title: Development of a Stochastically-driven, Forward Predictive Performance Model for PEMFCs

contributor:
Pharoah, Jon
Mechanical and Materials Engineering

rights: Attribution-NonCommercial-ShareAlike 3.0 United States

subject:
PEMFC
Fuel Cell
Model
Simulation
Catalyst
Performance
Transient
Two Phase

abstract: A one-dimensional multi-scale coupled, transient, and mechanistic performance model for a PEMFC membrane electrode assembly has been developed. The model explicitly includes each of the 5 layers within a membrane electrode assembly and solves for the transport of charge, heat, mass, species, dissolved water, and liquid water. Key features of the model include the use of a multi-step implementation of the HOR reaction on the anode, agglomerate catalyst sub-models for both the anode and cathode catalyst layers, a unique approach that links the composition of the catalyst layer to key properties within the agglomerate model and the implementation of a stochastic input-based approach for component material properties. The model employs a new methodology for validation using statistically varying input parameters and statistically-based experimental performance data; this model represents the first stochastic input driven unit cell performance model. The stochastic input driven performance model was used to identify optimal ionomer content within the cathode catalyst layer, demonstrate the role of material variation in potential low performing MEA materials, provide explanation for the performance of low-Pt loaded MEAs, and investigate the validity of transient-sweep experimental diagnostic methods.

abstract: PhD


title: Seeing Other People: An Enactivist Account of Hallucination as Perceptual Error

contributor:
Salay, Nancy
Philosophy

rights: Attribution-NonCommercial 3.0 United States

rights: Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada

rights: ProQuest PhD and Master's Theses International Dissemination Agreement

rights: Intellectual Property Guidelines at Queen's University

rights: This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.

subject:
Enactivism
Philosophy
Maurice Merleau-Ponty
Alva Noe
Hallucinations
Perceptual Error
Illusion
Perception
Vision

abstract:
In this essay, I explore the difference between Representational Theories of Content (RTC) and Embodied Enactivism, and argue that enactivist approaches of perception can account for hallucinatory experiences, a sensory phenomenon readily explained by the RTC approaches. RTC bases perceptual activity on the presence of representational features interpreted by the brain, and are defined by their relation to independently existing objects. The enactivist model uses success and failure to determine whether or not a perception is hallucinatory by appealing to the use of all of the body’s sensory modalities to navigate a perceptual error.
In Chapter two I present my arguments for an enactivist theory of hallucination, first by demonstrating that illusion and hallucination, broadly thought of as being two radically different phenomena, are actually one and the same. I also demonstrate how it is that bodily experiences affect the type of hallucination a patient will have, appealing to mood, repetitive tasks, and current environmental presences. My last strategy cleaves a wedge between visual imagery and hallucination, an assumption often made by representationalist accounts of cognition. RTC arguments made to support visual imagery are used to demonstrate how hallucinations are representational, but if the two experiences are actually different, then arguments for visual imagery become less convincing.
Chapter three focuses on some lingering concerns and interesting implications of the enactivist theory. Veridicality differs from successful/failed perceptions by appealing to the degree with which the agent can make sense of their perceptions. I also argue how smaller misperceptions are hallucinatory, as well as how auditory hallucinations and multi-modal halluciations are also explainable to the enactivist. Dreams pose the last challenge I address, for they exhibit some embodied characteristics all the while being impervious to the success/failure metric of perceptual activity.

abstract: M.A.


title: Landscape variability of vegetation change across the forest to tundra transition of central Canada

contributor:
Treitz, Paul
Danby, Ryan
Geography and Planning

subject:
NDVI
Landsat
Treeline
Canada
Vegetation productivity
Random Forest
Boreal forest
Tundra
Bulk vegetation volume
Greening
Arctic
Northwest Territories
Landscape variability
Forest-tundra ecotone
Time-series
Remote sensing

abstract: Widespread vegetation productivity increases in tundra ecosystems and stagnation, or even productivity decreases, in boreal forest ecosystems have been detected from coarse-scale remote sensing observations over the last few decades. However, finer-scale Landsat studies have shown that these changes are heterogeneous and may be related to landscape and regional variability in climate, land cover, topography and moisture. In this study, a Landsat Normalized Difference Vegetation Index (NDVI) time-series (1984-2016) was examined for a study area spanning the entirety of the sub-Arctic boreal forest to Low Arctic tundra transition of central Canada (i.e., Yellowknife to the Arctic Ocean). NDVI trend analysis indicated that 27 % of un-masked pixels in the study area exhibited a significant (p < 0.05) trend and virtually all (99.3 %) of those pixels were greening. Greening pixels were most common in the northern tundra zone and the southern forest-tundra ecotone zone. NDVI trends were positive throughout the study area, but were smallest in the forest zone and largest in the northern tundra zone. These results were supported by ground validation, which found a strong relationship (R2 = 0.81) between bulk vegetation volume (BVV) and NDVI for non-tree functional groups in the North Slave region of Northwest Territories. Field observations indicate that alder (Alnus spp.) shrublands and open woodland sites with shrubby understories were most likely to exhibit greening in that area. Random Forest (RF) modelling of the relationship between NDVI trends and environmental variables found that the magnitude and direction of trends differed across the forest to tundra transition. Increased summer temperatures, shrubland and forest land cover, closer proximity to major drainage systems, longer distances from major lakes and lower elevations were generally more important and associated with larger positive NDVI trends. These findings indicate that the largest positive NDVI trends were primarily associated with the increased productivity of shrubby environments, especially at, and north of the forest-tundra ecotone in areas with more favorable growing conditions. Smaller and less significant NDVI trends in boreal forest environments south of the forest-tundra ecotone were likely associated with long-term recovery from fire disturbance rather than the variables analyzed here.

abstract: M.Sc.


title: An Investigation of Patient Progression Through Rehabilitation with the Step-Up-and-Over Test

contributor:
Costigan, Patrick
Kinesiology and Health Studies

subject:
Anterior Cruciate Ligament
Rehabilitation
Step-Up-and-Over Test
Accelerometer

abstract:
The goal of surgery for patients undergoing anterior cruciate ligament reconstruction (ACLR) and subsequent rehabilitation is the restoration of normal knee function (van Grinsven et al., 2010). Having procedures that accurately assess and quantify recovery are crucial to ensure that physicians if patients are regaining knee function. However, there is no standardized, objective assessment of a patient’s improvement as they progress through the stages of rehabilitation. Currently, maximal effort testing is used to evaluate knee function to determine a patient’s readiness to return to unrestricted physical activity but, these tests place a high demand on the knee joint, which is contraindicated in early rehabilitation (Cascio et al., 2004) and may confound the patient’s results due to fear of re-injury. The step-up-and-over (SUAO) test is an objective, submaximal effort test that quantifies performance (van Grinsven et al., 2010) and, therefore, can be used to evaluate knee function throughout rehabilitation to gauge the patient’s progression.
Two studies were completed for this thesis. In the first study, 12 ACL-reconstructed individuals completed the SUAO test at each physiotherapy clinic visit until they were cleared to return to unrestricted physical activity by their physician or physiotherapist. They also completed the ACL-QoL, a questionnaire measuring the patient’s subjective knee function. In the second study, these 12 ACL-reconstructed patients completed a fear of re-injury questionnaire once a month and their pain was measured on each testing day to evaluate whether these two variables affected the results obtained from the SUAO test.
Results showed that the ACL-QoL was not related to the variables measured using the SUAO test and that the SUAO test was able to track an individual’s progression through rehabilitation. Results also showed that fear of re-injury did not affect the performance on each testing day but pain did. Together, these results indicate that the SUAO test is a clinically viable option to track an individual’s progression through rehabilitation without having fear of re-injury affect the results and that pain may affect performance of the SUAO test.

abstract: M.Sc.


title: Sensory-Mechanical Responses to High-Dose Methacholine Bronchoprovocation: The Modulating Effects of Deep Inspirations

contributor:
Lougheed, M Diane
Fisher, John
Biomedical and Molecular Sciences

subject:
Methacholine
Asthma
Cough
Deep Inspirations
Bronchodilating

abstract:
Rationale: The physiologic variables distinguishing classic asthma (CA), cough variant asthma (CVA), and methacholine (MCh)-induced cough with normal airway sensitivity (COUGH) are incompletely understood. Defining the range of normal responses associated with deep inspirations (DIs) during high-dose MCh is key to understand the clinical relevance of COUGH.
Purpose: To characterize responses to DI in healthy normal individuals (without asthma, chronic cough or asymptomatic airway hyperresponsiveness) during high-dose MCh and compare with responses in CA, CVA and COUGH.
Methods: Individuals aged 18-65 years with no history of asthma and/or chronic cough attended 2 visits. On visit 1, after baseline spirometry and body plethysmography, participants were randomized to perform either: (i) modified high-dose MCh challenge using partial and maximal expiratory flow-volume curves (PEFV/MEFV) and impulse oscillometry (IOS) or (ii) traditional high-dose MCh challenge using MEFV, at each dose to a maximum change (∆) in FEV1 of 50% from baseline (MAX). Previously published data (Wasilewski et al., 2016) was used to compare the responses of healthy individuals to individuals with CA (n=11), CVA (n=10) and COUGH (n=7).
Results: 15 participants (31.4±7.3years) (Mean±SD) completed the protocol. At MAX, participants developed minor but significant cough (3.2±4.7; p=0.022), dyspnea (Borg: 0.4±0.7; p=0.016), bronchoconstriction (%∆FEV1 -14.7±7.9%; p<0.001) and gas trapping (∆IC -0.20±0.36; p=0.001), compared to baseline. At MAX, the bronchodilation effect of DIs was preserved (DI index: 0.67±0.44 and -0.14 ± 0.15 at MAX and baseline, respectively; p<0.001). Compared to healthy individuals, the COUGH group developed more cough (p=0.006), dyspnea (p=0.029) but comparable bronchoconstriction and gas trapping in response to high-dose MCh. At MAX, the bronchodilating effect was preserved in CA, CVA and healthy participants but impaired in COUGH (DI Index: 0.67±0.97 (CA); 0.51±0.73 (CVA); 0.01±0.36 (COUGH); 0.68±0.45 (healthy participants); p=0.009).
Conclusion: The responses to high-dose MCh in healthy participants and participants with COUGH, CVA and CA lie on a continuum, which may reflect fundamental pathophysiological differences in terms of impairment versus preservation of the bronchodilating effect of DIs. COUGH appears to be a clinically relevant phenotype, distinct from healthy normal and CVA.

abstract: M.Sc.


title: Human Immunodeficiency Virus (HIV) and the Lived Experience of Male Inmates in Canadian Federal Penitentiaries: A Snapshot of the Ontario Region

contributor:
Fergus, Stevenson
Kinesiology and Health Studies

subject:
HIV
Qualitative Interviews
Stigma
Canadian Federal Prisons

abstract: The HIV prevalence rate inside Canadian Federal Penitentiaries is estimated to be 7 times higher than the rate in the general Canadian population. Additionally, a survey of Correctional Service of Canada (CSC) HIV-positive inmates showed that over half were worried about HIV-related stigma while incarcerated. This study of HIV-positive current and former inmates, the first Canadian study of its kind, investigated participants’ lived experiences in and out of prison. Topics investigated include experiences of stigma and disclosure of HIV status during incarceration. This study consisted of semi-structured, in-person interviews. A total of 20 interviews were conducted with 10 currently incarcerated, 5 recently released HIV-positive males, 4 Peer Education Course (PEC) workers and 1 recently released HIV-negative male. Currently incarcerated participants were recruited through the health care departments of penitentiaries in the Ontario Region of CSC. Formerly incarcerated participants were recruited from social service organizations in Kingston, Ontario, that focus on working with PLWH and formerly incarcerated individuals. Participants reported experiencing or witnessing enacted, perceived and internalized stigma in and out of the prison environment. Experiences of enacted stigma ranged from verbal insults to being ostracized, threats of violence, and actual violent attacks. Variations in experiences of enacted stigma were explained by non- or limited disclosure based on fears of discrimination, as well as perceived standing in the prison hierarchy. Additionally, the majority of participants reported having experienced a variety of childhood traumas and feelings of poor self-worth and suicidal ideation. HIV-related stigma is a common experience of HIV-positive current and former inmates. Although there are HIV prevention programs including testing, bleach kits, condom distribution, and HIV treatment within CSC prisons, there are no reported programs that specifically target the reduction of HIV-related stigma. As a result, future research is needed to develop and evaluate possible avenues for intervention to prevent experiences of stigma for people living with HIV, both within and outside of the prison environment.

abstract: M.Sc.


title: Using Eye Movements to Establish a Normative Database of Control Participants Across the Lifespan

contributor:
Munoz, Douglas
Neuroscience Studies

subject:
Saccades
Oculomotor System
Development
Aging
Eye Movements

abstract: As the brain develops and ages, cognitive abilities (e.g., attention and memory) undergo significant functional fluctuations. In order to differentiate neuropathology from natural changes that occur due to development and aging, the goal of our study is to develop an understanding of changes in cognitive control that occur across the lifespan. The oculomotor system is an ideal model to probe cognitive function through the analysis of saccadic eye movements. We used a video-based eye tracker capable of measuring various saccade metrics on an interleaved pro- and anti-saccade task in healthy participants 5-85 years of age. The interleaved pro- and anti-saccade task requires the generation of pro-saccades (automatic eye movements toward a salient stimulus) and/or anti-saccades (voluntary eye movements away from a salient stimulus) depending upon a visual colour instruction. Participant head position was stabilized using a fixed head mount and participants sat in front of a computer screen to conduct the task. Our results show that individuals between 17 and 29 years of age outperformed younger and older participants by generating the fastest correct pro- (Mean = 146ms to 160ms) and anti-saccades (Mean = 225ms to 232ms). Participants between 21 and 29 years of age generated the fewest anti-saccade direction errors (Mean = 13.3%), which occur when an automated pro-saccade is initiated towards the target. Younger children (5-13 years-old) and older adults (50-85 years-old) had the slowest anti-saccade reaction times (Mean = 285ms to 339ms and 265ms to 290ms, respectively). Among younger participants (5-16 years-old), direction error rates decreased with age (Mean = 60.3% to 29.8%). Taken together, these results demonstrate strong developmental- and age-related effects in participant performance, reflecting maturation and deterioration of the nervous system. This study provides valuable insight into the natural oculomotor changes that take place across the lifespan, providing a foundation for future comparisons between clinical, preclinical and healthy populations.

abstract: M.Sc.


title: Fractional Labelmap Representation of Anatomical Structures

contributor:
Fichtinger, Gabor
Computing

subject:
Fractional Labelmap
Structure Representation
Radiation Therapy
Dose Volume Histogram
Voxelization
Segmentation

abstract: INTRODUCTION: In medical imaging software, structures are often represented using image volumes known as labelmaps. Conversion of structures to labelmap representations results in a loss of information which impacts medical imaging algorithms, including those in radiation therapy (RT) treatment planning. RT treatment planning systems are used to optimize radiation delivery to structures, which are represented as planar contours. Errors from conversion affect metrics such as dose volume histograms (DVHs) that are the primary metric for RT plan optimization. The goal of this thesis is to develop fractional labelmaps as a structure representation that preserves more structural information and reduces conversion errors. METHODS: The effect of voxelization on treatment planning metrics was tested by comparing DVHs calculated using varying voxel sizes. An algorithm was implemented that triangulates planar contours to closed surface mesh and handles features such as branching, keyhole contours, and end-capping. Closed surfaces were converted into fractional labelmap representations, where each voxel represents occupancy between 0% and 100%. Existing segmentation methods were modified to allow fractional labelmaps to be edited directly. RESULTS: Algorithms were implemented in the open-source medical imaging platform 3D Slicer, and the SlicerRT toolkit. Voxel size was found to affect DVH accuracy for structures with small features or in regions with a high dose gradient. The planar contour to closed surface triangulation algorithm produced qualitatively good surfaces. Fractional labelmaps from closed surfaces were found to be up to 19.1% better at representing structure volume than binary labelmaps, with an average improvement of 6.8%. DVHs calculated from fractional labelmaps were found to be more accurate than DVHs calculated using binary labelmaps. Fractional segmentation methods were found to create good quality segmentations. CONCLUSION: Labelmap voxel size was found to be a contributing factor for DVH accuracy. Accurate conversion algorithms were implemented for planar contour to closed surface and closed surface to fractional labelmap conversions. When used for structure representation and DVH calculation, fractional labelmaps were more accurate than binary labelmaps at the same resolution. Fractional labelmaps were found to be an effective tool for structure representation in radiotherapy that could be expanded to other use cases.

abstract: M.Sc.


title: Heidegger and the Meaningfulness of Questioning and Thinking

contributor:
Fairfield, Paul
Philosophy

subject:
Heidegger
Continental Philosophy
German Philosophy
Hermeneutics

abstract: What does it mean to question and think? Questioning and thinking are two activities which we consider imperative to doing philosophy and the two activities that we involve ourselves in most of the time, albeit without much thought given to that involvement. Are questioning and thinking those activities normally thought of as those belonging to reason alone and among the ranks of various mental activities? I would like to argue that, according to Heidegger, questioning and thinking carry a different essence than just mental activities, all the while still being imperative to philosophy. The following study seeks to investigate Heidegger’s reconceptualization of the themes of questioning and thinking and the meaning that lies therein. My aim is in the vein of a reconstructive exposure: to lay out and follow along Heidegger’s thought behind his conceptions of questioning and thinking and, through building them back up, to expose their deeper meaning, new understanding, and potential for interpreting the situation of one’s “historical time.” In order to argue this deeper meaning, new understanding, and interpretation, I put forth the following statement: where we find questioning, there too do we find thinking, meaning that if we take questioning to be that activity which opens up one’s situation, it is then thinking that confronts the opened-up situation as a struggle against it. This struggle against, however, is not to be conceptualised as a struggle against something so as to end it. On the contrary, the struggle against is that which runs up against the confrontation opened-up through questioning; a running up against that, while a struggle, nevertheless is intimately related to the confrontation that it struggles against. Ultimately, what is revealed through questioning and thinking is the “place” which most concerns the being who questions and thinks: the always-already there.

abstract: M.A.


title: Differential Na+/K+ Pump Isoform Expression in Higher and Lower Brain Regions of the Mouse

contributor:
Bennett, Brian
Andrew, David
Neuroscience Studies

subject:
Na+/K+ Pump
Ischemia
Stroke
Aldh2
Mouse

abstract: It has been demonstrated both clinically and experimentally that the higher brain is highly vulnerable to ischemia, while the lower brain is comparatively resilient. Discovering how lower brain neurons naturally resist ischemic stress may help to design new strategies for improving higher brain survival following ischemia. Our laboratory has proposed that differential expression of Na+/K+-ATPase isoforms, the ion pumps responsible for maintaining the electrochemical gradients of neurons, may underlie this phenomenon. Specifically, the α3 isoform, but not the α1 isoform, possesses kinetic properties that allow it to function efficiently under low energy conditions, rendering it ischemia-resistant. The goal of this thesis was to characterize regional expression of Na+/K+-ATPase α1 and α3 isoforms in the brains of Aldh2+/+ and Aldh2-/- mice across the lifespan, under both baseline (naïve) and chronic unpredictable stress (CUS) conditions. Quantitative polymerase chain reaction was used to analyze mRNA expression levels of α1 and α3 isoforms within higher and lower brain regions of 5 – 7 month old and 15 – 19 month old naïve Aldh2+/+ and Aldh2-/- mice, as well as in 3 month old mice that underwent a 28-day CUS protocol, along with age-matched controls. In both young and aged naïve cohorts, the α3 isoform was proportionally more highly expressed in the brainstem compared to the neocortex, while α1 was proportionally more highly expressed in the neocortex and less so, in the hippocampus, compared to the brainstem. Exposure to the CUS protocol did not significantly alter α1 or α3 mRNA expression in any brain region compared to controls. Stress mice exhibited regional differences in α1 and α3 expression that were consistent with the results in naïve animals. There were no significant effects of genotype or sex on the expression of either isoform. Parallel studies from our laboratory have shown that protein expression correlates with mRNA expression. Future work in our laboratory will investigate how α1 or α3 expression may change and protect neurons in response to acute ischemia.

abstract: M.Sc.


title: From the Inside Out: Discussing Women's Empowerment with the Women's Studies Department at the University of Calicut

contributor:
Jefremovas, Villia
Cultural Studies

rights: Attribution-NonCommercial-NoDerivs 3.0 United States

subject:
Women's Education Kerala
Women's Rights
Women's Education
Kerala Education
Kerala Model

abstract: This paper will contribute to the academic discussion surrounding education and its effects on the empowerment of Keralite women. Kerala’s education system has been highly praised as a model for development due to its high performance in standard developmental indicators. This model, however, is increasingly becoming contested in academic scholarship, specifically due to its perpetuation of inequality amongst marginalized groups, such as women and members of lower castes. This work will explore the culture-specific relationship between women and their social surroundings and the critiques made by the women in the Women’s Studies Department at the University of Kerala will take an active role in participating in the discussion of education and its effects on the positionality of women in Kerala, illuminating new required avenues of scholarship and attention.

abstract: M.A.


title: An Examination of Patellofemoral Joint Function Over a Range of Tasks

contributor:
Rainbow, Michael
Mechanical and Materials Engineering

subject:
Biomechanics
Biplanar Videoradiography
Patella
PFJ
PFP
Rehabilitation
Motion Capture

abstract:
Current understanding of dynamic patellofemoral joint (PFJ) mechanics in literature is limited to static or very slow in vivo measurements.  Two studies were performed across a wide range of functional movements to improve upon our understanding on how the PFJ moves dynamically.  The first study aimed to provide foundational data of the PFJ and associated mechanisms such as medial patellofemoral ligament (MPFL) length, joint congruence, and engagement.  The second study looked at the effects of a gait rehabilitation program had on the PFJ.  The program altered hip mechanics to mitigate pain associated with patellofemoral pain.  Both studies used biplanar videoradiography (BVR) motion capture techniques in conjunction with a computed tomography scan of the knee to quantify and evaluate PFJ motion.

Four functional movements - walking, lunging, sidestepping, and running - were investigated.  We observed several linear correlations between MPFL length, lateral patellofemoral tilt, lateral patellofemoral displacement, orientation of the patella ridge within the trochlear groove, and patellofemoral volumetric congruence.   In the pilot gait rehabilitation study, we found that targeting the hip had significant effects on PFJ kinematics, mechanics, and congruence.  Whether these changes can be maintained or are beneficial is yet to be determined; however, they currently provide insights into mitigating PFP using non-surgical methods. These datasets can be used to provide the basis of our understanding of the PFJ and guide future studies.

abstract: M.A.Sc.


title: Talkin' Back to Johnny Mac: Interrupting John A. Macdonald & Learning to Curate from an Indigenous Framework

contributor:
Taunton, Carla
Robinson, Dylan
Cultural Studies

subject:
Curatorial Studies
Indigenous Studies
Indigenous Art
Performance Art
Aboriginal Art
Canadian Studies
Indigenous Methodologies
Indigenous Curatorial Methodologies

abstract:
From January to April 2015, I curated Talkin’ Back to Johnny Mac, a five-part performance series that took place in Katarokwi (Kingston, Ontario). The series, which took place during the bicentennial birthday year of Kingstonian Prime Minister Sir John A. Macdonald, interrupted the celebratory, nationalist, and settler colonial narratives that drove the celebration and critiqued the ways in which historical and colonial/settler icons like Macdonald are remembered. Each individual performance by artists David Garneau, Peter Morin, Adrian Stimson, Leah Decter, and Tanya Lukin Linkater embodied unacknowledged contradictions in the celebratory tone of Macdonald’s birthday year. Together, the performances built a critical dialogue that intervened in the colonial narrative that turned Macdonald into an icon. Taken together, this series of performative acts forced a consideration of his ongoing influence as the first Prime Minister of Canada on the undercurrent of discrimination and assimilation still so fundamental to state approaches to Indigenous issues in Canada.
Talkin’ Back to Johnny Mac is the first component of this project-based dissertation. Documentation of the performances that constituted the project is included in Chapter Three. The second component is this written section, which explores Indigenous curatorial methodologies by placing my experience of curating Talkin’ Back in conversation with the practices of six Indigenous curators. In so doing, I create a map of Indigenous curatorial history in Canada. The written component builds on the curatorial project, locating it within a discussion of Indigenous curating as a practice based in Indigenous epistemologies and ontologies.

abstract: PhD


title: Antifreeze Protein Engineering

contributor:
Davies, Peter
Biochemistry

subject:
Antifreeze Protein
Protein Engineering
Adhesion Protein
Adhesin
Diatom
Microfluidics
Ice-Binding Protein
Dendrimer
Intein
Protein Circularization
Thermal Stability
Protein Multimers
Marinomonas Primoryensis
Chaetoceros Neogracile
Peptide Backbone Circularization

abstract:
This thesis describes: 1) the use of protein engineering to increase ice-binding protein (IBP) activity and thermal stability, and 2) the binding interaction and microcolony formation between an Antarctic bacterium and diatom. IBPs, including the antifreeze proteins (AFPs) that prevent the freezing of organisms, are found in nearly all biological kingdoms. IBPs have potential applications in a variety of domains including the food industry, cryo-medicine, and biotechnology. Despite the variety of IBPs, most are difficult to produce in amounts needed for industrial applications. Consequently, there is a need to find or engineer IBPs with enhanced activity and stability. Previously, AFP activity was increased by fusing an AFP to another protein, or by increasing the size of the IBP’s ice-binding face. Here, I used a highly-branched polymer, known as a dendrimer, to fuse a range (6 to 12) of moderately-active type III AFPs from Macrozoarces americanus together. These AFP multimers had improved antifreeze and ice-recrystallization inhibition activity. Unexpectedly, AFPs multimers had enhanced recovery from heat treatment. I also achieved enhanced thermal stability in type III AFP through an alternative strategy. Using split-intein mediated end-terminal ligation, I fused the N- and C- termini of the type III AFP together. Peptide backbone circularization had no effect on antifreeze activity but significantly increased thermal stability compared to the non-cyclized form.
The IBP found on the cell surface of a Gram-negative Antarctic bacterium, Marinomonas primoryensis, is one region of an exceptionally large multi-domain 1.5 MDa protein, MpIBP. Using temperature-controlled microfluidics, I have shown that M. primoryensis forms bacterial clusters on ice. Binding is aided by the motility of the bacterium and is dependent on the functionality of its ice-binding domain. The strictly aerobic M. primoryensis is drawn and binds to, the Antarctic diatom Chaetoceros neogracile to form mixed cell clusters and adheres them to ice. We hypothesize that the ice-binding function of MpIBP keeps its host immediately under the surface ice in the phototrophic zone of the water column where oxygen and carbon compounds are more abundant. By recruiting diatoms to the ice, M. primoryensis helps these photosynthesizers form a symbiotic community where light is most abundant.

abstract: PhD


title: The Role of RNA Binding Proteins in Inflammation Mediated Reproductive Pathologies

contributor:
Tayade, Chandrakant
Biomedical and Molecular Sciences

subject:
Endometriosis
Pregnancy Loss
RNA Binding Protein
Post-Transcriptional Gene Regulation
Reproduction
Inflammation
Pathology

abstract: Endometriosis is a major reproductive pathology that affects more than 8.5 million women in North America alone, and 176 million worldwide. It is characterized by the growth of endometrial lining outside of the uterus and remains one of the most important global health challenges due to staggering health care costs, lack of non-invasive diagnostic tests, lack of a cure and significant side effects with current treatments.  Recurrent pregnancy loss is another major reproductive pathology, which affects 1-5% of pregnant women worldwide. It is now well established that aberrant inflammation is one of the most important contributing factors in the pathogenesis of these gynecological diseases. RNA binding proteins including Tristetraprolin (TTP) and Human antigen-R (HuR) families are regulators of inflammation, and modulate many hallmark inflammatory cytokines implicated in both endometriosis and RPL, including: tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6). To understand the unique contributions of RNA binding protein axis, we screened for TTP/HuR axis in endometriosis patients and investigated functional effects in vitro as well as in a syngeneic mouse model of endometriosis. We also sought out to determine endometrial-endothelial modes of intercellular communication and whether RNA binding proteins are shuttled via extracellular vesicles including exosomes.  We report aberrations in the TTP/HuR axis in endometriosis patients and demonstrate that knockdown of TTP in endometriotic epithelial cells yields differential inflammatory cytokine profiles compared to endometrial epithelial cells. We also report for the first time functional effects of endometrial-derived exosomes that participate in a form of intercellular communication with endothelial cells. Further, using a mouse model of RPL, we report downregulation of TTP protein while targets TNF-α and IL-6 are upregulated in placentas treated with Lipopolysaccharide compared to controls. Our results suggest that RNA-binding proteins such as TTP are expressed and involved in the modulation of inflammation-induced pregnancy pathologies.  Together, our data demonstrate unique contributions of the HuR/TTP RNA binding protein axis in the pathogenesis of endometriosis and pregnancy loss and opens up a new avenue of research to understand contributions of these RNA binding proteins in modulating inflammatory responses.

abstract: PhD


title: The Effects of Transcranial Magnetic Stimulation on Depression and the Associated Olfactory Dysfunction

contributor:
Milev, Roumen
Neuroscience Studies

subject:
Depression
Olfaction
Transcranial Magnetic Stimulation
Major Depression
Olfactory Dysfunction
Sensory Processing
Treatment for Depression

abstract:
Introduction: Depression negatively impacts olfactory functioning and as such, olfactory dysfunction has been found in individuals with depression. Expansions of this research have demonstrated an improvement in olfactory functioning after successful pharmaceutical and psychotherapy treatments for depression. However, it is unknown if intermittent theta burst stimulation (iTBS), a form of transcranial magnetic stimulation (TMS) has a similar effect.
Objectives: The current study examined the olfactory functioning and depression severity in depressed individuals before and after iTBS, comparing them to non-depressed controls. We hypothesized that depressed individuals would have significantly poorer olfactory functioning compared to controls before treatment, but little to no difference between after successful treatment. We also predicted that depression severity and olfactory dysfunction were negatively correlated.
Methods: We recruited 20 depressed individuals receiving iTBS and 9 non-depressed controls. The olfactory function of depressed patients was tested before and after treatment using Sniffin’ Sticks Extended Test (examining olfactory threshold, discrimination, and identification). Depression severity was also evaluated. Controls were tested in the same manner with a 5-6 week waiting period in lieu of iTBS.
Results: Both the comparison of olfaction before and after treatment in depressed patients and with controls found no significant differences. An effect of age (p<0.05) and baseline depression severity (p<0.05) were found in the depressed group, with younger and less severely depressed individuals having significantly better olfactory functioning than their counterparts both before and after treatment. There were a number of significant correlations between depression severity and olfactory discrimination, identification, and total olfaction score at both time points.
Discussion: While no significant difference was found between the depressed and control groups or within the depressed group, the impact of depression severity provided support for the assumption of a reciprocal relationship. The significant difference between younger and older depressed participants highlights the limitation of age present in the study that may have contributed to the lack of significant differences. Overall, the relationship between depression and olfaction has the potential to be an important part of early diagnosis, examination of treatment progression, and on quality of life of depressed individuals.

abstract: M.Sc.


title: Channel Optimized Scalar Quantization over Orthogonal Multiple Access Channels with Memory

contributor:
Alajaji, Fady
Linder, Tamas
Mathematics and Statistics

subject:
Channel Optimized Scalar Quantization
Multiple Access Channel
Correlated Sources
Compression and Transmission
Non Binary Noisy Discrete Channel

abstract:
In this thesis, the joint source-channel coding method, channel optimized scalar quantization, is applied to real-valued, correlated data. The data is sent over the orthogonal multiple access channel, with non-binary noisy discrete channels with memory as the two sub-channels. Three different schemes are compared for this system: in the first scheme encoding and decoding are performed independently, in the second scheme encoding is done independently and joint decoding is carried out, and the third scheme is with jointly optimized encoders and joint decoding. The goal is to derive optimality conditions that will result in a lower end-to-end distortion. To this end, necessary optimality conditions for the two latter schemes are fully derived and implemented for the bivariate Gaussian and bivariate Laplacian distributions of varying correlation.\\
The first and second methods are then further compared, by implementing them for an image transmission system. Here the images are first processed with the 2 dimensional discrete cosine transform, and then encoded using channel optimized scalar quantization. At the decoder, two different methods are used, the independent and joint decoder.\\
In addition to comparing the different coding methods, various channels characteristics are exploited. For example, the non-binary noisy discrete channel can be used to model memory and the $2^q$-ary output allows for performance improvement via soft-decision decoding. It is observed that by taking the source correlation into consideration, significant signal-to-distortion ratio gains can be achieved. For example, the highest gain incurred from the third scheme is when the bivariate Gaussian is compressed at rate 2, where the gain in signal-to-distortion ratio due to source correlation is 10.90 dB.

abstract: M.A.Sc.


title: Individual Variability in mRNA Expression Responses to Resistance Exercise

contributor:
Gurd, Brendon
Kinesiology and Health Studies

subject:
Individual Variability
mRNA Expression
Resistance Exercise

abstract: Several studies have observed variability in the individual mRNA expression responses to acute exercise. However, because observed responses contain a degree of measurement error and within-subject variability, it is unknown whether variability in the mRNA expression responses to acute exercise exists. The purpose of this thesis was to determine whether variability in the individual mRNA expression responses to acute exercise exists. Utilizing freely available microarray data, variability in observed responses to acute resistance exercise (RE) and CON were compared to determine the variability in mRNA expression responses to RE. The previously published microarray study (1) collected skeletal muscle biopsies before (PRE) and 24 hours after (POST) RE/CON and genome-wide mRNA expression responses were measured using Affymetrix microarray chips. Standard deviation (SD) in the observed responses to CON were subtracted from RE to determine an effect size of variability in the responses (ESIR) to RE. Although 15849 transcripts had an incalculable ESIR (i.e. SD in observed responses to CON > RE), 29933 transcripts had an ESIR > 0 and 1486 mRNA had a large ESIR (i.e. ESIR > 0.6). WebGestalt’s gene set enrichment analysis revealed that the 1486 mRNA with a large ESIR were involved in several pathways proposed to play roles in regulating the adaptive responses to resistance training (RT). The 1486 mRNA with a large ESIR were also compared to a group of 2756 mRNA (2) previously found to have acute expression responses that correlate with skeletal muscle strength and size adaptations following RT. 109 mRNA with large ESIR were also among the mRNA previously found to correlate with both skeletal muscle strength and size adaptations to RT. Together, these results suggest that individual variability in the mRNA expression responses to RE exist, and highlight 109 mRNA that potentially play key roles in predicting skeletal muscle adaptations to RT.

abstract: M.Sc.


title: Understanding Test Preparation Phenomenon Through Chinese Students' Journey Towards Success on High-Stakes English Language Tests

contributor:
Cheng, Liying
Education

subject:
Test Preparation
Washback
High-Stakes Tests
Chinese Students

abstract:
Many Chinese students take test preparation courses with an aim to achieve success on English language tests because of the high-stakes consequences associated with test scores. However, contrary to the massive test preparation industry in China and the huge claim of achieving high scores, there is very limited empirical evidence to help us understand how students are prepared and if the claim can be substantiated. Therefore, the purpose of my doctoral dissertation was to understand Chinese students’ test preparation for high-stakes English language tests, through examining the nature, the perceived effects, and the perceived value of test preparation practices for the Test of English as a Foreign Language Internet-based Test (TOEFL iBT) and the College English Test Band 4 (CET4).
This study employed a multiple-stage, multiple-method design to collect data from three participant groups, including students, teachers, and administrators. Three research sites reflecting the stages of test preparation experience were included: ‘currently’ taking test preparation courses, recently completing test preparation courses, and achieving success on tests. Data were collected from classroom observations and interviews with 18 students, eight teachers and three administrators, questionnaires with 534 students, and documents related to test preparation courses and test preparation centre’s administration.
Test familiarization, English skill improvement, and stress management were three major practices that helped Chinese students achieve success; however, the factors related to participants’ characteristics, perceptions, and their situated context interacted with each other to shape these practices. Although no immediate substantial test score gains were found, the practices that targeted at English skills were perceived to gradually improve test scores. The trustworthiness, the efficacy and the reorientation of the test preparation practices were valued to help with achieving success, although the extent of these aspects varied to individual students. Drawing on Green’s (2007) washback model, the findings contributed to the understanding of test preparation phenomenon that the variability in the nature of the test preparation practices influence the direction that test preparation practices work on test scores and English learning, and the perceived value are related to what students experienced (nature) and what they achieved (perceived effects).

abstract: PhD


title: Price Signals

contributor:
Head, Allen
Cotton, Chris
Economics

subject:
Economics
Signaling
Game Theory

abstract: This thesis contains three papers in which a player's price may signal his private information. Each paper contains a novel game theoretic model, analysis of the model, and a discussion of how the solution contributes to our understanding of real problems. In the first, a defendant's settlement offer may convey the strength of his case to a plaintiff. That papers addresses the questions of why discovery may be only partially utilized and why parties to a case may fail to settle despite the availability of discovery and disclosure. I show that the plaintiff may underutilize discovery in order to openly maintain his belief that the defendant may not have a strong case to affect the defendant disclosure and ultimately his settlement offer. I also consider a similar buyer-seller model with buyer inspection and embed it into two more complex models. The second paper extends the buyer-seller model with two types of sellers to one with three types, which introduces very different kinds of equilibria (ie. partial separation). The application there is to the labour market and, in particular, to the 1973-2006 period in which the US saw a simultaneous substantial fall in the 10th percentile male and female wages and substantial rise in residual wage inequality followed by reversals, which are patterns that other theories have been unable to generate. Under a kind of technological progress in line with the routinization hypothesis, the benefit that the middle type gets from mimicking the high type decreases, which causes him to prefer to separate. That generates the initial comovements and the continued technological progress generates the reversals. In the final paper, each firm may convey through its price its current marginal cost of production, which affects whether or not its customers will return in the next period. Price stickiness arises in the sense that a firm only uses two sale prices and one regular price despite the generality of its cost process.

abstract: PhD


title: The Zero Locus of Symmetric Polynomials

contributor:
Wehlau, David
Mathematics and Statistics

subject:
regular sequences
symmetric polynomials
homogeneous polynomials
power sums
complete symmetric polynomials

abstract: Homogeneous polynomials $f_1, f_2, \dots, f_n$ form a regular sequence in the polynomial ring $\mathbb{C}[x_1, x_2, \dots, x_n]$ when the reduced affine variety of these polynomials only contains the origin.  In this report, we will be particularly interested in regular sequences of power sum symmetric polynomials and complete symmetric polynomials in three variables.  As a result of this investigation, we are able to obtain a better understanding of when regular sequences of these polynomials occur.

abstract: M.Sc.


title: Structural and Functional Characterization of Iron-Containing Oxygenases from Pseudomonas aeruginosa

contributor:
Jia, Zongchao
Biomedical and Molecular Sciences

subject:
Heme
Heme oxygenase
2-oxoglutarate
2OG oxygenase
Heme-degrading enzyme

abstract:
Pseudomonas aeruginosa is a prevalent Gram-negative opportunistic human pathogen responsible for many hospital-acquired infections. It is a significant source of infection in burn victims and is the predominant cause of morbidity and mortality in cystic fibrosis patients. P. aeruginosa is of considerable medical importance due to its high antibiotic resistance.

Like most organisms, P. aeruginosa requires iron for survival and proliferation. As free iron is scarce within humans, with the majority of iron complexed with heme, this human pathogen expresses proteins responsible for heme uptake and breakdown. P. aeruginosa possesses two iron-regulated cytoplasmic heme proteins, PhuS and HemO. PhuS has been previously classified as merely a heme-trafficking protein, while HemO is the canonical heme oxygenase (HO) responsible for heme degradation to produce biliverdin, CO, and free iron. Determination of the crystal structures of PhuS in the apo- and heme-bound forms show unique structural differences compared to its homologue ChuS, the Escherichia coli O157:H7 HO. However, we have discovered that PhuS also has heme-degrading activity and is five times more potent than ChuS. We show that PhuS degrades heme to verdoheme and has a much lower energy barrier for this step than HemO. Thus, HemO is mainly responsible for the ring-opening reaction of verdoheme to biliverdin. We have also confirmed through kinetics analysis that the presence of PhuS and HemO together enhances heme degradation compared to HemO alone. These results combined have identified function coupling of this unique two-enzyme system that affords P. aeruginosa with more efficient heme breakdown and iron utilization.

As iron is used as a cofactor for many enzymatic processes, we focused on another family of iron-containing oxygenase called the 2-oxoglutarate/Fe(II)-dependent oxygenases (2OG oxygenases). P. aeruginosa encode four putative 2OG oxygenases, of which two of them are characterized here: MicL (PA4191) and PiuC (PA4515). We show that MicL has the ability to bind 2OG and Fe(II), while PiuC has potential protein substrates in EF-Tu and keto-acid isomerase. Through in vivo P. aeruginosa growth assays, we show that MicL and PiuC are important regulators of cell growth, allowing the pathogen to survive longer under greater levels of nutrient stress.

abstract: PhD


title: A Personalized Software Assistant Framework To Achieve User Goals

subject:
Internet of Things (IoT)
Personalized Software Assistants
Digital Assistant
User Interaction

abstract: The growing trend of devices participation in Internet of Things (IoTs) platforms has created billions of IoT devices for users. The rapid trend has made users to install IoT devices at homes to achieve their goals, such as to reduce electricity cost. Moreover, the increasing popularity of service-oriented computing makes more and more services available on the Web. Users make use of these services to achieve their personal goals, such as to book right tickets. Existing research with personalized software assistants has been conducted to assist users majorly in e-commerce sites for customized search recommendations. However, the potential of personalized software assistant systems usage in a user-centric model is highly unrealized in assisting users to achieve their personal goals through personalized context-aware interactions with users based on behavioural habits, such as to smartly recommend IoT devices usage in smart-homes to reduce electricity expenses, and engage users more during the process of service selection to achieve their goals. In this thesis, First, we propose an engine that identi es the behavioural patterns of IoT device users to make smart recommendations to reduce users cognitive overload. Then we propose an intellectually cognitive personalized assistant framework which helps users to achieve their personal goals through personalized context-aware interactions for selection of services. We have designed and developed a prototype as a proof of concept. We perform a case study to evaluate the e ectiveness of our framework. Our framework, utilizing the learning-to-rank algorithm, namely AdaRank, improves the nine baseline approaches by 12.02% - 31.52% in helping users  nd the desired services to achieve their goals. Further, we conduct a user study to obtain users' perception of using our framework to achieve their personal goals. Our user study results show that our framework is helpful in achieving user's goals and saves users time in  nding their personalized services faster.

abstract: M.A.Sc.


title: Distributed Sensing to Assess the Shear Behaviour of Reinforced Concrete Beams

contributor:
Hoult, Neil A.
Civil Engineering

subject:
Digital Image Correlation
Distributed Fibre Optic Sensor
Shear Behaviour
Stirrup Deterioration
Reinforced Concrete

abstract:
The long-term durability of infrastructure is a growing concern as assets built in the middle of the last century reach the end of their service lives. One solution to manage these assets is to use distributed monitoring technologies to assess their performance and the effects of deterioration. Distributed fibre optic sensors (FOS) based on measuring Rayleigh backscatter provide strain measurements along the full length of the fibre up to 70 m. Digital image correlation (DIC) can show crack formation over the surface of a structure and assist with the understanding of the strain data from the FOS. An experimental study using these two technologies was undertaken to investigate the shear behaviour of reinforced concrete (RC) beams.
In the first test series, seven reinforced concrete specimens with different stirrup spacing and longitudinal reinforcement ratios were instrumented with nylon coated FOS and tested in three point bending to investigate whether FOS could detect differences in behaviour. It was found that distributed strain measurements could detect the peak strain in the stirrups indicating the location of the crack crossing the stirrups as well as providing the strain distribution along the stirrup. The specimens all failed in flexure except the ones that violated the CSA A23.3-14 (2015) stirrup spacing limit.
In the second test series, five RC beams with artificial deterioration were instrumented and tested. Artificial deterioration mechanisms included having no bottom or top anchorage as well as pitting corrosion at the mid-height of the stirrup legs. Stirrups without bottom anchorage were found to have the largest impact on the specimen’s performance (the load carrying capacity was reduced by 20% and the failure mode changed from flexural to shear). The other two types of deterioration did not influence the load carrying capacity. Distributed sensing aided in understanding the failure mode.
Finite-element models were created using a two dimensional finite-element analysis (FEA) package to evaluate the accuracy of this software for use in structural assessments with distributed sensing. It was found that the results from the FE models were less conservative than the experimental results for most cases. Inaccuracies (i.e. load capacity, failure mode, strain distribution, crack pattern) were due to the use of incorrect modeling methods for the deteriorated stirrups and the use of smeared cracking.

abstract: M.A.Sc.


title: Brings Learning to Life: Exploring Teacher Learning in an International School Context

contributor:
Chin, J.
Luce-Kapler, R.
Education

subject:
Teacher Learning
International Teachers

abstract:
This study explored the lived learning experiences of six teachers at Czech International School (CIS). Taking a social, situated, and distributed (Putnam & Borko, 2000) view of learning, it sought teachers’ perspectives on learning and the factors that shaped it. The study was informed by research literature on teacher learning, responses to professional changes, intercultural competence and international mindedness.
	Participants were nominated by the school’s director, based on the criteria synthesized from literature. This study collected three types of data: 1) director interview, 2) teacher interviews, and 3) teachers’ written reflections. Influenced by a phenomenological approach, all interviews were modeled after Seidman’s (2006) in-depth interview structure, with one important adaptation: prior to each interview, participants were asked to engage in reflective writing exercises. Data were analyzed inductively and spirally by creation of emergent codes and themes. Four themes emerged from the data:  1) Learning to live in the host country, 2) Learning to teach diverse students, 3) Learning to navigate curricular differences, and 4) Learning to contribute to the school community.
	In summary, the key findings of this study are that teacher learning is complex, multifaceted, and embedded in everyday experiences inside and outside of the school context. Personal factors permeate all aspects of teacher learning and incur conscious choice. The schools’ ethos and support structures set the conditions for learning and frame how and what teachers learn. This study is crucial because it contributes a layered, in-depth teacher perspective on the source and nature of teacher learning in international schools to better understand and support it.

abstract: M.Ed.


title: Recovery of Gaseous HCL from Primarily Magnesium Chloride Solutions

contributor:
Ghahreman, Ahmad
Mining Engineering

subject:
HCl
Leaching
Recovery
Regeneration
Acid Recycling
Rare Earth Element Flowsheet
Laterite Flowsheet

abstract: Due to its many benefits over conventional H2SO4 leaching, the use of HCl for leaching has been increasing in many flowsheets, particularly for laterites and rare earth elements ores. However, HCl is more expensive than H2SO4 and an inexpensive method of regenerating it must be developed to ensure its economic viability in these flowsheets. This thesis presents a robust process which operates at low temperatures and atmospheric pressure thereby reducing operating costs. The addition of H2SO4 to MgCl2 solutions in the presence of air sparging is shown here to produce external HCl recoveries up to 64.6%. The effects of temperatures between 75 °C and 100 °C, airflow between 200 and 600 mL/min, stoichiometric H2SO4 addition between 100% and 300%, and initial chloride concentration between 4 and 10 M were investigated. Increasing chloride concentration and H2SO4 addition were found to be beneficial to HCl recovery, consistent with Le Chatelier’s Principle. The positive impact of increasing temperature and airflow were determined to be due to higher temperatures and increased airflows favouring the volatilization of HCl. Additionally, the impact of the incorporation of iron, calcium, sodium, and a combination of these ions were studied. The presence of calcium and sodium were found to be detrimental and iron beneficial to total HCl recoveries. After initial batch experiments were conducted, the process was scaled-up to a two-stage continuous mode operation which yielded a maximum HCl recovery of 56.4%. While overall recoveries were found to decrease in continuous operation, the temperature, airflow, H2SO4 addition, and initial chloride concentration trends were found to be consistent with the batch experiments. The inclusion of iron had a greater positive impact in the continuous experiments and sodium was less detrimental to the system. The resulting liquid and solid samples were analyzed using inductively coupled plasma, atomic absorption spectroscopy, x-ray powder diffraction, carbon-sulphur analysis, and thermogravimetric analysis as appropriate to examine the mass balance and precipitate formed. The precipitate was found to be MgSO4.2H2O, CaSO4.2H2O, and FeSO4.7H2O which will impact further treatment.

abstract: M.A.Sc.


title: Immunosuppression in the Prevention of Progesterone Resistance and Adverse Reproductive Outcomes in Diabetes

contributor:
Kan, Frederick
Biomedical and Molecular Sciences

subject:
Gestational Diabetes
Progesterone Resistance
Macrolide-mediated Immunosuppression
MUC1
PIASy
FKBP52
NOD mice
NONcNZO mice
Progesterone Receptor
Implantation
Obesity

abstract: Diabetes is a global epidemic health adversity that is often associated with female subfertility, repeated miscarriages and congenital malformations. Despite plethora of information suggesting an association between aberrant maternal immune responses during pregnancy and gestational complications in type 1 diabetes, mechanisms underlying pre-clinical gestational loss in obese and type 2 diabetic subjects are yet to be defined. Further, no comprehensive evaluation of the impact of diabetes on implantation has been completed. This study aimed at examining effects of diabetes on the natural events associated with mammalian implantation in-vivo. Using various functional, histological and postmortem analyses, impact of diabetes and that of the macrolide immunosuppressant tacrolimus on murine implantation and post- implantation pregnancy events and outcomes were compared across mouse models of type 1 and obesity-associated type 2 diabetes, the None-Obese Diabetic and the New- Zealand Obese mice, respectively. Results obtained in this study showed, for the first time, that naturally occurring diabetes significantly impeded endometrial progesterone receptor (PGR)-mediated influences, creating a hostile uterine milieu that is not receptive to the implanting embryo. Specifically, we have identified aberrancies in the endometrial expression and regulation of certain receptivity biomarkers including those of the anti-implantation mucin MUC1 and its upstream regulators of cytokines and transcriptional factors suggestive of heightened endometrial resistivity to the hormonal actions of progesterone at implantation in diabetes. Further immunological and molecular analyses of endometria obtained from diabetic mice revealed an augmented pro-inflammatory milieu and an aberrant expression of the PGR and two of its co-regulators, namely the protein inhibitor of activated STATy (PIASy) and the co-chaperone protein FKBP52 which are incompatible with successful implantation. Therapeutic interventions with tacrolimus abrogated these perturbations in endometrial PGR-mediated actions, restored glycemic control, promoted implantation and significantly inhibited fetal demise and malformations. Comparative studies with metformin suggested that factors beyond glycemic control are critically involved in the pathogenesis of failed implantation and diabetes- associated fetal malformations in the obese and diabetic subjects. These findings provide insights into molecular mechanisms linked to implantation failure in diabetes, and evidently demonstrate reproductive benefits for the pre-conceptional use of macrolide immunosuppression in subjects at risk thereof.

abstract: PhD


title: Socioemotional Flexibility in Mother-Daughter Dyads Across Multiple Time Scales: A Longitudinal Follow-Up

contributor:
Hollenstein, Tom
Psychology

subject:
Emotion Dynamics
Socioemotional Flexibility
Mother-Daughter Relationship
Psychosocial Functioning
Internalizing Symptoms
Adolescence

abstract: Socioemotional flexibility involves shifting in and out of emotion states, and the range of emotional states expressed during interpersonal interactions (Hollenstein et al., 2013). Previous research has shown that socioemotional flexibility is associated with greater psychosocial functioning, and its counterpart, rigidity, is associated with poor psychosocial functioning (van der Geissen, et al., 2014; Lougheed & Hollenstein, 2016; van der Geissen, & Bogels, 2017). In a longitudinal follow-up (Time 1, Lougheed & Hollenstein, 2016), we examined socioemotional flexibility of in 54 mothers and their adolescent daughters (M age = 16 years old) at three different timescales: (1) within positive and negative contexts (dynamic flexibility), (2) across contexts (reactive flexibility), and (3) across 2 years (developmental flexibility), and associations with psychosocial functioning. Mothers-daughter dyads completed the Emotional Rollercoaster task—a series of five 3-minute discussions on times they felt the following strong emotions towards each other: (1) Happy/Excited, (2) Worried/Sad, (3) Proud, (4) Frustrated/Annoyed, and (5) Grateful. Findings support the Entrenchment hypothesis, as mother-daughter flexibility remained consistent over two years. In general, greater daughter psychosocial functioning was associated with greater dynamic and reactive flexibility in mother-daughter dyads. Contrary to findings at Time 1, mother psychosocial functioning was not associated with flexibility at Time 2. The changes that characterizes mother-daughter relationships in late adolescence (i.e., decreased mother authority, increased daughter autonomy, and increased internalizing symptoms) are explored as possible explanations for the shift in the associated factors of socioemotional flexibility from Time 1 to Time 2.

abstract: M.Sc.


title: Gating of Long-Term Potentiation (LTP) in the Thalamocortical Auditory System of Rats by Serotonergic (5-HT) Receptors

contributor:
Dringenberg, Hans
Psychology

subject:
Auditory cortex
Serotonin
LTP
LTD
Neocortex
Plasticity

abstract: The neuromodulator serotonin (5-hydroxytryptamine, 5-HT) plays an important role in controlling the induction threshold and maintenance of long-term potentiation (LTP) in the visual cortex and hippocampus of rodents. Serotonergic fibers also innervate the rodent primary auditory cortex (A1), but the regulation of A1 plasticity by 5-HT receptors (5-HTRs) is largely uncharted. Thus, we examined the role of several, predominant 5-HT receptor classes (5-HT1ARs, 5-HT2Rs, and 5-HT3Rs) in gating in vivo LTP induction at A1 synapses of adult, urethane-anesthetized rats. Theta-burst stimulation (TBS) applied to the medial geniculate nucleus resulted in successful LTP induction of field postsynaptic potential generated by excitation of thalamocortical and intracortical A1 synapses. Local application (by reverse microdialysis in A1) of the broad-acting 5-HTR antagonist methiothepin suppressed LTP at both thalamocortical and intracortical synapses, an effect that was mimicked by the selective 5-HT2R antagonist ketanserin, but not the 5-HT1AR blocker WAY 100635. Interestingly, antagonism of 5-HT3Rs by granisetron selectively blocked LTP at thalamocortical, but not intracortical A1 synapses. Further, in the absence of TBS delivery, granisetron application resulted in a pronounced increase in fPSP amplitude, suggesting that 5-HT3Rs play an important role in regulating baseline (non-potentiated) transmission at A1 synapses. Together, these results indicate that activation of 5-HT2Rs and 5-HT3Rs, but not 5-HT1ARs, exerts a clear effect on LTP induction at A1 synapses, allowing 5-HT to act as a powerful regulator of long-term plasticity induction in the fully matured A1 of mammalian species.

abstract: M.Sc.


title: Computational and Empirical Water Quality Modeling in Lakes and Ponds

contributor:
Boegman, Leon
Civil Engineering

subject:
ELCOM
CAEDYM
Empirical Modeling
Storm-Water Ponds
Water Quality
Sensitivity Analysis
Oxygen
Lake
Hydrodynamic

abstract:
The water quality issues facing aquatic systems have made managers and stakeholders seek help from computational and empirical models. A 3-D hydrodynamic and biogeochemical model was applied to storm-water ponds in the City of Edmonton to examine the reasons behind excessive algae growth and eutrophication. In the hydrodynamic simulation (ELCOM), the atmospheric instability corrections led to more heat loss (up to ~33%) and resulted in more accurate simulation of the temperature profiles (root mean square error (RMSE) <3.03 ℃). The calibration involved tuning albedo and light attenuation coefficients, which was optimized by applying a sensitivity analysis tool that showed the model was more sensitive to albedo. Thereafter, the biogeochemical model (CAEDYM) was coupled with ELCOM and the water quality processes in the ponds were also investigated. The results demonstrated that the model predicted nutrient (nitrogen and phosphorus) components and dissolved oxygen (DO) variability with acceptable accuracy (0.016 mg/L < RMSE <2.85 mg/L), but underestimated the chlorophyll-a (RMSE <64.3 μg/L). However, the model predicted phytoplankton community contribution to the total chlorophyll-a with marginal error (<40% for different groups).
An empirical DO model, based on the measurements of hypolimnetic DO (to estimate DO depletion; dDO/dt) and the temperature profiles (to estimate hypolimnion thickness; H) in three lakes (Lake Erie, Lake Simcoe and Eagle Lake) was proposed. The model was developed by neglecting the vertical and horizontal fluxes in the DO budget during summer and considering only sediment oxygen demand (SOD) and hypolimnion oxygen demand (HOD) as the main parameters driving dDO/dt. HOD and SOD were empirically estimated by fitting to the observed dDO/dt and H. Thereafter, using computed H, estimated SOD and HOD and an initial DO, the hypolimnetic DO were simulated in the selected lakes (RMSE <2.67 mg/L). One of the main assumptions of the empirical prediction of DO, negligible vertical DO flux, was then examined by computing the flux of DO through the thermocline in Eagle Lake from microstructure casts. It is shown that the amount of vertical flux toward hypolimnion is 2 to 4 orders of magnitude lower than the other terms of the DO budget (HOD and SOD).

abstract: PhD


title: An Open-Source Device for Tendon Actuated Wrist Motion

contributor:
Sellens, Rick
Pichora, David
Mechanical and Materials Engineering

subject:
Open-Source
Open Source
Wrist Simulator
Wrist Actuator
Wrist Motion
Arduino
Biomechanics

abstract:
A wrist motion simulator or wrist motion actuator is a system that actuates a cadaver wrist to control the joint and move it through a variety of motions. Active wrist motion actuators apply forces directly to the tendons of interest to manipulate wrist position in a manner similar to in-vivo active motion.

Active wrist motion actuators have been approached in many diﬀerent ways, how ever no clear design standard has been developed. Existing systems often require hardware and software proprietary to the investigators, preventing other researchers from easily replicating the work. This thesis presents the development and testing of an economical, accessible and open-source wrist motion actuation system. The full design, software code and ﬁles needed to replicate the device are all available from an online repository.

An open-source system of four linear actuators driven by a micro-controller was developed to apply tension to cadaver wrist tendons under program control. The control algorithm compared current wrist angular position with a target position as a function of time and generated actuator motions to move the wrist towards the target position.

The actuation system was tested with a soft embalmed cadaver wrist that was suture connected to the system using four tendon attachment points. The system of four linear actuators driven by the micro-controller applied tension to the sutures under program control. Wrist angular position data was collected in real time using an electromagnetic tracking system and delivered to the Actuation System via serial communication link. The system was tested by taking the wrist through 25 cycles of ﬁve diﬀerent motions: ﬂexion-extension, radioulnar deviation, dart throw, clockwise and counter-clockwise circumduction and angular position data was recorded as a function of time.

This work shows that a functional wrist motion actuator can be constructed based on an economical micro-controller system to provide adequate control of four tendons through a simple C program.

abstract: M.A.Sc.


title: On the Hydrodynamics of Anomalocaris Tail Fins

contributor:
Rival, David
Mechanical and Materials Engineering

subject:
Hydrodynamics
Manoeuvrability
Fluid Dynamics
Biomimetics

abstract: This thesis examines the hydrodynamic performance of a tail-fin abstraction of Anomalocaris canadensis, a large arthropod from the Cambrian period believed to have been an apex predator. Through direct force measurements and stereoscopic particle image velocimetry, it was found that a flat plate with a multi-vane geometry inspired by preservations of Anomalocaris exhibited a region of enhanced steady-state lift and drag at angles of attack greater than 25° when compared to an equivalent delta-wing plate. These shapes showed little difference during acceleration from rest; however, at an angle of attack of 30°, the lift and drag measured on the multi-vane model were 15.3% and 17.0% higher than the delta-wing model, respectively. It was found that the secondary and tertiary vanes of the tail-fin abstraction encourage the formation of additional leading-edge vortices, similar to those frequently seen on natural propulsors. The formation of these additional leading-edge vortices is confirmed by the increase in streamwise circulation measured using particle image velocimetry near the additional leading edges along the length of the chord. The results of the current study suggest that the enhanced resultant normal force on the tail fin of Anomalocaris made it well-suited for manoeuvres, giving it the ability to turn quickly and through small radii of curvature.

abstract: M.A.Sc.


title: Performing Trauma: The It Gets Better Project as a Performance of White Trauma

contributor:
Salah, Patricia
Gender Studies

subject:
Trauma Studies
Psychoanalysis
Affect Theory

abstract: Taking the It Gets Better Project as its case study, this thesis argues that the ways in which the project represents trauma is through an events-based model that centers the experiences of young, cis, white, gay boys. This is accomplished through a narrative of trauma that puts forward the idea that all queer youth experience trauma as an effect of being queer and that through this normalization they are positioned as all experiencing trauma in the same way. Furthermore, this framing is based upon the centering of sexuality as the primary way trauma manifests, which erases experiences of trauma that are marked by other axes of identity. The first chapter introduces my political commitments and a theoretical framework for interpreting the It Gets Better Project’s representations of trauma. The second chapter addresses the ways in which the project’s mantra, “it gets better,” constructs a linear teleology of queer suffering through an affective attachment to happiness and a melancholic attachment to the figure of the innocent child. The third chapter situates the It Gets Better Project within a broader discourse of queer liberalism to suggest that the project itself works to strengthen the borders of the Canadian and American nation-states. The conclusion suggests that a different practice of reading or remembering death, one attentive to questions of history, can gesture towards a future where ‘it’ can ‘get better.’

abstract: M.A.


title: Perceptual Effects of Inconsistency in Human Animations

contributor:
Troje, Nikolaus F.
Psychology

subject:
Motion Capture
Retargeting
Animation
Avatars
Shape
Motion
Inconsistency
Perception
Action

abstract: Animation retargeting is a method of producing human-like animations for use in research, video games, and movies. The procedure consists of capturing the motion of a performer and applying it to a computerized avatar. In practice, the body shape of the avatar can be very different from the body shape of the original performer. Such animations are called inconsistent because they are generated from mismatching shape and motion components. However, actions seen in day-to-day life are typically composed of correlated and consistent information. As a result of this exposure it is believed that the visual system builds up expectations regarding the way a person should look and move. Here I asked whether the human visual system has a special sensitivity to shape-motion inconsistency that would modify the perception of realistic animations. I recorded 10 male performers with either light or heavy body weight carrying out three actions: pushing, lifting, and throwing objects. I extracted shape and motion estimates from each performer, creating consistent and inconsistent animations whose shape and motion components were either from the same performer or combined from performers in different body weight groups. I conducted three experiments in an immersive virtual reality environment. First, when tasked with detecting shape-motion inconsistency, participants had a small ability to select the inconsistent stimuli instead of the consistent stimuli over chance levels. Next, using judgements of animation characteristics as an alternative measure of sensitivity, I assessed the effect of inconsistency on perceived eeriness, humanness, and attractiveness of consistent and inconsistent stimuli. None of these measures were affected by inconsistency. However, in a final experiment where I asked performers to rate the perceived weight and thrown distance of objects, I found an influence of shape-motion inconsistency on the perception of action outcomes. This indicates that the visual system relies on its knowledge of shape and motion to perceive realistic human animations. I propose that animated avatars that involve object manipulations may present an opportunity for the visual system to reinterpret inconsistency as a change in the dynamics of an object, rather than as an unexpected combination of body shape and body motion.

abstract: PhD


title: Adropin Acts in the Paraventricular Nucleus of the Hypothalamus to Influence Neuronal Excitability

contributor:
Ferguson, Alastair
Neuroscience Studies

subject:
Adropin
Paraventricular Nucleus
Hypothalamus
Electrophysiology
Water Intake
Neuroendocrinology
PVN

abstract: Adropin is a peptide hormone with cardiovascular and metabolic roles in the periphery, including effects on glucose and lipid homeostasis. Central administration of adropin has been shown to inhibit water intake in rats; however, the site at which central adropin acts has yet to be elucidated. The hypothalamic paraventricular nucleus (PVN), a critical autonomic control center, plays essential roles in the control of fluid balance, energy homeostasis and cardiovascular regulation, and is therefore a potential target for centrally-acting adropin. In the present study, we used whole- cell patch-clamp techniques to examine the effects of adropin on the excitability of neurons within the PVN. All three neuronal subpopulations (magnocellular, preautonomic, and neuroendocrine) in the PVN were found to be responsive to bath-application of 10 nM adropin, which elicited responses in 68% of cells tested (n = 57/84). The majority of cells (58%) depolarized (5.2 ± 0.3 mV; n = 49) in response to adropin, while the remaining responsive cells (10%) hyperpolarized (−3.4 ± 0.5 mV; n = 8), effects which were shown to be concentration-dependent. Additionally, responses were maintained in the presence of 1 μM tetrodotoxin in 75% of cells tested (n = 9/12), and voltage-clamp analysis revealed that adropin had no effect on the amplitude or frequency of excitatory or inhibitory postsynaptic currents (EPSCs and IPSCs) in PVN neurons, suggesting the peptide exerts direct, postsynaptic actions on these neurons. The electrophysiological effects of adropin on PVN neurons appear to be mediated partly by modulation of the transient potassium current. Collectively, these findings suggest central adropin may exert its physiological effects through direct actions on neurons in the PVN.

abstract: M.Sc.


title: Unsteady Force Estimation Using a Lagrangian Drift-Volume Approach

contributor:
Rival, Cameron
Mechanical and Materials Engineering

subject:
Fluid Dynamics
Fluid Forces
Lagrangian Measurements
Measurement Science
Experimental Fluid Dynamics

abstract: A novel Lagrangian force estimation technique for unsteady fluid flows has been developed, using the concept of a Darwinian drift volume to measure the unsteady force on an accelerating body. A methodology using multiple drift volumes is described and evaluated on an experimental test case containing highly-separated, vortical flow. The inherent advantage of the force estimation technique presented is that, unlike many modern Eulerian techniques, gradient operations and near-body measurements are not required to be calculated. These noise amplifying processes are avoided since the drift volume is calculated only from particle displacements in the flow field, reducing the importance of having high quality acceleration and spatial gradient data near walls and in regions of high shear. The resultant unsteady force estimates from the proposed technique are shown to align with the measured drag force during high accelerations, a region in which comparable methods suffer. The critical aspects of understanding unsteady flows, relating to peak and time-resolved forces, often lie within the acceleration phase of the motions, which are well-captured by the drift-volume approach. Therefore, this Lagrangian force estimation technique opens the door to fluid-dynamic analyses in areas that, until now, were inaccessible by conventional means.

abstract: M.A.Sc.


title: From the Yonge Street Riot to the Carding Controversy: Policing and Surveilling the Black Community in Toronto, Canada, 1992-2016

contributor:
Walker, Barrington
Cultural Studies

subject:
Anti-Black Racism
Carding
Racial Profiling
Police Brutality
Resistance
Report Writing
Slavery

abstract: In the last decade, the conversation surrounding racial profiling and carding in the city of Toronto garnered much public and scholarly attention. Many journalists, academics and activists have examined the Community Contacts Policy, also known as carding, as well as mass incarceration and the police shootings and killings of unarmed, young Black men. The Yonge Street Uprising and the carding controversy in Toronto serve as two case studies to explore the ways that Black men have been disproportionately profiled, policed and surveilled in this country, particularly in the province of Ontario. Despite the fact that the Yonge Street Uprising and the carding controversy occurred decades apart, a common thread throughout both cases was the narrative of Black male criminality. In addition, it became apparent that many of the practices employed in contemporary society, such as racial profiling, carding and mass incarceration were derived from slavery, with the goal of limiting the freedom and mobility of Black people. Therefore, an examination of Canada’s historical treatment of Black people is necessary in order to demonstrate how practices rooted in slavery, such as, fugitive slave advertisements and historical representations of Black criminality helped inform current police practices. Through an analysis of historical, legal, criminological, and critical race scholarship, this work seeks to examine how and why Black people, specifically Black men, were and continue to be disproportionately more likely to be policed, surveilled and incarcerated. In addition, neighborhood contexts were examined to determine whether there was a relationship between police stop and search practices among different neighborhoods. An analysis of quantitative and qualitative data gathered from various bodies of criminological and legal research, and reports commissioned by the Ontario government, provide support for the theory that the Canadian state criminalize and incarcerates certain populations it deems undesirable. Additionally, a consistent theme throughout this analysis was a heightened sense of anxiety and threat that whites have historically exemplified in relation to Black immigration, mobilization and resistance.

abstract: M.A.


title: Probabilistic Analysis of Unreinforced and Reinforced Soil Slopes Using the Random Finite Element Method

contributor:
Bathurst, Richard J.
Civil Engineering

subject:
Probabilistic Analysis
Geosynthetic-Reinforced Soil Slopes
Slope Stability
Random Finite Element Method
Footing Bearing Capacity
Spatial Variability

abstract:
The focus of this thesis is probabilistic analysis of unreinforced and reinforced soil slopes using the random finite element method (RFEM). RFEM combines the finite element method (FEM) with soil properties that are described by either random (homogeneous) or spatial variability.
The RFEM approach is used for the first time to investigate the influence of spatially variable cohesive soil strength on probabilistic margins of safety for bearing capacity failure of a footing located close to the crest of a slope. Analyses showed that the coefficient of variation and the spatial correlation length of soil cohesion can have a large influence on footing bearing capacity, particularly for slopes with large height to footing width ratios.
Probabilistic slope stability analyses of simple geosynthetic reinforced soil slopes were carried out for the first time using the shear strength reduction method in combination with the RFEM approach. The FEM code was modified to include bar elements to model horizontal layers of geosynthetic reinforcement. Analysis results demonstrate that large reductions in probability of failure can be realized by adding geosynthetic reinforcement layers to constructed slopes.
The same modified RFEM code was used to carry out probabilistic stability analyses of constructed wrapped-face reinforced slopes (or embankments) using frictional soils. The influence of fill placed at different layer thickness and compacted to different levels was simulated by adjusting the soil strength and unit weight, and the vertical spatial correlation length in the anisotropic spatially variable strength field used in each slope realization. Numerical results showed that vertical spatial correlation lengths approaching the magnitude of fill lift heights can control the probability of failure for reinforced slopes constructed with weak fills placed in lift heights close to but less than the wrapped reinforcement spacing used in the study.
The RFEM codes developed in this study are used next to carry out numerical simulations of physical full-scale unreinforced and reinforced embankments loaded to failure using a strip footing. The results of analyses showed that the assumption of vertical spatial variability in soil properties due to compaction was able to capture the observed failure mechanisms in these structures.

abstract: PhD


title: Development of CO2-Switchable Technologies for Polymer-Based Applications

contributor:
Cunningham, Michael
Jessop, Philip
Chemical Engineering

subject:
ATRP
Carbon Dioxide
Emulsion
Polymer Latex
Surfactant

abstract: CO2-switchable materials use CO2 as the trigger. Their mechanism is the reversible protonation of tertiary amines or amidines in aqueous solution, in the absence or presence of CO2. The application of CO2-switchable materials is also useful in other areas of polymer chemistry, such as ATRP (Atom Transfer Radical Polymerization) and the preparation of polymer latexes. Firstly, CO2-switchable ligands, solvents and photo-catalyst were used individually or jointly to recycle ligands and purify polymer made by ATRP. Secondly, artificial polymer latexes, such as poly(butyl methacrylate) (PBMA), were separately prepared from bulk polymers using the CO2-switchable solvents. The joint use of the two approaches mentioned above can produce polymer latexes with controlled molecular weight, but without impurities such as ligand or metal catalyst. Also, a new benign means was developed for reversibly breaking emulsions and latexes using CO2-switchable water, an aqueous solution of switchable ionic strength. Furthermore, living CO2-switchable PMMA latexes were prepared using reverse ATRP emulsion polymerization and AGET ATRP miniemulsion polymerization; the prepared latexes can be switched between the aggregated and dispersed states using only CO2 as the trigger.

abstract: PhD


title: Exploring Relationships Between Occupational Prestige, Perceived Public Stigma, Mental Health Experiences of Stigma, and Professional Help-Seeking in the General Canadian Population

contributor:
Stuart, Heather
Public Health Sciences

subject:
Stigma
Help-Seeking
Occupational Prestige

abstract:
Background: Workplace mental health has increasingly become a public health concern in Canada as employees are missing work every week because of a mental health issue, costing the Canadian economy billions annually. This is the first study to examine occupational prestige and its relationship to perceived public stigma, mental health experiences of stigma, and professional help-seeking.
Methods: Cross-sectional survey data on a nationally representative sample of working Canadians between the ages of 15 and 75 from Statistics Canada’s 2010 Canadian Community Health Survey (CCHS) and rapid response stigma modules were used to explore both objectives (N=10,389). SAS 9.4 was used to conduct complex survey data analyses, all of which incorporated Statistics Canada’s recommended sampling weights and bootstrap variance estimation procedures. Multiple linear regression and logistic regression were used to examine the associations between occupational prestige, perceived public stigma toward depression, mental health experiences of stigma during the past 12 months because of a past or current emotional or mental health problem, and professional help-seeking. Considered covariates included: gender, age, ethnic or cultural background, education, household income, marital status, number of dependent children, chronic physical condition, self-rated general mental health, and contact with a work colleague who has received treatment for a mental illness.
Results: Controlling for perceived public stigma in the direct effect between occupational prestige and professional help-seeking (ORdirect=0.994, 95% CI: 0.970-1.020) did not attenuate the total effect between occupational prestige and professional help-seeking, without controlling for perceived public stigma (ORtotal=0.995, 95% CI: 0.972-1.020). The confidence interval for the indirect effect of perceived public stigma toward depression as a mediator in the relationship between occupational prestige and professional help-seeking crossed the null value of one (ORindirect=0.999, 95% CI: 0.949-1.053), indicating that perceived public stigma toward depression is not an important mediator. Higher occupational prestige scores significantly reduced the odds of experienced stigma during the past 12 months because of a past or current emotional or mental health problem (OR=0.954, 95% CI: 0.913-0.998). Occupational prestige was not significantly associated with negative opinions or unfair treatment affecting work life (OR=0.945, 95% CI: 0.762-1.173).
Conclusion: Perceived public stigma toward depression is not an important mediator in the explored relationship between occupational prestige and professional help-seeking. Higher occupational prestige scores might facilitate resistance against mental health experiences of stigma.

abstract: M.Sc.


title: Within Arm's Reach: Political Violence, Voluntary Organizing, and the Borderland Press During the Canadian Rebellion, 1834-1842

contributor:
McNairn, Jeffrey
History

subject: Borderlands

subject: Canada--History--Rebellion, 1837-1838

subject: Public Sphere

subject: Newspapers

subject: Voluntary Associations

subject: Filibustering

subject: Michigan, Ohio, New York, Vermont

subject: Hunters' Lodges, Patriot Hunters, Frères Chasseurs

subject: Bas-Canada--Lower Canada, Upper Canada

abstract: This project focuses on voluntary organizing by the patriots and their use of the press between 1834 and 1842 in the Canadas and the United States, particularly in relation to the Canadian Rebellion of 1837–1838. The dissertation argues that historians should conceive of the Rebellion as an attempt by the patriots to establish a new order through the press and voluntary associations, both before and after the outbreak of insurrection. First constitutionalists and then patriots turned to militarized organizing as a natural outgrowth of their voluntarist values. The press was an important factor in this organizing and beginning in 1836 saw the rise of a “patriot press” in Upper and Lower Canada. These newspapers existed as a republican borderland: they were committed to republicanism and independence for the Canadas and therefore sought to transcend the border by erasing the boundary between monarchy and republic in North America. Past scholarship on the Rebellion has been segmented by “pre” and “post” 1837 and selective focus amongst Lower Canada, Upper Canada, or the United States. Studies have also concentrated heavily on the secret society, the Hunter’s Lodges, and their incursions into the Canadas. The dissertation instead explores the evolving interplay between military organizing and civil society both in the U.S. and the Canadas, demonstrating the surprising extent to which this military organizing has been rooted in and shaped by traditions of liberal voluntary associations and the press. Going beyond the narrow time-frame of the Rebellion, the dissertation provides a comprehensive and longer-term picture of how the patriot press continued and changed with its exile in the United States. The dissertation outlines the catalytic and animating role played by patriot editors in fostering a sense of community and common cause amongst patriots and their sympathizers as well as in engaging combatively with their constitutionalist counterparts in the Canadas. Also documented are the activities undertaken by patriot editors to police vigilantly the boundaries and membership of patriot organizations, particularly in respect to minorities, and to seek to delineate acceptable roles for women in patriot organizing.

abstract: PhD


title: Reworking Canadian Understanding of Transnational Labour Exploitation

contributor:
Little, Margaret
Gender Studies

subject:
Labour
Women
Feminism
Anti-racism
Transnational Feminism
International Development

abstract: Within this thesis, I seek to dismantle the dominant narrative pertaining to transnational labour exploitation of garment workers by using the relationship between Canada and Bangladesh as sites of analysis. Overall, the goals of this project are to challenge dominant Canadian understandings of the exploitation of Bangladeshi women workers, and to disrupt the saviour narrative that has launched various ineffective global solidarity projects. I achieve these goals by highlighting the ways in which capitalism, white feminism, and global development programs impact garment workers in Canada and Bangladesh. My project is unique because within it, I bring together the insights of scholars who theorize separately about the Global North and Global South, while also conceptualizing the issue of labour exploitation as a transnational issue, caused by the collective global forces of capitalism, international development, and white feminism. I compare similarities in the struggles faced by garment workers in both Bangladesh and Canada, while also noting how they exhibit agency and challenge exploitation. The research methods that I employ in this project include institutional ethnography, archival research, and personal interviews. I conclude this project by offering more effective approaches to attaining solidarity with garment workers transnationally.

abstract: M.A.


title: Determining a promoter hypermethylation signature for the blood-based detection of basal and BRCA1-associated breast cancer

contributor:
Mueller, Christopher
Pathology and Molecular Medicine

subject:
Triple negative breast cancer
Promoter hypermethylation
Liquid biopsy
Circulating tumour DNA

abstract: M.Sc.


title: Examining the Relationship Between Insulin-Like Growth Factor-I and Breast Density in Post-Menopausal Women

contributor:
Richardson, Harriet
Public Health Sciences

subject:
Insulin-Like Growth Factor-I
Breast Density
Post-Menopausal

abstract:
Background: Breast density and insulin-like growth factor-I (IGF-I) have both been linked to breast cancer risk. Prior research has shown an overwhelmingly positive association between these two factors, but almost exclusively in pre-menopausal women. In fact, few studies have focused on this relationship in post-menopausal women. Evidence suggests that reproductive hormones, like estrogen, might play a role in the overarching pathways connecting IGF-I, breast density, and breast cancer.

Objective: The objectives of this thesis were to examine the relationship between IGF-I and breast density in post-menopausal women, and then determine if there was any effect modification of this association by estrogen level.

Methods: This thesis focused on a cohort of 568 post-menopausal women from a clinical trial that analyzed the efficacy of exemestane in reducing breast cancer risk. Cumulus software was used to calculate percent breast density values from provided mammograms. These values were then dichotomized as being either low (< 25%) or moderately high (≥ 25%). IGF-I concentrations were determined by ELISA from collected serum samples, and then standardized prior to data analysis. The association between IGF-I level (standardized) and percent breast density (dichotomized) was analyzed using multivariable modified Poisson regression. In addition, log-transformed percent breast density values were used to measure the association through multiple linear regression. Effect modification by treatment arm (i.e. exemestane or placebo) was examined to determine if estrogen level plays any part in this relationship.

Results: Percent breast density values were lower than anticipated (μ = 5.54%) with few women (13.9%) being classified as having moderately high breast density. Serum IGF-I levels were higher than expected (μ = 178.52 ng/mL), due in large part to exemestane administration. After identifying and controlling for potential covariates, there was no significant association detected between IGF-I and percent breast density in either its dichotomized (p = 0.30) or log-transformed (p = 0.60) form. The inclusion of an interaction term also returned a non-significant result for effect modification of these relationships by estrogen level.

Conclusion: There was no observed association between IGF-I and breast density in postmenopausal women. This was seen regardless of estrogen level, as determined by treatment arm.

abstract: M.Sc.