title: Sexual Trauma and Therapeutic Sexuality in the Works of Lydia Kwa

contributor:
Goellnicht, Donald
Attewell, Nadine
Dean, Amber
English and Cultural Studies

subject:
trauma
sexual violence
therapy
queer
Asian Canadian literature
Singaporean diasporic literature
Arts and Humanities
Feminist, Gender, and Sexuality Studies
Arts and Humanities

abstract: This thesis examines sexual trauma in Lydia Kwa’s This Place Called Absence (2000), Pulse (2010), and The Walking Boy (2005), and establishes how the domain of sexuality becomes operative in post-trauma healing. This project engages not only the traditional, Post-Traumatic Stress Disorder model of trauma, but, using Laura Brown and Maria Root, expands the definition of trauma by drawing attention to the insidious, everyday trauma that affects minority groups and sexual minorities. Kwa’s novels reveal the dynamics and complexities of sexual trauma, which encompasses acts of sexual violence such as rape and abuse, but also what is rarely acknowledged – the trauma that queer individuals face in a heteronormative society. This thesis also investigates the possibility of healing sexual trauma and locates viable modes of therapy in the area of sexuality, including sexual intimacy, sexual practices such as erotic bondage, and the formation of queer communities. This project seeks to illuminate the connections between queerness and trauma, and, via Kwa’s fiction, considers alternative avenues of healing and therapy beyond the medical field.

abstract: Master of Arts (MA)


title: The Effects of Aging on Motion Perception in Healthy Older Adults

contributor:
Bennett, Patrick J.
Sekuler, Allison
Lee, Tim
Neuroscience

subject:
aging
motion perception
vision
attention
contrast
random dot patterns
Cognitive Neuroscience
Cognitive Neuroscience

abstract: Motion perception is required for nearly all aspects of daily living. Previous work has shown that the ability to perceive a variety of different types of motion is significantly affected by increasing age. The research described in this thesis further probes the complex effects of aging on motion perception using a number of different stimulus configurations and performance measures. In order to relate psychophysical performance to neurophysiological recordings, we used two different notched-noise masking techniques to estimate the directional selectivity of masking in younger and older adults. We found evidence to suggest that the directionally-selective mechanisms of older adults are more broadly tuned than their younger counterparts, which is consistent with the animal literature that links decreased neural inhibition with broader directional tuning. Behaviourally however, task-specific contrast sensitivity may play a role in explaining that result. We also uncovered a previously unobserved difference between horizontal and vertical motion perception which bears further study. We also tested peripheral motion perception both under focused and divided attentional conditions. Older adults were impaired compared to younger adults when asked to make judgments about motion patterns in the peripheral vision field, but they were not differentially impaired under divided attention conditions. The findings presented in this thesis paint a more complex picture of how increasing age impairs motion perception than previously described. Specifically, our observations show that age effects interact with stimulus contrast, attention, and motion direction, and these interactions each present an interesting avenue for further exploration.

abstract: Doctor of Philosophy (PhD)


title: Photoneutron Spectroscopy of Nuclei Near Mass 200

contributor:
Prestwich, W.V.
Physics

subject: Physics Physics

abstract: A new technique has been developed for the study of photoneutron reactions in the 6 to 11 NeV photon energy range. The technique consists essentially of illuminating a target with a beam of neutron capture gamma rays and observing the neutrons with a high resolution helium-3 detector. Using this method, bismuth, lead, thallium, gold and tantalum targets were studied. Q-values, cross sections and reduced widths were obtained and the systematic variation of the latter two with respect to photon energy, residual excitation energy and neutron energy were investigated. In the case of gold and tantalum, previously undiscovered energy levels in the residual nuclei were determined. Based on these systematics, evidence is presented to suggest that the reactions occur predominantly off resonance and may have substantial direct or semidirect components. Fore-aft neutron emission asymmetry in lead has also been studied and a theoretical model has been derived in order to obtain approximations of the E2/E1 mixing ratios. Direct evidence of parity mixing is presented.

abstract: Doctor of Philosophy (PhD)


title: Type-Safety for Inverse Imaging Problems

contributor:
Anand, Christopher
Kahl, Wolfram
Computing and Software

subject: type-safety

subject: Inverse Imaging Problem

subject: Type Level Programming

subject: Haskell

subject: Regularization

subject: formalization

subject: Numerical Analysis and Scientific Computing

subject: Programming Languages and Compilers

abstract: This thesis gives a partial answer to the question: “Can type systems detect modeling errors in scientific computing, particularly for inverse problems derived from physical models?” by considering, in detail, the major aspects of inverse problems in Magnetic Resonance Imaging (MRI). We define a type-system that can capture all correctness properties for MRI inverse problems, including many properties that are not captured with current type-systems, e.g., frames of reference. We implemented a type-system in the Haskell language that can capture the errors arising in translating a mathe- matical model into a linear or nonlinear system, or alternatively into an objective function. Most models are (or can be approximated by) linear transformations, and we demonstrate the feasibility of capturing their correctness at the type level using what is arguably the most difficult case, the (discrete) Fourier transformation (DFT). By this, we mean that we are able to catch, at compile time, all known errors in ap- plying the DFT. The first part of this thesis describes the Haskell implementation of vector size, physical units, frame of reference, and so on required in the mathemat- ical modelling of inverse problems without regularization. To practically solve most inverse problems, especially those including noisy data or ill-conditioned systems, one must use regularization. The second part of this thesis addresses the question of defining new regularizers and identifying existing regularizers the correctness of which (in our estimation) can be formally verified at the type level. We describe such Bayesian regularization schemes based on probability theory, and describe a novel simple regularizer of this type. We leave as future work the formalization of such regularizers.

abstract: Master of Science (MSc)


title: Molecular Dynamics Simulations of Liquid Transport through Nanofiltration Membranes

contributor:
Dickson, James M.
Randall S. Dumont,  Carlos Filipe
Chemical Engineering

subject:
Molecular dynamics
Nanofiltration
Transport
Membrane
Membrane Science
Transport Phenomena
Membrane Science

abstract:
Nanofiltration (NF) is a pressure-driven membrane separation process, which is a nonequilibrium process because of the pressure difference and concentration difference across the membrane. As one type of molecular dynamics (MD) simulations, nonequilibrium molecular dynamics (NEMD) simulations can provide the dynamics properties of NF transport on a molecular level description, which can serve as a complement to conventional experimental studies.

In this thesis, NEMD simulations are proposed to study pressure-driven liquid flows through carbon nanotube (CNT) membranes and polyamide (PA) membranes at realistic NF conditions. Pure water flows passing through the membranes are studied primarily, and organic flows passing through the CNT membranes are also studied. Little research, that we are aware of, has been done to show the NF transport properties. The results of the NEMD simulations are analyzed to investigate the transport properties and the effects of the membrane structures on liquid transport, and the simulation results are compared with traditional models and/or literature data. This work shows that show that the liquid transport through the CNT membrane is extremely fast and cannot be predicted by the continuum equations due to the special properties of the CNT, and the water transport of the PA membrane is strongly related to the free-volume properties of the amorphous polymeric membrane.

The MD simulation studies proposed in this thesis are feasible as a tool for describing and investigating pressure-drive liquid transport and can provide some fundamental basis for NF transport.

abstract: Doctor of Philosophy (PhD)


title: Ethnicity, Identity, and Institution: The Relevance of Ethnic Identity for the Development of Diaspora Synagogues

contributor:
Runesson, Anders
Machiela, Daniel
Schuller, Eileen
Religious Studies

subject:
Early Judaism
Synagogues
Identity
Diaspora
Biblical Studies
Biblical Studies

abstract: The present study explores the relevance of ethnic boundary maintenance for the development of Diaspora synagogues in the Graeco-Roman world. By investigating the possible relationship between ethnicity and synagogue development, the synagogue will be analyzed as a communal and ‘religious’ institution that contributed to the maintenance of a specific ethnic identity within a Diaspora context that challenged its very survival and existence. The main goal of the present study is to provide a new perspective of development and maintenance for Diaspora synagogues that eschews the idea of a dichotomous relationship between these synagogues and the Jerusalem Temple. Instead, a socio-historical approach will be presented that focuses on Jewish communities as a distinctive ethnic group that existed alongside other similar groups in the Graeco-Roman world and sought to maintain their collective ethnic identity. The synagogue served as a key driving force within this process of maintenance.

abstract: Master of Arts (MA)


title: The Fluidity of Power: Complexities, Contradictions and Challenges of Visible Minority Women Working in Women’s Shelters

contributor:
Zhou, Y.R.
Sinding, C.
Schormans, Fudge A.
Social Work

subject: visible minority women; power; social service providers; women's shelter system; social work practice

subject: Social Work

subject: Social Work

abstract: Interrogating the concept of power is ethical social work practice. This research aims to investigate the manner in which visible minority women social service providers perceive the concept of power as non-managerial employees in the women’s shelter system. Therefore, the necessity to delineate the ongoing challenges and contradictions that shape the work experiences of visible minority women social service providers contributes and furthers our understanding of social justice, critical social work practice, and strategies to enhance workplace equity. In addressing the phenomenon of power from the viewpoint of those affected, this ultimately helps to broaden the understanding how as social workers it remains pivotal to raise awareness about the ongoing power imbalances in social services settings. Semi-structured, in-depth interviews with visible minority women employed in the women’s shelter system in southern, Ontario were conducted and complement the author’s own personal reflections as a visible minority woman previously employed in the Violence Against Women’s shelter system. This research suggests that due to ongoing power differentials, neoliberal restructuring and discriminatory incidents, continued attention is required in order to address social inequality and enhance workplace equity.

abstract: Master of Social Work (MSW)


title: On the Parallelization of a Search for Counterexamples to a Conjecture of Erd\H{o}s

contributor:
Deza, Antoine
Frantisek Franek, Ned Nedialkov
Computer Science

subject:
clique
coclique
Cayley graph
complete graph
subgraph
parallelization
Computer Sciences
Discrete Mathematics and Combinatorics
Theory and Algorithms
Computer Sciences

abstract:
Denote by $k_t(G)$ the number of cliques of order $t$ in a graph $G$ having $n$ vertices. Let $k_t(n) = \min\{k_t(G)+k_t(\overline{G}) \}$ where $\overline{G}$ denotes the complement of $G$. Let $c_t(n) = {k_t(n)}/{\tbinom{n}{t}}$ and $c_t$ be the limit of $c_t(n)$ for $n$ going to infinity. A 1962 conjecture of Erd\H{o}s stating that $c_t = 2^{1-\tbinom{t}{2}}$ was disproved by Thomason in 1989 for all $t\geq 4$. Tighter counterexamples have been constructed by Jagger, {\v S}{\v t}ov{\' \i}{\v c}ek and Thomason in 1996, by Thomason for $t\leq 6$ in 1997, and by Franek for $t=6$ in 2002. Further tightenings $t=6,7$ and $8$ was recently obtained by Deza, Franek, and Liu.

We investigate the computational framework used by Deza, Franek, and Liu. In particular, we present the benefits and limitations of different parallel computer memory architectures and parallel programming models. We propose a functional decomposition approach which is implemented in C++ with POSIX thread (Pthread) libraries for multi-threading. Computational benchmarking on the parallelized framework and a performance analysis including a comparison with the original computational framework are presented.

abstract: Master of Science (MSc)


title: USING GENE EXPRESSION ANALYSIS TO GUIDE AND IDENTIFY TREATMENTS FOR BREAST CANCER PATIENTS

contributor:
Hassell, John A
Biochemistry

subject:
Breast cancer
gene expression profiling
cancer stem cells
tumor-initating cells
biomarkers
Bioinformatics
Computational Biology
Genomics
Molecular Biology
Bioinformatics

abstract: Based on breast cancer clinical trial data accumulated over the last several decades it is obvious that standard breast cancer therapeutics extend survival in breast cancer patients. However, only a minority of patients within these trials derive benefit from treatment. In a population of breast cancer patients treated with adjuvant therapy after surgery, many patients are over-treated, as they would never experience relapse even without receiving adjuvant therapies. Among the remaining patients, some achieve durable remission from therapy, whereas others relapse despite therapy. Hence, there is an obvious need to develop biomarkers that can serve to identify these three populations of patients, such that only patients who are likely to benefit from available therapies are treated with these therapies, as well as to develop new therapies for the treatment of patients who aren’t afforded durable remission by approved treatments. Here, we present the identification of biomarkers to identify low risk breast cancer patients who experience excellent long-term survival even without adjuvant therapy. Conversely, high risk patients represent those patients most likely to benefit from intervention with aggressive treatment regimens. We also report on the identification of biomarkers which can predict the likelihood of response to approved chemotherapy regimens, which could be used to further stratify high risk patients into responders and non-responders. Finally, for high risk patients unlikely to be afforded durable remission from available therapies, we report on the identification of agents that target breast tumor-initiating cells, and may be effective for the treatment of these patients.

abstract: Doctor of Philosophy (PhD)


title: EHR READINESS AND CLINICAL INFORMATION MANAGEMENT: STAKEHOLDER CONSULTATION AND ANALYSIS

contributor:
Archer, Norman P.
McKibbon, Ann
Mondal, Tapas
Business

subject:
EHR
CPOE
EHR Readiness
EHR Information Management
Business
Business

abstract:
Electronic Health Record Systems (EHRs) are an important tool for today’s physicians. EHRs (commonly called EMRs in Canada) are used to store, retrieve and leverage patient information to achieve better clinical outcomes for patients. EHRs can also contribute to public policy by helping policy makers track population health data. There are barriers as well as drivers to successful implementation of EHRs. Also, with the introduction of EHRs and their accumulation of patient data physicians face challenges for better extraction and use of data as well as overall management of information within the clinic.

This thesis performs a literature review and presents evidence on the barriers and drivers that exist in the area of EHR (Electronic Health Records) implementation in the US. The thesis also includes a survey that tracks responses of primary care physicians in the US. The responses were analyzed to determine key factors impacting EHR implementation and information management. The key factors included workflow, optimization of information technology (IT) resources that include software, hardware assets and trained personnel, and plan for extraction of data. Our research found, among other things, the need to raise awareness among physicians about optimizing clinical workflow, management of information in the EHRs, the need for additional training on the EHRs and, in case of non-urban physicians, the need for improved levels of IT and Internet expertise in the clinic.

abstract: Master of Science (MSc)


title: Changing Marketing Strategies in the Canadian Housebuilding Industry: From Mass Production and Mass Markets Towards Niche Markets and Consumer Segmentation, c. 1945 – 2000

contributor:
Harris, Richard
Geography and Earth Sciences

subject:
Housing
Suburbs
Canada
Marketing history
Toronto
Advertising
Advertising and Promotion Management
Human Geography
Real Estate
Urban Studies and Planning
Advertising and Promotion Management

abstract:
Marketing means much more than mere advertising: trying to sell what manufacturers have decided to produce. It means the honing of product lines to suit ever-shifting consumer tastes. Studying the relationship between production and consumption is central to understanding modern consumer society. Housing is one of the most important consumer products most people will ever buy. Houses not only provide shelter but also are central to their occupants’ identity. At the same time, housing production and consumption are vitally important to the health of the economy. Yet, despite the importance of housing, marketing practices in the speculative homebuilding industry have received no systematic attention in the marketing, consumer culture, or urban studies literatures. This research begins to fill this gap. Using a case study approach, this thesis examines how the marketing practices of builders in the Toronto area, Canada’s largest real estate market, have evolved in response to shifts in consumer demand during the postwar period. The research draws on evidence from North American building and advertising trade journals and builders’ advertisements that appeared in the Toronto Star between 1940 and 2005.

This research shows that since the 1950s, the housebuilding industry has moved from a focus on efficiency in production towards a concern with the needs and preferences of the consumer. This consumer focus, however, has not been an uninterrupted trend, as historians of marketing in other industries have argued. Interest in determining and satisfying consumer demand has gained impetus during certain periods and ebbed during others. This cyclicality can be attributed to market cycles and the relationship between supply and demand. The consumer focus in the homebuilding industry has been strongest during buyers’ markets when supply has exceeded demand, periods of heightened competition between builders, and economic downturns.

abstract: Doctor of Philosophy (PhD)


title: Cortical thickness in major depressive disorder across the lifespan

contributor:
Hall, Geoffrey B.C.
Neuroscience

subject:
Magnetic resonance imaging
Major depressive disorder
cortical thickness
developmental neuroscience
age-of-onset
neuropsychiatric illness
Developmental Neuroscience
Mental Disorders
Neuroscience and Neurobiology
Neurosciences
Other Neuroscience and Neurobiology
Other Psychiatry and Psychology
Developmental Neuroscience

abstract:
This thesis presents research investigating structural neural correlates of major depressive disorder (MDD). Although there are clear clinical differences between early- and late-onset MDD, they are still subject to the same diagnostic criteria and treatment strategy. Whether these differences translate into differences in cortical structure was examined in this study. By directly comparing early-onset (EOD) and late-onset (LOD) patients, we test whether age-of-onset results in changes in the extent or spatial pattern of cortical thinning.

Chapter 1 provides a general background on the cerebral cortex, followed with a focus on cortical thickness. Chapter 2 presents a comprehensive review of the clinical and neurobiological literature on major depressive disorder as it pertains to age-of-onset. Three working hypotheses regarding the differences between early- and late-onset depression are presented and discussed.

The results presented in this thesis show that there are both differences and similarities in cortical thickness between patients with EOD and LOD, with differences reflecting spatial extent, region-specificity, and magnitude of thickness differences. We confirmed the hypothesis of greater thinning in the dorsal lateral prefrontal cortex in depressed patients compared to healthy controls. We also correlated cortical thickness with clinical variables, which resulted in the finding of a positive correlation in the posterior cingulate cortex with illness severity.

Few studies have used age-of-onset as a factor, which may account for some of the heterogeneity and inconsistent results seen in studies of MDD. We found that depression onset in early life is associated with greater disturbances in cortical thickness than LOD, possibly reflecting atypical development. These results provide novel insights into vulnerability and how development of depression is differentially affected by age.

abstract: Master of Science (MSc)


title: Tuning the Hardness and Wettability of Methacrylate Polymers

contributor:
Brook, Michael A.
Chemistry and Chemical Biology

subject:
Polymer Chemistry
Polymer Chemistry

abstract:
Silicones exhibit a fundamentally hydrophobic character. While the incorporation of hydrophilic surface moieties can be achieved by a variety of means, normally surface reversion leads to rapid recovery of hydrophobic surfaces. We were interested to learn if the hydrophobic character of silicones could be manifested on organic polymers and, moreover, if different degrees of wetting of organic surfaces could controlled by simultaneous use of more than one hydrophilic entity.

Herein, we present a method to control the hardness and wettability of methacrylate polymers with the addition of ACR A008-UP, a polymerizable, acrylate-based trisiloxane surfactant. Surface wettabilities were determined through the use of contact angle measurements, and the hardness modulus is determined through the use of a Shore OO durometer. The wettability and the hardness of the polymers were controlled by varying the ratio of surfactant to methacrylate monomers. As the proportion of surfactant monomer increased, the hardness of the copolymers was depressed. In a similar fashion, as the proportion of surfactant increased, the copolymer surfaces became increasingly wettable. However, at a certain threshold concentration the wettability decreased once again, which is ascribed to the formation of a hydrophobic brush at higher concentrations. The wettability and hardness of the polymers, and the stability of the trisiloxanes on the surface will be discussed.

abstract: Master of Science (MSc)


title: Behavioral and Neuronal Effects of EEG Synchronizing Stimuli in the Cat

contributor:
Smith, G. K.
Psychology

subject: Psychology Psychology

abstract: Electrical stimulation of the medical thalamus (MTH) and lateral preoptic area (LPO), which produces slow, rhythmic "synchronized" waves in the cortical EEG, has been reported also to induce sleep and to inhibit neurons of the brain stem reticular formation that produce fast, irregular "desynchronized" EEG waves. The present findings confirm that MTH and LPO have significant input to brain stem neurons, but that input is not exclusively inhibitory. MTH and LPO stimuli produce discrete cycles of excitation and inhibition in reticular neurons which alternately facilitate and suppress subsequent inputs, from visual (V) and auditory (A) systems for example, which converge with MTH and LPO inputs on single reticular cells. Conversely, it was found that V and A stimuli could facilitate and suppress MTH and LPO responses. These results support the view that synchronogenic and desynchronogenic mechanisms of the cortical EEG are reciprocally organized at a subcortical level, and that the organization involves complex excitatory and inhibitory interactions. However, no convincing evidence was found to support the contention that synchronogenic stimulation of MTH or LPO induces behavioral sleep.

abstract: Doctor of Philosophy (PhD)


title: Self-Excited Oscillations of the Impinging Planar Jet

contributor:
Ziada, Samir
Mechanical Engineering

subject:
Jet Noise
Acoustic Tone
Impinging Jet
Coherent Structure
Feedback Model
Self-Excited Flow
Acoustics, Dynamics, and Controls
Aerodynamics and Fluid Mechanics
Acoustics, Dynamics, and Controls

abstract: This thesis experimentally investigates the geometry of a high-speed subsonic planar jet impinging orthogonally on a large, rigid plate at some distance downstream. This geometry has been found to be liable to the production of intense narrowband acoustic tones produced by self-excited flow oscillations for a range of impingement ratio, Mach number and nozzle thickness. Self-excited flows and acoustic tones were found to be generated in two distinct flow regimes: a linear regime occurring at relatively low Mach number, and a fluid-resonant regime occurring at higher Mach numbers. The linear regime has been found to generate acoustic tones exhibiting relatively low pressure amplitudes with frequencies which scale approximately linearly with increasing Mach number, and is produced by a traditional feedback mechanism, whereas tones within the fluid-resonant regime are produced by coupling between the unstable hydrodynamic modes of the jet and trapped acoustic modes occurring between the nozzle and the plate, and produce tones at significantly larger amplitudes. Coupling with these trapped acoustic modes was found to dominate the self-excited response of the system in the fluid-resonant regime, with the frequencies of these acoustic modes determining the unstable mode of the jet being excited, and with the impingement ratio of the flow having only minor effects related to the convection speed. Phase-locked PIV measurements have revealed that self-excited flow oscillations in the fluid-resonant regime are produced by a series of five anti-symmetric modes of the jet, along with a single symmetric mode occurring for small impingement ratios. The behavior of large coherent flow structures forming in the flow has been investigated and quantified, and this information has been used to develop a new feedback model, which can be used to accurately predict the self-excited flow oscillation of the jet.

abstract: Doctor of Philosophy (PhD)


title: Representation of Immigrant Family Conflict in Popular Culture: Power, Essentialism and Emancipation

contributor:
Dumbrill, Gary
Sammon, Sheila
Schormans, Ann Fudge
Social Work

subject:
Immigrant
media
acculturation
assimilation
critical discourse analysis
CDA
Social Work
Social Work

abstract:
Immigration is a complex process that involves multiple social, economic and political challenges. Immigrants face numerous structural barriers throughout the settlement process including “stress, underemployment, downward mobility, discrimination, poor housing, lack of access to services, and inadequate social support” (Simich, Beiser, Stewart and Mwakarimba, 2010, p. 260) that contribute to their status as a marginalized social group. The discourse of ‘culture’ is a prevalent paradigm to explain the integration outcomes of immigrants in our society. From a critical perspective, the discourse of acculturation can be used to perpetuate social power imbalances by universalizing dominant culture, obscuring the effects of social power imbalances and essentializing immigrant identities.

This research examines the social justice implications of the public discourse on immigrant families through a critical discourse analysis of three popular culture films with the central theme of immigrant family conflict. Analysis of the films reveals that the discourse of immigrant family pathology is present in the narrative structure of all three films. At the same time, all of the films also represent counter narratives that highlight the complexity and fluidity of contemporary immigrant identities. It is argued that the films represent the protagonists engaging in the process of challenging both mainstream and traditional essentialized cultural identities. This process, termed ‘the third space’ by Bhabha (1990), is argued to have emancipatory potential for immigrant communities and for the pursuit of social justice.

abstract: Master of Social Work (MSW)


title: Exploring Discourses of Appropriation: Collecting Modern Canadian Cultural Identity

contributor:
York, Lorraine
O`Connor, Mary
Dean, Amber
English and Cultural Studies

subject:
material culture
collecting
Canadian identity
Canadian literature
literary theory
display politics
museums
colonial politics
Literature in English, North America
Literature in English, North America

abstract: By applying Canadian literary theory, museum theory, and material culture theory to 20th and 21st century Canadian literature, I argue that physical objects reflect Canada's continued engagement in colonial practices and the nation's resistance to acknowledging these practices. The act of selecting and including (which is also necessarily an act of excluding) objects in personal and institutional collections speak to the anxiety of the Euro-Canadian settler that is produced by a conflicting sense of privilege and colonial complicity. Collecting is a means of negotiating self- and shared knowledge, and by re-collecting and repatriating those things that haunt us we come closer to recognizing ourselves. Re-reading ourselves through objects will allow us to confront this anxiety and its implications, to destabilize the Euro-Canadian settler-as-victim, and to move forward as a nation.

abstract: Master of Arts (MA)


title: Ultra-thin Single-crystalline Silicon Membrane Solar Cells as a Light-trapping Test Platform

contributor:
Kleiman, Rafael
Engineering Physics

subject:
light-trapping
solar cells
silicon
thin
high-efficiency
low-cost
Other Engineering Science and Materials
Other Engineering Science and Materials

abstract: The photovoltaics (PV) research community is currently pursuing many approaches to reduce the cost of PV and increase the energy conversion efficiency. Single-crystalline silicon (sc-Si) solar cells are able to achieve high efficiency but have a higher cost relative to other technologies. It may be possible to drastically reduce the cost of sc-Si PV by fabricating solar cells which are an order of magnitude thinner than conventional solar cells, i.e. thinner than 30 microns. Aside from new fabrication paradigms, ultra-thin sc-Si solar cells require advanced light-trapping techniques to enhance the absorption of long-wave radiation which is otherwise transmitted through the cell. In this thesis, a novel process flow for the fabrication of ultra-thin sc-Si solar cells in the laboratory was designed and implemented with the aim of testing light-trapping structures in the context of actual ultra-thin sc-Si devices. The process flow uses 10 micron thick sc-Si membranes, 0.95 cm in diameter, fabricated on silicon-on-insulator wafers using double-sided processing. The best fabricated device incorporated a back surface field, a white paint diffuse rear reflector and a silicon nitride antireflection coating. It achieved a fill factor, efficiency, short circuit current and open circuit voltage of 0.67, 9.9%, 27.9 mA cm-2 and 0.53 V respectively. Simulations suggest the device efficiency can approach 15.4% without light-trapping and 16.5% with a diffuse rear reflector as a light trapping structure. This process flow is intended to be used as a platform on which to test further light-trapping structures with the continuation of this project.

abstract: Master of Applied Science (MASc)


title: DOSE-BASED EVALUATION OF A PROSTATE BED PROTOCOL

contributor:
Wierzbicki, Marcin
Kevin Diamond, Orest Ostapiak
Medical Physics

subject:
IGRT Protocol
Prostate Cancer Treatment
IMRT
Image Registration
Cumulative Dose
Medical Biophysics
Medical Biophysics

abstract:
The image-guided radiation therapy (IGRT) protocol used at Juravinski Cancer Center for post-prostatectomy patients involves acquiring a kV cone beam computed tomography (CBCT) image at each fraction and shifting the treatment couch to align surgical clips. This IGRT strategy is promising but its dosimetric impact is unknown, it requires significant resources, and delivers non-negligible doses to normal tissues. The objective of this work is to evaluate this IGRT protocol and investigate possible alternatives.

IGRT delivered dose is reconstructed by deforming the planning CT to the CBCT images acquired at each fraction, computing dose on the deformed images, and inversely transforming the dose back to the original geometry. The treatments of six patients were evaluated under four scenarios: no guidance (Non-IGRT), daily guidance as performed clinically (IGRT), guidance on alternating days (Alt-IGRT), and daily automated guidance (Auto-IGRT). For one patient, the impact of reducing the planning target volume (PTV) margin to five (IGRT-5) and eight (IGRT-8) mm isotropic was also evaluated.

With the standard clinical PTV margin of ten/seven mm, the evaluated alternatives produced similar results. The minimum dose to the CTV was decreased by 1.6±1.0, 1.2±0.7, and 0.8±0.8 Gy for Non-IGRT, Alt-IGRT, and IGRT, respectively. IGRT with manual shifting did not appear to significantly improve the delivered treatment dose compared to Auto-IGRT (difference in CTV minimum dose was 1.2±2.1Gy). Doses to the organs at risk varied but in general, an increased volume of the bladder and rectum received low doses while smaller portions received high doses. The IGRT-5 and -8 analyses showed the same CTV dose can be delivered with significant reduction in normal tissue exposure. Overall, the desired doses are delivered during IGRT although much of this may be attributed to the large PTV margins currently employed clinically.

abstract: Master of Science (MSc)


contributor:
Devereaux, Philip
Guyatt, Gordon
Thabane, Lehana
Health Research Methodology

subject:
Myocardial injury
Myocardial ischemia
Noncardiac surgery
Troponin
Perioperative
Medicine and Health Sciences
Medicine and Health Sciences

abstract:
Worldwide, more than 2 million patients die within 30 days after noncardiac surgery anually. Postoperative ischemic myocardial injury is frequent, however, no consensus exists about its definition.

Objective: to develop a term Myocardial Injury after Noncardiac Surgery (MINS) caused by myocardial ischemia, requiring at least, troponin T (TnT) elevation, and with prognostic relevance at 30 days after surgery.

Methods: we performed a prospective study including 15,167 patients ³45 years-old undergoing noncardiac surgery, who had fourth-generation TnT measurements during the first 3 postoperative days. We undertook Cox regression analyses with 30-day mortality after surgery as the dependent variable, using different TnT thresholds, clinical features and several perioperative variables. Non-ischemic etiologies were excluded. Furthermore, we developed a scoring system to predict risk in MINS patients.

Results: MINS was defined as TnT ≥0.03 ng/mL with or without clinical features, and it was an independent predictor of 30-day mortality (adjusted HR 3.82, CI 95% 2.84-5.10). We determined that MINS incidence was 8%, its population attributable risk 33.7%, and 30-days mortality rate 9.6%. Patients did not experience ischemic symptoms in 84% of MINS cases. Additionally, we developed a scoring system in patients suffering MINS with 3 independent predictors of death (age ≥75 years, new ST elevation or left bundle branch block, and anterior location of ECG changes),

Conclusion: Among patients undergoing noncardiac surgery, we defined MINS based on a TnT threshold ≥0.03 ng/mL. Mostly, MINS patients were asymptomatic. Therefore, this strongly suggests the importance of a troponin monitoring during the first few days after surgery.

abstract: Master of Health Sciences (MSc)


title: FAULT DIAGNOSIS AND FAULT-TOLERANT CONTROL OF CHEMICAL PROCESS SYSTEMS

contributor:
Mhaskar, Prashant
Chemical Engineering

subject:
Nonlinear systems
fault detection and isolation
fault diagnosis
fault-tolerant control
high-gain observers
output feedback control
Process Control and Systems
Process Control and Systems

abstract: This thesis considers the problem of fault diagnosis and fault-tolerant control (FTC) for chemical process systems with nonlinear dynamics. The primary objective of fault diagnosis discussed in this work is to identify the failed actuator or sensor by using the information embodied in a process model, as well as input and output data. To this end, an active fault isolation method is first proposed to identify actuator faults and process disturbances by utilizing control action and process nonlinearity. The key idea is to move the process to a region upon fault detection where the effect of each fault can be differentiated from others. The proposed method enables isolation of faults that may not be achievable under nominal operation. This work then investigates the problem of sensor fault isolation by exploiting model-based sensor redundancy through state observer design. Specifically, a high-gain observer is presented and the stability property of the closed-loop system is rigorously established. A method that uses a bank of high-gain observers is then proposed to isolate sensor faults, which explicitly accounts for process nonlinearity, and to continue nominal operation upon fault isolation. In addition to fault diagnosis, this work addresses the problem of handling severe actuator faults using a safe-parking approach and integrating fault diagnosis and safe-parking techniques in a unified fault-handling framework. In particular, several practical issues are considered for the design and implementation of safe-parking techniques, including changes in process dynamics, the network structure of a chemical plant, and actuators frozen at arbitrary positions. The advantage of this approach is that it enables stable process operation under faulty conditions, avoiding the partial or entire shutdown of a chemical plant and resulting economic losses. The efficacy of the proposed fault diagnosis and FTC methods is demonstrated through numerous simulations of chemical process examples.

abstract: Doctor of Philosophy (PhD)


title: NEOLIBERALISM AND CASE MANAGERS' TOOLS AT A FEDERAL PUBLIC SERVICE AGENCY

contributor:
Collins, Stephanie Baker
Aronson, Jane
Sinding, Chris
Social Work

subject:
managerialism
case managers
tools
texts
Social Work
Social Work

abstract:
Abstract

Neoliberalism and the new managerialism have become entrenched in Canadian social policy. This paper is an examination of how neoliberal philosophy and the new managerialism are embodied in case managers’ tools. The setting for this research is Veterans Affairs Canada. Presently, Veterans Affairs Canada is in the process of transforming policy and practice. Veterans Affairs Canada has implemented a managerial business model as the foundation of its transformation initiative.

This research examines how the ruling relations of the macro level have infiltrated the local practice of case managers. Institutional ethnography is utilized to examine the texts used by case managers. It is important to research the relationship between case managers’ tools and managerialism in order to understand impacts on the role, practice and discretion of case managers. Only by having a full understanding of the relationship between the underlying power structures of neoliberalism and managerialism can social workers fully appreciate the negative impacts to client service. Through this understanding, social workers can more effectively advocate for their clients and find ways to implement change.

abstract: Master of Social Work (MSW)


title: Modeling Hydrogen-Bonding in Diblock Copolymer/Homopolymer Blends

contributor:
Shi, An-Chang
Physics and Astronomy

subject:
SCFT
Diblock Copolymer
Homopolymer
Hydrogen Bonding
Self-Consistent Field Theory
Phase transitions
Biological and Chemical Physics
Condensed Matter Physics
Statistical Models
Biological and Chemical Physics

abstract: The phase behavior of AB diblock copolymers mixed with C homopolymers (AB/C), in which A and C are capable of forming hydrogen-bonds, is examined using self-consistent ﬁeld theory. The study focuses on the modeling of hydrogen-bonding in polymers. Speciﬁcally, we examine two models for the formation of hydrogen-bonds between polymer chains. The ﬁrst commonly used model assumes a large attractive interaction parameter between the A/C monomers. This model reproduces correct phase transition sequences as compared with experiments, but it fails to correctly describe the change of lamellar spacing induced by the addition of the C homopolymers. The second model is based on the fact that hydrogen-bonding leads to A/C complexation. We show that the interpolymer complexation model predicts correctly the order-order phase transition sequences and the decrease of lamellar spacing for strong hydrogen-bonding. Our analysis demonstrates that hydrogen-bonding of polymers should be modeled by interpolymer complexation.

abstract: Master of Science (MSc)


title: Identifying the Retention Mechanisms of (Bio)Colloids in Single, Saturated, Variable-Aperture Fractures

contributor: Monica Emelko, Carlos Filipe, Robert Pelton

subject:
Escherichia coli
retention
preferential transport
groundwater contamination
fractured aquifer
groundwater
Environmental Engineering
Environmental Engineering

abstract: Owing to the lack of knowledge pertaining to the fate and transport of microorganisms in fractured aquifers, the research presented in this thesis was designed to improve the mechanistic understanding of particulate transport in fractures by conducting tracer experiments in natural and epoxy replica fractures. This research demonstrated that particulate retention within fractures is heavily dependent on the equivalent mass balance aperture, followed by the coefficient of variation of the aperture field, and then by the flow conditions. It was also shown that the fracture aperture field alone, not the flow rate or the matrix properties, determines the number of fracture volume flushes required to achieve a 2-3 log decrease in effluent concentration. Moreover, a statistical model was developed that identifies the most important factors affecting particulate retention as the ratio of the ionic strength of solution to the charge of the collector, the ratio of the particle to collector charges, and the Peclet number. The model is able to reasonably predict particulate retention. Finally, tracer experiments conducted in a natural fracture and an epoxy replica of that fracture isolated the effects of matrix properties on attachment, and hence, retention. The transparent nature of the replica fracture was exploited to capture images of E. coli RS2-GFP transport. These images reveal preferential transport within the fracture, and also show that the preferential pathway broadens slightly under increasing flow conditions. This broadening is likely due to higher fluid pressures associated with larger specific discharges. In the groundwater field, there is so little fracture-specific information available that coupling the understanding of a critical environmental setting (fractures) with high-quality particulate tracer experiments and associated modeling represents a significant contribution to the body of science.

abstract: Doctor of Philosophy (PhD)


title: The Oxygen Isotope and Elemental Geochemistry of Archean Rocks From Northern Ontario

contributor:
McNutt, R. H.
Schwarcz, H. P.
Geology

subject: Geology Geology

abstract:
The oxygen isotope and chemical compositions (including rare earth elements) of Archean rocks from northern Ontario have been interpreted in terms of various magmatic, sedimentary, metamorphic and/or alteration processes that have occurred during the history of these samples.

The greenschist facies clastic metasedimentary rocks from the Wabigoon, Abitibi, and Uchi granite-greenstone belts have chemical compositions that indicate derivation from dominantly felsic source terrains. Their δ¹⁸O values range from 8.0 to 13.3 °/.., about 2 to 3 °/.. lower than Phanerozoic clastics, a result of the immature nature of the Archean metasediments. The most immature samples analyzed show no recognizable chemical or isotopic effects of residence in a sedimentary environment. More mature samples, however, have δ¹⁸O values (>9 °/..), and chemical discriminant function values that indicate chemical and isotopic modification during sedimentary processes. These characteristics are useful in the recognition of clastic sedimentary protoliths in Archean gneisses.

The felsic metavolcanic rocks, also from the granite-greenstone belts, have δ¹⁸O values of 7.5 to 13.0 °/... The higher values are probably due to low temperature alteration. Because of the overlap in δ¹⁸O values between the clastic metasedimentary rocks and the felsic metavolcanic rocks, oxygen isotope compositions cannot be used to distinguish between the two rock types.

The δ¹⁸O values of metabasalts (4.4 to 9.2 °/..) suggest that isotopic alteration has accompanied their metamorphism, but no consistent relationships between δ¹⁸O and usually mobile elements such as K, Rb, Sr and Ba were observed. The chemical composition of least-altered mafic metavolcanic rocks from the Burditt Lake - Lake Despair area is compatible with the formation of these rocks in an island-arc type environment.

Least-altered felsic metavolcanic rocks interlayered with the Burditt Lake - Lake Despair metabasalts have rare earth element compositions consistent with formation by moderate degrees of melting of quartz eclogite. Other samples of felsic metavolcanic rocks from the area have been chemically and isotopically altered by magmatic fluids accompanying the intrusion of the Burditt Lake granodiorite.

The Jackfish Lake Complex (diorite, quartz monzodiorite and monzodiorite, leucodiorite and leuco quartz diorite, granodiorite, and Na-syenite), which was intruded along the contact between the Burditt Lake - Lake Despair metavolcanics and the Footprint gneiss, differentiated along a 'gabbro-trondhjemite' trend (Na-enrichment). The most abundant rock type, diorite, has a chemical composition compatible with its formation by partial melting of eclogite. The other rock types were probably differentiated from the dioritic magma along a path first controlled by the crystallization of hornblende, and then by the precipitation of feldspar, especially microcline. The δ¹⁸O rock (6.4-9.2 °/..) and mineral values of the Complex result from this differentiation, except for a few samples, which have been depleted in ¹⁸O by low temperature interaction with meteoric water.

The Footprint gneiss also has a chemical composition that suggests that its protolith formed by partial melting of LREE-enriched quartz eclogite. Thus, most of the tonalitic to granodioritic rocks of the Burditt Lake - Lake Despair area are best interpreted as primitive additions to the Archean sialic crust derived from mantle depths.

The somewhat low average δ¹⁸O value (7.5 °/..) of many of the isotopically unaltered Archean meta-igneous gneisses and plutonic rocks also could be the result of formation from less differentiated, more mafic sources than Phanerozoic batholiths, which have δ¹⁸O values of 8 to 10 °/...

The δ¹⁸O values of ortho- and paragneisses (5.9-11.7 °/..) from the English River gneiss belt, and the Wabigoon granite-greenstone belt, span the range observed for least-metamorphosed meta-igneous and metasedimentary rocks. Up to middle amphibolite facies, the oxygen isotope compositions of the rock usually reflect the protolith of the gneiss. During the metamorphism, quartz-magnetite oxygen isotope temperatures are quenched at 500-600°C; quartz-biotite temperatures are lower (400 °C) and reflect continued isotopic exchange, mostly of biotite. This process results in the formation of low ¹⁸O biotites (<3 °/..).

Above middle amphibolite facies, the oxygen isotope composition of Archean gneisses cannot be relied upon to reflect the isotopic nature of protolith rock types. Partial melting seems to encourage isotopic exchange of the gneisses with a low ¹⁸O reservoir, probably basalt, and results in δ¹⁸O values for the gneisses of 6 to 7 °/.., regardless of their previous isotopic composition.

abstract: Doctor of Philosophy (PhD)


title: THE SOCIAL EXPERIENCES OF SPOUSES OF PERSONS WITH YOUNG-ONSET DEMENTIA

contributor:
McAiney, Carrie
Jenny Ploeg; Margaret Denton
Health and Aging

subject: young-onset

subject: dementia

subject: caregiver

subject: spouse

subject: social

subject: experience

subject: Clinical and Medical Social Work

subject: Cognitive Neuroscience

subject: Community Engagement

subject: Community Health

subject: Diseases

subject: Family, Life Course, and Society

subject: Geriatric Nursing

subject: Geriatrics

subject: Health Services Research

subject: Inequality and Stratification

subject: Leisure Studies

subject: Marriage and Family Therapy and Counseling

subject: Medicine and Health

subject: Mental and Social Health

subject: Neurology

subject: Neuroscience and Neurobiology

subject: Neurosciences

subject: Nursing

subject: Other Kinesiology

subject: Other Social and Behavioral Sciences

subject: Other Sociology

subject: Primary Care

subject: Psychiatric and Mental Health

subject: Psychiatric and Mental Health Nursing

subject: Psychiatry

subject: Quantitative, Qualitative, Comparative, and Historical Methodologies

subject: Recreational Therapy

subject: Regional Sociology

subject: Rehabilitation and Therapy

subject: Social and Behavioral Sciences

subject: Social Psychology and Interaction

subject: Social Work

subject: Sociology

subject: Sports Sciences

subject: Sports Studies

subject: Clinical and Medical Social Work

abstract: Spousal caregivers of persons with young-onset dementia (YOD) are known to experience significant social impacts, including family conflict, social avoidance, and marginalization. However, no qualitative study has examined the social experiences of YOD spousal caregivers within the Canadian context. This thesis examined the described social experiences of these caregivers. A descriptive, qualitative approach was used to study the nature of these social experiences using in-depth, semi-structured interviews. Ten YOD spousal caregivers living in Ontario completed the study. Four themes emerged from the analysis: sources of social support, giving up activities in favour of new activities, adapting and maintaining in social and recreational activities, and social spaces as safe spaces. Concepts of caregiver social adaptation, and choosing to give up social and recreational activities in favour of new ones builds upon existing research on theories of social support, activity restriction, caregiver adaptation, and avoidance previously described in the existing dementia literature. Themes of giving up activities in favour of new activities, and social spaces as safe spaces also represent new themes not previously discussed in the dementia caregiving literature. Previous, socially-relevant research on YOD spousal caregiving has focused primarily on examining social impacts, with little attention paid to caregiver perceptions of their social experiences in the Canadian context. These findings indicate that caregiving for a spouse with YOD entails complex social experiences, which extend beyond value-laden depictions of social outcomes recorded in the existing literature. These rich experiences challenge and expand our theoretical understanding of spousal caregiving for persons with YOD.

abstract: Master of Arts (MA)


title: Prototype Development for the Treatment of Periprosthetic Fractures of the Distal Femur

contributor:
Wohl, Gregory
Quenneville, Cheryl
Winemaker, Mitchell
Mechanical Engineering

subject:
periprosthetic fracture
distal femur
bilateral fracture fixation plates
biomechanics
biomechanical testing
finite element analysis
Biomedical devices and instrumentation
Biomedical devices and instrumentation

abstract:
Current stabilization methods for periprosthetic fractures of the distal femur have been inadequate in achieving sufficient fixation and can lead to complications rates as high as 29%. Therefore, the overall objective of this study was to design, manufacture and evaluate (experimentally and computationally) a novel plating method for improving the treatment of periprosthetic fractures of the distal femur.

Medial and lateral prototype plates were designed and manufactured based on the geometry of a synthetic femur and a femoral prosthesis. The two plates were linked via a compression screw and a small tab on each plate that inserts into pre-existing slots on the prosthesis to enhance rigidity of the construct. Synthetic femurs were used to assess the ability of the prototype plates to stabilize a periprosthetic fracture compared to a traditional single lateral plate. Each femur was subjected to a testing protocol that involved compressive and bending loading of the sample. The relative motion between the distal and proximal fragments during loading was then measured using both 2D and 3D motion tracking techniques. Both techniques revealed that the prototype bilateral plates were able to reduce motion of the fracture site compared to a single lateral plate.

The final objective concerned the development of a finite element model to represent the experimental testing. The fracture gap motion obtained from the final model did not completely agree with the experimental data; however, additional experimental measurements found that the majority of these differences could be attributed to simplification made at the tab-slot interaction. Despite the difference, the model represents a significant step forward in the simulation of periprosthetic fracture treatment, and further refinement would allow for optimization of the plate design.

Overall, the results of this thesis indicate that an alternative approach to treating periprosthetic fractures exists that is capable of improving fracture stabilization.

abstract: Master of Applied Science (MASc)


title: Security-Motivation in Obsessive-Compulsive Disorder

contributor:
Szechtman, Henry
Woody, Erik
Schmidt, Louis
Neuroscience

subject:
security
motivation
OCD
contamination
washing
checking
Psychological Phenomena and Processes
Psychological Phenomena and Processes

abstract: We present the results from a series of experiments which support a novel hypothesis for a special motivational circuit underlying both the detection and response to potential threat, and the typical symptoms of Obsessive-Compulsive Disorder (OCD). Szechtman and Woody (2004) proposed that the Security-Motivation System (SMS) has two primary responsibilities: surveillance of the environment for subtle cues that may indicate the potential for danger, and motivation towards avoidance of this harm through participation in appropriate behavioural motor programs. To determine the parameters under which the SMS operates, we designed and implemented several novel paradigms for examining both typical and atypical response of the SMS to potential threat in a number of populations. It was demonstrated that the SMS is specifically activated after exposure to cues that suggest the possibility of harm to the self or others, such as via threats to personal safety or contaminated objects. Once activated, the SMS can only be disengaged through participation in the appropriate motivated corrective behaviour – such as hand washing or checking for danger. Results showed that this essential termination feedback cannot be substituted with cognitive strategies, and that in the absence of these behaviours, activation of the SMS persists; the consequence of incomplete SMS termination strongly resembles the stereotypic compulsions in OCD. Indeed, results demonstrated that patients with OCD are unable to achieve satisfaction from task completion after corrective behaviour, resulting in continued SMS activation, after exposure to stimuli specific to the patients’ symptom profile. Our collective results provide a solid foundation for the view of OCD as a dysfunction of Security-Motivation, and indicate that the SMS is indeed an essential circuit for potential threat detection.

abstract: Doctor of Philosophy (PhD)


title: The Frequency of Blood Donation in Canada: An Exploration of Individual and Contextual Determinants

contributor:
Newbold, Bruce K.
Paez, Antonio
Heddle, Nancy
Earth and Environmental Sciences

subject:
blood donation
donation frequency
discrete choice models
accessibility
Geography
Geography

abstract: Blood products are used for transfusion in many routine procedures as well as emergency medical care. The balance between the supply and demand of blood products in Canada is being threatened by an increasing aging population, a growing immigrant population, and advances in medical technology which places additional strain on the blood supply. The objective of this research is to investigate the effects of demographic determinants and clinic accessibility on the frequency of blood donation in Canada excluding the province of Québec, providing a national assessment of blood donor correlates at the individual level. Exploration of these demographic factors in addition to clinic accessibility may help to explain why a limited number of repeat donors are currently contributing, with many donors giving blood only once a year. Repeat donors are vital to maintain a safe and secure blood supply, therefore it is important to retain existing donors in addition to recruiting new volunteers. In this study, individual donor and clinic information is obtained from the Canadian Blood Services 2008 national dataset, with contextual data from the 2006 Canadian Census. Discrete choice models are used to assess the effects of these variables on the frequency of blood donation across the country, highlighting the importance of clinic accessibility. The analysis is prepared for major Census Metropolitan Areas in Canada. Results may contribute to service optimization and targeted advertising, ultimately aiming to encourage the eligible population to donate.

abstract: Master of Arts (MA)


title: Mechanisms Underlying Rhythmic Activities of the Gastrointestinal Tract

contributor:
Huizinga, Jan D
Physiology and Pharmacology

subject:
ICC
motility
propulsion
rhythm
Digestive, Oral, and Skin Physiology
Digestive, Oral, and Skin Physiology

abstract:
The organs of the gastrointestinal (GI) tract display a variety of motor patterns, involved in grinding, mixing, enhancing absorption and propulsion of nutrients and waste products. Specialized motor patterns are generated by unique mechanisms inherent to the GI segment in which they are found. Rhythmic contractions are a feature of most motor patterns. Slow wave driven peristalsis is an acknowledged motor pattern associated with interstitial cells of Cajal (ICC) pacemakers, but propulsive motor patterns which are blocked by tetrodotoxin are seen to be exclusively generated by the enteric nervous system (ENS). This has not been proven, however, and the origin of rhythmicity of propulsive motor patterns needs further study, particularly related to a potential role of the pacemaker ICC found throughout the GI tract. The aim of this study was exploring the mechanisms which underlie various GI motor patterns, with particular focus on the origin of rhythmicity of these patterns.

I have demonstrated with manometry and spatiotemporal maps that murine rhythmic propulsion requires a myogenic pacemaker which is evoked by acetylcholine and substance P; nitric oxide is not involved. Calcium imaging evidence suggests that the pacemaker is the ICC of the deep muscular plexus, as these cells rhythmically activate to substance P. I observed rhythmic contractility patterns in human antrum, pylorus and duodenum when stimulated with carbachol. The hypothesis emerged that the ENS modifies the pyloric pacemaker into unique rhythmic patterns. Colonic muscle strip contractility from the rat has a low frequency rhythmic pattern which is myogenic. This pattern is augmented by the conditioned media from the probiotic E. coli Nissle 1917 through a non-neural mechanism.

The current explanation of entirely ENS generated motor patterns is not accurate. The ENS plays an important role in stimulating and regulating GI motor patterns in conjunction with myogenic pacemakers. It is only through acknowledgment of all GI cell types that we can understand the mechanisms governing motility.

abstract: Master of Science (MSc)


title: The Impact of Macrophage Polarity and the Tumor Microenvironment on NK Cell Phenotype and Function

contributor: Medical Sciences (Molecular Virology and Immunology Program)

subject:
NK cells
tumor associated macrophages
tumor microenvironment
Immunology and Infectious Disease
Immunology and Infectious Disease

abstract: NK cells play a pivotal role in tumor rejection; however, once present in the tumor microenvironment, they are characterized by decreased cytotoxicity and reduced expression of activating receptors. The mechanisms governing the inactivation of NK cells within tumors remain poorly understood. Since tumor associated macrophages (TAMs) are a highly abundant and suppressive cell type within tumors, we hypothesized that they are capable of altering the function of NK cells. Following the co-culture of alternatively activated macrophages (M2) or TAMs with NK cells we observed that the expression of the cytotoxic marker CD27 on NK cells was down-regulated as well as the ability of these cells to kill YAC-1 cells in a killing assay. We have demonstrated that the mechanism by which M2 cells inhibit NK cells is TGF-β dependent. Notably, the developmental stage of NK cells after interaction with TAMs was altered and the NK cells became phenoytpically mature and potentially exhausted (CD27lowCD11bhigh). This prompted our interest in examining the developmental stage of NK cells from polyoma MT antigen (pyMT) transgenic mouse (MMTV-pMT) breast tumors. Interestingly, in contrast to the in vitro results, we have shown that NK cells isolated from pyMT tumors are developmentally immature; however maintain their maturity within the spleen. Their immature phenotype correlates well with their decreased expression of perforin, granzyme, and NKp46. Both our in vitro studies with TAMs and our in vivo developmental studies using the pyMT model demonstrate that NK cells are altered by their surroundings. A better understanding of how NK cells are modified by the tumor microenvironment will help to develop strategies aimed at bolstering immune responses against tumors.

abstract: Master of Science (MSc)


title: An MRF-Based Approach to Image and Video Resolution Enhancement

contributor:
Shirani, Shahram
Electrical and Computer Engineering

subject:
Image Interpolation
Video De-Interlacing
Markov Random Fields
MAP-Based Estimation
Trellis
Viterbi Algorithm
Forward-Backward Algorithm
Signal Processing
Signal Processing

abstract: The main part of this thesis is concerned with detailed explanation of a newly proposed Markov random field-based de-interlacing algorithm. Previous works, assume a first or higher-order Markovian spatial inter-dependency between the pixel intensity values. In accord with the specific interpolation problem in hand, they try to approximate the Markov random field parameters using available original pixels. Then using the approximate model, they define an objective function such as energy function of the MRF to be optimized. The efficiency and accuracy of the optimization step is as important as the effectiveness of definition of the cost (objective function) as well as the MRF model.\\ \indent The major concept that distinguishes the newly proposed algorithm with the aforementioned MRF-based models is the definition of the MRF not over the intensity domain but over interpolator (interpolation method) domain. Unlike previous MRF-based models which try to estimate a two-dimensional array of pixel values, this new method estimates an MRF of interpolation function (interpolators) associated with the 2-D array of pixel intensity values.\\ \indent With some modifications, one can utilize the proposed model in different related fields such as image and video up-conversion, view interpolation and frame-rate up-conversion. To prove this potential of the proposed MRF-based model, we extend it to an image up-scaling algorithm. This algorithm uses a simplified version of the proposed MRF-based model for the purpose of image up-scaling by a factor of two in each spatial direction. Simulation results prove that the proposed model obtains competing performance results when applied in the two interpolation problems of video de-interlacing and image up-scaling.

abstract: Master of Applied Science (MASc)


title: Optimization-based Formulations for Operability Analysis and Control of Process Supply Chains

contributor:
Swartz, Christopher L.E.
Chemical Engineering

subject:
Supply Chain Optimization
Operability Analysis
Robust Model Predictive Control
Stochastic Optimization
Multi-objective (Pareto) Optimization
Process Control and Systems
Process Control and Systems

abstract:
Process operability represents the ability of a process plant to operate satisfactorily away from the nominal operating or design condition, where flexibility and dynamic operability are two important attributes of operability considered in this thesis. Today's companies are facing numerous challenges, many as a result of volatile market conditions. Key to sustainable profitable operation is a robust process supply chain. Within a wider business context, flexibility and responsiveness, i.e. dynamic operability, are regarded as key qualifications of a robust process supply chain.

The first part of this thesis develops methodologies to rigorously evaluate the dynamic operability and flexibility of a process supply chain. A model is developed which describes the response dynamics of a multi-product, multi-echelon supply chain system. Its incorporation within a dynamic operability analysis framework is shown, where a bi-criterion, two-stage stochastic programming approach is applied for the treatment of demand uncertainty, and for estimating the Pareto frontier between an economic and responsiveness criterion. Two case studies are presented to demonstrate the effect of supply chain design features on responsiveness. This thesis has also extended current paradigms for process flexibility analysis to supply chains. The flexibility analysis framework, where a steady-state supply chain model is considered, evaluates the ability to sustain feasible steady-state operation for a range of demand uncertainty.

The second part of this thesis develops a decision-support tool for supply chain management (SCM), by means of a robust model predictive control (MPC) strategy. An effective decision-support tool can fully leverage the qualifications from the operability analysis. The MPC formulation proposed in this thesis: (i) captures uncertainty in model parameters and demand by stochastic programming, (ii) accommodates hybrid process systems with decisions governed by logical conditions/rulesets, (iii) addresses multiple supply chain performance metrics including customer service and economics, and (iv) considers both open-loop and closed-loop prediction of uncertainty propagation. The developed robust framework is applied for the control of a multi-echelon, multi-product supply chain, and provides a substantial reduction in the occurrence of back orders when compared with a nominal MPC framework.

abstract: Master of Applied Science (MASc)


title: THE EFFECT OF ACUTE EXERCISE ON THE PRODUCTION OF REACTIVE OXYGEN SPECIES AND INFLAMMATORY MARKERS IN HEALTHY PRE-PUBERTAL AND ADULT MALES

contributor:
Timmons, Brian
Raha, Sandeep
Parise, Gianni
Health Sciences

subject:
children's exercise
oxidative stress
inflammation
flow cytometry
neutrophils
Pediatrics
Physiological Processes
Sports Sciences
Pediatrics

abstract: An acute bout of exercise causes short-term changes in the immune system in both children and adults. It has been well-established that exercise induces an inflammatory response. Especially in children, cytokines play an important role in balancing anabolic and catabolic processes of growth. Existing evidence suggests cross-talk between inflammation and oxidative stress. Reactive oxygen species are also found to transiently increase in response to exercise, affecting muscle adaptation post-exercise. Characterizing the exercise-induced inflammatory and oxidative stress responses in children compared to adults will start clarifying the transition from the child phenotype to that of an adult. Ten children aged 8-10 and 12 adults aged 19-21 performed 2×30min bouts of continuous cycling, separated by a 6min rest period, at a target work rate of 60% of their maximum aerobic capacity. Blood samples were collected pre-exercise and immediately post-exercise, and analyzed for neutrophil count, systemic oxidative and inflammatory markers (tumor necrosis factor alpha, interleukin 6, protein carbonyls, malondialdehyde, elastase), intracellular neutrophil-derived reactive oxygen species (using 3 fluorescent markers detected by flow cytometry), and in vitro production of neutrophil-derived myeloperoxidase and interleukin 8. Compared to the post-exercise increase in absolute neutrophils in men, boys showed no change. However, intracellular neutrophil reactive oxygen species production increased for boys and not for men. Boys also demonstrated higher overall protein carbonyl levels, whereas men showed higher overall malondialdehyde. Both boys and men showed a positive correlation between tumor necrosis factor alpha and elastase, with a steeper slope seen in boys. Although there were other correlations observed in boys and men, no others existed in both. The differences observed in the exercise-induced inflammatory and oxidative stress response may indicate growth-mediated adaptive responses to exercise during childhood development.

abstract: Master of Science (MSc)


title: HIGH-RESOLUTION CHARACTERZATION OF LOW-DIMENSIONAL DEFECTS IN SrTiO3

contributor:
Botton, Gianluigi
Materials Science and Engineering

subject:
Atomic level
EELS
STEM
SrTiO3
dopants
surfaces

abstract: I want delay publication of my dissertation until April 30 2013. Thanks.

abstract:
Strontium titanate (SrTiO3) has a wide range of applications in the electronic industry and attracts growing world-widely interest recently because of novel discoveries at its surfaces, interfaces and with selected dopants. The understanding of some of the structural properties of SrTiO3 and its optical properties have been lagging due to limited characterization techniques available to study single monolayers and dopants in this material.

In the present thesis, pure SrTiO3 single crystals with (2x1) and c(4x2) surface patterns were synthesized and samples (Pr, Al) doped SrTiO3 were prepared through ion implantation. The atomic and electronic structures of these samples were investigated by various high-resolution imaging and spectroscopic techniques available in an aberration-corrected transmission electron microscope. Particularly, the direct imaging of individual light atoms and vacancies within a bulk material containing heavier elements was demonstrated for the first time via the STEM-annular dark-field (ADF)/annular bright-field (ABF) images. In addition, the first electron energy-loss spectroscopy (EELS) 2-dimensional maps of dopants located in a lattice were obtained. These results provided a solid foundation regarding the mechanism of red light emission in doped SrTiO3. More importantly, a new experimental approach allowing the effective extraction of weak EELS signals from low-dimensional defects was developed and successfully applied to understand the chemical state and coordination of Ti cations within a single monolayer on a reconstructured SrTiO3 surface and the local defect configurations of injected Pr+ and Al+ ions within SrTiO3 single crystals.

abstract: Doctor of Philosophy (PhD)


title: Universal Algebra in Topoi

contributor:
Banaschewski, Bernhard
Mathematics

subject: Mathematics Mathematics

abstract:
This thesis represents an attempt to marry two distinct directions of research in Modern Algebra. On the one hand we have the theory of topoi which has been undergoing vigorous development within the last three years. This area grew out of careful consideration of the tools of Modern Algebraic Geometry as promoted by the French School under the leadership of Alexandre Grothendieck. Lawvere and Tierney have shown how the theory of topoi may be axiomatized conveniently and have established that much of Mathematics may be carried out in the environment of a topos, in which scheme the topos of definition replaces the category of sets. The second direction referred to is what is called Universal Algebra. By this we mean internal Universal Algebra, that is to say the study of equations and their solutions in mathematical structures. In the present work we undertake the study of the behaviour of universal algebras modelled in a topos.

In fact the topoi we choose to study are those arising as categories of sheaves of sets on a suitable parametrizing object (Grothendieck site). In this framework we introduce the notion of equation and solution, now for sheaves of algebras. We establish as major results that a compact Hausdorff sheaf of algebras is equationally (algebraically) compact and that for sheaves of modules, homological purity is equivalent to a form of equational purity. On the path towards the proof of these results we establish new facts about certain topoi, and some new facts regarding "external" universal algebra, that is, the purely categorical aspect of universal algebra. For example we characterize the points of the category of double negation sheaves on a topological space, we give a useful characterization of those continuous maps whose inverse image functor on the associated sheaf categories is cotripleable, we establish a Birkhoff-type subdirect representation theorem for sheaves of algebras and we exhibit sufficient conditions for injectivity to be well-behaved in the category of sheaves of universal algebras associated with a specified theory.

What we have carried out here represents only a beginning in terms of the possibilities inherent in studying universal algebras modelled in topoi. The old theorems of universal algebra take on a more dynamic and geometrical flavour in their new environment, which we hope will lead to their application in Combinatorics and Algebraic Geometry.

abstract: Doctor of Philosophy (PhD)


title: Policy-Oriented Models of Interregional Development

contributor:
Webber, Michael J.
Geography

subject: Geography Geography

abstract:
In this dissertation government influence is an endogenous component of interregional development. The purpose of the study is to determine some of the implications of economic and/or population goals, in terms of the types of government actions that will be required to meet these goals, and in turn, the effect that these actions will have on regional income and population levels over time. These planning issues are treated as optimal control problems, which are solved using Pontryagin's Maximum Principle. This study represents one of the first applications of Pontryagin's Maximum Principle to geographic systems, and was developed independent of other related studies.

Four models are analyzed. All are simple, and serve as precursors of more comprehensive models. The first deals with the magnitude of government intervention when economic projections do not concur with established goals. The second model focuses specifically on per capita regional government spending as a policy instrument. The third model emphasizes the feedback between production levels and migration. The fourth is particularly sensitive to regional disparity, as well as to regional growth.

Results of the models indicate that in planned regional economies, levels of per capita income and population will probably exhibit steady trends, without sharp upturns or downturns in either economic or population growth. This is true even when there are only constrains on the income and population levels at the end of the planning interval, but none on the trajectories during that interval. Underlying this scenario of steady trends, however, is the possibility of extremely drastic fiscal, monetary and immigration policies, which are required to maintain such trends. The severity of these policies will depend on the regions' economic and population goals, the magnitude of these goals relative to those of other regions, the propensity of migrants to move to the more prosperous regions, and the labour intensiveness of regions' economies.

abstract: Doctor of Philosophy (PhD)


title: Majority Real: "Realism" in Graeco-Roman Fable As Depicted Through the Crow and Raven

contributor:
Murgatroyd, Paul
Corner, Sean
Eilers, Claude
Classics

subject:
fable
realism
crow
raven
augury
ethology
Classical Literature and Philology
Classical Literature and Philology

abstract: The role of realism in the depiction of animals in Greaco-Roman fable is investigated. The crow and the raven have been chosen as the prism through which the investigation is carried out. Fable will be shown to be a genre founded on a contextually realistic depiction of animals, and this may especially be seen in the corvid fables. Realism must, however, be understood contextually, as what constitutes a realistic depiction of crows and ravens in Graeco-Roman times is quite different than what one would encounter at present. As a result of which the crow and raven are marked by attributes ranging from cleverness, parenting ability, resistance to weather, vocal mimicry, longevity, and augural significance, amongst a host of other characteristics which sometimes coincide with modern views but often do not. Thus Graeco-Roman fables dealing with crows and ravens can be broadly divided into two categories: fables dealing in various ways with their intelligence, and fables dealing with their augural significance.

abstract: Master of Arts (MA)


title: The Fractal Nature and Functional Connectivity of Brain Function as Measured by BOLD MRI in Alzheimer’s Disease

contributor:
Noseworthy, Michael D.
Molloy, William
Hasey, Gary M.
Biomedical Engineering

subject:
Magnetic Resonance Imaging
BOLD fMRI
Fractal Dimension Mapping
Resting State Networks
Magnetic Resonance Spectroscopy
Alzheimer's Disease
Susceptibility Weighted Imaging
Diagnosis
Engineering Physics
Geriatrics
Investigative Techniques
Knowledge Translation
Medical Biophysics
Mental Disorders
Nervous System Diseases
Neurosciences
Non-linear Dynamics
Other Mathematics
Psychiatric and Mental Health
Psychiatry
Radiology
Diagnosis

abstract:
Alzheimer’s disease (AD) is a degenerative disease with progressive deterioration of neural networks in the brain. Fractal dimension analysis (FD) of resting state blood oxygen level dependent (BOLD) signals acquired using functional magnetic resonance imaging (fMRI) allows us to quantify complex signalling in the brain and may offer a window into the network erosion. This novel approach can provide a sensitive tool to examine early stages of AD. As AD progresses, we expect to see a reduction in brain connectivity and signal complexity concurrent with biochemical changes (e.g. altered levels of N-acetyl aspartate (NAA), myoinositol (mI) and glutamate as measured using magnetic resonance spectroscopy, MRS), volumetric changes and abnormally high levels of brain iron.

Over a series of 4 studies we examined the relationship of BOLD signal complexity and functional connectivity with documented MRI markers of pathology in AD (n=38) as compared to normal controls (NC) (n=16). AD subjects were in early stage of illness (mild to moderate impairment on the mini mental state exam, MMSE). We validated the temporal (short term (within minutes) and longer term (over a number of months)) consistency of FD measurement and choice of BOLD acquisition method (spiral vs. EPI), provided MRI sequence repeat time (TR) was kept constant. FD reduction (decrease in signal complexity) correlated with worsening pathological values on MRS (NAA decrease and mI increase) and with a decrease in functional connectivity. This demonstrates that FD (signal complexity) reduces in proportion to AD severity. FD reduction is connected to functional connectivity measured through resting state network (RSN) analysis suggesting the reduction in FD relates to neuronal loss rather than altered vascularity. The narrow range of cognitive impairment (such as scores on the MMSE or the clinical dementia rating scale, CDR) likely precluded correlation between these measures and FD or RSN. Functional connectivity (RSN) was also reduced when brain iron levels were increased within certain network nodes (posterior cingulate cortex and lateral parietal cortex). Therefore iron deposition may play a role in network disruption of AD brains.

The overall conclusion of this thesis is that signal complexity of BOLD fMRI signals, as measured with FD, may detect early pathology in the progression of AD. FD can detect neuronal changes in deep brain structures before volume loss in these structures and before significant changes in MRS markers were detectable between the AD and NC groups. An FD change mirrors disruptions in functional connectivity but detection is not limited to RSN nodes in the brain. This novel approach could further our understanding of AD and may be applied to other pathologies of the brain.

abstract: Doctor of Philosophy (PhD)


title: The Deinomenids of Sicily: The Appearance and Representation of a Greek Dynastic Tyranny in the Western Colonies

contributor:
Pope, Spencer
Corner, Sean
Mattison, Kathryn
Classics

subject: The Deinomenids

subject: Sicily

subject: Classical Greece

subject: tyranny

subject: colonization

subject: propaganda

subject: Ancient History, Greek and Roman through Late Antiquity

abstract:
The aim of this thesis has been to investigate and analyze the tyranny of the Deinomenids (491 – 466 BC), a family who controlled several Greek colonies located on the island of Sicily. Modern classical scholarship has often ignored the history and contributions this family has made to the Greek world or has taken a limited view of the family.

I intend to present a comprehensive account of the Deinomenids and to demonstrate how this family, which has received little attention, played a major role in the Greek world. I will look into several aspects regarding their tyranny that have often been overlooked, including the ways in which they invented claims about themselves and manipulated their identities in order to elevate their status as rulers in Sicily. In addition to this, I will use the Deinomenids as a case study to illustrate the tension felt between the mainland and the Greek colonies in Sicily, as well as demonstrating how the West influenced and informed many of the advancements seen on the mainland in later generations.

The first section of this thesis will investigate Greek tyranny and Greek colonization in the West. This will provide the backdrop of my study of the Deinomenids. The next section will present a catalogue of the historical, literary, and archaeological evidence that survives regarding the family. The third section will focus on the various methods that the family used to secure their powerbase in Sicily. This included using poetry, coinage, buildings, and religious cults. The last section will look at the aftermath of the Deinomenid tyranny and the long-lasting impact their rule had on Sicily and the mainland of Greece.

abstract: Master of Arts (MA)


title: MEASUREMENT OF AMMONIUM IN HAEMOLYMPH AND MALPIGHIAN TUBULE SECRETION IN DROSOPHILA MELANOGASTER: APPLICATION OF A NOVEL AMMONIUM-SELECTIVE MICROELECTRODE

contributor:
O`Donnell, Michael J.
Wood, Chris M.
Scott, Graham
Biology

subject:
microelectrode
Drosophila
ammonia
ammonium
Malpighian tubule
selectivity coefficient
Zoology
Zoology

abstract: The transport of ammonia by various tissues throughout the body is of fundamental importance for nitrogen excretion in invertebrates, yet sites and mechanisms of ammonia transport are not presently well understood. In this thesis a novel ammonium-selective microelectrode was developed using the ionophore TD19C6, which is approximately 3800-fold more selective for NH4+ than Na+ compared with the 100-fold difference of nonactin used in previous microelectrodes. We investigated the accuracy of the ammonium microelectrode in solutions simulating Drosophila haemolymph (25 mM K+) and secreted fluid (120 mM K+). In haemolymph-like solutions, ammonium could be measured down to about 1 mM, with an error of 0.5 mM, while in secreted fluid-like conditions ammonium could be determined to within 0.3 mM down to a level of 1 mM NH4+ in the presence of 100 to 140 mM K+. These results suggested that the ammonium microelectrode could be used to measure ammonium in the presence of physiological levels of potassium, unlike previous studies. We also quantified ammonium secretion by the Malpighian (renal) tubules of larvae. Ammonium concentrations of secreted fluid were consistently equivalent to or above ammonium concentrations of bathing salines. With a lumen-positive transepithelial potential, these results suggested an active secretory mechanism for ammonia transport. Under conditions of low K+ concentrations, the ability of the tubules to concentrate ammonium in secreted fluid was significantly enhanced, indicating some level of competition between NH4+ and K+ for common transporters. The new ammonium-selective microelectrode is sufficiently sensitive to detect ammonium at the picomol level.

abstract: Master of Science (MSc)


title: A Life Unlived: The Roman Funerary Commemoration of Children From the First Century BC to the Mid-Second Century AD

contributor:
George, Michele
Haley, Evan W.
Beckmann, Martin
Classics

subject: Roman Family

subject: Roman Children

subject: Funerary Commemoration

subject: Latin Epigraphy

subject: Roman Material Culture

subject: Roman Social History

subject: Classical Archaeology and Art History

subject: Classics

abstract: This thesis is concerned with the representation of children on sculptural funerary commemoration, with a focus on freedmen panel reliefs and funerary altars. Although there is evidence found from all regions of the Empire, the majority of the material discussed here is from the city of Rome itself. Representations of young children first appear on freedmen panel reliefs, which date to the end of the Republic and were produced into the first century of the Empire. When this genre declined in popularity at the end of the first century AD, funerary altars emerged as the new, preferred form of commemoration. The goal of this thesis is to show that these two types of funerary monuments reveal much about the children themselves, but also provide insight into the social and cultural identity of their parents. Due to the family relationships expressed on these commemorations, I also evaluate the degree of affect demonstrated by the parents or the dedicator towards the children present on these monuments. The first chapter provides a socio-cultural background on the role of children in the family and Roman society as well as the importance of funerary commemoration. In this chapter I also discuss the likelihood of high infant and child mortality rates and explore reactions towards the death of children in literary evidence and social conventions. In the second chapter I provide a background on the significance of the freedman family, followed by an examination of the panel reliefs. The third chapter examines funerary altars that commemorate young children. The material discussed in this chapter is analyzed through a case study approach of nine altars, examining both the epigraphic elements and the sculptural components.

abstract: Master of Arts (MA)


title: A Low Power Electrical Method for Cell Accumulation and Lysis Using Microfluidics

contributor:
Selvaganapathy, Ravi P.
Mechanical Engineering

subject: Cell Lysis

subject: Microfluidics

subject: Electrical Lysis

subject: Bacterial Lysis

subject: Electroporation

subject: Polycarbonate Membrane

subject: Biochemical and Biomolecular Engineering

subject: Bioimaging and biomedical optics

subject: Biological Engineering

subject: Biomedical

subject: Electro-Mechanical Systems

subject: Membrane Science

subject: Molecular, cellular, and tissue engineering

subject: Nanoscience and Nanotechnology

subject: Other Mechanical Engineering

abstract:
Microbiological contamination from bacteria such as Escherichia coli and Salmonella is one of the main reasons for waterborne illness. Real time and accurate monitoring of water is needed in order to alleviate this human health concern. Performing multiple and parallel analysis of biomarkers such as DNA and mRNA that targets different regions of pathogen functionality provides a complete picture of its presence and viability in the shortest possible time. These biomarkers are present inside the cell and need to be extracted for analysis and detection. Hence, lysis of these pathogenic bacteria is an important part in the sample preparation for rapid detection. In addition, collecting a small amount of bacteria present in a large volume of sample and concentrating them before lysing is important as it facilitates the downstream assay. Various techniques, categorized as mechanical, chemical, thermal and electrical, have been used for lysing cells. In the electrical method, cells are lysed by exposure to an external electric field. The advantage of this method, in contrast to other methods, is that it allows lysis without the introduction of any chemical and biological reagents and permits rapid recovery of intercellular organelles. Despite the advantages, issues such as high voltage requirement, bubble generation and Joule heating are associated with the electrical method.

To alleviate the issues associated with electrical lysis, a new design and associated fabrication process for a microfluidic cell lysis device is described in this thesis. The device consists of a nanoporous polycarbonate (PCTE) membrane sandwiched between two PDMS microchannels with electrodes embedded at the reservoirs of the microchannels. Microcontact printing is used to attach this PCTE membrane with PDMS.

By using this PCTE membrane, it was possible to intensify the electric field at the interface of two channels while maintaining it low in the other sections of the device. Furthermore, the device also allowed electrophoretic trapping of cells before lysis at a lower applied potential. For instance, it could trap bacteria such as E. coli from a continuous flow into the intersection between two channels for lower electric field (308 V/cm) and lyse the cell when electric field was increased more than 1000 V/cm into that section.

Application of lower DC voltage with pressure driven flow alleviated adverse effect from Joule heating. Moreover, gas evolution and bubble generation was not observed during the operation of this device.

Accumulation and lysis of bacteria were studied under a fluorescence microscope and quantified by using intensity measurement. To observe the accumulation and lysis, LIVE/DEAD BacLight Bacterial Viability Kit consisting of two separate components of SYTO 9 and propidium iodide (PI) into the cell suspension in addition to GFP expressed E. coli were used. Finally, plate counting was done to determine the efficiency of the device and it was observed that the device could lyse 90% of bacteria for an operation voltage of 300V within 3 min.

In conclusion, a robust, reliable and flexible microfluidic cell lysis device was proposed and analyzed which is useful for sample pretreatment in a Micro Total Analysis System.

abstract: Master of Applied Science (MASc)


title: Working and Thinking Across Difference: A White Social Worker and an Indigenous World

contributor:
Dumbrill, Gary
Sammon, Sheila
Schormans, Ann Fudge
Social Work

subject:
Aboriginal
Indigenous Ways of Knowing
Autoethnography
Decolonization
Colonizer/Colonized
Anti-Oppressive Practice
Social Work
Social Work

abstract: Indigenous populations have experienced vast travesties due to the impacts of colonialism. Colonialism continues to be perpetuated through the services, programs and policies that Indigenous people encounter. This research thesis tackles the question of how non-Indigenous social workers, professionals and interested parties can work with Indigenous people in appropriate and respectful ways. It also reviews how non-Indigenous people can work and think across difference. This research represents my journey towards decolonizing myself to find new ways of being White that are compatible with Indigenous knowledge systems and ways of knowing. Autoethnography, relevant literature and interviews were used to explore ways of working with Indigenous populations. Three participants who had been identified by an Indigenous academic as people who had worked with Indigenous populations in appropriate and respectful ways were interviewed in Canada. An analysis of the three semi in-depth interviews produced several recommendations for non-Indigenous people in working with Indigenous populations. Results acknowledge the complexity of working and thinking across difference. Suggestions for working with Indigenous populations are highlighted and include such themes as acknowledging tensions and privilege, understanding that there is a large diversity within Indigenous populations, recognizing that there are aspects of dominant ways of knowing that are compatible with Indigenous ways of knowing, the importance of not being afraid to take risks and of trying not to make assumptions. Decolonization is an uneasy pursuit that is fraught with tension and this research hopes to encourage other social workers, professionals and interested parties to engage in similar processes.

abstract: Master of Social Work (MSW)


title: Functional outcomes of Radial head arthroplasty in people with complex radial head fractures and associated injuries

contributor:
MacDermid, Joy
Stratford, Paul
Ruby Grewal, Linda Woodhouse
Rehabilitation Science

subject:
Radial head
replacement
function
outcome measure
Physical Therapy
Rehabilitation and Therapy
Physical Therapy

abstract:
Radial head arthroplasty (RHAP) is proposed as the treatment of choice of complex radial head fractures not amenable to reconstruction. With advances in the understanding of elbow biomechanics and subsequently implant designs, low morbidity, few complications and good success has been reported with RHAP compared to internal fixation. Much of the success/complication post RHAP has been attributed to the fracture pattern and presence of associated injuries. While these are important parameters to reflect on, however, the outcome of surgery cannot be solely attributed to the methods of dealing with the radial head fracture. Importantly, the outcomes of RHAP are also influenced by patient factors. Hence, the purpose of this thesis was to assess the existing knowledge of functional outcomes post RHAP and explore the role of acute post surgical pain as a predictor of those outcomes.

The first manuscript in the thesis systematically examines the current available English literature regarding the functional outcomes of metal RHAP. Studies reviewed revealed significant heterogeneity in the study and patient characteristics. Likewise, the method of reporting fracture classification, clinician and patient reported outcomes are inconsistent. Based on the level 4 evidence studies in the review, we concluded that RHAP provides good to excellent outcomes in short-midterm follow up, with no evidence regarding the superiority of one implant over another.

The second manuscript explored the role of acute post surgical pain in development of chronic functional impairment post RHAP using the EVOLVE (Wright Medical Technology, Arlington, Tennessee) implant at 2 years post surgery. A total of 59 adults with complex radial head fractures treated with EVOLVE metal radial head implant were followed for a period of two years. Demographics, American Shoulder and Elbow Surgeon's-Elbow (ASES-e) pain subscale and Disability of Arm, Hand and Shoulder Questionnaire (DASH) data were collected at baseline and two years. Regression analyses revealed that acute post operative pain post RHAP is significantly related to the functional outcome at 2 years post RHAP. An ASES-e pain cut off score of 32/50 predicted the development of chronic functional impairment two years post RHAP.

The results of this thesis highlight the need for prospective longitudinal studies, comparative analyses and standardized methods of reporting concerning effectiveness of RHAP. It also emphasizes the significance of quantifying pain levels in the immediate post operative period and classifying the patient in high/low risk groups for developing chronic functional impairment based on the pain level.

abstract: Master of Science (MSc)