VictorJuiz/thesis huggingface dataset:
Understanding Experiences and Support Needs of Families Caring for Older Adults with Depression
Keywords: Caregiver
Depression
Family
Qualitative
Seniors

Background: The experiences and needs of caregivers of older adults with depression are not well understood. This study aims to explore their experiences and desired resources from the healthcare system. Methods: Eleven qualitative interviews were conducted with caregivers of older adults with a clinical depression diagnosis in Toronto, Canada. Findings were generated via thematic analysis. Findings: Caregivers perceived a transformation in the person with depression’s behaviours and personality that also changed the relationship between them. Caregivers modified their lifestyle, perceived stigma towards their love one related to depression, and experienced declines in their own well-being. Caregivers’ personal and external resources helped with caregiving role and additional resources are needed from the healthcare system. Conclusion: There is an immediate need for increased healthcare resources for older adults with depression and their family members. This study provides insight for clinicians and policy makers to implement resources to optimize the caregiving role.
Investigating the Role of LIMK1 Signaling in PKA-dependent LTP in the Hippocampus
Keywords: CP-AMPAR
LIMK1
LTP
PKA

Long-term potentiation (LTP) in the hippocampus is the most extensive form of long-lasting synaptic plasticity and is widely regarded as the cellular basis of memory formation. The canonical NMDA-receptor (NMDAR)-dependent form of LTP can be differentiated into protein kinase A (PKA)-dependent and -independent forms by the spacing between theta burst stimuli (TBS) induction. Key features of PKA-dependent LTP includes insertion of Ca2+ permeable AMPA receptors (CP-AMPARs) and initiation of de novo protein synthesis. However, the molecular mechanisms that elicit these processes remain unknown. Previous studies suggest PKA can regulate LIM-domain kinase (LIMK) 1, but this regulation has not been demonstrated in synaptic plasticity. Using a combination of electrophysiology, genetic mouse models, and pharmacology, I show that CP-AMPAR-dependent LTP requires PKA regardless of TBS spacing. Furthermore, I demonstrate that LIMK1 is required for PKA-dependent LTP. These findings provide insight into the molecular mechanisms underlying LTP and long-term memory formation.
Hemojuvelin Maintains Blood-brain Barrier Integrity
Keywords: Blood brain barrier
Hfe2
Light sheet
Neogenin
Repulsive Guidance molecule
RGMa

BBB integrity is crucial in maintaining healthy brain functions. Its disruption is seen in numerous diseases, leading to neuronal damage signicantly contributing to disease progression. Therefore, understanding the mechanism in uencing BBB functional turnover is extremely important for discovering potential therapeutic targets. Here I develop a novel light-sheet imaging technique and show that a liver-secreted protein, hemojuvelin (Hfe2), is essential for maintaining BBB function during regular homoeostasis. I show that Hfe2 counteracts the function of its homologue RGMa, which severely disrupts BBB integrity. Hfe2 exerts its inhibitory eect on RGMa through competitive binding to their receptor Neogenin, which is present on cerebral endothelial cells. This Hfe2/RGMa interplay on Neogenin is potentially involved in the pathogenesis of multiple sclerosis. The present study has implications for the normal homoeostasis of BBB integrity and may shed insight on the potential pharmaceutical treatment.
“Pass me the Hookah”: An Assessment of Toronto’s Shisha Ban as Related to Muslim Placemaking, Forced Displacement, and Racializing Surveillance
Keywords: Hookah
Muslim
Placemaking
Racializing surveillance
Surveillance
Toronto

Toronto’s ‘shisha ban’ came into effect on April 1st, 2016 and has since forced nearly 70 predominantly Black and brown Muslim migrant-owned businesses to close or restructure their livelihoods. Following the passing of the ban, Ali, the owner of Scarborough-based Habibiz Shisha Café, spoke to the cultural and religious significance of shisha and asked, “where else is there for us in this city?” (Hassan, 2016). Through semi-structured interviews and an analysis of the legislation enacted, I look to Ali’s question as a starting point to engage in a study of the relatively new bylaw and its impacts on Muslim placemaking in the Greater Toronto Area (GTA). Through this thesis, I put forward a non-exhaustive archive of Toronto’s shisha culture and look to traditions of Black, Indigenous, and racialized urban placemaking to consider collective futures beyond racializing surveillance and the unbelonging and displacement which often follows.
Small Molecule Probes for Photodynamic Therapy (PDT)
Keywords: Activatable Probes
Coumarin
Molecular Beacons
Nitroreductase
O6-Methylguanine DNA Methyltransferase
Photodynamic Therapy

Photodynamic therapy is a clinically approved cancer treatment that utilizes singlet oxygen generated via a combination of photosensitizer (PS), light and molecular oxygen to kill cells. Unfortunately, the technique remains under-utilized due to the indiscriminating phototoxicity of PSs upon irradiation, causing damage to healthy cells alongside cancer cells. Pro-drug derivatives of pre-existing PSs that are activated by enzymes overexpressed in cancer cells offer a great solution. Such derivatives are inactive until acted upon by cancer biomarkers, allowing for cancer targeted cell death. This work highlights the preliminary work in the development of 2 such activatable PSs, activated by the cancer biomarkers, O6-methylguanine-DNA-methlytransferase and Nitroreductase. In addition, the development and photophysical characterization of a novel coumarin based PS is also discussed.
Restoration Strategies to Improve Animal Movement in the Atlantic Forest
Keywords: Atlantic Forest
Functional Connectivity
Restoration strategies
Riparian Forest
Rivers

Habitat loss and fragmentation are leading causes of biodiversity decline worldwide. Animals sensitive to fragmentation suffer from decreased dispersal, breeding opportunities, and genetic diversity, making them vulnerable to extinction. Over the last decades the Atlantic Forest of Brazil has been extremely fragmented, with only 11-16% of forest remaining. Fortunately, ecological restoration is occurring throughout Brazil. Using computer modelling, I investigated how alternative restoration strategies improve the functional connectivity of the landscape. I used lion-tamarins of Southern Bahia, Brazil as a case study. I imposed three restoration strategies, Landowner Focused, Biodiversity Focused, and Random, on each of six sample landscapes, and five amounts of restoration (0%, 5%, 10%, 15%, 20%). I found both restoration strategy and amount had a significant effect on connectivity. Landowner and Biodiversity Focused strategies were significantly better at increasing connectivity than the Random strategy, and greater restoration amounts resulted in greater connectivity.
Identification of Three Potential SPARC Isoforms Expressed by the Larval Fat Body and Wing Imaginal Discs and the Requirement for the Collagen-binding Epitopes and the Disulfide-bridged EF-hand2 for Stereotypic BM Assembly in Drosophila Melanogaster
Keywords: basement membrane
collagen
intracellular
Isoform
SPARC

The assembly of basement membranes (BMs) into thin sheet-like extracellular matrix networks with tissue-specific thicknesses is poorly understood. Loss of dSPARC results in 2nd instar larval lethality characterized by a fibrotic-like accumulation of Collagen IV surrounding the fat body adipocytes and retention in large vesicle-like structures during 2nd instar. Fat body-derived dSPARC and Collagen IV are co-secreted and localized on the surface of distal tissues. Stereotypic BM assembly is dependent on the conservation of the Collagen-binding epitopes and the disulfide bridge EF-hand2 of fat body-derived dSPARC. Imaginal wing disc-derived dSPARC fails to localize with Collagen IV-rich matrices, indicating that distinct isoforms of dSPARC are expressed by different tissues. Intracellular dSPARC and human SPARC yielded a novel 67 kDa isoform. The data provides the first in vivo evidence of three different isoforms of dSPARC, with potentially distinct functions in BM assembly and larval survival in Drosophila.
Properties of Biopolymer Films in Ionic Solutions and their Applications as 3D Printed Personalized Wound Dressings
Keywords: 3D Printing
Biopolymer film
Cellulose Nanocrystals
Chitosan

This thesis describes the effects of ionic solutions on biopolymer films and the development of a 3D printed personalized wound dressing. Chitosan, gelatin, and composite chitosan/gelatin films were exposed to NaCl, Na2SO4, and CaCl2 solutions with varying ionic strength and their swelling and dissolution properties were measured. In addition, the release of the small ionic molecules Rhodamine B and Eosin Y from films into NaCl solutions of varying ionic strength was monitored. Next, a shear-thinning mixture of cellulose nanocrystals and chitosan-methacrylate was extruded with various patterns and polymerized by ultraviolet light irradiation or elevated temperature to form hydrogel wound dressings. Antimicrobial silver nanoparticles, a model protein (bovine serum albumin), and an antibiotic (gentamicin) were added to the hydrogel mixtures and their release from the dressings was monitored. In addition, phenol red-methacrylate was co-polymerized into the hydrogel dressing and exhibited a pH-responsive colour change suitable for the detection of infection.
Elucidating Effects of RYR1 in a Zebrafish and a Novel Recessive Mouse Model
Keywords: Ryanodine Receptor 1

Congenital myopathies are a genetically heterogeneous group of neuromuscular disorders that typically present in childhood and are associated with an estimated prevalence of one in 26,000 live births. These myopathies present with significant morbidities, including wheelchair and ventilator dependence. RYR1-related myopathies are defined by mutations in Ryanodine Receptor 1 or RYR1, the gene for the protein RyR1, an intracellular Ca2+ channel required for muscle contraction. Despite the severity of this disorder, there are no treatment options available for RYR1-related myopathy patients. To address this, I screened an ryr1a-/-; ryr1b-/- zebrafish mutant against 2,000 well-characterized compounds, none of which restored mutant levels to wild type. As a secondary aim, I performed a phenotypic analysis of a recessive mouse model that recapitulates several characteristics of these myopathies that will one day serve as a useful model for therapeutic development. This work herein explores the complicated spectrum of RYR1-related myopathies and expands our current understanding.
Probing drug-binding to NBD1 of SUR2A, the regulatory subunit in cardiac KATP channels
Keywords: ABC proteins
ATP-sensitive K+ channels
drug interactions
Fluorescence spectroscopy
NMR spectroscopy
nucleotide binding domains

The sulfonylurea receptor 2A (SUR2A) forms the regulatory subunit in ATP-sensitive potassium (KATP) channels in the heart. KATP channels open upon MgATP binding and hydrolysis at the SUR2A nucleotide-binding domains (NBDs). Channel gating by SUR2A is essential, as mutations in SUR2A NBDs cause cardiovascular disorders. Further, SUR proteins are binding sites for KATP channel openers (KCOs) drugs and pharmacological chaperones that rescue trafficking defects in mutant KATP channels. Previously we showed binding of KCO pinacidil to SUR2A NBD1 increases affinity of protein for MgATP, providing a mechanism by which pinacidil increases KATP channel gating. However, the site of drug binding is unknown. To this end, we used NMR spectroscopy to probe effects of mutations for drug binding. Our data showed drug-induced allostery with residues that bind MgATP. Structural information gained is essential for rationale design of more potent and selective drugs to treat molecular defects in the NBDs.
Inflammation and Mitochondrial Dysfunction in Type I Bipolar Disorder
Keywords: Biobank
Bipolar Disorder
Inflammation
Mitochondria
NLRP3 Inflammasome

Bipolar disorder (BD) is a chronic psychiatric illness and a leading cause of disability worldwide. Several lines of evidence suggest that mitochondrial dysfunction and inflammation are present in BD. Our objective was to investigate if there was evidence for NLRP3 inflammasome activation as a link between inflammation and mitochondrial dysfunction in peripheral samples of BD. Sera, peripheral blood mononuclear cells, and DNA were obtained from 205 participants with type I BD and 205 non-psychiatric controls. We observed large differences between recruitment sites in levels of serum cytokines and L-lactate. However, controls and BD cases were not recruited from the same sites and the observed differences were largely be explained by transit time 協 the time between blood draw and when the sample arrived at the central biospecimens laboratory. The present study highlights problems inherent involving collection of biospecimens for biobanks and provides recommendations for how future studies should be conducted.
Clinical and Economic Outcomes for Gastric Cancer Patients Treated with Gastrectomy at Centres With and Without Cancer Surgery Designation in Ontario
Keywords: Clinical Outcomes
Economic Outcomes
Gastrectomy
Gastric Cancer
Specialization

Gastric cancer places high clinical and economic burden on healthcare systems. This study compares patient outcomes between centres with and without cancer surgery centre designation (CSCD). Gastric cancer patients diagnosed 2002-2014, and treated with gastrectomy were identified using Ontario’s linked administrative databases. Outcomes included 90-day mortality, overall survival, and healthcare costs. Institutions with CSCD (n =1,436) were associated with lower 90-day mortality (OR 0.70, 95% CI 0.52-0.94, p=0.02), and similar overall survival (HR 0.94, 95% CI 0.85-1.04, p=0.24) as institutions without CSCD (n = 1,494). The cost analysis included 1,143, and 1,256 patients treated at institutions with and without CSCD, respectively. Adjusted mean monthly costs were $3,310 (95% CI $2,384-$4,595) for the CSCD group, and $3,430 (95% CI $2,469-$4,765) for the non-CSCD group (p=0.36). Treatment at institutions with CSCD may result in lower 90-day mortality, and similar overall survival, and costs of care for gastric cancer patients.
A Computational Fluid Dynamics Approach for Dissolved Oxygen Modelling with Application to Wind-powered Aeration Systems
Keywords: Aeration Systems
Aquaculture
CFD
Dissolved Oxygen

Dissolved oxygen is one of the most critical parameters of water quality in aquaculture. Aeration systems are generally used to improve oxygen levels and yields. However, these systems have high capital and operating cost, require electricity and, thus, are out of reach for farmers in developing countries. There is a need for affordable and sustainable aeration technologies. This thesis presents the development of a computational dissolved oxygen model which evaluates the spatial and temporal distribution of dissolved oxygen to enable evaluation and optimization of new aeration approaches. The three-dimensional model was developed based on Finite Volume Method and validated by bench-scale and field experiments. Results showed that the model was capable of predicting the dissolved oxygen concentration with an average prediction error of 7.2%.
The Synthesis and Optimization of Non-commercially Available Phthalonitriles and their Pathway to Novel Boron Subphthalocyanines
Keywords: Biomass Sources
Boron Subphthalocyanines
Halogenation
Methylation
Phthalonitriles
Solar Energy

Even though they are the precursors to boron subphthalocyanines, there are many phthalonitriles that are not commercially available; furthermore their synthesis has never been approached for the purposed of scale-up and the industrial manufacturing of boron subphthalocyanines. While the synthesis of brominated and iodinated phthalonitriles is not novel, their incorporation into boron subphthalocyanines for characterization and potential use as organic photovoltaics is. This work outlines the synthesis of 4-bromophthalonitrile, 4,5-dibromophthalonitrile, 4,5-diiodophthalonitrile, and 3-methylphthalonitrile and the pathway to their subsequent boron subphthalocyanines. Discussion is also included on the failure to synthesis 3,4,5,6-tetrabromophthalonitrile and 3,6-dimethylphthalonitrile.
Facilitators of, and Barriers to, Accessing Reproductive Care in Canada for Same-sex Male Couples (SSMC) and Single Men (SM)
Keywords: assisted reproductive technology
egg donation
health care experience
same-sex male couples
single men
surrogacy

Same-sex male couples (SSMCs) and single men (SM) are increasingly using assisted reproductive technologies (ART) to have children, yet research on their experience accessing care in Canada is limited. The objective of this preliminary study was to evaluate experiences of SSMCs and SM who have pursued ART in Canada. Data were collected from 08/2018 - 01/2019 through convenience sampling using a 58-item anonymous online survey. Seventy-two completed surveys were used for the analysis. Four of five participants (n=58, 80.5%) had a positive overall experience using ART. Resources such as high socio-economic status and social support were facilitators to accessing ART in Canada. Barriers to accessing care included: cost, time commitment, experience of stigma, and difficulties securing third parties when using ART. This research may guide practice and policy implications for reproductive healthcare services in Canada, such as provision of funding to make ART more accessible to all demographics.
Nutrition and Academic Achievement: How Nutrition Protocols Affect International Students’ Food-choices and Academic Achievement in Higher Education. A Case Study for African International Students at the University of Toronto, St. George Campus (UTSG)
Keywords: "Academic Achievement"
"African International Students"
"Food-Choices"
"Inclusion and Diversity"
"Organizational Culture"
"Policy and Human Rights"

The University of Toronto (U of T) is referred to as a “city within a city”. This maxim is meant to imply that the University of Toronto epitomises all the characteristics of the City of Toronto which is commonly portrayed as ‘the most diverse urban centres of the world’. But how diverse is the University of Toronto and how effective are the university’s diversity and inclusion policies? This thesis draws from a Culturally Sensitive Nutritional Framework (CSNF) to examine the extent to which African international students are excluded from the food-choices offered by the University of Toronto food-service providers and how such unintended actions affect those students’ academic success and overall life experience at the university. Using oral-interviews, in-depth review of the literature, secondary sources, websites, as well as reviewing U of T’s nutrition protocols and the university’s Equity, Diversity and Inclusion (EDI) policies, I examined three related questions. (1) What are the current U of T EDI policies and nutrition practices, operating systems, rules and regulations? (2) How sensitive are these strategies, schemes and codes to the nutritional needs of African international students? (3) What are the programming shortcomings in these policies, operating principles, practices, rules and regulations and how can they be addressed? More specifically, the aim of this research was twofold. First, to evaluate the extent to which these protocols enhance the academic performance of African international students at the St. George Campus; and second, to provide suggestions on how these protocols could be further enriched to better serve the interests of African international students. The goal was to analyze effects of these protocols at the University of Toronto St. George campus and evaluate their potential relevance to the well-being of African international students. I argued that high-academic achievement is possible if the University of Toronto provides culturally sensitive nutritional choices to all international students and specifically African international students. The findings indicated diverse perceptions of nutritional needs and consequences for African international students. There were also evidence of implicit gaps among existing nutrition protocols and inclusion policies. Four recommendations are suggested to bridge existing gaps to ensure all international students are offered justifiable opportunities to enjoy thriving lives during their academic careers at the University of Toronto.
Memories of Mistrust and Contamination: The Legacies of Cosmos 954 and Operation Morning Light in Denendeh
Keywords: community memory
Denendeh
environmental contamination
Indigenous
Northwest Territories
nuclear radiation

On January 24, 1978, the nuclear-powered Soviet satellite Cosmos 954 burned up over the Northwest Territories. Radioactive satellite debris dispersed across hundreds of square kilometres of land, including several communities. Working with nuclear emergency teams from the United States, the Canadian military undertook a months-long operation to recover this hazardous debris from the landscape. Government accounts of “Operation Morning Light” highlighted the mission’s successes in locating harmful debris, emphasizing the negligible risk that most debris posed to the predominantly Dene and Métis communities affected. These authoritative narratives obscured the legacies of Cosmos 954 in communities like Lutsel K’e and Fort Resolution, where people still question the effects of Cosmos 954 on their traditional land, Denendeh. Their memories of the event reveal a lingering mistrust of government risk assessments and an ongoing uncertainty about the hazards of Cosmos 954 debris, especially as part of larger concerns about environmental contamination in Denendeh.
Multi-UAV Path Planning and Guidance for Cooperative Hunting in a Cluttered Environment
Keywords: Collision avoidance
Cooperative hunting
Guidance
Path planning
Rendezvous
UAV

This thesis presents a path planning and guidance algorithm for cooperative hunting by a group of multi-rotor Unmanned Aerial Vehicles (UAVs). A group of intelligent UAVs called pursuers work together to capture a single evader. The target is known to be within a certain region called the target zone. Particle Swarm Optimization is used to generate near-optimal safe paths for the pursuers to get from their base location to the target zone in the presence of static obstacles. Once the pursuers reach the target zone, Proportional Navigation guidance law is used in conjunction with the Potential Field algorithm and Rendezvous Law to simultaneously encircle the target. Previous work done in the cooperative hunting problem does not address the important aspect of rendezvous. Simulations as well as experimental results are shown to demonstrate the feasibility and effectiveness of this work after testing in different scenarios.
Dissecting the Aactin Isoform Specificity of the Formin DIAPH3
Keywords: Actin cytoskeleton
DIAPH1
DIAPH3
Formin
Isoform-specific actin nucleation

The dynamic actin cytoskeleton, made up of structurally distinct actin filaments, drives a variety of basic biological processes, including cytokinesis, cellular migration, and differentiation. In mammals, actin filaments are polymerized from two or more near-identical actin isoforms that perform isoform-specific functions. The ubiquitous β- and γ-actin are distinctly regulated in part by the isoform-specific polymerization activity of the actin nucleators DIAPH1 and DIAPH3. Here, I report that DIAPH3’s β-actin specificity is dependent on a 19 amino acid sequence within the actin-binding FH2 domain, while DIAPH1’s γ-actin specificity appears to require additional components. I also identified additional actin processing proteins capable of polymerizing actin in an isoform-specific manner. Taken together, these results show that the isoform-specific function of β- and γ-actin are driven by isoform-specific regulation of actin polymerizing proteins. Furthermore, more than one mechanism exists to drive the isoform specificity of different actin nucleators.