10). Expanding the technology to pelvic reconstruction included consultations with surgeons, substantial design changes, prototyping and simple usability studies. This resulted in the creation of two proof of concept prototypes. Initial surgeon feedback supports the potential of FAST and the pelvic guidewire/screw positioning tool. Further improvements to the FAST and pelvic tool workflows and designs are suggested towards ultimately bringing these technologies into clinical practice.
The Role of Endothelial-Specific Intraflagellar Transport Protein 88 in Doxorubicin-Induced Cardiotoxicity
Keywords: Cardiovascular Sciences
Doxorubicin
Heart Failure
Mouse Study
Primary Cilia

Doxorubicin (DOX) has been associated with cardiotoxicity resulting in heart failure. Previous studies focused on cardiomyocytes as therapeutic targets. However, there has been a shift of focus toward endothelial cells (ECs) due to its importance in cardioprotective processes. Recently, a role for EC primary cilia as central structures that govern EC function through downstream signaling upon blood flow stimulation was identified. Intraflagellar transport protein 88 (IFT88) is critical for ciliary formation. In our study, mice with EC-specific loss of IFT88 expression (EC-IFT88-/-) were utilized to investigate the role of EC primary cilia in DOX-induced cardiotoxicity. We observed greater DOX-induced mortality and reduced cardiac function in EC-IFT88-/- mice compared to wild-type (WT) littermates. Furthermore, weakened statistical power may have contributed to unobservable significant differences in CM vacuolization and cardiac fibrosis of DOX-treated EC-IFT88-/- and WT littermates. Thus, EC primary cilia may be involved with processes that are protective of DOX-induced cardiotoxicity.