VictorJuiz/thesis huggingface dataset:
NMR Studies of Lateral Diffusion of a Transmembrane Peptide in DMPC/DHPC Bicelles and Morphological Characterization of DMPC/CHAPSO Bicelles

NMR is used as a technique to study diffusion and morphology in bicellar model membranes. 1H stimulated-echo pulsed-field-gradient NMR was used to study lateral diffusion of the alpha-helical transmembrane peptide WALP19 with a polyethylene glycol (PEG)(MW 2000) tag incorporated into magnetically aligned bicelles. Both peptide and control lipid DMPE-PEG2000 exhibited normal Gaussian diffusion and followed Arrhenius-type temperature dependence, befitting the free-area model for lateral diffusion. Activation energy for peptide lateral diffusion (75 kJ/mol) was larger by 25% than that of the lipid, which is consistent with the triple layer model of the lipid membrane. The bicelles used had the canonical mixture of 1,2-dimyristoyl-sn-glycero-3-phosphocholine(DMPC)/1,2-dihexanoyl-sn-glycero-3-phosphocholine(DHPC), and were also compared with bicelles composed of DMPC and bile salt analogue CHAPSO. As assessed by 31P-NMR, DMPC/DHPC bicelles exhibit greater order, but CHAPSO-containing bicelles maintain magnetic alignment at higher temperatures. Surface charge on DMPC/CHAPSO bicelles dampens their differences with DHPC-containing mixtures in order and alignment.

Keywords: bicelles
lateral diffusion
phosphorus NMR
pulsed field gradient NMR
Advisor: Macdonald, Peter
Flexibility in Motivation and Well-being

Research on motivation has increased in complexity by acknowledging the role of higher order processes in shaping behaviour. It has been advanced that motivation can take on different orientations, but what has been left out is the importance of the ability to appropriately shift motivation orientation according to changing contexts. The present research project explores the nature of flexibility in motivation to changing contexts, as well as the contribution of motivational flexibility towards well-being. Motivation orientations are differentiated in behaviour, and patterns of association between motivation and well-being being to emerge. This research project begins to elucidate representations of motivational flexibility in brain and behaviour by operationalizing the construct and establishing strategies for further investigation.

Keywords: Motivation
Flexibility
Well-being
Advisor: Cunningham, William
The Influence of Peer Groups in Organized Sport on Female Adolescents' Identity Development

The purpose of this study was to explore the potential influence of peer groups in organized sport on female adolescent identity development. Data were collected through photo-voice and semi-structured interviews of eight female athletes between the ages of 13 and 17 years. Participants in the study played a variety of sports and competed at various levels. Results revealed that female adolescents tend to learn about three major aspects of the self: the social self, the physical self, and the psychological self, through interactions with their teammates in sport. Each aspect of the self was described in detail by participants using examples of characteristics learned through their peer groups in sport. The results of this study are examined in relation to classic psychosocial theories (i.e. Erikson and Festinger) as well as current literature in the field of sport psychology. Recommendations for future research in this field of study are discussed.

Keywords: sport psychology
peer relationships
adolescents
identity development
Advisor: Kerr, Gretchen
Long Range Hybrid Plasmonics

Long-range hybrid plasmonic modes are described in this thesis. It is achieved in two non-identical hybrid plasmonic waveguides coupled within a common metal layer, which form TE and TM antisymmetric and symmetric supermodes. The structural asymmetry allows the modal properties to be engineered for various plasmonic applications. In addition, the TM symmetric mode in a 200 nm wide waveguide achieves an improved loss-confinement balance with propagation loss less than 0.03 dB/μm and submicron mode size. It has demonstrated broadband operation without modal cutoff at wavelength of 2.5 μm. Furthermore, it shows capabilities in directional coupling, bends, and power splitting components with compact footprint while maintaining low insertion loss superior to a few major types of existing plasmonic waveguides. It has potential to become the platform for various plasmonic devices with improved performance and reduced footprint. Experimental measurements of the first batch of waveguide samples have identified challenges and suggested improvements for fabrication and characterization.

Keywords: Plasmonic Waveguide
Advisor: Helmy, Amr S.
High Throughput Microfluidic Platform Capable of Mimicking Key Vascular Microenvironments

The process of finding a new drug against a chosen target for a vascular disease usually involves high-throughput screening in static multi-well plates. However, due to the disconnect between cell behavior in static culture and the physiological environment, only a small fraction of move on to clinical trials. To address this, I designed and fabricated a multi-channel microfluidic platform capable of mimicking key vascular environments to be used for drug screening. An experiment studying the effects of TNFα on moncyte-EC adhesion were performed under flow conditions using the platform and in a static multi-well plate. Results showed a similar response in monocyte adhesion with the increase in TNFα dose in both conditions. However, wells with non-treated ECs in static plates produced 40x more florescence than wells with no monocytes. The microfludic platform however circumvents this issue by washing away these weakly adhered ECs allowing small dose variations to be noticeable.

Keywords: Microfluidics
High throughput screening
Drug Screening
Monocyte adhesion
TNF-alpha
Advisor: Simmons, Craig
Postoperative Pain In Paediatric Patients After Dentistry Under General Anaesthesia In The Ambulatory Setting

Purpose: To determine the prevalence, severity, and duration of postoperative pain in children ages 4-6 years undergoing general anaesthesia for comprehensive dental treatment that included extractions and/or pulp therapy in an ambulatory surgicentre in Toronto, Canada. Methods: This prospective cross-sectional practice-based study included 33 ASA I or II, English-speaking patients. The primary outcome of pain was measured by Faces Pain Scale-Revised (FPS-R) and Parents' Postoperative Pain Measure (PPPM) in recovery and at home, 2hr, 12hr, 24hr, 48hr, and 72hr postoperatively. Analgesic administration practices at home were also monitored. Results and Conclusions: The prevalence of moderate-severe pain was 29.0% by FPS-R and 40.0% by PPPM at 2 hours after discharge. Pain subsided over 3 days. Postoperative pain scores were statistically different from baseline scores (p

Keywords: Ambulatory
Anaesthesia
Dental
Paediatric
Pain
Postoperative
Advisor: Haas, Daniel
Nanoscale formulation strategy for therapeutic agents in the prevention of acute lung injury

Acute lung injury is a morbid complication with numerous causes and currently no effective clinical treatment. Studies have shown that Src protein tyrosine kinases (PTK's) play an important role in the onset of such acute inflammatory responses. We have previously developed a novel strategy using nanoscale combinations of self-assembling peptides (SAPs) and amino acids (AAs) for delivery of the hydrophobic Src PTK inhibitor, PP2, which otherwise has great restrictions in its introduction into aqueous systems. In the present study, a high-throughput screening model relevant to ALI was established in order to optimize SAP and AA components for the effective delivery of PP2. This strategy was also successfully applied to other hydrophobic compounds (such as rottlerin and curcumin). In conclusion, the techniques and screening strategies developed in the present study are widely applicable to multiple hydrophobic drugs not only in prevention of ALI, but for a variety of diseases.

Keywords: Acute lung injury
Drug delivery
High-throughput screen
Hydrophobic drug
Nanotechnology
Self-assembling peptide
Advisor: Liu, Mingyao
Multi-dimensional Carbon Monoxide Emissions Predictor For Preliminary Gas Turbine Combustor Design Optimization

The objective of this thesis was to compare the predictive capabilities of a new proposed reactor network methodology, to past methods in an attempt to determine which best predicts Carbon Monoxide (CO) emissions from aviation combustors. The proposed methodology focused on three key characteristics affecting CO emissions; the internal combustor flow field, combustion chemistry and liquid fuel evaporation. The proposed model was able to capture these characteristics using cold flow computational fluid dynamics, ideal reactors and correlations for evaporation and droplet size. The predictive capabilities of the models were tested by comparing calculated CO emissions against measured data from four aviation industry combustors. The proposed methodology performed better than past methods at predicting CO emissions and trends associated with increased thrust and alterations in droplet size. Additional testing is needed on variations in chemical mechanisms, combustor geometries and internal flow fields to further verify the application of this tool.

Keywords: Emissions
Combustion
Carbon Monoxide
Advisor: Sampath, Parthasarathy
Groth, Clinton
Molecular Mechanisms Of Chain Elongation, A Fundamental Process In Bacterial Biofilm Formation

Biofilm formation, the agglomeration of microorganisms on a surface, can account for greater than 80% of all human microbial infections. In a large group of Gram(+) and Gram(-) bacteria, a vital part of the biofilm scaffold is polysaccharide intercellular adhesin (PIA). To study the PIA synthase mechanism, 6-deoxy and 6-azido derivatives of GlcNAc, potential synthase inhibitors, were synthesized using optimized protection group chemistry. In vitro, expressed PIA synthase in E. coli membrane extracts was analysed by DispersinB and a malachite green phosphate assay. Biofilm microtitre well assays monitoring the cell growth and biofilm formation of E. coli and S. carnosus revealed the inhibition of biofilm formation by compound VP1 (IC50=1.48 mM). Whole cell MAS-NMR analysis of S. carnosus bacteria showed distinct 1H-NMR signals, useful for the analysis the PIA production. Together, the presented GlcNAc derivatives and the developed biological assays will facilitate the study the PIA synthase mechanism.

Keywords: Biofilm formation
glycosyl transferases
PIA
PNAG
Advisor: Mark, Nitz
The Behavioural Characterization of Dopamine D2 Receptor-related Protein-protein Interactions

Dopamine is one of the prominent catecholamine neurotransmitters in mammalian central nervous system. Dopamine is critically involved in a wide range of physiological functions including movement, motivation, reward, learning and memory, etc. The dopaminergic system exerts or modulates these physiological actions through four major signaling pathways. Clinically, the dysfunctions of the dopaminergic system are implicated in the patho-physiology of disorders such as Parkinson’s disease (PD), schizophrenia, attention deficit/hyperactivity disorder (ADHD), etc. At the molecular level, dopamine exerts its actions via its binding to dopaminergic receptors such as dopamine D2 receptors (D2R). In this study, two D2R-related protein-protein interactions were examined in vivo regarding their behavioural effects. The disruption of D2R-DAT interaction was found to elevate voluntary movement in normal animals as well as in animals modeling acute dopamine depletion. On the other hand, the interference in the D2R-DISC1 protein complex exhibited anti-psychotic actions in two animal models of schizophrenia.

Keywords: Neuroscience
Behavioural Physiology
Protein Interaction
Advisor: Liu, Fang
Systemic Inflammation Increases the Efficacy of Anesthetics that Target GABAA Receptors

Systemic inflammation markedly increases the neurodepressive properties of general anesthetics, for reasons that have remained poorly understood. The pro-inflammatory cytokine interleukin-1 beta (IL-1β) increases the surface expression of γ-aminobutyric acid type A receptors (GABAARs), implying an increase in the number of receptors for anesthetics. In this thesis, it was first postulated that IL-1β increases the potentiation of GABAAR activity by anesthetics in vitro. The results showed that IL-1β-treatment of hippocampus neurons produced greater etomidate- and isoflurane-induced potentiation of GABAAR activity compared with vehicle-treated neurons. Subsequently, it was postulated that behavioural endpoints that are modified by GABAergic anesthetics would be enhanced by systemic inflammation. The results showed that systemic inflammation produced by lipopolysaccharide enhanced etomidate-mediated immobility, hypnosis, and amnesia, and isoflurane-mediated hypnosis in mice. In contrast, systemic inflammation did not alter isoflurane-mediated immobility. Together, this thesis supports the notion that systemic inflammation enhances the efficacy of general anesthetics that target GABAARs.

Keywords: anesthesia
neuroscience
GABAA receptor
inflammation
Advisor: Orser, Beverley A.
Rescue of deltaF508-CFTR by Kinase Inhibitors

ΔF508-CFTR is a trafficking mutant that is retained in the ER, unable to reach the plasma membrane. To identify corrector of this mutant, we screened a kinase inhibitor library enriched for compounds clinically available or in clinical trials for the treatment of other diseases, using our recently developed high-content functional screen. Several inhibitors of receptor tyrosine kinases exhibited strong rescue of ∆F508-CFTR. Moreover, prominent rescue was also observed with inhibitors of four major pathways: Ras/Raf/MEK/ERK, TAK1/p38, Wnt/GSK-3β, and PI3K/Akt/mTOR. A complimentary siRNA screen was also performed to identify pathways involved in the rescue. FGFR1 and several proteins downstream of FGFRs were identified suggesting a possible role of these receptors in regulating ΔF508- CFTR trafficking. Moreover, the use of compounds clinically available or in clinical trials for other diseases can expedite delivery of treatment for CF patients.

Keywords: Cell Biology
Advisor: Rotin, Daniela
HV EDMOS Design with Expansion Regime Suppression

Lateral Extended Drain MOSFET (EDMOS) is one of the most popular high voltage structures used to implement modern smart power integrated circuits. However, conventional EDMOS suffers from an expansion effect of the IV characteristics under high Vgs and Vds conditions. This greatly degrades the safe operating area (SOA) of the devices and the performance of the power ICs. In this thesis, effective methods to suppress the expansion regime without sacrificing the important baseline device characteristics are introduced and analyzed. Enhancements to the baseline device structure include the implementation of PBE (P-Buried Enhancement), double implanted RESURF (Reduced SURface Field), NDE (N-Drift Enhanced) and NBD (N-Buffered Drain) layers. The optimized design is simulated and verified experimentally. An n-type EDMOS with BV of 70V, Ron,sp of 48mΩmm2 and no expansion effect until Vgs reaches 5.5V is successfully fabricated and tested.

Keywords: EDMOS
Expansion Effect
Impact Ionization Effect
Advisor: Ng, Wai Tung
The Role of SAD-1 Kinase in Caenorhabditis elegans Neuronal Circuit Development and Function

The SAD kinases are conserved regulators of neuronal polarity and synapse morphology. Although SAD kinases have been shown to play many different roles, the pathways through which they function remain largely unknown. Knockout mice for mammalian SAD kinases die immediately after birth. By contrast, C. elegans sad-1 genetic null mutants are healthy and viable, but exhibit a specific and fully penetrant locomotion defect. In this thesis, I identified where sad-1 activity is most critically required to regulate C. elegans locomotion. Furthermore, I isolated and mapped several genetic suppressors of the sad-1 locomotion defects, and determined the molecular lesion of one such suppressor, hp733. hp733 is a mutation in a conserved amino acid residue of a two-pore domain potassium channel, TWK-40. Further studies are needed to elucidate how SAD-1 functions through/with TWK-40 to regulate synaptic development and locomotion in C. elegans.

Keywords: molecular genetics
neurobiology
synapse development
neuronal polarity
Advisor: Zhen, Mei
Controlled Differentiation of Human and Mouse Embryonic Stem Cells to Kidney Precursors

Every year, patients require transplants or undergo dialysis to treat kidney disease. Therefore, it is increasingly important to develop new therapies to treat kidney disease. My project focuses on understanding kidney development. The long-term goal is to use embryonic stem cell differentiation with co-culture on decellularized kidney matrices to determine if different types of kidney cells can be derived from embryonic stem cells. I have developed a kidney precursor differentiation protocol and determined that a decellularized kidney matrix possesses biomolecules to direct differentiation. The co-culture system I have developed will allow us to study the interaction between kidney cells and the extracellular matrix. This should help us to understand kidney development and aid in the development of cell based therapies for the treatment of kidney disease. The ultimate goal is to generate a three dimensional culture system using stem cells to assess the potential of candidate cells for kidney therapy.

Keywords: Decellularization
Kidney Matrix
Controlled Differentiation
Embryonic Stem Cells
Growth Factors
Kidney development
Advisor: Rogers, Ian
Race, Representation and the Commodification of Poverty: A Pathways Case

This thesis brings under critical analysis the processes involved in rendering poverty a commodity by examining the discourses and images of the racialized poor circulated by agencies involved in the non-profit sector in their fundraising activities. I analyze the materials of Pathways to Education Canada, a non-profit organization operating in Regent Park, Toronto, as a case study for this analysis. With the launch of Pathways as a national non-profit organization, the reliance on depictions of racialized populations as deficient became a central feature in the rhetoric produced by the organization in order to gain funding for its operations. Recognizing the fiercely competitive fund-raising environment in which the organization must operate, Pathways employs several platforms such as the use of visual imagery, text, print and statistics in order to demonstrate its overall effectiveness and to attract potential donors.

Advisor: Razack, Sherene
Locating the Liminal: Discursive Practice and the Challenge of Empathy

Few authors agree on a standard definition of empathy, yet empathy is widely assumed to be easily accessible and innately pro-social regardless of factors such as power dynamics or other manifestations of social injustice within a society. Such assumptions in dominant discursive practices, both academic and popular, obscure the emergence of two important questions: what does it mean when we cannot empathize with another? And could it be that we may gain greater insight from the examination of empathy's limits and failures than the hopes we have for its success? I propose that discussions of empathy must be grounded in social context and that assumptions must be continually troubled if one is to have a cogent conversation, whether as a philosopher, psychologist, social theorist, educator, or policy maker, about what empathy is (or is not) and what it does (or does not) make possible.

Keywords: Discourse
Edith Stein
Empathy
Social context
Advisor: Bialystok, Lauren
Promoting Language and Literacy Engagement within a Preschool Spanish Language Program

This study focuses on the effectiveness of promoting preschool children's interest in and engagement with Spanish language and literacy by means of a program offered through a children's bookstore that exposed them to Spanish books, stories, and games. Considerable research indicates that the younger children are exposed to a second language, the better the long-term language benefits. An action research methodology was used to investigate which instructional activities promoted language and literacy engagement among toddlers whose parents come from different cultural and linguistic backgrounds. Interviews with parents were conducted to understand perceptions of their children's language learning and literacy engagement both in the Spanish class and outside. The findings suggest that children's motivation towards language learning and literacy engagement can be enhanced through the implementation of a Spanish language program that includes engaging activities and appealing materials.

Keywords: Bilingualism
Biliteracy
Dual Language
Early Childhood Education
Literacy
Primary
Advisor: Cummins, Jim
Critical Embodiment: Investigating the Intersection of Critical Pedagogy and Embodiment for the Prevention of Eating Disorders in Schools

Eating disorders have the highest mortality rate of any mental illness. Currently schools address eating disorders through prevention programs and health education courses that have shown to be ineffective in terms of changing behaviors of students in the long run (Piran 2005). This qualitative study explores the use of critical pedagogy as a mechanism by which teachers and students can address body-related issues (i.e. gender, sexuality) in schools. The medical term eating disorder, in this study, is replaced by the perspective of embodiment that helps expand the notion that eating disorders happen exclusively in response to the thin ideal. This study investigates, through semi structured interviews, the perspectives of 5 teachers to understand a) the ways in which educators address critical perspectives on gender and embodiment in their classrooms, and b) The implications of using critical pedagogy in the field of eating disorders prevention.

Keywords: Critical Feminist Pedagogy
Critical Literacy
Critical pedagogy
Curriculum
Developmental Theory of Embodiment
Eating Disorders
Advisor: Simon, Rob
Role and Potential Benefit of Teacher Collaboration in Elementary School

This research examines teacher collaboration in elementary school, its role, and potential benefit. Creating a collaborative educational environment can build a community of people who are working together to achieve the most important goals in their career: increase the students` and teachers` performance. Whether educators collaborate with others using the model of team teaching, work conjointly with other individuals, school administration, parents or inspire their students themselves to learn together, collaborative learning opportunities in education can bring lots of positive outcomes and benefits for teachers and students. In this research, I observed, audiotaped, and interviewed elementary school teachers who work with diverse students. In this study, I strive to show that teacher collaboration is one of the aspects of teachers` professional development, able to create a safe climate for teachers in which to talk about their individual and professional identity.

Keywords: collaborative learning opportunities
goals and benefits of teacher collaboration
school culture
teacher collaboration
teacher learning opportunities
teacher professional development
Advisor: Beck, Clive