title: Trace Evidence Analysis of Forensic Samples Using Inductively Coupled Plasma

subject: ICP-OES ICP-MS Forensics

abstract:
At many crime scenes, little evidence is left behind; thus, the more tools available for the analysis of minute samples, the better. For instance, trace elemental impurities are not regulated in many commercial materials and thus could be a unique identifier. One of the best techniques for multi-elemental trace analysis is inductively coupled plasma (ICP) spectrometry; yet, it is seldom used for forensic analysis.  In this thesis, four different forensic applications will be explored using ICP spectrometry involving four different types of sample: human head hair, automotive paint, solder and gunshot residue.
Human hair and automotive paints were analyzed using electrothermal vaporization (ETV) coupled to ICP optical emission spectrometry (OES).  This combination is advantageous for the analysis of forensic materials, as ETV enables the direct analysis of milligrams of solid samples, which eliminates sample contamination that could happen during dissolution.  Moreover, as transport efficiency into the ICP is nearly 100%, a higher sensitivity results than with solution nebulization (SN). Qualitative analysis by ETV-ICP-OES in combination with multivariate statistical techniques, such as principal component analysis and linear discriminant analysis, enabled the discrimination of gender and general ethnicity from head hair as well as vehicle manufacturer, year of production and colour from an automotive paint chip.
Quantitative analysis by SN into ICP mass spectrometry (MS) following acid digestion constitutes an even more sensitive approach than ETV-ICP-OES.  The concentrations of trace impurities were measured by SN-ICP-MS in lead-tin solder, commonly used in the making of improvised explosive devices, to help to narrow down the list of suspects if pieces of solder salvaged at the crime scene are matched to unused pieces found in a suspect’s home.  Quantitative analysis by SN-ICP-MS is also useful to assess the health and safety of forensic personnel as well as cross-contamination in a forensic facility. Because forensic ballistic profiling requires a firearm discharge in an environmentally controlled range, a high concentration of lead accumulates on surfaces, exposing employees to potential lead-related health risks. In addition to quantifying the lead concentrations on surfaces in different areas, SN-ICP-MS also enabled the identification of an effective lead abatement method.

abstract: PhD


title: N-Heterocyclic Carbene Borenium Ions: Decomposition Pathways and Applications in Organic Synthesis

contributor:
Crudden, Cathleen
Chemistry

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

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

rights: Intellectual Property Guidelines at Queen's University

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

subject:
Hydrogenation
Boron
N-heterocyclic carbene
Hydrosilylation
Chiral phosphoric acid
Borocation

abstract: Borocations have been synthetically accessible entities for over 35 years, thought of as chemical curiosities too reactive to be synthetically useful until recently. Our group has contributed to the development of a class of three-coordinate dialkyl borocations, known as borenium ions, stabilized by N-heterocyclic carbenes (NHCs). Our NHC is based on the 1,2,3-triazolylidene ring system, a modular motif that we previously exploited in borenium-catalyzed hydrogenation reactions. This thesis describes our work on borenium ion catalysis as well as insight into unexpected decomposition pathways. First, we established a facile hydrosilylation protocol of imines and quinolines with triazolylidene borenium ion 1+ under mild conditions. With respect to quinoline reductions, 1+ does not completely reduce the N-heterocyclic ring, giving rise to a cyclic N-silyl enamine, which we applied in a Mukaiyama aldol-like reaction with aldehydes to produce unique γ-aminoalcohols. Interestingly, control experiments showed that 1+ catalyzed both the reduction and nucleophilic addition. Next, we attempted to reduce pyridines with dihydrogen, a classically difficult substrate class. Control reactions indicated that catalyst decomposition was favoured at high temperatures in the presence of a bulky secondary amine. To mitigate this problem, a hydrosilane was injected into the reaction, allowing for more mild hydrogen pressures and temperatures. Thus far, 1+ reductions are racemic and introduction of chiral NHCs or boranes has resulted in low stereoinduction. The avenue presented in this thesis to overcome this challenge is the preparation of NHC-boranes containing chiral phosphate substituents. Strong thermodynamic and kinetic hydricity of the NHC-borane was critical for facile synthesis of these molecules. Finally, we discovered that imidazolylidene-stabilized carbene boranes ring expand at elevated temperature to yield cyclic azaborines. Subsequent hydride abstraction of these cyclic systems resulted in 6-membered cyclic aromatic boron carbocations. The data presented in this thesis challenge the preconceived notions of high NHC stability with regard to exotic main group molecules and approaches to overcome these obstacles has resulted in new synthetic methodologies.

abstract: PhD


title: Essays In Empirical Corporate Finance

contributor:
Wang, Wei
Business

subject:
Mergers and Acquisitions
Supply Chain Financing
Trade Credit

abstract:
This thesis explores several aspects of empirical corporate finance. The three essays in my dissertation are in line with the two streams of empirical corporate finance research: mergers and acquisitions (M&A) is with the transaction-based stream whereas supply chain financing is in line with the contractual finance research.
In the first essay, I use the Jump Start Our Business Act (JOBS Act) in 2012 as a quasi-natural experiment to examine how increased access to the IPO market affects the bargaining power of private targets in mergers and acquisitions. I find that U.S. private targets are valued higher after the JOBS Act relative to public targets acquired by U.S. acquirers. The announcement returns of acquirers that took over U.S. private targets after the JOBS Act are lower. I find that the effect is more pronounced for target firms with higher disclosure costs and for firms with less bargaining power.
In the second essay, I examine the information role of media outlets, namely newspapers, in the supply chain. I exploit a comprehensive dataset of U.S. supplier-customer pairs as well as news coverage by newspapers, of customers over the period 2000 to 2016 to examine how suppliers utilize information from the media to manage their primary customers. I document that a one standard deviation change in the media coverage of a firm’s customer translates into a 5.29% increase in the possibility of it being recognized as a primary customer. Enhanced media coverage also leads to more liberal trade credit terms. I rely on local news outlets’ shutdowns and airline routes closedowns to establish causality.
In the third essay, I examine how investors’ acquisition of information from EDGAR filings influences firms’ trade credit. I use the download intensity of the SEC’s EDGAR system and find that more downloading decreases aggregate trade credit offering, and the effect is only significant for the distant investors who have less information about the firms.
The results are consistent with my model that information acquisition by investors without a complete understanding about the managers’ actions makes them focus on short-term performance.

abstract: PhD


title: Interprofessional Primary Care for Adults with Intellectual and Developmental Disabilities

contributor:
Donnelly, Catherine
Lysaght, Rosemary
Rehabilitation Science

subject:
Primary Care
Interprofessional
Health Care Teams
Intellectual Disabilities
Developmental Disabilities
Health Services

abstract:
Access to high-quality primary care has been identified as a pressing need for adults with intellectual and developmental disabilities (IDD). Adults with IDD live with complex physical and mental health conditions, use health services differently than the general population and continue to face challenges when accessing health services. Interprofessional primary care teams offer comprehensive and coordinated approaches to primary care delivery and are well-positioned to address the needs of adults with IDD and other vulnerable populations. Although interprofessional primary care teams are recommended, there is currently limited understanding of how interprofessional services are delivered and how this approach improves the health of adults with IDD. The overall objective of this research was to gain a detailed understanding of the current provision of interprofessional primary care for adults with IDD.
This dissertation presents the results of two studies. A scoping review was completed to examine the provision of interprofessional primary care for adults with IDD in a global context. A multiple case study was also conducted with five interprofessional primary care teams in Ontario, Canada. The aim of this study was to describe interprofessional primary care for adults with IDD within and across models of team-based care in one local health service context.
The results of the studies highlight that there are multiple approaches to the provision of interprofessional primary care for adults with IDD. In Ontario, adults with IDD are a small part of the patient population served and overall, this group was poorly identified. Key organizational attributes, as well as the experiences of patients, caregivers and health providers were described. Interestingly, despite the presence of interprofessional health providers, there were limited organizational processes to engage a wide-range of interprofessional services. There was no consistent reporting of outcomes and no processes in place to measure the impact of interprofessional services for this population. Results provide important insights into the current state of interprofessional primary care for adults with IDD in Ontario and highlight a critical need for further work in the field to develop processes to engage in team-based care and demonstrate the value of the approach for this population.

abstract: PhD


title: Effect of Coating Defect, Desiccation,  and Freeze-Thaw Cycles on Geosynthetic Clay Liner (GCLS) – Geomembrane Interface Transmissivity

contributor:
Rowe, Kerry
Civil Engineering

subject:
Interface Transmissivity
Geosynthetic Clay Liners
Conventional GCLs
Multicomponent Coated GCLs
Coating Defect
Desiccation
Freeze/Thaw Cycle

abstract:
A series of laboratory tests were conducted to investigate the effect of prehydration fluid, a 4-mm diameter central coating defect, coating defect position and nature, and the effect of coating orientation of a multi-component coated geosynthetic clay liner (GCL) on interface transmissivity, θ between the interfaces of GCL and a 1.5mm thick high-density polyethylene geomembrane (GMB) when permeated with a simulated municipal solid waste landfill leachate. Also, two different conventional GCLs were used to explore the effect of prehydration and permeant fluid, desiccation of GCL on θ and assess the self-healing capacity of desiccated GCLs for three different permeant solutions under a range of applied stresses (10-150 kPa). It was found that < 70 kPa, θ was dominated by variability in initial contact condition between the interfaces of GMB-GCL and the effect of other factors was largely masked by the contact variability. At 100-150 kPa the effects of initial variability were largely eliminated but there was no notable effect of other factors for both multi-component and conventional GCLs. Desiccation of GCLs increased transmissivity by up to three orders of magnitude compared to an intact specimen at 10-100 kPa. Even at 150 kPa desiccated specimens had θ ≤ 8.0x10-9 m2/s for all specimens tested. The chemical composition of permeant solutions, crack width, and nature of bentonite played an important role in healing the cracks of desiccated GCLs.
A new laboratory test setup was developed to apply freeze-thaw cycles at the GMB-GCL interfaces and tests were conducted to do a preliminary study of 5 and 16 freeze-thaw cycles effect, two different prehydration fluids and means of hydration of GCL during freeze-thaw cycles on θ, for a range of stresses (10-100kPa). The preliminary results showed that the new test setup successfully applied freeze/thaw cycles to the interfaces of GMB/GCL. The ice lenses, on thawing had a significant effect on θ at 10 kPa. When GCLs were externally prehydrated with RO water and pore water and then subjected to freeze-thaw cycles, there was no evidence of any significant effect of 5-freeze/thaw cycles but there was an effect of 16 freeze/thaw cycles on interface transmissivity.

abstract: M.A.Sc.


title: Vertical Jump Landing Fatigue: the Kinetic, Kinematic, and Muscular Adaptations

contributor:
Costigan, Patrick
Kinesiology and Health Studies

rights: Attribution-NonCommercial-ShareAlike 3.0 United States

subject:
Biomechanics
Jumping
Jump Landing
Fatigue
Landing

abstract:
Understanding how fatigue affects task performance is crucial for understanding injury risk. Historically, the tests used to measure fatigue and the effects of that fatigue were not always similar to the tasks that generated that fatigue. Many studies that examine fatigue in jumping implement a pre-fatigue test, followed by a fatiguing protocol, and then a post-fatigue test. If the pre-fatigue and post-fatigue tests are not functionally similar to the fatiguing task, then the information obtained may not accurately represent the true effect of fatigue on the specific task. To avoid misinterpretation the testing tasks must be similar, or ideally identical, to the repetitive, fatiguing task. Therefore, in this study, a vertical countermovement jumping task was recorded continuously and the landing biomechanics were analyzed over time to explore how fatigue was manifest as jump performance decreased. The purpose of this study was to identify how landing biomechanics changed as the degree of fatigue increased.

Kinematic, kinetic and muscular data were collected from 10 experienced jumpers, and 14 novice jumpers. For each participant, data were collected continuously during the continuous execution of 60 maximal vertical jumps, where the rest time between jumps was four seconds. Independent samples t-test assessed the difference between the novice and elite group. For the last 45 jumps of the fatigue protocol, slopes with 95% confidence intervals and correlations were computed to assess the rate of change for each variable and the relationship between the fatigue measures, and the landing biomechanical variables.

Results demonstrate there was no significant difference between the novice and elite group mean slope for all variables. Three of the landing biomechanical variables had slopes significantly different from zero: the maximum knee angle (Kmax), the location of the maximum ground reaction force (GRF Loc), and one of the stiffness measure (Stiff5). Additionally, the changes in jump height are not correlated with changes in landing biomechanical variables (correlations < 0.50), which presents an important consideration for using jump height as a single variable for determining if individuals are at risk for a fatigue-related injury.

abstract: M.Sc.


title: Effects of the Gut Microbiota on Intestinal Function

contributor:
McDonell, Abby
Neuroscience Studies

subject:
Gut-brain axis
Microbiota
Epithelial Permeability

abstract: A growing emphasis has been placed on the importance of the gut-brain axis (GBA) and its role in normal physiological functions of the body. This bidirectional axis links cognitive functions of the central nervous system (CNS) with a number of peripheral intestinal functions such as intestinal permeability, immune activation, and neuro-endocrine signalling. Studies have highlighted the possibility that the intestinal microbiota could influence the function of the gut-brain axis; however, mechanisms underlying these interactions are currently unknown. In hopes of better understanding how the microbiome may play a role in altering the gut-brain axis, I studied the epithelial barrier of the gut, as it acts as the interface between the microbiome and the gut-brain axis. I investigated whether disrupting the microbiome in vivo with antibiotics, and mimicking a healthy microbiome through the application of a commensal bacterial community (microbial ecosystems therapeutics-1; MET-1) can modulate epithelial barrier functions.  Using Ussing chambers, I investigated changes in colonic mucosal epithelial permeability in vitro in both antibiotic-treated animals and following the local application of MET-1 (1:1000). Additionally, I examined the effect of antibiotic treatment on paracellular permeability and intestinal transit in vivo, serotonin bioavailability, epithelial ion secretion, and neurotransmission. Paracellular permeability of the colon was significantly increased in vivo following a 7-day vancomycin treatment, and Veratridine-stimulated (30 µM) ion secretion was significantly diminished in colonic tissue of mice subjected to the treatment compared to controls. Apical application of MET-1 did not enhance epithelial barrier function in vitro. Moreover, no differences in intestinal motility, serotonin bioavailability, and ion secretion were found between antibiotic-treated animals and controls. These results indicate that the modulation of host microbiota leads to changes in mucosal permeability and Veratridine-stimulated ion secretion, which may facilitate the access of microbial metabolites to the nervous system.

abstract: M.Sc.


title: Evaluation of Polygonal Hollow Structural Steel Sections via Experimental and Finite Element Analyses

contributor:
MacDougall, Colin
Civil Engineering

subject:
Thin-walled Steel Sections
Local buckling
Polygonal hollow steel sections

abstract:
Thin-walled hollow sections such as rectangular hollow sections (RHS) have very high torsional rigidity, and thus make a very economic choice for applications which are susceptible to lateral torsional buckling. However, as the depth of a thin-walled RHS increases to ensure adequate bending stiffness, its depth-to-thickness ratio increases and the section is now susceptible to webcrippling/local buckling failure. This causes a reduction in its moment rotation capacity. Therefore, deep thin-walled RHS are not efficient when used as long un-braced spans that require high bending strength and rotational capacity. As such, a new polygonal hollow section (PHS) was developed and a research project initiated to compare the PHS to typical RHS via experimental and numerical analyses comprising four-point, three-point and cantilever bending tests. The results showed that the PHS has almost four times the moment rotation capacity of a comparable RHS and the potential to minimize web-crippling failure in thin-walled hollow sections.
Following completion of the flexural bending tests, cantilever bending tests using PHS and RHS beams were conducted. The results showed that lateral torsional bending is not significant for HSS as the lateral deflections recorded at the top and bottom flanges of all the beams were minimal (< 2 mm).
Finally, numerical analyses were conducted to simulate the bending behavior of PHS beams and to consider the effects of varying specimen dimensions that were not considered in the experimental program. The results showed that PHS beams have a higher bending moment capacity, almost twice that of RHS beams. This is rather remarkable given that the PHS beams have 4% lower cross-sectional area and 18% lower moment of inertia than comparable RHS beams. It is speculated that the provision of bends in the flanges and webs of the cross-section gave rise to the increase in the moment capacity of the PHS beams. Furthermore, in comparison to the CAN/CSA-S16-14 design guidelines, the results showed that within limits of 32 ≤ h/t ≤ 85 and 19 ≤ b/t ≤ 64 the PHS beams can be classified as Class 1 sections while the RHS beams were confirmed to be Class 3 and Class 4 sections.

abstract: PhD


title: Modelling and Analysis of Flare Stack Thermal Radiation on Offshore Oil and Gas Facilities

contributor:
Birk, Albrecht Michael
Mechanical and Materials Engineering

subject:
Thermal Radiation
CFD
Fluent
Propane Flares
Soot
Flare Stack
Solid Flame

abstract:
This research studied the capabilities of RANS-based computational fluid dynamics to model large scale 2-phase propane jet flares with considerations for thermal radiation, soot development, and other key flare properties. The goal of this work was to determine how modest CFD could be used in the generation and evaluation of large scale jet flares that are often only studied experimentally. Measurements of incident thermal radiation to remote targets, soot volume fraction, and relevant flare geometries are reported based on the CFD models produced and compared to various analytical and experimentally derived models.

The CFD study was completed using the commercial suite of tools from ANSYS, namely ICEM CFD 18 and Fluent 18. Emphasis was put on evaluating the pre-existing models within the solver. The standard
k-ε turbulence model was used in this study due to its support from literature, and performance in preliminary tests. A probability density function approach was used to model the non-premixed combustion, and the 2-step soot model was used to predict soot production. The P-1 radiation model was used as it is an economical, non-raytracing model that allows for the inclusion of radiation from soot.

The CFD results were compared to a solid flame model as well as empirical models and measurements. The CFD predicted soot volume fraction in the flare between 2.7×10^(-7) and 4.9×10^(-7) depending on the flare boundary temperature selected. Incident thermal radiation was found to agree strongly with a solid flame model; ranging from 1.6 kW/m^2  at a 2m distance, to 0.11 kW/m^2  at 15m. Agreement with experimental radiometer data was weak, with the CFD results predicting much lower levels of thermal radiation. Average surface emissive power of the flare was determined to be 100.3 kw/m^2  using literature based techniques and agreed well with various empirical models from literature. The radiative signature of the flare was also studied for crosswinds of up to 6m/s, showing expected increases in incident radiation to downstream targets - up to 9.1 kW/m^2  in the near field for 6m/s winds.

abstract: M.A.Sc.


title: Right Heart Adaptation to Pressure and Volume Overload: Epidemiology, Animal Models, and Molecular Mechanisms

contributor:
Archer, Stephen
Biomedical and Molecular Sciences

subject:
Pulmonary Hypertension
Mitochondria
Right Heart Failure
Pyruvate Kinase

abstract:
Background: Pulmonary hypertension (PH) is a syndrome in which an increase in mean pulmonary artery pressure>20 mmHg is associated with adverse pulmonary vascular remodeling, which results in right heart failure and death. The World Health Organization classified PH into 5 groups. The most common causes of PH are left heart diseases, which is classified as group 2 PH. Currently, there is no approved therapy for group 2 PH and treatments are largely supportive. The goal of my PhD work is to find effective therapeutic strategies for group 2 PH in preclinical rodent models.

Methods & Results: A retrospective cohort study was done on patients (n=9289) who had a transthoracic echocardiography at the Kingston Health Sciences Centre. We found that although 44.1% patients had elevated pulmonary pressure [right ventricular systolic pressure (RVSP)>30mmHg], only 3.1% carried a clinical diagnosis of PH. The rate of hospitalization increased in direct proportion to RVSP. We studied the supra-coronary aortic banding (SAB) rat model of group 2 PH, a preclinical model of aortic stenosis or coarctation. SAB rats developed group 2 PH and a metabolic shift in the terminal stage of glycolysis in their LV and RV myocardium. Specifically, the expression of pyruvate kinase muscle isoform 2 (PKM2) to 1 (PKM1) ratio was significantly upregulated in the SAB vs. control myocardium. We then treated SAB rats with the PKM2 inhibitor, shikonin, in SAB rats. Shikonin restored PKM2/PKM1 ratio and improved RV function. Finally, we examined the role of RV ischemia in group 1 PH. SAB increases right coronary artery systolic perfusion pressure, which improved RV perfusion, restored the RV PKM2/PKM1 ratio and improved RV function.

Conclusion: PH is common and portends adverse outcomes and yet is under-diagnosed by clinicians. Even mild elevation of pulmonary pressure (RVSP>30 mmHg) is associated with increased number of hospitalization and comorbidities. Elevated PKM2/PKM1 ratio is associated with RV dysfunction and failure in the SAB and MCT rat models of PH. Improving RV perfusion pressure and using PKM2 inhibitor, shikonin reduces PKM2/PKM1 ratio to normal level in MCT and SAB rats, respectively. Restoration of normal PKM2/PKM1 ratio is associated with reduced RV hypertrophy and improved RV function.

abstract: PhD


title: An Approach to Represent and Transform Application Specific Constraints for an Intrusion Detection System.

contributor:
Dean, Thomas
Electrical and Computer Engineering

subject:
Cyber Security
Intrusion Detection System
Air Traffic Control Security
Constraint
Constraint Transformation
Domain Specific constraint

abstract:
While the need for newer and more efficient network security techniques is increasing, refining the existing and proven techniques can also have potential benefits and outcomes. One of the aspects of such improvements in the existing system is making them flexible to adapt for the modification. Currently we have an intrusion detection system (IDS) that defines the normal patterns of a network behaviour using constraints. Failure of these network constraints indicates an intrusion in the network. The IDS dissects the network packets into network information to evaluate the constraints. In this research, we augment the existing IDS to validate constraints defined on application data. We augment the IDS to further dissect the data coming in the network packets. We define data constraints to find possible malicious inconsistencies in the application data of a closed network, such as in Air Traffic Control (ATC).

An ontology is defined for the domain of ATC. We use the ATC ontology for the ATC domain data representation and threat evaluation. We modify an existing air traffic system simulation which generates ATC data and use it to generate both clean and malicious data. The data is then structured using the rules and relations in the air traffic control ontology. Rules and queries are then developed for this data, representing detectable threats. The queries are then transformed into application data constraints readable by the IDS. Presently this transformation specification is manual. In the future, the IDS will be updated for the auto transformation using the sequence of steps specified in the manual transformation.

Finally, we demonstrate the working of the application constraints and queries for detecting violations. The data constraints are written in the same domain specific language (DSL), already used for the IDS. Moreover, we highlight the change  required by the DSL and the transformation to generate for the constraint engine of the IDS. The research successfully produces a proof of concept for representing presence of application data attack at the network level.

In the end we conclude that by validating the domain data constraints with IDS, we assert that the ATC domain data constraints are transformed and enforced at the network level. The proposed representation and manual transformation specification demonstrate the possibility of adding and testing new changes to critical systems with much ease.

abstract: M.A.Sc.


title: Placing Person-Centred Care

contributor:
Rosenberg, Mark
Geography and Planning

subject:
Geographical Gerontology
Relational Place
Long-Term Care

abstract: While the recent adoption of a person-centred approach to long-term care in Canada has done much to address the shortcomings of its biomedical predecessors (particularly bringing to light the social-psychological aspects of living with dementia), it has not resulted in notable increases in quality of life for those who live in long-term care facilities. The aim of this dissertation is to contribute a relational and place-sensitive perspective of person-centred care that highlights where the approach could be better aligned with its experience and ultimately informs a higher quality of life for people living in long-term care environments. To do so, empirically expressed tensions in the lived experiences of long-term care facilities espousing person-centred care are considered through the lens of a relational landscapes of long-term care framework derived from the burgeoning field of geographical gerontology. A qualitative, community-based, multi-site case study methodological design guided the collection of interviews with residents, staff and family members in three long-term care facilities designed to elicit their lived experiences. Observation periods in each facility contributed to my own perspective of the care environments. Tensions expressed within each of the empirically emergent themes that shaped the lived experiences of participants (atmosphere, flexibility and relationship-building) were considered as they relate to the core concepts of home(place), care and personhood to expand person-centered care and contribute to (while simultaneously arising through) the landscapes of long-term care framework. Specifically, the expansion of conceptions of home as a functional, familiar potential beyond its locational aspects; of care to incorporate a broader range of relationships and the potential of the built environment to foster these relationships; and of personhood as a de-centred process rather than a uni-directional outcome were found to be the potential nucleus of an expansion of person-centred care that addresses its experiential and conceptual tensions. Conceptually, the contribution of this research is an advancement of relational understandings of place and care in the long-term care context.

abstract: PhD


title: Anisotropic Strength-Based Topology Optimization for Part Design Using Additive Manufacturing

contributor:
Kim, Il Yong
Mechanical and Materials Engineering

subject:
Topology Optimization
Anisotropic Strength
Additive Manufacturing

abstract: Additive manufacturing (AM), specifically the process of Fused Deposition Modelling (FDM), is a manufacturing procedure where a part is constructed by extruding a melted filament in a layer-by-layer fashion from the bottom up. AM processes offer the ability to manufacture more complex features versus traditional subtractive and formative manufacturing methods. Topology optimization is a structural design tool which is known for generating high-stiffness designs having complex and organic features, making it an ideal tool for using with AM technologies. Traditional topology optimization performs well for stiffness design, but stress considerations are often neglected. A significant shortcoming of FDM is the tendency for tensile material properties in build direction to be significantly weaker than the strengths in the other axes. This work presents a methodology for maximizing the safety factor of structural components for fabrication using FDM AM technology by considering the anisotropy of the material strengths using the Tsai-Wu failure criterion. This is achieved through minimizing an aggregated failure index subject to a volume fraction constraint and is implemented into the framework of density-based topology optimization. Multiple numerical test cases are solved to test the behaviour and robustness of the methodology using fictious material properties. For simple test cases, then methodology does not provide competitive designs compared to the traditional stiffness-based topology optimization formulation; however, test cases which exhibit sharp corners and stress concentrations show significant improvements to the safety factor of the designs when compared to the traditional stiffness-based topology optimization formulation. Real-world material properties of plastic FDM are used to show that for the design of an L-shaped bracket, a common shape used in industrial topology optimization problems, the methodology successfully improves the strength of parts when compared to the equivalent stiffness-based topology optimization result.

abstract: M.A.Sc.


title: Software Security Flaw Prediction Using Rich Contextualized Language Use Vectors: A Case Study on the Linux Kernel

contributor:
Cordy, James R.
Computing

subject:
Vulnerability Prediction
RCLUV

abstract:
One of the major threats to the security of software systems is the occurrence of security vulnerabilities, which can potentially cause a variety of problems including, but not limited to, information loss, privilege escalation, data breach, and system failure. Software vulnerability prediction is therefore a critical part of software engineering. A variety of approaches have been proposed to detect the most likely locations of vulnerabilities in large codebases. Many of the existing methods rely on traditional software metrics such as lines of code, complexity and code churn. In this study, we explored the possibility of using Rich Contextualized Language Use Vectors (RCLUVs) as a feature set for predicting vulnerabilities in the context of the Linux kernel.
The RCLUV of a source code file contains elements representing the frequency of each programming language feature being used, both individually and in the context of other features. This code profile is generated by parsing the source code of a program and analyzing the resulting parse tree.

We mined vulnerabilities reported in the National Vulnerability Database (NVD) and built a dataset containing all known vulnerable files in the 14-year history of the Linux kernel. We built and evaluated RCLUV-based prediction models using different machine learning algorithms under both experimental and realistic scenarios. Analysis of the learning curves of the models demonstrates that RCLUVs are effective for training machine learning models to learn vulnerability patterns. Performance comparison of our models with four different popular vulnerability prediction models shows that our approach outperforms the models trained on includes, function calls, and software metrics in an experimental setup. Moreover, our models can successfully predict more than half of the future and unseen vulnerabilities in a real-life setting when given enough training data.

abstract: M.Sc.


title: Enhancing the Capabilities of the CANDU Gap Probe

contributor: Physics, Engineering Physics and Astronomy

subject:
CANDU
Eddy Current
LISS Nozzle
Gap Probe
Nuclear
Pressure Tube
Fuel Channel
Nuclear Reactor

abstract: Fuel channels in CANDU (CANadian Deuterium Uranium) nuclear reactors consist of two non-concentric tubes; an inner pressure tube (PT) and a larger diameter calandria tube (CT), within which the PT is contained. The gas annulus space between the tubes, known as the gap, ensures that hydride blisters do not form on the outer diameter of the PT, as these can lead to potential cracking. Consequently, accurate measurements are required to ensure that contact between PT and CT is not imminent. The PT-CT gap is monitored from within the PT using an electromagnetic eddy current probe called the gap probe. The gap probe has previously been investigated to extract additional information from the channel past its intended purpose, including a method to profile the inner PT surface by examining probe lift-off effects. This thesis looks at two other areas of enhancement of the gap probe’s functionality; extracting the liquid injection shutdown system (LISS) nozzle proximity to fuel channels, and extracting PT microstructural information by monitoring local PT electrical resistivity. LISS-PT proximity information was extracted from an experimental setup that could vary PT wall thickness, PT resistivity, PT-CT gap, LISS-PT proximity and gap probe lift-off. Empirical models were identified over two effective detection ranges, and out-performed remote field eddy current methods near LISS-CT contact. In addition, as PT-CT gap algorithms become more sophisticated, the ability of being able to extract local PT resistivity from gap inspection data will become available. The utility of local PT resistivity depends on research linking resistivity to characteristics of interest to CANDU reactor operators. This work identified that as PTs experience operating temperatures between 250-320 °C and their microstructure transforms, specifically decomposition of the beta-phase, the resistivity is found to decrease by up to 10%. This result has implications for some gap inspection algorithms that assume constant electrical resistivity. This change in resistivity due to heat treatment, if measured, could be leveraged to provide axial and circumferential microstructural information that could be used by probabilistic and deterministic fuel channel degradation models.

abstract: M.A.Sc.


title: Technologies to improve power density of power electronic systems

contributor:
Liu, Yan-Fei
Electrical and Computer Engineering

subject: Power electronics, power density, thermal performance

abstract:
Advanced power electronic supplies with high power density are strongly demanded in a wide range of power levels. This thesis proposes high power density and thermal management solutions for three levels of power system integration: chip level for low power converters with 5W to 30W power ratings; power device level to decrease the component size; and power converter level including DC-DC converters and AC-DC converters range from 1kW to 6.6kW.
High performance point of load converter structure is investigated for low power level compact module applications based on the power supply in inductor (PSI2) technology. This thesis proposes a 3D PSI2 integrated power module at 5V/8A output which reduces the size of POL module while maintaining a low junction temperature. Improved thermal modeling methodology is developed for integrated modules to achieve more accurate thermal analysis.
In device level, a novel micro electromechanical system (MEMS) power relay which uses tiny MEMS switches is designed. The MEMS switch is used to replace the bulky magnetic – metal contact structure in traditional power relay solutions. Much lower on state resistance than solid state relay (SSR) is achieved, therefore less thermal issue is address due to lower conduction loss.
Power density improvement and thermal design for discrete mid-level power converters from 1 to 20kW are studied and two high power density converters are proposed. The first implementation is a high current low voltage converter (with 14V/270A load) for electric vehicles (EVs). By building a multi-PCB cooling (MPC) cooling structure, the volume of converter is reduced by 31% while achieving the best heat dissipation performance.  The second research is a single stage LLC AC-DC converter with PFC for on board charger (OBC) application. The LLC converter is proposed which combines the functions of power factor correction (PFC), DC-DC voltage regulation and galvanic isolation in only one stage. Bulky magnetic components are saved, and high power density is achieved by the proposed converter.
In this thesis, multiple research methodologies including mathematical modeling, finite element analysis (FEA), SPICE based simulation and experimental test are employed to verify the proposals and theories.

abstract: PhD


title: Investigating and Understanding the Effects of Reclaimed Asphalt Pavement and Shingles on the Rheology and Performance Grading of Asphalt Cement.

contributor:
Hesp, Simon
Chemistry

subject:
Reclaimed Asphalt Pavement (RAP)
Reclaimed Asphalt Shingles (RAS)

abstract:
The incorporation of Recycled Asphalt Pavements (RAP) and Shingles (RAS) into neat asphalt binder is a useful development towards environmental sustainability apart from its economic savings benefits, which comes as a relief to the finances of the transportation sector. Recycling of pavements reduces the demand for non-renewable resources such as new asphalt binder and mineral aggregates. Unfortunately, there are no protocols to control and guide the sector or contractors on the appropriate and effective amount of RAP/RAS that can be used, which has created a monitoring problem on its usage.
The effects that RAP (Highway 7, 11, 403) and RAS have on the rheology of two sources of virgin asphalts of the same grade was studied under this research. Two binders of grade PG 58-28 were modified at different percentages (10%, 20% and 30%) of RAP and RAS. To simulate aging that occurs during Hot Mix Asphalt (HMA) production, laying and compaction and aging that occurs during service life, the modified binders were subjected to Rolling Thin Film Oven (RTFO) aging and Pressure Aging Vessel (PAV) aging. Rheological properties before and after modification and aging were measured using the Dynamic Shear Rheometer (DSR).  The resistance to fatigue cracking, permanent deformation, the performance at high and intermediate temperature were accessed using the DSR. The Fraass Breaking Point (FBP) instrument was used to determine the temperature at which cracks initiate which is related to the fatigue resistance in asphalt binders. The extent of oxidation after modification and aging was determined using the Fourier Transform Infrared (FTIR) spectrometer. The Modulated Differential Scanning Calorimetry (MDSC) technique was used to study the changes in glass transition temperatures between the different RAP/RAS at the same modification dosage and aging. The binder increased in stiffness as the percentage of modification increased and this differed with each RAP/RAS source. The binders showed it could take more than 30% dose of Highway 7. Highway 403 RAP and the RAS, from results, are unsuitable for surface course pavement construction. The aging effect was very prominent after aging the samples in the PAV for 40 hours as compared to the standard 20 hours. It was found that the determination of the low temperature performance of a binder using the limiting phase angle temperature at 30 is promising.

abstract: M.Sc.


title: Characterizing the roles of microRNA in metastatic lung adenocarcinoma and melanoma

contributor:
Craig, Andrew
Biomedical and Molecular Sciences

subject: Cancer Metastasis MicroRNA

abstract: Cancer metastasis is the greatest ongoing obstacle to improving therapeutic efficacy and patient outcomes. Metastasis is a complex process reliant on phenotypic plasticity and dynamic changes in gene expression. MicroRNA (miRNA) are a class of small, non-coding RNAs that are post-transcriptional repressors of gene expression. Due to specificity for multiple targets and functional redundancy in the genome, miRNA fine-tune expression of gene-networks involved in virtually every cellular process. In cancer, dysregulated miRNAs can act as tumor suppressors, oncogenes, and are useful biomarkers. In this work, we examined the expression and function of miRNA in metastatic lung adenocarcinoma (LUAD) and cutaneous melanoma to gain insights into mechanisms of disease progression and metastasis. Due to numerous reports identifying miR-206 as a metastasis-suppressor in multiple cancers, we characterized the effects of ectopic expression in LUAD, finding that miR-206 mediated suppression of tumor growth and metastasis through broad disruption of TGF-β signaling. However, the highly muscle-specific expression patterns of miR-206 imply that this miRNA plays no physiological role in preventing LUAD. To explore the reasons why miR-206 is widely identified in cancers outside of muscle, we analyzed miRNA expression in primary and metastatic melanoma tumors in The Cancer Genome Atlas cohort, as well as melanoma and stromal cell lines. We determined that miR-206 and several other highly-studied metastasis-suppressor miRNAs were likely identified due to enrichment in stromal cells, highlighting the need to consider cell-type composition in tissue-level miRNA data. Through characterizing miRNA expression in melanoma, we identified a novel subset harboring expression of the chromosome 19 miRNA cluster (C19MC). C19MC was associated with overexpression of cancer/testis antigens, altered global DNA methylation profiles, and enrichment of embryonic gene expression patterns consistent with dedifferentiation. Furthermore, we identified five melanoma cell lines with endogenous C19MC expression and established tumor xenograft models to compare tumor growth and metastasis potential in vivo. These models will facilitate further functional studies of C19MC in melanoma and identification of new therapeutic vulnerabilities. Overall, the findings presented here provide insights into the functional roles of miRNAs in metastatic cancers, highlighting challenges in research methodology, and the potential applications of this research in cancer.

abstract: PhD


title: Business, Security and Human Rights: Governance Insights from Canadian Transnational Mining Firms in Ghana and South Africa

contributor:
Grant, J. Andrew
Political Studies

subject: Business

subject: Security

subject: Human Rights

subject: Governance

subject: Canadian Transnational Mining Firms

subject: Ghana

subject: South Africa

subject: Institutional Dynamics

subject: Transnational Voluntary Governance Initiatives

subject: State-Business Interactions

subject: The Voluntary Principles on Security and Human Rights

subject: The United Nations Guiding Principles on Business and Human Rights

subject: North-South Dynamics

subject: Corporate Social Responsibility

subject: Host State

subject: Norm Adoption

subject: Home State

abstract: Over the last two decades, we have seen the proliferation of nonstate actors such as transnational corporations (TNCs) on the global stage. Despite evidence pointing to the socio-economic contributions of TNCs, there have also been numerous reports of business complicity in human rights abuses. As a result, transnational voluntary governance initiatives (TVGIs) such as the Voluntary Principles on Security and Human Rights (VPs) and the United Nations Guiding Principles on Business and Human Rights (UNGPs) have emerged to promote corporate social responsibility (CSR). The existence of inalienable human rights has been accepted by the 193 member countries of the United Nations; however, despite claims of respecting the Universal Declaration on Human Rights, cases of human rights abuses by TNCs continue to come to light, especially in the extractive sectors of the Global South. This begs the following question: To what extent can state-business participation in regulatory governance norms promote responsible business conduct (RBC) and sustainable development practices in mineral resource sectors? This dissertation seeks to answer the above question by analyzing the following puzzles: 1) Why and how do TNCs successfully interact with some host states to adopt TVGIs on business, security and human rights (BSHrs), but not with others? and 2) What are the drivers of BSHrs commitments and/or reporting among TNCs? Utilizing insights from field research, new institutionalisms, ‘global assemblages’, and a Transnational Business Governance Interactions (TBGI) framework, I argue that although home-country (Canada) commitments to TVGIs on BSHrs norms are essential for promoting responsible corporate behaviours, what largely drives and differentiates Canadian transnational mining firms’ commitments to BSHrs norms in mineral-rich host states (Ghana and South Africa) tend to be a combination of the host states’ institutional contexts (e.g., state-business strategic postures), the dynamics of legitimacy (the ‘social license to operate’) and transnational mineral governance assemblage (TMGA) for corporate human rights due diligence. Overall, my dissertation contributes to ‘eclectic scholarship’, improves the traditional scholarly discourse on CSR and human rights obligations, broadens the policy dialogue on sustainable development, and helps us understand how norm dynamics influence international ‘soft’ law, transnational mining investments and natural resource governance.

abstract: PhD


title: Assessing the Presence, Extractability, and Function of Core Histones in the Perinuclear Theca of Murid Spermatozoa

contributor:
Oko, Richard
Biomedical and Molecular Sciences

subject: Fertilization Embryogenesis Reproduction

abstract:
The perinuclear theca (PT) is a condensed cytosolic capsule that surrounds the eutherian sperm nucleus and contains various proteins involved in fertilization. Previously, proteomic analysis of the bovine PT revealed a novel population of four core histones residing in this distinctly non-nuclear location, despite the traditional role of histones in nuclear DNA stabilization. Utilizing immunocytochemistry, histones were localized to two sub-compartments of the murid PT, the post-acrosomal sheath and the murid-specific perforatorium. This finding created the framework to pursue our primary objective: to determine the role of PT core histones in fertilization and early embryogenesis. Specifically, given their inherent ability to bind DNA, we hypothesized that PT-associated histones stabilize sperm chromatin during male pronuclear formation in the developing zygote.
To investigate this, we assessed the consequences of performing intracytoplasmic sperm injection (ICSI) with histone-depleted (HD) sperm. The mouse model is ideal for such functional assays because only the sperm nucleus and PT are required to achieve fertilization via ICSI. To create a valid depletion model, histones were selectively extracted from the mouse PT under high salt conditions paired with mild sonication. SDS-PAGE analysis of KCl-treated murid sperm extracts revealed four low molecular weight bands which, by immunoblotting with anti-core histone antibodies, corresponded to calf thymus core histones (H3, H2B, H2A, H4) run in adjacent lanes. Conversely, PT-bound activating factor, PAWP, remained largely intact following high salt extraction, indicating selectivity of the protocol.
ICSI functional assays compared developmental patterns of mouse embryos fertilized with control or HD sperm. Using light microscopy, HD oocytes were found to initiate activation at the same rate as control groups but displayed significantly fewer 2-cell embryos and blastocysts at the appropriate developmental timepoints. This suggests that early embryonic development is delayed in the absence of PT-derived core histones, presumably as compensation for destabilization of the male chromatin following fertilization. While their direct influence on sperm chromatin was unclear by our methods, this thesis presents evidence for the influence of PT core histones on early embryogenesis, and proposes a model of PT histone depletion for future functional analyses.

abstract: M.Sc.


title: Regulation of the Glucocorticoid Receptor Promoter and Its Prognostic Value in Tamoxifen-Treated ER+ Breast Cancer

contributor:
Mueller, Christopher
Pathology and Molecular Medicine

subject:
Breast Cancer
Glucocorticoid Receptor
Biomarker
Tamoxifen
Estrogen Receptor
Methylation
NR3C1

abstract:
Most breast cancers are estrogen receptor positive (ER+) and therefore benefit from endocrine-based therapies such as tamoxifen which impair estrogen signaling. However, resistance is a major clinical concern and ER status alone is insufficient to predict treatment response. As a result, additional biomarkers are needed to predict resistance. The glucocorticoid receptor (GR) is an attractive candidate because it functions as a tumor suppressor in ER+ breast cancer and low GR expression has been associated with poor outcome in tamoxifen-treated patients. GR promoter methylation occurs frequently in ER+ tumors and coincides with particularly low GR expression. To investigate GR methylation as a potential biomarker, we developed a targeted multiplex bisulfite sequencing assay to detect promoter methylation in archival tumor samples. With this assay, we evaluated the prognostic and predictive value of GR methylation in ER+ patients from the CCTG MA.12 tamoxifen clinical trial. Region-specific GR promoter methylation was an independent marker of poor prognosis and identified a subset of patients with especially poor survival, particularly in the absence of tamoxifen treatment. This provides a foundation for the continued development of GR methylation as a prognostic marker in ER+ breast cancer.
Given the tumor suppressive role of GR in ER+ breast cancer, we examined the regulation of GR expression in the context of tamoxifen treatment. GR mRNA levels increased with tamoxifen in ER+ but not ER− breast cancer cells, suggesting ER is involved in regulating GR expression. The GR promoter is particularly complex with multiple first exons. By adapting 5’RACE for next-generation sequencing, we established that increased GR expression was mediated through the same exons in the proximal promoter in tamoxifen-treated ER+ cells. We then carried out a functional analysis of this promoter region in ER− cells transiently expressing ER or naturally-occurring ER mutants (Y537S or D538G). Our findings suggest tamoxifen upregulates GR through an ER-dependent non-classical signaling mechanism with differing characteristics depending on the ER mutation. Since GR has an established antiproliferative effect on ER+ breast cancer cells, tamoxifen-induced GR upregulation could be an important factor influencing treatment response. This work may have important clinical implications for tamoxifen-treated patients, including those with acquired ER mutations.

abstract: PhD


title: Movement and Mobility: Conceptual definitions and relevant measures

contributor:
Wilson, Rosemary
Nursing

subject: Movement

subject: Mobility

subject: Measures

abstract:
Movement and mobility are concepts that are frequently used in the nursing field. Movement is a fundamental human ability which changes as individuals grow and as a result of illness or injury. Movement is one of many factors which affects mobility. Decreased mobility can lead to decreased quality of life and independence. As individuals age the incidence of mobility difficulties increases, reaching 81% for women and 57% for men at the age of 90. Most of the tasks that nurses help their patients complete involve some degree of movement or mobility, so it is important for nurses to be able to determine if their interventions are returning patients to their optimal level of functioning in movement and mobility.
Despite the importance of these concepts, they are often confused or used interchangeably. These concepts need to be clarified to ensure proper measurement of outcomes. A concept analysis was completed to clarify and compare movement and mobility that was followed by a scoping review in order to identify and analyze measures that claimed to measure either movement or mobility. The measures were analysed using the International Classification of Functioning, Disability, and Health (ICF), an alpha-numeric system created to code health information. Because the code set generated by the scoping review was larger than the data sets seen in existing studies, existing methods for analyzing and presenting data were further developed. Finally, the concepts of movement and mobility were operationalized using an example case to show how the information from the scoping review can be used to select measures of movement and mobility for clinical and research purposes.

abstract: PhD


title: The Sociology of Emotions in Medical Practice: An Ethnographic Case Study of Health Care Interactions

contributor:
Burfoot, Annette
Sociology

subject:
sociology of emotions
labour studies
ethnography
qualitative
emotional labour
medical sociology
emotions
sociology

abstract: Typically, medical training does not prepare healthcare workers to deal with emotions in medical practice, which can cause them to shut down emotionally and withdraw from patients as a way of protecting themselves. Recent work demonstrates how emotions play an essential role in healthcare relations and patient care delivery and, as such, call for greater attention in sociological research. The primary aim of this exploratory research was to uncover and understand the emotional, social interactions of healthcare workers in a Canadian hospital context. The findings of this study come from a combination of ethnographic field research and 28 in-depth interviews with various healthcare professionals within one Canadian hospital. A principal finding is an expectation for healthcare workers to follow “feeling rules,” which are socialized through a hidden curriculum and specific ward cultures.  The main cause of sadness at work comes from what is commonly known as a “bad death,” while anger mainly emanates from poor interactions and relationships with colleagues. Participants report that interactions with colleagues are the primary source of happiness, along with recognition from their patients (the chief source of happiness and accomplishment). The encouragement to suppress emotions in the workplace and the lack of recognition and support for emotional distress from hospital management had a negative effect on the personal lives of healthcare staff. The workplace expectations for healthcare workers to hide their negative emotions render such experiences invisible, and further leave staff to deal with such emotions alone. These findings are important for understanding how to effectively prepare healthcare workers to recognize and process emotions encountered in medical practice, and to make negative emotional experiences visible.

abstract: PhD


title: Building resilience in forest-dependent communities through sustainable forest bioeconomy development

contributor:
Mabee, Warren
Geography and Planning

subject:
Bioeconomy
Forest Biomass
Resilience
Biorefining
Community Energy

abstract:
This thesis seeks to determine the characteristics of a future forest bioeconomy that will contribute to the resilience of forestry communities across northeastern Ontario to inform bioeconomy development in the region.  A regional approach is taken to evaluate pathways for forest bioeconomy development over the near and long-term.  This approach is unique in that all potential energy and non-energy uses for available low quality forest biomass in northeastern Ontario are considered, as is the regional infrastructure and characteristics of the forest sector and available biomass.  Some (commonly studied) pathways were ruled out early based on information in the literature and the characteristics of the existing regional forest sector.  Other pathways were deemed promising and further analyzed within the regional context.  The analysis assesses the regional performance of different conversion pathways and specific technologies within them.
Assessment of technologies for deployment in the near-term was done at the community level, using a case study approach to evaluate several options for displacing natural gas used primarily as heating fuel.  To assess pathways for advancing the forest bioeconomy over the long-term, a larger-scale regional method was applied to get a sense of what a coordinated approach to advanced biorefining might look like across eastern Canada.  The results of this analysis shed light on the type of advanced processing facilities that might be feasible in Northeastern Ontario and informed the analysis of advanced processing pathways.  As analysis of advanced conversion pathways progressed, it became clear that there was a lack of published information on advanced technologies that could be deployed in regions with a strong sawmilling sector but little pulp capacity, such as northeastern Ontario. Chapters 4 and 5 address gaps in knowledge that hinder further development while also providing insight into the economic feasibility and conversion characteristics and process improvements that could enhance feasibility.  Chapter 6 draws on the analysis in the previous chapters, and the deep body of resilience literature, to identify characteristics of a future forest bioeconomy that would maximize the resilience of communities across northeastern Ontario, and the forest sector upon which the region was built, over the near and long-term.

abstract: PhD


title: Racializing Subalternity: Space, Caste, and Gender in Muslim Mohallas of Lucknow (1947-1993)

contributor:
Walker, Barrington
Toor, Saadia
History

subject:
Race
Racialization
Subaltern
Caste
Gender
Islam
Space
Muslim Societies
Global and Local Histories

abstract: The dissertation seeks to examine systems of racialization that produce the “Indian Muslim” subaltern biologically, discursively, and historically while bearing in mind the material consequences for the group circumscribed within such frameworks. In the endeavor, the dissertation implicitly strives to reconsider the legacy of colonial vocabularies that have entered the mainstream consciousness of “South Asian Studies” and to interweave the approaches and frameworks of Subaltern Studies and Critical Race Studies via the site of the Indian Muslim. In particular the dissertation focuses on the structural, legal, and civic routes by which the pluralistic South Asian Muslim community was homogenized. Between 1947-1993, the enactment of polemical laws affected local Indian Muslim language rights, property ownership, gender relations, the occurrence of mass scale police violence, and notions of spirituality in Lucknow. Simultaneously the dissertation elicits the multiple strategies by which Muslims have resisted and deflected these processes. For both historicizing caste among Muslims and developing the salience of race as a category of analysis, this dissertation seeks to stage a major intervention in South Asian studies and histories of Islam across multiple scales – local, regional, national, and transnational.

abstract: PhD


title: Spectral Objecthood: Biology, Assembly, and the Ghostly Body in Eighteenth- and Nineteenth-Century Popular Fiction

contributor:
King, Shelley
English Language and Literature

subject:
ghost fiction
commodity culture
19th-century science
victorian literature

abstract: This dissertation examines two intersecting historical influences on Victorian supernatural fiction: commodity-driven cultures of object production and exchange, and discourses of nineteenth-century biological sciences. I argue that the appropriation of commodity-oriented and scientific languages in occult fiction and non-fiction coincided with a mass cultural shift in thought with regard to the soul, what it was made of in a material sense, and by extension, how it functioned. Authors were more and more drawn to spectral imageries that involved disassembly, reorientations of function, and fluid materiality that imagined the soul as something more readily preserved and made readable through material objects. As a result of Victorian commodity culture and professionalized science, depictions of spiritual and emotional transformations were more readily and complexly visualized as material exchanges that imbued the symbols of industrial and commodity-driven life with new relevance for ethical, spiritual life in the nineteenth century. Examining both the figure of the ghost as a site where boundaries between material and immaterial are often necessarily reinterpreted, and more abstract representations of the materialized soul such as the haunted portrait of Wilde’s Picture of Dorian Gray, this dissertation examines how supernatural fiction facilitated conversations pertaining to the adaptation of industrial and scientific life into a new imagined realm of ‘modern’ spiritual existence.

abstract: PhD


title: More than Getting Wasted: A Description of Youth Emergency Department Visits Attributable to Alcohol Use at Kingston Health Sciences Centre from 2013-2017

contributor:
Sytsma, Victoria
Murray, Heather
Sociology

rights: Attribution-ShareAlike 3.0 United States

subject:
Alcohol Use
Substance Use/Misuse
Youth
Post-secondary
Ritualized Drinking
Youth Alcohol Use
Binge Drinking
High-Intensity Drinking
University
College
Emergency Department
Mental Health
Alcohol-Related Injuries

abstract: The objective of this study is to describe youth presentation to the Emergency Department (ED) for alcohol-related issues.  Current alcohol-related research relies on self-reported data of individual-level alcohol consumption. While Canada and Ontario have reported stable population consumption rates, presentations to emergency departments and the costs associated with alcohol consumption have increased (Myran et. al. 2019 and; CSUCH, 2018).  This study is a chart review of patient visits for alcohol-related issues to the ED and Urgent Care Center at Kingston Health Sciences Center (KHSC) between September 1, 2013, and April 30, 2017.  All patients aged 12-24 who visited the ED and Urgent Care Center at KHSC for alcohol-related reasons were eligible for the study. An n= 2,479 of study eligible patients presented to KHSC over a four-year period for alcohol-related issues.  Young patients presenting for alcohol-related issues during the study period had an absolute increase of 1.37%.  Results suggest a conceptual split in the calendar between ‘ordinary’ drinking weeks and ‘ritualized drinking event dates’, and presentations in Kingston seem to follow a patterned trend that is connected to these ritualized dates. Ritualized drinking event dates in Kingston increased during the study period.  These dates comprise 4.6% of total days during the study period but account for 23.3% visits.

abstract: M.A.


title: Theoretical and Practical Considerations of Learning Algorithms in Image-guided Interventions

contributor:
Mousavi, Parvin
Computing

rights: Attribution-NonCommercial-NoDerivs 3.0 United States

subject:
Image-guided Interventions
Deep Learning
Machine Learning
Image Registration
Entropy
Temporal Enhanced Ultrasound
Prostate Cancer

abstract:
Image-guided Interventions (IGI) have revolutionized medical practice and improved the quality of life for patients by enabling less invasive surgeries and treatments. Recent advancements in computing power and learning algorithms, e.g., Deep Learning (DL), have allowed automated learning-based systems to identify diseases with accuracies comparable to clinicians, adding further capabilities and potential to IGI. In a typical IGI, image registration methods are utilized to incorporate pre-operatively identified lesions/information into the intra-operative procedure. This makes image registration a fundamental part of IGI. Furthermore, learning algorithms are utilized in both improving pre-operative to intra-operative information integration as well as enhancing interpretation of intra-operative images, procedures, and guidance.

The overall objective of this thesis is to identify and address several important considerations in each of these elements of IGI. In particular, for image registration, we propose solutions to enhance the explainability and interpretability of registration methods through a novel theoretical framework that connects the conventional information-theoretic based algorithms to the new deep metric-based methods; furthermore, we propose a new image registration approach based on deep probabilistic multi-class classifiers which can be utilized to estimate the uncertainty of registration. We test and evaluate our solutions in image registration on simulated neurosurgical data, and in a study using radiation therapy data from our local health sciences centre.

To enhance the interpretation of intra-operative imaging, we propose an application of unsupervised representation learning that considers the vagaries and noisy nature of the gold-standard labeling in biopsy data. We demonstrate that by mapping biopsy samples with similar properties close to each other on a hyper-lattice, we are able to successfully cluster regions of malignant and benign tissue in the prostate. We also investigate different techniques for pre- and intra-operative information fusion through deep learning. We demonstrate the significant potential of multi-modality integration of information from MRI and ultrasound to improve prostate cancer detection. Our developed solutions enable the generation of cancer probability maps that can augment prostate biopsies and improve targeting of cancer foci. Finally, we develop an open-source browser-based framework to make the deployment of learning algorithms in IGI more accessible to practitioners and for educational purposes.

abstract: PhD


title: Assessing the Phytoextraction of Organic and Inorganic Pollutants From Point Pelee National Park, Ontario and Iqaluit, Nunavut

contributor:
Rutter, Allison
Zeeb, Barbara
Environmental Studies

subject:
Phytoextraction
Phytoremediation
Dichlorodiphenyltrichloroethane (DDT)
Dieldrin
Lead
Arsenic
Mercury
Iqaluit

abstract:
This thesis investigated the phytoextraction of both organic and inorganic contaminants from two locations of Canada (Point Pelee National Park (PPNP), Ontario and Iqaluit, Nunavut). PPNP is a National Park that is highly contaminated with dichlorodiphenyltrichloroethane (DDT), dieldrin, arsenic and lead from historical agricultural and residential pesticide applications. Six planted native grass and weed species, and several naturally occuring species were analyzed for DDT, dieldrin, arsenic and lead in four contaminated plots of PPNP. A composting study was also completed to determine if composting of contaminated plant material is an effective and sustainable option for handling contaminated plant biomass. Of all plant species studied in PPNP, Andropogon gerardii (big bluestem) was deemed to have the most potential for phytoextraction because it had a large biomass and accumulated high amounts of all four contaminants of interest. For this reason, it was selected for a follow-up greenhouse study. Two seed sources of A. gerardii (one commercial and one collected from PNPP) were grown in PPNP soil contaminated with DDT concentrations of 1,059 ng/g (low) and 5,071 ng/g (high). Mean levels of DDT in plant shoots were significantly higher (100.64 ± 33.09 ng/g) in the high contaminated soil but did not statistically differ in dieldrin, arsenic and lead concentrations between soil types. Seed source had no effect on phytoextraction potential.
Mercury (Hg) concentrations within the Canadian Arctic are a current area of concern and research on merucry accumulation in terrestrial vegetation of the Arctic remains limited. Mercury levels in 24 soil samples, 23 plant, five lichen, and eight fungal (mushroom) species were assessed from eight locations in and around Iqaluit. Soil mercury levels across locations were not statistically different; however, median mercury concentrations of plant, lichen and fungi species ranged from 0.005 µg/g Hg dw in Saxifraga cernua (nodding saxifrage) to 1.6 µg/g in Lycoperdon perlatum (puffball).
Overall, this thesis contributes new information on pesticide and metal phytoremediation in PPNP, demonstrating that phytoextraction by A. gerardii may be a suitable option to remediate contaminated soils in this National Park, and that phytoextraction by some Canadian Arctic vegetation may lead to elevated mercury concentrations.

abstract: M.E.S.


title: Picture Delightful Calculations

contributor:
Upitis, Rena
Education

subject:
Drawing
Design
Geometry
Shape Grammars
K-6 Education

abstract: This research presents an argument for situating shape grammars as the core component of drawing and design through observation, and as a core component for improving spatial reasoning and visual spatial perception, especially in the practice of geometry and its relationship with algebra. The research demonstrates the potential for drawing and design to be taught throughout the curriculum, especially at the primary level. As my results show, the craft is, at its essence, transdisciplinary and one that ties all subject matter together. Those who have championed the importance of skills such as sketching, drawing, and design as being integral to the visual arts, have had their words fall on deaf ears in both broad educational contexts and in art education itself which. In part, this is because there has been no real way to standardize a best practice for learning a technique that is ambiguous. My research addresses this head on through the development of the ESPIAL (Elucidating Six Points for Insight Analysis of Likeness) tool. The tool offers a standardized means to assess the drawing process without determination of outcome. This research consisted of a 10-week intervention with pre- and post-testing where students in Grade 3 and Grade 4 were taught to draw and design using shape grammars. This mixed methods study took place in four sites in and around Montréal, Québec, Canada. The results showed students improved in standardized tests that measured visual motor integration and spatial manipulation tasks. Qualitatively, this research demonstrated that the shape grammar approach improved children’s drawings substantially. Children were able to render what they saw with nuance and sophistication. In particular their ability to manipulate, interpret, and see in multiple perspectives calls into question notions of stage development theories that place cognitive limitations on children’s vision based on age alone.

abstract: PhD


title: Bringing everyone to the table: the rise of community fresh food programs in Ontario’s small and medium-sized cities

contributor:
Donald, Betsy
Geography and Planning

subject:
Food Insecurity
Food Security
Community Food Project
Fresh Food Programs

abstract: Like hunger, food banks are widespread and found in nearly every community across Canada. The food bank model is an insufficient response to hunger and ignores the root cause of food insecurity: income. There is an increasingly popular approach to food security through a community food program model that has the potential to reduce stigma, build community, and challenge class divides. The purpose of this research is to examine community fresh food programming performed in Ontario’s small- and medium-sized urban areas. This includes determining what organizations run programming, the extent to which they operate, and the impact of fresh food programs. To answer these questions,  I compiled a database of organizations, administered phone surveys for those who participated in fresh food programming, performed in-depth interviews with select organizations, and acted as a participant observer to community food programs through my position as a Mitacs intern in Prince Rupert, BC. There were four major findings from this research. First, place is elemental to food work. Organizations often respond to place-based needs, and perform relationship-dependant, community-centred work at the local scale. Second, food can be used as a means to achieve other goals unrelated to food security and food insecurity, such as building food skills, bringing people together, building community, generating resiliency, breaking down barriers, building networks, increasing understanding of systemic issues, empowering people, and increasing civic engagement. Third, the actions of governments have a significant impact on the lives of people living in poverty and who are food insecure. Policy changes to social assistance and income are needed to eradicate food insecurity. Finally, food rescue is not a solution to either food waste nor food insecurity. Rather, food rescue is a resource drain for emergency food services in terms of time, energy, and finances. Food rescue acts as an ‘in the meantime’ solution that neglects to address the systemic cause of either issue. This study seeks to contribute to the literature on changing community food models. It also aims to inform policymakers of the challenges and areas for improvement within the charitable food and community food program sectors.

abstract: M.A.


title: Functional Dissection of the N-Terminal Domains of KIF14: A Mitotic Kinesin Required for Cell Abscission

contributor:
Allingham, John
Biomedical and Molecular Sciences

subject: Kinesin

subject: N-Terminal Extension

subject: Cytoskeleton

subject: Actin Structure Regulation

subject: Molecular Modeling

subject: Oncogene

subject: Cytokinesis

subject: KIF14

subject: Schrodinger Maestro Small Molecule Drug Docking Suite

abstract: Kinesins are the largest superfamily of microtubule-binding motor proteins in eukaryotic cells. All kinesins contain a motor domain that hydrolyzes ATP to power their directional movement along microtubules, or to catalyze the release of tubulin subunits from microtubule ends. These activities support essential functions such as vesicle and organelle transport, chromosome segregation during mitosis and meiosis, and regulation of microtubule dynamics for cell growth and division. The mitotic kinesin KIF14 is distinguished from other kinesins by a long N-terminal extension (NTE) (355 residues) of its motor domain that enables it to bind and bundle actin filaments. The ability of KIF14 to bind to actin is unusual because myosins have long been considered as the only cytoskeletal motors to act directly upon actin filaments. The actin binding ability of KIF14 appears to correlate with its co-localization within the actin-rich contractile ring at the cell midbody where it plays a vital, but undefined, role during cytokinesis. Accordingly, loss or disruption of KIF14 activity leads to cytokinesis failure. Conversely, KIF14 overexpression is associated with poor prognosis for multiple types of cancer. The first research aim of this thesis was to locate the binding sites of a panel of KIF14-selective inhibitors identified from a high-throughput screen. Unable to obtain crystal structures of the KIF14-inhibitor complexes, we used molecular docking to predict their interaction modes computationally. The docking software “Glide” identified a unique binding pocket between helix 2 and 3 of the KIF14 motor domain, which is directly adjacent to the site of ATP hydrolysis. Visual inspection and computational analysis of each inhibitor’s binding conformation enabled the design of a library of derivatives of these inhibitors; some of which were predicted to have improved affinity and specificity for KIF14 upon repeating the molecular docking workflow. The second aim was to understand how the NTE of KIF14 binds actin and affects actin filament structures. By systematically dissecting the human KIF14 NTE into a series of short polypeptide fragments, we were able to locate distinct microtubule- and actin-binding regions. By a combination of pyrene-actin polymerization assays and TIRF microscopy, we further identified the regions of the NTE that stimulate F-actin polymerization and F-actin bundling. We also obtained evidence that the NTE promotes actin polymerization by acting as an actin nucleation factor and an F-actin stabilizer. Interestingly, these abilities of the NTE are influenced by the microtubule-binding interactions of KIF14’s motor domain. These new insights provide the first building blocks of a molecular model that explains how KIF14 influences actin dynamics at the midzone during cytokinesis, and could help guide the development of strategies to inhibit KIF14 activities for the benefit of people living with cancer.

abstract: PhD


title: Evaluation and Improvement of the Stoichiometric Homeostasis Model for Understanding and Predicting the Structure and Functioning of a Low Arctic Tundra Plant Community

contributor:
Grogan, Paul
Biology

subject:
Arctic Tundra
Stoichiometric Homeostasis
Plant Community
Climate Change

abstract: Arctic tundra vegetation structure profoundly affects ecosystem processes and climatic regulation. Therefore, there is a growing urgency for more accurate biogeochemical models to better understand how tundra vegetation will respond to ongoing major environmental changes, including rising temperatures, enhanced soil nutrient availability, and increased snowfall. The stoichiometric homeostasis model (the H model) - which quantifies the ability of an organism to maintain its internal elemental concentrations despite variation in the availabilities of these elements as resources - may provide valuable insights into vegetation-environment feedbacks, but its application in the Arctic has not previously been investigated. In this thesis, I used a two-step approach to first evaluate and then improve the H model for understanding the structure and functioning of a low Arctic plant community. First, I tested the applicability of the H model in the tundra context. Second, I improved the accuracy for determining the homeostatic H values by comparing two methods for estimating soil nutrient availabilities (ion exchange membrane (IEM) incubation versus soil sample extraction methods). Third, I examined the applicability of the H model in predicting key aspects of species’ ecological performances under various experimental manipulation conditions over two successive 6-year periods at both the individual species and community levels. The IEM method was superior to the extraction method in providing biologically meaningful soil nutrient data for modeling the H values. The H indicator based on nitrogen (N):phosphorus (P) ratio (HN:P) was a more robust homeostatic indicator than those based on either single element (HN or HP). Furthermore, variation in plant P rather than N stoichiometry drove much of the differences in HN:P. In terms of functioning, tundra species with relatively high HN:P values were more dominant, more temporally stable, and less responsive to the effects of environmental change on soil available P. Finally, communities with higher HN:P values also had more aboveground biomass. Together, these results highlight the value of using the combination of both N and P for a more complete understanding of homeostatic regulation, and validate the potential of using H values to predict tundra plant community structure and functioning in a rapidly changing environment.

abstract: PhD


title: Enlightened Hobbism: Aspects of the Eighteenth-Century Reception of Hobbes in Britain

contributor:
Collins, Jeffrey
History

subject:
Thomas Hobbes
Shaftesbury
Mandeville
Intellectual History
Britain
Enlightenment
Samuel Clarke
William Warburton
Francis Hutcheson

abstract: Hobbes was Britain’s quintessential atheist at the dawn of the eighteenth century, and Hobbism (a widely recognized creed) was commonly used to identify and police theological and ecclesiological heterodoxy. A competing interpretation of Hobbism emerged over the first fifty years of the century. “Enlightened” Hobbism, like the traditional variant, took advantage of Hobbes’s notoriety, but now in a social and civil context. This dissertation explores an aspect of Hobbes’s reception from 1700 to 1760. The primary focus is on the works of Shaftesbury, Mandeville, Hutcheson, and Archibald Campbell. An analysis of these early British moralists reveals that they participated in a shared project of portraying Hobbes as a pessimistic egoist in moral terms. This was in sharp contrast with the majority of authors who highlighted Hobbes’s materialism, determinism, Erastianism, and moral conventionalism, as indicators of heresy and atheism. These two variants of Hobbism did not exist in isolation. “Enlightened” Hobbism was first articulated by Shaftesbury following accusations that he was an atheist in Hobbesian terms. Mandeville, Hutcheson, and Campbell subsequently had to navigate their own proximity to “Enlightened” Hobbism. Atheistic Hobbism was most suitable for a British context still obsessed with identifying theological truth. But as the priorities of civil society shifted and moralists challenged the theological basis of ethical discourse, British divines also had recourse to “Enlightened” Hobbism when justifying the necessity of the Church, God, and particular providence in the terms of civil prudence and utility. The primary goal of this dissertation is to explore the deployment of Hobbes and Hobbism in the moral discourse by these two groups: those who interpret morality through the lens of theology and the otherworldly, and those who view it as a fundamentally human endeavour. But this analysis also identifies a significant characteristic of the early British Enlightenment. As much as Enlightenment moralists forcefully distanced themselves from Hobbes, by rooting morality firmly in the human experience they contributed to the Hobbesian project of wresting authority from the Church and the otherworldly.

abstract: PhD


title: Functional genomics to discover genes responsible for root architecture and heavy metal tolerance in Populus

contributor:
Regan, Sharon
Biology

subject:
Phytoremediation
Populus
Heavy Metals Tolerance
Root Development
XBAT32
CYCLIND1
Poplar
Hydroponics
Activation Tagging

abstract: Anthropogenic activities have led to widespread of heavy metal contaminants such cadmium and arsenic. When left untreated, they pose risk to both human and ecosystem health as well as further reduce arable lands. Phytoremediation, which is the use of plants and their associated microorganisms to clean up such contaminants, is environmentally friendly and cost effective. Fast-growing trees such as Populus sp. are good candidates for phytoremediation because of their tolerance to heavy metals, high biomass and their distribution across much of the northern hemisphere. However, the molecular mechanisms underlying poplar’s phytoremediation are poorly understood. Although Populus is a model tree species, with a sequenced genome and many genetic and genomic resources, the identification of genes for important tree traits is still slower than in other model plants such as Arabidopsis. This study uses a functional genomics approach to identify genes related to phytoremediation by taking advantage of a large collection of activation tagged poplars (Populus tremula x P. alba hybrid 717-1B4) created by Dr. Sharon Regan’s Lab. After screening over 1700 independent transgenic lines for characteristics that could affect the phytoremediation, seven mutants had altered root biomass whereas 15 mutants had altered response to heavy metals. Of the seven root phenotypes identified, two previously studied mutants, called rippled leaf and adventitious root were further investigated. RT-qPCR analysis showed an up-regulation of CYCLIND1;2 and E3 ubiquitin-protein ligase XBAT32/33 in the roots of rippled leaf and adventitious root mutants respectively. The upregulation of CYCLIND1;2 is suspected to increase the root biomass through accelerated cell cycle division. XBAT32/33 on the other hand is suspected to promote the production of lateral roots through the regulation of ethylene biosynthesis. Altogether, this study provides a starting point in the quest to discover key genes responsible for phytoremediation and could lead ultimately to the development of biomarkers for selection of superior trees from natural population for clean-up purposes.

abstract: M.Sc.


title: Mechanisms underlying anoxic coma and spreading depolarization in Locusta mirgatoria

contributor:
Van Dusen, Rachel
Biology

subject: Neurobiology Anoxia

abstract: Spreading depolarization (SD) is neurological phenomenon that results in the depression of neural activity and is found in both vertebrate and invertebrate systems. SD is characterized as a propagating wave of neuronal and glial depolarization. In invertebrate models this leads to complete neuromuscular shutdown. SD has been investigated in mammalian models for decades, as it is associated with many human pathologies including stroke, migraine and traumatic brain injury, however its occurrence in insects has only recently been determined. In the African migratory locust, L. migratoria, SD is associated with entry into a reversible stress-induced coma. Although there are many physiological differences in CNS properties between mammals and insects, the characteristics of SD remain consistent. For my thesis I used pharmacological and electrophysiological approaches to investigate the occurrence of SD in L. migratoria in response to anoxia. I characterized the variation in anoxic coma induction and recovery using three methods of anoxia, CO2 and N2 gas, and water immersion. These results showed that water immersion had increased coma induction and recovery times, whereas CO2 lead to shorter induction times and intermediate recovery times. I conclude that water immersion and N2 gas are the most useful methods of anoxic coma induction for future investigations. Additionally, I investigated the role of adenosine and adenosine receptor manipulation on coma recovery. Mammalian research shows that adenosine contributes to delayed synaptic recovery following SD. My results show that adenosine does delay recovery, however caffeine, as an adenosine receptor antagonist, decreased recovery times in whole animals and increased recovery times in semi-intact preparations. I investigated the potential pathways of adenosine receptor activation, exploring both cAMP and ATP-sensitive K+ (KATP) channel activation and inhibition. These results show that cAMP activation and KATP inhibition increased time to recover. Given these results, I discuss the similarity with mammalian findings and consider how this information contributes to a better understanding of the underlying mechanisms of SD.

abstract: M.Sc.


title: Art for God's Sake: An Augustinian Defense of Theatre

contributor:
D'Elia, Anthony
Classics

subject: Augustine Theatre Plato Christianity

abstract: In City of God Augustine refers to the theatre as a “pestilence” on the morals of the Roman people. Further, he devotes a large portion of the third book of the Confessions to outlining his own sinful experiences with the theatre and a Platonic attack on the poetical arts. From these passages in his two most famous works it would be reasonable to see theatre as incompatible with an Augustinian worldview. However, by expanding upon O’Connell’s Art and the Christian Intelligence in St. Augustine, Smith’s “Staging the Incarnation: Revisioning Augustine’s Critique of Theatre”, and Drever’s “Entertaining Violence: Augustine on the Cross of Christ and the Commercialization of Suffering”, this study shows that a complete condemnation of the theatre cannot be sustained in light of the wider Christian framework within which Augustine operates. This thesis begins by examining the similarities between Plato and Augustine’s critiques of theatre on both ethical and ontological grounds. Having established that the basis of their attack lies in three elements: imitation, the emotions, and material images, an exploration of Augustine’s views on material creation, the Incarnation, Resurrection, and human persona shows that neither the emotions nor material images can be condemned on the Platonic assumption that their natures are inherently corrupting; in fact, both of these are shown to be moral goods that, while liable to corruption because of the Fall, are innately good. Given that they are moral goods, it becomes possible to make room in Augustine for the possibility of a ‘redeemed theatre’ where the mimetic imitation inherent to the theatrical arts is not a moral hindrance but a devotional aid. Indeed, Augustine’s use of theatrical elements in his own writing points to the efficacy of this method of evangelization.

abstract: M.A.


title: Self-supervised ECG Representation Learning for Affective Computing

contributor:
Etemad, Ali
Electrical and Computer Engineering

subject:
Deep Learning
Machine Learning
Self-supervised Learning

abstract: This work investigates the use of self-supervised learning for ECG-based affective computing. We propose a novel self-supervised ECG representation learning framework to address the limitations of fully-supervised learning. Our proposed framework is developed using four popular ECG-affect datasets that contain a wide variety of emotional attributes such as arousal, valence, stress, and others, collected in different experimental settings. Our proposed solution achieves promising results and sets new state-of-the-art in classifying affect in all four datasets. We present interesting insights regarding our proposed framework and analyze the relationship between the self-supervised tasks and emotion recognition. Further, we explore the concept of self-supervised affective computing and utilize the framework in an applied setting. To this end, we collect ECG and affect data from medical practitioners during a trauma simulation study, and utilize our proposed self-supervised framework for classification of cognitive load and levels of expertise, achieving great results and outperform fully supervised solutions.

abstract: M.A.Sc.


title: Fabrication of novel power sources for portable and wearable devices

contributor:
Barz, Dominik P.J.
Chemical Engineering

subject:
Microbattery
Supercapacitors
Hybrid battery-supercapacitors
Microfabrication
Thin-film battery
Gel electrolyte

abstract:
Practical applications of portable and wearable electronics is linked with the development of power sources that address the physical requirements of these electronic devices, such as flexibility and a small footprint. In this work, we report on the development of several promising power sources for microdevices and flexible electronics. We fabricate microbattery on a glass substrate because this is a well-defined material and very similar to silicon, a standard material for micro-electro-mechanical systems. However, the miniaturization of a nickel/metal hydride cell requires a different method of fabrication than that of macroscale batteries. Microfabrication techniques including electrodeposition, e-beam evaporation, and magnetron sputtering can be used to fabricate the electrodes of a microbattery. Thus, we introduce a process for the deposition of intermetallic thin-film alloy on a glass substrate. We use this technique for the fabrication of a coplanar thin-film Nickel-Metal hydride microbattery with a gel electrolyte. The performance of the electrodes and the device is evaluated using electrochemical methods, including cyclic voltammetry and galvanostatic charge-discharge and electrochemical impedance spectroscopy.
This work also presents the fabrication of a supercapacitor made by printing and reduction of graphene oxide inks. A leavening agent is added to enhance the capacity of the electrodes. The effect of the leavening agent electrode capacitance of the electrodes is investigated in terms of material characterization and electrochemical performance.
Finally, we introduce a novel hybrid battery supercapacitor based on the combination of a self-assembled graphene hydrogel that encapsulates a vanadium solution. The electrochemical characterization of device shows that the hydrogel combines the high specific surface area of the reduced graphene oxide and the redox activity of the vanadium ions, leading to a specific capacity of 200 mAh/g. This power source can be operated as a supercapacitor, as a battery, or as a hybrid, depending on the operating conditions. Its unique power-handling capabilities depend on the rate of discharge which makes it suitable for a wide range of applications. Additionally, this device offers further significant advantages, including fast charging capability (10 minutes), high durability, and mechanical flexibility.

abstract: PhD


title: Surgical versus medical treatment and mortality in patients with infective endocarditis: The effect of selection bias, immortal time bias, and time dependent confounding

contributor:
Brogly, Susan
Peng, Yingwei
Public Health Sciences

subject:
infective endocarditis
immortal time bias
time dependent confounding
selection bias
surgery

abstract:
Background: Infective endocarditis (IE) is a serious infection of the endocardium. Available evidence on the comparative effect of medical versus surgical treatment of IE is limited by systematic error. It is unclear if surgery, when compared with medical treatment, is protective against long-term mortality.
Objectives: 1) To complete a systematic review of the published studies that compare the effect of surgical versus medical IE treatment (modelled as time-dependent) on mortality. 2) To examine the effect of bias on the observed apparent long-term protective effect of surgery. 3) To determine whether surgical treatment of IE improves survival when compared to medical treatment.
Methods: Using a retrospective population-based cohort study design, the effect of surgical versus medical treatment of IE on mortality was explored using advanced methods to examine and correct for bias including marginal structural models with inverse probability weighting, time-dependent exposure and confounders and the creation of adjusted survival curves.
Results: The study cohort included 16,380 adult Ontarians with IE. In models with time-dependent treatment and confounders, the average risk of mortality at 30 days was increased in patients who underwent surgical versus medical treatment, (HR=1.22, 95% CI: 1.01-1.47), while those who underwent surgery had a decreased risk of mortality at one year (HR=0.75, 95% CI: 0.67-0.84) when compared to those treated medically.
Conclusions: This study demonstrates that bias in published studies likely contributed to the discrepant evidence of surgical versus medical treatment on survival. We are also the first to show the effect of time-dependent confounding in IE research, and that the effect of time-dependent confounding may vary between males and females. Future research into the effect of surgical versus medical treatment of IE on mortality should aim to limit three important sources of bias present in previously published IE studies: immortal time bias, selection bias, and time-dependent confounding.

abstract: M.Sc.