VictorJuiz/thesis huggingface dataset:
A Transformerless Dual Active Bridge DC-DC Converter for Point-of-load Power Supplies

Point-of-load (POL) power supplies contribute significantly to the overall volume, weight, and cost of many electronic devices. This comes as no surprise given the major power density limitations of the buck converter commonly used in these applications. The goal of this thesis is to present a solution which addresses these limitations. This is achieved through the proposal of a novel converter topology, referred to as a transformerless dual active bridge (DAB) dc-dc converter. The proposed converter uses an ac-link to transfer power, instead of the more conventional dc-link, since it offers a significant reduction in the volume of the bulky inductor, as well as soft switching and 50% duty cycle operation of all active devices. The advantages of the proposed converter have been verified with a 12-3.3 V, 10 A, 0.3-1 MHz experimental prototype. The results demonstrate a reduction of approximately 50% in the volume of reactive components, while maintaining high power processing efficiency.

Advisor: Prodic, Aleksandar
An Investigation of Anti-LGBT Hate Crime Victimization, Narrative Processing, and Mental Health

Building on the large body of research that examines the prevalence and severity of anti-LGBT hate crimes, researchers have recently shifted their focus to the intervening cognitive-affective processes that may protect against or exacerbate negative mental health outcomes experienced by victims. The current study contributes to this burgeoning area of research by examining the relationship between narrative processing and mental health. Thirty LGBT participants provided narratives of their hate crime experience and completed measures of posttraumatic symptomology and depression. The narratives were coded for coherence, redemption, and meaning making. Quantitative analyses revealed an inverse correlation between narrative coherence and the severity of posttraumatic symptomology. Qualitative analyses exposed the diverse ways in which victims redeem and find meaning in hate crime events. The significance of these results is discussed within the context of psychotherapy with anti-LGBT hate crime victims.

Keywords: hate crimes
lesbian
gay
bisexual
transgender
narrative processing
Advisor: Gillis, J. Roy
Use and Effect of Quantitative Clinical Feedback for Learning and Quality Improvement in Anesthesiology

Providing quantitative performance feedback to individual clinicians and clinical groups has been suggested as a useful strategy to reduce preventable morbidity and mortality within medicine. Anesthesiology groups wishing to design a program of quantitative performance feedback will encounter few published accounts of how such systems are influenced by their contexts and the features that promote effectiveness and usability. Two case studies are presented here which highlight how program design is related to context and perceived effectiveness. Design features which supported usability included prioritizing actionability when choosing metrics, involving the group or end-users during metric creation and goal setting and providing frequent communication of results. Contextual features which were found to support usability included resource availability, a mature safety and learning culture within the organization, and the provision of active leadership to create a sense of purpose, harness motivators and overcome barriers.

Keywords: Adult learning
Anesthesiology
Delivery of health care
Outcome assessment
Process assessment
Quality Improvement
Advisor: Baker, G Ross
Oxytocin, Aggression, and Neural Activity in the Naked Mole-rat

The neuropeptide Oxytocin (OT) is involved in social bonding and pro-social behaviour, however its role in aggression and social status is less clear. The naked mole-rat (Heterocephalus glaber) provides a unique model organism in which to study the effects of OT, exhibiting a social hierarchy that emphasizes certain roles for castes within the colony: soldiers defend colonies against outsiders and workers cooperate within the colony. Here, we wanted to determine whether OT is associated with defensive aggression in soldiers. We compared the behaviour of workers and soldiers using a modified resident-intruder paradigm and quantified neural activity of OT neurons in the hypothalamic paraventricular nucleus (PVN) using immunohistochemistry. Our results show that soldiers were more aggressive than workers when paired with an unfamiliar animal. However, preliminary analyses of the PVN suggest that workers have greater OT neural activity than soldiers, implying that OT is not associated with aggression in soldiers.

Keywords: Aggression
Naked Mole-Rat
Neural Activity
Oxytocin
Paraventricular Nucleus
Social Status
Advisor: Holmes, Melissa M
An Exploration of the Role of Influentials in Increasing the Uptake of Evidence-Based Practice in Nursing

Objective: The purpose of this study was to explore the role of persons who influence the uptake of evidence-based practice in nursing. Methods: This was a two-phase study. First, a scoping review of the literature was undertaken on influential persons (influentials) in nursing. Second, semi-structured interviews with front-line nurses were conducted using grounded theory. Results: Eleven studies were included in the scoping review and 18 nurses from hospitals in Ontario were interviewed. The results from the initial conceptual framework, scoping review and interviews were triangulated to form a theoretical model. This study found that influentials are credible individuals who use social, educational and leadership characteristics and strategies to change behaviors, attitudes and increase job satisfaction. Other factors of importance are supportive organizational leadership and awareness of barriers. Conclusions: Credible influentials appear to be a promising strategy to influence the uptake of evidence-based practice in nursing.

Keywords: Evidence-based nursing
Knowledge translation
Advisor: Kennedy, Erin
Human GPCR Interactome and Investigation of the KCTD/beta2-adrenergic Receptor Interactions

G-protein-coupled receptors (GPCRs) are the largest family of transmembrane receptors with key roles in regulating signaling pathways targeted by therapeutics. To identify novel components of their pathways, the modified membrane yeast two-hybrid (MYTH) approach was used to generate an interactome of 50 full-length human ligand-unoccupied GPCRs in their native membrane environment. To demonstrate the biological relevance for the GPCR-interactome, I focused on identifying novel interactors of beta-adrenergic GPCRs (beta-ARs) due to their involvement in human diseases. I characterized novel interactors of beta-ARs identified by MYTH, namely KCTDs (K+-channel tetramerization domain containing proteins). To understand beta-AR/KCTD interactions, I studied their specificity, mechanism, and functional importance and determined that KCTD5, 13, and 16 specifically interact with all three beta-ARs (but not all GPCRs), require the presence of the G-protein beta-subunit, and affect pERK levels of beta2-AR. Further study of the molecular functions of these novel interactions may lead to GPCR-based drug discovery.

Keywords: cell signalling
G-protein coupled receptors
interactome
KCTDs
protein-protein interactions
receptors
Advisor: Stagljar, Igor
Angers, Stephane
Citation Use and Identity Construction: Discourse Appropriation in Advanced Academic Literacy Practices

Using a case study approach, this research investigated the intersection between citation use and identity construction by examining, as examples of advanced academic literacy practices, referencing in the Discussion sections of 5 completed Masters' theses. To understand how the authors of the theses constructed their identities as educators and researchers, I analysed semi-structured interviews, identity questionnaires, and the Discussion sections of their Masters' theses. I interpreted the data using Ivanič's (1998) framework for the discoursal construction of identity to examine how citation choices contributed to identity formation in graduate students' thesis writing. Analyses revealed connections between citation practices and identity construction. Participants' responses were most frequent for the citation functions of support and alignment. These findings promote an understanding of the processes involved in using others' words and ideas to legitimize knowledge. Consequently, I call for the demystification of academic integrity and pedagogies that recognize the complexities of citation practices.

Keywords: Citation practices
Identity construction
Advisor: Cumming, Alister
CD109 Plays a Role in Osteoclastogenesis

Osteoclasts are large multinucleated cells that arise from the fusion of hematopoietic stem cells from the monocytes-macrophage lineage and play an important role in bone metabolism, specifically in bone resorption. To date, many of the factors involved in Osteoclast fusion remain unclear. The objective of this project was to identify novel factors that regulate Osteoclastogenesis. Methods: microarray, Rt-qPCR and Western blot analysis were performed to identify novel molecules involved in Osteoclastogenesis. A stable CD109 knockdown macrophage cell line was generated using a retroviral shRNA construct. Results: CD109 was identified as a novel molecule that varies its expression during RANKL induced OCG. CD109 KD cell lines showed a deficiency in their osteoclast fusion capacity. Conclusions: pre-osteoclasts express CD109 at different levels while undergoing OCG. CD109 might be an important regulator of OCG although further characterization of its activity is still required.

Keywords: CD109
osteoclastogenesis
Osteoclast
Advisor: Glogauer, Michael
Screening of a Histone Methyltransferase Inhibitor in Animal Models of Psychiatric Illness

Development of drugs for neuropsychiatric conditions is in crisis, with no mechanistically new medications for treating major mental disorders having been developed in the past 30 years. There is increasing evidence that current antidepressants and antipsychotics can alter epigenetic regulation in the brain. Thus, the epigenetic molecules modulated represent potential new targets for drug development. We screened a small-molecule inhibitor (UNC0642) of the H3K9 (histone-3-lysine-9) methyltransferase, G9a, in animal behaviour models relevant to depression, anxiety and psychosis. We found that acute treatment with UNC0642 produces an antipsychotic-like effect in apomorphine-disrupted pre-pulse inhibition. In addition, we found that chronic treatment with UNC0642 was able to increase time spent in the open arms of the elevated zero maze, indicating an anxiolytic-like effect. Our results suggest that G9a may be a useful target for the development of new drugs aimed at treating psychosis and anxiety.

Keywords: depression
drug discovery
epigenetics
histone
psychiatry
schizophrenia
Advisor: Wong, Albert H. C.
Capillary Displacement Extraction Using Surfactant-Based Washing Techniques

In this study, the use of surfactants and solvents to promote capillary displacement of bitumen from aged oil sands fine particles and of lipids from microalgae was explored. The surfactant-based washing fluid was used to reduce the interfacial tension to facilitate the removal of oil by inertial and shear forces. For most of the extractions, the amount of oil recovered can be estimated considering the effect of inertial forces on the emulsification of oil. Larger solvent to substrate ratios produced thicker films that were easily removed. Using surfactant-only extraction was not sufficient to remove bitumen from oil sands or fines. The extraction of bitumen from fines was more challenging than oil sands due to their smaller particle size. The surfactant-solvent systems performed better than water-solvent systems for low solvent to substrate ratios. For microalgae, recoveries of up to 70% of transesterifiable lipids were achieved with extended surfactants only and up to 82% with a conventional surfactant-cyclohexane system.

Advisor: Acosta, Edgar J.
Fluid Inertia Damping Effects on Dynamic Engine Response

Current trends in engine development are moving towards higher specific power (high rotor speed) and lower weight to improve the fuel efficiency of aircraft. Unfortunately, this has the adverse effect of increasing the level of engine vibrations - higher specific power results in larger unbalanced loads while lower weight reduces the structural stiffness. To reduce the effects of engine vibration, squeeze film dampers (SFDs) are used to add damping to the structure. SFDs are commonly modelled using the Reynolds equation, which assumes inertial effects have negligible impact on the damper forces. However, this assumption is not true at the higher operating speeds of current engine designs. This thesis compares different models that include the effect of inertia on damper forces. The models are implemented into rotor systems representative of current engine designs and conclusions are drawn as to the significance of inertia effects on engine response.

Advisor: Behdinan, Kamran
Posterior Tibial Nerve Stimulation: A Study of the Effects of Stimulation Parameters on Urodynamic Changes in Anesthetized Rats

Although posterior tibial nerve stimulation (PTNS) has been shown in both clinical and animal studies to mediate inhibition of bladder function, our understanding of the role of posterior tibial nerve (PTN) afferents that elicit this reflex is significantly limited. To this end, we investigated the effects of frequency-dependent PTNS in urethane-anesthetized rats undergoing repeated urodynamic fills. Electrical pulses applied at both 5 Hz and 10 Hz resulted in significant decreases in the frequency of bladder contractions during and after 10-minutes of stimulation (acute inhibition and post-stimulation effect). Selective electrical activation of the lateral or medial plantar nerves confirmed that each type of bladder reflex can be elicited by individual subsets of PTN afferents. Our findings indicate that PTNS-evoked bladder reflexes are tuned to specific stimulation frequencies. The neuromodulation of bladder function achieved by selective PTN branch stimulation provides a novel insight into these neural pathways and also suggests potential clinical application.

Keywords: lateral plantar nerve
medial plantar nerve
neuromodulation
overactive bladder
posterior tibial nerve stimulation
Advisor: Yoo, Paul B
Traffic Jam, a Large Maf Transcription Factor, Regulates the Formation of the Germline Stem Cell Niche in the Ovary of Drosophila melanogaster

Cap cells form a niche for 2-3 germline stem cells (GSCs) in a Drosophila ovariole. Cap cells are organised in a cluster at the base of a terminal filament stalk. The transcription factor Traffic Jam (Tj) is expressed in cap cells, but not in terminal filament and germline cells. In a hypomophic tj mutant, cap cells appear to be specified normally. However, their morphology and behaviour changes and they are integrated into the stalk forming long terminal filaments. This reduces the niche size. Consequently, on average only 1.5 GSCs are present and are maintained properly. In tj null mutants, cap cells appear to be transformed into terminal filament cells. The transformed cells recruit one GSC, but cannot maintain it. Together these data indicate that Tj is required for the formation of cap cells and their organization into a cluster so that they can support 2-3 GSCs.

Keywords: oogenesis
germline stem cell niche
Advisor: Dorothea, Godt
Temporal and Spatial Evolution of Hudson Bay Sea Ice (1971-2011)

Previous work has found Hudson Bay seasonal sea ice particularly sensitive to climate change with a strong signal of earlier breakup dates. This work extends the analysis to include eight more years of sea ice data spanning 1971 to 2011. In addition, a spatial analysis using a grid of 36 locations in the Bay was done. The expanded sea ice record revealed stronger and more statistically significant trends than the earlier work, largely due to the accelerated temperature increase observed over the last decade, especially notable with later freeze-up dates. The spatial analysis was done using clustering statistics. Clusters of sea ice data points were found to be consistent with observed patterns of sea ice breakup and freeze-up. Clustering along the coasts for all three metrics had the greatest coherency suggesting that the shoreline provides a constraint that enables the ice within to act in a coherent fashion.

Keywords: 1971-2011
Accelerating Trends
Hudson Bay
Sea Ice
Spatial Trends
Temporal Trends
Advisor: Gough, William
Modelling and Control of a Vortex Arc Lamp for RTP Applications

The objective of this thesis is to develop a controller that can ramp the temperature of a semiconductor wafer in a controllable fashion. The semiconductor wafers are heated using vortex arc lamps, placed on either side of the wafer. The wafer is heated from room temperature to an intermediate level of around 900 degrees C in a ramp wise fashion before it undergoes flash annealing from the top surface. This thesis focuses on the control of the bottom lamps during the process of heating to the intermediate phase. The challenge in designing this control system is that the wafer temperature measurements are not available during the initial phase of the ramp and also that the resulting lamp current profile should be smooth and free of fluctuations. To achieve this, a vortex arc lamp model, a semiconductor wafer model and a suitable control strategy has been developed.

Advisor: Dawson, Francis P
The Effects of Mechanical Ventilation on Neutrophil Extracellular Trap Formation

Mechanical ventilation can physically injure the lung and induce a proinflammatory state. Ventilator induced lung injury (VILI) is associated with neutrophil influx into the lung. Neutrophils can release DNA and granule proteins as cytotoxic neutrophil extracellular traps (NETs). This project aimed to determine if NETs were formed and contributed to injury in a two-hit LPS/VILI mouse model. We found that the combination of LPS and mechanical ventilation induced generation of NETs. High tidal volume mechanical ventilation increased release of HMGB1, an inducer of NETs, over low tidal volume control. The combination of LPS and high tidal volume was the greatest inducer of IL-1β, another potential inducer of NETs. Intratracheal DNase treatment reduced NETs and attenuated the loss of static compliance in the LPS/VILI model. NETosis represents a novel therapeutic target for VILI.

Keywords: Ventilator induced lung injury
NETosis
Advisor: Palaniyar, Nades
Kavanagh, Brian
Chromatin Looping and Cell Type-specific Regulation of Sox2 Expression

The Sox2 gene encodes a HMG box transcription factor that plays a critical role in maintaining the self-renewal of embryonic stem (ES) cells and regulating neuroectodermal differentiation. Although Sox2 is expressed in ES cells and embryonic brain, cell-type specific regulation of Sox2 transcription remains unclear. In this thesis, I found that the chromatin architecture surrounding the Sox2 locus is highly cell type specific. The Sox2 promoter and proximal enhancers interacted with a cluster of putative enhancer candidates located 80-120 kilobases (kb) downstream to Sox2 in ES cells but not in embryonic brain, whereas in embryonic brain the Sox2 proximal region adopted a more compact chromatin conformation than ES cells. Also, the distal enhancer cluster showed higher enhancer activities than the Sox2 proximal enhancers in ES cells. Together, these results suggest that the novel enhancer cluster downstream to Sox2 plays an important role in ES cell specific regulation of Sox2 transcription.

Keywords: embryonic stem cells
chromatin looping
enhancer
transcriptional regulation
Sox2
Advisor: Mitchell, Jennifer
The Effect of Insulin on Atherosclerosis and Restenosis

Diabetes mellitus and metabolic syndrome, which are states of insulin resistance, are both well-known to increase the risk of atherosclerosis and restenosis. We present evidence that insulin itself is anti-atherogenic and anti-restenotic. Systemic insulin treatment decreases atherosclerosis independent of its effects on glycemia. Insulin-treated ApoE -/- mice showed a 42% decrease in plaque burden in the descending aorta and an increase in markers of plaque stability in the aortic sinus. We have previously shown that systemic insulin treatment decreases neointima area after arterial injury. However, systemic insulin treatment has the risk of hypoglycemia. Therefore we explored an alternative local route of application of insulin around the vessel via Pluronic gel in rats. We found that regular insulin and neutral protamine Hagedorn (NPH) insulin significantly decrease neointima area by 24% and 17% respectively at 28 days. These studies suggest that insulin is vasculoprotective.

Keywords: insulin
atherosclerosis
restenosis
NPH
neointima
plaque
Advisor: Giacca, Adria
Characterization of the N-terminal Region of the RNA-Binding Protein Smaug in Post-transcriptional Regulation During Drosophila Embryogenesis

The Drosophila sequence-specific RNA-binding protein Smaug (Smg) regulates the expression of mRNAs in the early fly embryo. It is the founding member of a conserved family of post-transcriptional regulators defined by an RNA-binding sterile alpha motif (SAM) domain. Smg regulates gene expression through its ability to repress the translation, and/or induce degradation of target mRNAs. Through a structure-function analysis using smg truncation mutants, I show that sequences N- and C-terminal to the Smg SAM domain are involved, and have partially redundant roles in mRNA decay. Moreover, another conserved region of Smg modulates the mRNA decay function of the N-terminal sequences in a transcript-specific manner. Finally, sequences within the Smg N- and C-terminal regions are also required for the degradation of Smg protein.

Keywords: Smaug
post-transcriptional regulation
Drosophila
RNA
Advisor: Smibert, Craig
Preference and Acceptability of Alternative Delivery Vehicles for Prenatal Calcium Supplementation among Pregnant Women in Bangladesh

In populations with low dietary calcium intake, prenatal calcium supplementation is recommended by the WHO to decrease the risk of hypertensive diseases of pregnancy. This study evaluated preference and acceptability for four different calcium delivery vehicles (conventional tablets, chewable tablets, unflavoured powder, and flavoured powder) among pregnant women in urban Bangladesh. Participants (n=132) completed a 4-day run-in period in which each vehicle was sampled once, followed by a 21-day selection period during which participants were free to select a vehicle of their choice on each day. The probability that participants selected the conventional tablets was greatest (62%), followed by chewable tablets (19%), flavoured powder (12%), unflavoured powder (5%), and no delivery vehicle (2%). The present assessment of participants’ actual supplement use and expressed perceptions of acceptability suggested that a tablet formulation is likely to be the most appropriate calcium delivery vehicle for future use in field studies and scale-up planning.

Keywords: preference
acceptability
calcium
supplementation
preeclampsia
pregnancy
Bangladesh
nutrition
Advisor: Zlotkin, Stanley
Roth, Daniel