VictorJuiz/thesis huggingface dataset:
A Numerical Model for Oil/Water Separation from a Solid Particle
Keywords: spherical coordinates
Volume-of-Fluid
oil/water/particle separation

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.
Laboratory Aerosol Kinetics Studies of the Hydrolysis Reaction of N2O5 Using a Flow Tube Coupled to a New Chemical Ionization Mass Spectrometer
Keywords: N2O5
CIMS
Chemical Ionization Mass Spectrometer
kinetics
aerosols
uptake coefficient
flow tube
hydrolysis
heterogeneous
NOx
ozone
ammonium bisulphate
secondary organic aerosols
SOA

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.
Umbilical Cord Perivascular Cells: A Mesenchymal Cell Source for Treatment of Tendon and Ligament Injuries
Keywords: 0564

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.
Investigating Molecular Evolution of Rhodopsin Using Likelihood/Bayesian Phylogenetic Methods
Keywords: Molecular Evolution
Likelihood and Bayesian methods
Phylogenetics
Rhodopsin
Natural Selection
Codon Usage Bias
Nocturnality
Early mammals
Visual Pigment
Adaptive Evolution
Vision
GPCR

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.
A Responsive Variable Frequency Stimulator for Seizure Control in a Computational Model
Keywords: Electrical Stimulation
Seizure control

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.
Applications of Paleolimnology in Ecosystem Monitoring for Sirmilik National Park: Developing Indicators of Ecological Integrity
Keywords: diatoms, lakes, streams, freshwater, limnology, paleolimnology, arctic, climate change, Bylot, Sirmilik, National Park

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.
The Role of Von-Hippel Lindau (VHL) protein in Regulating Cell Cycle Progression and the Expression of Fibronectin in the Human Placenta
Keywords: Placenta
Preeclampsia
Von-Hippel Lindau

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.
Alterations of Cortical and Hippocampal Network Activity in MeCP2-Deficient Mice
Keywords: Rett Syndrome EEG mice MeCP2

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.
The Effects of Self-presentation on an Expressive Writing Task for Trauma Survivors
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

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.
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
Keywords: adult immigrants
esl
citizenship learning

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.
Investigating the Higher-order Protein Interactions Surrounding the STRIPAK Complex
Keywords: phosphatase
mass spectrometry

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.
On Moments of Class Numbers of Real Quadratic Fields
Keywords: analytic number theory
real quadratic fields
binary quadratic forms
class group moments

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.
Altered Affect, Monoamine Transmitters and Bioenergetic Homeostasis of Alpha-synuclein-transgenic Mice, in the Presence and Absence of Endogenous Alpha-synuclein
Keywords: Alpha-synuclein
affect

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.
Genetic Variation in Innate Immunity, Diet and Biomarkers of the Metabolic Syndrome
Keywords: Genetics
Toll-like receptor 4
Nucleotide binding oligomerization domain 1 and 2
dietary fat
metabolic syndrome

Chronic low-grade inflammation is associated the Metabolic Syndrome (MetS) and may contribute to its development. A diet high in saturated fat (SFA) has been associated with increased inflammation and development of the MetS. SFAs have been shown to elicit pro-inflammatory signaling through proteins of innate immunity, TLR4 and Nods 1 and 2. We determined whether common polymorphisms in the genes of these proteins could modify the association between fat intake and biomarkers of the MetS. Fat intake was measured using a food frequency questionnaire and genotyping was completed using real-time PCR. The TLR4 Asp299Gly (rs4986790) polymorphism was associated with decreased insulin sensitivity while an intronic polymorphism (rs5030728) modified the association between dietary SFA and HDL-cholesterol. The Nod1 Glu266Lys polymorphism modified the association between dietary SFA and HOMA-IR. These results suggest a role for innate immunity in mediating some of the effects of dietary SFAs on factors associated with the MetS.
The Development of an Animal Model of Complicated Atherosclerosis for Non-invasive Imaging
Keywords: Animal model
Atherosclerosis
Vessel wall disease
Medical imaging
Magnetic resonance imaging
Neovascularization

The goal of this thesis was to produce an animal model that develops atherosclerotic plaque featuring plaque neovascularization leading to intraplaque hemorrhage and is suitable for noninvasive imaging studies. Several strategies were tested for their effectiveness in producing such plaques in the rabbit aorta, including: a high cholesterol diet, vascular endothelial growth factor injections, therapeutic contrast ultrasound, and balloon catheter injury. It was found that a combination of the high cholesterol diet and balloon injury was able to achieve plaque neovascularization in a manner dependent on circulating plasma cholesterol levels. In addition, a contrast-enhanced magnetic resonance imaging technique implemented in the animal model was able to detect plaque neovascularization and monitor its change over time in a single group of animals. In conclusion, an animal model was created where plaque neovascularization occurs in a predictable fashion and can be studied with non-invasive magnetic resonance imaging.
Oxidative Stress and Risk of Cardiovascular Disease Associated with Low- and High-monounsaturated Fat Portfolio Diets
Keywords: oxidative stress
cholesterol

The objective was to assess the effect of a high-monounsaturated fat (MUFA) dietary portfolio of cholesterol-lowering foods on oxidative stress and cardiovascular risk. Twenty-four hyperlipidemic subjects followed a very low-saturated-fat therapeutic control diet for 4 weeks after which they were randomized to receive the dietary portfolio, consisting of soy protein (20g/1000kcal), viscous fibre (10.3g/1000kcal), plant sterols (2-3g) and almonds (21.5g/1000kcal), in combination with high- or low-MUFA (25.9% and 12.9% MUFA, respectively) for the next 4 weeks, where MUFA replaced 13.0% of dietary carbohydrate. On high-MUFA, there were significantly greater increases in HDL-C and apoA1 and significantly greater reductions in total:high-density lipoprotein cholesterol (total:HDL-C) ratio and high-sensitivity C-reactive protein (hs-CRP) compared to the low-MUFA dietary portfolio. In all diets there were significant increases in protein thiols and reductions in conjugated dienes and thiobarbituric acid reactive substances (TBARS) measured in the LDL-fraction, however no difference between the high- and low-MUFA diets.
Synthesis and Application of Polymer Stabilized Lanthanide Fluoride Nanoparticles
Keywords: lanthanide fluoride nanoparticle aggregates
folic acid
magnetic resonance imaging
contrast agents
targeted imaging

A new class of polymer coated lanthanide fluoride nanoparticle aggregates (NPAs) was developed as potential MRI contrast agents. The NPA synthesis has been perfected to control the size distribution and optimize relaxivities. Polyacrylic acid was used as a stabilizing polymer, and was conjugated to folic acid to improve targeting to SK-BR-3 breast cancer cells. Terbium was incorporated in the synthesis to study the passive and active targeting properties of NPAs. Through a series of microscopy experiments, a significant difference in uptake between NPAs with and without targeting moieties occurs after 48 hours of incubation. The relaxivity of the optimized nanoparticles was measured to be 56 s-1(mg/ml)-1 using a 1.5 T scanner, which may be compared to that of the commercially available Gd3+-DTPA [R1 = 7 s-1(mg/ml)-1]. Abdominal perfusion studies in rats also demonstrated that the NPAs provide better contrast of the vasculature than Gd3+-DTPA does at the same mass concentration.
The Role of FKBP5 in Influenza Virus Infection
Keywords: FKBP5
Influenza
Glucocorticoid

FK506 binding protein 5 (FKBP5) is a peptidyl propyl cis-trans isomerase that has been shown to interact with cellular immune pathways such as calcineurin and NF-κB. During an influenza infection, FKBP5 is up-regulated at the lung in an in vivo ferret infection model, yet the effect of FKBP5 on influenza replication and immune response is not understood. An in vitro model of human alveolar epithelial cell line A549 was established to study the cause and the function of FKBP5 up-regulation during an influenza infection. In this in vitro model, FKBP5 was not up-regulated by influenza replication, but instead it was up-regulated when A549 cells were treated with glucocorticoid. FKBP5 up-regulation did not have any effect on rate of influenza replication. However, FKBP5 up-regulation mediated the suppressive effect of glucocorticoid on pro-inflammatory cytokine production, since FKBP5 knock-down by siRNA increased cytokine production in the presence of glucocorticoid. Overall, the results suggested that the up-regulation of FKBP5 is a physiological response of lung cells to the increase of glucocorticoid during influenza infections, which facilitates the suppressive effect of glucocorticoid on pro-inflammatory cytokine production.
Examining the Wrongs Against the Present African Women: An Enquiry on Black Women’s Roles and Contributions from Antiquity - A Black African Male Scholarly Comparative Perspective
Keywords: African Women
Queen Hatshepsut
Afrocentricity
African Spirituality
African centered paradigms
Queen Nefertiti
Egypt
Black feminist
African civilization
Anti-Colonial
Meroë
Anti-Racist Theory
Colonialism
Africanist Historiography
Africa
Ancient civilization
African Feminist Thoughts
Neo-Colonialism annd Post-colonialisms
Myths and Mythology
Culture
Black
Women Empowerment
Indigeneity
African Cullture and Tradition
European colonization
indigenous order
Eurocentric education
Housewification and domestication of African women

The thesis examined the roles and contributions of Black women during the African ancient civilization by analyzing the lives, roles and contributions of Queen Hatshepsut and Nefertiti as case studies and interrogates how Black women positioned themselves as political, military and spiritual leaders during the age of antiquity. The argument is that African women were more involved as leaders in the affairs of their communities as compared to the contemporary times. By using African centered paradigms, Afrocentricity and juxtaposing robust anti-colonial and Black feminist thoughts, the thesis investigates and recreates systematic narratives of the past roles of African women at the very height of African civilization, discussed the changes in sex-gender roles and explained why contemporary women continue to experience difficulties in assessing position of leadership and resources. The study reproduces measured facts to confront the blurred roles and contributions of African women and situates it at the centre of education.
Farmers' Markets and their Practices Concerning Income, Privilege and Race: A Case Study of the Wychwood Artscape Barns in Toronto
Keywords: whiteness
farmers' markets
sustainability
equity

The popularity of Farmers’ markets is on the rise; in Canada there are 425 farmers’ markets, with over 130 in Ontario alone (Feagan, Morris, & Krug, 2004). Farmers’ markets provide high quality, local produce and are often considered an environmentally sustainable food practice (Taxel, 2003; King 2008). United States studies have scrutinized farmers’ markets as exclusionary white spaces that are not equitably accessible, but similar Canadian studies are rare. A case study at the Wychwood Artscape Barns, located in an economically and culturally diverse neighbourhood, in Toronto Ontario has been conducted. Demographics surveys of patrons were compared with existing demographic data; interviews were conducted to discover who shops at the market and for what reasons; results were analyzed using whiteness theory. Results were consistent with U.S. studies – Wychwood Farmers’ Market patrons were white, high income,individuals with university educations; these individuals shop at the market disproportionally to the demographic data.