VictorJuiz/thesis huggingface dataset:
A Framework for the Protection of Privacy in an Electronic Health Environment

This paper argues that given the proliferation of electronic health records (EHRs) in the health care system, legislative reform must occur to address the inadequacies of Ontario’s current health privacy legislation in accommodating EHRs. A coherent framework for legislation is necessary to capture the important role that privacy plays in public perception when it comes to legislating and managing EHRs in Ontario and, in turn, serve as a tool for legislators to understand the definitions and values of privacy associated with EHRs and the privacy problems worthy of protection in an electronic health environment. The failure to properly address these problems may lead to privacy losses and loss of public confidence in EHR systems. In applying this framework to three legislative options, it is evident that Ontario should amend the Personal Health Information Protection Act, 2004 to better contemplate the privacy protections necessary in an electronic health environment.

Keywords: privacy
electronic health record
Advisor: Austin, Lisa M.
Investigation of the Protein Components of the Zebra Mussel (Dreissena polymorpha) Byssal Adhesion Apparatus

The byssal adhesion mechanism of the biofouling species Dreissena polymorpha was investigated using a combination of studies on synthetic peptide mimics of tandem repeat sequences from byssal component Dreissena polymorpha foot protein 1 (Dpfp-1) and characterization of the regions of the byssus. A 20-residue fusion peptide incorporating two Dpfp-1 repeat sequences adopts a random coil and β-turn conformation in solution, and spontaneously forms a film at the solid-liquid interface in the presence of iron (III) cations. Infrared characterization of the byssus Amide I region showed that β-sheets dominate its secondary structure, although the proportion of different secondary structures varies between regions. Matrix-assisted laser desorption ionization (MALDI) mass spectrometry of intact byssal regions identified previously unknown differences in the composition of byssal threads, plaques, and the adhesive interface, which are believed to correlate to the different roles of these components in the overall structure.

Keywords: Zebra mussel
byssus
DOPA
Foot proteins
MALDI
FTIR
Advisor: Sone, Eli D.
Exploring Environmental Justice and Interrogating 'Community Engagement': A Case Study in the Latin American Community of Toronto

Equitable opportunity for participation in environmental decision-making is central to arguments for environmental justice, yet remains an under-explored area in the literature. This thesis investigates engagement on environmental health issues in the Latin American community of Toronto. Drawing on an environmental justice framework, the objective of this study was to better understand barriers and facilitators to environmental action in this community, while exploring underlying definitions of environmental health, environmentalism, and community engagement. In-depth interviews were carried out with representatives of agencies serving the Latin American community; qualitative data from focus groups and interviews with community members was also used. Results identify social inequality and the whiteness of the mainstream environmental movement as pervasive barriers to participation, and suggest the utility of linking environmental and social justice concerns for community mobilization. The findings of this research contribute to an emerging discourse on environmental justice and racism in Canada.

Keywords: Environmental Justice
Environmental Health
Community Engagement
Social Justice
Race
Immigration
Toronto
Advisor: Wakefield, Sarah
Post-stroke Fatigue: Refining the Concept

Post-stroke fatigue (PSF) is a common yet under-diagnosed and undertreated phenomenon. The unresolved debate over what is PSF has hampered the ability of clinicians to study and develop treatments for this condition. Patients with stroke (n=70) seeking neurorehabilitation at Toronto Rehabilitation Institute completed self-report ratings of fatigue, depressive and anxiety symptoms, and sleepiness. Data were collected from objective measures of stroke topography, sleep disorders, physical fatigability and comorbid medical conditions. A Principal-Components Analysis was performed. Factor 1, the “Distress” factor, was comprised of the all of the self-reported scales i.e. depression, anxiety, fatigue and sleepiness. Factor 2, the “Physical State” factor, was comprised of a diagnosis of Obstructive Sleep Apnea, stroke territory and total medical burden. Factor 3, the “Performance” factor, was comprised by the 6 Minute Walk Test. An orthogonal rotation was the most parsimonious fit to the data, suggesting that the three factors are uncorrelated to each other.

Keywords: stroke
fatigue
rehabilitation
mental health
Advisor: Flint, Alastair
Mg/Ca Ratios in Crustose Coralline Algae as Proxies for Reconstructing Labrador Current Variability

Climate variability in the North Atlantic has been linked in part to the North Atlantic Oscillation (NAO). The NAO influences marine ecosystems in the northwestern Atlantic and the transport variability of the cold Labrador Current (LC). Understanding historic patterns and predicting future changes in LC transport require long-term and high-resolution climate records that are not available from instrumental data sets. This thesis presents the first century-scale sea surface temperature (SST)reconstructions from the Northwestern Atlantic using Mg/Ca ratios in the long-lived crustose coralline algae Clathromorphum compactum. which is characterized by a high Mg-calcite skeleton exhibiting annual growth increments. Results indicate strong correlations between interannual variations in Mg/Ca ratios and instrumental SST. The 131-year algal Mg/Ca record reveals NAO-type periodicities and evidence of past cold events and warming periods associated with basin-wide ecosystem shifts. Negative correlations between LC volume transport and algal Mg/Ca reflect the cooling influence of the LC on eastern Canadian shelf ecosystems.

Keywords: Paleoclimate
Coralline Algae
Labrador Current
Sea Surface Temperature
Mg/Ca ratios
Climate Change
Northwestern Atlantic
Advisor: Halfar, Jochen
Hepatocyte Molecular Cytotoxic Mechanism Study of Fructose and its Metabolites Involved in Nonalcoholic Steatohepatitis and Hyperoxaluria

High chronic fructose consumption is linked to a nonalcoholic steatohepatitis (NASH) type of hepatotoxicity. Oxalate is the major endpoint of fructose metabolism, which accumulates in the kidney causing renal stone disease. Both diseases are life-threatening if not treated. Our objective was to study the molecular cytotoxicity mechanisms of fructose and some of its metabolites in the liver. Fructose metabolites were incubated with primary rat hepatocytes, but cytotoxicity only occurred if the hepatocytes were exposed to non-toxic amounts of hydrogen peroxide such as those released by activated immune cells. Glyoxal was most likely the endogenous toxin responsible for fructose induced toxicity formed via autoxidation of the fructose metabolite glycolaldehyde catalyzed by superoxide radicals, or oxidation by Fenton’s hydroxyl radicals. As for hyperoxaluria, glyoxylate was more cytotoxic than oxalate presumably because of the formation of condensation product oxalomalate causing mitochondrial toxicity and oxidative stress. Oxalate toxicity likely involved pro-oxidant iron complex formation.

Keywords: Fructose
Hepatocyte toxicity
Nonalcoholic Steatohepatitis
Hyperoxaluria
Advisor: O'Brien, Peter J.
Characterization of the Mobility of FcγRIIa in Primary Human Macrophages

Fcγ receptor-mediated phagocytosis is an active process requiring receptor clustering as a signal initiation event. The mechanisms controlling Fcγ receptor clustering are unknown, as are the parameters governing the receptor lateral mobility in the plasma membrane. This work investigated the lateral mobility of Fcγ receptor IIa in resting primary human macrophages using single-molecule tracking methodology. In the absence of ligands, the receptor was found to exist mostly as a monomeric species. Detailed receptor dynamics revealed the existence of two receptor populations: one that was mobile, the other confined. The actin cytoskeleton was shown to be important for receptor confinement but did not affect receptor diffusion. Such findings are important in understanding the mechanisms for receptor clustering and signal initiation in phagocytosis.

Keywords: Cell biology
Biochemistry
Advisor: Grinstein, Sergio
A Numerical Model for Oil/Water Separation from a Solid Particle

A computational fluid dynamics model has been developed to study an oil-coated particle immersed in a uniform aqueous flow, to determine the conditions that favour oil separation. The governing flow equations are discretized using a finite volume approach, and the oil/water interface is captured using the Volume-of-Fluid (VOF) method in a 2D spherical coordinate system. The model predicts different mechanisms for oil separation. At a Reynolds number, Re, equal to 1, and at a low capillary number, Ca << 1, the high interfacial tension can induce rapid contact line motion, to the extent that the oil film can advance past its equilibrium position and separate from the particle. This mechanism requires that the contact angle measured through the oil phase is large. On the other hand, as Ca approaches 1, the shear exerted by the external flow stretches the oil into a thread that will eventually rupture and separate.

Keywords: spherical coordinates
Volume-of-Fluid
oil/water/particle separation
Advisor: Bussmann, Markus
Acosta, Edgar
Laboratory Aerosol Kinetics Studies of the Hydrolysis Reaction of N2O5 Using a Flow Tube Coupled to a New Chemical Ionization Mass Spectrometer

The hydrolysis reaction of N2O5 was investigated at room temperature on two aerosol types using a flow tube coupled to a newly built Chemical Ionization Mass Spectrometer (CIMS). This instrument was fully constructed and optimized during this research period, as well as employed to conduct one of two aerosol studies. The first examined the reaction on ammonium bisulphate aerosols using a new ion detection method, I-•N2O5 cluster formation, which proved to be highly advantageous over the common approach of dissociative charge transfer, yielding a sensitivity for I-•N2O5 of 0.024 Hz/pptv. The uptake coefficients at 30% and 50% relative humidity were 0.0067 ± 0.0002 and 0.0120 ±0.0014, respectively. The second study was performed using a different CIMS previously assembled in the laboratory. In this case, the reaction was investigated on secondary organic aerosols produced through the ozonolysis of α-pinene, and resulted in an uptake coefficient of 8.5x10-5 ± 7x10-6 at 0% relative humidity.

Keywords: N2O5
CIMS
Chemical Ionization Mass Spectrometer
kinetics
aerosols
uptake coefficient
flow tube
hydrolysis
heterogeneous
NOx
ozone
ammonium bisulphate
secondary organic aerosols
SOA
Advisor: Abbatt, Jonathan P. D.
Umbilical Cord Perivascular Cells: A Mesenchymal Cell Source for Treatment of Tendon and Ligament Injuries

We investigated the capacity of human umbilical cord perivascular cells (HUCPVCs) to repair tendon damage in a collagenase tendon injury model in rats. Our hypothesis was that HUCPVCs would be able to produce an organized extracellular matrix and facilitate tissue regeneration in this rat model. HUCPVCs were injected, in collagenase, into the Achilles tendon of nude rats. Harvested tendons showed the presence of HUCPVCs at the site of injury, whose morphology changed from rounded to elongated over the post-injury time of 30 days. Human genes for collagen type 1 and -actin were expressed at all time points and there was also a signi cant increase in the tensile strength and sti ness values at 30 day post-injury in the experimental group. We conclude that HUCPVCs facilitated regeneration in our model, and thus may be a putative cell source for the treatment of tendon and ligament injuries.

Keywords: 0564
Advisor: Davies, John Edward
Investigating Molecular Evolution of Rhodopsin Using Likelihood/Bayesian Phylogenetic Methods

Rhodopsin, a visual pigment protein found in retinal photoreceptors, mediates vision at low-light levels. Recent studies focusing primarily in human and mouse have challenged the assumption of neutral evolution of synonymous substitutions in mammals. Using recently developed likelihood-based codon models accounting for mutational bias and selection, we find significant evidence for selective constraint on synonymous substitutions in mammalian rhodopsins, and a preference for cytosine at 3rd codon positions. A second project investigated adaptive evolution in rhodopsin, in view of theories of nocturnality in early mammals. We detected a significant acceleration of non-synonymous substitution rates at the origins of therian mammals, and a tendency of synonymous substitutions towards C-ending codons prior to that. These findings suggest an evolutionary scenario in which synonymous substitutions that increase mRNA stability and/or translation efficiency may have preceded adaptive non-synonymous evolution in early mammalian rhodopsins. These findings have important implications for theories of early mammalian nocturnality.

Keywords: Molecular Evolution
Likelihood and Bayesian methods
Phylogenetics
Rhodopsin
Natural Selection
Codon Usage Bias
Nocturnality
Early mammals
Visual Pigment
Adaptive Evolution
Vision
GPCR
Advisor: Chang, Belinda
A Responsive Variable Frequency Stimulator for Seizure Control in a Computational Model

Epilepsy, which manifests itself as spontaneous bouts of abnormal low complexity brain activity, is the second most common neurological disorder after stroke. This thesis explores the effect of variable frequency stimulation on seizure control. A responsive variable frequency electrical stimulation system is proposed and validated using a computational model capable of generating spontaneous seizure like events. The proposed stimulation system is demonstrated to outperform open-loop fixed frequency stimulation and responsive fixed frequency stimulation using seizure time based measures and a control energy measure.

Keywords: Electrical Stimulation
Seizure control
Advisor: Bardakjian, Berj
Applications of Paleolimnology in Ecosystem Monitoring for Sirmilik National Park: Developing Indicators of Ecological Integrity

Water chemistry and bioindicators (diatoms and invertebrates) were examined for freshwater lakes, ponds and streams in two regions within Sirmilik National Park, northern Baffin Island, Nunavut. Significant differences were recorded between the water chemistry and diatom and invertebrate assemblages of the two regions. Modern diatom assemblages were explained mainly by specific conductivity, ORP, pH, temperature, elevation and distance from the coast. Paleolimnological techniques were applied to a sediment core from Lake BY14 on Bylot Island. Fossil diatom assemblages indicate increases in nutrients and temperature since 1935 AD. The diatom biostratigraphy does not show as large an increase in diversity and production since the middle 20th century as has been noted elsewhere, and this may be a reflection of the more nutrient-rich status of the lake relative to other Arctic lakes.

Keywords: diatoms, lakes, streams, freshwater, limnology, paleolimnology, arctic, climate change, Bylot, Sirmilik, National Park
Advisor: Sarah, Finkelstein
The Role of Von-Hippel Lindau (VHL) protein in Regulating Cell Cycle Progression and the Expression of Fibronectin in the Human Placenta

Von Hippel Lindau (VHL) is a tumour suppressor protein classically known to target the α subunit of hypoxia inducible factor (HIF) for proteasomal degradation. Emerging evidence has underscored a novel role for VHL in both cell cycle regulation and extracellular matrix assembly. Herein, we provide evidence of VHL multitasking in normal and pathological placentation. Using ex vivo, first trimester human placental tissue and in vitro, JEG-3 choriocarcinoma cell line model we demonstrate that VHL plays a role in regulating the expression of cell cycle modulator CCND1 via a mechanism involving its inhibitor, p15 and HIF-2α. In addition, using a similar experimental strategy we provide evidence supporting a role for VHL in regulating the expression of fibronectin and its receptor integrin α5. Moreover, altered VHL expression observed in preeclampsia is associated with altered expression of cell cycle regulators and contributes to altered FN protein levels which are characteristic of this pathology.

Keywords: Placenta
Preeclampsia
Von-Hippel Lindau
Advisor: Caniggia, Isabella
Alterations of Cortical and Hippocampal Network Activity in MeCP2-Deficient Mice

Intractable epilepsy remains one of the top issues affecting the quality of living in Rett children. While several MeCP2-deficient mouse models of Rett Syndrome have been established, minimal information exists on how the loss of MeCP2 affects brain network activity. To address this issue, in vivo recordings of the hippocampus and somatosensory cortex of MeCP2-deficient mice were taken during exploration, immobility, and sleep. The frequency of hippocampal theta oscillations was significantly attenuated in MeCP2-deficient mice during exploration. A subset of MeCP2-heterozygotes displayed spontaneous, cortical epileptiform-like discharges in the immobile-awake state. Similar epileptiform-like discharges were observed in one of the four Mecp2-null mice recorded. Aside from these EEG abnormalities, basal network activity was preserved. Further, convulsive seizures were not seen. Collectively, these findings indicate that a deficiency of MeCP2 in mice leads to only subtle alterations in brain wave activity, contrasting the severely abnormal EEG observed in Rett girls.

Keywords: Rett Syndrome EEG mice MeCP2
Advisor: Eubanks, James
The Effects of Self-presentation on an Expressive Writing Task for Trauma Survivors

Expressive Writing (EW) involves writing in an emotionally expressive manner about an experienced event, and has been shown to be related to increases in psychological and physical well-being. The purpose of the current study was to extend previous work by examining how self-presentation affects psychological and physical gains following the EW task. Forty one participants who have experienced a traumatic event were recruited from the community and given either an EW or control activity. Measures assessing self-presentation and various indices of health were administered at baseline and again at one month follow-up to determine changes in symptomatology. Results indicated that higher levels of perfectionistic self-presentation were significantly associated with less improvement in symptoms of depression and posttraumatic stress. Further, a nonsignificant moderation trend emerged whereby higher levels of perfectionistic self-presentation were associated with more improvement in symptoms of depression and posttraumatic stress in the EW group but not control group.

Keywords: Expressive Writing
Emotions
Writing
Self-Presentation
Impression Management
Trauma
Post Traumatic Stress
Journal
Diary
Self-Disclosure
DIsclosure
Emotional Experiencing
Expression
Emotional Expression
Therapy
Intervention
Traumatic
Perfectionism
Advisor: Watson, Jeanne
Citizenship Learning of Adult Immigrants in ESL Programs: It will help you pass the citizenship test, but it won't make you (m)any Canadian friends

This study explores which concept of citizenship is typically promoted in ESL programs available to adult immigrants in Canada: citizenship as status, citizenship as identity, citizenship as a set of civic virtues or citizenship as agency. Is there a difference between the stated purpose of ESL programs, the integration and active participation of immigrants in Canadian society through language development, and the actual citizenship learning that occurs in these programs? What influences this? The study traces the historical link between citizenship education and ESL in Canada, and draws on existing research to reveal how citizenship concepts are presented in ESL classrooms. These findings are then matched with data from my textbook analysis, classroom observations and student interviews obtained from two advanced ESL courses offered by COSTI, as an indication of the citizenship learning and the citizenship concepts most likely to be promoted in ESL programs for adult immigrants across Canada.

Keywords: adult immigrants
esl
citizenship learning
Advisor: Schugurensky, Daniel
Investigating the Higher-order Protein Interactions Surrounding the STRIPAK Complex

Reversible protein phosphorylation is an essential regulatory mechanism used by eukaryotes to coordinate the biochemical processes of the cell. The PP2A phosphatase functions to dephosphorylate specific proteins originally targeted by stimulus-activated protein kinases. The identification of a sub-network surrounding the human PP2A-Striatin holoenzyme, termed STRIPAK, provides insight into novel mechanisms for PP2A function and regulation. I reveal that STRIPAK participates in at least two mutually-exclusive sub-complexes, one of which contains the putative cortactin-binding protein, CTTNBP2NL. I show that CTTNBP2NL is enriched at the actin cytoskeleton, likely in a STRIPAK-independent manner. This study also reveals that STRIPAK interacts with a subunit of the dynein motor, at least partially, through CTTNBP2NL. This work will serve as a platform for the structural and functional characterization of STRIPAK and will ultimately assist in defining novel mechanisms of regulation and function for the human PP2A phosphatase.

Keywords: phosphatase
mass spectrometry
Advisor: Gingras, Anne-Claude
On Moments of Class Numbers of Real Quadratic Fields

Class numbers of algebraic number fields are central invariants. Once the underlying field has an infinite unit group they behave very irregularly due to a non-trivial regulator. This phenomenon occurs already in the simplest case of real quadratic number fields of which very little is known. Hooley derived a conjectural formula for the average of class numbers of real quadratic fields. In this thesis we extend his methods to obtain conjectural formulae and bounds for any moment, i.e., the average of an arbitrary real power of class numbers. Our formulae and bounds are based on similar (quite reasonable) assumptions of Hooley's work. In the final chapter we consider the case of the -1 power from a numerical point of view and develop an efficient algorithm to compute the average for the -1 class number power without computing class numbers.

Keywords: analytic number theory
real quadratic fields
binary quadratic forms
class group moments
Advisor: Blomer, Valentin
Altered Affect, Monoamine Transmitters and Bioenergetic Homeostasis of Alpha-synuclein-transgenic Mice, in the Presence and Absence of Endogenous Alpha-synuclein

Parkinson’s disease can be caused by A53T or A30P mutations in the α-synuclein (SNCA) gene, or by multiplication of the gene locus. Patients often experience depression and anxiety. We investigated affect, serotonin content and bioenergetic homeostasis of mice expressing human wild-type (WT), A53T, A30P or A53T+A30P (DM) SNCA transgenes. A30P-Tg mice displayed altered affect, increased serotonin turnover and reduced ATP and complex I+III activity. To determine whether murine α-synuclein (Snca) might mask effects SNCA transgenes we re-examined effects of SNCA transgenes in Snca-/- mice. SNCA transgenes rescued anxiety, serotonin levels and ATP content in Snca-/- mice. Only A53T SNCA abrogated behavioural despair associated with decreased norepinephrine in Snca-/- brains. The A53T residue is the natural sequence of murine Snca, and appears to be important for synuclein function in mice. The Snca-/- mouse provides a means to study the effects of SNCA mutants, and the physiologic roles of Snca in vivo.

Keywords: Alpha-synuclein
affect
Advisor: Mount, Howard