VictorJuiz/thesis huggingface dataset:
3R Ambassadors and the Governance of Recycling Practices in Toronto
Keywords: community building
everyday environmentalisms
neoliberalisms
recycling
volunteer

The mainstreaming of environmental concern has projected environmental intervention and regulations into all aspects of contemporary everyday life. Yet everyday environmentalisms are often critiqued as ineffectual neoliberal instruments that depoliticise environmental action, and narrow the possibilities of systemic change. In this thesis, I explore the logics of everyday environmentalisms through recycling volunteers in Toronto. Volunteers demonstrated neoliberal tendencies in their narratives of social change, and through affective responsibilisation. But for the most part, volunteers drew meaning from place-based social ties and attachments. Furthermore, volunteers’ experience were often more than about the environment. In some cases, the recycling project was also bound up with multiple politics; for instance, over decision-making or resource allocation authority, the various ways one participated within a supposedly technocratic waste regime, and re-directing flows of discarded materials. Taken together, the case of Toronto’s 3R Ambassadors show that such mundane practices embody possibilities and potential for everyday environmental governance to circumvent dominant neoliberal logics.
THE EFFECTS OF PHONOLOGICAL SHORT-TERM MEMORY AND EXECUTIVE WORKING MEMORY ON READING COMPREHENSION IN ELEMENTARY STUDENTS: A LONGITUDINAL STUDY
Keywords: ELL students
English language proficiency
Executive working memory
Phonological short-term memory
Reading comprehension

This longitudinal study looked at the contributions of executive working memory (EWM) and phonological short-term memory (PSTM) to reading comprehension in ELL elementary students while controlling for English language proficiency. Participants were assessed once a year, in grades 4-6. Results revealed that EWM contributed to reading comprehension above and beyond PSTM across the three years. The mediating effect of English language proficiency on the association between EWM and reading comprehension was also studied. Results showed that the association between EWM and reading comprehension was partially mediated by English language proficiency in Year 1, and fully mediated in Years 2 and 3 respectively. Growth model analysis did not show a developmental trajectory in reading comprehension across the three years. To conclude, EWM had a unique contribution to reading comprehension, which was greater than PSTM. Language proficiency had a mediating effect on EWM’s contribution to reading comprehension.
Resolving the synovial fluid proteome and peptidome for disease-specific mediators of inflammatory arthritis
Keywords: Mass spectrometry
Peptidomics
Proteomics
Psoriatic arthritis
Rheumatoid arthritis
Synovial Fluid

Early administration of therapeutic agents is a leading approach to impede the progressive destruction of articular joints plagued by inflammatory arthritis (IA). Unfortunately, diagnostic tools for the detection of IA during its pre-clinical stage are greatly lacking. Soluble biomarkers originating from sites of synovitis may reveal the molecular constituents of aberrant signalling pathways leading to the development of arthritis. Our objective was to facilitate the discovery of putative biomarkers of IA and its subtypes, rheumatoid arthritis (RA) and psoriatic arthritis (PsA), by mining for proteins and peptides secreted into the synovial fluid (SF). Using a label-free, mass spectrometry (MS)-based approach, 419 proteins and 288 peptides were identified in IA SF. When supplemented with bioinformatic analysis, 11 and 16 high-priority protein and peptide candidate biomarkers were identified, respectively. Investigations into the biological and molecular relevance of selected candidates has revealed possible pathogenic roles in IA and its specific subtypes.
Method for the Selection of High Quality Sperm via Two-dimensional Slither Swimming
Keywords: fertility
intracytoplasmic sperm injection
in vitro fertilization
planar swimming sperm
slither swimming sperm
sperm selection

Sperm locomotion is central to natural conception and assisted reproduction. Most sperm selection technologies rely on sperm motility in bulk fluid. In vivo, however, sperm tend to accumulate and transit near surfaces, often using a two-dimensional slither swimming mode, where the entire body of the sperm is confined within 1 μm of the surface. The most significant contribution of this thesis is the finding that a subpopulation of sperm capable of slither swimming possess enhanced DNA integrity compared to the motile and raw sperm populations. This result is found in both high-quality donor as well as low-quality patient semen samples. Selection of sperm based on their ability to swim in a slither mode was made possible in this work by the development of a microfluidic platform, which additionally offers a means to readily implement this sperm selection strategy in clinical workflow.
The Association of COG5 and SRD5A3 Gene Mutations to ER Stress Activation and their Role in Retinal Degeneration
Keywords: DNA Damage
Endoplasmic reticulum
Golgi
Leber congenital amaurosis
PERK
Unfolded protein response

Five individuals were diagnosed with Leber’s congenital amaurosis, an early-onset inherited vision disorder. Two unrelated individuals have a homozygous mutation in SRD5A3 (p.W19X). The remaining three are siblings that have compound heterozygous mutations in COG5 (p.M32R; p.S777Q_fs*14). Both SRD5A3 and COG5 play critical roles in glycosylation, which if disrupted could result in ER stress. Transfection of wild-type or mutant variants of SRD5A3 or COG5 in vitro found no link between SRD5A3 and ER stress. However, PERK was significantly upregulated in response to compound transfection of the mutant COG5 variants. Immunocytochemical staining revealed that the compound COG5 mutants lead to a significant increase in Golgi fragmentation and DNA damage. Treatment of the transfected cells with PERK inhibitor, GSK2606414, reduced DNA damage levels to that of the control. This study is the first to associate COG5 disruption with ER stress and has identified a potential therapeutic target for patients with COG5-related disorders.
The Influence of the Hypogastric Nerve in the Bladder Inhibitory Reflex Induced by Saphenous Nerve Stimulation in Anesthetized Rats
Keywords: Bladder
Hypogastric Nerve
Saphenous Nerve
Saphenous Stimulation

Saphenous nerve (SAFN) stimulation has been shown to modulate bladder activity however, the reflex mechanism remains unknown. This study analyzed the influence of the hypogastric nerve (HGN) in the SAFN-bladder activation pathway. The SAFN was stimulated for 40-minutes (50 and 100 µA intensity) in 33 female rats during continuous cystometry. Animals were divided into four experimental groups: (1) HGN intact, saline, (2) HGN transected, saline, (3) HGN intact, acetic acid, and (4) HGN transected, acetic acid (HGNt-a). Stimulation in HGNt-a animals elicited significant changes in urodynamic activity and, in all groups, SAFN stimulation suppressed reflex bladder contractions (25-50% incidence rate). Results suggest that HGN efferent fibers are not critical in this inhibitory mechanism; rather, HGN afferent fibers provide an excitatory input that counters bladder inhibition during SAFN stimulation. From a clinical perspective, SAFN stimulation may be relevant for treating urinary symptoms associated with interstitial cystitis.
Aprepitant for the Prevention of Acute Chemotherapy-Induced Nausea and Vomiting in Children: Overcoming Barriers
Keywords: aprepitant
chemotherapy-induced nausea and vomiting
clinical practice guidelines
drug interactions
pharmacokinetics

Aprepitant is an effective antiemetic for the prevention of acute chemotherapy-induced nausea and vomiting (CINV) in children. This thesis presents an updated clinical practice guideline for the prevention of acute CINV that recommends children receiving highly emetogenic chemotherapy be given an antiemetic regimen that includes aprepitant. However, aprepitant-antineoplastic drug interactions and lack of a commercially available aprepitant oral liquid formulation limit its utility. A systematic review of aprepitant-drug interactions was undertaken to identify clinically significant interactions. Significant pharmacokinetic interactions were found between aprepitant and the following antineoplastic agents: bosutinib, cabazitaxel and cyclophosphamide. A crossover study was conducted in healthy adult volunteers to establish the relative bioavailability of an extemporaneous aprepitant oral suspension compared to the commercially available capsule. Relative bioavailability of the oral suspension was found to be 82.3%, demonstrating sufficient absorption of aprepitant to have an antiemetic effect. Overall, these projects have addressed barriers to aprepitant use in children.
Laboratory Methods to Improve Quantification of Microplastic Ingestion by Marine Organisms Under Climate Change Stressors
Keywords: Climate Change
Microplastic Pollution
Multiple Stressors
Ocean Acidification
Ocean Warming

Human impacts on the environment pose serious threats to the planet’s oceans. This thesis presents methods to quantify microplastic ingestion by marine organisms under ocean warming and acidification. First, a study utilizing a novel high-throughput screening device with CO2 concentration and temperature gradients was completed to quantify microplastic ingestion by copepod, Tisbe biminiensis, under multiple temperature and CO2 levels. Due to limitations in the methods of that study, three additional methods were developed: (i) a low-cost customizable climate-change incubator capable of regulating temperature and CO2 for larger volumes and longer exposures; (ii) a fluorescent microplastic dyeing method enabling tracking of different microplastic types and shapes in exposure studies; and (iii) a digestible fluorescent microplastic coating method enabling enumeration of microplastic ingestion. The methods developed here enable screening impacts of multiple stressors, and improve realism in microplastic experiments, to properly depict future ocean conditions and their subsequent effects on marine life.
Exploring Approaches to Enhance the Anti-Leukemic Function of Double Negative T Cell Therapy
Keywords: acute myeloid leukemia
adoptive cellular therapy
cancer immunotherapy
chemotherapy
CRISPR screen

Chemotherapy resistance in acute myeloid leukemia (AML) is a prevalent problem that contributes to disease relapse and patient death; hence, novel therapies are needed to improve patient outcomes. Our lab has shown that allogeneic double negative T cells (DNTs) target the majority, but not the entirety, of primary AML blasts in vitro and in patient-derived xenograft models. Given the differences in the modes of action of DNTs and chemotherapy, we sought to determine if DNT therapy can be combined with conventional chemotherapy to target chemotherapy-resistant disease. To this end, we employed a xenograft model and in vitro assays. To further understand AML resistance or susceptibility to DNTs, we conducted a CRISPR screen to discover genes that may influence DNT-mediated cytotoxicity of AML. Overall, our results demonstrate the enhanced efficacy of DNT therapy following conventional chemotherapy and also shed light on mechanisms involved in the interactions between DNTs and AML.
A Descriptive Analysis of Older Adults Who Initiated Denosumab in Ontario, 2012/02 – 2015/03
Keywords: denosumab
osteoporosis
pharmacoepidemiology
rheumatology

Denosumab was added to the Ontario Drug Benefit formulary for patients at high risk of osteoporotic fractures in 2012/02. We described patients who initiated denosumab from 2012/02-2015/03, stratified by community and long-term care (LTC) residence. We identified 46,797 patients (97% female; 13% LTC), averaging 1,263±187.1 new patients monthly. Patient characteristics remained relatively stable, yet one-fifth had no prior osteoporosis drug use, which increased over time. Community-dwelling patients had a higher prevalence of bone mineral density testing, yet were younger, and had a lower prevalence of hospitalizations and hip fractures, compared to LTC patients. Patients received an average of four denosumab doses and persisted for 1.7±1.1 years: 75.2% ≥1 year, 59.8% ≥2 years, and 49.2% ≥3 years. Of those who stopped, 58.4% returned ≤4 years. New exposure to denosumab is increasing steadily in Ontario, yet further research examining how patient characteristics impact the safety and effectiveness of denosumab is warranted.
Regulation of SH3PX1 by dNedd4-long at the Drosophila melanogaster neuromuscular junction
Keywords: sorting nexin
synaptogenesis
ubiquitin ligase

Drosophila Nedd4 (dNedd4) is a HECT E3 ubiquitin ligase present in two isoforms: short (dNedd4S) and long (dNedd4Lo), with the latter containing two unique regions (N-terminus and Middle). While dNedd4S promotes neuromuscular synaptogenesis (NMS), dNedd4Lo inhibits it and impairs larval locomotion. To explain how dNedd4Lo inhibits NMS, mass spectrometry was performed to search for binding partners and identified SH3PX1, which binds dNedd4Lo unique Middle region. SH3PX1 contains SH3, PX and BAR domains, and regulates active zone ultrastructure and presynaptic neurotransmitter release at NMJs. Here, I demonstrate direct binding of SH3PX1 to the dNedd4Lo Middle region via the SH3PX1-SH3 domain. Overexpression of dNedd4Lo in the muscle, but not presynaptic terminals, reduces levels of SH3PX1 at the SSR. While dNedd4Lo does not genetically interact with SH3PX1 to regulate larval locomotion, larvae that overexpress dNedd4Lo and are heterozygous for SH3PX1 display increased neurotransmission compared to dNedd4Lo or SH3PX1 mutant larvae alone.
Biochemical Analysis of Strains of α-Synuclein Aggregates
Keywords: Neurodegeneration
Prion-like
Protein misfolding
Strains
Synucleinopathies
α-Synuclein

The synucleinopathies are progressive, neurodegenerative diseases of aging characterized by the accumulation of α-synuclein aggregates. α-Synuclein aggregates are prion-like and amplify in a prion-like manner. A key feature of prions is the existence of different strains, where depending on the conformation, a different prion disease is manifested. The existence of α-synuclein aggregate strains is an area of active research and provides a potential explanation for the clinical heterogeneity of the synucleinopathies. The overarching aim of this project was to investigate α-synuclein’s ability to form strains and understand their biological consequences. Using recombinant protein, we created and characterized two unique strains of α-synuclein fibrils, which induced different clinicopathological disease phenotypes in a mouse model (TgM83 mice). This approach provides evidence that conformational differences alone are sufficient for causing different disease phenotypes, demonstrating α-synuclein’s ability to form strains and that strains may be biologically relevant to disease pathogenesis.
Analysis of Specialized Subcellular Regions in Cardiac Myocytes in Health and Disease
Keywords: Cardiac
Nucleoplasmic reticulum
Pressure-overload cardiac hypertrophy
Super-resolution microscopy

The nucleoplasmic reticulum (NR) and sarcoplasmic reticulum (SR) are critical intracellular subdomains within the cardiomyocyte. Despite their importance, there are large gaps of knowledge regarding these compartments. Here, I elucidated some of the molecular constituents within the NR of mouse ventricular cardiomyocytes, which contain SR and endoplasmic reticulum (ER) proteins, including SERCA2A, RyR2, and calnexin. For the first time, I revealed the presence of STIM1 within these invaginations, suggesting the existence of store-operated Ca2+ entry (SOCE) mechanisms within nuclei. Furthermore, super-resolution imaging (dSTORM) quantitatively assessed nanoscale changes in SR protein cluster properties with pressure-overload cardiac hypertrophy. DHPR and RyR2 reorganized into dispersed, low-density protein clusters; in contrast, SERCA2A became sequestered into highly dense protein clusters. Moreover, the amount and size of SERCA2A-containing nuclear invaginations increased in pathological hypertrophy. These findings shed light on the molecular constituents of the NR and reveal the dynamic nature of the SR in disease.
Microbe and host-derived mechanisms of protection from autoimmune diabetes in non-obese diabetic mice
Keywords: autoimmune
CD4
diabetes
islet
microbiota

Autoimmune diabetes results from T cell-mediated destruction of insulin-producing pancreatic β cells in both humans and non-obese diabetic (NOD) mice. Our lab previously observed that cecal microbial transfer from male NOD mice into weanling females (MF) conferred protection in the recipients. The goal of this thesis was to investigate the effects of microbial transfer on autoantigen presentation and islet-reactive CD4+ T cell responses. We found that the proliferation of islet-reactive T cells did not vary in response to autoantigen presentation in MF recipients compared to controls. However, peripheral antigen presenting cells from MF recipients promoted a more activated T cell phenotype ex vivo compared to controls. Moreover, CD4+ T cells with major diabetogenic potential were identified in the islets. Since CD4+ T cells are central to immunological events in autoimmune diabetes, analysis of islet-reactive CD4+ T cell responses will shed light in mechanisms of microbe-dependent protection from autoimmune diabetes.
Differential Atrial and Ventricular Remodeling in Response to Endurance Exercise
Keywords: Atrial Fibrillation
Cardiac remodeling
Endurance exercise
Mechanotransduction
TNFÎą
WNT

Cardiac remodeling, classified as physiological (i.e.exercise) or pathophysiological (i.e.heart disease), refers to biochemical, genetic, structural and functional cardiac changes that occur in response to stress. We have identified distinct remodeling patterns in mouse atria and ventricles in response to endurance swim exercise: exercise induced fibrosis, inflammation and atrial fibrillation(AF) in atria, while improving contractility and reducing arrhythmia vulnerability in ventricles. Although there is a strong link between AF and endurance exercise in humans, the underlying mechanisms are unknown. Pharmacological TNFÎą inhibition at 3-weeks after exercise commencement does not reverse the pathological atrial remodeling, indicating that remodeling occurs quickly and early. RNA-sequencing on 2-week exercised mouse atria and ventricles suggested that the ventricle undergoes a lesser degree of exercise-induced transcriptomic remodeling compared to the atria, and that TNFÎą-mediated atrial(but not ventricular) remodeling by TNFÎą is associated to changes in cell-cell adhesion and mechanotransduction-associated pathways(i.e.focal adhesion and integrin).
The Okapi (Oka) FERM Domain Protein Regulates Somatic Stem Cell Numbers and Cell Intercalation during Drosophila Oogenesis
Keywords: Drosophila melanogaster
FERM Domain Protein
Intercalation
Oogenesis
Proliferation
Stem Cells

Okapi (Oka) is a Drosophila melanogaster FERM domain protein that is essential for oogenesis. oka (CG34347) mutants are viable but display defects during oogenesis. Mutant ovaries showed enlarged and multilayered interfollicular stalks and germline disorganization. I generated endogenously and exogenously GFP-tagged Oka protein to examine the distribution of Oka. Oka was present in somatic cells of the ovary and localized to adherens junctions (AJs) in the germarium and follicles, including cap cells, follicular epithelium, intercalating cells that form the interfollicular stalk, and in migratory border cell clusters and centripetal cells. I found that oka mutant ovaries contained an increased number of follicle stem cells (FSCs), which could explain the increased somatic cell numbers, and is reminiscent of overactive signalling pathways such as Hippo and Hedgehog. My findings suggest that Oka is a component of AJs that negatively regulates FSC numbers and is required for the intercalation of interfollicular stalk cells.
Identifying novel urinary tract pacemaker cell markers sheds insight into the development and function of those cells
Keywords: hydronephrosis
Kidney
Urinary tract pacemaker cells

Non-obstructive hydronephrosis, defined as dilatation of the urinary pelvis is the most commonly detected antenatal abnormality. Previously, our lab demonstrated that reduced Hedgehog-signaling in the metanephric kidney causes non-obstructive hydronephrosis with abnormal urinary tract peristalsis and loss of urinary-tract-pacemaker-cell (utPMC) markers. Our lab also demonstrated that utPMCs develop from the neural-crest-cell (NCC) lineage. UtPMCs are comprised of HCN3+ cells, and cKIT+ cells. Investigations of utPMCs are hindered by a lack of knowledge of markers and earlier developmental markers expressed before E15.5 (the onset of HCN3/cKIT expression). Markers enriched in HCN3+ utPMC RNA-sequencing were verified by qPCR and analyzed in cKIT+ cells. This identified 9 HCN3-cell markers, 2 of which were shared with cKIT-cells. Immunofluorescence revealed that PTK2Î˛ is expressed in NCCs at E12.5 and sustained till adulthood. Functional analysis revealed that PTK2Î˛ contributes to utPMC function. Identifying markers expressed earlier than E15.5 allows studies on utPMCs and hydronephrosis.
Co-delivery of Chondroitinase ABC and Pre-differentiated Progeny of Human Neuroepithelial Cells in Hydrogels to the Injured Spinal Cord
Keywords: Biomaterials
Cell Transplantation
Chondroitinase ABC
Hydrogels
Neuronal Precursor Cells
Spinal Cord Injury

The inability of injured axons to regenerate across the lesion that forms following a spinal cord injury is largely attributed to their reduced growth capacity, and the inhibitory microenvironment surrounding the lesion. To overcome these obstacles, a combinatorial strategy was designed involving the delivery of the enzyme chondroitinase ABC (chABC), from a methylcellulose hydrogel to degrade inhibitory molecules, and the transplantation of neuronal precursor cells in a hyaluronan-methylcellulose hydrogel to bridge the lesion. Although motor and sensory functionality was not recovered through this strategy in rat models of spinal cord injury, high levels of transplanted cells remained 8 weeks after transplantation, the cells retained a neuronal phenotype and migrated toward the lesion, despite being injected 1 mm away from the injury site. Future work involves determining the effect that chABC had in this system, and what modifications can be made to achieve functional recovery through this type of combinatorial strategy.
The Role of Sphingosine-1-Phosphate in Regulation of Multidrug Resistance at the Developing Blood-brain Barrier
Keywords: Brain development
Endothelial
Multidrug resistance
P-glycoprotein
Sphingolipids
Sphingosine-1-phosphate

P-glycoprotein (P-gp) is an efflux transporter on brain endothelial cells (BECs) that protects the developing brain. Sphingosine-1-phosphate (S1P) can modify P-gp function in the adult blood- brain barrier (BBB). This thesis determined the effect of S1P on the developing BBB. We hypothesized that S1P reduces P-gp function in primary cultured guinea pig BECs dependent on developmental age. Treatment of BECs with exogenous S1P or FTY720P (S1P analog) had no effect on P-gp function. BECs treated with high doses of FTY720 (precursor of FTY720P and inhibitor of S1P production) decreased cellular S1P and decreased P-gp function. Extended incubation with the highest dose of FTY720 or SKi II (inhibitor of S1P production) increased P- gp function. These results indicate that S1P is important for maintaining P-gp activity and disruption of the S1P-ceramide rheostat can change P-gp function at the BBB, altering brain exposure to P-gp substrates and potentially adversely affecting brain development.